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CROSS REFERENCE TO RELATED APPLICATION
The present application claims priority to German Patent Application No. 102013206373.3, filed Apr. 11, 2013, the content of which is hereby incorporated by reference for all purposes.
FIELD
The present disclosure relates to an internal combustion engine with a centrifugal pendulum device.
BACKGROUND AND SUMMARY
Engines include a number of rotational components such as crankshafts. The rotary oscillations of the crankshaft lead to rotational speed oscillations of the internal combustion engine, and are also transmitted via the timing drive or camshaft drive to the camshaft, the camshaft itself also being an oscillatory system which can excite vibration in further systems, such as valve mechanisms. The transmission of vibration to other ancillary units via components driven by the crankshaft is also possible. In addition, the oscillations of the crankshaft are transmitted to the drive train, via which they may be transmitted onwards to the transmission and the drive shafts and as far as the tires of a vehicle. Centrifugal pendulum devices may be used in engines to attenuate vibrations in the crankshaft and drive train.
The German published patent application DE 10 2006 028 556 A1 describes such a centrifugal pendulum device. The device is positioned in a drive train of a motor vehicle and used to absorb and/or damp rotary oscillations in the drive train. The centrifugal pendulum device of DE 10 2006 028 556 A1 has a pendulum mass carrier rotatable about an axis of rotation and at least one pendulum mass pair comprising two pendulum masses arranged movably on the pendulum mass carrier opposite one another and at a distance from the axis of rotation. The pendulum masses are connected to the pendulum mass carrier, the pendulum masses having arcuate openings in which rollers provided on the pendulum mass carrier are supported and guided. The arcuate openings form the tracks for the rollers and guide the movement of the pendulum masses. Prior art FIGS. 1 a , 1 b and 1 c show in a simplified schematic representation a prior art centrifugal pendulum device as disclosed in DE 10 2006 028 556 A1, FIG. 1 a showing the prior art centrifugal pendulum device in the so-called zero state, FIG. 1 b shows the prior art device in a working position, and FIG. 1 c shows the prior art device in a position when the vehicle stationary, that is, when the internal combustion engine inoperative and not producing output power. Another centrifugal pendulum device is described in the German published patent application DE 10 2011 105 029 A1.
The centrifugal pendulum device 21 represented in the prior art figures has a pendulum mass carrier 23 rotating about an axis of rotation 22 and two pendulum masses 24 a , 24 b arranged movably on the pendulum mass carrier 23 and forming a pendulum mass pair 24 . The pendulum masses 24 a , 24 b have arcuate openings 26 a , 26 b , are located opposite one another, are spaced from the axis of rotation 22 , and are mounted and positively guided kinematically by means of roller pins 25 a , 25 b of the pendulum mass carrier 23 engaging in the openings 26 a , 26 b . The pendulum masses 24 a , 24 b of FIG. 1 b are located opposite one another and the pendulum masses 24 a , 24 b are spaced away from the axis of rotation 22 as soon as their centers of gravity are at a distance from the axis of rotation 22 . The arcuate openings 26 a , 26 b represent the tracks 26 a , 26 b for the roller pins 25 a , 25 b and therefore guide movement of the pendulum masses 24 a , 24 b.
When the internal combustion engine is inoperative and the vehicle at a standstill, and when the pendulum mass carrier is stationary, the pendulum masses 24 a , 24 b can adopt the position represented in FIG. 1 c and thus form an unbalanced mass. This gives rise to problems, especially when the pendulum mass carrier 23 is set in rotation again. For example, when the internal combustion engine is started and the pendulum masses 24 a , 24 b must first settle into a working position as represented in prior art FIG. 1 b during this start-up process, that is, as the rotary motion begins. Increased noises, combined with high stress on the pendulum mass bearings, in particular the roller pins, may result from the prior art centrifugal pendulum device illustrated in FIGS. 1 a , 1 b , and 1 c.
As such in one approach, a centrifugal pendulum device in an engine is provided. The centrifugal pendulum device includes a pendulum mass carrier, a moveable coupling element rotatably coupled to the pendulum mass carrier via a first bearing element, the coupling element forming a continuous piece of material, and two pendulum masses spaced away from one another and rotatably coupled to the coupling element via a second bearing element and a third bearing element.
Jointly rotationally coupling the pendulum masses via common coupling elements enables one of the masses to compensate for the other when the first mass is urged into an offset position, such as when the engine is inoperative and not producing a rotational output. In this way, the pendulum masses may be cooperatively moved to provide mass balance in the centrifugal pendulum device. As a result, vibration cause by unbalance masses during engine restart is reduced (e.g., substantially eliminated), thereby reducing noise, vibration, and harshness (NVH) in the engine. Moreover, rotationally coupling the mass carrier, pendulum masses, and coupling element reduces the wear in the coupling mechanism when compared to prior centrifugal pendulum devices. As a result, the longevity of the centrifugal pendulum devices is increased.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure. Additionally, the above issues have been recognized by the inventor herein, and are not admitted to be known.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A shows schematically in a side view of a prior art centrifugal pendulum device in the zero state;
FIG. 1B shows schematically in a side view the prior art centrifugal pendulum device represented in FIG. 1A in a working position;
FIG. 1C shows schematically in a side view the centrifugal pendulum device represented in FIG. 1A in a position in which the internal combustion engine is inoperative;
FIG. 2A shows schematically in a side view a centrifugal pendulum device of a first embodiment of the internal combustion engine in the zero state;
FIG. 2B shows schematically in a side view the centrifugal pendulum device represented in FIG. 2A in a working position;
FIG. 2C shows schematically in a side view the centrifugal pendulum device represented in FIG. 2A in a position in which the internal combustion engine is inoperative; and
FIG. 3 shows a method for producing a centrifugal pendulum device.
DETAILED DESCRIPTION
Vibration is taking on increasing importance in the construction and design of motor vehicles and internal combustion engines. Attempts are being made, inter alia, to influence the noise caused by the internal combustion engine. This development work is also motivated by recognition of the fact that a customer's purchasing decision is partly influenced by the noise of the internal combustion engine and of the vehicle, especially from the point of view of comfort. The transmission of structure-borne noise to the body via the engine mountings is of special significance for acoustic driving comfort.
The phenomenon of vibration will be briefly explained in more detail with reference to the example of the crank gear and the crankshaft. The crankshaft, together with the engine parts coupled thereto, forms an oscillatory system. The crankshaft is excited to produce rotary oscillations by the time-variable rotational forces transmitted to the crankshaft via the connecting rods coupled to the individual crank pins. The rotary oscillations of the crankshaft generate noise both through structure-borne noise radiation and through transmission of structure-borne noise to the body and to the internal combustion engine. If the crankshaft is excited within its natural frequency range, large rotary oscillation amplitudes can occur, and can even lead to fatigue fracture. This last consideration indicates that vibration also plays a part with regard to the strength of components.
The rotary oscillations of the crankshaft lead to rotational speed oscillations of the internal combustion engine, and are also transmitted via the timing drive or camshaft drive to the camshaft, the camshaft itself also being an oscillatory system which can excite vibration in further systems, in particular the valve mechanism. The transmission of vibration to other ancillary units via traction drives driven by the crankshaft is also possible. In addition, the oscillations of the crankshaft are transmitted to the drive train, via which they may be transmitted onwards to the transmission and the drive shafts and as far as the tires of a vehicle.
In order to reduce rotational speed fluctuations, the mass of the oscillatory system is increased by arranging a flywheel on the crankshaft. As a result of the greater mass, the system has increased inertia. The rotary motion of the crankshaft becomes more uniform.
If the flywheel, which generally is fastened on one side to the crankshaft and on the other side via the clutch to the transmission, is in the form of a dual-mass flywheel, the flywheel additionally takes on the function of a vibration damper which reduces the rotary oscillations between the clutch and drive train.
To attenuate the rotary oscillations of the crankshaft and in the drive train, rotary oscillation dampers, that is, torsional vibration dampers, may be provided. As a result of a relative movement of the mass of the vibration damper with respect to the crankshaft, a portion of the rotary oscillation energy is dissipated through frictional work.
Centrifugal pendulum devices, the pendulum masses which do not lie within the power flow and which, when excited, move oppositely to the exciting oscillations, thus leading to the elimination or damping of the latter, may be used as torsional vibration dampers. With prior dampers or vibration absorbers, this effect occurs only at a certain frequency, namely the resonance frequency of the damper. A centrifugal pendulum device in which the restoring force is determined primarily by the centrifugal forces acting on the pendulum masses, by contrast, is a rotational-speed adaptive vibration absorber the natural frequency of which changes with rotational speed since the centrifugal forces are dependent on rotational speed. By means of a centrifugal pendulum device, therefore, it is possible to absorb a fixed order of excitation and not only a fixed frequency. This has particular advantages in internal combustion engines, in which a centrifugal pendulum device can be tuned to absorb any desired order of excitation.
The number of starts or restarts of an internal combustion engine is increasing. For instance, in some vehicles stop-and-go operation, also referred to as start/stop mode, may be implemented where the engine is switched off in the absence of an instantaneous power requirement in order to reduce fuel consumption, instead of allowing them to idle. In practice, this means that the internal combustion engine is switched off while the vehicle is not moving. One application of stop-and-go operation is the traffic situation arising, for example, in congestion on motorways and major roads. In inner-city traffic stop-and-go operation may be highly desired, as a result of the presence of uncoordinated traffic lights, railway crossing, etc. The number of start-up processes is therefore increasing.
To overcome at least a portion of the aforementioned prior art shortcomings, an internal combustion engine with a centrifugal pendulum device is described herein. The centrifugal pendulum device includes at least one pendulum mass carrier which is rotatable about an axis of rotation and at least one pendulum mass pair comprising two pendulum masses arranged movably on the pendulum mass carrier, opposite one another and at a distance from the axis of rotation. A method for producing the aforementioned centrifugal pendulum device is also described herein.
In one example, an internal combustion engine is provided. The engine includes a centrifugal pendulum device having at least one pendulum mass carrier which is rotatable about an axis of rotation and at least one pendulum mass pair comprising two pendulum masses arranged movably on the pendulum mass carrier opposite one another and at a distance from the axis of rotation, wherein the pendulum masses are connected to one another by means of at least two movable coupling elements arranged on each side of the axis of rotation and at a distance from the axis rotation, and wherein each coupling element is pivoted to each of the two pendulum masses in order to form the connection of the two pendulum masses, and each coupling element is pivoted to the pendulum mass carrier.
The aforementioned configuration of the centrifugal pendulum device has the result that, even with the internal combustion engine inoperative and the pendulum mass carrier stationary, the pendulum masses cannot form an unbalanced mass by adopting corresponding positions. The problems known from the prior art resulting from the fact that the pendulum masses must first be moved from an unbalanced position to a working position when the stationary pendulum mass carrier is set into rotation again, for example when starting the internal combustion engine, are thereby substantially eliminated.
Further in one example, the two pendulum masses forming a pendulum mass pair are connected to one another by the use of coupling elements, as previously discussed. The coupling elements provide a kinematic coupling of the two pendulum masses or of their movements and ensure that, if one pendulum mass adopts a position deviating from the zero state, the other pendulum mass adopts a compensating position with regard to the formation of an unbalanced mass. The movement executed by one pendulum mass of a pendulum mass pair is not independent of the movement of the respective other pendulum mass, but rather is in a permanent interrelationship with this movement or pendulum mass.
The coupling elements themselves are arranged movably on each side of and at a distance from the axis of rotation and are pivoted to the pendulum mass carrier. The coupling elements therefore provide not only a connection of the pendulum masses to one another, but also guidance of the pendulum masses on the pendulum mass carrier along predefined paths, that is, along predefined movement curves. A more extensive positive control, as known from the prior art, for example by means of openings formed in the pendulum masses and rollers or pins provided on the pendulum mass carrier, may not be needed, if desired.
As compared to the centrifugal pendulum devices described in the prior art, which have a kinematically over-determined and very complex positive guidance of the pendulum masses, the centrifugal pendulum device described herein is additionally distinguished by simple construction and the small number of components. The simple construction of the device considerably lowers the manufacturing cost of the device.
The small number of components lowers the production costs, the assembly time and therefore the assembly costs for the centrifugal pendulum device. In addition, assembly errors are mitigated. The susceptibility to failure of the centrifugal pendulum device decreases, ensuring a high degree of operational reliability and increasing durability and service life.
With the internal combustion engine described herein, some of the problems of prior art pendulum absorbers are overcome. In one example, each coupling element in the centrifugal pendulum device has a bar-shaped configuration. A bar-shaped coupling element makes possible the articulated connection of the pendulum masses with small utilization of material. Thus, each coupling element may have a rectangular shape.
In another example, each coupling element in the centrifugal pendulum device is pivoted at its center. The central pivoting of the coupling elements enables a symmetrical connection of the two pendulum masses forming a pendulum mass pair and for similar relationships of forces in the articulated connections to the pendulum masses.
In yet another example, the pendulum mass carrier in the centrifugal pendulum device has a pin and the coupling elements a bore corresponding to this pin, in order to form a bearing arrangement between the coupling element and the pendulum mass carrier. The pin and the bore enable an articulated connection of a coupling element to the pendulum mass carrier in a manner similar to a plain bearing to be formed, while using a decreased number of components, if desired. In addition, this provides the possibility of forming, that is, producing, the pin integrally with the pendulum mass carrier and in a single work cycle, if desired.
To form the bearing arrangement, the coupling element may have the pin and the pendulum mass carrier, the bore corresponding to the pin. The bearing arrangement may also include intermediate elements such as bearing shells or rolling bearings.
In another example, each pendulum mass in the centrifugal pendulum device may have a curved, crescent-shaped form. Thus, the pendulum masses may have a crescent shape, in one example. A curved shape enables, firstly, a large amount of mass to be positioned at a distance from the axis of rotation. The curved shape also enables the two crescent-shaped pendulum masses to lie opposite each other at their ends, simplifying the connection of the pendulum masses by means of coupling elements.
Further in one example, the two pendulum masses in the centrifugal pendulum device form a pendulum mass pair and are connected to one another at their ends by coupling elements. In yet another example, in the centrifugal pendulum device a bearing arrangement may be formed between a coupling element and a pendulum mass, the pendulum mass has a spigot and the coupling element includes a bore corresponding to this spigot. What has been discussed above regarding the coupling arrangement (e.g., bearing arrangement) between a coupling element and the pendulum mass carrier may also be applied analogously to the coupling arrangement (e.g., bearing arrangement) between a coupling element and a pendulum mass. In particular, in order to form the bearing arrangement the coupling element may include the spigot and the pendulum mass, the bore corresponding to the spigot. The use of intermediate elements, as in the bearing arrangement on the pendulum mass carrier described herein, may also be used.
Additionally in one example, the pendulum masses in the centrifugal pendulum device may be connected to the pendulum mass carrier only via coupling elements. However, other coupling techniques have been contemplated.
The omission of additional positive control of the pendulum masses on the pendulum mass carrier, for example by means of openings and rollers as described in the prior art, considerably simplifies the centrifugal pendulum device. The simple construction of the device reduces the number of components and lowers the manufacturing costs. If a pin and/or a spigot is/are provided for the bearing arrangement of a coupling element, examples of the internal combustion engine in which the spigot of the pendulum mass and/or the pin of the at least one pendulum mass carrier is/are coated with a substance may be used.
If a pin and/or a spigot is/are provided for the bearing arrangement of a coupling element, embodiments of the internal combustion engine in which the spigot of the pendulum mass and/or the pin of the at least one pendulum mass carrier is/are surface-treated with a substance may be utilized.
If a pin and/or a spigot is/are provided for the bearing arrangement of a coupling element, embodiments of the internal combustion engine in which the bore of the coupling element corresponding to a pin and/or the bore of the coupling element corresponding to a spigot is/are coated may be used.
If a pin and/or a spigot is/are provided for the bearing arrangement of a coupling element, embodiments of the internal combustion engine in which the bore of the coupling element corresponding to a pin and/or the bore of the coupling element corresponding to a spigot is/are surface-treated with a substance may be utilized.
A coating or a surface-treatment of the pin, the spigot and/or the bore according to the above examples can serve to set a coefficient of friction in the bearing arrangement and therefore to tune the centrifugal pendulum device in which the restoring force, although determined by the centrifugal forces acting on the pendulum masses, is also determined by the frictional forces in the bearings to a predetermined order of excitation.
Embodiments of the internal combustion engine in which the internal combustion engine can be operated in the stop-and-go mode may also be used. Thus, the engine may be configured to be operated in the stop-and-go mode.
As already mentioned, the pendulum masses of the centrifugal pendulum device described herein may not be configured to adopt positions in which they form an unbalanced mass even when the pendulum mass carrier is stationary. If the stationary pendulum mass carrier is then set in rotation, for example when starting the internal combustion engine, the pendulum masses are either in the zero state or already in a working position and may not need to be moved out of a position in which they form an unbalanced mass. The centrifugal pendulum device described herein is therefore especially suited for internal combustion engines which are operable or are operated in the stop-and-go mode.
Embodiments of the internal combustion engine in which the centrifugal pendulum device is configured in combination with a dual-mass flywheel may also be used. If the centrifugal pendulum device or the pendulum masses thereof are to be tuned to the primary order of excitation of the internal combustion engine in order to absorb the excitation oscillations, this may not be achieved if the device is arranged on the crankshaft or on a rigid flywheel, since the engine irregularities are too large and the angles of oscillation and the masses may not be selected large enough because of the small space available.
On the other hand, effective absorption can be achieved if the centrifugal pendulum device is combined with a dual-mass flywheel. In this case the centrifugal pendulum device is coupled to the secondary side of the dual-mass flywheel, that is, to the element which is subjected to only a fraction of the original oscillation. Substantially smaller pendulum masses and angles of oscillation may then be sufficient to compensate the residual oscillations.
A method for producing a centrifugal pendulum device of an internal combustion engine of an aforementioned type is also described herein. The method may include manufacturing a centrifugal pendulum device in which a pin and/or a spigot is/are provided for the bearing arrangement of a coupling element. The method may include forming in one piece at least one pendulum mass carrier together with pins, and/or the pendulum masses of the pendulum mass pair together with spigots. The one-piece configuration of pendulum mass carrier and pin, or pendulum mass and spigot, makes it possible to produce the pendulum mass carrier together with pins, and the pendulum masses together with spigots, in one work cycle, if desired.
Furthermore, the one-piece configuration by its nature produces a connection of the pendulum mass carrier to the pins, or of the pendulum mass to the spigot, by a material joint, so that the connecting elements previously needed for a non-positive or positive connection may be dispensed with if desired, together with the time required for producing the connection.
The structure of the centrifugal pendulum device may be simplified by the small number of components. This reduces the manufacturing costs of the device. The features of the internal combustion engines may be constructed via the aforementioned manufacturing method. Embodiments of the method in which the at least one pendulum mass carrier together with pins, and/or the pendulum masses of the at least one pendulum mass pair together with spigots, are produced in one piece via cold forming may be used. The cold forming method may have high dimensional accuracy. The coefficient of friction in the bearing arrangement between a coupling element and a pendulum mass, and/or the coefficient of friction in the bearing arrangement between a coupling element and the pendulum mass carrier, may be set in a specified manner by after-treatment of the bore, the spigot and/or the pin, in on example.
FIG. 2 a shows schematically in a side view a centrifugal pendulum device 1 of a first embodiment of the internal combustion engine in the zero state. A zero state of the device is when the device's rotational speed is substantially 0. The differences from the centrifugal pendulum device according to the prior art represented in prior art FIG. 1 a are discussed in greater detail herein. For like components, that is, for components having like functions, corresponding reference symbols are used.
The centrifugal pendulum device 1 of FIG. 2 a has a pendulum mass carrier 3 which is rotatable about an axis of rotation 2 and a pendulum mass pair 4 comprising two pendulum masses 4 a , 4 b which are arranged movably on the pendulum mass carrier 3 opposite one another and at a distance from the axis of rotation 2 . The centrifugal pendulum device 1 may be included in an engine 50 . It will be appreciated that the engine is configured to provide a rotational output to the pendulum mass carrier 3 .
In contrast to the centrifugal pendulum device 21 represented in FIG. 1 a , the crescent-shaped pendulum masses 4 a , 4 b , shown in FIG. 2 a are connected to one another at their ends by means of two movable coupling elements 5 ′, 5 ″ arranged on each side of the axis of rotation 2 and at a distance from the axis of rotation 2 .
The bar-shaped coupling elements 5 ′, 5 ″ are themselves pivoted at their centers on the pendulum mass carrier 3 , the pendulum mass carrier 3 having a pin 8 ′, 8 ″ and the coupling element 5 ′, 5 ″ having a bore 9 ′, 9 ″ corresponding to this pin 8 ′, 8 ″ in order to form the bearing arrangement 6 ′, 6 ″ between a coupling element 5 ′, 5 ″ and the pendulum mass carrier 3 . Thus the coupling elements are rotationally coupled to the pendulum mass carrier. It will be appreciated that the coupling elements have a rectangular shape. However, other coupling element shapes have been contemplated.
Additionally, in order to form the connection between the two pendulum masses 4 a , 4 b , each coupling element 5 ′, 5 ″ is pivoted (e.g., rotationally coupled) to each of the pendulum masses 4 a , 4 b , the pendulum mass 4 a , 4 b having a spigot and the coupling element 5 ′, 5 ″ having a bore corresponding to this spigot in order to form the bearing arrangement 7 a ′, 7 a ″, 7 b ′, 7 b ″ between a coupling element 5 ′, 5 ″ and a pendulum mass 4 a , 4 b . The bearing arrangements are radially aligned, in the depicted example. Therefore it will be appreciated that the bearing arrangements may be spigot bearings, in one example. However, other types of bearing arrangements have been contemplated.
The coupling elements 5 ′, 5 ″ provide not only a connection between the pendulum masses 4 a , 4 b , but also guidance of the pendulum masses 4 a , 4 b on the pendulum mass carrier 3 along predefined paths. FIG. 2 b shows the centrifugal pendulum device 1 in a working position with the pendulum mass carrier 3 revolving. More extensive positive control, for example by means of openings and rollers may not be used, if desired.
The coupling elements 5 ′, 5 ″ provide a kinematic coupling between the two pendulum masses 4 a , 4 b , especially when a pendulum mass 4 a , 4 b adopts a position deviating from the zero state of FIG. 2 a . The movement performed by one of the pendulum masses 4 a , 4 b of the pendulum mass pair 4 is not independent of the movement of the other pendulum mass but rather is in permanent interrelationship therewith. Consequently, the pendulum masses 4 a , 4 b do not form an unbalanced mass even when the internal combustion engine is inoperative and the pendulum mass carrier 3 is stationary, as can be seen from FIG. 2 c . In other words, the coupling elements jointly urge the pendulum masses in different directions to provide mass balance in the device. Thus, one of the pendulum masses may be urged in a first direction and the other pendulum mass may be urged in a second direction offsetting the change in position of the first pendulum mass to provide the mass balance.
FIG. 3 shows a method 300 for producing a centrifugal pendulum device of an internal combustion engine. The method 300 may be used to produce the centrifugal pendulum device described above with regard to FIGS. 2 a -2 c or may be used to produce another suitable centrifugal pendulum device.
At 302 the method includes manufacturing a centrifugal pendulum device including a centrifugal pendulum device having at least one pendulum mass carrier which is rotatable about an axis of rotation and at least one pendulum mass pair comprising two pendulum masses which are arranged movably on the pendulum mass carrier opposite one another and at a distance from the axis of rotation. The pendulum masses may be connected to one another by at least two movable coupling elements arranged on each side of the axis of rotation and at a distance from the axis of rotation, each coupling element, pivotally coupled to each of the two pendulum masses in order to form the connection between the two pendulum masses, and pivotally coupled to the pendulum mass carrier. Additionally, the at least one pendulum mass carrier together with pins, and the pendulum masses of the at least one pendulum mass pair together with spigots, may be formed in one piece.
In one example, at least one of the pendulum mass carrier together with pins, and the pendulum masses of the at least one pendulum mass pair together with spigots, are produced in one piece by cold forming. In another example, the coefficient of friction in the bearing arrangement between a coupling element and a pendulum mass, and the coefficient of friction in the bearing arrangement between a coupling element and the pendulum mass carrier, may be determined by an after-treatment of at least one of the bore, of the spigot, and of the pin.
It will be appreciated by those skilled in the art that although the invention has been described by way of example with reference to one or more embodiments it is not limited to the disclosed embodiments and that alternative embodiments could be constructed without departing from the scope of the invention as defined by the appended claims.
Note that the example control and estimation routines included herein can be used with various engine and/or vehicle system configurations. The specific routines described herein may represent one or more of any number of processing strategies such as event-driven, interrupt-driven, multi-tasking, multi-threading, and the like. As such, various actions, operations, and/or functions illustrated may be performed in the sequence illustrated, in parallel, or in some cases omitted. Likewise, the order of processing is not necessarily required to achieve the features and advantages of the examples described herein, but is provided for ease of illustration and description. One or more of the illustrated actions, operations and/or functions may be repeatedly performed depending on the particular strategy being used.
It will be appreciated that the configurations and routines disclosed herein are exemplary in nature, and that these specific examples are not to be considered in a limiting sense, because numerous variations are possible. For example, the above technology can be applied to V-6, I-4, I-6, V-12, opposed 4, and other engine types. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations, and other features, functions, and/or properties disclosed herein.
The following claims particularly point out certain combinations and sub-combinations regarded as novel and non-obvious. These claims may refer to “an” element or “a first” element or the equivalent thereof. Such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and sub-combinations of the disclosed features, functions, elements, and/or properties may be claimed through amendment of the present claims or through presentation of new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope to the original claims, also are regarded as included within the subject matter of the present disclosure. | An internal combustion engine with a centrifugal pendulum device having a pendulum mass carrier, a moveable coupling element rotatably coupled to the pendulum mass carrier via a first bearing element, the coupling element forming a continuous piece of material, and two pendulum masses spaced away from one another and rotatably coupled to the coupling element via a second bearing element and a third bearing element. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention claims priority from Japanese Patent Application No. 9-277623 filed Oct. 9, 1997, which is incorporated herein by reference. It relates to the molding of plastics, particularly to the shape of the mold used in molding techniques wherein the deformation occurring during cooling is predicted and the plastic molded product is removed from the mold at high temperature.
[0003] 2. Description of Related Art
[0004] A widely practiced method of molding plastic is to extrude high-temperature molten plastic in a tubular shape, enclose this in a mold and cause it to expand by blowing air into the tube. A conventional example of this will be explained with reference to FIG. 3 to FIG. 6, which show the process of manufacturing a container by blow molding.
[0005] As shown in FIG. 3, molten plastic in tubular shape (the parison) is extruded into the middle of a split mold, and as shown in FIG. 4, the mold is then closed. As shown in FIG. 5, when air is blown into the molten plastic, the plastic adheres to the inner wall of the mold and assumes the same shape as this inner wall. At this point in time the molten plastic is at a high temperature of for example 200° C., and it is cooled and solidified by keeping it in the mold while continuing to blow in high-pressure air. The time required for this cooling varies according to the type of plastic and the form of the molded product, and cooling time has hitherto been determined on the basis of the criterion that deformation due to thermal shrinkage of the resin after removal from the mold is linear. As shown in FIG. 6, when the mold is opened, the molded product is removed.
[0006] The molded product shown in FIG. 6 is a container (a bottle) which will be marketed after being filled with a liquid, and the resin temperature at which a mold is opened is usually about 50° C. A dozen or so seconds are required for this cooling.
[0007] It thus takes time to cool the high-temperature molten plastic to a point at which the mold can be opened. Production per unit time and production cost are in inverse proportion, and in a manufacturing process in which time management is carried out in units of seconds, even a short cooling time of a dozen or so seconds should be shortened in order to achieve lower production cost.
[0008] In order to obtain data relating to the shortest practical cooling time, the inventors performed repeated experiments in which a molded product was released from a mold while still at a high temperature. These experiments showed that if a mold is opened up before the conventionally employed cooling time has elapsed, the high-temperature molten plastic shrinks greatly and undergoes nonlinear deformation, so that the target molded product shape is not obtained. In other words, it was found that cooling time could not be shortened.
[0009] It would therefore be desirable to predict the nonlinear deformation of a high-temperature molded product after it has been released from a mold, and to develop a mold which enables molten plastic to be molded in such a way that the shape after deformation is the desired shape.
SUMMARY OF THE INVENTION
[0010] It is therefore an object of the present invention to provide a mold such that a target molded product shape can be obtained even though the cooling time in the plastic molding process is shortened.
[0011] Plastic which has been released from a mold undergoes shrinkage deformation in the course of cooling to ordinary temperature. Conventionally, removal of the plastic at a low temperature ensures a regularity in the resulting deformation, i.e. the deformation is linear, and therefore by taking the shrinkage factor into account when designing the mold size so as to make the mold suitably larger, the manufacturability of the target molded product shape (i.e. its design dimensions) can be guaranteed.
[0012] However, the broad regularity mentioned above is not found in the course of the nonlinear shrinkage which occurs when a plastic molded product is removed from a mold at high temperature. The inventors have therefore invented a method and apparatus for a mold design whereby a target molded product shape is obtained even when a molded product is removed from a mold at high temperature. This is achieved by using the finite element method to simulate deformation behavior, and by taking this deformation into account beforehand when fabricating the shape of the mold (Japanese Patent Application Laid-open No. 9-277260). This method and apparatus for mold design ensure that a mold shape which takes nonlinear deformation into account in advance is achieved.
[0013] According to a first aspect of the present invention, a mold for blow molding a thermoplastic product is formed so that the difference between the maximum and minimum shrinkage of the external size of the body portion of the molded product relative to the size of the mold cavity exceeds 0% and is at most 18.0%.
[0014] High-density polyethylene (HDPE) can be used for the aforementioned thermoplastic, and in this case the mold cavity is preferably formed so that the difference between the maximum and minimum shrinkage of the external size of the body portion of the molded product relative to the size of the mold cavity is at least 1.4% and at most 18.0%.
[0015] Polypropylene (PP) can also be used for the aforementioned thermoplastic, in which case the mold cavity is preferably formed so that the difference between the maximum and minimum shrinkage of the external size of the body portion of the molded product relative to the size of the mold cavity exceeds 0% and is at most 8.0%.
[0016] According to a second aspect of the present invention, a blow molded product and a molding method using the mold are provided.
[0017] According to a third aspect of the invention, a blow molded product on the body portion of which an in-mold label has been affixed during blow molding uses the aforementioned mold, said in-mold label excluding labels which do not thermally shrink after removal from a mold.
[0018] As has been explained above, the present invention is capable of providing a mold such that a target molded product shape can be obtained even though the cooling time in the plastic molding process is shortened.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] [0019]FIG. 1 shows the front of a mold according to an embodiment of the present invention.
[0020] [0020]FIG. 2 shows the side of a mold according to an embodiment of the present invention.
[0021] [0021]FIG. 3 to FIG. 6 show the processes involved in manufacturing a container by blow molding.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Embodiments of the invention will be explained with reference to FIG. 1 and FIG. 2, which respectively show the front and side of a mold according to embodiments of this invention. The broken lines in these figures indicate the shape of the molded product after cooling.
[0023] This invention is a mold 1 for blow molding a bottle, which is a blow molded product consisting of a thermoplastic, in which the mold cavity is formed so that the difference between the maximum and minimum shrinkage of the external size of the body portion of the molded product relative to the size of the cavity of mold 1 exceeds 0% and is at most 18.0%.
[0024] High-density polyethylene (HDPE) can be used for the aforementioned thermoplastic, and in this case the mold cavity is formed so that the difference between the maximum and minimum shrinkage of the external size of the body portion of the molded product relative to the size of the cavity of mold 1 is at least 1.4% and at most 18.0%.
[0025] Polypropylene (PP) can also be used for the aforementioned thermoplastic, in which case the mold cavity is formed so that the difference between the maximum and minimum shrinkage of the external size of the body portion of the molded product relative to the size of the cavity of mold 1 exceeds 0% and is at most 8.0%.
[0026] In-mold label 2 is affixed to the molded product during blow molding, said in-mold label excluding labels which do not thermally shrink after removal from a mold.
[0027] These embodiments of the invention will now be further explained with reference to the following table.
Table
[0028] [0028] TABLE Type of plastic HDPE PP embodiments A B C D E difference between max. and width 1.4 2.7 4.0 0.0 0.4 min. shrinkage of external depth 5.8 2.9 17.5 3.3 7.6 size of body portion of molded product relative to size of mold cavity (%) cooling time (seconds) 5.5 5.0 7.0 7.0 4.5 removal temperature (° C.) 94 104 80 85 82
[0029] High-density polyethylene (HDPE) and polypropylene (PP) are used in these embodiments as the material for the bottle. When HDPE is used, the temperature of the body portion of the molded product when it is removed from mold 1 according to these embodiments is 80° C. to 104° C. This removal temperature was measured at the body portion of the molded product immediately after it was removed from mold 1 , using a radiation thermometer (a TVS-100 manufactured by Nippon Avionics Co., Ltd.). The body portion here means the portion of the container from the bottom face to the neck. Hence the molded product can be removed from the mold at a considerably higher temperature than the conventional removal temperature of 45 ° C. to 57° C.
[0030] When HDPE is used, mold 1 from which a molded product can be removed at high temperature has a mold cavity formed so that the difference between the maximum and minimum shrinkage of the external size of the body portion of the molded product relative to the size of the cavity of mold 1 is at least 1.4% and at most 18.0%.
[0031] The preferred embodiments in the case of HDPE are high-speed products A and C. For these, the difference between the maximum and minimum shrinkage of the external size of the body portion of the molded product relative to the size of the mold cavity is respectively 1.4% and 17.5%. Preferably, the difference between the maximum and minimum shrinkage of the external size of the body portion of the molded product relative to the size of the cavity of mold 1 is at least 1.4% and at most 17.5%.
[0032] In an embodiment in which the molded product has a waist, the difference between the maximum and minimum shrinkage of the body portion of the molded product is at least 10.0% and at most 17.5%.
[0033] In the prior art the difference between the maximum and minimum shrinkage of the external size of the body portion of the molded product relative to the size of the mold cavity was approximately 0%.
[0034] When PP is used, the temperature of the body portion of the molded product when it is removed from a mold according to these embodiments is 82° C. to 85° C. This removal temperature was measured in the same way as in the case of the HDPE molded products. The molded PP product can be removed from the mold at a considerably higher temperature than the conventional mold removal temperature of 46° C. to 62° C.
[0035] When PP is used, mold 1 from which a molded product can be removed at high temperature has a mold cavity formed so that the difference between the maximum and minimum shrinkage of the external size of the body portion of the molded product relative to the size of the cavity of mold 1 exceeds 0% and is at most 8.0%.
[0036] The preferred embodiment in the case of PP is high-speed molded product D. For this, the difference between the maximum and minimum shrinkage of the external size of the body portion of the molded product relative to the size of the cavity of mold 1 is approximately 3.3%. Preferably, the difference between the maximum and minimum shrinkage of the external size of the body portion of the molded product relative to the size of the cavity of mold 1 is at least 3.3% and at most 5.9%.
[0037] In the prior art the difference between the maximum and minimum shrinkage of the external size of the body portion of the molded product relative to the size of the mold cavity exceeded 0% and was at most 1.1%. As shown in the table, the cooling time can be reduced from the 7 to 12 seconds required with a prior art mold to 4.5 to 7.0 seconds. | In order to provide a mold of a shape which has been designed to take into account the deformation occurring during the cooling process, the mold cavity is formed so that the difference between the maximum and minimum shrinkage of the external size of the body portion of the molded product relative to the size of the mold cavity has a prescribed value. | 1 |
BACKGROUND OF THE INVENTION
(1) Field of the Invention
This invention is concerned with a shoe upper conforming machine for use in lasting side portions of shoe uppers. The term "shoe" where used herein is used generically as indicating articles of outer footwear generally including such articles in the course of manufacture.
(2) Prior Art
It has recently been proposed to provide a shoe upper conforming machine for use in lasting side portions of shoe uppers comprising a support for a shoe last on which an upper, the side portions of which are to be lasted, and an insole are positioned, and two side lasting assemblies arranged so as to act on opposite side portions of an upper positioned on a last supported by said support, wherein each side lasting assembly comprises clamping means, comprising at least one clamp member, movable towards the last support to cause a side portion of the upper to be held against the last, on which it is positioned and which is supported by the last support, at a locality spaced from the featherline thereof, and lasting band means comprising at least one upper-engaging band portion of flexible sheet material arranged to be interposed between the shoe upper and the clamp member(s), and further wherein the or each upper-engaging band portion is held by the clamp member(s), in the operation of the machine, against the upper positioned on its last under a pressure which does not prevent movement of the upper-engaging band portion(s) relative to the clamp member(s) but which is sufficient to cause such movement of said portions(s) to apply a drafting force to the portion of the upper engaged thereby, the arrangement being such that, in the operation of the machine, movement of the upper-engaging band portion(s) is caused to take place relative to the clamp member(s) whereby a drafting force is applied to the upper by said portion(s) heightwise of the last in the direction of the featherline of the shoe, and lasting marginal portions of the side portion of the upper are caused to be wiped over corresponding marginal portions of the insole and be pressed thereagainst. In this way, a controlled drafting force can be applied to the upper through the upper-engaging band portion(s) the control being specifically achieved by the action of the clamp member(s) acting on the band portion(s).
The locality of the last at which the or each clamp member is caused to press the side portion of the upper may be relatively flat, so that no difficulty arises in applying adequate pressure to the lasting band(s) by the clamp member(s). Where, however, the last in said locality has a significant lengthwise contour, it has been found that, even though a plurality of independently operable clamp members may be used, the pressure applied thereby may be inadequate because the whole of the pressure-applying surface is not in contact with the band portion. This is especially the case where the lasting band means comprises a plurality of band portions arranged in pairs, each such pair being held in pressing engagement with the upper by one of the clamp members as aforesaid. This leads to inadequate drafting force being applied to the upper.
It is thus one of the various objects of the present invention to provide a side lasting machine in which the application of a controlled drafting force to the upper, using lasting band means pressed against the upper on its last by means of a plurality of clamp members, can be more reliably achieved.
BRIEF SUMMARY OF THE INVENTION
The invention provides, in one of its several aspects, a shoe upper conforming machine for use in lasting side portions of shoe uppers comprising a support for a shoe last on which an upper, the side portions of which are to be lasted, and an insole are positioned, and two side lasting assemblies arranged so as to act on opposite side portions of an upper positioned on a last supported by said support, wherein each side lasting assembly comprises clamping means, comprising a plurality of clamp members movable independently towards the last support to cause a side portion of the upper to be held against the last, on which it is positioned and which is supported by the last support, at localities spaced from the featherline thereof, and lasting band means comprising at least one upper-engaging band portion of flexible sheet material arranged to be interposed between the shoe upper and the clamp members, the or each upper-engaging band portion being held by the clamp members, in the operation of the machine, against the upper positioned on its last under a pressure which does not prevent movement of the upper-engaging band portions(s) relative to the clamp members but which is sufficient to cause such movement of said portion(s) to apply a drafting force to the portion of the upper engaged thereby, the arrangement being such that, in the operation of the machine, a drafting force is applied to the upper by said portion(s) heightwise of the last in the direction of the featherline of the shoe and lasting marginal portions of the upper are caused to be wiped over corresponding marginal portions of the insole and be pressed thereagainst, wherein each clamp member is mounted for pivotal movement about an axis extending heightwise of the last.
It will thus be appreciated that, using a machine in accordance with the invention, the clamp members can more readily conform to the lengthwise contour of the side of the last, and thereby more reliably cause the desired drafting force to be applied to the upper by the upper-engaging band portion(s) held against the upper by the clamp members.
It will be appreciated that the position of the axis in relation to the clamp member body and also the cross-sectional shape of each clamp member, viewed along said axis, should be such as to enable pivoting to take place without adjacent clamp members binding on one another, while still providing a suitable pressing surface for engagement with the band portion(s).
In the machine which has recently been proposed, as mentioned above, the lasting band means of each side lasting assembly comprises a plurality of band portions, arranged in pairs and each pair being associated with one clamp member, each clamp member thus being arranged to hold two band portions in pressing engagement with the upper as aforesaid. Furthermore, in said machine, each side lasting assembly further comprises lasting element means, comprising a plurality of lasting elements arranged side-by-side and movable inwardly towards the last support so as to cause lasting marginal portions of the side portion of the upper to be wiped over corresponding marginal portions of the insole and be pressed thereagainst, the inward movement of the lasting elements towards the last support as aforesaid being effective to cause movement of the upper-engaging band portions to take place relative to the clamp members whereby a drafting force is applied to the upper by said portions heightwise of the last as aforesaid.
It has, however, been found that using such an arrangement pleats may form in the wiped over lasting marginal portions of the upper, such pleats being formed, in the operation of the machine, in the region of gaps between adjacent band portions and their associated lasting elements.
It is thus another object of the present invention to provide a side lasting machine in which the lasting element means of each side lasting assembly comprises a plurality of lasting elements arranged side-by-side, but in the operation of which the risk of pleats in the wiped over lasting marginal portions of the upper is mitigated.
The invention thus also provides, in another of its several aspects, a shoe upper conforming machine for use in lasting side portions of shoe uppers comprising a support for a shoe last on which an upper, the side portions of which are to be lasted, and an insole are positioned, and two side lasting assemblies arranged so as to act on opposite side portions of an upper positioned on a last supported by said support, wherein each side lasting assembly comprises lasting element means, comprising a plurality of lasting elements arranged side-by-side and movable inwardly towards the last support so as to cause lasting marginal portions of the side portion of the upper to be wiped over corresponding marginal portions of the insole and be presssed thereagainst, and lasting band means of flexible sheet material held under tension by resilient means and arranged to be interposed between the shoe upper and the lasting elements, the arrangement being such that as inward movement of the lasting elements towards the last support is effected as aforesaid, the lasting band means is drawn heightwise of the last, in a direction of the featherline thereof, and also about the featherline region, thus to assist in wiping the lasting marginal portions of the upper over corresponding marginal portions of the insole and in pressing them thereagainst, wherein the lasting band means of each side lasting assembly comprises at least one upper-engaging band portion, and wherein the or each band portion is interposed as aforesaid between the upper and not less than two adjacent lasting elements.
In the machine as recently proposed, the lasting element means of each side lasting assembly comprises eight lasting elements, arranged in pairs, and each pair has associated therewith a clamp member. Furthermore, said machine comprises operator-actuatable selector means whereby any one pair of lasting elements and its associated clamp member may be rendered inoperative. In such a machine, therefore, it is desirable that the lasting band means of each side lasting assembly comprises four band portions, one associated with each pair of lasting elements. However, for a particular application, it may be desired to omit the selector means, in which case a single lasting band portion may be provided for co-operating with all the lasting elements of the side lasting assembly. Again, it is likely that the two most heelwardly disposed pairs of lasting elements will operate together, and a further lasting band means arrangement may thus comprise a single band portion extending across the width of said two most heelwardly disposed pairs of lasting elements, while separate band portions are provided associated with each of the other two pairs.
It will be appreciated that by provided a single band portion extending beyond the width of one lasting element, such band portion serves to fill the gap which may arise between adjacent lasting elements, with a result that pleating of the wiped lasting marginal portions of the upper in that region is prevented. Of course, in cases where the lasting band means comprises more than one band portion, necessarily a compromise arises, such compromise being dictated by the requirements of use of the machine: for example, where the machine operates on a range of sizes, the two most heelwardly disposed pairs of lasting elements may suffice to last the whole of the side portion, while with a larger shoe it may be necessary for three or four pairs of lasting elements to be used to effect a comparable lasting operation.
As previously mentioned, the or each upper-engaging band portion is held under tension by resilient means, said means being connected to one end of the or each band portion. The opposite end of the or each band portion is connected to its associated lasting elements so that inward movement of the lasting element means as aforesaid is effective to draw the lasting band portion(s) heightwise of the last and inwardly over the feather region thereof as aforesaid.
BRIEF DESCRIPTION OF THE DRAWINGS
The various objects and several aspects of the invention will become clearer from the following detailed description, to be read with reference to the accompanying drawings, of one machine in accordance with the invention, this machine having been selected for description merely by way of exemplification of the invention and not by way of limitation thereof.
In the accompanying drawings
FIG. 1 is a front perspective view of the machine in accordance with the invention; and
FIG. 2 is a view in front elevation, showing details of a left-hand side lasting assembly of said machine.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The machine in accordance with the invention now to be described is a combined heel seat and side last machine comprising a last support 10 on which a last can be supported, bottom uppermost, with an insole I located on the bottom thereof and a shoe upper U positioned thereon, as shown in FIG. 1. The machine further comprises heel seat wiping instrumentalities 12 and a heel band 14, shown in FIG. 2, and also two side lasting assemblies generally designated 16, arranged forwardly of the heel seat lasting instrumentalities, one at either side of the last support 10. The side lasting assemblies are mirror-opposites of one another and the left-hand assembly will be described with reference to FIG. 2.
The side lasting assembly 16 comprises a sub-frame 18 carried on a forwardly extending plate 20 mounted on a main machine frame 22 by pin-and-slot connections whereby the side lasting assembly 16 can pivot bodily about an axis extending transversely of the machine through a leading edge of the heel seat wipers 12 when in their advanced condition. For pivoting the sub-frame, a handle 30 is provided on the front thereof.
Forming part of the sub-frame 18 is a block 32 which accommodates four push-rods 34 for sliding movement in a direction transversely of the bottom of a last L carried by the last support 10, said rods being arranged side-by-side fore-and-aft of the machine. Mounted at the end, near the last support 10, of each push-rod 34 is a block 36 carrying a pivot pin 38 which extends fore-and-aft of the machine and on which a pair of levers 40 are each supported for pivotal movement. Each lever 40 supports a further pivot pin 42, extending transversely of the machine, and carrying an arm 44 which supports a lasting element 46. Each side lasting assembly 16 thus comprises eight such lasting elements. Each element 46 is carried by a pivot pin 48 mounted in the arm 44, the axis of said pin extending fore-and-aft of the machine. A spring 50 urges the lasting element downwardly about the pin 48 (counterclockwise, viewing FIG. 2). The lasting element 46 has a flat pressure-applying surface 52, while the end of said element facing the last support 10 is rounded at its top and bottom.
It will be appreciated that each block 36 thus carries two lasting elements 44, each independently pivotable about its own pin 42. Furthermore, it is to be noted that, when the pressure-applying surface 52 is horizontal, the axis of the pin 42 lies in the plane of said surface.
For urging each lever 40 about its pin 38, furthermore, four piston-and-cylinder arrangements 66 are provided, each acting on two associated levers 40 and each being carried by a bracket 68 carried on a mounting 70 secured to a rearward end of its associated push-rod 34. In each pair of levers 40 one is shorter than the other and there is provided, pivotally connected to the shorter lever and connected by a pin-and-slot connection to the longer lever, a link 92 itself connected by a pin-and-slot connection to a piston rod 90 of its associated piston-and-cylinder arrangement 66. In this manner, the levers 40 can be pivoted about the pin 38 independently of one another using a single piston-and-cylinder arrangement. The amount of movement in a clockwise direction of each lever is determined by a stop pin 94 carried by the bracket 68.
Mounted in the block 32, one beneath each of the push-rods 34, are four further push-rods 80. At the end, nearer the last support 10, of each push-rod 80 is secured a plate 78 to which is in turn secured a C-shaped bracket 74', between the arms of which is secured a pivot pin 136, on which is freely pivotable a clamp pad 72 of polyurethane material. The polyurethane material has a Shore A hardness of 70. The position of the pin 136 and the cross-sectional shape, viewed in plan, of each pad 72 is such that pivoting movement of each pad can take place, independently of the other pads, without adjacent pads binding on one another.
Also mounted adjacent said end of each push-rod 80 is a block 96 which is connected to a piston rod 82 of a piston-and-cylinder arrangement 84, there being four such arrangements 84 each pivotally mounted on the sub-frame 18. Furthermore, each block 96 is arranged to be in engagement, in the rest condition of the machine, with a face of a depending portion of its associated block 36. Thus, when each piston-and-cylinder arrangement 84 is operated, the push-rod 80 associated therewith is moved inwardly to move the clamp pad 72 inwardly towards the last support and, by engagement of the block 96 with the block 36, the wiping elements 46 associated with said pad are moved inwardly also.
At the end of the inward movement of each clamp pad 72, locking means is actuated to lock the push-rod 80 in position, said locking means comprising an apertured plate 98 through a restricted aperture 100 of which passes the push-rod 80 (and through a larger aperture 102 of which passes the push-rod 34). Each plate 98 is pivoted at 104 on a lug of the block 32 and is urged by a spring 106 into a locking position in which the aperture 100 binds on the push-rod 80 in the manner of a bar lock. For releasing the lock, a bar 108 is mounted for pivotal movement on lugs of the block 32, said bar carrying four adjustable stop screws 110 each of which can engage with one of the plates 98. For pivoting the bar 108, a piston-and-cylinder arrangement 112 is mounted on the block 32 and acts through a link 114 connecting the piston rod 116 thereof with said bar.
Carried on a depending portion of each block 96 is a bracket 118 supporting a piston-and-cylinder arrangement 56 a piston rod 58 of which is pivotally connected to a lever 60 pivoted, intermediate its length, on a rearward end of its associated push-rod 80, and connected by a pin-and-slot connection at its other end to the mounting 70 on the rearward end of its associated push-rod 34.
The machine in accordance with the invention also comprises lasting band means comprising a first band 128' which extends over the two most heelwardly disposed pairs of lasting elements 46, and two further bands 128" one associated with each of the other pairs of lasting elements 46. The bands are connected by clamp plates 130 to upper surfaces of the arms 44 by which the lasting elements 46 associated with the bands are carried, and each band extends over the inwardly facing end face of its associated lasting elements 46 and the inwardly facing face of its associated pad(s) 72. The lower end of each band is connected by springs 132 to a bracket 134 mounted on the lower end of the plate 78. The spring 132 merely serve to control the lower end of the bands but do not affect the function of the bands, to be hereinafter described.
In the operation of the machine, when in a rest condition the lasting elements 46, under the action of their associated cylinders 66, are in a first, raised, condition in which they are spaced above the plane of the last bottom; in addition, the lasting elements 46 and the clamp pads 72, are in a retracted position, as shown in FIG. 1. When a shoe to be operated upon has been placed on the last support 10, piston-and-cylinder arrangements 84 are actuated to cause the clamp pads, and thus the lasting elements 46 therewith, to be moved inwardly towards the last support until the clamp pads, independently of one another, are pressing their associated bands into contact with the shoe upper. As the clamp pads are moved into pressing engagement with the bands as aforesaid, they are free to pivot, independently of one another, each about the axis of its pin 136, so that the surface of each pad, through which surface pressure is applied as aforesaid, engages, over substantially the whole of its width, its associated band. The pressure applied by the pads is in the order of 1.4 kgf/sq. cm. (20 lbs./sq. in.). In this position, piston-and-cylinder arrangement 112 is deactuated and the bar lock is applied, the clamp pads now being locked in said position. At this stage, the lasting elements 46 are still in their first, raised, condition. Thereafter, piston-and-cylinder arrangements 56 are actuated whereupon, through their associated levers 60, the pivots of which on the push-rods 80 are now stationary, the push-rods 34, and thus the lasting elements 46 are moved inwardly relative to the clamp pads, and at the same time piston-and-cylinder arrangements 66 are actuated to cause the lasting elements 46 to be moved downwardly to a second, operative, condition in which the pressure-applying surface 52 of each lasting element 46 can engage the shoe through its associated band 128' (128"). The inward movement of the elements 46 under the action of the cylinder 56 is limited by engagement of the forward face of the block 36 with the plate 78; the distance through which the elements 46 can move inwardly relative to the pads 72, is of the order of 50 mm.
The effect of the inward and downward movement of the lasting elements 46 is to cause the bands 128' (128") associated therewith to be drawn relative to the pads 72 heightwise of the last and about the featherline region thereof. To this end, the pressure applied by the pads is sufficient to hold the bands in pressing engagement with the upper while allowing such slippage to take place, and further the surface of each band engaging the upper is such that it can apply a frictional drafting force to the upper while the surface of the pad 72 is coated with a low-friction coating, e.g. polytetrafluoroethylene, so that the band can readily slip relative thereto.
Also during the inward and downward movement of the lasting elements 46, because of the action of the springs 50 in urging the elements counterclockwise (viewing FIG. 2) about the pins 48, the pressure-applying surface 52 of each element is brought into early engagement, along its length, with the feather edge of the shoe bottom, through its associated lasting band, and after such engagement is progressively caused to pivot, in a clockwise direction (viewing FIG. 2) about its pin 48 until it reaches its second condition in which it overlays the lasting marginal portion of the upper and serves to press them against corresponding marginal portions of the insole. This progressive action of each lasting element 46 has an "ironing" effect on the marginal portions of the upper.
It will be appreciated that the material of the lasting bands should not be significantly stretchy for this function, while being relatively flexible so as to conform to the shape of the shoe being operated upon. It has been found that a suitable material is a polyurethane having a Shore A hardness in the range of 70 to 90 and a modulus not less than 850 p.s.i. at 100% elongation (as per the ASTM test procedure). Furthermore, each band has a thickness in the range of 1.5 to 3.0 mm. (1/16 to 1/8 ins.).
When all the lasting elements 46 have reached their second condition, and are in pressing engagemenet with the shoe bottom, a bedding pressure can be applied thereby to the wiped-over lasting marginal portions of the upper, and to this end the fluid pressure control circuit of the machine is arranged so that the piston-and-cylinder arrangements 66 can be supplied with pressure fluid at two different pressures. Furthermore, when bedding pressure is applied, the piston-and-cylinder arrangements 112 of each assembly is again actuated, thereby releasing the bar lock arrangement against the action of the springs 106, whereupon the action of the piston-and-cylinder arrangements 56 is effective to cause the levers 60 to pivot about their pin-and-slot connection with the mountings 70 to cause a small withdrawal movement of the push-rods 80 away from the last support, and thus of the clamp members 72, thereby discontinuing their pressing of the bands against the upper. In this way, the bands 128', 128" and clamp members 72, do not interfere with the application of bedding pressure to the shoe bottom.
The machine in accordance with the invention also comprises selector means whereby any one pair of lasting elements 46 can be rendered inoperative. In the arrangement described above, namely wherein the two most heelwardly disposed pairs of lasting elements 46 have a single band 128', it is envisaged that the selector means will not be utilized to render inoperative either one of said pairs. (Should it be necessary, for a particular shoe, to render one of said pairs inoperative, then it would also be necessary to exchange two separate bands 128" for the single band described above.) If, on the other hand, it is expected that the third pair (counting from the heel end) of lasting elements will also not be rendered inoperative, then a single band may be provided in the machine in accordance with the invention covering all three heelwardly disposed pairs of lasting elements 46. Of course, if desired, also a single band may be utilized covering all four pairs of lasting elements. In the latter cases, the bands 128" associated with each of the third and fourth pairs, or with the fourth pair respectively, will of course be dispensed with. | Side lasting machine has a last support and two side lasting assemblies each comprising a plurality of lasting fingers, a plurality of clamp pads arranged beneath the fingers, one associated with each pair of fingers, and, depending from each finger and interposed between the pads and the upper, a plurality of lasting bands. Each band extends over the width of not less than two fingers; preferably in the region of the two most heelwardly disposed pairs, a single band is provided. Each pad is mounted for independent pivotal movement about a vertical axis, to enable it to conform more readily to the last contour. The pads hold the bands against the upper under a pressure sufficient to allow slipping therebetween, the band thus applying an updrafting force to the upper as the fingers move inwardly. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This is a continuation of and claims the benefit (35 U.S.C.§120 and 365(c)) of copending International Application PCT/DE 2003/002409 of Jul. 17, 2003, which designated inter alia the United States and which claims the priority of German Application DE 102 39 652.3 of Aug. 26, 2002. The entire contents of each application is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention pertains to a ball socket for a ball and socket joint especially for motor vehicles, to the process for manufacturing the ball socket, as well as to the ball and socket joint per se.
BACKGROUND OF THE INVENTION
[0003] Bearing shells for ball and socket joints especially for motor vehicles are known, for example, from DE 29 617 276 U1. DE 29 617 276 U1 discloses a ball and socket joint, which is extrusion-coated according to a one-component process and in which the bearing shell is produced from a single plastic according to the injection molding technology. This design leads in practice to the problem that when a relatively favorable plastic is used, it is either well suited tribologically in the unreinforced form but lacks sufficient strength, or it possesses good strength properties only if it is reinforced with fibers. However, the fiber reinforcement causes the plastic to loose its good tribological properties. In addition, there is a risk for increased wear due to direct contact and consequently facilitated abrasion on the joint ball of the ball bearing due to the additives added to reinforce the plastic. It would be possible to offer a remedy with a material possessing good mechanical properties and at the same time good tribological properties, but such a material is disadvantageously very expensive.
[0004] A process for manufacturing a bearing shell for a ball and socket joint is known, furthermore, from DE 41 082 19 C2. DE 41 082 19 C2 describes a two-component process, in which a sliding layer is first applied to a joint ball. Another layer, consisting of a fiber braiding, is applied to this layer in another operation, which is especially suitable for this purpose. The ball pivot thus coated twice is then inserted into a mounting device, which will then be introduced into the housing of the ball and socket joint. The two-component plastic is injected, so that it embeds in itself the fiber braiding which is in contact with the surface of the joint ball and forms a bearing shell in this combination after cooling. The ball and socket joint is removed from the device after the curing of the plastic and supported with a cover. The drawback of this process is the considerable assembly effort, as a result of which the manufacture is time-comsuming, expensive and prone to errors. The separate operation necessary for applying the fiber braiding also causes additional costs.
[0005] The low-pressure process is used for the low-flow application of film and textile decoration backings for the aesthetic covering of plastic moldings for the interior trim of vehicles.
SUMMARY OF THE INVENTION
[0006] The object of the present invention is to provide a bearing shell that can be manufactured with good strength and creep properties, coupled with good tribological properties, simply and inexpensively.
[0007] The bearing shell according to the present invention, which may be either a one-part or multipart design, has a reinforced plastic, which is jacketed by a film in the area of the joint ball contact surface. Due to the jacketing, the reinforced plastic is advantageously separated from being in direct contact with the joint ball, so that the risk for wear, which may develop on the joint ball due to fibers or mica added for reinforcement, is reduced. This advantageously leads to prolonged service life, because the contact surfaces of the joint ball are protected without having to miss the strength and creep properties improved by the reinforcement.
[0008] The process for manufacturing the bearing shell according to the present invention begins with the insertion of a film into an injection mold. After the mold has been closed, a plastic, which forms the core of the bearing shell, is injected behind the film. A bearing shell, which has a film with good tribological properties at least in the area of the joint ball, is thus formed after cooling. Depending on the plastic processed, either the conventional injection molding or the low-pressure process is employed. Components that are largely free from internal stress and have low distortion can be advantageously obtained by the low-pressure process because of the uniform pressure distribution and the comparatively short flow paths. This one-step process is especially advantageous for the processing of duroplastics. Both the conventional injection molding and the low-pressure process may be used to process thermoplastics. Due to the good adhesive properties of duroplastics and thermoplastics, the adhesion between the film and the core does not usually pose any problem. The film and the core adhere to one another without the need for an additional adhesive or an additional heat treatment.
[0009] The film and the core may be advantageously manufactured from the said basic material, as a result of which the material costs are reduced. Thermoplastics frequently tend to creep under load at high temperatures. The strength values also decrease as the operating temperature increases. The strength and creep properties can be improved by adding fibers, micas, minerals and/or beads to the core of the bearing shell. An individual adaptation to the strength and creep values required corresponding to the load is possible simply by selecting the quantity of the reinforcing additives to be added to the basic material. Duroplastics have the property of not creeping under load and have a high stability. Moreover, the strength can be increased and the thermal expansion reduced by means of suitable additives.
[0010] The good tribological properties of the basic material and consequently also of the film used, which is backed with the reinforced material, avoid abrasive wear on the joint ball of the ball and socket joint, which may develop due to the friction of additives on the joint ball during the operation.
[0011] In another embodiment, the bearing shell has slots in the core area, which make possible the tolerance compensation of the bearing shell during the operation. Another possibility of compensating tolerances is offered by the mounting of a rubber ring under the bearing shell.
[0012] Possible exemplary embodiments of the subject of the present invention will be explained in greater detail below on the basis of drawings. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] [0013]FIG. 1 is a cross sectional view through a bearing shell lower part located in the mold;
[0014] [0014]FIG. 2 is a cross sectional view exemplary embodiments for a one-part bearing shell lower part;
[0015] [0015]FIG. 3 is a cross sectional view showing the manufacture of a bearing shell upper part with a pole cap cutout; and
[0016] [0016]FIG. 4 is a cross sectional view of a bearing shell upper part with a pole cap cutout.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] [0017]FIG. 1 shows a cross section through a bearing shell lower part 2 of a multipart bearing shell, which is in the mold 1 . The bearing shell lower part 2 has a film 3 with good tribological properties, which is backed with a reinforcing core 4 . To prepare the bearing shell lower part 2 , a film 3 is first placed into the mold 1 . The film 3 may have been preformed in a preceding step, or the forming may be performed by the heated upper part of the mold 1 only when the film 3 is inserted. After the film 3 has been placed into the mold 1 , the mold 1 is closed and a plastic 4 used for reinforcement is sprayed behind the film 3 . To do so, a corresponding plastic is allowed to enter the closed mold via the sprue 5 . Depending on the plastic to be processed, various processes are used. In case of the processing of thermoplastics, the backing of the film is performed predominantly according to a conventional injection molding process. Because of the good adhesive properties of the plastics used, an additional bonding of the film with the backed plastic is not necessary.
[0018] [0018]FIG. 2 shows various embodiments of a bearing shell lower part manufactured according to FIG. 1. Depending on the shape of the mold, the bottom of the bearing shell lower part may have an angular 6 or round 7 design. An outwardly directed circumferential collar 8 may be made integrally in one piece with the bearing shell lower part in the upper area of the bearing shell. This collar 8 is used as a contact surface of the upper shell to be attached in another step. Slots, not shown, in the area of the backing, i.e., in the area of the reinforced plastic, can cause an additional tolerance compensation. Depending on the arrangement of the slots, it may be necessary to provide a plurality of sprue points.
[0019] [0019]FIG. 3 shows an exemplary embodiment of a mold which makes it possible to produce a bearing shell upper part, as is also shown in FIG. 4, with a pole cap cutout. The special shape of the mold 1 in the form of a projection 9 makes it possible to produce pole cap cutouts 10 , into which a ball pivot, not shown, is later inserted.
[0020] The manufacture of a one-part bearing shell is not shown. The manufacture of a one-part bearing shell is also possible due to the corresponding design of the mold with a corresponding shape of the film.
[0021] While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
List of Reference Numbers:
[0022] 1 Mold
[0023] 2 Bearing shell lower part
[0024] 3 Film
[0025] 4 Backed plastic
[0026] 5 Sprue
[0027] 6 Bearing shell lower part with angular bottom
[0028] 7 Bearing shell lower part with round bottom
[0029] 8 Circumferential collar
[0030] 9 Projection, mold
[0031] 10 Pole cap cutout
[0032] 11 Bearing shell upper part | A bearing shell for a ball and socket joint has a core made of plastic, which is jacketed by a film at least in some areas. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to the chlorination of titaniferous materials using a special porous carbon reductant.
Titaniferous materials are often subjected to chlorination as chlorination is an efficient and economical way to obtain a high purity source of titanium for making titanium alloys, titanium compounds, and especially pigmentary titanium dioxide. Several processes have been described in the art for the chlorination of titaniferous materials. Such processes generally react a titanium-containing raw material such as rutile ore or ilmenite ore, with a chlorine-providing material and a carbon reductant at an elevated temperature according to one or both of the following equations:
TiO.sub.2 +2Cl.sub.2 (g)+C(s)→TiCl.sub.4 (g)+CO.sub.2 (g)
TiO.sub.2 +2Cl.sub.2 (g)+2C(s)→TiCl.sub.4 (g)+2CO(g)
Conventional chlorination reactions are generally carried out at about 1000° C., but can be carried out at any temperature in the range from about 800° C. to about 2000° C., using various conventional carbon reductants and chlorine sources.
The chlorination reactions can be carried out in a variety of reaction zone configurations. Fixed-bed, fluidized-bed, and flow reaction zones have been utilized. Each type of reaction zone has known advantages and disadvantages; however, the fluid-bed reaction zone is by far the preferred type for commercial processes. A key disadvantage of the flow processes has been that the chlorination reactions proceed at a relatively slow rate under most conveniently achieved reaction conditions and therefore an extremely long reaction chamber is required to provide the necessary residence time for the reactants within the chamber and a large excess of ore is required to cause the chlorine to react substantially completely.
It has now been found that a flow process for the chlorination of titaniferous materials can be accomplished within a reaction zone of reasonable size in an efficient fashion if the carbonaceous reductant utilized is a porous carbon having micropores with a pore diameter of less than about 20 A.
One embodiment of the present invention is to chlorinate powdered titanium-containing materials and ores in a down-flow chlorination reaction zone wherein powdered porous carbon reductant and the titanium-containing material are entrained in a stream of down-flowing chlorine-providing gas. The chlorination reactions proceed substantially to completion as the material falls through the reaction chamber.
Another process is to chlorinate titanium- and iron-containing materials and ores to produce titanium chlorides and by-product metallic iron in a laminar-flow process. According to this process, the stoichiometry of the reactants is controlled along with the reaction temperature and the flows of the process are designed to prevent any back mixing within the reaction chamber, thus a metallic iron by-product is produced instead of the conventionally produced iron chloride by-product.
It is an object and advantage of the present process that it utilizes a flow of reactants rather than a fixed or a fluidized bed.
It is a further object of the present invention that powdered raw materials instead of granular raw materials can be utilized in the present process, such powdered materials being readily available and largely commercially overlooked because of the expense of processing. A further object and advantage of the present invention is that reaction times and reaction rates are greatly enhanced, thus allowing for the use of smaller reaction zones for the above-described flow processes.
These and other objects and advantages of the present invention will become more apparent from the detailed description of the invention.
SUMMARY OF THE INVENTION
The present invention is a flow process for chlorinating a titaniferous material. The process comprises reacting discrete particles of titaniferous material and a chlorine-providing material selected from the group consisting of chlorine gas, an organochloride, and mixtures thereof in the presence of a porous carbon reductant while said particles of titaniferous material flow through a chlorination reaction zone at a temperature of at least about 800° C. The porous carbon reductant is characterized by having a pore diameter of less than about 20 A and preferably having a surface area within said micropores of at least about 10 m 2 /g. The present process has been found effective and efficient for substantially chlorinating the titanium values of most titanium-bearing ores, and particularly of powdered ores having a particle size of less than about 0.1 mm.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of the experimental apparatus used in Example 1 to demonstrate a down-flow embodiment of the present invention.
FIG. 2 is a graph showing the results of experimental chlorination of Brazilian Anatase using conventional carbon and using the present special microporous carbon.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is a flow process for chlorinating a titaniferous material. The titaniferous material is reacted with a chlorine-providing material in the presence of a porous carbon reductant while the particles of titaniferous material flow through a chlorination reaction zone.
Porous carbon reductants useful in the present invention contain micropores having a pore diameter of less than about 20 A. Typically, such porous carbon reductants will have at least about 10 m 2 /g. of surface area in such micropores, advantageously about 100 m 2 /g. of surface area in such micropores and preferably about 500 m 2 /g. of such internal surface. Non-porous carbons and carbons having exclusively large pores, e.g. charcoal, are not within the scope of the present process. In addition, the preferred carbons used in the present invention should have less than about 1500 m 2 /g. of internal surface area and preferably less than about 1000 m 2 /g. of internal surface area in said micropores. Surface area as expressed here and throughout this specification is "effective surface area" as determined from the N 2 absorption isotherm at -195° C. and application of the standard Brunauer, Emmett, and Teller (BET) Procedure. A Digisorb 2500-Automatic Multi-Gas Surface Area and Pore Volume Analyzer manufactured by Micromeritics Instrument Corporation, Norcross, Ga., was used to make these measurements.
The carbon particles can have any size useful in the present chlorination process. In a down-flow chlorination reaction zone the carbon particles must be small enough to fall at a rate similar to the titaniferous material particles, such rate of fall being sufficiently slow to allow an adequate time within a reactor for chlorination to take place. Powdered materials of about -200 mesh are generally adequate; however, various sizes, generally -140 mesh and finer, may be useful. In a laminar-flow process the carbon particles must also be appropriately sized; however, in this case they must also be sized so as to pass through the reaction zone without back mixing in a substantially plug flow with the titaniferous material. Suitable materials can be predominantly less than about 40 microns and preferably substantially all will pass through a 325-mesh sieve.
A preferred porous carbon is appropriately sized coal treated to increase its internal surface area by making it porous. Coal is an inexpensive source of carbon and it can be obtained relatively free of undesirable impurities. It is readily available in various sizes and size distributions useful in the present invention. Coal is also an amorphous form of carbon and this attribute has been found to be advantageous in the present invention.
The titaniferous material useful in the present invention can be any titanium-containing compound or raw material such as rutile ore, ilmenite ore, or other. A particularly advantageous raw material is a powdered titaniferous material which in its raw state has too small a particle size for a fluid-bed chlorination process. Such materials occur in the tailings of certain copper mining operations and in some naturally occurring anatase ore deposits. Typically, the titaniferous material will be similarly sized to the carbon reductant with which it reacts. Various sizes from about -100 mesh to about -325 mesh can be useful. In addition, a titaniferous material can be substantially pure or contain a wide variety of impurities. In this respect, a greater variety of impurity compounds are permissive in flow chlorination processes than in fluid-bed or fixed-bed processes. In the flow process, the impurities do not build up in the beds causing sticky deposits to accumulate. Therefore, larger amounts of impurities can be tolerated without repetitive frequent shutdowns to clean the chlorination reactors. For example, in the laminar-flow process, the titaniferous material preferably contains a substantial proportion of iron for practical commercial scale operations. Most often, an Fe/Ti ratio of about 0.5 to about 1.5 is utilized.
The feed solids (titaniferous material plus carbon) concentration within the reaction zone is typically maintained at about 0.01 lb/ft 3 to about 0.20 lb/ft 3 and preferably less than about 0.06 lb/ft 3 when measured at reaction temperatures.
The chlorine-providing material can be chlorine gas, an organochloride, or a mixture thereof. Chlorine gas (Cl 2 ) is preferred because it contains a high percentage of chlorine per volume of gas.
The chlorination reaction zone useful in the present flow process is preferably an elongated chamber having an inlet for the particulate reactants and the chlorine-providing gas near one end of the chamber and an outlet for titanium chlorides and by-product materials near the other end of the chamber. The particulate materials flow through the chamber either by gravity, as in a down-flow chamber, or carried on the chlorine-providing gas stream or on a secondary carrying gas stream flowing through the chamber. The down-flow design is preferred for convenience and economy. When the down-flow design is utilized and gravity provides the carrying force for the reactants to flow through the reaction zone, the walls of the chamber should be inclined within 15 degrees of vertical to prevent buildup and allow for continuous operation.
During the reaction process, the temperature within the chlorination reaction zone is maintained at greater than about 800° C. and advantageously greater than about 1000° C. The off-gas stream is collected at the outlet end of the chlorination reaction zone and cooled to condense the products and facilitate their collection.
According to the down-flow embodiment of the present invention, powdered porous carbon and powdered titaniferous material are entrained in a stream of chlorine-providing gas and introduced into the chlorination reaction zone wherein they proceed in a substantially downward path. The chlorination reaction temperature is maintained at a temperature from about 800° C. to about 1200° C. and the reaction zone is sufficiently long so that the falling carbon and titaniferous material experience a retention of between about 1 and 20 seconds within the chlorination reaction zone.
According to the laminar-flow process, the titaniferous material is reacted substantially as described in U.S. Pat. No. 4,183,899, except that the porous carbon reductant of the present invention is substituted for the carbons described in that patent. Accordingly, a mixture of powdered porous carbon reductant and titaniferous material is passed in substantially laminar or plug flow (i.e. without back mixing) through a chlorination reaction zone maintained at about 1050° C. to about 1950° C., preferably 1350° C. to 1950° C., the atomic ratio of carbon in said mixture to the oxygen content in said mixture being greater than 1:1 for formation of CO, the ratio of the moles of chlorine in said chlorinating agent to said titanium in said titaniferous materials being not substantially above about 2 and the ratio of iron to titanium (Fe/Ti) and the titaniferous material passed into said zone being not substantially above 2.
The off-gas stream from the chlorination reaction zone contains product titanium chlorides, by-product gases, and particulates. The off-gas stream is cooled to condense the product titanium chlorides and to facilitate their separation from the impurities in the off-gas stream. A convenient way to separate the product chlorides from the by-products is by a solid-gas separation at a temperature above the temperature at which the titanium chlorides condense. A preferred solid-gas separation is the use of a cyclone separator at a temperature of about 140° C. to about 300° C. and preferably about 175° to 200° C.; such separation being similar to that used in a conventional chlorination process to collect particulates in the TiCl 4 off-gas stream. Separation can be practiced after the titanium chloride products have been condensed, in which case a solid-liquid separation such as decanting or filtration would be used.
The porous carbon reductant useful in the present invention can be produced from non-porous carbons by reacting in a fluidized bed at an elevated temperature with air, CO 2 , and/or steam until micropores are produced. Typically, about 5% or more of the carbon will be burned off during such treatment. Generally, the more micropores produced and the higher internal surface area created, the higher the carbon burn-off will be. Therefore, it is preferred to treat to a minimum effective internal surface area in order to obtain the maximum yield from the carbon raw materials. This treatment should be carried out above about 400° C. When steam or CO 2 is used, the reaction is endothermic. When air is used, the reaction is exothermic and will maintain itself without the introduction of any outside heat source. Preferably, such processes can be carried out on a continuous basis with the continuous feeding of carbon and removal of treated product.
An economic and advantageous carbon source is coal. Preferably, the coal used is high rank (anthracite) rather than low rank (bituminous) because the high rank coals attain a higher internal surface area during the above treatment. The coal introduced into the treatment process can be either wet or dry. Dry coal is actually preferred; however, wet coal is a more readily available commercial product. Water is present in such wet coals to hold down dusting during transportation, as a remnant from washing, flotation, or other processing or from unprotected storage. Other processes for making porous carbons are readily available. Any available process for increasing the internal surface area of carbon can be used for making a porous carbon reductant useful in the present invention, so long as a sufficient amount of the internal micropores are produced. Such processes are typically used for producing activated carbon. Commercially available activated carbons have surface areas of up to about 3000 m 2 /g. and are effective in the instant process. However, such materials are substantially more expensive at this time than the above-described treated coals.
The following examples will show ways in which this invention has been practiced. These examples are not intended to be limiting of the invention. In the examples, all temperatures are in degrees Centigrade and all percentages in parts by weight, unless otherwise specified.
INTRODUCTION TO THE EXAMPLES
Referring to FIG. 1, a predetermined Ti ore/carbon charge was prepared and charged into hopper 1 for each run. Vertical quartz reactor tube 8 having an inside diameter of 7.0 cm. and a heated length of 105 cm. was heated to operating temperature of 1000° C. by electrical resistance furnace 7. During heatup the system was purged with argon introduced through line 3. When the temperature of the reactor stabilized at the desired operating temperature, the argon was turned off. Then, simultaneously the solids feeder 2 was then turned on, Cl 2 was introduced through line 6, and N 2 was introduced through line 3.
The solids feeder was calibrated for feed rate vs. motor speed setting for each new batch of Ti ore/carbon. The Ti ore/carbon ratio was about 1.56 to 1.58 in all runs.
Samples of gas leaving the bottom of the chlorination zone were taken by sampler 12 and analyzed for CO, CO 2 , N 2 , and Cl 2 by gas chromatography. The amount of unreacted Cl 2 , if any, was calculated from the known inlet flows of Cl 2 and N 2 and the measured flows in the chlorinator off-gas.
In all of the examples, the Ti ore was Brazilian Anatase containing about 86.5% TiO 2 , 3.3% Fe 2 O 3 , and 0.3% combined H, plus other impurities which do not participate in the present process. Three different carbons were used in the examples. The characteristics of these carbons are shown in Table I.
TABLE 1______________________________________ Porous Petroleum Porous Carbon Coke Carbon A B______________________________________% C 98 80 91% H 0.08 0.82 0.46% Ash 0.4 12 1.5Surface Area (m.sup.2 /g) <1 590 350Surface Area in microporesof <20 A diameter (m.sup.2 /g) 0 210 90______________________________________
The Stoichiometric Factor was calculated for each run based on the amount of Ti, Fe, and combined H in the feed solids available to react with Cl 2 to give TiCl 4 , FeCl 2 , and HCl. A factor of 1.0 indicates the stoichiometric amount of Ti, Fe, and H is present to react with the Cl 2 . A factor of 2.0 indicates a two-fold excess of Ti, Fe, and H.
The feed rates and gas flows in each experimental run were controlled to provide an approximate retention time for Cl 2 gas and feed solids in the reactor of 8 to 10 seconds.
EXAMPLE 1
Feed solids containing Brazilian Anatase and petroleum coke were ball milled to 75% past 325 mesh and charged into hopper 1. These feed solids were reacted with Cl 2 as described above. Three runs were made using this procedure. In one run, the Stoichiometric Factor was about 1.5, in the second about 1.9 and in the third about 3.8. Data are shown in FIG. 2.
EXAMPLE 2
The procedure of Example 1 was followed except that the feed solids were ball milled to 96% past 325 mesh. Four runs were made following this procedure. In these runs the Stoichiometric Factors were 1.9, 2.2, 3.2, and 4.9, respectively. Data are shown in FIG. 2.
EXAMPLE 3
In this example, feed solids containing Brazilian Anatase and Porous Carbon A ball milled to 96% past 325 mesh were charged into hopper 1 and reacted with Cl 2 as described. Three runs were made following this procedure. In these runs, the Stoichiometric Factors were 0.8, 1.1, and 1.6, respectively. Data are shown in FIG. 2.
EXAMPLE 4
In this example, feed solids containing Brazilian Anatase and Porous Carbon B were used. The feed solids had a fineness of about 76% past 325 mesh. Five runs were made following this procedure. In these runs, the Stoichiometric Factors were 1.9, 2.2, 2.6, 2.9, and 3.4, respectively. Data are shown in FIG. 2.
EXAMPLE 5
The procedure of Example 4 was followed except that the feed solids were ball milled to 96% past 325 mesh prior to reaction. Four runs were made following this procedure. In these runs, the Stoichiometric Factors were 1.05, 1.1, 1.3, and 1.8, respectively. Data are shown in FIG. 2.
It is readily apparent that the present carbons are surprisingly effective in the chlorination of titaniferous materials compared to a conventional carbon such as petroleum coke. The use of the present carbons allows the reactions to go substantially closer to completion at significantly lower Stoichiometric Factors. For example, when reacting with petroleum coke, a Stoichiometric Factor of about 4.9 is required for the reaction to go substantially to completion. With Porous Carbon B, a factor of no more than about 2.9 is required, and with Porous Carbon A, a factor of only about 1.6 is required. The reduction of this factor significantly improves the efficiency and economy of the present process. | A flow process is described for the chlorination of titaniferous materials. The process utilizes a special microporous carbon characterized by having pores with a pore diameter of less than 20 A. Improved reaction rates and completeness of reaction are achieved. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Pursuant to 35 U.S.C. §119(e), this application claims priority from and the benefit of and hereby incorporates by reference for all purposes, U.S. Provisional Application No. 61/269,593, filed Jun. 26, 2009, entitled “Integrated Safety Rail Protection System,” naming Richard J. Whiting as the inventor.
TECHNICAL FIELD
[0002] This invention relates to roof and floor safety protection rail systems and ergonomical methods of safe ingress and egress to reduce or eliminate hazards to personnel, including protection of people above and below a scuttle hatch, access ports, skylights and elevated decks.
BACKGROUND
[0003] While it is of the most importance for personnel to egress and ingress through an access portal in a safe manner it is also important for building owners and proprietors to reduce loss and liability. The act of climbing to or from an elevated height to egress or ingress a roof scuttle hatch, floor opening, skylight, or other elevated portal is often a very dangerous undertaking. Numerous hazards can cause an employee to trip, slip, or fall. In fact records with U.S. Department of Labor Occupational Safety & Health Administration (OSHA) show tragic accidents that often result in death. Occupational fatalities caused by falls remain a serious public health problem throughout the United States. According to the United States Department of Labor News report of Oct. 31, 2007 reported, in the Washington, D.C. metropolitan area, falls to a lower level was the most frequent type of fatal occupational injury; this was also true in New York, Chicago, Los Angeles, Miami, and Boston.
[0004] Personnel having a need to ascend or descend through an access portal, which usually requires a climb to an unsafe height above a floor or deck, face numerous safety concerns. For example, the location of an access portal is most often in a darkened and out of the way location within a building subsequently making it very difficult for personnel to see during exit. Further, due to the often dark indoor lighting near the portal, which is often above a drop ceiling, ascending personnel that have become accustomed to low light levels may be suddenly exposed the bright sunlight making if difficult to visualize a good secure grab hold. Moreover, while personnel are descending or exiting from the bright sunlight of the outdoors into the dark area adjacent to the portal, they may be suddenly exposed to low light levels further impairing their vision to secure a good grab hold while descending.
[0005] Flat roofed buildings, roadways, catwalks, attics, skylights, and other similar structures, commonly include portals, such as a roof portal, manhole, or other similar structure, with or without a hatch or lid, for ingress and egress to the roof, roadway, catwalk, etc. For example, commercial warehouses or other flat roofed buildings, commonly include one or more hatch-like roof portals for ingress and egress to the roof. Many times, these roof portals are located in positions away from walls or other supporting structures, thereby, necessitating the user to make steep climbs over high elevations for ingress and egress to the roof. With high elevations and steep climbs the risk of harm to a user from a fall is already great; however, when factoring in a user's fear of heights, vertigo, or other emotional and/or physiological responses, the risk of harm to the user from falling greatly increases. Moreover, additional factors, such as transporting equipment through the portals, may further increase the risk of harm to the user.
[0006] A problem existing with current portals, such as a roof or scuttle hatch, without a safety rail and or grab holds is that personnel have to precariously perch on the top rung of a ladder with the only hand hold approximately 1 foot above their feet on the top of the portal's curb in order to exit or enter the portal, which is a rather difficult and dangerous balancing act that subjects the personnel to increased risk of harm.
[0007] Additional problems exists while ascending or descending, such as personnel often have to dangerously reach backwards with one hand while awkwardly holding on with the other hand to the portal's curb or top ladder rung to open or close an often heavy portal/hatch cover, which may or may not have worn or damaged spring load assist or latches, and may be subject to constant or changing wind loads while being opened or closed.
SUMMARY
[0008] Embodiments of the integrated safety rail protection system may utilize an ergonomic and structurally rigid railing system, which may include a gate, that provides the user with multiple ergonomic projections for hand and/or foot support while ingressing or egressng through a portal, such as a roof portal or other portal opening.
[0009] In accordance with one aspect of the present invention, a railing system that may be positioned on a roof adjacent to a roof opening portal having an upwardly lifting lid is provided and includes a first side rail with a first side gate projection, a second side rail with a second side gate projection; and a hinged gate operable to open outwardly.
[0010] In yet another embodiment of the integrated safety rail protection system, the railing system further comprises a back rail positioned substantially between the first side rail and the second side rail.
[0011] In yet another embodiment of the integrated safety rail protection system, the hinged gate interfaces with the first side gate projection.
[0012] In yet another embodiment of the integrated safety rail protection system, the hinged gate may interface with the second side gate projection.
[0013] In yet another embodiment of the integrated safety rail protection system, the railing system further comprises a hinge structure positioned adjacent to the interface of the hinged gate and the first side gate projection.
[0014] In yet another embodiment of the integrated safety rail protection system, the railing system further comprises a biasing structure positioned adjacent to the interface of the hinged gate and the first side gate projection.
[0015] In yet another embodiment of the integrated safety rail protection system, the railing system further comprises a latching structure positioned adjacent to the interface of the hinged gate and the second side gate projection.
[0016] In yet another embodiment of the integrated safety rail protection system, the first side rail further comprises a first side hand-grip projection.
[0017] In yet another embodiment of the integrated safety rail protection system, the second side rail further comprises a second side hand-grip projection.
[0018] In yet another embodiment of the integrated safety rail protection system, the rails system is at least partially knurled.
[0019] In yet another embodiment of the integrated safety rail protection system, the first side rail further comprises a cross rail member.
[0020] In yet another embodiment of the integrated safety rail protection system, the second side rail further comprises a cross rail member.
[0021] In yet another embodiment of the integrated safety rail protection system, the first side rail is formed from a single continuous tube.
[0022] In yet another embodiment of the integrated safety rail protection system, the second side rail is formed from a single continuous tube.
[0023] In yet another embodiment of the integrated safety rail protection system, the hinged gate is formed from a single continuous tube.
[0024] In yet another embodiment of the integrated safety rail protection system, the railing system further comprises a second hinged gate.
[0025] In yet another embodiment of the integrated safety rail protection system, the first hinged gate interfaces with the first side rail and the second hinged gate interfaces with the second side rail.
[0026] In yet another embodiment of the integrated safety rail protection system, the first hinged gate interfaces with the second hinged gate at a position between said first side rail and said second side rail.
[0027] In yet another embodiment of the integrated safety rail protection system, the railing system further comprises a latching structure positioned adjacent to at least one of the interface of said first hinged gate and said second hinged gate.
[0028] In yet another embodiment of the integrated safety rail protection system, the railing system further comprises a hinge structure positioned adjacent to the interface of the second hinged gate and the second side gate projection.
[0029] In yet another embodiment of the integrated safety rail protection system, the railing system further comprises a biasing structure positioned adjacent to the interface of the second hinged gate and the second side gate projection.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is an isometric view showing one embodiment of the integrated safety rail protection system mounted onto a portal;
[0031] FIG. 2 is a side view showing one embodiment of the integrated safety rail protection system mounted onto a portal and having a latch structure;
[0032] FIG. 3 is a side view showing one embodiment of the integrated safety rail protection system, wherein the rail system is mounted to the portal using fasteners;
[0033] FIG. 4 is a front view showing one embodiment of the integrated safety rail protection system mounted onto a portal and having a latch structure;
[0034] FIG. 5 is a back view showing one embodiment of the integrated safety rail protection system mounted onto a portal and having a hinge structure, biasing structure, and a latch structure;
[0035] FIG. 6 is a top view showing one embodiment of the integrated safety rail protection system;
[0036] FIG. 7 is a side view showing one embodiment of the integrated safety rail protection system mounted onto a portal with an alternative hand grip projection;
[0037] FIG. 8 is a partially exploded side view showing one embodiment of the integrated safety rail protection system utilizing corner rails;
[0038] FIG. 9 is a front view showing embodiments of the integrated safety rail protection system of FIG. 8 utilizing corner rails;
[0039] FIG. 10 is an exploded front view showing one embodiment of a rail mounting system having a hollow mounting structure;
[0040] FIG. 11 is a front view showing one embodiment of a rail mounting system that mounts the integrated safety rail protection system to a portal using fasteners, such as screws or bolts;
[0041] FIG. 12 is an isometric view showing one embodiment of a rail mounting system prior to installation of the rail mounting system;
[0042] FIG. 13 is a side cutaway view of one embodiment of a pinchless hinge structure;
[0043] FIG. 14 is a top isometric view of a housing of a pinchless hinge structure having a partial recess in one end of the housing;
[0044] FIG. 15 is a bottom isometric view of a housing of a pinchless hinge structure having a full recess in one end of the housing;
[0045] FIG. 16 is a front view of a hinge shaft of a pinchless hinge structure having a protrusion on the hinge shaft;
[0046] FIG. 17 is a side view of a hinge shaft of a pinchless hinge assembly having a protrusion on the hinge shaft;
[0047] FIG. 18 is an isometric view of an external stop hinge structure interfacing a side rail and a gate in a manner where the external stop will engage to prevent further movement of the gate;
[0048] FIG. 19 is an isometric view of an external stop hinge structure interfacing a side rail and a gate in a manner where the hinge shaft has been raised to allow the shaft to freely rotate;
[0049] FIG. 20 is an isometric view of an external stop hinge structure interfacing a side rail and a gate in a manner where the external stop is engaged; and
[0050] FIG. 21 is an isometric view showing one embodiment of the integrated safety rail protection system having a first and a second gate.
DETAILED DESCRIPTION
[0051] It should be understood at the outset that although an exemplary implementation of the present invention is illustrated below, the present invention may be implemented using any number of techniques, materials, designs, and configurations whether currently known or in existence. The present invention should in no way be limited to the exemplary implementations, drawings, and techniques illustrated below, including the exemplary designs and implementations illustrated and described herein.
[0052] In the description which follows, like parts are marked throughout the specification and drawings with the same reference numerals, respectively. The drawings are not necessarily to scale and certain features may be shown exaggerated in scale or in somewhat schematic form in the interest of clarity and conciseness.
[0053] Referring initially to FIGS. 1 , 2 , 4 , 5 , 6 , and 12 , an embodiment of the integrated safety rail protection system 1 is provided and includes, in one form, a first substantially vertical side rail 10 , a second substantially vertical side rail 12 , and a hinged gate 40 . It should be noted that the second side rail 12 operates and functions in substantially the same manner as the first side rail 10 , as further described herein. In other embodiments, a side rail 10 may have a cross rail member 14 extending longitudinally or diagonally within a plane passing through the side rail. In yet other embodiments, a back rail member 30 may extend between the first side rail 10 and the second side rail 12 , at a location generally adjacent to the opposite end from the gate portion of the integrated safety rail protection system 1 , but in other embodiments the back rail member 30 may extend between the first side rail 10 and the second side rail 12 , at a location anywhere suitable along the length of the side rails ( 10 and 12 ).
[0054] Referring to FIGS. 1 and 2 , in other embodiments, a side rail 10 may have a generally horizontal top rail 20 for structural strength and to provide the user with a gripping surface for aiding in ingress and egress through a portal 6 , such as a roof portal. The side rail 10 may further have a generally vertical down rail 22 for structural strength and to provide the user with a gripping surface for aiding in ingress and egress through the portal 6 . In yet another embodiment, the side rail 10 may further have a side gate projection 28 for structural strength, to interface with the hinged gate 40 , and to provide the user with an ergonomic gripping surface for aiding in ingress and egress through the portal 6 . In yet another embodiment, the side rail 10 may further have a side hand-grip projection 29 for structural strength and to provide the user with an ergonomic gripping surface for aiding in ingress and egress through the portal 6 . In yet other embodiments, the side gate projection 28 and the side hand-grip projection 29 may have the form of straight and curved lengths with arcuate bends of varying angles. For example, in some embodiments, as seen in FIG. 2 , the front portion of the side rail 10 , may have a first segment 24 , extending from the top rail 20 at a downward angle of about 25-degrees from the top rail 20 , transitioning to a second segment 25 , extending from the first segment 24 at downward angle of about 135-degrees from a line substantially parallel to the top rail 20 , wherein the combination of the first segment 24 and second segment 25 form the front side gate projection 28 , transitioning to a third segment 26 , extending downward from the second segment 25 at a downward angle of about 60-degrees from a line substantially parallel to the top rail 20 , transitioning to a fourth segment 27 , extending from the third segment 26 at a downward angle of about 125-degrees from a line substantially parallel to the top rail 20 , wherein the combination of the third segment 26 and fourth segment 27 form the front hand-grip projection 29 . Alternatively, in other embodiments as illustrated in FIG. 7 , and described in more detail below, the first segment 24 may transition to a second segment 25 at a downward angle of about 120-degrees from a line substantially parallel to the top rail 20 , wherein the combination of the first segment 24 and second segment 25 form the front side gate projection 50 , and wherein the second segment 25 extends downward to the base of the side rail 10 . The embodiments of the front side gate projections and hand-grip projections are not limited to the angles described, but as one of ordinary skill in the art would recognize, can be composed of any number of segments at any number of angles to achieve one or more ergonomic or desired grab holds or hand-grips for a user.
[0055] In yet other embodiments, the side rail 10 may be made from a single length of metallic tubing that is bent to form a one piece side rail 10 to provide the added benefit, in certain embodiments, of ease of manufacture, ease of assembly, structural strength, and no loosening of joint fittings. However, in yet other embodiments, the side rail 10 may be crafted from multiple pieces of tubing or other suitable material fastened together, via bolts, welds, screws, or other suitable means. Additionally, in other embodiments the side rail 10 may further include a cross rail member 14 to aid in structural strength and provide the user with an additional gripping surface for aiding in ingress and egress through the portal 6 .
[0056] Referring to FIGS. 1 , 3 , 4 , 5 , 11 , and 12 , in other embodiments, the side rail 10 may have a front mounting projection 15 for fastening, via screws, bolts, welds, or other suitable means, the rail 10 to the front flange 2 , and side rail 10 may have a rear mounting projection 18 for fastening, via screws, bolts, welds, or other suitable means, the rail 10 to the rear flange 3 of the portal 6 , although in other embodiments, the front mounting projection 15 and the rear mounting projection 18 may be positioned for mounting the side rail 10 to the side flange 5 . However, fastening to the front flange 2 and rear flange 3 of a portal 6 provides the benefit of strengthening the capability of the side rail 10 to withstand side-to-side and front-to-back forces that might cause railing systems to fail or otherwise separate from their mountings under the stress of a user's weight.
[0057] Referring to FIG. 10 , in other embodiments, a mounting projection 15 may be mounted adjacent to the portal 6 using a mounting structure 120 having an opening 122 for receiving the mounting projection 15 , which may be fastened to the mounting structure 120 , via screws, bolts, welds, or other suitable means, and which the mounting structure 120 itself is mounted adjacent to the portal 6 , via screws, bolts, welds, or other suitable means. The opening 122 of the mounting structure 120 may be a hollow or tubularly shaped opening, or other suitable opening for receiving the mounting projection 15 . For example, in one embodiment, the mounting structure 120 may be a hollow metal tube with protruding surfaces for attaching the mounting structure 120 to the front flange 2 or rear flange 3 of the portal 6 , wherein a mounting projection 15 may be inserted into the hollow portion of the metal tube and fastened therein using welds, bolts, screws, or other suitable means. The mounting structure 120 may be made from metal, fiberglass, composite, or other suitable materials, and allow for quick and easy attachment adjacent to the portal 6 or ground surface, allow for flexibility in fitting the railing system to various sized portals 6 , and allow for increased strength and rigidity by providing more contact surface to the mounting projection 15 than might be accomplished using traditional direct fastening, via screws, bolts, or welds, of the mounting projection 15 adjacent to the portal 6 .
[0058] Referring to FIGS. 2 , 4 , 5 , 6 , 7 , and 12 , in one embodiment, the hinged gate 40 is positioned to rest adjacent to the side gate projection 28 a of the first side rail 10 and the side gate projection 28 b of the second side rail 12 and operable to open outwardly from the portal 6 and return to its resting or closed position (i.e., interfaced with both the side gate projection 28 a of the first side rail 10 and the side gate projection 28 b of the second side rail 12 ) via gravity, as shown in FIGS. 1 and 12 . In some embodiments, the hinged gate 40 is rectangular in shape, although any suitable shape, such as square, oval, circular, etc., may be used. In some embodiments, the hinged gate 40 may be made from a single length of metallic tubing that is bent to form a one piece side hinged gate 40 , to provide the added benefit of ease of manufacture, ease of assembly, structural strength, and no loosening of joint fittings. However, in yet other embodiments, the hinged gate 40 may be crafted from multiple pieces of tubing or other suitable material, fastened together, via bolts, welds, screws, or other suitable means. In yet other embodiments, the hinged gate 40 may comprise segments that may telescope fully or partially within adjacent segments, or utilize spacers between the segments, to allow for a gate having adjustable dimensions to accommodate the installation of the rail system 1 adjacent to portals 6 of various sizes. In some embodiments, the hinged gate 40 includes a recess or projection for mating with a projection or recess of one of the side gate projection 28 a of the first side rail 10 and the side gate projection 28 b of the second side rail 12 to form a hinge upon which the hinged gate 40 may swing outwardly from its resting position. In yet other embodiments, as illustrated in FIGS. 5 and 6 , a hinge structure 42 may be used to interface the hinged gate 40 with of one of the side gate projection 28 a of the first side rail 10 and the side gate projection 28 b of the second side rail 12 to allow the hinged gate 40 to swing outwardly from its resting position. In yet other embodiments, as illustrated in FIGS. 2 , 4 , 5 , and 6 , a latch structure 44 may be used to latch the hinged gate 40 to of one or both of the side gate projection 28 a of the first side rail 10 and the side gate projection 28 b of the second side rail 12 , which provides added security from the wind or users accidentally opening the hinged gate 40 at a time when opening of the hinged gate 40 is not intended. Such a latching mechanism may be a simple hook and loop, such as the gravity rocker latch illustrated in FIG. 2 , magnetic, or other suitable latching means positioned in any of a variety of positions.
[0059] In yet other embodiments, as illustrated in FIG. 5 , a biasing structure 46 may be used to bias the hinged gate 40 to a side gate projection 28 of the first side rail 10 or the second side rail 12 , which, alone or in combination with gravity, causes the hinged gate 40 to rest in a closed position interfacing with the side gate projections 28 of the first side rail 10 and the second side rail 12 . The biasing structure 46 may be a spring, piston, or any other suitable means for influencing the movement of the hinged gate 40 . The use of a biasing structure 46 provides added security from the wind or users accidentally opening the hinged gate 40 at a time when opening of the hinged gate 40 is not intended. In other embodiments, the gravity operation of the gate functions by positioning the hinged gate 40 to rest adjacent to the side gate projection 28 a of the first side rail 10 and the side gate projection 28 b of the second side rail 12 , at an angle from vertical, as measured by at least one plane passing through the hinged gate 40 and the open volume enclosed by it, which in the preferred embodiment is an acute angle from vertical as measured from the lowermost point of reference of the hinged gate 40 as the apex of the angle with vertical. This creates the situation where the hinged gate 40 swings outward from its interface with one of the side gate projection 28 a of the first side rail 10 and the side gate projection 28 b of the second side rail 12 at an angle offset from vertical, thereby, causing the hinged gate 40 to return to its resting position or closed position via the force applied by gravity to its mass. Such a gravity gate feature provides the added benefit of having the gate automatically close or biased to close when not in use, thereby eliminating or reducing the safety concern of a user forgetting to close the gate and risking a fall by a user therethrough. It should be noted that in other embodiments, the hinged gate 40 may interface directly with the side rails 10 and 12 or any portion of the side rails 10 and 12 as opposed to the side gate projections 28 a and 28 b . In yet other embodiments, the hinged gate 40 is restricted, via the hinge, side gate projections, or other mechanical block, from opening in an inward direction towards the area formed between the first side rail 10 and the second side rail 12 and/or substantially over the opening of the portal 6 . In yet other embodiments, the hinged gate 40 is restricted, via the hinge, side gate projections, or other mechanical block, from opening in an outward direction past a point that would prohibit the return of the gate 40 to its resting or closed position via gravity.
[0060] Referring to FIGS. 13 , 14 , 15 , 16 , and 17 , in yet other embodiments, the hinge structure 42 of FIGS. 5 , 6 , and 21 may be a pinchless hinge structure 140 that can be attached to the structures to be hinged by weld, bolt, or other means. The hinge structure 140 of these embodiments comprises a hinge housing 150 , a hinge shaft 160 , a hinge shaft protrusion 162 , and a partial hinge housing recess 152 on one end of the housing 150 . In operation, when the shaft is inserted into the pinchless hinge structure 140 , the rotation of the shaft is impeded by the interface of the shaft protrusion 162 with the partial housing recess 152 ; however, by simply raising the shaft 160 in relation to the housing 150 , the shaft protrusion 162 can be moved to clear the impediment of the partial housing recess 152 , and thus, the shaft 160 can fully rotate within the housing 150 . Other embodiments may further include a full 360 degree hinge housing recess 154 in one end of the housing 150 to allow for free rotation of the hinge shaft 160 despite the inclusion of a hinge shaft protrusion 162 . In other embodiments, the hinge structure 140 can be opened and closed by an internal or external spring, torsion bar, or other powered device via a splined shaft/gear mechanism or other suitable means, as one of ordinary skill in the art would understand.
[0061] Referring to FIGS. 18 , 19 , and 20 , in yet other embodiments, the hinge structure 42 may be an external stop hinge structure 170 that can be attached to the structures to be hinged by weld, bolt, or other means. The hinge structure 170 of these embodiments comprises a hinge housing 180 , a hinge shaft 190 , a hinge shaft cap 192 , a housing protrusion 182 , and a hinge cap protrusion 194 . The hinge shaft 190 is attached to the hinge shaft cap 192 , which has the hinge cap protrusion 194 attached thereto. The hinge shaft 190 is inserted into an opening formed within the hinge housing 180 for receiving the hinge shaft 190 for rotation. The hinge cap protrusion 194 interfaces with the housing protrusion 182 , which is attached to the exterior of the hinge housing 180 , said interface limits the degree of rotation of the hinge shaft 190 within the hinge housing 180 . In other embodiments, the hinge shaft 190 may be raised in elevation relative to the hinge housing 180 , thereby eliminating any interference between the hinge cap protrusion 194 and the hinge housing protrusion 182 , which allows for full 360 degree rotation of the hinge shaft 190 within the hinge housing 180 . In other embodiments, the hinge structure 170 can be opened and closed by an internal or external spring, torsion bar, or other powered device via a splined shaft/gear mechanism or other suitable means, as one of ordinary skill in the art would understand.
[0062] Referring to FIG. 21 , in yet another embodiment, a second hinged gate 48 is included in the safety rail system 1 . In this embodiment, the first hinged gate 40 interfaces with a first side gate projection 28 a , although it may interface directly with any portion of the first side rail 10 . As previously described, the interface between the hinged gate 40 and the first side gate projection 28 a may include projections and recesses or a hinge structure 42 for a hinge-type mating between the hinged gate 40 and the first side gate projection 28 a . Additionally, in some embodiments, as previously described, a biasing structure may be included to influence the movement of the hinged gate 40 and the hinged gate may be positioned at an acute angle from vertical to utilize the force of gravity for influencing the movement of the hinged gate 40 . The first hinged gate 40 does not directly interface with the second side gate projection 28 b or any portion of the second side rail 12 ; instead, the second hinged gate 48 is positioned, operates, and interfaces with the second side gate projection 28 b or any portion of the second side rail 12 in a manner substantially similar to the position, operation, and interface between the first hinged gate 40 and the first side gate projection 28 a or any portion of the first side rail 10 . In operation of one embodiment, portions of the first hinged gate 40 and the second hinged gate 48 interface at a point between the first side gate projection 28 a and the second side gate projection 28 b , and may include a latching mechanism 44 operable to latch the first hinged gate 40 to the second hinged gate 48 .
[0063] Referring again to FIG. 7 , in one embodiment of the integrated safety rail protection system, the side rail 10 may include a combination side gate projection and hand-grip projection 50 , comprising a first segment 24 , extending downward at an angle less than 180 degrees from the top rail 20 , and a second segment 25 , extending downward from the first segment 24 to interface with the portal 6 . In addition to the economic features of fewer bends in the railing system, some users find the straight lines ergonomically advantageous.
[0064] Referring to FIGS. 8 and 9 , in yet another embodiment, a corner rail system 200 is shown that may be positioned adjacent to a portal 6 , and comprises a front left corner rail 210 with a first front left corner mounting projection 220 , a second front left corner mounting projection 230 , and a front left corner gate projection 240 , wherein said first front left corner mounting projection 220 is positioned substantially perpendicular to said second front left corner mounting projection 230 , and wherein said front left corner gate projection 240 interfaces with the hinged gate 40 , for example where said front left corner gate projection 240 extends at least partially into the area enclosed by the gate 40 . The corner rail system 200 further comprises a front right corner rail 250 with a first front right corner mounting projection 260 , a second front right corner mounting projection 270 , and a front right corner gate projection 280 , wherein said first front right corner mounting projection 260 is positioned substantially perpendicular to said second front right corner mounting projection 270 , and wherein said front right corner gate projection 280 extends at least partially into the area enclosed by the gate 40 . The hinged gate 40 operates in the same fashion as described above in reference to the side rail system 1 . In some embodiments, the front left corner rail 210 and the front right corner rail 250 may each have a generally horizontal top rail ( 212 and 252 , respectively) for an ergonomic grab hold. In yet other embodiments, the front left corner gate projection 240 may extend from the top rail 212 , and the front right corner gate projection 280 may extend from the top rail 252 . The remaining structure associated with the front left corner rail 210 and the front right corner rail 250 may take on various forms, including, as described above in reference to the side rail system 1 , straight structures and angled structures that provide ergonomic or desired grab holds or hand-grips. In some embodiments, as with the side rail 10 of the rail system 1 , the front left corner rail 210 and the front right corner rail 250 can each be formed from a continuous tube of metal, although other materials, such as fiberglass, composite, carbon fiber, etc., may also be used. The benefit of using a continuous tube or other continuous structure is its strength and rigidity as well as ease of manufacture. In yet other embodiments, as with the side rail 10 of the rail system 1 , the front left corner rail 210 and the front right corner rail 250 can each be formed from segments of metal tubing or other suitable materials, such as fiberglass, composite, carbon fiber, etc., that fastened together by screws, bolts, welds, or other suitable fastening means.
[0065] Referring again to FIG. 8 , in yet other embodiments of the corner rail system 200 , the system 200 may further comprise a back right corner rail 300 with a first back right corner mounting projection 310 and a second back right corner mounting projection 320 , wherein said first back right corner mounting projection 310 is positioned substantially perpendicular to said second back right corner mounting projection 320 . In yet other embodiments, a back left corner rail 350 (not illustrated) may be used that operates in the substantially same manner as the back right corner rail 300 as described above.
[0066] In yet another embodiment, a back rail member 352 (not illustrated), such as a metal tube or other structure of suitable size, shape and material, is mounted between the back right corner rail 300 and the back left corner rail 350 (not illustrated) for enhanced stability between the two corner rails, and to provide yet another grab hold or hand grip for the user. Because the corner rail system 200 may accommodate portals of various lengths and widths, in a kit or retrofit form, the back rail member may be supplied in a manner to be cut down to desired length for installation of the portal at issue.
[0067] Referring again to FIG. 8 , in yet another embodiment, a cross rail member 360 may be mounted between the front right corner rail 250 and the back right corner rail 300 for enhanced stability between the two corner rails, to lessen the risk of a user falling between the rails, and to provide yet another grab hold or hand grip for the user. In yet another embodiment, a cross rail member 360 may be mounted between the front left corner rail 210 and the back left corner rail 350 in the same fashion and with the same benefits as previously described. Because the corner rail system 200 may accommodate portals of various lengths and widths, in a kit or retrofit form, the cross rail member may be supplied in a manner to be cut down to desired length for installation of the portal at issue.
[0068] In yet another embodiment, the corner rail system 200 may include a single corner rail 210 for mounting adjacent to a portal 6 . Such a single corner rail system may be used where multiple corner rail systems are cost prohibitive, but at least some ergonomic and sturdy grab holds or hand-grips are desired.
[0069] Referring again to FIGS. 8 and 9 , by having the mounting projections, for example mounting projections 260 and 270 , of the corner rails (front or back) at substantially right angles to one another, easy mounting (via screws, bolts, welds, or other suitable fastening means) of the corner rails adjacent to a portal 6 may occur, since many portals have 90-degree corners that easily, or with minimal adjustment, match up to the substantially perpendicular mounting projections. An additional benefit of substantially perpendicular mounting projections is that the respective corner rail may have enhanced stability, when mounted, against forces acting on the corner rail from all sides. If the mounting area adjacent to the portal 6 does not have a ninety degree corner, the mounting projections may be adjusted, by bending, use of spacers, or otherwise, to accommodate the shape of the portal 6 . Additionally, in some embodiments, a mounting structure 120 , as described above and referred to in FIG. 10 , may be used to fasten a mounting projection, for example mounting projections 260 or 270 , to the portal 6 , for ease of mounting installation, adjustability in mounting the corner rails ( 210 , 250 , 300 , 350 ) adjacent to portals 6 of various sizes, and strength of the mount due to increased surface area on the mounting projection. Absent use of a mounting structure 120 , the mounting projections are directly mounted adjacent to the portal 6 using screws, bolts, welds, or other suitable fastening means.
[0070] In yet other embodiments, a corner rail 210 (or any corner rail, including 250 , 300 , and 350 ) may have only one mounting projection for mounting (via a mounting structure 120 or by screws, bolts, welds, or other suitable fastening means) to any side or portion of the portal 6 where the position of the corner rail 210 is desired. Referring again to FIGS. 8 and 9 , in yet other embodiments, a corner rail 210 (or any corner rail, including 250 , 300 , and 350 ) may have a first mounting projection 220 and a second mounting projection 230 , where such mounting projections are parallel or substantially parallel to each other (as illustrated, for example, by the dashed lines of FIG. 9 ) for ease of mounting and strength of the mount to any side, or front portion of the portal 6 where the position of the corner rail 210 is desired.
[0071] In yet another embodiment, the corner rail system 200 may be provided in kit form for retrofitting existing portals, such as roof openings, manholes, skylights, etc., wherein the kit may include a front left corner rail 210 , a front right corner rail 250 , and a hinged gate 40 . As described above, the hinged gate 40 may be adjustable in dimensions, with spacer segments, telescoping segments, etc., to accommodate varied widths of portals 6 . Such a system would provide substantial protection from a user falling during ingress or egress through the portal 6 , especially in light of the various shapes and angles of the grab holds or hand-grips. In yet another embodiment, the kit may include a back right corner rail 300 and/or a back left corner rail 350 to provide additional safety from a user falling during ingress or egress through the portal 6 . In yet other embodiments, the kit may include a back rail 352 for providing additional barriers between the corner rails to provide additional safety from a user falling during ingress or egress through the portal 6 . In yet other embodiments, the kit may include a top rail 360 for providing additional barriers between the corner rails to provide additional safety from a user falling during ingress or egress through the portal 6 . In yet other embodiments, the kit may include a cross rail 362 for providing additional barriers between the corner rails to provide additional safety from a user falling during ingress or egress through the portal 6 . In yet other embodiments, the kit may include one or more mounting structures 120 and/or mounting hardware, such as screws, bolts, etc.
[0072] It should be noted that the elements making up any chosen embodiment of the invention described herein may be made of metal, ceramics, plastics, carbon fiber, fiberglass, wood, and other materials with suitable properties. Additionally, all or selected portions of surfaces of the safety rail system 10 may be knurled for grip, which includes surface texturing, surface projections, textured paint or powder coating, textured grip tape, or any other method of surface texturing to aid in gripping by a user's hands or feet.
[0073] Although embodiments of the integrated safety rail protection system have been described in detail, those skilled in the art will also recognize that various substitutions and modifications may be made without departing from the scope and spirit of the appended claims. | A unique safety rail system with integrated ergonomically effective hand-grip projections, structures for affixing said system for the safe and easy egress and ingress through an opening, such as roof or floor access holes. Said safety rail system is designed to reduce the risk of falls while ascending or descending a ladder through an access hole while providing additional protection and prevention of personnel accidentally falling through an open access. A self-closing gravity gate may be provided acting as additional hand-grip, support, and barrier. This invention may employ cost effective methods of construction and assembly using a unique continuous tubular structure of converging vertical and angular upright post with horizontal upper safety rail, forward protruding ergonomically effecting hand-grip and opposing directionally horizontal lower attachment support means reducing lateral motion and allows efficient installation for new construction or retro fitting of existing openings. | 4 |
RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 10/983,332, filed Nov. 5, 2004, now U.S. Pat. No. 7,665,576, which claims the benefit of U.S. Provisional Application No. 60/517,659, filed Nov. 6, 2003. The entire teachings of the above applications are incorporated herein by reference.
BACKGROUND
Workers on elevated construction projects, such as roofs, should have protection from falling, for example, while installing roof panels, insulation, fastenings, or other component parts of the roofing system. These workers are at risk of falling in the region extending in front of the installed roof panels. When insulation is spread over structural members ahead of the workers' position, and ahead of the installed roof panels, the layer of insulation can give workers a false sense of security, since the insulation covers the structural members. However, the insulation is not strong enough to prevent a worker from falling through the insulation. One method of providing protection for workers against such falls is to apply netting over the entire roof structure, which is then covered by the insulation and roof panels. This method is not only expensive but the installation of the netting can also be dangerous. Another method of providing protection against falls is to secure safety lines to the workers. This method becomes unwieldy when multiple workers are moving back and forth over the roof, and often the workers end up disconnecting the lines.
SUMMARY
The present invention provides a movable safety barrier system which can be extended over structural members on elevated projects along the leading edge of construction, and can be advanced as the work progresses.
The barrier system can include a flexible barrier member having a barrier member length with first and second ends, and a width. The barrier member can have a construction that is flexible in both directions along the length and width of the barrier member. First and second end supports are provided which are capable of supporting respective first and second ends of the length of the barrier member when the barrier member is extended between the end supports. The end supports can allow the extended barrier member to move in a direction transverse to the width of the barrier member when desired.
In particular embodiments, the flexible barrier member can be extended across support members of a structure. The flexible barrier member can be made of netting material which can be a slippery plastic mesh-type material. The width of the flexible barrier member has a leading edge which can be reinforced to allow the barrier member to slide more evenly across the support members of the structure. The leading edge can be reinforced with a thin plastic member. The flexible barrier member can extend from at least one end from a roll. When at least one end of the flexible barrier member extends from a roll, the roll can be connected to a windup/unwind mechanism that is capable of locking in selected positions for selecting the tension of the barrier member.
First and second movable carriages can be employed for maintaining a fixed distance between the first and second ends of the length of the flexible barrier member when extended. The first and second carriages can move along selected support members of the structure. Each carriage can include a roller system for engaging and traveling along at least one selected support member of the structure. The roller system can include a series of side rollers and top rollers. Selected rollers are adjustable for adjusting to different sizes and spacings of the support members of the structure. The roller system can include at least one roller assembly for capturing and traveling along a selected support member of the structure. The at least one roller assembly can include opposed side rollers, and top rollers. The position of the at least one roller assembly can be adjustable relative to the carriage.
In one embodiment, first and second cables can be included to which the first and second ends of the length of the flexible barrier member are slidably secured, respectively. The barrier member is capable of sliding along the first and second cables in the direction transverse to the width of the barrier member. The first and second cables are retained by the carriages in the general region of the barrier member for maintaining the fixed distance between the first and second ends of the length of the barrier member when extended.
In another embodiment, the first and second ends of the length of the barrier member can be fixed to the first and second carriages, respectively. Each carriage can be generally triangular in shape. The flexible barrier member can extend over two sides of the triangle. The two sides can have recessed top surfaces to allow the barrier member to extend closer to the supports of the structure.
The present invention also provides a movable safety barrier system including a flexible barrier member having a barrier member length with first and second ends, and a width. The barrier member can extend from at least one end, from a roll. First and second end supports are provided which are capable of supporting respective first and second ends of the length of the barrier member when the barrier member is extended between the end supports. The end supports can allow the extended barrier member to move in a direction transverse to the width of the barrier member when desired. A windup/unwind mechanism can be connected to the roll and is capable of locking in selected positions for selecting the tension of the barrier member.
The present invention further provides a method of providing protection against falls with a movable safety barrier system when installing construction components over support members of a structure. A flexible barrier member can be positioned over the support members of the structure. The flexible barrier member has a barrier member length with first and second ends, and a width. The barrier member can have a construction that is flexible in both directions along the length and width of the barrier member. The width of the barrier member can be extended forward of a leading edge of construction. Respective first and second ends of the length of the barrier member can be supported while the barrier member is extended between first and second end supports. The end supports can allow the extended barrier member to move in a direction transverse to the width of the barrier member when desired. The construction components can be positioned over the support members of the structure with portions extending over part of the barrier member. The position of the barrier member can be moved forward by an amount that allows additional construction components to be positioned over the support members of the structure with portions extending over a part of the barrier member, while the width of the barrier member still extends forward of the construction components.
Embodiments of the movable safety barrier system can be easily and quickly set up and placed into position on a construction project, and can be quickly dismantled for reuse, thereby being economical. Once in place, the safety barrier system can be easily moved by the workers as the construction progresses.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of particular embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
FIG. 1 is a schematic drawing of a worker securing a roof panel in place with a barrier member of an embodiment of a movable safety barrier system in the present invention being in position under the leading edge of insulation and roofing.
FIG. 2 is a schematic drawing of the worker advancing the barrier member forward to a new position.
FIG. 3 is a schematic drawing of the worker placing a roof panel over insulation covering the new position of the barrier member.
FIG. 4 is a schematic drawing of the worker securing the new roof panel in place.
FIG. 5 is a schematic drawing of the worker again advancing the barrier member forward to a new position.
FIG. 6 is a schematic drawing of the worker placing insulation over the barrier member in its new position.
FIG. 7 is a perspective view of a roof being installed on a building with the movable safety barrier system in position at the leading edge of construction.
FIG. 8 is a top view of a roof being installed on a building with the movable safety barrier system in position at the leading edge of construction.
FIG. 9 is a side schematic view of the movable safety barrier system showing an embodiment of a cable arrangement.
FIG. 10 is a top view of one end of the movable safety barrier system showing a portion of a movable carriage and the end of the barrier member slidably secured to a cable.
FIG. 11 is a perspective view of a roller assembly of a movable carriage.
FIG. 12 is a perspective leading end view of a portion of the movable carriage showing an outboard top roller and a cable retention roller assembly.
FIG. 13 is a leading end view of the carriage traveling on roof beams, with an end of the barrier member extending from a roll.
FIG. 14 is a perspective view of one configuration for joining metal roof beams together.
FIG. 15 is a side view of the leading edge of an embodiment of the barrier member.
FIG. 16 is a perspective view of a roof being installed on a building with another embodiment of the present invention movable safety barrier system, in position at the leading edge of construction.
FIG. 17 is a top perspective view of a portion of one end of the embodiment of the movable safety barrier system of FIG. 16 showing the barrier member secured to a movable carriage traveling on roof beams.
FIG. 18 is a top perspective view of the carriage of FIG. 17 traveling on roof beams, with the barrier member omitted.
FIG. 19 is a leading end view of the carriage of FIG. 17 traveling on roof beams, with an end of the barrier member extending from a roll fixed to the carriage.
FIG. 20 is a perspective view of one roller assembly on the trailing end of the carriage of FIG. 17 .
FIG. 21 is a perspective view of another roller assembly on the trailing end of the carriage of FIG. 17 .
FIG. 22 is a top perspective view of a portion of the carriage of FIG. 17 showing an optional roller assembly.
FIG. 23 is an end schematic view of a roof with the movable carriages of the movable safety barrier system of FIG. 16 being positioned on one half of the roof.
FIG. 24 is an end schematic view of a roof with the movable carriages of the movable safety barrier system of FIG. 16 being positioned on opposite sides of the roof.
FIG. 25 is a schematic drawing of the safety barrier system of FIG. 16 showing the safety barrier member extending from rolls of two carriages and including extension segments.
DETAILED DESCRIPTION
Referring to FIG. 1 , movable safety barrier system 10 is an embodiment in the present invention which can be extended over elevated structures undergoing construction for catching and preventing a worker 20 from falling to the ground. In the application shown in FIG. 1 , the elevated structure is the roof 15 on a building 24 , but it is understood that the elevated structure can be other structures, for example, elevated platforms, elevated roads, bridges, etc. In the example shown in FIG. 1 , a flexible safety barrier sheet member 12 of the barrier system 10 extends over the roof support members or beams 14 of the building 24 along the leading edge of construction. In this example, the roof 15 includes a layer of insulation 18 and a series of roof panels 16 which are secured to the support beams 14 . The barrier member 12 extends under the leading edge of the insulation 18 and roof panels 16 . The worker 20 is shown securing a row of roof panels 16 and insulation 18 to the support beams 14 with fasteners 22 . Since the barrier member 12 is incrementally moved forward, the fasteners 22 are inserted at a location short of the barrier member 12 so as not to fasten the barrier member 12 to the support beam 14 . The barrier member 12 extends under a region covered solely by the insulation 18 to a position ahead of the insulation 18 . As a result, if the worker 20 happens to step through or beyond this region of insulation 18 , the barrier member 12 will catch the worker 20 and prevent the worker 20 from falling.
Referring to FIG. 2 , as work progresses, the worker 20 then advances the position of the barrier member 12 so that the trailing edge at position “A” is moved, for example, by a pole 26 , to the edge of the insulation 18 at position “B”, and the leading edge at position “C” is moved forward to the new position “C”. This slides the barrier member 12 forward under the insulation 18 and positions the barrier member 12 in the proper location for continued installation of insulation 18 and roof panels 16 . The pole 26 can have structures at the distal end for gripping or catching the barrier member 12 , such as a hook or other suitable gripping protrusions. In addition, the pole 26 can have a marker 26 a located at a position on the pole 26 corresponding to the distance that the barrier member 12 should be advanced relative to the roof panels 16 , to act as a guide for the worker 20 .
Referring to FIG. 3 , another row of insulation 18 and roof panels 16 are placed over the barrier member 12 and the support beams 14 . As seen, the trailing edge of the barrier member 12 has moved from the former position “A” to the former position “B”, now becoming the new position “A”. The leading edge of the barrier member 12 has moved to a new position “C” ahead of the insulation 18 and roof panels 16 so as to provide protection for the worker 20 against falling. Referring to FIG. 4 , the worker 20 then fastens the new roof panels 16 and insulation 18 to the support beams 14 just short of the barrier member 12 .
Referring to FIG. 5 , the worker 20 again advances the barrier member 12 forward, which moves the trailing edge of the barrier member 12 to a new position “A” near the edge of the insulation 18 and roof panel 16 . Almost all of the width “W” of the barrier member 12 extends forward relative to the edge of the construction. Referring to FIG. 6 , the worker 20 then places another row of insulation 18 in position, which extends over a portion of the barrier member 12 , and the process continues. Once the roof 15 is near completion, the safety barrier system can be removed from the roof 15 for reuse on another project.
In the building 24 depicted in FIGS. 7 and 8 , the support beams 14 typically extend across the tops of a series of main frame members 32 . The building 24 is covered with corrugated siding 25 a and the eaves on the sides 23 include closure pieces 25 b which are shaped to mate with and seal any corrugations in the roof panels 16 . The length of the barrier member 12 of the movable safety barrier system 10 can be extended across substantially the width of the roof 15 of the building 24 over the peak with the width “W” extending forward from the leading edge of the construction to provide protection against falls for the workers 20 . The ends 28 of the barrier member 12 can be positioned near the sides 23 of building 24 . The ends 28 are slidably secured to a pair of cables 34 ( FIGS. 8-10 ) which in turn are secured to opposite sides 23 of the building 24 . Referring to FIG. 9 , each cable 34 can be secured at an anchor point 38 a on one end wall 21 and extend around a pulley assembly 38 b on the opposite end wall 21 before extending down to a winch assembly 19 . The winch assembly 19 allows tightening of the cable 34 . For long buildings 24 , the cables 34 can be extended only along part of the length of the building at one time, and if the building 24 is wide, some cables 34 can be positioned at inward locations. The distance between the ends 28 of the barrier member 12 can be maintained at a fixed distance by two opposed or parallel carriages 30 which travel on support beams 14 located near the cables 34 ( FIGS. 10-13 ).
Each carriage 30 can have a cable retaining roller assembly 66 which is mounted to a carriage arm 60 of the carriage 30 by a bracket 68 , and which engages a cable 34 with a grooved wheel 66 a such as a pulley, to prevent lateral movement of the cable 34 inwardly in the direction of arrow 69 ( FIG. 12 ). This also keeps the ends 28 of the barrier member 12 generally parallel to each other. The carriages 30 can be connected to the barrier member 12 by a connector 36 ( FIGS. 8 and 10 ). Each carriage 30 also includes a roller system having a roller assembly 50 mounted to the carriage arm 60 for capturing and rolling along one support beam 14 , and an outboard roller 62 extending from an end of the carriage arm 60 for engaging and rolling along the top of another support beam 14 . The roller assembly 50 can have a cross piece 50 b with two fixed lateral side rollers 52 spaced apart on one side and one adjustable lateral side roller 54 intermediately spaced on the opposite side for laterally engaging and capturing opposite sides of a support beam 14 in a rolling fashion, and two top rollers 56 spaced apart for engaging and riding on the top of the support beam 14 in a rolling fashion ( FIGS. 10 , 11 and 13 ). The roller assembly 50 is adjustably mounted to the carriage arm 60 by an adjustment sleeve 50 a having a series of locking cams 64 ( FIG. 11 ). The carriage arm 60 can be formed of square tubing, as shown. Rollers 52 and 56 can be positioned on opposite sides of carriage arm 60 by cross piece 50 b . Although FIGS. 2 and 5 depicted the barrier member 12 as being advanced by a pole 26 , alternatively, carriages 30 can be powered by motors, and be remotely controlled for advancing the barrier member 12 .
The position of the roller assembly 50 can be adjusted along the carriage arm 60 to adjust for varying distances between support beams 14 from one building 24 or structure to the next. Loosening the locking cams 64 on the adjustment sleeve 50 a allows the roller assembly 50 to be slid along the carriage arm 60 , and tightening the locking cams 64 locks the roller assembly 50 in the desired position. The adjustment mechanism 58 for the adjustable lateral roller 54 provides adjustment towards and away from rollers 52 which allows the roller assembly 50 to be adjusted to accommodate support beams 14 of varying widths. When properly adjusted, the roller assembly 50 can move along a support beam 14 without significant twisting.
By having the outboard roller 62 of carriage 30 roll on the top of the support beam 14 , the carriage 30 can travel over the support beams 14 without having to extend around or ride on the sides 23 of the building 24 . This allows the siding 25 a and closure pieces 25 b to be installed before the roof panels 16 on the roof 15 , without risk of damage by any lateral rollers riding on the sides 23 . In the figures, the support members or beams 14 are shown as metal joists or purlins, but can be a variety of types of support beams such as I-beams, trusses, wood beams, etc.
One or both of the ends 28 of barrier member 12 can extend from rolls 40 ( FIGS. 10 and 13 ). The rolls 40 are slidably mounted to the cables 34 by connecting members 44 extending from the ends of the rolls 40 and slide members 46 . The slide members 46 can be pulleys. The connectors 36 extending between the carriage arms 60 and the connecting members 44 connect the carriages 30 to the barrier member 12 . The connectors 36 can be flexible, for example, being made from a chain or a cable, or can be rigid. The carriages 30 can also be pushed for advancing the barrier member 12 forward.
A windup/unwind mechanism 42 can be connected to the rolls 40 for winding or unwinding the length of the barrier member 12 , as well as for tightening the length of the barrier member 12 to the desired tension. The windup/unwind mechanism 42 can be a hand-operated device, such as a ratchet, or can be motorized. In some embodiments, the barrier member 12 can be extended from both rolls 40 on two sides and secured together. In other embodiments the barrier member 12 can be extended only from one roll 40 and secured to the opposite roll 40 or other suitable structure. As seen in FIG. 13 , the barrier member 12 can extend over the top of the roll 40 so that if a worker 20 falls into or on top of the barrier member 12 , the resultant tension is better resisted by the carriages 30 .
Referring to FIG. 14 , the support beams 14 , when metal purlins or joists, can be formed of overlapping lengths, for example, 14 a and 14 b , which are overlapped at a region 13 . The length 14 a can be overlapped over length 14 b so that there is a step down, moving in the direction of construction. With such an overlap configuration, the barrier member 12 can be moved in the direction of construction without catching or getting hung up at region 13 . If the lengths 14 a and 14 b are overlapped the opposite way, stepping up in the direction of construction, the overlapped region 13 can be treated, for example, with a piece of adhesive tape, to provide smooth sliding of the barrier member 12 over the step up.
Referring to FIG. 15 , the barrier member 12 can be formed of netting material, such as a slippery plastic mesh which allows wind to easily pass through, to prevent billowing. This plastic mesh can be reinforced with a reinforcing member such as a thin plastic strip 11 to promote smoother or more even sliding of the leading edge 12 b over the support beams 14 . This can reduce the number of push points needed for advancing the barrier member 12 . The reinforcing plastic strip 11 can be captured by folding over a portion 12 a of the barrier member 12 material and stitching or sealing in place. The plastic strip 11 can be formed of suitable materials such as nylon, delrin, polytetrafluorethylene (PTFE), etc. Alternatively, the leading edge 12 b can be reinforced integrally during the manufacturing of the barrier member 12 . The trailing edge of the barrier member 12 can also be reinforced if desired. The barrier member 12 is typically flexible in both directions along the length and the width. Runners extending across the width “W” in the same direction and spacing as the support beams 14 are not required for promoting sliding on the support beams 14 . However, if desired, stiffeners can be added across the width “W” of the barrier member 12 . Such stiffeners can be flexible. In some applications, the width “W” of the barrier member 12 can be seven feet, such as when the roof panels 16 are three feet wide, the insulation is six feet wide, and where the barrier member 12 is meant to be positioned to be about one foot ahead of the insulation 18 without leaving a void between the roof panels 16 and the barrier member 12 . It is understood that both the width “W” and the length of the barrier member 12 can vary depending upon the application at hand.
Although the barrier member 12 has been described to be made of a plastic mesh-type netting, it is understood that the barrier member 12 can be formed of other suitable materials such as maritime-type netting, woven and unwoven textiles, fabric sheets, plastic, laminates or composite sheets, tarp-type sheets, metallic screen materials, etc. For barrier members 12 of generally solid sheet construction, openings can be provided to allow the passage of wind. The barrier member 12 is typically formed of material that can satisfy OSHA regulations, for example, 400 lbs. being dropped into the barrier member 12 . The material is also typically thin to allow the barrier member 12 to be rolled up on roll 40 without taking up a lot of space and to allow the barrier member 12 to slide easily when sandwiched between the roof panels 16 , insulation 18 and support beams 14 . In some embodiments, each roll 40 can hold about twenty to thirty feet of barrier member 12 . Other embodiments can contain lesser or greater amounts. A thin material also allows the barrier member 12 to be light weight and carried easily by workers 20 .
Referring to FIGS. 16-19 , movable safety barrier system 70 is another embodiment in the present invention which differs form barrier system 10 in that the barrier system 70 includes two opposed or parallel carriages 72 having a construction where the cables 34 can be omitted and the ends 28 of the barrier member 12 can be mounted to the carriages 72 instead of to the cables 34 . Referring to FIGS. 17-19 , a roll 40 from which the barrier member 12 is extended, can be mounted to a carriage arm 76 of a carriage 72 by brackets 78 . In the embodiment shown, carriage 72 has a generally triangular shape with carriage arm 76 being connected to carriage arms 74 and 79 . Carriage arm 76 is positioned to be parallel to the support beams 14 and sides 23 of the building 24 . The carriage arm 74 can be perpendicular to carriage arm 76 and is on the leading edge end of the carriage 72 . The carriage arm 74 can have two roller assemblies 50 mounted along the length which are similar to those in safety barrier system 10 for capturing and riding or rolling along separate support beams 14 . The roller assemblies 50 can resist twisting forces on the carriage 72 . The roller assemblies 50 are slidably adjustable relative to carriage arm 74 to adjust for varying positions and distances between the support beams 14 . The outboard top roller 62 can have an adjustable stem 62 a extending from the end of carriage arm 74 for further adjustment purposes. A locking knob 62 b can be included for locking the stem 62 in the desired position. Carriage arms 76 and 79 are on the trailing end of the carriage 72 with arm 79 forming the hypotenuse of the triangle.
As can be seen in FIG. 17 , the barrier member 12 can extend over carriage arms 76 and 79 . In order to allow the barrier member 12 to extend across the carriage 72 and be as close as possible to the support members 14 , carriage arm 76 has a low profile or recessed distal portion 76 b which steps down from a proximal portion 76 a , and carriage arm 79 is positioned in a low profile or recessed manner by connecting brackets 84 a and 84 b . The low profile of carriage arms 76 and 79 is also desirable because the insulation 18 and roof panels 16 can extend over a portion of these carriage arms 76 and 79 , and a low profile brings these portions of carriage arms 76 and 79 close to the level of the support beams 14 and allows the carriage arms 76 and 79 to slide easily out from under the insulation 18 and roof panels 16 . The roll 40 can be mounted to the recessed distal portion 76 b of the carriage arm 76 , as seen in FIG. 19 . While carriage arms 74 and 76 can be made of square tubing as shown, carriage arm 79 can be a thin bar or rod to aid in providing the low or recessed profile. Alternatively, selected carriage arms can be made of round tubing, as well as angle, channel or bar stock, etc. Typically, the structural components of both carriages 30 and 72 are made of aluminum for purposes of light weight, but can be made of any suitable material.
The carriage arm 79 can include roller assemblies 80 and 82 for rollably engaging the sides of separate support beams 14 and further resisting lateral twisting of carriage 72 . Referring to FIG. 20 , roller assembly 80 can have a lateral side roller 98 which is mounted to carriage arm 79 by bracket 92 and clamping fingers 96 . Roller 98 can be mounted to extend adjacent to and below carriage arm 79 . The carriage arm 79 can have steps 94 formed on opposite edges so that the bracket 92 and clamping fingers 96 can be mounted to the carriage arm 79 in a low profile manner. The position of the roller assembly 80 can be adjusted relative to the carriage arm 79 to adjust for different spacings and sizes of the support beams 14 .
Referring to FIG. 21 , roller assembly 82 can have a lateral side roller 100 which is mounted to carriage arm 79 by bracket 104 and clamping fingers 96 . Roller 100 can be mounted below carriage arm 79 . Adjustment knobs 102 can be used to loosen and tighten the clamping fingers 96 on the steps 94 for providing adjustment of the position of roller assembly 82 relative to carriage arm 79 to allow for different spacings and sizes of the support beams 14 . The adjustment knobs 102 can also be employed with roller assembly 80 . The use of roller assemblies 80 and 82 can depend upon the type and configuration of the support beams 14 . Some configurations of the support beams 14 may allow more than one roller assembly 80 or more than one roller assembly 82 , in a variety of combinations. In addition, the roller assemblies 80 and 82 can be of other suitable configuration than those shown, and can have vertical adjustment capabilities and vertical rollers. As with carriages 30 , carriages 72 can be powered by motors and remotely operated.
Referring to FIGS. 18 and 22 , the carriage 72 can optionally include an auxiliary outboard roller assembly 84 having a top outboard roller 90 which rides over the top of the same support beam 14 as outboard roller 62 , but is spaced apart from roller 62 . The auxiliary roller assembly 84 can provide further stability for the carriage 72 and further support the trailing end of the carriage 72 . The auxiliary roller assembly 84 can be secured to the carriage arm 76 , for example, at the proximal portion 76 a , where a protrusion 86 a locks within a mating socket 86 b . The auxiliary roller assembly 84 has a longitudinal spacing arm 86 and a cross arm 88 which positions the outboard roller 90 spaced apart from, and generally in line with roller 62 . The outboard roller 90 can have an adjustment stem 90 a for adjusting the position of the outboard roller 90 and a locking knob 90 b for locking the stem 90 a in the desired position.
FIG. 23 depicts the use of movable safety barrier system 70 on one side of the roof 15 or peak of a building 24 . This can be a construction style decision, or based on the length of the barrier member 12 . The construction of the carriages 72 allows the barrier member 12 to be positioned near the sides 23 of the building 24 without engaging surfaces of the sides 23 , so that the siding 25 a and closure pieces 25 b do not become damaged.
FIG. 24 , depicts the movable safety barrier system 70 being positioned across the width of the roof 15 such as seen in FIG. 16 . In cases where the width across the roof 15 is greater than the length of the barrier member 12 stored on the carriages 72 , one or more extension segments 107 can be used for increasing the length of the barrier member 12 ( FIG. 25 ). The segments 107 can be connected by a series of fasteners such as rings 106 to each other, and the portions of the barrier member 12 which extend from the rolls 40 . The rings 106 can have spring loaded entrance portions. In example, if the rolls 40 each hold thirty feet of barrier member material, the total length of the barrier member 12 can be sixty feet plus the length of the extension segments 107 used.
While this invention has been particularly shown and described with references to particular embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
For example, although the present invention has been mostly described for use when installing insulation and corrugated roof panels on a shallow sloped roof, it is understood that the present invention can be used on a variety of elevated structures for the installation of a number of different components. The surfaces can be flat as well as sloped. In addition, carriages 30 and 70 can have other shapes and configurations than those shown, depending upon the situation at hand. A variety of different roller systems and roller assemblies are possible. Furthermore, various features of the embodiments discussed above can be omitted or combined. | A movable safety barrier system includes a flexible barrier member having a barrier member length with first and second ends, and a width. The barrier member can have a construction that is flexible in both directions along the length and width of the barrier member. First and second end supports are provided which are capable of supporting respective first and second ends of the length of the barrier member when the barrier member is extended between the end supports. The end supports can allow the extended barrier member to move in a direction transverse to the width of the barrier member when desired. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to waveguide devices, and more particularly, to size and guide wavelength modification for waveguide devices.
2. Description of Related Art
A significant disadvantage of conventional waveguides is their size and large guide wavelength. For example, WR-975 waveguides (which can be obtained from such companies as Mega Industries and are designed for use between the frequencies of 0.75 and 1.12 GHz) has a width of 9.75 inches and a height of 4.875 inches. The height of a conventional waveguide can be reduced without affecting the fundamental-mode cutoff frequency and guide wavelength, but the same is not true of its width.
Moreover, reductions in cross-sectional area in ridged waveguides require that the gap between the ridges be on the order of one-quarter the height of the waveguide. This substantially reduces the power-carrying capacity of the waveguide, leaving it susceptible to breakdown at high power levels. In addition, the guide wavelength in ridged waveguides is approximately equal to that in other conventional waveguides, so that nearly equal lengths of either ridged or conventional waveguides are required to achieve a given phase shift.
SUMMARY OF THE INVENTION
In accordance with the teachings of the present invention, an apparatus is provided for propagating electromagnetic waves at a predetermined reduced guide wavelength. A waveguide is provided for receiving and guiding the electromagnetic waves. A dielectric is disposed in the waveguide to decrease the guide wavelength of the received electromagnetic waves.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a conventional waveguide with electric field lines depicted;
FIGS. 2a and 2b are electric field line diagrams showing degenerate TE 10 and TE 01 modes respectively for a conventional square waveguide;
FIGS. 3a and 3b are perspective views showing respectively a conventional full-height WR-975 waveguide and a full-height reduced-size waveguide that utilizes the techniques of the present invention.
FIGS. 4a and 4b are perspective views showing respectively a conventional half-height WR-975 waveguide and a half-height reduced-size waveguide that utilizes the techniques of the present invention.
FIGS. 5a and 5b are top and side views respectively of an artificial dielectric;
FIG. 6 is a perspective view of the measurement set-up for measuring dielectric constants and loss tangents; and
FIG. 7 is an x-y graph depicting normalized transmission loss through a cavity vs. frequency.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a cross section of a conventional rectangular waveguide 20. The desired mode of propagation in such a waveguide is usually the TE 10 mode, whose electric field lines 22 are as shown in FIG. 1. The cutoff frequency f c for this mode is ##EQU1## where ε R is the relative permittivity of the dielectric filling the waveguide 20 and the term c is velocity of light constant. If the width a of waveguide 20 is chosen to maintain the cutoff frequency at some desired value, then a must decrease as ε R increases. For example, WR-975 waveguide, which is designed for use with RF frequencies between 0.75 and 1.12 GHz, has a=9.75" and b=4.875". Its cutoff frequency is 0.605 GHz. If the guide is filled with a dielectric having ε R =4, a can be reduced by a factor of two (to 4.875") without changing the cutoff frequency of the TE 10 mode.
While the guide could be filled with a conventional isotropic dielectric and achieve the same size reduction, this approach can be costly (depending on the material) and adds significantly to the weight of the waveguide. Also, for the example considered above, it results in a square waveguide in which the TE 10 (FIG. 2a) and TE 01 (FIG. 2b) modes are degenerate, i.e., they have the same cutoff frequency, which is undesirable in many applications.
FIG. 3a depicts a conventional full-height WR-975 waveguide 27a. Conventional waveguide 27a has a cutoff frequency of 605 MHZ and a height and width respectively of: 4.875 inches and 9.75 inches.
FIG. 3b depicts a novel full-height reduced-size waveguide 27b that has been filled with dielectric 28. The dielectric-filled waveguide 27b has the same cutoff frequency as conventional waveguide 27a but has only half the width (i.e., 4.875 inches) Accordingly, the novel dielectric-filled waveguide 27b has the decided advantage of consuming less space than conventional waveguide 27a.
As another example, FIG. 4a depicts a conventional half-height WR-975 waveguide 29a with a cutoff frequency of 605 MHZ and a height and width respectively of: 2.4375 inches and 9.75 inches.
FIG. 4b depicts a novel half-height reduced-size waveguide 29b that has been filled with dielectric 28. The dielectric-filled waveguide 29b has the same cutoff frequency as conventional waveguide 29a but has only half the width (i.e., 4.875 inches).
The present invention preferably includes dielectric 28 being an anisotropic artificial dielectric with metallic scatterers embedded in a lightweight substrate, in order to reduce the width of the waveguide while not affecting the cutoff frequency of the waveguide. By using a lightweight anisotropic artificial dielectric, e.g., one having ε R =4 for a vertically-polarized electric field and ε R =1 for a horizontally-polarized electric field, a factor of two reduction in size is obtained with little or no weight penalty and the cutoff frequency of the TE 01 mode is unaffected by the presence of the artificial dielectric.
FIGS. 5a and 5b depict an embodiment of an artificial dielectric 28 which is embedded with small metallic scatterers 30 in a lightweight substrate 32 (e.g., a foam, such as Styrofoam). If the individual scatterers 30 are small relative to the wavelength of interest, then the permittivity of the artificial dielectric 28 is given by:
ε.sub.R =1+nα, (2)
where n is the number of scatterers per unit volume, and α is the polarizability of an individual scatterer.
While there are many scatterer shapes that can be selected, a long, thin wire with its major axis parallel to the electric field is particularly effective. The polarizability of an individual wire can be calculated numerically by using the method of moments to calculate the free-space scattered far field due to an incident plane wave having its electric field polarized parallel to the axis of the wire. The scattered far field E.sub.θ of a wire having dipole moment p is given by: ##EQU2## The dipole moment p is determined by equating the calculated amplitude of the scattered far field at broadside (θ=90°) to the amplitude in the above expression (3): ##EQU3## The polarizability is proportional to the ratio of the dipole moment to the incident electric field. For a wire scatterer (30) one-half cm in length and 0.6 mm in diameter, the polarizability is found to be: ##EQU4## where E inc is the electric-field amplitude of the plane wave incident on the wire (1 V/m in this case and the term P wire represents the dipole moment of the wire).
If it is desired to reduce the width of a given waveguide by a factor of two, then it is filled with a material having ε R =4. The artificial dielectric should satisfy:
nα.sub.wire 3,= (6)
where n is the density of scatterers in the artificial dielectric. Given the value of α wire determined above, the required density is given by the following equation: ##EQU5##
With reference to FIG. 5b, an artificial dielectric 28 was constructed in four layers (layers 34, 36, 38, and 40), each 0.5 cm thick and containing a rectangular grid of vertical wire scatterers 30 with 0.2 cm between nearest neighbors in the plane of each layer. To prevent wires in adjoining layers from touching, the grid patterns were offset in alternating layers, and thin sheets of Mylar (42, 46 and 48) were placed between neighboring layers to provide extra insulation against breakdown.
With reference to FIG. 6, measurements of the electromagnetic properties of the dielectric 28 were made using a perturbation technique, in which the dielectric 28 was placed inside a cavity 50 and its properties determined by its perturbing effect on the cavity's resonant frequency and bandwidth. The dielectric 28 was placed inside a metallic cavity 50, constructed from a piece of WR-975 waveguide. The length of cavity 50 was adjusted so that the TE 101 cavity mode would resonate near 915 MHZ, the frequency at which the properties of the dielectric 28 were desired.
The resonant frequency and bandwidth of the cavity 50 were measured by means of two coaxial probes 52 and 54 connected to a network analyzer 56 which was capable of measuring the insertion loss through cavity 50. At resonance, the insertion loss between the probes (52 and 54) is decreased to a small but measurable value, over a small bandwidth (the coaxial probes 52 and 54 were constructed so that they had little coupling into cavity 50 in order to maintain a relatively high loaded cavity Q). The cavity resonant frequency and bandwidth could then be measured with or without a dielectric inserted inside the waveguide cavity.
With the setup in FIG. 6, the relative dielectric constant of the sample was shown to be approximately: ##EQU6## where: ε r =Relative dielectric constant of the sample,
F r1 =Cavity resonant frequency with no sample,
F r2 =Cavity resonant frequency with sample,
E 1 =Electric field inside cavity with no sample,
V=Volume of cavity, and
ΔV=Volume of sample.
The electric field (E 1 ) is known from waveguide theory to be the TE 101 mode of cavity 50. Similarly, the loss tangent can be shown to be approximately: ##EQU7## where δ=Loss tangent of the sample,
B 1 =Cavity bandwidth with no sample, and
B 2 =Cavity bandwidth with sample.
Three measurements of the cavity insertion loss were performed (using the network analyzer 56): the empty cavity 50, the cavity 50 with the dielectric 28, and cavity 50 with a known sample of dielectric TEFLON (i.e., polytetrafluoroethylene) having the same size as dielectric 28.
Plots of the insertion loss versus frequency for these three cases are shown in FIG. 7: plot 64 which plots the relationship for when cavity 50 was empty; plot 60 which plots the relationship for when cavity 50 contained artificial dielectric 28; and plot 62 for when cavity 50 contained a sample of TEFLON. From the insertion loss data of FIG. 7, the resonant frequency and bandwidth of the insertion loss could be found. This information is summarized in Table 1.
TABLE 1______________________________________ TransmissionSample Resonant Frequency Bandwidth______________________________________None 911.78 MHZ 372.30 kHzArtificial 906.22 MHZ 399.96 kHzDielectricTEFLON 909.88 MHZ 392.65 kHz______________________________________
From the information in Table 1, and using Equations (8) and (9), the dielectric constant and loss tangent of the samples were computed. These values are shown in Table 2.
TABLE 2______________________________________Sample Dielectric Constant Loss Tangent______________________________________None N/A N/AArtificial 4.18 0.0020DielectricTEFLON 2.09 0.0029______________________________________
From Table 2, it can be seen that the dielectric constant for the TEFLON sample was measured to be 2.09. Typically in the literature, TEFLON is reported to have a dielectric constant of about 2.1, which makes this measurement very close. The loss tangent of the TEFLON was measured at 0.0029.
When dielectric 28 is used in a waveguide carrying significant amounts of RF (radio frequency) power, it is designed to have a reasonable voltage-standoff capability. A dc high voltage was placed across dielectric 28 described above. Voltage breakdown did not occur for any voltage applied to dielectric 28. Styrofoam pads (not shown) were used to separate the top and bottom surfaces of dielectric 28 from the electrodes, which resulted in a separation of 1.1 inches (2.794 cm) between electrodes. At the maximum applied voltage of 30 kV, the electric field strength corresponding to this separation was 10.7 kV/cm. The significance of this is seen by calculating the power-handling capability of an artificial-dielectric filled reduced-size waveguide through which is propagating a TE 10 mode having a peak electric-field amplitude of 10.7 kV/cm. The propagating power is: ##EQU8## where η 0 =377 Ω and is the impedance of free space and the term f c is the cutoff frequency, and the term a is the width and the term b is the length. The propagating power is proportional to the product of the area and √ε R . When this product is held constant as the waveguide dimensions are reduced, the power-carrying capacity remains constant. Consider a reduced-size version of WR-975 waveguide in which the width was reduced by a factor of two, resulting in a square waveguide having "a=b=4.875" (12.3825 cm) and a resulting cross-sectional area of 23.77 in 2 . With f c =605 MHZ and f=915 MHZ, the maximum power P max that can be propagated through this waveguide without breakdown satisfies the following equation: ##EQU9## where E max =10.7 kV/cm. The 17.5 MW is a lower limit and not an absolute limit. The present invention includes an artificial dielectric that safely stands off 15 kV/cm. For such a material, the power-handling capacity of the waveguide described above increases to 34.3 MW, which is substantially similar to the rated power-handling capacity of a conventional WR-975 waveguide at this frequency.
It will be appreciated by those skilled in the art that various changes and modifications may be made to the embodiments discussed in the specification without departing from the spirit and scope of the invention as defined by the appended claims. For example, while an artificial dielectric has been discussed, the present invention also includes using a dielectric consisting of naturally occurring materials, such as Corning 7070 glass, for which ε=4.0 and tan δ=1.2×10 -3 at 3 GHz. | An apparatus for propagating electromagnetic waves at a predetermined reduced guide wavelength. A waveguide (27b) is provided for receiving and guiding the electromagnetic waves. A dielectric (28) is disposed in the waveguide (27b) to decrease the guide wavelength of the received electromagnetic waves. The dielectric (28) allows the width of the waveguide (27b) to be reduced without significantly compromising its power-carrying capability. | 7 |
This is a continuation, of application Ser. No. 098,749 filed Nov. 30, 1979, and now abandoned.
BACKGROUND AND FIELD OF THE INVENTION
The present invention relates to amplifiers, and more particularly to an amplifier employing digital switching of incremental signal sources for amplifying an amplitude and frequency varying input signal to high power levels.
In amplifier design, one important consideration is the efficiency at which the amplifier operates. Other important considerations include reliability, size, etc. It may be well appreciated that these considerations assume exaggerated importance in very high power amplifiers, such as those used in the modulating circuits of conventional broadcast transmitters. These audio amplifiers must amplify an input audio signal up to a power level ranging from several kilowatts to several tens of kilowatts.
An additional consideration in the selection of an amplifier design is the compatibility of that design with available solid state devices. Solid state devices, such as transistors, VFETs, SCR's, etc. are preferred over vacuum tube devices in view of their size, relative efficiency, and reliability. Unfortunately, such solid state devices as are readily available do not generally have sufficient power handling capabilities for use in standard very high power amplifier designs.
In the prior art, pulse duration modulation has been used effectively in increasing the efficiency of these high power amplifiers. Thus, as shown in the patent to Swanson, U.S. Pat. No. 3,506,920, high power amplification may be obtained by pulse width modulating a carrier signal in accordance with the changing level of an audio signal, amplifying the resulting bi-level pulse waveform, and then recovering an amplified audio signal by filtering the resulting amplified PDM signal. Even with these PDM amplifiers, however, no entirely satisfactory design has been found which employs high powered solid state devices in view of the existing limitations on power and speed of these devices.
One approach which has been taken in order to resolve this incompatibility is described in the patent to Swanson, U.S. Pat. No. 4,164,714, entitled "Polyphase PDM Amplifier". The amplifier described in this patent receives a time varying input signal and converts it into a plurality of modulated pulse trains of like polarity and frequency (each of which may, for example, be a PDM signal) and which are phase displaced from one another by a known amount. The pulse trains are combined to form a composite signal of increased magnitude and of substantially the same waveform as the input signal. Unlike previous PDM amplifiers, the design of this Polyphase PDM amplifier has been found to be compatible with existing solid state devices.
SUMMARY OF THE INVENTION
It is a general object of the present invention to provide an improved high power amplifier.
It is another object of the present invention to provide a high power amplifier whose design is compatible for use with conventional solid state elements.
It is yet another object of the present invention to provide an amplifier for providing power amplification with high efficiency.
It is still another object of the present invention to provide an amplifier which performs in accordance with the objects set forth above, and which has reduced output filtering requirement.
It is a further object of the present invention to provide an amplifier for use in an RF amplitude modulation system which achieves the foregoing objects.
In accordance with one aspect of the present invention, an amplifier is provided for amplifying an amplitude and frequency varying input signal. The amplifier includes means responsive to the input signal to provide a digital representation thereof. A plurality of signal sources are provided which each provide an associated signal. Combining means combines selected ones of these associated signals in accordance with the digital representation to provide a first combined signal having substantially the same waveform as, but of greater magnitude than, the input signal.
In accordance with another aspect of the present invention, means are further included for providing an error signal which varies in accordance with the difference between the desired and actual forms of the first combined signal. This error signal is combined with the first combined signal to form an error-corrected first combined signal.
More specifically, there is disclosed hereinafter an amplifier including a converter which is responsive to the amplitude and frequency varying input signal to provide a digital word including plural bits which together indicate and change with the analog level of the amplitude and frequency varying input signal. Each of the bits of this word has an assigned value representing its contribution to the total signal. Means are further provided responsive to this digital word for reconstructing the input signal in amplified form. This means comprises a plurality of incremental voltage sources, each having a value corresponding to the value assigned to the corresponding one of the bit positions of the individual words. A plurality of switching means are also incorporated in the reconstructing means, each associated with a corresponding one of the incremental voltage sources. Each of the switching means has at least two selectable states. In the first state the associated incremental voltage source is interconnected in series with the other selected voltage sources across the output, whereas in the other state the associated incremental voltage source is disconnected from the output. The state of each of the switching means is selected by the bit in the corresponding bit position of the digital word.
In another of the described embodiments of the present invention, the amplifier as defined above includes a pulse duration modulation stage for adding an incremental pulse duration modulated (PDM) signal onto the reconstructed analog signal, wherein the width of the pulses in the PDM carrier signal are modulated in accordance with the difference between the reconstructed signal and the input signal. A sum signal is then provided corresponding to the additive sum of this PDM signal and the reconstructed analog signal.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other aspects and advantages of the present invention will become more readily apparent from the following detailed description, as taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a block diagramatic representation of one embodiment of an amplifier in accordance with the teachings of the present invention;
FIG. 2 is a block diagram of another embodiment of an amplifier in accordance with the teachings of the present invention, wherein a PDM stage has been added;
FIGS. 2A and is a block diagram of an alternative embodiment of a portion of the amplifier of FIG. 2;
FIG. 3 is a block diagram of a third embodiment of the present invention;
FIG. 4 is a circuit diagram of an incremental voltage source such as might be useful in the embodiments of FIGS. 1-3;
FIG. 5 is a schematic illustration of a switching circuit useful for switching the incremental power sources as required by the embodiments of FIGS. 1-3; and
FIG. 6 is an illustration of a reconstructed analog waveform produced by an amplifier in accordance with the teachings of the present invention.
DETAILED DESCRIPTION
In the following description, the invention will largely be described with respect to an ampifier used in the RF modulation stage of a conventional AM transmitter. This specific embodiment is utilized for exemplary purposes only, however, and it should be appreciated that the amplifier described hereinafter will find extensive use in many applications wherein high power amplification of an amplitude and frequency varying input signal is required.
Referring now to FIG. 1, there is illustrated an AM transmitter incorporating an amplifier in accordance with the teachings of the present invention. In this figure, a transmitter system 10 includes an audio signal source 12 which generates the amplitude and frequency varying audio signal which is to be transmitted. This audio signal (V in ) is supplied to an amplifier 14 which amplifies it to a high power level and provides the resulting amplitude signal (V out ) at its output to filter stage 16. The filter 16 removes out-of-band artifacts of the amplification process from the amplified signal. The resulting amplified and filtered signal is then supplied to the audio input of a conventional RF power amplifier 18 where it amplitude modulates an RF carrier supplied by an RF oscillator 20. The resulting AM signal is then transmitted over a conventional antenna or antenna array 22.
In accordance with the present invention, the amplifier 14 includes a circuit 24 to which the input signal is applied. This circuit 24 converts this amplitude and frequency varying input signal into a digital word comprised of plural individual bits, each provided upon a corresponding output line 26 at the output of the circuit 24. These bits together indicate the instantaneous level of the input audio signal to within an incremental limit, and change with time to indicate the changing level of the audio signal. In FIG. 1, the circuit 24 comprises a conventional analog-to-digital (A/D) converter. The digital word provided along the output line 26 therefore comprises a binary representation of the input signal, with the four bits provided along the four output lines 26 of converter 24 have a weighting of 8-4-2-1. This digital word will vary between a lower limit of "0000", to an upper limit of "1111" in accordance with changes in the instantaneous level of the audio signal V in , and will have an average or D.C. value of "1000". For some A/D convertors, it may be necessary to D.C. bias the input signal at one half of the supply voltage to achieve this result.
The A/D convertor 24 may be either clocked (i.e., updates the value of the output digital word only upon a "convert" command) or unclocked (i.e., the output digital word continually reflects the value of the input analog signal). If the former, the conversion rate should be great enough that the output word essentially changes concurrently with any changes in the analog input signal.
The digital word provided along the line 26 at the output of A/D 24 is supplied to a circuit generally indicated at 28 whose purpose is to reconstruct the analog audio signal therefrom in amplified form. This recontruction circuit 28 includes a plurality of incremental D.C. voltage sources 30, 32, 34, and 36. Each of the incremental voltage sources includes a switching circuit comprised of a corresponding switch 38, 40, 42 and 44, and a corresponding bypass diode 46, 48, 50 and 52. (For convenience of description, the combination of an incremental voltage source and its associated switching circuit and bypass diode will be referred to occasionally hereinafter as an amplifier "cell".) The level of D.C. voltage supplied by the various incremental voltage sources will be selected to correspond to the weighting of the individual bits provided at the output of the converter 24. Thus, in the embodiment illustrated in FIG. 1, the four incremental voltage sources 30, 32, 34 and 36 will have a weighting of 8-4-2-1, since the digital word is coded in binary form. Moreover, each source will "float" with respect to the other sources. Consequently, different output voltages can be formed by simply connecting the necessary voltage sources together in series.
The switching circuits associated with each of the incremental voltage sources are controlled by the bit having the corresponding value. At any given time, this bit can assume either of two possible values, a binary "0" or a "1". When the bit has one value, then the incremental voltage source will be connected in series with other selected incremental voltage sources across the load, in this case comprised of the filter circuit 16 and the RF power amplifier 18. When the bit has the second binary state, however, the switching circuit will instead disconnect the incremental voltage source from the output, so that the incremental voltage of that source provides no contribution to the composite signal appearing across the load.
Although, in FIG. 1, the switches 38-44 are illustrated as convention SPST mechanical switches, in a practical embodiment solid state switches, such as described hereinafter, will instead be used.
To better understand the operation of the reconstruction circuit 28, consider the amplifier cell including incremental voltage source 36 and its associated switching elements 44 and 52, which are exemplary of the remaining cells in the reconstruction circuit. In this amplifier cell, as in all others, the incremental voltage source 36 is connected in series with its associated switch 44, and in parallel with the bypassing diode 52. Furthermore, this cell is connected in series with all of the other cells in the reconstruction circuit 28. When the switch 44 is "open", then the voltage source 36 is disconnected and thus does not contribute to the total signal supplied at the output of the amplifier. The disconnection of the voltage source does not, however, interfere with the operation of the remaining incremental voltage sources, since the diode 52 provides a path for current to bypass the incremental voltage source 36, and thereby flow into the load connected to the output of the amplifier. When the switch 44 is "closed", however, then the voltage source 36 will effectively reverse bias the associated bypassing diode 52, and will instead connect the incremental voltage source 36 into a series combination with the remaining cells in the amplifier. Each of the incremental voltage sources 30-36 may thus be connected in series with any selected combination of the remaining incremental voltage sources.
At any given time, the ones of the voltage sources 30, 32, 34 and 36 connected in series across the output of the amplifier will be dependent strictly upon the binary word provided at the output of the A/D converter 24. If this binary word were, for example, "1011", then the voltage appearing across the load circuit would be 8 V 1 plus 2 V 1 plus V 1 , or 11 V 1 . Since each switching circuit has two possible states, there are a total of 2 4 , or sixteen different combinations of the incremental voltage sources possible. Consequently, there are sixteen different analog voltage levels which may be provided at the output, under the control of the digital signals provided by the A/D converter 24. Since the A/D converter 24 is controlled by the analog signal provided by audio signal source 12, and since the coding of the digital word is the same as the weighting of the incremental voltage sources, this output signal will mirror the input signal in a stepwise fashion. Because the size of the steps (equal to the smallest incremental voltage V 1 ), is dependent only on the magnitude of the voltages provided by the voltage sources, this output signal may be of much greater magnitude by appropriate scaling of these voltages.
FIG. 6 illustrates an analog input signal V in and the output signal V out which the amplifier of FIG. 1 will provide in response thereto. Although, for convenience of illustration, V in and V out are shown as having approximately the same magnitude, the steps in V out will generally be very much larger, leading to significant voltage gain through amplifier 14.
As is apparent from FIG. 6, the reconstructed analog signal includes step transitions from each signal level to the next succeeding level, thereby introducing unwanted high frequency components to the reconstructed waveform. The filter 16, illustrated in FIG. 1 as a conventional T network comprised of inductors 54 and 56 and a capacitor 58, will be designed to filter out the high frequency components introduced by the step transitions, thereby smoothing the reconstructed waveform.
FIG. 2 illustrates an alternative embodiment of the amplifier of FIG. 1, incorporating a pulse width modulation (PWM) amplifier cell to provide improved resolution of the reconstructed waveform. In this circuit, the analog signal V in will again be provided by an analog signal source such as audio source 12 of FIG. 1. The amplifier will of course amplify this signal to provide an amplified signal to a load such as filter 16 and transmitter 18.
The amplifier 60 of FIG. 2 includes a first portion 14 which may be substantially identical to the amplifier 14 of FIG. 1. As stated previously, the reconstructed waveform provided at the output of the amplifier 14 will have stepwise transitions between the sixteen different levels thereof. A certain degree of inaccuracy of amplification arises from the finite number of steps in the output signal. Greater resolution of amplification could be provided by including an A/D converter 24 having greater resolution, such as 8, 10, or 12 bit resolutions, together with a correspondingly greater number of weighted amplifier cells. Presuming that the A/D converter provides a binary coded output and again presuming that the incremental voltage sources are weighted in corresponding fashion, the inclusion of each subsequent cell of amplification multiplies the total possible number of amplifier levels by a factor of 2. The use of an eight-bit A/D converter in conjunction with an eight-cell amplifier would therefore provide 256 possible analog levels at the output. At some point, however, a minimum step size will be found such that it will be impractical to provide cells including smaller incremental voltages. The amplifier 60 of FIG. 2 utilizes a PWM amplifier stage 62 to increase the resolution even beyond this limit.
The amplifier 62 includes an additional amplifier cell 64 which, as with the previous cells, incorporates an incremental voltage source 66, a switch 68, and a bypassing diode 70. In the embodiment illustrated in FIG. 2, the incremental voltage source 66 associated with the cell 64 has an output voltage which is equal to the difference in amplitude between adjacent voltage levels obtainable by the amplifier 14. Thus, if the amplifier 14 is constructed as the amplifier 14 of FIG. 1, then this voltage source 66 will provide the same incremental voltage as the voltage source 36. The switching of the incremental voltage source 66 into and out of the circuit is again accomplished by means of the solid state switch 68. Switch 68, however, is in this embodiment controlled by a pulse width modulator 72, which may take any conventional form (as disclosed, for example, in the aforementioned patent of Swanson, U.S. Pat. No. 4,164,714).
The pulse width modulator 72 has for its input an analog signal representing the difference between the reconstructed waveform generated by amplifier 14 (divided down to be of equal amplitude to the input signal) and the input signal V in . To scale the reconstructed waveform down to be of the same gain as the input signal V in , a resistive divider is provided comprised of a fixed resistor 74 in series with a potentiometer 76. The tap on the potentiometer 76 will be adjusted until the voltage appearing at the tap is of substantially the same scale as the analog signal provided to the input of the amplifier. A difference amplifier 78 will then subtract one from the other and will provide a signal at its output representative of the difference between the desired waveform (represented by the input signal V in ) and the actual reconstructed waveform, as derived from the tap on the potentiometer 76. The output of PWM 72 will be a pulse train, the pulses of which occur at an appropriate frequency (for example 100 kHz) and with a duty cycle ranging from 0% to 100% in direct dependence upon the amplitude of the signal provided by difference amplifier 78.
In operation, the voltage provided by the differential amplifier 78 will be very small or zero when the reconstructed waveform coincides exactly with the ideal waveform. In that case, the output signal provided by the pulse width modulator 72 will have a very small, or perhaps zero duty cycle, thus the switch 68 will remain open and the reconstructed waveform will pass through the amplifier 62 substantially without change. As the difference between the reconstructed waveform and the desired waveform becomes greater and greater, however, the duty cycle of the cyclical signal at the output of the pulse width modulator 72 will increase, thus switching the incremental voltage source at a corresponding duty cycle, and adding a PWM component to the output signal V out . Just prior to amplifier 14 switching to the next successive amplitude level, the PWM waveform will have a nearly 100% duty cycle. Upon the switching of the amplifier 14 to the next successive level, of course, the difference between the desired amplitude and the actual amplitude will drop to substantially zero, causing the duty cycle of the pulse width modulator to similarly drop to zero. Since the cell 64 is connected essentially in series with the cells of the amplifier 14, the PWM signal is added into the reconstructed waveform in the same fashion as are the incremental voltages provided by the other cells in amplifier 14.
The insert I in FIG. 6 illustrates, on an expanded scale, the appearance of the output waveform V out for the amplifier of FIG. 2 when an input signal V in is applied thereto.
Although illustrated in FIG. 2 with the amplifier 62 interposed between the amplifier 14 and filter 16, the circuit could have as easily have been constructed with the amplifier 62 located between the last cell in amplifier 14 and ground. In this event, however, the scaled signal provided to the differential amplifier 76 would have to be derived in a different manner. For example, as shown in FIG. 2A the outputs 26 of A/D converter 24 of FIG. 1 could each be connected into a single, common input of a current amplifier 80 through corresponding resistors 82 so as to develop a current signal into the current amplifier which varies with the digital word provided on the output 26. By weighting the resistors 82 by factors of 1, 1/2, 1/4 and 1/8, as illustrated, the total current going into the input of the amplifier can be made to correspond linearly with the magnitude of the reconstructed waveform appearing across the amplifier cells controlled by these outputs. The voltage output thereof would then correspond to the current input from the four lines 26, and hence would reflect the contribution to the reconstructed waveform provided by the amplifier 14. This voltage signal would then be provided to the input to differential amplifier 76 in place of the connection to the tap of potentiometer 74 in the embodiment of FIG. 2. The resulting operation will be essentially identical to the operation provided by the amplifier of FIG. 2.
In the embodiments illustrated in FIGS. 1 and 2, one of the incremental voltage sources will always have an incremental voltage equal to substantially half of the total voltage range over which the output signal may change. In FIG. 1, for example, the incremental voltage source 30 has a magnitude of 8 V 1 , when the total voltage range is only 16 V 1 . Although this will not represent a problem for many applications, it does represent a significant constraint in those applications requiring output voltages extending into the kilovolt range, and beyond. This is essentially because the solid state elements utilized to switch the incremental voltage sources are limited in the voltages which they can handle. Consequently, if the amplifier designs of FIGS. 1 and 2 were strictly followed, the total voltage range of the output signal will be constrained to twice this limiting voltage. Practical considerations will even further limit this, since the highest power switching elements are quite expensive and may not be cost effective in many applications.
FIG. 3 illustrates another embodiment of the invention, not limited in the amplitude of voltage which may be provided at the output thereof. In this embodiment, as in the embodiment of FIGS. 1 and 2, an amplifier 98 is provided including a circuit 100 for converting the incoming analog signal into a multibit digital representation thereof. In this embodiment, the circuit 100 will comprise any of the conventionally available "level detector" circuits such as the Texas Instruments TL490 or others. This level detector, contrary to the A/D convertor of FIG. 1, does not include outputs which are differently weighted. Instead, each of the outputs represents an equivalent voltage increment, with the total voltage range representable by this circuit equaling this voltage increment times the number of outputs. When the instantaneous level of the input signal is at the lowest level representable by the level detector (i.e., negative full scale), all of the output lines of the level detector will be low. If the input signal is then steadily increased, the number of high output lines will also steadily increase until the input signal reaches the highest level representable by the level detector (i.e., positive full scale), when all of the outputs will be high. Of course, the D.C. level of the input signal will normally be biased halfway between positive and negative full scale.
As previously, the output of the circuit 100 is directed to a reconstruction circuit having a plurality of cells 102, with each cell including an incremental voltage source 104, the solid state switch 106, and a bypassing diode 108. In this embodiment, contrary to previous embodiments, each of the incremental voltages 104 provides an output voltage which is substantially equal to the output voltages provided by each of the other incremental voltage sources. This is possible because the outputs of the level detector 100 are equally weighted, rather than being coded in binary, BCD, or other fashion, as with the embodiments of FIGS. 1 and 2. Each of the incremental voltages 104 will thus have a value equal to the smallest incremental change required. The incremental voltages will therefore not be large enough to introduce difficulties associated with limiting operating voltages of the solid state switches used therewith.
The number of incremental voltage steps, however, will of course be much greater than that in the embodiments illustrated in FIGS. 1 and 2, since one incremental voltage source must be provided for each of the possible voltage steps. In other words, if 256 different levels of output signals are desired, then 256 different amplifier cells must be provided. The complexity of the circuit may be reduced by reducing the number of cells, however this reduces the number of possible voltage steps available and limits the resolution of the reconstructed waveform.
In the embodiment of FIG. 3, the competing constraints of signal resolution and system complexity are resolved by providing an additional amplifier stage 110 is series with the amplifier cells 102. This amplifier stage 110 may be substantially identical to either the amplifier 14 illustrated in FIG. 1, the amplifier 62 illustrated in FIG. 2, or the amplifier 60 of FIG. 2, representing the series combination of amplifiers 14 and 62. By using the amplifier 14 of FIG. 1 in combination with the previously described amplifier cells 102, the number of incremental voltage sources 104 required for any given degree of signal resolution may be diminished by a factor of 16. This is because, between each sequential setting of the cells 102, 16 different voltage steps will be provided by various combinations of the four differently weighted cells in the amplifier 14. Even greater resolution will be achieved by utilizing the amplifier 60 in series with the amplifier 98. Whichever amplifier is used for stage 110, the various incremental voltage sources 104 associated with the amplifier 98 may be selected to have voltages approaching the practical and economic limits of the switching elements associated therewith, and resolution between these various incremental voltage steps will be accomplished by the amplifiers 16 and/or 62 of FIG. 2.
When an amplifier 110 is used in series with the amplifier 98, the voltage signal provided at the input of that auxiliary amplifier 110 must, again, represent the difference between the stepwise signal provided across the amplifier 98 and the desired waveform. In FIG. 3, this difference signal is again derived by dividing down the signal appearing across the amplifier 98 with a fixed resistor 111 and a potentiometer 112. A tap on the potentiometer 112 provides a signal which is subtracted from the input signal V n by a differential amplifier 114. Once more, as with the embodiment of FIG. 2, the amplifier stages 98 and 110 may be interchanged so that the amplifier 110 is located between the amplifier 98 and ground, and in this case the control signal to amplifier stage 110 will be derived in a different manner, such as the manner illustrated in FIG. 2A. If the technique of FIG. 2A is utilized, however, the resistors feeding the input to the current amplifier will of course have equal values, since the outputs of the level detector 100 are equally weighted.
FIGS. 4 and 5, respectively, illustrate specific forms which the incremental power sources and solid state switching elements of the embodiments of FIGS. 1, 2 and 3 could take. Of course, any number of alternative embodiments are possible, and these embodiments are only set forth as examples.
Referring now to the circuitry of FIG. 4, an incremental power source is shown which consists essentially of a three-phase power transformer 120, six diodes 122 connected together to a conventional full wave three-phase rectifying circuit, and a filter capacitor 124. If desired, regulating elements may be included to further stabilize the voltage provided at the output of the incremental voltage source, rather than directly taking the output of the filter capacitor 124. It will be noted that, due to the isolation provided by the transformer 120, the voltage appearing across the filter capacitor 124 will float with respect to earth ground and also with respect to the other incremental voltage sources.
FIG. 5 illustrates one form which the switching circuits could take. In FIG. 5, a high power transistor 126 is used for switching the incremental voltage source, with the remainder of the circuitry illustrated in FIG. 5 being utilized to drive this transistor 126. When connected in with an amplifier cell as shown in any of the previous figures, the collector connection P will be connected to the positive terminal on the associated incremental voltage source, whereas the emitter connection N will be connected to the cathode of the bypassing diode of that cell.
In FIG. 5, the driver circuit 128 is isolated from the control lines by means of a light emitting diode 130 and an optically coupled photo diode 132. When a high logic signal is applied to the input terminal 134, this voltage signal will be converted to a current by a resistor 136, with the current then passing through the diode 130. The diode 130 will emit light to the photo diode 132 which will respond by switching from a high impedence state to a low impedance state.
A fiber optic link may be provided between the LED 130 and the photo diode 132. A fiber optic link of this nature would be quite advantageous where the coding circuitry which produces the control signals is located at a physically remote location from the switching circuitry and incremental voltage sources. Thus, fiber optic links are not susceptible to electromagnetic noise, nor would they introduce reactance in the manner of conventional multi-conductor cables.
In any event, the application of a logic 1 signal to terminal 134 will cause the diode 132 to drop to a low impedance state, thereby permitting the current to flow through a resistor 135 and into the base of transistor 137. This, in turn, will turn on transistors 138 and 140, thereby switching "on" the output transistor 126. The amount of current drive provided to the output transistor 126 by transistor 140 is regulated by a "baker clamp" consisting of a diode 142. As transistor 126 drops toward saturation, a point is eventually reached at which the diode 142 becomes forward biased, thereby shunting base drive away from the transistor 140. If transistor 126 rises out of saturation, however, then diode 142 will become reversed biased, thereby increasing base drive to transistor 140 and again dropping the output transistor 126 into saturation.
When the voltage applied to terminal 134 drops to zero, the diode 132 will return to a high impedance state, thus switching off transistors 137, 138 and 140. Due to carrier storage in these transistors, however, the output transistor 126 might not turn off immediately were it not for the inclusion of an additional transistor 143. This transistor couples the base of the output transistor 126 to ground when transistor 138 switches off, thereby insuring that rapid, positive disablement of the output transistor 126 occurs.
The switching circuitry 128 thus described will be powered by positive and negative voltage supplies 144 and 146 which will be referenced to the terminal N in the fashion illustrated in FIG. 5. To permit this referencing, the power supplies 144 and 146 will be isolated from the AC power line by means of transformer coupling (not shown), as with the incremental power source of FIG. 4.
Although the invention has been described with respect to preferred embodiments, it will be appreciated that various rearrangements and alterations of parts may be made without departing from the spirit and scope of the invention, as defined in the appended claims. Thus, although voltage sources have been used as the incremental power sources in the specifically described embodiments, it will be appreciated that any other appropriate power sources (e.g., current sources) could instead be employed. | An amplifier (FIGS. 1-3) is disclosed for amplifying an amplitude and frequency varying input signal. The amplifier includes a circuit (24, 100) responsive to the input signal to provide a digital representation thereof. In addition, a plurality of signal sources (30-36) are provided which each provide an associated signal. Another circuit (38-52) combines selected ones of the associated signals in accordance with the digital representation to provide a first combined signal having substantially the same waveform as, but of greater amplitude than the input signal.
In several embodiments, a circuit (74, 76-78) provides an error signal in accordance with the difference between the desired and actual forms of the first signal. This error signal is combined with the first combined signal to derive an error corrected signal. | 7 |
This application is a divisional of application Ser. No. 09/532,094, filed on Mar. 21, 2000, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of semiconductor memory devices and, more particularly to a structure having improved static refresh properties in dynamic random access memory devices and a method of making it.
2. Description of the Related Art
Metal oxide semiconductor (MOS) structures are basic electronic devices used in many integrated circuits. One such structure is the metal oxide semiconductor field effect transistor (MOSFET), which is typically formed in a semiconductor substrate by providing a gate structure over the substrate to define a channel region, and by forming source and drain regions on opposing sides of the channel region.
To keep pace with the current trend toward maximizing the number of circuit devices contained in a single chip, integrated circuit designers continue to design integrated circuit devices with smaller and smaller feature sizes. For example, not too long ago it was not uncommon to have MOSFET devices (including CMOS devices) having channel lengths of 2 microns or more. The current state of the art for production MOSFET devices includes channel lengths of less than a ¼ micron.
As the channel lengths of MOSFET devices have been reduced, MOSFETS have become more susceptible to certain problems. One common problem is increased junction leakage, a condition affecting the refresh characteristics of a dynamic random access memory (DRAM) memory cell. DRAM is a specific category of random access memory (RAM) containing an array of individual memory cells, where each cell includes a capacitor for holding a charge and a transistor for accessing the charge held in the capacitor. Due to junction leakage, the stored charge must be re-stored in the capacitor on a periodic basis through a process known as refresh. Increased junction leakage leads to a premature depletion of the capacitor's stored charge, necessitating more frequent refresh cycles. Because resources are expended in refreshing the DRAM cells, the longer the period between refresh cycles, the better. The term “pause” is often used to represent the amount of time that a DRAM cell, or group of cells, can maintain their charge without undergoing a refresh operation. That is, how long can the DRAM control circuitry pause between refresh operations and still maintain the stored state of the DRAM memory cell. It is desirable to extend the pause period of, and improve the static refresh of, the DRAM.
A manufacturer may want to improve static refresh performance of the DRAM to provide customers with the capability to perform more memory operations (e.g., reads and writes) between refresh cycles. This reduces the overhead required to utilize the DRAM. Moreover, a manufacturer may want to improve static refresh performance to improve the operating specifications of the DRAM. For example, DRAMs typically have a low-power or standby specification requiring the DRAM to operate within a maximum current during a low-power mode. Since memory cells must be refreshed during the lower-power mode, reducing the frequency of the refresh operations will improve the DRAM's operational performance for the low-power mode.
FIG. 1 illustrates a prior art MOSFET memory array device 5 . The device 5 and its fabrication method are described in U.S. Pat. No. 5,534,449 (Dennison et al.), which is hereby incorporated by reference in its entirety. Briefly, the fabrication of the device 5 is initiated by forming a gate structure 10 on a substrate 8 . The substrate 8 is typically a bulk silicon substrate, which may have a doped well therein in which transistors are formed. The gate structure 10 (referred to in the ′449 patent as a gate line) typically comprises a gate oxide 12 , a conductive polysilicon layer 14 , an overlying WSi x layer 16 , an overlying novellus oxide layer 18 and a Si 3 N 4 capping layer 20 . The cross sectional width of this prior art gate structure 10 is 0.40 microns.
Once the gate structure 10 is formed, the device 5 is subjected to oxidizing conditions. This process step is often referred to as a “re-ox” step or a thermal re-ox step. Oxidized sidewalls 22 , 24 are formed on the gate structure 10 , and oxide regions 26 , 28 are formed on the substrate, as a result of the re-ox step. Subsequent to the re-ox step, a blanket phosphorous implant step is performed to form diffusion regions 30 , 32 . This blanket phosphorous implant is performed at an energy level ranging from 30 Kev to 60 Kev with a dose ranging from 7×10 12 ions/cm 2 to 1.5×10 13 ions/cm 2 to provide an average dopant concentration for the diffusion regions 30 , 32 ranging from 1×10 17 ions/cm 3 to 1×10 19 ions/cm 3 . For the prior art device 5 , this blanket phosphorous implant step is performed after the re-ox step to prevent the phosphorous from diffusing too far underneath the gate structure 10 , which could cause transistor leakage problems.
The fabrication process of the device 5 typically includes the formation of oxide or nitride sidewall spacers 40 , 42 on the sidewalls of the gate structure 10 . Further processing may be performed as described in the '449 patent. Although the MOSFET memory array device 5 is a vast improvement over earlier memory array devices, it can still benefit from improved static refresh performance. Thus, it is still desirable to improve as much as possible the static refresh performance of the memory device.
SUMMARY OF THE INVENTION
The present invention provides a memory array device having improved static refresh over prior art memory array devices.
The above and other features and advantages of the invention are achieved by a double blanket ion implant method for forming diffusion regions in memory array devices, such as a MOSFET access device. The method provides a semiconductor substrate with a gate structure formed on its surface. Next, a first pair of diffusion regions are formed in a region adjacent to the channel region by a first blanket ion implantation process. The first blanket ion implantation process has a first energy level and dose. The device is subjected to oxidizing conditions, which form oxidized sidewalls on the gate structure. A second blanket ion implantation process is conducted at the same location as the first ion implantation process adding additional dopant to the diffusion regions. The second blanket ion implantation process has a second energy level and dose. The resultant diffusion regions provide the device with improved static refresh performance over prior art devices. In addition, the first and second energy levels and doses are substantially lower than an energy level and dose used in a prior art single implantation process.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other advantages and features of the invention will become more apparent from the detailed description of the preferred embodiments of the invention given below with reference to the accompanying drawings in which:
FIG. 1 is a fragmentary vertical cross-sectional view of a prior art memory array device conventional diffision regions;
FIG. 2 is a fragmentary vertical cross sectional view of an integrated circuit memory array device formed in accordance with the present invention;
FIG. 3 is a fragmentary vertical cross sectional view of the device illustrated in FIG. 2 at an early stage of formation;
FIG. 4 is a fragmentary vertical cross sectional view of the device illustrated in FIG. 3 at a later stage of formation;
FIG. 5 is a fragmentary vertical cross sectional view of the device illustrated in FIG. 4 at a later stage of formation;
FIG. 6 is a fragmentary vertical cross sectional view of the device illustrated in FIG. 5 at a later stage of formation;
FIG. 7 is a fragmentary vertical cross sectional view of the device illustrated in FIG. 6 at a later stage of formation;
FIG. 8 is a graph illustrating the dopant concentration of diffusion regions within the devices illustrated in FIGS. 1 and 2;
FIGS. 9 and 10 are graphs illustrating the static refresh performance of the devices illustrated in FIGS. 1 and 2; and
FIG. 11 is block diagram of a processor-based system including a memory device formed in accordance with the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention will be described as set forth in the preferred embodiments illustrated in FIGS. 2-7 and 11 . Other embodiments may be utilized and structural or logical changes may be made without departing from the spirit or scope of the present invention. Like items are referred to by like reference numerals.
FIG. 2 illustrates a portion of an integrated circuit MOSFET memory array device 105 constructed in accordance with the present invention. The device 105 is preferably used as an access device of a DRAM memory cell. As will be described with reference to FIGS. 3 to 7 , the device 105 including diffusion regions 130 , 132 is fabricated using two blanket phosphorous ion implant steps sandwiched around a conventional re-ox step. Since two implant steps are performed, diffusion region 130 comprises two regions 130 a , 130 b having different dopant concentrations. Similarly, diffusion region 132 comprises two regions 132 a , 132 b having different dopant concentrations. As described with reference to FIGS. 9 and 10, the uniquely formed diffusion regions 130 , 132 provide the device 105 with improved static refresh performance over the prior device 5 (illustrated in FIG. 1 ). Since the method uses two separate blanket phosphorous ion implant steps, it will be referred to hereinafter as a “double blanket ion implant method”.
Hereinafter, the terms “wafer” and “substrate” are used interchangeably and are to be understood as including silicon-on-insulator (SOI) or silicon-on-sapphire (SOS) technology, doped and undoped semiconductors, epitaxial layers of silicon supported by a base semiconductor foundation, and other semiconductor structures. Furthermore, when reference is made to a “wafer” or “substrate” in the following description, previous process steps may have been utilized to form regions or junctions in the base semiconductor structure or foundation.
In addition, no particular order is required for the method steps described below, with the exception of those logically requiring the results of prior steps, for example formation of spacers 40 , 42 adjacent to the sidewalls of the gate structure 10 logically requires the prior formation of the gate structure 10 and its sidewalls. Otherwise, enumerated steps are provided below in an exemplary order which may be altered, for instance the several ion implant steps may be rearranged using masking and etching steps as is known in the art.
FIG. 3 shows the integrated circuit MOSFET memory array device 105 in accordance with the present invention at an early stage of formation. A gate structure 100 is provided on the substrate 8 as is known in the art and described in the '449 patent to Dennison et al. The substrate 8 is typically a bulk silicon substrate, which may have a doped well in which access transistors are to be formed. The gate structure 110 comprises a gate oxide 12 , a conductive polysilicon layer 14 , an overlying WSi x layer 16 , an overlying oxide layer 18 and a Si 3 N 4 capping layer 20 . Unlike the gate structure 10 of the prior art device 5 illustrated in FIG. 1, the cross sectional length of the gate structure 110 may be substantially reduced. For example, the cross sectional length of the gate structure 110 can be substantially to approximately 0.20 microns. An advantage of the present invention is that the length of the gate structure 110 is reduced in comparison to the prior art due to the unique fabrication processing of the present invention (described below).
Referring now to FIG. 4, diffusion regions 130 a , 132 a are formed in the substrate 8 adjacent the sidewalls of the gate structure 110 and extend laterally away from the gate structure 110 . It should be noted that a portion of the diffusion regions 130 a , 132 a diffuse beneath the gate structure 110 . To create the diffusion regions 130 a , 132 a , the substrate 8 undergoes a first blanket implant step. It is desirable that an n-type be used, which makes the device 105 an NMOS device. It is desirable that the n-type dopant be phosphorous. However, it should be noted that other dopants can be used if so desired. For example, other n-type dopants such as arsenic or antimony could be used. If it were desirable for the device 105 to be a PMOS device, a p-type dopant such as boron, boron bifluoride (BF 2 ) or borane (B 2 H 10 ,) could be used. This first blanket phosphorous implant may be performed, for example, at an energy level of approximately 15 Kev with a dose of approximately 2×10 12 ions/cm 2 . It should be appreciated that any other suitable dose and energy level can be used for this step. One exemplary range for the first blanket phosphorous implant may include an energy level between approximately 5 Kev to 45 Kev with a dose of approximately 1×10 12 ions/cm 2 to slightly less than 7×10 12 ions/cm 2 .
It must be noted that this blanket phosphorous implant step is performed prior to a subsequent re-ox step since the energy level and dose is substantially lower than the dose used in the prior art (i.e., energy level ranging from 30 Kev to 60 Kev with a dose ranging from 7×10 12 ions/cm 2 to 1.5×10 13 ions/cm 2 to provide an average dopant concentration for the diffusion regions 30 , 32 ranging from 1×10 17 ions/cm 3 to 1×10 19 ions/cm 3 ). Thus, the first blanket phosphorous implant step can be performed prior to the re-ox step without having the phosphorous diffuse too far underneath the gate structure 110 and without causing subsequent transistor leakage problems.
Referring now to FIG. 5, a re-ox step is performed forming oxidized sidewalls 22 , 24 on the gate structure 110 and oxide regions 26 , 28 on the substrate 8 . It should be appreciated that any conventional re-ox process can be performed at this point, such as a thermal re-ox process or a source/drain thermal re-ox process. Referring to FIG. 6, diffusion regions 130 b , 132 b are formed in the substrate 8 at the same location as diffusion regions 130 a , 132 b . To create the second diffusion regions 130 b , 132 b , the substrate 8 undergoes a second blanket implant step. As with the first blanket implant step, it is desirable that the dopant used is phosphorous. However, it should be noted that other dopants can be used if so desired, particularly if a different conductivity type of the device 105 is desired. This second blanket phosphorous implant may be performed at an energy level of approximately 20 Kev with a dose of approximately 4×10 12 ions/cm 2 . It should be appreciated that any other suitable dose and energy level can be used for this step. One exemplary range for the second blanket phosphorous implant may include an energy level between approximately 5 Kev to 60 Kev with a dose of approximately 1×10 12 ions/cm 2 to 1×10 13 ions/cm 2 .
The oxidized sidewalls 22 , 24 on the gate structure 110 prevent the second implant from diffusing underneath the gate structure 110 , which helps in the formation of the individual diffusion regions 130 a , 130 b , 132 a , 132 b . The two diffusion regions 130 a , 130 b combine to form one diffusion region 130 . The resultant diffusion region 130 will have two different dopant concentrations, one from region 130 a and one from region 130 b . There will be a smooth transition between the dopant concentrations of the two regions 130 a , 130 b . Similarly, the two diffusion regions 132 a , 132 b combine to form one diffusion region 132 . The resultant diffusion region 132 will have two different dopant concentrations, one from region 132 a and one from region 132 b . There will be a smooth transition between the dopant concentrations of the two regions 132 a , 132 b . As will be discussed below, these uniquely formed diffusion regions 130 , 132 allow the device 105 to have substantially better static refresh performance in comparison to the prior art device 5 (FIG. 1 ).
Referring to FIG. 7, oxide or nitride sidewall spacers 40 , 42 may be formed on the on the sidewalls of the gate structure 110 (as described in the '449 patent or by any other known method). In addition, further processing may be performed to form a memory cell as described in the '449 patent. It can be seen that the device 105 has two diffusion regions 130 , 132 , each having a pair of diffusion regions 130 a , 130 b , 132 a , 132 b , respectively.
FIG. 8 illustrates an exemplary phosphorous concentration 150 of the second diffusion region 132 with respect to its length (illustrated by arrow X). It should be noted that the first diffusion region 130 would have a similar concentration, but in a direction opposite the direction indicated by arrow X. An exemplary phosphorous concentration 152 of the prior art device is also illustrated. From the curves 150 , 152 it can be seen how the second diffusion region 132 has a more graded concentration of phosphorous than the prior art diffusion regions (e.g., region 32 in FIG. 1 ). By more graded, we mean that the net doping concentration versus distance changes gradually. By contrast, as shown by curve 152 , the diffusion region 32 (FIG. 1) of the prior art device has an abrupt change in concentration of phosphorous versus distance. That is, the net doping concentration of the prior art curve 152 undergoes a steep change with respect to distance. With a graded dopant concentration of the diffusion regions, the resistance to current flow is less than the diffusion regions of the prior art. Although the invention is not to be bound to any specific theory, it is believed that the more graded concentration of the present invention improves the static refresh of the device 105 by improving the junction at the storage node of the DRAM memory cell.
Referring again to FIG. 7, it can be seen that the two diffusion regions 130 , 132 slightly diffuse below the gate structure 110 . That is, there is a first region 140 of the first diffusion region 130 that resides underneath a portion of the gate structure 110 . Similarly, there is a second region 142 of the second diffusion region 132 that resides underneath a portion of the gate structure 110 . These regions 140 , 142 , which can be referred to as “overlap” regions, make the device 105 more robust to reliability stressing. That is, the overlap regions 140 , 142 are less likely to degrade when high voltage is applied to the device, such as the types of voltages applied during manufacturing stress testing. These regions 140 , 142 , which are not present in the prior art device 5 (FIG. 1 ), are formed by the first blanket phosphorous implant step (FIG. 4 ). That is, by having the first blanket phosphorous implant step (FIG. 4) prior to the re-ox step (FIG. 5) some dopant can diffuse underneath the gate structure 110 forming region 140 , 142 and causing the device 105 to have the above-mentioned robustness. This is another benefit of the present invention.
A standard measure of refresh performance is known as a “time to unrepairable calculation”. The term “repair” is sometimes used to indicate that a memory cell or memory bit has been repaired by electrical replacement with a redundant element. The terms “un repaired” or “un-repairable” are often used to indicate that the number of failing bits exceeds the capability of repair by redundant elements. In the time to un-repairable test, data is written into the bits of memory cells in the DRAM array. Measurements are taken to determine when a predetermined number of bits have lost their charge and within what time. The time it takes for the bits to lose their charge is commonly referred to as the “time to un-repairable” (TTUR).
Referring now to FIGS. 1, 2 and 9 . The inventors ran experiments to compare TTUR results using the prior art device 5 (FIG. 1) with the results using the device 105 (FIG. 2) constructed in accordance with the present invention. FIG. 9 illustrates results from TTUR tests based on finding 100 bits that have lost their charge. The y-axis indicates the probability that 100 bits have lost their charge. The x-axis indicates the time when the charge was lost (and when a refresh operation became necessary). The first set of data 160 illustrates the results using the device 105 of the present invention. The second set of data 162 illustrates the results using the device 5 of the prior art. From the data 160 , 162 , it can be seen that 100 bits lost their charge (with 50% probability, i.e., 0.5 on the y-axis) using the prior art device 5 at approximately 120 milliseconds, while 100 bits lost their charge using the device 105 at approximately 210 milliseconds. That is, there is almost a 90 millisecond improvement in the device 105 constructed in accordance with the present invention. It is believed that this improvement is due to the uniquely formed diffusion regions 130 , 132 of the device 105 .
Referring now to FIGS. 1, 2 and 10 . FIG. 10 illustrates results from TTUR tests based on finding 200 bits that have lost their charge. The y-axis indicates the probability that 200 bits have lost their charge. The x-axis indicates the time when the charge was lost (and when a refresh operation became necessary). The first set of data 170 illustrates the results using the device 105 while the second set of data 172 illustrates the results using the device 5 . From the data 170 , 172 , it can be seen that 200 bits lost their charge (with 50% probability, i.e., 0.5 on the y-axis) using the prior art device at approximately 240 milliseconds, while 200 bits lost their charge using the device 105 at approximately 310 milliseconds. That is, there is almost a 70 millisecond improvement.
FIG. 11 illustrates a block diagram of a processor based system 200 utilizing a DRAM memory circuit 208 constructed in accordance with the present invention. That is, the memory circuit 208 utilizes the MOSFET memory array device 105 (FIG. 2) constructed in accordance with the present invention (FIGS. 3 to 7 ). The processor-based system 200 may be a computer system, a process control system or any other system employing a processor and associated memory. The system 200 includes a central processing unit (CPU) 202 , e.g., a microprocessor, that communicates with the DRAM memory circuit 208 and an I/O device 204 over a bus 220 . It must be noted that the bus 220 may be a series of buses and bridges commonly used in a processor-based system, but for convenience purposes only, the bus 220 has been illustrated as a single bus. A second I/O device 206 is illustrated, but is not necessary to practice the invention. The processor-based system 200 also includes a read-only memory (ROM) circuit 210 and may include peripheral devices such as a floppy disk drive 212 and a compact disk (CD) ROM drive 214 that also communicates with the CPU 202 over the bus 220 as is well known in the art. It should be noted that the CPU 202 can be combined on a single chip with one or more DRAM memory circuits 208 and ROM circuits 210 .
While the invention has been described in detail in connection with the preferred embodiments known at the time, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims. | A double blanket ion implant method for forming diffusion regions in memory array devices, such as a MOSFET access device is disclosed. The method provides a semiconductor substrate with a gate structure formed on its surface. Next, a first pair of diffusion regions are formed in a region adjacent to the channel region by a first blanket ion implantation process. The first blanket ion implantation process has a first energy level and dose. The device is subjected to oxidizing conditions, which form oxidized sidewalls on the gate structure. A second blanket ion implantation process is conducted at the same location as the first ion implantation process adding additional dopant to the diffusion regions. The second blanket ion implantation process has a second energy level and dose. The resultant diffusion regions provide the device with improved static refresh performance over prior art devices. In addition, the first and second energy levels and doses are substantially lower than an energy level and dose used in a prior art single implantation process. | 7 |
TECHNICAL FIELD
[0001] The present invention relates to an airbag module for a vehicle occupant restraint system, comprising an airbag and a gas generator that is connected via at least one first outflow opening to an airbag chamber that is at least partially formed by the interior of the airbag.
[0002] Moreover, the invention relates to a method of restraining a vehicle occupant with such an airbag module.
BACKGROUND OF THE INVENTION
[0003] In the early days of the development of vehicle occupant restraint systems using airbags, the main focus was initially to recognize a restraint situation reliably and quickly as well as to cause the airbag to be filled rapidly in order to protect a vehicle occupant. Starting from those basic requirements, the demands made of modern vehicle occupant restraint systems have increased dramatically since that time. Additional requirements that have come to the fore are, for example, that the response of the restraint system be adapted to the restraint position of the vehicle occupant and to the anticipated impact momentum of the vehicle occupant.
[0004] The state of the art describes numerous attempts to meet these ever-higher demands. Thus, for example, U.S. patent application 2004/0012180 A1 describes a vehicle occupant restraint system that can release an additional airbag volume as a function of the situation and, at the same time, can close an opening in the module housing. The basic idea here is to be able to use an inexpensive, one-stage gas generator that is configured for the optimal filling of the maximum airbag volume. In order to achieve approximately the same airbag hardness for the smaller airbag volume, excess gas is vented through an opening in the module housing. Depending on the embodiment, the opening or the closing of airbag openings can be coupled to the release of the larger airbag volume.
[0005] The object of the present invention is to create an airbag module with simple means that responds as specifically as possible to changes in individual parameters of a restraint situation such as, for example, the vehicle occupant position or the anticipated impact momentum of the vehicle occupant.
BRIEF SUMMARY OF THE INVENTION
[0006] This is achieved in an airbag module for a vehicle occupant restraint system including an airbag and a gas generator that is connected via at least one first outflow opening to an airbag chamber, the airbag chamber being at least partially formed by the interior of the airbag, an actuator unit being provided on the gas generator and, when the actuator unit is activated, it releases a traction means that causes a pressure reduction in the airbag, an activation of the actuator unit also leading to an opening of a second outflow opening in the gas generator, which vents generator gas to an environment without this vented gas flowing into the airbag chamber.
[0007] The term airbag chamber is used within the scope of this invention to refer to the space that essentially reaches airbag internal pressure when the airbag is deployed. As a rule, this space comprises the airbag interior and, depending on the attachment site of an airbag orifice, possibly also comprises sections of the housing of a module.
[0008] The second outflow opening is provided directly in the gas generator and, in general, has a relatively small outflow cross section. Therefore, a gas mass flow with a decisive effect on the airbag deployment and airbag hardness can only be vented at high pressure via the second outflow opening. Corresponding pressures of up to 150 bar (or even more, depending on the design of the gas generator) prevail in the gas generator directly after its activation. In contrast, the traction means that causes a pressure reduction in the airbag is only especially effective once a certain internal pressure has built up in the entire airbag chamber, especially in the interior of the airbag, that is to say, precisely not at the beginning of the deployment phase of the airbag. Consequently, in an inexpensive and advantageous manner, only one actuator unit has to be provided that releases the traction means as well as the second outflow opening although, depending on the point in time of the release, the effect of the traction means compared with the effect of the second outflow opening is negligible and vice versa. Consequently, a single actuator unit can respond to two independent cases such as, for example, the restraint position of the vehicle occupant and the weight of the vehicle occupant, largely independently of each other.
[0009] In one embodiment, when the actuator unit is activated, the traction means opens at least one airbag opening and/or releases an enlarged airbag volume. Both of these measures are very simple and effective ways to reduce the pressure in the airbag.
[0010] Preferably, the actuator unit has a pyrotechnical device. Pyrotechnically driven actuators are relatively inexpensive and have a fast response or activation time.
[0011] Together with the actuator unit, the gas generator can form a cylinder/piston unit, the piston being moved by the activation of the actuator unit, thus opening the second outflow opening. This cylinder/piston unit is a very reliable device and merely has to be slid in order to open the outflow openings. No closure devices have to be destroyed, as a result of which no free membrane fragments or the like are created that could enter the airbag and damage it.
[0012] In this embodiment, the piston preferably has an opening, the gas vented through the second outflow opening flowing through that opening. The cross section of this opening can serve to define the ratio of the pressures present on both sides of the piston above which ratio the piston moves. Moreover, the opening in the piston, together with the second outflow opening, defines the outflow cross section and thus the mass flow of gas that can be vented through the second outflow opening.
[0013] In a preferred embodiment, the vented gas exits the airbag module when it flows through the second outflow opening. Due to this direct outflow of the excess gas into the environment, an especially effective and fast pressure relief is achieved inside the airbag chamber. This significant reduction of the internal pressure in the airbag is especially necessary for vehicle occupants who are positioned relatively close to the airbag module.
[0014] In another embodiment, the gas generator has a separate base section and a distribution section that are securely and preferably directly connected to each other, the actuator unit being attached to the distribution section. This offers the advantage that decisive gas generator components such as the base section, can remain unchanged and only secondary components such as the distribution section have to be modified in order to receive the actuator unit.
[0015] Moreover, at least one airbag opening can be provided, the ratio of the outflow cross section of all of the second outflow openings to the outflow cross section of all of the airbag openings being between 1:2 and 1:8, preferably between 1:3 and 1:5. At these ratios, the timing of the effects caused by the second outflow opening and by the airbag opening are uncoupled from each other especially well.
[0016] The invention also provides a method of restraining a vehicle occupant, the method having the following steps:
[0017] a) activation of a gas generator of a vehicle occupant restraint system in case of a restraint event, whereupon the gas generator feeds gas into an airbag chamber via at least one first outflow opening;
[0018] b) checking the vehicle occupant position on the basis of sensor data at a prescribed first point in time;
[0019] c) activation of an actuator unit if the vehicle occupant is in a position that is unsuitable for a restraint, as a result of which a second outflow opening as well as a traction means are released and a pressure reduction takes place decisively as a result of venting gas into the environment through the second outflow opening;
[0020] d) assessment of an impact momentum of the vehicle occupant against the airbag based on sensor data at a prescribed second point in time;
[0021] e) activation of the actuator unit if the actuator unit was not yet activated in Step c) and if the anticipated impact momentum of the vehicle occupant lies below a predefined limit value, as a result of which the second outflow opening and the traction means are released and a pressure reduction in the airbag takes place decisively as a result of releasing the traction means. This method offers the advantage that only one actuator unit is needed to be able to respond to two different restraint parameters largely independently of each other. A significant aspect here is the point in time of the activation of the actuator unit, the configuration of the traction means and of the second outflow opening as well as the way in which they are coordinated with each other.
[0022] It is especially advantageous for the restraint of the vehicle occupant for the first point in time to be between 0 ms and 15 ms and for the second point in time to be between 25 ms and 40 ms after the restraint case has been recognized.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 shows a longitudinal section through the gas generator of an airbag module according to the invention, the actuator unit not having been activated;
[0024] FIG. 2 shows a longitudinal section through the gas generator of FIG. 1 , the actuator unit having been activated;
[0025] FIG. 3 shows the schematic representation of an airbag module according to the invention in a first embodiment;
[0026] FIG. 4 shows the schematic representation of an airbag module according to the invention in a second embodiment; and
[0027] FIG. 5 shows a flowchart relating to a preferred method variant according to the invention for restraining a vehicle occupant.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] FIG. 1 shows an airbag module having a gas generator 10 consisting essentially of a base section 12 and a distribution section 14 , the base section 12 being a pressure chamber section and/or a combustion chamber section. In the embodiment depicted, which is a hybrid gas generator, the base section 12 is closed by a membrane 15 . It is immaterial, however, whether the generator gas is already present in the form of compressed gas, whether it is generated as combustion gas or whether it exits from the base section 12 as mixed gas. The only important aspect is that the base section 12 has to have an activation means 16 and has to be able to establish a flow connection with the distribution section 14 in order to feed generator gas into the distribution section 14 . In the example shown, this is done by destroying the membrane 15 in response to the activation of the activation means 16 . It is especially preferred for all of the generator gas to be fed into the distribution section 14 and to be distributed there.
[0029] In the embodiment according to FIG. 1 , the distribution section 14 is placed as a separate part onto the base section 12 . The two sections 12 , 14 , however, are securely and permanently connected directly to each other, for example, by means of welding, screwing or press forming so that they form a preassembled unit. In other embodiments, the distribution section 14 is formed integrally with the base section 12 . In the present example, the gas generator 10 is configured as a tubular gas generator, the base section 12 and the distribution section 14 having a shared axis A.
[0030] A circumferential wall 17 of the distribution section 14 has first outflow openings 18 and second outflow openings 20 in a radial direction, the first outflow openings 18 being situated axially closer to the base section 12 than the second outflow openings 20 . The first and second outflow openings 18 , 20 are preferably distributed along the circumference of the distribution section 14 in such a way that the generator gas is dissipated in a shear-neutral manner when it flows through the first and/or second outflow openings 18 , 20 .
[0031] An airbag 22 is attached by its airbag orifice 24 to the circumferential wall 17 of the distribution section 14 in the axial direction between the first outflow openings 18 and the second outflow openings 20 so that generator gas that is flowing through the first outflow openings 18 is released into an airbag chamber 28 that starts outside of the gas generator 10 , and generator gas that is flowing through the second outflow openings 20 is dissipated into the environment outside of the airbag chamber 28 .
[0032] At one axial end of the gas generator 10 , the distribution section 14 has a face wall 30 with an axial projection 34 facing outwards, a centered opening 32 being provided in the face wall 30 and in the projection 34 . An actuator unit 36 , including a piston 38 running inside the distribution section 14 and a pyrotechnical device 40 , extends through the opening 32 . The pyrotechnical device 40 is, for example, an igniter or a detonator. The pyrotechnical device 40 extends from outside of the gas generator 10 into the opening 32 and is securely and tightly connected to the axial projection 34 , for example, welded. The axially movable piston 38 has a circumferential piston wall 42 that makes a transition into a base plate 44 having an axial piston projection 46 . The piston projection 46 likewise extends into the opening 32 so that it is adjacent to the pyrotechnical device 40 , forming a virtually gas-tight pressure chamber 47 with the pyrotechnical device 40 . Moreover, a hook-shaped holder 48 is formed integrally with the piston projection 46 , the holder 48 extending outwards through the opening 32 and through the pyrotechnical device 40 .
[0033] In an initial position according to FIG. 1 , the second outflow openings 20 are closed by the piston 38 , or to put it more precisely, by the piston wall 42 . The base plate 44 of the piston 38 has openings 52 and, in the initial position, the base plate 44 lies against the face wall 30 of the distribution section 14 so that the openings 52 are likewise closed.
[0034] Outside of the gas generator 10 , the hook-shaped holder 48 engages with the pyrotechnical device 40 , thereby affixing a traction means 50 . The traction means 50 is preferably a cable or a fabric strip so that it can easily be affixed to the holder 48 by means of a loop or a recess.
[0035] FIG. 2 shows the section according to FIG. 1 , but now after an activation of the actuator unit 36 . As a result of this activation, such a high pressure builds up in the pressure chamber 47 that the piston 38 is moved in the direction of the base section 12 . Due to this movement, the openings 52 in the base plate 44 move away from the face wall 30 . Furthermore, the piston wall 42 slides along the circumferential wall 26 of the distribution section 14 and releases the second outflow openings 20 . In this activation position, generator gas can flow through the first outflow openings 18 into the airbag chamber 28 as well as through the openings 52 and through the second outflow openings 20 to outside of the airbag chamber 28 .
[0036] As a rule, the actuator unit 36 is activated after the activation of the gas generator 10 so that a certain pressure already prevails in the distribution section 14 . The actuator unit 36 has to be configured in such a way that it can move the piston 38 against this pressure. Here, the requisite force can be influenced by the size of the openings 52 . Before the piston wall 42 reaches the first outflow openings 18 , the circumferential wall 26 of the distribution section 14 tapers slightly so that the movement of the piston 38 is stopped. Before the piston 38 reaches the tapered section, the axial piston projection 46 emerges from the opening 32 of the face wall 30 so that an equalization takes place between the pressure in the distribution section 14 and the pressure in the pressure chamber 47 . In order to prevent the piston 38 from being forced back in the direction of the pyrotechnical device 40 due to the outflowing generator gas after the piston 38 has moved in the direction of the base section 12 , a stop has to be provided so that the second outflow openings 20 continuously remain open.
[0037] For example, the piston projection 46 can be slightly pre-tensioned outwards relative to the axial projection 34 of the face wall 30 in the radial direction so that it widens slightly and latches outwards after emerging from the opening 32 . Due to this widening, the piston projection 46 can no longer move back into the opening 32 of the face wall 30 but rather strikes one edge of the opening. As an alternative, a spring-loaded pin 53 (indicated by means of a broken line) can also be provided in the face wall 30 . When the piston 38 moves, this pin 53 slides on the piston projection 46 until the latter emerges from the opening 32 and the pin 53 then snaps in the direction of the axis A. The pin 53 then constitutes a stop for the piston 38 and prevents the second outflow openings 20 from closing again.
[0038] The hook-shaped holder 48 also moves when the piston 38 moves from the initial position according to FIG. 1 into the activation position according to FIG. 2 . The pyrotechnical device 40 and the holder 48 are no longer engaged, as a result of which the traction means 50 is released (see FIG. 2 ).
[0039] FIGS. 3 and 4 are schematic depictions of examples of possible variants of the traction means.
[0040] FIG. 3 shows the airbag module in its initial position, the traction means 50 preferably being a wide fabric strip that covers an airbag opening 54 , that is to say, closes it. One end of the traction means 50 is permanently attached, preferably sewn, to the airbag 22 on the outside.
[0041] When the actuator unit 36 is activated and the piston 38 subsequently moves, an opposite end of the traction means 50 and thus the airbag opening 54 are released in order to reduce the pressure in the airbag 22 . The airbag opening 54 is provided in the movable part of the airbag 22 , that is to say, outside of a module housing (not shown here). Consequently, it only achieves its full effect once the airbag 22 is already in an advanced stage of its deployment.
[0042] A second variant of the pressure reduction in the airbag 22 is shown in FIG. 4 . Once again, the airbag module is shown in its initial position, in this case, the airbag 22 being prevented from deploying completely by the traction means 50 . Here, the traction means 50 consists of two traction cables or traction strips, one respective end of which is attached to an airbag wall facing the vehicle occupant. The respective opposite ends of the two traction cables or traction strips are affixed onto the gas generator 10 by means of the holder 48 .
[0043] After the activation of the actuator unit 36 and the resultant release of the traction means 50 , the airbag 22 can occupy a larger volume, as a result of which the internal pressure in the airbag chamber 28 is reduced, which makes the airbag 22 softer.
[0044] In other embodiments, the traction means variants according to FIGS. 3 and 4 are combined.
[0045] FIG. 5 shows the sequence of a preferred method variant for the restraint of a vehicle occupant.
[0046] First of all, at a point in time 0 , a restraint case is detected and the gas generator 10 is activated. As a rule, one or more suitable sensors are provided on or in the vehicle in order to detect the restraint case. At this point in time, the second outflow openings 20 are closed and the traction means 50 has not been released. This corresponds to the situation shown in FIG. 1 .
[0047] After 0 to 15 ms, a first sensor detection determines the position of the vehicle occupant. If the sensor system ascertains an unsatisfactory restraint position of the vehicle occupant or if such a position is stored (e.g. if the vehicle occupant is monitored before the collision), then the actuator unit 36 is activated. This means that the second outflow openings 20 as well as the traction means 50 (secondary in terms of its effect) are released. At such an early point in time, the airbag 22 is hardly or not at all unfolded, although a high pressure is already present in the gas generator 10 . This is why the venting of the gas through the second outflow openings 20 in the gas generator 10 is decisive for the inflation behavior. Even at relatively small cross sections (diameter <5 mm), a gas mass flow of 30% to 50% of the total generator gas that is present can be branched off through the second outflow openings 20 . Before this backdrop, the further pressure reduction that occurs after a certain unfolding due to the release of the traction means 50 is negligible and possibly even desirable.
[0048] If the vehicle occupant is in a good restraint position, then the actuator unit 36 does not respond at first and a second sensor detection is carried out after 25 to 40 ms. During this sensor detection, an anticipated impact momentum of the vehicle occupant onto the airbag is compared to a predefined, empirically determined limit value. The anticipated impact momentum is determined on the basis of the decisive sensor data such as the weight of the vehicle occupant, sitting position and/or deceleration values (as indicators of the severity of the collision). Here, of course, it is also possible that the data for determining the impact momentum or even the impact momentum itself is already present or was determined ahead of time.
[0049] If the anticipated impact momentum lies above the predefined limit value, which is often the case especially with excessively heavy vehicle occupants, then the actuator unit 36 does not respond and the airbag 22 reaches its maximum restraint capability. This is also the case in the embodiments in which the airbag 22 then does not reach its maximum restraint volume ( FIG. 4 ), since the airbag is very hard.
[0050] If the anticipated impact momentum lies below the predefined limit value, then the actuator unit 36 is activated. This means that the traction means 50 as well as the second outflow openings 20 (secondary in terms of their effect) are released. At this relatively late point in time, the airbag 22 is already largely unfolded. The pressure in the gas generator 10 and in the airbag chamber 28 has already equalized and is relatively low (approximately 0.5 bar above atmospheric pressure). Therefore, in this case, no appreciable pressure reduction due to the small second outflow openings 20 in the gas generator 10 is to be expected. At this point in time, the traction means is decisive, either releasing an airbag opening and/or an enlarged airbag volume.
[0051] In the embodiment with an airbag opening 54 , the ratio of the outflow cross section of all of the second outflow openings 20 to the outflow cross section of all of the airbag openings 54 lies between 1:2 and 1:8, preferably between 1:3 and 1:5. Hence, up to the time of a vehicle occupant impact, a gas mass flow in the order of magnitude of about 10% of the total generator gas can be dissipated. This increases especially the restraint comfort for lightweight vehicle occupants or at low vehicle speeds. An equivalent effect can be provided by the variant in which an additional airbag volume is made available by releasing the traction means 50 . This additional airbag volume likewise corresponds to about 10% of the original airbag volume. | An airbag module for a vehicle occupant restraint system includes an airbag ( 22 ) and a gas generator ( 10 ) that is connected via at least one first outflow opening ( 18 ) to an airbag chamber ( 28 ), the airbag chamber ( 28 ) being at least partially formed by the interior of the airbag ( 22 ), an actuator unit ( 36 ) being provided on the gas generator ( 10 ) and, when the actuator unit ( 36 ) is activated, it releases a traction means ( 50 ) that causes a pressure reduction in the airbag ( 22 ), an activation of the actuator unit ( 36 ) also leading to an opening of a second outflow opening ( 20 ) in the gas generator ( 10 ), which vents generator gas to an environment without this vented gas flowing into the airbag chamber ( 28 ). Moreover, the invention relates to a method of restraining a vehicle occupant with such an airbag module. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Applications Ser. Nos. 61/545,253 and 61/545,262, both filed Oct. 10, 2011, which provisional applications are incorporated herein by reference.
TECHNICAL FIELD
[0002] This disclosure relates to scintillator materials used for detecting ionizing radiation, such as X-rays, gamma rays and thermal neutron radiation, in security, medical imaging, particle physics and other applications. This disclosure relates particularly to metal halide scintillator materials. Certain arrangements also relate to specific compositions of such scintillator material, method of making the same and devices with such scintillator materials as components.
BACKGROUND
[0003] Scintillator materials, which emit light pulses in response to impinging radiation, such as X-rays, gamma rays and thermal neutron radiation, are used in detectors that have a wide range of applications in medical imaging, particle physics, geological exploration, security and other related areas. Considerations in selecting scintillator materials typically include, but are not limited to, luminosity, decay time, emission wavelengths, and stability of the scintillation material in the intended environment.
[0004] While a variety of scintillator materials have been made, there is a continuous need for superior scintillator materials.
SUMMARY OF THE DISCLOSURE
[0005] The present disclosure relates generally to metal halide scintillator materials and method of making such scintillator materials. In one arrangement, a scintillator material comprises a metal halide with one or more additional group-13 elements. An example of such a compound is Ce:LaBr 3 with thallium (Tl) added, either as a codopant or in a stoichiometric admixture and/or solid solution between LaBr 3 and TlBr.
[0006] A further aspect of the present disclosure relates to a method of making chloride scintillator materials of the above-mentioned compositions. In one example, high-purity starting halides (such as LaBr 3 , TlBr and CeBr 3 ) are mixed and melted to synthesize a compound of the desired composition of the scintillator material. A single crystal of the scintillator material is then grown from the synthesized compound by the Bridgman method (or Vertical Gradient Freeze (VGF) method), in which a sealed ampoule containing the synthesized compound is transported from a hot zone to a cold zone through a controlled temperature gradient at a controlled speed to form a single-crystalline scintillator from molten synthesized compound.
[0007] Another aspect of the present disclosure relates to a method of using a detector comprising one of the scintillation materials described above for imaging.
DETAILED DESCRIPTION
[0008] Metal halides are scintillation compositions commonly known from their good energy resolution and relatively high light output. One significant disadvantage of these materials, however, is their high solubility in water. This high solubility, or hygroscopicity is one of the main reasons that slow down the process of commercialization of these compounds. Crystal growth processes, following a multistage purification, zone refining and drying all require very well controlled atmosphere with depleted content of water and oxygen. Moreover, handling and post-growth processing of these materials typically must be performed in an ultra-dry environment to avoid degradation of the materials. Additionally, these materials typically can be used only in hermetically sealed packaging that prevents materials from degradation due to the hydration effects. Such stringent conditions for making and using metal halide scintillation materials present a significant barrier to commercial application of these materials. Therefore, it is highly desirable to improve or develop new scintillator materials with significantly lower hygroscopicity.
[0009] This disclosure relates to new compositions of metal halide scintillator substance, in particular rear earth metal halides scintillator materials, for gamma and neutron detection with reduced hygroscopicity. The disclosure includes, but is not being limited to, the following families of metal halides compositions described by general chemical formulas:
[0000] A′ (1-x) B′ x Ca (1-y) Eu y C′ 3 (1),
[0000] A′ 3(1-x) B′ 3x M′Br 6(1-y) Cl 6y (2),
[0000] A′ (1-x) B′ x M′ 2 Br 7(1-y) Cl 7y (3),
[0000] A′ (1-x) B′ x M″ 1-y Eu y I 3 (4),
[0000] A′ 3(1-x) B′ 3x M″ 1-y Eu y I 5 (5),
[0000] A′ (1-x) B′ x M″ 2(1-y) Eu 2y I 5 (6),
[0000] A′ 3(1-x) B′ 3x M′Cl 6 (7),
[0000] A′ (1-x) B′ x M′ 2 Cl 7 (8), and
[0000] M′ (1-x) B′ x C′ 3 (9),
[0000] where:
A′=Li, Na, K, Rb, Cs or any combination thereof, B′=B, Al, Ga, In, Tl or any combination thereof, C′=Cl, Br, I or any combination thereof, M′ consist of Ce, Sc, V, La, Lu, Gd, Pr, Tb, Yb, Nd or any combination of them, M″ consists of Sr, Ca, Ba or any combination of thereof, x is included within the range: 0≦x≦1, and y is included within the range: 0≦y≦1.
[0017] The physical forms of the scintillator substance include, but are not limited to, crystal, polycrystalline, ceramic, powder or any of composite forms of the material.
[0018] A reduction in the hygroscopicity is achieved by co-doping and/or changes in the stoichiometry of a scintillator substance. These changes may be achieved by stoichiometric admixture and/or solid solution of compounds containing elements from group-13 periodic table. These elements are: B, Al, Ga, In, Tl and any combinations of them.
[0019] One way of the implementation of this innovation is a codoping with group-13 of elements in concentrations that does not alternate significantly the symmetry of the crystal lattice of the scintillator of choice. Another way includes a complete modification of the crystal structure of the scintillator composition by stoichiometric change or solid solution of scintillator compounds and other compounds containing at least one of group-13 elements. In these cases, new scintillator materials are created with significantly reduced hygroscopicity.
[0020] In a particular, non-limiting, example, thallium (Tl) is introduced into the crystallographic lattice of LaBr 3 compound (formula 9). In this specific example, a strong Tl—Br covalent bond (as opposed to ionic bond in LaBr 3 ) is created that significantly reduces the reactivity of the compound with water.
[0021] In the higher concentration of Tl it is possible to create scintillator materials with altered crystallographic lattice. That includes also a stoichiometry change in the crystal itself. The strength of Tl—Br bond is demonstrated in TlBr compound that is known from significantly lower hygroscopicity in comparison to the other metal halides. The expected changes in solubility can be explained based on the HSAB concept, explained in more detail below.
[0022] Moreover, introduction of the elements from group-13 into the crystal structure of metal halides often improves scintillation characteristics of these materials. Addition of Tl as a codopant or stoichiometric admixture to certain compositions of metal halides creates very efficient scintillation centers. These centers contribute to the scintillation light output.
[0023] In addition, using compounds of group-13 elements can favorably increase the density of the material. Improvement in the density is particularly important in radiation detection applications. The new scintillator materials have applications in Positron Emission Tomography (PET), Single Photon Emission Computed Tomography (SPECT), Computerized Tomography (CT), and other applications used in homeland security and well logging industry.
[0024] This disclosure also relates to the method of growing scintillator that includes crystallization of the melted or dissolved scintillator compounds under controlled environment.
[0025] The changes in solubility of new metal halides scintillators disclosed herein may be understood based on HSAB concept.
[0026] The HSAB is an acronym for “Hard and Soft Acids and Bases” known also, as the Pearson acid-base concept. This concept attempts to unify inorganic and organic reaction chemistry and can be used to explain in qualitative rather than quantitative way the stability of compounds, reaction mechanisms and pathways. The concept assigns the terms ‘hard’ or ‘soft’, and ‘acid’ or ‘base’ to variety of chemical species. ‘Hard’ applies to species which are small based on their Ionic radii, have high charge states (the charge criterion applies mainly to acids, to a lesser extent to bases), and are weakly polarizable. ‘Soft’ applies to species which are big, have low charge states and are strongly polarizable. Polarizable species can form covalent bonds, whereas non-polarizable form ionic bonds. See, for example, (1) Jolly, W. L., Modern Inorganic Chemistry, New York: McGraw-Hill (1984); and (2) E.-C. Koch, Acid-Base Interactions in Energetic Materials: I. The Hard and Soft Acids and Bases (HSAB) Principle-Insights to Reactivity and Sensitivity of Energetic Materials, Prop., Expl., Pyrotech. 30 2005, 5. Both of the references are incorporated herein by reference.
[0027] In the context of this disclosure the HSAB theory helps in understanding the predominant factors which drive chemical properties and reactions. In this case, the qualitative factor is solubility in water. On the one hand, water is a hard acid and hard base combination, so it is compatible with hard acid and bases. Thallium bromide is, on another hand, a soft acid and soft base combination, so it is not soluble in water.
[0028] According to the HSAB theory, soft acids react faster and form stronger bonds with soft bases, whereas hard acids react faster and form stronger bonds with hard bases, all other factors being equal.
[0029] Hard acids and hard bases tend to have the following characteristics:
small atomic/ionic radius high oxidation state low polarlzabllity high electronegativity (bases)
[0034] Examples of hard acids include: H + , light alkali ions (for example, Li through K all have small ionic radius), Ti 4+ , Cr 3+ , Cr6+ , BF 3 . Examples of hard bases are: OH − , F − , Cl − , NH 3 , CH 3 COO − and CO 3 2− . The affinity of hard acids and hard bases for each other is mainly ionic in nature.
[0035] Soft acids and soft bases tend to have the following characteristics:
large atomic/ionic radius low or zero oxidation state high polarizability low electronegativity
[0040] Examples of soft acids are: CH 3 Hg + , Pt 2+ , Pd 2+ , Ag + , Au + , Hg 2+ , Hg 2 2+ , Cd 2+ , BH 3 and group-13 in +1 oxidation state. Examples of soft bases include: H − , R 3 P, SCN − and I − . The affinity of soft acids and bases for each other is mainly covalent in nature.
[0041] There are also borderline cases identified as borderline acids for example: trimethylborane, sulfur dioxide and ferrous Fe 2+ , cobalt Co 2+ , cesium Cs + and lead Pb 2+ cations, and borderline bases such as bromine, nitrate and sulfate anions.
[0042] Generally speaking, acids and bases interact and the most stable interactions are hard-hard (ionogenic character) and soft-soft (covalent character).
[0043] In the specific case presented as an example compounds such as LaBr 3 and TlBr have the following elements to consider following reaction with water: La +3 , Br − , Tl + , H + , OH − .
La +3 : This is a strong acid. High positive charge (+3) small ionic radius. Br − : This is a soft base. Large ionic radius small charge (−1). Tl + : This is a soft acid. Low charge and large ionic radius. H + : This is a hard acid. Low ionic radius and high charge density. OH − : This is a hard base. Low charge, small ionic radius.
[0049] Thus the reaction of LaBr 3 and water takes place in according to the following scheme:
[0000] [La +3 , Br − ]+[H + , OH − ]→[La +3 , OH − ]+[H + , Br].
[0050] The left hand side of the equation has two components that are being mixed. The right hand side represents products after mixing. One can see that the strong acid La +3 with the strong base OH − , are joined together because it makes a strong acid and base combination. The Br − is driven from the La +3 and thus it is complexed with H + , forming hydrobromic acid.
[0051] The reaction of TlBr with water following the scheme:
[0000] [Tl + , Br − ]+[H + , OH − ]→[Tl + , Br − ]+[H + , OH − ].
[0052] In this case, Tl + and Br − are favored because they are a combination of soft-soft acid and base. While the H + and OH − are hard acid and base combination. The TlBr is a covalent compound and will dissolve in covalent solvents.
[0053] Therefore, in the case of LaBr 3 , the hard acid La +3 “seeks” out OH − , resulting in a high reactivity in water. In contrast, TlBr (soft-soft) does not “seek” water (and vice versa). The result is a low degree of interaction, including solubility with water.
[0054] In the examples given above in this disclosure, the addition of TlBr as a co-dopant or in stoichiometric amounts reduces the hygroscopicity of the LaBr 3 .
[0055] A further aspect of the present disclosure relates to a method of making scintillator materials of the above-mentioned compositions. In one example, high-purity starting compounds (such as LaBr 3 and TlBr) are mixed and melted to synthesize a compound of the desired composition of the scintillator material. A single crystal of the scintillator material is then grown from the synthesized compound by the Bridgman method (or Vertical Gradient Freeze (VGF) method), in which a sealed ampoule containing the synthesized compound is transported from a hot zone to a cold zone through a controlled temperature gradient at a controlled speed to form a single-crystalline scintillator from molten synthesized compound.
[0056] Thus, metal halide scintillation materials with improved moisture resistance, density and/or light output can be made with the addition of group-13 elements such as Tl. Because 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. | The present disclosure discloses, in one arrangement, a scintillator material made of a metal halide with one or more additional group-13 elements. An example of such a compound is Ce:LaBr 3 with thallium (Tl) added, either as a codopant or in a stoichiometric admixture and/or solid solution between LaBr 3 and TlBr. In another arrangement, the above single crystalline iodide scintillator material can be made by first synthesizing a compound of the above composition and then forming a single crystal from the synthesized compound by, for example, the Vertical Gradient Freeze method. Applications of the scintillator materials include radiation detectors and their use in medical and security imaging. | 6 |
This is a continuation of application Ser. No. 08/473,316 filed on Jun. 7, 1995 now U.S. Pat. No. 5,730,883, which is a continuation-in-part of application Ser. No. 08/097,967 filed on Jul. 26, 1993, now abandoned, which is a continuation-in-part of application of application Ser. No. 07/965,088 filed on Oct. 22, 1992, now U.S. Pat. No. 5,370,802, which is a continuation-in-part of application Ser. No. 07/814,403 filed on Dec. 23, 1991, now abandoned.
FIELD OF THE INVENTION
The invention generally relates to blood processing systems and methods.
BACKGROUND OF THE INVENTION
Today people routinely separate whole blood by centrifugation into its various therapeutic components, such as red blood cells, platelets, and plasma.
Certain therapies transfuse large volumes of blood components. For example, some patients undergoing chemotherapy require the transfusion of large numbers of platelets on a routine basis. Manual blood bag systems simply are not an efficient way to collect these large numbers of platelets from individual donors.
On line blood separation systems are today used to collect large numbers of platelets to meet this demand. On line systems perform the separation steps necessary to separate concentration of platelets from whole blood in a sequential process with the donor present. On line systems establish a flow of whole blood from the donor, separate out the desired platelets from the flow, and return the remaining red blood cells and plasma to the donor, all in a sequential flow loop.
Large volumes of whole blood (for example, 2.0 liters) can be processed using an on line system. Due to the large processing volumes, large yields of concentrated platelets (for example, 4×10 11 platelets suspended in 200 ml of fluid) can be collected. Moreover, since the donor's red blood cells are returned, the donor can donate whole blood for on line processing much more frequently than donors for processing in multiple blood bag systems.
Nevertheless, a need still exists for further improved systems and methods for collecting cellular-rich concentrates from blood components in a way that lends itself to use in high volume, on line blood collection environments, where higher yields of critically needed cellular blood components like platelets can be realized.
As the operational and performance demands upon such fluid processing systems become more complex and sophisticated, the need exists for automated process controllers that can gather and generate more detailed information and control signals to aid the operator in maximizing processing and separation efficiencies.
SUMMARY OF THE INVENTION
The invention provides blood processing systems and methods that separate whole blood into red blood cells and a plasma constituent within a rotating centrifugal separation device. The systems and methods convey whole blood into the separation device through an inlet path including a pump operable at a prescribed rate. The systems and methods remove plasma constituent from the separation device through an outlet path including a pump operable at a prescribed rate.
According to the invention, the systems and methods derive a value H b representing an apparent hematocrit of whole blood entering the separation device, where: ##EQU2## and where H rbc is a value relating to hematocrit of red blood cells in the separation device.
In a preferred embodiment, the systems and methods generate a control command based, at least in part, upon H b . In one implementation, the control command recirculates at least a portion of plasma constituent for mixing with whole blood conveyed into the separation device. In another implementation, the control command controls Q b .
In a preferred embodiment, the systems and methods generate an output based, at least in part, upon H b . In one implementation, the output comprises a value η representing efficiency of separation in the separation device, where: ##EQU3##
In a preferred embodiment, the value H rbc represents apparent hematocrit of red blood cells in the separation device, where: ##EQU4## where: q b is inlet blood flow rate (cm 3 /sec), which when converted to ml/min, corresponds with Q b ,
q p is measured plasma flow rate (in cm 3 /sec), which, when converted to ml/min corresponds with Q p ,
β is a shear rate dependent term, and S Y is a red blood cell sedimentation coefficient (sec) and β/S Y =15.8×10 6 sec -1 ,
A is the area of the separation device (cm 2 ),
g is the centrifugal acceleration (cm/sec 2 ), which is the radius of the separation device multiplied by the rate of rotation squared Ω 2 (rad/sec 2 ), and
k is a viscosity constant=0.625, and K is a viscosity constant based upon k and another viscosity constant α=4.5, where: ##EQU5##
In a preferred embodiment, the systems and methods operate free of any a sensor to measure blood hematocrit either in the separation device or in the inlet path.
In a preferred embodiment, the systems and methods recirculate at least a portion of plasma constituent from the separation device at a prescribed rate Q Recirc for mixing with whole blood conveyed into the separation device. In this embodiment, the systems and methods control Q Recirc to achieve a desired hematocrit H i for whole blood conveyed into the separation device as follows: ##EQU6##
The various aspects of the invention are especially well suited for on line blood separation processes.
Other features and advantages of the invention will become apparent from the following description, the drawings, and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic view of a dual needle platelet collection system that includes a controller that embodies the features of the invention;
FIG. 2 is a diagrammatic flow chart view of the controller and associated system optimization application that embodies the features of the invention;
FIG. 3 is a diagrammatic view of the function utilities contained within the system optimization application shown in FIG. 2;
FIG. 4 is a diagrammatic flow chart view of the utility function contained within the system optimization application that derives the yield of platelets during a given processing session;
FIG. 5 is a diagrammatic flow chart view of the utility functions contained within the system optimization application that provide processing status and parameter information, generate control variables for achieving optimal separation efficiencies, and generate control variables that control the rate of citrate infusion during a given processing session;
FIG. 6 is a diagrammatic flow chart view of the utility function contained within the system optimization application that recommends optimal storage parameters based upon the yield of platelets during a given processing session;
FIG. 7 is a diagrammatic flow chart view of the utility function contained within the system optimization application that estimates the processing time before commencing a given processing session;
FIG. 8 is a graphical depiction of an algorithm used by the utility function shown in FIG. 4 expressing the relationship between the efficiency of platelet separation in the second stage chamber and a dimensionless parameter, which takes into account the size of the platelets, the plasma flow rate, the area of the chamber, and the speed of rotation;
FIG. 9 is a graph showing the relationship between the partial pressure of oxygen and the permeation of a particular storage container, which the utility function shown in FIG. 6 takes into account in recommending optimal storage parameters in terms of the number of storage containers;
FIG. 10 is a graph showing the relationship between the consumption of bicarbonate and storage thrombocytocrit for a particular storage container, which the utility function shown in FIG. 6 takes into account in recommending optimal storage parameters I n terms of the volume of plasma storage medium; and
FIG. 11 is a graph showing the efficiency of platelet separation, expressed in terms of mean platelet volume, in terms of inlet hematocrit, which a utility function shown in FIG. 5 takes into account in generating a control variable governing plasma recirculation during processing.
The various aspects of the invention may be embodied in several forms without departing from its spirit or essential characteristics. The scope of the invention is defined in the appended claims, rather than in the specific description preceding them. All embodiments that fall within the meaning and range of equivalency of the claims are therefore intended to be embraced by the claims.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows in diagrammatic form an on line blood processing system 10 for carrying out an automated platelet collection procedure. The system 10 in many respects typifies a conventional two needle blood collection network, although a convention single needle network could also be used. The system 10 includes a processing controller 18 embodying the features of the invention.
I. The Separation System
The system 10 includes an arrangement of durable hardware elements, whose operation is governed by the processing controller 18. The hardware elements include a centrifuge 12, in which whole blood (WB) is separated into its various therapeutic components, like platelets, plasma, and red blood cells (RBC). The hardware elements will also include various pumps, which are typically peristaltic (designated P1 to P4); and various in line clamps and valves (designated V1 to V3). Of course, other types of hardware elements may typically be present, which FIG. 1 does not show, like solenoids, pressure monitors, and the like.
The system 10 typically also includes some form of a disposable fluid processing assembly 14 used in association with the hardware elements.
In the illustrated blood processing system 10, the assembly 14 includes a two stage processing chamber 16. In use, the centrifuge 12 rotates the processing chamber 16 to centrifugally separate blood components. A representative centrifuge that can be used is shown in Williamson et al U.S. Pat. No. 5,360,542, which is incorporated herein by reference.
The construction of the two stage processing chamber 16 can vary. For example, it can take the form of double bags, like the processing chambers shown in Cullis et al. U.S. Pat. No. 4,146,172. Alternatively, the processing chamber 16 can take the form of an elongated two stage integral bag, like that shown in Brown U.S. Pat. No. 5,370,802.
In the illustrated blood processing system 10, the processing assembly 14 also includes an array of flexible tubing that forms a fluid circuit. The fluid circuit conveys liquids to and from the processing chamber 16. The pumps P1-P4 and the valves V1-V3 engage the tubing to govern the fluid flow in prescribed ways. The fluid circuit further includes a number of containers (designated C1 to C3) to dispense and receive liquids during processing.
The controller 18 governs the operation of the various hardware elements to carry out one or more processing tasks using the assembly 14. The controller 18 also performs real time evaluation of processing conditions and outputs information to aid the operator in maximizing the separation and collection of blood components. The invention specifically concerns important attributes of the controller 18.
The system 10 can be configured to accomplish diverse types of blood separation processes. FIG. 1 shows the system 10 configured to carry out an automated two needle platelet collection procedure.
In a collection mode, a first tubing branch 20 and the whole blood inlet pump P2 direct WB from a draw needle 22 into the first stage 24 of the processing chamber 16. Meanwhile, an auxiliary tubing branch 26 meters anticoagulant from the container C1 to the WB flow through the anticoagulant pump P1. While the type of anticoagulant can vary, the illustrated embodiment uses ACDA, which is a commonly used anticoagulant for pheresis.
The container C2 holds saline solution. Another auxiliary tubing branch 28 conveys the saline into the first tubing branch 20, via the in line valve V1, for use in priming and purging air from the system 10 before processing begins. Saline solution is also introduced again after processing ends to flush residual components from the assembly 14 for return to the donor.
Anticoagulated WB enters and fills the first stage 24 of the processing chamber 24. There, centrifugal forces generated during rotation of the centrifuge 12 separate WB into red blood cells (RBC) and platelet-rich plasma (PRP).
The PRP pump P4 operates to draw PRP from the first stage 24 of the processing chamber 16 into a second tubing branch 30 for transport to the second stage 32 of the processing chamber 16. There, the PRP is separated into platelet concentrate (PC) and platelet-poor plasma (PPP).
Optionally, the PRP can be conveyed through a filter F to remove leukocytes before separation in the second stage 32. The filter F can employ filter media containing fibers of the type disclosed in Nishimura et al U.S. Pat. No. 4,936,998, which is incorporated herein by reference. Filter media containing these fibers are commercially sold by Asahi Medical Company in filters under the trade name SEPACELL.
The system 10 includes a recirculation tubing branch 34 and an associated recirculation pump P3. The processing controller 18 operates the pump P3 to divert a portion of the PRP exiting the first stage 24 of the processing chamber 16 for remixing with the WB entering the first stage 24 of the processing chamber 16. The recirculation of PRP establishes desired conditions in the entry region of the first stage 24 to provide maximal separation of RBC and PRP.
As WB is drawn into the first chamber stage 24 for separation, the illustrated two needle system simultaneously returns RBC from the first chamber stage 24, along with a portion of the PPP from the second chamber stage 32, to the donor through a return needle 36 through tubing branches 38 and 40 and in line valve V2.
The system 10 also collects PC (resuspended in a volume of PPP) in some of the containers C3 through tubing branches 38 and 42 and in line valve V3 for storage and beneficial use. Preferable, the container(s) C3 intended to store the PC are made of materials that, when compared to DEHP-plasticized polyvinyl chloride materials, have greater gas permeability that is beneficial for platelet storage. For example, polyolefin material (as disclosed in Gajewski et al U.S. Pat. No. 4,140,162), or a polyvinyl chloride material plasticized with tri-2-ethylhexyl trimellitate (TEHTM) can be used.
The system 10 can also collect PPP in some of the containers C3 through the same fluid path. The continuous retention of PPP serves multiple purposes, both during and after the component separation process.
The retention of PPP serves a therapeutic purpose during processing. PPP contains most of the anticoagulant that is metered into WB during the component separation process. By retaining a portion of PPP instead of returning it all to the donor, the overall volume of anticoagulant received by the donor during processing is reduced. This reduction is particularly significant when large blood volumes are processed. The retention of PPP during processing also keeps the donor's circulating platelet count higher and more uniform during processing.
The system 10 can also derive processing benefits from the retained PPP.
The system 10 can, in an alternative recirculation mode, recirculate a portion of the retained PPP, instead of PRP, for mixing with WB entering the first compartment 24. Or, should WB flow be temporarily halted during processing, the system 10 can draw upon the retained volume of PPP as an anticoagulated "keep-open" fluid to keep fluid lines patent. In addition, at the end of the separation process, the system 10 draws upon the retained volume of PPP as a "rinse-back" fluid, to resuspend and purge RBC from the first stage compartment 24 for return to the donor through the return branch 40. After the separation process, the system 10 also operates in a resuspension mode to draw upon a portion of the retained PPP to resuspend PC in the second compartment 24 for transfer and storage in the collection container(s) C3.
II. The System Controller
The controller 18 carries out the overall process control and monitoring functions for the system 10 as just described.
In the illustrated and preferred embodiment (see FIG. 2), the controller comprises a main processing unit (MPU) 44. In the preferred embodiment, the MPU 44 comprises a type 68030 microprocessor made by Motorola Corporation, although other types of conventional microprocessors can be used.
In the preferred embodiment, the MPU 44 employs conventional real time multi-tasking to allocate MPU cycles to processing tasks. A periodic timer interrupt (for example, every 5 milliseconds) preempts the executing task and schedules another that is in a ready state for execution. If a reschedule is requested, the highest priority task in the ready state is scheduled. Otherwise, the next task on the list in the ready state is schedule.
A. Functional Hardware Control
The MPU 44 includes an application control manager 46. The application control manager 46 administers the activation of a library 48 of control applications (designated A1 to A3). Each control application A1-A3 prescribes procedures for carrying out given functional tasks using the system hardware (e.g., the centrifuge 12, the pumps P1-P4, and the valves V1-V3) in a predetermined way. In the illustrated and preferred embodiment, the applications A1-A3 reside as process software in EPROM's in the MPU 44.
The number of applications A1-A3 can vary. In the illustrated and preferred embodiment, the library 48 includes at least one clinical procedure application A1. The procedure application A1 contains the steps to carry out one prescribed clinical processing procedure. For the sake of example in the illustrated embodiment, the library 48 includes a procedure application A1 for carrying out the dual needle platelet collection process, as already generally described in connection with FIG. 1. Of course, additional procedure applications can be, and typically will be, included. For example, the library 48 can include a procedure application for carrying out a conventional single needle platelet collection process.
In the illustrated and preferred embodiment, the library 48 also includes a system optimization application A2. The system optimization application A2 contains interrelated, specialized utility functions that process information based upon real time processing conditions and empirical estimations to derive information and control variables that optimize system performance. Further details of the optimization application A2 will be described later.
The library 48 also includes a main menu application A3, which coordinates the selection of the various applications A1-A3 by the operator, as will also be described in greater detail later.
Of course, additional non-clinical procedure applications can be, and typically will be, included. For example, the library 48 can include a configuration application, which contains the procedures for allowing the operator to configure the default operating parameters of the system 10. As a further example, the library 48 can include a diagnostic application, which contains the procedures aiding service personnel in diagnosing and troubleshooting the functional integrity of the system, and a system restart application, which performs a full restart of the system, should the system become unable to manage or recover from an error condition.
An instrument manager 50 also resides as process software in EPROM's in the MPU 44. The instrument manager 50 communicates with the application control manager 46. The instrument manager 50 also communicates with low level peripheral controllers 52 for the pumps, solenoids, valves, and other functional hardware of the system.
As FIG. 2 shows, the application control manager 46 sends specified function commands to the instrument manager 50, as called up by the activated application A1-A3. The instrument manager 50 identifies the peripheral controller or controllers 52 for performing the function and compiles hardware-specific commands. The peripheral controllers 52 communicate directly with the hardware to implement the hardware-specific commands, causing the hardware to operate in a specified way. A communication manager 54 manages low-level protocol and communications between the instrument manager 50 and the peripheral controllers 52.
As FIG. 2 also shows, the instrument manager 50 also conveys back to the application control manager 46 status data about the operational and functional conditions of the processing procedure. The status data is expressed in terms of, for example, fluid flow rates, sensed pressures, and fluid volumes measured.
The application control manager 46 transmits selected status data for display to the operator. The application control manager 46 transmits operational and functional conditions to the procedure application A1 and the performance monitoring application A2.
B. User Interface Control
In the illustrated embodiment, the MPU 44 also includes an interactive user interface 58. The interface 58 allows the operator to view and comprehend information regarding the operation of the system 10. The interface 58 also allows the operator to select applications residing in the application control manager 46, as well as to change certain functions and performance criteria of the system 10.
The interface 58 includes an interface screen 60 and, preferably, an audio device 62. The interface screen 60 displays information for viewing by the operator in alpha-numeric format and as graphical images. The audio device 62 provides audible prompts either to gain the operator's attention or to acknowledge operator actions.
In the illustrated and preferred embodiment, the interface screen 60 also serves as an input device. It receives input from the operator by conventional touch activation. Alternatively or in combination with touch activation, a mouse or keyboard could be used as input devices.
An interface controller 64 communicates with the interface screen 60 and audio device 62. The interface controller 64, in turn, communicates with an interface manager 66, which in turn communicates with the application control manager 46. The interface controller 64 and the interface manager 66 reside as process software in EPROM's in the MPU 44.
Further details of the interface 58 are disclosed in copending application Ser. No. xxx.
C. The System Optimization
Application
In the illustrated embodiment (as FIG. 3 shows), the system optimization application A2 contains six specialized yet interrelated utility functions, designated F1 to F6. Of course, the number and type of utility functions can vary.
In the illustrated embodiment, a utility function F1 derives the yield of the system 10 for the particular cellular component targeted for collection. For the platelet collection procedure application A1, the utility function F1 ascertains both the instantaneous physical condition of the system 10 in terms of its separation efficiencies and the instantaneous physiological condition of the donor in terms of the number of circulating platelets available for collection. From these, the utility function F1 derive the instantaneous yield of platelets continuously over the processing period.
Yet another utility function F2 relies upon the calculated platelet yield and other processing conditions to generate selected informational status values and parameters. These values and parameters are displayed on the interface 58 to aid the operator in establishing and maintaining optimal performance conditions. The status values and parameters derived by the utility function F2 can vary. For example, in the illustrated embodiment, the utility function F2 reports remaining volumes to be processed, remaining processing times, and the component collection volumes and rates.
Another utility function F3 calculates and recommends, based upon the platelet yield derived by the utility function F1, the optimal storage parameters for the platelets in terms of the number of storage containers and the volume amount of PPP storage media to use.
Other utility functions generate control variables based upon ongoing processing conditions for use by the applications control manager 46 to establish and maintain optimal processing conditions. For example, one utility function F4 generates control variables to optimize platelet separation conditions in the first stage 24. Another utility function F5 generates control variables to control the rate at which citrate anticoagulant is returned with the PPP to the donor to avoid potential citrate toxicity reactions.
Yet another utility function F6 derives an estimated procedure time, which predicts the collection time before the donor is connected.
Further details of these utility functions F1 to F6 will now be described in greater detail.
III. Deriving Platelet Yield
The utility function F1 (see FIG. 4) makes continuous calculations of the platelet separation efficiency (η Plt ) of the system 10. The utility function F1 treats the platelet separation efficiency η Ptl as being the same as the ratio of plasma volume separated from the donor's whole blood relative to the total plasma volume available in the whole blood. The utility function F1 thereby assumes that every platelet in the plasma volume separated from the donor's whole blood will be harvested.
The donor's hematocrit changes due to anticoagulant dilution and plasma depletion effects during processing, so the separation efficiency η Plt does not remain at a constant value, but changes throughout the procedure. The utility function F1 contends with these process-dependent changes by monitoring yields incrementally. These yields, called incremental cleared volumes (ΔClrVol), are calculated by multiplying the current separation efficiency η Plt by the current incremental volume of donor whole blood, diluted with anticoagulant, being processed, as follows: ##EQU7## where: ΔVol Proc is the incremental whole blood volume being processed, and
ACDil is an anticoagulant dilution factor for the incremental whole blood volume, computed as follows: ##EQU8## where: AC is the selected ratio of whole blood volume to anticoagulant volume (for example 10:1 or "10"). AC may comprise a fixed value during the processing period. Alternatively, AC may be varied in a staged fashion according to prescribed criteria during the processing period.
For example, AC can be set at the outset of processing at a lesser ratio for a set initial period of time, and then increased in steps after subsequent time periods; for example, AC can be set at 6:1 for the first minute of processing, then raised to 8:1 for the next 2.5 to 3 minutes; and finally raised to the processing level of 10:1.
The introduction of anticoagulant can also staged by monitoring the inlet pressure of PRP entering the second processing stage 32. For example, AC can be set at 6:1 until the initial pressure (e.g. at 500 mmHg) falls to a set threshold level (e.g., 200 mmHg to 300 mmHg). AC can then be raised in steps up to the processing level of 10:1, while monitoring the pressure to assure it remains at the desired level.
The utility function F1 also makes continuous estimates of the donor's current circulating platelet count (Plt Circ ), expressed in terms of 1000 platelets per microliter (μl) of plasma volume (or k/μl). Like η Plt , Plt Circ will change during processing due to the effects of dilution and depletion. The utility function F1 incrementally monitors the platelet yield in increments, too, by multiplying each incremental cleared plasma volume ΔClrVol (based upon an instantaneous calculation of η Plt ) by an instantaneous estimation of the circulating platelet count Plt Cir . The product is an incremental platelet yield (Δyld), typically expressed as e n platelets, where e n =0.5×10 n platelets (e 11 =0.5×10 11 platelets).
At any given time, the sum of the incremental platelet yields ΔYld constitutes the current platelet yield Yld current , which can also be expressed as follows: ##EQU9## where: Yld old is the last calculated Yld Current , and ##EQU10## where: Plt Current is the current (instantaneous) estimate of the circulating platelet count of the donor.
ΔYld is divided by 100,000 in Eq (4) to balance units.
The following provides further details in the derivation of the above-described processing variables by the utility function F1.
A. Deriving Overall Separation Efficiency η Plt
The overall system efficiency η Plt is the product of the individual efficiencies of the parts of the system, as expressed as follows: ##EQU11## where: η 1stSep is the efficiency of the separation of PRP from WB in the first separation stage.
η 2ndSep is the efficiency of separation PC from PRP in the second separation stage.
η Anc is the product of the efficiencies of other ancillary processing steps in the system.
1. First Stage Separation Efficiency η 1stSep
The utility function F1 (see FIG. 4) derives η 1stSep continuously over the course of a procedure based upon measured and empirical processing values, using the following expression: ##EQU12## where: Q b is the measured whole blood flow rate (in ml/min).
Q p is the measured PRP flow rate (in ml/min).
H b is the apparent hematocrit of the anticoagulated whole blood entering the first stage separation compartment. H b is a value derived by the utility based upon sensed flow conditions and theoretical considerations. The utility function F1 therefore requires no on-line hematocrit sensor to measure actual WB hematocrit.
The utility function F1 derives H b based upon the following relationship: ##EQU13## where: H rbc is the apparent hematocrit of the RBC bed within the first stage separation chamber, based upon sensed operating conditions and the physical dimensions of the first stage separation chamber. As with H b , the utility function F1 requires no physical sensor to determine H rbc , which is derived by the utility function according to the following expression: ##EQU14## where: q b is inlet blood flow rate (cm 3 /sec), which is a known quantity which, when converted to ml/min, corresponds with Q b in Eq (6).
q p is measured PRP flow rate (in cm 3 /sec), which is a known quantity which, when converted to ml/min corresponds with Q p in Eq (6).
β is a shear rate dependent term, and S Y is the red blood cell sedimentation coefficient (sec). Based upon empirical data, Eq (8) assumes that β/S Y =15.8×10 6 sec -1 .
A is the area of the separation chamber (cm 2 ), which is a known dimension.
g is the centrifugal acceleration (cm/sec 2 ), which is the radius of the first separation chamber (a known dimension) multiplied by the rate of rotation squared Ω 2 (rad/sec 2 ) (another known quantity).
k is a viscosity constant=0.625, and K is a viscosity constant based upon k and another viscosity constant α=4.5, where: ##EQU15##
Eq (8) is derived from the relationships expressed in the following Eq (10): ##EQU16## set forth in Brown, The Physics of Continuous Flow Centrifugal Cell Separation, "Artificial Organs" 1989; 13(1):4-20)). Eq (8) solves Eq (10) for H rbc .
2. The Second Stage Separation Efficiency η 2ndSep
The utility function F1 (see FIG. 4) also derives η 2ndSep continuously over the course of a procedure based upon an algorithm, derived from computer modeling, that calculates what fraction of log-normally distributed platelets will be collected in the second separation stage 32 as a function of their size (mean platelet volume, or MPV), the flow rate (Q p ), area (A) of the separation stage 32, and centrifugal acceleration (g, which is the spin radius of the second stage multiplied by the rate of rotation squared Ω 2 ).
The algorithm can be expressed in terms of a function shown graphically in FIG. 8. The graph plots η 2ndSep in terms of a single dimensionless parameter gAS p /Q p ,
where:
S.sub.p =1.8×10.sup.-9 MPV.sup.2/3 (sec),
and
MPV is the mean platelet volume (femtoliters, fl, or cubic microns), which can be measured by conventional techniques from a sample of the donor's blood collected before processing. There can be variations in MPV due to use of different counters. The utility function therefore may include a look up table to standardize MPV for use by the function according to the type of counter used. Alternatively, MPV can be estimated based upon a function derived from statistical evaluation of clinical platelet precount Plt PRE data, which the utility function can use. The inventor believes, based upon his evaluation of such clinical data, that the MPV function can be expressed as:
MPV(fl)≈11.5-0.009Plt.sub.PRE (k/μl)
3. Ancillary Separation Efficiencies η Anc
η Anc takes into account the efficiency (in terms of platelet loss) of other portions of the processing system. η Anc takes into account the efficiency of transporting platelets (in PRP) from the first stage chamber to the second stage chamber; the efficiency of transporting platelets (also in PRP) through the leukocyte removal filter; the efficiency of resuspension and transferral of platelets (in PC) from the second stage chamber after processing; and the efficiency of reprocessing previously processed blood in either a single needle or a double needle configuration.
The efficiencies of these ancillary process steps can be assessed based upon clinical data or estimated based upon computer modeling. Based upon these considerations, a predicted value for η Anc can be assigned, which Eq (5) treats as constant over the course of a given procedure.
B. Deriving Donor Platelet Count (Plt circ )
The utility function F1 (see FIG. 4) relies upon a kinetic model to predict the donor's current circulating platelet count Plt Circ during processing. The model estimates the donor's blood volume, and then estimates the effects of dilution and depletion during processing, to derive Plt Circ , according to the following relationships: ##EQU17## where: Plt pre is the donor's circulating platelet count before processing begins (k/μl), which can be measured by conventional techniques from a sample of whole blood taken from the donor before processing. There can be variations in Plt pre due to use of different counters (see, e.g., Peoples et al., "A Multi-Site Study of Variables Affecting Platelet Counting for Blood Component Quality Control," Transfusion (Special Abstract Supplement, 47th Annual Meeting), v. 34, No. 10S, October 1994 Supplement). The utility function therefore may include a look up table to standardize all platelet counts (such as, Plt pre and Pltpost, described later) for use by the function according to the type of counter used.
Dilution is a factor that reduces the donor's preprocessing circulating platelet count Plt pre due to increases in the donor's apparent circulating blood volume caused by the priming volume of the system and the delivery of anticoagulant. Dilution also takes into account the continuous removal of fluid from the vascular space by the kidneys during the procedure.
Depletion is a factor that takes into account the depletion of the donor's available circulating platelet pool by processing. Depletion also takes into account the counter mobilization of the spleen in restoring platelets into the circulating blood volume during processing.
1. Estimating Dilution
The utility function F1 estimates the dilution factor based upon the following expression: ##EQU18## where: Prime is the priming volume of the system (ml).
ACD is the volume of anticoagulant used (current or end-point, depending upon the time the derivation is made)(ml).
PPP is the volume of PPP collected (current or goal) (ml).
DonVol (ml) is the donor's blood volume based upon models that take into account the donor's height, weight, and sex. These models are further simplified using empirical data to plot blood volume against donor weight linearized through regression to the following, more streamlined expression: ##EQU19## where: Wgt is the donor's weight (kg).
2. Estimating Depletion
The continuous collection of platelets depletes the available circulating platelet pool. A first order model predicts that the donor's platelet count is reduced by the platelet yield (Yld) (current or goal) divided by the donor's circulating blood volume (DonVol), expressed as follows: ##EQU20## where: Yld is the current instantaneous or goal platelet yield (k/μl). In Eq (14), Yld is multiplied by 100,000 to balance units.
Eq (14) does not take into account splenic mobilization of replacement platelets, which is called the splenic mobilization factor (or Spleen). Spleen indicates that donors with low platelets counts nevertheless have a large platelet reserve held in the spleen. During processing, as circulating platelets are withdrawn from the donor's blood, the spleen releases platelets it holds in reserve into the blood, thereby partially offsetting the drop in circulating platelets. The inventor has discovered that, even though platelet precounts vary over a wide range among donors, the total available platelet volume remains remarkably constant among donors. An average apparent donor volume is 3.10±0.25 ml of platelets per liter of blood. The coefficient of variation is 8.1%, only slightly higher than the coefficient of variation in hematocrit seen in normal donors.
The inventor has derived the mobilization factor Spleen from comparing actual measured depletion to Depl (Eq (14)), which is plotted and linearized as a function of Plt pre . Spleen (which is restricted to a lower limit of 1) is set forth as follows: ##EQU21##
Based upon Eqs (14) and (15), the utility function derives Depletion as follows: ##EQU22##
C. Real Time Procedure Modifications
The operator will not always have a current platelet pre-count Plt Pre for every donor at the beginning of the procedure. The utility function F1 allows the system to launch under default parameters, or values from a previous procedure. The utility function F1 allows the actual platelet pre-count Plt Pre , to be entered by the operator later during the procedure. The utility function F1 recalculates platelet yields determined under one set of conditions to reflect the newly entered values. The utility function F1 uses the current yield to calculate an effective cleared volume and then uses that volume to calculate the new current yield, preserving the platelet pre-count dependent nature of splenic mobilization.
The utility function F1 uses the current yield to calculate an effective cleared volume as follows: ##EQU23## where: ClrVol is the cleared plasma volume.
DonVol is the donor's circulating blood volume, calculated according to Eq (13).
Yld Current is the current platelet yield calculated according to Eq (3) based upon current processing conditions.
Prime is the blood-side priming volume (ml).
ACD is the volume of anticoagulant used (ml).
PPP is the volume of platelet-poor plasma collected (ml).
Pre Old is the donor's platelet count before processing entered before processing begun (k/μl).
Spleen old is the splenic mobilization factor calculated using Eq (16) based upon Pre old .
The utility function F1 uses ClrVol calculated using Eq (17) to calculate the new current yield as follows: ##EQU24## where: Pre New is the revised donor platelet pre-count entered during processing (k/μl).
Yld New is the new platelet yield that takes into account the revised donor platelet pre-count Pre New .
ClrVol is the cleared plasma volume, calculated according to Eq (17).
DonVol is the donor's circulating blood volume, calculated according to Eq (13), same as in Eq (17).
Prime is the blood-side priming volume (ml), same as in Eq (17).
ACD is the volume of anticoagulant used (ml), same as in Eq (17).
PPP is the volume of platelet-poor plasma collected (ml), same as in Eq (17).
Spleen New is the splenic mobilization factor calculated using Eq (15) based upon Pre New .
IV. Deriving Other Processing Information
The utility function F2 (see FIG. 5) relies upon the calculation of Yld by the first utility function F1 to derive other informational values and parameters to aid the operator in determining the optimum operating conditions for the procedure. The follow processing values exemplify derivations that the utility function F2 can provide.
A. Remaining Volume to be Processed
The utility function F2 calculates the additional processed volume needed to achieve a desired platelet yield Vb rem (in ml) by dividing the remaining yield to be collected by the expected average platelet count over the remainder of the procedure, with corrections to reflect the current operating efficiency η Plt . The utility function F2 derives this value using the following expression: ##EQU25## where: Yld Goal is the desired platelet yield (k/μl),
where:
Vb rem is the additional processing volume (ml) needed to achieve Yld Goal .
Yld Current is the current platelet yield (k/μl), calculated using Eq (3) based upon current processing values.
η Plt is the present (instantaneous) platelet collection efficiency, calculated using Eq (5) based upon current processing values.
ACDil is the anticoagulant dilution factor (Eq (2)).
Plt current is the current (instantaneous) circulating donor platelet count, calculated using Eq (11) based upon current processing values.
Plt post is the expected donor platelet count after processing, also calculated using Eq (11) based upon total processing values.
B. Remaining Procedure Time
The utility function F2 also calculates remaining collection time (t rem ) (in min) as follows: ##EQU26## where: Vb rem is the remaining volume to be processed, calculated using Eq (19) based upon current processing conditions.
Qb is the whole blood flow rate, which is either set by the user or calculated as Qb Opt using Eq (31), as will be described later.
C. Plasma Collection
The utility function F2 adds the various plasma collection requirements to derive the plasma collection volume (PPP Goal ) (in ml) as follows: ##EQU27## where: PPP PC is the platelet-poor plasma volume selected for the PC product, which can have a typical default value of 250 ml, or be calculated as an optimal value Plt med according to Eq (28), as will be described later.
PPP Source is the platelet-poor plasma volume selected for collection as source plasma.
PPP Waste is the platelet-poor plasma volume selected to be held in reserve for various processing purposes (Default=30 ml).
PPP CollCham is the volume of the plasma collection chamber (Default=40 ml).
PPP Reinfuse is the platelet-poor plasma volume that will be reinfusion during processing.
D. Plasma Collection Rate
The utility function F2 calculates the plasma collection rate (Q ppp ) (in ml/min) as follows: ##EQU28## where: PPP Goal is the desired platelet-poor plasma collection volume (ml).
PPP Current is the current volume of platelet-poor plasma collected (ml).
t rem is the time remaining in collection, calculated using Eq (20) based upon current processing conditions.
E. Total Anticipated AC Usage
The utility function F2 can also calculate the total volume of anticoagulant expected to be used during processing (ACD End ) (in ml) as follows: ##EQU29## where: ACD Current is the current volume of anticoagulant used (ml).
AC is the selected anticoagulant ratio,
Q b is the whole blood flow rate, which is either set by the user or calculated using Eq (31) as Qb Opt based upon current processing conditions.
t rem is the time remaining in collection, calculated using Eq (20) based upon current processing conditions.
V. Recommending Optimum Platelet Storage Parameters
The utility function F3 (see FIG. 6) relies upon the calculation of Yld by the utility function F1 to aid the operator in determining the optimum storage conditions for the platelets collected during processing.
The utility function F3 derives the optimum storage conditions to sustain the platelets during the expected storage period in terms of the number of preselected storage containers required for the platelets Plt Bag and the volume of plasma (PPP) Plt Med (in ml) to reside as a storage medium with the platelets.
The optimal storage conditions for platelets depends upon the volume being stored Plt vol , expressed as follows: ##EQU30## where: Yld is the number of platelets collected, and
MPV is the mean platelet volume.
As Plt Vol increases, so too does the platelets' demand for oxygen during the storage period. As Plt Vol increases, the platelets' glucose consumption to support metabolism and the generation of carbon dioxide and lactate as a result of metabolism also increase. The physical characteristics of the storage containers in terms of surface area, thickness, and material are selected to provide a desired degree of gas permeability to allow oxygen to enter and carbon dioxide to escape the container during the storage period.
The plasma storage medium contains bicarbonate HCO 3 , which buffers the lactate generated by platelet metabolism, keeping the pH at a level to sustain platelet viability. As Plt vol increases, the demand for the buffer effect of HCO 3 , and thus more plasma volume during storage, also increases.
A. Deriving Plt Bag
The partial pressure of oxygen pO 2 (mmHg) of platelets stored within a storage container having a given permeation decreases in relation to the total platelet volume Plt Vol the container holds. FIG. 9 is a graph based upon test data showing the relationship between pO 2 measured after one day of storage for a storage container of given permeation. The storage container upon which FIG. 9 is based has a surface area of 54.458 in 2 and a capacity of 1000 ml. The storage container has a permeability to O 2 of 194 cc/100 in 2 /day, and a permeability to CO 2 1282 cc/100 in 2 /day.
When the partial pressure pO 2 drops below 20 mmHg, platelets are observed to become anaerobic, and the volume of lactate byproduct increases significantly. FIG. 9 shows that the selected storage container can maintain pO 2 of 40 mmHg (well above the aerobic region) at Plt Vol ≦4.0 ml. On this conservative basis, the 4.0 ml volume is selected as the target volume Plt TVol for this container. Target volumes Plt TVol for other containers can be determined using this same methodology.
The utility function F3 uses the target platelet volume Plt TVol to compute Plt Bag as follows: ##EQU31## and: Plt Bag =1 when BAG≦1.0, otherwise
Plt Bag =[BAG+1], where [BAG+1] is the integer part of the quantity BAG+1.
For example, given a donor MPV of 9.5 fl, and a Yld of 4×10 11 platelets (Plt Vol =3.8 ml), and given Plt TVol =4.0 ml, BAG=0.95, and Plt Bag =1. If the donor MPV is 11.0 fl and the yield Yld and Plt TVol remain the same (Plt Vol =4.4 ml), BAG=1.1 and Plt Bag =2.
When Plt Bag >1, Plt Vol is divided equally among the number of containers called for.
B. Deriving Plt Med
The amount of bicarbonate used each day is a function of the storage thrombocytocrit Tct (%), which can be expressed as follows: ##EQU32##
The relationship between bicarbonate HC0 3 consumption per day and Tct can be empirically determined for the selected storage container. FIG. 10 shows a graph showing this relationship for the same container that the graph in FIG. 9 is based upon. The y-axis in FIG. 10 shows the empirically measured consumption of bicarbonate per day (in Meq/L) based upon Tct for that container. The utility function F3 includes the data expressed in FIG. 10 in a look-up table.
The utility function F3 derives the anticipated decay of bicarbonate per day over the storage period ΔHCO 3 as follows: ##EQU33## where: Don HCO3 is the measured bicarbonate level in the donor's blood (Meq/L), or alternatively, is the bicarbonate level for a typical donor, which is believed to be 19.0 Meq/L±1.3, and
Stor is the desired storage interval (in days, typically between 3 to 6 days).
Given ΔHCO 3 , the utility function F3 derives Tct from the look up table for selected storage container. For the storage container upon which FIG. 10 is based, a Tct of about 1.35 to 1.5% is believed to be conservatively appropriate in most instances for a six day storage interval.
Knowing Tct and Plt Vol , the utility function F3 computes Plt Med based upon Eq (25), as follows: ##EQU34##
When Plt Bag >1, Plt Med is divided equally among the number of containers called for. PPP PC is set to Plt Med in Eq (21).
VI. Deriving Control Variables
The utility functions F4 and F5 rely upon the above-described matrix of physical and physiological relationships to derive process control variables, which the application control manager 46 uses to optimize system performance. The follow control variables exemplify derivations that the utility functions F4 and F5 can provide for this purpose.
A. Promoting High Platelet Separation Efficiencies By Recirculation
A high mean platelet value MPV for collected platelets is desirable, as it denotes a high separation efficiency for the first separation stage and the system overall. Most platelets average about 8 to 10 femtoliters, as measured by the Sysmex K-1000 machine (the smallest of red blood cells begin at about 30 femtoliters). The remaining minority of the platelet population constitutes platelets that are physically larger. These larger platelets typically occupy over 15×10 -15 liter per platelet, and some are larger than 30 femtoliters.
These larger platelets settle upon the RBC interface in the first separation chamber quicker than most platelets. These larger platelets are most likely to become entrapped in the RBC interface and not enter the PRP for collection. Efficient separation of platelets in the first separation chamber lifts the larger platelets from the interface for collection in the PRP. This, in turn, results a greater population of larger platelets in the PRP, and therefore a higher MPV.
FIG. 11, derived from clinical data, shows that the efficiency of platelet separation, expressed in terms of MPV, is highly dependent upon the inlet hematocrit of WB entering the first stage processing chamber. This is especially true at hematocrits of 30% and below, where significant increases in separation efficiencies can be obtained.
Based upon this consideration, the utility function F4 sets a rate for recirculating PRP back to the inlet of the first separation stage Q Recirc to achieve a desired inlet hematocrit H i selected to achieve a high MPV. The utility function F4 selects H i based upon the following red cell balance equation: ##EQU35##
In a preferred implementation, H i is no greater that about 40%, and, most preferably, is about 32%.
B. Citrate Infusion Rate
Citrate in the anticoagulant is rapidly metabolized by the body, thus allowing its continuous infusion in returned PPP during processing. However, at some level of citrate infusion, donors will experience citrate toxicity. These reactions vary in both strength and nature, and different donors have different threshold levels. A nominal a-symptomatic citrate infusion rate (CIR), based upon empirical data, is believed to about 1.25 mg/kg/min. This is based upon empirical data that shows virtually all donors can tolerate apheresis comfortably at an anticoagulated blood flow rates of 45 ml/min with an anticoagulant (ACD-A anticoagulant) ratio of 10:1.
Taking into account that citrate does not enter the red cells, the amount given to the donor can be reduced by continuously collecting some fraction of the plasma throughout the procedure, which the system accomplishes. By doing so, the donor can be run at a higher flow rate than would be expected otherwise. The maximum a-symptomatic equivalent blood flow rate (EqQb CIR ) (in ml/min) under these conditions is believed to be: ##EQU36## where: CIR is the selected nominal a-symptomatic citrate infusion rate, or 1.25 mg/kg/min.
AC is the selected anticoagulant ratio, or 10:1.
Wgt is the donor's weight (kg).
CitrateConc is the citrate concentration in the selected anticoagulant, which is 21.4 mg/ml for ACD-A anticoagulant.
C. Optimum Anticoagulated Blood Flow
The remaining volume of plasma that will be returned to the donor is equal to the total amount available reduced by the amount still to be collected. This ratio is used by the utility function F5 (see FIG. 5) to determine the maximum, or optimum, a-symptomatic blood flow rate (Qb Opt ) (in ml/min) that can be drawn from the donor, as follows: ##EQU37## where: H b is the anticoagulated hematocrit, calculated using Eq (7) based upon current processing conditions.
Vb Rem is the remaining volume to be processed, calculated using Eq (19) based upon current processing conditions.
EqQB CIR is the citrate equivalent blood flow rate, calculated using Eq (30) based upon current processing conditions.
PPP Goal is the total plasma volume to be collected (ml).
PPP Current is the current plasma volume collected (ml).
VII. Estimated Procedure Time
The utility function F6 (see FIG. 7) derives an estimated procedure time (t)(in min), which predicts the collection time before the donor is connected. To derive the estimated procedure time t, the utility function F6 requires the operator to input the desired yield Yld Goal and desired plasma collection volume PPP Goal , and further requires the donor weight Wgt, platelet pre-count Plt Pre , and hematocrit H b or a default estimate of it. If the operator wants recommended platelet storage parameters, the utility function requires MPV as an input.
The utility function F6 derives the estimated procedure time t as follows: ##EQU38## and where:
H eq is a linearized expression of the RBC hematocrit H RBC , as follows: ##EQU39## where: H b is the donor's anticoagulated hematocrit, actual or default estimation.
EqQb CIR is the maximum a-symptomatic equivalent blood flow rate calculated according to Eq (30).
and ##EQU40## where: Ω is the rotation speed of the processing chamber (rpm).
and where:
PPP is the desired volume of plasma to be collected (ml).
PV is the partial processed volume, which is that volume that would need to be processed if the overall separation efficiency η Plt was 100%, derived as follows: ##EQU41## where: ACDil is the anticoagulant dilution factor (Eq (2)).
ClrVol is the cleared volume, derived as: ##EQU42## where: Yld is the desired platelet yield.
DonVol is the donor's blood volume=1024+51Wgt (ml).
Prime is the blood side priming volume of the system (ml).
ACD Est is the estimated anticoagulant volume to be used (ml).
Plt Pre is the donor's platelet count before processing, or a default estimation of it.
Spleen is the is the splenic mobilization factor calculated using Eq (16) based upon Plt Pre .
The function F6 also derives the volume of whole blood needed to be processed to obtain the desired Yld Goal . This processing volume, WBVol, is expressed as follows: ##EQU43## where: t is the estimated procedure time derived according to Eq(32).
H b is the donor's anticoagulated hematocrit, actual or default estimation.
EqQb CIR is the maximum a-symptomatic equivalent blood flow rate calculated according to Eq (30).
PPP GOAL is the desired plasma collection volume.
WB RES is the residual volume of whole blood left in the system after processing, which is a known system variable and depends upon the priming volume of the system.
Various features of the inventions are set forth in the following claims. | Blood processing systems and methods separate whole blood into red blood cells and a plasma constituent within a rotating centrifugal separation device. The systems and methods convey whole blood into the separation device through an inlet path including a pump operable at a prescribed rate. The systems and methods remove plasma constituent from the separation device through an outlet path including a pump operable at a prescribed rate. The systems and methods derive a value H b representing an apparent hematocrit of whole blood entering the separation device, where: ##EQU1## and where H rbc is a value relating to hematocrit of red blood cells in the separation device. The systems and methods generate outputs and control commands based, at least in part, upon H b . | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Patent Application No. 60/661,831, filed Mar. 15, 2005, which is incorporated by reference.
BACKGROUND
[0002] Consumer demand for wireless local area network (WLAN) products (e.g. smart phones) grew rapidly in the recent past as the cost of WLAN chipsets and software fell while efficiencies rose. Along with the popularity, however, came inevitable and necessary security concerns.
[0003] The Institute of Electrical and Electronics Engineers (IEEE) initially attempted to address wireless security issues through the Wired Equivalent Privacy (WEP) standard. Unfortunately, the WEP standard quickly proved inadequate at providing the privacy it advertised and the IEEE developed the 802.11i specification in response. 802.11i provides a framework in which only trusted users are allowed to access WLAN network resources. RFC 2284, setting out an in-depth discussion of Point-to-Point Protocol Extensible Authentication Protocol (PPP EAP) by Merit Network, Inc (available at http://rfc.net/rfc2284.html as of Mar. 9, 2006), is one example of the 802.11i network authentication process and is incorporated by reference.
[0004] A typical wireless network based on the 802.11i specification comprises a supplicant common known as a client (e.g. a laptop computer), a number of wireless access points (AP), and an authentication server. In some implementations, the APs also act as authenticators that keep the WLAN closed to all unauthenticated traffic. To access the WLAN securely, an encryption key known as the Pairwise Master Key (PMK) must first be established between the client and an AP. The client and the AP then exchange a sequence of four messages known as the “four-way handshake.” The four-way handshake produces encryption keys unique to the client that are subsequently used to perform bulk data protection (e.g. message source authentication, message integrity assurance, message confidentiality, etc.).
[0005] A handoff occurs when the client roams from one AP to another. Prior to 802.11i, it was necessary for the client to re-authenticate itself each time it associates with an AP. This renegotiation results in significant latencies and may prove fatal for real-time exchanges such as voice data transfer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Embodiments of the present invention are illustrated in the figures. However, the embodiments and figures are illustrative rather than limiting; they provide examples of the present invention.
[0007] FIG. 1 is a block diagram illustrating an example of a WLAN system.
[0008] FIG. 2 is a block diagram illustrating an example of a WLAN system including one or more authenticators.
[0009] FIG. 3 is a block diagram illustrating an example of a WLAN system including one or more authentication domains.
[0010] FIG. 4 depicts a flowchart of an example of a method for secure network communication.
[0011] FIG. 5 depicts a flowchart of another example of a method for secure network communication.
[0012] FIG. 6 depicts a flowchart of a method to obtain an encryption key for secure network communication.
[0013] The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.
DETAILED DESCRIPTION
[0014] In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without one or more of these specific details or in combination with other components or process steps. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the present invention.
[0015] FIG. 1 is a block diagram illustrating an example of a Wireless Local Area Network (WLAN) system 100 . In the example of FIG. 1 , the WLAN system 100 includes an authentication server 102 , switches 104 - 1 to 104 -N (referred to collectively hereinafter as switches 104 ), Access Points (APs) 106 - 1 to 106 -N (referred to collectively hereinafter as APs 106 ), and clients 108 - 1 to 108 -N (referred to collectively hereinafter as clients 108 ).
[0016] In the example of FIG. 1 , the authentication server 102 may be any computer system that facilitates authentication of a client in a manner described later with reference to FIGS. 4-6 . The authentication server 102 may be coupled to one or more of the switches 104 through, for example, a wired network, a wireless network, or a network such as the Internet. The term “Internet” as used herein refers to a network of networks which uses certain protocols, such as the TCP/IP protocol, and possibly other protocols such as the hypertext transfer protocol (HTTP) for hypertext markup language (HTML) documents that make up the World Wide Web (the web). The physical connections of the Internet and the protocols and communication procedures of the Internet are well known to those of skill in the art. In an alternative embodiment, the authentication server 102 may reside on one of the switches 104 (or, equivalently, one of the switches 104 may reside on the authentication server).
[0017] In the example of FIG. 1 , the switches 104 may be any computer system that serves as an intermediary between a subset of the APs 106 and the server 102 . In an alternative, the APs may include the functionality of the switches 104 , obviating the need for the switches 104 .
[0018] In the example of FIG. 1 , the APs 106 typically include a communication port for communicating with one or more of the clients 108 . The communication port for communicating with the clients 108 typically includes a radio. In an embodiment, at least some of the clients 108 are wireless clients. Accordingly, APs 108 may be referred to in the alternative as “wireless access points” since the APs 106 provide wireless access for the clients 108 to a network, such as a Local Area Network (LAN) or Virtual LAN (VLAN). The APs 106 may be coupled to the network through network interfaces, which can be Ethernet network or other network interfaces. The network may also be coupled to a gateway computer system (not shown) that can provide firewall and other Internet-related services for the network. This gateway computer system may be coupled to an Internet Service Provider (ISP) to provide Internet connectivity to the clients 108 . The gateway computer system can be a conventional server computer system.
[0019] In the example of FIG. 1 , the clients 108 may include any wireless device. It should be noted that clients may or not be wireless, but for illustrative purposes only, the clients 108 are assumed to include wireless devices, such as by way of example but not limitation, cell phones, PDAs, laptops, notebook computers, or any other device that makes use of 802.11 or other wireless standards. When the clients 108 are authenticated, they can communicate with the network. For illustrative purposes, clients 108 are coupled to the APs 106 by lines 110 , which represent a secure connection.
[0020] In the example of FIG. 1 , in operation, to communicate through data traffic in the WLAN system 100 , the clients 108 typically initiate a request to access the network. An authenticator (not shown) logically stands between the clients 108 and the network to authenticate the client's identity and ensure secure communication. The authenticator may reside in any convenient location on the network, such as on one, some, or all of the APs 106 , on one, some, or all of the switches 104 , or at some other location. Within the 802.11i context, the authenticator ensures secure communication by encryption schemes including the distribution of encryption keys. For example, the authenticator may distribute the encryption keys using existing encryption protocols such as, by way of example but not limitation, the Otway-Rees and the Wide-Mouth Frog protocols. The authenticator may distribute the encryption keys in a known or convenient manner, as described later with reference to FIGS. 4-6 .
[0021] In the example of FIG. 1 , a client may transition from one authenticator to another and establish secure communication via a second authenticator. The change from one authenticator to another is illustrated in FIG. 1 as a dotted line 112 connecting the client 108 -N to the AP 106 -N. In a non-limiting embodiment, the secure communication via the second authenticator may be accomplished with one encryption key as long as both the first and second authenticators are coupled to the same authentication server 102 . In alternative embodiments, this may or may not be the case.
[0022] FIG. 2 is a block diagram illustrating an example of a WLAN system 200 including one or more authenticators. In the example of FIG. 2 , the WLAN system 200 includes authenticators 204 - 1 to 204 -N (referred to hereinafter as the authenticators 204 ), and a client 208 . As was previously indicated with reference to FIG. 1 , the authenticators 204 may reside on APs (see, e.g., FIG. 1 ), switches (see, e.g., FIG. 1 ) or at some other location in a network.
[0023] In the example of FIG. 2 , in a non-limiting embodiment, the client 208 scans different channels for an access point with which to associate in order to access the network. In an alternative embodiment, scanning may or may not be necessary to detect an access point. For example, the client 208 may know of an appropriate access point, obviating the need to scan for one. The access point may or may not have a minimum set of requirements, such as level of security or Quality of Service (QoS). In the example of FIG. 2 , the client 208 determines that access point meets the required level of service and thereafter sends an association request. In an embodiment, the access request includes information such as client ID and cryptographic data. The request may be made in the form of a data packet. In another embodiment, the client 208 may generate and later send information including cryptographic data when that data is requested.
[0024] In the example of FIG. 2 , the authenticator 204 - 1 authenticates the client 208 . By way of example but not limitation, the authenticator 204 - 1 may first obtain a session encryption key (SEK) in order to authenticate the client 208 . In one implementation, the authenticator requests the SEK and relies on an existing protocol (e.g. 802.1X) to generate a PMK as the SEK. In an alternative implementation, the SEK is pre-configured by mapping a preset value (e.g. user password) into a SEK. In the event that a preset value is used, convenient or well-known methods such as periodically resetting the value, or remapping the value with randomly generated numbers, may be employed to ensure security. In this example, once the authenticator 204 - 1 obtains the SEK, it proceeds to a four-way handshake whereby a new set of session keys are established for data transactions originating from client 208 . Typically, the client 208 need not be authenticated again while it communicates via the authenticator 204 - 1 . In the example of FIG. 2 , the connection between the client 208 and the server 204 - 1 is represented by the line 210 .
[0025] In the example of FIG. 2 , the client 208 roams from the authenticator 204 - 1 to the authenticator 204 -N. The connection process is represented by the arrows 212 to 216 . In an embodiment, when the client 208 roams, the server 202 verifies the identity of the (new) authenticator 204 -N and the client 208 . When roaming, the client 208 sends a cryptographic message to authenticator 204 -N including the identity of the client 208 (IDc); the identity of the server 202 (IDs); a first payload including the identity of the authenticator 204 -N (IDa) and a randomly generated key (k) encrypted by a key that client 208 and the server 202 share (eskey); and a second payload including the SEK encrypted by the random key k. This cryptographic message is represented in FIG. 2 as arrow 212 . In an alternative embodiment, the client 208 sends the cryptographic message along with its initial association request.
[0026] In the example of FIG. 2 , in an embodiment, once authenticator 204 -N receives the cryptographic message, it keeps a copy of the encrypted SEK, identifies the server 202 by the IDs, and sends a message to the server 202 including the identity of the client IDc and the first payload from the original cryptographic message having the identity of the authenticator IDa and the random key k encrypted by the share key eskey.
[0027] In the example of FIG. 2 , when the server 202 receives the message from authenticator 204 -N, it looks up the shared key eskey based on the identity of the client IDc and decrypts the message using the eskey. The server 202 then verifies that a trusted entity known by IDa exists and, if so, constructs another message consisting of the random key k encrypted with a key the server 202 shares with authenticator 204 -N (askey) and sends that message to the authenticator 204 -N. However, if the server 202 can not verify the authenticator 204 -N according to IDa, the process ends and client 201 cannot access the network through the authenticator 204 -N. In the event that the authenticator 204 -N cannot be verified the client may attempt to access the network via another authenticator after a preset waiting period elapses.
[0028] Upon receipt of the message from the server 202 , the authenticator 204 -N decrypts the random key k using the shared key askey and uses k to decrypt the encryption key SEK. Having obtained the encryption key SEK, the authenticator 204 -N may then proceed with a four-way handshake, which is represented in FIG. 2 for illustrative purposes as arrows 214 and 216 , and allow secure data traffic between the client 208 and the network.
[0029] Advantageously, the authentication system illustrated in FIG. 2 enables a client 208 to roam efficiently from authenticator to authenticator by allowing the client 208 to keep the same encryption key SEK when transitioning between authenticators coupled to the same server 202 . For example, the client 208 can move the SEK securely between authenticators by using a trusted third party (e.g. the server 202 ) that negotiates the distribution of the SEK without storing the SEK itself.
[0030] FIG. 3 is a block diagram illustrating an example of a WLAN system 300 including one or more authentication domains. In the example of FIG. 3 , the WLAN system 300 includes a server 302 , authentication domains 304 - 1 to 304 -N (referred to hereinafter as authentication domains 304 ), and a network 306 . The server 302 and the network 306 are similar to those described previously with reference to FIGS. 1 and 2 . The authentication domains 304 include any WLANs, including virtual LANs, that are associated with individual authenticators similar to those described with reference to FIGS. 1 and 2 .
[0031] The scope and boundary of the authentication domains 304 may be determined according to parameters such as geographic locations, load balancing requirements, etc. For illustrative purposes, the client 308 is depicted as roaming from the authentication domain 304 - 1 to the authentication domain 304 -N. This may be accomplished by any known or convenient means, such as that described with reference to FIGS. 1 and 2 .
[0032] FIGS. 4 to 6 , which follow, serve only to illustrate by way of example. The modules are interchangeable in order and fewer or more modules may be used to promote additional features such as security or efficiency. For example, in an alternative embodiment, a client may increase security by generating and distributing a unique random key to each authenticator. In another alternative embodiment of the present invention, the authenticator employs a known or convenient encryption protocol (e.g. Otway-Rees, Wide-Mouth Frog, etc.) to obtain the encryption key.
[0033] FIG. 4 depicts a flowchart of an example of a method for secure network communication. In the example of FIG. 4 , the flowchart starts at module 401 where a client sends an association request to an access point. The flowchart continues at decision point 403 where it is determined whether a preconfigured encryption key is used. If it is determined that a preconfigured encryption key is not to be used ( 403 -NO), then the flowchart continues at module 405 with requesting an encryption key and at decision point 407 with waiting for the encryption key to be received.
[0034] In the example of FIG. 4 , if a preconfigured encryption key is provided at module 403 , or an encryption key has been received ( 407 -YES), then the flowchart continues at module 409 with a four-way handshake. The flowchart then continues at module 411 where data traffic commences, and the flowchart continues to decision point 413 where it is determined whether the client is ready to transition to a new authentication domain.
[0035] In the example of FIG. 4 , if it is determined that a client is ready to transition to a new authentication domain ( 413 -YES), then the flowchart continues at module 415 when the client sends a cryptographic message to the new authenticator. In an alternative embodiment, the client sends the cryptographic message along with its initial association request and skips module 415 .
[0036] The flowchart continues at module 417 , where once the new authenticator receives the cryptographic message, the new authenticator sends a message to the server. If at decision point 419 the authenticator is not verified, the flowchart ends. Otherwise, the server sends a message to the authenticator at module 421 . The flowchart continues at module 423 where the authenticator obtains an encryption key, at module 424 where the client and the authenticator enter a four-way handshake, and at module 427 where data traffic commences.
[0037] FIG. 5 depicts a flowchart of another example of a method for secure network communication. In the example of FIG. 5 , the flowchart begins at module 501 where a client makes an association request. The flowchart continues at decision point 503 , where it is determined whether a preconfigured encryption key is available. If it is determined that a preconfigured encryption key is not available ( 503 -NO) then the flowchart continues at module 505 , where an encryption key is requested, and at decision point 507 where it is determined whether an encryption key is received. If it is determined that an encryption is not received ( 507 -NO), the flowchart continues from module 505 . If, on the other hand, it is determined that an encryption key is received ( 507 -YES), or if a preconfigured encryption key is available ( 503 -YES), then the flowchart continues at module 509 with a four-way handshake. In the example of FIG. 5 , the flowchart continues at module 511 , where data traffic commences, and at decision point 513 , where it is determined whether a client is ready to transition. If it is determined that a client is not ready to transition ( 513 -NO), then the flowchart continues at module 511 and at decision point 513 until the client is ready to transition ( 513 -YES). The flowchart continues at module 515 , where an authenticator obtains an encryption key using an established cryptographic protocol. The flowchart continues at module 517 with a four-way handshake, and at module 519 where data traffic commences.
[0038] FIG. 6 depicts a flowchart of a method to obtain an encryption key for secure network communication. In one embodiment, a client transitions from a first authenticator to a second authenticator, both of which coupled to the same server, and establishes secure communication with the first and the second authenticator using one encryption key.
[0039] At module 601 , a client generates a first key. In one embodiment, the first key is randomly generated. In an alternative embodiment, the first key is generated according to a preset value such as by requesting a value (e.g. password) from a user. In yet another alternative embodiment, the first key is a constant value such as a combination of the current date, time, etc.
[0040] At module 603 , the client obtains a second key. In one implementation, the generation of the second key relies on an existing protocol (e.g. 802.1X). In an alternative implementation, the second key is pre-configured (e.g. user password). In yet another alternative implementation, the second key is a combination of a pre-configured value and a randomly generated value.
[0041] At module 605 , the client constructs a first message using the first key and the second key. In one embodiment, the message is a data packet comprising cryptographic data using the first and the second key. Furthermore, in one embodiment, the first message comprises the second key encrypted with the first key.
[0042] At module 607 , the client sends the first message to an authenticator. In one embodiment, the authenticator is a second authenticator from which the client transitions from a first authenticator.
[0043] At module 609 , the authenticator constructs a second message using data from the first message. In one implementation, the authenticator constructs the second message comprising the client's identity, and an encrypted portion having identity of the authenticator and the first key.
[0044] At module 611 , the authenticator sends the second message to a server with which the authenticator is coupled. At module 613 , the server decrypts an encrypted portion of the second message. In one implementation, the encrypted portion of the second message comprises the identity of the authenticator and the first key.
[0045] Subsequently at module 615 , the server verifies the authenticator with the decrypted identity information extracted from the second message. If the server cannot verify the authenticator according to the identification information, as shown at decision point 617 , the client cannot communicate through the authenticator. If, on the other hand, the server verifies the authenticator, the server constructs a third message with the first key that it extracted from the second message at module 619 . In one implementation, the third message comprises the first key encrypted with a third key that the server shares with the authenticator. The server then sends the third message to the authenticator at module 621 .
[0046] After receiving the third message, the authenticator extracts the first key from the message at module 623 . In one implementation, the authenticator extracts the first key using a third key it shares with the server. With the first key, the authenticator then decrypts the cryptographic data in the first message and extracts the second key at module 625 . Having obtained the second key, the authenticator establishes secure data traffic/communication with the client using the second key. In one embodiment, the authenticator is a second authenticator to which the client transitions from a first authenticator coupled to the server, and the client communicates securely with both the first and the second authenticator using the second key.
[0047] As used herein, the term “embodiment” means an embodiment that serves to illustrate by way of example but not limitation. It may be noted that, in an embodiment, timestamps can be observed to measure roaming time.
[0048] It will be appreciated to those skilled in the art that the preceding examples and embodiments are exemplary and not limiting to the scope of the present invention. It is intended that all permutations, enhancements, equivalents, and improvements thereto that are apparent to those skilled in the art upon a reading of the specification and a study of the drawings are included within the true spirit and scope of the present invention. It is therefore intended that the following appended claims include all such modifications, permutations and equivalents as fall within the true spirit and scope of the present invention. | A technique for improving authentication speed when a client roams from a first authentication domain to a second authentication domain involves coupling authenticators associated with the first and second authentication domains to an authentication server. A system according to the technique may include, for example, a first authenticator using an encryption key to ensure secure network communication, a second authenticator using the same encryption key to ensure secure network communication, and a server coupled to the first authenticator and the second authenticator wherein the server distributes, to the first authenticator and the second authenticator, information to extract the encryption key from messages that a client sends to the first authenticator and the second authenticator. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method and a device for image data noise filtering, and to a display apparatus comprising such a device.
2. Description of the Related Art
In a motion adaptive first-order temporal recursive filter as proposed in References (1) and (2), for every pixel position x=(x, y) T , with T indicating transposition, and an input luminance value F(x, t), the filter output F F (x, t) is defined as:
F.sub.F (x, t)=kF(x, t)+(1-k)F.sub.F (x, t-T) (1)
where k is a control parameter, defining the filter characteristics and T is the field period of the video signal, which equals 20 ms in a 50 Hz environment. In an interlaced scan environment'x has to be increased (x+(0, 1) T ) or decreased (x-(0, 1) T ) with one line, as the corresponding pixel in the previous field does not exist. In an advantageous implementation (Reference (3)), the vertical position is field alternatively increased or decreased: ##EQU1## where N F is the field number. The variable k is determined with a so-called motion detector, the processing of which can be expressed as: ##EQU2## where N 1 and N 2 are (usually small) neighborhoods around the current pixel, and LUT is a monotonous, non-linear Look-Up Table function that translates its argument into a value usually between 1/32 and 1.
Although the filter is adapted to perform less filtering in case of motion, see equation (3), usually some blurring of fine low-contrast detail is still visible. If the motion detector of equation (3) is set more sensitive in order to prevent this blurring, the noise reduction capability decreases dramatically as the noise itself is seen as motion.
Another disadvantage of the classical temporal filter described, is that it causes a "dirty window effect", i.e., the filter suppresses the higher temporal frequencies which "freezes" the noise on the screen. In undetailed moving areas, therefore, the noise appears as a dirt on the screen behind which the undetailed body moves.
SUMMARY OF THE INVENTION
It is, inter alia, an object of the invention to provide improved image data noise filtering techniques. To this end, a first aspect of the invention provides a method of image data noise filtering in dependence upon a local image spectrum, wherein the filtering is stronger for low frequencies than for higher frequencies. A second aspect of the invention provides a device for image data noise filtering in dependence upon a local image spectrum, wherein the filtering is stronger for low frequencies than for higher frequencies. A third aspect of the invention provides a display apparatus comprising a display device (D) and a image data noise filtering device, as noted above, in a video signal processing path connected to said display device (D).
A primary aspect of the invention provides a method of image data noise filtering in dependence upon a local image spectrum, wherein the filtering is stronger for low frequencies than for higher frequencies.
These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 shows the noise weighting curve as proposed by the CCIR recommendation 421-1;
FIG. 2 illustrates a desired filtering for an implicit high frequency bypass;
FIG. 3 shows an embodiment of a noise filter in accordance with the invention with explicit high frequency bypass;
FIG. 4 shows a first more elaborate embodiment of a noise filter in accordance with the invention;
FIG. 5 shows a second more elaborate embodiment of a noise filter in accordance with the invention;
FIG. 6 shows yet another implementation of a noise reduction filter in accordance with the invention;
FIG. 7 shows an embodiment of a vertical recursive noise filter in accordance with the invention;
FIG. 8 shows an embodiment of an extended recursive noise filter in accordance with the invention;
FIG. 9 shows another embodiment of a vertical recursive noise filter in accordance with the invention; and
FIG. 10 shows another embodiment of an extended recursive noise filter in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention is based on the recognition that both problems, the blindness of the motion detector for low-contrast high frequencies and the dirty window effect, are related to the filtering of low-contrast high spatial frequencies. The invention is further based on the recognition that high frequency noise is much less annoying than low-frequency noise. This suggests the attractiveness of a filter design that suppresses high spatial frequencies less than low spatial frequencies.
There is yet another reason to look for options in which the high spatial frequencies are filtered less. Let us consider a sinusoidal pattern in the horizontal spatial domain which is moving in horizontal direction. This can be described as:
F(x,t+T)=F(x+D(x,t),t) (4)
where D(x, t) is a displacement or motion vector, and
F(x, t)=sin (ωx) (5)
or combining equations (4) and (5):
F(x, t+T)=sin ((x+D(x,t))ω) (6)
Using: ##EQU3## we find that in first order approximation and small displacements (velocities), the amplitude of the resulting field difference FD, i.e., the difference between equations (4) and (6), due to motion amounts to: ##EQU4## This implies that, for a given velocity of a sinusoidal pattern, the blurring of the first order recursive noise filter will linearly increase with the frequency.
It makes sense, therefore, to reduce the effect of the temporal recursive filtering with increasing spatial frequency. For a given acceptable degree of filtering in the high frequencies, this means a stronger filtering in the lower spatial frequencies, and therefore a higher gain in (weighted) signal to noise ratio. Or, reversely, for a sufficient increase in signal to noise ratio with the noise filter, less blurring of low-contrast detail will occur, while further, the noise freezing disappears.
The lesser filtering in the high frequencies does not cause a dramatic fall in S/N gain as this gain (weighted) is mainly determined by the low-frequency noise reduction, as can be seen from FIG. 1 which shows the PAL/SECAM noise weighting curve as proposed by the CCIR recommendation 421-1 (Reference (4)). The horizontal axis shows the frequency Fr in MHz, and the vertical axis shows the relative sensitivity RS. FIG. 2 illustrates a desired noise reduction filtering involving an implicit high frequency bypass. The horizontal axis shows the frequency Fr, and the vertical axis shows the filter transfer function |H(f)|. Alternatively, it is possible to provide an explicit bypassing of the high-frequency signal components around the noise filter.
In such explicit high-frequency bypassing noise filters, the motion detector from the prior art temporal recursive filter can be replaced by a 2-D spatial high-pass filter. Consequently, the high-frequency signal components pass the recursive filter without attenuation, while the lower spatial frequencies are temporally filtered. In the z-domain, we can describe this as:
F.sub.F (z.sub.x, z.sub.y, z.sub.t)=H.sub.HP (z.sub.x, z.sub.y)F(z.sub.x, z.sub.y, z.sub.t)+(1-H.sub.HP (z.sub.x, z.sub.y)) . z.sub.t.sup.-1 . F.sub.F (z.sub.x, z.sub.y, z.sub.t) (9)
FIG. 3 shows a simple embodiment of a noise filter in accordance with the invention with explicit high frequency bypass. The noise filter is part of a video signal processing path connected to a display device D; the other elements of the video signal processing path are not shown. An input signal F is applied to a 2-D low-pass filter 3a. An output signal of the LPF 3a is subtracted from the input signal F by a subtracter 3b to obtain the bypassed high frequency signal components. The low-frequency signal components from the LPF 3a are applied to a noise reduction filter 4, the output of which is added to the bypassed high frequency signal components by an adder 6 to obtain the output signal F F which is applied to the display device D. Preferably, the two-dimensional low-pass filter 3a has a bandwidth that is larger than that of the noise weighting function. The bypassed filter circuit shown in FIG. 3 appeared to yield a better performance than the noise reduction filter 4 alone. The following reasons can be given for this improved performance:
The input of the noise filter 4 lacks the high frequencies. Consequently, in an implementation of the noise filter 4 in which samples used in the actual filtering operation are selected from a plurality of potentially available samples, a selection of samples used in the noise reduction filtering will be more consistent throughout the image, which will give a smoother picture. Also, in a recursive implementation of the noise filter 4, the chance that a recursion is interrupted by vertical transients in the image is decreased.
In the output of the total filter arrangement, more high frequencies remain present; they are not affected by the noise reduction filtering. Moreover, the remaining high frequency noise masks any artifacts that a filter would have in the higher frequencies (e.g., phase shifts), and adds a subjective sharpness to the image. The presence of high frequency noise shows a more consistent and appreciated picture to the human visual system.
The difference between a signal at the input of the high-pass filter and at its output can be used to control the filter. When this difference is outside an interval which is controlled by the standard deviation of the noise σ n , the filter is switched off. In this case the transfer function of the filter becomes:
F.sub.F (z.sub.x, z.sub.y, z.sub.t)=H.sub.m (z.sub.x, z.sub.y)F(z.sub.x, z.sub.y, z.sub.t)+(1-H.sub.m (z.sub.x, z.sub.y)) . z.sub.t.sup.-1 . F.sub.F (z.sub..x, z.sub.y, z.sub.t) (10)
where Hm is the modified transfer function of the high-pass filter (HPF), defined as ##EQU5## where alpha is an experimentally optimized constant, and a and b are the input signal and the output signal of the high-pass filter, respectively. This implementation is shown in FIG. 4.
In FIG. 4, an input signal F is applied to a non-inverting input of a subtracter 1, the inverting input of which receives a delayed filtered signal z t -1 .F F . FF. The output signal a of the subtracter 1 is applied to a 2-D high-pass filter 3, the output signal b of which is subtracted from the input signal a of the high-pass filter 3 by a subtracter 5. The output signal (a-b) of the subtracter 5 is applied to a coring circuit 7 which is controlled by the standard deviation of the noise σ n . The output-signal of the coring circuit 7 is added to the output signal b of the high-pass filter 3 and to the delayed filtered signal z t -1 .F F by an adder 9, which provides the filtered output signal F F . This filtered output signal F F is applied to a field delay circuit 11 to obtain the delayed filtered signal z t -1 .F F .
Another, more sophisticated, implementation is given in FIG. 5. Rather than rendering the high-pass filter 3 ineffective by means of the elements 5 and 7, its filtering can be decreased by applying a mixer 13 controlled by a coefficient k, calculated on the base of the absolute difference |a-b| between the signal a at the input of the high-pass filter 3 and the signal b at its output as follows:
H.sub.m (z.sub.x, z.sub.y)=(1-k). H.sub.HP (z.sub.x, z.sub.y)+k(12)
with: ##EQU6## The circuit 7a calculates the mixer coefficients k and 1-k in dependence upon the signals a and b and the standard deviation of the noise σ n . The adder 9' sums the output signal of the mixer 13 and the delayed filtered signal z t -1 .F F to obtain the filtered output signal F F . Thus, the 2-D high-pass filter 3 is used to obtain less filtering in the higher spatial frequencies, and the mixer 13 is used to decrease the filtering.
FIG. 6 shows yet another implementation of the noise reduction filter in accordance with the invention. The input signal F is applied to a (2-D) low-pass filter 3a to obtain a low-frequency signal LF. A subtracter 3b subtracts the signal LF from the input signal F to obtain a high-frequency signal HF. The signal LF is applied to a mixer 13a, the output signal of which is added to the signal HF by an adder 9a to obtain the filtered output signal F F . The output signal of the mixer 13a is also applied to a field delay arrangement 11', comprising a block-summator 11a which calculates the average value of a block of pixels values, a block field delay 11b, which only needs to store one average value per block instead of all pixel values of each block, and a bi-linear interpolator 11c, to obtain delayed pixel values for all pixel positions. The low-frequency signal LF and the output signal of the field delay arrangement 11' are applied to a motion detector 7b to obtain mixer coefficients k and 1-k for the mixer 13a. In this embodiment, the high-frequency signals HF are not subjected to the noise filtering operation carried out by the field delay arrangement 11' and the mixer 13a.
As set out above, the performance of a temporal recursive noise filter can be improved when the spatial high frequencies are not filtered. The high frequencies need not to be filtered, because they are less perceptible. No filtering of the high frequencies also means an improvement of the filter's behavior in the case of movement in the image. In a conventional recursive noise reducing filter in which an attenuated difference between a new signal and a delayed signal is added to the delayed signal, the (implicit) high bypass can be introduced by replacing the attenuation of the difference with a two-dimensional spatial high-pass filter. This filter can be seen as a control filter that adapts the amount of recursion in dependence upon the spatial frequency content.
The same idea of recursive filtering can be extended into the spatial domain. The field delay is replaced by a delay in a spatial direction (e.g., horizontal, vertical, or a diagonal direction). The attenuation of the difference between new and delayed information can be adapted to the image content as follows:
Adaptation to high frequencies: a high-pass control filter (orthogonal to the filtering direction) is used instead of a fixed attenuation factor. In this way, the attenuation factor is increased at high frequencies to provide for an implicit bypass of the high frequencies.
Adaptation to transients: a noise filter which is selective to the image content should decrease its filtering at steep transients in the image. The absolute difference between input and output of the high-pass filter can be used as a detector of transients in the filtering direction. The adaptation of transients is achieved by using the absolute difference to fade the input of the second summation node between the input and the output of the high-pass filter, see fader 79 in FIGS. 7-10.
Adaptation to noise level: the effect of the fader is controlled by the current noise level in the image. In this way, a degradation of almost noise-free images is prevented. For example, a higher noise level increases the thresholds Th1 and Th2 in the non-linear fading function in fader circuit 77 of FIG. 7.
FIG. 7 shows an embodiment of a vertical recursive noise filter in accordance with the invention. The delay element 83 is a line delay, and the high-pass filter 73 is a non-recursive horizontal high-pass control filter with filter coefficients -1/4, 1/2, and -1/4. The filter is thus a recursive filter of which the filtering decreases with increasing spatial frequency in a direction (horizontal) which does not coincide with the direction of the recursion loop (vertical). Alternatively, a pixel delay is used as the delay element 83 in the recursion loop, and the high-pass filter 73 is a vertical filter having line delays. However, to obtain good filtering results, the high-pass filter 73 should contain at least two delay elements, so that this alternative is more expensive (as it needs 2 line delays) than the embodiment in which the recursion loop contains a single line delay 83 and the high-pass filter 73 contains two pixel delays.
In FIG. 7, the input signal F is applied to a non-inverting input of a subtracter 71, the inverting input of which receives a recursive pixel input Rec-pix-in from a line delay 83 to which the filtered output signal F F is applied. The output signal x of the subtracter 71 is applied to a horizontal high-pass filter 73. The output signal y and the input signal x of the high-pass filter 73 are applied to an absolute difference calculating circuit 75, the output of which is applied to a non-linear fading circuit 77 to obtain a fading control signal p. The output signal y and the input signal x of the high-pass filter 73 are also applied to a fading circuit 79 in which they are combined in dependence upon the fading control signal p. The output signal of the fading circuit 79 is added to the recursive pixel input Rec-pix-in from the line delay 83 to obtain the filtered output signal F F .
FIG. 8 shows an embodiment of an extended recursive noise filter in accordance with the invention. This filter can be seen as a few recursive noise filters connected in parallel. In this way, a filter that filters in more directions than the recursive noise filter of FIG. 7 is constructed with just a little extra cost, since the additional pixels do not require an extra line delay but only extra horizontal delays and extra horizontal control filters. The combination of the outputs of the parallel recursive noise filters is achieved by a weighted summation of the parallel branches. Through this form of summation, the branch that currently has the strongest recursive filtering, will have the strongest weight at the output of the overall filter. This allows the filter to change the direction of the filtering without a very large change of the recursive strength of the filter. In more detail, a plurality of pixel delays 85-1 . . . 85-(n-1), each delaying by n pixel periods τ p , is connected to the output of the line delay 83. At the output of each pixel delay 83-i, a recursive pixel input Rec-pix-i can be obtained, while recursive pixel input Rec-pix-n is obtained from the output of the line delay 83. In FIG. 8, only the first parallel branch is elaborated. That branch corresponds to the elements 71 . . . 81 of FIG. 7; the reference number of each element being augmented by the suffix "-1". The output Out 1 of the adder 81-1 is not applied to the line delay 83, but is applied to a weighted averager 87 which also receives the fading control signal p 1 from the non-linear fading circuit 77-1 as a weighting coefficient. In a similar manner, the outputs Out i from the other branches 73-i . . . 81-i are applied to the weighted averager 87 together with their respective fading control signals p i . The fading control signals p i indicate the filtering strengths of the respective parallel branches. The weighted averager 87 supplies the output signal F F to the circuit output and to the line delay 83.
FIG. 9 shows another embodiment of a vertical recursive noise filter in accordance with the invention. This embodiment corresponds to that of FIG. 7, but the high-pass filter 73 of FIG. 7 is replaced by a band-pass filter 73a, and the absolute difference calculating circuit 75 of FIG. 7 is replaced by the cascade connection of a subtracter 75a, a first low-pass filter 75b, an absolute value circuit 75c, and a second low-pass filter 75d. For example, a band-pass filter with tap coefficients -1, 0, 2, 0, -1 can be used at a sample frequency of 16 MHz.
FIG. 10 shows another embodiment of an extended recursive noise filter in accordance with the invention. This embodiment corresponds to that of FIG. 8, but the high-pass filters 73-i of FIG. 8 are replaced by band-pass filters 73a-i, and the absolute difference calculating circuits 75-i of FIG. 7 are replaced by respective cascade connections of a subtracter 75a-i, a first low-pass filter 75b-i, an absolute value circuit 75c-i, and a second low-pass filter 75d-i.
Obviously, it is possible to include motion compensation in the feedback loop of the temporal recursive filter. Although, as discussed above, the filter is less critical for motion blurring, motion compensation proves experimentally to be still a useful sophistication.
A primary aspect of the invention can be summarized as follows. Motion adaptive first order recursive temporal filters are popular in television noise filtering, but introduce comet tails in moving scenes and cause freezing of the noise as the most annoying defects. The current invention proposes a modification to this classical filter that largely eliminates its disadvantages, simplifies the motion detector design, and reduces the need for motion compensation. A primary embodiment of the invention provides a temporal recursive (first order) noise filter for image data, in which the temporal filtering depends on the local spatial image spectrum, such that the temporal filtering is strongest for low spatial frequencies and weaker for higher spatial frequencies. Preferably, the filtering is reduced for all spectral content if the effect of the filter is large, compared to the noise amplitude. Advantageously, motion compensation is included in the feedback loop.
It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. While recursive embodiments are shown, non-recursive (i.e., transversal) implementations are also possible. The invention can be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer.
References:
1! R. N. Jackson and M. J. J. C. Annegarn, "Compatible Systems for High-Quality Television", SMPTE Journal, July 1983.
2! T. Grafe and G. Scheffler, "Interfield Noise and Cross Color Reduction IC for Flicker Free TV Receivers", IEEE transactions on Consumer Electronics, Vol. 34, No. 3, August 1988, pp. 402-408.
3! J. G. Raven, "Noise suppression circuit for a video signal" UK Patent Application no. GB 2083317 A, August 1981, (PHN 9822).
4! "CCIR recommendation 421-1, annex III", Documents de la XIe assemblee pleniere, Oslo, 1966, Volume V, Geneve, 1967, pp. 81-82. | An image data recursive noise filter wherein relatively high spatial frequency components of the image data are either not filtered at all or are filtered to a lesser degree than relatively low spatial frequency components of the image data. This minimizes blurring of fine low-contrast detail and also avoids "freezing" of noise in undetailed moving areas of the image. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims benefit of priority under 35 U.S.C. § 119 to Patent Cooperation Treaty Application No. PCT/FR97/00976, filed on Jun. 3, 1997, the entire contents of which are incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to machine-tools and more particularly, to the arrangement of functional parts of a machine-tool for high speed machining to ensure handling and maintenance under the best conditions.
2. Discussion of Background
High speed machining generally takes place using a tool rotatably driven by the motor driven axis of an electric spindle installed in a ram, wherein the ram is mounted to be movable along X-, Y-, and Z-axes, which are mutually perpendicular to each other.
A machine-tool is typically provided with four main working stations, which are:
(1) an actual machining station, including the machine-tool, driven rotationally by the motor driven axis of the electric spindle, wherein the machine-tool shapes the workpiece to be machined;
(2) a driving station situated up-line (or upstream) from the machining station, wherein the driving station is made up of a group of devices that ensure, in particular, X-, Y-, and Z-axes movements of the ram of the electric spindle, as well as feeding of the electric spindle for the rotation of the electric spindle's tool carrier axis;
(3) a control station operating together with the driving station, wherein the control station functions by using a program of pre-established instructions to take charge of the different stages of machining of the workpiece; and
(4) a magazine for storing tools in order to keep the machine-tools, to be used in the machining process, near the machining area, during the different stages of machining of the workpiece.
The machining station includes the machine-tool and electric spindle for machining the workpiece, wherein the machine-tool is driven by the motor driven axis of the electric spindle, which is fed by electric cables coming from the control station. The electric spindle is housed in a ram, which is movable in the X-, Y-, and Z-axes directions.
The driving station includes all of the motor elements to ensure the X-, Y-, and Z-axes movements of the ram.
The control station is connected to an electric group and a hydraulic group, as necessary, in order to distribute electric and hydraulic power, respectively, and to ensure control of the components using the electric and hydraulic power, respectively.
The function of the machine-tools is to machine the workpiece, in a minimum of time and with a maximum of precision. The shape of the workpieces to be machined is becoming more and more complex, thus requiring the use of several tools, from the nearby tool magazine, or even several machine-tools to ensure complete machining of the workpiece. A configuration including several of the machine-tools taking part in the machining of the same workpiece is called a “machine transfer.” A “machine transfer” can become a “flexible workshop” to ensure the complete machining of several different workpieces. A “machine transfer” is a group of machine-tools which are placed perpendicular to the production line of the workpiece to achieve all the machining stages of that workpiece. Such an installation takes place with respect to limiting factors, namely, the dimension of the machine-tools and especially, the floorspace available for the machine-tools. It is therefore essential, for reasons of cost and space taken up, that the machine-tools be compact in order to enable the installation of a “flexible workshop” or a “machine transfer.” In fact, a principal disadvantage of conventional machine-tools is that they take up a very large amount of floorspace, despite the miniaturization of the components that can presently be achieved. The size of the machine-tool corresponds, first of all, to the machining to be done. In other words, to have a machine-tool that can be flexible, it has to adapt to all machining types and to all dimensions. In any case, the electric spindle needs to be of large dimensions to ensure a high speed of rotation or a large engine power to enable the use of machine-tools of large dimensions. This leads to important dimensions of the ram and consequently, important dimensions of the motor elements to ensure the ram's movements in X-, Y-, and Z-axes directions. In the field in which the present invention applies, the machine-tools are of very large dimensions, so that the users lacking sufficient floorspace to house a machine-tool, must undertake extensions to their premises. This puts a considerable strain on the cost of installing there machine-tools, in addition to the actual cost of the machine-tools.
Another disadvantage of the machine-tools for high speed machining is the fact that it is necessary to authorize access to all the functional parts or components of the machine-tool to ensure adequate maintenance thereof. As a result, access areas which permit an operator to ensure the maintenance of the vital part of the machine-tool, in particular, access areas of the driving station, must be provided around doors, hatches, or windows. The doors, hatches, or windows were conceived to authorize maintenance of the machine-tool, but increase the floorspace needed to set up each machine-tool. In “machine transfers,” even more floorspace is needed, so that not only the amount of floorspace needed to install the machine-tool is increased, but the number of conveyors conveying the workpieces from one machine-tool to another is increased as well.
Another disadvantage of the machine-tools for high speed machining is that they require the presence of a cooling group. In fact, the functioning of the machine-tools raises the temperature of the workpieces at the driving station to a level which would be detrimental for the lifespan of the workpieces, if subsidiary cooling was not set up. This rise in temperature could also lead to the dilatation of the parts of the driving station, which would have as a consequence thereof, a non-negligible loss of precision in the machining of workpieces. The cooling groups are generally of large dimension and are difficult to integrate into the machine-tools.
Starting with these considerations with respect to the original configuration of a machine-tool, applicant has attempted to reduce the floorspace requirement of the machine-tool, while making it easier to access the vital parts for handling, replacement, repair, etc. The configuration of the machine-tools of the present invention rests on a flexible ergonomic arrangement of the functional parts thereof, while avoiding the disadvantages described above with respect to conventional machine-tools.
SUMMARY OF THE INVENTION
According to the present invention, the machine-tool for high speed machining includes a mechanical module made up of a machining station, a driving station, and an equipment module. The equipment module has a variable number “n” of different parts located up-line. The bases of the mechanical and equipment modules are connected to a common or communal supporting frame. The mechanical module is fixedly connected to the common supporting frame. A longitudinal axis of the machine-tool for the equipment module is slidingly connected to the common supporting frame. The machine-tool has different parts, which are mobile and which adopt either of two positions, as follows:
(1) a first or “folded” position, wherein the equipment module and all of its different parts are placed against one another and against the mechanical module; and
(2) a second or “extended” position, wherein the entire equipment module, or a subset of its component parts, have slid on the supporting frame, towards the rear of the machine-tool, so as to form a first handling passage, which runs transversely through the machine-tool.
The above-described flexible ergonomic arrangement has the advantage of adding only the width of the first handling passage to the length necessary for installing the machine-tool. The access areas to the vital parts of the machine-tool are considerably increased by the creation of the handling passage through the machine-tool, between each of the mechanical and equipment modules and between each different part constituting the mechanical and equipment modules.
Another advantage of the flexible ergonomic arrangement of the machine-tool of the present invention is the creation of a handling space running transversely through the machine-tool, while permitting the operator access to the core of the machine-tool. Thus, access for the handling or the maintenance of the different parts, from the inside of the machine-tool, permits the sides of the machine-tool to be kept free from any component needing intervention or handling.
Another advantage of the flexible ergonomic arrangement of the machine-tool of the present invention is that it is easier to reach the motor elements of the machine-tool from its core than from the side. Consequently, instead of opening onto the outside perimeter of the machine-tool, the access hatches can open into a handling passage, created for this purpose by the separation of the control station and the driving station.
Another advantage of the presence of the handling passage is that a machine-tool can be placed with one side against a wall, while staying entirely functional and accessible for its maintenance. In addition, the closing and the opening of the handling passage permits the placement of the machine-tool so as to be positioned in such a way that, its rear part is against a corner of the wall. Thus, the closing of the handling passage into its “folded” position permits access to the rear of the machine-tool and, the opening of the handling passage between both mechanical and equipment modules, or between the parts of the equipment module, permits access to the internal components.
The “folded” position has the advantage of creating a compact machine-tool. The closing of the handling passage ensures the protection of the mechanical, electrical, and hydraulic vital parts from the outside environment.
According to a particularly advantageous characteristic of the present invention, the machine-tool for high speed machining has a supporting frame, on which the equipment module slides. The supporting frame has a length such that when the equipment module does slide towards the rear of the machine-tool, either partially or as entirely, to arrive at the end of its course to go from a “folded” position to an “extended” position, a second handling passage is opened to permit handling between both mechanical and equipment modules, so that when the equipment module slides, only partly in any direction, the second handling passage between the different parts is opened and the first handling passage, that was previously open, is closed.
According to another preferred embodiment of the present invention, the machine-tool for high speed machining includes a machining station, a driving station, a control station, and a control desk. The machining, driving, and-control stations are connected to a common supporting frame. The machining, driving, and control stations are fixed to the common supporting frame so that the machining station and the driving station are situated up-line from the common supporting frame, and are separated from the control station by a handling passage running transversely through the machine-tool to permit access for an operator.
Two to three machine-tools can be placed in contact with one another. The machine-tools must have parallel Z-axes to ensure a savings of space due to the suppression of the intended gap between the machine-tools. This gap was previously necessary in order to enable an operator access from the side for maintenance. Furthermore, when two or three machine-tools are placed laterally against one another, the first and second handling passages, which are now fixed, pass through the aligned machine-tools to ensure communication between the first and second handling passages from one machine to another.
According to another particularly advantageous characteristic of the present invention, the mechanical and equipment modules of the machine-tool for high speed machining adopt a significantly parallelepipedic shape of the same width, thus ensuring a perfect symmetry about the Z-axis. The symmetry of the machine-tool as a whole permits several machine-tools to be place side by side in order to ensure a compact configuration to save on the necessary space. This savings of space is at the level of the clearance areas and permits the integration of more machine-tools onto the same floor area, when the machining line already includes a large number of machines. In addition, during the building and studying of the machine-tool installation on site, the symmetry considerably simplifies the process in abolishing the constraints of clearance areas and in setting up the accessories, such as the tool magazine or the control desk, which can be placed either on the right side or the left side of the machine-tool, depending on the way it was set up.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
The fundamental concepts of the present invention having been exposed hereinabove in their most elementary form, more details and characteristics will come out more clearly when reading the description hereinafter, using as a non-limitative example and having regard to the attached drawings, an embodiment of a machine-tool for high speed machining with a flexible ergonomic arrangement of the functional parts according to the present invention. This description refers to the enclosed drawing figures, as follow.
FIG. 1 is a perspective view of a machine-tool adopting the present invention's flexible ergonomic arrangement of the functional parts.
FIG. 2 is a top view of a machine-tool adopting a fixed position of the handling passage and the control station.
FIG. 3 is a top view of a “machine transfer”, including several machine-tools, to ensure the machining of a workpiece, and illustrates the possibilities of the configuration offered by the flexible ergonomic arrangement of the functional pars of the machine-tools for high speed machining of FIG. 2 .
FIGS. 4 a, 4 b, and 4 c are top views of the machine-tool of FIG. 1 adopting several configurations.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, the machine-tool M for high speed machining includes a mechanical module and an equipment module. The mechanical module includes a machining station P 2 , a driving station P 1 , and a storage station P 4 . The driving station P 1 includes all of the motor elements. The storage station P 4 includes a tool magazine which permits keeping all of the tools necessary for the different machining stages that the machine-tool M has to execute available in a sealed chamber. The equipment module includes a control station P 3 which includes several cupboards and power groups.
According to the main characteristic of the present invention, the mechanical and equipment modules are connected to a common supporting frame 700 on a base. The mechanical module is fixedly connected to the common supporting frame 700 and the equipment module is slidingly connected to the longitudinal axis of the machine-tool M.
As shown in FIG. 4 a, the machine-tool M for high speed machining has an equipment module which is formed of two different parts. A first of the two different parts is a hydraulic group 600 , which is placed against the mechanical module, when the machine-tool M is in its “folded” position, as illustrated. A second of the two different parts is a subset including a cooling group 300 and an electric cupboard 200 . The cooling group 300 and the electric cupboard 200 are situated at the rear of the machine-tool M so that movement therein creates first and second handling passages 100 and 100 ′, respectively.
The first handling passage 100 is opened between the mechanical module, formed by the machining station P 2 and the driving station P 1 , and the hydraulic group 600 , as shown in FIG. 4 b. Thus, access to the hatch 500 of the driving station P 1 is permitted, as well as to the control parts of the hydraulic group 600 , which are situated on the side of the electric cupboard 200 of the hydraulic group 600 .
The second handling passage 100 ′ is opened by the movement of the electric cupboard 200 of the hydraulic group 600 towards the driving station P 1 up to the position in full lock of the electric cupboard 200 . Thus, the first handling passage 100 , between the hydraulic group 600 and the subset (i.e., the cooling group 300 and the electric cupboard 200 ) is closed, as shown in FIG. 4 c. The second handling passage 100 ′ permits access to the hydraulic control parts situated on the side of the hydraulic group 600 and to the electric parts situated in the electric cupboard 200 , when the access doors 210 and 220 are opened.
According to a preferred embodiment of the present invention, the electric cupboard 200 , formed by the hydraulic group 600 , does not have a transverse wall when in the “folded” position. The walls of the driving station P 1 , on the one hand, and the walls of the electric cupboard 200 , on the other hand, seal the parallelepiped formed by the electric cupboard 200 of the hydraulic group 600 .
According to a preferred embodiment of the present invention, the equipment module is formed by the subset (i.e., the electric cupboard 200 and the cooling group 300 ) and the hydraulic group 600 . The hydraulic group 600 is slidingly mounted so as to translate on longitudinal slides. When the machine-tool M goes from the “folded” position, as shown in FIG. 4 a, to an “extended” position, as shown in FIGS. 4 b or 4 c, the first and second handling passages 100 and 100 ′ are fitted with first and second duckboards 110 and 110 , respectively. This permits an operator to have access from above, between the longitudinal slides.
According to a particularly judicious characteristic, the second duckboard 110 ′ is fixed at the base of the hydraulic group 600 . Thus, the second duckboard 110 ′ shows solidarity in all of its movements. The second duckboard 110 ′ also fits under the electric cupboard 200 , when the hydraulic group 600 is placed against the electric cupboard 200 . Another advantage is that the hoses feeding the power are not disturbed by the presence of the second duckboard 110 ′, which is fixed, when communicating under the electric cupboards 200 , between the different parts of the equipment module, and between the mechanical and equipment modules.
According to another preferred embodiment of the present invention, the subset (i.e., the cooling group 300 and the electric cupboard 200 ) has a width equal to twice the width of the hydraulic group 600 . The length, of the supporting frame 700 of the longitudinal slides, which permit sliding movement, is such that, when the machine-tool M is in its “folded” position, the total course of the equipment module or of only the subset, opens a handling passage having a width equal to the width of the hydraulic group 600 . Therefore, the width of the handling passage is equal to half the width of the subset. This characteristic is important in that, as shown in FIG. 1, it enables the machine-tool M to extend to a length longer than the length of the sliding of the supporting frame 700 . Thus, the subset is permitted an overhand of equal to half of its width. A shorter length of the frame 700 allows for freedom from any obstacle or guidance part at the rear area of the machine-tool M. Thus, an optimal compactness of the machine-tool M in the “folded” position is guaranteed.
As shown in FIG. 2, the machine-tool M for high speed machining, according to a second embodiment as illustrated, includes a machining station P 2 , a driving station P 1 , a control station P 3 , and a control desk 400 . The machining, driving and control stations P 2 , P 1 , and P 3 are connected to a common supporting frame 700 . The machine-tool M for high speed machining has different stations which are fixed to the common supporting frame 700 . Thus, the machining station P 2 and the driving station P 1 , which are situated up-line, are separated from the control station P 3 by a first handling passage 100 running transversely through the machine-tool M to permit access for an operator. The control station P 3 includes an electric cupboard 200 to ensure the distribution and the control of the electric parts of the machine-tool M and of a cooling group 300 , which has its control on a side of the first handling passage 100 , to ensure a controlled temperature to the electric parts, which are susceptible to a rise in temperature and to buckling.
According to a particularly advantageous characteristic of the present invention, the cooling group 300 is situated so as to open at the rear of the machine-tool M so that an operator can have access to the controls thereof. The advantage of this arrangement it that the cooling group 300 is left with an air gap opening to the outside, thereby permitting optimal ventilation. This advantage would not have been possible if the cooling group 300 had been situated between the electric cupboard 200 and the first handling passage 100 . Furthermore, the electric cupboard 200 , which includes the electric components, is situated between the cooling group 300 and the first handling passage 100 . The access doors 210 and 220 of the electric cupboard 200 open into the first handling passage 100 . This particular arrangement has the advantage of including all of the electric control components in the same chamber. Since the chamber is accessible from the first handling passage 100 , it does not need a door or access hatch on the side of the machine-tool M.
According to a particularly advantageous characteristic of the present invention, a control desk 400 of the machine-tool M is placed in the first handling passage 100 and is pivotally mounted on a bracket 410 . The bracket 410 is mounted on a vertical axis of the frame 700 of the machine-tool M. In this way, the control desk 400 is either: in a turned position (as represented by broken lines) so that the first handling passage 100 is free for the operator; or is back inside of the first handling passage 100 (as represented by continuous lines) so as to prevent the entire machine-tool M from having any “wart-shaped” components on a side thereof.
According to another particularly advantageous characteristic of the present invention, the driving station P 1 is fitted with an access hatch 500 , which opens into the first handling passage 100 , thus permitting access to the vital parts of the machine-tool M (i.e., to the driving motor elements). This ensures the movement of the ram 800 in the X-, Y-, and Z-axes directions. The electric spindle 810 is housed in the ram 800 to ensure the rotational driving of a tool or spindle 820 .
According to a preferred embodiment of the present invention, the hydraulic plate used to distribute the hydraulic power is situated in the driving station P 1 . Thus, the hydraulic plate is accessible from the access hatch 500 of the driving station P 1 .
The control desk 400 of the machine-tool M is housed, by rotation (continuous lines) of its bracket 410 on which it is fixed, inside of the first handling passage 100 . It can therefore move apart to leave free passage to an operator (broken lines). The electric cupboard 200 and the cooling group 300 have a parallelepipedic shape which make their disposition easier in the compact group of the machine-tool M and permits the machine-tool M to adopt a perfectly symmetrical configuration given that the tool magazine and the control desk 400 of the machine-tool M can change sides.
The “machine transfer”, as shown in FIG. 3, shows several machine-tools M for high speed machining, placed in a machining line so as to participate in the machining of one or more workpieces. From the particular arrangement of the functional parts, these machines can be placed one against the other by two or three, while being completely functional as to the maintenance of the vital parts, such as electric components in the electric cupboard 200 , are carried out from the rear of the machine-tool M and that the maintenance of the motor elements of the driving station P 1 or of the parts of the cooling group 300 , are carried out in the core of the machine-tool M from the first handling passage 100 . The groups of machine-tools M, placed one against another, are moved apart so as to permit access to the machining station P 2 and to the tool magazine P 4 . The tool magazine P 4 is advantageously placed on the side permitting access. The access to the tool magazine P 4 and to the machining station P 2 of the machine-tool M situated between two other tool-machines M is allowed when no machine-tools M are placed opposite to it. A “machine transfer” carried out with the machine-tools M of the present invention takes a lot less space than with conventional machine-tools for high speed machining.
Another advantage of the machine-tools M having a flexible ergonomic arrangement of functional parts thereof and in “machine transfer” is that the first handling passages 100 of each of the machine-tools M are in a line to form a large handling passage permitting the creation of a continuous handling line.
It is understood that the machine-tool for high speed machining of the present invention adopts a flexible, ergonomic arrangement for its functional parts which have been described and represented hereinabove. The functional parts are given for the purpose of disclosure and not limitation. It is obvious that various arrangements of, as well as modifications and improvements to, the above-described example will be possible without departing from the scope of the present invention taken in its broadest aspects and spirit. For example, several technological solutions could be adopted to ensure the movement of the functional parts of the equipment module of the module as a whole on the longitudinal axis of the machine-tool.
In order to permit better understanding of the drawings, a list of the reference symbols with their explanations is presented, as follows:
M machine-tool;
P 1 driving station;
P 2 machining station;
P 3 control station;
P 4 tool storage station;
100 first handling passage;
100 ′ second handling passage;
110 first duckboard;
110 ′ second duckboard;
200 electric cupboard;
210 access door (to electric cupboard 200 );
220 access door (to electric cupboard 200 );
300 cooling group;
400 control desk;
410 bracket;
500 access hatch (to driving station P 1 );
600 hydraulic group;
700 common supporting frame;
800 ram;
810 electric spindle; and
820 tool or spindle. | A high speed machining machine-tool including a mechanical module having a machining station and a driving station and an equipment module with “n” number different parts located up line. The module bases are connected to a common supporting frame, with the mechanical module being fixedly connected thereto. The equipment module is connected to the machine so as to slide on its longitudinal axis. The different mobile parts of the machine-tool adopt two positions: a first, so-called “folded” position, in which the equipment module and all its parts engage each other and the mechanical module; a second, so-called “extended” position, in which the whole equipment module or a subset of its component parts have slid on the supporting frame towards the rear so as to form a transversal handling passage running through and through the machine. The invention is useful for high speed machining. | 8 |
This is a continuation-in-part of application Ser. No. 07/940,247, filed Sep. 4, 1992, now abandoned.
FIELD OF THE INVENTION
The present invention relates to elastomeric compositions comprising blends of epoxidized natural rubber and natural rubber.
BACKGROUND OF THE INVENTION
The various situations requiring elastic materials have led to the development of a wide range of natural and synthetic rubbers. Many of the more demanding situations have required blends of these rubbers to provide the proper mix of characteristics. For example, vehicle tires often include styrene-butadiene rubber (SBR), which is the most common synthetic elastomer, polybutadiene (BR), and even natural rubber. The characteristics usually associated with natural rubber, i.e., abrasion resistance, resilience, good high- and low-temperature performance, and tear strength are ideal for tires and similar applications, which experience great punishment.
However, other environments have less demanding strength requirements, but make other strict demands on elastomers. For example, in the clothing industry, elastomers used for form fitting clothing have a unique set of requirements. These include a low stretch modulus, high dimensional stability (to retain the article's shape), low permanent set (to avoid losing the snug fit of a garment), and tear resistance (to avoid tearing while being punctured by the sewing needle). These demands are compounded, for example, when the garment is swimwear. In this area, in addition to the clothing fit requirements, the garment may be exposed to large amounts of sunlight, chlorine from pool water, salt-water, and oils from body perspiration and sun protection lotions.
A common choice of elastomer for clothing elastication purposes is natural rubber (cis-1,4-polyisoprene). It provides excellent elongation properties, can be made soft, has very good tear resistance and is strong. However, it is severely deficient in resistance to sunlight, oils, or chlorine. A common synthetic substitute for natural rubber in clothing is Neoprene tape, which has excellent resistance to oil, ozone, abrasion and solvents. Unfortunately, the neoprene is not as elastic as the natural rubber, and it takes a permanent set when it stretches that can range up to 25%, which greatly distorts a garment. Neoprene is also much more expensive than natural rubber and has a lower yield due to its higher specific gravity.
In recent years, a new type of elastomer has become available, namely epoxidized natural rubber (ENR). ENR is usually produced by the chemical modification of natural rubber latex with peroxycarboxylic acids. A key advantage gained by this modification is increased resistance to swelling by hydrocarbon oils and solvents. ENR also has excellent tensile strength and fatigue properties. In addition, a high degree of reinforcement may be obtained with silica fillers, even in the absence of a coupling agent. However, the surface characteristics (i.e., the look and feel) of the epoxidized natural rubber do not match those of natural rubber, making epoxidized natural rubber a less than ideal choice for garments. Epoxidized natural rubber is also more difficult to sew than natural rubber, partly because of a tendency to tear due to the sewing needle. ENR also has an undesirably high permanent set.
To take advantage of the benefits of both the natural rubber and the epoxidized natural rubber, a hybrid would be ideal. However, it has been found that the specific interactions between the hydrogens of isoprene units (in the natural rubber) and the oxirane oxygens of epoxidized isoprene moieties (in the ENR), are weak. Previous tests have shown that the two materials do not mix well. Without proper uniformity in the attempted blends, it has been difficult to form a blend that has consistent properties needed for applications such as vehicle tires or footwear. In Japanese patent application 1992-126737, a composition of ENR and natural rubber is disclosed, although large percentages of carbon black and oils are necessary to produce the tire treads disclosed therein.
It is thus an object of the invention to provide a composition for use in elastication of garments that has the superior qualities of both natural rubber and epoxidized natural rubber.
It is another object that the composition have high chlorine, salt-water, and oil resistance; a low permanent set; snug gather; and resistance to sunlight exposure.
It is a further object of the invention to provide a composition that attains the desired properties, while being cost-efficient.
SUMMARY OF THE INVENTION
In view of the foregoing objects, an elastic composite is provided having natural rubber and epoxidized natural rubber components that are blended together in proportions described below. When formed in a tape, the composition is extremely useful for legbands, straps and contours of swimwear and other garments.
The foregoing and other objects and advantages will become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to the invention, a composition comprising a component of natural rubber and a component of epoxidized natural rubber (ENR) is provided. Usually, epoxidized natural rubber is epoxidized in solution by acids, such as perbenzoic, perphthallic, and peracetic acids. The two most commonly available forms of ENR are ENR25 (25 mole % epoxidized) and ENR50 (50 mole % epoxidized), now available from Guthrie, Inc. of Malaysia. Other grades of epoxidized natural rubber may be used.
The natural rubber component is preferably supplied in a bulk crumb form. The natural rubber and epoxidized natural rubber are mixed in a BANBURY internal heated mixer for a time sufficient to mix the two components into a uniform blend, although it is assumed that the mixing only occurs on the granular level, and not the molecular level. The resulting blends have a high degree of homogeneity. Other conventional mixers, such as an open mill mixer, rubber mill, Brabender mixer, or twin-screw continuous mixer may also be used.
While the mixing continues, additional ingredients are added. Such ingredients may include, but are not limited to, accelerators, antioxidants, prevulcanization inhibitors, reinforcement fibers, pigments, dyes, and process oils. These and other processing aids are added in normal fashion depending on the specific mixing protocol used. Such techniques are well known to those skilled in the art. The specific components and their parts per hundred rubber are shown in Table 1. Alternate vulcanizing/accelerator combinations commonly used for rubber compounding may also be used with similar results.
TABLE 1______________________________________ PARTS PER HUNDRED RUBBER Em- Em- Em- Preferred bodiment bodiment bodimentINGREDIENT Ranges #1 #2 #3______________________________________Crumb Natural 25.00-65.00 50.00 47.50 30.00RubberENR 35.00-75.00 50.00 47.50 50.00Antioxidant 0.75-1.50 1.25 1.25 1.25Activators 3.50-6.50 5.00 5.00 4.00Fillers 7.00-60.00 31.00 31.00 30.00Accelerators 1.25-3.75 2.55 2.55 2.36Pigment 0.25-1.00 0.47 0.47 0.0Vulcanizing 0.65-1.80 0.98 0.98 2.00AgentsMethacrylate 0.00-10.00 0.00 5.00 0.00Grafted NREPDM 10.00-35.00 0.00 0.00 20.00______________________________________
The filler listed may be a talc or calcium carbonate or other soft filler and may include titanium dioxide, which can be totally or partially replaced with Silica filler and/or clays. For some applications, it is contemplated that up to 60 parts per hundred rubber of filler might be used. EPDM is an ozone-resistance agent--EPDM terpolymer (ethylene--propylene/diene monomer). A preferred EPDM is Royalene 525, available from Uniroyal. Conventional antioxidants, such as those from the hindered phenol family, may be used. A pre-vulcanization inhibitor, such as N-(cyclohexyl-thio)phthalimide sold under the tradename Santogard PVI by Monsanto, may optionally be employed. If desired a process oil or extender, such as naphthenic acid, may be added.
The activator preferably includes zinc oxide and stearic acid. The accelerators preferably include benzothiazyl disulfide and di-morpholino disulfide. The vulcanizing agents preferably include sulfur and alkyl phenol disulfide.
In the case of the second embodiment of the invention, methacrylate grafted NR (MGNR) is added as a compatibility improvement agent. MGNR may be obtained from Heveatex of Rhode Island. Both the natural rubber and epoxidized natural rubber exhibit increased compatibility with the MGNR than with each other, so the MGNR acts as a bridge to improve the bond between adjacent grains of natural rubber and epoxidized natural rubber. Compatabilizing agents other than MGNR can also be used, such as other graft or block copolymers that preferably have at least one segment which is compatible with the natural rubber being used and at least one segment that is compatible with epoxidized natural rubber. An example is SIS (styrene-isoprene-styrene) copolymer.
The preferred epoxidation level of the ENR is 50. Since ENR with varied epoxidation levels can be produced, it is preferred that the amount of the ENR satisfy the following equation: ##EQU1## wherein % mole (ENR) is the mole % epoxidation level of the ENR and pph (ENR) is the parts per hundred rubber of the ENR. While the level of epoxidation may be varied and still satisfy the equation, it is preferred that the pph(ENR) remain within the range of about 35 to about 75. After the composition is well blended, it is calendared to form a thin sheet of predetermined thickness, depending on the desired application (between about 0.010 and about 0.040 inches in thickness). The sheet is then cured, e.g. by continuous extrusion through a hot air oven. The cured sheet is then slit into tape form. Various widths of tape are prepared to meet different requirements for use in garments, e.g., arm bands, waist bands and leg bands. The tape is desirably slit into widths of between about 1/16 and 1 inch. The tape may then be festooned in continuous length into a box for shipping. Alternatively, the tape may be spooled.
As can be seen in Table 2, the first and second embodiments according to the present invention provide as good or better elasticity than natural rubber alone or neoprene. The oil resistance of the two compositions, as measured by the growth in the volume of a sample (oil swell %) and the rise in percentage weight over time (oil absorption %) is from 2 to 10 times better than natural rubber alone. The oil properties can be determined in a known manner, such as by immersion in oil for several hours. Suitable oils for immersion are desirably selected from those likely to be encountered by a garment while worn, e.g., baby oil, tanning oil, and sunblock formulations.
TABLE 2______________________________________ Embodiment Embodiment NEO- no. 1 no. 2 NR PRENE______________________________________Modulus of 170 +/- 20 190 +/- 20 180-240 220-280Elasticity@100% (PSI)Oil Swell 5 +/- 1 2 +/- 1 13-15 n.a.(%)Oil 10 +/- 2 4.5 +/- 2 35-40 4-7Absorption(%)Permanent 7 +/- 2 8 +/- 2 7-14 17-22Set (%)______________________________________
As shown in Table 2, the present compositions exhibit a lower modulus of elasticity with respect to either natural rubber alone or neoprene. The oil swell and oil absorption properties are also lower than natural rubber, and in the case of embodiment No. 2, lower than both.
The permanent set, i.e., the non-recoverable stretch, of the ENR-NR compositions is half that for neoprene and lower than that for natural rubber alone. Although not shown in table 2, the tear strength of the present compositions is higher than for ENR alone. Whereas most common elastomers used in swimwear turn yellow after prolonged exposure to light and/or chlorinated pool water, the ENR-NR compositions turn bluer, adding to the aesthetic appeal of the ENR-NR compositions.
Thus, the composition of the present invention is particularly useful in forming an article of manufacture that achieves several optimum properties simultaneously. Previous compositions provided benefits in terms of one or two properties while lacking in others. Specifically, the composition can be used in an article that has the advantageous properties of low oil swell and oil absorption, low permanent set, low modulus of elasticity, and high tear strength. In the preferred embodiment, the composition of the present invention can be use in the manufacture of garments, such as swimwear, which would take advantage of the enhanced properties of the present composition.
Another preferred embodiment of the present invention (Embodiment No. 3 in Table 2) is described below. This embodiment incorporates an agent to enhance the oil resistance and ozone resistance of the elastic composition. Ozone resistance is important to prevent degradation of the composition upon extended exposure to low concentrations of ozone which may be present in the atmosphere. For example, for garments displayed in a store window, fluorescent lamps tend to increase local ozone levels. In Table 3 below, a natural rubber-EPDM elastic tape exhibiting ozone resistance (Control), is compared to inventive Embodiment No. 3.
TABLE 3______________________________________PHYSICALPROPERTIES CONTROL Embodiment #3______________________________________Modulus 100% psi 238 182Modulus 200% psi 403 318Modulus 300% psi 656 492Permanent Set % 18.0 13.5Heat age % Retained 95.0 85.0Oil Swell (4 hr.) % 19.6 8.3Oil Absorption % 74.0 31.0Ozone Exposure no cracks no cracks(12 weeks) Test______________________________________
As can be seen from Table 3, the inventive elastomer (Embodiment No. 3) containing both EPDM and ENR-50 is ozone-resistant. However, the oil absorption and oil swell properties of the inventive elastomer are greatly improved compared with the control.
The ozone exposure test was conducted by subjecting the elastomer sample in tape form to 20% elongation, and exposing the sample to an air environment containing a sufficient concentration of ozone to degrade natural rubber over a one-week period. After the 12-week test period, the sample is visually examined for cracking and or deterioration.
While the embodiments shown and described are fully capable of achieving the objects and advantages of the invention, it is to be understood that these embodiments are shown and described for the purpose of illustration and not for the purpose of limitation. | An elastic composite is provided having natural rubber and epoxidized natural rubber components. Compared to known composites, the present composition achieves reduced oil swell and absorption, lower permanent set, lower modulus of elasticity, and high tear strength. When formed in a tape, the composition is extremely useful for legbands, straps and contours of swimwear and other garments. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to packaging according to the preamble of Claim 1 .
2. Description of the Related Art
Packaging of this type is currently used, for example, for packing food products such as confectionery: pralines chocolates and the like. On this subject, see, for example, some of the packagings forming the subject of the International Models DM/033113 or DM/040299.
The aforesaid packagings are usually intended to contain one or several rows, possibly one layer above the other, of similar or different products.
Should the package house different products, it could prove advantageous to ensure that some products—perhaps because they are considered especially select or attractive—can be made to stand out from the others. This can be achieved, for example, by using wrappings for these products of a color which contrasts with that of the other products.
This arrangement is not always possible to put into practice however. There are situations, for example, where the products one would like to stand out have traditional wrappers which it would be a mistake to alter only to draw attention to them in a mixed pack. The same argument may apply in a complementary manner to the wrappers of other products intended for such packaging.
In any case, the above arrangement does not solve the problem of how to make particular products to stand out when the package, generally a box, is not viewed in plan (that is from a perspective that is perpendicular or substantially perpendicular to the plane of the row or rows of products) but from the side, with a fairly restricted angle of observation: typically, this situation occurs when the package is arranged on a shelf of a shop window or on a counter and is viewed horizontally or almost horizontally. It will be appreciated that this type of problem also arises in packs which contain products which are all the same.
SUMMARY OF THE INVENTION
The object of the present invention is thus to provide packaging of the type described above which is able to meet the requirements specified above, while avoiding the disadvantages described.
This object is achieved, according to the invention, by providing packaging having the characteristics claimed in the appended Claims.
In addition to providing an entirely satisfactory response to the requirements set out above, the packaging of the invention has the additional advantage that the characteristic lens formations of the packaging give a jewel-like effect, with reflected light creating an attractive sparkling effect which catches the attention of anyone looking at the packaging and the products contained therein.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The invention will now be described, purely by way of non-limitative example, with reference to the appended drawings, in which:
FIG. 1 is a perspective view of a package according to the invention,
FIG. 2 is a section taken on the line II—II of FIG. 1,
FIG. 2A is a section through an alternative embodiment of the package shown in FIG. 1; and
FIG. 3 illustrates a possible variant of the arrangement of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the drawings, the reference number 1 generally indicates a package which can be used, for example, to pack food products such as confectionery, that is pralines, chocolates and the like.
For example (without, of course, intending to limit the scope of the invention), the products P could be constituted for, example, by confectionery such as that sold under the brand names Ferrero Rocher, Confetteria Raffaello, Mon Cheri or Pocket Coffee by companies of the Ferrero group.
In the embodiments illustrated here, the package 1 is substantially in the shape of a more or less flattened box, comprising a bottom tray-shape part 2 with an associated removable lid 3 which closes the opening thereof.
In the examples illustrated, both the bottom 2 and the lid 3 are made entirely of a transparent material and the lens formations 4 , which will be described in greater detail later, are present only on the lid 3 .
It must be emphasized that these choices are purely by way of example as, for instance, the bottom tray 2 could be made, at least in part, of a non-transparent material, while the lens formations 4 could be only on the bottom tray 2 (around the sides thereof, for example) instead of only on the lid 3 , or could be both on the bottom 2 and on the lid 3 .
As will be understood more clearly from the description which follows, the use of a transparent material is important only in order to achieve the characteristic optical effect of the lens formations 4 . The preferred choice, at least for the transparent components, is a plastics material such as clear polystyrene, for example.
Other options are of course possible, especially for the non-transparent portions (typically cardboard or card).
In the same way, the fact that the embodiments illustrated here refer to prismatic box-shaped packages which receive flat rows of products P inside them, should not be seen in any way as limiting the scope of the invention.
The arrangement of the invention is suited, in fact, to be applied to packaging of any shape (in addition, for example, to the rectangular box illustrated here, it could be circular, elliptical, heart-shaped, lobed, ring-shaped or any other curved and/or linear shape) and also to packaging intended to hold superposed layers of rows of products. It is also clear that the typical effect achieved by the use of the lens formations 4 applies primarily to the products arranged in a housing positions adjacent the said formations rather than to products which are concealed by other products—for instance as a result of several layers being one on top of the other.
The specific criteria involved in the manufacture of the package have little bearing on the achievement of the characteristic result of the invention (and are thus able to be modified within a broad range of possible alternative arrangements), in particular with regard to the housing and positioning of the products P within the packaging.
In this context, the appended drawings refer, purely by way of example, to an arrangement in which the bottom part 2 is constituted essentially by a sort of tray (see FIG. 2 ), comprising a flat bottom wall 20 surrounded by peripheral walls 21 , with a liner 22 inserted therein. The latter is usually made of plastics material (so-called acetate), shaped, usually by heat molding, so as to form a plurality of cavities 23 . Each cavity 23 forms, within the packaging 1 , a housing for a product P. In the embodiment illustrated here, the products P are shown as approximately spherical pralines, wrapped in sheet material and resting in respective cups B of folded card.
A vital characteristic of the arrangement of the invention consists in the fact that a respective lens formation 4 is arranged over each housing position of a product P, defined by a cavity 23 (see the examples of FIGS. 1 and 2 ), or over only some positions thereof (see the arrangement of FIG. 3 ).
In the embodiments illustrated here by way of example, the formations 4 are formed in the lid 3 : however, as stated earlier, formations of this type could be arranged alternatively on the body 2 rather than on the lid 3 , or both on the body 2 and on the lid 3 .
In the embodiment illustrated, the lens formations 4 are defined by local variations in the thickness of the wall of the lid 3 . In particular, each lens formation 4 is constituted by a respective portion of lid in the shape of a very squat, square-based pyramid. In other words, the lid is mo[u]lded in a raised, “diamond” pattern.
This embodiment has proved particularly advantageous in achieving the aim of drawing attention to a respective product P as described in the introduction to the present description. This is especially true (thanks to the number of faces making up each pyramid or diamond formation) of the so-called “jewel” effect observed when the packaging is viewed from a narrow angle of vision, as shown schematically by the arrow V of FIG. 2 .
It is clear, however, that the aforesaid lens formations could also be shaped entirely differently. For example, while retaining a general pyramid shape, the base could differ from the square illustrated, being a triangle, a pentagon, a hexagon etc. Similarly, instead of having a pyramid shape, the formations 4 could be a frustum of a pyramid or of a cone, a section or a segment of a sphere etc.
Although the embodiment illustrated here provides for the thickness of the lid 3 (or, in general, of the respective part of the package 1 ) to vary at the site of each formation 4 , so as to form an (at least slight) outward projection or protuberance on the packaging 1 , this choice is in no way compulsory.
For example, the variation in the thickness of the wall could go in the opposite direction, as shown in FIG. 2A, thereby keeping the outside of the box smooth, with the aforesaid projections or protuberances facing inwardly of the packaging, or forming convex or concave surfaces both inwardly and outwardly of the packaging 1 .
The variation in the thickness of the wall, which in the example illustrated aims essentially to provide formations with a convex projecting surface (outwardly or inwardly of the packaging), could also work in the exact opposite way, creating a concave rather than convex surface at the site of each lens formation.
It is not in fact essential to act on the thickness of the wall, since the desired effect can be achieved, at least in some cases, by simply shaping the wall, rather than actually varying the thickness thereof.
The expressions “lens formation” and/or “lens means” are thus used here in the broadest meaning of the terms, thereby indicating any body of at least partially transparent material (the material may in fact be pigmented) limited by two surfaces, the one flat and the other shaped or both shaped.
It will be appreciated that, as indicated earlier, the arrangement of the invention is suited either to drawing attention to all the products P in the packaging 1 or to just some of these.
Thus, in the embodiment illustrated in FIGS. 1 and 2, a lens formation 4 is provided for each position housing a product P. In this case, all the products P contained in the packaging adjacent the lid 3 benefit from the characteristic ability of the invention to draw attention.
In the embodiment of FIG. 3 on the other hand, only a few of the positions provided for housing products P have associated lens formations 4 in the lid 3 . In this case, the characteristic ability of the invention to draw attention is focused on the products P housed in the said positions, although not exclusively.
Naturally, the principle of the invention remaining the same, manufacturing details and embodiments may be widely varied from those described and illustrated, without departing thereby from the scope of the present invention. | Packaging is preferably constituted by a box which includes a base part and a lid, preferably of transparent plastics material. Adjacent at least some of the sites provided to house the products, constituted usually by confectionery such as pralines, chocolates and the like, lens formations are arranged which draw attention to the corresponding products, both by creating light-reflecting effects similar to those seen in a jewel, and by making it easier to see the products, even when the packaging is viewed from a very narrow angle. | 0 |
BACKGROUND OF THE NEW VARIETY
The present invention relates to a new and distinct variety of distinct variety of peach tree, ‘ Prunus persica ’, and which has been denominated varietally as ‘Burpeachtwentysix’.
ORIGIN
The present variety of peach tree resulted from an on-going program of fruit and nut tree breeding. The purpose of this program is to improve the commercial quality of deciduous fruit and nut varieties, and rootstocks, by creating and releasing promising selections of Prunus, Malus and Juglans regia species. To this end we make both controlled and hybrid cross pollinations each year in order to produce seedling populations from which improved progenies are evaluated and selected.
The seedling, ‘Burpeachtwentysix’ was originated by us and selected from a population of seedlings growing in our experimental orchards located near Fowler, Calif. The seedlings, which were grown on their own roots, were derived from a cross that we made in 2004 of the yellow-fleshed freestone peach identified as E62.012, which was used as the seed parent; and a white-fleshed freestone peach tree identified as E48.050, which was used as the pollen parent. As the fruit ripened the resulting seed from this cross was stratified, germinated, and then was subsequently grown in a greenhouse to an appropriate stage of development. Subsequently, the new plants were field planted, and then grown for further evaluation. One seedling, which is the present variety, exhibited especially desirable characteristics, and was then designated as ‘P4.099’. This seedling was then marked for subsequent observation. After the 2006 fruiting season, the new variety of peach tree ‘P4.099’, now named ‘Burpeachtwentysix’ was selected for advanced evaluation and repropagation.
ASEXUAL REPRODUCTION
Asexual reproduction of this new and distinct variety of peach tree was accomplished by budding the new peach tree ‘P4.099’ onto ‘Nemaguard’ Rootstock (unpatented). This was performed by us in our experimental orchard which is located near Fowler, Calif. Subsequent evaluations of these asexually reproduced plants have shown those asexual reproductions run true to the original tree. All characteristics of the original tree, and its fruit, were established, and appear to be transmitted through these succeeding asexual propagations.
SUMMARY OF THE VARIETY
‘Burpeachtwentysix’ is a new and distinct variety of peach tree, which is considered of medium to medium large size, and which has a moderately vigorous growth characteristic. This new peach tree is also a regular and productive bearer of relatively large, firm, yellow-fleshed, freestone fruit which have a good flavor and eating qualities. This new peach tree has a medium chilling requirement of approximately 550 hours, and further produces relatively uniformly sized fruit throughout the tree. In addition to the foregoing, the fruit of the new peach tree also appears to have good handling and shipping qualities.
The ‘Burpeachtwentysix’ peach tree bears fruit which are ripe for commercial harvesting and shipment on approximately August 10 to August 17 under the ecological conditions prevailing in the San Joaquin Valley of central California. In relative comparison to the ‘Burpeachfour’ peach tree (U.S. Pat. No. 12,405), which produces fruit having a similar harvesting date, the new variety of peach tree bears fruit which exhibits a higher level (approximately 3-7 brix) of soluble solids than the ‘Burpeachfour’ when both varieties have been grown and evaluated under the same cultural conditions, and at the same geographical location. Further fruit of the subject variety generally exhibits a more oblate shape than does the ‘Burpeachfour’. Further, with respect to the pollen parent (E48.050) this variety ripens about one month earlier than the present variety. Additionally, with respect to the seed parent (E62.012) this variety ripens one month later than the new variety.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawing, which is provided, is a color photograph of the new peach tree variety. The photograph depicts two whole mature fruit showing the top and bottom characteristics thereof, and one mature fruit bisected laterally along the equatorial plane, and which reveals the flesh characteristics thereof. The external coloration of the fruit as shown in the photograph is sufficiently matured for harvesting and shipment. Additionally, the photograph displays a sample vegetative shoot bearing typical leaves, and a typical stone, with the flesh removed to display the surface characteristics thereof. The colors in this photograph are as nearly true as is reasonably possible in a color representation of this type. Due to chemical development, processing, and printing, the leaves and fruit depicted in this photograph may or may not be accurate when compared to the actual specimen. For this reason, future color references should be made to the color plates (Royal Horticultural Society) and descriptions provided, hereinafter.
NOT A COMMERCIAL WARRANTY
The following detailed description has been prepared to solely comply with the provisions of 35 U.S.C. §112, and does not constitute a commercial warranty, (either expressed or implied), that the present variety will in the future display the botanical, pomological or other characteristics as set forth, hereinafter. Therefore, this disclosure may not be relied upon to support any future legal claims including, but not limited to, breach of warranty of merchantability, or fitness for any particular purpose, or non-infringement which is directed, in whole, or in part, to the present variety.
DETAILED DESCRIPTION
Referring more specifically to the pomological details of this new and distinct variety of peach tree, the following has been observed during the fourth fruiting season under the ecological conditions prevailing at the orchards of the assignee which are located near the town of Fowler, county of Fresno, state of California. All major color code designations are by reference to The R.H.S. Colour Chart (Fourth Edition) provided by The Royal Horticultural Society of Great Britain. Common color names are also occasionally used.
TREE
Size: Generally. Considered medium to medium large as compared to other common commercial peach cultivars ripening in the late season of maturity. The trees of the present variety were pruned to a height of approximately 280.0 cm to about 300.0 cm at commercial maturity.
Vigor: Considered vigorous. The present peach tree variety grew from about 170.0 cm to about 175.0 cm in height during the first growing season. The new variety was pruned to a height of approximately 160.0 cm during the first dormant season, and primary scaffolds were then selected for the desired tree structure.
Productivity: Productive. Fruit set varies from more than the desired crop load to levels much higher than desired levels when grown in a suitable horticultural zone, and under normal commercial conditions. The fruit set is spaced by selective thinning to develop the remaining fruit into the desired market-sized fruit. The number of the fruit set varies with the prevailing climatic conditions and cultural practices. Therefore, productivity is not a distinctive characteristic of the new variety.
Fruit bearing: Regular. Fruit set has been above average during the previous years of observation, and thinning was necessary during the past 4 years on both the original seedling and on subsequently asexually produced trees.
Form: Upright, and pruned into a vase shape.
Density: Considered moderately dense. It has been discovered that pruning the branches from the center of the trees to obtain a resulting vase shape allows for air movement and appropriate amounts of sunlight to enhance fruit coloration, and renewal of fruiting wood throughout the tree.
Hardiness: The present tree was grown and evaluated in USDA Hardiness Zone 9. The calculated winter chilling requirements of the new tree is approximately 550 hours at a temperature below 7.0 degrees C. The present variety appears to be hardy under typical central San Joaquin Valley climatic conditions.
TRUNK
Diameter: Approximately 12.5 cm in diameter when measured at a distance of approximately 15.24 cm above the soil level. This measurement was taken at the end of the fourth growing season.
Bark texture: Considered moderately rough, with numerous folds of papery scarfskin being present. Since bark development and coloration change with the tree age this characteristic varies with tree vigor, age and regional environmental conditions, and therefore is not a dependable descriptor of the variety.
Lenticels: Numerous flat, oval lenticels are present. The lenticels range in size from approximately 4.0 millimeters to about 6.0 mm in width, and between about 1.0 and about 2.0 millimeters in height. The development and size of the trunk lenticels can be influenced, to some degree, by the ambient growing conditions, and are not, necessarily, a dependable characteristic of this variety. As trees of this variety mature, lenticels are present but are generally covered by increasing layers of cork (mature bark) and therefore are less apparent.
Lenticel color: Considered an orange brown, (RHS Greyed-Yellow Group 162 C).
Bark coloration: Variable, but it is generally considered to be a medium brown, (RHS Greyed-Orange Group 166 B). This bark description was taken from trees in their fifth leaf which have not yet ruptured the scarf skin, nor developed bark furrowing which is much more typical of the bark of older trees. It should be noted that the coloration of the bark varies as the smoother, darker background color approaches other bark features such as the bark lenticels and the initial fissures which become present during scarf skin development.
BRANCHES
Size: Considered medium for the variety.
Diameter: Average as compared to other peach varieties. The branches have a diameter of about 7.5 centimeters when measured during the fourth year after grafting.
Surface texture: Average, and appearing furrowed on wood which is several years old.
Crotch angles: Primary branches are considered variable, and are usually growing at an angle of about 51 to about 58 degrees when measured from a horizontal plane. This particular characteristic is not considered distinctive of the variety as this characteristic can be influenced, to some degree, by tree vigor, rootstock and other cultural conditions.
Current season shoots: Surface texture—Substantially glabrous.
Internode length: Approximately 2.5 cm.
Color of mature branches: Grey brown, (RHS Grey-Brown Group N199 D).
Current seasons shoots: Color.—Medium-light green, (RHS Green Group 143 B). The color of new shoot tips is considered a bright and shiny green (RHS Green Group 143 A). The vegetative shoot color can be significantly influenced by plant nutrition, irrigation practices and exposure to sunlight, and therefore should not be considered a consistent botanical characteristic of this variety.
LEAVES
Size: Considered medium for the species. Leaf measurements have been taken from vigorous, upright, current-season growth, at approximately mid-shoot. It should be understood that the leaf size is often influenced by prevailing growing conditions, the amount of sunlight, and the location of the leaf within the tree canopy. For this reason, leaf sizes can vary significantly based upon the factors listed above and are not typically considered a dependable botanical descriptor. Leaf bud burst typically occurs about March 8-10 under typical cultural conditions.
Leaf length: Approximately 150.0 to about 170.0 millimeters.
Leaf width: Approximately 27.0 to about 33.0 millimeters.
Leaf base-shape: The leaves generally exhibit equal marginal symmetry relative to the leaf longitudinal axis.
Leaf form: Lanceolate.
Leaf tip form: Acuminate.
Leaf color: Upper Leaf Surface—Dark green, (approximately RHS Green Group 131 B).
Leaf texture: Glabrous.
Leaf color: Lower Surface—Deep green, (approximately RHS Yellow-Green Group 146 B).
Leaf venation: Relatively broadly pinnately veined.
Mid-vein: Color.—Considered a light yellow-green, (approximately RHS Yellow-Green Group 150 C) in the early to mid period of the growing season.
Leaf margins: Gently undulating.
Form: Considered bluntly serrate, occasionally biserrate.
Uniformity: Considered generally uniform.
Leaf petioles:
Form.— Considered canaliculate but having a shallow channel and more pronounced trough from the dorsal aspect. Rounded from the ventral aspect. Size.— Considered medium large for the species. Length.— About 9.0 to about 11.0 mm. Diameter.— About 1.5 to about 2.0 mm.
Color: Pale green, (approximately RHS Yellow-Green Group N144 C).
Leaf glands:
Size.— Considered small for the species; approximately 1.0 mm in length, and about 1.0 mm in height. Number.— Generally one to two glands per marginal side are found. Observations of more than two glands per marginal side are more uncommon. Type.— Generally considered to be a tight, small reniform shaped gland. Color.— Considered a pale green, approximately (RHS Green Group 143 B). Typically the coloration of the glands darkens and occasionally begins to desiccate during and after the mid-late growing season.
Leaf stipules:
Size.— Medium large for the variety. Number.— Typically 2 per leaf bud, and up to 6 per shoot tip. Form.— Lanceolate in form and having a serrated marginal edge. Color.— Green, (approximately RHS Green Group 137 A) when young, but graduating to a brown color, (approximately RHS Greyed-Orange group 164 C) with advancing senescence. The leaf stipules are generally considered to be early deciduous.
FLOWER
Flower buds: Hardiness.—No winter injury (bud death) has been noted during the last several years of observation in the central San Joaquin Valley. The new variety of peach tree has not been intentionally subjected to drought or heat stress, and therefore this information is not available.
Date of first bloom: Observed on Feb. 24, 2010. Flower bud color at slight bud swell is reddish-purple (RHS Grey-purple 183C).
Blooming time: Considered medium in relative comparison to other commercial peach cultivars grown in the central San Joaquin Valley. The date of full bloom was observed on Feb. 30, 2010. The date of full bloom varies slightly with climatic conditions, and prevailing cultural practices. The bloom has a slight pleasant fragrance.
Duration of bloom: Approximately 9 days. This characteristic varies slightly with the prevailing climatic conditions.
Flower type: The variety is considered to have a showy type flower.
Flower petals .—About 17-21 mm. in length; About 14-18 mm. in width; Ovoid in shape; Marginal form .—Undulating; Color .—Light pink (RHS Red-purple group 65C); An apical groove is typically present; Petal claw shape .—Triangular; Width — 7.0-9.0 mm.; Length — 10-12 mm.; Flower pedicel .—Length — About 4.0-5.0 mm.; Width — about 2.0-2.5 mm.; Color .—Dull green (RHS Green group 143B) when bud scales are removed.
Bloom quantity: Considered abundant.
Floral nectarines .—Color — Deep grey-orange (RHS Grey-orange group N167B).
Flower bud frequency: Normally two flower buds appear per node, occasionally one, rarely more than two.
Pollen Production—Abundant. Pollen Color .—(RHS Yellow-orange group 17B. Fertility .—Self fertile.
Petal count: Nearly always 5.
Calyx .—Size — About 6-8 mm. in width; about 10 mm. in length; conical in shape; Color .—Dull purple (RHS Grey-purple group N186C).
Anthers:
Generally .—Medium to small for the species. Color .—Dull red/purple, approximately (RHS Greyed-Red Group 179A).
Filiments:
Size .—Variable in length, approximately 15.0 to 17.0 millimeters in length; Color .—Considered a medium to pale pink, (RHS Red-Purple Group 65 C).
Pistil:
Number .—Usually 1, rarely 2; Generally .—Medium in size; Length .—Approximately 16.0-18.0 millimeters in length including the ovary; Color .—Considered a pale green, (approximately RHS Yellow-Green Group 145 C); and Surface texture .—The variety has a long pubescent pistil.
FRUIT
Maturity when described: Firm ripe condition (shipping ripe).
Date of first picking: Aug. 10, 2010. Date of last picking. — Aug. 17, 2010. The date of harvest varies slightly with the prevailing climatic conditions and cultural practices.
Size: Generally—Considered large, and uniform.
Average cheek diameter: Approximately 68.0 to about 79.0 millimeters, and sometimes larger.
Average axial diameter: Approximately 62.0 to about 68.0 millimeters, and sometimes larger.
Typical weight: Approximately 278.0 grams. This characteristic is quite dependent upon the prevailing cultural practices, and therefore is not particularly distinctive of the new variety.
Fruit form: Generally—Considered slightly oblate. The fruit is generally uniform in symmetry.
Fruit suture: No apparent protrusion, callousing or stitching exists along the suture line.
Suture: Color—Generally blushed to the same degree as the skin, (approximately RHS Red Group 42 A).
Ventral surface: Form—Quite even and uniform in appearance when viewed from the lateral sutorial plane.
Apex: Generally-Rounded.
Base: Shape—Gently refuse.
Stem cavity: Generally—Rounded and uniform in shape. The average depth of the stem cavity is about 7.0 mm. Average width of the stem cavity is about 12.0 mm. Average length of the in the sutorial plane is about 20.0 mm.
Fruit skin:
Thickness.— Considered medium in thickness, and tenacious to the flesh. Surface texture.— Short, fine and pubescent. The pubescence is moderately abundant. Taste.— Non-astringent. Tendency to crack.— Not observed in the current or previous years of evaluation.
Fruit skin color:
Blush color.— Generally speaking, a red blush exists on a majority of the skin of the fruit (approximately RHS Orange-Red Group N34 A), and is typically more present on the portions of the fruit facing the sunlight. The blush covers approximately 70-80% of the fruit skin surface. The percentage of the blush on the fruit skin surface can vary, and is generally dependent upon the fruit's exposure to direct sunlight; specific fruit maturity; and also the prevailing ecological and cultural conditions under which the fruit is grown. It should noted that the presence of darker pigmentation ‘striping’ or ‘tigering’ is generally observed laterally, above the equatorial plane and generally increases in frequency in progression toward the fruit's apex. This additional pigmentation generally deepens the hue of the surrounding surface. Ground color.— Yellow, (approximately RHS Yellow-Orange Group 21 D). The ground color of the fruit can vary significantly based upon the maturity of the fruit when this measurement is taken.
Fruit stem:
Size .—Medium in length, approximately 6.0 to about 9.0 millimeters. Diameter.— Approximately 2.0 to about 3.0 millimeters. Color.— Pale yellow-green, (approximately RHS Yellow-Green Group N144 B). Occasionally ‘stem tear’ (skin of the fruit, when picked, partially detaches from the flesh leaving a loose flap of skin at the base of the stem well/hilum interface) can be observed.
Fruit flesh:
Ripening.— Considered even. Texture.— Firm, juicy and dense. Considered non-melting. Fibers.— Few are found. Aroma.— Slight. Eating quality.— Considered very good. Flavor.— Considered very sweet and with moderate to low acidity. The flavor is considered both pleasant and balanced. Juice production.— Moderate. Brix.— About 15.0 to 20.0 degrees. This characteristic varies slightly with the number of fruit per tree; the maturity of fruit when harvested; the prevailing cultural practices; and the ambient climatic conditions. This brix is 3-7 brix higher than fruit produced by U.S. Plant Pat. No. 12,405 when grown under the same growing conditions. Flesh color.— Is considered an orange-yellow, (approximately RHS Yellow-Orange 16 A). It should be noted that the flesh can develop a reddish color at the outer margin of the pit cavity that can radiate into the flesh. This deepening color generally occurs as the fruit increasingly matures, but it is not distinctive of the variety.
STONE
Type: Considered freestone.
Size: Considered medium-large for the variety. The stone size varies significantly depending upon the tree vigor, crop load and prevailing growing conditions.
Length: Average, about 34.0 to about 41.0 millimeters.
Width: Average, about 27.0 to about 36.0 millimeters.
Diameter: Average, about 18.0 to about 24.0 millimeters.
Form: Roughly acuminate.
Base: The stone is quadrate in shape at the basal axis.
Apex: Shape.—The stone exhibits a slight to prominently acute apex.
Stone surface:
Surface texture.— Considered relatively course. Surface pitting is generally more noted toward the dorsal edges of the stone. Ridges.— Ridging is generally more prominent and is usually oriented parallel, and laterally relative to the ventral margin. Ventral edge.— The ventral edge is generally considered troughed with two reasonably distinguished edges running parallel to, and on both sides of, the stone's suture. These distinct edges continue from the hilum to the apex. Dorsal edge .—Shape — Generally considered moderately rough and uneven. The folds of the surface ridges appearing on the external margins often end abruptly along the external margin of the dorsal surface creating an irregular edge. There is often substantial lobbing or a pronounced extension of the dorsal margin at its mid-point in length.
Stone color: The color of a mature, dry stone is generally considered a reddish brown, approximately (RHS Greyed-Purple Group N186 C). This depends, to some degree, on the moisture content of the stone. This color is variable, however, and may also be affected by oxidation and sun bleaching.
Tendency to split: Splitting has rarely been noted.
Kernel:
Size.— The kernel is considered medium-small in size. Form.— Considered generally ovoid. Pellicle.— Slightly pubescent. Color.— (RHS Greyed-Orange Group N167 B).
Use: The present variety ‘Burpeachtwentysix’ is considered to be a peach tree of the late season of maturity, and which produces fruit which are considered to be firm, attractively colored, and which are useful for both local and long distance shipping.
Keeping quality: Appears excellent. The fruit of the present variety has stored well for up to 30 days after harvest at 1.0 degree Celsius.
Shipping quality: Good. The fruit of the new peach tree variety showed minimal bruising of flesh or skin damage after being subjected to normal harvesting and packing procedures.
Resistance to insects and disease: No particular susceptibilities were noted. The present variety has not been tested to expose or detect any susceptibilities or resistances to any known plant and/or fruit diseases.
Although the new variety of peach tree possesses the described characteristics when grown under the ecological conditions prevailing near Fowler, Calif., in the Central part of the San Joaquin Valley of California, it should be understood that variations of the usual magnitude and characteristics incident to changes in growing conditions, fertilization, pruning, pest control, frost, climatic variables and horticultural management are to be expected. | A new and distinct variety of peach tree ( Prunus persica ), which is denominated varietally as ‘Burpeachtwentysix’, and which produces an attractively colored yellow-fleshed, freestone peach which is mature for harvesting and shipment approximately August 10 to August 17 under the ecological conditions prevailing in the San Joaquin Valley of central California. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention pertains to a method and an apparatus for the improvement in the quality of well-head natural gas and in the prevention of pipeline corrosion in natural gas transport through the removal carbon dioxide (CO 2 ) naturally occurring in the gas.
2. Brief Description of the Problem and the Prior Art
The term natural gas refers to mixtures of inert and light hydrocarbon components as well as non-hydrocarbon components which are recovered from natural gas wells or from gas coproduced in the production of oil. The removal of CO 2 as well as other gaseous impurities has been the subject of much work in the past. The overwhelming majority of this work is directed toward the separation of CO 2 from natural gas as opposed to its conversion to a different molecular species. These separations are typically performed through absorption or adsorption methodologies or alternatively through chemical scrubbing using techniques such as chemical chelation. The disadvantage of these current techniques lies mainly in their cumbersome characteristics which require replenishment of consumable chemical absorbents, adsorbents, or complexing agents. This renders these techniques less than optimal for remote application at a well-head.
The presence of CO 2 and water is well known to play a role in the corrosion of pipelines. Corrosion of natural gas pipelines raises costs by both necessitating the replacement of pipelines and by the concomitant production loss during the resulting downtime. CO 2 in the presence of water is in equilibrium with carbonic acid, bicarbonate, and carbonate ions. The pH-modifying nature of these species renders them corrosive to the pipelines used in natural gas transport. The chemistry is represented below:
CO 2 +H 2 O⇄H 2 CO 3
H 2 CO 3 ⇄HCO 3 − +H +
HCO 3 −⇄CO 3 −2 +H +
The problem can be alleviated by the removal of water, CO 2 , or both. One way to remove water is to lower the water dew point below the pipeline temperature. Temperature control through the expected distances of a natural gas pipeline is likely to be logistically difficult and cost prohibitive. Water may also be remove by various adsorption and absorption techniques that can be applied to CO 2 . Again, the regeneration or replacement of consumable chemical adsorbents and absorbents is a disadvantage of this method. Traditional natural gas purification by CO 2 removal alone has also been based on adsorption and absorption.
An object of the present invention is a chemical process that is a self contained with respect to the replenishment of chemical reactants and heat, and which converts carbon dioxide in well-head natural gas to methane prior to pipeline shipment to non-remote locations. The primary goal of the present invention is the prevention of corrosion to transmission pipelines of natural gas through the removal of carbon dioxide, while a further object of the present invention is an environmentally friendly mechanism to remove CO 2 from natural gas without venting to the atmosphere. Additionally, the present invention is useful for the improvement in quality of a natural gas effluent from a well-head prior to transmission to other locations.
U.S. Pat. No. 5,938,819 describes the bulk separation of carbon dioxide from methane using natural clinoptilolite. This is a zeolite-type chemical species whose mode of action is inclusion complexation, a non-covalent form of binding which is generally reversible under mild conditions. Purification of the gas stream is achieved through selective inclusion complexation. These types of adsorption systems are characterized by the need to regenerate the adsorbent species. In the '819 patent, this is achieved through a technique commonly known as pressure swing adsorption (PSA). The system requires a supply of dry air for regeneration of the CO 2 adsorbate. The requirement that reactants and/or adsorbents must be replenished or regenerated with an external supply of dry air detracts from the ease of remote application of the process at the well-head.
U.S. Pat. No. 5,411,721 describes the removal of CO 2 from natural gas through a combination system utilizing membrane permeability selective techniques as well as pressure swing adsorption. Separation systems based on membrane permeability typically require high pressures, while those that rely on pressure swing adsorption are relatively inefficient at higher pressures. The '721 patent combines the two techniques in such a way that the permeate feedstream is fed to the PSA system after passing the membrane. This nicely takes advantage of the pressure drop across the membrane in a a two step system is employed which minimizes pressure constraints and results in high purity, but has the disadvantage of a relatively high degree of complexity. The more complex a system of purification is, the less amenable it is to remote application at the well-head. The systems amenable to remote applications are ideally less cumbersome.
U.S. Pat. No. 5,089,034 uses multiple stage temperature swing adsorption (TSA) to purify natural gas by stepwise removal of H 2 O and CO 2 . By first removing water, the gas stream can later be treated at a lower temperature in the second adsorption zone for more efficient and less expensive carbon dioxide removal. This is based upon different chemistry and is of greater complexity than the present invention which makes the system less desirable for remote applications.
Still other systems separate impurities from natural gas streams through techniques of countercurrent chromatography. This technique is essentially a liquid-gas extraction. U.S. Pat. No. 5,660,603 uses an aqueous liquid, ideally seawater, as the liquid extraction medium. By using seawater at selected temperatures and pressures, hydrates of CO 2 or other light hydrocarbons are formed. The liquid extraction medium is regenerated by the release of the complexed impurity gases by variations in temperature or pressure. It differs from the present invention in having the obvious disadvantages of requiring externally supplied heat and pressure. This results in a complex operation again not optimally suited for remote application at the well-head. Rather it is better suited for downstream use at a gas processing facility prior to distribution to gas customers.
Other and further chemistries are employed to selectively remove gaseous impurities from natural gas streams. U.S. Pat. No. 4,871,468 describes a method of removing hydrogen sulfide and carbon dioxide using a mixture of a polyvalent metal chelate in a carbon dioxide selective absorbent solvent at varying values of pH. Replenishment of solvents and reagents necessary to control pH are disadvantages here. The overall process involves reasonably complex solution chemistry it is better suited for a processing facility than a remote location such as well-head.
Numerous other patents exist that are variations on the same themes. Unlike the present invention, they variously employ complexation chemistry or selective adsorption and/or absorption as the separatory step. U.S. Pat. No. 4,741,745 employs a liquid-gas extraction technique where a liquid adsorbent is judiciously chosen. U.S. Pat. No. 4,409,102 combines a liquid-gas adsorption in a countercurrent extraction mode with a chemical scrubbing step.
All of this prior art differs fundamentally from the present invention in the chemistries employed. None of them are based on the removal of CO 2 through its conversion to methane, and all are characterized by the need to regularly replenish reagents or require an external supply of heat and/or pressure.
SUMMARY OF THE INVENTION
In the preferred embodiment, a method and processor is used to purify a natural gas stream by removal of carbon dioxide through a methanation reaction which converts the carbon dioxide to methane by using molecular hydrogen obtained by chemical means from a portion of the natural gas stream to be purified. The system therefore consists of two reaction chemistries.
In one embodiment, a side stream of the main natural gas stream is diverted to a combustion device to generate heat that may be used to drive one or both of the chemical reactions. Such heat is also used to internally regenerate catalyst. The transfer of heat from the combustion device to one or both of the reactions may be regulated by ordinary means.
In the preferred embodiment, the methanation reaction is catalytic. In this embodiment, the catalyst interface may be configured in any number of conventional ways. Typically, this takes the form of columns or beds. Non-conventional forms may be used as well. One example of the methanation reaction is that commonly used in analytical gas chromatographic applications for the detection of carbon dioxide. This involves the use of a nickel-based catalyst and a temperature of 380° C.
The hydrogen separator reaction chamber consists of a hydrocarbon reformation reactor in the preferred embodiment. Preferred chemistries are those commonly used in hydrocarbon reformation chemistry, particularly fuel cell technology. These typically use nickel, platinum, or palladium based catalyst.
The process involves redirection of side streams of raw natural gas to the hydrogen separator reaction chamber where the molecular hydrogen is extracted for subsequent use in combination with the main natural gas stream in the methanation reaction chamber. Upon methanation of the carbon dioxide in the raw natural gas stream, a purified stream emerges which is less concentrated in carbon dioxide than is the raw stream.
Further objects of the present invention utilize analogous chemistries substituted for the methanation reaction chemistry and/or for the hydrogen separator reaction. They involve the extraction of hydrogen from the main gas stream and the subsequent use of the extracted hydrogen to convert carbon dioxide to methane.
Other and further objects, features, and advantages would be apparent and eventually more readily understood upon a reading of the specification and by reference to the accompanying drawings forming a part thereof, and the examples given therein of the presently preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a schematic of the core of the processor in block diagram demonstrating how the main stream of raw natural gas is cleansed of carbon dioxide in a self-contained process.
FIG. 2 illustrates a schematic of the processor in block diagram including heat generating elements.
FIG. 3 is a schematic of the multiple column mode of the methanation reaction.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
It is readily apparent to one skilled in the art that various embodiments and modifications may be made to the invention disclosed in this application without departing from the scope and spirit of the invention.
As used herein a “conduit” means any means for transferring gaseous material. Examples are a pipe or hose.
As used herein the term “hydrocarbon reformation” refers to the chemical conversion of hydrocarbons to solid carbon or to oxides of carbon and gaseous hydrogen.
As used herein the term “hydrogen separator reaction chamber” refers to the reaction chamber where the hydrocarbon reformation occurs.
As used herein the term “methanation reaction chamber” refers to the reaction chamber wherein carbon dioxide is converted to methane.
One embodiment of the present invention is seen in FIG. 1 and includes an apparatus 1 for in-situ removal of CO 2 from natural gas streams at the well-head by the chemical conversion of CO 2 to methane. The exit port of the well-head 3 is connected to one end of main conduit 4 and the other end of main conduit 4 is connected to inlet port 28 of the methanation reaction chamber 25 within apparatus 1 . As the natural gas exits the well-head, it flows through main conduit 4 into apparatus 1 . One end of side stream conduit 7 is tapped into the main conduit 4 for the diversion of a first small stream of natural gas, and the other end of side stream conduit 7 is connected to the hydrogen separator reaction chamber 10 through inlet port 13 . The natural gas flowing through side stream conduit 7 enters the hydrogen separator reaction chamber 10 , and is chemically converted to hydrogen and solid carbon or to oxides of carbon and hydrogen. The hydrogen flows from the hydrogen separator reaction chamber 10 through the outlet port 16 into one end of the conduit 19 connected to said outlet port 16 . The other end of the said conduit 19 is connected to the inlet port 22 of the methanation reaction chamber 25 where it combines with the natural gas flowing into the methanation reaction chamber 25 through inlet port 28 from the main pipe 4 . The methanation reaction chamber 25 combines the hydrogen gas from the methanation reaction chamber 25 , and the CO 2 in the natural gas in the presence of a catalyst to convert the hydrogen gas and CO 2 to CH 4 . The resulting CH 4 is mixed with the natural gas and this mixture flows through outlet port 31 which is connected to conduit 33 for further delivery of lower-CO 2 natural gas to the user.
One skilled in the art recognizes that the natural gas could be delivered to a storage facility or other facility prior to delivery to the methanation reaction chamber. Further, the lower CO 2 wellhead gas can be delivered to a storage facility or other facility prior to distribution.
In another specific embodiment, the apparatus can be modified as shown in FIG. 2 . In this embodiment, the end of a second side stream conduit 34 is tapped into the main conduit 4 for diversion of a second small stream of natural gas into combustion devices 37 and 38 . Although FIG. 2 shows separate combustion devices 37 and 38 , one skilled in the art recognizes that one combustion device could be used. The single combustion device could be used to heat both the hydrogen separator reaction chamber 10 and the methanation reaction chamber 25 . Alternatively, only one of the hydrogen separator reaction chamber 10 or methanation reaction chamber 25 is heated. Reference number 43 represents the thermal contact-between respective combustion device and the chamber to be heated.
Although the inlet port 22 on the methanation reaction chamber 25 for the connecting conduit 19 and the inlet port 28 on the methanation reaction chamber 25 are depicted as separate ports on FIG. 1, one skilled in the art recognizes they can be single ports in which both conduits 19 and 4 attach on conduit 19 and feed into conduit 4 at a location upstream to conduit 4 's attachment to inlet port 28 .
In specific embodiments, any or all of the main conduit 4 , first side stream conduit 7 , second side stream conduit 34 , connecting conduit 19 and pipeline 33 can have flow regulators 40 attached to regulate the flow of gas in the pipes.
In a specific method of the present invention, the fraction of the well-head gas which flows through first side stream conduit 7 is usually less than 5% of the overall volume of well-head gas flowing through main conduit 4 but may be more depending upon the relative CO 2 content of the well-head gas.
The catalytic reaction of the preferred embodiment may also be configured in any number of ways so as to maximize surface contact area between the gaseous reactants and the catalyst. A specific embodiment includes a scaled-up version of methanation as it is performed in analytical gas chromatographic applications. Solid catalyst of good porosity in the form of small pellets or powder are immobilized in a column. The column may be stainless steel or any other material having good strength and preferably little tendency to corrode. While the simplest column configuration would consist of a single column, alternatively, a multi-column configuration could be employed, as depicted in FIG. 3 . The incoming feedstream of hydrogen of conduit 19 and well-head gas from main conduit 4 , upon mixing, could be split by a manifold 24 into multiple parallel columns 27 with pressure or flow regulation 40 . The multi-column mode is particularly useful where regeneration of catalyst using a regeneration cycle is envisioned. Such regeneration is further discussed below. The purified effluent streams are recombined as output 18 . The column or columns are housed in the reaction chamber which is heated to the reaction operating temperature, typically 380° C. Prior to entering the column or manifold, the stream is mixed with the gaseous effluent from the hydrocarbon reformation reaction chamber. It is preferable to incorporate a form of pressure regulation for the incoming hydrocarbon reformation effluent to regulate the partial pressure of hydrogen from the incoming gaseous mixture to optimize the methanation reaction. This can be achieved by considering such variables as 1) flow or pressure of the incoming main gas stream, 2) relative-CO 2 content of the incoming gas stream, 3) the nature of the catalytic reaction chemistry employed. The relative CO 2 -content of the incoming gas stream is a characteristic of the gas being recovered and this measurement may be performed remotely or directly at the well-head. It is envisioned that a computer-controlled feedback loop analytical system may be employed which continuously varies the pressure of the incoming hydrocarbon reformation effluent in real time to keep the methanation reaction optimized.
It should be noted that there are numerous variations to the aforementioned methanation reaction chemistry and the present invention envisions the use of any catalytic system useful for methanation that is appropriate given the level of carbon dioxide removal that is desired. In the preferred embodiment, the methanation reaction chamber consists of a scale-up of a gas chromatographic apparatus utilizing methanation chemistry for the enhanced detection of carbon dioxide.
In a preferred embodiment, the use of multiple layers or stages of of catalytic beds may be employed. In this configuration, the natural gas effluent emerging from the well-head is passed over the multiple catalytic beds or stages at the temperatures, pressures, and flow rates optimized to the nature of the catalytic reaction employed and the physical characteristics of the catalyst such as surface area, porosity, etc.
The invention herein disclosed does not involve a separation step in the main natural gas stream wherein a low level, undesirable gaseous impurity is separated. Rather, the removal of CO 2 is effected by the catalytic conversion of it to methane, CH 4 . The catalyst is neither produced not consumed in a catalytic chemical reaction. The remaining chemical reactants, apart from the catalyst, are inherently present in the system itself. The hydrogen used to perform the conversion is obtained from the hydrocarbon reformation of the methane in the natural gas stream. Heat required for the reaction is obtained by burning a small side stream of the natural gas effluent. The methane product is a major component of natural gas; the substitution of it for carbon dioxide represents an enhancement in the quality of the natural gas stream.
By decreasing the CO 2 content of the natural gas stream at or near the well-head, transmission pipeline corrosion is minimized. Concerns regarding the venting of CO 2 to the atmosphere from an environmental standpoint may be obviated because the invention involves the conversion of CO 2 to a useful molecular species and not merely its separation. The present invention is amenable to the elimination of disposal problems and thereby addresses environmental concerns. As carbon dioxide is merely being separated by prior methods, disposal would still be an issue. Typically, this disposal is simply venting to the atmosphere. For environmental reasons, this disposal method is becoming increasingly unacceptable. CO 2 is a known greenhouse gas which is suspected to cause global warming. Various international agreements has mandated reductions in the atmospheric release of the gas over scheduled periods. Thus the removal of the gas from the natural gas stream has environmental benefits in addition to the economic advantages that should accrue from the improvement in pipeline transmission efficiencies.
From the standpoint of logistics and feasibility, the improvement lies in the relatively self contained nature of the process, its novel combination of known and proven chemistries, its relative simplicity, and the resulting amenability to application at remote locations; in particular, at the well-head. It affords improvements in the pipeline transport of natural gas streams by purification at the well-head or immediately after its emergence from the well-head.
A standard methanation reaction is to be used for carbon dioxide removal. Presently, such reactions are used on an analytical scale in the gas chromatographic analysis of CO 2 . By converting CO 2 to CH 4 prior to flame ionization detection in a gas chromatograph, analytical sensitivity is greatly enhanced and much lower limits of detection may be achieved. The preferred embodiment of the present invention lies, in part, on a scale-up of this analytical conversion.
Methanation has also been applied on a larger scale in the petroleum industry in the past. The chemistry is treated in detail in U.S. Pat. Nos. 5,052,482, 4,706,751, 4,372,386, and 4,893,391, among others. These patents use the methanation process for its heat releasing properties. Unlike the present invention, the conversion of CO 2 or CO to CH 4 in the aforementioned references is incidental. The exothermic reaction releases heat which is then used to vaporize water. The heat generated steam was the desired product in those technologies. The technique of steam injection downhole into a well to lower the viscosity of heavy oil and thereby enhance recovery has been in use for a number of years. Prior to the use of the methanation process to produce high quality steam, the “huff and puff” method was used to inject steam down a well hole to enhance oil recovery. This had a number of disadvantages, the primary disadvantage being the loss of heat during transport down the well hole. Thus a system was desired which would yield high quality steam at the point of use or as close to the point of use as possible to minimize heat losses. As a result, the methanation step was applied downhole. The heat released inside the well would be used to heat water and create steam which was then used to enhance heavy oil recovery. The patents using methanation reactions for petroleum recovery differ additionally from the present invention in that they use an externally supplied Syngas feed to supply the required hydrogen (H 2 ) for the methanation reaction. The present invention uses the natural gas stream itself as its hydrogen source, obviating the need for an external supply of hydrogen. This attribute partially accounts for the self-contained nature of the present apparatus and process.
Known hydrocarbon reformation reactions are employed to produce hydrogen used for methanation. These reactions may be divided into CO 2 -forming and non-CO 2 -forming reactions. The non-CO 2 -forming reactions are well-known processes, and are commonly termed “thermal decomposition” when applied to natural gas. U.S. Pat. No. 3,284,161 describes the use of alumina, silica-alumina, among others, to convert gaseous hydrocarbons to carbon and gaseous hydrogen. Other references have exploited the higher catalytic activities of metal-based catalysts such as cobalt, chromium, copper, nickel, iron, platinum, palladium, and ruthenium. See Callahan, M. Proceedings of 26 th Power Sources Symposium, PSC Publishers; Red Bank, N.J., 1974, p. 181; and Parmon, V.; Kuvshinov, G.; Sobyanian, V. Proceedings of the 11 th World Hydrogen Energy Conference, Stuttgart; Schon & Wetzel GmbH; Frankfurt am Main, 1996; pp. 2439-2448. These typically take the form of metal-oxides. The temperature-dependant activities of various metal and metal-oxide thermal decomposition catalysts have been studied. See Muradov, N. Z.; Proceedings of the 11 th World Hydrogen Energy Conference, Stuttgart; Schon & Wetzel GmbH; Frankfurt am Main, 1996; pp. 697-702. Recently, results for carbon-based catalysis and metal-based catalysis have been compared. See Muradov, N. Z. Energy & Fuels, 1998, 12, 41-48. The buildup of carbon on the surface of the metal-based catalysts resulted in the eventual poisoning of the catalyst. This is reversed by the burn-off of carbon to carbon dioxide. In the case of carbon-based catalysts, a fluidized bed reactor for the continuous removal of carbon from the catalytic surface is employed to remove carbon byproduct which is less tightly bound to the catalyst in such cases. Basic hydrocarbon reformation chemistry is well-known in the art and is described in detail in many literature sources in the field. See, e.g., Fuel Cell Systems, edited by Leo M. J. Blomen and Michael Mugerwa, Plenum Press, New York, 1993. The catalyst system may also be a combination of different individual catalyst species.
In the present invention, either catalytic system is employed for hydrogen generation. In cases where the accumulation of solid carbon by-product necessitates regeneration of catalyst, multi-column or multi-bed catalysts arrangement are used in conjunction with a multi-stage process. In one stage (the catalytic stage), one or more columns or beds are used in the catalytic reaction to remove CO 2 . When regeneration is required, a regeneration stage (typically a burn-off cycle) is applied to these previously used columns or beds. The flow of raw natural gas is redirected to a series of new or previously regenerated columns or beds such that the overall process may proceed unabated, if desired. During this regeneration stage, the original columns or beds are regenerated with a burn off cycle which effectively removes the carbon product by conversion to oxides of carbon by the application of heat. These oxides of carbon are directed away from the natural gas stream and may be sequestered or otherwise disposed of. In the case of carbon-based catalyst, mechanical or chemical methods are employed in lieu of the burn out method to removed the less tightly bound carbon byproduct.
Alternatively, CO 2 -producing methods of hydrocarbon reformation are employed, but this requires employing techniques of CO 2 sequestration to avoid CO 2 introduction into the downstream methanation process. Techniques such as those applied in fuel cell applications to output only the desired hydrogen while sequestering the carbonaceous by-product are equally applicable here. See, e.g., Fuel Cell Systems, Leo M. J. Blomen and Michael Mugerwa, Eds., Plenum Press, New York, 1993; Blok, K.; Williams, R. Katofsky, R., Hendriks, C. Energy, 1997, 22, pp. 161-168: Andus, H.; Kaarstad, O.; Kowal, M.; Proceedings of the 11 th World Hydrogen Energy Conference, Stuttgart; Schon & Wetzel GmbH; Frankfurt am Main, 1996; pp. 525-534.
In the preferred embodiment of the methanation reaction, the raw stream of natural gas is combined with hydrogen from the reformation reaction and passed over a catalytic bed typically consisting of a catalyst and solid support of high surface area. As discussed, large scale methanation is currently used in oil recovery technology where the by-product of heat is used to produce steam which is used downhole to enhance oil recovery. As is the case in oil recovery applications, improvements in methanation chemistry, be they catalytic or non-catalytic, would enjoy application in the present apparatus and process.
The catalytic reaction of the preferred embodiment may also be configured in any number of ways so as to maximize surface contact area between the gaseous reactants and the catalyst. A specific configuration is one which is a scaled-up version of methanation as it is performed in analytical gas chromatographic applications. Solid catalyst of good porosity in the form of small pellets or powder are immobilized in a column. The column may be stainless steel or any other material having good strength and preferably little tendency to corrode.
REFERENCES
All patents and publications mentioned in the specification are indicative of the level of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.
U.S. Patent Documents
5,938,819
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Seery
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Doshi et al.
5,089,034
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James, Jr. et al.
5,660,603
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Chen et al.
4,871,468
10/1989
Jeffrey
4,741,745
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Saotome et al.
4,409,102
10/1983
Tanner
5,052,482
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Gonduin
4,706,751
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Gonduin
4,372,386
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Meeks et al.
4,839,391
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Range et al.
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Other Publications
(1) Callahan, M. Proceedings of 26 th Power Sources Symposium, PSC Publishers; Red Bank, N.J., 1974, p. 181.
(2) Parmon, V.; Kuvshinov, G.; Sobyanian, V. Proceedings of the 11 th World Hydrogen Energy Conference, Stuttgart; Schon & Wetzel GmbH; Frankfurt am Main, 1996; pp. 2439-2448.
(3) Muradov, N. Z.; Proceedings of the 11 th World Hydrogen Energy Conference, Stuttgart; Schon & Wetzel GmbH; Frankfurt am Main, 1996; pp. 697-702.
(4) Muradov, N. Z. Energy & Fuels, 1998, 12, 41-48.
(5) See, e.g., Fuel Cell Systems, edited by Leo M. J. Blumen and Michael Mugerwa, Plenum Press, New York, 1993.
(6) Blok, K.; Williams, R. Katofsky, R., Hendriks, C. Energy, 1997, 22, pp. 161-168.
(7) Andus, H.; Kaarstad, O.; Kowal, M.; Proceedings of the 11 th World Hydrogen Energy Conference, Stuttgart; Schon & Wetzel GmbH; Frankfurt am Main, 1996; pp. 525-534.
One skilled in the art readily appreciates that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned as well as those inherent therein. Systems, methods, procedures and techniques described herein are presently representative of the preferred embodiments and are intended to be exemplary and are not intended as limitations of the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention or defined by the scope of the pending claims. | A process is provided for the in-situ removal of carbon dioxide out of natural gas by diverting a stream of the natural gas to a hydrocarbon reformation unit, which converts this diverted stream of the natural gas into a hydrogen-containing gas, and feeding this hydrogen-containing gas and the (undiverted) natural gas into a methanation unit, where the hydrogen reacts with carbon dioxide to form methane, thereby decreasing the amount of carbon dioxide in the natural gas. A second steam of the natural gas may be diverted from the natural gas and combusted, thereby generating heat which may be used for catalyst regeneration and/or for providing any heat necessary for the reactions occurring in the methanation unit or the hydrocarbon reformation unit. | 2 |
PRIORITY
[0001] This application claims priority to an application entitled “System And Method For Periodic Ranging In Sleep Mode In Broadband Wireless Access Communication System” filed in the Korean Industrial Property Office on Mar. 5, 2004 and assigned Serial No. 2004-15219, the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a broadband wireless access communication system, and more particularly to a system and method for periodic ranging for a subscriber station (SS) in a sleep mode.
[0004] 2. Description of the Related Art
[0005] In a 4 th generation (4G) communication system (which is the next generation communication system), research is being actively pursued to provide users with services having various qualities of service (QoSs) at a high transmission speed. Currently, in the 4G communication system, research is being undertaken to support high speed services while ensuring mobility and QoS for Broadband Wireless Access (BWA) communication systems such as a wireless local area network (LAN) and a metropolitan area network (MAN) system. Representative communication systems arranged in order to achieve such goals as described above include the Institute of Electrical and Electronics Engineers (IEEE) 802.16a communication system and the IEEE 802.16e communication system.
[0006] The IEEE 802.16a communication system and the IEEE 802.16e communication system employ an Orthogonal Frequency Division Multiplexing (OFDM) scheme and an Orthogonal Frequency Division Multiple Access (OFDMA) scheme in order to support a broadband transmission network for a physical channel of the wireless MAN system. The IEEE 802.16a communication system considers only a single cell structure and stationary subscriber stations, which means the system does not in any way reflect mobility of the SSs at all. In contrast, the IEEE 802.16e communication system has been defined as a system reflecting the mobility of a SS in addition to the IEEE 802.16a communication system. Here, an SS having the mobility is referred to as a mobile subscriber station (MSS).
[0007] FIG. 1 is a block diagram schematically illustrating the structure of a conventional IEEE 802.16e communication system.
[0008] Referring to FIG. 1 , the IEEE 802.16e communication system has a multi-cell structure (e.g., a cell 100 and a cell 150 ). Also, the IEEE 802.16e communication system includes a base station (BS) 110 controlling the cell 100 , a BS 140 controlling the cell 150 , and a plurality of MSSs 111 , 113 , 130 , 151 , and 153 . The transmission/reception of signals between the BSs 110 and 140 and the MSSs 111 , 113 , 130 , 151 , and 153 is accomplished using an OFDM/OFDMA scheme. Herein, the MSS 130 from among the MSSs 111 , 113 , 130 , 151 , and 153 is located in a boundary area (i.e., handover area) between the cell 100 and the cell 150 . Accordingly, when the MSS 130 moves into the cell 150 controlled by the BS 140 while transmitting/receiving a signal to/from the BS 110 , the serving BS for the MSS 130 changes from the BS 110 to the BS 140 .
[0009] In the IEEE 802.16e communication system reflecting the mobility of MSS, the power consumption of an MSS plays an important part in the performance of the entire system. Therefore, a sleep mode operation and an awake mode operation have been proposed for the BS and the MSS in order to minimize the power consumption of the MSS. Further, in order to cope with a channel state change between the MSS and the BS, the MSS periodically performs ranging for adjusting the timing offset, the frequency offset, and the transmit power between the BS and the MSS. Especially, in the IEEE 802.16e communication system reflecting the mobility of MSS, a periodic ranging from among the ranging as described above emerges as an important issue.
[0010] Hereinafter, a sleep mode operation of the IEEE 802.16e communication system will be described with reference to FIG. 2 .
[0011] FIG. 2 schematically illustrates a sleep mode operation of a conventional IEEE 802.16e communication system.
[0012] The sleep mode has been proposed in order to minimize the power consumption of the MSS during the idle interval during which the packet data is not being transmitted. That is, in the idle interval, both the BS and the MSS mode-transit into the sleep mode, thereby minimizing the power consumption of an MSS during the idle interval during which the packet data is not transmitted.
[0013] In general, the packet data is transmitted in a burst when generated. Accordingly, it is unreasonable that the same operation is performed in both an interval in which packet data is not transmitted and an interval in which packet data is transmitted. For this reason, the sleep mode operation as described above has been proposed. In contrast, when packet data to be transmitted is generated while the MSS is in the sleep mode, both the BS and the MSS must mode-transit into the awake mode and transmit/receive the packet data.
[0014] The sleep mode is also useful for minimizing interference between channel signals as well as the power consumption. However, because the packet data is highly reliable on the traffic state, the sleep mode operation must be performed with consideration given to the traffic characteristic and the transmission scheme characteristic of the packet data.
[0015] Referring to FIG. 2 , reference numeral 211 illustrates the generation pattern of packet data, which is a plurality of ON and OFF intervals. The ON intervals are burst intervals in which packet data (i.e., traffic) is generated and the OFF intervals are idle intervals in which the traffic is not generated. The MSS and the base station are shifted between the sleep mode and the awake mode according to the traffic generation patterns as described above, so that the power consumption of the MSS can be minimized and interference between channel signals can be prevented.
[0016] Reference numeral 213 illustrates the mode change pattern of the BS and the MSS, which includes a plurality of awake modes and sleep modes. In the awake modes, traffic is generated and the MSS and the BS actually transmit/receive packet data. In contrast, in the sleep modes, traffic is not generated and there is no actual transmission/reception of packet data between the MSS and the BS.
[0017] Reference numeral 215 illustrates the power level of the MSS. As shown, the power level of the MSS in the awake mode is K and the power level of the MSS in the sleep mode is M. Herein, when the power level K of the MSS in the awake mode is compared with the power level M of the MSS in the sleep mode, it is noted that the value of M is much smaller than the value of K. That is, in the sleep mode, the MSS consumes almost no power since there is no transmission/reception of packet data.
[0018] Hereinafter, existing schemes for the IEEE 802.16e communication system in order to support operation in the sleep mode will be described.
[0019] First, in order to mode-transit into the sleep mode, the MSS must receive permission for the mode transition from the BS. The BS permits mode transition of the MSS into the sleep mode and transmits a packet data to the MSS. Also, the BS must inform the MSS of existence of packet data to be transmitted during a listening interval of the MSS. Herein, the MSS awakes from the sleep mode and checks whether there exist a packet data to be transmitted from the BS to the MSS. The listening interval will be described below in more detail.
[0020] As a result of the checking, when packet data to be transmitted from the BS to the MSS exists, the MSS mode-transits to the awake mode from the sleep mode and receives the packet data from the BS. In contrast, when packet data to be transmitted from the BS to the MSS does not exist, the MSS can stay in the awake mode or can return to the sleep mode.
[0021] Hereinafter, parameters necessary in order to support operation in the sleep mode and the awake mode will be described.
[0022] 1) Sleep Identifier (SLPID)
[0023] The SLPID proposed by the IEEE 802.16e communication system is a value assigned to the MSS through a sleep response (SLP_RSP) message when the MSS mode-transits into the sleep mode. The SLPIDs are used only for the MSSs staying in the sleep mode. That is, only the MSSs in the sleep mode including the listening interval can use the SLPID. Also, when an MSS having used an SLPID transits back to the awake mode, the SLPID is returned to the BS and can be reused by another MSS which will transit into the sleep mode. The SLPID has a size of 10 bits and thus can identify 1024 MSSs performing the sleep mode operation.
[0024] 2) Sleep Interval
[0025] The sleep interval is an interval, which is requested by an MSS and assigned by a BS according to the request of the MSS. The sleep interval represents a time interval during which the MSS maintains a sleep mode from a mode-transition of the MSS into the sleep mode to a beginning of the listening interval. In other words, the sleep interval is defined as an interval during which the MSS stays in the sleep mode.
[0026] When there is no data to be transmitted from the BS to the MSS, the MSS may continue to stay in the sleep mode even after the sleep interval is over. In this case, the MSS updates the sleep interval by increasing the sleep interval by means of an initial sleep window value and a final sleep window value set in advance. Herein, the initial sleep window value corresponds to a minimum sleep window value and the final sleep window value corresponds to a maximum sleep window value. Further, the initial sleep window value and the final sleep window value may be expressed by the number of frames. Since the minimum window value and the maximum window will be described in detail below, a further description is omitted here.
[0027] The listening interval is an interval, which is requested by an MSS and assigned by a BS according to the request of the MSS. The listening interval represents a time interval from a time point at which the MSS awakens from the sleep mode to a time point at which the MSS synchronizes with the downlink signal of the BS and receives downlink messages such as a traffic indication (TRF_IND) message. Herein, the TRF_IND message is a message representing whether a traffic (i.e., packet data) to be transmitted to the MSS exists. Since the TRF_IND message will be described below, a further detailed description is omitted here.
[0028] Throughout the listening interval, the MSS waits for the TRF_IND message. When a bit representing the MSS in a sleep indicator bitmap contained in the TRF_IND message has a value representing a positive indication, the MSS continues to stay in the awake mode, so that the MSS resultantly mode-transits into the awake mode. In contrast, when the bit representing the MSS in a sleep indicator bitmap contained in the TRF_IND message has a value representing a negative indication, the MSS mode-transits into the sleep mode again.
[0029] 3) Sleep Interval Update Algorithm
[0030] When the MSS mode-transits into the sleep mode, it determines a sleep interval while regarding a preset minimum window value as a minimum sleep mode interval. After the sleep interval passes, the MSS awakes from the sleep mode for the listening interval and checks for the existence or the absence of packet data to be transmitted from the BS. As a result of the checking, if packet data to be transmitted does not exist, the MSS renews the sleep interval to be twice as long as that of a previous sleep interval and continues to stay in the sleep mode. For example, when the minimum window value is “2”, the MSS sets the sleep interval to be 2 frames and stays in the sleep mode during 2 frames. After passage of the 2 frames, the MSS awakes from the sleep mode and determines whether the TRF_IND message has been received. When the TRF_IND message has not been received (that is, when packet data transmitted from the BS to the MSS does not exist), the MSS sets the sleep interval to be 4 frames (twice as many as 2 frames) and stays in the sleep mode during 4 frames. In this way, the sleep interval increases within a range from the initial sleep window value to the final sleep window value. The algorithm for updating the sleep interval as described above is the sleep interval update algorithm.
[0031] Hereinafter, messages currently defined in the IEEE 802.16e communication system in order to support operations in the sleep mode and the awake mode will be described.
[0032] 1) Sleep Request (SLP_REQ) Message
[0033] The SLP_REQ message refers to a message which is transmitted from an MSS to a BS and used when the MSS requests a mode-transition to the sleep mode. The SLP_REQ message contains parameters (i.e., information elements (IEs)), required when the MSS transits into the sleep mode. Table 1 illustrates the format of the SLP_REQ message.
TABLE 1 Syntax Size Notes SLP-REQ_Message_Format( ) { Management message type = 46 8 bits initial-sleep window 6 bits final-sleep window 10 bits listening interval 6 bits reserved 2 bits }
[0034] The SLP_REQ message is a dedicated message transmitted based on a connection identifier (CID) of an MSS. The information elements of the SLP_REQ message as illustrated in Table 1 will be described hereinafter.
[0035] First, the Management Message Type represents a type of a message being currently transmitted. When the Management Message Type has a value of 45 (Management Message Type=45), it represents the SLP_REQmessage. The Initial-sleep Window value represents a start value requested for the sleep interval, and the Final-sleep Window value represents a stop value requested for the sleep interval. That is, as described above for the sleep interval update algorithm, the sleep interval may be updated within a range from the initial-sleep window value to the final-sleep window value. The listening interval also can be expressed by frame values.
[0036] 2) Sleep Response(SLP_RSP) Message
[0037] The SLP_RSP message is a message in response to the SLP_REQmessage. The SLP_RSP message may be used as a message representing whether to approve or deny the mode-transition into the sleep mode requested by the MSS, or a message representing an unsolicited instruction. The SLP_RSP message contains information elements required when the MSS operates in the sleep mode. Table 2 illustrates the format of the SLP_RSP message.
TABLE 2 Syntax Size Notes SLP-RSP_Message_Format( ) { Management message type = 47 8 bits Sleep-approved 1 bit 0: Sleep-mode request denied 1: Sleep-mode request approved If (Sleep-approved == 0) { After-REQ-action 1 bit 0: The MSS may retransmit the MOB_SLPREQ message after the time duration (REQduration) given by the BS in this message 1: The MSS shall not retransmit the MOB_SLPREQ message and shall await the MOB_SLPRSP message from the BS REQ-duration 4 bits Time duration for case where After-REQ-action value is 0. reserved 2 bits } else { Start frame initial-sleep window 6 bits final-sleep windows 10 bits listening interval 6 bits SLPID 10 bits } }
[0038] The SLP_RSP message is also a dedicated message transmitted based on the CID of an MSS, and the SLP_RSP message includes information elements as illustrated in Table 2, which will be described hereinafter.
[0039] First, the Management Message Type represents a type of a message currently being transmitted. For instance, when the Management Message Type has a value of 46 (Management Message Type=46), it represents the SLP_RSP message. The Sleep-approved value is one bit in length. When the Sleep-approved value is equal to 0, it implies that the request for the transition into the sleep mode has been denied. In contrast, when the Sleep-approved value is equal to 1, it implies that the request for the transition into the sleep mode has been approved. When the request of the MSS for the transition into the sleep mode has been denied (e.g., when the Sleep-approved value is set to 0), the MSS either transmits the SLP_REQ message or waits for a SLP_RSP message representing an unsolicited instruction. When the Sleep-approved value is equal to 1, the SLP_RSP message contains values of Start Frame, Initial Sleep Window, Final Sleep Window, Listening Interval, and SLPID as described above. When the Sleep-approved value is equal to 0, the SLP_RSP message contains values of REQ-Action and REQ-Duration.
[0040] Here, the value Start Frame refers to the number of frames (not including the frames in which the message has been received) until the MSS shall enter the first sleep interval. That is, the MSS enters a sleep mode after frames corresponding to the start time value have passed from the frame directly after the frame carrying the received SLP_RSP message. The SLPID is used in order to identify MSSs in the sleep mode and can identify 1024 MSSs in the sleep mode.
[0041] The Initial Sleep Window represents a start value for the sleep interval (measured in frames). The Listening Interval represents a value for the listening interval (measured in frames). The Final Sleep Window represents a stop value for the sleep interval (measured in frames). The REQ-Action represents an operation which the MSS must do when the request of transition into the sleep mode by the MSS has been denied.
[0042] 3) TRF_IND Message
[0043] The TRF_IND message is a message transmitted to an MSS during the listening interval and representing the existence or absence of packet data to be transmitted from a BS to the MSS. Table 3 illustrates the format of the TRF_IND message.
TABLE 3 Syntax Size Notes TRF-IND_Message_Format( ) { Management message type = 47 8 bits SLPID bit-map Variable }
[0044] The TRF_IND message is a broadcasting message transmitted according to the broadcasting method, differently from the SLP_REQ message or the SLP_RSP message. The TRF_IND message is a message representing whether packet data to be transmitted from the BS to an MSS exists. The MSS decodes the broadcasted TRF_IND message during the listening interval and determines whether to mode-transit into the awake mode or to return to the sleep mode.
[0045] When the MSS mode-transits into the awake mode, the MSS confirms a frame sync. As a result of the confirmation, when the frame sync does not coincide with a frame sequence number expected by the MSS, the MSS can request retransmission of packet data lost in the awake mode. Meanwhile, when the MSS fails to receive the TRF_IND message during the listening interval or the TRF_IND message received by the MSS does not contain a positive indication, the MSS returns to the sleep mode.
[0046] Hereinafter, the information elements of the TRF_IND message as illustrated in Table 3 will be described.
[0047] First, the Management Message Type is information representing a type of a message currently being transmitted. For instance, when the Management Message Type has a value of 48 (Management Message Type=48), it represents the TRF_IND message. The SLPID bit-map represents a set of indication indices having bits which are assigned to SLPIDs (one bit to one SLPID), the SLPIDs being assigned to the MSSs in order to identify the MSSs in the sleep mode. That is, the SLPID bit-map represents a group of bits which are assigned to the SLPIDs (with a maximum value of −1) assigned to the MSSs currently in the sleep mode (one bit to each MSS). The SLPID bit-map may be assigned a dummy bit for byte alignment.
[0048] The bit assigned to each MSS represents existence or absence of data to be transmitted from the BS to the MSS. Therefore, the MSS in the sleep mode reads a sleep identifier assigned during the transition into the sleep mode together with a mapped bit from the TRF_IND message received during the listening interval. From the reading, when the sleep identifier has a positive indication value (a value of 1), the MSS maintains the awake mode, thereby resulting in mode-transition into the awake mode. When the sleep identifier has a negative indication value (a value of 0), the MSS mode-transits into the sleep mode.
[0049] The sleep mode operation of the conventional IEEE 802.16e communication system has been described above with reference to FIG. 2 . Hereinafter, a ranging operation of the conventional IEEE 802.16e communication system will be described above with reference to FIG. 3 .
[0050] FIG. 3 is a signal flow diagram for schematically illustrating a ranging process of a conventional IEEE 802.16e communication system.
[0051] Referring to FIG. 3 , first, when the MSS 300 is powered on, the MSS 300 monitors all frequency bands set in advance in the MSS 300 and detects a pilot signal having a largest intensity (i.e., a largest Carrier to Interference and Noise Ratio (CINR)). Further, the MSS 300 determines a BS transmitting the pilot signal having the largest CINR as the serving BS 320 which means a BS to which the MSS 300 currently belongs. Then, the MSS 300 receives a preamble of a downlink frame transmitted from the serving BS 320 and acquires a system synch the MSS 300 and the serving BS 320 .
[0052] When the MSS 300 has acquired the system synch between the MSS 300 and the serving BS 320 , the serving BS 320 transmits a downlink(DL)_MAP message and a (uplink(UL)_MAP message to the MSS 300 (steps 311 and 313 ). Here, the DL_MAP message has a message format as illustrated in Table 4.
TABLE 4 Syntax Size Notes DL_MAP_Message_Format( ) { Management Message Type=2 8 bits PHY Synchronization Field Variable See Appropriate PHY specification DCD Count 8 bits Base Station ID 48 bits Number of DL_MAP Element n 16 bits Begin PHY Spceific section { See Applicable PHY section for (i=1; i<=n; i++) For each DL_MAP element 1 to n DL_MAP Information Element( ) Variable See corresponding PHY specification if!(byte boundary) { 4 bits Padding to reach byte boundary Padding Nibble } } } }
[0053] As illustrated in Table 4, the DL_MAP message contains a plurality of IEs, such as Management Message Type representing a type of a message being currently transmitted, PHY synchronization set correspondingly to the modulation scheme and demodulation scheme applied to a physical (PHY) channel for acquisition of synch, DCD count representing a count corresponding to changes in a configuration of a Downlink Channel Descriptor (DCD) message including a downlink burst profile, Base Station ID representing a BS identifier, and Number of DL_MAP Elements n representing the number of the elements following the Base Station ID. Although not shown in FIG. 4 , the DL_MAP message contains information about ranging codes allocated to each ranging in the OFDMA communication system. Especially, the MSS 300 can use the DL_MAP message in detecting information about downlink bursts constituting the downlink frame. Therefore, the MSS can receive the data (i.e. data frame) in the bursts by identifying the downlink bursts in the downlink frame.
[0054] The UL_MAP message has a message format as illustrated in Table 5.
TABLE 5 Syntax Size Notes UL_MAP_Message_Format( ) { Management Message Type=3 8 bits Uplink Channel ID 8 bits UCD Count 8 bits Number of UL_MAP Element n 16 bits Allocation Start Time 32 bits Begin PHY Specific section { See Applicable PHY section for (i=1; i<=n; i++) For each UL_MAP element 2 to n UL_MAP_Information_Element( ) Variable See corresponding PHY specification } } }
[0055] As illustrated n in Table 5, the UL_MAP message contains a plurality of IEs, such as Management Message Type representing a type of a message being currently transmitted, Uplink Channel ID representing an uplink channel identifier, UCD count representing a count corresponding to changes in a configuration of an Uplink Channel Descriptor (UCD) message including an uplink burst profile, and Number of UL_MAP Elements n representing the number of the elements following the UCD count. Here, the Uplink Channel ID is assigned only in a Medium access control (MAC)-sublayer.
[0056] Meanwhile, after acquiring the synch between the MSS 300 and the serving BS 320 , that is, after identifying locations for actual data transmission/reception and downlink/uplink control information, the MSS 300 transmits a ranging request (RNG_REQ) message to the serving BS 320 (step 315 ). Upon receiving the RNG_REQ message, the serving BS 320 transmits to the MSS 300 a ranging response (RNG_RSP) message including information for updating the frequency, time, and transmit power for the ranging (step 317 ).
[0057] Hereinafter, the ranging can be classified into an initial ranging and a maintenance ranging, that is, a periodic ranging and a bandwidth request ranging. Before transmitting data through an uplink, the MSS can adjust the transmit power and update the timing offset and frequency offset by the ranging.
[0058] First, the initial ranging will be described.
[0059] The initial ranging is ranging which is performed by the MSS in order to acquire a synch between the BS and the MSS, match the time offset between the BS and the MSS, and adjust the transmit power. That is, after the MSS is powered on, the MSS receives messages including a DL_MAP message and a UL_MAP message and acquires synch between the BS and the MSS. Therefore, the MSS performs the initial ranging in order to adjust the time offset and the transmit power between the BS and the MSS.
[0060] Second, the periodic ranging will be described.
[0061] The periodic ranging is ranging which is periodically performed by the MSS in order to adjust the channel condition, etc. between the BS and the MSS after adjusting the adjust the time offset and the transmit power between the BS and the MSS through the initial ranging.
[0062] Third, the bandwidth request ranging will be described.
[0063] The bandwidth request ranging is ranging which is performed by the MSS in order to request allocation of bandwidth necessary for actual communication, after adjusting the adjust the time offset and the transmit power between the BS and the MSS through the initial ranging.
[0064] Since the IEEE 802.16e communication system reflects the mobility of the MSS as described above, the periodic ranging by the MSS plays a very important role in ensuring a reliable communication between the BS and the MSS. The periodic ranging is an operation for measuring and updating parameters necessary in order to enable the MSS to reliably communicate with the BS. Therefore, the BS must allocate an uplink resource so that the MSS can perform the periodic ranging, that is, so that the MSS can transmit the ranging request message to the BS. In other words, the BS must allocate an uplink resource to the MSS for the periodic ranging of the MSS and report to the MSS the uplink resource allocation information through the UL_MAP message. Then, the MSS transmits the ranging request message to the BS through the allocated uplink resource and begins to perform the periodic ranging between the BS and the MSS. In response to the ranging request message from the MSS, the BS updates the transmit power, the timing offset, and the frequency offset, and then transmits to the MSS a ranging response message which is a message responding to the ranging request message. Then, the periodic ranging is completed.
[0065] However, in the current IEEE 802.16e communication system, the ranging operation (especially, the periodic ranging operation) has been proposed as being independent from the sleep mode operation and having no relation with the sleep mode operation at all. In other words, even an MSS in a sleep mode must perform the periodic ranging in order to perform a reliable communication with the BS. However, the MSS in the sleep mode cannot receive any messages from the BS at all and it is thus impossible for the MSS to receive a resource allocated for the periodic ranging. Therefore, there emerges a necessity for a periodic ranging scheme of an MSS in a sleep mode.
SUMMARY OF THE INVENTION
[0066] Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and an object of the present invention is to provide a system and a method for performing periodic ranging in a sleep mode in a broadband wireless access communication system.
[0067] In order to accomplish this object, there is provided a method for performing periodic ranging in a broadband wireless access communication system having an awake mode in which data to be transmitted between a mobile subscriber station and a base station exists and the sleep mode in which data to be transmitted between the mobile subscriber station and the base station is non-existent, the sleep mode having a sleep interval and a listening interval, the mobile subscriber station being capable of receiving data in the listening interval and being incapable of receiving data in the sleep interval. The method comprises the steps of reporting, by the base station. to the mobile subscriber station in a listening interval before the sleep interval that the mobile subscriber station must perform the periodic ranging in the sleep interval, when the base station detects that it is necessary for the mobile subscriber station in the sleep mode to perform the periodic ranging at a particular time point in the sleep interval; and receiving, by the mobile subscriber station, the report from the base station in the listening interval, transiting from the sleep mode into the awake mode, and performing the periodic ranging at the particular time point.
[0068] In accordance with another aspect of the present invention, there is provided a method for performing periodic ranging in a broadband wireless access communication system having an awake mode in which data to be transmitted between a mobile subscriber station and a base station exists and the sleep mode in which data to be transmitted between the mobile subscriber station and the base station is non-existent, the sleep mode having a sleep interval and a listening interval, the mobile subscriber station being capable of receiving data in the listening interval and being incapable of receiving data in the sleep interval. The method comprises the steps of reporting, by the base station, to the mobile subscriber station in a listening interval before the sleep interval that the mobile subscriber station must perform the periodic ranging after staying in the sleep interval during a predetermined interval from a start point of the sleep interval, when the base station detects that it is necessary for the mobile subscriber station in the sleep mode to perform the periodic ranging at a particular time point in the sleep interval; and receiving, by the mobile subscriber station, the report from the base station in the listening interval, staying in the sleep interval during the predetermined interval, transiting from the sleep mode into the awake mode, and performing the periodic ranging.
[0069] In accordance with another aspect of the present invention, there is provided a method for performing periodic ranging in a broadband wireless access communication system having an awake mode in which data to be transmitted between a mobile subscriber station and a base station exists and the sleep mode in which data to be transmitted between the mobile subscriber station and the base station is non-existent, the sleep mode having a sleep-interval and a listening interval, the mobile subscriber station being capable of receiving data in the listening interval and being incapable of receiving data in the sleep interval. The method comprises the steps of reporting, by the base station, to the mobile subscriber station in a listening interval before the sleep interval that the mobile subscriber station must perform the periodic ranging and receive control information after staying in the sleep interval during a predetermined interval from a start point of the sleep interval, when the base station detects that it is necessary for the mobile subscriber station in the sleep mode to perform the periodic ranging at a particular time point in the sleep interval and then receive the control information; and receiving, by the mobile subscriber station, the report from the base station in the listening interval, staying in the sleep interval during the predetermined interval, transiting from the sleep mode into the awake mode, performing the periodic ranging, and receiving the control information.
[0070] In accordance with another aspect of the present invention, there is provided a method for performing periodic ranging in a broadband wireless access communication system having an awake mode in which data to be transmitted between a mobile subscriber station and a base station exists and the sleep mode in which data to be transmitted between the mobile subscriber station and the base station is non-existent, the sleep mode having a sleep interval and a listening interval, the mobile subscriber station being capable of receiving data in the listening interval and being incapable of receiving data in the sleep interval. The method comprises the steps of detecting that it is necessary for the mobile subscriber station in the sleep mode to perform the periodic ranging at a particular time point in the sleep interval; and reporting to the mobile subscriber station in a listening interval before the sleep interval that the mobile subscriber station must perform the periodic ranging in the sleep interval.
[0071] In accordance with another aspect of the present invention, there is provided a method for performing periodic ranging in a broadband wireless access communication system having an awake mode in which data to be transmitted between a mobile subscriber station and a base station exists and the sleep mode in which data to be transmitted between the mobile subscriber station and the base station is non-existent, the sleep mode having a sleep interval and a listening interval, the mobile subscriber station being capable of receiving data in the listening interval and being incapable of receiving data in the sleep interval. The method comprises the steps of detecting that it is necessary for the mobile subscriber station in the sleep mode to perform the periodic ranging at a particular time point in the sleep interval; and reporting to the mobile subscriber station in a listening interval before the sleep interval that the mobile subscriber station must perform the periodic ranging after staying in the sleep interval during a predetermined interval from a start point of the sleep interval.
[0072] In accordance with another aspect of the present invention, there is provided a method for performing periodic ranging in a broadband wireless access communication system having an awake mode in which data to be transmitted between a mobile subscriber station and a base station exists and the sleep mode in which data to be transmitted between the mobile subscriber station and the base station is non-existent, the sleep mode having a sleep interval and a listening interval, the mobile subscriber station being capable of receiving data in the listening interval and being incapable of receiving data in the sleep interval. The method comprises the steps of detecting that it is necessary for the mobile subscriber station in the sleep mode to perform the periodic ranging at a particular time point in the sleep interval and then receive control information from the base station; and reporting to the mobile subscriber station in a listening interval before the sleep interval that the mobile subscriber station must perform the periodic ranging and then receive the control information after staying in the sleep interval during a predetermined interval from a start point of the sleep interval.
[0073] In accordance with another aspect of the present invention, there is provided a method for performing periodic ranging in a broadband wireless access communication system having an awake mode in which data to be transmitted between a mobile subscriber station and a base station exists and the sleep mode in which data to be transmitted between the mobile subscriber station and the base station is non-existent, the sleep mode having a sleep interval and a listening interval, the mobile subscriber station being capable of receiving data in the listening interval and being incapable of receiving data in the sleep interval. The method comprises the step of receiving a report in a listening interval before the sleep interval that it is necessary to perform together with the base station the periodic ranging after staying in the sleep interval during a predetermined interval from a start point of the sleep interval.
[0074] In accordance with another aspect of the present invention, there is provided a method for performing periodic ranging in a broadband wireless access communication system having an awake mode in which data to be transmitted between a mobile subscriber station and a base station exists and the sleep mode in which data to be transmitted between the mobile subscriber station and the base station is non-existent, the sleep mode having a sleep interval and a listening interval, the mobile subscriber station being capable of receiving data in the listening interval and being incapable of receiving data in the sleep interval. The method comprises the step of receiving a report in a listening interval before the sleep interval that it is necessary to perform together with the base station the periodic ranging and then receive the control information after staying in the sleep interval during a predetermined interval from a start point of the sleep interval.
[0075] In accordance with another aspect of the present invention, there is provided a system for performing periodic ranging in a broadband wireless access communication system having an awake mode in which data to be transmitted between a mobile subscriber station and a base station exists and the sleep mode in which data to be transmitted between the mobile subscriber station and the base station is non-existent, the sleep mode having a sleep interval and a listening interval, the mobile subscriber station being capable of receiving data in the listening interval and being incapable of receiving data in the sleep interval. The system comprises the base station which reports to the mobile subscriber station in a listening interval before the sleep interval that the mobile subscriber station must perform the periodic ranging in the sleep interval when the base station detects that it is necessary for the mobile subscriber station in the sleep mode to perform the periodic ranging at a particular time point in the sleep interval; and the mobile subscriber station which receives the report from the base station in the listening interval, transits from the sleep mode into the awake mode, and then performs the periodic ranging at the particular time point together with the base station.
[0076] In accordance with another aspect of the present invention, there is provided a system for performing periodic ranging in a broadband wireless access communication system having an awake mode in which data to be transmitted between a mobile subscriber station and a base station exists and the sleep mode in which data to be transmitted between the mobile subscriber station and the base station is non-existent, the sleep mode having a sleep interval and a listening interval, the mobile subscriber station being capable of receiving data in the listening interval and being incapable of receiving data in the sleep interval. The system comprises the base station which reports to the mobile subscriber station in a listening interval before the sleep interval that the mobile subscriber station must perform the periodic ranging after staying in the sleep interval during a predetermined interval from a start point of the sleep interval when the base station detects that it is necessary for the mobile subscriber station in the sleep mode to perform the periodic ranging at a particular time point in the sleep interval; and the mobile subscriber station which receives the report from the base station in the listening interval, stays in the sleep interval during the predetermined interval, transits from the sleep mode into the awake mode, and performs the periodic ranging together with the base station.
[0077] In accordance with another aspect of the present invention, there is provided a system for performing periodic ranging in a broadband wireless access communication system having an awake mode in which data to be transmitted between a mobile subscriber station and a base station exists and the sleep mode in which data to be transmitted between the mobile subscriber station and the base station is non-existent, the sleep mode having a sleep interval and a listening interval, the mobile subscriber station being capable of receiving data in the listening interval and being incapable of receiving data in the sleep interval. The system comprises the base station which reports to the mobile subscriber station in a listening interval before the sleep interval that the mobile subscriber station must perform the periodic ranging and then receive control information after staying in the sleep interval during a predetermined interval from a start point of the sleep interval when the base station detects that it is necessary for the mobile subscriber station in the sleep mode to perform the periodic ranging at a particular time point in the sleep interval and then receive the control information; and the mobile subscriber station which receives the report from the base station in the listening interval, stays in the sleep interval during the predetermined interval, transits from the sleep mode into the awake mode, performs the periodic ranging together with the base station, and then receives the control information.
BRIEF DESCRIPTION OF THE DRAWINGS
[0078] The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0079] FIG. 1 is a block diagram schematically illustrating the structure of a conventional IEEE 802.16e communication system;
[0080] FIG. 2 schematically illustrates a sleep mode operation of a conventional IEEE 802.16e communication system;
[0081] FIG. 3 is a flow diagram for schematically illustrating a ranging process of a conventional IEEE 802.16e communication system;
[0082] FIG. 4 is a schematic view for illustrating the periodic ranging scheme of an MSS in the sleep mode in the IEEE 802.16e communication system according to the first embodiment of the present invention;
[0083] FIG. 5 is a schematic view for illustrating the periodic ranging of an MSS in the sleep mode in the IEEE 802.16e communication system according to the second embodiment of the present invention;
[0084] FIGS. 6A and 6B are flow charts illustrating the operation process of an MSS in the IEEE 802.16e communication system according to the second embodiment of the present invention; and
[0085] FIGS. 7A and 7B are flow charts illustrating the operation process of the BS in the IEEE 802.16e communication system according to the second embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0086] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention unclear.
[0087] The present invention proposes a periodic ranging scheme of an MSS in a sleep mode in an IEEE 802.16e communication system, which is a Broadband Wireless Access (BWA) communication system. That is to say, the present invention proposes a scheme for allocating an uplink resource for the periodic ranging even to an MSS in the sleep mode, thereby enabling the MSS to perform the periodic ranging and perform a reliable communication. The IEEE 802.16e communication system is a BWA communication system employing an Orthogonal Frequency Division Multiple Access (OFDMA) scheme, in which physical channel signals are transmitted by a plurality of sub-carriers to achieve high speed data transmission and a multi-cell structure is employed to support the mobility of the MSS. Although the present invention employs the IEEE 802.16e communication system as an embodiment thereof, it goes without saying that the present invention can be applied to any communication system supporting the sleep mode operation and the periodic ranging operation.
First Embodiment
[0088] The first embodiment of the present invention proposes a periodic ranging scheme of an MSS in the sleep mode, which employs a traffic indication (TRF_IND) message using the conventional format of the IEEE 802.16e communication system. That is, in the periodic ranging scheme of an MSS according to the first embodiment of the present invention, when the MSS in the sleep mode is controlled to perform the periodic ranging, the BS forcibly sets a SLPID bit for the MSS as a positive indication, the SLPID bit representing the MSS in an SLPID bitmap of a traffic indication message broadcasted by the BS during the listening interval before the beginning of the sleep interval.
[0089] Hereinafter, the periodic ranging scheme of an MSS in the sleep mode in the IEEE 802.16e communication system according to the first embodiment of the present invention will be described with reference to FIG. 4 .
[0090] FIG. 4 is a schematic view for illustrating the periodic ranging scheme of an MSS in the sleep mode in the IEEE 802.16e communication system according to the first embodiment of the present invention.
[0091] Since the MSS is in the sleep mode, the MSS receives the traffic indication message broadcasted from the BS (while repeatedly experiencing the listening interval and the sleep interval) and determines whether data targeting the MSS will be transmitted from the BS. As described above in relation to the prior art, in the conventional IEEE 802.16e communication system, when there is no data to be transmitted targeting the MSS, the sleep identifier bit representing the MSS in the sleep identifier bitmap contained in the traffic indication message is set as a negative indication. However, according to the first embodiment of the present invention, if it is necessary for the MSS to perform the periodic ranging while the MSS is in the sleep mode (especially in the sleep interval), even when there is no data to be transmitted targeting the MSS, the sleep identifier bit representing the MSS in the sleep identifier bitmap contained in the traffic indication message is set as a positive indication and transmitted during the listening interval before the beginning of the periodic ranging.
[0092] Here, the sleep identifier bit representing the MSS is set as a positive indication is in order to enable the MSS to receive the UL_MAP message from the BS for the periodic ranging and recognize the uplink resource allocation information even when there isn't any actual data which the MSS must receive. That is, by transmitting the sleep identifier bit representing the MSS as a positive indication, the BS forces the MSS to stay in the listening interval instead of returning to the sleep interval from the listening interval. Then, the MSS receives the traffic indication message and is forced to mode-transit from the sleep mode to the awake mode, so that the MSS can perform the periodic ranging between the BS and the MSS.
[0093] While the MSS performs the periodic ranging, that is, while the MSS transmits a ranging request (RNG_REQ) message to the BS and then receives a ranging response (RNG_RSP) message responding to the RNG_REQ message, the MSS cannot transit into the sleep mode. Therefore, in order to transit into the sleep mode, the MSS must receive either the RNG_RSP message responding to the RNG_REQ message or a sleep response message of an unsolicited instruction type from the BS.
[0094] Referring to FIG. 4 , because the MSS can operate in the sleep mode, the MSS receives the TRF_IND message 403 broadcasted from the BS in the listening interval 401 . Here, the MSS must start the periodic ranging 407 with the BS in the sleep interval 405 after the listening interval 401 . For the beginning of the periodic ranging 407 , the BS marks a positive indication on the SLPID bit representing the MSS in the SLPID bitmap contained in the TRF_IND message 403 and broadcasts the marked SLPID bit in the listening interval 401 .
[0095] Upon receiving the TRF_IND message 403 , the MSS transits into the awake mode 409 instead of returning to the sleep interval 405 , based on the positive indication of the SLPID bits for the MSS in the TRF_IND message. In the awake mode 409 , the MSS performs the periodic ranging between the BS and the MSS.
Second Embodiment
[0096] The second embodiment of the present invention proposes a periodic ranging scheme of an MSS in the sleep mode, which employs a TRF_IND message using a format different from the conventional format of the IEEE 802.16e communication system.
[0097] In the periodic ranging scheme of an MSS according to the first embodiment of the present invention, when the MSS in the sleep mode must perform the periodic ranging, the BS transmits a TRF_IND message in the listening interval before the beginning of the sleep interval so that the MSS can transits into the awake mode. However, as described above in relation to the prior art, the sleep interval according to the sleep interval update algorithm is set as a relatively long interval, power may be unnecessarily consumed because the MSS must maintain the awake mode before starting the periodic ranging. Therefore, the second embodiment of the present invention proposes a TRF_IND message format as illustrated in Table 6 in order to prevent unnecessary power consumption caused by maintaining the awake mode for the periodic ranging.
TABLE 6 Syntax Size Notes TRF-IND_Message_Format( ) { Management message type = 47 8 bits Byte of SLPID bit-map SLPID bit-map with Padding Variable the 2 bit are allocated for MSS as SLPID respectively byte-alignment NUM_of_MSS_Periodic_Ranging 8 bit For(i=0; i<NUM_of_Periodic_Ranging; i++) { Frame Offset of Awake for Periodic 10 bit [Frame] Ranging } Padding Variable }
[0098] As illustrated in Table 6, the TRF_IND message proposed by the second embodiment of the present invention uses an SLPID bitmap representing MSSs in the sleep mode. However, in the TRF_IND message proposed by the second embodiment of the present invention, as compared to the TRF_IND message of the conventional IEEE 802.16e communication system, two SLPID bits are allocated to each MSS in order to identify operations which must be performed by the MSS during the listening interval. Here, the two SLPID bits are called “SLPID bit pair”.
[0099] Hereinafter, Information Elements (IEs) of the TRF_IND message as illustrated in Table 6 will be described.
[0100] First, the Management Message Type is information representing a type of a message currently being transmitted. For instance, when the Management Message Type has a value of 47 (Management Message Type=47), it represents the TRF_IND message. The Byte of the SLPID bit-map represents the number of bytes of the SLPID bitmap. The SLPID bitmap represents SLPID bit pairs of the MSSs in the sleep mode. From among the two bits of each SLPID bit pair, the preceding bit represents whether or not the MSS must perform the periodic ranging (the bit set as a positive indication represents that the MSS must perform the periodic ranging, while the bit set as a negative indication represents that the MSS needs not perform the periodic ranging), and the following bit represents existence (or absence of) data targeting the MSS. Here, as is in the prior art, the SLPID bitmap may be padded with a dummy bit for byte alignment. The padding implies addition of a dummy bit in order to solve the byte alignment problem which may be caused by the awake frame offset having a size of 10 bits, and the awake frame offset will be described later in detail. The number of the periodic ranging of the MSS (NUM_of_MSS_Periodic Ranging) represents the number of MSSs which must transit into the next sleep interval and perform the periodic ranging from among MSSs currently receiving the TRF_IND message in the current listening interval.
[0101] The awake frame offset (Frame Offset of Awake for Periodic Ranging) represents a frame in the sleep interval at which the MSS must awake in order to perform the periodic ranging. Here, the awake frame offset has a size of 10 bits since it may have the same size as that of a maximum sleep interval (i.e., maximum window) in which the MSS can stay, and the value of the awake frame offset represents the number of frames from the start frame of the sleep interval to the start frame of the periodic ranging (i.e., the frame at which the periodic ranging starts). For example, when the awake frame offset has a value of 10, the MSS must transit into the awake mode at the 2 nd frame of the sleep interval in order to start the periodic ranging. Here, if the MSS receives a TRF_IND message representing the negative indication during the listening interval, the MSS can transit back into the sleep mode even before the listening interval is ended. The transition into the sleep mode in this case is not include in the value of the awake frame offset.
[0102] Hereinafter, the SLPID bit pair will be described.
[0103] First, the SLPID bit pair includes 2 bits representing different information as described above.
[0104] (2 bits)=(necessity to perform the periodic ranging or not:existence or absence of traffic). Herein, the first bit of 2 bits represents an information of necessity to perform the periodic ranging or not, and the second bit of 2 bits represents an information of existence or absence of traffic.
[0105] In the SLPID bit pair, the preceding bit represents whether the MSS must perform the periodic ranging. When the preceding bit has been set as 1, it represents that it is necessary to perform the periodic ranging in the following sleep interval. Then, the MSS must read the awake frame offset value and perform a corresponding operation.
[0106] In the SLPID bit pair, the following bit represents various meanings according to the value of the preceding bit. Specifically, when the preceding bit is marked as 0, that is, when the preceding bit represents that it is unnecessary to perform the periodic ranging in the following sleep interval, the following bit has the same meaning as that of the SLPID bit of a conventional IEEE 802.16e communication system. That is, when the following bit is marked as 1, it means that traffic exists (i.e., data exists) targeting the MSS, so the MSS must transit into the awake mode. In contrast, when the following bit is marked as 0, it means that there exists no traffic targeting the MSS, so the MSS must continue to stay in the sleep mode.
[0107] However, when the preceding bit is marked as 1, that is, when the preceding bit represents that it is necessary to perform the periodic ranging in the following sleep interval, the following bit marked as 0 represents that the MSS must transit again into the sleep mode after completing the periodic ranging in the next sleep mode while the following bit marked as 1 represents that the MSS must maintain the awake mode and receive the traffic transmitted from the BS.
[0108] After the periodic ranging between the BS and the MSS, when the BS has a Medium Access Control (MAC) management message to additionally transmit to the MSS or when the MSS needs to receive the MAC management message broadcasted by the BS, the BS marks 1 on both the preceding bit and 1 on the following bit in the transmitted SLPID bit pair. For example, when the MSS must perform the periodic ranging during the sleep interval and receive a MAC management message such as a Uplink Channel Descriptor(UCD) message containing UCD information changed through the periodic ranging, the BS marks 11 (binary) on the SLPID bit pair and then transmits it.
[0109] The MSS having received the TRF_IND message containing the SLPID bit pair marked as 11 must stay in the awake mode and receive the control information (i.e., a MAC management message) from the BS even after completing the periodic ranging. In contrast, when the BS has no control information to transmit to the MSS, the BS marks 10 on the SLPID bit pair and transmits it.
[0110] Hereinafter, the operations of the MSS according to the values of the SLPID bit pair will be described.
[0111] 1) In the Case where the SLPID Bit Pair is Marked as 00
[0112] Because the preceding bit of the SLPID bit pair is 0, this case is equivalent to the case where the SLPID bit of the TRF_IND message of the conventional IEEE 802.16e communication system is marked as a negative indication. Therefore, the MSS stays in the sleep mode during the sleep interval by the sleep interval update algorithm.
[0113] 2) In the Case where the SLPID Bit Pair is Marked as 01
[0114] Because the preceding bit of the SLPID bit pair is 0, this case is equal to the case where the SLPID bit of the TRF_IND message of the conventional IEEE 802.16e communication system is marked as a positive indication. Therefore, the MSS transits from the sleep mode into the awake mode.
[0115] 3) In the Case where the SLPID Bit Pair is Marked as 10
[0116] Because the preceding bit of the SLPID bit pair is 1, the MSS returns to the sleep interval during the sleep interval increased by the sleep interval update algorithm. However, the MSS must perform the periodic ranging during the sleep interval, so the MSS must temporarily transit into the awake mode at the frame from which the periodic ranging begins, that is, at the frame at which the UL_MAP message allocated an uplink resource (i.e., an uplink burst) for the periodic ranging of the MSS by the BS is transmitted. Therefore, the MSS must read the awake frame offset value of the TRF_IND message.
[0117] Specifically, the MSS reads the SLPID bit map of the TRF_IND message and detects the ordinal number of the MSS itself from among the MSSs each of which is assigned an SLPID bit pair having a preceding bit marked as 1. That is, each of the MSSs assigned an SLPID bit pair marked as 10 or 11 must detect its own ordinal number from among the MSSs. For example, if there are M number of MSSs each of which is assigned an SLPID bit pair having a preceding bit marked as 1 in total, the K-th MSS from among the M number of MSSs must the K-th awake frame offset from among the total M awake frame offsets located after the SLPID bitmap.
[0118] The MSS stays in the sleep mode during the interval corresponding to the detected awake frame offset and then temporarily transits into the awake mode for the periodic ranging. Further, since the following bit of the SLPID bit pair assigned to the MSS is marked as 0, the MSS transits again into the sleep mode after completing the periodic ranging. If the periodic ranging is performed up to the time point at which the sleep interval is ended, the MSS must operate following a received next TRF_IND message during the listening interval.
[0119] 4) In the Case where the SLPID Bit Pair is Marked as 11
[0120] In the case where the SLPID bit pair is marked as 11, the MSS operates nearly the same as in the case where the SLPID bit pair is marked as 10. The only difference is that the MSS maintains the awake mode even after completing the periodic ranging in the present case.
[0121] Hereinafter, the periodic ranging of an MSS in the sleep mode in the IEEE 802.16e communication system according to the second embodiment of the present invention will be described with reference to FIG. 5 .
[0122] FIG. 5 is a schematic view for illustrating the periodic ranging of an MSS in the sleep mode in an IEEE 802.16e communication system according to the second embodiment of the present invention.
[0123] Before describing FIG. 5 , it is assumed that four MSSs are in the sleep mode within an area controlled by one BS and the four MSSs receive TRF_IND messages containing SLPID bit pairs marked as 00, 01, 10, and 11 (binary), respectively. Initially, the four MSSs receive TRF_IND messages 511 transmitted from the BS.
[0124] First, an MSS having received a TRF_IND message containing an SLPID bit pair marked as 01 during the listening interval 513 transits into the awake mode 515 , since it operates in the same way as in the case where the SLPID bit of the TRF_IND message of the conventional IEEE 802.16e communication system is marked as a positive indication as described above.
[0125] Second, an MSS having received a TRF_IND message containing an SLPID bit pair marked as 00 during the listening interval 517 transits back into the sleep mode 519 , since it operates in the same way as in the case where the SLPID bit of the TRF_IND message of the conventional IEEE 802.16e communication system is marked as a negative indication as described above. Further, the MSS performs continuous sleep mode operation and receives a TRF_IND message 523 broadcasted from the BS during another listening interval 521 .
[0126] Third, an MSS having received a TRF_IND message 511 containing an SLPID bit pair marked as 10 during the listening interval 525 recognizes necessity to perform the periodic ranging in the sleep interval after the listening interval 525 and performs the corresponding operation by detecting an awake frame offset of the TRF_IND message 511 . Specifically, since the MSS is the first MSS from among MSSs each of which is assigned an SLPID bit pair having a preceding bit marked as 1 among MSSs in the sleep mode within the boundary of the BS, the MSS detects the first awake frame offset of the TRF_ND message 511 . Then, the MSS calculates based on the detected awake frame offset the frame at which the MSS must awake in the next sleep interval, and then transits into the awake mode 529 in order to start the periodic ranging 527 in the corresponding frame. However, since the periodic ranging is completed after the next sleep interval, the MSS must receive the TRF_IND message 531 transmitted from the BS. Although the MSS must transit into the sleep mode following the TRF_IND message 511 which the MSS has previously received, the MSS must perform next operation corresponding to the SLPID bitpair of the TRF_IND message 511 because the MSS already is within the listening interval 533 .
[0127] Fourth, an MSS having received a TRF_IND message 511 containing an SLPID bit pair marked as 11 during the listening interval 535 recognizes necessity to perform the periodic ranging in the sleep interval after the listening interval 535 and performs the corresponding operation by detecting an awake frame offset of the TRF_IND message 511 . Specifically, since the MSS is the second MSS from among MSSs each of which is assigned an SLPID bit pair having a preceding bit marked as 1 among MSSs in the sleep mode within the boundary of the BS, the MSS detects the second awake frame offset of the TRF_IND message 511 . Then, the MSS calculates based on the detected awake frame offset the frame at which the MSS must awake in the next sleep interval, and then transits into the awake mode 539 in order to start the periodic ranging 537 in the corresponding frame. After completing the periodic ranging, the MSS continues to stay in awake mode 541 since the following bit of the SLPID bit pair is marked as 1.
[0128] Next, the operation process of an MSS in the IEEE 802.16e communication system according to the second embodiment of the present invention will be described with reference to FIGS. 6A and 6B .
[0129] FIGS. 6A and 6B are flow diagrams illustrating the operation process of an MSS in an IEEE 802.16e communication system according to the second embodiment of the present invention.
[0130] First, in step 611 , the MSS performs the sleep mode operation. In step 613 , the MSS checks whether the sleep interval is ended. As a result of the checking, when the sleep interval is not ended, the MSS proceeds to step 615 . In step 615 , while still in the sleep interval, the MSS examines whether the periodic ranging has been performed. As a result of the examination, when it is concluded that the MSS has not performed the periodic ranging within the sleep interval, that is, when the MSS is performing a conventional sleep mode operation without performing the periodic ranging, the MSS returns to step 613 in order to continuously perform the sleep mode operation until the sleep interval is ended. In contrast, as a result of the examination, when it is concluded that the MSS has already completed the periodic ranging within the sleep interval, that is, when the MSS has completed the periodic ranging before the sleep interval completely lapses in a state where the MSS has been ordered to return to the sleep mode after completing the periodic ranging in step 643 , the MSS proceeds to step 645 and prevents power consumption during the remaining sleep interval. That is, in 645 , the MSS transits into the sleep mode and then terminates the process.
[0131] Meanwhile, as a result of the checking in step 613 , when the sleep interval is ended, the MSS proceeds to step 617 . In step 617 , the MSS checks whether the listening interval is ended. As a result of the checking, when the listening interval is ended, the MSS proceeds to step 645 . As a result of the checking in step 617 , when the listening interval is not ended yet, the MSS proceeds to step 619 . In step 619 , the MSS checks whether a TRF_IND message from the BS has been received. As a result of the checking, if a TRF_IND message from the BS has not been received, the MSS returns to step 617 .
[0132] As a result of the checking in step 619 , when a TRF_IND message from the BS has been received, the MSS proceeds to step 621 . In step 621 , the MSS checks whether the received TRF_IND message contains a SLPID bit pair indicating the MSS. As a result of the checking, when the TRF_IND message does not contain the SLPID bit pair indicating the MSS, the MSS proceeds to step 647 . Here, the fact that the TRF_IND message does not contain the SLPID bit pair indicating the MSS implies that the synch for information does not coincide between the MSS and the BS. In step 647 , the MSS transits into the awake mode and then terminates the process.
[0133] As a result of the checking in step 621 , when the TRF_IND message contains the SLPID bit pair indicating the MSS, the MSS proceeds to step 623 . In step 623 , the MSS checks whether the SLPID bit pair is marked as 00. As a result of the checking, when the SLPID bit pair is marked as 00, the MSS proceeds to step 645 . When the SLPID bit pair is not marked as 00, the MSS proceeds to step 625 . In step 625 , the MSS checks whether the SLPID bit pair is marked as 01. When the SLPID bit pair is marked as 01, the MSS proceeds to step 647 .
[0134] As a result of the checking in step 625 , when the SLPID bit pair is not marked as 01, the MSS proceeds to step 627 . In step 627 , the MSS checks whether the SLPID bit pair is marked as 10. When the SLPID bit pair is not marked as 10, that is, when the SLPID bit pair is marked as 11, the MSS proceeds to step 631 . In step 631 , the MSS recognizes that it is necessary to perform the periodic ranging in the next sleep interval since the SLPID bit pair is marked as 11 and that the MSS must stay in the awake mode after performing the periodic ranging since traffic targeting the MSS exists, and then the MSS proceeds to step 633 .
[0135] As a result of the checking in step 627 , when the SLPID bit pair is marked as 10, the MSS proceeds to step 629 . In step 629 , the MSS recognizes that it is necessary to perform the periodic ranging in the next sleep interval since the SLPID bit pair is marked as 10 and that the MSS must transit into the sleep mode after performing the periodic ranging since traffic targeting the MSS does not exist, and then the MSS proceeds to step 633 .
[0136] In step 633 , the MSS detects awake mode offset corresponding to the MSS in the TRF_IND message. In step 635 , the MSS transits into the sleep mode. In step 637 , the MSS checks whether a time interval corresponding to the awake mode offset has lapsed. As a result of the checking, when a time interval corresponding to the awake mode offset has lapsed, the MSS proceeds to step 639 . In step 639 , the MSS performs the periodic ranging between the BS and the MSS. In step 641 , the MSS checks whether the periodic ranging has been completed. As a result of the checking, when the periodic ranging has been completed, the MSS proceeds to step 643 .
[0137] In step 643 , the MSS checks whether the MSS must transit into the awake mode. Here, whether or not the MSS must transit into the awake mode after performing the periodic ranging can be determined using the SLPID bit pair value contained in the TRF_IND message. That is, in determining whether the MSS must transit into the awake mode, the MSS depends on the result of the checking in step 629 or step 631 . As a result of the checking in step 643 , when the MSS does not have to switch into the awake mode, the MSS returns to step 613 . Alternatively, if the MSS must switch into the awake mode, the MSS proceeds to step 647 .
[0138] The above description with reference to FIGS. 6A and 6B is given of the operation process of an MSS in the IEEE 802.16e communication system according to the second embodiment of the present invention. Now, the operation process of the BS in the IEEE 802.16e communication system according to the second embodiment of the present invention will be described with reference to FIGS. 7A and 7B .
[0139] FIGS. 7A and 7B are a flow diagrams illustrating the operation process of the BS in an IEEE 802.16e communication system according to the second embodiment of the present invention.
[0140] Referring to FIGS. 7A and 7B , in step 711 , the BS sets two bits mapped to an SLPID to be allocated to a corresponding MSS, in order to constitute a single TRF_IND message containing instruction about operations which all MSSs in the sleep mode must perform, that is, in order to constitute a single TRF_IND message to be transmitted to said all MSSs in the sleep mode (here, the BS may perform the setting of two bits from SLPID 1 and the TRF_IND message is completely constituted when the BS has performed the setting of two bits for all SLPIDs from SLPID 1). In step 713 , the BS checks whether the SLPID has been allocated to the corresponding MSS. When the SLPID has not been allocated to the corresponding MSS, it implies that the corresponding MSS having been using the SLPID has already transited into the awake mode, that the SLPID is now an unused SLPID which is available for another MSS which will transit into the sleep mode, and that the two bits have meaningless values, so the BS proceeds to step 735 . In step 735 , the BS marks 00 on an SLPID bit pair targeting the corresponding MSS in the SLPID bitmap of the TRF_IND message and proceeds to step 739 .
[0141] As a result of the checking in step 713 , when the SLPID has been allocated to the corresponding MSS, that is, when there is an MSS using the SLPID, the BS proceeds to step 715 . In step 715 , the BS selects the corresponding MSS allocated the SLPID and proceeds to step 717 . In step 717 , the BS checks whether the sleep interval of the selected MSS has ended. As a result of the checking, when the sleep interval of the selected MSS has not ended yet, the BS proceeds to step 735 . In contrast, when the sleep interval of the selected MSS has ended, the BS proceeds to step 719 . In step 719 , the BS checks whether traffic to be transmitted to the selected MSS exists. If traffic to be transmitted to the selected MSS exists, the BS proceeds to step 723 . In step 723 , the BS marks 01 on an SLPID bit pair targeting the selected MSS in the SLPID bitmap of the TRF_IND message and proceeds to step 739 .
[0142] As a result of the checking in step 719 , if traffic to be transmitted to the selected MSS does not exist, the BS proceeds to step 721 . In step 721 , the BS checks whether the MSS must perform the periodic ranging in the next sleep interval. As a result of the checking, when the MSS need not perform the periodic ranging in the next sleep interval, the BS proceeds to step 725 . In step 725 , the BS marks 00 on the SLPID bit pair targeting the selected MSS in the SLPID bitmap of the TRF_IND message and proceeds to step 739 .
[0143] As a result of the checking in step 721 , when the MSS must perform the periodic ranging in the next sleep interval, the BS proceeds to step 727 . In step 727 , the BS calculates the awake frame offset for the periodic ranging in the next sleep interval and inserts the calculated awake frame offset in the SLPID bitmap of the TRF_IND message. In step 729 , the BS checks whether the BS must transmit additional control information (i.e., MAC message) to the MSS after the periodic ranging between the BS and the MSS. When it is necessary to transmit additional control information, the BS proceeds to step 731 . In step 731 , the BS marks 11 on the SLPID bit pair targeting the MSS in the SLPID bitmap of the TRF_IND message and proceeds to step 739 . In contrast, if it is unnecessary to transmit additional control information, the BS proceeds to step 733 . In step 733 , the BS marks 10 on the SLPID bit pair targeting the MSS in the SLPID bitmap of the TRF_IND message and proceeds to step 739 .
[0144] In step 739 , the BS checks whether the SLPID of the MSS has a maximum value from among the values which the BS can allocate. When the SLPID of the MSS does not have the maximum value, the BS proceeds to step 737 . In step 737 , the BS increases the SLPID by 1 (SLPID=SLPID+1), and then returns to step 713 in order to set two bits to be mapped to an SLPID for operation of a next MSS. As a result of the checking in step 739 , when the SLPID of the MSS does has the maximum value, which implies that there are no more bit pair to be set for operation of another MSS, the BS proceeds to step 741 . In step 741 , the BS transmits the TRF_IND message to the corresponding MSS and ends the process.
[0145] The present invention as described above can simultaneously support the periodic ranging together with sleep mode and awake mode operations of a broadband wireless access communication system employing an OFDM/OFDMA scheme, such as an IEEE 802.16e communication system. Moreover, the present invention supports the periodic ranging of an MSS in the sleep mode in an IEEE 802.16e communication system, thereby providing a reliable communication with minimum power consumption while guaranteeing backward compatibility. As a result, the present invention can provide a communication with an improved service quality.
[0146] While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. | A method and a system for periodic ranging in a sleep mode of a broadband wireless access communication system having an awake mode in which data to be transmitted between a mobile subscriber station (MSS) and a base station (BS) exists and the sleep mode in which data to be transmitted between the MS and the BS does not exist, the sleep mode having a sleep interval and a listening interval, the MSS being capable and incapable of receiving data in the listening interval and in the sleep interval, respectively. The BS reports to the MSS in a listening interval before the sleep interval that the MSS must perform the periodic ranging in the sleep interval when the BS detects that it is necessary for the MSS in the sleep mode to perform the periodic ranging at a particular time point in the sleep interval. | 8 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a 35 U.S.C. §371 National Phase Application from PCT/SE2007/050495, filed Jul. 4, 2007, and designating the United States, which claims the benefit of Swedish Patent Application No. 0601532-5, filed Jul. 7, 2006.
TECHNICAL FIELD
The present invention relates to methods and arrangements in a telecommunication system, in particular to improvements in an evolved Universal Terrestrial Radio Access Network (E-UTRAN.
BACKGROUND
The development of E-UTRAN shall ensure competitiveness of future mobile communication systems in a long-term perspective, i.e. 10 years and beyond. The overall target is to further reduce operator and end-user costs and to improve service provisioning. Possible ways of reaching this target are to study ways to achieve reduced latency, to achieve higher user data rates, and improve the system capacity and coverage. One of the main novelties introduced for E-UTRAN in order to achieve these targets is the introduction of a new physical layer. This new physical layer applies Orthogonal Frequency Division Multiplexing (OFDM) for the downlink and Single Carrier Frequency Division Multiple Access (SC-FDMA) for the uplink. These choices were made, e.g., to achieve greater spectrum flexibility and enabling deployment in various spectrum allocations; to achieve the possibility of frequency domain adaptation and enabling higher spectrum efficiency; to achieve enhanced efficiency for broadcast services in the downlink due to the inherent macro-diversity combining properties of OFDM; and to achieve reduced receiver complexity, especially at high bandwidths and in conjunction with MIMO.
An evolved UTRAN can apply either a frequency-division duplex (FDD) transmission mode or a time-division duplex (TDD) transmission mode. When applying the time-division transmission mode, the evolved UTRAN uses the same frequency band for both uplink and downlink communication. Thus, some time slots are reserved for the uplink while others are reserved for the downlink. This is typically configured by the network. One time slot is assigned mandatory for the downlink, e.g. the first time slot in a radio frame. By reading control information in this time slot, the UE then knows the configuration of the other time slots, uplink or downlink.
SUMMARY
The present invention addresses problems that occur when more than one radio access network applying a time-division duplex transmission mode, e.g. UTRAN and E-UTRAN, need to co-exist on a same carrier. The invention addresses further problems concerning an efficient allocation of uplink resources and resource allocation in a handover situation.
It is thus the object of the present invention to improve the capabilities of an evolved Universal Terrestrial Radio Access Network coexisting with a normal Universal Terrestrial Radio Access Network.
It is the basic idea of the present invention to assign an attribute in form of a distinguishing value to the time slots used for the uplink and downlink transmission on said carrier such as to avoid scheduling of transmissions via a first radio access network, e.g. the UTRAN, in downlink or uplink time slots assigned to the second radio access network, e.g. the E-UTRAN, and to avoid scheduling of transmissions via said second radio access network in uplink time slots assigned for transmissions in said first radio access network.
The present invention thus implies the advantage to provide a radio base station node that is capable to handle transmissions of more than one radio access network applying a time-division duplex transmission mode and using a same carrier. Correspondingly, user equipments applying a time-division transmission mode can be used in areas with co-existing radio access networks applying time-divided transmission on a same frequency carrier.
The present invention further implies the advantage of a more efficient resource allocation to user equipments connected to said radio base stations.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 a and 1 b illustrate the present invention according to the second improvement.
FIG. 2 shows an example communication network within which the present invention can be applied.
FIG. 3 illustrates a network node, e.g. a radio base station, according to the present invention.
FIG. 4 illustrates a user equipment according to the present invention.
DETAILED DESCRIPTION
FIG. 2 illustrates a part of an E-UTRAN comprising radio base stations 21 , 25 (or evolved NodeB, eNB) that is connected to a core network 24 via an interface node 23 and provides communication services to user equipments 22 . The radio base station 21 can be equipped to also serve in another radio access network, e.g. a UTRAN.
One aspect of the present invention addresses problems when transmissions on an evolved UTRAN and another radio access network, e.g. a UTRAN or “pre-LTE”-system, need to coexist on a same carrier. Transmissions via the UTRAN system shall not be allowed on uplinks assigned to the E-UTRAN. This is obtained by configuring the uplink time slots assigned to the UTRAN only for those instances when an uplink transmission on the UTRAN is supposed to happen. The other time slots are assigned for UTRAN downlink, E-UTRAN uplink, or E-UTRAN downlink. The network can thus avoid scheduling of transmissions via the UTRAN in the downlink time slots of the E-UTRAN. This also applies vice versa, i.e. transmissions via the E-UTRAN do not transmit in uplink time slots assigned to the UTRAN. A terminal that is configured for communication via the UTRAN may listen for the downlink channels also in time slots that are supposed for the downlink of an E-UTRAN. The mobile may thereby, unintentionally, find signaling that relates to the communication on the E-UTRAN and obey to the content of this signaling. Therefore, the present invention introduces an attribute for each time slot carrying distinguishing values. For instance, three values can be applied: ‘UL’, ‘DL’, and ‘DTX/DRX’. In time slots that are marked as ‘DTX/DRX’ time slots, the user equipment should not listen to any downlink transmission, nor transmit anything on the uplink.
The same principle of this invention is also applicable for handling synchronous hybrid ARQ (synch HARQ) in the uplink.
With sync HARQ, retransmissions occur at a predefined uplink time slot. If this time slot is used for other purposes, e.g. random access, it should not be configured as uplink time slot for data purposes. However, it should not be configured as downlink time slot either as this would imply that the user equipment is trying to find control signaling. Hence, it is beneficial to separate the indications of uplink and downlink time slots from each other.
Regarding guard times, the principle of this invention might be applied to signal three different subframe types to the user equipment (denoted, e.g., “downlink subframe”, “uplink subframe”, “inactive subframe”) which will be beneficial for the coexistence of a UTRAN with an E-UTRAN. Inactive subframes ensure that user equipments that are designed for communication via the UTRAN do not—by mistake—decode control signaling sent on the downlink of the E-UTRAN.
Further, for synchronous hybrid ARQ it is not always possible to simply “avoid scheduling” as it may be that a sync retransmission takes place. There is therefore a need to signal some kind of information indicating subframes that are available for uplink transmissions to the user equipment. Subframes that are not available for the uplink can be used for the downlink or for random access. The sync HARQ process numbering is done on the UL-available subframes (and may therefore not be an even multiple of the 10 ms radio frame).
Another aspect of the present invention relates to an efficient allocation of transmission resources. A user equipment can, according to one embodiment of the present invention, take into account the presence of certain types of common control (overhead) channels that are known to be transmitted in some subframes. For instance, BCH, PCH, or FACH will be mapped to the first subframe in a radio frame which is known to both the radio base station node and the user equipment. One subframe carries BCH, PCH, and FACH while others do not. Regarding the uplink, some uplink subframes may contain common overhead channels for random access. As a consequence, some subframes can contain more user data than other subframes. Scheduling control signaling is used to indicate which “data resources” a user equipment is supposed to receive. As it is, however, undesirable to have different scheduling control signaling structures in the different subframes, this embodiment of the present invention applies the a-priori knowledge on subframes containing said overhead channels, either predefined (as for the BCH) or semi-statically configured based on BCH information (as for the PCH or FACH). The user equipment, thus, can take this knowledge into account when interpreting the scheduling control signaling both for downlink and uplink scheduling. There is no need for special control signaling for the first subframe and the user equipment accounts for the presence of BCH/PCH/FACH. For instance, FIG. 1 a illustrates a series of resource blocks 10 whereof a fraction 11 of said resource blocks, particularly resource blocks 3 - 14 , is assigned to a user equipment by means of control signaling. The user equipment receives and processes the complete fraction of said resource blocks as it knows that no overhead channels use the subframes of said fraction. In the example of FIG. 1 b , the user equipment uses all resource blocks of said fraction except for resource blocks 4 , 8 , 12 , and 16 (selected by means of an illustrating example only) as the user equipment can apply a-priori knowledge that the excepted resource blocks are used for overhead control channels.
Uplink transmission resources can, according to one embodiment of the present invention be assigned by means of a scheduling grant controlling the uplink transmission that does not point directly to the resources to use for the uplink transmission but indicates which hopping sequence is to be used. As there is no uplink channel-dependent scheduling in the frequency domain, interference diversity is important together with hopping on, e.g., on a 0.5 ms basis. The uplink resources that are used for transmission can be retrieved from a function taking as an input one or more of, e.g., the following: The resources that are assigned by the scheduler, the connection frame number, the cell-ID, or any other appropriate parameter.
A further embodiment of the present invention relates to resource scheduling for handover access between the radio base station 21 of a source cell and the radio base station 25 of a target cell. After that the radio base station 21 of the source cell has requested handover resources from the radio base station 25 of the target cell, the target cell radio base station 25 allocates resource blocks dedicated to a “handover access”, e.g. periodically occurring resource blocks due to the handover request (i.e. the target cell stops using these resource blocks for own user equipments; although the target cell may also allocate the resources to be used by the new entering user equipment 22 after the handover access phase). The target cell radio base station 25 adapts its scheduling (if needed) such as to provide that the allocated handover resources will contribute with little interference and are not allocated to own user equipments and indicates then the allocated handover access resources to the source cell radio base station 21 , which in turn indicates the allocated handover access resources to the user equipment 22 . After that the user equipment 22 has moved to the target cell and started to use said handover resources, the target cell radio base station 25 can start scheduling the user equipment 22 according to Qos requirements while the allocated handover resource blocks can be utilized again as normal resource blocks.
FIG. 3 illustrates a network node 21 , e.g. a radio base station, according to the present invention. The network node 21 is located in a communication system applying a time-division duplex transmission of time slots on a same frequency band for uplink and downlink transmissions to user equipments and support access to at least a first and a second co-existing radio access network. The network node 21 comprises means 211 for assigning to each time slot an attribute distinguishing transmission mode and direction of transmission in said time slot. According to further embodiments of the present invention, the network node 21 can also comprise means 212 for providing signalling information of subframes that are available for the user equipment 22 for uplink transmission and/or means 213 for performing a resource allocation for an uplink transmission by indicating the hopping sequence to be used for said transmission.
FIG. 4 illustrates a user equipment 22 according to the present invention, said user equipment connected to a network node 21 applying a time-division duplex transmission of time slots on the same frequency band for uplink and downlink transmissions to said user equipment 22 . The network node 21 supports access to at least a first and a second co-existing radio access network, whereby said user equipment 22 has access via said first radio access network. The user equipment 22 comprises means 221 for retrieving information on an attribute assigned to the time slots of a received transmission from the network node 21 and means 222 for omitting time slots that are marked with a value prohibiting the usage of such time slots to user equipments accessing said network node 21 via the first radio access network. According to further embodiments of the present invention, the user equipment can further comprise means 223 for retrieving information signalled by the network node 21 of subframes that are available for the user equipment 22 for uplink transmission and/or means 224 for determining control channels in certain subframes by applying pre- or semi-statically configured information of said channels in a storage means 225 and deriving an indication of the resource allocation for uplink or downlink subframes by accounting said determined control channel information. | The present invention relates to methods and arrangements for improving the capabilities of an evolved Universal Terrestrial Radio Access Network, in particular for cases when more than one radio access network applying a time-division duplex transmission mode need to co-exist on a same carrier. The invention addresses further problems concerning an efficient allocation of uplink resources and resource allocation in a handover situation. The present invention assigns an attribute in form of a distinguishing value to the time slots used for the uplink and downlink transmission on said carrier such as to avoid scheduling of transmissions via a first radio access network in downlink or uplink time slots assigned to the second radio access network and to avoid scheduling of transmissions via the second radio access network in uplink time slots assigned for transmissions in the first radio access network. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to warp knitting machines and in particular to a warp knitting machine that is provided with a weft thread inserting device.
Prior art attempts at using a weft inserting device with a warp knitting machine have been very limited. Since the knitting needles are positioned relatively close together, the ability to cross over more than one or two warp threads has created insurmountable problems. The woven nature of the fabric produced with prior art techniques is interrupted by chain stitches occuring in very small strips. To overcome the basic problems it is necessary to device a means for installing a weft inserter into the relatively very narrow spacing between warp threads with the ability to work within the shed while being anchored outside the shed. It is also necessary to be able to span a relatively large number of warp threads and span at least two needles spaced relatively far apart.
The present invention overcomes the shortcomings of the prior art by reducing and virtually eliminating chain stitches which normally occur at narrow intervals across the width of the fabric thereby simulating the effect of woven fabric.
An object of the present invention is to provide a knitted fabric having an unusual characteristic.
Another object of the present invention is to provide a knitted fabric which has some of the features and characteristics of woven fabric.
Still another object of the present invention is to provide a means for knitting fabrics more rapidly and less expensively, with characteristics of woven cloth.
SUMMARY OF THE INVENTION
A warp knitting machine, according to the principles of the present invention, includes a needle bar with a plurality of needles affixed thereon, weft thread inserters, warp threads biased towards the needle bar, and a source of driving power, all of which are known in the art, and further includes the improvement which comprises; shed thread guides cooperating with the warp threads and alternately reciprocating groups of warp threads towards and away from the needles to form a shed with the needles disposed therein. The warp threads are provided with an enlarged opening between each of the groups. Weft thread inserters are angularly formed and disposed within the enlarged warp thread openings in close proximity to the needles. The weft thread inserters are driven to span at least a pair of said needles in addition to being reciprocated towards and away from said needles. A group of warp threads comprises from four to six warp threads displaced from the needles in one direction with a like number of warp threads displaced in the opposite direction forming the shed.
The above objects, as well as further objects and advantages of the present invention will become readily apparent after reading the description of a non-limiting illustrative embodiment and the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more fully understood, it will now be described, by way of example, with reference to the drawing in which:
FIG. 1 is a partial sectional view and pictorial representation in elevation through the knitting portion of a warp knitting machine of a preferred embodiment, according to the principles of the present invention;
FIG. 2 is a partial plan view of the shed thread guides used in FIG. 1;
FIG. 3 is a partial plan view of the weft thread inserters disposed within the enlarged opening of each group of warp threads shown in FIG. 1;
FIG. 4 is a partial plan view of the system of FIG. 3 showing the position of the weft thread inserters within the enlarged opening and displaced in a lateral direction; and
FIG. 5 is a partial plan view of an alternate embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, and particulary to FIG. 1, in which there is shown a partial view in section combined with a pictorial representation of the knitting portion 10 of a warp knitting machine. The warp threads 12 a, b, c, d and 14 a, b, c, d extend a vertical direction normally biased towards the needle bar 16 which has affixed thereon a plurality of needles 18 which are illustrated as being of the latching type. The needle bar 16 and needles 18 are driven by a conventional source of driving power, not shown, in a vertical direction (up and down) as shown by arrow 20 in accordance with the proper timed sequence.
The warp threads 12 a, b, c, d, e extend through the openings 22 a, b, c, d, e respectively, which are provided in the end portion of warp thread guides 24 a, b, c, d, e. The warp thread guides 24 a, b, c, d, e are affixed in a conventional manner to guide bar 26 which is connected to linkage mechanism 28 that includes the levers 30 and 32; and a connecting rod 34. The end 36 of the lever 32 is operatively coupled to the source of driving power and, displacing it in the direction of arrow 38 (vertical), will cause the connecting rod 34, the guide bar 26 and the warp thread guides 24 a, b, c, d, e to move in the direction of arrow 40, which is towards and away from the needles 18.
In a similar manner, warp threads 14 a, b, c, d, e extend through the openings 44 a, b, c, d, e respectively, which are provided in the end portion of warp thread guides 46 a, b, c, d, e. The warp thread guides 46 a, b, c, d, e are affixed in a conventional manner, to guide bar 48 which is connected to linkage mechanism 50 that includes the levers 52 and 54; and a connecting rod 56. The end 58 of the lever 54 is operatively coupled to the source of driving power and, displacing it in the direction of arrow 60 (vertical), will cause the connecting rod 56, the guide bar 48 and the warp thread guides 46 a, b, c, d, e to move in the direction of arrow 60, which is towards and away from the needles 18.
The movements of the guide bar 26 and the guide bar 48 are in opposite directions reciprocated, and synchronized with the other stitch forming mechanisms, in a conventional manner as is well known in the art. The guide bars, by their movement, displace the warp threads 12 a, b, c, d, e, and 14 a, b, c, d, e to form an opening 62 which extends in the lateral direction, in the same direction as the needle bar, and will be referred to hereinafter as the shed opening. The guide bars 26 and 48 and their associated warp thread guides 24 a, b, c, d, e, and 46 a, b, c, d, e, respectively, will be referred to hereinafter as the shed guides 24 and 46, respectively.
It can be seen that reciprocating the shed guides 24 and 46 towards the needles 18 and away therefrom will provide a shed opening 62 with the warp threads 12 a, b, c, d, e and 14 a, b, c, d, e alternately exchanging positions. Thus, warp threads 12 a, b, c, d, e are located, at one point in the cycle, in front of the needles 18, and 14 a, b, c, d, e are located behind the needles as shown in FIG. I. At the next lap, the former group of threads are located behind the needles and the latter in front of the needles with the needles always being disposed within shed 62.
It is important that the shed forming thread guides 24 and 46 are vertically separated as shown in FIG. 1 so that from the insertion of one weft to the next a new shed may be formed. In FIG. 1 as shown this shed is formed by threads 12 and 14. In this way a weft thread 88 is inserted. Then the shed changes. Thus the shed guides 24 go to the right hand side and the shed guides 46 go to the left hand side, so that then a new shed is formed with threads 14 on the left hand side and threads 12 on the right hand side and into this new shed weft threads 88 are inserted and so forth. This situation may be recognized from the plan drawing of FIG. 2 which shows the travel of 46 to the left and 24 to the right. FIG. 2 thus shows the reverse orientation of FIG. 4.
In the preferred embodiment of the invention, the shed 62 is formed by reciprocating a group of warp threads varying from four to six. However, it is to be understood that the present invention is not so limited and any number of warp threads may be reciprocated in accordance with the present invention.
FIG. 2 illustrates a plan view of the shed thread guides 24 and 46 in their most forward or closed position wherein FIG. 1 shows the shed thread guides in their most rearward open position; their direction of movement being indicated by arrows 40 and 60, respectively. In addition, shed thread guides 26 and 48 may be periodically moved in the direction of arrows 64 and 66, respectively, to permit the warp threads to lap or lay across the needles 18.
FIG. 1 further includes a sinker assembly 68 which holds the fabric 70 during the upward motion of the needles 18, to influence the lapping of the threads so that they arrive safely under the laches or heads of the needles, to push the previously formed row of stitches onto the closed needles and to cast them off over the new row of loops with the aid of the knockover edge 69 provided thereon.
In addition, FIG. 1 includes weft thread inserters 72 a, b, c which are affixed to bar 74, in a conventional manner. Weft bar 74 is driven from the source of driving power in synchronism with the other stitch forming mechanisms in the direction of arrow 76, and is also dirven in the direction of arrow 78 from its start position shown in FIG. 3 to its end position shown in FIG. 4. The weft bar 74 has affixed thereon, in a conventional manner, a weft thread inserter 80 which is provided with thread guide openings 82, 84, and 86 to guide the weft thread 88 to the needle 18.
Referring now to FIG. 3 wherein there is shown three groups of warp threads; 12 a, b, c, d, e and 14 a, b, c, d, e; 90 a - e and 92 a - e; and 94 a - e and 96 a- e.Each group is formed with two sets of fine warp threads angularly displaced with respect to the plane formed by the needles 18, 19 and 21. The warp threads are maintained in their correct position by their respective shed guides and explained hereinbefore. Between each group of weft threads an enlarged opening 98, 100, 102 and 104 is provided to permit the entrance therein of weft thread inserters.
Weft thread inserter 72a enters enlarged opening 100, inserter 72b enters enlarged opening 102, and inserter 72c enters enlarged opening 104. Moving weft bar 74 in the direction of arrow 78 permits the weft thread inserters 72a to move from a position proximate needle 19 to a position proximate needle 18 and weft thread inserter 72b to move from a position proximate needle 18 to needle 21, etc. (Refer to FIGS. 3 and 4). Thus with the arrangement set forth in the present invention each weft inserter may span a plurality of warp threads and span at least two needles which are located relatively far apart. Inserting weft threads may be done at various times in the knit cycle, thereby creating new, different and useful fabric types.
An alternate embodiment of the present invention is disclosed in FIG. 5. The alternate embodiment shown therein functions in the same manner as the preferred embodiment and includes a weft bar 112 which has affixed thereon weft thread inserters 114 and 116 positioned on one side (front) of the needle bar 118, which has needles 120, 121 and 122 affixed thereon, and weft thread inserters 124 and 126 positioned on the other side (rear) of the needle bar 118. Weft inserters 114 and 116 are adapted to be driven in the direction of arrow 128 and weft bar 129 which includes weft inserter 130 and 132 is adapted to be driven in the direction of arrow 134 in addition to being reciprocated towards and away from the needle bar 118.
The shed is formed, as described earlier, by the opening of the warp threads 136 a - d and 138 a - d in the first group; threads 140 a - d and 142 a - d in the second group; 144 a - d and 146 a - d in the third group and 148 a - d and 150 a - d in the fourth group. Each of the groups are separated by enlarged openings 152, 154, 156 and 158 which permit the weft inserters to enter the shed.
It is to be noted that the warp threads shown in FIGS. 3 and 4 are positioned by the warp thread guides at an angle to the needle bar 16 and that the central portion of the weft thread inserters 72 a, b, c are fabricated essentially parallel to the warp threads, thus permitting maximum movement in the direction of arrow 78 within the shed, thereby encompassing or spanning fine warp threads.
In the embodiment shown in FIG. 5 the central portion of the weft thread inserters 114, 116, 130 and 132 are also parallel to the warp threads and the warp threads are positioned in a plane parallel to the needle bar 118, thus also permitting maximum movement in the direction of arrow 128 for inserters 114 and 116; and in the direction of arrow 134 for inserters 130 and 132.
In operation, the weft inserters are driven in synchronism with the knitting mechanisms as is well known in the art and are able to insert one or more weft threads during knitting for unusual results.
Hereinbefore, has been disclosed a novel means for inserting a weft thread in a warp knitting machine which is capable of operating with needles spaced relatively large distances apart and spanning a relatively large number of weft threads.
It will be understood that various changes in the details, materials, arrangements of parts and operating conditions which have been herein described and illustrated in order to explain the nature of the invention may be made by those skilled in the art within the principles and scope of the present invention. | A warp knitting machine produces an unusual effect by including a weft thread inserting device capable of operating over a relatively large number of needles eliminating the chain stitches which normally occur at narrow intervals. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Pursuant to 35 U.S.C. § 119(e), a right of priority to U.S. Provisional Patent Application No. 60/918,190 filed on Mar. 15, 2007 and entitled “Active, Micro-well Thermal Control Subsystem” is asserted.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] (Not Applicable)
BACKGROUND OF THE INVENTION
[0003] The present invention relates to devices and systems for providing active thermal control of sample-containing assay trays and, more specifically, to devices and systems that provide improved, uniform heat transfer from a sample-containing assay tray using thermo-electric devices, heat spreader plates, and liquid heat exchangers.
[0004] Protocols for amplification of RNA or DNA, for example, during polymerase chain reaction (PCR), bDNA, and similar testing, require rapid and uniform heating and cooling of a plurality of sample-containing vessels. Because such testing typically is performed in batches, the rapid and uniform heating and cooling is applied to the plurality of sample-containing vessels simultaneously.
[0005] Conventionally, heat transfer for thermo-electric devices and/or heating elements is accomplished by conduction, while cooling of thermal system components is done by convection, or, more conventionally, by air convection. However, thermal performance of such systems is limited by the space needs of relatively large thermal components.
[0006] Therefore, it would be desirable to provide a liquid heat-transferring concept that transfers heat by liquid convection rather than by air convection to improve heat transfer and to provide a more compact thermal component size. Thermal control of sensitive reagents used in these protocols is also highly desirable.
SUMMARY OF THE INVENTION
[0007] An active thermal control subsystem for controlling the temperature of a sample-containing holding device used in connection with bDNA testing, polymerase chain reaction testing, chemiluminescent immuno-assay testing, and the like is disclosed. The thermal control subsystem includes first and second assemblies, a pump, and a heat exchange device that are fluidly-coupled via a fluidic circuit.
[0008] The first and second assemblies include a heat removal device and a thermo-electric device(s). One or more of the first and the second assemblies includes a heat spreader. The heat spreader is further thermally-coupled to the sample-containing holding device, such as a micro-well assay tray. The thermo-electric device(s) is/are disposed between the heat removal device and the heat spreader. Current transmitted to the thermo-electric device(s) is controlled. Depending on the voltage at each junction, heat can be transferred bi-directionally, either from the heat spreader to the heat removal device or from the heat removal device to the heat spreader.
[0009] A testing system having active thermal control of a sample-holding device and/or a reagent-containing device is also disclosed. The system includes the thermal control subsystem described above and a controller. The controller controls operation of the pump, the heat exchange device, and the thermo-electric device(s) associated with the first and second assemblies to control the temperature of the sample-holding device and/or reagent-containing device.
[0010] Optionally, the system can include a holding device for retaining reagent-containing vessels that is fluidly-coupled to the fluidic system and/or a drain line that is fluidly-coupled to the fluidic system for removing heat-transferring fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention will be better understood by reference to the following more detailed description and accompanying drawings where like reference numbers refer to like parts:
[0012] FIG. 1 shows a diagram of a well subsystem in accordance with the present invention;
[0013] FIG. 2 shows a diagram of micro-well assay trays disposed between first and second heater plates in accordance with the present invention;
[0014] FIG. 3A shows a diagram of a plan view of a heat sink (taken from the bottom) in accordance with the present invention; and
[0015] FIG. 3B shows a diagram of an isometric view of the heat sink of FIG. 3A .
DETAILED DESCRIPTION OF THE INVENTION
[0016] U.S. Provisional Patent Application No. 60/918,190 filed on Mar. 15, 2007 and entitled “Active, Micro-well Thermal Control Subsystem”, from which priority is claimed, is incorporated herein by reference.
[0017] An active control, micro-well thermal breadboard/micro-well thermal subsystem, e.g., for a bDNA testing system, a chemiluminescent immunoassay system, a PCR testing system, and the like, is disclosed. Referring to FIG. 1 , there is shown an active thermal control subsystem 10 for controlling the temperature of at least one micro-well assay tray (not shown). The micro-well assay tray discussed in this disclosure corresponds to a conventional micro-well titer plate for holding multiple, i.e., 96, sample-containing cuvettes. The invention, however, is applicable to other sample-holding devices.
[0018] The subsystem 10 is structured and arranged to maintain micro-well plate incubation temperatures between about 20 degrees Centigrade (° C.) and about 70° C., which is to say, between about 68 degrees Fahrenheit (° F.) and 158° F., respectively. Moreover, the subsystem 10 is structured and arranged so that the average temperature of the micro-well assay trays can be maintained within approximately ±0.5° C. of the specified or desired temperature and, moreover, so that the temperature difference between adjacent micro-well assay trays does not exceed approximately ±0.5° C. Optionally, the subsystem 10 of the present invention can also be structured and arranged to control the temperature of sensitive reagents used in the course of the PCR, chemiluminescent or other testing.
[0019] The micro-well thermal subsystem 10 of the present invention includes first and second heater trays 14 and 16 , a heat exchanger 15 , a pump 18 , and a fluidic system 19 . Optionally, the micro-well thermal subsystem 10 can include a reagent holding device 12 and/or a system controller 20 , which in FIG. 1 is shown separate from the micro-well thermal subsystem 10 .
[0020] Each of the first and second heater trays 14 and 16 , the heat exchanger 15 , and the reagent holding device 12 are fluidly-coupled via a common fluidic system 19 . The fluidic system 19 includes fluid conduits, such as flexible tubing, for circulating a heat-transferring liquid. A drain line 17 can be provided to drain the fluidic system 19 and/or to bleed off excess heat-transferring liquid within the fluidic system 19 .
[0021] A centrifugal pump 18 , such as the RD-05CV24 manufactured by Iwaki Co., Ltd. of Tokyo, Japan, is also fluidly-coupled to the fluidic system 19 . The centrifugal pump 18 is adapted to circulate a heat-transferring liquid, such as a water and ethylene-glycol (WEG) mixture, between the first and second heater trays 14 and 16 and the heat exchanger 15 , to transfer heat from or transfer heat to the first and second heater trays 14 and 16 ; between the reagent holding device 12 and the heat exchanger 15 , to transfer heat from or transfer heat to the reagent-containing vessels disposed in the reagent holding device 12 ; and between the fluidic system 19 and a coolant reservoir 25 , to add heat-transferring liquid to or to drain heat-transferring liquid from the fluidic system 19 .
[0022] The reagent holding device 12 of the present invention includes inlet and outlet ports 26 and 28 , respectively, and associated internal fluidic connections (not shown) for controlling the temperature of reagent-containing vessels, e.g., test tubes, disposed in the reagent holding device 12 . The inlet and outlet ports 26 and 28 are releasably attachable to the external fluidic system 19 for circulating a heat-transferring liquid through the fluidic connections and about the reagent-containing vessels, to control the temperature of the reagent-containing test tubes by liquid convection.
[0023] The heat exchanger 15 can be a conventional, radiator-type heat exchanger, having a coolant reservoir 22 , a plurality of coils 23 , and at least one fan assembly 21 . The coolant reservoir 22 is adapted to hold heat-transferring liquid that has been heated in the first or second heater trays 14 and 16 and elsewhere in the fluidic system 19 temporarily. The plurality of coils 23 is adapted to circulate heat-transferring liquid from the coolant reservoir 22 to the fluidic system 19 . The fan assembly(ies) 21 is/are adapted to move ambient air against and around the coils 23 , to remove heat from the heat-transferring liquid circulating therein. Once sufficient heat has been removed from the heat-transferring liquid circulating in the coils 23 , the heat-transferring liquid is re-circulated to the first and second heater trays 14 and 16 , to the reagent holding device 12 , and/or to the coolant reservoir 22 .
[0024] Referring to FIG. 2 , a first side of each of the first and second heater trays 14 and 16 is operationally- and thermally-coupled to the item(s) being thermally-controlled, e.g., at least one 96-position micro-well assay tray 39 . The first side of the second heater tray 16 shown in FIG. 1 and FIG. 2 includes two sub-portions 24 and 27 , each of which is adapted for holding a conventional, 96-position micro-well titer plate 39 . The first side of the first heater tray 14 includes two sealing pads 37 and 38 that are also adapted, in combination with the associated sub-portions 24 and 27 of the second heater tray 16 , for securing the 96-position micro-well titer plates 39 therebetween.
[0025] As shown in FIG. 2 , the sub-portions 24 and 27 of the second heater plate 16 are thermally-coupled to a heat spreader 31 . Optionally (as shown in FIG. 2 ), the sealing pads 37 and 38 of the first heater tray 14 also can be thermally-coupled to a heat spreader 32 . Experimentation by the inventors evinced that micro-well thermal performance is more greatly influenced by the second (lower) heater tray 16 than by the first (upper) heater tray 14 . Hence, a heat spreader 32 for the first (upper) heater tray 14 can be omitted to reduce cost and simplify design.
[0026] The heat spreaders 31 and 32 are adapted to avoid hot or cold spots within the micro-well assay trays 39 , especially during rapid, ramp temperature changes. The heat spreaders 31 and 32 also prevent direct heat transfer from thermo-electric devices (TEDs) 35 , which are disposed on the opposite sides of the heat spreaders 31 and 32 , to the center of the micro-well assay trays 39 .
[0027] Heat spreaders 31 and 32 can be manufactured of copper, aluminum or some other relatively-highly thermally-conductive material. More specifically, the heat spreaders 31 and 32 are adapted to ensure that each micro-well assay tray 39 is maintained within approximately ±0.5° C. (±about 1° F.) of the specified temperature; that the temperature difference between adjacent micro-well assay trays 39 does not exceed approximately ±0.5° C.; that the ramp temperature change rate, i.e., “ramping”, for heating or cooling the micro-well assay trays 39 is between approximately 1° C./minute (about 2° F.) and approximately 10° C./minute (about 18° F./minute) and, more preferably, between approximately 1° C./minute and approximately 7° C./minute (about 13° F./minute); and that, during ramping, the upper (or lower) target temperature is not exceeded by more than approximately 0.5° C.
[0028] As mentioned above, one side of each of the heat spreaders 31 and 32 is operationally- and thermally-coupled to a plurality of thermo-electric devices (TED) 35 , which are disposed to be in registration with the sub-portions 24 and 27 and the micro-well assay trays 39 . TEDs 35 are thermal controllers that transfer heat across their thickness by the Peltier effect. According to the Peltier effect, applying voltage to the junctions of two dissimilar metals causes a temperature difference between the two junctions. Hence, by varying the polarity of the voltages applied to the junctions, temperatures can be increased or decreased and, more importantly, heat can be transferred from one side of the TED 35 to the other side of the TED 35 in either direction.
[0029] Advantageously, heat can be transferred from heat removal devices, i.e., heat sinks 11 and 13 , respectively, to the heat spreaders 31 and 32 , when ramping up the temperature of the micro-well assay trays 39 . Alternatively, heat can be transferred from the heat spreaders 31 and 32 to the heat sinks 11 and 13 , respectively, when ramping down the temperature of the micro-well assay trays 39 .
[0030] Heat sinks 11 and 13 are thermal masses used for removing heat by conduction and/or by convection. Heat sinks 11 and 13 are well known to the art and will not be discussed in great detail. However, referring to FIGS. 3A and 3B , heat sinks 11 and 13 can include two opposing, relatively-highly thermally-conductive plates 42 and 44 that are releasably attachable to one another. At least one fluid-carrying channel 45 is disposed between the two plates 42 and 44 . The fluid-carrying channel(s) 45 of the heat sinks 11 and 13 includes an inlet port 49 and an outlet port 47 , which are fluidly-coupled to the fluidic system 19 .
[0031] During operation, the direction of heat transfer between the heat sinks 11 and 13 and the micro-well assay trays 39 depends on whether the TEDs 35 are in a heating or in a cooling mode. During a heating mode, a rapid ramp-up temperature change of the micro-well assay tray(s) 39 is desired. For example, during PCR testing, conventionally, an analyte-containing sample is heated from ambient temperature to about 70° C. (about 158° F.) during the initial de-naturing cycle.
[0032] Accordingly, voltages at the junctions of the TEDs 35 are controlled so that heat is transferred from the heat sinks 11 and 13 to the micro-well assay trays 39 . More specifically, the heat-transferring liquid in the fluidic system 19 is heated to an elevated temperature (or is allowed to remain at an elevated temperature) sufficient to transfer the necessary heat from the heat-transferring liquid to the heat sink(s) 11 and/or 13 . In some instances, the available heat in the heat sink(s) 11 or 13 may be sufficient to rapidly change the temperature of the micro-well assay trays 39 without using a heated liquid to heat the heat sink(s) 11 or 13 .
[0033] During a cooling mode, a rapid ramp-down temperature change of the micro-well assay tray(s) 39 is desired. Accordingly, voltages at the junctions of the TEDs 35 are controlled so that heat is transferred from the micro-well assay trays 39 to the heat sink(s) 11 and/or 13 via the TEDs 35 . Heat-transferring liquid circulating though the channels disposed in the heat sink(s) 11 and/or 13 removes heat from the heat sink(s) 11 and/or 13 .
[0034] A controller 20 ( FIG. 1 ) is electrically-coupled to the system 10 , for the purpose of controlling the centrifugal pump 18 , the heat exchanger 15 , and each of the TEDs 35 associated with the first and second heater trays 14 and 16 . The controller 20 can include electronic hardware, software, and/or applications, driver programs, and other algorithms as well as input/output devices to control the machination of the centrifugal pump 18 , the heat exchanger 15 , and each of the TEDs 35 . More specifically, the controller 20 is adapted to control the temperature of the heat-transferring liquid and, further, to control the heat transfer direction of the TEDs 35 , to heat or cool the micro-well assay tray(s) 39 automatically, and in accordance with the protocol of the PCR, bDNA, and related tests.
[0035] In one aspect of the present invention, the first heater tray 14 is releasably attachable to the second heater tray 16 . Any clamping or other means for temporarily securing the first heater tray 14 to the second heater tray 16 can be used. FIG. 1 shows a fastener-based embodiment, whereby a plurality of fasteners 51 , e.g., machine screws, bolts, and the like, are disposed through holes 53 in upper and lower clamping portions 52 and 54 , respectively, and, further disposed in associated openings 55 disposed in the second heater tray 16 . As the fastening devices 51 are tightened, the upper and lower clamping portions 52 and 54 secure the upper heater tray 14 . As the fastening devices 51 are tightened more, the upper and lower heater trays 14 and 16 are tightly secured about the micro-well assay tray(s) 39 .
[0036] The invention has been described in detail including the preferred embodiments thereof. However, those skilled in the art, upon considering the present disclosure, may make modifications and improvements within the spirit and scope of the invention. | Devices and systems for active thermal control of sample holding devices for bDNA testing, polymerase chain reaction testing, chemiluminescent immuno-assay testing, and so forth. The thermal control subsystem includes a fluidic circuit, first and second heater assemblies, a centrifugal pump, and a heat exchange device. The first and second heater assemblies include a heat removal device and a controllable thermo-electric device. One or both of the heater assemblies can include a heat spreader. A controller actively controls the pump, the heat removal device, and the thermo-electric devices, to thermally-control sample-containing vessels retained in the holding device. | 5 |
TECHNICAL FIELD
The present invention relates generally to the field of surgery and medical implants, and more particularly, to surgical tools and methods for use in positioning an intervertebral device between vertebral members of a patient.
BACKGROUND OF THE INVENTION
The human spine is a biomechanical structure with thirty-three vertebral members, and is responsible for protecting the spinal cord, nerve roots and internal organs of the thorax and abdomen. The spine also provides structure support for the body while permitting flexibility of motion. A significant portion of the population will experience back pain at some point in their lives resulting from a spinal condition. The pain may range from general discomfort to disabling pain that immobilizes the individual. Back pain may result from a trauma to the spine, be caused by the natural aging process, or may be the result of a degenerative disease or condition.
Procedures to remedy back problems sometimes require correcting the distance between vertebral members by inserting an intervertebral device (e.g., spacer) between the members. The spacer, which is carefully positioned within the disc space and aligned relative to the vertebral members, is sized to position the vertebral members in a manner to alleviate the patient's back pain.
Further, the intervertebral device is preferably designed to facilitate insertion into a patient. That is, the shape and size of the device are designed to provide for minimal intrusion to a patient during insertion, but still be effective post-insertion to alleviate the pain and provide maximum mobility to the patient. A spinal cavity for receiving the intervertebral device must be prepared prior to inserting the device therein.
Thus, a need exists for enhanced surgical instruments and methods for positioning an intervertebral device between vertebral members of a patient, and for enhanced surgical instruments and methods for preparing a spinal cavity to receive such an intervertebral device.
SUMMARY OF THE INVENTION
The present invention provides, in an aspect, a spinal disc replacement surgical instrument which includes a first contacting member positionable along an endplate of a first vertebra. A second contacting member is positionable along an endplate of a second vertebra. The first vertebra and the second vertebra define the spinal cavity. The second contacting member is moveable relative to the first contacting member. A handle assembly is coupled to the first contacting member and the second contacting member. At least one actuating member is positioned between the first and second contacting members. The at least one actuating member is moveable by the hand assembly from a first position, wherein the first and second members include an unexpanded configuration relative to one another for insertion in the spinal cavity, to a second position providing an expanded configuration. The actuating member is configured to displace at least one of the first contacting member and the second contacting member away from each other to move the first contacting member and the second contacting member between the first position and the second position. The first contacting member has a first distal end and the second contacting member has a second distal end. The first end has a first end shape configured to conform to a shape of the first vertebra and the second end has a second end shape configured to conform to a shape of the second vertebra. The first end shape and the second end shape are different shapes.
The present invention provides, in another aspect, a spinal disc replacement surgical instrument which includes a first contacting member positionable along an endplate of a first vertebra. A second contacting member is positionable along an endplate of a second vertebra. The first vertebra and the second vertebra define a spinal cavity. The second contacting member is moveable relative to the first contacting member. The first contacting member is connected to a handle assembly by a first extending arm and the second member is connected to the handle assembly by a second extending arm. An adjustable depth regulator extends from the handle assembly toward the first member and the second member. The adjustable depth regulator is located at least partially longitudinally offset relative to at least one of the first arm and the second arm. The adjustable depth regulator includes at least one stop member positionable in contact with one of the first vertebra and the second vertebra to limit an insertion depth of the first contacting member and the second contacting member in the spinal cavity.
The present invention provides, in a further aspect, a spinal disc replacement surgical instrument which includes a first member positionable along an endplate of a first vertebra and a second member positionable along an endplate of a second vertebra. The first vertebra and the second vertebra define a spinal cavity. The second member is moveable relative to the first member. The first member and the second member are moveable between an unexpanded configuration relative to one another for insertion in the spinal cavity and an expanded configuration relative to one another. The handle assembly includes a distal end coupled to the first member and the second member. The handle assembly includes a proximal end connectable to a releaseable handle. The proximal end includes a handle assembly cavity for receiving an end of the handle and the handle assembly cavity includes an interior surface connectable to the handle. The handle assembly cavity includes an impactable head configured to receive an impact and to transfer the impact to the handle assembly and to at least one of the first contacting member and the second contacting member.
The present invention provides, in yet another aspect, a method for use in spinal disc replacement which includes positioning a first contact member of a surgical instrument along an endplate of first vertebra. A second contacting member of the surgical instrument is positioned along an endplate of a second vertebra. The first vertebra and the second vertebra define a spinal cavity. The first contacting member is coupled to the second contacting member by a handle assembly of the surgical instrument. At least one actuating member of the surgical instrument is positioned between the first contacting member and the second contacting member. The actuating member is moved from a first position, wherein the first contacting member and the second contacting member include an unexpanded configuration relative to one another for insertion in the spinal cavity, to a second position, wherein the first contacting member and the second contacting member include an expanded configuration relative to one another. The first contacting member has a first distal end and the second contacting member has a second distal end. The first distal end has a first shape configured to conform to a shape of the first vertebra and a second end has a second end shape configured to conform to a shape of the second vertebra. The first end shape and the second end shape are different shapes.
The present invention provides, in yet a further aspect, a method for use in spinal disc replacement which includes positioning a first contacting member of a surgical instrument along an endplate of a first vertebra of a spinal cavity. A second contacting member of the surgical instrument is positioned along an endplate of the second vertebra. The first vertebra and the second vertebra define a spinal cavity. The first contacting member is connected to a handle assembly of the surgical instrument by a first extending arm and the second contacting member is connected to the handle assembly by a second extending arm. An adjustable depth regulator is extended from the handle assembly toward the first contacting member and the second contacting member such that the adjustable depth regulator is located at least partially longitudinally offset relative to at least one of the first arm and the second arm. The adjustable depth regulator is contacted with one of the first vertebra and the second vertebra to limit an insertion depth of the first contacting member and the second contacting member into the spinal cavity.
The present invention provides, in another aspect, a method for use in replacing a spinal disc which includes providing a spinal disc replacement surgical tool having a handle assembly with a distal end coupled to a first contacting member positionable along a endplate of a first vertebra defining a spinal cavity and a second contacting member positionable along an endplate of a second vertebra defining the spinal cavity. The handle assembly includes a proximal end having a handle assembly cavity connectable to a releasable handle. An impactable head in the handle assembly is impacted to cause movement of the surgical tool toward the spinal cavity.
BRIEF DESCRIPTION OF THE DRAWINGS
The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention will be apparent from the following detailed description of preferred embodiments taken in conjunction with the accompanying drawings in which:
FIG. 1 is a perspective view of one embodiment of a spinal disc replacement surgical instrument with a keel cutter in a top slot of the instrument, according to an aspect of the present invention;
FIG. 2 is a side elevational view of a portion of the instrument of FIG. 1 showing a first contacting member and a second contacting member in an unexpanded configuration in accordance with an aspect of the present invention;
FIG. 3 is a side elevational view of a portion of the instrument of FIG. 1 showing a first contacting member and a second contacting member in an expanded configuration, in accordance with an aspect of the present invention;
FIG. 4 is a top perspective view of a portion of the instrument of FIG. 1 showing a first extending arm, a handle assembly, and a controlling mechanism, in accordance with an aspect of the present invention;
FIG. 5 is a bottom perspective view of the instrument of FIG. 1 further including a keel cutter in a bottom slot of the instrument, in accordance with an aspect of the present invention;
FIG. 6 is a perspective view of a proximal end of the handle assembly of the instrument of FIG. 1 , in accordance with an aspect of the present invention; and
FIG. 7 is a perspective view of the proximal end of the handle assembly of FIG. 6 further including a releasable handle attached thereto, in accordance with an aspect of the present invention.
DETAILED DESCRIPTION
In accordance with the principles of the present invention, a spinal disc replacement surgical instrument, and methods for use in implanting a prosthetic disc in a spinal cavity, are provided.
As depicted in FIG. 1 , a surgical tool 10 includes a first arm 100 , a second arm 200 , and a handle assembly 300 connected to first arm 100 and second arm 200 . First arm 100 and second arm 200 are hingedly and/or pivotally connected to handle assembly 300 to allow the arms to be separated from one another and moved toward one another. More specifically, first arm and second arm 200 are movable to a collapsed position ( FIG. 2 ) such that a front end (i.e., distal end) 20 of tool 10 may be positionable in a space between adjacent vertebra (not shown) defining a spinal cavity (not shown). The arms may be remotely manipulated by a user (e.g., a surgeon) to increase a separation distance and/or angulation between endplates of adjacent vertebra defining such a spinal cavity, as depicted for example in FIG. 3 . The distance between the arms may be increased (or decreased) by the manipulation of handle assembly 300 thereby adjusting a distance between the vertebra, as further described below.
First arm 100 is connected to a first contacting member 110 and second arm 200 is connected a second contacting member 210 . Alternatively, each arm and respective contacting member may be formed integral to one another. The members may be formed of plates having opposite faces positionable against endplates of adjacent vertebra (not shown) defining a spinal cavity (not shown) to provide a separation force to the endplates when manipulated with handle assembly 300 . Other forms for contacting members 110 , 210 are also contemplated, including single blades, U-shaped blades, or other suitable structure for contacting the adjacent vertebral endplate. As depicted in FIGS. 1-3 and 5 , a distal end of first contacting member 110 and a distal end of second contacting member 210 may have different shapes and may extend distally (i.e., in a direction away from handle assembly 300 ) a different distance relative to one another. The contacting members may be tapered toward the arms at an intersection point between each arm and each contacting member. Opposite sides of the contacting members may be substantially parallel to a longitudinal axis of the contacting members and/or the arms. For example, first contacting member 110 may have a square front end 117 and second contacting member 210 may have a rounded front end 217 as best depicted in FIG. 5 .
Also, the different shapes of the front ends (e.g., front ends 117 and 217 ) allow a user to more readily determine the correct orientation of the tool, i.e., which side (e.g., first contacting member 110 ) is to be used adjacent an upper vertebra and which slide (e.g., second contacting member 210 ) is to be used adjacent a lower vertebra. In the example depicted in the figures, a user would know from the square shape of first contacting member 110 that tool 10 is configured to be inserted such that first contacting member 110 is on a top (i.e., superior) side of the tool and is configured to abut an upper vertebra of a spinal cavity. Similarly, the user would know from the rounded or curved shape of second contacting member 210 that tool 10 is configured to be inserted such that second contacting member 210 is on a bottom (i.e., inferior) side of the tool and is configured to abut a lower vertebra of the spinal cavity. Also, the distal ends of the contacting members could be formed of any shape which conforms to the shape of a vertebra which it will abut, or come in close proximity to. For example, it may be necessary to use particular surgical instruments (e.g., tool 10 ) having contacting members with different shaped ends according to which vertebra in a spinal column needs to be replaced. Further, the contacting members and/or arms may be releasably connectable to each other and/or the remainder of tool 10 to allow such varying shapes and/or thicknesses of the contacting members and/or arms to be utilized.
A depth adjustment system 400 is connected to handle assembly 300 and second contacting member 210 as depicted in FIGS. 1 , 4 and 5 . Adjustment system 400 includes a depth regulator or stopper 410 protruding from a bottom side of a connecting member 420 movably attached to an underside 215 of second contacting member 210 . Depth stopper 410 may be connected, or integral, to a connecting member 420 . Depth stopper 410 is configured (e.g., shaped and dimensioned) to inhibit front end 20 of tool 10 from proceeding past a desired point into a spinal cavity. More specifically, depth stopper 410 may abut an exterior surface (i.e., a surface of a vertebra outside the spinal cavity, (not shown) of a bottom vertebra (not shown) defining a spinal cavity (not shown)) such that depth stopper 410 remains outside the spinal cavity abutting the exterior surface of the bottom vertebra defining the cavity.
Upwardly extending portions 412 of connecting member 420 may extend through apertures 212 in second contacting member 210 as depicted in FIGS. 1 , 2 and 5 . Apertures 212 are elongated in a longitudinal direction relative to second contacting member 210 and tool 10 such that upwardly extending portions 412 may move in a longitudinal direction within aperture 212 . Connecting member 420 connects second contacting member 210 to a controlling mechanism configured to cause the movement of connecting member 420 and depth stopper 410 . Such movement allows the adjustment of the depth to which front end 20 of tool 10 may extend into a spinal cavity.
For example, such a controlling mechanism may include a rotatable knob or thumbwheel 450 having an internal thread (not shown) configured to mate with threads (not shown) on an outer surface of connecting member 420 , as depicted in FIGS. 1 and 4 . The rotation of thumbwheel 450 may cause connecting member 420 to move toward, or away from, rounded front end 217 of second contacting member 210 . For example, the rotation of thumbwheel 450 in a clockwise direction may cause connecting member 420 to move toward rounded front end 217 until rotation is stopped at a position which corresponds to a minimum depth of the tool in a spinal cavity. Rotation of thumbwheel 450 in a counterclockwise direction may cause movement of the connecting member and the depth stopper away from rounded front end 217 to a maximum depth of tool 10 in the spinal cavity. As noted above, the movement of connecting member 420 , along with depth stopper 410 , controls the extent to which tool 10 (i.e., front end 20 ) may extend into a spinal cavity.
Thumbwheel 450 and, some or all of, the remainder of depth adjustment system 400 may be offset relative to the remainder of tool 10 . For example, thumbwheel 450 may be located laterally relative to a longitudinal axis of handle assembly 300 and/or arms 100 and 200 as depicted in FIGS. 1 and 4 . Connecting member 420 may also be located at least partially laterally relative to the arms (e.g., first arm 100 and second arm 200 ), and may be separated therefrom by a space along some or all of its length as depicted in FIGS. 1 , 4 , and 5 . For example, connecting member 420 may be spaced from first arm 100 and second arm 200 , along a length of connecting member 420 in a direction toward first contacting member 110 and second contacting member 210 from handle assembly 300 until a point of contact of connecting member 420 with one of the contacting members (e.g., second contacting member 210 ). As noted above, depth stopper 410 may be located on underside 215 of second contacting member 210 and located aligned with the longitudinal axis of second contacting member 210 , handle assembly 300 and/or tool 10 .
In the example depicted (see e.g., FIG. 5 ), connecting member 420 extends (i.e., curves) from a thumbwheel 450 toward arms 100 , 200 to a lateral position 421 spaced from (and parallel to, along at least a portion of the length of) the arms and to a position 422 further away from the longitudinal axis of tool 10 to connect connecting member 420 to second contacting member 210 at an outer edge of second contacting member 210 . The curves of connecting member 420 toward such longitudinal axis and away therefrom allows connecting member 420 to follow a contour of second arm 200 between thumbwheel 450 and second contacting member 210 . Also, connecting member 420 may include a transverse portion 423 extending transversely relative to a longitudinal axis of tool 10 , first contacting member 110 and second contacting member 210 , first arm 100 and/or second arm 200 as depicted in FIG. 5 . In an undepicted example, connecting member 420 may be connected to second contacting member 210 at one location instead of the two locations opposite depth stopper 410 depicted in FIG. 5 . It will be understood by one skilled in the art that connecting member 420 may be formed of any shape such that it connects thumbwheel 450 and depth stopper 410 such that thumbwheel 450 and connecting member 420 are at least partially offset from a longitudinal axis of first arm 100 and/or second arm 200 and such that depth stopper 410 is connected to first contacting member 110 or second contacting member 210 and is located at about a longitudinal axis of tool 10 , arms 100 , 200 , and/or first member 110 and second member 210 .
The offset (e.g., lateral) location of adjustment system 400 relative to the arms and the remainder of tool 10 allows ready access to the user. For example, the location of thumbwheel 450 offset from the longitudinal axis of handle assembly 300 and/or arms 100 and 200 allows the user to easily locate thumbwheel 450 and therefore move depth stopper 410 during use. Also, the location of thumbwheel 450 and the remainder of depth adjustment system 400 at least partially offset from a longitudinal axis of tool 10 and arms 100 , 200 allow the depth adjustment system 400 to avoid interfering with hinges 302 located at the intersection of the arms and handle assembly 300 . The offset nature of depth adjustment system 300 therefore allows the arms to be readily moved relative to handle assembly 300 at the hinges.
A top side 120 of first contacting member 110 and first arm 100 may include a slot 122 configured to receive a keel cutter 500 , as depicted in FIGS. 1 and 4 . A bottom side 220 of second contacting member 210 and second arm 200 may also include a bottom slot 222 configured (e.g., shaped and dimensioned) to receive keel cutter 500 as depicted in FIG. 5 . Keel cutter 500 is utilized to cut or form a keel or channel in a top and/or bottom vertebra defining a spinal cavity in which a spinal implant is to be inserted. Also, the slots on arms 100 and 200 (e.g., slot 122 and slot 222 ) guide the cutting of the keel by maintaining the keel aligned with a longitudinal axis of arms 100 , 200 and first and second contacting members 110 , 210 . Depth stopper 410 located on bottom side 220 may be a closed loop with the interior of the loop configured to receive keel cutter 500 as depicted in FIG. 5 . The closed nature of depth stopper 410 inhibits movement of keel cutter 500 out of bottom slot 222 away from bottom side 220 . More specifically, the interior surface of the loop would retain the keel cutter in the interior of the loop if the keel cutter was to be displaced away from slot 22 . Similarly, a keel holder 130 on upper side 120 is a closed loop which inhibits movement of keel cutter 500 away from slot 122 and upper surface 120 . By inhibiting movement of keel cutter 500 away from tool 10 , inadvertent damage to the patient, which could be caused by keel cutter 500 contacting unintended portions of the patient's anatomy, is minimized.
A proximal end 311 of handle assembly 300 includes a receiving flange 310 having a cavity 315 partially defined by a threaded interior radial surface 320 and having an impactable surface 330 , as depicted in FIGS. 6-7 . Receiving flange 310 is connectable to a suitable handle, such as a T-handle 340 , which may be manipulated (e.g., rotated) by a user when connected to flange 310 to move arms 100 and 200 , along with first and second contacting member 110 and 210 , away from, and toward, one another. More specifically, an outer surface 345 of an end 347 of T-handle 340 may have threads configured to engage threaded interior radial surface 320 of the flange, which may include threads. Also, flange 310 may include a Hudson type connector or any other suitable structure for engagement with the T-handle.
For example, flange 310 may include one or more notches 312 at proximal end 311 of flange 310 configured (e.g., shaped and dimensioned) to receive finger tip(s) of the user. The notches allow the user to avoid having his finger(s) caught between proximal end 311 and another portion of T-handle 340 (e.g., a sleeve connecting portion 314 ) when an outer sleeve 313 moves toward flange 310 to attach T-handle 340 to flange 310 in the case of a Hudson type connection for example, as will be understood by those skilled in the art. Sleeve connecting portion 314 may connect outer sleeve 313 of T-handle 340 to an inner shaft (not shown) of T-handle 340 . Outer sleeve 313 may be spring-loaded such that, when previously retracted relative to the shaft, outer sleeve 313 moves toward flange 310 when released by the user.
Expansion bar 350 may have threads 305 located at a proximal end thereof opposite front end 20 of tool 10 . Threads 305 may engage with an inner threaded surface (not shown) of flange 310 . Rotation of flange 310 itself or by T-handle 340 thus causes such movement of arms 100 and 200 , along with first and second contacting members 110 and 210 via expansion bar 350 . For example, flange 310 may be connected to an expansion bar 350 , which may be driven forward by rotation of flange 310 by itself or flange 310 and T-handle 340 . The movement of bar 350 forward may cause the arms and members to separate from one another as bar 350 contacts arms 100 , 200 and/or first and second contacting members 110 , 210 to distract the upper and lower vertebras to approximate heights or positions as described above. Movement of bar 350 away from front end 20 by flange 310 may cause or allow the arms and members to move from an expanded position to a collapsed position, for example.
Also, a distraction indicator is coupled to an actuating member such as expansion bar 350 , which moves longitudinally therewith to provide an indication of the position of expansion bar 350 relative to first and second contacting members 110 , 210 thereby providing an indication of a distance between the inner surfaces or outer surfaces of the members. For example, a distraction indicator, such as distraction height indicia 433 on expansion bar 350 viewable through a window 435 correspond to the distraction height of first and second contacting members 110 and 210 in the posterior end (i.e., front ends 117 and 217 ) thereof provided by the longitudinal positioning of expansion bar 350 therebetween. The measuring of the distance between the contacting members and thus the vertebra allow the user (e.g., the surgeon) to determine whether the space defined by the vertebra is of an appropriate size to begin the procedure for implanting a prosthetic in the spinal cavity. For example, if a measurement is taken revealing that the spinal cavity is not large enough, the contacting members may be further distracted via the T-handle and expansion bar until an appropriate space between the vertebra is created.
Further, when the T-handle is not attached to the flange, impactable surface 330 (e.g., a rigid head) may be accessed such that the user may impact the impactable surface 330 (e.g., with a hammer) to cause movement of tool 10 into the spinal cavity. More specifically, impactable surface 330 is coupled to first contacting member 110 and second contacting member 210 . For example, impactable surface 330 may be connected to expansion bar 350 thereby connecting impactable surface 330 , handle assembly, 300 , arms 100 and 200 , and first and second contacting members 110 and 210 . Also, impactable surface 330 may be located entirely within receiving cavity 315 . Further, impactable surface 330 may be located within a portion of T-handle 340 when T-handle 340 is received in cavity 315 and/or connected to flange 310 . The location of impactable surface 330 within flange 310 allows a user to impact impactable surface 330 itself without the need for a cap to cover flange 310 to avoid damaging the flange. More particularly, instead of placing a cap over flange 310 to drive tool 10 into a spinal cavity, a user may directly impact impactable surface 330 which is located within cavity 315 . The integral nature of impactable surface 330 avoids the necessity for a separate cap to protect flange 310 from damage to its internal threads or other portions thereof which may otherwise occur. Further, such integral nature prevents misplacement or loss of such a protective cap. Moreover, the location of impactable surface 330 within cavity 315 allows any impact to the remainder of flange 310 to be avoided due to its central interior location, i.e., away from other surfaces which could potentially by impacted and damaged.
The contacting members (e.g., first contacting member 110 and second contacting member 210 ) have radial interior surfaces (e.g., first radial interior surface 111 ) opposite each other, which may include aligning elements such as guide pins 112 located on such interior surface (e.g., interior surface 111 ) as depicted in FIGS. 2-3 . Guide pins 112 may be radio opaque and may be aligned such that an imaginary line connecting them is substantially orthogonal to a longitudinal axis of the contacting members, arms (e.g., arms 100 , 200 ) and/or tool 10 . Also, guide pins 112 may be spaced equidistant from such a longitudinal axis of the arms, members and/or tool 10 as a whole. The guide pins may allow the alignment of tool 10 on a mid-line of a spine. More particularly, the guide pins may be aligned with one another (i.e., one behind the other) when viewed via a lateral x-ray image of the spinal cavity with tool 10 inserted therein. Such alignment may thereby locate a longitudinal axis of tool 10 or portions thereof (e.g., arms 100 , 200 or first and second contacting members 110 , 210 ) on a mid-line (not shown) of the spine (not shown). The guide pins may also be utilized to align tool 10 other than on the mid-line. For example, the tool may be aligned based on the position of the pins in a lateral x-ray, or the x-ray itself may be taken from a different direction.
Although preferred embodiments have been depicted and described in detail herein, it will be apparent to those skilled in the relevant art that various modifications, additions, substitutions and the like can be made without departing from the spirit of the invention and these are therefore considered to be within the scope of the invention as defined in the following claims. | A spinal disc replacement surgical instrument includes a first contacting member positionable along an endplate of a first vertebra and a second contacting member positionable along an endplate of second vertebra. The second contacting member is moveable relative to the first contacting member. A handle assembly is coupled to the first contacting member and the second contacting member. At least one actuating member is positioned between the first contacting member and the second contacting member. The at least one actuating member is moveable by the hand assembly from a first position, wherein the first and second contacting members include an unexpanded configuration relative to one another for insertion in the spinal cavity, to a second position providing expanded configuration relative to one another. The actuating member is configured to displace at least one of the first contacting member and the second contacting member away from each other to move the first contacting member and the second contacting member between the first position and the second position. The first contacting member has a first distal end and the second contacting member has a second distal end. The first end has a first end shape configured to conform to a shape of the first vertebra and the second end has a second end shape configured to conform to a shape of the second vertebra. The first end shape and the second end shape are different shapes. | 0 |
This application is a continuation-in-part of application Ser. No. 07,452,495, filed Dec. 19, 1989, now abandoned.
BACKGROUND OF THE INVENTION
The present invention generally relates to conductive plug forming methods, and more particularly to a conductive plug forming method in which a plug is formed in a via hole by applying an energy beam to melt a metal layer which is deposited in the vicinity of the via hole.
When a metal layer for interconnection is deposited on a surface which is not perfectly planar by a vapor deposition or a sputtering process, it is known that the step coverage of the metal layer is generally poor. The deposition of the metal layer is poor especially at an inner surface of a via hole such as a contact hole and a through hole. As the integration density of semiconductor devices increases and the device count per chip increases, the interconnection become extremely fine and the via hole also becomes extremely fine. As a result, it becomes more and more difficult to ensure positive deposition of the metal, and it is extremely difficult to form a satisfactory interconnection by simply depositing the metal layer by the vapor deposition or sputtering processes.
On the other hand, there is a method of irradiating a pulse laser beam on the metal layer to carry out a planarization process step. The inside of the via, hole is filled by the metal by this planarization step, but it is difficult to control the thickness of the metal layer and keep it uniform when the metal layer is not perfectly planar. For this reason, inconveniences are introduced when the metal layer is etched in a latter process.
Accordingly, a method of filling a metal inside the via hole before depositing a metal layer thereon was proposed in a Japanese Laid-Open Patent Application No.58-115835.
However, various kinds of via holes exist in semiconductor devices and the size and depth of these via holes are quite different depending on the use of the via holes. As a result, it is extremely difficult to satisfactorily fill the inside of each of the various kinds of via holes.
SUMMARY OF THE INVENTION
Accordingly, it is a general object of the present invention to provide a novel and useful conductive plug forming method in which the problems described above are eliminated.
Another and more specific object of the present invention is to provide a conductive plug forming method comprising the steps of forming a conductor layer only in the vicinity of each of a plurality of via holes which are formed in a substrate layer, and irradiating an energy beam on the conductor layer to melt the conductor layer so that the melted conductor material of the conductor layer completely fills the via holes, thereby forming a conductive plug in each of the via holes. According to the conductive plug forming method of the present invention, it is possible to form conductive plugs which completely fill the via holes. For this reason, an interconnection layer which is formed after the formation of the conductive plugs will be electrically connected to the conductive plugs, and the interconnection layer, can be formed to a uniform thickness so that it may be etched easily in a latter process.
Still another object of the present invention is to provide a conductive plug forming method comprising the steps of forming a conductor layer only in the vicinity of one or a plurality of via holes which are formed in a first layer which is formed on a second layer, and irradiating an energy beam on the conductor layer to melt the conductor layer so that a melted conductor material of the conductor layer completely fills the via holes thereby forming a conductive plug in each of the via holes. The first layer is substantially transparent with respect to the energy beam, and the conductor layer is made of a material having an absorption coefficient greater than that of the material constituting the second layer. According to the conductive plug forming method of the present invention, it is possible to prevent undesirable effects of the energy beam on the second layer, and it is thus possible to prevent damage and disconnection of an interconnection when the second layer is used as an interconnection layer.
A further object of the present invention is to provide a conductive plug forming method comprising the steps of forming a first conductor layer only in the vicinity of one or a plurality of via holes which are formed in a first layer which is formed on a second layer, forming a second conductor layer on the first conductor layer, and irradiating an energy beam on the second conductor layer to melt the first and second conductor layers so that the melted conductor materials of the first and second conductor layers completely fill the via holes, thereby forming a conductive plug in each of the via holes. The first layer is substantially transparent with respect to the energy beam, and the second conductor layer is made of a material having an absorption coefficient greater than that of the materials constituting the first conductor layer and the second layer. According to the conductive plug forming method of the present invention, it is possible to prevent undesirable effects of the energy beam on the second layer, and it is thus possible to prevent damage and disconnection of an interconnection when the second layer is used as an interconnection layer.
Another object of the present invention is to provide a conductive plug forming method comprising the steps of forming a conductor layer only in the vicinity of each of a plurality of via holes which are formed in an insulator layer and a reflection layer which is formed on the insulator layer, and irradiating an energy beam on the conductor layer to the conductor layer so that the melted conductor material of the conductor layer completely fills the via holes, thereby forming a conductive plug in each of the via holes. The insulator layer is substantially transparent with respect to the energy beam, and the reflection layer is made of a material having a reflectivity greater than that of the insulator layer. According to the conductive plug forming method of the present invention, it is possible to prevent undesirable effects of the energy beam on a layer which is provided below the insulator layer, and it is thus possible to prevent damage and disconnection of an interconnection when the layer is used as an interconnection layer.
Still another object of the present invention is to provide a conductive plug forming method comprising the steps of forming a conductor layer only in the vicinity of each of a plurality of via holes which are formed in an insulator layer, forming an absorption layer over the conductor layer and the insulator layer, and irradiating an energy beam on the conductor layer to melt the conductor layer so that a melted conductor material of the conductor layer completely fills the via holes, thereby forming a conductive plug in each of the via holes. The insulator layer is substantially transparent with respect to the energy beam, and the absorption layer is made of a material having a reflectivity smaller than that of the insulator layer and an absorption coefficient which is greater than that of the insulator layer. According to the conductive plug forming method of the present invention, it is possible to prevent undesirable effects of the energy beam on a layer which is provided below the insulator layer, and it is thus possible to prevent damage and disconnection of an interconnection when the layer is used as an interconnection layer.
Other objects and further features of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view showing via holes in which plugs are formed by a first embodiment of a conductive plug forming method according to the present invention;
FIGS. 2A and 2B respectively are cross sectional views for explaining the first embodiment under a first condition;
FIGS. 3A and 3B respectively are cross sectional views for explaining the first embodiment under a second condition;
FIGS. 4A and 4B respectively are cross sectional views for explaining the first embodiment under a third condition;
FIGS. 5A and 5B respectively are a plan view and a cross sectional view for explaining a second embodiment of the conductive plug forming method according to the present invention;
FIGS. 6A and 6B respectively are a plan view and a cross sectional view for explaining a third embodiment of the conductive plug forming method according to the present invention;
FIGS. 7A and 7B respectively are a plan view and a cross sectional view for explaining a fourth embodiment of the conductive plug forming method according to the present invention;
FIGS. 8A and 8B are cross sectional views for explaining a fifth embodiment of the conductive plug forming method according to the present invention;
FIGS. 9A and 9B are cross sectional views for explaining a sixth embodiment of the conductive plug forming method according to the present invention;
FIGS. 10A through 10C are cross sectional views for explaining a seventh embodiment of the conductive plug forming method according to the present invention; and
FIGS. 11A and 11B are cross sectional views for explaining an eighth embodiment of the conductive plug forming method according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First, a description will be given of a first embodiment of a conductive plug forming method according to the present invention, by referring to FIGS. 1, 2A, 2B, 3A, 3B, 4A and 4B. In this embodiment, plugs are formed in two via holes 10 and 12 shown in FIG. 1 which have identical sizes and depths. The via holes 10 and 12 each have a size of 2 μm×2 μm and a depth of 1.5 μm. In this case, a total volume V 0 of the two via holes 10 and 12 can be described by the following.
V.sub.0 =2×(2×2×1.5)=12 μm.sup.3
After a metal layer 14 is deposited on a substrate (or a layer) 8 in a rectangular shape of 4 μm×8 μm as shown in FIG. 1, a laser beam is irradiated on the metal layer 14 as an energy beam under the following conditions.
Laser beam: XeCl excimer laser
Energy Density: 2.2 J/cm 2
Irradiation Frequency: 4 times
Substrate Heating Temperature: 300° C.
Ambient Condition During Irradiation: Vacuum
(4×10 -5 Torr)
By the irradiation of the laser beam, the metal layer 14 melts and flows into the via holes 10 and 12. As a result, plugs 16 and 18 are respectively formed inside the via holes 10 and 12.
FIG. 2A shows a case where the thickness of the metal layer 14 is set to 2 μm. Assuming that essentially no metal layer 14 is deposited initially in the via holes 10 and 12, a volume V m of the deposited metal layer 14 is described by the following. ##EQU1## In this case, there is too much metal and no plugs are formed solely in the via holes 10 and 12 because the metal also flows to the periphery of the via holes 10 and 12 as shown in FIG. 2B.
FIG. 3A shows a case where the thickness of the metal layer 14 is set to 1 μm. Assuming that essentially no metal layer 14 is deposited initially in the via holes 10 and 12, a volume V m of the deposited metal layer 14 is described by the following. ##EQU2## In this case, the plugs 16 and 18 are respectively formed in the via holes 10 and 12 and extend above the surface of substrate 8 but without any conductor material remaining on the substrate surface in the vicinity of (i.e., adjacent to and surrounding) the via holes as shown in FIG. 3B.
FIG. 4A shows a case where the thickness of the metal layer 14 is set to 0.5 μm. Assuming that essentially no metal layer 14 is deposited initially in the via holes 10 and 12, a volume V m of the deposited metal layer 14 is described by the following. ##EQU3## In this case, the plugs 16 and 18 are respectively formed in the via holes 10 and 12 as shown in FIG. 4B. The height of the plugs 16 and 18 formed in FIG. 4B is lower than that of the plugs 16 and 18 formed in FIG. 3B.
As may be seen from FIGS. 2A through 4B, satisfactory plugs 16 and 18 are respectively formed in the via holes 10 and 12 when the volume of the metal layer 14 in the vicinity of (i.e., surrounding) the adjacent via holes 10 and 12 is less than or equal to two times the total volume of the via holes 10 and 12 (i.e., two times the sum of the respective volumes of the via holes 10 and 12).
Although the area of the metal layer 14 is the same for each of the cases shown in FIGS. 2A, 3A and 4A, the area of the metal layer 14 may be made larger in each case as long as the melted metal flows into the via holes 10 and 12.
Next, descriptions will be given of embodiments of the conductive plug forming method according to the present invention where the volume of the via hole 10 is different from that of the via hole 12.
In a second embodiment, the volume of the via hole 10 is smaller than that of the via hole 12. In FIGS. 5A and 5B, the via hole 10 has a size of 2 μm×2 μm, and the via hole 12 has a size of 4 μm×4 μm. The via holes 10 and 12 have the same depth of 1.5 μm. In this case, a total volume V O of the two via holes 10 and 12 can be described by the following.
V.sub.0 =1.5×(2×2+4×4)=30 μm.sup.3
The metal layer 14 is deposited on the substrate (or the layer) 8 in a shape shown in FIG. 5A with an area of 60 μm 2 so that the volume of the metal layer 14 deposited in the vicinity of the via hole 12 is larger than that in the vicinity of the via hole 10. A laser beam is irradiated on the metal layer 14 as an energy beam under conditions similar to the first embodiment. By the irradiation of the laser beam, the metal layer 14 melts and flows into the via holes 10 and 12. As a result, plugs are respectively formed inside the via holes 10 and 12.
FIG. 5A shows a case where the thickness of the metal layer 14 is set to 1 μm. Assuming that essentially no metal layer 14 is deposited initially in the via holes 10 and 12, a volume V m of the deposited metal layer 14 is described by the following. ##EQU4## In this embodiment, it can be seen that satisfactory plugs are formed when the metal layer 14 is formed to a thickness of 1 μm or less with an area of 60 μm 2 or less.
In a third embodiment, the volume of the via hole 10 is also smaller than that of the via hole 12. In FIGS. 6A and 6B, the via hole 10 has a size of 2 μm×2 μm, and the via hole 12 has a size of 2 μm×4 μm. The via holes 10 and 12 have the same depth of 1.5 μm. In this case, a total volume V 0 of the two via holes 10 and 12 can be described by the following.
V.sub.0 =1.5×(2×2+2×4)=18 μm.sup.3
The metal layer 14 is deposited on the substrate (or the layer) 8 in a rectangular shape shown in FIG. 6A with an area of 36 μm 2 . A laser beam is irradiated on the metal layer 14 as an energy beam under conditions similar to the first embodiment. By the irradiation of the laser beam, the metal layer 14 melts and flows into the via holes 10 and 12. As a result, plugs are respectively formed inside the via holes 10 and 12.
FIG. 6A shows a case where the thickness of the metal layer 14 is set to 1 μm. Assuming that essentially no metal layer 14 is deposited initially in the via holes 10 and 12, a volume V m of the deposited metal layer 14 is described by the following. ##EQU5## In this embodiment, it can be seen that satisfactory plugs are formed when the metal layer 14 is formed to a thickness of 1 μm or less with an area of 36 μm 2 or less.
In a fourth embodiment, the volume of the via hole 10 is also smaller than that of the via hole 12. In FIGS. 7A and 7B, the via holes 10 and 12 respectively have a size of 2 μm×2 μm, but the via hole 10 has a depth of 1.5 μm while the via hole 12 has a depth of 3 μm. In this case, a total volume V 0 of the two via holes 10 and 12 can be described by the following.
V.sub.0 =(1.5×2×2+3×2×2)=18 μm.sup.3
The metal layer 14 is deposited on the substrate (or the layer) 8 in a rectangular shape shown in FIG. 7A with an area of 36 μm 2 . A laser beam is irradiated on the metal layer 14 as an energy beam under conditions similar to the first embodiment. By the irradiation of the laser beam, the metal layer 14 melts and flows into the via holes 10 and 12. As a result, plugs are respectively formed inside the via holes 10 and 12.
FIG. 7A shows a case where the thickness of the metal layer 14 is set to 1 μm. Assuming that essentially no metal layer 14 is deposited initially in the via holes 10 and 12, a volume V m of the deposited metal layer 14 is described by the following. ##EQU6## In this embodiment, it can be seen that satisfactory plugs are formed when the metal layer 14 is formed to a thickness of 1 μm or less with an area of 36 μm 2 or less.
Accordingly, by setting the area and thickness of the metal layer so that the volume of the metal layer in the vicinity of two adjacent via holes is less than or equal to two times the total volume of the via holes, it becomes unnecessary to independently form a metal layer for each via hole and it is sufficient to form one metal layer which covers a plurality of via holes.
Of course, the number of via holes is not limited to two and the via holes may have shapes different from those of the first through fourth embodiments. For example, the metal layer may be made of aluminum (Al), metals other than Al, or an alloy which includes selected metals such as Al. In addition, the metal layer may be replaced by any suitable conductor layer.
In FIGS. 2A through 7B, the illustration of a conductor layer such as an interconnection layer which makes contact with the plugs is omitted for the sake of convenience. But in actual practice, an interconnection layer makes contact with the two plugs in FIGS. 3B, 4B, 5B and 6B, and first and second interconnection layers of a multi-level interconnection respectively make contact with the two plugs of different depths in FIG. 7B.
Depending on the configuration of the semiconductor device, the semiconductor device may have a multi-level interconnection. For example, a first interconnection layer is formed on a substrate (or an insulator layer), a second interconnection layer is formed on an interlayer insulator layer which is formed on the first interconnection layer, and the first and second interconnection layers are connected via a via hole. But when forming a plug within the via hole prior to forming the second interconnection layer, a portion of the interlayer insulator layer, other than in the vicinity of the via hole, is directly subjected to the pulse laser beam when melting a metal layer which is formed in the vicinity of the via hole as in the case of the above described embodiments.
Normally, the interlayer insulator layer is made of a phospho-silicate glass (PSG), silicon dioxide (SiO 2 ) or the like which is transparent with respect to the pulse laser beam. For this reason, when the pulse laser beam is irradiated on the interlayer insulator layer, the pulse laser beam is irradiated on the first interconnection layer below the interlayer insulator layer and melts the first interconnection layer. When the first interconnection layer melts, there are problems in that the pattern of the first interconnection layer becomes damaged and disconnected.
Next, descriptions will be given of embodiments of the conductive plug forming method according to the present invention in which these problems can be overcome.
In a fifth embodiment of the conductive plug forming method according to the present invention, a metal layer, which is formed on an interlayer insulator layer in the vicinity of a via hole similarly to the first through fourth embodiments is made of a material which melts at a pulse laser energy density lower than that of a material which is used to form an interconnection layer below the interlayer insulator layer. According to this embodiment, it is possible to prevent the interconnection layer below the interlayer insulator layer from melting when forming a plug inside the via hole.
In FIG. 8A, a SiO 2 layer 22 is formed on a Si substrate 21, and a first interconnection layer 23 is formed on the SiO 2 layer 22. In this embodiment, the SiO 2 layer 22 has a thickness of 0.8 μm, and the first interconnection layer 23 is made of Al and has a thickness of 0.5 μm. An interlayer insulator layer 24 is formed on the first interconnection layer 23, and a via hole 25 is formed in the interlayer insulator layer 24. For example, the interlayer insulator layer 24 is made of PSG and has a thickness of 0.5 μm. A metal layer 26 is formed on the interlayer insulator layer 24 in a vicinity of the via hole 25. This metal layer 26 is made of copper (Cu) and has a thickness of 0.6 μm. The metal layer 26 is formed similarly to the first through fourth embodiments so that the melted metal flows into the via hole 25 when the pulse laser beam is irradiated on the metal layer 26.
The absorption coefficient of Cu is approximately 0.9×10 6 /cm for optical wavelengths of 190 nm to 350 nm, while the absorption coefficient of Al is approximately 1.3×10 6 /cm for the same optical wavelengths. Hence, the absorption coefficients of Cu and Al are approximately the same, and 80% or more of the incident light is absorbed to a depth of approximately 10 nm from the surface in each of the Cu layer and Al layer. On the other hand, the reflectivity of Cu is approximately 20% while, the reflectivity of Al is 90% or more. As a result, the irradiated pulse laser beam is absorbed approximately 70% more in the Cu layer than in the Al layer, and the Cu layer is heated by this absorption. Although the melting point of Cu is 1084° C. which is higher than that of Al which is 660° C., the Cu layer can be melted at a pulse laser energy density which is lower than that required to melt the Al layer. When the XeCl excimer laser is used, it requires a pulse laser energy density of 6 J/cm 2 to melt Al but the Cu can be melted at a low pulse laser energy density of 2 J/cm 2 .
Therefore, a plug 28 can be formed in the via hole 25 as shown in FIG. 8B by simply melting the metal (Cu) layer 26 at the pulse laser energy density of 2 J/cm 2 . Although the pulse laser beam is irradiated on the interconnection layer 23 through the interlayer insulator layer 24 which is transparent with respect to the pulse laser beam, the pulse laser energy density is sufficiently low such that the melting of the interconnection layer 23 is prevented. Hence, there is no danger of the interconnection layer 23 being damaged and disconnected by the irradiation of the pulse laser beam.
In a sixth embodiment of the conductive plug forming method according to the present invention, a metal layer which is formed on an interlayer insulator layer in a vicinity of a via hole similarly to the first through fourth embodiments has a 2-layer stacked structure. The 2-layer stacked structure comprises a first metal layer which is formed on the interlayer insulator layer, and a second metal layer which is formed on the first metal layer. The second metal layer is made of a material which melts at a pulse laser energy density lower than that of a material which constitutes the first metal layer and lower than that of a material which is used to form an interconnection layer below the interlayer insulator layer. According to this embodiment, it is possible to prevent the interconnection layer below the interlayer insulator layer from melting when forming a plug inside the via hole.
In FIGS. 9A and 9B, those parts which are essentially the same as those corresponding parts in FIGS. 8A and 8B are designated by the same reference numerals, and a description thereof will be omitted. In FIG. 9A, an Al layer 31 is formed on the interlayer insulator layer 24 in the vicinity of the via hole 25, and a Cu layer 32 is formed on the Al layer 31. For example, the Al layer 31 has a thickness of 0.5 μm, the Cu layer 32 has a thickness of 100 Å, and the via hole 25 has a diameter of 0.8 μm. When the pulse laser beam is applied on the Cu layer 32, approximately 20% of the pulse laser beam is reflected but the remaining 80% is absorbed in the Cu layer 32. The Cu layer 32 is thus heated, and this heat is transmitted to the Al layer 31 and melts the Al layer 31. As a result, a plug 33 which is made of an alloy of Cu and Al is formed in the via hole 25 as shown in FIG. 9B. Because the pulse laser energy density required to melt the Cu layer 32 is only 2 J/cm 2 , it is possible to prevent the melting of the interconnection layer 23.
In the fifth and sixth embodiments, only one via hole is shown for the sake of convenience. However, it is of course possible to apply these embodiments to cases where two or more via holes are provided in the semiconductor device. In addition, it is possible to use titanium (Ti) in place of Cu. Furthermore, if the interconnection layer immediately below the interlayer insulator layer is made of silicide, silicon or the like, it is possible to use Al in place of Cu (Ti) for the second metal layer which is formed in the vicinity of the via hole.
Of course, the metal layer in the fifth and sixth embodiments can be replaced by any suitable conductor layer.
Depending on the material used for the metal layer which is formed in the vicinity of the via hole and also depending on the configuration of the semiconductor device said the material used for the interconnection layer below the interlayer insulator layer, it may be inevitable to melt the metal layer at a relatively high pulse laser energy density. In this case, there is a problem in that the layer below the interlayer insulator layer such as the interconnection layer becomes damaged by the pulse laser beam.
Next, descriptions will be given of embodiments of the conductive plug forming method according to the present invention in which this problem is overcome.
In a seventh embodiment of the conductive plug forming method according to the present invention, a reflection layer is formed on the interlayer insulator layer so as to prevent the pulse laser beam from transmitting through the interlayer insulator layer when forming the plug. In FIG. 10A, an Al interconnection layer 43 is formed on a base layer 42, and a PSG interlayer insulator layer 44 is formed on the Al interconnection layer 43. A reflection layer 45 is formed on the PSG interlayer insulator layer 44, and an aluminum-silicon (Al-Si) metal layer 46 is formed on the reflection layer 45. For example, the reflection layer 45 is made of iridium (Ir) or rhodium (Rh). In this embodiment, the PSG interlayer insulator layer 44 has a thickness of 1 μm , the reflection layer 45 has a thickness of 10 nm, and the Al-Si metal layer 46 has a thickness of 1 μm.
A patterning step is carried out to form a via hole 47 and an etching step is performed so that a metal layer 46A remains only in the vicinity of the via hole 47 as shown in FIG. 10B. The via hole 47 penetrates the layers 45 and 44 and exposes the corresponding surface of the Al interconnection layer 43.
Then an XeCl system excimer laser beam having a wavelength of 308 nm is irradiated on the entire surface portion of the structure shown in FIG. 10B. By this laser beam irradiation, the metal layer 46A is melted and flows into the via hole 47 to form a plug 48 as shown in FIG. 10C. Since the reflection layer 45 has a high reflectivity with respect to the XeCl system excimer laser beam and also has a high melting point, the metal layer 46A can be melted satisfactorily into the via hole 47 without the danger of the laser beam damaging the Al interconnection layer 43 through the PSG interlayer insulator layer 44. With respect to the XeCl system excimer laser beam having the wavelength of 308 nm, Ir has a reflectivity of approximately 80% and a melting point of 2454° C., and Rh has a reflectivity of approximately 70% and a melting point of 1966° C.
In an eighth embodiment of the conductive plug forming method according to the present invention, an absorption layer is formed on the interlayer insulator layer so as to prevent the pulse laser beam from transmitting through the interlayer insulator layer when forming the plug. In FIGS. 11A and 11B, those parts which are essentially the same as those corresponding parts in FIGS. 10A through 10C are designated by the same reference numerals, and a description thereof will be omitted.
In FIG. 11A, an absorption layer 51 is formed on the entire surface portion of the structure which is basically the same as that shown in FIG. 10B except that no reflection layer is provided in FIG. 11A. In this embodiment, the Al interconnection layer 43 has a thickness of 1 μm, the PSG interlayer insulator layer 44 has a thickness of 1 μm, and the absorption layer 51 is made of polysilicon and has a thickness of 50 nm. Polysilicon has a reflectivity of approximately 40% with respect to ArF system excimer laser beam. Hence, when the ArF system excimer laser beam is irradiated on the entire surface portion of the structure shown in FIG. 11A, the Al metal layer 46A in the vicinity of the via hole 47 melts and flows into the via hole 47 to form a plug 58 as shown in FIG. 11B. A polysilicon absorption layer 51A remains on the PSG interlayer insulator layer 44 at a portion other than the vicinity of the via hole 47. Because the melting point of PSG is higher than that of Al, the PSG interlayer insulator layer 44 will not melt by the heat which is absorbed by the absorption layer 51 (51A) and there is no danger of the interconnection layer 43 becoming damaged and disconnected.
In the seventh and eighth embodiments, only one via hole is shown for the sake of convenience. However, it is of course possible to apply these embodiments to cases where two or more via holes are provided in the semiconductor device. In addition, the materials used for the reflection layer and the absorption layer are not limited to those of the seventh and eighth embodiments. Of course, the layer immediately below the interlayer insulator layer is not limited to the interconnection layer. The purpose of providing the reflection layer in the seventh embodiment and the absorption layer in the eighth embodiment is to prevent damage to the layer below the interlayer insulator layer when forming the plug. Moreover, the metal layer may be replaced by any suitable conductor layer.
In addition, in each of the described embodiments, the via holes may have arbitrary shapes.
Further, the present invention is not limited to these embodiments, but various variations and modifications may be made without departing from the scope of the present invention. | In a conductive plug forming method, a conductor layer is formed on the main surface of an insulator layer, only in the vicinity of a plurality of adjacent via holes in which plugs are to be formed, the conductor layer having a periphery defining a boundary encompassing the plurality of adjacent via holes. The volume of the material of the conductor layer within the boundary is of a predetermined amount, ranging from a minimum volume approximately equal to, to a maximum volume approximately equal to two times the total interior volume of the via holes. An energy beam is irradiated on the conductor layer to melt the conductor layer, so that the melted conductor material of the conductor layer flows toward and into the via holes, thereby forming a conductive plug in each of the via holes and without leaving any conductor layer material on the main surface of the substrate. The plurality of adjacent via holes may include at least first and second via holes of the same or different volume, and which may have the same or different depths in the insulator layer and/or areas in the plane of the main surface of the insulator layer. Multiple layer structures are disclosed which provide multiple layer interconnects and also include selectively positioned, reflective and/or energy absorptive layers for facilitating and selectively controlling the melting of the conductor layer while protecting other layers exposed to and irradiated by and/or otherwise heated by the irradiating energy beam. | 7 |
FIELD OF THE INVENTION
This invention relates to a novel antitumor antibiotic substance, a pharmaceutically acceptable salt thereof, and a method of producing them.
BACKGROUND OF THE INVENTION
It is known that microorganisms produce a variety of antitumor antibiotics. For example, it has been reported that pluramycin (J. Antibiotics 9A, 75, 1956), neopluramycin (J. Antibiotics 23, 354, 1970), kidamycin (J. Antibiotics 24, 599, 1971) and hedamycin (Helv. Chim. Acta 60, 896, 1977) are all elaborated by microorganisms. However, there is a constant demand for new and better substances having antitumor activity of value-for use as medicines.
To meet the above-mentioned demand, the inventors of this invention made a diligent exploration for substances having antitumor activity and discovered in culture broths of a certain microorganism of the genus Streptomyces a substance having a cytotoxic effect on mouse leukemia cells (P-388) as well as other antitumor and antimicrobial activities. The substance was isolated its physicochemical and biological properties were determined, thus this invention was accomplished.
SUMMARY OF THE INVENTION
An object of this invention is to provide a novel antitumor antibiotic substance (hereinafter referred to as "Substance SF2587")represented by formula (I): ##STR2## and a pharmaceutically acceptable salt thereof.
Another object of this invention is to provide a method of producing said Substance SF2587 of formula(I) or said salt thereof, which comprises cultivating a Substance SF2587-producing strain of the genus Streptomyces and recovering th substance produced from the cultured cells.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an ultraviolet absorption spectrum of Substance SF2587 in methanol;
FIG. 2 is an infrared absorption spectrum of Substance SF2587 as determined in a potassium bromide tablet;
FIG. 3 is a 1 H nuclear magnetic resonance spectrum of Substance SF2587 as determined in deuteriochloroform using tetramethylsilane as an internal standard; and
FIG. 4 is a 13 C nuclear magnetic resonance spectrum of Substance SF2587 as determined in deuteriochloroform using tetramethylsilane as an internal standard.
DETAILED DESCRIPTION OF THE INVENTION
As an example of the SF2587-producing strain to be used in accordance with this invention, there may be mentioned strain SF2587 which was newly isolated from the soil sample collected in Takatsuki City, Osaka Prefecture (Japan).
The bacteriological characteristics of strain SF2587 are as follows.
I. Morphology
The vegetative mycelium is long-extending and well branched, and is not fragmented under usual conditions. The aerial mycelium is abundant, with good sporulation, on oatmeal agar, inorganic salts-starch agar, yeast extract-malt extract agar, etc. The aerial mycelium is monopodially branched, with no apparent whirl formation. The spore chain at the terminal end of the aerial mycelium is mostly spiral but at times undulating. Electron microscopy reveals that the spore is elipsoidal to cylindrical and measures 0.5 to 0.9×0.7 to 1.3 μm. The spore wall ornamentation is smooth. Usually 20 or more spores occur in chains. The sporangium, motile spore, sclerotium, etc. are not observed.
II. Cultural characteristics
The cultural characteristics of strain SF2587 on various media are shown in Table 1. In the description of color, the color standards given in parentheses are those used in Container Corporation of America's Color Harmony Manual. The observation was made after 14-21 days of incubation at 28° C.
TABLE 1______________________________________ Growth (reverse Aerial SolubleMedium color) mycerium pigment______________________________________Sucrose nitrate Good, topas Abundant, Noneagar (3 ne) gray (2 fe)Glucose asparagine Poor-fair, None Noneagar light yellow (2 ec)Glycerol asparagine Fair, color- Fair, gray Noneagar less (3 fe)Calcium malate Fair, gray Abundant, Noneagar yellow (2 ne) gray (3 fe)Inorganic salts- Good, rose- Abundant, Nonestarch agar beige (4 ge) gray (3 fe)Oatmeal agar Good, rose- Abundant, None beige (4 ge) gray (3 fe)Yeast extract- Good, light Abundant, Palemalt extract agar brown (3 lg) gray (3 fe) yellowTyrosine agar Fair, tan Abundant, None (3 ie) gray (3 fe)Nutrient agar Fair, topas Sparse, white None (3 ne)Bennett agar Fair, gray Fair, gray None yellow (2 gc) (3 fe)______________________________________
III. Physiological characteristics
(1) Temperature range for growth: On yeast extract-malt extract agar, growth occurs in the temperature range of 14-45° C. and good growth at 26-37° C.
(2) Liquefaction of gelatin: Positive
(3) Hydrolysis of starch: Positive
(4) Reduction of nitrate: Negative
(5) Peptonization of skimmed milk: Positive Coagulation of skimmed milk: Positive
(6) Salt resistance: Growth occurs in media containing 10% NaCl but does not in media containing 12% or more of NaCl.
(7) Production of melanoid pigment: Negative
IV. Utilization of carbon sources (ISP No. 9 medium)
All of D-glucose, glycerol, D-xylose, L-arabinose, L-rhamnose, D-mannitol, D-fructose, raffinose, myoinositol and sucrose are well assimilated.
V. Cell wall composition
As analyzed by the method of Becker et al. (Appl. Microbiol. 13, 236, 1965), the cell wall fraction contains LL-diaminopimellic acid.
Thus, strain SF2587 is considered to belong to the genus Streptomyces, which is among actinomycetes, with aerial mycelium in the Gray color series, the terminal end of aerial mycelium being mostly spiral, a smooth spore surface, and a reverse color of gray yellow with a tinge of red, and does not produce melanoid pigments.
Accordingly, the inventors of this invention designated strain SF2587 as Streptomyces sp. SF2587.
This strain has been deposited with the Fermentation Research Institute of the Agency of Industrial Science and Technology under the accession number of FERM BP-2244 in accordance with the Budapest treaty.
Like other actinomycetes, strain SF2587 is liable to undergo variation in characteristics. For example, mutant strains (spontaneous or induced) as well as transductants and transformants (genetically engineered) of, or derived from, strain SF2587 can also be used for the purposes of this invention only if they are able to produce Substance SF2587. In the method of this invention, the above-mentioned strain is cultivated in a medium containing the ordinary nutrients which microorganisms may utilize. Thus, as nutrient sources, those known sources which have been conventionally utilized in the culture of actinomycetes can be utilized. For example, as carbon sources, use can be made of glucose, glucose or maltose syrup, dextrin, starch, sucrose, molasses, and animal or vegetable oils, preferably maltose syrup, starch, glucose, soybean oil and sucrose. As nitrogen sources, use can be made of soybean meal, wheat germs, corn steep liquor, cottonseed meal, meat extract, peptone, yeast extract, ammonium sulfate, sodium nitrate, urea and so on, preferably soybean meal and Pharmamedia (trade name of cottonseed meal produced by Troders oil Mill Co., Texas). In addition, it is sometimes advantageous to incorporate various inorganic salts capable of providing sodium, potassium, calcium, magnesium, cobalt, chlorine, phosphate, sulfate and other ions. Preferable examples of inorganic salts include CaCO 3 , FeSO 4 .7H 2 O and CoCl 2 .6H 2 O. It is also appropriate to add suitable amounts of organic and/or inorganic substances which assist in the growth of the microorganism and promote production of Substance SF2587. A preferable example thereof is distiller's solubles.
The pH value of the medium preferably ranges from 6.0 to 7.5.
To grow the strain, aerobic culture is carried out, and submerged aerobic culture is particularly advantageous. While the incubation temperature may range from 26 to 37° C., it is appropriate to carry out the cultivation at about 28° C. in many instances. Though it depends on the medium and cultural conditions used, accumulation of Substance SF2587 reaches a peak generally in 2 to 7 days, whether in shake culture or in tank culture (preferably tank culture). When the accumulation of Substance SF2587 has become maximal, the incubation is stopped and the desired substance is isolated and purified from the resulting cultured cells.
Since Substance SF2587 obtained according to this invention is fat-soluble, this property can be exploited in its isolation and purification from the culture broth. Thus, there can be advantageously utilized methods of column chromatography using synthetic adsorbents such as Amberlite XAD-2 (Rhom & Haas Co.), Diaion HP-20 (Mitsubishi Kasei Corporation), etc., gel filtration aids such as Sephadex LH-20 (Pharmacia Fine Chemicals), Toyopearl HW-40 (Tosoh Corporation), etc., silica gel, alumina, etc. or solvent extraction processes using ethyl acetate, chloroform and so on.
By any or a suitable combination of these techniques, Substance SF2587 can be isolated in high purity. The physicochemical properties of Substance SF2587 thus obtained are as follows.
(A) Molecular weight: 589 (EI-MS, m/z 589, M + )
(B) Molecular formula: C 33 H 35 NO 9
(C) Melting point: Gradual browning from about 224° C., without a definite melting point.
(D) Specific rotation: [α] D 25 =+233° (c=0.1 , chloroform)
(E) Ultraviolet absorption spectrum: The UV spectrum determined in methanol is shown in FIG. 1.
(F) Infrared absorption spectrum: The IR spectrum determined in a KBr tablet is shown in FIG. 2.
(G) 1 H nuclear magnetic resonance spectrum: The 1 H NMR spectrum determined in deuteriochloroform at 400 MHz is shown in FIG. 3.
(H) 13 C nuclear magnetic resonance spectrum: The 13 C NMR spectrum determined in deuteriochloroform at 100 MHz is shown in FIG. 4.
(I) Solubility: Soluble in chloroform; only sparingly soluble in methanol, ethanol, ethyl acetate, acetone, diethyl ether and n-hexane; and insoluble in water.
(J) Color reactions: Positive against potassium permanganate, 10% sulfuric acid, and molybdatophosphoric acid reagents. Nagative against ninhydrin reagent.
(K) Thin-layer chromatography: Silica gel thin-layer plate (Merck, Art 5714). The developer solvent systems=chloroform-methanol (5:1):Rf 0.23 and n-butanol-acetic acid-water (4:1:2):Rf 0.37.
(L) Appearance: Yellow powder
Based on the above data and further structural studies, the chemical structure of Substance SF2587 was established to be as represented by formula (I) given hereinbefore.
The biological characteristic of Substance SF2587 are as follows.
(1) Antimicrobial activity
The antibacterial and antifungal activities of Substance SF2587 against various bacteria and fungi were determined by the paper disk method (at 37° C.. for 16 hours). The results are shown in Table 2.
TABLE 2______________________________________ Diameter of inhibition zone (mm)Concentration Test organism(μg/ml) 1 2 3 4 5 6______________________________________500 26.0 21.7 16.1 19.3 0 0125 24.2 19.1 14.1 18.0 0 0 31 19.6 14.0 11.3 13.0 0 0 8 12.4 9.8 0 0 0 0______________________________________ 1. Micrococcus luteus ATCC 9341 (gram positive) 2. Staphylococcus aureus 209P (gram positive) 3. Bacillus subtilis ATCC 6633 (gram positive) 4. Escherichia coli NIHJ (gram negative) 5. Candida albicans M9001 6. Candida pseudotropicalis M9035
(2) Antitumor activity
A Substance SF2587-containing dimethylsulfoxide solution (dimethylsulfoxide concentration: not more than 10%) was administered in a single intraperitoneal dose to mice transplanted i.p. with P-388 tumo cells. After 60 days of feeding, the life span-prolonging effect (T/C%) of Substance SF2587 was determined. The results are shown in Table 3.
TABLE 3______________________________________ Antitumor effectDosage (μg/kg) P-388 (TlC %)______________________________________500 226250 167130 148 63 133______________________________________
Since, as .shown in Table 2, Substance SF2587 according to this invention shows antibacterial activity against gram-positive and gram-negative bacteria, this substance has a potential of use as-an-antibacterial agent. Furthermore, as shown in Table 3, it can be seen that Substance SF2587 has antitumor activity. Therefore, it is also considered to be of value as an antitumor agent.
The salts of Substance SF2587 can be prepared by modifying Substance SF2587 in a conventional manner. Examples of the salts include a hydrochloric acid salt, a hydrobromic acid salt, a sulfuric acid salt, a phosphoric acid salt and an acetic acid salt.
The following example is intended to illustrate this invention and should by no means be construed to be limitative of the invention. It should, of course, be understood that many changes and modifications can be made by those skilled in the art without departing from the scope of this invention.
EXAMPLE
As a seed culture medium, a medium composed of 2.0% starch, 1.0% glucose, 0.6% wheat germ, 0.5% polypeptone, 0.3% yeast extract, 0.2% soybean meal, and 0.2% calcium carbonate was used.
As a production medium, a medium composed of 2.0% maltose syrup, 0.15% soybean oil, 1.0% soybean meal, 0.5% Pharmamedia, 0.25% distiller's solubles, 0.1% calcium carbonate, 0.0005% ferrous sulfate (7H 2 O), 0.00005% cobalt chloride (6H 2 O) and 0.00005% nickel chloride (6H 2 O) was used. Each medium was adjusted to pH 7.0 prior to sterilization.
A 100 ml Erlenmeyer flask containing 20 ml of the above seed culture medium was sterilized at 120° C. for 30 minutes and, then, inoculated with 2-3 loopfuls of Streptomyces sp. SF2587 (FERM BP-2244) grown on an agar slant. The incubation was performed under shaking at 28° C. for 3 days to give a first seed culture. Then, a 500 ml Erlenmeyer flask containing 80 ml of the same seed culture medium as above was sterilized at 120° C. for 30 minutes and, after cooling, inoculated with 2.4 ml of the above-prepared first seed culture. The incubation was carried out under shaking at 28° C. for one day to give a second seed culture.
Four jar fermenters of 50-liter capacity, each containing 35 liters of the production medium which was previously sterilized at 120° C. for 30 minutes were inoculated with 300 ml portions of said second seed culture. The incubation was carried out at 28° C. for 4 days under aeration (20 l/min.) and stirring (250 rpm).
After completion of incubation, the culture broth was filtered with the aid of diatomaceous earth to provide a cell-containing solid fraction.
This solid fraction was extracted with 60l of 67% acetone-water at 20° C. with stirring and, then, filtered to remove the solid matter. This extract was distilled to remove acetone under reduced pressure and 10 l of the resulting concentrate was extracted with 15l of ethyl acetate. The ethyl acetate layer was dehydrated over anhydrous sodium sulfate and concentrated under reduced pressure to give 8.98 g of oil. This oil was evenly mixed with 9 g of diatomaceous earth and dried under reduced pressure for 16 hours. It was then applied to a column in which 400 ml of silica gel C-200 (Wako Pure Chemical Industries) was packed with chloroform. The column was washed with chloroform and chloroform-methanol mixtures (100:1, 50:1, 20:1 and 10:1) in the order mentioned and finally elution was carried out with chloroform-methanol (5:1). The eluate was subjected to the cytotoxicity assay (MTT assay) against mouse leukemia cells (P-388) and the fractions rich in cytotoxicity, which show 50% growth inhibition against P-388 when diluted 1:200, were pooled and concentrated to dryness under reduced pressure to provide 235 mg of oil. This oil was dissolved in a small amount of methanol and applied to a column in which 300 m(of Toyopearl HW-40 (Tosoh coporation) was packed with methanol and elution was carried out with methanol. The eluate was subjected to the cytotoxicity assay using mouse leukimia cells (P-388) and the active fractions, which show 100% growth inhibition against P-388 when diluted 1:122,000, were pooled, concentrated under reduced pressure and allowed to stand at 5° C. for 16 hours. As a result, Substance SF2587 separated out as a yellow precipitate. This precipitate was recovered by filtration and dried under reduced pressure at 40° C. for 16 hours, whereby 3.0 mg of purified Substance SF2587 was obtained as a yellow powder. This product had the physicochemical properties described hereinbefore.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. | An antibiotic substance represented by formula (I) ##STR1## or a pharmaceutically acceptable salt thereof, which is produced by cultivating a microorganism belonging to the genus Streptomyces and isolating the substance from the cultured cells. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
This is a division of application Ser. No. 08/653,200 filed May 24, 1996 now U.S. Pat. No. 5,675,154, which is a continuation-in-part of Ser. No. 08/388,068 filed Feb. 10, 1995 and entitled "Scanning Probe Microscope For Use in Fluids", in the name of the same inventors and assigned to the same entity. It is hereby incorporated herein by reference as if set forth fully herein.
BACKGROUND OF THE INVENTION
This invention relates to scanning probe microscopes, such as the scanning tunneling microscope (STM) and atomic force microscope (AFM), used for profiling the surface of a sample at high resolution. More particularly, the present invention relates to scanning probe microscope apparatus having a hinged motor drive apparatus, video optical microscope, bow correction, a desk-top isolation chamber, a gas sparging system and/or a glove box loading system.
Scanning probe microscopes make use of a fine probe tip which is scanned over the surface of a sample in order to record the topography of the surface by means of the interaction between the probe tip and a sample. A typical layout of an atomic force microscope 10 is shown in FIG. 1. Here, the sample surface 12 of sample 14 is sandwiched between a top sensing assembly 16 and a bottom scanning assembly 18. Sensing assembly 16 contains a laser 20 which emits a beam 22 that is reflected off of the back of a flexible cantilever assembly 24 to generate a reflected beam 26. Small motions of cantilever 28 of cantilever assembly 24 modulate the position of beam 26 and are detected by a position sensitive detector 30 which may be a bi-cell, multi-cell, or other type of light beam position sensitive measuring device. Scanning of the sample surface 12 is achieved by a piezo-electric transducer or "scanner" 32 which moves the sample both up and down (i.e., towards and away from flexible cantilever assembly 24 in the "Z" axial direction) and side to side in the "X-Y" planar direction (normal to the Z-axis), so as to generate a raster-scan of sample surface 12 under the cantilever 28. Scanner 32 is attached to a base 34 and positioning screw drives 36, 38 are used to position top sensing assembly 16 so that cantilever 28 is close to sample surface 12.
While fit for its intended purpose, the foregoing arrangement suffers from a number of drawbacks, most notably the fact that the sample 14 must be sandwiched between bottom scanning assembly 18 and top sensing assembly 16. Access to sample 14 is therefore restricted, so that the use of an optical microscope to examine sample 14 while in position on scanner 32 is made difficult. Sample mounting is also somewhat complex as is sample translation. It is desirable to be able to examine the scanning probe with an optical microscope as an aid to alignment of laser beam 22 onto the cantilever while the sample 14 and cantilever 24 are in place. In the past, this has been achieved by clearing a path for viewing as illustrated in FIG. 2. In FIG. 2, the incident laser beam 40 is now incident from one side, and deflected down onto the cantilever 42 by a beam-splitter 42 which is mounted on an optical window 44. The reflected beam 46 from the back 48 of cantilever 42 is picked off by a mirror 50 which transmits reflected beam 52 to the detector (not shown in FIG. 2, but disposed along the path of beam 52). A long-working-distance objective 54 of an optical microscope 56 is placed over the top of optical window 44 and focused onto the back 48 of cantilever 42. This arrangement requires that the scanning probe microscope be situated at the position normally occupied by the optical microscope stage. This requires the use of an optical microscope considerably larger than the scanning probe microscope itself. In addition, the whole assembly must then be set on a large table located so that an operator can have access to the eyepieces of the optical microscope. Since vibration isolation is required for high resolution scanning probe microscopy, an expensive and cumbersome air-table is usually required for optimum results.
It is often desirable to observe the sample from below while it is scanned from above. This may be done if the sample is transparent by placing the scanning assembly on the optical stage of an inverted optical microscope. An example of such an arrangement is the BioScope™ available from Digital Instruments, Inc. of Santa Barbara, Calif. It is shown schematically in FIG. 3. A massive frame 58 holds a scanning probe assembly 60 with a probe 62 lowered down onto the sample 64 which is on the stage 66 of an inverted optical microscope 68, the objective lens of which is shown as 70. The detector 72 for reflected light 74 from laser beam 76 is held off to one side of the probe assembly 60 and both are rigidly attached to a rigid and massive frame 58 which is also rigidly attached to the inverted optical microscope stage 66. Once again, a large support such as an air table is required to support the whole assembly in order to achieve optimum results.
Many of the problems associated with the conventional scanning probe microscope of FIG. 1 were solved by an invention disclosed by S. M. Lindsay and T. Jing in U.S. patent application Ser. No. 08/388,068 entitled: "Scanning Probe Microscope for Use in Fluids". The scanning probe microscope arrangement of the above-identified disclosure is illustrated generally in FIG. 4. Here, a single microscope body 78 holds both mechanical vertical tripod adjustments 80, 82 and 84 and sample stage 86 which is held on to the bottom of the mechanical adjustments by magnetic balls, two of which are shown at 88 and 90. The scanning assembly 92 scans either an STM probe or an AFM probe over the surface of a sample which is attached to the upper surface 94 of sample stage 86. In this way, the sample may be accessed from below. A containment may be used to surround the sample so as to control the sample environment. A motor 96 which drives at least one of the mechanical adjustments 80, 82, 84 (here, 80) is housed on an assembly 98 which is seated on top of the microscope body 78. Motor 96 is coupled to mechanical adjustment 80 which may be a screw driven by a sleeve 100 which permits translation of the screw 80 as it is rotated. In order to gain access to the other adjustments 82, 84, it is necessary to have an opening 102 in the housing 104. Even so, it can be difficult to make adjustments to the scanning assembly 92.
In order to realize this top-down scanning arrangement for the AFM, a tracking method is required so that the laser beam remains aligned on the force sensing cantilever as it is moved over the surface of the sample. Such an arrangement has been achieved by a prior invention disclosed by P. S. Jung and D. R. Yaniv in U.S. Pat. No. 5,440,920, hereby incorporated herein by reference. A general arrangement of this optical tracking scheme is shown in FIG. 5A. A lens 106 is used to focus a collimated beam 108 from a laser (not shown) onto the reflective back 110 of a cantilever-type probe 112. Both the lens 106 and the cantilever-type probe 112 are physically coupled to or constrained to move with the scanning transducer 114. In this way, a focused laser spot from beam 108 tracks and follows cantilever 112 as it is moved over the surface of the sample. This action is illustrated in FIG. 5B. The transducer 114 is bent so as to move the tip 116 of probe 112 to a new position. Lens 106 has been translated with scanning transducer 114, so that the focused laser spot remains on the back 110 of the cantilever 112.
FIG. 5B illustrates a problem associated with this method of tracking the incident beam with the cantilever. It does not compensate for the angular deflection of the cantilever due to the bending of the scanner. Since this angular deflection adds or subtracts from the angular deflection whereby changes in height of a scanned sample are detected, it introduces an error in the output signal of the detector which causes a flat surface to appear to be curved or "bowed". When the microscope is scanning a sample, this bow can become quite complicated. For example, if the cantilever probe is in contact with the sample surface and adhering to it, when the transducer is pushed forward and up in order to lift the cantilever from the surface (as shown in FIG. 6A) the microscope can become unstable because the cantilever will jump from the surface when the force pulling it up becomes comparable to the adhesion force. Furthermore, the direction of the bowing error is difficult to predict because it depends upon the location of the laser spot on the cantilever. The bowing is more predictable in the opposite scan direction where (as shown in FIG. 6B) the tip tends to be pushed into the surface. The tip is also more stable in this configuration, but, for a given deflection of the laser beam, the contact force between the probe and the sample is significantly increased as the tip is pushed into the surface. This is a disadvantage when scanning soft surfaces. U.S. Pat. No. 5,440,920, discussed above, describes a solution to this problem using an "S"-shaped scanner. According to this arrangement, a pair of scanning tubes are connected together in a manner which results in translation without angular deflection. However, this arrangement may not always be desirable because it requires a longer scanning tube which can result in the introduction of more mechanical drift and noise in the system.
OBJECTS AND ADVANTAGES OF THE INVENTION
Accordingly, it is an object of the present invention to provide a scanning probe microscope in which an adjustment motor is placed above the scanning stage in a manner which permits easy access to the scanning stage for adjustments.
It is a further object of the present invention to provide a magnetic clutch for coupling a motor controlling an adjustable leg which in turn supports a sample platen of a scanning probe microscope.
It is a further object of the present invention to provide a microscope in which optical access is available so that the position of the laser spot on the back of the cantilever is easily imaged by an optical microscope to aid alignment of the microscope.
It is another object of the present invention to provide a television camera or similar imaging device in the optical path from the back of the atomic force microscope cantilever in order to provide electronic images of the position of the light beam of the back of the cantilever.
It is yet another object of the present invention to provide a microscope that can also be placed onto the stage of an inverted optical microscope so that an optically transparent sample being scanned may be viewed from below.
It is yet another object of the present invention to reduce or eliminate bowing errors without the need of a large increase in the total scanner length for a given scanning range.
It is yet another object of the present invention to provide a glove box type of loading system for a scanning probe microscope.
It is yet another object of the present invention to provide a gas sparging system for use with a scanning probe microscope.
It is yet another object of the present invention to provide a convenient, desk-top anti-vibration and acoustic isolation system.
These and many other objects and advantages of the present invention will become apparent to those of ordinary skill in the art from a consideration of the drawings and ensuing description of the invention.
SUMMARY OF THE INVENTION
Features for incorporation with scanning probe microscopes are provided which may be used separately or together. The features include constructing the microscope with a hinged top housing providing easy access to the heart of the microscope; a self-aligning and torque limiting magnetic clutch coupling a motor drive powering at least one vertical adjustment screw of the microscope; a removable microscope head for easy adjustment; an optical microscope, optionally mounted to an electronic camera and imaging system, installed adjacent to the head; operation on an inverted microscope stage; bowing error correction; a gas sparging system providing contaminant and noise reduction; a glove box type of loading system so that reactive materials may be safely loaded into the microscope; and a compact desk-top chamber which provides acoustic and vibration isolation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a typical arrangement of an atomic force microscope according to the prior art.
FIG. 2 shows an arrangement for optical microscope access to the back of a scanning cantilever-type probe according to the prior art.
FIG. 3 shows a scanning probe microscope for use on an inverted optical microscope according to the prior art.
FIG. 4 shows the arrangement of a scanning probe microscope with the adjustment screws and motor mounted above the sample.
FIGS. 5A and 5B show an optical tracking system according to the prior art whereby the laser spot remains focused on the cantilever as it is scanned over the sample. FIG. 5A shows the scanning tube prior to deflection and FIG. 5B shows the scanning tube after deflection.
FIGS. 6A and 6B shows deformations of the cantilever during scanning which give rise to bowing error. FIG. 6A shows the deformation when the transducer swings up so as to lift the cantilever from the surface. FIG. 6B shows the deformation when the transducer pulls back so as to push the transducer into the surface.
FIG. 7 shows a general layout of the scanning probe microscope according to a presently preferred embodiment of the present invention.
FIG. 8 shows the microscope of the present invention with the head swung back to disengage the motor and expose the scanning head according to a preferred embodiment of the present invention.
FIG. 9 shows the magnetic clutch and drive-sleeve which releasably couple the motor to the adjustment screw according to a preferred embodiment of the present invention.
FIG. 9A is a cross sectional view taken along line 9A--9A of FIG. 9.
FIG. 9B is a cross sectional view taken along line 9B--9B of FIG. 9.
FIG. 9C is a cross sectional view taken along line 9C--9C of FIG. 9.
FIG. 10 shows the placement of a video microscope for viewing the back of a cantilever-type probe in a scanning probe microscope according to a presently preferred embodiment of the present invention.
FIG. 11 is a side view showing the optical train used in the video microscope portion of a scanning probe microscope according to a presently preferred embodiment of the present invention.
FIG. 12 is a top plan view taken along line 12--12 of FIG. 11 of the front of the optical train used in the video microscope portion of a scanning probe microscope according to a presently preferred embodiment of the present invention.
FIG. 13 is a cross-sectional side view of the microscope placement on an inverted optical microscope stage in a scanning probe microscope according to a presently preferred embodiment of the present invention.
FIG. 14 shows the relationship of a scan direction (chosen to be the "Y" axis here) to the deflection signal generated by cantilever distortions due to the angular swing of the scanner in a scanning probe microscope according to a presently preferred embodiment of the present invention.
FIG. 15 shows an electronic circuit for compensating for bow so that contact force is not increased in a scanning probe microscope according to a presently preferred embodiment of the present invention.
FIG. 16A is a cross-sectional diagram of a bow-compensating scanner according to a presently preferred embodiment of the present invention.
FIG. 16B is a side view of a bow-compensating scanner according to a presently preferred embodiment of the present invention.
FIG. 16C is a top view of a bow-compensating scanner according to a presently preferred embodiment of the present invention.
FIG. 16D is a side view of a bow-corrected scanning probe microscope utilizing a pair of cooperating piezoelectric cylinders according to a presently preferred embodiment of the present invention.
FIG. 17 shows a desk-top vibration and acoustic-noise isolation chamber for use with a scanning probe microscope according to a presently preferred embodiment of the present invention.
FIG. 18 shows a gas sparging system for a scanning probe microscope according to a presently preferred embodiment of the present invention.
FIG. 19 shows an Atomic Force Microscope detector fine adjustment apparatus according to a presently preferred embodiment of the present invention.
FIG. 20 shows an alternate view of an Atomic Force Microscope detector fine adjustment apparatus according to a presently preferred embodiment of the present invention.
FIG. 21 shows a perspective view of a glove box loading system according to a presently preferred embodiment of the present invention.
FIG. 22 is a side elevational view of a portion of the glove box loading system according to a presently preferred embodiment of the present invention.
FIG. 23 shows an adjustable sample platen with adjustable kinematic mounts.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Those of ordinary skill in the art will realize that the following description of the present invention is illustrative only and is not intended to be in any way limiting. Other embodiments of the invention will readily suggest themselves to such skilled persons from an examination of the within disclosure.
Hinged Head Assembly and Magnetic Clutch Mechanism
Turning now to FIG. 7, a side elevation view of the scanning probe microscope having a hinged housing according to a presently preferred embodiment of the present invention is shown. The microscope body 118 rests on a supporting base 120 which may also preferably serve as a hermetically sealed sample enclosure. The sample stage 122 is fabricated from material that is attracted to magnets and is held in place on three magnetic balls, two of which are shown as 124 and 126, which are affixed to the end of mechanical linear positioners, such as screw drives 128, 130 and 132. The scanning probe 134 protrudes into the area above sample stage 122. One of the mechanical linear positioners, 132, is a screw coupled to a motor 136 driven in order to permit automated advance of the sample on sample stage 122 towards the scanning probe 134. The motor 136 is coupled to screw 132 by a coupling sleeve 138 that is free to ride up and down on the shaft of screw 132, but grips it for rotational motion as shown in more detail in FIG. 9. The coupling sleeve 138 is coupled to the motor drive shaft 140 by a self-aligning magnetic clutch assembly 142 (shown in more detail in FIG. 9). The motor, 136 is mounted on a head assembly 144. The head assembly 144 is connected, at one point on its circumference, by a hinge 146 which permits the head assembly 144 to swing back with respect to the microscope body 118. An opening 148 in head assembly 144 permits access to the inside of head assembly 144 when head assembly 144 is in the down or closed position shown in FIG. 7, allowing the operator to view probe 134 via a window in the scanning assembly 150 either directly or with an optical microscope.
The head assembly 144, as open and swung back for access to the alignment screws 128, 130, is shown in FIG. 8. The head assembly 144 rests on the hinge assembly 146 which is, in turn, connected to the body 118 of the microscope. While the head assembly 144 is open, the magnetic clutch 142 is disengaged so that its bottom part 138 rests on screw 132 while its top part 140 remains attached to motor 136. The bottom element 152 of hinge assembly 146 is shaped so that the top element 154 of hinge assembly 146 comes to rest on it with the microscope head assembly 144 pulled back at a convenient angle as shown in FIG. 8. By these means, easy access is gained to the adjustment screws 128 and 130 and the scanner assembly 150 by the simple expedient of pulling the head assembly 144 back. When the head assembly 144 is closed against the body 118, the magnetic clutch engages and self-aligns, so that the microscope is immediately ready for operation. The head assembly 144 is preferably retained in its (normal) closed position by spring-loaded pins (not shown) which are pushed in (or released) by the operator in order to swing the head back for access.
The arrangement of the magnetic clutch 142 is shown in more detail in FIG. 9. The sleeve or bottom part 138 of the clutch 142 rides on motor driven adjustment screw 132 and is capable of translation up and down while still grasping the screw 132 for rotation. This is because a non-circular and/or keyed cross-section is used for this sleeve 138 as shown, for example, at 156 where sleeve 138 surrounds hexagonal adjustment screw 132 as shown so that up-down motion is permitted, but not relative rotational motion. More detail of the magnetic clutch 142 is shown at 158 and 160. Four magnets 162, 164, 166, 168 are preferably mounted in the top of the motor drive shaft 140. Similarly, four mating magnets 170, 172, 174, 176 are mounted in the top of sleeve 138 as shown. The magnets may be mounted with all north poles projecting downward from motor drive shaft 142 and all south poles projecting upwardly from sleeve 138 so that simple engagement may be achieved every 90 degrees. Alternatively, a different keying scheme may be used so that only one orientation is possible is such an arrangement is desired, for example, 3 norths and a south from the top could mate with 3 souths and a north from the bottom so that engagement between parts 138 and 140 could only occur in one angular orientation. Used with small rare-earth disk magnets (e.g., 3/16" diameter) this arrangement gives ample force to pull the sleeve up into position from as much as a centimeter and ample torque to drive the adjustment screw 132. Yet it offers very little resistance when the head is tilted back. Thus, the motor assembly is automatically disconnected and reconnected each time the head is tilted away and back again without the need for any complicated mechanical connection/disconnection.
Optical Train
An optical microscope 178 which allows the top of the AFM cantilever of the scanning probe to be monitored during alignment and scanning is shown in FIGS. 10 and 11. FIG. 10 shows the overall arrangement of optical microscope 178 in relation to the scanning probe microscope 180. The optical microscope assembly 178 is mounted onto the scanning probe microscope body 118. The front part 182 of the optical microscope 178 passes through an opening 184 in scanner assembly 150 so that a view of the scanning cantilever is possible. The opening 148 allows the head assembly 144 to swing back to the open state while the optical microscope 178 remains attached to the scanning probe microscope body 118.
The optical train or path of the scanning probe microscope AFM head is shown in FIG. 11. This figure shows the optical train used for sensing deflection of cantilever 186, so that the relationship between the two optical systems is clear. A collimated laser beam 188 from a laser (not shown in FIG. 11) passes through a converging lens 190 attached to scanner 192 preferably at or near its bottom 194. Beam 188 is focused down onto the back 194 of cantilever 186 which is held in the glass block 196 attached to the bottom 194 of scanner 192. The reflected beam 198 from the back 194 of cantilever 186 is incident on position sensitive detector 200. The optical microscope 178 is arranged so as to view the back portion 194 of cantilever 186 as illuminated by the incident beam 188 of the laser. A small mirror 202 is set to one side of and just above position sensitive detector 200 so as to collect some light from the back 194 of cantilever 186. This arrangement is illustrated in a top plan view in FIG. 12 as taken along line 12--12 of FIG. 11. The laser spot 204 is seen on the back 194 of cantilever 186 in this view. Mirror 202 sits off to one side of the detector 200 (the detector is situated above the laser spot and not shown in FIG. 12). Diffuse light from the back 194 of cantilever 186 is passed to a first lens 206. Returning to the side view (FIG. 11), first lens 206, second lens 208 and bending mirror 210 form an image of the back 194 of cantilever 186 on the image plane of a charge coupled device (CCD) camera 212. The long-working distance required by the lens assembly of lenses 206 and 208 (typically 40 mm) limits the magnification of the system to 5 or 10 times if the distance to the camera 212 is not to be unwieldy. However, this is adequate to fill the sensitive area of a CCD imaging chip (approximately a 1 mm by 1 mm square) with a view of the cantilever back 194 (approximately a 0.1 mm by 0.1 mm image area). The remainder of the magnification is purely electronic and results from the projection of the CCD image from camera 212 onto a TV monitor (not shown).
In another embodiment of the system, shown in FIG. 13, the microscope 220 may be placed on the optical stage 222 of an inverted microscope 224 so that the scanning of a transparent sample may be viewed from below. This is achieved using the free-standing mode of operation of the microscope as described in U.S. patent application Ser. No. 08/388,068, referred to above. The sample stage has been removed so that the magnetic balls, two of which are shown at 226, 228, now ride on the glass stage 222 of an inverted optical microscope 224. The objective lens 230 of the inverted optical microscope 224 is focused through a transparent sample container or substrate 232 onto the region scanned by the scanning probe 234. The position of the microscope 220 on sample stage 222 of optical microscope 224 is adjusted by means of micrometer screws (not shown) which translate the whole assembly 220 over the surface of the glass plate 220 of the optical stage of the inverted microscope 224. These optical stages are normally rigid and smooth, and form an ideal surface for moving the microscope over.
Bow Error Correction and Reduction
The bow-correction system useable with the scanning probe microscope hereinbefore described is illustrated in FIGS. 14 and 15. The geometry of the top-down scanner 240 is illustrated in FIG. 14. The collimated laser beam 242 from a laser light source (not shown in FIG. 14) is focused onto the back 244 of a cantilever probe 246 by a converging lens 248. Both the lens 248 and cantilever 246 are preferably attached to the bottom (or near the bottom) of a scanner element 250. The reflected beam 252 falls onto a position sensitive detector 254. Detector 254 is arranged to sense vertical movement of the cantilever by means of the arrangement of two segments 256 (A) and 258 (B). Segments 256 and 258 are positioned so that if the cantilever 246 moves up, then more light is reflected onto segment 256. Segment 256 produces an output signal A and segment 258 produces an output signal B. The deflection signal is obtained from the difference between the signals from the two segments, A-B divided by their sum A+B so that the deflection signal is independent of the absolute magnitude of the laser signal, reflection, etc. In FIG. 14, movement of the probe is defined in the direction formed by the intersection of the plane of the beams 242 and 252 and the sample surface plane as movement in the y direction. Movement in the perpendicular direction in the plane of the sample surface is in the x direction. Bow is caused by the fact that the scanner 250 does not remain on a fixed plane, but introduces vertical motion and angular deflection as the scanner tube is bent in order to scan. Bow in the x direction will not affect the signal (A-B)/(A+B) unless the unwanted deflection is so large that it causes the reflected beam 252 to miss detector 254 entirely. Bow caused by the y scan does introduce undesirable signal, and, as shown earlier, it has the effect of causing the cantilever 246 to be pushed down into the surface being scanned when the scan is away from the detector and to be pulled up from it when the scan is towards the detector. This is the result of the action of the feedback control system used with scanning probe microscopes and well known to those of skill in the art which moves the scanner up and down in an attempt to keep the deflection signal constant. Pulling up can have the undesirable effect of causing cantilever 246 to lift-off the surface being scanned, but this only happens at large angular excursions, so the effect is easily minimized by using a relatively long scanning tube. Pushing down into the surface is always undesirable because it increases the tracking force used in the microscope and this disrupts soft surfaces such as biological materials which it is desirable to be able to scan. However, this error is approximately linear as a function of scan voltage. It can be corrected for by adding a voltage proportional to the scan voltage to the deflection signal in such a sense as to cause the scanner to lift up in just an amount to compensate for the pushing-down that would occur otherwise. This is done with the circuit shown in FIG. 15. A fraction of the y-scan voltage (denoted signal "y") is set by the resistive divider comprising resistors R1 and R2. In one direction of scan (the y sweep away from the detector), this signal is subtracted from the deflection signal A-B/A+B using operational amplifier 260. In the other direction of scan (where the y scan polarity is reversed and the cantilever sweeps towards the detector) the signal is shorted out by the diode D1 and no correction is applied. The ratio, R1/R2, depends upon the sensitivity of the scanner element 250. This design of correction circuit can accommodate different scanners through the simple expedient of placing R2 (for example) in the scanner body, so that, as the scanner is changed, so is the value of R2. Similarly, a variable resistor could also be used and set in any of a number of ways well known to those of ordinary skill in the art.
Alternatively, the bow can be corrected by use of a novel scanner arrangement as described below. This novel scanner has the advantage of eliminating the lift-off of the cantilever when a large displacement is made in the direction that lifts the cantilever (as shown in FIG. 6A). The distortion of the cantilever due to bow is determined by the angle formed by the bending of the scanning tube in the y direction (as defined in FIG. 14). P. S. Jung and D. R. Yaniv, supra, and Elings et al., in U.S. Pat. No. 5,306,919, describe a scheme for removing angular displacements of the cantilever of a scanning probe microscope by using two equal and opposite angular deflections of a long tube, so that the total displacement describes an "S"-like shape, the end of the tube being translated but not subject to angular deflection. As previously stated, this scheme requires the use of a substantially increased length of scanning tube for a given range of scan. While fit for its intended purpose, this configuration is both electrically and mechanically more noisy than a shorter tube. Since, however, it is correction of the angular deflection that is required, it is not necessary to use tubes of equal dimension to achieve the benefits of the device described by Jung et al. and Elings et al. Elings et al., in another approach described in U.S. Pat. No. 4,871,938, describe an STM system where the tip is placed on one side of the tube at its circumference and that side is deflected so as to compensate for the angular deflection. However, while fit for its intended purpose, this arrangement results in a substantial reduction of the scan range available from a given tube employing the invention herein.
The same corrective effect can be obtained by using a much shorter opposing deflection, but by applying it across a much shorter distance, so that the total angular correction is the same as would be obtained with a longer tube bent over a longer distance. A scanner 270 according to this invention is shown in FIG. 16A in cross section. A side view is shown in FIG. 16B and a top view is shown in FIG. 16C. In a conventional scanner, there are four electrodes disposed along the length of the scanner tube. These are generally denoted, travelling about the circumference in clockwise fashion, +Y, +X, -Y, and -X. The +X electrode is opposite the -X electrode and the +Y electrode is opposite the -Y electrode. The +X and -X segments are connected to voltages of opposite polarity so that as one side of the tube is expanded in response to the application of a positive voltage, the other side will contract due to application of a negative voltage. The net effect is that the tube bends in a controlled manner in response to the application of voltages.
According to a presently preferred embodiment of the present invention, a short segment 272 of the +Y electrode 274 is isolated to form a separate electrode and that electrode is powered by the -Y voltage supply. Thus the lower portion of the scanning tube on the +Y side is deflected in a direction opposite to the remainder of the tube on the +Y side. If the length of opposing electrode 272 is less than half the total length of the scanner tube 270, then the opposing angular deflection is less than that needed to compensate for the angular deflection caused by the upper part of the tube. If however, the small, opposing displacement from opposing electrode 272 is applied across a distance much less than the diameter of the scanner tube 270, a larger compensating angular deflection can be generated. According to a presently preferred embodiment of the present invention, cantilever probe assembly 276 is mounted on a rocking block 278 held in place on a wedge-shaped fulcrum 280 and a ball 282 by the action of a magnet 284 that pulls rocking block 278 up against ferromagnetic material 286 on the end of scanner 270. The distance "d" between fulcrum 280 and ball 282 is chosen such that the angular deflection due to the opposing electrode 272 is equal in magnitude (but opposite in sign) to the angular deflection produced in the y direction by the rest of the tube.
It is to be appreciated that ball 282 can be fabricated of a magnet and attached to block 278, thus obviating the need for magnet 284, similarly, portion 286 could be fabricated of a magnet, ball 282 of a material attracted to magnets, and magnet 284 obviated. Other similar arrangements will appear to those of ordinary skill in the art.
Another embodiment of a bow-correction system is shown in FIG. 16D. This version uses two small piezoelectric cylinders, shown as 288a and 288b in FIG. 16D. Each cylinder has an outer and an inner electrode surface allowing it to be expanded or contracted in vertical length. One end of each cylinder is rigidly attached to a housing 290 which is in turn, rigidly attached to the free end of the main scanning tube 292. The lower ends of the tubes 288a and 288b are rigidly attached to a cantilever housing 294 to which the force sensing cantilever 296 is, in turn, attached. The required angular displacement is obtained by contracting one tube (e.g., 288a) and expanding the other (e.g., 288b). The deflection signal is somewhat reduced because of the stiffness of the mounting elements (i.e., the tubes 288a and 288b) but this arrangement has the advantage of increased mechanical stability. Once again, by placing two small tubes close together, an adequate angular deflection can be obtained, without the disadvantage of a reduced scan range as in the prior art. The control of the signals necessary to accomplish this can be supplied by a power supply under the control of a computer as well known to those of ordinary skill in the art.
Scanning probe microscopes usually require vibration isolation and it is common to do this by setting them on a heavy slab mounted on elastic cords or springs. Another approach is to use an air-table. Although the air-table generally functions less well than a slab on springs, it is commonly used because of its ability to keep the microscope at a convenient height for the operator. It is usually necessary to provide some additional isolation to keep out acoustic noise (such as a heavy box placed over the whole system). It is, however, possible to optimize the parameters of slab and spring system so that the displacement caused by putting the microscope on the isolation stage is small and acoustic isolation is straightforward. Such an isolation system is shown in FIG. 17. An acoustic isolation box 300 is used as the support for a vibration isolation system within the box 300. Box 300 is shown with its access door 302 open. The vibration isolation system consists of elastic cords 304, 306, 308 and a forth cord hidden by the wall of the box 300 suspending a massive slab 310. Such suspensions have usually been assembled as large systems (e.g., suspended from a ceiling). However, the only requirement is that the system has a low resonant frequency, typically 1 Hz for longitudinal vibrations. If the slab 310 (plus microscope) extend the elastic cords 304, 306, 308 and the hidden one, by an amount x, then it follows from elementary mechanics that the resonant frequency, f, of the assembly is: ##EQU1## where g is the acceleration due to gravity. Thus, a resonant frequency of 1 Hz is obtained for an extension (x) of 25 cm, independent of the size of the isolation system. By using stiff cords 304, 306, 308, etc. and a very massive slab 310, a small system can be built. This approach also has the advantage that the extra movement caused by putting the microscope onto the slab 310 is small (because the fractional added mass is small). So, if the slab is near desk height to begin with, it moves only a little when the microscope is placed onto it. One successful embodiment used four commonly available 1/4" diameter bungee cords to hold a 60 pound lead-loaded slab. The height of the whole enclosure is only 3' and it sits conveniently on a desk top. By building the enclosure from a dense material with a well-fitting door, excellent acoustic isolation is also obtained. A microscope operated in this desk-top enclosure gives atomic resolution routinely in high ambient noise environments.
Gas Sparging System
The inventors have discovered that it is often desirable to remove dissolved gasses, particularly oxygen, from solutions used in a scanning probe microscope. This is because the chemical reactivity of oxygen limits the range of electrochemical potential that can be used and limits the nature of the compounds that can be studied in the microscope. A somewhat similar problem arises in liquid chromatography and it has been described in detail by Bakalyar et al. S. R. Bakalyar, M. P. T. Bradley and R. Honganen, Journal of Chromatography, 158, 277-293 (1978)!. These workers found that sparging (bubbling a gas through) the solution with helium effectively removed all the dissolved oxygen. Helium has a very low solubility in most solvents, so that it not only replaces the undesired gas, but is less likely to form bubbles than other gasses with a higher solubility.
The present design of the microscope lends itself to sparging of the liquid sample by gasses. FIG. 18 shows a presently preferred embodiment of the present invention employing a gas sparging system. The sample cell 312 situated on the sample platen 314 is in place in the hermetically sealed sample chamber 316 of the microscope. Inert gas may be passed directly into the liquid 318 in cell 312 for degassing by sparging using one of the liquid input lines 320 previously described in U.S. patent application Ser. No. 08/388,068, discussed supra. Inert gas is also preferably passed into the body of the chamber 316 via an inlet 322. An outlet 324 permits flow of the gas through the system. The direct sparging of the sample cell 312 is only required in order to accelerate the initial degassing. Degassing will still occur (but more slowly) so long as a flow is maintained through the chamber 316 such as is adequate to prevent the back-diffusion of air into the sample chamber 316. Thus, in operation, gas may be flowed through inlet 322 and outlet 324 initially, and the flow directly into the sample (via line 320) stopped and flow through the chamber maintained. The sample can thus be maintained oxygen free without direct bubbling, avoiding mechanical noise during microscopy.
Nitrogen and argon both work well as sparging gasses, but helium has a particular advantage. Because of its unusual acoustic properties (i.e., its low density and thus, high speed of sound) it provides a poor acoustic impedance match to sound waves that originate in air (which is predominantly nitrogen). Therefore, vibrations of the chamber wall 316 caused by sound are less readily coupled into the chamber if it is filled with helium. Thus, the helium serves a further purpose of providing acoustic isolation, improving the operation of the microscope.
AFM Detector Fine Adjustment
As described in U.S. patent application Ser. No. 08/388,068, discussed supra, the AFM detector unit is aligned in one direction by sliding it in the slot on the microscope head and in the other (perpendicular) direction by rotating the entire AFM scanning assembly. Another embodiment of the detector unit which permits fine adjustment in this latter direction is shown in FIGS. 19 and 20. This arrangement permits a further (and finer) adjustment beyond that achieved by rotating the scanner head. In this alternative embodiment, the detector housing 326 housing detector 325 is made narrower than the channel 328 that houses it by an amount "d" on each side. Housing 326 is held into channel 328 by means of magnets 330 glued into the detector housing 326 and serving to hold housing 326 in the channel 328 (which is made of a magnetic material). A pin, 332 fixes one point of the housing 326 with respect to the channel 328, so serving to define a rocking motion as indicated by the curved arrow 334 in FIG. 19. The rocking motion is made by means of a handle 336 inserted into the back of the detector housing 326. Lateral motion Y1 of the handle is demagnified in the diminished motion Y2 of the detector. The demagnification ratio is set by the ratio of X1 (the distance between the center of detector 325 and the center of pin 332) to X2 (the distance between the center of pin 332 and the end 338 of handle 336). In this way, fine adjustment of the lateral position of the AFM detector 325 is achieved.
Glove Box Loading System
The use of a hermetically-sealed housing for the microscope sample chamber as discussed in U.S. patent application Ser. No. 08/388,068, supra, permits reactive samples to be studied. However, it is often difficult to load such samples into the microscope chamber in the first place. If the entire microscope is placed into a sealed glove box, it may be exposed to reactive chemicals. Furthermore, it would not be possible to start sparging of the microscope sample chamber until after the microscope is passed out of the glove box and gas lines connected to the sample chamber. An adapter which allows easy mating of the microscope with a glove box is shown in FIGS. 21 and 22. Referring to FIG. 21, the microscope 340 seats against a plate 342 to form a hermetic seal. A glass chamber 344 may be attached to the bottom of the plate 342. The plate 342 is bolted onto a glove box 346. Inert gas may be passed through the glove box 346 by means of the gas supply lines 348, 350. A similar pair of gas supply lines 352, 354 permits gas flow through the glass chamber 344 when it is in place. The gas supply lines 348, 350, 352, 354 may be shut off by means of corresponding gas valves 348a, 350a, 352a, 354a when not in use. A detailed section is shown in FIG. 22. The microscope body 340 is pushed into the plate 342 where it is retained by an O-ring 356. The plate 343 seats against the glove box 346, to which it is affixed by bolts 358a, 358b. Magnets 360 pull a magnetic ring 362 up against the plate 342. The glass chamber 344 is affixed to the magnetic ring 362. Thus, the glass chamber 344 may be easily pushed into place and retained by the magnets 360.
The plate 342 is first bolted into place on the glove box 346 and the microscope body 340 inserted into the plate 342. The gas supply lines 352, 354 through plate 342 are sealed with valves 352a and 354a and inert gas flowed through the glove box 346 using the gas supply lines 348 and 350 until the glove box 346 is purged of oxygen and other undesired gasses and vapors. At this point, the sample can be prepared, placed on sample platen 364, and sample platen 364 mounted to the microscope 340 in the inert atmosphere maintained by glove box 346. Once the sample platen 364 is mounted to microscope 340, the glass chamber 344 may then be placed into position on the plate 342 and gas flow started through the gas supply lines 352, 354. The plate 342 may now be unbolted from the glove box 346 with the sample protected inside the glass chamber 344. The microscope, now resting on the glass chamber 344 to which it is sealed, may now be placed into an enclosure for high resolution microscopy. With long gas lines 352, 354 connected to the chamber 344, this enclosure can be situated remotely from the glove box 346 in operation. For low resolution microscopy, when acoustic isolation of the microscope is not so important, the microscope may be operated in-situ in the glove box 346.
Sample Platen with Adjustable Kinematic Mounts
The sample platen described in U.S. patent application Ser. No. 08/388,068, supra, is translated by means of adjustment pegs which locate in slots in the sample platen. However, it is sometimes desirable to be able to remove and replace the sample platen while retaining its position with respect to the microscope tip. For example, a very small sample might be used and positioned with the use of an optical microscope. It would be desirable to be able to remove and replace the sample platen with no loss of alignment. FIG. 23 shows an arrangement which permits this. The sample platen 366 mounts onto the magnetic balls disposed at the ends of threaded vertical adjustment rods by means of the cone 368 vee-groove 370 and plane bearings 372 which form a standard kinematic mount, allowing precise removal and replacement of the sample platen 366. In order to allow adjustment of the tip with respect to a sample mounted on this platen 366, the vee groove 370 is made adjustable. It is formed into a piece 374 which slides in a slot 376 in the platen 366. The sliding piece 374 is locked into position by means of two bolts 378, 380 which slide, respectively, in slots 382, 384. In the microscope, the tip is located over the sample in one direction of movement by sliding the vee-groove 370 in its slot 376. It is then locked into place with the bolts 378, 380. The perpendicular adjustment is achieved by rotating the scanner in the body of the microscope.
Alternative Embodiments
Although illustrative presently preferred embodiments and applications of this invention are shown and described herein, many variations and modifications are possible which remain within the concept, scope, and spirit of the invention, and these variations would become clear to those of skill in the art after perusal of this application. The invention, therefore, is not to be limited except in the spirit of the appended claims. | Features for incorporation with scanning probe microscopes are provided which may be used separately or together. The features include constructing the microscope with a hinged top housing providing easy access to the heart of the microscope; a self-aligning and torque limiting magnetic clutch coupling a motor drive powering at least one vertical adjustment screw of the microscope; a removable microscope head for easy adjustment; an optical microscope, optionally mounted to an electronic camera and imaging system, installed adjacent to the head; operation on an inverted microscope stage; bowing error correction; a gas sparging system providing contaminant and noise reduction; a glove box type of loading system so that reactive materials may be safely loaded into the microscope; and a compact desk-top chamber which provides acoustic and vibration isolation. | 8 |
This is a divisional application of application Ser. No. 226,063, filed Feb. 14, 1972 now U.S. Pat. No. 3,736,469.
BACKGROUND OF THE INVENTION
This invention relates generally to a heating system for multiple position plate heaters utilizing vapor condensing at the same pressure throughout the system. More particularly, the invention relates to a condensing steam heating apparatus for synthetic yarn processing, and process therefor, having a very high overall coefficient of heat transfer even when the yarn is under the yarn-contacting heating surface.
As is well-known, vapor condensing systems are more suitable than electrical heating systems where it is necessary to heat uniformly moving threadlines of yarn such as polyester by means of contact with a hot plate. This is particularly so when adjacent positions are operated at different heat loads on account of different threadline deniers, number of threadlines etc. and most particularly so when the heating surface is approximately vertical. For example the temperature profile of an electrically heated hot plate of a commercial texturizing machine was determined under various conditions and the results are shown in FIG. 1. The hot plate is 4 ft. long and 1 inch broad, has two threading grooves and a matte chrome finish, is in the vertical position and is enclosed by a door to prevent heat escaping and draughts from changing the temperature profile; and has uniform electrical heating (6 volt, 30 amps) along its length. Without any yarn running on the hot plate and the thermostat at the top of the plate set to 180° C., it can be seen that the bottom of the hot plate is at about 110° C., i.e. there is a 70° C. temperature differential. With one threadline of yarn running downwards on the plate the temperature differential is reduced to 40° C., and with two threadlines the temperature differential is reduced to 20° C. By having non-uniform electrical heating along the length of the hot plate it is possible to marginally reduce the temperature gradient for a given set of fixed conditions (threadline speed, number of threadlines etc.), but such a system is still highly inflexible and the product made from a twin threadline process cannot be merged with the product from a single threadline process (e.g. caused by one of the threadlines breaking or running out) on account of its significantly different properties such as ability to absorb dye etc.
Various heating systems of the vapor condensing type have been devised, and include, for example, that disclosed in U.S. Pat. No. 3,177,931 which claims "In apparatus for modifying heat-settable yarns, the combination comprising closed means including a source of vaporized heating fluid substantially completely free of incondensable gases, and a plurality of tubular members for receiving said fluid from said source, said tubular members being disposed in close adjacent side-by-side relation and being inclined for drainage of condensate back to said source, a yarn guide conduit in the form of an open trough generally v-shaped in transverse section and extending along and seated directly upon said tubular members with opposite sides thereof respectively engaging said tubular members for being heated thereby and means for drawing said yarn lengthwise of said tubular means and conduit in contact with the latter for being heated thereby." However, it has hitherto been considered both unnecessary and undesirable in such condensing vapor systems to have the yarn under the heating surface, because of the greater temperature variability resulting from the increase in thickness of the condensation film between the vapor and the plate heating the yarn. Accordingly none of the prior art of which the applicant is aware discloses a vapor condensing hot plate with the yarn running under the hot plate, e.g. FIG. 6 of the forementioned U.S. Pat. No. 3,177,931.
The applicants have now discovered that there would be certain processing advantages in having the yarn run under the vapor heated hot plate. In particular, when hot plates several feet long are used on a multiposition machine it is very much easier for the operator of the machine to string-up the threadline on the underside of a plate inclined at, say, 30° to the vertical than to string-up a machine which is similar except that it has vertical hot plate. Longer hot plates may be used and thereby higher processing speeds. Also heat losses are marginally reduced: according to "The Efficient Use of Steam" by Oliver Lyle (H.M. Stationery Office), Table XXVI on page 853, heat losses are roughly proportional to the square of the air velocity, and the convection air velocity adjacent to a vertical hot plate is greater than the convection air velocity for the underside of the same hot plate inclined to the vertical.
SUMMARY OF THE INVENTION
It is therefore an object of the instant invention to provide a multiple condensing vapor heating system which not only heats yarns uniformly at varying heat loads by virtue of a high overall coefficient of heat ransfer, but in addition permits such yarn heating processes to be operated at maximum speeds in the simplest possible manner by the operator, with minimum waste of heat and with minimum maintenance, by a technique which may include the yarn being under the yarn-contacting heating surface.
Very surprisingly the applicant has now found that such a system is achieved by incorporating a trace of a so-called filming amine into mineral-free heating-fluid which causes the vapor to condense as discrete droplets rather than a film. Also it is preferred to use a sealed closed-loop heating system with the vapor entering at the top of each hot plate, and with the condensate returning from the bottom of each hot plate to a single package boiler which heats the liquid directly by passing an electric current through the liquid. Many filming amines, such as octadecylamine, are themselves effective in preventing corrosion by the traces of gases such as oxygen and carbon dioxide that remain within the system even after the application of high vacuum at start-up; but sometimes it may be desirable to include a so-called neutralizing amine in addition. Many different heating fluids may be used, but steam is particularly convenient at temperatures up to 350° C.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the high temperature gradients of prior art vertical electrical heaters.
FIG. 2 is a schematic diagram of a multiple position plate heater system utilizing vapor condensing at the same pressure throughout the closed-loop system.
FIG. 3 and FIG. 4 illustrate a typical vapor-heated plate heater.
FIG. 5 illustrates a typical electric resistance heating boiler.
FIGS. 6 and 7 illustrate the much lower temperature gradients obtained with the instant invention in contrast to the prior art.
All of the foregoing are described in detail below, particularly in the examples.
DETAILED DESCRIPTION OF THE INVENTION
The improved heating system of the instant invention is applicable to any process wherein synthetic yarn is processed at elevated temperatures on a multiposition machine, and where, for reasons of product uniformity and mergability, it is essential to maintain very good temperature control on all positions. The invention is exemplified with respect to its applicability to a multiposition drawtwister, but of course is obviously applicable to numerous other process steps involving heat treatment of at least one moving threadline, whether twisted or untwisted; whether the threadline is being stretched, shrunk or treated at constant length; and whether or not each threadline is subsequently or concurrently comingled, interlaced, entangled, twisted with or otherwise intimately joined together with another threadline which may or may not have been treated by the process of the instant invention.
The preferred apparatus of the instant-invention differs principally from prior art heating condensing vapor heating systems for synthetic yarn processing by virtue of two improvements: firstly, the inside surface of the hot plate has a coating which has a contact angle with the condensed vapor in excess of 90° ; and secondly, the yarn-contacting surface is substantially under the vapor in the hot plates (the term "substantially under" is meant to include all angles of inclination to the horizontal of the yarn contacting surface up to 85°).
The first improvement of having a coating on the inside surface, which coating has a contact angle with the condensed vapor in excess of 90° , ensures that the vapor condenses as discrete droplets (rather than as a film) which are rapidly removed by gravity, and thereby permits very efficient heat transfer without high temperature gradients. When the heating fluid is steam the coating can be conveniently achieved by incorporating a trace of a "filming amine" into the mineral-free heating fluid. Filming amines are discussed in the "Betz Handbook", p. 202-203 and their use in promoting heat transfer is therein described. Filming amines function by forming on the metal surfaces contacted an impervious non-wettable film of substantially monomolecular thickness, across which the temperature drop is insignificant. The film thickness does not increase in thickness with continued treatment. In addition to providing a thin non-wetting surface many filming amines are therefore effective in preventing corrosion by oxygen and carbon dioxide, traces of which may be present even though the system has been evacuated at the initial charging of the vaporizable fluid. The filming amines of value in the prevention of corrosion are the high molecular weight amines and amine salts having straight carbon chains containing 10-18 carbon atoms, such as octadecylamine (C 18 H 37 NH 2 ), hexadecylamine (C 16 H 33 NH 2 ) and dioctadecylamine (C 36 H 74 NH). Octadecylamine is particularly suitable. Since filming amines have the ability to loosen and remove old corrosion films, they may therefore be used to preclean the inside of the boiler, pipes and hot plates etc. Filming amines are reasonably stable at high temperatures and it is believed a self-enclosed system could be operated for several years without any need to replace the contents thereof. In any event samples could be taken occasionally to determine the extent of any decomposition. The amount of filming amine needed never exceeds 100 parts per million based on the weight of water present, and in practice it is most preferred to use less than 15 parts per million.
Instead of using steam and a filming amine, it may sometimes be preferable to use diphenyl ether containing trace amounts of polyethylene glycol, on account of the lower pressure obtainable at a given temperature with such a system.
With regard to the second improvement it is preferred to use inclination angles of from 45° to 85° in conjunction with from 2 feet to 10 feet length of yarn contacting surface; it is most preferred for the yarn-contacting surface to be inclined at an angle from 55° to 75° to the horizontal in conjunction with from 3 feet to 6 feet length of yarn-contacting surface. It is also preferred that all the yarn-contacting surfaces on the multiposition machine should lie substantially in a single plane which is inclined to the horizontal. The foregoing conditions both reduce heat losses and permit quick and simple string-up of the threadlines by the operator.
If desired trace amounts of a "neutralizing amine" may also be added in addition to the filming amine, e.g. those described in the "Betz Handbook" at page 200 and including cyclohexylamine (C 6 H 11 NH 2 ) and morpholine (C 4 H 9 NO). These amines volatilize with the steam and combine with the carbon dioxide in the condensate to neutralize its acidity.
It is preferred to use a sealed closed-loop heating system such as that shown in FIG. 2 with the vapor entering at the top of each hot plate, and with the condensate returning from the bottom of each hot plate to a single boiler. This ensures that make-up problems are kept to a minimum. It is also preferred to use a single package boiler (FIG. 2) which heats the liquid directly by passing an electric current through the liquid (FIG. 5). The boiler need be controlled by a single thermostat only, with reduction in capital cost as compared wih the electrical system which needs a separate controller on each hot plate.
It is preferred to run the yarn along a groove (FIGS. 3 and 4) in the wall of the heating tube rather than have a separate wear plate seated thereon, in order to reduce the resistance to heat transfer. It is preferred to have this groove treated with a ceramic coating such as chromium oxide, titanium oxide, aluminum oxide or a combination of these in order to increase its life during operation to several years.
The following examples illustrate but do not limit the invention.
EXAMPLES I-VI
A twelve position hot plate system with each hot plate positioned between a feed roll and a draw roll of a standard drawtwist machine is constructed in the following way.
The condensing steam heater system consists as shown in FIG. 2 of a high pressure boiler which supplies steam at a controlled pressure and temperature to a manifold which consists of a row of pipes that act as heaters. Steam condenses in the pipes inclined at an angle of 60° to the horizontal and the resulting condensate flows by gravity back through the surge chamber to the boiler where it begins another cycle. Construction of the manifold is such that a 39 inch section of pipe is available at each position on the drawtwister and acts as a heater. Some heaters are equipped with removable wear plates which are grooved to provide a yarn track. Others heaters consist of only a grooved steam pipe which is lagged except for the front (see FIGS. 3 and 4). To insure good yarn contact from top to bottom each heater surface exhibits a uniform convex curvature 3/8"±1/16" from straight at the mid-point. This curvature remains in the heaters at elevated temperatures, e.g. 250° C.
Steam is supplied to the manifold by a high pressure steam boiler manufactured by Electric Boiler Corporation (EBCOR). The EBCOR boiler (FIGS. 2 and 5) consists of a pressure tank in which a cylinder, open at the bottom, is welded to the inside upper head of the tank thus dividing the tank into two concentric chambers, a steam generating chamber, (A) and a regulating chamber (B). Three solid alloy electrodes (C) are suspended equidistant apart in the chamber, each forming an apex of a triangle. Chambers (A & B) are connected by a steam header (D) in which there is a pressure control valve which is normally open (E of FIG. 5 and PVC of FIG. 2). When not operating, the water seeks a common level in each chamber, covering the top of the electrodes. A small amount of potassium chloride and five parts per million by weight of octadecylamine is added to the water upon initial start-up. The potassium chloride increases the flow of current through the water between the electrodes, and the octadecylamine promotes dropwise condensation. Heat is produced by the electrical resistance of the water. Steam is generated in Chamber (A) and passes to the steam-consuming load. As it builds up in excess of load requirements, it passes through the heater and through the pressure regulator to Chamber (B). As the actual pressure reaches the set pressure, the regulator starts to close. As it reaches this unbalanced condition, the water level drops in Chamber (A), and rises in Chamber (B), uncovering part of the electrodes resulting in less consumption of electricity until such time as the steam is made at a rate equal to the requirement. This is a unique method of modulating the electric power in exact balance with the loads without off-on high-maintenance switches, and without excessive electrical demand. Target temperatures are set by a control which determines the pressure at which the control valve closes. The temperature is the corresponding temperature of saturated steam at this pressure. The steam boiler is also provided with a rupture disc (RD of FIG. 2) in case of excessive pressure buildup in the boiler.
Prior to start-up and pressurizing, the steam system is evacuated with an auxiliary vacuum pump (FIG. 2) to rid the system of air. The system requires about two hours to heat up from a cold start. Once up to temperature, a current of about fifty amps is required from the power supply (FIG. 2) to maintain set point temperature with no load on the system. To change from one set point temperature to another of 50° C. higher requires about twenty minutes. Due to the simplicity of the steam system virtually no maintenance is required. The pressure control valve is a "bellows" packless type (PCV of FIG. 2).
Temperature measurements of the hot plates were made with an ordinary thermocouple and also with an Alnor surface pyrometer. The measurements made with the surface pyrometer (FIG. 6) showed less of a temperature gradient from top to bottom than did the measurements made with the thermocouple (FIG. 7). This can be explained by the greater effect of convection currents on the thermocouple junction, particularly at the bottom of the hot plate, whereas an Alnor sensing head, being insulated from convection currents, shows less of a gradient.
FIGS. 6 and 7 show conclusively the superiority of the vapor system over the electrically heated system and also the superiority of the bare steam pipes over the heaters with removable wear strips. In particular, condensing steam systems without wear strips exhibit a temperature profile from top to bottom which ranges no more than 1° C. compared to 4° C. and 20° C. for condensing steam heaters with wear strips and Barmag electrical heaters respectively.
Similar improvements in temperature profile were obtained over a period of seven weeks when drawtwisting 1000 denier polyester yarn at 3,000 ft./min., with the total temperature range of 275 temperature measurements made on 12 heaters without wear strips being ±31/2° C. The process without wear strips has an overall coefficient of heat transfer in excess of 1000 BTU/sq.ft./hr./° F. | There is provided an improved heating apparatus of the multiple condensing-vapor substantially air-free type used for uniformly heating moving threadlines of yarn up to 350° C. and which includes a pressurized boiler containing a vaporizable liquid, means for heating the liquid in the boiler to generate hot vapor, means for distributing the hot vapor to the inside of multiple plates where the vapor condenses and thereby heats threadlines of yarn separately moved in frictional contact witn an outer yarn-contacting surface of each hot plate, and possibly means for returning the condensate to the boiler, wherein the improvement comprises having a coating on the inside surface of each said hot plate, said coating having a contact angle with said vaporizable liquid of at least 90°. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims the benefit of the filing date of U.S. Provisional Patent Application No. 60/212,467, filed Jun. 16, 2000.
FIELD OF THE INVENTION
[0002] The present invention relates to shoe press units used, for example, in papermaking for pressing a paper web. The invention relates more particularly to a method and a shoe press unit in which excess lubricating oil that is expelled from between a pressing surface of a press shoe and a flexible belt is captured and evacuated from the shoe press unit.
BACKGROUND OF THE INVENTION
[0003] A shoe press unit typically comprises a support beam, a shoe element movably supported on the beam, a pressing unit arranged between the beam and the shoe element for urging the shoe element away from the beam and toward a counter element such as a counter roll, and a flexible belt that is arranged to slide over the pressing surface of the shoe element. To reduce friction between the belt and the shoe element and thereby reduce the frictional heating of the belt, it is common to supply a lubricating oil between the pressing surface of the shoe element and the belt. The oil both lubricates and cools the belt and the pressing surface. Excess oil is expelled from between the belt and the pressing surface as a result of the pressure exerted in the nip between the shoe element and the counter element. The excess oil is expelled from an upstream edge region of the pressing surface, and is then evacuated from the shoe press unit by an oil evacuation arrangement.
[0004] U.S. Pat. No. 5,935,385 discloses a shoe press unit having an oil evacuation arrangement in which an inlet opening of the oil evacuation arrangement is arranged on the beam at a distance from the shoe element. Therefore, the oil evacuation arrangement does not move with the shoe element. The inlet opening is so located that most or all of the initial kinetic energy of the excess oil exiting from between the belt and pressing surface is lost before the excess oil passes through the inlet opening. Thus, this kinetic energy of the oil is not available to assist in evacuating the oil. Another disadvantage of the oil evacuation arrangement is that it does not prevent the excess oil from flowing in various directions within the shoe press unit, and hence the oil tends to accumulate in the shoe press unit. The accumulated oil tends to mix with air, which makes evacuation of the oil more difficult and also requires a subsequent processing of the evacuated oil to separate the air from the oil prior to reusing the oil. The accumulated oil, which is relatively hot because of the heat transfer from the belt to the oil, also tends to conduct heat to other parts of the shoe press unit before it is evacuated, which results in an undesirable temperature increase inside the shoe press unit. Moreover, it is disadvantageous to have an accumulation of oil in the shoe press unit because this requires an increased power consumption. Finally, constructing the oil evacuation arrangement as an integral part of the shoe element requires relatively costly manufacturing methods.
SUMMARY OF THE INVENTION
[0005] The present invention addresses the above and other needs by providing a method and a shoe press unit in which an oil evacuation arrangement is affixed to the shoe element proximate an upstream edge region of its pressing surface, such that the shoe element and oil evacuation arrangement move together as a unit. The oil evacuation arrangement includes an evacuation duct for evacuating the excess oil expelled from between the belt and the shoe element. The evacuation duct is coupled to an outlet pipe for the evacuated oil within the shoe press unit. The evacuation duct is fixed relative to the shoe element and the outlet pipe is fixed relative to the beam, and the evacuation duct is movably connected to the outlet pipe such that the duct can move relative to the outlet pipe in at least the pressing direction along which the shoe element is moved by the pressing unit.
[0006] In accordance with a preferred embodiment of the invention, the oil evacuation arrangement comprises a container having a bottom and a plurality of wall elements upstanding from the bottom. The excess oil is squirted out from between the belt and pressing surface through an inlet opening of the container. The evacuation duct preferably includes a substantially rigid tubular member that is affixed in the container. In one embodiment, the tubular member extends through a through-hole formed in the beam and connects with the outlet pipe arranged in the interior of the beam.
[0007] The duct is coupled to the outlet pipe in one embodiment via a flexible sealing device that accommodates relative movement between the duct and outlet pipe in at least the pressing direction, and preferably also accommodates lateral movement of the duct that can arise for example from thermal expansion or lateral movement of the shoe element. In one embodiment, the sealing device comprises a bellows formed of an elastomeric material such as rubber. In another embodiment, the duct is coupled to the outlet pipe via a pair of tubular members one of which is slidably and sealingly received in the other. One of the tubular members can be fixedly connected to the container on the shoe element, and the other tubular member can be fixedly coupled with the outlet pipe. In yet another embodiment, the tubular member fixed to the container is slidably received in a sealing manner in an opening formed through a wall of the outlet pipe. The tubular member is sealed relative to the outlet pipe by one or more seals arranged at the opening in the outlet pipe.
[0008] The shoe press unit in a preferred embodiment comprises a closed shoe press unit, and the interior of the shoe press unit has an overpressure relative to the pressure outside the shoe press unit of 10-500 mbar. More preferably, the interior overpressure is below 200 mbar, and most preferably is below 50 mbar. The outlet pipe can be connected to a vacuum source outside the shoe press unit to facilitate the evacuation of oil.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The above and other objects, features, and advantages of the invention will become more apparent from the following description of certain preferred embodiments thereof, when taken in conjunction with the accompanying drawings in which:
[0010] [0010]FIG. 1 is a cross-sectional view, viewed in a cross-machine direction, of a shoe press unit in accordance with one preferred embodiment of the invention;
[0011] [0011]FIG. 2 is an elevation, viewed in the cross-machine direction and partly in cross-section, of the shoe press unit of FIG. 1;
[0012] [0012]FIG. 3 is a perspective view of an oil evacuation component in accordance with a preferred embodiment of the invention; and
[0013] [0013]FIG. 4 is a cross-sectional view of an alternative embodiment of an evacuation duct arrangement in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
[0015] [0015]FIG. 1 shows, partly in cross section, a shoe press unit according to one embodiment of the invention. The shoe press unit comprises a support beam 1 , in which a recess is arranged for a pressing unit 3 , 5 for a shoe element 2 . The pressing unit 3 , 5 preferably comprises a hydraulic piston 3 , which is arranged in a sealing manner inside a hydraulic cylinder 5 , so that the shoe element 2 can be moved hydraulically back and forth in a direction R, which is at right angles in relation to the extent of the shoe element 2 in the longitudinal direction. A support heel 9 is arranged at one short end of the shoe element 2 . An endless, flexible belt/jacket 6 is arranged so as to interact, by means of its one surface 6 A, with a pressing surface 21 of the shoe element 2 and, by means of its other surface 6 B, with a counter-roll (not shown). The endless belt 6 moves from right to left in FIG. 1. The heel 9 is therefore arranged at the downstream end of the shoe element 2 . The shoe unit 2 is, according to the illustrated embodiment, symmetrically formed in each edge region of the pressing surface 21 . In the upstream end of the shoe element 2 there is a marked end region Z 1 -Z 2 , which is a region with a convex curved surface 21 A. As can be seen from the figure, the lengthwise extent L of the upstream edge region 21 A is considerably shorter than the concave part 21 of the pressing surface. Within the upstream edge region 21 A there is a transversely extending line X at which contact is first made between the belt 6 and the pressing surface 21 of the shoe unit.
[0016] At the upstream end of the shoe element is a distribution chamber 7 which in a known manner supplies the pressing surface 21 with oil via ducts (not shown). At said distribution chamber there is an oil evacuation arrangement 4 which comprises a guide plate or partition 42 , a container part 45 , 44 , 46 , 43 A, 43 B, an evacuation duct 8 and an inlet opening 41 . The container part consists of a first longitudinal wall element 45 , a plane bottom portion 44 , a second longitudinal wall element 46 and two end walls 43 A, 43 B. The upstream longitudinal wall 46 is divided into a lower section 46 A and an upper section 46 B. The lower wall section 46 A is arranged at an acute angle X in relation to a plane P containing the plane bottom surface 44 . According to the preferred embodiment, the angle X is approximately 60-70°. The upper section 46 B is arranged at a smaller acute angle in relation to the plane P. In this way, the upper section 46 B preferably has an inclination that differs only by a few degrees from the tangent of the belt 6 in the region of the upper section 46 B. The upper section therefore converges slightly towards the inner surface of the belt. The end 41 B of the upper section forms an upper delimiting surface of the inlet opening 41 , which is slot-shaped. It is advantageous that this upper delimiting surface 41 B be positioned close to, or in certain cases even in contact with, the inner surface of the belt 6 , so that as small a gap as possible is formed between them. The downstream wall element 45 is also arranged at an acute angle in relation to the plane P. According to the preferred embodiment, the downstream wall element 45 forms an angle β which is essentially the same as the angle X of the other wall element 46 A. End walls 43 A, 43 B are arranged at either short end of the container. A lower delimiting surface 41 A of the inlet opening 41 is formed by the upper edge of the downstream longitudinal wall element 45 . All the components forming part of the container advantageously are made of thin sheet metal. In the preferred case, the sheet is 2 mm thick. Extending at right angles from the lower delimiting surface 41 A in the direction of and up to the shoe element 2 is a guide plate or partition 42 . The guide plate 42 is also made from thin sheet metal and it and the container are suitably made from one and the same piece of sheet metal which is suitably first stamped out and then bent into the desired final shape, after which the end walls 43 A, 43 B are connected in a sealing manner, suitably by means of welding, to the parts which have been bent up to form the container. Arranged in the bottom of the container is a circular hole 49 , in which an evacuation pipe 8 is arranged in a sealing manner. Suitably, the evacuation pipe 8 is made of a sufficiently rigid material, e.g., metal, that it cannot be compressed by the outer overpressure normally existing inside the shoe press unit. The container portion is fixed by means of screw connections 48 to the distribution chamber 7 which is in turn connected (usually screwed) to one longitudinal side wall 23 of the shoe element. The evacuation arrangement 4 is therefore firmly anchored on the shoe element 2 , so that these are movable as a unit.
[0017] For the purpose of enabling movement of the shoe element and the evacuation arrangement 4 , the oil evacuation arrangement 4 comprises a first evacuation duct 48 A, a rubber bellows 48 C, an upper connection duct 48 B and an outlet pipe 49 . It is clear that the rubber bellows 48 C can offer good flexibility in many directions, not only for vertical movement between the two ducts 48 A, 48 B but also with regard to angular deviations and also displacements in the transverse direction which may occur under certain operating conditions. The two ducts 48 A, 48 B are suitably made from a dimensionally stable material, for example metal, so that they cannot be compressed by outer overpressure. FIG. 1 also shows that the shoe press unit is provided with a secondary oil evacuation arrangement 11 which is suitably used as an oil evacuation system when at a standstill. The figure also shows that the shoe press unit is provided with belt guides 12 which are arranged on a support plate 13 and the purpose of which is to make possible installation/removal of the belt/jacket 6 .
[0018] As already mentioned, the evacuation arrangement 4 is positioned with its upper delimiting surface 41 B of the inlet opening 41 relatively close to the surface of the belt, so that the distance S between them during operation is sufficiently small to prevent any significant quantity of oil escaping between the opening 41 and the belt 6 . The distance S preferably should not exceed 10 mm. The inlet opening 41 should moreover be positioned in such a manner that the quantity of excess oil which is pressed out can squirt directly into the inlet opening 41 . According to the preferred embodiment, this is brought about by virtue of the fact that the tangent Tx of the convex curved surface at the contact line X between the belt 6 and the shoe element 2 extends between the lower delimiting surface 41 A and the upper delimiting surface 41 B. In this case, the geometries between the edge region 21 A and the inlet opening should be arranged so that the tangent Tx (which can be considered to represent a kind of median vector for the oil excess which normally squirts out in a divergent manner) of the contact line X deviates by a maximum of 15° from at least one of the imaginary straight lines Y 1 and Y 2 that extend respectively between the contact line X and the lower delimiting surface 41 A and between the contact line X and the upper delimiting surface 41 B of the inlet opening 41 . Furthermore, the inlet opening 41 should be positioned close to the upstream edge region 21 A, suitably spaced about 10-150 mm, but more preferably at a maximum of 100 mm, from the edge region 21 A.
[0019] The device according to FIG. 1 functions in the following manner. When the machine is started up for operation, the inner surface of the belt is provided with an oil film in order to lubricate between the belt 6 and the pressing surface 21 of the shoe element 2 but also in order to cool the shoe press unit. Oil supply usually takes place in a number of different positions, including through the distribution chamber 7 , which lubricates in the central zone of the pressing surface 21 and also usually at least somewhere else directly on the inner surface of the belt. The shoe element 2 exerts, through the force exerted by the pressing unit 3 , 5 , a pressure against a counter roll (not shown) so that a fibrous web disposed between the counter roll and the belt 6 is subjected to the desired treatment, for example, dewatering. In this connection, the excess oil that accompanies the belt 6 to the upstream end of the shoe element will be pressed out of the converging zone formed between the inner surface 6 A of the belt and the upstream edge region 21 A of the shoe element. The excess oil O is in this way given an initial kinetic energy and will squirt backwards, counter to the direction of movement of the belt, into the inlet opening 41 to be collected inside the container portion 43 A, 43 B, 44 , 45 , 46 . By virtue of a slight overpressure inside the shoe press unit (when a closed shoe press unit is used), the oil collected in the container will be pressed out through the first part 48 A of the evacuation duct, on through the rubber bellows 48 C and then, via the connection pipe 48 B, into the outlet pipe 49 , to arrive finally in a collecting vessel (not shown). In certain applications, the outlet pipe 49 is connected to a source of vacuum (not shown) in order to ensure adequate oil evacuation. It is usual to try to operate a closed shoe press unit with an inner overpressure of less than 50 mbar.
[0020] A certain quantity of oil will not be forcibly expelled in a jet, but will instead follow the surface in the edge region 21 A of the shoe element down towards the end wall 23 of the shoe element. By virtue of the guide plate 42 , however, which bears against the end wall 23 of the shoe element, this quantity of oil will also be guided towards the inlet opening 41 . In the embodiment shown in FIG. 1, gravity assists in this connection in bringing about this extra oil inflow to the container. It should be pointed out, however, that this is not a necessity because a certain underpressure can be brought about in the region adjacent to the inlet opening 41 so that this inflow of excess oil can take place even without the influence of gravity. The fact that the evacuation arrangement is arranged with the evacuation pipe vertical does not therefore constitute a limitation of the invention shown.
[0021] [0021]FIG. 3 shows in perspective the aforementioned container 43 A, 43 B, 44 , 45 , 46 in the form of a unit with a guide plate 42 and an evacuation pipe 48 A. It can also be seen that the guide plate 42 is provided with a number of holes 47 for arranging fixing screws 50 . By virtue of the fact that the evacuation arrangement in the preferred case is sectioned, in such a manner that a number of containers of limited length are arranged next to one another on the shoe element 2 , the inlet opening 41 , which preferably extends along the entire width of the container, of each container will always be optimally positioned in relation to the squirting oil irrespective of deflection of the beam 1 .
[0022] According to the preferred embodiment, the length of each container is approximately 1 meter. The length of a container should suitably not be less than 500 mm or more than 1500 mm, so that optimum evacuation can be achieved. For the same reason, the diameter of the evacuation duct/pipe should not be too small; suitably it is approximately 60 mm. The diameter should preferably not be less than 10 mm and should suitably not exceed 50 mm.
[0023] [0023]FIG. 4 shows a first alternative embodiment according to the invention, the evacuation duct 48 being provided with two telescopically arranged parts 48 A, 48 B. The 30 first part 48 A of the evacuation duct is in this connection provided with a relatively large diameter D 1 , while the second part 48 B of the evacuation duct is provided with a considerably smaller diameter D 2 . The two duct parts are arranged so that, in the rest position, they overlap over a considerable length l which is preferably at least the same as the diameter of the first duct part 48 A. Arranged in the annular gap 60 formed between the overlapping pipe parts is a seal 61 which, according to the preferred embodiment, is fixed to the end of the second duct part 48 B. Movement is therefore possible between the seal 61 and the first duct part 48 A, a sliding movement taking place in the cylindrical contact region 62 between the seal 61 and the inner surface of the first duct part 48 A.
[0024] According to another alternative embodiment according to the invention, the evacuation pipe 48 A which is fixed to the container is sufficiently long to be capable of entering the outlet pipe 49 through its opening 49 A. In this case, a seal, for example one or more O-rings, is arranged directly in the opening 49 A on the outlet pipe 49 , these seals interacting directly with the outer surface of the evacuation pipe 48 A. By virtue of the fact that the outlet pipe 49 can be made with a large diameter, suitably between 100-200 mm, the end of the evacuation pipe 48 A can move freely inside the outlet pipe 49 because the maximum stroke length of a shoe element 2 does not normally ever exceed 50 mm, usually lying between 20-35 mm.
[0025] In many applications, it is advantageous if the sealing connection between the first duct part 48 A and the adjacent part of the oil evacuation arrangement is flexible in more than one direction so that the connection is flexible in the lateral direction also, because the shoe element can during operation be caused (by lateral forces and/or heat) to make certain lateral movements, which movements the first duct part 48 A has to be capable of following without the risk of complications.
[0026] Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. For example, the evacuation arrangement can be made of many other materials than thin sheet metal, for example a polymer material. It is also clear that the inlet opening 41 of the evacuation arrangement can be divided (for example, for reasons of strength) so that a number of elongate openings next to one another is formed. It is also clear that the component parts of the evacuation arrangement do not necessarily have to made of/from one and the same material, but can be made from a number of different components/materials, which can be arranged with/connected to one another in many alternative ways that will be self-evident to the person skilled in the art. It is also clear that it is only for the purpose of exemplification that the evacuation arrangement is shown as being attached to a distribution block. The evacuation arrangement can of course be affixed directly on the shoe element 2 , for example, along its side wall 23 . In some cases, the evacuation arrangement can be firmly anchored to the pressing unit of the shoe element, which unit is movable together with the shoe element. It is also clear that devices other than a rubber bellows 48 C can be provided for making the flexible, sealing connection between the two pipe members in the evacuation arrangement, for example a fiber-reinforced flexible and impermeable polymer material other than rubber, or a liquid-tight fabric material. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. | A shoe press unit comprises a support beam, a shoe element movably supported on the beam, a pressing unit arranged between the beam and the shoe element for urging the shoe element away from the beam and toward a counter element, and a flexible belt that is arranged to slide over the pressing surface of the shoe element. An oil evacuation arrangement is affixed to the shoe element proximate an upstream edge region thereof. The oil evacuation arrangement has an inlet opening located such that excess oil expelled from between the belt and the shoe element passes through the inlet opening. An evacuation duct is connected with the container for evacuating oil therefrom, and the duct is movably connected to an outlet pipe within the shoe press unit. In one embodiment, the duct is connected via a flexible bellows to a pipe fixed to the outlet pipe. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a pattern matching system that determines how much a plurality of images accords to each other.
2. Description of the Related Art
A pattern matching system that determines how much a plurality of images compares to each other is known. In the known pattern matching system, the entire captured image is divided into smaller pieces and the luminance values of the individual pieces are compared to the luminance values of corresponding pieces in the same location of different image. The determination of how similar the compared images are to one another is based on the number of corresponding pieces that have the same luminance values. In such a pattern matching method, it is difficult to carry out the pattern matching accurately when the brightness of the images varies substantially.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a pattern matching system that accurately carries out the pattern matching for images with a wide variation in brightness.
According to the present invention, a pattern matching system, comprising a receiver, a comparison block, a calculation block, an output block, a ratio reading block, and a controller, is provided. The pattern matching system outputs a likeness value. The likeness value indicates how much a first and second image accords to each other. The receiver receives a first and second image signal corresponding to the first and second images, respectively, as an area signal. The area signal comprises first and second color signal components or luminance and chrominance difference signal components corresponding to the color of a pattern area of which the first and second images are comprised. The comparison block compares signal levels of the area signals corresponding to the pattern areas at the relatively same location of the first and second images. The calculation block calculates the likeness value. The likeness value varies according to the number of the pattern areas where the absolute value of the difference between the compared signal levels of the area signal of the first and second images is less than a predetermined standard value. The output block outputs the likeness value. The ratio reading block reads an amplification ratio by which the first and second image signals are amplified. The controller changes the type of the signal components of the area signal used for the comparison by the comparison block and used for the calculation of the likeness value by the calculation block.
Further, the controller orders the comparison block and the calculation block to compare signal levels and to calculate the likeness value, respectively, using only the first color signal component or the luminance signal component when the amplification ratio is greater than a predetermined threshold value. The controller orders the comparison block and the calculation block to compare signal levels and to calculate the likeness value, respectively, using the first and second color signal components or the luminance and chrominance difference signal components when the amplification ratio is less than a predetermined threshold value.
According to the present invention, a pattern matching system, comprising an image signal generator, a detection block, a selection block, and a pattern matching block, is provided. The pattern matching system estimates how similar a first and second image are to one another. The image signal generator generates plural types of image signals corresponding to the first and second images. The detection block detects the brightness of the first and second image. The selection block selects a number of different types of the image signals for pattern matching based on the detected brightness so that an increase in the number of the selected types is directly proportional to the detected brightness. The pattern matching block carries out pattern matching of the first and second image using the selected type of image signal.
Further, the selection block selects a singular type of the image signal when the detected brightness is less than a predetermined brightness.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and advantages of the present invention will be better understood from the following description, with reference to the accompanying drawings in which:
FIG. 1 is a block diagram showing the internal structure of a digital camera having a pattern matching system of a first embodiment of the present invention;
FIG. 2 is a block diagram showing the structure of the light-receiving surface of the imaging device;
FIG. 3 is a block diagram showing the internal structure of the DSP of a first embodiment;
FIG. 4 is a block diagram showing the internal structure of the pursuit block of a first embodiment;
FIG. 5 shows the light-receiving surface for explaining the form of the scanning area comprising pixel blocks;
FIG. 6 shows the structure of the ERA of the imaging device;
FIG. 7 shows a location of the CA 1 relative to the SA;
FIG. 8 shows a location of the CA 2 relative to the SA;
FIG. 9 shows a location of the CA 3 relative to the SA;
FIG. 10 shows a location of the CA 4 relative to the SA;
FIG. 11 shows a location of the CA 5 relative to the SA;
FIG. 12 shows a location of the CA 6 relative to the SA;
FIG. 13 shows a location of the CA 7 relative to the SA;
FIG. 14 shows a location of the CA 8 relative to the SA;
FIG. 15 shows an example of signal level of the green signal components of the pixel blocks included in the SA
FIG. 16 shows the green signal components of the pixel blocks described in FIG. 15 that have been converted to binary values;
FIG. 17 shows an example of the green signal components of the pixel blocks included in the CA 1 that have been converted to binary values;
FIG. 18 is a first flowchart explaining the process for designation of the scanning area carried out by the pursuit block;
FIG. 19 is a second flowchart explaining the process for designation of the scanning area carried out by the pursuit block;
FIG. 20 is a flowchart explaining the process for a first determination carried out by the pursuit block; and
FIG. 21 is a flowchart explaining the process for a second determination carried out by the pursuit block.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is described below with reference to the first and second embodiments shown in the drawings.
In FIG. 1 , a digital camera 10 comprises a photographic optical system 11 , an imaging device 12 , an analog front end (AFE) 13 , a digital signal processor (DSP) 14 , an input block 15 , a zooming driver 16 , a focusing driver 17 , and other components.
The photographic optical system 11 is optically connected to the imaging device 12 . An optical image of an object through the photographic optical system 11 is incident to the light-receiving surface of the imaging device 12 . The imaging device 12 is, for example, a CCD area sensor. When the imaging device 12 captures the optical image of the object upon its light-receiving surface, the imaging device 12 generates an image signal corresponding to the captured optical image.
The photographic optical system 11 comprises plural lenses, including a zoom lens 11 a and a focus lens 11 b . The zoom lens 11 a and the focus lens 11 b are movable along the optical axis of the photographic optical system 11 .
The zoom lens 11 a and the focus lens 11 b form a zoom optical system. The focal length of the photographic optical system 11 is adjusted by moving the zoom lens 11 a and the focus lens 11 b in relationship to each other. An optical image of an object can be focused on the light-receiving surface of the imaging device 12 by moving the focus lens 11 b.
The zoom lens 11 a and the focus lens 11 b can be moved along the optical axis by the manual operation of a user. In addition, the zoom lens 11 a and the focus lens 11 b can also be moved by the zooming driver 16 . In addition, the focus lens 11 b can be moved by the focusing driver 17 for the focus adjustment. Incidentally, the focus adjustment is automatically carried out when an auto focus function, as described later, is commenced.
A diaphragm 18 and a shutter 19 are mounted between the photographic optical system 11 and the imaging device 12 . The intensity of light made incident on the light-receiving surface of the imaging device 12 can be varied by adjusting the aperture ratio of the diaphragm 18 . An optical image reaches the light-receiving surface by opening the shutter 19 , and an optical image is shielded from the light-receiving surface by closing the shutter 19 . A diaphragm-driver 20 drives the diaphragm 18 so that the aperture ratio can be adjusted. A shutter-driver 21 drives the shutter 19 so that the shutter 19 can be opened and closed.
Incidentally, the zooming driver 16 , the focusing driver 17 , the diaphragm driver 20 , and the shutter driver 21 are all connected to the DSP 14 . The DSP 14 controls the operations of the zooming driver 16 , the focusing driver 17 , the diaphragm driver 20 , and the shutter driver 21 .
The imaging device 12 is electrically connected to the DSP 14 via the AFE 13 . A clock signal is sent from the DSP 14 to the AFE 13 , which generates a frame signal and an imaging device driving signal based on the received clock signal. The imaging device driving signal is sent to the imaging device 12 . The imaging device 12 is driven, based on the imaging device driving signal, to generate an image signal that is synchronized with the frame signal.
As shown in FIG. 2 , a plurality of pixels 12 p are arranged in a matrix on the light-receiving surface of the imaging device 12 . Each pixel 12 p within an effective receiving area, hereinafter referred to as an ERA, is covered with one of either a red, green, or blue color filter. The red, green, and blue color filters are arranged according to the Bayer color array.
A red pixel 12 pr which is covered with the red color filter generates a red signal charge according to the intensity of the red light component incident to the red pixel 12 pr . A green pixel 12 pg which is covered with the green color filter generates a green signal charge according to the intensity of the green light component incident to the green pixel 12 pg . A blue pixel 12 pb which is covered with the blue color filter generates a blue signal charge according to the intensity of the blue light component incident to the blue pixel 12 pb.
Incidentally, the imaging device 12 comprises vertical CCDs 12 v , a horizontal CCD 12 h , and an output block 12 o . The red, green, and blue signal charges are transmitted in order to the output block 12 o through the vertical and horizontal CCDs 12 v , 12 h . The output block 12 o converts the red, green, blue signal charges into red, green, and blue pixel signals that are potential signals, respectively. Incidentally, the image signal comprises red, green, and blue pixel signals.
The generated image signal is sent to the AFE 13 (see FIG. 1 ). The AFE 13 carries out correlated double sampling on the image signal and amplifies the image signal by an amplification ratio (or gain) that is designated by the DSP 14 . Next, the image signal is converted to image data, which is digital data, and is sent to the DSP 14 .
The DSP 14 is connected to a dynamic random access memory (DRAM) 22 , which is used as a work memory for the signal processing that is carried out by the DSP 14 . The image data received by the DSP 14 is temporarily stored in the DRAM 22 . The DSP 14 carries out predetermined data processing on the image data stored in the DRAM 22 .
The DSP 14 is connected to a monitor 23 . The image data, having undergone predetermined signal processing, is sent to the monitor 23 that is able to display an image corresponding to the received image data.
The DSP 14 is connected to a card-interface 24 that can be connected to a memory card (not depicted). When a release operation is carried out, as described later, the image data, having undergone predetermined data processing, is stored in the memory card.
The DSP 14 is connected to the input block 15 , where a user inputs operational commands. The input block 15 comprises a release button (not depicted), a multi-functional cross-key (not depicted), a power button (not depicted), and other buttons. The DSP 14 orders each component of the digital camera 10 to carry out a necessary operation according to a user's command input to the input block 15 .
For example, by depressing the release button halfway, a first switch (not depicted) is switched on, and exposure adjustment and focus adjustment are then carried out.
In the exposure adjustment, adjustment of the aperture ratio of the diaphragm 18 , adjustment of shutter speed, and the gain adjustment of the image data by the AFE 13 , are carried out. For the gain adjustment, the DSP 14 designates the amplification ratio. For the designation of the amplification ratio, the DSP 14 generates luminance data corresponding to each pixel based on red, green, and blue pixel signals. The amplification ratio is designated so that the average data level of luminance data corresponding to an image signal is equal to a predetermined data level. Consequently, when the intensity of light incident to the light-receiving surface is low, the DSP 14 designates a high amplification ratio. Then, the AFE 13 amplifies the image signal by the high amplification ratio. In the focus adjustment, the position of the focus lens 11 b is adjusted so that an optical image of the object can be focused on the light-receiving surface.
Further, by fully depressing the release button, a second switch (not depicted) is switched on. Then, the shutter 19 is driven so as to open and close, and the imaging device 12 is driven so as to capture a static optical image.
Next, the internal structure of the DSP 14 is explained below, using FIG. 3 . The DSP 14 comprises a first data processing block 14 p 1 , a second data processing block 14 p 2 , a pursuit block 30 , an AF adjustment block 14 a , and a control block 14 c.
The image data sent from the AFE 13 is input to the first data processing block 14 p 1 , which stores the received image data in the DRAM 22 . In addition, the first data processing block 14 p 1 carries out predetermined data processing, such as color interpolation processing, white balance processing, and luminance data generation processing on the stored image data. The first data processing block 14 p 1 then sends the image data, after having undergone predetermined data processing, to the second data processing block 14 p 2 .
The second data processing block 14 p 2 carries out predetermined data processing, such as cramp processing and blanking processing, on the received image data. Afterwards, the second data processing block 14 p 2 sends the image data to the monitor 23 or the memory card via the card-interface 24 .
The first data processing block 14 p 1 also sends the image data to the pursuit block 30 and the AF adjustment block 14 a . Based on the received image data, the pursuit block 30 and the AF adjustment block 14 a determine, in cooperation with each other, the position of the focus lens 11 b so that a desired object is brought into focus on the light-receiving surface of the imaging device 12 .
The pursuit block 30 designates one partial area of the entire captured image as a scanning area, hereinafter referred to as the SA. The SA is used for capturing an optical image of an object that is desired by the user to be in focus on the light-receiving surface. If the targeted object, which is the object desired to be in focus, moves within the captured image, the pursuit block 30 pursues the targeted object by sequentially re-designating a new partial area where the targeted object has moved, effectively updating the SA.
The AF adjustment block 14 a determines the position of the focus lens 11 b so that an optical image captured by the SA is in focus. Incidentally, the position of the focus lens 11 b is determined according to the contrast detection method.
The digital camera 10 has both normal auto focus and pursuit auto focus functions. By carrying out the normal auto focus function, an object that is located in a fixed partial area of the entire captured image is brought into focus. By carrying out the pursuit auto focus function, an object that moves within the entire captured image is brought into focus. Either the normal auto focus function or the pursuit auto focus function is selected by an operational command to the input block 15 .
An input signal that corresponds to an operational command input to the input block 15 is sent from the input block 15 to the control block 14 c . The control block 14 c controls the first data processing block 14 p 1 , the second data processing block 14 p 2 , the pursuit block 30 , the AF adjustment block 14 a , and each component of the digital camera 10 according to the received input signal.
For example, in the exposure adjustment the control block 14 c controls both the diaphragm driver 20 to drive the diaphragm 18 and the shutter driver 21 to open and close the shutter 19 .
Further, the control block 14 c controls the focusing driver 17 to re-position the focus lens 11 b in the focus adjustment. In the focus adjustment, the control block 14 c receives lens position data corresponding to the position of the focus lens 11 b , as determined by the AF adjustment block 14 a . The control block 14 c controls the focusing driver 17 based on the received lens position data.
Further, the control block 14 c designates the amplification ratio used for amplification of the image signal by the AFE 13 . In addition, when the pursuit auto focus function is carried out, the control block 14 c determines whether or not the designated amplification ratio is greater than a first threshold value. When the amplification ratio is greater than the first threshold value, the control block 14 c orders the pursuit block 30 to pursue the targeted object using the green pixel signal components in the image data. On the other hand, when the amplification ratio is less than the first threshold value, the control block 14 c orders the pursuit block 30 to pursue the targeted object using the red, green, and blue pixel signal components in the image data.
The brighter the optical image of the object, the lower the designated amplification ratio, in general. Accordingly, when the optical image of the object is bright enough to designate an amplification ratio that is less than the first amplification value, the pursuit of the targeted object is carried out using signal components corresponding to red, green, and blue color components. On the other hand, when the optical image of the object is dark enough to designate an amplification ratio that is greater than the first amplification value, the pursuit of the targeted object is carried out using only one signal component that corresponds to the green color component.
Next, the structure and operation of the pursuit block 30 are explained in detail below, using FIG. 4 . The pursuit block 30 comprises a first setting block 31 , a second setting block 32 , a recognition block 33 , and a third setting block 34 . Incidentally, each component is controlled by the control block 14 c.
On carrying out the focusing adjustment, the first setting block 31 initially designates an SA on the light-receiving surface. As shown in FIG. 5 , the SA comprises thirty two pixel blocks 12 b . In addition, the form of the SA is in the shape of a cross shape, created by removing four corner blocks from a rectangle comprising pixel blocks 12 b of six columns across by six rows down.
As shown in FIG. 6 , the pixel block 12 b is a unit of area representing 1/400 of the ERA, which has been equally partitioned into twenty rows and twenty columns. The pixel block 12 b is equally partitioned itself, so that the pixel block 12 b comprises one hundred pixels arranged in a matrix of ten rows by ten columns. Incidentally, the pattern matching described later is carried out based on a signal component corresponding to the pixel block 12 b in the pursuit function that minimizes processing time.
The first setting block 31 determines the initial location of the SA so that the centers of both the ERA of the imaging device 12 and the SA agree with each other (see FIG. 5 ).
Incidentally, the pixel blocks 12 b on the ERA are separated from each other by borderlines formed by a plurality of vertical and horizontal lines demarcating the columns and rows created from partitioning the ERA. One of the many intersection points formed by the crosshairs of intersecting vertical and horizontal borderlines can be decided upon as the center of the SA, and the location of the initial SA is designated from the location of the center of the SA. The location of the SA is designated based on the operational command which is input to the input block 15 .
Data corresponding to the initially designated SA is sent to the second setting block 32 . The second setting block 32 designates eight candidate areas which are of the same size as the current SA, but whose locations are different and determined by displacing the current SA by the same magnitude, but in eight different directions.
The first˜eighth directions are predetermined as the eight directions in which to displace the SA to designate the candidate areas. The upper, upper left, left, lower left, lower, lower right, right, and upper right directions are predetermined as the first, second, third, fourth, fifth, sixth, seventh, and eighth directions, respectively, as in FIG. 5 .
One pixel block 12 b is predetermined to correspond to the distance from the SA to each candidate area. Incidentally, the locations of first˜eighth candidate areas are explained below.
A candidate area displaced through one pixel block 12 b from the SA in the first direction is designated to be the first candidate area, hereinafter referred to as CA 1 , shown in FIG. 7 . A candidate area displaced through one pixel block 12 b from the SA in the second direction is designated to be the second candidate area, hereinafter referred to as CA 2 , shown in FIG. 8 . A candidate area displaced through one pixel block 12 b from the SA in the third direction is designated to be the third candidate area, hereinafter referred to as CA 3 , shown in FIG. 9 . A candidate area displaced through one pixel block 12 b from the SA in the fourth direction is designated to be the fourth candidate area, hereinafter referred to as CA 4 , shown in FIG. 10 . A candidate area displaced through one pixel block 12 b from the SA in the fifth direction is designated to be the fifth candidate area, hereinafter referred to as CA 5 , shown in FIG. 11 . A candidate area displaced through one pixel block 12 b from the SA in the sixth direction is designated to be the sixth candidate area, hereinafter referred to as CA 6 , shown in FIG. 12 . A candidate area displaced through one pixel block 12 b from the SA in the seventh direction is designated to be the seventh candidate area, hereinafter referred to as CA 7 , shown in FIG. 13 . A candidate area displaced through one pixel block 12 b from the SA in the eighth direction is designated to be the eighth candidate area, hereinafter referred to as CA 8 , shown in FIG. 14 .
Data corresponding to the designated CA 1 ˜CA 8 is sent to the recognition block 33 , as is data corresponding to the SA initially designated by the first setting block 32 . In addition, the red, green, and blue pixel signal components for each pixel in the image data are sent to the recognition block 33 from the first data processing block 14 p 1 .
The recognition block 33 generates either a green signal component or red, green, and blue signal components for each pixel block 12 b comprising the SA and the CA 1 ˜CA 8 , comprises based on one frame of image data. Incidentally, only the green signal component is generated for the pixel blocks 12 b when the amplification ratio is greater than the first threshold value. The red, green, and blue signal components of the pixel blocks 12 b are generated when the amplification ratio is less than the first threshold value.
The green signal component of the pixel blocks 12 b is calculated by averaging the green pixel signals of the pixels 12 p in the pixel blocks 12 b comprising the SA and the CA 1 ˜CA 8 . The red, green, and blue pixel block signal components of the pixel block 12 b are calculated by averaging the red, green, and blue pixel signals in the pixel blocks 12 b comprising the SA and the CA 1 ˜CA 8 , respectively.
For example, assuming the image data sent at a first point in time contains the green signal levels 120 , 30 , 60 , 55 , 70 , 110 , 100 , 70 , 40 , 105 , 40 , 85 , 95 , 65 , 25 , 40 , 150 , 120 , 60 , 30 , 25 , 45 , 100 , 120 , 110 , 95 , 80 , 50 , 90 , 75 , 80 , and 20 for the pixel blocks 12 b comprising the SA from left to right and from top to bottom, respectively, these signal levels are calculated as the green signal components corresponding to the SA at the first point in time (see FIG. 15 ).
The green signal components or the red, green, and blue signal components for the pixel blocks 12 b of the SA and the CA 1 ˜CA 8 are converted to binary values, for example 0 or 1, based on the generated signal components. For the conversion to binary values, an average value of the signal levels of each color pixel signal components for the pixel blocks 12 b comprising the SA and the CA 1 ˜CA 8 is calculated, and each individual signal level is subsequently compared to the average signal level. If a signal level is higher than the average signal level, the signal level is converted to 1. If a signal level is lower than the average signal level, the signal level is converted to 0.
For example, the average of the signal levels of the green signal components of the pixel blocks 12 b in the SA shown in FIG. 15 is 73.75. In the conversion to binary values, the signal level of the green signal components for the pixel blocks 12 b in the SA are converted to 1, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, and 0 from left to right and from top to bottom, respectively (see FIG. 16 ). Incidentally, the signal levels of the red, green, and blue signal components of the pixel blocks 12 b are converted to binary values in a similar manner.
Data corresponding to the green signal components of the pixel blocks 12 b that have been converted to binary values is sent to the third setting block 34 , which infers to which of the CA 1 ˜CA 8 the target object, which has been captured by the SA at the current point in time, is moved to at the subsequent time of image capture.
Incidentally, the inference is carried out based on the green signal components of the pixel blocks 12 b in the SA that have been converted to binary values at one point in time, and the green signal components of the pixel blocks 12 b in the CA 1 ˜CA 8 that are generated and converted to binary values from a different frame of image data captured at as subsequent point in time.
The calculation of the first˜eighth likeness values is prerequisite to determining which candidate area is selected from the CA 1 ˜CA 8 . The determination of the selected candidate area based on the calculated first˜eighth likeness values is described in detail below.
The first˜eighth likeness values are calculated values that indicate how similar the image captured in the SA is to the images captured in the CA 1 ˜CA 8 at the time of subsequent image capture. To calculate each likeness value, two green signal components converted to binary values for pixel blocks 12 b at the relatively same location in both the SA and the CA 1 ˜CA 8 are compared to each other, and it is determined whether or not they are equal to each other. The likeness value is the number of combinations of green signal components compared to one another whose signal levels are unequal. Accordingly, the lower the likeness value, the greater the similarity inferred between the images captured in the SA and the candidate area.
The third setting block 34 comprises an exclusive-or circuit (not depicted). The green signal components of the pixel blocks 12 b at the relatively same location in the SA and the CA 1 that have been converted to binary values are input to the exclusive-or circuit. When the green signal components of the pixel blocks 12 b at the relatively same location in the SA and the CA 1 that have been converted to binary values are equal to each other, the exclusive-or circuit outputs 0. On the other hand, when the green signal components of the pixel blocks 12 b at the relatively same location in the SA and the CA 1 that have been converted to binary values are unequal to each other, the exclusive-or circuit outputs 1.
For example, the green signal components for the pixel blocks 12 b in the CA 1 that have been converted to binary values are 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 1, 1, and 0 from left to right and from top to bottom, respectively, as shown in FIG. 17 . When the green signal components in the top row and leftmost column for the pixel block 12 b in the SA and the CA 1 that have been converted to binary values are input to the exclusive-or circuit, the exclusive-or circuit outputs 1. Similarly, when the green signal components in the top row and second to leftmost column for the pixel block 12 b in the SA and the CA 1 that have been converted to binary value are input to the exclusive-or circuit, the exclusive-or circuit outputs 0. Hereinafter, similarly, when the combinations of the green signal components converted to binary values of the pixel block 12 b in the SA and the CA 1 at the relatively same location are input to the exclusive-or circuit from left to right and from top to bottom, the exclusive-or circuit outputs 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, and 0, respectively. The number of times the exclusive-or circuit outputs 1 is counted and saved as a first likeness value, hereinafter referred to as U(exor).
Similarly, the SA and the CA 2 are compared to each other, and the second likeness value, hereinafter referred to as UL(exor), is calculated. Similarly, the SA and the CA 3 are compared to each other, and the third likeness value, hereinafter referred to as L(exor), is calculated. Similarly, the SA and the CA 4 are compared to each other, and the fourth likeness value, hereinafter referred to as DL(exor), is calculated. Similarly, the SA and the CA 5 are compared to each other, and the fifth likeness value, hereinafter referred to as D(exor), is calculated. Similarly, the SA and the CA 6 are compared to each other, and the sixth likeness value, hereinafter referred to as DR(exor), is calculated. Similarly, the SA and the CA 7 are compared to each other, and the seventh likeness value, hereinafter referred to as R(exor), is calculated. Similarly, the SA and the CA 8 are compared to each other, and the eighth likeness value, hereinafter referred to as UR(exor), is calculated.
The third setting block 34 determines the lowest likeness value among U(exor), UL(exor), L(exor), DL(exor), D(exor), DR(exor), R(exor), and UR(exor). The candidate area of which the likeness value is the lowest is determined and selected by the third setting block 34 as the area where the targeted object has moved from the scanning area. The selected candidate area is re-designated as the new scanning area.
Incidentally, when the recognition block 33 generates the red, green, and blue signal components of the pixel blocks 12 b , the first˜eighth red likeness values, first˜eighth green likeness values, and first˜eighth blue likeness values are calculated based on the signal level of the red, green, and blue signal components of the pixel blocks 12 b , similar to the above. Next, the first red, green, and blue likeness values are summed up and calculated as the U(exor). The UL(exor), L(exor), DL(exor), D(exor), DR(exor), R(exor), and UR(exor) are calculated similar to the U(exor). Lastly, the third setting block 34 determines the lowest likeness value among the U(exor), UL(exor), L(exor), DL(exor), D(exor), DR(exor), R(exor), and UR(exor). The candidate area of which likeness value is the lowest is determined and selected by the third setting block 34 as the area where the targeted object has moved from the scanning area. The selected candidate area is re-designated as the new scanning area.
Incidentally, when the normal auto focus function is carried out, only the first setting block 31 in the pursuit block 30 is functional, while the second setting block 32 , the recognition block 33 , and the third setting block 34 are suspended.
Data corresponding to the SA initially designated by the first setting block 31 is sent to the AF adjustment block 14 a through the recognition block 33 and the third setting block 34 . Incidentally, the initially designated SA remains the SA in the normal auto focus function, dissimilar to the pursuit auto focus function.
Next, the process for designation of the scanning area carried out by the pursuit block 30 is explained using the flowchart of FIGS. 18 and 19 .
The process for designation of the scanning area starts when the release button is depressed halfway, effectively switching on the pursuit auto focus function. Incidentally, the process for designation of the scanning area is repeated until the power button is switched off or the pursuit auto focus function is switched off.
At step S 100 , the SA is initially designated. The SA is designated so that the center of the SA is located at a point in accordance to a user's command input.
At step S 101 subsequent to step S 100 , one frame of image data is received. After receiving the image data, the process proceeds to step S 102 , where the CA 1 ˜CA 8 are designated based on the designated SA.
After designation of the CA 1 ˜CA 8 , the process proceeds to step S 103 , where the control block 14 c reads the amplification ratio used in the AFE 13 . At step S 104 subsequent to step S 103 , the amplification ratio is compared to the first threshold value.
When the amplification ratio is greater than the first threshold value, the process proceeds to step S 105 , where the green signal components of the pixel blocks 12 b in the SA are generated based on the latest received image data. On the other hand, when the amplification ratio is less than the first threshold value, the process proceeds to step S 106 , where the red, green, and blue signal components of the pixel blocks 12 b in the SA are generated based on the latest received image data.
After either step S 105 or step S 106 is complete, the process proceeds to step S 107 , where the green signal components generated at step S 105 or the red, green, and blue signal components generated at step S 106 are converted to binary values.
After conversion to binary values, the process proceeds to step S 108 , where the pursuit block 30 receives a frame of subsequently generated image data. At step S 109 subsequent to step S 108 , the amplification ratio of the latest received image data is compared to the first threshold value.
When the amplification ratio is greater than the first threshold value, the process proceeds to step S 110 , where the green signal components of the pixel blocks 12 b in the CA 1 ˜CA 8 are generated based on the latest received image data. On the other hand, when the amplification ratio is less than the first threshold value, the process proceeds to step S 111 , where the red, green, and blue signal components of the pixel blocks 12 b in the CA 1 ˜CA 8 are generated based on the latest received image data.
After either step S 110 or step S 111 is complete, the process proceeds to step S 112 , where the green signal components generated at step S 110 or the red, green, and blue signal components generated at step S 111 are converted to binary values.
After conversion to binary values, the process proceeds to step S 113 , where the U(exor), UL(exor), L(exor), DL(exor), D(exor), DR(exor), R(exor), and UR(exor) are calculated based on the color signal components of the pixel blocks 12 b in the SA and the CA 1 ˜CA 8 that have been converted to binary values.
At step S 114 subsequent to step S 113 , the candidate area, of which the likeness value is the lowest among the U(exor), UL(exor), L(exor), DL(exor), D(exor), DR(exor), R(exor), and UR(exor), is designated as the new SA.
After completion of step S 114 , the process returns to step S 102 , and steps S 102 ˜ 114 are repeated.
In the above first embodiment, the signal component used for the pattern matching can be changed to either the singular green signal component, or the aggregate of the red, green, and blue signal components, according to the amplification ratio by the AFE 13 based on the brightness of the object.
In general, the accuracy of pattern matching can be improved by using many different color signal components. On the other hand, when the signal level of the pixel signal prior to the amplification is low because of a low amount of light received by a pixel 12 p , the S/N is also decreased accordingly. In such a case, the accuracy of pattern matching may deteriorate by using many different color signal components.
It is general knowledge for a prior digital camera to lower an amplification ratio when an optical image of an object is bright and to raise the amplification ratio when the optical image is dark. So, by changing the color signal components used for the pattern matching, according to the amplification ratio, the capability exists to carry out accurate pattern matching for an object whether the optical image of the object is bright or dark.
Next, a pattern matching system of the second embodiment is explained below, using FIGS. 20 , 21 . The primary difference between the second embodiment and the first embodiment, which is explained below, is the type of signal component used for pattern matching. Incidentally, the same symbols are used for the structures that are comparable to those in the first embodiment.
The structures and functions of the digital camera of the second embodiment, with the exception of the DSP, are the same as those of the first embodiment. The functions of the first data processing block 140 p 1 and a pursuit block 300 of the DSP 300 are especially different from those of the first embodiment (see FIG. 20 ).
The first data processing block 140 p 1 carries out chrominance difference data generation processing in addition to the predetermined data processing of the first embodiment. Incidentally, by luminance data generation processing and chrominance difference data generation processing, data corresponding to luminance, hereinafter referred to as Y, and data corresponding to chrominance difference, hereinafter referred to as Cr and Cb are generated. Further, the first data processing block 140 p 1 sends the image data, having undergone predetermined data processing, to the second data processing block 140 p 2 .
The second data processing block 140 p 2 carries out predetermined data processing similar to the first embodiment.
The first data processing block 140 p 1 sends the image data to the pursuit block 300 . Based on the received image data, the pursuit block 300 pursues the targeted object.
In the pursuit block 300 , only the functions of the recognition block 330 and the third setting block 340 are different from those of the first embodiment (see FIG. 21 ). The first setting block 31 initially designates an SA, similar to the first embodiment. In addition, the second setting block designates the CA 1 ˜CA 8 .
Data corresponding to the initially designated SA and the designated CA 1 ˜CA 8 is sent from the first setting block 31 and the second setting block 32 , respectively, to the recognition block 330 , similar to the first embodiment. In addition, data corresponding to the Y and the Cr/Cb of each pixel 12 p are sent from the first data processing block 140 p 1 to the recognition block 330 .
The recognition block 330 generates the Y and Cr/Cb of each pixel block 12 b comprising the SA and the CA 1 ˜CA 8 . Incidentally, only the Y of the pixel blocks 12 b is generated when the amplification ratio is greater than the first threshold value. However, both Y and Cr/Cb of the pixel blocks 12 b are generated when the amplification ratio is less than the first threshold value.
The Y of the pixel blocks 12 b is calculated by averaging the Y of the pixels 12 p in the pixel blocks 12 b comprising the SA and the CA 1 ˜CA 8 . The Y and Cr/Cb of the pixel blocks 12 b are calculated by averaging the Y and Cr/Cb of the pixel blocks 12 b comprising the SA and the CA 1 ˜CA 8 , respectively.
The singular Y or the combination of Y and Cr/Cb of the pixel blocks 12 b of the SA and the CA 1 ˜CA 8 are converted to binary values.
Data corresponding to the singular Y or the combination of Y and Cr/Cb of the pixel blocks 12 b that have been converted to binary values is sent to the third setting block 340 , which infers to which one of the CA 1 ˜CA 8 the target object has moved at the time of a captured image that is subsequent to target object's previous capture by the SA at an earlier point in time.
Incidentally, the inference is carried out based on the singular Y or the combination of Y and Cr/Cb of the pixel blocks 12 b in the SA that were converted to binary values, at one point in time; and the singular Y or the combination of Y and Cr/Cb of the pixel blocks 12 b in the CA 1 ˜CA 8 that were converted to binary values, at subsequent point in time.
The U(exor), UL(exor), L(exor), DL(exor), D(exor), DR(exor), R(exor), and UR(exor) are calculated similar to the first embodiment, and one candidate area is selected from the CA 1 ˜CA 8 based on the U(exor), UL(exor), L(exor), DL(exor), D(exor), DR(exor), R(exor), and UR(exor).
In the above second embodiment, the signal component used for the pattern matching can be changed to either the singular Y, or the combination of Y and Cr/Cb, according to the amplification ratio determined by the AFE 13 based on the brightness of the object being pursued. Accordingly, accurate pattern matching can be accomplished for an object whether an optical image of the object is bright or dark, similar to the first embodiment.
In addition, in the above first and second embodiments, pattern matching can be carried out with greater stability because the signal components of each pixel block 12 b are converted to binary values. For example, when the SA or a candidate area receives light emitted from a light source generating flicker, such as fluorescent light, a portion of the calculated likeness value may not accord to the actual optical image. However, because influence of such flicker is reduced upon the conversion to binary values, pattern matching can be carried out with greater stability.
In the first embodiment, when the amplification ratio is less than the first threshold value, the red, green and blue signal components are used for the pattern matching. However, the pattern matching may be carried out using only the red and green signal components, or only the green and blue signal components, when the amplification ratio is in the range between the first threshold value and a second threshold value that is less than the first threshold value. In addition, when the amplification ratio is less than the second threshold value, three different color signal components may be used. Even if only two different color signal components are used, pattern matching is still more accurate than that using only the green signal component.
In the second embodiment, when the amplification ratio is less than the first threshold value, the Y and Cr/Cb are used for the pattern matching. However, the pattern matching may be carried out using the Y and only one of either the Cr or Cb.
For pattern matching, only the green signal component is used when the amplification ratio is greater than the first threshold value, and the red, green, and blue signal components are used when the amplification ratio is less than the first threshold value, in the first embodiment. However, the type of the signal component used for pattern matching may be changed according to the amplification ratio.
For example, when the amplification ratio is great, the red, green, and blue signal components can be used for pattern matching. Generally, when the amplification ratio is great, it is preferable to use a singular signal component for the pattern matching as described in the above embodiments. However, if the color component of an optical image of an object is extremely partial, the accuracy of pattern matching using a singular color signal component may deteriorate. In such a case, it is preferable to increase the type of the color signal components used for the pattern matching, according to the amplification ratio.
Similarly, for pattern matching, only the Y is used when the amplification ratio is greater than the first threshold value, while both the Y and Cr/Cb are used when the amplification ratio is less than the first threshold value, in the second embodiment. However, the type of the signal component used for pattern matching may be changed according to the amplification ratio.
The number of the pixel blocks 12 b comprising the SA and the candidate area is thirty two, in the above first and second embodiments. However, any numbers are adaptable. In addition, the shape of the SA and the candidate area is in the shape of a cross, in the first and second embodiments. However, any shape is adaptable.
One direction in which the targeted object is moved is determined from the first˜eighth directions in the above first and second embodiments. However, one direction may be determined from a plurality of directions.
One pixel block 12 b corresponds to the magnitude of displacement from the SA to the CA 1 ˜CA 8 , in the above first and second embodiments. However, any number of pixel blocks 12 b can correspond to the magnitude of displacement.
The signal components of the pixel blocks 12 b comprising the SA and the CA 1 ˜CA 8 are converted to binary values in the above first and second embodiments. However, the signal components can be converted to any number of different levels, or, such conversions may not be carried out at all. Of course, the effect as described above is achieved by carrying out the conversion to binary values or into values of a level that is different from that of binary values.
The exclusive-or circuit outputs 0 when the signal components converted to binary value of the pixel blocks 12 b at the relatively same location of the SA and the CA 1 ˜CA 8 are equal to each other, in the above first and second embodiments. However, an arithmetical circuit mounted in the third setting block 34 may output 0 when the absolute value of the difference between the converted or non-converted signal components of the pixel blocks 12 b at the relatively same location of the SA and the CA 1 ˜CA 8 is lower than a predetermined standard value. Also, the number of pixel blocks 12 b outputting 1 by the arithmetical circuit may be counted as the likeness value. Incidentally, the predetermined standard value is 0 in the above first and second embodiments.
The exclusive-or circuit is used in the above first and second embodiments to determine whether or not the signal components converted to binary values of the pixel blocks 12 b in the SA, and those of CA 1 ˜CA 8 are similar to each other. Another arithmetical circuit, such as an exclusive-nor circuit, can be used for the purpose of this determination.
The position of the focus lens 11 b where an object is brought into focus is determined according to the contrast detection method, in the above first and second embodiments. However, the position of the focus lens 11 b can be determined according to any other method, such as the phase difference detection method.
The primary color filters, which are red, green, and blue filters, are mounted on the imaging device 12 in the above first and second embodiments. However, any other type of color filter, such as a complementary color filter, is adaptable.
The pixels are arranged in a matrix within the ERA, in the above first and second embodiments. However, the arrangement of pixels is not restricted to a matrix and can be arranged in any two-dimensional pattern.
The auto focus functions are carried out for the targeted object pursued by the pursuit block 30 in the above first and second embodiments. However, the pursuit function utilized by the pursuit block 30 to pursue the movement of the targeted object can be adapted to another function. For example, a monitoring camera can display a moving targeted object and a mark showing the targeted object by being adapted to the monitoring camera. Or the exposure adjustment can be automatically carried out for a moving targeted object.
The pattern matching system is used for the pursuit function in the above first and second embodiments. However, the pattern matching system can be used for other functions, such as a face identification system.
Although the embodiments of the present invention have been described herein with reference to the accompanying drawings, obviously many modifications and changes may be made by those skilled in this art without departing from the scope of the invention.
The present disclosure relates to subject matter contained in Japanese Patent Application No. 2006-081218 (filed on Mar. 23, 2006), which is expressly incorporated herein, by reference, in its entirety. | A pattern matching system, comprising a receiver, a comparison block, a calculation block, an output block, a ratio reading block, and a controller, is provided. A likeness value indicates how much a first and second image accords to each other. The receiver receives first and second image signal corresponding to the first and second images as an area signal. The comparison block compares the signal levels of the area signals corresponding to the pattern areas at the relatively same location of the first and second images. The calculation block calculates the likeness value. The ratio reading block reads a amplification ratio by which the first and second image signals are amplified. The controller changes the type of the signal components of the area signal used for the comparison by the comparison block and the calculation of the likeness value by the calculation block. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates to the field of dynamic brakes for electric motors, and, more particularly, to an electronic braking circuit system and method for providing an electromotive braking force for an electric motor having no permanent magnets, for example, in an emergency situation such as a motion controller failure, or actuation of a limit switch by a driven member of a linear motor.
[0003] 2. Related Art
[0004] Braking of electric motors having permanent magnets typically is accomplished by shorting the motor coils, for example, through a resistor thereby applying a large load to the electromotive force generated in the motor's coils in the presence of permanent magnets. Of course, such a solution is not possible with motors having no permanent magnets. For example, according to U.S. Pat. No. 3,832,613, a permanent magnet motor is simply controlled by a dynamic brake 162 which takes advantage of the generator action of the motor to create a reverse torque for braking. Dynamic brakes for DC motors are also described in U.S. Pat. Nos. 3,786,329 and 4,767,970.
[0005] A method and system for braking an electric motor having no permanent magnets is described in U.S. Pat. No. 5,828,195. However, the braking system according to this patent incorporates position tracking sensors, which, inter alia, significantly increases the cost of the system. In addition, for braking a linear motor the sensors have to be mounted on the moving member, which requires special fixtures and expensive flex cables. The accuracy of the location of the sensor in relation to the specific motor parts is very critical, because a small displacement from the optimum position can significantly affect the braking performance or even cause acceleration of the motor.
[0006] It can be seen from above, that there exists in the art a requirement for a system and method, of braking without using any position tracking devices, for braking an electric motor having no permanent magnets.
[0007] Thus, it is one object of the present invention to provide a sensorless braking system for utilization in braking electric motors having no permanent magnets.
SUMMARY OF THE INVENTION
[0008] The problems and failures of the prior art are solved by the principles of the present invention, an electronic sensorless braking system which applies pulsed current to at least one phase coil of the motor for reversing and thereby braking motor movement (in the case of a linear motor) or rotation (in the case of a rotational motor).
[0009] In a first general aspect, the present invention provides a system for braking either a linear or rotary electric motor having no permanent magnets and having either a stator or a rotor with equally spaced teeth comprising:
at least one servo amplifier, having an output and current error signal; at least one motor phase coil connected said output; at least one electronic circuit responsive to said current error signal, and producing a current command required for braking; and means for said servo amplifier to use said current command to produce a current necessary for braking in said motor phase coil.
BRIEF DESCRIPTION OF DRAWINGS
[0014] FIG. 1 depicts a schematic view of an embodiment of a system, in accordance with the present invention;
[0015] FIG. 2 depicts a schematic view of a second embodiment of a system wherein a digital signal processor (DSP calculates the current error signal, in accordance with the present invention;
[0016] FIG. 3 depicts a method, or flowchart, in accordance with the present invention; and
[0017] FIG. 4 depicts the current error signal, the current command, and the current in the motor phase coil as a function of time during the braking process, in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Although certain embodiments of the present invention will be shown and described in detail, it should be understood that various changes and modifications may be made without departing from the scope of the appended claims. The scope of the present invention will in no way be limited to the number of constituting components, the materials thereof, the shapes thereof, the relative arrangement thereof, etc., and are disclosed simply as an example of an embodiment. The features and advantages of the present invention are illustrated in detail in the accompanying drawings, wherein like reference numerals refer to like elements throughout the drawings.
[0019] As a preface to the detailed description, it should be noted that, as used in this specification and the appended claims, the singular forms “a”, “an” and “the” include plural referents, unless the context clearly dictates otherwise.
[0020] The present invention is directed to the braking of an electric motor without permanent magnets in an emergency through the generation of an electromotive force opposite to the direction of motor motion. This braking is employed in the event motor motion must be rapidly ceased as a result of an emergency. Examples include but are not limited to motion controller system failure, limit switch actuation, line power failure, or any other emergency event which should trigger the braking force.
[0021] The present invention will be described in the context of an uncoupled variable reluctance linear motor used for moving a member from one end of a linear track to another. As used herein, the term uncoupled describes the arrangement where each phase of the motor produces magnetic flux that is for practical purposes not coupled to other phases. Such linear motors are typically utilized in robotic systems, for example, pick and place systems, in which a first linear motor moves a beam mounted to a sliding device along one axis and a second linear motor moves a carriage along the beam on an orthogonal axis so as to provide Cartesian movement of robotics end effector mounted on the carriage over a desired work area. The present invention is not limited to this use. It may also be used to brake many electric motor types, which have no permanent magnets. The present invention also is adaptable to rotary motors.
[0022] The first number of each element in a given figure represents the figure number where said element first appears. For a given element, the same element number is used in subsequent figures in which said element appears.
[0023] FIGS. 1 and 2 show a servo system controlled via a motion controller 110 . The motion controller 110 , using data from an encoder (not shown), provides a control signal (current command 116 ) to achieve a desired motor movement. In the event of an emergency, such as a motion controller system failure, a braking system is required for braking the motor. This braking system is the subject of this invention.
[0024] FIG. 1 further shows all signals used to generate the pulsing output current in a motor phase coil 120 necessary for braking. It also shows how the current error signal 122 is calculated: by subtraction of the current sense signal 124 from the current command signal 116 . This is the definition of the current error signal 122 used in the following detailed description. A dotted line indicates how the brake request signal 118 disconnects the motion controller 110 from the servo amplifier and connects the current command 116 from the output of the electronic circuit responsive to the current error signal 112 to the servo amplifier input.
[0025] With regards to FIG. 2 , in an embodiment, the current sense signal 124 is converted to digital signal by an analog to digital converter 226 connected to the digital signal processor (DSP) 220 . The Brake Signal request 118 is also connected to the DSP 220 . It initiates the braking process according to the flow chart shown in FIG. 3 . DSP 220 generates the current command signal 116 in response to the current error signal 124 . The embodiment uses a PWM servo amplifier power stage 224 , and the DSP 220 converts the current command signal 116 to the power stage control signal(s) 222 .
[0026] Referring now to FIGS. 3 and 4 , if there is an event which triggers an emergency brake request signal, control is switched from the normal operation of the motion control procedure, Step 312 , to the braking procedure, Step 340 , to provide a control signal for braking. The first step of braking procedure 340 is to determine if the brake request was just initiated, Step 314 , if so then produce a lower value of current command, Step 316 and wait for greater of rise time or the fall time, Step 318 . The next step is to calculate the current error, Step 320 . If the calculated current error is greater than or equal to zero then a lower level current command 116 is produced, Step 330 , else if the current error is less than zero a higher level current command 116 is produced, Step 324 . This procedure includes waiting for a specific period of time after each current command 116 change. This time is required in order for the circuit to avoid responding to the effect of the rise time 410 or fall time 412 of the current in the motor phase coils 120 on the current error signal 122 . It has to be at least as long as the rise time 410 when current command 116 changes to the higher value 414 , Step 328 , or at least as long as the fall time 412 of this current when current command 116 changes to the lower value 412 , Step 334 . This time can be found experimentally for each motor.
[0027] FIG. 4 illustrates the effect of the current rise time 410 and fall time 412 on the current error signal during the braking process. In this illustration, the current error 122 starts out above zero, and the current command 116 and the current in the motor phase coil are at their lower values. The current error signal eventually falls below zero and the current command 116 changes from a lower value 416 to a higher value 414 . In response to this, the phase current in the motor coil starts to increase. During the current rise time 410 , the current error signal 122 is positive. One may wait at least as long as the rise time 410 before responding to the change of current error signal in order to avoid continuous oscillation of the current command 116 . The current error signal returns to below zero when the current in the phase coil reaches its higher value.
[0028] When the current error signal 122 becomes greater than zero, the current command 116 changes from a higher value 414 to a lower value 416 . In response to this the phase current in the motor coil starts to decrease. During the current fall time 412 , current error signal 122 is negative. One may wait at least as long as the fall time 412 before responding to the change of current error signal in order to avoid continuous oscillation of the current command 116 . The current error signal returns to above zero when the current in the phase coil reaches its lower value.
[0029] The above description provides a basic description of the operation of the braking system. Numerous variations are appropriate to achieve variations in performance, reliability, size, ease of manufacturing, cost, and other design features. Moreover, with experimentation, different versions may better suit other specific applications. Other embodiments and applications of the present invention may come to mind by reading the above description of the present invention. Moreover, the scope of the present invention should only be deemed to be limited by the claims that follow. | System for braking either linear or rotary electric motor having no permanent magnets comprising at least one servo amplifier and an electronic circuit for generating a pulsed control signal for controlling the braking of the motor. The electronic circuit of the present invention may be responsive to any emergency such as loss of the line power, a motion controller failure, or actuation of a limit switch by a driven member. A method of braking is also disclosed. | 7 |
BACKGROUND OF THE INVENTION
The field of the invention is illumination with viewing mirror and the invention is particularly concerned with a lighted vanity mirror for the visor of an automobile which lights when tilted into the operative vertical position.
Vanity mirrors for mounting on the visors of automobiles are known and it is also known to illuminate these vanity mirrors. Dry cell batteries are used for the illumination circuits and the circuits are manually operated by off/on switches.
A problem with these prior art illuminated vanity mirrors is the failure to turn off the illumination and in a very short time the dry cell batteries expire and the bulbs no longer provide illumination.
SUMMARY OF THE INVENTION
Having in mind the limitations of the prior art, it is an object of the present invention to provide an illuminated vanity mirror which lights up only when in use.
Another object of the present invention is to provide an illuminated vanity mirror which does not light when the mirror is stored in a horizontal position.
Yet another object of the present invention is to provide an illuminated vanity mirror which does not light when the mirror is stored in an upside down position.
A principal object of the present invention is to provide an illuminated vanity mirror which lights up when in an operative, vertical, right side up position.
Still another object of the present invention is to provide an on/off switch in the illumination circuit which prevents the lighting circuits from engaging even when the vanity mirror is in the vertical position.
All of these objects are achieved by a lighting circuit having a conductive ball switch which completes the illumination circuit when the vanity mirror is moved to the vertical position and gravity pulls the ball from an inoperative to an operative position.
A manual switch presses against the ball in the off position to prevent contact. In the on position, the ball can make contact and complete the circuit only when gravity is sufficient to draw the ball into the operative position.
BRIEF DESCRIPTION ON THE DRAWINGS
The automatic lighted automobile vanity mirror and lighting circuit therefore is best described by reference to the drawings, wherein:
FIG. 1 is a front edge view of the vanity mirror of the present invention, showing the vanity case clamped to the sun visor of a vehicle;
FIG. 2 is a front view of the vanity mirror of FIG. 1;
FIG. 3 is a side view, taken on the line 3--3 of FIG. 2;
FIG. 4 is an enlarged vertical sectional view, taken on the line 4--4 of FIG. 2;
FIG. 5 is a fragmentary horizontal sectional view, taken on the staggered section line 5--5 of FIG. 4;
FIG. 6 is an enlarged fragmentary vertical sectional view, taken on the line 6--6 of FIG. 5;
FIG. 7 is a fragmentary vertical sectional view, taken on the line 7--7 of FIG. 5;
FIG. 8 is an isometric view of the switch ball ramp;
FIG. 9 is an isometric view of the ball switch bridging element; and
FIG. 10 is a schematic circuit diagram for the vanity mirror.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With particular reference to FIG. 1, the vanity case 2 is shown attached to an automobile sun visor 4 in the horizontal position by clamps 6 and 8.
The vanity case 2 has a lower base portion 10 and an upper mirror portion 12. Located on the upper mirror portion 12 is an on/off switch 14.
As seen in FIG. 2, the sun visor 4 has a support arm 16 about which the sun visor and vanity case rotate from a horizontal stowed position to a vertical position.
FIG. 2 also shows the mirror 18 and the lenses 20 and 22 and in the partial cut-away portions of the lenses, the bulbs 24 and 26 are exposed.
Hinges 28 and 30 are shown at the top of FIG. 2 about which base 10 and mirror portion 12 rotate.
FIG. 3 shows the vanity case and sun visor in the vertical position with an arrow 31 indicating the direction of rotation of the mirror portion 12 away from the base portion 10.
From the cross-sectional view of FIG. 4, the operation of the ball switch can be seen and described. Conductive ball 32 is shown in its operative position where it has been drawn by gravity when the vanity case is in the vertical position. In this operative position, the conductive ball makes contact with switch ball ramp 34 and ball switch bridging element 36. Phantom ball 32a shows the conductive ball when it is in the inoperative or horizontal position and over hole 41.
Switch 14 is shown in FIG. 4 in the ON position with slider 38 in its most extended or open position abutting ball 32. When manual switch 14 is moved vertically to the OFF position, slider 38 presses against ball 32 and moves it away from the lower end of ball switch bridging element 36 and electrical contact is thereby broken.
All of the elements 32, 34 and 36 are composed of conductive materials such as copper or copper containing metal. Base 10 and upper mirror portion 12 of the vanity case are composed of non-conductive material such as plastic. Suitable plastics are injection molded nylon, polystyrene and polyvinylchloride.
As shown in FIGS. 8 and 9, the switch ball ramp 34 has spring tongue 40, ball retainer hole 42, which is slightly larger than hole 41, and negative dry cell battery contacts 44 and 46. Ball switch bridging element 36 has vertical sides 48 and 50 functioning as positive dry cell battery contacts, top surface 52 and ball contact tabs 54 and 56.
FIGS. 5, 6 and 7 show how the circuits for light bulbs 24 and 26 are completed. Non-conductive ball ramp housing 58 is shown in FIG. 6 having negative contacts 44 and 46 on the outer sides thereof. Vertical cerrations 60, 62 and 64 function as ball retainers along with retainer holes 41 and 42 when the ball is in the inactive position. The negative contact ends of dry cells 66 and 68 make pressure contact with contacts 44 and 46 respectively.
FIG. 7 shows vertical, non-conductive ramp sides 70 and 72 extending from base 10. Conductive vertical sides 48 and 50 are positioned on the outer surfaces of ramp sides 70 and 72. The positive contact ends of dry cells 74 and 76 make pressure contact with conductive sides 48 and 50 respectively.
Slider 38 is shown in FIG. 5 with guides 78 and 80 on either side thereof. Ball 32 is shown in FIG. 5 in the operative position contacting tongue 40 and contact tabs 54 and 56. When the slider is moved upward as indicated by arrow 82, the ball is forced away from contact with tabs 54 and 56 and the circuits are broken.
FIG. 10 shows the two circuits for bulbs 24 and 26, both of which are completed by ball 32. The left hand circuit comprises in ball ramp 34, ball 32, contact tab 54, positive contact 48, battery 74, negative electrode 84, bulb 24, positive electrode 86, battery 66 and negative contact 44. The right hand circuit comprises in ball ramp 34, ball 32, contact tab 56, positive contact 50, positive battery 76, negative electrode 88, bulb 26, positive electrode 90, battery 68 and negative contact 46.
The components 32, 34 and 36 are common to both the left and right hand circuits and if one circuit is inoperative because of a dead bulb or battery, the other circuit will function.
BEST MODE OF CARRYING OUT THE INVENTION
Batteries 66, 68, 74 and 76 are mounted in vanity 2 according to the circuit diagram of FIG. 10. This is accomplished by opening the vanity as indicated in FIG. 3 by rotation about hinges 28,30 in the upward direction of arrow 31, inserting the dry cell batteries and closing the vanity.
Switch 14 is in the upward OFF position. The vanity case is rotated into the vertical or near vertical position. With switch 14 in the off position, slider 38 abuts ball 32 and no circuits are complete because ball 32 does not come into contact with any of the conductive portions of ball switch bridging element 36.
When switch 14 is moved to the downward ON position as shown in FIG. 4, the slider 38 permits gravity to draw ball 32 into contact with tabs 54 and 56 and the circuits are completed. These completed circuits pass through elements 34 to 32 to 36.
Even with switch 14 in the ON position when the sun visor and vanity case are moved into the horizontal or upside down position, the ball 32 is drawn by gravity into position 32a (FIG. 4) and electrical contact is broken. | A lighted automobile vanity mirror for mounting on an automobile sun visor has a switch for operating the illumination only when the vanity mirror is in the vertical position. This switch is a ball contact switch which rolls from an inoperative horizontal position of the vanity mirror to an operative vertical position where gravity draws the ball switch into contact with the circuits. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
MICROFICHE APPENDIX
Not Applicable
BACKGROUND OF THE INVENTION
The invention relates to an arrangement for the exclusive connection of a selectable specimen from a plurality of loads, each of which can be switched on via an individual activation switch between the poles of a voltage source.
Arrangements of this type are required if there is a need to prevent various electrical loads being set in operation at the same time, whether it is unintentional or deliberate. In many cases, switching on of more than one load simultaneously can lead to undesirable results, for instance when, a common current supply source is overloaded, or if loads which are switched on simultaneously interfere with one another in their operation or effect. Devices for example, which serve for the spatial adjustment of objects of various sizes, frequently contain a corresponding plurality of electrical drives, the simultaneous activation of which could not be dealt with by the adjustment mechanism or which would make control more difficult for the user or which would overload the current supply source beyond the desired amount. This can arise in motor vehicles, for instance in the devices for adjusting the seat or the steering column.
Various devices are known for the mutual interlocking of any number of switch devices such that only one of the switch devices can be switched on, see for instance, known devices described in DE-PS 1 040 111, DE-AS 20 08 460 and 20 57 296 and also DE 30 26 619 C2. In the devices described there, the switch devices are respectively electromechanical relays, each of which contain further contacts besides the main contact forming the actual circuit break, for instance for the lock of the relay and/or for closing and opening of additional auxiliary circuit breaks which interrupt, upon actuation of the relay, the exciting currents of the respective other relays.
In a known device described in DE-AS 1 640 995, the simultaneous activation of several relays is prevented by a resistor which is switched on before a common exciting current-supply transmission line to the relays. A large drop in voltage occurs across the resistor, upon simultaneous actuation of two or more switches, such that the residual voltage remaining between the transmission lines no longer suffices to allow a relay coil to respond. This embodiment may function without additional relay contacts, but it is sensitive to fluctuations in the supply voltage and requires very exact designing of the electrical components.
A further disadvantage in the above-mentioned known arrangements is that actuation of the switch devices is only possible via contact switches.
BRIEF SUMMARY OF THE INVENTION
The object of the present invention is the creation of an arrangement of the type described above with relatively simple and compact components and which places no severe requirements on the tolerances of the components utilized.
This objective is achieved according to the invention by an arrangement with the features of claim 1. Advantageous developments of the invention are characterized in the sub-claims.
According to the invention, one individual, electrically controllable safety switch respectively is assigned to all loads or to some but not all loads, the safety switch having a control input and a circuit break lying in the feed circuit of the pertinent load, said circuit break normally conducting and being interrupted only if an activation signal occurs at the control input. Furthermore, there is, according to the invention, assigned to each load, an individual electrical sensing device, which, when circuit voltage is applied to the pertinent load, delivers an activation signal to its output, said signal being delivered to the control inputs of the safety switches which are assigned to the other loads.
The invention is different from the state of the art described above principally in that, after switching on a load, the blocking of the other loads results from additional isolation of the pertinent load circuits and not, at in the known devices, by preventing actuation of the assigned actuation switch. In the arrangement according to the invention there is no need for a locking effect to occur on the actuation switch. Any type of actuation switch may be used which can be different from load to load without a special accommodation of the remaining components. This is of particular advantage in the installation of the arrangement into an already existing load system, with actuation switches already installed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is the electrical wiring diagram of the arrangement according to the invention for selective and exclusive connection respectively of one of three reversible electric motors with equality of access; and,
FIG. 2 shows the arrangement according to FIG. 1 in a modification for the priority status of one of the electric motors.
DETAILED DESCRIPTION OF THE INVENTION
According to FIG. 1, the terminals of three reversible direct-current electric motors M1, M2 and M3 are connectable via one supply respectively, a1, b1 or a2, b2 or a3, b3 and one assigned actuation switch B1 or B2 or B3 to two voltage transmission lines m and p, the first of which is connected to an earth voltage (0 volt) and the second of which is connected to a circuit voltage (+12 volt) which is delivered by a circuit voltage source (not shown) such as, for example, a battery. Each of the selective switches B1, B2, B3 is represented symbolically as a combination of two single-pole reversing, switches, the movable contacts or "arms" of each pair of reversing switches being connected to the pair of terminal suppliers of the assigned electric motor, while the one fixed contact of each pair of reversing switches is connected to the earth ground transmission line m and the other fixed contact of each pair of reversing switches is connected to the circuit voltage transmission line p via a relay circuit break contact k1 or k2 or k3.
Altogether, there are, therefore, three such relay break contacts present, k1, k2, and k3, each of which respectively is assigned to one of the actuation switches B1, B2, B3 and hence to one of the electric motors M1, M2, M3 respectively; and, upon opening, the break contact interrupts the current supply circuit for the pertinent motor, irrespective of the switching state in which the pertinent actuation switch is placed.
Each actuation switch B1, B2, B3 can be actuated by hand to various switching states in which the connected motor is either switched OFF or switched ON for a first direction of rotation or a second opposite direction of rotation. For example, for the actuation switch B1, if both switch arms are in the shown left position in which both connection lines a1 and b1 and hence both terminals of the electric motor M1 obtain earth ground voltage from the earth transmission line m the motor is switched OFF. If, in a second switching state of the actuation switch B1, the left arm is situated in the right-hand position and the right arm in the shown left hand position, then the left terminal of the motor M1 receives circuit voltage from the transmission line p via the connection line a1 (the relay contact k1 being closed) while the other motor terminal b1 receives earth ground voltage from the transmission line m via the connection line b1 so that the motor is turned ON in a first direction, for example, clockwise.
If, in a third state of the actuation switch B1, the left switch arm is in the shown left position and the right switch arm is in the right position, then the left motor terminal receives earth ground voltage from the transmission line m via the connection line a1, while the right motor terminal receives circuit voltage from the transmission line p via the connection line b1 (the relay contact k1 being closed) so that the motor is switched ON for the reverse direction of rotation, e.g. anti-clockwise.
The actuation switches B2 and B3 function in exactly the same manner for controlling the motors M2 and M3.
In order to prevent a further motor from being switched ON in the switched-ON state of one of the motors, the relay contacts lying in the current supply circuit of the other motors are opened by exciting the assigned relay coils respectively. As is shown, a relay coil S1 or S2 or S3 is assigned to each relay coil k1, k2, k3. Each coil is connected with one of its ends to the earth ground transmission line m. The other end of each relay coil is connected via one diode respectively to each terminal supply line of all those electric motors whose current supply runs over the circuit break contacts of the other relay coils respectively. Each diode is polarized in such a way that it conducts, upon application of the circuit voltage on the motor terminal supply line connected to it, and hence delivers activation voltage to excite the relay coil connected to it. Thus, when one of the motors is switched ON, the relay contacts assigned to the other motors are opened so that the current supply for these other motors is interrupted; and, even by actuating the assigned actuation switch, cannot be switched ON.
In detail, when the motor M1 is switched by the actuation switch B1 (left arm to the right, right arm to the left), the terminal supply line a1 is set to the (positive) circuit voltage so that positive voltage proceeds via the diode D12 to the relay coil S2 and via the diode D14 to the relay coil S3. Relay coils S2, S3 are hence excited so that the contacts k2 and k3 are opened and the assigned motors M2 and M3 can no longer be switched ON. In a similar manner, when the motor M1 is switched ON (left arm to the left, right arm to the right), the terminal supply line b1 is set to the positive circuit voltage so that positive voltage proceeds via the diode D11 to the relay coil S2 and via the diode D13 to the relay coil S3. Both these relay coils are therefore excited so that, as a result of opening the relay contacts k2 and k3, the motors M2 and M3 cannot be switched ON.
The relay coils S2 and S3 form therefore an electrically controllable safety switch with the assigned circuit break contacts k2 and k3 respectively for preventing the assigned motor load from being switched ON. The diodes D11, D12, D13, and D14 form a sensing circuit, which recognizes the switched-ON state of the motor M1 and consequently delivers an activation voltage for opening these safety switches.
In an analogous manner, the relay coil S1 also forms, in common with its circuit break contact k1, a safety switch which is assigned to the motor M1. Also in an analogous manner, the diodes D21, D22, D23, D24, which are connected to the terminal supply lines a2, b2, of the motor M2, form a sensing circuit which recognizes the switched-ON state of the motor M2 and consequently delivers an activation voltage for exciting the relay coils S1 and S3 so that the contacts k1 and k3 are opened and the current supply to the motors M1 and M3 is interrupted. Correspondingly, the diodes D31, D32, D33, D34, form a sensing circuit which recognizes the switched-ON state of the motor M3 and consequently delivers the activation voltage for exciting the relay coils S1 and S2 so that the switches k1 and k2 are closed and the current supply route for the motors M1 and M2 is interrupted.
The circuit arrangement shown in FIG. 1 guarantees therefore that, when any one of the motors M1, M2, M3, is switched ON, the other motors respectively can no longer be switched ON without priority being given to one of the motors.
A modification of the arrangement with priority status for one of the motors is shown in FIG. 2. The arrangement according to FIG. 2 differs from the described arrangement according to FIG. 1 solely in that the safety switch S1, k1 has been eliminated in the current supply route for the motor M1 and also the corresponding diode connections (D21, D22, D33, D34 in FIG. 1) have been omitted. It can be easily seen that, in the arrangement of FIG. 2, priority status is given to motor M1 for switching ON. The motors M2 and M3 are given mutual equal status, as in the case of FIG. 1, i.e. after one of them is switched ON, the other can no longer be switched ON. The motor M1, on the other hand, may hence be switched ON, which leads to the immediate switching-OFF of both of the other motors M2 and M3. The embodiments described presently with reference to FIGS. 1 and 2 should only be regarded as examples of the invention. Instead of the described three loads in the form of reversible electric motors, only two or more than three loads may be provided. Non-reversible motors may also be used as the loads, which reduces the circuit cost for the sensing devices considerably, because, in this case, each sensing device for exciting the electrical state would only need to be provided for one of the two terminal supply lines. The type of load is also not restricted to electric motors. An arrangement according to the invention may be used wherever it is essential in a group of any electrical loads for a simultaneous switching-ON state to be prevented in more than one load.
The arrangement of the actuation switches, the safety switches and the sensing devices according to the invention is not restricted to the embodiments which are described with reference to the drawings. For example, the safety switches can also be semiconductor elements, and, for the sensing devices, devices other than the voltagesensing diode networks can be used, for instance current-sensitive elements with ohmic resistors or optical couplers or inductive or capacitive transformers, the latter especially in the case of alternating current loads. | A switching system for plural electrical loads connected to a common power line and each individually energized by a separate user actuated line switch between the respective load and the line. A separate normally closed, electrically opened safety switch is series connected with each of the line switches. Separate sensors, preferably diodes, are connected respectively to each load and each sensor also connected to electrically open each of the remaining safety switches upon sensing voltage to its respective load. Preferably the safety switches are electromagnetic relays. | 8 |
FIELD OF THE INVENTION
The present invention relates generally to electrophotographic devices and, more specifically, to techniques for extending fuser life.
BACKGROUND OF THE INVENTION
In electrophotography, an imaging system forms a latent image by exposing select portions of an electrostatically charged photoconductive surface to laser light. Essentially, the density of the electrostatic charge on the photoconductive surface is altered in areas exposed to a laser beam relative to those areas unexposed to the laser beam. The latent electrostatic image thus created is developed into a visible image by exposing the photoconductive surface to toner, which contains pigment components and thermoplastic components. When so exposed, the toner is attracted to the photoconductive surface in a manner that corresponds to the electrostatic density altered by the laser beam. The toner pattern is subsequently transferred from the photoconductive surface to the surface of a print substrate, such as paper, which has been given an electrostatic charge opposite that of the toner. The substrate then passes through a fuser that applies heat and pressure thereto. The applied heat causes constituents including the thermoplastic components of the toner to flow onto the surface and into the interstices between the fibers of the substrate. The applied pressure produces intimate contact between toner and fibers and promotes settling of the toner constituents into these interstitial spaces. As the toner subsequently cools, it solidifies adhering the image to the substrate.
The fuser typically includes cooperating fusing members that form a nip area capable of delivering heat and pressure to the substrate passing through the nip. Exemplary nip forming members include a fuser roll and a backup roll, a fuser roll and a backup belt and a fuser belt and backup roll. A heat source associated with one or both of the nip forming members raises the temperature of the fusing members at the nip area to a temperature required by a particular fusing application. As the substrate passes through the nip area, the toner is adhered to the substrate by the pressure between the nip forming members at the nip area and the heat resident in the fusing region.
Successful adherence of the toner to the substrate, known as fusegrade, is determined by fusing parameters including temperature, pressure and time in the nip area. Poor fusegrade, resulting in poor adhesion of the toner to the substrate, may be caused by insufficient temperature, pressure or time in the nip area. Moreover, excessive temperature, pressure or time in the nip area may cause damage to the toner image known as image mottle. Excessive temperature, pressure or time in the nip area may also cause the toner to stick to the fusing members rather than the substrate. For example, the toner may peel from the substrate and stick to the fuser members, a condition known as hot offset, or the toner with substrate attached may wrap about a fusing member.
In order to achieve proper fusegrade, the fuser parameters should ideally be maintained within an operating window defined between parameter values that result in poor fusegrade and parameter values that may result in image mottle, hot offset and/or wrap.
SUMMARY OF THE INVENTION
In accordance with an aspect of the present invention, a method of controlling a fusing temperature in a fuser assembly is provided. The method may comprise setting a temperature setpoint value to a predetermined initial value, setting a fusing temperature to correspond with the temperature setpoint value at least during fusing operations, providing a predetermined count threshold corresponding to a substrate count event, counting a number of substrates conveyed through the fuser assembly defining a substrate count, comparing the substrate count to the predetermined count threshold and performing a temperature compensation if the substrate count corresponds to the predetermined count threshold.
Performing a temperature compensation if the substrate count corresponds to the predetermined count threshold may comprise adjusting the temperature setpoint value to a compensated temperature setpoint value and adjusting the fusing temperature to correspond with the compensated temperature setpoint value. The compensated temperature setpoint value may be configured to extend the operating life of the fuser assembly.
In accordance with another aspect of the present invention, a fuser assembly within an image forming apparatus having a paper path along which substrates travel through the image forming apparatus is provided. The fuser assembly may comprise a fusing member, a backup member cooperating with the fusing member to form a fusing region at a nip therebetween for fusing images onto substrates passing through the nip and a heating structure associated with at least one of the fusing member and the backup member for heating the fusing region to a fusing temperature at least during fusing operations. The fusing temperature may correspond to a temperature setpoint value and the temperature setpoint value may be set to a predetermined initial value.
The fuser assembly may further comprise a conveying structure for conveying substrates along the paper path into the nip, a substrate detector for determining a number of substrates passing through the nip and a controller for controlling the fusing temperature. The controller may count the number of substrates passing through the nip defining a substrate count. The controller may compare the substrate count to the predetermined count threshold and perform a temperature compensation if the substrate count corresponds to the predetermined count threshold.
The temperature compensation may adjust the temperature setpoint value to a compensated temperature setpoint value and may adjust the fusing temperature to correspond to the compensated temperature setpoint value. The compensated temperature setpoint value may be configured to extend the operating life of the fuser assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
The following detailed description of the preferred embodiments of the present invention can best be understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals, and in which:
FIG. 1 is a diagrammatic side view of an electrophotgraphic printer illustrating an image forming apparatus, a substrate conveying structure and a fuser assembly;
FIG. 2 is a block diagram of an aspect of the present invention illustrating a fuser assembly, a controller and a storage device;
FIG. 3 is a flow chart illustrating how an aspect of the present invention may be practiced;
FIG. 4 is a flow chart illustrating how another aspect of the present invention may be practiced; and
FIG. 5 is a flow chart illustrating how another aspect of the present invention may be practiced.
DETAILED DESCRIPTION OF THE INVENTION
In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration, and not by way of limitation, specific preferred embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and that changes may be made without departing from the spirit and scope of the present invention.
According to an aspect of the present invention, an operating lifetime of a fuser assembly for use in an electrophotographic imaging apparatus may be extended by counting a number of fusing operations performed by the fuser assembly and adjusting a fusing temperature when a predetermined number of fusing operations have been performed. The fusing temperature may be adjusted to a higher temperature or to a lower temperature and the adjustment may be made at one or more predetermined counting events during the lifetime of the fuser assembly. Moreover, the changes to the fusing temperature may be selected so as to maintain the fusing temperature within a predefined temperature operating window. The fusing temperature adjustments may be selected, for example, to compensate for changes that occur in fuser components as a result of use.
Referring now to FIG. 1 , a color electrophotographic (EP) printer 10 is illustrated including four image forming stations 12 , 14 , 16 , 18 for creating yellow (Y), cyan (C), magenta (M) and black (K) toner images. Each image forming station 12 , 14 , 16 and 18 includes a laser printhead 20 , a toner supply 22 , a rotatable photoconductive (PC) drum 24 and a developing assembly 56 . A uniform charge is provided on each PC drum 24 , which is selectively dissipated by a scanning laser beam generated by its corresponding printhead 20 , such that a latent image is formed on each PC drum 24 according to a bitmap image file of an associated one of the CYMK color image planes. The latent image formed on each PC drum 24 is then developed during an image development process via the corresponding toner supply 22 and developing assembly 56 , in which electrically charged toner particles are transferred to the surface of each PC drum 24 in a pattern corresponding to the latent image formed thereon.
Each image forming station also includes an electrically biased transfer roller 26 that opposes its corresponding PC drum 24 . An intermediate transfer member (ITM) belt 28 that is common to each image transfer station travels in an endless loop and passes through a nip defined between each PC drum 24 and its corresponding transfer roller 26 . The toner image developed on each PC drum 24 is transferred during a first transfer operation to the ITM belt 28 by an electrically biased roller transfer operation. In this regard, each PC drum 24 and its corresponding transfer roller 26 constitutes a first image transfer station 32 that transfers its corresponding one of the yellow, cyan, magenta or black toner images to the ITM belt 28 .
At a second image transfer station 34 , a composite toner image, i.e., the registered yellow (Y), cyan (C), magenta (M) and black (K) toner images, is transferred from the ITM belt 28 to a substrate 36 . The second image transfer station 34 includes a backup roller 38 , on the inside of the ITM belt 28 , and a transfer roller 40 , positioned opposite the backup roller 38 . Substrates 36 , such as paper, cardstock, labels, envelopes or transparencies, are fed from a substrate supply 42 to the second image transfer station 34 so as to be in registration with the composite toner image on the ITM belt 28 . Structure for conveying substrates from the supply 42 to the second image transfer station 34 may comprise a pick mechanism 42 A that draws a top sheet from the supply 42 and a speed compensation assembly 43 . The composite image is then transferred from the ITM belt 28 to the substrate 36 . A conveying structure 37 conveys the substrate 36 to a fuser assembly 48 , where the toner image is fused to the substrate 36 . The substrate 36 including the fused toner image continues along a paper path 50 until it exits the printer 10 into an exit tray 51 .
The paper path 50 taken by the substrates 36 in the printer 10 is illustrated schematically by a dot-dashed line in FIG. 1 . It will be appreciated that other printer configurations having different paper paths may be used. Further, a duplex unit (not shown) for printing on both sides of the print media and one or more additional media supplies or trays, including manually fed media trays, may be provided.
The fuser assembly 48 in the illustrated embodiment includes a fuser hot roller 70 or fusing roller defining a heating member, and a backup member 72 cooperating with the hot roller 70 to define a nip for conveying substrates 36 therebetween. The hot roller 70 may comprise a hollow metal core member 74 covered with a thermally conductive elastomeric material layer 76 . The hot roller 70 may also include a polyperfluoroalkoxy-tetrafluoroethylene (PFA) sleeve (not shown) around its elastomeric material layer 76 . A heating element 78 , such as a halogen tungsten-filament heater, may be located inside the core 74 of the hot roller 70 for providing heat energy to the hot roller 70 under control of a controller 80 . The heating element 78 may comprise a filament that provides an end boost along a predetermined portion adjacent at each end of the heating element 78 to provide a greater heat output adjacent the ends than at a central portion of the heating element 78 . It should be understood that the illustrated embodiment is not limited to a particular mechanism or structure for heating the hot roller 70 and that any known means of heating a roller may be implemented within the scope of this invention.
The backup member 72 may comprise any structure for cooperating with the hot roller 70 to create a nip whereby a substrate passing through the fuser assembly 48 is pressed into engagement with the hot roller 70 . The illustrated backup member 72 comprises a belt backup member. However, it should be understood that the backup member 72 may comprise other nip forming structures including, without limitation, a cooperating backup roller. Additionally, a second heating element may be associated with the backup member 72 .
The controller 80 may comprise a microprocessor, a discrete logic array or other device controlling arrangement. The controller 80 may be provided to control various aspects of the printer systems and components, including the fuser assembly 48 . Additionally, the controller 80 may be utilized to control the fusing temperature utilized by the fuser assembly 48 in such a way as to extend the life of the fuser assembly 48 as will be described in greater detail herein.
Referring now to FIG. 2 , a block diagram 100 illustrates an exemplary fuser assembly 48 A and control arrangement according to various aspects of the present invention. The fuser assembly 48 A represents another exemplary fuser arrangement that may be utilized in an electrophotographic apparatus, such as the printer 10 , as will be described in greater detail below.
As illustrated, the fuser assembly 48 A comprises a fusing member 110 and a backup member 112 defining a nip 114 therebetween through which substrates 36 pass. A distance 116 in a process direction P between the fusing member 110 and the backup member 112 within which temperature and pressure are applied to the substrate 36 defines a fusing region 118 . As illustrated in FIG. 2 , the backup member 112 is a backup roller rather than the belt backup member 72 shown in FIG. 1 . A first heating element 120 is associated with the fusing member 110 and a second heating element 122 may be optionally associated with the backup member 112 . Together, the first heating element 120 and the optional second heating element 122 comprise a heating structure 124 . The heating structure 124 is under the control of the controller 80 as will be described more thoroughly herein.
After a toner image has been transferred to a substrate 36 as previously described with reference to FIG. 1 , the substrate 36 is conveyed to the nip 114 by a conveying structure 37 as described with reference to FIG. 1 . The toner image comprises unfused toner containing pigment components and thermoplastic components. When the substrate 36 passes through the nip 114 , the heat applied to the toner causes constituents including the thermoplastic components in the toner to melt and flow onto the surface and into interstices between the fibers of the substrate 36 . The applied pressure produces intimate contact between toner and fibers and promotes settling of the toner constituents into these interstitial spaces. As the toner subsequently cools, it solidifies adhering the image to the substrate 36 .
Successful adherence of the toner to the media, known as fusegrade, is determined substantially by the temperature applied to the toner, the pressure applied between the toner image and the substrate surface while the toner is heated and the time that the temperature and pressure are simultaneously applied, i.e., the time in the fusing region 118 . If the temperature or pressure applied to the toner is insufficient or the time that the toner spends in the fusing region 118 is too little, the toner may not properly adhere to the substrate, resulting in poor fusegrade. On the other hand, if the temperature or pressure applied to the toner is excessive or the time that the toner spends in the fusing region 118 is too long, the toner may stick to the fusing members rather than the substrate 36 . This may cause the toner to peel from the substrate 36 and adhere to the fusing members, a condition known as hot offset. Should the toner adhere sufficiently to both the substrate and the fusing member, the substrate may wrap around the fusing member. Additionally, excessive temperature, pressure or time in the fusing region 118 may damage the toner image, resulting in image mottle.
Fusegrade may be correlated with fusing temperature. As such, in order to achieve proper fusegrade while avoiding image mottle, hot offset and wrap, the fusing temperature may be maintained within a predetermined temperature range, also referred to herein as a temperature operating window. For example, the temperature operating window may define a fusing temperature range that extends from a relatively low temperature just suitable to achieve proper fusegrade to a relatively high temperature that achieves proper fusegrade and avoids image mottle, hot offset and wrap, etc.
Fusegrade may also be correlated with nip pressure times the square of the time in the fusing region 118 . The pressure exerted on the toner is determined substantially by the force applied between the fusing member 110 and the backup member 112 divided by the distance 116 that defines the fusing region 118 . The pressure may vary between different points in the fusing region 118 .
As illustrated in FIG. 2 , the fusing member 110 may comprise a hollow metal core 126 surrounded by a thermally conductive elastomeric layer 128 . Similarly, the backup member 112 may comprise a hollow metal core 130 surrounded by a thermally conductive elastomeric layer 132 . Alternatively, the backup member 112 may comprise any structure for cooperating with the fusing member 110 such that a compressive pressure is applied to opposite sides of the substrate 36 as it is conveyed through the nip 114 .
Because one or both of the fusing member 110 and the backup member 112 is compliant at least in the thermally conductive elastomeric layers 128 and 132 , respectively, the outer portion of one or both of the fusing member 110 and the backup member 112 deforms in the fusing region 118 defined by the distance 116 . For a given pressure between the fusing member 110 and the backup member 112 , the amount that the fusing member 110 and/or the backup member 112 deforms will vary substantially in accordance with the hardness of the compliant portions of the fusing member 110 and the backup member 112 .
The distance 116 corresponds to the amount of deformation that occurs in the fusing member 110 and the backup member 112 . As a result, the distance 116 varies in accordance with the hardness of the fusing member 110 and the backup member 112 . In this fashion, the distance 116 is increased as the hardness of the fusing member 110 and the backup member 116 , i.e., the nip forming members decreases. Conversely, the distance 116 decreases as the hardness of the nip forming members increases.
The time that the temperature and pressure are applied to the toner, i.e., the time in the fusing region 118 , is a function of the distance 116 and the velocity of the substrate 36 as it is conveyed through the nip 114 . As previously mentioned, the distance 116 corresponds to the shape and hardness of the fusing member 110 and the backup member 112 and the force applied therebetween. Thus, for a given substrate velocity, the time that the toner spends in the fusing region 118 corresponds to the hardness of the fusing member 110 and the backup member 112 .
The compliant portions of the fusing member 110 and the backup member 112 may be harder when new, i.e., at a beginning of fuser life, and may soften with age as a result of repetitive turning under pressure. As a result, the distance 116 may be smaller at the beginning of fuser life and may increase as the fuser assembly ages and the nip forming members soften. The increase in the distance 116 results in a corresponding increasing in time that substrate 36 spends in the fusing region 118 if the substrate velocity remains constant. For this reason, fusegrade may be lower at the beginning of fuser life and may improve with use. Thus, it may be practical to select a fuser operating temperature high enough to achieve adequate fusegrade at the beginning of fuser life. Subsequently, as the nip forming members age and soften, resulting in an increase in the distance 116 and a corresponding increase in the time that the substrate 36 spends within the fusing region 118 , it may be unnecessary to operate the fuser assembly at the same high temperature in order to achieve adequate fusegrade.
In one example, fusing temperature may refer to the temperature to which the fusing member 110 is regulated. The fusing member may be in contact with a substrate surface upon which an un-fused toner image has been deposited. Backup member temperature may refer to the temperature to which the backup member 112 may be regulated if the backup member 112 is separately heated. Alternatively, backup member temperature may refer to the surface temperature of the backup member 112 if the backup member 112 is heated by contact with the heated fusing member 110 and is not otherwise heated. Backup member temperature may normally be lower than fusing temperature.
The fusing member 110 and the backup member 112 in the fuser assembly 48 A illustrated in FIG. 2 have a useful lifetime that is inversely related to fuser operating temperature, hereinafter fusing temperature. The lifetime of the fusing member 110 may correspond to the fusing temperature to which the fusing member 110 is exposed and the lifetime of the backup member 112 may correspond to the backup member temperature to which the backup member 112 is exposed. For example, in accordance with an application of the Arrhenius model in the context of evaluating the effect of temperature on the fuser assembly 48 A, it has been observed that the operating life of a fusing member such as fusing member 110 may be extended by a factor of two for every 7 to 10 degree C reduction in fusing temperature.
As previously discussed, the time spent within the fusing region 118 may increase with fuser life due to softening of the nip forming members, resulting in improved fusegrade. As a result, it may be possible to operate the fuser assembly 48 A at a reduced fusing temperature at some point later in the lifetime of the fuser assembly 48 A while still maintaining adequate fusegrade. By taking advantage of the improvement in fusegrade that may occur due to the softening of the nip forming members with age, it may be possible to extend the operating lifetime of the components of the fuser assembly 48 A by reducing the fusing temperature at one or more point(s) in the lifetime of the fuser assembly 48 A without producing unacceptable fusegrade.
For example, for a fusing member 110 comprising a metal core 126 surrounded by an elastomeric layer 128 , failures generally occur first at the interface between the elastomeric layer 128 and the metal core 126 or within the elastomeric layer 128 because the temperature is highest at these points during fusing operations. By reducing the fusing temperature at some point in the lifetime of the fuser assembly 48 A, it may be possible to avoid, postpone or otherwise mitigate such occurrences.
As another illustrative example, the hardness of the nip forming members may decrease sufficiently during the lifetime of the fuser assembly 48 A such that the distance 116 of the fusing region 118 increases enough that the time spent in the fusing region 118 is sufficient to cause hot offset, image mottle or wraps if the fusing temperature remains constant over the lifetime of the fuser assembly 48 A. In this case it may not be possible to establish a single temperature range that will assure adequate fusegrade while avoiding hot offset, image mottle and/or wraps over the entire operating lifetime of the fuser assembly 48 A. As a result, it may be necessary to lower the fusing temperature at some point during the lifetime of the fuser assembly 48 A in order to maintain the fusing temperature within the temperature operating window as previously defined. By maintaining the fusing temperature within the temperature operating window so as to avoid hot offset, image mottle and/or wraps it may be possible to operate the fuser assembly 48 A beyond a point in fuser life where such conditions might otherwise necessitate maintenance or repair, and a functional life of the fuser assembly 48 A may be extended.
As yet a further illustrative example, certain materials sometimes used in fuser nip forming members may harden rather than soften with use. For example, a fuser nip forming member having a soft silicone rubber layer may harden during use as a silicone oil within the rubber is driven out due to repetitive turning under pressure at elevated temperature. As another example, a fuser nip forming member having a rubber layer that is not fully cured may harden during use as the rubber continues to cure when it is exposed to elevated temperature during fusing operations. As the nip forming member hardens, the distance 116 decreases, and the substrate 36 spends less time in the fusing region 118 . In this situation, fusegrade generally decreases over the lifetime of the fuser assembly 48 A. In order to maintain adequate fusegrade, the fusing temperature may be raised at one or more point(s) during the lifetime of the fuser assembly 48 A. Though the higher fusing temperature may decrease the life of the nip forming members as previously discussed, it may be possible to maintain adequate fusegrade beyond a point in fuser life where fusegrade would otherwise become unacceptable if the temperature were not increased. In this fashion, the functional life of the fuser assembly 48 A may be extended.
The controller 80 is communicably coupled to the fuser assembly 48 A. The controller 80 may comprise a microprocessor, microcontroller, discrete logic array or other controlling arrangement. The controller 80 includes a fuser temperature control module 134 communicating with one or more power switching devices (not shown) connected to the heating structure 124 . In this fashion, the fuser temperature control module 134 may cause the power switching device or devices (not shown) to energize the first heating element 120 and/or the second heating element 122 either individually or in conjunction causing the fusing temperature to increase. Conversely, the fuser temperature control module 134 may cause the power switching device or devices (not shown) to de-energize the first heating element 120 and/or the second heating element 122 allowing the fusing temperature to decrease.
The controller 80 also includes a substrate count module 138 . The substrate count module 138 is configured to count a number of substrates 36 , passing through the fuser assembly 48 A. The substrate count module 138 may communicate with a substrate detector in the fuser assembly 48 A or elsewhere in the printer 10 . The substrate detector may comprise an optoelectronic substrate detector, an electromechanical substrate detector, a paper pick mechanism, a bump sensor, a software implemented substrate detector within the controller 80 or other suitable means for detecting substrates approaching the fuser assembly 48 A. In this fashion, a total number of substrates 36 that have passed through the fuser assembly 48 A, defining a substrate count, may be compiled.
For example, the substrate detector may comprise an optical interrupter having a mechanical flag that is moved out of an optical path when a substrate 36 is conveyed past the substrate detector. One or more substrate detectors may be provided in a substrate path in the printer 10 . Any such substrate detector may communicate with the controller 80 for purposes of counting the number of substrates 36 passing through the fuser assembly 48 A.
As another example, a substrate detector may be located in the printer 10 in a location in the substrate path where substrates 36 that have passed through the fuser have entered a duplex paper path provided to allow the printer 10 to convey the substrate 36 through the image transfer station 34 a second time such that the substrate 36 may be printed on an opposite side. Because the substrate 36 passes through the fuser assembly 48 A a second time to fuse a toner image on the opposite side but passes through a substrate detector located in the duplex paper path only once, the substrate count module 138 of the controller 80 may add two to the substrate count to account for two fusing operations corresponding to a fusing operation to fuse a toner image on each side of the substrate 36 .
A media type module 142 is also provided within the controller 80 . The media type module 142 is configured to determine a media type of the substrate 36 that is to be fused in the fuser assembly 48 A. The media type module 142 may acquire media type information from a media type sensor, an operator control panel, a print driver module, or a print data stream. The fuser temperature control module 134 may control the fusing temperature of the fuser assembly 48 A in accordance with the media type as determined by the media type module 142 . Furthermore, a unique substrate count corresponding to a total number of substrates 36 of each of a plurality of media types that have passed through the fuser assembly 48 A may be compiled by the substrate count module 138 .
Also included in the controller 80 is a fuser temperature compensation module 144 . The fuser temperature compensation module 144 is configured to compensate the fusing temperature of the fuser assembly 48 A in accordance with the substrate count as will be described more thoroughly herein.
A storage device 146 is connected to the controller 80 . The storage device 146 may comprise NVRAM or any other suitable storage for non volatile storage of program and data information for use by the controller 80 . For example, the previously mentioned plurality of substrate counts corresponding to different media types may be stored in the storage device 146 .
In accordance with an aspect of the present invention, the fuser temperature control module 134 may operate the fuser assembly 48 A at a predetermined initial fusing temperature, hereinafter a temperature setpoint, for example, 175 degrees Centigrade (C), when fusing toner images on a substrate 36 comprising 20 lb. (75 g/m 2 ) plain paper. The fuser assembly 48 A may be expected to fuse 120,000, 20 lb. plain paper substrates 36 while maintaining adequate fusegrade before replacement of the nip forming members may be recommended. In order to extend the lifetime of the fuser assembly 48 A the fuser temperature compensation module 144 may adjust the temperature setpoint downward by, for example, 3 degrees C to 172 degrees C, after a total of 15,000, 20 lb. plain paper substrates 36 have been fused. The reduction in the temperature setpoint and the corresponding reduction in fusing temperature contributes to an extension of the operating lifetime of the fuser assembly 48 A during the period of the fuser lifetime after the initial 15,000 substrates 36 have been fused. It may not be necessary to make any further adjustments in fusing temperature over the remaining lifetime of the fuser assembly 48 A.
In accordance with another aspect of the present invention, the fuser temperature compensation module 144 may adjust the temperature setpoint downward a first time to 172 degrees C. after a total of 15,000, 20 lb. plain paper substrates 36 have been fused as previously described. Subsequently, the fuser temperature compensation module 144 may adjust the fusing temperature by a second predetermined amount, for example, by −4 degrees C. from the initial setpoint value to 171 degrees C, after a total of 30,000, 20 lb. plain paper substrates 36 have been fused. The second reduction in the temperature setpoint contributes to an extension of the operating lifetime of the fuser during the period of the fuser lifetime after the initial 30,000 substrates 36 have been fused. Further, the temperature setpoint may be adjusted by a third amount, for example, by −5 degrees C from the initial setpoint value to 170 degrees C, after a total of 40,000, 20 lb. plain paper substrates 36 have been fused. The third reduction in the temperature setpoint contributes to an extension of the operating lifetime of the fuser during the period of the fuser lifetime after the initial 40,000 substrates 36 have been fused. Still further, the temperature setpoint may be adjusted by a fourth amount, for example, by −6 degree C from the initial setpoint value to 169 degrees C, after a total of 50,000, 20 lb. plain paper substrates 36 have been fused. The fourth reduction in the temperature setpoint contributes to an extension of the operating lifetime of the fuser during the period of the fuser lifetime after the initial 50,000 substrates 36 have been fused.
The above adjustment examples are presented by way of illustration and not by way of limitation. In practice, other temperature setpoint adjustment amounts may be made. Moreover, the substrate count events corresponding to temperature adjustments may be different than the above example. Still further, additional or fewer adjustments may be made. The implemented adjustments may be based, for example, upon factors such as the particular components and component characteristics of the particular fuser assembly and of the particular substrates and fusing requirements of particular applications.
Though the preceding discussion refer to substrates 36 comprising 20 lb. plain paper sheets, the present invention is not limited to such material and is applicable to any media type to which toner images may be fused, e.g., card stock, labels, envelopes, transparency stock, heavier or lighter weight paper, etc. For example, 110 lb. card stock may require a higher initial fusing temperature than 20 lb. plain paper. The fuser assembly 48 A in accordance with the principles and concepts of the present invention may operate at the higher fusing temperature when fusing images onto substrates 36 comprising 110 lb. card stock. The fuser assembly 48 A may then operate at an adjusted fusing temperature after a predetermined number of substrates 36 comprising 110 lb. card stock have been fused in order to extend the operating lifetime of the fuser assembly 48 A. The temperature adjustment amount may be determined empirically and may be a greater or lesser adjustment than the temperature adjustment previously discussed with respect to 20 lb. plain paper substrates 36 . Furthermore, the number of temperature adjustments performed over the lifetime of the fuser assembly 48 A may be more or fewer than the number of adjustments made when processing 20 lb. plain paper substrates 36 .
In yet another aspect of the present invention, the substrate count module 138 may compile a plurality of substrate counts corresponding to a total number of substrates 36 of a plurality of different media types that have passed through the fuser assembly 48 A. When the media type module 142 determines that a substrate 36 about to be fused by the fuser assembly 48 A is of a specific media type, the controller 80 may set the temperature setpoint to a specific value corresponding to a fusing temperature corresponding to the specific media type. The fuser temperature control module 134 may now control the heating structure 124 such that the fusing temperature corresponds to the temperature setpoint corresponding to the specific media type. Further, the fuser temperature compensation module 144 may adjust the temperature setpoint upward or downward when the specific substrate count corresponding to the specific media type to be fused corresponds with a predetermined substrate count value as previously described. In this way, the fuser temperature control module 134 may now adjust the fusing temperature in accordance with the compensated temperature setpoint. As previously described, the temperature setpoint may be adjusted once or a plurality of times during the lifetime of the fuser assembly 48 A and the fusing temperature may be adjusted downward or upward as a result.
According to an aspect of the present invention, substrates 36 comprising media types that are rarely fused by the fuser assembly 48 A may have little effect upon the operating life of the fuser assembly 48 A, and the temperature compensation module 144 may ignore compensating the temperature setpoint when such substrates are fused.
In yet another aspect of the present invention, a temperature compensation table may be provided. An exemplary temperature compensation table is shown below:
Temperature Compensation Table
Temperature Compensation Value
Predetermined Count Threshold
Degrees C.
0-14,999
0
15,000-29,999
−3
30,000-39,999
−4
40,000-49,999
−5
50,000->50,000
−6
The exemplary temperature compensation table includes a plurality of compensation table records. Each compensation table record includes a predetermined count threshold component and a corresponding temperature compensation value component. The predetermined count threshold corresponds to a substrate count event when the fusing temperature is to be compensated, and the corresponding temperature compensation value indicates the amount of the temperature compensation. As substrates 36 pass through the fuser assembly 48 A, the substrate count module 138 compiles a substrate count corresponding to a total number of substrates 36 that have been fused as previously described.
The controller 80 compares the substrate count to the predetermined count threshold values in the temperature compensation table and the fuser temperature compensation component 144 adjusts the setpoint temperature in accordance with the corresponding temperature compensation value from the temperature compensation table. For example, as each substrate 36 is fused in the fuser assembly 48 A, the substrate count module 138 increments the substrate count by one and compares the new substrate count value to the temperature compensation table predetermined count threshold values. In the example above, the fuser temperature compensation module 144 does not adjust the setpoint temperature until the substrate count reaches 15,000 because the temperature compensation table records indicate a temperature compensation value of 0 for all predetermined count threshold values less than 15,000.
When the substrate count reaches 15,000 the fuser temperature compensation module 144 adjusts the temperature setpoint by the corresponding temperature compensation value, e.g., −3 degrees C. in the illustrated example. When the substrate count reaches 30,000, the fuser temperature compensation module 144 adjusts the temperature setpoint by the corresponding temperature compensation value, e.g., −4 degrees C. When the substrate count reaches 40,000 the fuser temperature compensation module 144 adjusts the temperature setpoint by the corresponding temperature compensation value, e.g., −5 degrees C. In like fashion, when the substrate count reaches 50,000 the fuser temperature compensation module 144 adjusts the temperature setpoint by the corresponding temperature compensation value, e.g., −6 degrees C. In the illustrated example, the temperature compensation value remains −6 degrees C. for all substrate count values above 50,000.
The temperature compensation table may be stored in the storage device 146 where it may be accessed by the controller 80 . The controller 80 may include a table address pointer for specifying which compensation table record to access and the table address pointer may be stored in the storage device 146 .
The number of compensation table records and the predetermined count threshold values and corresponding temperature compensation values may be determined empirically by the fuser designers and are not limited to the exemplary compensation table values illustrated above. For example, the temperature compensation table may include more or fewer compensation table records, and other embodiments of the present invention may include different predetermined count and temperature compensation value data than the exemplary temperature compensation table depicted above. For example, the temperature compensation data may be represented in fashions other than offsets from the initial set point value.
In another aspect of the present invention, a plurality of temperature compensation tables may be provided. Each of the plurality of temperature compensation tables may correspond to one of a plurality of media types that may be processed by the fuser assembly 48 A. Each of the plurality of temperature compensation tables may include a plurality of compensation table records comprising a predetermined count threshold component and a corresponding temperature compensation value component corresponding to a specific media type. In this fashion, individual temperature compensation tables may be provided comprising predetermined count threshold values and corresponding temperature compensation values to be used when fusing substrates 36 of a plurality of differing media types. A plurality of table address pointers corresponding to each of the plurality of temperature compensation tables may be provided for specifying which compensation table record to access. The plurality of temperature compensation tables and the plurality of corresponding table address pointers may be stored in the storage device 146 .
Referring now to FIG. 3 , a flowchart 300 illustrates process steps implemented by the controller 80 for practicing an aspect of the present invention. The controller 80 may implement the process steps indicated in FIG. 3 each time a toner image is to be fused to a substrate 36 by the fuser assembly 48 A. The temperature compensation process begins at step 302 . When the controller 80 determines that a substrate 36 is to be fused by the fuser assembly 48 A, the process proceeds to step 304 .
In step 304 , the controller may optionally retrieve the current substrate count from the substrate count module 138 . Alternatively, the controller 80 may retrieve the current substrate count from the substrate count module 138 prior to step 304 . The process now proceeds to step 306 .
In step 306 , the controller 80 determines if it is appropriate to compensate the temperature setpoint. If the controller 80 determines that temperature compensation is not indicated in step 306 the process proceeds to step 310 . If the controller 80 determines that temperature compensation is appropriate in step 306 , the process proceeds to step 308 .
In step 308 the fuser temperature compensation module 144 compensates the temperature setpoint by adjusting the temperature setpoint value to equal a compensated temperature setpoint value. The compensated temperature setpoint value is configured to extend the operating life of the fuser assembly 48 A as previously described. The compensated temperature setpoint value may be retrieved from, for example, a table or other logical arrangement stored in the storage device 146 . The process now proceeds to step 312 .
In step 310 , the controller 80 may set the temperature setpoint value to a predetermined initial value. Alternatively, the temperature setpoint value may be set to the predetermined initial value prior to step 310 . The process now proceeds to step 312 .
In step 312 , the fuser temperature control module 134 adjusts the fusing temperature of the fuser assembly 48 A to correspond with the temperature setpoint value as determined in step 308 or 310 , at least during fusing operations. The process now proceeds to step 314 .
In step 314 , the substrate 36 is fused by the fuser assembly 48 A at a fusing temperature corresponding to the temperature setpoint value as determined in step 308 or 310 . The process now proceeds to step 316 .
In step 316 the substrate count module 138 increments the substrate count by one so that the substrate count now corresponds to a total number of substrates 36 fused by the fuser assembly 48 A including the substrate 36 just fused. The substrate count module 138 may store the new substrate count value in the storage device 146 . The process now proceeds to step 318 .
Step 318 is an ending step where the process may stop. Alternatively, the process may proceed to step 302 where the process may begin again when the controller 80 determines that another substrate 36 is to be fused by the fuser assembly 48 A.
Referring now to FIG. 4 , a flowchart 400 illustrates process steps implemented by the processor 80 for practicing another aspect of the present invention. The controller 80 may implement the process steps indicated in FIG. 4 each time a toner image is to be fused to a substrate 36 by the fuser assembly 48 A. The temperature compensation process begins at step 402 . When the controller 80 determines that a substrate 36 is to be fused by the fuser assembly 48 A, the process proceeds to step 404 .
In step 404 , the controller 80 sets the temperature setpoint value to a predetermined initial value corresponding to a desired fusing temperature. The predetermined initial value may be determined by the fuser designers and may have been stored in the storage device 146 before the process begins at step 402 . The temperature setpoint value may optionally be stored in the storage device 146 . The process now proceeds to step 406 .
In step 406 , the fuser temperature control module 134 controls the heating structure 124 such that the fusing temperature of the fuser assembly 48 A corresponds to the temperature setpoint value at least during fusing operations. The fuser temperature control module 134 may cause the heating structure 124 to raise the fusing temperature of the fuser assembly 48 A to a temperature corresponding to the temperature setpoint value only during a time when a substrate 36 is being fused in the fuser assembly 48 A. Alternatively, the fuser temperature control module 134 may cause the heating structure 124 to raise the fusing temperature of the fuser assembly 48 A to a temperature corresponding to the temperature setpoint value in advance of a time when the substrate 36 is to be fused in the fuser assembly 48 A. The process now proceeds to step 408 .
In step 408 , the controller 80 acquires a predetermined count threshold corresponding to a substrate count event when the temperature setpoint value shall be compensated. The predetermined count threshold may be determined by the fuser designers and may have been stored in the storage device 146 before the process begins at step 402 . The process now proceeds to step 410 .
In step 410 , the controller 80 acquires the current substrate count from the substrate count module 138 . The process now proceeds to step 412 .
In step 412 , the controller 80 determines if it is appropriate to compensate the temperature setpoint value from the predetermined initial value to which it was set in step 404 . The controller 80 may do this by comparing the substrate count to the predetermined count threshold acquired in step 408 . If the substrate count does not correspond to the predetermined count threshold, the process proceeds to step 418 . If the substrate count corresponds to the predetermined count threshold, the process proceeds to step 414 .
In step 414 the fuser temperature compensation module 144 compensates the temperature setpoint creating a compensated temperature setpoint value. The compensated temperature setpoint value is configured to extend the operating life of the fuser assembly 48 A as previously described. The process now proceeds to step 416 .
In step 416 the fuser temperature control module 134 adjusts the fuser assembly 48 A fusing temperature to correspond with the compensated temperature setpoint value. The process now proceeds to step 418 .
In step 418 , the substrate 36 is fused at a fusing temperature corresponding to the temperature setpoint value as determined in step 404 or 414 . The process now proceeds to step 420 .
In step 420 the substrate count module 138 increments the substrate count by one so that the substrate count now corresponds to a total number of substrates 36 fused by the fuser assembly 48 A including the substrate 36 just fused. The substrate count module 138 may store the new substrate count value in the storage device 146 . The process now proceeds to step 422 .
Step 422 is an ending step where the process may stop. Alternatively, the process may proceed to step 402 where the process may begin again when the controller 80 determines that another substrate 36 is to be fused by the fuser assembly 48 A
Referring now to FIG. 5 , a flowchart 500 illustrates process steps implemented by the controller 80 for practicing another aspect of the present invention. The controller 80 may implement the steps indicated in FIG. 5 each time a print job is received by the printer 10 . A print job may comprise the printing of one or more substrates 36 of the same or different media type. Beginning at step 502 , the controller 80 is initially in an idle state such as when the printer 10 is initially turned on or when no print jobs have been received by the printer 10 .
In step 504 , the process waits until the controller 80 determines that a print job has been received. The process then proceeds to step 506 .
In step 506 , the media type module 142 determines which of a plurality of media types the substrate 36 comprises. Indication of a specific media type may be stored in the storage device 146 . The process now proceeds to step 508 .
In step 508 , the controller 80 sets the temperature setpoint value to a predetermined initial value corresponding to one of a plurality of media types that may be fused in the fuser assembly 48 A. The predetermined initial value corresponds to a desired fusing temperature for the media type of the substrate 36 about to be fused. The predetermined initial value may be determined by the fuser designers and may have been stored in the storage device 146 before processing begins at step 502 . For example, the predetermined initial value corresponding to the desired fusing temperature for the specific media type may have been stored in a table or other logical arrangement in the storage device 146 . The processing now proceeds to step 510 .
In step 510 , the controller 80 fuser temperature control module 134 controls the fuser assembly 48 A heating structure 124 such that the fusing temperature corresponds to the temperature setpoint value as set in step 508 at least during fusing operations. In this fashion, the fusing temperature corresponds to the desired fusing temperature for the media type of the substrate 36 about to be fused. The fuser temperature control module 134 may cause the heating structure 124 to raise the fusing temperature of the fuser assembly 48 A to the temperature corresponding to the temperature setpoint value only during a time when the substrate 36 is being fused in the fuser assembly 48 A. Alternatively, the fuser temperature control module 134 may cause the heating structure 124 to raise the fusing temperature of the fuser assembly 48 A to the temperature corresponding to the temperature setpoint value in advance of a time when the substrate 36 is to be fused in the fuser assembly 48 A. The processing now proceeds to step 512 .
In step 512 , the controller 80 determines a temperature compensation value to be used by the fuser temperature compensation module 144 to compensate the temperature setpoint as will be discussed next. The controller 80 may retrieve the temperature compensation value from a temperature compensation table as previously described. For example, the controller 80 may maintain a table address pointer to provide a table address of a temperature compensation table record that includes a predetermined count threshold and a corresponding temperature compensation value. The controller 80 may maintain a plurality of table address pointers corresponding to a plurality of temperature compensation tables, each of which includes a plurality of records including a predetermined count threshold component and a corresponding temperature compensation value component corresponding to a specific media type. Each of the plurality of table address pointers may be stored in the storage device 146 . The process now proceeds to step 514 .
In step 514 , the fuser temperature compensation module 144 compensates the temperature setpoint value creating a compensated temperature setpoint value. The compensated temperature setpoint value is a sum of the predetermined initial value to which the temperature setpoint was set in step 508 and the temperature compensation value as determined in step 514 . The compensated temperature setpoint value is configured to extend the operating life of the fuser assembly 48 A. The compensated temperature setpoint value may be stored in the storage device 146 . The process now proceeds to step 516 .
In step 516 , the fuser temperature control module 134 controls the fuser heating structure 124 such that the fusing temperature of the fuser assembly 48 A corresponds to the compensated temperature setpoint value. The process now proceeds to step 520 .
In step 518 , the substrate 36 is fused at the fusing temperature corresponding to the compensated temperature setpoint value and the process waits until fusing of the substrate 36 is finished. When the fuser assembly 48 A has finished fusing the substrate 36 , the process continues to step 520 .
In step 520 , the substrate count module 138 increments the substrate count by one so that the substrate count now indicates a total number of substrates 36 fused by the fuser assembly 48 A including the substrate 36 just fused. The substrate count module 138 may compile and maintain a plurality of individual substrate counts corresponding to a plurality of substrates 36 of a plurality of media types as determined by the media type module 142 and fused in the fuser assembly 48 A. Individual substrate counts for substrates 36 of certain media types that are rarely processed by the printer 10 and fused in the fuser assembly 48 A may not be compiled and maintained. Each of the plurality of substrate counts may be stored in the storage device 146 . Upon completion of step 520 , the process returns to step 504 where the process waits until another print job has been received or another substrate 36 within the same print job is detected.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention. | A method for extending the operating life of a fuser used in an electrophotographic imaging apparatus is disclosed. A control algorithm monitors the number of substrates processed over the lifetime of the fuser and adjusts the fusing temperature of the fuser to compensate for changes occurring in the nip forming members of the fuser. The useful lifetime of the fuser is extended while fusing quality is maintained. A corresponding fuser assembly is also disclosed. | 6 |
FIELD OF THE INVENTION
The present invention relates generally to a clocking scheme for digital circuits, and more particularly, to a clocking scheme for reducing the clock skew sensitivity of a shift register.
BACKGROUND OF THE INVENTION
Shift registers are well known in the construction of digital circuits. A basic shift register structure comprises a series of flip flops having a common clock input where the output of one flip flop is coupled to the input of the next flip flop. Each flip flop in the shift register has setup time and hold time requirements which define a forbidden zone of the active clock edge, i.e. clock skew, to ensure the correct function of the shift register. In order for a shift register to function properly, the clock skew between a transmitting and a receiving flip flop in a shift register must be less than the intrinsic delay of the transmitting flip flop minus the hold time of the receiving flip flop.
One particular use of such shift registers is for boundary-scan testing, otherwise known as Joint Test Action Group (JTAG). Boundary-scan testing is a non-intrusive method for testing interconnects on printed circuit boards that is implemented at the integrated circuit level. Since its adoption by IEEE as Standard 1149.1, boundary-scan testing has been applied in high volume to high-end consumer products, telecommunication products, defense systems, peripherals, computers and avionics. Current JTAG implementations utilize boundary scan cells coupled to each other so that the cells function as a shift register, and thus are very sensitive to clock skew. A Test Access Port (TAP) controller generates all required control signals for the boundary scan cells including the clock signal. The conventional JTAG clocking scheme routes the JTAG clock as one signal net. However, boundary scan cells need to be placed close to the input or output cell to which it belongs and are therefore distributed along the sides of the die. This distribution causes long net delays which can result in a high skew on a clock net.
As the intrinsic delay in fast sub-micron technologies becomes smaller, it becomes more difficult to achieve the requirements for clock skew. As a result, the use of shift registers in digital circuits, such as for boundary-scan testing, becomes more difficult to implement and increases the effort required during layout resulting in many additional days to complete the layout. Moreover, in some cases it is impossible to achieve the minimum skew required for a secure shift operation of the shift registers. One typical example is a design with several hardmacros (i.e. logic functions with fixed layout, for example Random Access Memories (RAMs)). Ideally, hardmacros should be placed close to the Input/Output (I/O) region of the die in order to easily connect the power rings of the hardmacros to the power rings in the I/O area. This arrangement, however, interferes with the requirement that the boundary scan cells be placed close to the I/O region. For critical outputs (i.e. signals where the delay needs to be as small as possible) the boundary scan cell needs to be placed right next to the output buffer between the I/O area and the hardmacro. This configuration causes big skew on the clock skew since the layout tools can only control the clock skew effectively if there is no blocking area between the clock trunk (placed in the middle of the die) and the flip flop. Because the wire is too long, the skew needs to be balanced manually by slowing down the delay of the other flip flops using balance cells.
SUMMARY OF THE INVENTION
In accordance with the present invention, a system and method for a clocking scheme is implemented to reduce the clock skew sensitivity of a shift register. The system of the present invention advantageously transmits a clock signal through the cells in a shift register in a direction which is against the direction of the data flow of the shift registers. To ensure that the hold time of each cell of the shift register is adequate, a delay circuit is provided in each cell of the shift register to delay the clock signal before transmitting it to the next cell of the shift register. The clocking scheme of the present invention advantageously reduces the sensitivity of the shift register to clock skew and is easy and fast to implement in layout.
The system of the present invention comprises a control circuit, and a first cell and a last cell of the shift register. The control circuit generates a clock signal to the first cell of the shift register. The first cell of the shift register contains a delay circuit for delaying the clock signal before transmitting the clock signal to the next cell of the shift register. The clock signal is continuously delayed by each cell of the shift register as it is transmitted from the first cell to the last cell of the shift register and through the cells of the shift register. The shift register may contain any number of cells, where each cell contains a delay circuit for delaying the clock signal before transmitting it to the next cell in the register. At the same time that the clock signal is transmitted to the first cell of the shift register, a test data circuit line transmits data to the last cell in the shift register. The data is received by the last cell of the shift register and is transmitted through the cells of the shift register in a direction which is against the direction of the clock signal. The present invention also includes a method for reducing the clock skew sensitivity of a shift register. The method includes the steps of generating and transmitting a clocked signal to the first cell of a shift register in a first direction; receiving at the first cell the generated clock signal, delaying the clock signal in the first cell by means of a delay circuit, and transmitting the clock signal to the next cell of the shift register. The method also requires transmitting data to the last cell of a shift register in a second direction which is in the opposite direction of the first direction.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a shift register clocking system embodying the principles of the present invention.
FIG. 2 is a timing diagram of a clock signal and the data flow of a shift register clocking system in accordance with the present invention.
FIG. 3 is a block diagram of one embodiment of a shift register cell in accordance with the present invention.
FIGS. 4A-4C are block diagrams of other embodiments of boundary scan cells in accordance with the present invention.
FIG. 5 is a table summarizing the details of one embodiment implementing the present invention.
FIG. 6 is a table summarizing the results of using three different types of buffers in a boundary scan cell implementation embodying the principles of the present invention.
FIG. 7 is a block diagram of one embodiment of a clocking system for a plurality of shift registers in accordance with the present invention.
FIG. 8 is a timing diagram of a clock signal and the data flow of a plurality of shift registers in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a block diagram of a shift register clocking system 100 in accordance with the present invention. System 100 comprises a plurality of cells 102 , a control circuit 104 , a test data circuit input line 108 , and a non-inverting buffer 110 . A clock signal input line 112 , a clock signal output line 114 , a test data input line 116 , and a test data output line 118 are coupled to each cell 102 . Cells 102 may also include other input and output lines coupled to cell 102 which are not shown here for simplification purposes but would be evident to one skilled in the art when coupling individual cells as a shift register. Cells 102 are flip flops having an internal delay circuit for delaying the input clock signal from clock signal input line 112 . The operation and configuration of cell 102 is described below in more detail with reference to FIG. 3 . Cells 102 are coupled to one another as shown in FIG. 1 to form a shift register, and in a preferred embodiment of the present invention are boundary scan cells for a JTAG implementation. More specifically, system 100 comprises a first cell 102 A and a last cell 102 B. System 100 may also contain any number of intermediary cells 102 coupled to one another and to first cell 102 A and last cell 102 B to form a shift register as shown in FIG. 1 . Cells 102 A, 102 B, and intermediary cells 102 are coupled to each other such that the clock signal output line 114 of one cell 102 is coupled to the clock signal input line 112 of the next cell 102 , and the test data input line 116 of one cell 102 is coupled to the test data output line 118 of the next cell 102 .
Control circuit 104 is coupled through a clock signal generator line 120 to the clock signal input line 112 of the first cell 102 A. The control circuit 104 is also coupled through the test data output line 118 to the first cell 102 A. Control circuit 104 may be any type of conventional control circuit which generates control signals, including a clock signal, to first cell 102 A of the shift register. In a preferred embodiment of the present invention, control circuit 104 is a Test Access Port (TAP) controller for generating control signals for the boundary scan cells in a JTAG implementation. Because control circuit 104 only clocks first cell 102 A, the driving strength of the driving buffer can be reduced from a dedicated clock buffer to a normal non-inverting buffer. One advantage of this configuration is its flexibility and easy implementation. A dedicated clock buffer consists of large transistors which are only available in the I/O ring of the die thus requiring long routing to connect control circuit 104 to the buffer and to drive all 102 cells using big clock trunks. As a result, conventional systems require additional layout steps for implementation and results in wasted silicon area are on the die. Systems embodying the principles of the present invention, however, enable a shortened connection between control circuit 104 and first cell 102 A which can be routed automatically in layout.
In a preferred embodiment, the present invention is a JTAG implementation. In such an embodiment, test data input line 116 is coupled to the test data circuit input (TDI) pin of the JTAG. Test data circuit input line (TDI) 108 is coupled to a buffer 110 which in turn is coupled to test data input line 116 of last cell 102 B in the shift register. In a preferred embodiment, TDI 108 is the data input of the JTAG implementation for all values that need to be loaded either in the boundary scan cells or TAP controllers. Buffer 110 , which is a conventional buffer and preferably, a non-inverting buffer, is usually used to supply the required driving strength since the routing from TDI 108 to last cell 102 B may be quite long.
During operation of system 100 , the clock signal generated by control circuit 104 flows in a direction opposite to the direction of the data flow transmitted by TDI 108 . Control circuit 104 transmits a clock signal along clock signal generator line 120 to first cell 102 A. First cell 102 A receives the clock signal at clock signal input line 112 . First cell 102 A delays the clock signal for a specified amount of time and then transmits the clock signal along the clock signal output line 114 to last cell 102 B. If system 100 comprises a plurality of intermediary cells 102 coupled to 102 A and 102 B, then first cell 102 A delays the clock signal for a specified amount of time and then transmits the clock signal along clock signal output line 114 to the next intermediary cell 102 in the shift register. The signal is then propagated through intermediary cells 102 of the shift register until the clock signal reaches last cell 102 B in the shift register. At the same time that control circuit 104 transmits a clock signal along clock signal generator line 120 to first cell 102 A, TDI 108 transmits a test data signal along test data input line 116 to last cell 102 B of the shift register. Last cell 102 B of the shift register then transmits the test data signal along the test data output line 118 to first cell 102 A. If system 100 comprises a plurality of intermediary cells 102 coupled to 102 A and 102 B, then last cell 102 B transmits the test data signal along the test data output line 118 to the next intermediary cell 102 in the shift register. Next intermediary cell 102 receives the test signal data at test data input line 116 and transmits the test signal data along the test data output line 118 to the next intermediary cell 102 . The signal is then propagated through intermediary cells 102 of the shift register until the test data signal reaches first cell 102 A in the shift register. From first cell 102 A of the shift register, the test signal data is transmitted along test data output line 118 to control circuit 104 . FIG. 2 shows a timing diagram of the clock signal and test data signal for system 100 in accordance with the present invention.
FIG. 3 shows a block diagram of one embodiment of a cell 102 in accordance with the present invention. Cell 102 is preferably a boundary scan cell and comprises a flip flop 310 coupled through the clock signal input line 112 to a delay circuit 320 . The clock signal output line 114 is also coupled to the delay circuit 320 . Delay circuit 320 is directly inserted in each cell 102 . Cell 102 may include other input and output lines which are not shown but which would be obvious to one skilled in the art. In a preferred embodiment of the present invention, delay circuit 320 is a non-inverting buffer. The present invention ensures that the shift operation operates correctly as long as the intrinsic delay of delay circuit 320 for the clock signal is longer than the intrinsic delay of the flip flop 310 of the previous cell itself. FIGS. 4A-4C are other examples of cells 102 embodying the principles of the present invention. The cells 102 in FIGS. 4A-4C are conventional boundary scan cells with a delay circuit 320 inserted directly into each boundary scan cell. Each cell 102 also includes a clock signal input line 112 , a clock signal output line 114 , a test data input line 116 , and a test data output line 118 . Cells 102 in FIGS. 4A-4C also include other input and output lines coupled to cells 102 and/or within cells 102 which are not shown here for simplification purposes but would be evident to one skilled in the art.
In a preferred embodiment, the present invention is implemented in an existing design using LCB500K technology which already contains JTAG inserted by JTAG builder. Cells 102 are boundary scan cells and are preferably the boundary scan cells as illustrated in FIG. 4 A. Referring now to FIG. 5, a table summarizing the details of a preferred embodiment is shown. In such an embodiment, the die size is approximately 11.9 mm by 11.9 mm with 180 boundary scan cells, 50 inputs, 58 outputs and 52 bidirects. The embodiment represents an average size of a state-of-the-art design. In this particular embodiment, the number of boundary scan cells is smaller than the total number of inputs/outputs because not all inputs and output were included into JTAG. Referring now to FIG. 6, a table summarizing the performance of the preferred embodiment using three different buffers 320 to delay the clock signal. Version 1 uses a lclkbuf 1 buffer, version 2 uses a lclkbuf 3 a buffer, and version 3 uses two serial inverters n 1 b. The second column of FIG. 6 shows the delay on the JTAG clock measured from the first boundary scan cell clocked directly by the TAP controller to the last boundary scan cell at the end of the clock chain. The values inside brackets are based on pre-layout c-MDE delay calculation, and the values without brackets are based on actual layout information. The third column of FIG. 6 gives an approximate frequency for which the JTAG will still run. For this estimation, a 50% duty cycle of the external clock is assumed. The maximum frequency is determined by the delay of the JTAG clock along the clock chain and the control signals of the TAP controller derived from the negative clock edge of the external clock. For calculating the frequencies shown in FIG. 6, the path of the shift signal to the last boundary scan cell with the longest clock delay was taken. As seen in FIG. 6, the best results can be achieved by using lclkbuf 3 a as the delay buffer for delay circuit 320 in cell 102 .
FIG. 7 shows another embodiment of a system 400 in accordance with the present invention. System 400 comprises a control circuit 402 , a first shift register 404 A, a last shift register 404 B, and a plurality of data lockup latches 406 . System 400 may also contain any number of intermediary shift registers 404 coupled to one another in between first shift register 404 A and last shift register 404 B to form a chain of shift registers as shown in FIG. 7 . Each shift register ( 404 A, 404 B, and 404 ) may comprise any number of cells 102 (not shown) coupled to each other as a shift register and includes at least a first cell 408 and a last cell 410 . Control circuit 402 may be any type of conventional control circuit which generates control signals to first shift register 404 A, last shift register 404 B including a clock signal, and any intermediary shift register 404 in system 400 . In a preferred embodiment of the present invention, control circuit 402 is a Test Access Port (TAP) controller for generating control signals for the boundary scan cells in a JTAG implementation. Data lockup latches 406 are conventional data lockup latches and are generally used to ensure correct capturing of data of the shift register if the clock of the receiving flip flop of the shift register is slower than the clock of the sending flip flop of the shift register. A data lockup latch in front of the data input of the receiving flip flop of the shift register ensure correct functionality by allowing data to pass only during a low clock signal. A test data circuit input line (TDI) 412 is coupled to the last cell 410 in the first shift register 404 A. A clock signal generator line 416 is coupled to each shift register 404 . More specifically, control circuit 402 is coupled through the clock signal generator line 416 to the first cell 408 of each shift register 404 and to each data lockup latch 406 . The data lockup latches 406 are coupled through the test data output lines 418 to the first cells 408 of each shift register 404 except for the first cell 408 of the last shift register 404 B. The data lockup latches 406 are also coupled through the test data input lines 420 to the last cells 410 of each shift register 404 except for the last cell 410 of the first shift register 404 A.
During operation, control circuit 402 generates and transmits a clock signal along the clock signal generator line 416 to the first cell 408 of each shift register 404 , 404 A and 404 B. The clock signal is propagated through the cells 102 of the shift register from the first cell 408 to the last cell 410 of the shift register. At the same time that control circuit 402 generates and transmits a clock signal to the first cell 408 of each shift register 404 , 404 A, and 404 B, TDI line 412 transmits a test data signal from a test circuit to the last cell 410 of the first shift register 404 A. The test data signal is propagated through the cells 102 of the first shift register 404 A and is transmitted from the first cell 408 along the test data output line 418 to the data lockup latch 406 . The test data signal is then transmitted from the data lockup latch 406 to the last cell 410 of the last shift register 404 B via test data input line 420 . If system 400 comprises a plurality of intermediary shift registers 404 coupled in between 404 A and 404 B as shown in FIG. 7, then the data lockup latch 406 transmits the test data signal received from the first cell 408 of first shift register 404 A to the last cell 410 of the next intermediary shift register 404 via test data input line 420 . The signal is then propagated through cells 102 of intermediary shift register 404 until the test data signal reaches first cell 408 of the intermediary shift register 404 . The test data signal is propagated through the shift registers 404 and data lockup latches 406 until the test data signal reaches the first cell 408 of last shift register 404 B. The test data signal is then transmitted from first cell 408 of last shift register 404 B to control circuit 402 via test data output line 418 . FIG. 8 shows a timing diagram of the test data signal and the clock signal of system 400 in accordance with the present invention.
It is to be understood that the specific mechanisms and techniques which have been described are merely illustrative of certain applications of the principles of the invention. Numerous modifications may be made to the system and methods described without departing from the true spirit and scope of the invention. | The system and method of the present invention for reducing the clock skew sensitivity of a shift register provides a control circuit for generating a clock signal to the first cell of the shift register. The first cell of the shift register receives the clock signal at its input and delays the clock signal for a specified time before transmitting the clock signal to the last cell in the shift register. The clock signal is propagated from the first cell of the shift register to the last cell of the shift register in a first direction. A test data circuit line is coupled to the last cell of the shift register. A test data signal is transmitted by the test data circuit line to the last cell of the shift register and is propagated through the shift register in a second direction, wherein the second direction is in a direction opposite from the direction of the clock signal. Thus, the clock signal is propagated through the cells in the shift register against the flow of the test data signal through the shift register. | 6 |
TECHNICAL FIELD
This invention is to feeding sheets in a manner, which causes the sheets to be accurately received in transport mechanism so as to be properly positioned for imaging. Typically the sheets are intended to be manually inserted in the imaging device.
BACKGROUND OF THE INVENTION
In imaging devices, such as printers, feeding sheets individually from external of the imaging device allows selection of individual sheets having unique characteristics, such as letterhead or preprinted borders, or selected width. It is common to either simply provide a slot leading to the sheet transport mechanism of the device or to provide an external tray on which the sheet is slid across so as to be more reliably positioned in the sheet transport.
Reliably positioning the sheet is important because, if the sheet sags against the imaging device structure, the sheet may not feed evenly. When the sheet sags against the device an uneven frictional drag can occur and the sheet enters the sheet feed mechanism turned from the intended position. Accurate registration of the sheet is then lost and not normally recovered, and the final image is turned from the correct position. In extreme cases the sheet jams within the printer.
In those devices in which no guide structure is provided, entire reliance is on the careful insertion of the sheet by the operator. Experience indicates that defective insertions will occur fairly frequently, especially with new operators.
Those devices that have a guide tray are generally effective in achieving proper insertion of the sheets. However, such guide surfaces necessarily extend from the side of the imaging device during use. To avoid such extension being permanent and thereby always defining a perimeter of the imaging device, the guide trays are generally thin structures, which slide into or out of the imaging device or fold out from the device or otherwise need to be positioned by the operator. Such operator intervention reduces productivity and requires some training of the operator. The tray structures themselves add cost to the imaging device, and, since they are thin and relatively unprotected, they are subject to damage.
DISCLOSURE OF THE INVENTION
This invention provides a sheet guide at or near the wall of the imaging device that causes the sheet to bend along the direction of insertion and therefore not sag. Operation is intuitive because pertinent structures are at or near the opening into which the operator necessarily must insert the sheet. Guide structures may be at each end of an entrance opening, with the opposing guide structures each having lower surfaces higher than the center of the opening and upper surfaces sloped downward to reach at least somewhat below the upper level of the lower surfaces. A wide variety of alternative structures configured to force the sheet to bend, and it is the bending which provides beam strength so that the sheet does not sag against the image device. One alternative is an entrance slot in the form of an arc with the low point in the center and of limited height so as to only accept a bowed sheet.
It is widely understood in the paper feed and imaging art that a bent paper or other such sheet has increased beam strength perpendicular to the line of the bend. Only a single bend is necessary in accordance with this invention, but structures that provide multiple, parallel bends would similarly prevent sag and function in accordance with this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The details of this invention will be described in connection with the accompanying drawings, in which:
FIG. 1 is illustrative of a printer having a manual entry sheet feed in accordance with this invention:
FIG. 2 is a partial view from a right perspective of the printer of FIG. 1 with parts omitted to show the opposing guide structures in relations to the sheet feed mechanism into which a sheet is fed;
FIG. 3 illustrates the opposing sheet guides as mounted for lateral movement;
FIG. 4 is a front view showing the opposing sheet guides in relation to the entry slot in which they are located; and
FIG. 5 is illustrative of an alternative embodiment in which the slot itself is bent.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The printer 1 in FIG. 1 is shown without details as it is intended to be illustrative since this invention would be operable with virtually any imaging device. The imaging engine of printer 1 (internal and not shown) might be a conventional xerographic system. Printer 1 has an internal paper tray to supply paper from a stack of paper without manual intervention except to refill the tray. The imaged paper or other sheet is exited onto the top surface or tray 3 of printer 1 . A sheet of paper 4 inserted in accordance with this invention is shown, in dotted outline for overall clarity of FIG. 1 .
The paper 4 has a bowed configuration along the direction of entry, which is required by the left, and right guide structures, 5 a and 5 aa respectively. The center of paper 4 is at or near the bottom of slot 7 , while the configuration of guide structures 5 a and 5 aa lift the left and right sides of paper 4 above the bottom of slot 7 .
Slot 7 is an opening in the front side 9 of printer 1 which is directly opposite sheet feed mechanism of printer 1 , shown in FIG. 2 with respect to this embodiment. Stationary upper guide ribs 20 receive paper from slot 7 and direct it against lower guide ribs 22 . The paper 4 is then in the proper position to enter a nip between upper feed rollers 24 and lower feed rollers (not shown). Such sheet feed mechanism is essentially entirely conventional and therefore will not be discussed in further detail. FIG. 2 also shows the guide structures 5 a and 5 aa , thereby showing the spacing relationship between the sheet feed mechanisms and the guides structures 5 a and 5 aa.
The guide structures 5 a and 5 aa are shown just with their mounting elements in FIG. 3 . The guide structures 5 a and 5 aa are mirror images of each other. The ribbed, outer sides 40 a and 40 aa respectively are handles for grasping by the operator. Guide structure 5 a is fixedly mounted to an upper supporting plate 42 a , which has a toothed rack extending toward guide structure 5 aa . Similarly, guide structure 5 aa if fixedly mounted to upper supporting plate 42 aa , which has a toothed rack extending toward guide structure 5 a . The teeth of structures 5 a and 5 aa face each other, and engage mating teeth of wheel 44 (shown only in small part) which depends from drag ring 46 . This combination provides a structure in which the two guide structures 5 a , 5 aa can be moved different widths manually, by pushing one or both of the guide structures 5 a , 5 aa while remaining centered in slot 7 . Friction from drag ring 46 then holds guide structures 5 a , 5 aa in place until they are again manually moved with force to overcome that friction. The guide structures 5 a , 5 aa are thereby positioned to receive paper 4 of other sheets of different widths.
The front view of FIG. 4 best illustrates the forcing action of guide structures 5 a and 5 aa . The bottom surface of each structure 5 a , 5 aa is an upward sloping section 50 a , 50 aa , sections 50 a , 50 aa being lower at the front of the printer 1 and higher on the side more internal to printer 1 . The upper surface 52 a , 52 aa are downward sloping. Each structure 52 a , 52 aa respectively terminates downward at a location as shown, which is below the final height of the sections 50 a , 50 aa . Depending stationary blocking elements 54 located in near the center of slot 7 terminate at a location substantially equal in height to the final height of the sections 50 a , 50 aa . Blocking elements 54 are visually apparent and thereby further discourage incorrect insertion of paper 4 by at least appearing to block paper 4 from passing through slot 7 while horizontal.
An operator beginning to insert paper in slot 7 necessarily observes that the paper 4 must be bent downward in the middle, as the paper 4 would be blocked in other configurations. This is also a natural way to grasp paper. When the paper 4 is inserted, it is under surfaces 52 a , 52 b , and, as it is moved by the operator into printer 1 , it encounters upward sloping sections 50 a , 50 aa , and thereby is forced into a bowed configuration.
With paper 4 in such a bowed configuration, it will not sag against the body of printer 1 and therefore will be accurately received by feed rollers 24 . This assures that paper will not drag against the front surface of printer 1 when being fed. Elimination of such drag is a necessary component of ensuing good registration. However, other factors as the media enters, such as the user loading the paper 4 or other sheet perpendicular to the feed rollers 24 and the mechanical accuracy of the feed mechanism of printer 1 or other imaging device as the media enters, are also important to accurate sheet registration.
A wide variety of configurations could provide the bowed configuration by which this invention functions. One alternative is shown in FIG. 5 . Slot 7 a is an open slot leading directly to sheet feed mechanism as is slot 7 . However, slot 7 a is in the form of a bow and has no guide on each side. Slot 7 a should be of sufficient height to permit relatively easy insertion, but a disadvantage is that is must be sufficiently narrow in height so as to not allow flat insertion of the paper in slot 7 a.
Accordingly, a wide variety of implementations are anticipated, as is intended to be understood with respect to the accompanying claims. | An entrance guide for externally fed sheet ( 4 ) to printer ( 1 ) is configured to bow the sheets. In one embodiment guides ( 5 a, 5 aa ) within slot 7 have upper and lower configurations which force sheet into a bow. In one embodiment slot ( 7 a ) is bowed and is sufficiently narrow in height to only accept a bowed sheet. The bowed sheets do not sag against the printer ( 1 ), which aids in sheet registration. | 1 |
FIELD OF THE INVENTION
The present invention relates to an apparatus and process for removing suspended dregs from green liquor in a kraft pulp mill and washing the same in preparation for disposal. This application is specifically directed to an apparatus and process that uses much less water than conventional processes.
BACKGROUND OF THE INVENTION
Wood pulp or cellulose is prepared from wood or other vegetable material by a process of chemical dissolving and softening. The wood or other vegetable material is subjected to a preliminary cleaning treatment, mechanically chopped up and then boiled in large tanks with hot solutions. The boiling process, known as digesting, is performed with a caustic liquid referred to as white liquor. Lignin, which acts to adhere cellulose fibers, is dissolved by this treatment and is, in part, chemically decomposed, leaving a soft pulp which consists primarily of cellulose.
The present invention is intended for use in kraft pulp mills. Kraft pulping is performed by cooking wood chips in a highly alkaline liquor that selectively dissolves lignin and releases cellulosic fibers from the wood matrix. The two principal chemicals in the liquor are sodium hydroxide and sodium sulphide. Sodium sulphide, also a strong alkali, readily hydrolyses in water, producing sodium hydroxide and sodium hydrosulphide.
At the beginning of the kraft process, white liquor is fed to the digester. This liquor contains a high amount of effective alkali which, as explained above, is used to digest the wood. At the terminus of the digester, spent liquor, known as black liquor, is removed from the digester.
The pulping chemicals are then recovered from the black liquor by a process that is referred to as the recovery process. To begin with, black liquor from the digester contains low levels of effective alkali. Black liquor also contains large amounts of organic compounds that are removed and burned in a recovery furnace. The resultant mass of inorganic residue, called smelt, is dissolved to form green liquor having a low concentration of effective alkali and a high concentration of sodium carbonate. The green liquor is led to a green liquor clarifier for the removal of solid particles called dregs.
The clarified green liquor is subsequently causticized in a conventional process. Note, for example the process described in U.S. Pat. No. 4,941,945 to Pettersson. In particular, white liquor is regenerated from the green liquor by causticizing the carbonate through addition of lime. After the recausticizing operation, a small residual amount of sodium carbonate is carried to the digester. The total amount of sodium hydroxide, sodium sulphide and sodium carbonate is called the total titratable alkali (TTA).
The chemistry of the causticizing reaction is simple and known to those skilled in the art. In particular, lime (CaO) reacts with sodium carbonate (Na 2 CO 3 ) in the green liquor to produce sodium hydroxide (NaOH) and calcium carbonate (CaCO 3 ), called lime mud. Because of its low solubility, calcium carbonate precipitates from solution.
Although the chemistry of the reaction is simple, the continuous nature of the process involves a number of unit operations--filtration, classification, mixing, sedimentation, calcining, and material handling. The entire process may be thought of a closed circuit operation involving solids as one cycle and the liquor as another. The two are brought together to furnish the cooking liquor and each subsequently is recycled and converted to that chemical form necessary to achieve the causticizing of the liquor. There are, however, some waste products. One such waste product is the dregs that are removed from the green liquor by the green liquor clarifier.
Since a kraft pulp mill produces large quantities of dregs, it is highly desirable to dispose of dregs in an inexpensive manner such as landfill. A problem arises, however, if the pH of the dregs exceeds the EPA standard for alkaline waste. Specifically, any solid waste material that is aqueous and has a pH above 12.5 is classified as a "hazardous waste" and is subject to extremely cumbersome regulations. Accordingly, the dregs must be washed to a pH below 12.5 before disposal in a landfill.
In addition, the material must be solid, so that it does not drip; a "paint filter" test is conventionally used--if it does not drip any water in five minutes, then it is considered solid. If foreign materials are added to make the dregs solid, then the dregs must be subjected to a compression test at 60 psi to see if it is "solid". This application is specifically directed to an apparatus and process for treating dregs to achieve a solid mass having a pH below 12.5, ideally about 12.0 or less.
The treatment of dregs produced while recausticizing kraft green liquor is discussed in several U.S. patents. For example, U.S. Pat. No. 4,668,342 to Blackwell describes a process for recausticizing kraft green liquor in which the underflow from the green liquor clarifier is filtered in a rotary vacuum filter and washed with hot water. The dregs are then passed to waste.
U.S. Pat. No. 4,941,945 to Pettersson describes a method for clarifying green liquor in which the green liquor is clarified by filtering and the sludge separated by the filter is discarded for dumping.
U.S. Pat. No. 5,082,526 to Dorris discloses a process by which raw green liquor is passed through a buffer tank and into a clarifier to remove dregs. The dregs then pass to a green dregs filter.
Likewise, U.S. Pat. No. 5,145,556 to Westerberg et al. discloses a process in which dregs that settle in the green liquor clarifier are pumped to a dregs precoat filter for thickening and washing. The patent also suggests that mixing lime mud and grits with the unclarified green liquor enhances the settling of the dregs in the clarifier and the washing on the precoat filter.
U.S. Pat. No. 5,282,931 to Le Clerc et al. discloses a process by which dreg deposits are filtered in a precoat dregs filter before passing through the disposal line.
Finally, U.S. Pat. No. 4,322,266 to Nelson discloses a process by which some dregs are pumped back to the recovery furnace.
None of these patents seem to acknowledge, much less address, the need to reduce the pH of dregs. One conventional system for reducing the pH of dregs involves washing dregs using a sedimentation dregs washer located upstream of a precoat dregs filter. In one known embodiment, about 20% of the available wash water is used to wash the dregs. This recovers approximately 80% of the soda in the dregs underflow. The dregs washer underflow is sent to a standard precoat dregs filter where it is dewatered to about 50% solids, and further washed with 1.65 displacements. This lowers the soda in the dregs cake to 0.14%, and the pH to an acceptable 11.93.
The trouble with the conventional dregs washing system is that it uses too much water and sends too much soda to the weak wash system. The dregs washer overflow and the dregs filter filtrate must go to the weak wash system. This can be viewed as diverting wash water from the mud, or adding soda to the mud washing system, but the result is the same--mud washing suffers. Other problems are also expected.
Likewise, washing the dregs to the required pH on a precoat dregs filter is not practical. The number of wash displacements is so great that the washing efficiency cannot be maintained. Moreover, it is doubtful that the required amount of water would flow through the cake, even at half the filter loading.
Thus, there is a need for an alternative process for washing dregs.
Finally, in describing the kraft pulp mill process, the terms overflow and underflow are commonly used. These are terms of art. In general, the term "underflow" is used to refer to the material, typically solid concentrate, that is removed from the flow or retained by the filter or clarifier. The term "overflow" refers to the filtrate or the material that passes through the filter or clarifier.
SUMMARY OF THE INVENTION
The present invention proposes an alternative process by which dregs are filtered, rather than washed, before passing to the precoat dregs filter. Assuming the existing green liquor clarifier is of adequate size and performance, a simple filter is used to dewater the underflow, from 5-7% suspended solids to 50% suspended solids. Since the material has passed through the green liquid clarifier, the filtrate (green liquor) can be returned to storage, rather than the weak wash.
The process of the present invention includes the steps of: clarifying the green liquor in a green liquor clarifier to separate the green liquor into an overflow comprising clarified green liquor and an underflow comprising dregs and green liquor; filtering the underflow to form a first dregs cake that is at least 50% solid; diluting the dregs cake, preferably by water flushing, to less than 20% solid; filtering the diluted dregs cake to form a second dregs cake that is at least 50% solid.
The apparatus of the present invention includes a green liquor clarifier for separating green liquor into an overflow containing clarified green liquor and an underflow containing dregs and green liquor; a first filter for filtering green liquor from the underflow so as to form a dregs cake; means for diluting the dregs cake; and a second filter for filtering the diluted dregs cake.
Through the use of a simple filter, it is possible to filter the dregs to form a dregs cake that is about 50% solid. In this way, about 92% of the soda is removed in this initial filtering step and returned to the green liquor system. The resultant dregs cake will contain much less soda than the underflow of a conventional dregs washer. By back-flushing the dregs cake with water to a dilution of 15%, then filtering and washing on the dregs filter, the soda content is further reduced and the pH of the dregs cake is reduced to an acceptable level.
The process of the present invention requires only a small fraction of the amount of water required by conventional dregs washing. According to one proposed application of this process, the dregs filter filtrate is the only water sent back to the weak wash system. As a result, less than 2% of the water needed with conventional technology is used in this embodiment of the present invention.
Thus, the present invention differs from known kraft mill processes and provides an alternative to dregs washing. According to this alternative, a filter is used in place of the dregs washer. Thus, two stage filtration is used instead of a simple dregs filter or a sedimentation dregs washer followed by filtration.
A precoat filter is often used as the dregs filter in a conventional kraft pulp mill having one filter with or without dregs washing. In the two stage filtration process of the present invention, two precoat filters in series could be used.
The inventor has found, however, that there are disadvantages associated with the use of two precoat filters in series. To begin with, two filters means two precoats using two to three times the lime mud used by a single standard precoat filter. Another problem is oxidation: the precoat vacuum filter will suck a lot of air through the cake, oxidizing an appreciable amount of the sodium sulphide to sodium thiosulfate which is highly corrosive.
Accordingly, in accordance with the best mode currently contemplated by the present invention, the initial filtration is performed by a cassette type pressure filter such as that sold under the trademark CAUSTEC™ by Kvaerner Pulping Technologies AB of Karlstad, Sweden. The CAUSTEC™ casette filter is an enclosed vessel containing a series of perforated tubes covered with a filter media. The CAUSTEC™ cassette filter does not require a precoat and uses the pressure of the liquid feed pump to provide the driving force for filtration, thus, there is no vacuum pump and no air infiltration. Moreover, the system uses much less power. At the same time, a greater differential power is developed, so a drier cake is formed. This filter can recover at least 93% of the soda in the green liquor clarifier underflow. Since liquor is simply filtered out of the dregs, there is no dilution, and the filtrate can be returned to green liquor storage without any problems.
Naturally, other suitable filters could be used. In that regard, it should be appreciated that one of the advantages of the present invention is that a variety of conventional filters can be used to perform the novel step of filtering the dregs before the dregs are sent to the precoat dregs filter.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same become better understood by reference to the following detailed descriptions when considered in connection with the accompanying drawings, in which:
FIG. 1 depicts a conventional kraft mill recausticizing system;
FIG. 2 represents a portion of the kraft mill recausticizing system employing an embodiment of the present invention, the green liquor filter; and
FIG. 3 depicts a preferred embodiment of the present invention in which a sump tank is used in conjunction with the dregs filter of the present invention in a kraft mill recausticizing system.
DETAILED DESCRIPTION
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, and more particularly to FIG. 1 thereof, in a conventional kraft liquor cycle, the digestion of wood chips takes place in one or more digesters employing an aqueous mixture of sodium hydroxide and sodium sulfide called white liquor. After the cooking operation, the waste liquor, sometimes referred to as black liquor, is separated from the pulp fibers, concentrated and burnt in a recovery furnace to form a smelt. The smelt, which consists mainly of sodium carbonate and sodium sulfide, is then dissolved in an aqueous solution, usually referred to as a weak wash, to form the green liquor.
FIG. 1 shows schematically a recausticizing plant wherein the smelt and water are added to a smelt dissolver tank 101. The raw green liquor is then passed to a green liquor clarifier 102 where the dregs, comprising mainly carbonaceous particles and metallic compounds insoluble in the green liquor are removed. The dregs are conveyed to dregs storage 103 and then to a dregs filter 104. The clarified green liquor is mixed with lime in a combination slaker 105 to convert the sodium carbonate to sodium hydroxide in accordance with the formula:
CaO+Na.sub.2 CO.sub.3 +H.sub.2 O␣2NaOH+CaCO.sub.3
(The lime is added by means of a number of components comprising a hot lime conveyor 106, a lime bucket elevator 107, a combination lime bin 108, and a lime screen feeder 109.) During this reaction the lime and calcium carbonate are insoluble and are, therefore, present in the liquid as suspended solids. Several other impurities from the lime or from the dregs are also insoluble and become part of the suspended solids. The mixture of these insoluble compounds forms the lime mud.
To complete the reaction, the slurry, which comprises sodium hydroxide and calcium carbonate particles, is passed through a series of agitated vessels called causticizers 110. The slurry is allowed to react at temperatures between about 90° and 105° C. for a period varying from 60 to 180 minutes. The reacted mixture is then passed to a white liquor clarifier 111 to separate the lime mud from the white liquor. The white liquor then goes to the white liquor storage 112 for use in the digestion of wood chips and contains mostly an aqueous solution of sodium hydroxide and sodium sulfide.
The thickened lime mud is washed in a lime mud washer 113, passes through a lime mud storage tank 114 and a lime mud filter 115 where it is dewatered and then calcined in a lime kiln 116 or in a fluidized bed calciner 117 to yield reburned lime which is reused for causticizing green liquor in the slaker.
In the conventional process shown in FIG. 1, the underflow of the green liquor clarifier is passed directly to a dregs filter 104. The dregs filter is typically a precoat filter. The dregs cake formed on the precoat filter is discarded, while the overflow is directed to a weak wash storage tank 118. This process does not reduce the pH of the dregs to an acceptable level, however. Thus, in accordance with the process of the present invention, the underflow from the green liquor clarifier is subjected to a preliminary filtering step to remove green liquor from the underflow so that the dregs constitute about 50% suspended solids. In this way, a significant percentage of the soda is removed from the underflow before the precoat dregs filter step.
FIG. 2 depicts one embodiment of the apparatus of the present invention in which the kraft mill recausticizing system employs a green liquor filter. More specifically, the raw green liquor passes through a conduit 1 to a green liquor clarifier 2. The overflow from the green liquor clarifier flows on through additional conduit 3 for the green liquor circuit. The underflow from the green liquor clarifier passes on to a green liquor filter 4, which filters the underflow. The filtrate from the green liquor filter is returned to the conduit 3 constituting the green liquor circuit. The resultant cake from this filter is washed with water and passes on to a precoat filter 5.
This precoat filter operates in a conventional fashion, in which there is an initial cake formation and the resultant overflow from formation of the cake is passed through conduit 6 to the white liquor. The cake is subsequently washed and the washing is also passed through to the white liquor conduit 6. By virtue of this process, the pH of the dregs cake is reduced to an acceptable level. The cake resulting from the wash is then discarded as waste 7.
FIG. 3 depicts a preferred embodiment of the present invention in which the underflow of the green liquor clarifier 2 is directed to a sump tank 8, the contents of which are pumped by pump 9, either periodically or continuously, to the green liquor filter 4 (alternatively referred to as a dregs filter). The filtrate is then directed to the green liquor circuit 3, while the underflow is directed to the precoat filter 5 (or second dregs filter) indicated in FIG. 2.
Other features of the invention will become apparent in the course of the following descriptions of exemplary embodiments which are provided for illustration of the invention and are not intended to be limiting thereof.
In the description of the invention, all percentages are given in term of a ratio of weight to weight.
A production rate of 1680 BDTPD (bone dry tons per day) kraft linerboard on two lines and 450 BDST/day (bone dry short tons) semichemical corrugating medium is assumed, using a modified green liquor cooking in which the green liquor/white liquor ratio is higher than the normal 1.2.
______________________________________White liquor flow 734 GPMGreen liquor to semichem 50 GPMGreen liquor flow 924 GPMGreen liquor to slaker 874 GPM (depends on WLC U- flow consistency)TTA (total titratable alkali) 7.800 lb./cu. ft.AA (active alkali) 6.668 lb./cu. ft.EA (effective alkali) 5.835 lb./cu. ft.Sulfidity 25%- of AACausticity 81.5%Lime availability 85%Scrubber recycle 0% (precipitator, dry return)Dregs 2774 ppm or 17.0 lb./BDT pulpWLC (white liquor clarifier) underflow 42% ss (suspended solids)LMW (lime mud washer) underflow 44% ssLM (lime mud) filter feed 34% ssLM filter cake 75% TS (total solids)Wash displacements 0.9 (30 GPM) (gallons per minute)EQUIPMENT SIZEGreen liquor clarifier 70 ft. dia. × 40 ft. highDregs filter 6 ft. dia × 8 ft. face______________________________________
The process of the present invention requires two stage filtration of the underflow of the green liquor clarifier. This could be done using two precoat filters in series, but this means two precoats, using two to three times the lime mud. In such an example, the estimated total lime mud required is 40 TPD or 8% of the process flow. In contrast, a standard precoat filter would use about 15 TPD or 3% of the process flow.
According to the best mode of the present invention, a CAUSTEC™ pressure filter is used for this application. Adapted as a green liquor filter, the CAUSTEC™ cassette filter requires no precoat and can recover at least 93% of the soda in the green liquor clarifier underflow. Since the liquor is simply filtered out of the dregs, there is no dilution, and the filtrate can be returned to green liquor storage without any problems.
The CAUSTEC™ cassette filter is an enclosed vessel, which uses the pressure of the liquor feed pump to provide the driving force for filtration. Thus, there is no vacuum pump and no resultant air infiltration, and the system uses much less power. At the same time a greater differential pressure is developed, so a drier cake is formed.
The soda content of the dregs in the green liquor clarifier underflow is about 44%. The soda content in the green liquor filter cake at 50% ss is about 9.4%. Specifically, 1912 lb./hr. of soda is recovered. Out of 2068 lb./hr.in the underflow, only 156 lb./hr. of soda is left in the cake. 50% solids in the filter cake has been assumed for the calculations, but 70% solids or more can be achieved in a preferred embodiment employing green liquor filtration.
The cake is washed after cake formation. Calculations show that a very reasonable amount of wash, between approximately 1 and 2 displacements, should be sufficient to wash the cake down to a pH of 12.
The dregs cake is sluiced off the CAUSTEC™ cassette filter by backwashing with water. This water also serves to wash out a great deal of soda when the dregs are filtered on a precoat filter. In this example sufficient water is used to form a 10% suspended solids slurry to feed the precoat filter. This is thin enough to form a good cake and do a good washing job. Consideration of the mechanism of precoat filtration shows that adding more water at this point does not affect the precoat filter sizing, which is based on solids, not liquid flow. The dregs filter filtrate flow is only 39 GPM and can be easily absorbed in the weak-wash system. The weak-wash flow is calculated at 914 GPM, so the dregs filtrate is about 4% of the total weak wash flow.
In alternate embodiments of the present invention, filters other than a CAUSTEC™ cassette filter may be employed. Such filters can be conventional filter devices employed in the industry which can effectively separate the underflow from the green liquor clarifier.
Tables 1 and 2 further demonstrate the advantages offered by the present invention relative to the prior art. Table 1 represents a flowsheet summary of a conventional kraft mill recausticizing system. Table 2 depicts a flowsheet summary of a kraft mill recausticizing system embodying the present invention.
TABLE 1__________________________________________________________________________ 05/18/93 "WLC2DW" WATER SOLIDSEXAMPLE FLOWSHEET SUMMARY CFD CFH GPM LB/HR LB/HR STPD %__________________________________________________________________________ Na2O1A RAW GREEN LIQUOR FLOW 90° C. 148538 6189 772 372481 753 9.01B G L CLARIFIER OVERFLOW 90° C. 144776 6032 752 363492 44.2 0.51C G L CLARIFIER UNDERFLOW 3265 136 17 7741 708 8.5 44.2%2A WATER TO DREGS WASHER 16352 681 85 415902B DREGS WASHER FEED 20324 847 106 50580 704 8.4 44.3%2C DREGS WASHER OVERFLOW 16565 690 86.1 41590 4.3 0.12D DREGS WASHER UNDERFLOW 3761 157 19.5 8989 704 8.4 21.5%3A DREGS FILTER LIME MUD PRECOAT 568 23.6 2.9 1054 1056 12.73B TOTAL TO DREGS FILTER 4328 180 22.5 10043 1760 21.1 10.8%5A FIRST DREGS FILTER CAKE 70° C. 1037 43.2 5.4 1756 1760 21.1 0.44%4 DREGS FILTER WASH WATER 70° C. 1139 47.5 5.9 28985B WASHED DREGS FILTER CAKE 70° C. 1037 43.2 5.4 1756 1760 21.1 0.14%6 DREGS FILTER FILTRATE 70° C. 3983 166 20.7 10131 0.0 0.07 TOTAL DREGS SYSTEM OVERFLOW 20336 847 105.6 51721 4.3 0.18 WATER TO SLAKE LIME (95° C.) 2788 116.2 14.5 69779 LIME USE, BONE DRY 6179 257 32.1 25549 306.6 MUD GENERATED, BONE DRY 6179 257 32.1 42592 511.110 GRIT LOSS (WET) 182 7.6 0.9 275 511 6.111 GRIT WASH WATER 108 4.5 0.6 27512 FLOW THROUGH CAUSTICIZERS 95° C. 148601 6192 772 356515 42126 505.513 WHITE LIQUOR FLOW AT 95° C. 124579 5191 647 311702 37.3 0.4514 W L C UNDERFLOW AT 95° C. 24017 1001 125 44813 42088 505.1 12.2% W L C UNDERFLOW AT 70° C. 23726 989 123 44813 42088 505.115 SCRUBBER RECYCLE 70° C. 81438 3393 423 204455 7242 86.926 FILTRATES 66366 2765 345 168791 8.5 0.17 DREGS SYSTEM OVERFLOW 20336 847 106 51721 4.3 0.116 L M W FEED 70° C. 175520 7313 912 428191 49382 592.6 14.1%17 L M W OVERFLOW (WEAK WASH) 70° C. 146457 6102 761 372481 38.1 0.4618 L M W U'FLOW TO MUD STORAGE 70° C. 29063 1211 151 55710 49344 592.1 2.94% DILUTION WATER-DF PRECOAT 758 32 3.9 1928 DILUTION WATER-LMF FEED 34651 1444 180 8813019 TOTAL DILUTION WATER 35409 1475 184 9005820 LIME MUD TO DREGS FILTER 1380 57 7.2 3120 1056 12.721 FILTER FEED SLURRY 63091 2629 328 142647 48288 579.5 3.00%22 CAKE WASH WATER 15778 657 82 4012923 FILTER CAKE 13315 555 69 16052 48279 579.4 0.086%24 LMF FILTRATE 70° C. 65554 2731 341 166725 8.5 0.1025 DREGS FILT PRECOAT FILTRATE 812 34 4.2 206626 TOTAL FILTRATES 66366 2765 345 168791 8.5 0.1027 SMELT 715 8.628 SMELT & WEAK WASH (RAW GREEN LIQUOR)__________________________________________________________________________ SLURRY SLURRY LB/HR BREAKDOWN OF CHEM-LB/HREXAMPLE FLOWSHEET SUMMARY SS SP GR CHEM TTA NaOH Na2S SO4 Na2CO3__________________________________________________________________________1A RAW GREEN LIQUOR FLOW 90° C. 1669 1.17 77809 47859 4520 17088 3554 526471B G L CLARIFIER OVERFLOW 90° C. 100 1.17 78430 47251 4520 16325 4940 526441C G L CLARIFIER UNDERFLOW 7.00% 1.19 1670 1006 96 348 105 11212A WATER TO DREGS WASHER 0.98 625 -605 -762 13862B DREGS WASHER FEED 1.3% 1.00 1670 1006 96 348 105 11212C DREGS WASHER OVERFLOW 100 1.00 1305 786 75 272 82 8762D DREGS WASHER UNDERFLOW 7.00% 1.03 365.5 220.2 21.1 76.1 23.0 245.43A DREGS FILTER LIME MUD PRECOAT 38.6% 1.853B TOTAL TO DREGS FILTER 13.1% 1.20 365.5 220.2 21.1 76.1 23.0 245.45A FIRST DREGS FILTER CAKE 70° C. 36.5% 1.79 12.4 7.5 0.72 2.59 0.78 8.354 DREGS FILTER WASH WATER 70° C. 0.98 4.0 2.4 0.23 0.82 0.25 2.665B WASHED DREGS FILTER CAKE 70° C. 50.0% 1.31 361.6 217.8 20.8 75.3 22.8 242.76 DREGS FILTER FILTRATE 70° C. 1.01 361.6 217.8 20.8 75.3 22.8 242.77 TOTAL DREGS SYSTEM OVERFLOW 0.98 1666.4 1003.9 96.0 346.9 105.0 1118.58 WATER TO SLAKE LIME (95° C.) 0.96 -10035 0 30882 CAUSTICIZING -409189 LIME USE, BONE DRY 100% 1.59 625 -605 -762 1386 OXIDATION MUD GENERATED, BONE DRY 100% 2.6510 GRIT LOSS (WET) 65.0% 1.66 -9411 -605 30882 -762 1386 -4091811 GRIT WASH WATER 0.9812 FLOW THROUGH CAUSTICIZERS 95° C. 9.0% 1.21 69019 46647 35402 15564 6326 1172713 WHITE LIQUOR FLOW AT 95° C. 1.15 60889 40255 30952 12942 6743 1025314 W L C UNDERFLOW AT 95° C. 44.0% 1.53 8754 5787 4450 1861 969 1474 W L C UNDERFLOW AT 70° C. 44.0% 1.55 624 -605 -761 138615 SCRUBBER RECYCLE 70° C. 3.3% 1.0526 FILTRATES 0.99 2205 1294 924 341 414 5277 DREGS SYSTEM OVERFLOW 1666 1004 96 347 105 111916 L M W FEED 70° C. 10.3% 1.05 12625 8086 5469 2548 1488 311917 L M W OVERFLOW (WEAK WASH) 70° C. 99 0.98 10547 6571 4520 1967 1483 257818 L M W U'FLOW TO MUD STORAGE 70° C. 46.0% 1.42 2216 1381 950 413 312 541 DILUTION WATER-DF PRECOAT 0.98 138 -134 -168 306 DILUTION WATER-LMF FEED 0.9819 TOTAL DILUTION WATER 0.9820 LIME MUD TO DREGS FILTER 25.0% 1.18 47 3021 FILTER FEED SLURRY 25.0% 1.18 2216 1381 950 413 312 54122 CAKE WASH WATER 0.98 51 -50 -63 11423 FILTER CAKE 75.0% 1.86 62 36 26 10 12 1524 LMF FILTRATE 70° C. 51 0.9825 DREGS FILT PRECOAT FILTRATE 0.9826 TOTAL FILTRATES 50 0.99 2205 1294 924 341 414 52727 SMELT 67261 41287 0 15121 2071 5006928 SMELT & WEAK WASH 77809 47859 4520 17088 3554 52647 (RAW GREEN LIQUOR)__________________________________________________________________________ BREAKDOWN OF TTA-LB/HREXAMPLE FLOWSHEET SUMMARY NaOH Na2S SO4 Na2CO3 TOT S R.E.__________________________________________________________________________1A RAW GREEN LIQUOR FLOW 90° C. 3502 13570 1551 30786 15121 89.74%1B G L CLARIFIER OVERFLOW 90° C. 3502 12965 2156 30785 15120 85.74%1C G L CLARIFIER UNDERFLOW 75 276 46 656 322 85.74%2A WATER TO DREGS WASHER -605 605 CLC RE LOSS = -4.00%2B DREGS WASHER FEED 75 276 46 656 322 85.74%2C DREGS WASHER OVERFLOW 58 216 36 512 252 85.74%2D DREGS WASHER UNDERFLOW 16.3 60.4 10.0 143.5 70.5 85.74%3A DREGS FILTER LIME MUD PRECOAT3B TOTAL TO DREGS FILTER 16.3 60.4 10.0 143.5 70.5 85.74%5A FIRST DREGS FILTER CAKE 70° C. 0.56 2.06 0.34 4.88 2.40 85.74%4 DREGS FILTER WASH WATER 70° C. 0.18 0.65 0.11 1.56 0.76 85.74%5B WASHED DREGS FILTER CAKE 70° C. 16.1 59.8 9.9 141.9 69.7 85.74%6 DREGS FILTER FILTRATE 70° C. 16.1 59.8 9.9 141.9 69.7 85.74%7 TOTAL DREGS SYSTEM OVERFLOW 74.4 275.5 45.8 654.1 321.3 85.74%8 WATER TO SLAKE LIME (95° C.) 23928 -239289 LIME USE, BONE DRY -605 605 S + C RE LOSS -4.00% MUD GENERATED, BONE DRY10 GRIT LOSS (WET) 23928 -605 605 -23928 011 GRIT WASH WATER12 FLOW THROUGH CAUSTICIZERS 95° C. 27429 12360 2760 6857 15120 81.74%13 WHITE LIQUOR FLOW AT 95° C. 23981 10278 2942 5995 13220 77.75%14 W L C UNDERFLOW AT 95° C. 3448 1478 423 862 1901 77.75% W L C UNDERFLOW AT 70° C. -605 605 WLC RE LOSS = -4.00%15 SCRUBBER RECYCLE 70° C.26 FILTRATES 716 271 181 308 451 60.00%7 DREGS SYSTEM OVERFLOW 74 275 46 654 321 85.74%16 L M W FEED 70° C. 4238 2024 649 1824 2673 75.71%17 L M W OVERFLOW (WEAK WASH) 70° C. 3502 1562 647 1507 2209 70.71%18 L M W U'FLOW TO MUD STORAGE 70° C. 736 328 136 317 464 70.71% DILUTION WATER-DF PRECOAT -134 134 LMW RE LOSS = -5.00% DILUTION WATER-LMF FEED19 TOTAL DILUTION WATER20 LIME MUD TO DREGS FILTER21 FILTER FEED SLURRY 736 328 136 317 464 70.71%22 CAKE WASH WATER -50 50 LMF RE LOSS = -10.71%23 FILTER CAKE 20 8 5 9 13 60.00%24 LMF FILTRATE 70° C.25 DREGS FILT PRECOAT FILTRATE26 TOTAL FILTRATES 716 271 181 308 451 60.00%27 SMELT 0 12008 904 29279 12912 93.00%28 SMELT & WEAK WASH 3502 13570 1551 30786 15121 89.74% (RAW GREEN LIQUOR)__________________________________________________________________________
TABLE 2__________________________________________________________________________ 05/18/93 "WLCGLF2" WATER SOLIDSEXAMPLE FLOWSHEET SUMMARY CFD CFH GPM LB/HR LB/HR STPD %__________________________________________________________________________ Na2O1 RAW GREEN LIQUOR FLOW 90° C. 145041 6043 753 363703 750 9.02A G L CLARIFIER UNDERFLOW 3254 136 17 7715 706 7.5 44.2%2B G L FILTER CAKE 258 11 1.3 194 706 8.5 3.5%2C G L FILTER FILTRATE 90° C. 2996 125 15.6 7522 0.23 0.003A DILUTION WATER 1496 62 8 38053B GLF UNDERFLOW SLURRY-, % ss 1773 74 9 3998 706 8.5 3.5%3C DREGS FILTER LIME MUD PRECOAT 569 23.7 3.0 1056 1058 12.74 DREGS FILTER WASH WATER 70° C. 1141 47.6 5.9 29035 DREGS FILTER CAKE 70° C. 1038 43.2 5.4 1759 1764 21.2 0.16%6 DREGS FILTER FILTRATE 70° C. 2437 102 12.7 61987A G L CLARIFIER OVERFLOW 90° C. 141787 5908 737 355987.3 43.9 0.57B CLARIFIED GREEN LIQUOR FLOW 90° C. 144783 6033 751 363509 44.2 0.58 WATER TO SLAKE LIME (95° C.) 2788 116.2 14.5 69779 LIME USE, BONE DRY 6179 257 32.1 25549 306.6 MUD GENERATED, BONE DRY 6179 257 32.1 42593 511.110 GRIT LOSS (WET) 182 7.6 0.9 275 511 6.111 GRIT WASH WATER 108 4.5 0.6 27512 FLOW THROUGH CAUSTICIZERS 95° C. 148608 6192 772 356533 42126 505.513 WHITE LIQUOR FLOW AT 95° C. 124579 5191 647 311702 37.3 0.4514 W L C UNDERFLOW AT 95° C. 24024 1001 125 44831 42088 505.1 12.2% W L C UNDERFLOW AT 70° C. 23732 989 123 44831 42088 505.115 SCRUBBER RECYCLE 70° C. 79566 3315 413 199698 7234 86.826 LMF FILTRATES 66424 2768 345 168938 8.5 0.16 DREGS FILTER FILTRATE 70° C. 2437 102 13 619816 L M W FEED 70° C. 172159 7173 894 419663 49331 592.0 12.5%17 L M W OVERFLOW (WEAK WASH) 70° C. 143005 5959 743 363703 37.3 0.4518 L M W U'FLOW TO MUD STORAGE 70° C. 29154 1215 151 55961 49294 591.5 2.59% DILUTION WATER-DF PRECOAT 760 32 3.9 1932 DILUTION WATER-LMF FEED 34616 1442 180 8804119 TOTAL DILUTION WATER 35375 1474 184 8997320 LIME MUD TO DREGS FILTER 1386 58 7.2 3133 1058 12.721 FILTER FEED SLURRY 63144 2631 328 142800 48235 578.8 2.65%22 CAKE WASH WATER 15766 657 82 4010023 FILTER CAKE 13303 554 69 16040 48227 578.7 0.075%24 LMF FILTRATE 70° C. 65607 2734 341 166860 8.5 0.1025 DREGS FILT PRECOAT FILTRATE 817 34 4.2 207826 TOTAL FILTRATES 66424 2768 345 168938 8.5 0.1027 SMELT 713 8.628 SMELT & WEAK WASH (RAW GREEN LIQUOR)__________________________________________________________________________ SLURRY SLURRY LB/HR BREAKDOWN OF CHEM-LB/HREXAMPLE FLOWSHEET SUMMARY SS SP GR CHEM TTA NaOH Na2S SO4 Na2CO3__________________________________________________________________________1 RAW GREEN LIQUOR FLOW 90° C. 1696 1.17 77721 47874 4428 17086 3410 527982A G L CLARIFIER UNDERFLOW 7.00% 1.19 1662 1003 94 347 102 11212B G L FILTER CAKE 75.00% 1.40 42 25 2 9 3 282C G L FILTER FILTRATE 90° C. 26 1.17 1620 978 92 338 99 10923A DILUTION WATER 0.98 612 -602 -766 13783B GLF UNDERFLOW SLURRY-, % ss 14.9% 1.03 41.7 25.2 2.4 8.7 2.5 28.13C DREGS FILTER LIME MUD PRECOAT 38.8% 1.844 DREGS FILTER WASH WATER 70° C. 0.985 DREGS FILTER CAKE 70° C. 50.0% 1.31 4.6 2.8 0.3 1.0 0.3 3.16 DREGS FILTER FILTRATE 70° C. 0.98 37.1 22.4 2.1 7.7 2.3 25.07A G L CLARIFIER OVERFLOW 90° C. 1.17 76683 46270 4336 15981 4688 516777B CLARIFIED GREEN LIQUOR FLOW 90° C. 100 1.17 78304 47248 4427 16319 4787 527698 WATER TO SLAKE LIME (95° C.) 0.96 -10066 0 30976 CAUSTICIZING -410429 LIME USE, BONE DRY 100% 1.59 622 -602 -758 1380 OXIDATION MUD GENERATED, BONE DRY 100% 2.6510 GRIT LOSS (WET) 65.0% 1.66 -9444 -602 30976 -758 1380 -4104211 GRIT WASH WATER 0.9812 FLOW THROUGH CAUSTICIZERS 95° C. 9.0% 1.21 68859 46646 35404 15561 6167 1172713 WHITE LIQUOR FLOW AT 95° C. 1.15 60744 40255 30952 12942 6598 1025314 W L C UNDERFLOW AT 95° C. 44.0% 1.53 8737 5790 4452 1861 949 1475 W L C UNDERFLOW AT 70° C. 44.0% 1.55 622 -602 -758 138015 SCRUBBER RECYCLE 70° C. 3.4% 1.0426 LMF FILTRATES 0.99 1894 1134 924 298 361 3116 DREGS FILTER FILTRATE 70° C. 0.98 37 22 2 8 2 2516 L M W FEED 70° C. 10.5% 1.05 10668 6946 5378 2167 1312 181117 L M W OVERFLOW (WEAK WASH) 70° C. 100 0.98 8881 5625 4428 1665 1297 149118 L M W U'FLOW TO MUD STORAGE 70° C. 46.0% 1.41 1906 1207 950 357 278 320 DILUTION WATER-DF PRECOAT 0.98 118 -115 -144 263 DILUTION WATER-LMF FEED 0.9819 TOTAL DILUTION WATER 0.9820 LIME MUD TO DREGS FILTER 25.0% 1.17 41 2621 FILTER FEED SLURRY 25.0% 1.17 1906 1207 950 357 278 32022 CAKE WASH WATER 0.98 42 -41 -51 9323 FILTER CAKE 75.0% 1.86 53 32 26 8 10 924 LMF FILTRATE 70° C. 51 0.9825 DREGS FILT PRECOAT FILTRATE 0.9826 TOTAL FILTRATES 50 0.99 1894 1134 924 298 361 31127 SMELT 68841 42250 0 15421 2113 5130728 SMELT & WEAK WASH 77721 47874 4428 17086 3410 52798 (RAW GREEN LIQUOR)__________________________________________________________________________ BREAKDOWN OF TTA-LB/HREXAMPLE FLOWSHEET SUMMARY NaOH Na2S SO4 Na2CO3 TOT S R.E.__________________________________________________________________________1 RAW GREEN LIQUOR FLOW 90° C. 3431 13569 1488 30874 15057 90.12%2A G L CLARIFIER UNDERFLOW 73 275 44 655 320 86.12%2B G L FILTER CAKE 1.8 6.9 1.1 16.4 8.0 86.12%2C G L FILTER FILTRATE 90° C. 71 268 43 639 312 86.12%3A DILUTION WATER -602 602 CLC RE LOSS = -4.00%3B GLF UNDERFLOW SLURRY-, % ss 1.8 6.9 1.1 16.4 8.0 86.12%3C DREGS FILTER LIME MUD PRECOAT4 DREGS FILTER WASH WATER 70° C.5 DREGS FILTER CAKE 70° C. 0.2 0.8 0.1 1.8 0.9 86.12%6 DREGS FILTER FILTRATE 70° C. 1.6 6.1 1.0 14.6 7.1 86.12%7A G L CLARIFIER OVERFLOW 90° C. 3359 12692 2046 30219 14737 86.12%7B CLARIFIED GREEN LIQUOR FLOW 90° C. 3430 12960 2089 30858 15049 86.12%8 WATER TO SLAKE LIME (95° C.) 24000 -240009 LIME USE, BONE DRY -602 602 S + C RE LOSS -4.00% MUD GENERATED, BONE DRY10 GRIT LOSS (WET) 24000 -602 602 -24000 011 GRIT WASH WATER12 FLOW THROUGH CAUSTICIZERS 95° C. 27431 12358 2691 6858 15049 82.12%13 WHITE LIQUOR FLOW AT 95° C. 23981 10278 2879 5995 13157 78.12%14 W L C UNDERFLOW AT 95° C. 3449 1478 414 862 1892 78.12% W L C UNDERFLOW AT 70° C. -602 602 WLC RE LOSS = -4.00%15 SCRUBBER RECYCLE 70° C.26 LMF FILTRATES 716 236 158 182 394 60.00%6 DREGS FILTER FILTRATE 70° C. 2 6 1 15 7 86.12%16 L M W FEED 70° C. 4167 1721 573 1059 2294 75.03%17 L M W OVERFLOW (WEAK WASH) 70° C. 3431 1322 566 872 1888 70.03%18 L M W U'FLOW TO MUD STORAGE 70° C. 736 284 121 187 405 70.03% DILUTION WATER-DF PRECOAT -115 115 LMW RE LOSS = -5.00% DILUTION WATER-LMF FEED19 TOTAL DILUTION WATER20 LIME MUD TO DREGS FILTER21 FILTER FEED SLURRY 736 284 121 187 405 70.03%22 CAKE WASH WATER -41 41 LMF RE LOSS = -10.03%23 FILTER CAKE 20 7 4 5 11 60.00%24 LMF FILTRATE 70° C.25 DREGS FILT PRECOAT FILTRATE26 TOTAL FILTRATES 716 236 158 182 394 60.00%27 SMELT 0 12247 922 30003 13169 93.00%28 SMELT & WEAK WASH 3431 13569 1488 30874 15057 90.12% (RAW GREEN LIQUOR)__________________________________________________________________________
Additionally, Charts 1 and 2 demonstrate the superior characteristics of dregs obtained with the present invention relative to dregs produced by the conventional processes. In Chart 1, the Untreated column designates the pH of the untreated underflow of the green liquor clarifier, the Precoat Only column designates the pH of dregs resulting from precoat dregs filter treatment only, the CAUSTEC Only column designates the pH of dregs resulting from CAUSTEC™ treatment only, and the CAUSTEC+Precoat column designates the pH of dregs resulting from CAUSTEC™ and precoat dregs filter treatment dregs. As shown, it is only with the process of the present invention that an acceptable pH level is reached. In Chart 2, comparative data is presented regarding % Na 2 O (a measure of the amount of alkali) in the dregs resulting from the processes described above. As above, the Untreated column designates the amount of alkali in the untreated underflow of the green liquor clarifier, the Precoat Only column designates the amount of alkali in dregs resulting from precoat dregs filter treatment only, the CAUSETEC Only column designates the amount of alkali in dregs resulting from CAUSTEC™ treatment only, and the CAUSTEC+Precoat column designates the amount of alkali in dregs resulting from CAUSTEC™ and precoat dregs filter treatment dregs. Again, the dregs produced by the present invention utilizing a CAUSTEC cassette dregs filter in combination with a dregs precoat filter contains much less alkali then the other processes.
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 is specifically described herein. | In a kraft pulp mill, a process and apparatus for removing and washing dregs from green liquor so that the pH of the dregs is below "hazardous waste" levels. Specifically, green liquor clarifier underflow is filtered using a simple non-precoat cassette filter to form a first dregs cake. The dregs cake is diluted, preferably with water. The diluted dregs cake is then filtered in a precoat dregs filter to produce a dregs cake that is at least 50% solid and has a pH of about 12.0 or less. | 8 |
This application is a national stage application under 35 U.S.C. §371 of PCT Application No. PCT/EP2015/051376, filed Jan. 23, 2015, which claims the priority benefit of Italian Patent Application No. MI2014A000097, filed Jan. 24, 2014.
FIELD OF THE INVENTION
The present invention concerns the field of ion channels, and in particular relates to peptides which are suitable for use in the treatment of conditions where the L-type calcium channel density is altered.
STATE OF THE ART
Ion channels are integral membrane proteins that help establish and control the small voltage gradient across the plasma membrane of living cells by allowing the flow of ions down their electrochemical gradient. They are present in the membranes that surround all biological cells regulating the flow of ions across it.
L-Type Calcium Channels (LTCCs) are ion channels that couple membrane depolarization to cellular Ca 2+ entry 1 . LTCCs are critical for numerous processes including cardiac action potential propagation, muscle contraction, Ca 2+ -dependent gene expression, synaptic efficacy, and cell survival by contributing to various signaling cascades. LTCCs play a critical role in Ca 2+ dependent signaling processes in a variety of cell types and are mostly found in skeletal muscle, smooth muscle, bone (osteoblasts), atrial and ventricular myocytes (responsible for prolonged action potential in cardiac cell; also termed DHP receptors), dendrites and dendritic spines of cortical neurons. In particular LTCCs can be found in excitable cells such as cardiac and skeletal muscles, smooth muscles, neuronal cells, cells which are present in the eye and are responsible for vision.
LTCCs are the initiators of the Ca 2+ -induced Ca 2+ release (CICR) process in the heart and are composed of different subunits: the pore-forming subunit Ca v α1.2 and the accessory Ca v β2 and Ca v α2δ subunits. The number of functional LTCCs at the plasma membrane strongly influences the strength and duration of Ca 2+ signals triggering myocardial systolic/diastolic cycles and cardiac rhythm and changes in the LTCC density have been observed in aging and various diseases.
Indeed, a trend for the Ca 2+ channel density to decline has been found with the progression of pathological hypertrophy, dilated cardiomyopathy, atrial/ventricular fibrillation, and diabetic cardiomyopathy. In addition, recent evidence has revealed that loss-of-function mutations in genes coding for subunits of the LTCC, once considered rare, are now recognized as relatively common and to be associated with a wide variety of inherited cardiac arrhythmic syndromes, including Timothy, early repolarization, short QT syndrome and Brugada syndromes. Thus, these observations highlight the pivotal role of LTCCs in health and disease and support the view that LTCCs may represent a reasonable pharmacologic target for the treatment of variety of pathological conditions that need novel therapeutic approaches to reduce their morbidity and mortality.
In the past few years major advancements have been made in the understanding of the abnormalities of Ca 2+ regulation present in human diseases and efforts are being made to turn this knowledge into novel therapeutic strategies targeting Ca 2+ -related ion exchangers, binding proteins and ion-channels to prevent or reverse Ca 2+ handling dysfunction.
Exhaustive understandings of the molecular mechanisms underlying LTCC structural and functional alterations occurring in cardiac pathologies as well as in other LTCC-related (or Ca 2+ -dependent) pathologies in general, are required.
The need and importance is increasingly felt for the development of small molecules such as therapeutic peptides for the treatment of conditions having altered LTCC functionality, which are more target-specific and avoid adverse effects of currently available drugs.
It is therefore object of the present invention the development of novel mimetic peptides as innovative tools, which allow to modulate the quantity of intracellular Ca 2+ available for activating excitable cells (i.e. for binding and activating muscle contractile proteins).
SUMMARY OF THE INVENTION
The present invention concerns an isolated peptide comprising the amino acid sequence of SEQ ID NO:10, and its use as a peptide binding domain. The amino acid sequence set forth in SEQ ID NO:10 corresponds to a previously unknown binding domain [hereafter referred to as Tail Interacting Domain (TID), see Example 1] of the Ca v β2 target protein, which is the binding site of the peptides (set forth in SEQ ID NO:1 to 9 and SEQ ID NO:12 to 22) and which, upon binding to the TID, extend the half-life of the Ca v α1.2 protein, pore-forming subunit of LTCCs. This modulation of LTCC density restores the intracellular Ca 2+ handling in conditions where alterations of Ca 2+ homeostasis in excitable cells determine the extent and severity of the disease.
The invention also relates to mimetic peptides set forth in SEQ ID NO:1 to 9 and SEQ ID NO:12 to 22 that bind to the peptide binding domain TID of the Ca v β2 protein according to SEQ ID NO:10, thus acting on the modulation of the density and function of LTCCs.
As will be further described in the detailed description of the invention, the present invention concerns an isolated peptide having an amino acid sequence chosen from the group consisting of:
(SEQ ID NO: 2) A-Arg-Pro-Asp-Arg-Glu-Ala-Pro-B or (SEQ ID NO: 1) A-Arg-Pro-Asp-Arg-Asp-Ala-Pro-B or (SEQ ID NO: 8) Lys-Gln-Arg-Asp-Arg-His-Lys-Glu-Lys-Asp, or, (SEQ ID NO: 9) Lys-Gln-Arg-Asp-Arg-His-Lys-Asp-Lys-Asp; or (SEQ ID NO: 21) Lys-Gln-Arg-Ser-Arg-His-Lys-Glu-Lys-Asp, or (SEQ ID NO 22) Lys-Gln-Arg-Ser-Arg-His-Lys-Asp-Lys-Asp,
wherein:
A is an amino acid sequence which is optionally present, and if present is chosen from the group consisting of Asp-Gln-, and B is an amino acid sequence which is optionally present, and if present is chosen from the group consisting of: Arg-, Arg-Ser, Arg-Ser-Gln-Ala-Glu-Glu-Glu-Pro-Cys (SEQ ID NO:23), Arg-Ser-Gln-Ala-Glu-Glu-Glu-Pro-Cys-Leu-Glu-Pro-Val-Lys-Lys (SEQ ID NO:24), Arg-Ser-Gln-Ala-Glu-Glu-Glu-Pro-Cys-Leu-Glu-Pro-Val-Lys-Lys-Ser-Gln-His-Arg (SEQ ID NO:25), Arg-Ser-Gln, or Arg-Ser-Gln-Ala-Glu-Glu-Glu-Pro-Cys-Leu-Glu-Pro (SEQ ID NO:26).
The peptides of the present invention have the advantages of being specific for LTCCs as they bind to a pocket domain (TID, SEQ ID NO:10) in the Ca v β2 protein, subunit of the LTCC.
A further aspect of the present invention is the use of an isolated peptide chosen from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22 for the preparation of a medicament.
In a still further aspect the invention relates to the use of an isolated peptide chosen from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22 for the treatment of conditions having altered LTCC density and function.
A further aspect of the present invention relates to a pharmaceutical composition comprising one or more peptides chosen from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22 and/or pharmaceutically acceptable carrier.
A further aspect of the present invention relates to the use of the isolated peptide chosen from the SEQ ID NO:10 for further optimization and development of novel peptides (in addition to SEQ ID NO:1-9 and SEQ ID NO:12-22) or synthetic compounds able to bind the TID binding domain in Ca v β2 and to modulate LTCC density and function.
BRIEF DESCRIPTION OF THE DRAWINGS
The characteristics and advantages of the present invention will be apparent from the detailed description reported below, from the Examples given for illustrative and non-limiting purposes, and from the annexed FIGS. 1-9 , wherein:
FIG. 1 : shows schematic working model of modulation of LTCC half-life in basal (top left), engineered (bottom left), and pathological (right) conditions.
FIG. 2 : shows identification of a previously unknown binding domain in Ca v β2 (TID; SEQ ID NO:10) as described in Example 1. (a, top) schematic representation of Ca v β2 [dark grey box (globular domain); dark grey line (coiled-coil); light grey box (TID); black (Akt consensus site)]. (a, bottom) 3D structure of Ca v β2 (Ca v β2 PDB code: 1T3S 2 ) where solvent accessibility of the TID for a potential protein-protein interaction is shown in light grey; (b) Yeast two-hybrid co-transformation: b-galactosidase activity (dark grey) in streaks of yeast cells on a culture plate, Hu=human, Ms= mus musculus ; labels show the bait and/or prey plasmids transformed into the yeast cells; and (c) co-immunoprecipitation assay of identified positive clones. HEK293 and tSA-201 cells were transfected as indicated (n=4).
FIG. 3 : shows the effects of site-specific mutagenesis in the TID binding site and Ca v α1.2 stability as described in Example 1. a) Western blotting analysis (left) and densitometry measurements (right) of Ca v α1.2 and GAPDH protein levels of total protein lysates from HEK293 transfected cells; b) Yeast two-hybrid co-trasformation: b-galactosidase activity (dark grey) in streaks of yeast cells on a culture plate; labels show the bait and/or prey plasmids transformed into the yeast cells; (c) Ca 2+ flux analysis from HEK293 transfected cells; (d) Ca 2+ current measurements in tSA-201 transfected cells. HEK293 and tSA-201 cells were transfected as indicated. Ca v α1.2 protein degradation was elicited in vitro with cell starvation (serum removal). Protein levels were normalized to GAPDH. (n=4). Data are shown as the means±SEM; *, P<0.05, **, P<0.005; ***, P<0.001.
FIG. 4 : shows the effects of peptides on Ca v α1.2 protein stability and function as described in Example 2 and 3.
a) Western blotting analysis of Ca v α1.2 and GAPDH protein levels of total protein lysates; b) Intracellular Ca 2+ fluxes; (c) Molecular modeling and docking of a peptide (SEQ ID NO:2, dark grey) to TID region (SEQ ID NO:10, light grey) of Ca v β2.; (d) Western blotting analysis of Ca v α1.2 and GAPDH protein levels of total protein lysates; (e) Confocal analyses of adult cardiomyocytes treated with TAT-MP- and TAT-scramble-and stained with di 8-ANEPPS dye. MP=SEQ ID NO:3, scramble=SEQ ID NO:11. (f) Western blotting analysis of Ca v α1.2 and GAPDH protein levels of total protein lysates from HEK293 cells treated with increasing doses of MP; (g) Ca 2+ current measurements in tSA-201 cells previously transfected. For Western blotting analyses, HEK293 or tSA-201 cells transfected or treated as indicated. Protein levels were normalized to GAPDH. (n=4). Data are shown as the means±SEM; *, P<0.05, **, P<0.005; ***, P<0.001. Peptides are chosen from the group listed in Table 1.
FIG. 5 : shows the effects of site-specific mutagenesis in the TID binding site and Ca v α1.2 stability as described in Example 2. Western blotting analysis of Ca v α1.2 and GAPDH protein levels of total protein lysates from HEK293 transfected cells. Ca v α1.2 protein degradation was elicited in vitro with cell starvation (serum removal). HEK293 cells were transfected as indicated. Protein levels were normalized to GAPDH. (n=4).
FIG. 6 : shows the therapeutic potential of mimetic peptide in a genetic mouse model of heart failure as described in Example 4. (a, top) Design of study. Echo, echocardiography. (a, bottom) Fractional shortening (%) as determined by echocardiography in pdk1 knockout mice treated with mimetic peptide (TAT-MP) or scramble (TAT-scramble). (b) Western blotting analysis of Ca v α1.2 and GAPDH protein levels of total protein lysates from left ventricular homogenates. Protein levels were normalized to GAPDH. (n=4) MP=SEQ ID NO:3, scramble=SEQ ID NO:11. Tamoxifen (TAM) and peptide was injected daily as indicated. Protein levels were normalized to GAPDH. Data are shown as the means±SEM; *, P<0.05.
FIG. 7 : shows the therapeutic potential of mimetic peptide in a mouse model of diabetic cardiomyopathy. (a, top) Design of study. Echo, echocardiography. (a, bottom) Fractional shortening (%) as determined by echocardiography in mice treated with streptozotocin (STZ) and mimetic peptide (TAT-MP) or scramble (TAT-scramble). (n=10) (b) Western blotting analysis and densitometry of Ca v α1.2 and GAPDH protein levels of total protein lysates from left ventricular homogenates. (c) Ca 2+ current measurements in cardiomyocytes isolated from treated mice. (d, top) contractility and (d, middle and bottom) systolic and diastolic Ca 2+ transient measurements in cardiomyocytes isolated from treated mice. Cardiomyocytes were analyzed at different pacing (Hz). MP=SEQ ID NO:3, scramble=SEQ ID NO:11. Protein levels were normalized to GAPDH. STZ and peptide were injected daily as indicated. Data are shown as the means±SEM; *, P<0.05, **, P<0.005; ***, P<0.001.
FIG. 8 : shows the therapeutic potential of mimetic peptide in a human cardiac model as described in Example 6. (a) Western blotting analysis of Ca v α1.2 and GAPDH protein levels of total protein lysates from cardiomyocytes (CMs) differentiated from induced pluripotent stem cells (iPSCs) and previously derived from skin fibroblasts of healthy individuals. (n=4) Cells were untreated or treated with an Akt-inhibitor. MP=SEQ ID NO:3, scramble=SEQ ID NO:11.
FIG. 9 : shows the therapeutic potential of mimetic peptide in a model of inherited cardiac arrhythmic syndrome (Brugada) as described in Example 6. I Ca current density was normalized for cell capacitance. The Ca v α1.2 mutation occurs within the Q420E site. HEK293 cells were transfected as indicated. MP=SEQ ID NO:3 (n=15 cells/group). * p<0.05 vs. baseline for MP groups.
DETAILED DESCRIPTION OF THE INVENTION
The present invention concerns an isolated peptide comprising the amino acid sequence of SEQ ID NO:10, corresponding to the TID binding domain of the Ca v β2 target protein.
Ca v β2 is the Voltage-dependent L-type calcium channel subunit beta-2, also known as CACNB2 [gene ID 783 ( Homo sapiens ), gene ID 12296 ( Mus musculus )].
The TID binding site of the Ca v β2 (SEQ ID NO:10) was previously unknown and it has been here revealed as a triggering domain for the modulation of Ca v α1.2 protein half-life. In particular, peptides binding to the TID induce a molecular mechanism that increases Ca v α1.2 protein density and function at the plasma membrane.
The importance of identifying the exact binding site of the Ca v β2, (SEQ ID NO:10 Ile-Ser-Phe-Glu-Ala-Lys-Asp-Phe-Leu-His-Val-Lys-Glu-Lys-Phe-Asn-Asn-Asp-Trp-Trp-Ile-Gly-Arg-Leu-Val-Lys-Glu-Gly-Cys-Gludle-Gly-Phe-Ile) and in particular the amino acids (highlighted in bold in SEQ ID NO:10 Ile-Ser-Phe-Glu-Ala-Lys-Asp-Phe-Leu-His-Val-Lys-Glu-Lys-Phe-Asn-Asn-Asp-Trp-Trp-Ile-Gly-Arg-Leu-Val-Lys-Glu-Gly-Cys-Gludle-Gly-Phe-Ile (SEQ ID NO:10) and further described in example 1) which are responsible for the direct ionic bond between the TID in Ca v β2 and the activator peptides (SEQ ID NO: 1 to 9 and SEQ ID NO: 12 to 22) is widely recognized and allowed the identification of mimetic peptides which modulate the channel's density and activity.
In a further aspect the invention relates to the use of the isolated peptide of SEQ ID NO:10 as a peptide binding domain. In particular, this peptide-binding domain in Ca v β2 is relevant for further optimization and development of novel mimetic peptides or synthetic compounds that are more specific for the binding to the TID domain in Ca v β2 and lead to a modulation of LTCC density and function. In a further aspect the invention concerns mimetic peptides (SEQ ID NO: 1 to 9 and SEQ ID NO:12 to 22) that bind to the TID peptide binding domain of the Ca v β2 protein according to SEQ ID NO:10, thus acting on density and function of voltage dependent LTCCs.
In a preferred aspect the invention concerns an isolated peptide having an amino acid sequence chosen from the group consisting of:
(SEQ ID NO: 2) A-Arg-Pro-Asp-Arg-Glu-Ala-Pro-B or (SEQ ID NO: 1) A-Arg-Pro-Asp-Arg-Asp-Ala-Pro-B or (SEQ ID NO: 8) Lys-Gln-Arg-Asp-Arg-His-Lys-Glu-Lys-Asp, or, (SEQ ID NO: 9) Lys-Gln-Arg-Asp-Arg-His-Lys-Asp-Lys-Asp; or (SEQ ID NO: 21) Lys-Gln-Arg-Ser-Arg-His-Lys-Glu-Lys-Asp, or (SEQ ID NO: 22) Lys-Gln-Arg-Ser-Arg-His-Lys-Asp-Lys-Asp,
wherein:
A is an amino acid sequence which is optionally present, and if present is chosen from the group consisting of Asp-Gln-, and B is an amino acid sequence which is optionally present, and if present is chosen from the group consisting of: Arg-, Arg-Ser, Arg-Ser-Gln-Ala-Glu-Glu-Glu-Pro-Cys (SEQ ID NO:23), Arg-Ser-Gln-Ala-Glu-Glu-Glu-Pro-Cys-Leu-Glu-Pro-Val-Lys-Lys (SEQ ID NO:24), Arg-Ser-Gln-Ala-Glu-Glu-Glu-Pro-Cys-Leu-Glu-Pro-Val-Lys-Lys-Ser-Gln-His-Arg (SEQ ID NO:25), Arg-Ser-Gln, or Arg-Ser-Gln-Ala-Glu-Glu-Glu-Pro-Cys-Leu-Glu-Pro (SEQ ID NO:26).
TABLE 1
Peptide
SEQ
peptide amino acid sequence
peptide amino acid sequence
number
ID NO.
(three letter code)
(one letter code)
1
SEQ ID NO: 1
Arg-Pro-Asp-Arg-Asp-Ala-Pro
RPDRDAP
2
SEQ ID NO: 2
Arg-Pro-Asp-Arg-Glu-Ala-Pro
RPDREAP
3
SEQ ID NO: 3
Asp-Gln-Arg-Pro-Asp-Arg-Glu-
DQRPDREAPRS
Ala-Pro-Arg-Ser
4
SEQ ID NO: 4
Asp-Gln-Arg-Pro-Asp-Arg-Glu-
DQRPDREAPR
Ala-Pro-Arg
5
SEQ ID NO: 5
Asp-Gln-Arg-Pro-Asp-Arg-Glu-
DQRPDREAPRSASQAEEEPC
Ala-Pro-Arg-Ser-Ala-Ser-Gln-
Ala-Glu-Glu-Glu-Pro-Cys
6
SEQ ID NO: 6
Asp-Gln-Arg-Pro-Asp-Arg-Glu-
DQRPDREAPRSASQAEEEPC
Ala-Pro-Arg-Ser-Ala-Ser-Gln-
LEPVKK
Ala-Glu-Glu-Glu-Pro-Cys-Leu-
Glu-Pro-Val-Lys-Lys
7
SEQ ID NO: 7
Asp-Gln-Arg-Pro-Asp-Arg-Glu-
DQRPDREAPRSASQAEEEPCLEPV
Ala-Pro-Arg-Ser-Ala-Ser-Gln-
KKSQHR
Ala-Glu-Glu-Glu-Pro-Cys-Leu-
Glu-Pro-Val-Lys-Lys-Ser-Gln-
His-Arg
8
SEQ ID NO: 8
Lys-Gln-Arg-Asp-Arg-His-Lys-
KQRDRHKEKD
Glu-Lys-Asp
9
SEQ ID NO: 9
Lys-Gln-Arg-Asp-Arg-His-Lys-
KQRDRHKDKD
Asp-Lys-Asp
10
SEQ ID NO: 10
Ile-Ser-Phe-Glu-Ala-Lys-Asp-
ISFEAKDFLHVKEKFNNDWW
Phe-Leu-His-Val-Lys-Glu-Lys-
IGRLVKEGCEIGFI
Phe-Asn-Asn-Asp-Trp-Trp-Ile-
Gly-Arg-Leu-Val-Lys-Glu-Gly-
Cys-Glu-Ile-Gly-Phe-Ile
11
SEQ ID NO: 11
Asp-Gln-Pro-Pro-Ser-Arg-Arg-
DQPPSRRDERA
Asp-Glu-Arg-Ala
12
SEQ ID NO: 12
Asp-Gln-Arg-Pro-Asp-Arg-Glu-
DQRPDREAPRSASQAEEEPCLEP
Ala-Pro-Arg-Ser-Ala-Ser-Gln-
Ala-Glu-Glu-Glu-Pro-Cys-
Leu-Glu-Pro
13
SEQ ID NO: 13
Asp-Gln-Arg-Pro-Asp-Arg-Glu-
DQRPDREAPRSASQ
Ala-Pro-Arg-Ser-Ala-Ser-Gln
14
SEQ ID NO: 14
Asp-Gln-Arg-Pro-Asp-Arg-Asp-
DQRPDRDAPRS
Ala-Pro-Arg-Ser
15
SEQ ID NO: 15
Asp-Gln-Arg-Pro-Asp-Arg-Asp-
DQRPDRDAPR
Ala-Pro-Arg
16
SEQ ID NO: 16
Asp-Gln-Arg-Pro-Asp-Arg-Asp-
DQRPDRDAPRSASQAEEEPC
Ala-Pro-Arg-Ser-Ala-Ser-Gln-
Ala-Glu-Glu-Glu-Pro-Cys
17
SEQ ID NO: 17
Asp-Gln-Arg-Pro-Asp-Arg-Asp-
DQRPDRDAPRSASQAEEEPC
Ala-Pro-Arg-Ser-Ala-Ser-Gln-
LEPVKK
Ala-Glu-Glu-Glu-Pro-Cys-Leu-
Glu-Pro-Val-Lys-Lys
18
SEQ ID NO: 18
Asp-Gln-Arg-Pro-Asp-Arg-Asp-
DQRPDRDAPRSASQAEEEPCLEPV
Ala-Pro-Arg-Ser-Ala-Ser-Gln-
KKSQHR
Ala-Glu-Glu-Glu-Pro-Cys-Leu-
Glu-Pro-Val-Lys-Lys-Ser-Gln-
His-Arg
19
SEQ ID NO: 19
Asp-Gln-Arg-Pro-Asp-Arg-Asp-
DQRPDRDAPRSASQAEEEPCLEP
Ala-Pro-Arg-Ser-Ala-Ser-Gln-
Ala-Glu-Glu-Glu-Pro-Cys-Leu-
Glu-Pro
20
SEQ ID NO: 20
Asp-Gln-Arg-Pro-Asp-Arg-Asp-
DQRPDRDAPRSASQ
Ala-Pro-Arg-Ser-Ala-Ser-Gln
21
SEQ ID NO: 21
Lys-Gln-Arg-Ser-Arg-His-Lys-
KQRSRHKEKD
Glu-Lys-Asp
22
SEQ ID NO: 22
Lys-Gln-Arg-Ser-Arg-His-Lys-
KQRSRHKDKD
Asp-Lys-Asp
23
SEQ ID NO: 23
Arg-Ser-Gln-Ala-Glu-Glu-Glu-
RSQAEEEPC
Pro-Cys
24
SEQ ID NO: 24
Arg-Ser-Gln-Ala-Glu-Glu-Glu-
RSQAEEEPCLEPVKK
Pro-Cys-Leu-Glu-Pro-Val-Lys-
Lys
25
SEQ ID NO: 25
Arg-Ser-Gln-Ala-Glu-Glu-Glu-
RSQAEEEPCLEPVKKSQHR
Pro-Cys-Leu-Glu-Pro-Val-Lys-
Lys-Ser-Gln-His-Arg
26
SEQ ID NO: 26
Arg-Ser-Gln-Ala-Glu-Glu-Glu-
RSQAEEEPCLEP
Pro-Cys-Leu-Glu-Pro
For the purposes of the present invention, each isolated peptide has a corresponding SEQ ID NO., according to the following Table 1.
The isolated peptides of the present invention have the amino acid sequences defined in Table 1, in which the three and one letter IUPAC amino acid code is used (ie. Arg and R corresponds to the amino acid Arginine, Pro and P corresponds to the amino acid Proline). Each peptide has a peptide number and a corresponding SEQ ID NO., as above reported in the Table 1.
The subject of the invention is therefore a novel group of low molecular weight peptides, which can be chemically synthesized.
These peptides are of synthetic origin and are therefore easy to manufacture in large quantities, and they can be modified chemically and biologically or conjugates to other moieties (i.e. carriers).
These peptides have the advantages of being of synthetic origin, and therefore do not have the disadvantages seen in natural peptides such as the tendency to induce inflammatory response and pathogen transfer due to undefined factors that cannot be eliminated by purification prior to implantation, the significant degree of variability between different lots and the difficulty of availability of large scale sources.
When compared with proteins/antibodies or even small organic molecules, the peptides according to the present invention offer advantages such as: i) good biocompatibility; ii) reduced side effects due to limited systemic toxicity or drug—drug interactions (e.g. degradation products are amino acids); iii) reduced secondary complications (e.g. minor tissue accumulation) due to a relatively short half-life of peptides (or their metabolites); (in addition, proteolysis can be prevented by chemical modifications); iv) generally less immunogenicity; v) potentially more penetrating into tissues due to smaller size; vi) good efficacy, selectivity and specificity and limited off-target binding; vii) ease of chemical synthesis and modification, free of impurities and side products; viii) low manufacturing costs.
In addition, since the therapeutic peptide-binding site in the protein target is known and set forth in SEQ ID NO:10, this allows for further drug optimization (i.e. drug design for increased selectivity).
In a further aspect, the invention regards an isolated peptide, wherein:
(SEQ ID NO: 2) A-Arg-Pro-Asp-Arg-Glu-Ala-Pro-B or (SEQ ID NO: 1) A-Arg-Pro-Asp-Arg-Asp-Ala-Pro-B or (SEQ ID NO: 8) Lys-Gln-Arg-Asp-Arg-His-Lys-Glu-Lys-Asp, or, (SEQ ID NO: 9) Lys-Gln-Arg-Asp-Arg-His-Lys-Asp-Lys-Asp; or (SEQ ID NO: 21) Lys-Gln-Arg-Ser-Arg-His-Lys-Glu-Lys-Asp, or (SEQ ID NO: 22) Lys-Gln-Arg-Ser-Arg-His-Lys-Asp-Lys-Asp,
wherein:
A is an amino acid sequence which is optionally present, and if present is chosen from the group consisting of Asp-Gln-, and B is an amino acid sequence which is optionally present, and if present is chosen from the group consisting of: Arg-, Arg-Ser, Arg-Ser-Gln-Ala-Glu-Glu-Glu-Pro-Cys (SEQ ID NO:23), Arg-Ser-Gln-Ala-Glu-Glu-Glu-Pro-Cys-Leu-Glu-Pro-Val-Lys-Lys (SEQ ID NO:24), Arg-Ser-Gln-Ala-Glu-Glu-Glu-Pro-Cys-Leu-Glu-Pro-Val-Lys-Lys-Ser-Gln-His-Arg (SEQ ID NO:25), Arg-Ser-Gln, or Arg-Ser-Gln-Ala-Glu-Glu-Glu-Pro-Cys-Leu-Glu-Pro (SEQ ID NO:26).
In a preferred aspect, the invention relates to an isolated peptide according to the invention, chosen from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22.
In a further aspect the invention relates to the use of an isolated peptide chosen from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22 for the preparation of a medicament.
The peptides of the present invention surprisingly have been shown to be useful in the preparation of a medicament (Examples 4, 5, 6, and 7).
In a still further embodiment the invention relates to the use of an isolated peptide chosen from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22 for the treatment of conditions having altered LTCC density (Examples 4, 5, 6, and 7)
In general, peptides of the invention may be useful in any situation involving conditions having altered LTCC density or in those conditions where an intervention for the modulation of LTCC density or intracellular Ca 2+ concentration is preferable. Such conditions may occur as a result of genetic and/or metabolic disorders, and/or other diseases and/or conditions.
Peptides of the invention aim at augmenting LTCC protein density by extending the calcium channel half-life through a mechanism that rely on the binding of peptides to a solvent-exposed domain (TID, SEQ ID NO:10) in Ca v β2 protein, subunit of LTCC.
Certain peptides of the present invention may be used to ameliorate the effects of diseases such as heart pathology.
In a preferred aspect the invention relates to the use of an isolated peptide chosen from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22 wherein said conditions having altered LTCC density and function are cardiovascular dysfunctions selected from the group consisting of heart failure, reduction of myocardial contraction, fibrillation, diabetic cardiomyopathy, dilated cardiomyopathy, genetic-based disorders (i.e. channelopathies such as Brugada syndrome, Timothy syndrome, or short QT syndrome), cardiac hypertrophy, hypotension, hyperthyroidism, hypothyroidism, acute heart failure, chronic heart failure, myocardial infarction.
In a still further aspect the invention relates to the use of an isolated peptide chosen from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21 wherein said conditions having altered LTCC density and function are ophthalmological conditions selected from the group consisting of lens transparency, and altered intraocular pressure.
In a still further aspect the invention relates to the use of an isolated peptide chosen from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22 wherein said conditions having altered LTCC density and function are neurological conditions selected from the group consisting of vascular dementia, Alzheimer's disease, Parkinson's disease, Prion disease and hypokalemic periodic paralysis.
In a further aspect, the invention relates to a pharmaceutical composition comprising one or more peptides chosen from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22 and/or pharmaceutically acceptable carrier.
Exemplary pharmaceutically acceptable carriers or excipients include any and all solvents, dispersion media, diluents, or other liquid vehicles, dispersion or suspension aids, surface active agents, isotonic agents, thickening or emulsifying agents, preservatives, solid binders, lubricants and the like, nanoparticles, nucleic acids (i.e aptamers), cell-penetrating molecules or peptides as suited to the particular form of administration and dosage.
The pharmaceutical composition according to the present invention can be for enteral and parenteral administration (i.e. intravenous, intraperitoneal, oral, sublingual, aerosol, inhalation, spray, rectal, intraocular, topical or transdermal). In another aspect the invention relates to method of screening for a peptide or other synthetic molecule which binds the amino acid sequence of SEQ ID NO:10 comprising the steps of:
a) transfecting a mammalian cell with a nucleic acid construct comprising SEQ ID NO:10; b) contacting said mammalian cell with a screening compound; c) detecting the binding of the screening compound to the mammalian cell; or d) virtual high throughput screening of compound library database to identify peptides or molecules of novel chemical structure that bind to the Ca v β2 macromolecular target comprising SEQ ID NO:10; or e) computer-aided drug design of compounds that bind to the Ca v β2 macromolecular target comprising SEQ ID NO:10.
In a still further embodiment the invention relates to peptides or synthetic molecules which are identified and obtained in the method of screening wherein said peptide or synthetic molecule binds the amino acid sequence of SEQ ID NO:10 in the method described above in the present invention.
In particular, the invention relates to a peptide or synthetic molecule which binds the amino acid sequence of SEQ ID NO:10 obtainable according to the method of screening comprising the steps of:
a) transfecting a mammalian cell with a nucleic acid construct comprising SEQ ID NO:10; b) contacting said mammalian cell with a screening compound; c) detecting the binding of the screening compound to the mammalian cell; or d) virtual high throughput screening of compound library database to identify peptides or molecules of novel chemical structure that bind to the Ca v β2 macromolecular target comprising SEQ ID NO:10; or e) computer-aided drug design of compounds that bind to the Ca v β2 macromolecular target comprising SEQ ID NO:10.
Use of the peptide or synthetic molecule which binds the amino acid sequence of SEQ ID NO:10 for the treatment of conditions having altered LTCC density and function, said peptide or synthetic molecule obtainable according to the method of screening comprising the steps of:
a) transfecting a mammalian cell with a nucleic acid construct comprising SEQ ID NO:10; b) contacting said mammalian cell with a screening compound; c) detecting the binding of the screening compound to the mammalian cell; or d) virtual high throughput screening of compound library database to identify peptides or molecules of novel chemical structure that bind to the Ca v β2 macromolecular target comprising SEQ ID NO:10; or e) computer-aided drug design of compounds that bind to the Ca v β2 macromolecular target comprising SEQ ID NO:10.
EXAMPLES
Results below were partially funded by Fondazione Cariplo (grant n° 2008.2504)
Example 1
Identification of a Previously Unknown Binding Domain in Ca v β2 (TID; SEQ ID NO:10)
Our previous in vitro findings showed that an Akt-dependent phosphorylation of Ca v β2, either directly through the kinase or by introduction of an Akt-phosphomimetic mutation (Ser to Glu, Ca v β2-SE) in the Akt consensus-site of Ca v β2 cDNA, was sufficient to enhance the Ca v α1.2(and thus LTCC) half-life and thus intracellular Ca 2+ handlings and cardiomyocyte contractility ( FIG. 1 ) 3 . Based on this evidence, we designed experiments to determine the sequence of structural and molecular events that link Akt-mediated phosphorylation of Ca v β2 to the inhibition of Ca v α1.2 degradation. As a first step, we investigated whether upon Akt-phosphorylation, Ca v β2 recruits additional interacting partners to inhibit Ca v α1.2 degradation. We performed a yeast-two-hybrid screening using Akt-phosphomimetic Ca v β2 cDNA (Ca v β2-SE) as a bait and either human or mouse heart cDNA expression libraries as preys. Remarkably, several positive clones corresponded to Ca v β2 in a region belonging to the globular domain ( FIG. 2 a,b ), whereas no Ca v β2 clones were found when the assay was repeated with a wildtype Ca v β2-WT bait. Co-immunoprecipitation analyses of lysates obtained from HEK293 cells co-transfected with the Ca v β2-SE bait and either mouse or human Ca v β2-prey clones confirmed the specificity of the interaction ( FIG. 2 c ).
Finally, when amino acid sequences from the identified positive clones were aligned ( FIG. 2 a , top) and analyzed for solvent accessibility ( FIG. 2 a , bottom), we identified a minimal common region potentially binding to the Ca v β2 C-terminal region, which we named Tail Interacting Domain (TID; SEQ ID NO:10).
To assess whether TID plays a direct role in the molecular mechanism that protects Ca v α1.2 from protein degradation, we used site-specific mutagenesis forreplacing positively charged Lysines (K) at positions 6, 14, and 26 in the TID (SEQ ID NO:10) sequence with Glutamines (Q) to destroy any potential ionic interaction between the binding domain and the coiled-coil. Whereas co-transfection of HEK293 cells with Ca v α1.2 and Ca v β2-SE resulted in unaltered Ca v α1.2 protein levels when Akt was not activated (i.e. upon serum removal), the introduction of the K26Q site mutation in TID strongly impaired the protective effect ( FIG. 3 a , right panel). Similar results, but to a different extent, were obtained when the other amino acids in the TID were mutated ( FIG. 3 a , right panel). A yeast two-hybrid assay with Ca v β2-SE as a bait and the K26Q mutated Ca v β2 as a prey showed no interaction, confirming the direct role of K26 in SEQ ID NO:10 for the interaction ( FIG. 3 b ). Subsequently, a fluorescence-based Ca 2+ assay was used to analyze LTCC-mediated intracellular Ca 2+ flux. Co-transfection of Ca v α1.2 with any of the mutated Ca v β2-SE constructs resulted in a significant reduction in Ca 2+ flux upon serum removal, down to a level that was similar to the one of the control condition ( FIG. 3 c ). In addition, I Ca measurements showed a significant reduction in current when tSA-201 cells were transfected with Ca v β2-SE-K26Q compared to Ca v β2-SE ( FIG. 3 d ).
Example 2
Mimetic Peptides (MPs) Affect LTCC Protein Stability and Function In Vitro
Based on the evidence shown in example 1, we next investigated whether mimetic peptides (MPs) might recapitulate the mechanism by which LTCCs are protected from protein degradation by binding to the TID domain. Thus, we transfected HEK293 cells with an array of partially overlapping peptides (length from 7 to 25 amino acids) belonging to the Ca v β2 terminal coiled-coil region and subsequently performed Western blot ( FIG. 4 a ) and intracellular Ca 2+ measurements ( FIG. 4 b ), identifying several peptides that, to different extents, were efficient in protecting LTCC protein stability and function upon serum removal. No evidence for significant apoptosis was found ( FIG. 4 a ).
By computational docking simulation, we tested the ability of the identified MPs to recognize the TID region and predicted that MP most specifically recognize the TID region by direct interaction with the lysine residue K26 and formation of electrostatic interactions between two arginine residues and negatively charged regions of the functional core of the Ca v β2 ( FIG. 4 c ). In line with this, additional site-directed mutagenesis analyses in Ca v β2 further supported this prediction and found E4, D7, E27, and E30 in SEQ ID NO:10 relevant for the binding MP-TID ( FIG. 5 ). The specificity of the selected MP (SEQ ID NO: 3) was subsequently confirmed in vitro as the protective effect of the selected MP on Ca v α1.2 was completely lost when specific mutations within either the MP or Ca v α1.2 abolished the predicted interaction between MP and TID ( FIG. 4 d ).
Example 3
Modified MP Penetrates the Plasma Membrane and Affect LTCC Function In Vitro
To facilitate the intracellular uptake, a cell-penetrating peptide (CPP) was conjugated to the MP (SEQ ID NO: 3). To overcome any potential steric hindrance that a CPP might have when fused to the MP, we evaluated our Ca v β2-MP 3D model ( FIG. 4 d ) and predicted the N-terminus of MP as a suitable region for CCP fusion. Thus, the trans-activating transcriptional activator (TAT) from Human Immunodeficiency Virus 1 (HIV-1) was used. When administered to isolated cardiomyocytes, this cell-penetrating derivative of the MP peptide (TAT-MP) was shown to specifically co-localize with LTCCs ( FIG. 4 e ), protect Ca v α1.2 from protein degradation ( FIG. 4 f ), and preserve Ca 2+ current ( FIG. 4 g ) upon serum removal. On the other hand, none of these effects were observed when a scramble peptide was used. TAT-MP=SEQ ID NO: 3; TAT-scramble=scramble=SEQ ID NO:11.
Example 4
Therapeutic Potential of Mimetic Peptides (Genetic Mouse Model of Heart Failure)
To explore the in vivo therapeutic potential, MP was used in an inducible and cardiac specific knockout of the phosphoinositide-dependent kinase 1 (PDK1), the upstream activator of all three Akt isoforms. As previously reported 3 , deletion of PDK1 by tamoxifen injection resulted with a reduction of cardiac function as evaluated by echocardiographic analysis. We then treated the mice with either cell penetrating MP or scramble peptides and followed the phenotype for the following days. Whereas animals treated with scrambles displayed progressive impairment of left ventricular function, animals treated with MP showed significant attenuation of the impairment of cardiac function that corresponded to a restoration of LTCC protein levels ( FIG. 6 ). MP=SEQ ID NO: 3; TAT-scramble=scramble=SEQ ID NO:11.
Example 5
Therapeutic Potential of Mimetic Peptides (Diabetic Cardiomyopathy)
To further explore the potential therapeutic application, we assessed the effects of the TAT-MP in a mouse model of cardiomyopathy in which LTCC density, and consequently cardiac contractility, is downregulated (i.e. diabetic cardiomyopathy, DM). Alterations in Ca 2+ signaling within cardiac muscle cells are a hallmark of DM. The defects identified in the mechanical activity of hearts from diabetic animals are attributed to a reduction in Ica, a decrease in systolic Ca 2+ , and a lengthening of the systolic Ca 2+ transient, primarily resulting from dysfunction of the SR. To induce DM, mice were injected with streptozotocin (STZ), a compound that is toxic for the insulin-producing beta cells of the pancreas ( FIG. 7 ). In line with the effects of the insulin/Akt signaling on LTCCs, cardiac dysfunction in DM mice was associated with reduced Caval 0.2 protein levels in DM mice compared to control mice ( FIG. 7 b ). Intriguingly, 4 days of treatment of DM mice with TAT-MP (MP=SEQ ID NO: 3) nearly completely restored cardiac function ( FIG. 7 a ), while no effects were obtained when vehicle or TAT-scramble (scramble=SEQ ID NO:11) where administered. In addition, functional analyses of cardiomyocytes isolated from the same treated mice revealed that the TAT-MP restored I C a as well as cell contractility and systolic Ca 2+ amplitudes ( FIG. 7 c,d ).
Example 6
Therapeutic Potential of Mimetic Peptides (Human Cardiac Model)
To pursue the cardiac therapeutic potential of MP, we employed a human cardiac model that is based on cardiomyocytes (CMs) differentiated from induced pluripotent stem cells (iPSCs) and previously derived from skin fibroblasts of healthy individuals 4 . iPSC-CMs subjected to an Akt inhibitor showed a downregulation of Ca v α1.2 protein levels that was prevented when cells were co-treated with MP (MP=SEQ ID NO: 3) ( FIG. 8 a ). On the other hand, no rescuing effects were obtained when scramble peptide was used. Based on this, we next performed functional analyses and examined the iPSC-CM beating clusters (BCs) for Ca 2+ handling properties. While administration of Akt-inhibitor to BCs showed a significant slowing of Ca 2+ transient development, indicating an alteration between LTCC activity and evoked Ca 2+ release from the sarcoplasmatic reticulum, MP administration was sufficient for reducing this delay ( FIG. 8 b,c ). On the other hand, no effects were observed when BCs were co-treated with scramble.
Example 7
Therapeutic Potential of Mimetic Peptides (Inherited Cardiac Arrhythmic Disease, i.e Brugada Syndrome)
To test whether the potential therapeutic use of the TAT-MP (MP=SEQ ID NO:3) may also exert a corrective effect in conditions of patients are affected by Brugada Syndrome (BrS) and who are carriers of loss of function mutations in the CACNA1C gene encoding for the Ca v α1.2 subunit of the LTCC. BrS is an inherited arrhythmogenic disease estimated to account for 20% of sudden deaths in young patients with an otherwise normal hearts. Thus, we investigated whether the loss of function in the LTCC caused by missense mutations (i.e the substitution of Glutamine at position 428 with a Glutamic Acid found in a patient diagnosed after a cardiac arrest at 32 years of age occurring at rest) in the CACNA1C gene identified in BrS patients could be reverted by the administration of TAT-MP. Membrane currents were measured using whole-cell patch clamp procedures to obtain the current-voltage (I-V) relationship. The current-voltage (I-V) relationships between WT and Q428E showed that amplitudes of current were significantly reduced as compared to WT ( FIG. 8 ). Treatment of cells expressing mutant Ca v α1.2 with TAT-MP nearly completely reverted the loss-of-current phenotype induced by the Ca v α1.2 mutation.
From the above description and the above-noted examples, the advantage attained by the product described and obtained according to the present invention are apparent.
REFERENCES
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2 Opatowsky, Y., Chen, C. C., Campbell, K. P. & Hirsch, J. A. Structural analysis of the voltage-dependent calcium channel beta subunit functional core and its complex with the alpha 1 interaction domain. Neuron 42, 387-399 (2004).
3 Catalucci, D. et al. Akt regulates L-type Ca2+ channel activity by modulating Cavalphal protein stability. The Journal of cell biology 184, 923-933, doi:10.1083/jcb.200805063 (2009).
4 Di Pasquale, E. et al. CaMKII inhibition rectifies arrhythmic phenotype in a patient-specific model of catecholaminergic polymorphic ventricular tachycardia. Cell death & disease 4, e843, doi:10.1038/cddis.2013.369 (2013). | The present invention concerns the field of ion channels, and in particular relates to peptides which are suitable for use in the treatment of conditions where the L-type calcium channel (LTCC) density and function is altered. LTCCs are located on the membrane of all excitable cells and control the small voltage gradient across the plasma membrane by allowing the flow of Ca 2+ ions down their electrochemical gradient. This Ca 2+ flux is critical for numerous processes including cardiac action potential propagation, muscle contraction, Ca 2+ -dependent gene expression, synaptic efficacy, and cell survival by contributing to various signaling cascades. Reduction of the inward calcium current (I Ca ) conducted through the LTCCs is seen in several diseases and medications to improve or restores impaired intracellular Ca 2+ homeostasis are limited. The present invention reports mimetic peptides (MPs) that through a novel mechanism directly targets LTCCs and, by modulation of LTCC density and function, increases I Ca . This invention supports a therapeutic role for MP to treat human diseases associated with altered cellular Ca 2+ homeostasis. | 0 |
This is a continuation of application Ser. No. 592,384, filed Mar. 22, 1984, which was a continuation of application Ser. No. 496,010, filed on May 19, 1983, now U.S. Pat. No. 4,440,102, dated Apr. 3, 1984.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a tufting machine and method of producing tufts in a base fabric and is more particularly concerned with a tufting machine and method of tufting for producing multiple rows of tufts with single lengths of yarn.
2. Description of the Prior Art
In the past, tufting machines with laterally shiftable needle bars have been devised. U.S. Pat. Nos. 3,026,830 issued Mar. 27, 1962 to Bryant et al.; 3,109,395 issued Nov. 5, 1963 to Batty et al.; 3,396,687 issued Aug. 13, 1968 to Nowicki and my U.S. Pat. No. 4,366,761 issued Jan. 4, 1983 all disclose tufting machines with laterally shiftable needle bars so as to permit a needle to selectively operate with one of two or more adjacent loopers. Of those patents listed above, U.S. Pat. No. 3,026,830 to Bryant et al. discloses a tufting machine which uses a disc shaped cam, the rotation of which is synchronized with the needle operation so as to shift the needle bar laterally in timed relationship to the operation of the needles. The prior art machines disclosed in the above-listed patents, all must be shifted in needle gauge increments and must therefore have quite close tolorances so that in one position all needles are in registry with a prescribed set of loopers and when shifted to another position the same needles are all in registry with another set of loopers.
Also, zig-zag tufted fabrics have been produced by shifting the base fabric or backing material by laterally moving a support beneath the needle bar. In such an operation, neither the needle bars nor the loopers are shifted. U.S. Pat. Nos. 3,577,943 and 3,301,205 show machines for doing this type of tufting.
In the past, narrow gauge tufting machines, because of the limited space between adjacent needles, have been restricted to using small diameter yarns. Such small diameter yarns are expensive to produce, break easily and do not bloom after tufting, as well as the comparable larger diameter yarns. The present invention is particularly suited to producing narrow gauge tufted products using larger diameter yarns than heretofore used, since one needle will produce two or more longitudinal rows of tufting.
In the past, the gauge of combination cut and loop pile tufting machines have been limited as to the narrowness of the gauge, due to the necessity for access to the looper assembly required for each needle. The present invention is particularly suited for use in such combination machines because it can produce narrow gauge goods without the necessity of a needle for each longitudinal row.
SUMMARY OF THE INVENTION
Briefly described, the apparatus of the present invention includes a conventional tufting machine through which a backing material is fed in a linear path across the bed of the tufting machine, so that successive transverse increments of the backing material are positioned beneath a transverse row of needles carried by the needle bar. The conventional tufting machine also has loopers below and in vertical alignment or registry with the side of the needle for engaging, respectively, the loops of yarns inserted through the backing material by the needles.
A needle bar shifting assembly shifts the needle bar laterally back and forth during only a portion of the cycle of the needle bar, between the time the needles are retracted from the fabric and the time they reach bottom dead center, whereby the needles are in a laterally shifted condition, offset from alignment with the loopers, when they enter the fabric and are then moved back into their aligned or in registry positions, with their loopers, before they reach the position of their stroke in which the loopers engage and hold the inserted loops of yarn.
The needles are withdrawn in a straight vertical path and the natural resiliency of the backing material usually returns the transverse increment of backing material, which was laterally shifted to its normal linear path of movement.
The needle bar is usually shifted first laterally in one direction by about one-fourth the gauge of the machine, during a first down stroke of the needles, and, then, laterally by about one-fourth the gauge of the machine in the other direction, during the first portions of a second or alternate down stroke so that successive increments of the backing material are shifted in opposite directions by the penetrating needles whereby each needle and looper combination produces two longitudinal rows of tufts with the successive tufts. The amount of lateral shifting, however, can be varied, as desired.
The needle bar shifting assembly includes a shifting bar connected to the needle bar so that the needle bar is shifted thereby. The needle bar shifting assembly includes a transversely moveable shifting bar, the end of which carries a plurality of spaced guide rollers which form a guide for a vertically disposed shifting bar follower. The shifting bar follower is fixed to the needle bar so that it is reciprocated vertically therewith, within the path defined by the rollers. Lateral movement of the shifting bar, moves the vertically reciprocating follower and needle bar laterally during their vertical reciprocation. Spaced cam followers on the shifting bar ride along diametrically opposed portions of the periphery of a cam or camming wheel or plate which has alternate recesses and lobes which are equally circumferentially spaced along the periphery of the camming plate. The cam is rotated in synchronization with the reciprocation of the needle bar to shift the needle bar as described above.
Accordingly, it is an object of the present invention to provide a tufting machine and process of tufting which will produce multiple rows of tufts with a single length of yarn carried by a single needle.
Another object of the present invention is to provide a tufting machine which, for the gauge of carpeting produced, is inexpensive to manufacture, durable in structure and efficient in operation.
Another object of the present invention is to provide a tufting machine whch can sew two or more longitudinal rows of tufts using a single needle and single looper.
Another object of the present invention is to provide a tufting machine which requires no special adjustment for enabling a single needle to sew a plurality of longitudinal rows of tufts in a backing material.
Another object of the present invention is to provide a method and apparatus of tufting wherein a plurality of dense longitudinal rows of tufting can be produced using a relatively wide gauge machine.
Another object of the present invention is to provide an apparatus for producing, comparatively inexpensively, a finer gauge tufted product.
Another object of the present invention is to provide a process of tufting wherein the holes, created in the backing material for the tufts, are provided with a better spacing than heretofor provided.
Another object of the present invention is to provide an apparatus and method of tufting wherein a narrow gauge fabric is produced using larger diameter yarn than has heretofor been used.
Another object of the present invention is to provide a tufting process and apparatus which will create back stitches over the warp yarns and filling yarns of a woven backing material, thereby providing a relatively stronger tufted product.
Another object of the present invention is to provide an apparatus and method of tufting which will give a better distribution of tufts in the base fabric.
Another object of the present invention is to provide a method and apparatus of tufting which is particularly useful in producing selectively loop and cut pile fabric, the apparatus and method permitting greater space between adjacent needles for receiving the loopers.
Another object of the present invention is to provide a tufted product with a stronger backing material and larger diameter yarn.
Other objects, features and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings wherein like characters of reference designate corresponding parts throughout the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially broken away side elevational view of a portion of a shiftable needle bar tufting machine constructed in accordance with the present invention, the cam and a portion of the shifting bar being rotated 90° for clarity;
FIG. 2 is a fragmentary, schematic, bottom plan view of a tufted product produced according to the present invention;
FIG. 3 is a fragmentary, schematic, top plan view of a prior art tufted product comparable to the tufted product depicted in FIG. 2;
FIG. 4 is a schematic diagram depicting the respective positions of the needles, loopers and cam during a typical operation of the tufting machine depicted in FIG. 1, the broken lines for the cam showing an alternate manner of shifting; and
FIGS. 5-18 are fragmentary side elevational views of a portion of the needle bar of the tufting machine depicted in FIG. 1, the needle bar being illustrated in successive figures as moving through one cycle (two reciprocations of the needle bar) of the machine of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now in detail to the embodiment chosen for the purpose of illustrating the present invention, numeral 10 denotes generally a tufting machine of the type found in U.S. Pat. No. 3,026,830 issued to Clifford Aldine Bryant, Robert F. Hackney, and Otis C. Payne, all of Dalton, Ga., on Mar. 27, 1962, entitled Tufting Machine and Method for Producing Multi-Color Designs in Carpeting and the Like. This tufting machine 10 is of the type having a transversely disposed needle bar 11 which is reciprocated vertically by means of reciprocating piston rods 12 and is shifted laterally by means of a needle bar shifting assembly which includes a transversely moveable shifting bar 19, the end of which carries a plurality of spaced guide rollers 8 which form a guide for a vertically disposed shifting bar follower 9. The shifting bar follower 9 is fixed by its lower end portion to the needle bar 11 so that it is reciprocated vertically therewith, within the path defined by the rollers 8. Lateral movement of the shifting bar 11, moves the vertically reciprocating follower 9 and needle bar 11 laterally during their vertical reciprocation, in its central portion, with a slot 13 surrounding a drive shaft 14. The shift bar 19 is reciprocated laterally by means of a pair of spaced, cam followers 15a and 15b which project sidewise from bar 19. The cam followers 15a and 15b ride on the diametrically opposed peripheral portions of the periphery 16 of a disc shaped cam or camming plate 17. The disc shaped cam 17, in turn, is carried by the shaft 14 rotated in timed or synchronized relationship to the reciprocation of the reciprocating shaft 12, i.e., needle bar 11, so that upon one cycle of reciprocation from top dead center back to top dead center of the needle bar 11, the or cam 17 will have been rotated through 36° or one tenth a revolution of the cam 17.
It will be understood by those skilled in the art that the base fabric or backing material 20 is fed in a longitudinal linear path over a bed 18 on the tufting machine 10 so that successive transverse increments of the backing material are beneath the reciprocating needle bar 11 and so that the needle bar 11 extends transversely with respect to the linear longitudinal path of travel of the base fabric or backing material 20. Backing material 20 is fed intermittently by rolls (not shown) disposed on the side of the tufting machine 10 and thus, a successive increment of the backing material 20 is disposed below the needle bar 11 upon each cycle of the machine.
As in the conventional tufting machine, the needle bar 11 is provided with a plurality of evenly spaced, parallel, downwardly extending, tufting needles 21, which are arranged in one or a plurality of transverse rows. For each needle 21, there is one and only one associated looper 24 in a transversely fixed position for loop engaging action and each needle 21 is in its normal unshifted condition in registry with its looper, or is brought into a position where one side of the needle is in alignment with its associated looper 24 before the needle 21 reaches the bottom dead center position for the needles 21. Yarns 22 respectively pass through the eyes adjacent to the points of the needles 21, so that when the needle bar 11 is moved from its top dead center position, downwardly, points of the needles 21 simultaneously penetrate a transverse increment of the backing material 20 and insert their loops or yarn 22 through the backing material 20. When the needles 21 penetrate the backing material 20 sufficiently, the loops 23 of the yarns 22, are formed in and beneath the base material 20, and these loops 23 are respectively caught by the loopers 24 when the eyes of needles 21 approach bottom dead center, the loopers 24 catching and retaining the loops 23 in a conventional way and holding them for a sufficient time to permit the needles to be withdrawn in axial, vertical, linear, parallel paths from the backing material 20.
According to the present invention, the periphery or peripheral surface 16 of the circular or disc shaped cam 17 is provided with an odd number of lobes 25a, 25b, 25c, 25d and 25e, equally spaced circumferentially around cam 17. Each lobe 25a, 25b, 25c, 25d and 25e has an inclined outwardly protruding leading edge or surface 26a and an inclined inwardly protruding trailing edge or surface 26b the outer ends of which are joined by a flat or concentrically arcuate, central surface 26c. The height of each lobe 25a, 25b, 25c, 25d and 25e in the preferred embodiment is equal to approximately one-fourth the gauge of the tufting machine, i.e., one-fourth the transverse distance between the axis of one needle 21 and the axis of the adjacent needle 21. Each pair of surfaces 26a and 26b tapers outwardly.
Midway circumferentially, between each of the lobes 25a, 25b, 25c, 25d and 25e are a like number of recesses or valleys 27a, 27b, 27c, 27d and 27e, the recesses 27a, 27b, 27c, 27d and 27e being diametrically opposed to the lobes 25a, 25b, 25c, 25d and 25e, respectively. Furthermore, each recess 27a, 27b, 27c, 27d and 27e has an inclined inwardly protruding leading edge or surface 28a and an inclined trailing edge or surface 28b which tapers inwardly, the inner ends of these edges 28 and 28b being joined by a flat or concentric e.g., arcuate central surface 28c. The depth of each valley 27a, 27b, 27c, 27d and 27e corresponds to the height of its associated diametrically opposed lobe 25a, 25b, 25c, 25 d and 25e, whereby each time a lobe and a valley are in contact with a cam follower 15a or 15b it causes a laterally shifting of the shift bar 19 by a distance which is approximately one-fourth the distance between adjacent needles 21. The shifting in both directions is essentially over a period of less than one-half the period of the downstroke of the needle 21. Also, the initial shifting in one direction must occur while the needles 21 are retracted from the base material 20, i.e., prior to the penetration of the needles 21 into the backing material 20. The subsequent shifting in the other direction must occur after the needles 21 have penetrated the backing material 20, but prior to bottom dead center, i.e., the time that the hooks of the loopers 24 extend into the loops 23 of the yarns 22.
In FIG. 2 it is seen that, when using the cam 17, adjacent pairs of longitudinal rows of tufts are produced by each individual yarn 22 the back stitches 30 being in a zig zag fashion. The back stitches 30 extending diagonally in one direction and then diagonally in the other, between successive holes created by each needle 21 in the backing material 20. The tufts formed by loops 23 are, thus, staggered in each pair of longitudinal rows of tufts in the backing material and are also in parallel transverse rows. Contrary to the in line longitudinal holes 124 of the prior art, the staggered holes are not as closely adjacent to each other. Thus, the backing material 20 will not split as readily, when stretched for laying, as the comparable prior art backing material 120.
In the operation of the preferred embodiment of the machine of the invention, needles 21 begin a cycle at top dead center depicted in FIG. 5 of the drawing and being illustrated in FIG. 4 as the first position. In this position the loopers 24 are engaging the previously formed loops and the needles 21 are retracted or withdrawn out of the fabric. In FIG. 6, the needles 21 begin their travel downwardly and are shifted to the right by the cam follower 15a being received in a recess, such as recess 27b, and the cam follower 15b being engaged by a lobe 25d. It will be understood from FIG. 4 that the loopers 13 are still engaging the loops 23 to prevent a back drawing of the loops.
In FIG. 7, the needles are depicted as entering the backing material 20, with the loopes 24 still engaged in the previously formed loops 23. In the bottom portion of FIG. 4 it will be seen that the curve denoted by the numeral 40, depicts the position of the tip of a needle 21 with respect to the backing material 20 and that when the needles 21 are in the position, shown in FIG. 7, the tips of the needles 21 are just penetrating the backing material 20. It will also be seen that immediately after top dead center (T.D.C.) the leading edge 26a of the lobe 25d engages the follower 15b so as to begin the shifting of the control bar 19. By the time that the needles 21 have progressed downwardly and any appreciable distance, the needles 21 have been fully shifted to the right in FIG. 1 as a result of the follower 51b riding upon the flat or slightly arcuate central portion or surface 26b of the lobe 25d. As the needle 21 continues its travel downwardly to penetrate the backing material 20, as indicated in FIG. 4 by the broken line 40 passing the backing material 20 as depicted in FIG. 7, the cam follower 15b has reached the trailing edge or surface 26b. Further movement of the needles 21 so as to penetrate and engage the backing material 20, results in all of the needles 21 moving the penetrated increment of the backing material 20, which is closely adjacent to their points of penetration, to the left, as the follower 15b rides along the trailing edge or surface 26c of the lobe 25d. The shift laterally of the increment is only one-fourth the gauge of the machine and therefore is not sufficient to alter the overall linear path of travel of backing material 20.
In FIG. 8, it is seen that the loopers 24 have released the previous loop 23, since the diagonal back stitch 30 has been laid down by the insertion of the needle 21 into the backing material 20. Since all needles 21 penetrated the backing material 20 before the cam follower 15b descended along the incline 26c, the lateral shifting of the increment of the backing material 20, which has been penetrated, will take place during the travel of the cam follower 15b along the incline surface 26c. This shifting of the backing material will correspond, in distance, to the height of the lobe 25d, i.e., the difference in the radius of the peripheral surface 16 and the radius of the surface 26c.
The needles 21 continue their descent until the needles 21 reach bottom dead center (B.D.C.) as depicted in FIG. 9. At that time, the loopers 24 are still not engaging the loops 23; however, the loops 23 have been inserted through the backing material 20 to the full extent of the travel of the needles 21.
When the needles 21 begin their ascent or retraction back toward top dead center, it will be understood that since the cam followers 15a and 15b both ride along the periphery 16 throughout this travel, the needles 21 travel along parallel linear vertical paths in registry with their loopers to top dead center.
As the needles exit from the backing material, as shown in FIG. 11, the transverse increment of backing material 20, which has been previously shifted laterally, is released and due to the natural resiliency, i.e., the fact that the backing material has not been stretched beyond its elastic limints, and/or due to the tension applied by the tufting machine in a longitudinal direction of travel to the backing material 20, this increment moves laterally, returning to the normal straight linear path followed by the backing material 20.
Even if the backing material 20 is a non-resilient web or has been stretched beyond its elastic limits, the subsequent one-half cycle of the process (a 360° or one cycle travel for the needle bar 11) will have the effect of shifting the increment in the appropriate direction, because of the positive shifting by the needles 21 of the subsequent transverse increment as will now be described.
With the emergence of the needles 21 from the backing material, the needle bar 11 can be shifted laterally to the left, at any time prior to the needles 21 again entering the backing material. The tufting machine 10, however, is programmed by the cam 17 to accomplish the initial lateral shifting (left or right, as the case may be) for that half cycle of the process during an initial part of each down stroke. Thus, upon exiting as shown in FIG. 11, the needles 21 continue their travel in their linear vertical paths, to top dead center, as shown in FIG. 12, whence the needles 21 again begin their descent from the FIG. 12 position to the FIG. 13 position. During this travel, cam follower 15b passes into valley 27b as cam follower 15a ride on lobe 25b, the effect being that the needle bar 11 is shifted left by one-fourth the distance between axes of adjacent needles 21 and the needles 21 descend to their penetrating position as shown in FIG. 14, while being so shifted.
After entry, the progressive rotation of cam 17 removes the lobe from follower 15a and removes valley 27b from follower 15b, thereby causing a right shift so as to return the needle 21 to their unshifted or normal or centerline position, as depicted in FIG. 15. The needles 21 continue their downward travel to bottom dead center as illustrated in FIG. 16, and then begin their ascent, as illustrated in FIG. 17. As in the previous one half cycle, the loopers 24 engage the loops 23 while the needles 21 travel upwardly along their normal centerline axes, the needles 21 traveling linearly along these axes during the entire period in which they are ascending from bottom dead center to top dead center. As the needles exit, the backing material 20, the resiliency or springiness of the material cause the second increment of material which has been provided with the loops to spring back laterally into their original path of linear travel. The needles 21 then continue their upward travel to the top dead center position as depicted in FIG. 5 and commence another cycle of the process or machine.
With backing material 20 which does not readily spring back to its linear travel position, double shifting of the backing material 20 by the needles 21 during a single cycle of the machine will solve this problem. In the alternate form of operation, as depicted in FIG. 4, this double lateral shifting of the backing material 20 is accomplished by providing the periphery of cam 17 with twice the number of lobes and valleys, a lobe 126occurring immediately prior to each valley 27a, 27b, 27c, 27d, 27e and a valley 127 occurring immediately prior to each lobe 25a, 25b, 25c, 25d, 25e.
When the machine is operated in this alternate mode, the needles are first shifted in one lateral direction while they are free of the backing 20, then the needles 21 are inserted in the backing and shifted in the other lateral direction for accomplishing its tufting operation, as described for the preferred operation; however, the additional lobes 126 and valleys 127 causes the needles 21 to be shifted laterally, a second time, during each upstroke, and prior to the retraction of the needles 21 from the backing material 20, the shifting being in the same direction and to the same extent as the shifting took place during the initial portion of the cycle when the needles 21 were free of the backing material 20. The result, therefore, is that the increment of the backing material 20 which was shifted in one direction for the tufts inserting operation is shifted by the needles 21 back to its original linear path of travel, before the needles 21 are retracted from the backing material 20.
While we have chosen to describe the needles as shifting by one-fourth the gauge of the machine, so as to produce two rows of tufts spaced apart by one half the gauge, it will readily be understood that the needles 21 can be shifted by any increment desired or shifted successively from the normal position in only one direction, rather than in alternate directions. Thus, any reasonable number of longitudinal lines of tufts can be produced using a single needle 21 by shifting it appropriately to the left or right, as desired. Of course, a longitudinal line of tufting can be produced by cycling the needles 21 without shifting them at all.
The present invention is equally applicable to tufting machines for producing both cut pile and loop pile, it being understood that the term "looper" or "looper means" applies equally to a loop pile looper or to the cut pile looper and the knife. When I state that the loop is released by the looper or the hook of the looper, I mean that the loop 12 can be released as a loop or can be servered by a knife and hence released as cut pile. The looper can be a single looper or a plurality of loopers in vertical alignment such as in a combination cut and loop pile machine wherein certain of the loops formed by a single needle are cut and others are uncut. The machine and process of the present invention is particularly suited for use in such combination cut and loop pile machines since the looper construction for each needle has, in the past, limited the narrowness of the gauge of the machine to relatively wide distances between adjacent needles.
It will be obvious to those skilled in the art that many variations may be made in the embodiment chosen for the purpose of illustrating the invention without departing from the scope thereof as defined by the claims. | A laterally shiftable needle bar of a tufting machine, carrying a plurality of laterally spaced needles, is reciprocated in a vertical path for simultaneously inserting loops of yarn, carried by the needles, through a base fabric, the fabric being fed in a linear longitudinal path beneath the needles. Each needle has an individual looper below the base fabric, in registery and cooperating with the needle for engaging and temporarily holding the loop of yarn, inserted by the needle through the base fabric, as the needle is retracted.
During a first portion of a cycle of the needle bar, prior to the insertion of the needles through the base fabric, a needle bar shifting assembly shifts the needle bar laterally, in one direction or the other. Then, after the needles have penetrated the base fabric, the needle bar shifting assembly shifts the needle bar laterally in an opposite direction, so as to cause the needles to move the penetrated portion of the base fabric laterally out of its normal linear path and align the needles with their loopers beneath the base fabric for engagement of the loops by the loopers, as the needles are withdrawn vertically from the base fabric. The resiliency of the base fabric returns the shifted portion of the base fabric to its original linear path across the machine and the yarn inserting cycle is then repeated. By appropriate manipulating of the lateral shifting of the needle bar one or, indeed, a plurality of longitudinal rows of tufts are produced by each needle and its individual looper. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for the photometric determination of biological agglutination using light scattering. More particularly, the present invention relates to a method and apparatus for the photometric determination of biological agglutination of test samples by detecting scattered light through the test samples using a laser beam source and at least one photodetector.
The importance of determining biological agglutination systems such as antigens, antibodies, blood clotting, etc. with precision has long been recognized in various fields of life sciences as well as in the field of the therapy, and there has been stronger desire for the development of quantitative determination of antigens, antibodies, blood clotting, etc. with high precision as demand therefor has increased in recent years.
Determination heretofore prevailing which is a plate immune diffusion takes one or a few days and the judgement of the results obtained by this method is very complicated and requires skill. From this it follows that the judgement varies from person to person. This is one of the major defects of the conventional method.
Recently, there has been proposed a nephelometric immunoassay in order to detect the formation of antigen-antibody complexes with light scattering, thus improving operability and precision in quantitative determination. However, the conventional nephelometric immunoassay practically takes a relatively long time ranging from several tens of minutes to several hours and therefore is unsatisfactory when urgent detection or high speed treatment of a large amount of test samples is needed.
Further, it has heretofore been known to detect antigens or antibodies by reacting latex particles on which an antigen or an antibody is supported with a corresponding antibody or antigen on a glass plate and observing visually the state of agglutination which occurs. This method is disadvantageous since it gives only qualitative data by judging whether or not agglutination occurs on the glass plate and the judgement as to whether or not agglutination occurred will be apt to vary depending on personal conditions of those who carry out the detection in the borderline regions. A further disadvantage is that with the above method it is necessary to prepare a series of seriously diluted samples and judgement must be made on each diluted sample, which not only requires a lot of time and effort but also gives rise to semiquantitative data only, thus achieving but low precision.
On the other hand, it has been known to measure optical absorbance of a test sample in a reactor with a light whose wavelength falls in the near-infrared region in order to qualitatively determine the agglutination state. This method is disadvantageous in that on one hand, most of the transmission light to be detected is blank information which is ascribable to reduction by latex particles in a non-agglutinated state, and the change in the transmission light ascribable to the minor part of the latex particles which agglutinated is very small as compared with the blank value, and on the other hand, when measuring transmission, light sensitivity is lowered further because of multiple scattering in the light path since test samples has a very high turbidity and also it tends to be influenced by movement of the particles in the light path.
In the case where scattered light is utilized, a conventional method using an integrating-sphere photometer is also disadvantageous since the background value is large relative to the value due to agglutination as in the case of measuring the optical absorbance, resulting in decreases in sensitivity and stability.
As stated above, the conventional methods for measuring agglutination reactions are not satisfactory with respect to their precision since they are difficult to carry out in a stable manner with high sensitivity.
On the other hand, blood coagulation tests are extremely important and useful for successful therapy of a bleeding disorder in the patient or for the followup manangement of patients receiving therapy using an anticoagulant. Also, these tests must be done before an operation can be initiated.
The coagulation tests include measurements of prothrombin time hereafter referred to as "PT" and of activated partial thromboplastin time hereafter referred to as "APTT" which are well known and effected as measurements of an extrinsic blood clotting mechanism and intrinsic blood clotting mechanism, respectively.
Further, at present various automatic clottage detection devices capable of measuring PT and APTT are available commercially.
The process of blood coagulation is said to be an extremely complex chain reaction and involves blood coagulation factors I to XIII. It is therefore necessary to carry out quantitative determination of blood factors to see which factors are short and to what extent they are short in the case where disorder in PT or APTT is found.
For determining blood factors, a method has heretofore been used in which corrective reagents is used in PT or APTT tests to qualitatively detect which factor is insufficient and then a calibration curve should be obtained by the PT or APTT test using an appropriate blood factor-lacking plasma. This conventional method requires very complicated procedures and much work. In addition, the quantitative determination of the results is not so accurate since the determination method is indirect in nature.
In contrast to tests based on the gross blood coagulation, direct determination of each blood factor has recently been proposed which involves measurement of immune activity using an antigen-antibody reaction of measurement of biological activities using an enzymatic reaction with a synthetic substrate.
According to this method direct measurement can be carried out with ease and high specificity and precision. However, conventional apparatus for the measurement of PT or APTT cannot be used for this method and it is therefore necessary to provide therewith new costly devices so that the apparatus can be adapted to the direct measurement method described above.
On the contrary, conventional apparatus adapted for the direct determination of blood factors by the above method cannot be used for carrying out screening tests which are very useful in blood coagulating tests such as PT, APTT, etc.
SUMMARY OF THE INVENTION
As a result of extensive research it has been found that in a nephelometric immunoassay using a laser beam as a light source, there is a selective range of detection angle at which the intensity of scattered light due to antigen-antibody complex changes very sharply in the initial stage of the reaction where antigen-antibody complex is formed in the fluid sample. The present invention is based on the above findings.
Therefore, the present invention provides a photometric method for measuring a biological agglutination reaction comprising irradiating a biological agglutination reaction system with a laser beam and selectively detecting the intensity of scattered light from the reaction system at a scattering angle (θ) of 30° to 60°.
Further, the present invention provides a photometric apparatus for measuring a biological agglutination reaction system comprising a laser beam source and at least one photodetector for detecting scattered light from a test sample, the method comprising arranging a photodetector so as to be capable of detecting the scattered light at a scatter angle (θ) of 30° to 60°.
According to the present invention biological agglutination reactions can be measured quantitatively by simple operations. Further, antigen-antibody reactions can be measured in a very short time with high precision as compared with conventional nephelometric immunoassays.
Further, according to the present invention immunological agglutination reactions can be determined quantitatively with high stability and precision.
Still further, according to the prsent invention, determination of blood coagulation such as conventional PT and APTT tests and immunological determination of blood factors using antigen-antibody reactions can be carried out efficiently in a single device, which makes it possible to conduct screening tests and quantitative determination tests with ease and high precision.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described in detail with reference to the drawings in which:
FIG. 1 is a schematical illustration of the principle of the photometric system of the present invention;
FIG. 2 (a) is a graph plotting against time the intensity of scattered light from a fluid sample;
FIG. 2 (b) is a graph showing time differential characteristics of the curve A in FIG. 2 (a);
FIG. 3 is a graph showing a calibration curve plotting the concentration of an antigen versus the intensity of scattered light in the determination of IgG;
FIG. 4 is a graph showing a calibration curve plotting the concentration of an antigen versus maximum speed (peak rate) of the change in the intensity of scattered light;
FIG. 5 is a graph plotting against time the change in the intensity of scattered light obtained by irradiating reaction mixtures composed of standard FIB solutions at various concentrations and anti-FIB solutions at various concentrations and anti-FIB-sensitized latex with a laser beam having a wavelength of 780 nm;
FIG. 6 is a graph showing a calibration curve plotting the maximum speed of the change in the intensity of scattered light versus the concentration of a standard FIB solution;
FIG. 7 is a graph plotting the intensity of scattered light versus time of a test fluid sample of a blood coagulation reaction;
FIG. 8 is a graph showing an activity curve obtained in the measurement of PT; and
FIG. 9 is a block diagram of a photometric apparatus for measuring the intensity of scattered light according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Examples of suitable laser beams include a helium neon laser having an oscillation wavelength of 632.8 nm or visible - near-infrared semiconductor laser having an oscillation wavelength of 700-800 nm.
In the present invention, there can be used insoluble carrier particles of organic high molecular substances which are insoluble in a liquid medium used in the measurement and have an average particle size of not larger than 0.1 micron, such as latex of organic polymer e.g., polystyrene, styrene-butadiene copolymer, etc. obtained by emulsion polymerization, or inorganic oxides such as silica, alumina, etc.
FIG. 1 shows the arrangement of a laser beam source, a test fluid sample which is a scattered light source, and a photodetector according to one embodiment of the present invention. A predetermined amount of laser beam flux emitted from a laser beam source 1 is irradiated to a cuvette 2, which contains a test fluid sample 3, and the sample scatters the laser beam.
A photodetector 4 for measuring the intensity of the scattered light and converting it into an electric signal is provided at a specific position with respect to the reaction cuvette 2. The laser beam source 1 may be a visible semiconductor laser having an oscillation wavelength of about 780 nm. The reaction cuvette 2 may be a test tube cuvette having an inner diameter of 5 mm, for example. The photodetector 3 may be a silicon photocell.
Assuming the angle of the photodetector 4 with respect to the laser beam axis passing the center of the reaction cuvette 2 is θ, time response of the intensity of scattered light according to the formation of antigen-antibody complex differs depending on the angle at which scattered light is detected.
In FIG. 2 (a), A is a curve plotting against time the change in the intensity of scattered light (S) as the reaction between an antigen and a corresponding antibody to form a complex proceeds as measured at a scatter light angle (θ) of 50° in the above described apparatus.
The moment when a solution containing an antigen or antibody to be determined is mixed with an reagent containing a corresponding antibody or antigen the intensity of scattered light (S) begins to increase and reaches a stationary level after time T A and this level is maintained thereafter.
In so-called "end point" method, the height of this final level after time T A is used for quantitative determination of antigens and antibodies.
Therefore, the shorter the time required in which the final level is reached, i.e., the higher the speed at which the intensity of scattered light (S) increases, the more rapidly can the determination be carried out.
In conventional nephelometric immunoassays forward scattered light (scatter angle θ is not smaller than 90°) is used.
In FIG. 2 (a), the curve B is a plot against time of the intensity of scattered light measured at a scatter angle (θ) of 150°. In FIG. 2 (a), the vertical axis is normalized taking the amount of light finally reached as 100 in order to enable one to compare the results obtained by measuring at a scatter angle of 50°.
It has been found when θ is 150°, the time T B required for reaching a stationary level is several fold longer than the corresponding time T A which is obtained when θ is 50°. Practically, T A is on the order of a few minutes in contrast to T B which is on the order of several tens of minutes. This supports the view that the sensitivity of detection in the initial stage of the formation of an antigen-antibody complex is higher in the measurement of backward scattered light than in the measurement of forward scattered light, and that this difference is ascribable to the difference in spatial distribution of the intensity of scattered light due to the size of the antigen-antibody complex.
In conventional nephelometric immunoassays the measurement of forward scattered light is generally used aiming at obtaining higher intensity of scattered light. On the contrary, fixing their eye on the sensitivity of detection in the initial stage of antigen-antibody reaction the present inventors have found that backward scattered light reflects the state of the reaction in its initial stage very sensitively.
It has also been found that at a scatter angle of smaller than 30° the signal of scattered light itself is weak and the influence of a reflected light reflected by the reactor is strong, thus the precision of determination being reduced.
Further, it has been found according to the present invention that a scatter angle range of from 30° to 60° is most sensitive to the leading edge of the antigen-antibody reaction and enables one to carry out photometric determination with high precision. If photometric detection is done at a scatter angle in this range, signals of a level sufficient for further processing in a conventional electric circuit can be obtained.
Therefore, photometric measurement with high precision can be carried out in a time (T A ) by several tenths shorter than time T B required for the measurement according to conventional nephelometric immunoassays.
FIG. 2 (b) is a graph plotting a first time differential (dS/dT) of A in FIG. 2 (a) which is a curve showing time response of the intensity of scattered light according to the present invention.
In the dynamic nephelometric immunoassay, the maximum value (P) of the above first time-differential signal is used in the quantitative determination of antigen or antibody.
Time required for the measurement is Time T C , which is the time from the initiation of reaction to the appearance of P, and it is observed that T C is shorter than T A . This means that the time required for measurement is further shortened than required for the end point method.
FIG. 3 shows a calibration curve for human immunoglobulin G (IgG) obtained by using the above described apparatus.
In this embodiment, 30 microliters each of 301 fold diluted solutions of standard serum containing various concentrations of human IgG were added to 300 microliters of a 12.5 fold diluted solution of anti-IgG serum (sheep), and the mixture was incubated for 5 minutes at room temperature. Then, the output of the photodetector was read and the relationship between the difference in the intensity ΔS (i.e., the intensity of scattered light after 5 minutes from the initiation of the reaction minus that of scattered light before the reaction took place) and concentration was obtained.
In 5 minutes calibration relation sufficient for the quantitative determination was obtained. In contrast it takes about 30 minutes to about 1 hour for a like determination according to conventional end point method. Thus, the photometric system of the present invention is more efficient than the prior art.
More speedy measurement can be achieved using a method in which the concentration of an antigen or antibody can be determined from the speed of change in the intensity of scattered light (i.e., dynamic nephelometric immunoassay).
FIG. 4 shows a calibration curve for the determination of fibrinogen in blood serum (hereafter referred to as "FIB") obtained by a dynamic nephelometric immunoassay using P by the use of the above described apparatus.
More particularly, 50 microliters of a 21 fold diluted solution of standard plasma containing an FIB antigen at different concentrations was added to 300 microliters of a 12.5 fold diluted solution of an anti-FIB serum (rabbit), and the mixture was detected by the above described apparatus. The output of the photodetector was processed by a conventional differential electric circuit and the relationship between the maximum value P of the first time-differential and the concentration of the sample was obtained.
In the dynamic nephelometric immunoassay, high detection sensitivity is needed in the initial stage of the reaction. The present invention is advantageous in this respect since it permits highly sensitive detection immediately after the initiation of the reaction.
FIG. 5 shows a time response of the intensity of scattered light accompanying an agglutination reaction at its initial stage when it is carried out using polystyrene latex having an average particle size of 0.08 microns and detection was carried out at a scatter angle (θ) of 50° using the above described apparatus of the present invention.
The polystyrene latex used is a product of Dow Chemical Inc. and sensitized with human fibrinogen (FIB) antibody (rabbit) by the method described in Journal of Laboratory and Chemical Medicine 50 pp 113-118.
Output S of the photodetector of the above apparatus was recorded from the point in time when 50 microliters of standard plasma containing different concentrations of FIB antigen was added to 300 microliters of the sensitized latex.
In FIG. 5, the vertical axis ΔS indicates that the observed values are adjusted by deducing therefrom the ouput S 0 of the photodetector at the moment when the latex solution and the FIB antigen solution were mixed with each other, as a blank value.
In the Figure, curves A, B, C, D, E and F correspond to the concentrations of the FIB: 0.0298, 0.0595, 0.119, 0.238, 0.476 and 0.952 mg/dl, respectively.
According to the present invention, as will be clear from the figure, it is possible to detect the change in the intensity of scattered light due to the agglutination which occurs in an extremely turbid test fluid sample, in a very stable state and with high sensitivity.
FIG. 6 shows a calibration curve prepared from the maximum speed of the time response of agglutination signal ΔS shown in FIG. 5. That is, the signal ΔS obtained by correcting the output (S) of the photodetector with the blank value was processed by a conventional differential electric circuit and the relationship between the maximum differential value P=(d(ΔS)/dT) Max and the concentration of FIB was obtained. The time required for the measurement of one sample was 15 seconds only.
The present invention thus provides a photometric method and system which are very sensitive in the detection of the initial stage of an agglutination reaction and permit rapid measurement.
Further, blood coagulation can be measured using the photodetector 4 in FIG. 1. FIG. 7 is a graph showing a time response of the intensity of scattered light (S) in the reaction of blood coagulation using the photodetector 4.
In FIG. 7, which is a graph showing a time response of the intensity of scattered light (S) in the reaction of blood coagulation, portion a represents a state in which the coagulation reaction proceeds after mixing a test sample with a reagent but precipitation of fibrin is not observed, portion b represents a state in which precipitation of fibrin proceeds vigorously, portion c represents a state conversion of fibrinogen (FIB) into fibrin and precipitation of fibrin was completed. It is empirically known that the point in time T c at which the switch over from a to b occurs corresponds to the initiation of the precipitation of fibrin.
FIG. 8 shows the relationship of the degree of dilution of human plasma from a sound person with physiological saline and T c in the PT measurement (hereafter referred to as "activity curve" obtained by the use of the device described above.
More particularly, 100 microliters of a citric acid-added normal human plasma diluted with physiological saline, 100 microliters of thromboplastin preparation (derived from rabbit brain) and 100 microliters of an aqueous solution of 0.02 M calcium chloride were mixed and the change in the intensity of scattered light from the resulting mixture was observed. From the results T c was obtained and the relation between the degree of dilution of the normal human plasma preparation and T c were plotted.
According to the present invention, stable activity curves were obtained even when samples having coagulation activity as low as 10 fold dilution were used.
Although it is known to obtain T c from the change in the intensity of scattered light accompanying the blood coagulation reaction it is unexpected that the measurement of blood coagulation can be carried out with high sensitivity and stability even when low activity coagulation reactions are measured if a laser beam having a high intensity and excellent monochromaticity is used.
According to the above embodiment of the present invention, the measurement of a coagulation reaction and that of an antigen-antibody reaction can be carried out using the same photodetector, so that the photometric system can be simplified.
FIG. 9 is a block diagram of the apparatus for the determination of scattered light which comprises two photodetectors.
In FIG. 9, photodetectors 4 and 5 convert the intensity signal of scattered light into an electric signal, which is then input to a signal preconditioner 6 and processed thereby. A signal switch 12 determines which of the signals from the photodetectors 4 and 5 is to be input to a signal preconditioner 6 and processed therein. The signal preconditioner 6 further differentiates the results when the measurement of the antigen-antibody reaction utilizing P is carried out using electrical amplification and the results obtained are input to an A/D converter 7. A computer 8 is provided so that it can evaluate the information in the form of the intensity of scattered light converted into digital amount by the A/D convertor, judge the point of coagulation when blood coagulation is measured and calculate the concentration of antigens or antibodies when an antigen-antibody reaction is measured.
It is obvious to one skilled in the art that in addition to the above described embodiments various procedures can be used and various programs therefor can be formulated as methods for judging the point of blood coagulation, and for calculating the concentration of antigens or antibodies. These modifications are not understood to limit the present invention in anyway.
Further, a display and print portion 9 is provided for displaying and printing the data processed by the computer 8. Also, a recorder 11 is provided so as to continuously observe the process of the reaction. Further, the system comprises a reagent dispensing means and sample preparation means 10.
As stated above, a combination of the present invention and conventional techniques will bring about automated, energy conservated measurement of scattered light and apparatus therefor with ease.
Further, the present invention can determine the change in the intensity of scattered light from biological agglutination systems such as an immunological agglutination reaction system very stably and with high sensitivity and quantitative reproducibility and therefore, data with high precision can be obtained rapidly.
Further, the present invention enables one to determine blood coagulation and antigen-antibody reactions, which have been unable to be determined by a single apparatus of conventional techniques, with high precision, and therefore it contributes greatly to efficient and rationalized measurement. Further, according to the present invention, detailed clinical data can be obtained before clinical tests can be conducted, thus adding to the field of therapy greatly. | A photometric method and apparatus for measuring agglutination in a biological agglutination reaction system test sample using a laser beam source and at least one photodetector for detecting light scattered by the test sample. The method includes the following steps: (1) arranging the at least one photodetector so as to be capable of detecting scattered light from the test sample at a scatter angle of 30 to 60 with respect to a laser beam directed at the test sample from the laser beam source; (2) irradiating the test sample with the laser beam from the laser beam source; (3) selectively detecting the intensity of scattered light from the test sample at the scatter angle of 30 to 60 using the at least one photodetector which provides an output indicative thereof; and (4) determining the first derivative of the output of the at least one photodetector with respect to time and obtaining the maximum value thereof. In addition to the laser beam source and the at least one photodetector, the apparatus also includes a reaction cuvette for containing the test sample. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a sputtering device that forms a thin layer on a long film, and a method for producing a long film with a thin layer.
[0003] 2. Description of Related Art
[0004] A sputtering method is widely used as a method for forming a thin layer in vacuum. In the sputtering method, plasma of sputtering gas is generated by applying a voltage between a base substrate and a target with the base substrate kept at an anodic potential and the target kept at a cathodic potential in a sputtering gas such as a low-pressure argon gas. Sputtering gas ions in the plasma strike the target, so that a constituent material of the target is driven out. The constituent material of the target, which is driven out, is deposited on the base substrate to form a thin layer.
[0005] As a transparent conductive layer, a thin layer of indium-tin-oxide (ITO) is widely used. When a thin layer of an oxide such as indium-tin-oxide (ITO) is formed, a reactive sputtering method is used. In the reactive sputtering method, a reactive gas such as oxygen is supplied in addition to a sputtering gas such as argon. In the reactive sputtering method, a constituent material of a target, which is driven out, reacts with a reactive gas, so that the constituent material of the target, such as an oxide, is formed and deposited on a base substrate.
[0006] In a sputtering device, a target and a cathode are usually mechanically and electrically integrated. The base substrate and the target face each other with a predetermined distance therebetween. The sputtering gas and the reactive gas are usually supplied between the base substrate and the target. The sputtering gas and the reactive gas may be supplied separately, or may be supplied in mixture.
[0007] In a sputtering device in which the base substrate is a silicon wafer or a glass plate, the base substrate is transferred using a robot arm, a roller conveyor, or the like. When the silicon wafer or the glass plate is charged, charges are removed by an electricity removing apparatus (ion generating apparatus) before the silicon wafer or the glass plate comes into contact with the robot arm or the roller conveyor.
[0008] However, when the base substrate is a long film, it is handled differently from the silicon wafer or the glass plate. A sputtering device and a sputtering method for a long film are described in, for example, JP-A-2009-19246. In the case of a long film, it is impossible to form a sputtered layer over the whole of the long film at a time. Accordingly, the long film delivered from a supply roll is guided by a guide roll on the delivery side to a film depositing roll (also referred to as a can roll). The long film is wound around the film depositing roll by less than one round, and the film depositing roll is rotated at a constant speed to cause the long film to run at a constant speed. A film is deposited on a portion of the long film which faces the target. The long film after completion of film deposition is guided by a guide roll on the storage side and wound around a storage roll.
[0009] As the long film, single films or laminated films of polyethylene terephthalate, polybutylene terephthalate, polyamide, polyvinyl chloride, polycarbonate, polystyrene, polypropylene, polyethylene, and the like are generally used. When a long film formed of an insulating polymer material is delivered from a supply roll, the long film is often charged with static electricity. The charge voltage of the long film reaches several tens of thousands of volts.
[0010] When the guide roll on the delivery side has the same potential as that of a vacuum chamber, static electricity charged on the long film delivered from the supply roll may be discharged to the guide roll to damage the long film.
[0011] Usually, for preventing discharge, ions are supplied to the long film between the supply roll and the guide roll by an electricity removing apparatus (ion generating apparatus) to remove charges on the long film. However, when the long film is conveyed at a high speed, removal of electricity may be incomplete.
[0012] JP-A-2009-19246 describes that “a guide roll in contact with a conductive thin layer on a long film is isolated from a vacuum chamber and kept at a floating potential”. In the sputtering method, charged particles in plasma enters a conductive thin layer, so that the conductive thin layer is charged. If the guide roll is grounded, a current passes through the conductive thin layer to generate Joule heat, so that a film on which the conductive thin layer is formed is thermally stretched. In JP-A-2009-19246, it is not necessary to keep a guide roll, which is not in contact with a conductive thin layer, at a floating potential.
[0013] The long film is charged not only when the long film is delivered from the supply roll. Unlike Joule heat cited as the problem in JP-A-2009-19246, discharge of static electricity occurs even when the long film is not provided with conductive thin layer. Therefore, the long film may discharge static electricity to all guide rolls. Thus, if ion electricity removing apparatuses are used, electricity removing apparatuses must be installed on all guide rolls. In the case of a large-scale sputtering device, there are more than 100 guide rolls, so that the number of electricity removing apparatuses increases, and it is difficult to provide spaces for installing electricity removing apparatuses.
SUMMARY OF THE INVENTION
[0014] It is an object of the present invention to provide a sputtering device capable of preventing discharge of static electricity charged on a long film to a guide roll, and a method for producing a long film with a thin layer in which discharge of static electricity from a long film to a guide roll is prevented.
[0015] The summary of the present invention is described as below.
[0016] (1) The sputtering device of the present invention is configured to form a thin layer on a long film. In a first preferred aspect, a sputtering device according to the present invention includes: a vacuum chamber; a vacuum pump for evacuating the vacuum chamber; a supply roll for supplying a long film; a storage roll for storing the long film; a film depositing roll that is provided in the vacuum chamber and conveys the long film along a surface thereof; a target facing the film depositing roll; a gas pipe for supplying a gas into the vacuum chamber; a plurality of guide rolls for guiding the long film; a plurality of guide roll shafts provided at each of both ends of the plurality of guide rolls; a plurality of bearings for supporting the plurality of guide roll shafts; and an insulator configured to insulate each guide roll shaft and each bearing from each other, in which contact surfaces of the guide rolls with the long film are kept at a floating potential.
[0017] (2) The sputtering device of the present invention is configured to form a thin layer on a long film. In a second preferred aspect, a sputtering device according to the present invention includes: a vacuum chamber; a vacuum pump for evacuating the vacuum chamber; a supply roll for supplying a long film; a storage roll for storing the long film; a film depositing roll that is provided in the vacuum chamber and conveys the long film along a surface thereof; a target facing the film depositing roll; a gas pipe for supplying a gas into the vacuum chamber; a plurality of guide rolls for guiding the long film; and a plurality of insulators configured to insulate and cover contact surfaces of the plurality of guide rolls with the long film, in which the contact surfaces of the guide rolls with the long film are kept at a floating potential.
[0018] (3) In a third preferred aspect, a method for producing a long film with a thin layer according to the present invention includes a step of conveying a long film in a vacuum chamber using guide rolls, in which contact surfaces of the guide rolls with the long film are kept at a floating potential.
[0019] (4) In a fourth preferred aspect of the method for producing a long film with a thin layer according to the present invention, each of the guide rolls includes: a plurality of guide roll shafts provided at each of both ends of each guide roll; a plurality of bearings for supporting the plurality of guide roll shafts; and a plurality of insulators configured to insulate the guide roll shafts and the plurality of bearings from each other, and a contact surface of each of the guide rolls with the long film is kept at a floating potential.
[0020] (5) In a fifth preferred aspect of the method for producing a long film with a thin layer according to the present invention, each of the guide rolls includes: an insulator configured to insulate and cover a contact surface of the guide roll with the long film, and the contact surface of the guide roll with the long film is kept at a floating potential.
[0021] In the sputtering device of the present invention, static electricity is not discharged from a long film to a guide roll even when the long film is charged with static electricity. The long film is thereby prevented from being damaged by discharge.
[0022] In the method for producing a long film with a thin layer according to the present invention, the long film is conveyed using a plurality of guide rolls kept at a floating potential, and therefore static electricity is not discharged from the long film to the guide rolls even when the long film is charged with static electricity. The long film is thereby prevented from being damaged by discharge.
[0023] Each of the guide rolls, in which a contact surface of the guide roll with a long film is kept at a floating potential, is hereinafter referred to as an “insulating guide roll”. When a conductive layer is formed on the long film, the conductive layer-formed surface of the long film becomes conductive. However, guidance of the conductive long film by the insulating guide roll causes no particular problem because the long film is not damaged.
[0024] For a full understanding of the present invention, reference should now be made to the following detailed description of the preferred embodiments of the invention as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a perspective view of a whole of a sputtering device of the present invention; and
[0026] FIG. 2 ( a ) is a perspective view of a first example of an insulating guide roll to be used in the present invention, and FIG. 2 ( b ) is a perspective view of a second example of an insulating guide roll to be used in the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] The preferred embodiments of the present invention will now be described with reference to FIGS. 1 to 2 . Identical elements in the figure are designated with the same reference numerals.
[0028] FIG. 1 is a perspective view of the whole of one example of a sputtering device 10 of the present invention. The sputtering device 10 of the present invention includes a vacuum chamber 11 , and a vacuum pump 12 for evacuating the vacuum chamber 11 . A supply roll 13 , an insulating guide roll 14 , a film depositing roll 15 , and a storage roll 16 are provided in the vacuum chamber 11 . A long film 17 is delivered from the supply roll 13 , guided by the insulating guide roll 14 , wound around the film depositing roll 15 by less than one round, guided again by the insulating guide roll 14 , and stored in the storage roll 16 . A target 18 faces the film depositing roll 15 with a predetermined distance therebetween. On the long film 17 continuously running over the film depositing roll 15 , sputtered layers are formed so as to face the target 18 . While FIG. 1 illustrates two targets 18 , the number of targets 18 is not limited. A gas pipe 21 for supplying a sputtering gas (e.g., argon gas) and a reactive gas (e.g., oxygen gas) is provided between the target 18 and the film depositing roll 15 .
[0029] In the sputtering device 10 of the present invention, plasma of sputtering gas is generated by applying a voltage between the film depositing roll 15 and the target 18 with the film depositing roll 15 kept at an anodic potential and the target 18 kept at a cathodic potential in a sputtering gas such as a low-pressure argon gas. Sputtering gas ions in the plasma strike the target 18 , so that a constituent material of the target 18 is driven out. The constituent material of the target 18 , which is driven out, is deposited on the long film 17 to form a thin layer. The film depositing roll 15 is controlled to a constant temperature within a range of, for example, 20° C. to 250° C. for obtaining a film of high quality.
[0030] As a transparent conductive layer, a thin layer of indium-tin-oxide (ITO) is widely used. When a thin layer of an oxide such as indium-tin-oxide (ITO) is formed, a reactive sputtering method is used. In the reactive sputtering method, a reactive gas such as oxygen is supplied in addition to a sputtering gas such as argon. In the reactive sputtering method, the constituent material of the target 18 , which is driven out, reacts with a reactive gas, so that the constituent material of the target 18 , such as an oxide, is deposited on the long film 17 .
[0031] In the sputtering device 10 of the present invention, the target 18 and a cathode 19 are mechanically and electrically integrated. The long film 17 and the target 18 face each other with a predetermined distance therebetween. The sputtering gas and the reactive gas are supplied between the long film 17 and the target 18 . The sputtering gas and the reactive gas may be supplied separately, or may be supplied in mixture.
[0032] FIG. 2 ( a ) is a perspective view of a first example of an insulating guide roll 14 a to be used in the sputtering device 10 of the present invention. FIG. 2 ( b ) is a perspective view of a second example of an insulating guide roll 14 b to be used in the sputtering device 10 of the present invention.
[0033] The insulating guide roll 14 a in FIG. 2 ( a ), a plurality of guide roll shafts 24 , and a plurality of bearings 25 for supporting the plurality of guide roll shafts 24 are insulated from each other by a plurality of doughnut-shaped insulators 26 , and a contact surface of a guide roll 28 with the long film 17 is kept at a floating potential. The plurality of bearings 25 are kept at a potential equal to that of the vacuum chamber 11 . The guide roll 28 and the guide roll shafts 24 of the insulating guide roll 14 a are metal (e.g., one obtained by plating a surface of an aluminum cylinder with hard chromium). Thus, a contact surface of the guide roll 28 with the long film 17 is metal (e.g., hard chromium-plated surface).
[0034] However, since the guide roll 28 and the guide roll shafts 24 are kept at a floating potential, the contact surface with the long film 17 is also kept at a floating potential. Therefore, even when the charged long film 17 comes into contact with the insulating guide roll 14 a, static electricity is not discharged from the long film 17 to the insulating guide roll 14 a. Therefore, the long film 17 is not damaged by discharge.
[0035] As a material of the doughnut-shaped insulator 26 inserted between the guide roll shaft 24 and the bearing 25 , a polyether ether ketone material (PEEK (registered trademark)) as an engineering plastic is suitable in view of dielectric strength voltage and mechanical strength.
[0036] In the insulating guide roll 14 b in FIG. 2 ( b ), the surface of a guide roll 31 is covered with an insulator 32 , and the contact surface with the long film 17 is kept at a floating potential. The guide roll 31 and a plurality of guide roll shafts 34 are metal (e.g., aluminum), and therefore kept at a potential equal to that of the vacuum chamber 11 .
[0037] However, since the contact surface with the long film 17 is covered with the insulator 32 , static electricity is not discharged from the long film 17 to the insulating guide roll 14 b even when the charged long film 17 comes into contact with the insulating guide roll 14 b. Therefore, the long film 17 is not damaged by discharge.
[0038] As a material of the insulator 32 for covering the surface of the guide roll 31 , a ceramic spray layer of aluminum oxide, silicon nitride, or the like is suitable in view of dielectric strength voltage and ease of forming a layer.
[0039] The long film 17 is easily charged when the long film 17 is delivered from the supply roll 13 . However, the long film 17 may be charged not only at the time of delivery, but also in a conveyance path of the long film 17 . In a large-scale sputtering device, 100 or more guide rolls are used. Since the long film 17 is damaged when discharge occurs in any of the guide rolls, it is preferable to use insulating guide rolls 14 a or 14 b for all of the guide rolls.
[0040] A method for producing a long film with a thin layer according to the present invention will now be described in detail. In the vacuum chamber 11 in FIG. 1 , the insulating long film 17 is delivered from the supply roll 13 , guided by the insulating guide roll 14 , and wound around the film depositing roll 15 by less than one round. For example, a transparent conductive layer is formed on a portion of the long film 17 which faces the target 18 , while the film depositing roll 15 is rotated at a constant speed to cause the long film 17 to run at a constant speed. The long film 17 after completion of film deposition is guided by the insulating guide roll 14 on the storage side and wound around the storage roll 16 . The film depositing roll 15 is controlled to a constant temperature within a range of, for example, 20° C. to 250° C. for obtaining a film of high quality.
[0041] At the time of sputtering, a direct-current voltage (or alternating-current voltage) is applied between the film depositing roll 15 and the target 18 to generate plasma of sputtering gas (e.g., argon gas). The direct-current voltage is, for example, 0 V (earth potential) for the film depositing roll 15 and −400 V to −100 V for the target 18 . Sputtering gas ions are caused to strike the target 18 , and a material (e.g., indium atom or tin atom) of the target 18 which is scattered from the target 18 is deposited on the long film 17 .
[0042] When the insulating long film 17 is delivered from the supply roll 13 , the long film 17 is often charged with static electricity. When the guide roll on the delivery side is in conduction with the vacuum chamber 11 and is kept at an earth potential, static electricity charged on the long film delivered from the supply roll may be discharged to the guide roll to damage the long film.
[0043] However, in the method for producing a long film with a thin layer according to the present invention, the long film 17 is guided by the insulating guide roll 14 , and therefore even when the long film 17 is charged, there is no possibility that the charge may be discharged to the insulating guide roll 14 . Therefore, the long film 17 is prevented from being damaged by discharge.
[0044] When the long film 17 is in contact with the insulating guide roll 14 on the storage side, a surface on the transparent conductive layer side is not charged because a transparent conductive layer is formed on the long film 17 . However, there is no particular problem even when the guide roll on the storage side is the insulating guide roll 14 .
INDUSTRIAL APPLICABILITY
[0045] The sputtering device and the sputtering method of the present invention are useful for forming a thin layer, particularly, a transparent conductive layer of indium-tin-oxide (ITO) or the like, on a long film.
[0046] This application claims priority from Japanese Patent Application No. 2013-150055, which is incorporated herein by reference.
[0047] There have thus been shown and described a novel sputtering device and a novel method for producing a long film with thin layer which fulfill all the objects and advantages sought therefor. Many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art after considering this specification and the accompanying drawings which disclose the preferred embodiments thereof. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is to be limited only by the claims which follow. | A sputtering device includes: a vacuum chamber; a vacuum pump for evacuating the vacuum chamber; a supply roll for supplying a long film; a storage roll for storing the long film; a film depositing roll that is provided in the vacuum chamber and conveys the long film along a surface thereof; a target facing the film depositing roll; a gas pipe for supplying a gas into the vacuum chamber; a plurality of guide rolls for guiding the long film; a plurality of guide roll shafts provided at each of both ends of the plurality of guide rolls; a plurality of bearings for supporting the guide roll shafts; and a plurality of insulators configured to insulate the guide roll shafts and the bearings from each other, wherein contact surfaces of the guide rolls with the long film are kept at a floating potential. | 2 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention disclosed and claimed herein generally pertains to a method and system for notifying a telephone user that the quality of his or her speech or other audio information, as received at another telephone, is not acceptable. More particularly, the invention pertains to a method of the above type wherein a telephone speaker is notified of his or her deficient audio quality, while a phone call or conference is still in progress.
[0003] 2. Description of the Related Art
[0004] During a telephone call, and particularly during conference calls, the audio or line quality of a listening participant may not be acceptable, and may in fact be disruptive to the call. Moreover, if the party that is speaking is using a hands-free device such as a speaker phone, the audio input to that device will be muted, in order to avoid feedback. This will prevent other participants on the call from verbally informing the speaker that a problem exists with his or her audio quality. In this situation, the person speaking may continue for a long period of time without knowing that an audio problem exists, while the party or parties listening have no means of notifying the speaker of the problem.
[0005] At present, solutions to the above problem do not appear to be available. Some phones indicate signal quality by using graphic displays such as a series of “signal bars”, where the bars depict signal strength between the phone and an associated active tower. However, the state of these signal bars frequently is not indicative of the actual audio quality. At present, the method used most commonly to correct audio degradation is simply for participants to wait until the speaker pauses long enough for another participant to verbally inform the speaker of the problem. Even this method may not succeed, if the person speaking is having inbound as well as outbound audio problems.
[0006] It is thus apparent that there is definite need for a mechanism to inform a speaking party on a telephone call that an audio problem exists, so that alternative communication and/or conferencing measures may be undertaken.
SUMMARY OF THE INVENTION
[0007] The invention generally provides a method and system or apparatus for notifying a telephone speaker engaged in a call or conference that the audio quality being received by one or more listeners is not acceptable. The notice is provided before the call or conference has ended, so that effective action can be taken to continue the conference. Embodiments of the invention can include both automatic and manual methods for informing a participant in a telephone call that audio distortion is occurring. An automated method uses audio sampling and comparative logic, while a manual method is accomplished using phone programming and a key entry sequence. A further embodiment provides means for any participant on a call to verify the audio quality of his or her own telephone. One embodiment of the invention, directed to a method used to send an audio message from a speaking party to at least one listening party, includes the step of transmitting the audio message from a first phone operated by the speaking party to a second phone operated by the listening party. The method further includes detecting a deficiency in the audio quality of a first portion of the audio message, and notifying the speaking party of the deficiency before the audio message has ended.
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] FIGS. 1A-1E are schematic diagrams respectively illustrating an embodiment of the invention.
[0010] FIGS. 2A-2B are schematic diagrams respectively illustrating a second embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] Modern telephones and telephonic devices (referred to herein as telephones or phones) are full duplex and can transmit and receive information simultaneously. Speaker phones, cell phones, VOIP-based phones and other high quality phones mask this capability by disabling the audio speaker on the active device while speech is in process, in order to remove possible feedback loops. Such loops are especially troublesome in conference call environments. Additionally, these phones have the capability of being programmed, and of taking automatic action when a programmed function is activated. One example of such behavior is the *69 (star-six-nine) feature of a phone, which when activated causes a telephone to dial the number of the last incoming call. These capabilities are used in embodiments of the invention, as described herein.
[0012] Referring to FIG. 1A , there is shown a telephone system 100 that includes telephones 102 and 104 , and possibly one or more additional phones 106 . System 100 is used for a telephone conference wherein a user (not shown) of phone 102 is the speaking party, and users (not shown) of phones 104 and 106 are listening parties. Thus, phone 102 receives an audio message or information from its user, and transmits signals representing the audio message to phones 104 and 106 . Phones 104 and 106 recover the audio message, and make it available to the respective users listening at these phones.
[0013] FIG. 1A further shows phone 102 provided with a data processing component 108 . In an embodiment of the invention, processor component 108 is configured to automatically commence a procedure to detect distortion in the audio signals received at listener phones such as 104 , and to alert the speaker at phone 102 of the distortion. More particularly, component 108 commences successive sampling intervals, whereby a sample of the audio message at speaker phone 102 is recorded during each interval. Moreover, processor component 108 causes a message 110 to be sent, instructing phone 104 to also record a sample of the audio message, as the message is received at phone 104 , during one of the intervals. This activity is carried out by means of a data processor component 112 contained in phone 104 .
[0014] Referring to FIG. 1B , there is shown a sample 114 of the audio message, recorded at phone 104 during an interval, being sent to phone 102 by means of a link or transmission path 116 . If the phone system is operating at a frequency of 900 GHz, there may be an available independent sideband signal, of 8 Khz for example, that could be used for both message 110 and transmission path 116 .
[0015] As illustrated by FIG. 1C , at phone 102 the audio sample 114 from phone 104 is compared with an audio sample 118 , which is recorded at phone 102 during the same interval. If samples 114 and 118 are in analog form, the amplitudes of corresponding spectral components of the two samples could be compared, in order to determine whether amplitude variances between the samples are within a specified limit or tolerance. If samples 114 and 118 are in digital form, a bit counting technique could be used for the comparison. The principal issue is to determine the comparative signal strengths between the two samples.
[0016] If variance between the two samples is found to be within the specified tolerance, as shown by FIG. 1C , further audio samples 114 and 118 are acquired and compared. However, if the variance or difference is outside of the tolerance, as shown by FIG. 1D , phone 102 is activated to notify the speaker of an audio problem. Speaker notification is depicted in FIG. 1E by changing the display window 120 of phone 102 . Of course, any suitable notification method may be used, such as causing phone 102 to vibrate, or to flash a light source, display a text message, play a set audio message or pop up a message box. Additionally, the notification method can vary according to the type of device used for phone 102 .
[0017] In a useful embodiment of the invention, samples of the audio message could be recorded during periods on the order of 5 to 30 seconds. In determining the sample duration and interval time between samples, it is important to recognize that a longer sample duration will create a larger sample size which takes more time to transmit and analyze. On the other hand, a sample duration that is too small may not capture intermittent errors. Also, sampling should take into account patterns of an average speaker. For example, if the speaker only pauses every 3 minutes, sending quality data every 10 seconds is not helpful. In view of these variables, a reasonable sample duration would be from 5 to 10 seconds, and a reasonable sample interval would be every 60 to 90 seconds. Sampling could also be auto-adjusted based on speaking patterns. Thus, during an interactive conversation, smaller and more frequent samples may be taken. During a conference call, where there is one predominant speaker, a larger and less frequent sample could be used.
[0018] The phones used in phone system 100 of FIG. 1A could, without limitation, include land-set, computer (VOIP) or cell-based types. Phones of all such types are currently available that include computer chips or small data processing components. It is anticipated that such chips or firmware therein could be readily modified or updated, in order to provide processor components that have the capabilities of components 108 and 112 , as described above.
[0019] When an audio message is broadcast to multiple listening phones 104 and 106 , embodiments of the invention can include the ability to compare audio quality at different phones. For example, processor component 108 can have additional logic that determines the only audio problem is with phone 104 , when quality checks returned by other listening phones are found to be within tolerance. The user of phone 104 would then be notified of this situation.
[0020] The above embodiment also provides the means for an individual participant on a call to verify his or her own audio quality. To do this, a participant phone would record audio during the sample period, both when the user is a listener and a speaker. Then, at any point in time the user could input a programmed key sequence such as *77 (star-seven-seven) and have the audio from his or her last speaking session played back. As an example, during a lull in a conference call a user could press keys *77, and at a prompt press another key to select a duration of playback, such as key 5 in order to play back the last 5 seconds of the speaking time of that user. One of a number of well known logarithms could be used in order to select a sample of best, worst or medium quality. By means of this feature, the user would know what he or she sounds like at other phones.
[0021] A further embodiment of the invention provides a manual and participant-independent means for enabling a telephone listener to notify the speaker of an audio problem. In this case, the listener recognizes that the quality of a received audio message is not acceptable. To notify the speaker, the listener uses the keypad of his or her phone to enter a specific key sequence, which is then transferred to the speaker's phone.
[0022] As an example, FIG. 2A shows a telephone system 200 , wherein the user (not shown) of phone 202 is speaking, and the user (not shown) of phone 204 is listening. Upon realizing that audio quality is deficient, the following events occur:
(1) The listener enters a key sequence, such as *99 (star-nine-nine) into phone 204 . (2) The sequence causes an alert to be sent to phone 202 , used by the active speaker, by means of a transmission path 206 . (3) The alert causes a notification action to occur at phone 202 , as described above in connection with FIG. 1E .
[0026] FIG. 2B depicts notification of phone 202 by changing the display 208 thereof. FIGS. 2A and 2B further depict phones 202 and 204 provided with data processing components 210 and 212 , respectively, which have been configured to implement the events described above.
[0027] As an enhancement to the above embodiments, the user of phone 204 could additionally send a specific message to phone 202 . As an example, upon entering the initial alert key sequence, the user of phone 204 could have the option of rating the audio quality received from phone 202 by depressing an additional key. This rating could take the form of a percentage, where depressing a number key would indicate a subjective percentage of quality (e.g., the 5 key would indicate 50% audio quality). Alternatively, depressing a number key could select a menu such as:
1. static or noise on the line 2. minor voice dropout 3. moderate voice dropout 4. severe voice dropout 5. complete audio loss
[0033] Upon selection, the percentage for a specific message would be transmitted to phone 202 , and could, for example, be played audibly or displayed as text to provide additional information to the user of phone 202 . This embodiment may be readily used in connection with multi-participant calls and provides additional features in such environments. For example, if several listening participants activate the “rate by percentage” feature in a given period of time, logic in phone 202 could average the input and provide a single aggregate message to the user of phone 202 . Alternatively, when menu-based messages are used, an aggregation of all inputs could produce a summary message such as “four participants have indicated static on the line and three participants have indicated minor voice dropout.” Hybrid combinations of these and other methods likewise would be available for use and notification.
[0034] Embodiments of the invention, as described herein, may also be modified to permit a detected audio problem to be reported back to the carrier of the associated telephone system. For example, a phone user could press a key sequence, e.g., *611 (star-six-one-one), to send a recorded fragment of an audio message with a date/time stamp back to the carrier. Such qualitative documentation would permit faster diagnosis, particularly for intermittent quality issues. Without implementation of this feature, the caller would have to hang up, dial a carrier, wait to speak to a carrier representative, and describe the problem. It would then be necessary to wait for the arrival of a technician, at which time the audio problem may or may not be replicable. By providing the audio fragment with the date/time stamp, which would include an actual recording of the noise or other audio distortion, troubleshooting of the problem may be significantly expedited.
[0035] 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. | A method and apparatus is provided for notifying a telephone speaker engaged in a call or conference that the audio quality being received by one or more listeners is not acceptable. The notice is provided before the call or conference has ended, so that effective action can be taken to continue the conference. Embodiments of the invention can include both automatic and manual methods for informing a participant in a telephone call that audio distortion is occurring. An automated method uses audio sampling and comparative logic, while a manual method is accomplished using phone programming and a key entry sequence. A further embodiment provides means for any participant on a call to verify the audio quality of his or her own telephone. | 7 |
RELATED APPLICATIONS
The present application is related to a U.S. patent application entitled “Positive Pressure Protective Helmet” by the same inventor and filed on an even date herewith.
The present application is also related to a U.S. patent application entitled “Protective Helmet with Selectively Covered Aperture” by the same inventor and filed on an even date herewith.
The entire disclosures of the above mentioned applications are hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates generally to protective helmets. More particularly, the present invention relates to protective helmets for use when operating recreational vehicles.
BACKGROUND OF THE INVENTION
In the field of recreational vehicles (e.g., motorcycles, all terrain vehicles (ATVs), snowmobiles, sport trucks, dune buggies, sandrails, and the like) protective helmets are often worn to protect the user's head. Particulates such as sand and dust may enter the helmet during use and interfere with the user's ability to operate the vehicle. The more particulates a helmet keeps away from the user's face and eyes, the more comfortable the user will be. Even a few particulates in a user's eye may cause great discomfort.
Protective helmets are typically subjected to standardized performance tests to ensure the user is as safe as possible if a collision occurs. The Department of Transportation (DOT) and Snell are two major organizations that set safety standards for crash-helmets in the United States. DOT sets minimum standards for all helmets designed for motorcyclists and other motor vehicle users. The standard is Federal Motor Vehicle Safety Standard 218 and is codified at 49 C.F.R. §571.218. The Snell 2000 Standard for Protective Headgear establishes performance characteristics for helmets for use in open motorized vehicles such as motorcycles, ATVs, and snowmobiles.
The DOT subjects crash-helmets to an impact attenuation test. Impact attenuation is determined by measuring the acceleration experienced by a helmeted test headform during a collision. The helmeted headform is dropped on both a hemispherical and flat steel anvil. The height for the helmet and test headform combination fall onto the hemispherical anvil is set so that the impact speed is 5.2 m/sec. The minimum drop height is 138.4 cm. The guided freefall drop height for the helmet and test headform combination unto the flat anvil is set so that the minimum impact speed is 6.0 m/sec, with a minimum drop height of 182.9 cm.
When an impact attenuation test is conducted as described above, the following criteria are used to determine if a helmet passes; the test headform must not experience a peak acceleration over 400 G, accelerations in excess of 200 G must not exceed a cumulative duration of 2.0 milliseconds, and accelerations over 150 G must not exceed a cumulative duration of 4.0 milliseconds. The Snell impact management test involves a series of controlled impacts. First, the helmet is positioned on a head test platform. The helmeted headform is then dropped in guided falls onto test anvils. The impact energy must be a minimum of 150 Joules. If the peak acceleration imparted to the headform exceeds 300 G, the helmet fails.
SUMMARY OF THE INVENTION
The present invention relates generally to protective helmets. More particularly, the present invention relates to protective helmets for use when operating recreational vehicles (e.g., motorcycles, all terrain vehicles (ATVs), snowmobiles, sport trucks, dune buggies, sandrails, and the like). A protective helmet in accordance with an exemplary embodiment of the present invention comprises a first shell piece defining a head space and a second shell piece detachably attached to the first shell piece at an interface.
In accordance with one feature of the present invention, the interface has a pre-selected separation force. In some advantageous implementations, the pre-selected separation force of the interface is selected so that the second shell piece separates from the first shell piece when a pre-selected force is applied across the interface. In certain implementations, the pre-selected force less than a force required to dislodge a vehicle rider from a vehicle. Some embodiments of the present invention also feature a water tight seal formed between the first shell piece and the second shell piece.
In some embodiments of the present invention, the interface comprises a plurality of fasteners. Examples of fasteners which may be suitable in some applications include hook and loop fasteners, snaps, threaded fasteners, and pins. In certain embodiments, each fasteners comprises a shaft. This shaft may be advantageously adapted to break when a pre-selected breaking force is applied thereto. In some embodiments, the pre-selected breaking force is an axial force. In other embodiments, the pre-selected breaking force is a shear force. In some case, a diameter of the shaft may be dimensioned so that the shaft breaks when the pre-selected breaking force is applied to the shaft.
The first shell piece and the second shell piece may define a channel in some embodiments. When this is the case, a blower may be advantageously arranged for urging air into the channel. For example, the blower may draw air from the atmosphere outside the helmet and forcing the air into the air channel defined by the first shell piece and the second shell piece.
The second shell piece is defines the top portion of a channel while the second shell piece is detachably attached to the first shell piece. In an exemplary implementation, the second shell piece comprises a first edge flange and a second edge flange. The flanges preferably contact the first edge and second edge of the first shell piece to help detachably attach the first shell piece and the second shell piece. The second shell piece also comprises an intermediate portion which has a curved shape in lateral cross-section and which extends between the first edge flange and the second edge flange. In some advantageous implementations of the present invention, the first shell piece has sufficient strength to pass the DOT and Snell impact management tests whether or not the second shell piece is detachably attached. This may be accomplished by providing a wall of first shell piece having a desired combination of material strength and wall thickness.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a helmet in accordance with an exemplary embodiment of the present invention.
FIG. 2 is an additional perspective view of helmet shown in the previous figure.
FIG. 3 is a plan view of a helmet in accordance with an exemplary embodiment of the present invention.
FIG. 4 is an additional plan view of helmet shown in the previous figure.
FIG. 5 is an additional plan view of helmet shown in the previous figure.
FIG. 6 is an exploded assembly view of a helmet in accordance with an exemplary embodiment of the present invention.
FIG. 7 is a cross sectional view of a helmet in accordance with the present invention.
FIG. 8 is a plan view of a back side of a protective helmet in accordance with an exemplary embodiment of the present invention.
FIG. 9 is a partial cross sectional view of a helmet in accordance with an exemplary embodiment of the present invention.
FIG. 10 is a partial cross sectional view of a helmet in accordance with an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered identically. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. Accordingly, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings.
FIG. 1 is a perspective view of a helmet 100 in accordance with an exemplary embodiment of the present invention. Helmet 100 comprises a first shell piece 102 defining a front opening 104 . First shell piece 102 may advantageously include an inner shell comprising an energy absorbing material and an outer shell. The inner shell of first shell piece 102 may define a head space. In the embodiment of FIG. 1, a shield 106 is disposed over front opening 104 . Also in the embodiment of FIG. 1, helmet 100 includes a visor 108 . Visor 108 and shield 106 are preferably detachably attached to first shell piece 102 of helmet 100 .
FIG. 2 is an additional perspective view of helmet 100 shown in the previous figure. In the embodiment of FIG. 2, visor 108 has been detached from first shell piece 102 . In FIG. 2 it may be appreciated that helmet 100 includes a second shell piece 120 . In some advantageous embodiments of the present invention, second shell piece 120 is detachably coupled to first shell piece 102 at an interface 122 . In the embodiment of FIG. 2, interface 122 comprises a plurality of fasteners 124 . Various types of fasteners may be utilized without deviating from the spirit and scope of the present invention. Examples of fasteners that may be suitable in some applications include hook and loop fasteners, snaps, pins, rivets, screws, and adhesives.
In FIG. 2, it may be appreciated that second shell piece 120 comprises a front flange 126 , a first edge flange 128 , and a second edge flange 130 . An intermediate portion 132 of second shell piece 120 is shown extending between first edge flange 128 and second edge flange 130 . In some embodiments of the present invention, intermediate portion 132 of second shell piece 120 has a curved shape in lateral cross-section. In the embodiment of FIG. 2, an outer surface of each flange is substantially flush with an outer surface 136 of first shell piece 102 .
FIG. 3 is a plan view of a helmet 100 in accordance with an exemplary embodiment of the present invention. Helmet 100 comprises a first shell piece 102 and a second shell piece 120 . In the embodiment of FIG. 3, first shell piece 102 and second shell piece 120 define an air flow channel 138 .
In FIG. 3 a portion of a blower 140 can be seen extending beyond second shell piece 120 . In an advantageous embodiment of the present invention, blower 140 is adapted draw air from the atmosphere 142 surrounding helmet 100 . This air may be blown through flow channel 138 and may enter a head space 146 of helmet 100 via one or more apertures defined by first shell piece 102 . In some advantageous embodiments of the present invention, blower 140 is capable of producing an air flow through flow channel 138 that is sufficient to provide a positive pressure inside head space 146 . In these advantageous embodiments, the positive pressure inside head space 146 is preferably greater than an ambient pressure found in atmosphere 142 outside of first shell piece 102 .
In the embodiment of FIG. 3, blower 140 comprises a motor 150 which may be used to turn an impeller. In the embodiment of FIG. 3, a battery pack 152 is coupled to motor 150 of blower 140 via a cable 154 . Battery pack 152 may be worn, for example, clipped to the belt of a rider. In the embodiment of FIG. 3, blower 140 is disposed proximate a back side 156 of first shell piece 102 . In FIG. 3, it may be appreciated that blower 140 is disposed proximate a bottom extent 158 of first shell piece 102 .
FIG. 4 is an additional plan view of helmet 100 shown in the previous figure. In the embodiment of FIG. 4, second shell piece 120 has been separated from first shell piece 102 . The previous position of second shell piece 120 is illustrated with a dashed line in FIG. 4 . Thus, in FIG. 4 it may be appreciated that second shell piece 120 and first shell piece 102 cooperate to define flow channel 138 .
In FIG. 4 it may be appreciated that first shell piece 102 defines a trough 160 . An outer shell 166 of first shell piece 102 defines a plurality of apertures 162 that fluidly communicate with flow channel 138 . In some advantageous embodiments of the present invention, apertures 162 are dimensioned such that they will not allow objects having a particular size to pass into head space 146 defined by first shell piece 102 . In some embodiments, for example, the maximum span of each aperture 162 is less than about 13.0 millimeters.
FIG. 5 is an additional plan view of helmet 100 shown in the previous figure. An inner shell 170 of first shell piece 102 is visible in FIG. 5 . In some advantageous embodiments of the present invention inner shell 170 comprises an energy absorbing material. In the embodiment of FIG. 5, inner shell 170 of first shell piece 102 defines a head space 146 . In FIG. 5 it may be appreciated that inner shell 170 of first shell piece 102 defines a plurality of lumens 174 . Each lumen 174 preferably communicates with an aperture defined by an outer shell 166 of first shell piece 102 .
In FIG. 5 it may be appreciated that second shell piece 120 comprises a front flange 126 , a first edge flange 128 and a second edge flange 130 . An intermediate portion 132 of second shell piece 120 is shown extending between first edge flange 128 and second edge flange 130 . In some embodiments of the present invention, intermediate portion 132 of second shell piece 120 has a curved shape in lateral cross-section. In the embodiment of FIG. 5, second shell piece 120 also includes a front flange 126 . In FIG. 5, it may be appreciated that an outer surface of each flange is substantially flush with an outer surface 136 of first shell piece 102 .
FIG. 6 is an exploded assembly view of a helmet 200 in accordance with an exemplary embodiment of the present invention. Helmet 200 of FIG. 6 includes a blower 240 . In the embodiment of FIG. 6, blower 240 comprises a motor 250 for turning an impeller 276 . In the embodiment of FIG. 6, impeller 276 is disposed within a shroud 278 . Also in the embodiment of FIG. 6, a filter frame 280 is coupled to blower 240 .
Helmet 200 also includes a filter sock 282 defining a cavity 284 that is preferably dimensioned to receive filter frame 280 . A proximal end of filter sock 282 may be fixed around the circumference of blower 240 using an elastic ring 286 . Blower 240 may be advantageously utilized to create an air stream flowing through filter sock 282 . Filtered air may then enter a head space 246 defined by a first shell piece 202 of helmet 200 . A second shell piece 220 may be selectively coupled to first shell piece 202 utilizing a plurality of fasteners 224 . In the embodiment of FIG. 6, each fastener 224 has a shaft 290 .
FIG. 7 is a cross sectional view of a helmet 300 in accordance with the present invention. In the embodiment of FIG. 7, a filter sock 382 is disposed within a flow channel 338 defined by a first shell piece 302 and a second shell piece 320 . In FIG. 7, it may be appreciated that an outer shell 366 of first shell piece 302 defines an aperture 362 that provides fluid communication between flow channel 338 and a head space 346 defined by an inner shell 370 of first shell piece 302 . Inner shell 370 defines a lumen 392 in the embodiment of FIG. 7 .
In some advantageous implementations, flow channel 338 is shaped to provide smooth airflow with relatively low back pressure. In the embodiment of FIG. 7, the lateral cross sectional area of flow channel 338 gradually decreases along an air path extending from blower 340 to aperture 362 . Also in the embodiment of FIG. 7, flow channel 338 has a radius of curvature similar to a dimension of a human head.
A filter sock 382 defining a cavity 384 is shown disposed within flow channel 338 . A proximal end of filter sock 382 is shown fixed around the circumference of blower 340 by elastic ring 386 . In FIG. 7 an air stream 394 is shown passing through filter sock 382 . Blower 340 may be advantageously utilized to draw air from an atmosphere 342 surrounding helmet 300 and push this air through filter sock 382 . Filtered air may then enter a head space 346 defined by a first shell piece 302 .
In some advantageous embodiments of the present invention inner shell 370 of first shell piece 302 comprises an energy absorbing material. In the embodiment of figure 7, inner shell 370 defines a head space 346 . In FIG. 7 it may be appreciated that inner shell 370 defines a lumen 392 that fluidly communicates with aperture 362 .
In FIG. 7, it may be appreciated that second shell piece substantially covers aperture 362 while second shell piece 320 is attached to first shell piece 302 . In certain advantageous embodiments, first shell piece 302 has sufficient strength to pass the DOT and Snell impact management tests whether or not the second shell piece 320 is detachably attached. This may be accomplished by providing a wall 396 of first shell piece 302 having a desired combination of material strength and wall thickness.
In the embodiment of FIG. 7, first shell piece 302 defines a trough 360 that is dimensioned to receive second shell piece 320 . Also in the embodiment of FIG. 7, second shell piece 320 includes a front flange 326 . Trough 360 of first shell piece 302 includes a shoulder 398 that is dimensioned such that front flange 326 of second shell piece 320 rests on shoulder 398 of trough 360 while second shell piece 320 is attached to first shell piece 302 .
In FIG. 7, it may be appreciated that shoulder 398 of trough 360 is located at a depth corresponding to a thickness of front flange 326 of second shell piece 320 . Accordingly, an outer surface of front flange 326 is substantially flush with an outer surface 336 of the first shell piece 302 in the embodiment of FIG. 7 .
FIG. 8 is a plan view of a back side 456 of a protective helmet 400 in accordance with an exemplary embodiment of the present invention. In the embodiment of FIG. 8, a second shell piece 420 of protective helmet 400 includes a housing 488 that is dimensioned to receive a blower 440 . Second shell piece 420 and a first shell piece 402 define a flow channel 438 . Blower 440 may be arranged to urge a stream of air through flow channel 438 and into a head space 446 of helmet 400 .
A plurality of fasteners 424 are visible in FIG. 8 . Fasteners 424 may be utilized to selectively attach second shell piece 420 to first shell piece 402 . In some advantageous embodiments of the present invention, blower 440 is fixed to second shell piece 420 , and blower 440 is free from attachment to first shell piece 402 . In these advantageous embodiments, blower 440 separates from first shell piece 402 when second shell piece 420 is separated from first shell piece 402 .
FIG. 9 is a partial cross sectional view of a helmet 500 in accordance with an exemplary embodiment of the present invention. Helmet 500 includes a first shell piece 502 comprising an outer shell 566 and an inner shell 570 . In FIG. 9, it may be appreciated that first shell piece 502 defines a head space 546 . In the embodiment of FIG. 9, first shell piece 502 defines a trough 560 that is dimensioned to receive a second shell piece 520 . In FIG. 9 it may be appreciated that second shell piece 520 and first shell piece 502 define a flow channel 538 .
In FIG. 9 it may be appreciated that second shell piece 520 is attached to first shell piece 502 at an interface 522 . In the embodiment of FIG. 9, interface 522 comprises a strip 544 that is disposed between first shell piece 502 and second shell piece 520 . In some advantageous embodiments of the present invention, strip 544 provides a water tight seal between first shell piece 502 and second shell piece 520 . Strip 544 may comprise various elements without deviating from the spirit and scope of the present invention. Examples of elements that suitable in some applications include a gasket, a bead of adhesive material, double sided foam tape, hook and loop fastener strips, and the like.
A first edge flange 528 and an intermediate portion 532 of second shell piece 520 are visible in FIG. 9 . Second shell piece 520 of helmet 500 may comprise a first edge flange, a second edge flange, and an intermediate portion 532 extending between the first edge flange and the second edge flange. In the embodiment of FIG. 9, intermediate portion 532 of second shell piece 520 has a curved shape in lateral cross-section.
In the embodiment of FIG. 9, trough 560 includes a shoulder 598 that is dimensioned such that first edge flange 528 of the second shell piece 520 rests on shoulder 598 of trough 560 while second shell piece 520 is attached to first shell piece 502 . In FIG. 9, it may be appreciated that shoulder 598 of trough 560 is located at a depth corresponding to a thickness of first edge flange 528 of second shell piece 520 . Accordingly, an outer surface 537 of first edge flange 528 is substantially flush with an outer surface 536 of first shell piece 502 in the embodiment of FIG. 9 .
In certain advantageous embodiments of the present invention, interface 522 has a pre-selected separation force. When this is the case, first shell piece 502 and second shell piece 520 will separate if the force applied across interface 522 exceeds a pre-selected value. In some embodiments, the pre-selected separation force may be selected to reduce the likelihood that a vehicle rider will be dislodged from a vehicle by a force applied to second shell piece 520 during riding. Embodiments of the present invention are possible in which the material forming strip 544 is selected such that an adhesive joint is broken if the force applied across interface 522 exceeds the pre-selected level. Embodiments of the present invention are also possible in which strip 544 breaks if the force applied across interface 522 exceeds a pre-selected level.
FIG. 10 is a partial cross sectional view of a helmet 600 in accordance with an exemplary embodiment of the present invention. Helmet 600 of FIG. 10 includes a second shell piece 620 that is attached to a first shell piece 602 at an interface 622 . In the embodiment of FIG. 10, interface 622 comprises a fastener 624 . In the embodiment of FIG. 10, fastener 624 comprises a shaft 690 .
In the embodiment of FIG. 10, second shell piece 620 is disposed within a trough 660 defined by first shell piece 602 so that second shell piece 620 and first shell piece 602 define a flow channel 638 . In the embodiment of FIG. 10, trough 660 includes a shoulder 698 that is dimensioned such that a first edge flange 628 of the second shell piece 620 rests on shoulder 698 of trough 660 while second shell piece 620 is attached to first shell piece 602 . In FIG. 10, it may be appreciated that shoulder 698 of trough 660 is located at a depth corresponding to a thickness of first edge flange 628 of second shell piece 620 . Accordingly, an outer surface 637 of first edge flange 628 is substantially flush with an outer surface 636 of first shell piece 602 in the embodiment of FIG. 10 .
In certain advantageous embodiments of the present invention, interface 622 has a pre-selected separation force. When this is the case, first shell piece 602 and second shell piece 620 will separate if the force applied across interface 622 exceeds a pre-selected value. In some embodiments, the pre-selected separation force may be selected to reduce the likelihood that a vehicle rider will be dislodged from a vehicle by a force applied to second shell piece 620 during riding. Embodiments of the present invention are possible in which each fastener 624 may be adapted to release at a pre-selected force. Embodiments of the present invention are also possible in which shaft 690 of fastener 624 is adapted to break when a pre-selected breaking force is applied thereto. For example, the material forming fastener 624 and the diameter of shaft 690 may be selected so that shaft 690 breaks when the pre-selected breaking force is applied to the shaft. The pre-selected breaking force may be, for example, an axial force. The pre-selected breaking force may also be, for example, a shear force.
While the invention has been described in conjunction with specific embodiments thereof, it is evident that other alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations that fall within the spirit and broad scope of the invention. | Protective helmet comprising a two piece shell, an electric motor and impeller useful for creating a positive pressure environment in the head space, and a filter for removing particulates and other substances. The impeller introduces atmospheric air into an air channel defined by two detachably attached shell pieces. The air is pushed through a particulate filter in the air channel and then through at least one aperture into the head space. A heating element may be used to heat the air flow. | 0 |
BACKGROUND OF THE INVENTION
The present invention concerns a machine for cutting flat stock, especially sheets of material. It has a counter that accommodates the stock and a cutting assembly. The cutting assembly comprises a knife mounted on a beam that travels up and down toward and away from the counter in a machinery frame. The beam accommodates at least two separated and knife-positioning components that support the back of the knife against the beam.
A wide range of flat-stock cutting machines are known, from European Patent 0 056 874 for example.
Machines of the genus initially described herein are known in practice. The knife is secured to the beam by several screws. The screws screw into threaded bores in the knife and through slots in the beam that extend vertically in relation to the surface of the counter. The knife can accordingly be adjusted on the beam in order to compensate for wear and sharpening. The knife in flat-stock cutting machines wherein the knife can be adjusted in relation to the beam is usually attached to the beam at at least two points in addition to the aforementioned screws. This is usually done either with setscrews that can be screwed in and out parallel to the knife's stroke or with cams that apply force to the back of the knife. There is a drawback in that setscrews and cams tend to dig into the soft back of the knife, which accordingly changes position in relation to the beam. The knife can accordingly be damaged during continuous operation when the back slips out for example, and precise cutting will no longer be possible.
SUMMARY OF THE INVENTION
The object of the present invention is a simple improvement in a machine of the aforesaid genus ensuring that the knife will reliably maintain its position on the beam for a long time.
This object is attained in accordance with the present invention in a machine of the aforesaid genus in that each knife-positioning component rests against a pressure-accommodating component on the back of the knife whereby at least that area of the pressure-accommodating component that comes into contact with the knife-positioning component is hard. Since the hard pressure-accommodating component is a separate component, it will be unnecessary to harden the metal knife as a whole in order to prevent the knife-positioning component from digging into its back. All that is necessary is to satisfactorily harden the contact between the knife-positioning component and the pressure-accommodating component. No such property is necessary between the pressure-accommodating component and the back of the knife, where the pressure is very slight.
The knife-positioning components can be cams or setscrews. They can be of hardened metal. The area of the pressure-accommodating component that comes into contact with the knife-positioning component can also be hard, made of hardened metal for example. The components can basically be of any appropriate materials that are hard enough to withstand considerable pressure. The hardness of the pressure-accommodating component allows the knife to be in two parts, a holder of soft metal and a blade that does the actual cutting. The blade is accommodated in a recess in the holder and hard-soldered to it. The material is accordingly hardened only where necessary to accommodate powerful force or pressure. In other areas less expensive unhardened materials can be employed.
The knife-positioning component in one preferred embodiment of the present invention includes a cam mounted in a practical way on a perpendicular blade-positioning component supporting shaft and accommodated in the knife. The cam can accordingly be rotated relative to the knife beam, varying the position of the knife to the knife beam over a wide range. The circumference of the cam can include a section extending half way around a circle that can be brought into contact with the back of the knife. The axis of the shaft can be positioned off the center of the circle, resulting in an eccentricity that allows maximal displacement as the cam rotates approximately 180°. The cam can of course also rotate farther, up to 300° for example, if it is helical instead of circular. It will basically be sufficient for the cam to rotate relative to the shaft and be stabilized against the back of the knife by the beam. It is, however, of advantage for the cam to be mounted tight on the blade-positioning component supporting shaft. The shaft can in this event be prevented from rotating backward and can be secured axially by a clamp. The cam can alternatively be secured by friction-generating material between it and the beam. The friction-generating material can be in addition to the clamp.
To particularly facilitate operation of the machine, the blade-positioning component supporting shaft should extend through a bore in the knife holder and accordingly be accessible for rotation and positioning by the operator.
It is particularly significant that the pressure-accommodating component is not part of the overall machinery but inserted between the back of the knife and the knife positioning component. The pressure-accommodating component will accordingly always rest optimally against the back of the knife even when it is distorted or not precisely positioned for other reasons. The pressure-accommodating component in one particular embodiment of the present invention is attached to a flat guide positioned between the cam and the beam and extending behind the blade-positioning component supporting shaft. The guide is accordingly secured between the cam and the beam, and its extension behind the shaft ensures that is will be suspended from the shaft when the knife is removed. It will be practical for the blade-positioning component supporting shaft to extend through a slot in the guide. The guide will accordingly be positioned between the cam and the beam in this embodiment and cannot get lost, although it can be displaced along the slot as the cam rotates.
One particular advanced version of the present invention includes a spacer between the pressure-accommodating component and the knife. The spacer is employed when the knife is worn down too far for its back to be far enough away from the beam even when the knife-positioning components have been maximally adjusted. The knife can in his event still be adjusted, depending on the thickness of the spacer. It will be practical for the spacer to be attached to and particularly screwed to the knife.
It will be of advantage for the pressure-accommodating components and spacers to be accommodated only where pressure needs to be distributed. It will also be of advantage for the pressure-accommodating components and spacers or both to be parallelepipedal.
To ensure that the knife is secured to the beam in accordance with the differences in their positions, the beam can have several slots paralleling the displacement of the knife relative to the knife holder, at least one threaded bore in the knife can be associated with each slot, and a setscrew can extend through the bore and the slot. In the event that a spacer is employed to extend the possible displacement of the knife relative to the beam, the knife should have several bores associated with and distributed along each slot. The slots can accordingly be relatively short and the displacement extended by screwing each screw into the bore associated with the particular slot.
Further characteristics of the present invention will be evident from the following specification and from the figures. All characteristics and combinations thereof are essential to the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The figures illustrate two embodiments of a machine for cutting flat stock in accordance with the present invention without limiting its scope in any way.
FIG. 1 is a front view of the machine.
FIG. 2 is a detail of the area A in FIG. 1, illustrating one version of how the knife can be suspended.
FIG. 3 is a section along the line B B in FIG. 2.
FIG. 4 illustrates how the knife illustrated in FIG. 2 is suspended with a spacer.
FIG. 5 is a section illustrating another version of how the knife can be suspended in the embodiment illustrated in FIG. 3.
FIG. 6 is an end view of a shaft shown in FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The machine 1 for cutting flat stock illustrated in FIG. 1 comprises a base 2 and a counter 3 along with a guillotine 4 that extends over it. The stacks of material to be cut are deposited on the surface 6 of counter 3, perpendicular to the major plane of the material, which is essentially in the form of sheets.
FIG. 1 illustrates machine 1 as seen by the operator.
Accommodated behind guillotine 4 and in counter 3 is a rake-like saddle 7 with prongs 8 that advance the material perpendicular to its major plane. A beam 9 travels up and down, along the major plane of the material, that is, in guillotine 4. Behind beam 9 and with only its lower edge visible is a knife 10 with an edge 13. Knife 10 is screwed to beam 9. Unillustrated screws extend through several vertical slots 11 in beam 9 and into matching threaded bores in knife 10. Behind knife 10 and with only its lower edge visible is a hold-down 12 with a lower surface 5 for securing the material while it is being cut. The lower edges of beam 9 and knife 10 slope toward the surface 6 of counter 3 in FIG. 1 because they are in the process of producing a rocking cut and accordingly come to rest paralleling surface 6 only at their lower dead point. FIG. 1 represents beam 9, knife 10, and hold-down 12 lifted.
Also illustrated in FIG. 1 is a data-input pad 14, a display screen 15, a switch 16, pushbuttons 17, a pedal 19 for initiating the cut, and lateral baffles 18.
As will be evident from FIG. 1, machine 1 has in the vicinity of beam 9 two horizontally separated knife-positioning components 20. Two versions of such a component are illustrated in FIGS. 2 through 5.
FIG. 2 illustrates how knife 10 is attached to beam 9 in the vicinity of two slots 11 in beam 9. Each slot 11 has a screw 21, only the threaded section of which is illustrated, extending through it from the front. Each screw screws into a matching threaded bore in knife 10. Since slots 11 are vertical in relation to the surface 6 of counter 3, it is possible to vary the distance between the lower edge 13 of the knife and surface 6 without moving beam 9. Knife-positioning components 20 can maintain knife 10 in any desired position. A cam 22 is provided for this purpose. As will be evident from FIGS. 2 and 3, one section 23 of the circumference of cam 22 extends in the form of a helix around an angle of approximately 300°. A perpendicular blade-positioning component supporting shaft 24 extends tightly through cam 22 and loosely through horizontal bore 25 in beam 9. The helix curves around the axis 26 of shaft 24. Shaft 24 is force fit to cam 22 by a square section that matches an opening in the cam.
Between cam 22 and the back 28 of knife 10 is a parallelepipedal pressure-accommodating component 29 of hard metal. Pressure-accommodating component 29 is fastened to a flat guide 31 by two screws 30. Guide 31 extends vertically with its lower end accommodating pressure-accommodating component 29. The guide has an axially parallel slot 32 in the center. Guide 31 is positioned between cam 22 and beam 9, with shaft 24 extending through slot 32.
The materials employed in the vicinity of knife 10 will now be specified. Cam 22 and pressure-accommodating component 29 are hardened steel, allowing accommodation of the pressure deriving from the linearity of the contact between them. Due to the relatively low pressure between pressure-accommodating components 29 and the back 28 of knife 10, the knife is in two parts. It comprises in a known way a holder 33 and a blade 34. Holder 33 is of non-hardened steel and incorporates back 28. Blade 34 is of hardened steel and does the actual cutting and incorporates edge 13. The blade fits into a recess in holder 33, to which it is hard-soldered. Knife 10 can be reground in accordance with the vertical breadth of blade 34, in which case the vertical breadth of the knife itself will decrease. A machine for cutting flat stock with a blade-positioning component in accordance with the present invention allows precise positioning of even a completely ground-down knife 10 due to the separated cams 22. FIG. 2 illustrates the height x' of a new knife 10. When knife 10 is fresh, cam 22 will be rotated about 180° out of the position illustrated in FIG. 2, and its circumference section 23 will be in contact with pressure-accommodating component 29. When knife 10 wears down, it will be removed from beam 9, while pressure-accommodating component 29 remains freely but securely suspended from beam 9 by way of the guide 31 in associated blade-positioning component supporting shaft 24. Once knife 10 has been sharpened, it will be attached to beam 9 by screws 21, and both cams 22 will be rotated and adjusted in relation to pressure-accommodating components 29 such that the edge 13 of knife 10 can penetrate slightly into an unillustrated cutting strip in counter 3 when beam 9 is at its lower dead point. Screws 21 are then tightened. As will be evident from FIG. 2, the supporting action of cam 22 will be in effect as long as the breadth of knife 10 at least equals dimension x. To allow use of a knife 10 that has been ground down beyond that point, a parallelepipedal spacer 35 of non-hardened metal is, as illustrated in FIG. 4, fastened by several screws 36 to holder 33 in the vicinity of the back 28 of knife 10. As will be evident from the figure, cam 22 will be able to execute its entire stroke again as long as there is a spacer 35 between pressure-accommodating component 29 and knife 10. Although screws 21 will be approximately at the top of slots 11 while knife 10 is fresh, they will be approximately at the middle once cams 22 have rotated all the way without the spacer and at the bottom once the cams have rotated all the way in the presence of a spacer 35.
Slots 11 can be shorter if more threaded bores 21 are provided along them in knife 10, allowing different bores to be employed depending on the breadth of knife 10. Every slot 32 in each guide 31 will be long enough to allow a shaft 24 through when the slot is off center.
The cam 22 in the embodiment illustrated in FIG. 5 is crimped onto the rear end of blade-positioning component supporting shaft 24. Shaft 24 extends through the bore 25 in beam 9 and can be fastened at the front, the section remote from its associated cam 22, by a clamping plate 37. Clamping plate 37 has a cutout 38 in beam 9 and a bore that is slightly wider than the outside diameter of shaft 24. Clamping plate 37 has a threaded bore 39 paralleling the axis 26 of shaft 24. Bore 39 accommodates a screw 40. The shaft of screw 40 extends through a bore 41 that itself extends part-way through beam 9. As screw 40 screws into bore 41, clamping plate 37 will tilt slightly and secure its associated shaft 24 both axial and rotationally. To prevent clamping plate 37 from getting lost while shaft 24 is not secure, the front of the shaft has a safety ring 42. To allow rotation of each shaft 24 and hence of its associated cam 22, the shaft has a hexagonal depression 43 facing the operator that will accommodate a hexagonal-headed key. | A machine for cutting flat stock, especially sheets of material. The machine has a counter that accommodates the stock and a cutting assembly. The cutting assembly has a knife mounted on a beam that travels up and down toward and away from the counter in a machinery frame. The beam accommodates at least two separate knife-positioning components that force the back of the knife against the beam. Each knife-positioning component rests against a pressure-accommodating component on the back of the knife. At least that area of the pressure-accommodating component that comes into contact with the knife-positioning component is hard. | 1 |
PRIORITY INFORMATION
[0001] This application is based on and claims priority to Japanese Patent Application No. 2001-132607, filed Apr. 27, 2001 and to the Provisional Application No. 60/322239, filed Sep. 13, 2001, (Attorney Docket No. FS.20014US0PR) the entire contents of which is hereby expressly incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to an oil pressure system for an engine, and more particularly to an oil pressure monitoring system to warn the operator of an inadequate lubrication pressure in a watercraft engine.
DESCRIPTION OF THE RELATED ART
[0003] Watercraft engines typically incorporate lubrication systems. The lubrication system embodies an oil pump driven by the engine and provides lubricant under pressure to vital moving parts throughout the engine. The lubricant acts to lubricate as well as help cool these vital moving parts of the engine.
[0004] Watercraft may operate in rough water environments. The oil pump in the lubrication system may suck up air instead of the intended lubricant because the oil is being pushed away from the oil pump suction passage during rough operation. The importance of the lubrication system is essential and therefore many lubrication systems incorporate a monitoring system with an alarm in order to warn the operator if the oil pressure is inadequate to safely lubricate the engine.
SUMMARY OF THE INVENTION
[0005] Certain reductions in oil pressure are more essential to the correct engine operation than others. For example, a small drop or short reduction in oil pressure at low engine speed is less vital to the engine than if there is a lack of lubrication pressure for prolonged periods of time at higher engine speeds.
[0006] One aspect of the invention is a lubrication control system wherein the oil pressure is accurately monitored for the higher engine speeds and operational environments in order to provide the operator with a precise condition of the lubrication system. Such an advanced lubrication control system allows for a long, maintenance free engine life.
[0007] Another aspect of the present invention is to accurately monitor the engine lubrication pressure and compare the measured pressure with a calculated pressure dependent on engine speed, engine temperature, and oil temperature. A further aspect of the present invention further sets oil pressure limits each corresponding to a timer. The operator is given warning if the oil pressure falls below a set limit for an extended period of time as set by a corresponding limit timer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The foregoing features, aspects, and advantages of the present invention will now be described with reference to the drawings of a preferred embodiment that is intended to illustrate and not to limit the invention. The drawings comprise eleven figures in which:
[0009] [0009]FIG. 1 is a side elevational view of an outboard motor configured in accordance with a preferred embodiment of the present invention, with an associated watercraft partially shown in section;
[0010] [0010]FIG. 2 is a side elevational view of an upper section of an outboard motor configured in accordance with a preferred embodiment of the present invention, with various parts shown in phantom;
[0011] [0011]FIG. 3 is a top view of an outboard motor configured in accordance with a preferred embodiment of the present invention, with various parts shown in phantom;
[0012] [0012]FIG. 4 is a schematic diagram of the electronic control unit and its control parameters;
[0013] [0013]FIG. 5 is a top view of an outboard motor configured in accordance with a preferred embodiment of the present invention, with various electronically controlled parameters shown;
[0014] [0014]FIG. 6 is a graphical view showing engine oil pressure with reference to engine speed;
[0015] [0015]FIG. 7 is a graphical view showing the relationship between the oil pressure sending unit output voltage and the engine oil pressure;
[0016] [0016]FIG. 8 is a graphical view showing the relationship between timer values and engine oil pressure;
[0017] [0017]FIG. 9 is a graphical view showing various engine oil pressures with reference to time;
[0018] [0018]FIG. 10 is a flowchart representing a control routine arranged and configured in accordance with certain features, aspects, and advantages of the present invention; and
[0019] [0019]FIG. 11 is a flowchart representing another control routine arranged and configured in accordance with certain features, aspects, and advantages of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The Overall Construction
[0020] With reference to FIGS. 1 - 5 , an outboard motor 10 includes a drive unit 12 and a bracket assembly 14 . The bracket assembly 14 attaches the drive unit 12 to a transom 16 of an associated watercraft 18 and supports a marine propulsion device such as propeller 57 in a submerged position relative to a surface of a body of water.
[0021] As used to this description, the terms “forward,” “forwardly,” and “front” mean at or to the side where the bracket assembly 14 is located, unless indicated otherwise or otherwise readily apparent from the context use. The terms “rear,” “reverse,” “backwardly,” and “rearwardly” mean at or to the opposite side of the front side.
[0022] The illustrated drive unit 12 includes a power head 20 and the housing unit 22 . Unit 22 includes a drive shaft housing 24 and the lower unit 26 . The power head 20 is disposed atop the housing unit 22 and includes an internal combustion engine 28 within a protective cowling assembly 30 , which advantageously is made of plastic. The protective cowling assembly 30 typically defines a generally closed cavity 32 in which the engine 28 is disposed. The engine 28 is thereby is generally protected by the cowling assembly 30 from environmental elements.
[0023] The protective cowling assembly 30 includes a top cowling member 34 and a bottom cowling member 36 . The top cowling member 34 is advantageously detachably affixed to the bottom cowling member 36 by a suitable coupling mechanism to facilitate access to the engine and other related components.
[0024] The top cowling member 34 includes a rear intake opening (not shown) defined from an upper end portion. This rear intake member with one or more air ducts can, for example, be formed with, or affixed to, the top cowling member 34 . The rear intake member, together with the upper rear portion of the top cowling member 34 , generally defines a rear air intake space. Ambient air is drawn into the closed cavity 32 near the rear intake opening and the air ducts of the rear intake member. Typically, the top cowling member 34 tapers in girth toward its top surface, which is in the general proximity of the air intake opening. This taper reduces the lateral dimension of the outboard motor, which helps to reduce the air drag on the watercraft 18 during movement.
[0025] The bottom cowling member 36 has an opening for which an upper portion of an exhaust guide member 38 extends. The exhaust guide member 38 advantageously is made of aluminum alloy and is affixed to the top of the driveshaft housing 24 . The bottom cowling member 36 and the exhaust guide member 38 together generally form a tray. The engine 28 is placed on to this tray and can be connected to the exhaust guide member 38 . The exhaust guide member 38 also defines an exhaust discharge passage through which burnt charges (e.g., exhaust gases) from the engine 28 pass.
[0026] The engine 28 in the illustrated embodiment preferably operates on a four-cycle combustion principle. With reference now to FIGS. 2 and 3, the engine embodiment illustrated is a DOHC six-cylinder engine having a V-shaped cylinder block 40 . The cylinder block 40 thus defines two cylinder banks, which extend generally side by side with each other. In the illustrated arrangement, each cylinder bank has three cylinder bores such that the cylinder block 40 has six cylinder bores in total. The cylinder bores of each bank extend generally horizontally and are generally vertically spaced from one another. This type of engine, however, merely exemplifies one type of engine. Engines having other numbers of cylinders, having other cylinder arrangements (in line, opposing, etc.), and operating on other combustion principles (e.g., crankcase compression, two-stroke or rotary) can be used in other embodiments.
[0027] As used in this description, the term “horizontally” means that members or components extend generally and parallel to the water surface (i.e., generally normal to the direction of gravity) when the associated watercraft 18 is substantially stationary with respect to the water surface and when the drive unit 12 is not tilted (i.e., as shown in FIG. 1). The term “vertically” in turn means that proportions, members or components extend generally normal to those that extend horizontally.
[0028] A movable member, such as a reciprocating piston, moves relative to the cylinder block 40 in a suitable manner. In the illustrated arrangement, a piston (not shown) reciprocates within each cylinder bore. Because the cylinder block 40 is split into the two cylinder banks, each cylinder bank extends outward at an angle to an independent first end in the illustrated arrangement. A pair of cylinder head members 42 are fixed to the respective first ends of the cylinder banks to close those ends of the cylinder bores. The cylinder head members 42 together with the associated pistons and cylinder bores provide six combustion chambers (not shown). Of course, the number of combustion chambers can vary, as indicated above. Each of the cylinder head member 42 is covered with the cylinder head cover member 44 .
[0029] A crankcase member 46 is coupled with the cylinder block 40 and a crankcase cover member 48 is further coupled with a crankcase member 46 . The crankcase member 46 and a crankcase cover member 48 close the other end of the cylinder bores and, together with the cylinder block 40 , define the crankcase chamber. Crankshaft 50 extends generally vertically through the crankcase chamber and journaled for rotation about a rotational axis by several bearing blocks. Connecting rods couple the crankshaft 50 with the respective pistons in any suitable manner. Thus, a reciprocal movement of the pistons rotates the crankshaft 50 .
[0030] With reference again to FIG. 1, the driveshaft housing 24 depends from the power head 20 to support a drive shaft 52 , which is coupled with crankshaft 50 and which extends generally vertically through driveshaft housing 24 . A driveshaft 52 is journaled for rotation and is driven by the crankshaft 50 .
[0031] The lower unit 26 depends from the driveshaft housing 24 and supports a propulsion shaft 54 that is driven by the driveshaft 52 through a transmission unit 56 . A propulsion device is attached to the propulsion shaft 54 . In the illustrated arrangement, the propulsion device is the propeller 57 that is fixed to the transmission unit 56 . The propulsion device, however, can take the form of a dual counter-rotating system, a hydrodynamic jet, or any of a number of other suitable propulsion devices.
[0032] Preferably, at least three major engine portions 40 , 42 , 44 , 46 , and 48 are made of aluminum alloy. In some arrangements, the cylinder head cover members 44 can be unitarily formed with the respective cylinder members 42 . Also, the crankcase cover member 48 can be unitarily formed with the crankcase member 46 .
[0033] The engine 28 also comprises an air intake system 58 . The air intake system 58 draws air from within the cavity 32 to the combustion chambers. The air intake system 58 shown comprises six intake passages 60 and a pair of plenum chambers 62 . In the illustrated arrangement, each cylinder bank communicates with three intake passages 60 and one plenum chamber 62 .
[0034] The most downstream portions of the intake passages 60 are defined within the cylinder head member 42 as inner intake passages. The inner intake passages communicate with the combustion chambers through intake ports, which are formed at inner surfaces of the cylinder head members 42 . Typically, each of the combustion chambers has one or more intake ports. Intake valves are slidably disposed at each cylinder head member 42 to move between an open position and a closed position. As such, the valves act to open and close the ports to control the flow of air into the combustion chamber. Biasing members, such as springs, are used to urge the intake valves toward their respective closed positions by acting between a mounting boss formed on each cylinder head member 42 and a corresponding retainer that is affixed to each of the valves. When each intake valve is in the open position, the inner intake passage thus associated with the intake port communicates with the associated combustion chamber.
[0035] Other portions of the intake passages 60 , which are disposed outside of the cylinder head members 42 , preferably are defined with intake conduits 64 . In the illustrated arrangement, each intake conduit 64 is formed with two pieces. One piece is a throttle body 66 , in which a throttle valve assembly 68 is positioned. Throttle valve assemblies 68 are schematically illustrated in FIG. 2. The throttle bodies 66 are connected to the inner intake passages. Another piece is an intake runner 70 disposed upstream of the throttle body 66 . The respective intake conduit 64 extend forwardly alongside surfaces of the engine 28 on both the port side and the starboard side from the respective cylinder head members 42 to the front of the crankcase cover member 48 . The intake conduits 64 on the same side extend generally and parallel to each other and are vertically spaced apart from one another.
[0036] Each throttle valve assembly 68 preferably includes a throttle valve. Preferably, the throttle valves are butterfly valves that have valve shafts journaled for pivotal movement about generally vertical axis. In some arrangements, the valve shafts are linked together and are connected to a control linkage. The control linkage is connected to an operational member, such as a throttle lever, that is provided on the watercraft or otherwise proximate the operator of the watercraft 18 . The operator can control the opening degree of the throttle valves in accordance with operator request through the control linkage. That is, the throttle valve assembly 68 can measure or regulate amounts of air that flow through intake passages 60 through the combustion chambers in response to the operation of the operational member by the operator. Normally, the greater the opening degree, the higher the rate of air flow and the higher the engine speed.
[0037] The respective plenum chambers 62 are connected with each other through one or more connecting pipes 72 (FIG. 3) to substantially equalize the internal pressures within each chamber 62 . The plenum chambers 62 coordinate or smooth air delivered to each intake passage 60 and also act as silencers to reduce intake noise.
[0038] The air within the closed cavity 32 is drawn into the plenum chamber 62 . The air expands within the plenum chamber 62 to reduce pulsations and then enters the outer intake passages 60 . The air passes through the outer intake passage 60 and flows into the inner intake passages. The throttle valve assembly 68 measures the level of airflow before the air enters into the inner intake passages.
[0039] The engine 28 further includes an exhaust system that routes burnt charges, i.e., exhaust gases, to a location outside of the outboard motor 10 . Each cylinder head member 42 defines a set of inner exhaust passages that communicate with the combustion chambers to one or more exhaust ports which may be defined at the inner surfaces of the respective cylinder head members 42 . The exhaust ports can be selectively opened and closed by exhaust valves. The construction of each exhaust valve and the arrangement of the exhaust valves are substantially the same as the intake valve and the arrangement thereof, respectively. Thus, further description of these components is deemed unnecessary.
[0040] Exhaust manifolds preferably are defined generally vertically with the cylinder block 40 between the cylinder bores of both the cylinder banks. The exhaust manifolds communicate with the combustion chambers through the inner exhaust passages and the exhaust ports to collect the exhaust gas therefrom. The exhaust manifolds are coupled with the exhaust discharge passage of the exhaust guide member 38 . When the exhaust ports are opened, the combustion chambers communicate with the exhaust discharge passage through the exhaust manifolds. A valve cam mechanism preferably is provided for actuating the intake and exhaust valves in each cylinder bank. In the embodiment shown, the valve cam mechanism includes second rotatable members such as a pair of camshafts 74 per cylinder bank. The camshafts 74 typically comprise intake and exhaust camshafts that extend generally vertically and are journaled for rotation between the cylinder head members 42 and the cylinder head cover members 44 . The camshafts 74 have cam lobes (not shown) to push valve lifters that are fixed to the respective ends of the intake and exhaust valves in any suitable manner. Cam lobes repeatedly push the valve lifters in a timely manner, which is in proportion to the engine speed. The movement of the lifters generally is timed by rotation of the camshaft 74 to appropriately actuate the intake and exhaust valves.
[0041] The camshaft drive mechanism 76 preferably is provided for driving the valve cam mechanism. The camshaft drive mechanism 76 in the illustrated arrangement is formed above a top surface 78 (see FIG. 2) of the engine 28 and includes driven sprockets 80 positioned atop at least one of each pair of camshafts 74 , a drive sprocket 82 positioned atop the crankshaft 50 and the flexible transmitter, such as a timing belt or chain 84 , for instance, wound around the driven sprockets 80 and the drive sprocket 82 . The crankshaft 50 thus drives the respective crankshaft 74 through the time belt 84 in the timed relationship.
[0042] The illustrated engine 28 further includes indirect, port or intake passage fuel injection. In one arrangement, the engine 28 comprises fuel injection and, in another arrangement, the engine 28 is carburated. The illustrated fuel injection system shown includes six fuel injectors 86 with one fuel injector allotted to each one of the respective combustion chambers. The fuel injectors 86 preferably are mounted on the throttle body 66 of the respective banks.
[0043] Each fuel injector 86 has advantageously an injection nozzle directed downstream within the associated intake passage 60 . The injection nozzle preferably is disposed downstream of the throttle valve assembly 60 . The fuel injectors 86 spray fuel into the intake passages 60 under control of an electronic control unit (ECU) 88 (FIG. 4). The ECU 88 controls both the initiation, timing and the duration of the fuel injection cycle of the fuel injector 86 so that the nozzle spray a desired amount of fuel for each combustion cycle.
[0044] A vapor separator 90 preferably is in full communication with the tank and the fuel rails, and can be disposed along the conduits in one arrangement. The vapor separator 90 separates vapor from the fuel and can be mounted on the engine 28 at the side service of the port side.
[0045] The fuel injection system preferably employs at least two fuel pumps to deliver the fuel to the vapor separator 90 and to send out the fuel therefrom. More specifically, in the illustrated arrangement, a lower pressure pump 92 , which is affixed to the vapor separator 90 , pressurizes the fuel toward the vapor separator 90 and the high pressure pump (not shown), which is disposed within the vapor separator 90 , pressurizes the fuel passing out of the fuel separator 90 .
[0046] A vapor delivery conduit 94 couples the vapor separator 90 with at least one of the plenum chambers 62 . The vapor removed from the fuel supply by the vapor separator 90 thus can be delivered to the plenum chambers 62 for delivery to the combustion chambers with the combustion air. In other applications, the engine 28 can be provided with a ventilation system arranged to send lubricant vapor to the plenum chamber(s). In such applications, the fuel vapor also can be sent to the plenum chambers via the ventilation system.
[0047] The engine 28 further includes an ignition system. Each combustion chamber is provided with a spark plug 96 (see FIG. 4), advantageously disposed between the intake and exhaust valves. Each spark plug 96 has electrodes that are exposed in the associated combustion chamber. The electrodes are spaced apart from each other by a small gap. The spark plugs 96 are connected to the ECU 88 through ignition coils 98 . One or more ignition triggering sensors 100 are positioned around a flywheel assembly 102 to trigger the ignition coils, which in return trigger the spark plugs 96 . The spark plugs 96 generate a spark between the electrodes to ignite an air/fuel charge in the combustion chamber according to desired ignition timing maps or other forms of controls.
[0048] Generally, during an intake stroke, air is drawn into the combustion chambers through the air intake passages 60 and fuel is mixed with the air by the fuel injectors 86 . The mixed air/fuel charge is introduced to the combustion chambers. The mixture is then compressed during the compression stroke. Just prior to a power stroke, the respective spark plugs ignite the compressed air/fuel charge in the respective combustion chambers. The air/fuel charge thus rapidly burns during the power stroke to move the pistons. The burnt charge, i.e., exhaust gases, then is discharged from the combustion chambers during an exhaust stroke.
[0049] The flywheel assembly 102 , which is schematically illustrated with phantom line in FIG. 3, preferably is positioned atop the crankshaft 50 and is positioned for rotation with the crankshaft 50 . The flywheel assembly 102 advantageously includes a flywheel magneto for AC generator that supplies electric power directly or indirectly via a battery to various electrical components such as the fuel injection system, the ignition system and the ECU 88 . An engine cover 104 preferably extends over almost all of the engine 28 , including the flywheel assembly 102 .
[0050] In the embodiment of FIG. 1, the driveshaft housing 24 defines an internal section of the exhaust system that leaves the majority of the exhaust gases to the lower unit 26 . The internal section includes an idle discharge portion that extends from a main portion of the internal section to discharge idle exhaust gases directly to the atmosphere through a discharge port that is formed on a rear surface of the driveshaft housing 24 .
[0051] Lower unit 26 also defines an internal section of the exhaust system that is connected with the internal exhaust section of the driveshaft housing 24 . At engine speeds above idle, the exhaust gases are generally discharged to the body of water surrounding the outboard motor 10 through the internal sections and then a discharge section defined within the hub of the propeller 57 .
[0052] The engine 28 may include other systems, mechanisms, devices, accessories, and components other than those described above such as, for example, a cooling system. The crankshaft 50 through a flexible transmitter, such as timing belt 84 can directly or indirectly drive those systems, mechanisms, devices, accessories, and components.
The Oil Pressure Control System
[0053] The illustrated engine includes a lubrication system to lubricate the moving parts within the engine 28 . The lubrication system is a pressure fed system for lubricating the bearings and other rotating surfaces. The oil pressure control system described informs the operator of the status of the lubrication pressure in the engine and sounds an alarm if there is inadequate lubrication pressure.
[0054] Referring to FIG. 5, the lubrication oil is collected from an oil pan 106 within the engine 28 by an oil pump 108 and is delivered under pressure through an oil filter 110 . Referring to FIG. 4, an oil pressure sensor 112 measures the pressure of the lubrication system, which relays the information to the ECU 88 . The lubricating oil may also travel through an oil thermostat and oil cooler in order to maintain a proper lubricating temperature. The oil is then dispersed throughout the engine to lubricate the internal moving parts. The oil pump 108 may be directly driven from the crankshaft 50 . The oil pump 108 may also be driven by, for example, the camshafts 74 , an intermediate shaft, or an auxiliary shaft.
[0055] As illustrated in FIG. 6, the oil pressure advantageously rises as a function of engine speed. The engine speed is calculated by the ECU using the ignition triggering sensors 100 coupled to ECU 88 . Thus, when the engine 28 is operating at idle or a low speed the corresponding oil pressure is less than when the engine is operating at a higher speed. At increasing engine speeds lubrication pressure becomes more important and vital to long engine life and proper engine operation.
[0056] The graph of FIG. 7 illustrates the relationship of the oil pressure sensor voltage and the actual pressure of the lubricating system. As the oil pressure rises, the oil pressure sensor voltage rises linearly. This oil pressure sensor voltage accurately represents the actual engine lubrication pressure for constant monitoring by the ECU 88 .
[0057] The viscosity, or degree of resistance of a substance to oppose displacement forces, of the oil in the engine is higher at cold engine temperatures and decreases as the engine temperature rises. Therefore, the oil pressure will be higher in a cold engine at a particular engine speed than in a warm engine operating at the same speed. In a preferred embodiment the oil pressure control system incorporates an engine temperature sensor 116 located in the engine block 40 as well as oil temperature switches 118 , 120 in each cylinder head member 42 to properly translate the engine and individual cylinder head temperatures to the ECU 88 . The ECU 88 is programmed to use these temperature value inputs to accurately evaluate proper lubrication pressures for the engine 28 .
[0058] In one embodiment of the present invention the predetermined oil pressure values are dependent on the engine speed. For example, at higher engine speeds the predetermined oil pressure threshold value is higher because a increased oil pressure is necessary to effectively lubricate and protect the rotating engine components. At a lower engine speed a lower oil pressure threshold is adequate to effectively lubricate and protect the rotating engine components. Therefore, the operator will be correctly warned at every engine speed if an inadequate oil pressure is present. As described above, ECU 88 is coupled to the ignition triggering sensors 108 and is programmed to initiate different oil pressure alarm timed sequences depending upon engine speed.
[0059] A significant feature of the engine embodiment illustrated is that oil pressure alarm limits are also a function of predetermined time intervals. FIG. 8 illustrates a graph showing how different pressure threshold values, Po, P 1 , and P 2 correspond to different timers To, T 1 , and T 2 . When a particular pressure is detected, the corresponding timer is activated. As the detected oil pressure becomes lower and passes a lower oil pressure threshold, a shorter timer is activated.
[0060] [0060]FIG. 9 illustrates examples of various changing oil pressure values, how the oil pressure control system monitors the oil pressure, and at which point the system triggers an alarm to warn the operator of a lapse of lubrication pressure. At a point 122 when an oil pressure value drops below an initial pressure threshold Po, a corresponding timer To is initiated. By way of specific example, the pressure Po may represent a pressure of 350 kilopascals (kpa) and To sets a predetermined time internal of one second. If the oil pressure remains below the initial pressure Po for the predetermined amount of time designated by the timer To, for example at point 124 one second later than point 122 , an alarm system will be activated to warn the operator of inadequate oil pressure. The warning alarm system may include, but is not limited to, an audible alarm 123 and/or a visual alarm 125 . If, however, during this time internal To, the oil pressure rises above the pressure threshold Po, for example at point 126 on a pressure trace depicted by a dashed line 128 , the timer To is automatically reset and no alarm is activated.
[0061] In another example shown in FIG. 9, the oil pressure value drops below a second pressure threshold P 1 and a corresponding timer T 1 is initiated. By way of specific example, P 1 may represent a pressure of 300 kpa and T 1 is set to a time corresponding to 0.5 seconds. If during this time internal T 1 , the oil pressure remains below the second pressure P 1 for the predetermined amount of time designated by the timer T 1 , for example at point 132 0.5 seconds later than point 130 , an alarm will be activated to warn the operator of inadequate oil pressure. If, however, during the time interval T 1 , the oil pressure rises above the pressure threshold P 1 , for example at points 134 on pressure traces depicted by dashed lines 128 or 136 , the timer T 1 is reset and no alarm is activated.
[0062] At yet another point 138 when an oil pressure value drops below a third pressure threshold P 2 , a corresponding timer T 2 is initiated. T 2 can be set to a time corresponding to 0.2 seconds. P 2 may represent a pressure of 250 kpa. If the oil pressure remains below the third pressure P 2 for the predetermined amount of time designated by the timer T 2 , for example at point 140 , an alarm will be activated to properly warn the operator of inadequate oil pressure. If, however the oil pressure at any time after the timer T 2 begins rises above the pressure threshold P 2 , for example at point 142 on the pressure trace depicted by a dashed line 136 , the timer T 2 is reset and no alarm is activated.
[0063] The flow charts in FIGS. 10 and 11 further illustrate the function of the control system. The first flow chart in FIG. 10 corresponds to the oil pressure system using one pressure threshold to activate an alarm and properly warn the operator of an inadequate lubrication pressure. FIG. 11 shows another flow chart corresponding to the oil pressure system using three pressure thresholds to activate an alarm and properly warn the operator of an inadequate lubrication pressure.
[0064] [0064]FIG. 10 shows a control routine 144 of ECU 88 that is arranged and configured in accordance with certain features, aspects, and advantages of the present invention. The control routine 144 begins and moves to a first operation block P 10 in which the engine oil pressure Pa is measured and stored. Advantageously, the ECU 88 is programmed to perform the oil pressure determination method. The control routine 144 then moves to decision block P 11 .
[0065] In decision block P 11 it is determined if the measured pressure Pa is less than a threshold pressure Po. If the measured oil pressure Pa is not less than the threshold pressure Po, the control routine returns to the input of block P 10 . If, however, the measured pressure Pa is less than the threshold pressure Po, the control routine 144 moves to operation block P 12 .
[0066] In operation block P 12 , the timer To is started. The control routine 144 moves to operation block P 13
[0067] In operation block P 13 a second oil pressure Pb is detected. The control routine 144 moves to a decision block P 14
[0068] In decision block P 14 the second measured oil pressure Pb is compared to the threshold pressure Po. If the second measured pressure Pb is greater than the threshold pressure Po, the control routine 144 moves to operation block P 15 . If, however the second measured oil pressure Pb is not greater than the threshold pressure Po, the control routine 144 moves to decision block P 16 .
[0069] In operation block P 15 the timer To is reset and the control routine 144 returns.
[0070] In decision block P 16 it is determined if timer To has elapsed. If the timer To has not elapsed, the control routine 144 moves to the operation block P 13 . If, however, in decision block P 16 the timer To has elapsed, the control routine 144 moves to operation block P 17 .
[0071] In operation block P 17 a drop in oil pressure is determined. The control routine 144 moves to operation block P 18 .
[0072] In operation block P 18 a warning system is initiated. The warning system may contain, but is not limited to, an audible alarm system and/or a visual alarm system. The control routine 144 moves to operation block P 19 .
[0073] In operation block P 19 the timer To is reset and the control routine 144 returns.
[0074] [0074]FIG. 11 shows a control routine 148 of ECU 88 that is arranged and configured in accordance with certain features, aspects, and advantages of the present invention. The control routine 148 begins and moves to operation block P 20 where an oil pressure Pa is measured and stored. The control routine 148 moves to decision block P 21 .
[0075] In decision block P 21 it is determined if the measured oil pressure Pa is less than Po. If the measured pressure Pa is not less than the pressure threshold Po, the control routine 148 returns. If, however, the measured oil pressure Pa is less than the threshold pressure Po, the control routine 148 moves to operation block P 22 .
[0076] In operation block P 22 a timer To is started. The timer To corresponds to the threshold pressure Po. The control routine 148 moves to operation block P 23 .
[0077] In operation block P 23 a second oil pressure Pb is detected. The operation block 148 moves to decision block P 24 .
[0078] In decision block P 24 it is determined if the second measured oil pressure Pb is greater than the threshold pressure Po. If the measured oil pressure Pb is greater than threshold pressure Po, the control routine 148 moves to operation block P 25 . If, however, in decision block P 24 it is determined that the measured oil pressure Pb is not greater than the threshold pressure Po, the control routine 148 moves to decision block P 26 .
[0079] In operation block P 25 the timer To is reset and the control routine 148 returns.
[0080] In decision block P 26 it is determined if the second measured oil pressure Pb is less than a second threshold pressure P 1 . If the second measured oil pressure Pb is not less than the second oil pressure threshold P 1 , the control routine 148 moves to decision block P 38 . If, however in decision block P 26 the second measured oil pressure Pb is less than the second threshold oil pressure P 1 , the control routine 148 moves to operation block P 27 .
[0081] In operation block P 27 a timer T 1 is started and the control routine 148 moves to operation block P 28 .
[0082] In operation block P 28 a third oil pressure Pc is measured. The control routine 148 moves to decision block P 29 .
[0083] In decision block P 29 it is determined if the third measured oil pressure Pc is greater than the second threshold pressure P 1 . If the third measured oil pressure Pc is greater than the second threshold oil pressure P 1 , the control routine 148 moves to operation block P 30 . If in decision block P 29 , it is determined that the third measured oil pressure PC is not greater than the second threshold pressure P 1 , the operation block P 48 moves to decision block P 31 .
[0084] In operation block P 30 the timer T 1 is reset and the control routine 148 moves to the decision block P 26 .
[0085] In decision block P 31 it is determined if the third measured oil pressure Pc is less than the third oil pressure threshold P 2 . If the third measured oil pressure Pc is not less than the third oil pressure threshold P 2 , the control routine 148 moves to decision block P 32 . If the second measured oil pressure Pc is less than the third oil pressure threshold P 2 , the control routine 148 moves to operation block P 33 .
[0086] In decision block P 32 it is determined if the timer T 1 has elapsed. If the timer T 1 has elapsed, the control routine 148 moves to operation block P 39 . If the timer T 1 has not elapsed, the control routine 148 returns to operation block P 28 .
[0087] In operation block P 33 a timer T 2 is started and the control routine 148 moves to operation block P 35 .
[0088] In operation block P 35 a fourth oil pressure Pd is detected and the control routine 148 moves to decision block P 36 .
[0089] In decision block P 36 it is determined if the fourth measured oil pressure Pd is greater than the third oil pressure threshold P 2 . If the fourth measured oil pressure Pd is greater than the third oil pressure threshold P 2 , the control routine 148 moves to operation block P 34 . If the fourth measured oil pressure Pd is not greater than the third pressure threshold P 2 , the control routine 148 moves to decision block P 37 .
[0090] In operation block P 34 the timer T 2 is reset and the control routine 148 moves to decision block P 31 .
[0091] In decision block P 37 , it is determined if the timer T 2 has elapsed. If the timer T 2 has not elapsed, the control routine 148 moves to operation block P 35 . If, however, the timer T 2 has elapsed, the control routine 148 moves to operation block P 39 .
[0092] In operation block P 39 a drop in oil pressure is determined and the control routine 148 moves to operation block P 40 .
[0093] In operation block P 40 a warning system is initiated. The warning system may contain, but is not limited to, an audible alarm system and/or a visual alarm system. The control routine 148 moves to operation block P 41 .
[0094] In operation block P 41 the timers T 0 , T 1 , and T 2 are reset and the control routine 148 returns.
[0095] It is to be noted that embodiments of the control systems described above may be in the form of a hard-wired feedback control circuits. Alternatively, the control systems may be constructed of a dedicated processor and memory for storing a computer program configured to perform the steps described above in the context of the flowcharts. Additionally, the control systems may be constructed of a general-purpose computer having a general-purpose processor and memory for storing the computer program for performing the routines. Preferably, however, the control systems are incorporated into the ECU 88 , in any of the above-mentioned forms.
[0096] Although the present invention has been described in terms of a certain preferred embodiments, other embodiments apparent to those of ordinary skill in the art also are within the scope of this invention. Thus, various changes and modifications may be made without departing from the spirit and scope of the invention. For instance, various steps within the routines may be combined, separated, or reordered. In addition, some of the indicators sensed (e.g., engine speed and throttle position) to determine certain operating conditions (e.g., rapid deceleration) can be replaced by other indicators of the same or similar operating conditions. Moreover, not all of the features, aspects and advantages are necessarily required to practice the present invention. Accordingly, the scope of the present invention is intended to be defined only by the claims that follow. | An oil pressure control warning system for an outboard motor which uses timers dependent on various predetermined oil pressures to correctly determine actual harmful lubrication deficiencies and warn the operator of such lubrication deficiencies. The alarm warning can include an audible and visual operation and is turned off as soon as the correct oil pressure is resumed. | 5 |
TECHNICAL FIELD
[0001] The invention is directed to a process for the treatment of a sweet whey material containing cGMP (caseinoGlycoMacroPeptide), so that to obtain a protein material suitable for hypoallergenic infant formulae.
BACKGROUND OF THE INVENTION
[0002] Human Breast Milk and breast feeding represent the uncontested gold standard in terms of infant nutrition. Infant formulae that serve as a substitute for or complement to human breast milk should satisfy the nutritional requirements of infants, have an acceptable taste and be hypoallergenic when targeted to infants at risk of allergy. Infant formulae must comply with regulatory nutritional requirements, such as European Commission Directive 91/321/EEC of May 14, 1991 on infant formulae in Europe, and a similar corresponding regulatory document of the Food and Drug Administration (FDA) in the USA.
[0003] It is known that allergies to cows' milk and to infant formulae containing cow's milk protein are due to the fact that the proteins of cows' milk differ from the proteins of mother's milk and can constitute allergens for humans. Bovine whey protein and/or casein are often used as the milk protein source in infant formulae. To reduce allergenicity, cow's milk proteins are hydrolysed by enzymes and thus reduced to peptides. Current hypoallergenic formulae composed of such cow's milk proteins hydrolysates aimed at allergy prevention also comprise other nutrients such as animal oils, vegetable oils, starch, maltodextrin, lactose and sucrose. These protein hydrolysates may also be incorporated into an adult milk drink or food supplements.
[0004] The hydrolysis process used to produce these hydrolysates must be carefully monitored so that the final product hydrolysate retains its nutritional value and desired physical properties but is hypoallergenic. Hydrolysates may be characterized as “partial” or “extensive” depending on the degree to which the hydrolysis reaction is carried out. In the current invention, a partial hydrolysate is one in which 60% of the protein/peptide population has a molecular weight of less than 1000 Daltons. Partial hydrolysates are considered as hypoallergenic (HA).
[0005] An essential amino acid or indispensable amino acid is an amino acid that cannot be synthesised de novo (from scratch) by the organism being considered, and therefore must be supplied in its diet. There are nine amino acids humans cannot synthesize including threonine and tryptophan. The requirements of infant formulae regulations also encompass the contents in amino acids, particularly threonine and tryptophan.
[0006] U.S. Pat. No. 687,158 is directed to a process for the separation of glycomacropeptide or caseinoglycomacropeptide (“cGMP”) from lactic raw material.
[0007] cGMP is a phosphorylated and partially sialylated macropeptide which is formed by the action of a protease, for example rennet, on mammalian milk kappa-casein. cGMP represents about 20% by weight of the proteins in sweet whey obtained after separation of casein during cheese manufacture.
[0008] U.S. Pat. No. 6,787,158 relates to a process for the extraction of cGMP from a lactic raw material comprising the steps of removing cations from a lactic raw material for a sufficient amount of time to obtain a substantially deionised lactic raw material having a pH of about 1 to 4.5; contacting the substantially deionised lactic raw material with an anionic resin having a hydrophobic matrix for a sufficient amount of time and at a sufficient temperature to remove cGMP from the substantially deionised lactic raw material and to obtain a treated liquid material; separating the resin from the treated liquid material; and rinsing the resin to obtain the cGMP therefrom. When using a fluidized bed reactor, the cGMP is removed in a range from 85 to 91% of the starting cGMP.
[0009] The treated liquid material that is obtained from sweet whey has an amino acid profile reduced in threonine and enriched in aromatic amino acids such as tryptophan. It is useful in an infant or dietetic product as a protein source or raw material. From up to now, this treated liquid was used in standard infant formulae in which the proteins were intact. These infant formulae are such that the casein/whey ratio is about 30/70. This treated liquid was also used in hypoallergenic infant formulae, in admixture with other protein raw material, so that to fulfill the regulatory requirements.
[0010] However, there is a growing need of hypoallergenic formulae in which the proteins are partially hydrolyzed. These formulae are based on a protein raw material made of 100% whey. Thus, the existing process described in U.S. Pat. No. 6,787,158 fails to provide a protein material meeting the protein requirements of these hypoallergenic formulae.
[0011] It is therefore an object of the invention to provide a process for removing cGMP from a sweet whey material, in order to obtain a protein raw material suitable for hypoallergenic infant formulae, or to at least provide a useful alternative.
SUMMARY OF THE INVENTION
[0012] In an aspect of the invention, there is provided a process for the treatment of a sweet whey material containing cGMP (caseinoGlycoMacroPeptide), said process comprising the following steps:
Decationising the sweet whey material so as to obtain sweet whey having a pH value of 1 to 4.5; treating said sweet whey in a fluidized bed reactor in the presence of a specific volume of an anionic resin, at a temperature between 10 and 18° C., wherein said sweet whey contacts said resin so that the resin absorbs between 52% and 58% of the cGMP present in the sweet whey; and Recovering a protein material.
[0016] Surprisingly, it has been found that the absorption in the resin of a lower level of the cGMP present in the sweet whey, with respect to the level absorbed in the prior art, has not effect on the corresponding absorption of the anions in the resin, in particular chloride and phosphorous anions: the resin still absorbs at least 90% of the anions present in the sweet whey.
[0017] In a preferred embodiment of the invention, the protein material is suitable for hypoallergenic infant formulae.
BRIEF DESCRIPTION OF THE FIGURES
[0018] FIG. 1 is a schematic representation of a device for use in a process of the present invention.
DETAILED DESCRIPTION
[0019] For a complete understanding of the present invention and the advantages thereof, reference is made to the following detailed description of the invention.
[0020] It should be appreciated that various embodiments of the present invention can be combined with other embodiments of the invention and are merely illustrative of the specific ways to make and use the invention, and do not limit the scope of the invention when taken into consideration with the claims and the following detailed description.
[0021] In the present description, the following words are given a definition that should be taken into account when reading and interpreting the description, examples and claims.
[0022] As used herein, the following terms have the following meanings.
[0023] The term “removal of a compound” means that the compound present in a product is absorbed in the resin thereby producing a product having a lower content of the compound. The corresponding percentage is the percentage of the compound in the product which is removed from the product by absorption in the resin.
[0024] The term “suitable for infant formulae” means that the product can be directly used in infant formulae, without any adaptation. This means that there is no need for mixing the product with at least one different source of proteins and/or amino acids.
[0025] The term “hypoallergenic” means that 60% of the protein/peptide population has a molecular weight of less than 1000 Daltons.
[0026] The term “infant” means a child under the age of 12 months.
[0027] The term “preterm infant” (or “premature infant”) means an infant born prior to 37 weeks gestational age.
[0028] The term “infant formula” means a foodstuff intended for particular nutritional use by infants during the first four to six months of life and satisfying by itself the nutritional requirements of this category of person (Article 1.2 of the European Commission Directive 91/321/EEC of May 14, 1991 on infant formulae and follow-on formulae).
[0029] The term “preterm infant formula” means an infant formula intended for a preterm infant.
[0030] As used in this specification, the words “comprises”, “comprising”, and similar words, are not to be interpreted in an exclusive or exhaustive sense. In other words, they are intended to mean “including, but not limited to”.
[0031] Any reference to prior art documents in this specification is not to be considered an admission that such prior art is widely known or forms part of the common general knowledge in the field.
[0032] The process according to the invention is advantageously such that the protein material is suitable for hypoallergenic infant formulae. It means that undesired products such as anions and cGMP have been absorbed by the resin during the process so that they are present at acceptable levels (impurity traces) in the protein material. It means also the protein content of the sweet whey material has been modified such that amino acids such as Tryptophan and Threonine are present at acceptable levels in the protein material, since the resins has absorbed proteins and/or macropeptides (such as cGMP).
[0033] The decationising step does not change substantially the content of anions or cGMP in the sweet whey material. Thus, the absorption in the resin of the cGMP and anions can relate either to their content in the sweet whey material or to their content in the sweet whey material. We choose here to refer to their content in the sweet whey.
[0034] In a preferred embodiment of the invention, the resin absorbs around 55% of the cGMP present in the sweet whey.
[0035] In a preferred embodiment of the invention, the resin absorbs at least 90% of the anions present in the sweet whey.
[0036] The anions are generally selected from the group consisting of chlorine, phosphorous, citrate, sulphate and lactate.
[0037] In a preferred embodiment of the invention, the resin absorbs at least 90% of the chlorine and of the phosphorous present in the sweet whey.
[0038] In a preferred embodiment of the invention, the treatment of the sweet whey in the fluidized bed reactor is implemented at a ratio of protein over resin of 0.20 to 0.35 kg/L.
[0039] In a preferred embodiment of the invention, the treatment of the sweet whey in the fluidized bed reactor is implemented at a ratio of cGMP over resin between 39 and 41 g/L.
[0040] In this process, the sweet whey material can be one of sweet whey obtained after separation of casein coagulated with rennet, a concentrate of sweet whey, a sweet whey or such a whey demineralized to by electrodialysis, ion exchange, reverse osmosis, electrodeionisation or a combination of these procedures, a concentrate of sweet whey demineralized by electrodialysis, ion exchange, reverse osmosis, electrodeionisation or a combination of these procedures, a concentrate of proteins of substantially lactose-free sweet whey obtained by ultrafiltration, followed by diafiltration (ultrafiltration with washing), mother liquors of the crystallization of lactose from sweet whey, a permeate of ultrafiltration of a sweet whey, the product of hydrolysis, by a protease, of a native casein obtained by acid precipitation of skimmed milk with an inorganic acid or by biological acidification, obtained by microfiltration of a skimmed milk, or the product of hydrolysis of a caseinate by a protease. Preferably, the sweet whey has a solid content of about 10 to 30 percent by weight after its decationisation.
[0041] The sweet whey material is usually a liquid which can be obtained from dispersion and/or dissolution of solid whey powders in a liquid.
[0042] Advantageously, the resin is treated with an alkaline material prior to contact with the sweet whey. Preferably, the sweet whey contacts the resin in a gently stirred reactor at a temperature of less than 50° C. for one to ten hours to adsorb the suitable amount of cGMP onto the resin. A suitable resin is one that is basic and in macroporous or macrocross-linked gel form. The sweet whey usually contacts the resin until the treated liquid material attains a constant pH of between about 4.2 to about 5.8 to indicate that the reaction has proceeded to completion. Advantageously, the sweet whey and the resin are present in a volume ratio of 1:1 to 30:1, preferably 1:2 to 1:10.
[0043] The protein material obtained by the process according to the invention is a protein source intended for use by infants, including preterm infants or low birth weight infants, specifically in hypoallergenic infant formulae, including hypoallergenic preterm infant formulae. These formulas fulfil all the regulatory requirements for infants that is to say that they comprise, in addition to this protein source, additional components such as a source of available carbohydrates and a lipid source.
[0044] The chlorine content of the protein material is usually between 1 mg/100 g, preferably between 5 and 80 mg/100 g and/or the phosphorous content of the protein material is between 50 and 150 mg/100 g, preferably between 90 and 160 mg/100 g.
[0045] The tryptophan over threonine ratio of the protein material is generally between 0.350 and 0.360, more preferably around 0.355.
[0046] The protein material is advantagously suitable for hypoallergenic infant formulae.
[0047] FIG. 1 illustrates a device for use in the process of the present invention. A reactor 1 has in its upper section a principal tank 2 connected to a lower part having a compartment 3 through a smaller diameter than that of the tank 2 . Tank 2 has a rinsing liquid inlet channel 4 , an inlet 5 to allow entry of pressurized gas, a safety valve 6 to regulate the gas pressure in reactor 1 . Close to the base of tank 2 there is a strainer 7 and a channel 8 for drawing off liquid.
[0048] Connected to compartment 3 , the reactor has a pH-meter 9 , a gas inlet 10 and a three-way valve 11 connected to an inlet channel 12 for liquid to be treated and a discharge channel 13 to remove treated liquid. The base of compartment 3 has a grid or a perforated plate 14 which collects resin beads 15 . Under grid 14 , a drawing-off channel 16 removes the liquid via pump 17 to a buffer tank 18 , which has a level controlling device 19 . Channel 20 via pump 21 removes liquid from buffer tank 18 . Channel 20 is connected either to the channel 12 , or to the discharge overflow 22 .
[0049] The process using the device is now described, which was implemented in the following examples.
[0050] The initial sweet whey material (dispersion of powder whey in water), was formerly decationised by the means of cationic resin columns in the successive order: weak/strong/strong. The resulting sweet whey was introduced via channel 12 into reactor 1 . Air was introduced by bubbling into compartment 3 through the base by the inlet 10 via a non-return valve 23 . A fluidized bed of resin beads 15 was created comprising weakly anionic resin of hydrophobic matrix based on polystyrene (IMAC HP 661, Rohm & Haas, regenerated in OH − form). The resin beads 15 were stirred for 4 h in contact with the dispersion due to the turbulence created by the fluidization. The pH of the liquid was constantly controlled by means of the pH-meter 9 . Constant analysis of the sweet whey by high-performance liquid chromatography (“HPLC”) (not shown) showed when the reaction removed 55% of the cGMP present in the sweet whey. At this point, the desired content of cGMP being removed, the air supply at inlet 10 was cut off and air was introduced through inlet 5 at the top of the reactor above the liquid level 24 . The liquid was pressurized and the resin beads settled in the lower part of compartment 3 of reactor 2 where they were retained by grid 14 . The treated liquid material was drawn off by gravity and/or pumping through channel 8 and through channel 16 by means of pump 17 towards buffer tank 18 . The treated liquid material was then discharged by channel 20 by means of pump 21 and directed towards the outlet by channels 12 and 13 .
[0051] The treated liquid material was standardized and pH adjusted, concentrated by evaporation or nano filtration and the concentrate was spray-dried in a drying tower.
[0052] The recovery of cGMP is optional. It is nevertheless illustrated in FIG. 1 . To recover the cGMP, the reactor and the resin were washed with deionised water introduced through inlet channel 25 , via valve 26 , and inlet channel 4 and flushed through the reactor via channels 12 and 13 . The cGMP was eluted twice through the same circuit with aqueous 2% NaOH introduced via channel 27 and valve 28 and rinsed with 30 l of deionised water. After combining the eluate and washing volumes, the volume was concentrated by ultrafiltration or nanofiltration with a membrane having a nominal cut-off of 3000 daltons to obtain a retentate and a filtrate. The retentate was freeze-dried.
[0053] Periodically, the resin could be subjected to acidic regeneration after alkaline regeneration once the equivalent of 10 volumes of resin bed had been treated. After elution of the cGMP with the alkaline solution as described above, the resin was washed with a concentrated aqueous solution of HCl supplied by channel 29 and valve 30 , followed by water supplied by channel 25 and valve 26 . The resin was converted to the OH − form by passing a concentrated aqueous solution of NaOH supplied by channel 27 followed by water from channel 25 , into channel 4 . The solutions were removed from reactor 1 via channel 16 , transferred by pump 17 to the buffer tank 18 . From buffer tank 18 , the solutions were removed by pump 21 , discharged by channel 20 and overflow 22 into the effluent treatment. Following this operation, the resin was ready for another treatment cycle.
[0054] The treated liquid was removed and used as a protein material according to the invention.
[0055] The invention is further described with reference to the following examples. It will be appreciated that the invention as claimed is not intended to be limited in any way by these examples.
EXAMPLES
Example 1: Process Adapted from U.S. Pat. No. 6,787,158 Removing at Least 90% of the cGMP from the Sweet Whey Material
[0056] The sweet whey material was whey concentrate WPC 31.5. It was decationised with weak/strong/strong cation exchange resins. The weak resin was IMAC HP 336 and the strong resin was IMAX 1110Na, both sold by Dow Chemical (formerly Rohm & Haas). The resulting sweet whey had a protein content of around 31.5% on DM (for Dry Matter) with a total solid content of 18% and a pH of 1.85. 3700 kg of this sweet whey were pumped into the reactor 1 containing 7500 liters of weak anion exchange resin (HP 661 food grade). The entire sweet whey volume was contacted with the resin. The resin and the sweet whey were suspended together for 4 hours at a temperature of 15 to 18° C. The pH was increasing from 1.85 to a final pH of 5.1 to 5.3 over the 4 hours of reaction time. The cGMP removal was monitored by HPLC.
[0057] After 4 hours of reaction time, the resulting demineralized and cGMP depleted whey was pumped out of the reactor. This protein material whey was pushed out and the resin was washed with water in order to reduce losses on proteins and dry matter. The cGMP was recovered by a combined step of elution and regeneration with 4% NaOH. After the regeneration the NaOH was pushed out with water and rinsed with water until the pH reached around 10.5. Once this pH was reached the reactor was ready for the next production. After standard neutralization with NaOH and KOH, the product was heat treated, evaporated and spray dried.
[0058] The data relevant to the process is summarized in Table 1 below.
[0000]
Dry matter (DM) load (kg)
3700
Resin HP 661amount (L)
7500
DM per liter of resin (kg/L)
0.60
Protein per liter of resin (kg/L)
0.19
cGMP bound per liter resin (g/L)
39
NaOH (100%) per kg DM (g/L)
85
Reaction time (h)
4
Cycle time (h)
12
Trp/Thr ratio
0.42
Example 2 (According to the Invention): Process According to the Invention Removing 55% of the cGMP from the Sweet Whey Material
[0059] The sweet whey material was whey concentrate WPC 80. It was decationised with weak/strong/strong cation exchange resins. The weak resin was IMAC HP 336 and the strong resin was IMAX 1110Na, both sold by Dow Chemical (formerly Rohm & Haas). The resulting sweet whey had a protein content of around 82% on DM (for Dry Matter) with a total solid content of 12% and a pH of 3.40. 4235 kg of this sweet whey were pumped into the reactor containing 11,600 liters of weak anion exchange resin (HP 661 food grade). The entire sweet whey volume was contacted with the resin. The resin and the sweet whey were suspended together for 4 hours at a temperature of 15 to 18° C. The pH was increasing from 3.40 to a final pH of 4.80 over the 4 hours of reaction time. The cGMP removal was monitored by HPLC.
[0060] After 4 hours of reaction time, the resulting demineralized and cGMP sweet whey was reduced by 55% and this protein material was pumped out of the reactor. This protein material was pushed out and the resin was washed with water in order to reduce losses on proteins and dry matter. The cGMP was recovered by a combined step of elution and regeneration with 4% NaOH. After the regeneration, the NaOH was pushed out with water and rinsed with water until the pH reached around 10.5. Once this pH was reached the reactor was ready for the next production. After standard neutralization with NaOH and KOH, the product was heat treated, evaporated and spray dried.
[0061] The data relevant to the process is summarized in Table 2 below.
[0000]
Dry matter (DM) load (kg)
4235 kg
Resin amount (L)
11600
DM per liter of resin (kg/L)
0.37
Protein per liter of resin (kg/L)
0.30
cGMP bound per liter resin (g/L)
39
NaOH (100%) per kg DM (g/L)
123
Reaction time (h)
4
Cycle time (h)
12
Trp/Thr ratio
0.36
[0062] The tryptophan/threonine (Trp/Thr) ratio was identical to said ratio in the on-sale hypoallergenic infant formula NAN 1 HA from Nestlè.
[0063] The capacity (i.e. dry matter load) of the reactor, with respect to the parameter protein per liter of resin, was increased by 35%. The efficiency of the regeneration (g NaOH/kg of DM) was improved from 51 g NaOH/L resin (=85×0.6, numerals in Table 1) down to 36.9 g NaOH/L resin (=39×0.37, numerals in Table 2). Therefore also less waste water was generated per kg DM.
[0064] Furthermore, the content of chloride in the protein material issued from the process applying a 90% cGMP removal was 11 mg/100 g of chloride and 100 mg/100 g of phosphorous, which helps to make this protein material suitable for hypoallergenic infant formulae.
[0065] Surprisingly, although only 55% of the cGMP were removed, the mineral anions such as chloride (CI), phosphorous (P), and citrate, were still 90% removed from the sweet whey.
[0066] Actually, the content of chloride and phosphorous anions in the sweet whey material were 180 mg/100 g of chloride and 370 mg/100 g of phosphorous. The contents of chloride and phosphorous anions in the protein material issued from the comparative process applying a 90% cGMP removal were 11 mg/100 g of chloride and 100 mg/100 g of phosphorous.
[0067] On this basis, one would expect that around 55% of cGMP removal should lead to the following calculated (theoretical) values: 100 mg/100 g of chlorine and 200 mg/100 g of phosphorous. Actually, the content of chloride in the protein material issued from the process applying a 55% cGMP removal was 9 mg/100 g of chloride and 104 mg/100 g of phosphorous.
[0068] Thus the protein material obtained by the process according to the invention, with 55% cGMP removal, showed surprisingly the same mineral profile as a 90% removal process which helps to make the protein material suitable for hypoallergenic infant formulae.
Example 3 (According to the Invention): Process According to the Invention Removing 55% of the cGMP from the Sweet Whey Material
[0069] The sweet whey material was whey concentrate WPC 31.5. It was decationised with weak/strong/strong cation exchange resins. The weak resin was IMAC HP 336 and the strong resin was IMAX 1110Na, both sold by Dow Chemical (formerly Rohm & Haas). The resulting sweet whey had a protein content of around 31.5% on DM (for Dry Matter) with a total solid content of 18% and a pH of 1.75. 6785 kg of this sweet whey were pumped into the reactor containing 8,500 liters of weak anion exchange resin (HP 661 food grade). The entire sweet whey volume was contacted with the resin. The resin and the sweet whey were suspended together for 4 hours at a temperature of 15 to 18° C. The pH was increasing from 1.75 to a final pH of 4.90 over the 4 hours of reaction time. The cGMP removal was monitored by HPLC.
[0070] After 4 hours of reaction time, the resulting demineralized and cGMP sweet whey was reduced by 55% and this protein material was pumped out of the reactor. This protein material was pushed out and the resin was washed with water in order to reduce losses on proteins and dry matter. The cGMP was recovered by a combined step of elution and regeneration with 4% NaOH. After the regeneration the NaOH was pushed out with water and rinsed with water until the pH reached around 10.5. Once this pH was reached the reactor was ready for the next production. After standard neutralization with NaOH and KOH, the product was heat treated, evaporated and spray dried.
[0071] The data relevant to the process is summarized in Table 3 below.
[0000]
Dry matter (DM) load (kg)
6785 kg
Resin amount (L)
8500
DM per liter of resin (kg/L)
0.80
Protein per liter of resin (kg/L)
0.25
cGMP bound per liter resin (g/L)
39
NaOH (100%) per kg DM (g/L)
55
Reaction time (h)
4
Cycle time (h)
12
Trp/Thr ratio
0.36
[0072] The tryptophan/threonine (Trp/Thr) ratio was identical to said ratio in the on-sale hypoallergenic infant formula NAN 1 HA from Nestlè.
[0073] The capacity of the reactor, with respect to the parameter protein per liter of resin, was increased by 15%. The efficiency of the regeneration (g NaOH/kg of DM) was improved from 51 g NaOH/L resin (=85×0.6, numerals in Table 1) down to 44 g NaOH/L resin (=55×0.8, numerals in Table 3). Therefore, also less waste water is generated per kg DM.
[0074] Actually, the content of chloride in the protein material issued from the process applying a 55% cGMP removal was 14 mg/100 g of chloride and 135 mg/100 g of phosphorous.
[0075] Thus, the protein material obtained by the process according to the invention, with 55% cGMP removal, shows surprisingly the same mineral profile as a 90% removal process which made this protein material suitable for hypoallergenic infant formulae.
[0076] Although the invention has been described by way of examples, it should be appreciated that variations and modifications may be made without departing from the scope of the invention as defined in the claims. Furthermore, where known equivalents exist to specific features, such equivalents are incorporated as if specifically referred in this specification. | The invention concerns a process for the treatment of a sweet whey material containing cGMP (caseinoGlycoMacroPeptide), said process comprising the following steps: —Decationising the sweet whey material so as to obtain sweet whey material having a pH value of 1 to 4.5; —Treating said sweet whey in a fluidized bed reactor comprising a specific volume of an anionic resin, at a temperature between 10 and 18° C., wherein said sweet whey contacts said resin for a sufficient amount of time so that the resin absorbs between 52% and 58% of the cGMP present in the sweet whey; and—Recovering a protein material. Advantageously, the protein material is suitable for hypoallergenic infant formulae. | 0 |
[0001] This application claims the benefit of Taiwan application Serial No. 92131002, filed Nov. 5, 2003, the subject matter of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates in general to a scanning apparatus having an adjusting means for adjusting the position of the optical scanning module, and more particularly to the adjusting means for lifting the optical scanning module up and against the platen during the scanning operation.
[0004] 2. Description of the Related Art
[0005] In the Age of high technology, scanner has been required in the modern life due to its great functions of scanning the original drafts, such as the pictures, the photos and the documents, and then transforming and saving the image as the digital files. It is a very convenient way for the users to keep or find the original drafts. The structure and the principle of the scanner are described below.
[0006] A conventional optical scanner has a transparent platen for placing an original to be scanned document. A moving carriage assembly and the drive mechanisms are positioned underneath the transparent platen. The moving carriage assembly, including an optical scanning module supported by a carriage, contains the optical and electronic or reflective components, and moves across the complete length of the document during scanning. The components commonly used for the carriage assembly are the light source, the reflector, the lens and the photo-electronic sensing device. Drive mechanisms for moving the carriage assembly are varied. During scanning, the light emitted from the light source is reflected by the original to be scanned document, and then further reflected by the lens and focused on the photo-electronic sensing device by the lens. Afterward, the light signal received by the photo-electronic sensing device is converted into electronic signals, and then produce machine-readable data, which is representative of the image of the original document. The photo-electronic sensing device can be any device capable of converting the light signal into the electric signal, such as charged coupled device (CCD) or contact image device (CIS).
[0007] During scanning, the carriage assembly is required to move against the transparent platen, particularly the carriage assembly using contact image device (CIS) (which has a short scene depth of about 0.3 mm) as the photo-electronic sensing device. FIG. 1 is an explosive view schematically showing a conventional structure of the contact image device (CIS) module and the carriage apparatus. The transparent platen 10 is used for placing an original to be scanned document. Under the transparent platen 10 , the optical scanning module 12 is loaded in the carriage 14 which is positioned on a shaft (not shown) by a connecting means 16 , and the drive mechanism (not shown) drives the carriage 14 to move along the scanning direction on the shaft. Also, a spring 18 is interposed between the optical scanning module 12 and the carriage 14 . The spring 18 provides an upward elastic force to lift the optical scanning module 12 up until contacting the bottom surface of the transparent platen 10 , thereby making the optical scanning module 12 move against the transparent platen 10 during a scanning operation.
[0008] As be known, the degree of fidelity with which the information presented by the to be scanned document is recorded depends on the accuracy with which the moving carriage assembly is guided during the scanning operation. The reproduction is liable to be impaired even by small changes in either the direction of relative scanning movement or the spacing between the document and the optical scanning module 12 from one moment to another in the scanning operation. The conventional design with a spring 18 between the scanning apparatus and the carriage, however, is difficult to keep the optical scanning module 12 in balance, particularly in a scanning movement. It is also difficult to precisely and firmly locate the spring 18 at the center of the carriage 14 . In practice it would be desirable to design not only an easy to be assembled but also a more reliable and stable structure to lift the scanning module up for contacting with the platen, thereby obtaining an optimal scanning image result with a high standard of accuracy.
SUMMARY OF THE INVENTION
[0009] It is therefore an object of the invention to provide a scanning apparatus having an adjusting mean for adjusting the position of the optical scanning module. In the invention, one of two objects in contact rotates simultaneously makes the other object rotates due to friction between two objects. Therefore, an upward force directly or indirectly acts on the optical scanning module and lifts it up and against the platen.
[0010] The invention achieves the objects by providing a scanning apparatus having an adjusting mean for adjusting the position of the optical scanning module. The scanning apparatus comprises a platen for placing a to-be-scanned document; an optical scanning module disposed under the platen for scanning and acquiring an scanned image of the to-be-scanned document; and a carriage for carrying the optical scanning module to move backward and forward in the scanning apparatus. The carriage has an adjusting means, comprising a roller and a rotated portion, to change the position of the optical scanning module.
[0011] When the roller is rotating, friction between the rotated portion and the roller makes the rotated portion rotate until touching the optical scanning module, thereby lifting the optical scanning module upward and against the platen during a scanning operation.
[0012] According to the object of the invention, a first contacting manner of the adjusting means is provided. The rotated portion comprises: a shaft, penetrating a through hole of the roller; a swim, connected to one end of the shaft and firmly contacting with the first surface of the roller; a secured body, connected to the other end of the shaft; and a spring, received in a hole of the roller, and two ends of the spring respectively connected to the secured body and the roller. The elastic force of the spring pushes the secured body away from the roller so as to make the swim firmly contact with the first surface of the roller.
[0013] According to the object of the invention, a second contacting manner of the adjusting means is provided. The rotated portion comprises: a shaft, penetrating through a first hole of the roller; a swim, connected to one end of the shaft; a secured body, connected to the other end of the shaft; and a spring, received in a second hole of the roller, and two ends of the spring respectively connected to the swim and the secured body. An inward elastic force of the spring pulls the secured body and the swim toward the roller thereby forcing the swim and the secured body to firmly contact with the first surface and the second surface of the rollers, respectively.
[0014] According to the object of the invention, a third contacting manner of the adjusting means is provided. The rotated portion comprises: a shaft, penetrating a through hole of the roller; a swim, connected to one end of the shaft, and disposed on an opposite side of the first surface of the roller; a secured body, connected to the other end of the shaft; and a spring, received in a hole of the roller, and two ends of the spring respectively connected to the swim and the roller. The elastic force of the spring pushes the swim away from the roller so as to make the secured body firmly contact with the second surface of the roller.
[0015] Other objects, features, and advantages of the invention will become apparent from the following detailed description of the preferred but non-limiting embodiments. The following description is made with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 (prior art) is an explosive view schematically showing a conventional structure of the contact image device (CIS) module and the carriage apparatus;
[0017] FIG. 2 schematically illustrates a side view of the optical scanning module, the carriage and the adjusting means in accordance with the preferred embodiment of the invention;
[0018] FIG. 3 is a partial enlarged sectional view of an adjusting means shown in FIG. 2 ;
[0019] FIG. 4 schematically illustrates the adjusting means of FIG. 2 from a bottom view angle;
[0020] FIG. 5 is a cross-sectional diagrammatic side view of the adjusting means taken along the section line A-A of FIG. 3 ;
[0021] FIG. 6A illustrates the first contacting manner of the adjusting means according to the invention;
[0022] FIG. 6B illustrates the second contacting manner of the adjusting means according to the invention; and
[0023] FIG. 6C illustrates the third contacting manner of the adjusting means according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0024] In the present invention, an adjusting means assembled with the carriage is mechanically constructed by using two objects in contact. When the first object rotates, the second object could be directly or indirectly rotated to provide an external force on the optical scanning module, thereby lifting the optical scanning module upwardly and against the transparent platen.
[0025] Additionally, the drawings used for illustrating the embodiments of the invention only show the major characteristic parts in order to avoid obscuring the invention. Accordingly, the specification and the drawing are to be regard as an illustrative sense rather than a restrictive sense.
[0026] FIG. 2 schematically illustrates a side view of the optical scanning module, the carriage and the adjusting means in accordance with the preferred embodiment of the invention. The optical scanning module 22 is loaded in the carriage 24 which is mounted on a shaft (not shown) by a connecting means 16 and moved by the drive mechanism (not shown) along the scanning direction on the shaft. Also, there are two adjusting means 28 a and 28 b assembled on the both sides of the bottom surface of the carriage 24 for lifting the optical scanning module 22 up.
[0027] Although two adjusting means are illustrated in the preferred embodiment, it is not for the purpose of limiting the present invention. Noted that the object of lifting the optical scanning module can still be achieved even only one adjusting means is provided, for example, at or close to the center of the carriage.
[0028] FIG. 3 is a partial enlarged sectional view of an adjusting means shown in FIG. 2 . As appears from FIG. 3 , the carriage 24 is mounted on the shaft 32 through the connecting means 26 , and moved on the shaft 32 along the scanning direction. The adjusting means at least comprises a roller 34 and a swim 36 , which the swim 36 is able to press the roller 36 firmly after assembling. Also, the roller 34 touches the bottom surface of the scanner's housing, so that the roller 34 will simultaneously rotates with the movement of the carriage 24 . When the optical scanning module 22 (loaded in the carriage 24 ) is moving along the scanning direction (as indicated by arrow F in FIG. 2 ), the rotating roller 34 will bring the firmly attached swim 36 up by doing the clockwise rotation simultaneously. The swim 36 is going to rotate until touching the bottom surface of the optical scanning module 22 ; consequently, the upward swim 36 forces the optical scanning module 22 up to contact the transparent platen 31 .
[0029] After actual scanning operation, the carriage 24 is moved backward (opposite to the direction indicated by arrow F) to return to its original position, and the swim 36 is consequently doing the counterclockwise rotation. When the bottom surface of the optical scanning module 22 is not being touched by the swim 36 , the external force vanishes and the optical scanning module 22 returns to its original position. Moreover, a fixing pin 37 could be optically constructed to maintain the swim 36 at a resting position. In practice the fixing pin 37 could be formed on the bottom housing of the carriage 24 .
[0030] FIG. 4 schematically illustrates the adjusting means of FIG. 2 from a bottom view angle. The optical scanning module 22 is loaded in the carriage 24 . In practice an opening of the carriage 24 would be optimal formed to expose a partial of the bottom surface 22 a of the optical scanning module 22 for being touched by the swim 36 .
[0031] FIG. 5 is a cross-sectional diagrammatic side view of the adjusting means taken along the section line A-A of FIG. 3 . The roller 34 has a first surface 34 a and a second surface 34 b . The swim 36 tightly presses on the first surface 34 a of the roller 34 . The adjusting means further has a shaft 42 penetrating the roller 34 , and one end of the shaft 34 is connected to the swim 36 . In practice the shaft 42 and the swim 36 could be integrated as a whole. When the roller 34 rotates, friction between the first surface 34 a of the roller 34 and the swim 36 in contact resists the relative motion of the roller 34 and swim 36 thereby simultaneously bringing the swim 36 upward with the rotating roller 34 to lift the optical scanning module 22 .
[0032] In the embodiment, the other end of the shaft 42 is connected to a secured body 43 that tightly presses on the second surface 34 b of the roller 34 . Therefore, friction between the second surface 34 b of the roller 34 and the secured body 43 also makes the secured body 43 , the shaft 42 and the swim 36 rotate with the rotating roller 34 .
[0033] Moreover, a spring 46 could be preferably added between the roller 34 and the secured body 43 , for preventing the secured body 43 away from the roller 34 and enhancing friction between thereof. Alternatively, the spring 46 could be compressed between the roller 34 and the secured body 43 to push the secured body 43 outwardly, thereby making the swim 36 tightly press on the first surface 34 a of the roller 34 .
[0034] In this embodiment, it is very beneficial for the rotated swim 36 of the adjusting means to make the swim 36 and the secured body 43 tightly contact with the first surface 34 a and the second surface 34 b of the roller 34 , respectively. When the roller 34 is rotating, friction existing on two sides of the roller 34 simultaneously brings the swim 36 into a rotating situation until the swim 36 touches the bottom surface 22 a of the optical scanning module 22 . During a scanning operation, the rollers keeps rotating with the movement of the carriage 24 , so that the swim 36 continuously push the optical scanning module 22 upwardly and against the transparent platen 31 to acquire the optical image of the to be scanned document.
[0035] Although friction existing at two different places (i.e. between the roller 34 and the swim 36 , and between the roller 34 and the secured body 43 ) are constructed in the preferred embodiment (as illustrated in FIG. 3 , FIG. 4 and FIG. 5 ), only one contacting friction would be applicable in practice to accomplish the purpose of lifting the optical scanning module 22 . There are three tightly contacting manners illustrated below.
[0036] FIG. 6A illustrates the first contacting manner of the adjusting means according to the invention. The shaft 62 penetrates through the roller 64 in the center, and one end of the shaft 62 is connected to the swim 66 as a whole. The roller 64 has a first surface 64 a and a second surface 64 b . The swim 66 firmly presses on the first surface 64 a of the roller 64 . When the roller 64 is rotating, friction between the first surface 64 a of the roller 64 and the swim 66 makes the swim 36 rotate, thereby lifting the optical scanning module 22 up and against the transparent platen 31 . Also, it would be practically to add a securing means on the other end of the shaft 62 , for example, an E-ring, for the purpose of preventing the shaft 62 as well as the swim 66 apart from the roller 64 .
[0037] FIG. 6B illustrates the second contacting manner of the adjusting means according to the invention. The secured body 63 and the swim 66 firmly contact with the second surface 64 b and the first surface 64 a of the rollers 64 , respectively. When the roller 64 rotates, not only the friction existing on the right side of the roller 64 makes the swim 66 rotate but also the friction existing on the left side of the roller 64 brings the secured body 63 into a rotating movement. The preferred embodiment ( FIG. 3 , FIG. 4 and FIG. 5 ) is one illustration of the second contacting manners of the adjusting means. Also, there is a hole through the roller 64 for receiving the spring 46 , and two ends of the spring 46 are connected to the secured body 63 and the swim 66 . An inward elastic force of the spring 46 pulls the secured body 63 and the swim 66 toward the roller 64 so that the secured body 63 and the swim 66 are forced to firmly contact with the second surface 64 b and the first surface 64 a of the rollers 64 , respectively. Moreover, at least one of the secured body 63 and the swim 66 is able to slide on the shaft 62 , and a round hole thereof is preferably constructed for receiving a non-round shaft 62 .
[0038] FIG. 6C illustrates the third contacting manner of the adjusting means according to the invention. The secured body 63 firmly presses on the second surface 64 b of the roller 64 but the swim 66 doesn't entirely contact with the first surface 64 a of the roller 64 . The hole in the roller 64 for receiving the spring 46 is constructed close to the swim 66 . An elastic force of the spring 46 pushes the swim 66 away from the roller 64 so as to make the secured body 64 firmly attach on the second surface 64 b of the roller 64 . When the roller 64 rotates, friction between the roller 64 and the secured body 63 causes the secured body 63 to turn, and simultaneously brings the swim 66 into a rotating situation via the shaft 62 .
[0039] According to the aforementioned description, one of two objects in contact rotates simultaneously makes the other rotates, due to friction between two objects. When the roller (the first object) rotates, the swim (the second object, directly contacting with the first object) could be directly rotated, or indirectly brought into a rotating movement (via the secured body contacting with the first object). Additionally, roughing the surfaces in contact could enhance friction between the first and the second objects.
[0040] Compared to the conventional design that installs a spring between the carriage and the optical scanning module, it is easy for the adjusting means disclosed herein to assemble with the carriage and to keep the optical scanning module in balance. Also, the mechanical construction of the adjusting means according to the invention has a long useful life.
[0041] While the invention has been described by way of examples and in terms of the preferred embodiments, it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures. | A scanning apparatus having an adjusting means is provided to allow the optical scanning module against the platen. The adjusting means is assembled with the carriage that carries the optical scanning module. The adjusting means at least comprises a roller and a rotated portion, wherein the roller tightly contacts the rotated portion. When the carriage is moving (during a scanning operation), the roller is rotating and friction (between the roller and the rotating assembly) causes the rotated portion to turn until contacting with the bottom surface of the optical scanning module, thereby allowing the optical scanning module against the platen. | 7 |
[0001] This application is based upon and claims priority to Japanese Patent Application No. 2006-242779, filed on Sep. 7, 2006, the contents being incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a transmission device equipped with Generalized Multiprotocol Label Switching (GMPLS) that allows automatic generation of transmission paths within networks, based on traffic transmission path generation instructions between any two nodes from an operator in a SONET/SDH network.
[0004] 2. Description of the Related Art
[0005] At present, in order to reduce operating costs, GMPLS functions are provided in SONET/SDH transmission devices, and more and more transmission devices are equipped with extended functions, such as automatically configuring transmission paths (cross-connects) in devices, without performing manual configuration by administrators.
[0006] GMPLS in a SONET/SDH transmission device gathers adjacent information between nodes using Link Management Protocol LMP (RFC 4204), acquires network topology information using a routing protocol, such as Open Shortest First for Traffic Engineering—OSPF-TE (RFC 1850, RFC 3630), and then establishes a transmission path (cross-connect) using an arbitrary bandwidth between nodes according to a signaling protocol, such as Resource Reservation Protocol for Traffic Engineering-RSVP-TE (RFC 2205, RFC 3209, RFC 3473).
[0007] An example of an automatic setup of a transmission path will be shown. FIG. 1 shows a state in which transmission paths are generated connecting two locations by a network within a carrier network. When automatically establishing a transmission path between site α and site β of end user A in this type of network, the carrier network administrator provides instructions to generate a path for Node 1 with a bandwidth required between Node 6 .
[0008] When this is done, the route for Node 1 will be calculated from the node itself to Node 6 from network topology information collected by a routing protocol.
[0009] FIG. 2 shows a state when using this route information to exchange signaling protocol control packets (using RSVP-TE in this example) from end-to-end to establish a cross-connect. The information exchanged here consists of PATH messages sent from Node 1 , that received the transmission path generation instructions from the administrator, and RESV messages sent from Node 6 , specified as a termination node.
[0010] The PATH messages include objects such as a session that indicates which node and port there is a link between, a PHOP (Previous HOP) that indicates which adjacent node the PATH message was sent from, a Label Request that indicates the existence of a path generation request (label request), an Explicit Route that shows the end-to-end route, a Session Attribute that shows the attributes of a session such as a connected session name, a Sender Template used to designate the node where the path generation was requested, a Sender Tspec that shows the bandwidth required for the path to be generated, and a Record Route used to record the PATH message relay route.
[0011] The PATH message relay node records each piece of this information and then transitions to a relay preparation state for a RESV message arriving later. The RESV message includes objects such as a Session that indicates which node and port there is a link between, a PHOP that indicates which adjacent node the RESV message was sent from, a Style that shows the style of the allocated bandwidth, FlowSpec that shows the bandwidth allocated to the transmission path, a Label allocated in order to generate the transmission path, and a Record used to record the RESV message relay route.
[0012] If Node 6 , which received a PATH message, judges that the requested bandwidth is capable of being allocated and such operation is possible, the label for the transmission path (LSP) (for example, an object that can specify a SONET/SDH time slot) is extracted, a cross connection is established with the specified port in the requested bandwidth, and an RESV message, which includes the extracted label, is sent to adjacent Node 5 where the PATH message was sent.
[0013] Node 5 , which received the RESV message, extracts the label used for the connection with Node 4 , establishes a cross connection with the time slot specified by the label included in the RESV message, and then sends a RESV message to Node 4 . Labels are distributed to each node between Node 1 and Node 6 by means of repeating this operation until reaching Node 1 , and a transmission path is automatically generated.
[0014] When SONET/SDH performs time division multiplexing on traffic, the time slot (transmission path) that has a specified bandwidth linking two locations within the network by a point-to-point is secured, but all this bandwidth is used for the transmission of traffic between the two locations. When there is an increase in mutually communicating sites, transmission paths must be generated between each of two locations.
[0015] In contrast to this, when transmitting traffic forecast to have a statistical multiplexing effect, such as Ethernet® communication, sometimes it is preferable to share the transmission paths in order to efficiently utilize the bandwidth within the network when there is an increase in mutually communicating sites, if pre-established transmission paths exist on these routes.
[0016] In other words, this is a management technique that, for example, generates one transmission path as a backbone within the network and then shares this with multiple sites. Two types of reservation formats (styles) for sharing bandwidth are defined in RSVP-TE. If Wildcard Filtering (WF) is used from among these styles, the transmission paths can be shared (bandwidth sharing), although sharing according to WF does not distinguish the owners of the traffic being transmitted.
[0017] In other words, it is possible that different end users could share identical transmission paths. FIG. 3 shows a condition when end users who should not share are sharing paths. If a path is generated between sites γ and δ of end user B, where a transmission path already exists between sites α and β of end user A, and a WF style is indicated, the RSVP-TE will not differentiate between the end users. Because of this, the path used for end user A will form a path connection such that it is simultaneously used by end user B.
[0018] This is not a preferred situation because carriers who provide services which guaranty a certain bandwidth for each user as stated in the Service Level Agreement (SLA) contract might not be able to adhere to the SLA. In addition, if a Shared Explicit (SE) style is adopted, a Multi point-to-point connection can be specified explicitly. In other words, although it is possible to limit node groups which can share paths, this is done under the condition that the Explicit Route must be the same.
[0019] FIG. 4 shows a state in which a user transmission path desired to be shared cannot be shared. If a connection is made between sites ε and ζ of end user A, while there exists a transmission path between sites α and β of end user A and a transmission path between sites γ and δ of end user B, as the path used for end user A already exists, end user A will want to share this path. However, since the Explicit Route is different, it cannot be shared and a new path will be generated resulting in consumption of valuable network bandwidth.
SUMMARY OF THE INVENTION
[0020] According to an aspect of an embodiment, a transmission device, that automatically generates transmission paths within a transmission network, includes a storing unit that stores first information that indicates which end user a link, where a transmission path is contained, and a path bandwidth, which is used to generate the transmission path, are assigned and second information that indicates whether the path can be shared by the end users; and a sending unit that sends third information to identify the end user and the second information to an adjacent node.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 shows an example when transmission paths are generated connecting two locations within a carrier network.
[0022] FIG. 2 shows when RSVP-TE control packets are sent and received between nodes and a cross-connect is established in order to generate the transmission path of FIG. 1 .
[0023] FIG. 3 shows the transmission path for end user A being shared, which should not be shared, by end user B when using a WF connection state of RSVP-TE.
[0024] FIG. 4 shows the transmission path between sites α and β of end user A that is desired to be shared, which is not being allowed to be shared, between sites ε and ζ of the same end user A when using an SE connection state of RSVP-TE.
[0025] FIG. 5 shows an example of an embodiment of the present invention.
[0026] FIG. 6 shows an example of USER information table.
[0027] FIG. 7 shows the composition of a USER object.
[0028] FIG. 8 shows an example of a bandwidth management table.
[0029] FIGS. 9A and 9B show the process flow of a USER information processing unit.
[0030] FIGS. 10A and 10B show the process flow of a path sharing management unit.
[0031] FIG. 11 is a network diagram showing a network that describes an example of path sharing.
[0032] FIG. 12 is a USER information table showing USER information for describing an example of path sharing.
[0033] FIG. 13 is a network diagram showing a network that describes an example of path sharing (after completing shared label establishment).
[0034] FIG. 14 is a USER information table showing USER information for describing an example of path sharing (after completing shared label establishment).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] In the following, an embodiment will be described by referring to the drawings. FIG. 5 shows an embodiment. In FIG. 5 the system includes a cross-connect control unit 501 and a GMPLS control unit 500 inside the transmission device (which corresponds to a node). The cross-connect control unit 501 includes a cross-connect database (DB) 513 (nodes with available bandwidth or used bandwidth can be discovered by means of examining this DB) that functions to store cross-connect setup information, a cross-connect setup management unit 514 that searches the cross-connect DB 513 and controls a switch fabric 515 , and the switch fabric 515 . The GMPLS control unit 500 is connected to adjacent nodes by a control channel.
[0036] In addition, the GMPLS control unit 500 includes an IP transmission unit 503 that sends and receives control packets to adjacent nodes through the control channel, a link information collection processing unit 502 (LMP) that monitors and collects the state of links (such as optical fiber) used for connections between adjacent nodes, a routing protocol processing unit 504 (OSPF-TE) that builds network topology information, a signaling protocol processing unit 505 that executes signaling to establish and delete transmission paths, a USER information table 509 that functions to take links used to transmit traffic and label numbers used to generate transmission paths and give them correspondence with end users, a bandwidth management table 510 that shows how much bandwidth is allocated to each end user within each link within a node, a used bandwidth monitoring processing unit 512 that searches a bandwidth management table and notifies administrators of the usage state of the bandwidth (warns administrators that the remaining bandwidth that can be allocated is low), and a maintenance terminal interface unit 511 used by administrators for control, such as searching and updating USER information.
[0037] The signaling protocol processing unit 505 further includes an RSVP-TE processing unit 506 that executes conventional RSVP-TE processes and also executes instructions to generate shared paths to a USER information processing unit or instructions for RSVP-TE control message processing, a USER information processing unit 507 that processes USER objects (added to PATH/RESV/PATH TEARDOWN/RESV TEARDOWN messages of RSVP-TE) for the purpose of identifying end users of each transmission path, and a path sharing management unit 508 that searches shared paths based on the processing results of a USER information processing unit and also provides cross-connect setting instructions to the cross-connect control unit 501 .
[0038] FIG. 6 shows the composition of a USER information table with entries for an end user identifier 70 and shareability 71 . A USER information table has the following entries: a link identifier 60 that identifies links that contain transmission paths, an end user identifier 61 that is either set through a maintenance terminal interface or is included in the USER object added to a received RSVP-TE control packet, a label number 62 used to generate a transmission path, a bandwidth 63 allocated to a transmission path, shareability information 64 that indicates whether or not labels are sharable, and a sharing number 65 that shows how many transmission paths are sharing the applicable labels.
[0039] FIG. 7 shows the composition of a USER object. FIG. 8 shows the composition of a bandwidth management table. A bandwidth management table has the following entries: a link identifier 80 that identifies links that contain transmission paths, an end user identifier 81 that is setup by an administrator through a maintenance terminal interface, a maximum bandwidth 82 that can be allocated to an applicable end user, and a warning threshold value 83 (judgment standard) to warn that the remaining bandwidth that can be allocated is low. The used bandwidth monitoring processing unit 512 periodically monitors the entries of the bandwidth management table 510 and then judges whether or not the warning threshold value has been exceeded for each end user with a specified maximum bandwidth. If the warning threshold value is exceeded, a warning is sent to an administrator through a maintenance terminal interface.
[0040] FIGS. 9A and 9B show the process flow of a USER information processing unit.
[0041] After the start S 920 , in operation S 901 , the USER information processing unit receives, from a RSVP-TE processing unit, shared path generation instructions as part of instructions to generate a path issued by an administrator, or receives RSVP-TE control packets received from a control channel.
[0042] In operations S 902 , when RSVP-TE control packets are received, a USER information processing unit judges whether or not these packets are share confirmation messages.
[0043] In operation S 919 , if the packets are share confirmation messages, the USER information processing unit returns the messages, with a message indicating that the path can be shared, to the adjacent nodes from which the confirmation messages were sent through the control channel that received the control packets. This share confirmation message is a message used when nodes not equipped with the embodiments discussed herein are adjacent nodes. If the bandwidth reservation style is not WF, when labels included in received RESV messages are already being used for other traffic, the nodes not equipped with the present invention will not share these labels.
[0044] For the reasons described above, it is thought that almost no carrier networks use WF. As a result of avoiding this technology, errors that occur in the signaling and transmission paths are not generated. In order to avoid this type of situation, when a message used to confirm shareability is sent to adjacent nodes before an RESV message is sent to the adjacent nodes, and a response message is not returned within a fixed time (in other words, when the adjacent nodes are not equipped with the embodiments discussed herein), the nodes equipped with the embodiments discussed herein will cancel the path sharing, generate a label used to generate a new path, and then create and send an RESV message. Consequently, even if nodes not equipped with the embodiments discussed herein exist within a network, the automatic generation of paths in a conventional system is guaranteed.
[0045] In operation S 903 , it is confirmed whether or not an administrator issued instructions to generate a path when there is no share confirmation message.
[0046] In operation S 912 , when there are instructions to generate a shared path, there is information that indicates which Add/Drop port of the node that received the generation instructions should be connected to which Add/Drop port of which node within the network, information that indicates whether or not the transmission path connecting between two ports is shared, and the bandwidth required for the transmission path. The RSVP-TE processing unit searches end-to-end route information (link information between each node for linking end points) based on instructions of an administrator and then instructs an end user identifier together with a USER information processing unit to generate a USER object.
[0047] In operation S 911 , the USER information processing unit that received the instructions searches the USER information table, extracts shareability information that conforms to the received end user identifier and link identifier, generates a USER object, and then adds the user object to an RSVP-TE control packet (in this case, a PATH or PATH TEARDOWN message). Then the process ends S 921 .
[0048] In operation S 904 , when a USER information processing unit receives an RSVP-TE control packet, different processes will be executed depending on the type of message. The message classifications processed by the USER information processing unit are judged to be one of the following four types: PATH, RESV, PATH TEARDOWN, or RESV TEARDOWN.
[0049] In operation S 905 , when an RESV message is received, it is examined to determine whether or not a USER object is included and is judged for shareability.
[0050] In operation S 906 , when sharing is not possible, the path sharing management unit is instructed to generate a new path to allow sharing. When sharing is possible, an end user identifier included in the USER object will be registered in a USER information table and then a check made to verify whether a sharable label exists in the link that received the RESV message.
[0051] In operation S 916 , if an end user identifier is not registered or a sharable label does not exist, the end user identifier and RESV message receive link are passed to a path sharing management unit and a new label is generated.
[0052] In operation S 907 , it is judged whether or not a registered sharable label exists.
[0053] In operation S 908 , if a sharable label exists and the RESV message is not addressed to the node itself, a share confirmation message will be sent to the adjacent node of the destination link of the site opposite the link (in other words, the link that sent the RESV message) that received a RESV message and then wait a fixed time for a response.
[0054] In operation S 909 , it is confirmed whether or not there is a sharable response.
[0055] In operation S 917 , if there is no response, the path sharing management unit will be instructed to generate a new label, because the adjacent node is not equipped with the embodiments discussed herein.
[0056] In operation S 910 , if there is a response, the end user identifier and the shared label number of the RESV message receive link are passed to the path sharing management unit and instructions are given to use the applicable label to generate a path as a shared label.
[0057] In operation S 913 , it is confirmed whether or not a PATH message was received.
[0058] In operation S 914 , it is checked whether the final destination of the PATH message is the node itself. If it is the node address itself, a process will execute identical to when a RESV message is received. If it is not the node address itself, a PATH message, appended with a USER object as is, will be sent to the link of the site opposite the link that received a PATH message. In other words, if there is no terminal node, the USER object is transferred as is. In the same manner, when a PATH TEARDOWN message is received, it is checked whether the final destination is the node itself. If it is the node address itself, a process will execute identical to when a RESV TEARDOWN message is received. If it is not the node address itself, a PATH TEARDOWN message, appended with a USER object as is, will be sent to the link of the site opposite the link that received a PATH TEARDOWN message. In other words, if there is no terminal node, the USER object is transferred as is.
[0059] In operation S 915 , it is confirmed whether a PATH TEARDOWN message or a RESV TEARDOWN message addressed to the node itself was received when an instruction other than any of the following is received: shared path generation instruction from the RSVP-TE processing unit, RESV message, or PATH message.
[0060] In operation S 918 , when a RESV TEARDOWN message is received, the end user identifier included in the USER object is located from the USER information table and an instruction is sent to the path sharing management unit to delete the path.
[0061] FIGS. 10A and 10B shows the operation flow of the path sharing management unit. After the start S 915 , in operation S 101 , the path sharing management unit operates by receiving instructions from the USER information processing unit. First, the path sharing management unit judges whether the USER information processing unit instructions are using existing shared labels.
[0062] In operation S 102 , the USER information processing unit instructions are judged as to whether they are instructions to generate a new label.
[0063] In operation S 112 , if the instructions are instructions to use a shared label, there will be instructions to delete the path. Entries matching combinations of end user identifiers passed from the USER information processing unit and message receive links are located from the USER information table and the shared label numbers are extracted.
[0064] In operation S 113 , since the number of shares is included in the entries of the USER information table to indicate how many end users are sharing the applicable shared path, when extracting a shared label number, this number will decrement.
[0065] In operation S 114 , it is judged whether or not the decremented result is 0.
[0066] In operation S 107 , since the applicable shared labels will not be used by anyone if the number of shares is 0, the cross-connect will cancel and the entries of the USER information table will be deleted. When USER information processing unit instructions are to generate new labels or delete labels, the search results of the cross-connect DB or the search results of the USER information table are used to instruct a cross-connect control unit to establish or cancel a cross-connect.
[0067] In operation S 109 , if the instructions are instructions to generate a new label, the cross-connect DB will be examined and available bandwidth is searched for bandwidth that satisfies the required bandwidth of the instruction.
[0068] In operation S 110 , it is judged whether or not end user identifiers and RESV message receive links have been received from the USER information processing unit. If the end user identifiers and RESV message receive links have not been received, the cross-connect control unit 501 is instructed to cross connect the located available bandwidth.
[0069] In operation S 111 , if the end user identifiers and RESV message receive links have been received, the end user identifiers, bandwidth, and the label numbers corresponding to the located available bandwidth will be registered in the USER information table as shared label numbers of RESV message receive links.
[0070] In operation S 103 , if the instructions from a USER information processing unit are instructions to use existing labels, entries matching the end user identifiers received from the USER information processing unit and the shared label numbers of RESV message receive links are searched for and the bandwidth extracted.
[0071] In operation S 104 , it is judged whether or not the bandwidth extracted from the USER information table satisfies the required bandwidth passed from the USER information processing unit.
[0072] In operation S 105 , if the bandwidth is insufficient, the cross-connect control unit 501 will be instructed to delete the applicable path one time, available bandwidth (label numbers) that satisfy the required bandwidth will be searched for, the cross-connect control unit 501 is instructed to generate a new cross-connect, and the shared label numbers of the USER information table are updated. When establishing a cross-connect so as to connect an Add/Drop port, if a cross-connect already exists such that the applicable port passes through, the cross-connect control unit 501 is instructed to establish a Dual Transmit & Drop and Continue cross-connect. (In other words, a cross-connect configuration that broadcasts added traffic, drops traffic received from a network, and transmits to adjacent nodes.) Furthermore, when regenerating a cross-connect, if the device has a LCAS (Link Capacity Adjustment Scheme) function and the transmission path is configured by Virtual Concatenation, the configuration can be such that instructions are given to add Virtual Concatenation bandwidth to the LCAS control unit. In this type of configuration, the bandwidth can be changed without disturbing the traffic transmission service.
[0073] In operation S 106 , when registrations and updates to a USER information table are complete, the number of shares of the USER information table is incremented and if the bandwidth changes, it will be updated.
[0074] In operation S 108 , it is instructed for the RSVP-TE processing unit to use the shared label numbers of the search results above as label values of RSVP-TE control messages. The settings for shared labels end users can be made by means of the operations of each of the process units mentioned above. This will be described in the following. The process ends at S 116 .
[0075] FIG. 11 shows a virtual network. Each node is equipped with the embodiments discussed herein. FIG. 12 shows USER information of each node within the network of FIG. 11 . USER information tables as shown in FIG. 12 are built for each Node 2 ( 303 ), Node 3 ( 304 ), and Node 5 ( 306 ). Sites ε and ζ of end user A share and connect the transmission path already held by the same end users for sites α and β, and statistical multiplexed traffic is transmitted.
[0076] The administrator gives instructions to Node 2 , such that the Add/Drop port (temporarily 1 - 1 ) of Node 2 , where site ε of end user A is connected and the Add/Drop port (temporarily 2 - 1 ) of Node 5 , where site ζ is connected, are to connect a 1 Gbps in a shared state.
[0077] As the instructions are path generation instructions, the USER information processing unit of Node 2 that received the instructions examines whether or not end user A exists in the USER information table, creates an end user identifier and a USER object set to allow sharing, adds these to control packets (PATH messages), and transmits them to Node 3 (The route up to Node 5 is managed by a signaling protocol control unit and appends to a PATH message as ERO. In addition, the 1 Gbps required bandwidth is reported as a Sender Tspec object of a PATH message.).
[0078] As Node 3 that received the PATH message is not addressed to itself, a PATH message is sent as-is to Node 5 for the USER object. The USER information processing unit of Node 5 that received the PATH message starts the processing since it is a PATH message addressed to itself. A USER object is added to the PATH message establishing it as being sharable and the USER information table is examined to check whether or not the end user is registered. End user A is already registered in the USER information table of Node 5 and a shared label already exists for the link that received the PATH message ( 1 - 1 ). [0062] Because of this, a share confirmation message is sent to Node 3 , which is the RESV message transmission destination. As Node 3 is equipped with the embodiments discussed herein, when a USER information processing unit receives a share confirmation message, the share confirmation message will be sent to Node 5 . As a sharable message is received, the USER information processing unit of Node 5 is used as a shared label, and a path sharing management unit is instructed that 1 Gbps is required as the required bandwidth. The path sharing management unit that received the instruction is not instructed to generate a new label. Consequently, entries matching end user identifiers A and label numbers 1 - 1 passed from a USER information processing unit are located from a USER information table and 50 Mbps is extracted as the bandwidth of the applicable shared label of the link that received the PATH message.
[0079] Since the required bandwidth is not satisfied, a cross-connect is deleted once after confirming the information in the cross-connect DB and instructions are given for a cross-connect with the required bandwidth. Thereafter, the bandwidth on the East side of a USER information table is updated, the number of shares is incremented, and instructions are given to use 1 - 1 (shared label number) for Node 3 and then an RESV message is sent.
[0080] The USER information processing unit of Node 3 that received the RESV message performs the message processing. As a USER object is added to the received RESV message and set to be sharable, a check is made to determine whether or not an end user is registered in the USER information table. In addition, since end userA is already registered in the USER information table of Node 3 and a shared label already exists at the link that received the RESV message, this (the USER information processing unit) is used.
[0081] As a shared label already exists at the link to be sent, a share confirmation message will be sent to Node 2 (the RESV message send destination). As Node 2 is equipped with the present invention, when the USER information processing unit receives a share confirmation message, the sharable message will be sent to Node 3 . Since a sharable message is received, the USER information processing unit of Node 3 uses 1 - 1 as a shared label and the path sharing management unit is instructed that 1 Gbps is necessary as the required bandwidth. As the path sharing management unit that received the instructions is not instructed to generate a new label, entries matching end user identifiers A and path numbers 1 - 1 passed from a USER information processing unit are located from a USER information table and 50 Mbps is extracted as the bandwidth of the applicable shared path of the site that received the RESV message.
[0082] Since the required bandwidth is not satisfied, a cross-connect is deleted once, and a cross-connect with the required bandwidth is newly generated. Thereafter, the USER information table is updated, the number of shares is incremented, and instructions are given to use 1 - 1 (shared label number) for Node 2 , and then an RESV message is sent. The USER information processing unit of Node 2 that received the RESV message processes the message. As a USER object is added to the received RESV message and the message is set to be sharable, a check is made to determine whether or not an end user is registered in the USER information table.
[0083] In addition, since end user A is already registered in the USER information table of Node 2 and a shared path already exists at the link that received the RESV message, this (the USER information processing unit) is used. The USER information processing unit of Node 2 uses 1 - 1 as a shared label and the path sharing management unit is instructed that 1 Gbps is necessary as the required bandwidth. As the path sharing management unit that received the instructions is not instructed to generate a new label, entries matching end user identifiers A and path numbers 1 - 1 passed from a USER information processing unit are located from a USER information table and 50 Mbps is extracted as the bandwidth of the applicable shared path of the link that received the RESV message.
[0084] Since the required bandwidth is not satisfied, a cross-connect is deleted once and a cross-connect with the required bandwidth newly generated. Thereafter, the USER information table is updated and the number of shares is incremented.
[0085] FIG. 13 shows path connections within a network. This figure shows the path of end user A shared within the network. FIG. 14 shows a USER information table when sharing paths. It is understood that the path of end user A is a shared path within the network and USER A of end user identifier 142 becomes 2 at number of shares 146 .
[0086] When a network is configured using a transmission device equipped with the path sharing management system of the present invention, if there is network traffic that can be statistically multiplexed, transmission paths within networks can share multiple data flows, allowing more efficient utilization of network bandwidth, compared to a conventional network, without losing the advantage of lower operating costs gained by automatically generating paths using GMPLS.
[0087] Although a few preferred embodiments have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. | According to an aspect of an embodiment, a transmission device, that automatically generates transmission paths within a transmission network, includes a storing unit that stores first information that indicates an end user to which a link, where a transmission path is contained, and a path bandwidth, which is used to generate the transmission path, are assigned and second information that indicates whether the path can be shared each of the end users; and a sending unit sending third information to identify the end user and the second information to a adjacent node. | 7 |
The current application claims a priority to U.S. 61/548,894 filed on Oct. 19, 2011.
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to an optical imaging system using incoherent structured illumination, and more particularly, to a sub-diffraction scattered light imaging system using incoherent structured illumination.
2. Background
Fluorescent microscopy (FM) is known for its high sensitivity, high molecular discrimination, and simultaneous multicolor imaging capability, and is therefore a crucial tool for studying the fine structures of cells and organisms through fluorescent labeling. However, FM has two major weaknesses: the photo-bleaching of fluorescent dye and the insufficient spatial resolution of fluorescent images due to diffraction limit. Conventional wide-field FM provides a lateral resolution of from 220 to 300 nm and an axial resolution of from 800 to 1000 nm. Confocal laser scanning fluorescent microscopy increases the axial resolution from 400 to 500 nm and provides three dimensional (3D) sectioning images, but the increase of the lateral resolution is limited. In recent years, structured illumination microscopy (SIM) utilizes a structured light pattern to illuminate samples in order to break the diffraction limit to achieve a doubled resolution in fluorescence images.
As one application, three-dimensional structured illumination fluorescence microscopy (3D-SIFM) utilizes three diffracted laser beams to generate a 3D interference pattern for sample illumination, and accordingly transfers the high spatial frequency image data to be covered by the scope of the optical transfer function (OTF) of a wide-field microscope. The high frequency image data under irradiation at various pattern orientations are collected and processed by the image reconstruction algorithm to retrieve a high-resolution fluorescence image according to Gustafsson et al. 3D-SIFM is now able to provide twice as much resolution in both lateral and axial directions with true optical sectioning as compared to the conventional wide-field fluorescence microscopy.
SIM-based techniques are widely applied to the measurement of fluorescent light, but not frequently used in the measurement of scattered light from samples. Scattered light imaging can image transparent and label-free specimens of strong scattering in their native environment. The increasing importance of noble metal nanoparticles in biological and biomedical applications further makes scattered light imaging an attractive modality to investigate the behavior and interactions at the sub-cell level. Apart from having excellent biocompatibility and stability, noble metal nanoparticles feature a strong ability to scatter light and resistance to photobleaching.
The adoption of 3D-SIM to scattered light imaging is complicated. In 3D-SIFM, a coherent or partially coherent light source is used to generate a 3D interference pattern with high modulation contrast. Because the fluorescent light emitted from a sample is incoherent, studied equations and procedures for incoherent imaging can be followed to retrieve a high resolution image. In contrast, light scattered from a sample is a coherent process. With a coherent light source, the known mathematical modality for fluorescence image reconstruction is unsuitable. New coherent image retrieving procedures are required but the complexity in mathematical derivation prohibits advancement in the technology. Additionally, scattered light imaging suffers from the interference of reflected light generated at interfaces of different materials due to no emission filter to block the incident light. Although a dark-field scheme adds a mask to block the reflected light, this design unavoidably reduces the intensity of the scattered light and degrades the image resolution.
FIG. 1 shows a conventional optical system for 3D structured illumination 10 . A coherent light beam is outputted by a coherent light source 11 and is received by a spatial light modulator (SLM) 12 positioned on the optical path created by the coherent light source 11 . The SLM 12 then diffracts the single inputting light beam into a plurality of higher order beams, for example, 0, +1, and −1 order diffracted beams, as shown in FIG. 1 . In order to converge the parallel diffracted beams, the convex lens L 1 is positioned at a distance f 1 from the SLM 12 , wherein f 1 is the focal length of the convex lens L 1 .
The parallel beams passing through lens L 1 are converged and then diverged to enter convex lens L 2 . Lens L 2 is positioned at a distance f 2 from the convergent points and produces parallel beams which intersect each other, wherein the distance f 2 is the focal length of the lens L 2 . The structured pattern is formed at a conjugate image plane 16 , or a Fourier plane, at the distance f 2 away from the lens L 2 . A convex lens L 3 is positioned at a distance f 3 away from the conjugate image plane 16 , receiving the parallel beams and producing three converging beams toward objective lens L obj . The depiction of the objective lens L obj in FIG. 1 is rather a high-level presentation, practically a set of lenses are arranged in the objective 17 . The distance between the objective lens L obj and the lens L 3 is the sum of f 3 and f obj , wherein f 3 is the focal length of the lens L 3 , and f obj is the focal length of the objective lens L obj , respectively. In particular, f 3 is the distance between the lens L 3 and the back focal plane 16 ′ of the objective lens L obj ; whereas f obj is the distance between the objective lens L obj and its back focal plane 16 ′. In the case where a set of lenses are arranged in the objective 17 , the f obj is the effective focal length of the set of lenses. Three parallel beams passing through the objective lens L obj then intersect each other at another image plane where a stage 15 accommodating a sample is positioned. The intersection of three parallel coherent beams produces a 3D structured pattern at the stage 15 where a sample having virtual thickness can be imaged in a sectioning fashion to reconstruct its 3D image.
FIG. 2 shows an optical imaging system 20 for 3D structured illumination. The combination of the coherent light source 21 , the SLM 22 , the stage 25 , the objective 27 , and a set of optical lenses (L 1 ′, L 2 ′, L 3 ′, L 4 ′, L 5 ′, L obj ′) is substantially identical to the optical system shown in FIG. 1 with only a minor variation of the lens arrangement for the sake of experimental convenience. An adjustable mask 23 is positioned on or off the optical path to selectively filter the diffracted beams. The use of the mask 23 also adds versatility to the structured illumination optical system, for the system to operate in a wide-field (preserve only the 0 order diffracted beam) or a 2D structured pattern illumination (preserve only the +1 and −1 order diffracted beam) mode. The mask 23 depicted in FIG. 2 is positioned off the optical path, therefore no diffracted beam is blocked. A charge-coupled device (CCD) camera 24 is placed at a position suitable for receiving fluorescent light emitting from the sample, and a real space image can be reconstructed based on the signal received by the CCD camera 24 .
The present invention is the first to combine 3D-SIM and scattered light imaging, successfully generating 3D incoherent structured illumination to avoid speckle scattering and complicated coherent image retrieval. A reflective light scattering microscope with 3D structured illumination (SI-RLSM) is disclosed in the present invention, and a lateral/axial resolution of 120 nm/430 nm is demonstrated based on the high-resolution SI-RLS image of 100 nm noble metal nanoparticles. The present invention can be applied to detect noble metal nanoparticles or strong scatters in biological specimens to provide high resolution and high contrast 3D scattered light images.
SUMMARY
One aspect of the present invention discloses an optical system generating incoherent structured illumination, comprising: a coherent light source outputting coherent light which forms an optical path; a spatial light modulator positioned on the optical path and receiving the coherent light, wherein the patterns of the spatial light modulator are designed to generate a plurality of diffracted coherent light beams at a selected phase and orientation; a plurality of optical lenses positioned on the optical path and forming at least one image plane where the plurality of diffracted coherent light beams intersect to form a structured pattern; a rotating or vibrating diffuser positioned on one of the conjugate image planes, configured to destroy the coherence of the diffracted coherent light beams; an objective receiving the plurality of diffracted light beams with destroyed coherence; and a stage in proximity to the objective, accommodating a sample and positioned near the front focal plane of the objective.
Another aspect of the present invention discloses an optical imaging system using incoherent structured illumination, comprising an optical microscope which includes an objective having a first side in proximity to a sample and a second side far from the sample; a stage placed at the first side of the objective, configured to be moved in a direction toward or away from the objective and to accommodate the sample at the surface of the stage close to the objective; a 50/50 beam splitter placed on the optical path to reflect the incident light beams on the second side of the objective and to transmit scattered light from the sample to an imaging recoding device; a coherent light source emitting coherent light which forms an optical path passing through the objective; a spatial light modulator positioned on the optical path and configured to generate a structured pattern of the coherent light at the focal plane of the objective; a plurality of optical lenses and mirrors disposed on the optical path, wherein at least one conjugate image plane of the structured pattern is formed on the optical path; and a rotating diffuser configured to destroy the coherence of the coherent light, disposed on the at least one conjugate image plane.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter, and form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures or processes for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The objectives and advantages of the present invention are illustrated with the following description and upon reference to the accompanying drawings in which:
FIG. 1 illustrates an optical system for structured illumination;
FIG. 2 illustrates an optical imaging system for structured illumination;
FIG. 3 depicts an optical system to effectively destroy light coherence according to one embodiment of the present invention;
FIG. 4 depicts an optical imaging system to effectively destroy light coherence according to one embodiment of the present invention;
FIG. 5 depicts an optical imaging system to effectively destroy light coherence according to one embodiment of the present invention;
FIG. 6 shows one design category (0°, five phases) of the spatial light modulator patterns and their corresponding illumination patterns at a selected z height according to one embodiment of the present invention;
FIG. 7 shows another design category (45°, five phases) of the spatial light modulator patterns and their corresponding illumination patterns at a selected z height according to another embodiment of the present invention;
FIG. 8 shows projections of wide-field images of 100 nm gold nanoparticles by the illumination of 0 order diffraction when positioning a rotating diffuser at a) S 1 , b) S 2 , and c) halogen light illumination with no diffuser, wherein the upper image is a lateral (xy) projection while the lower image is an axial (xz) projection;
FIG. 9 shows a theoretical simulation of a 0° 3D structured illumination pattern on an xz plane and the corresponding three perspective planes according to different z heights;
FIG. 10 shows the axial extents of the 3D-structured patterns when positioning a rotating diffuser at a) S 1 , and b) S 2 ;
FIG. 11 shows projections of (a) wide-field (WF) and (b) SI-RLS images of 100 nm gold nanoparticles, wherein the upper image is a lateral (xy) projection while the lower image is an axial (xz) projection; (c) lateral and axial profiles of a single gold nanoparticle with a Gaussian fit; and
FIG. 12 shows a (a) 2D differential interference contrast image of an internalized HeLa cell; 3D view of a (b) wide-field; and a (c) SI-RLS image of 100 nm gold nanoparticles within the box of (a).
DETAILED DESCRIPTION
The structured illumination reflective light scattering microscope (SI-RLSM) disclosed in the present invention utilizes an SLM to quickly and accurately change the orientation, contrast, and phase of the structured pattern, and with the placement of a rotating diffuser exactly at the Fourier plane to effectively destroy the coherence of the structured pattern at another downstream Fourier plane where a sample resides. The present disclosure makes use of the mathematical algorithm for incoherent image reconstruction proposed by M. G. L. Gustafsson et al. to reconstruct SI-RLS images. The rotating diffuser disposed at the Fourier plane averages out the phase distribution and transforms the image reconstruction algorithm from the complex coherent processes to the simple incoherent processes. The appropriate application of a simulated 3D optical transfer function (OTF) of the SI-RLSM in the present invention further improves resolution.
FIG. 3 shows an optical system 30 that effectively destroys light coherence according to one embodiment of the present invention. The optical elements such as a coherent light source 31 , an SLM 32 , a stage 35 holding samples, an objective 37 , and a set of optical lenses (L 1 ″, L 2 ″, L 3 ″, L obj ″) are arranged in the same fashion as that in the conventional optical system 10 shown in FIG. 1 . The system shown in FIG. 3 is characterized by the placement of a rotating holographic diffuser 33 at the conjugate image plane 36 , or the Fourier plane, of the system. Since the desired effect of the present invention is to create a 3D structured illumination pattern at the downstream image plane where the sample-carrying stage 35 resides, and at the same time reduce the coherence of the structured light illuminating on the sample, a rotating holographic diffuser 33 placed at the position depicted can simultaneously satisfy the two seemingly contradictory goals. The optical system 30 of FIG. 3 , wherein the set of optical lenses are arranged in specific positions such that the +1 and −1 order diffracted beams from the spatial light modulator are close to the edge of the objective lens L obj ″ and the diffracted beams are focused on the back focal plane 36 ′ of the objective lens L obj ″.
FIG. 3 shows another embodiment of the present invention including an optical system similar to that described above but with an additional mask 34 to generate a wide-field or a 2D structured illumination pattern. The mask can be adjusted to block the +1 and −1 order diffracted beams, such that a wide-field image would be presented at the image plane; the mask can also be adjusted to block the 0 order diffracted beams, such that the structured pattern formed at the image plane where the sample resides can be a 2D pattern, that is, only on the plane parallel to the surface of the stage 35 .
FIG. 4 depicts an optical imaging system 40 according to one embodiment of the present invention. The system 40 is tailored for SI-RLS imaging and is equipped with optical elements described below. A coherent light source, for example, a He—Ne laser 41 operating at 543 nm, emits coherent light which forms an optical path. The coherent light is expanded by passing through a 10× beam expander 42 and diffracted with a phase-only SLM 44 into laser beams of 0, +1, and −1 orders. The laser beams are then focused with five lenses ( 45 a , 45 b , 45 c , 45 d , 45 e ) in a set, passing through a 50/50 beam splitter 411 , on to the back focal plane 48 of an objective 47 , wherein the lens 45 e can be positioned inside the optical microscope 414 .
In the optical imaging system 40 of FIG. 4 , the set of optical lenses are arranged in specific positions such that the +1 and −1 order diffracted beams from the spatial light modulator are close to the edge of the objective 47 and the diffracted beams are focused on the back focal plane 48 of the objective 47 . The light scattered from the sample positioned on the stage 43 is collected by the objective 47 and then passes through a 50/50 beam splitter 411 , a tube lens 412 and a 2× relay lens 413 , and is detected with an electron-multiplying CCD camera 49 . In one embodiment of the present invention, an upright optical microscope 414 comprises the lens 45 e , the beam splitter 411 , the tube lens 412 , the 2× relay lens 413 , the objective 47 , the stage 43 , and the CCD 49 . The stage 43 is controlled by a piezoelectric transducer (PZT) for stepping the sample toward or away from the objective 47 , in order to obtain the sectioning images along the z direction.
In FIG. 4 , three positions on the optical path are marked with S 1 , S 2 , and S 3 . The rotating holographic diffuser 46 in the present embodiment is positioned at S 2 instead of S 1 for the following reason. If the diffuser 46 is disposed at S 1 , the light coherence is partially destroyed immediately upon exiting the coherent He—Ne laser 41 . Because the partially coherent light retains some degree of coherence, three diffracted light beams of partial coherence can intersect to generate a structured illumination pattern at the focal plane where samples reside. On the other hand, each point in one of the three incoherent diffracted beams, along with the corresponding point in the other two incoherent diffracted beams, are considered coherent, therefore coherent point triplets are formed. A structured illumination pattern can also be formed from an incoherent superposition of the coherent point triplets. To sum up, the structured pattern generated with the diffuser positioning at S 1 is a superposition of the incoherent and coherent portion of the three diffracted light beams.
If the diffuser is positioned at S 2 shown in FIG. 4 , the light coherence is destroyed effectively to lead to a nearly complete incoherent illumination. S 2 is at the conjugate image plane where three diffracted beams intersect to form a structured illumination pattern. Therefore, not only the coherence of the structured pattern is greatly reduced, but also the incoherent structured illumination pattern can be imaged at the image plane where samples reside.
If the diffuser is positioned at S 3 of FIG. 4 , a similar structured illumination pattern can be observed as if the diffuser is positioned at S 2 . In another embodiment of the present invention, more than one diffuser is instrumented in the optical system. For instance, in an optical system with two diffusers, one diffuser is positioned at S 2 and the other diffuser at S 3 , a similar structured illumination pattern could still be formed, but with a much weaker intensity.
FIG. 5 depicts an optical imaging system 50 according to one embodiment of the present invention. Compare to the optical system 40 , the optical imaging system 50 further comprising a quarter wave plate 55 ′, positioned between the lenses 55 a and 55 b . The quarter wave plate 55 ′ is configured to produce circularly polarized light in order to generate the illumination patterns at different orientations with nearly the same contrast.
In one embodiment of the present invention, a rotating holographic diffuser is used. In another embodiment of the present invention, a rotating plate having a roughened surface or an optical coating at the surface is used. In another embodiment of the present invention, a rotating ground glass is used as a diffuser. In another embodiment of the present invention, a vibrating plate having a roughened surface or an optical coating at the surface is used. All the diffusers or processed plates listed above have common characteristics in that they are transparent to the impinging light and they rapidly rotate or vibrate around the axis of the optical path. Because a diffuser imposes a random phase change on the incident light, the rotation or vibration movement is maintained, preferably under a constant rate, in order to average out the phase contribution in the mathematical expression for imaging.
In one embodiment of the present invention, the amplitude of scattered signals on the CCD plane U i (x,y,t) can be described as
U i ( x,y,t )= U g ( x,y,t ) h ( x,y )=[√{square root over ( S ( x,y ))}· E ( x,y )· e iφ(t) ] h ( x,y ),
in which the distribution of scattered signals on the sample plane is represented by U g (x,y,t), the coherent point spread function (PSF) is represented by h(x,y), the reflective intensity in the image of noble metal nanoparticles is represented by S(x,y), the amplitude of the illuminating light is represented by E(x,y), and phase distribution induced by a rotating diffuser is represented by φ(t). As the diffuser rotates rapidly during the exposure for imaging, the time average of φ(t) is zero. The detected signal I i (x,y) is thus the temporal average of the intensity of the scattered signals,
I i ( x,y )= | U i ( x,y,t )| 2 =[S ( x,y )| E ( x,y )| 2 ] |h ( x,y )| 2 .
This equation corresponds to an incoherent image, consistent with the experimental observation in the present embodiment.
Refer to FIG. 4 , the SLM used in the present embodiment comprises a patterned object 44 a , such as a patterned plate, an optical grating, or a liquid crystal SLM, wherein the liquid crystal SLM (LC-SLM) can rapidly change the orientation, phase, and contrast of the structured illumination pattern. The LC-SLM serves as a two-level phase grating. As shown in FIG. 6 , the white pixels represent a phase modulation of the liquid crystal at an input gray level whereas the black pixels represent no phase modulation. The upper 5 boxes demonstrate pixels generated by LC-SLM of 0° orientation with 5 different phases φ 1 to φ 5 , and the lower boxes show the corresponding illumination patterns observed at the xy focal plane of the objective at a selected z height. The pixels show a period of length 7 and the lateral period of the corresponding illumination patterns is 274 nm. On shifting one pixel (one square) for each SLM pattern, the corresponding illumination patterns shift laterally 4π/7 in phase.
Similarly, as shown in FIG. 7 , the upper boxes demonstrate pixels generated by LC-SLM of 45° orientation with 5 different phases φ 1 to φ 5 , and the lower boxes show the corresponding illumination patterns of the xy focal plane of the objective. The pixels show a period of length 5√{square root over (2)}, in diagonal and the lateral period of the corresponding 45° illumination patterns is 277 nm. On shifting one pixel (one square) for each SLM pattern, the corresponding illumination patterns shift laterally 4π/5 in phase.
The periods of lengths 7 and 5√{square root over (2)} on SLM is designed to have a small difference, ˜1%, so that the corresponding illumination patterns have nearly equivalent lateral periods, consequently yielding nearly equal resolution enhancement in the lateral direction. The design in periods can be different, but a large difference would result in the resolution enhancement unequally in various orientations. Moreover, the numbers of white and black pixels or the gray levels of white pixels control the intensity ratios of the zero and first order light. On substituting one black column with one white column in each SLM pattern and by setting 0.875 π phase retardation in the white pixels, the light of zero and first order generating structured illumination in all orientations with nearly the same contrast is obtained.
The optical lenses are positioned on the optical path to adjust the lateral periodicity of the structured illumination patterns. Before the diffuser is placed at S 2 , the distance between the plurality of optical lenses in one embodiment of the present invention is determined by the following criteria: 1) the impinging position of the diffracted beam of +1 and −1 order has to be close to the peripheral of the objective, so that the lateral periodicity of the structured pattern can approach the diffraction limit; and
2) the three diffracted beams should be converged and focused at the back focal plane of the objective such that the structured pattern formed at the conjugate image plane can be observed at the image plane where the sample resides.
In one embodiment of the present invention, a diffracted beam of 0 order is illuminated on the sample which has 100 nm gold nanoparticles immersed in water on a coverslip to form a wide-field scattered light image. FIG. 8 compares the projected wide-field images between the placement of a rotating holographic diffuser at (a) S 1 , (b) S 2 of FIG. 5 under a coherent laser light source; and (c) no diffuser but under an incoherent halogen light source. The upper images are the lateral projection of plane xy, while the lower images are the axial projection of plane xz. Every axial projection contains a stack of thirty-one images taken by stepping the sample at a step of 100 nm in the z direction. The image in (a) suffers from an axially periodic background that results mainly from the multiple reflections on various interfaces; accordingly, the illumination retains some degree of coherence under (a). In contrast, the background in (b) is negligible, and the image is comparable to that as shown in (c). The effective deterioration of coherence by placing a rotating diffuser at S 2 leads to a quasi-incoherent image.
FIG. 9 shows a theoretical simulation of a 0° 3D structured illumination pattern on an xz plane (left image) and three perspective planes with respect to different z heights (right images). The 3D structured pattern is formed with three s-polarized coherent light sources so that the contrast of the modulation is maximized. The use of circularly polarized lights reduces the contrast of the modulation but maintains the same periodicity. FIG. 9 demonstrates that the periodicity is not only in the lateral direction but also in the z direction such that the image stack accumulated by sectioning can be carried out in the present embodiment. The PZT stage accommodating the sample accurately steps the position along the z direction through the thickness of the 3D structured pattern, and the signal reflected is then received by CCD for image reconstruction.
FIG. 10 shows the axial extents (xz plane) of the 3D-structured patterns when positioning a rotating diffuser at (a) S 1 and (b) S 2 of FIG. 5 , respectively. In the present embodiment, the images in a stack are taken at z step of 100 nm by placing a silicon wafer on the sample stage, and the structured pattern is formed by the intersection of the diffraction beams of 0, +1, and −1 orders. Without any diffuser on the optical path, the 3D structured pattern has an infinite axial extent as shown in FIG. 9 as the three coherent diffraction beams intersect around the sample focal plane. In contrast, the placement of a rotating diffuser reduces the axial extents in FIG. 10 . In FIG. 10( a ) , the structured pattern has a finite axial extent due to a superposition of the incoherence and coherence of the three diffraction beams around the sample focal plane. In FIG. 10( b ) , the 3D structured pattern imaged at the sample plane reveals an axial extent comparable to the observable region of the microscope in the z direction. Clearly, placing a diffuser at S 2 most effectively destroys the coherence of the coherent laser light and therefore allows the reconstruction of a SI-RLS image using incoherent image processes.
FIG. 11 shows the projections of (a) wide-field and (b) SI-RLS images of 100 nm gold nanoparticles immersed in water on a coverslip, and (c) the lateral and axial profiles of individual gold nanoparticles. The SI-RLS image reveals an improved image contrast and superior resolution in both lateral and axial directions. The average full width at half maximum (FWHM) are 262±6 and 867±19 nm in the lateral and axial directions of the wide-field image. The corresponding FWHM in the SI-RLS image are 117±10 and 428±18 nm, respectively. The resolution is improved by factors of ˜2.2 laterally and ˜2.0 axially. This improvement is comparable to that in 3D-SIM fluorescence imaging.
FIG. 12 shows the differential interference contrast image of a HeLa cell. A plurality of 100 nm gold nanoparticles is internalized by the HeLa cell in advance. Within the box shown in FIG. 12( a ) , a 3D view of the wide field image illuminated with a halogen light source and the SI-RLS image are shown in FIG. 12( b ) and FIG. 12( c ) for comparison. The SI-RLS image achieves a decreased background and improves the resolution to enable the differentiation of adjacent nanoparticles. FIG. 12 demonstrates the biological applications of the SI-RLS system disclosed in the present invention.
Although the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims. For example, many of the processes discussed above can be implemented in different methodologies and replaced by other processes, or a combination thereof.
Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, and composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present disclosure. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. | The present invention discloses an optical system to generate incoherent structured illumination and an optical imaging system using incoherent structured illumination. The optical system includes: at least one coherent light source, a spatial light modulator, a plurality of optical lenses, a rotating diffuser for destroying the coherence of the structured illumination pattern, an objective, and a stage accommodating samples. The optical imaging system using incoherent structured illumination includes: an optical microscope having an objective and a beam splitter, a charge-coupled device camera for recording a sequence of images of the samples, a stage for accommodating and moving samples; a coherent light source; a spatial light modulator; a quarter wave plate, a plurality of optical lenses and mirrors; and a diffuser rotating 360 degrees or vibrating rapidly around the axis of the optical path continuously. | 6 |
FIELD OF THE INVENTION
The present invention is in the field of retaining walls and blocks used to construct retaining walls where a soil reinforcement matrix or geogrid is used to reinforce the wall structure to withstand earth pressures.
BACKGROUND OF THE INVENTION
Numerous methods and materials exist for the construction of retaining walls. Such methods include the use of natural stone, poured in place concrete, masonry, and landscape timbers or railroad ties. In recent years, segmental concrete retaining wall units which are dry stacked (i.e., built without the use of mortar) have become a widely accepted product for the construction of retaining walls. Examples of such units are described in U.S. Pat. No. RE 34,314 (Forsberg) and in U.S. Pat. No. 5,294,216 (Sievert).
Segmental concrete retaining wall units have gained popularity because they can be mass produced, and thus, are relatively inexpensive. In addition, they are structurally sound, easy and relatively inexpensive to install, and combine the durability of concrete with the attractiveness of various architectural finishes.
The retaining wall system described in U.S. Pat. No. RE 34,314 includes a block design that incorporates, among other elements, a system of pins that interlocks and aligns the retaining wall units, allowing structural strength and relatively quick installation. The system may be adapted for the construction of large walls by employing geogrids which can be hooked over the pins. Such a system is described in U.S. Pat. No. 4,914,876 (Forsberg).
Numerous block designs have used a shear connector embodied in the block's shape to align the blocks with a setback, or batter. A common form of such shear connectors is a rear, downwardly projecting lip or flange. In forming a multi-course wall, the blocks are placed such that the flanges contact the upper back edge of the blocks located in the course below. As such, blocks having flanges are caused to become aligned with the blocks positioned below, while at the same time providing a degree of resistance against displacement of individual blocks by earth pressures. In walls formed using blocks of this type, the rear flanges of the blocks cause the wall to slope backward at an angle which is predetermined by the width of the flanges.
Retaining walls using blocks having a rear flange are well known in the art. For example, U.S. Pat. No. 2,323,363 (Schmitt) describes an early use of a retaining wall block with a rear flange. More recently, U.S. Pat. No. 5,294,216 (Sievert) describes a geogrid reinforced retaining wall constructed with retaining wall blocks having rear flanges. Such blocks function adequately for small walls where soil reinforcement is not necessary because they are relatively simple to install and require no special pieces for capping the top course of the wall.
Modular retaining walls are designed to function either as gravity walls or reinforced earth structures. A gravity wall relies only on the mass of the retaining wall units to resist the earth pressures that act on the wall to cause it to bulge, slide out, or overturn. Modular retaining wall blocks are suitable for construction of gravity walls up to certain heights, typically in the range of about three to six feet, depending on the particular block design employed.
For taller walls or walls subjected to additional loads due to other factors, reinforced soil methods are available to construct the wall. Such methods include the use of (1) geogrids (synthetic mats or matrices that are connected to the retaining wall units and laid out horizontally into the backfill area as the wall is built), (2) synthetic fabrics that are used in a similar fashion to geogrids, and (3) steel matrices, strips, or mats. Using soil reinforcement techniques, walls having heights in excess 50 feet can be built.
The use of soil reinforcing matrices or geogrids with modular retaining wall products is well known in the art. Previously referenced U.S. Pat. No. 4,914,876 (Forsberg) describes a wall construction having a geogrid connected to the blocks forming the wall in which apertures in the geogrid are hooked over pins extending from the blocks. The pins also serve to connect and vertically align adjacent blocks. Thus, in such a system, the geogrid is mechanically connected to the wall face. Although blocks having rear flanges may be used to build soil-reinforced walls, such systems suffer from several disadvantages. Previously referenced U.S. Pat. No. 5,294,216 (Sievert) describes a wall structure in which a geogrid is used with a rear flanged retaining wall block. In this system, the geogrid layer is passed below the flange. As a result, the geogrid is distorted out of a single plane as it passes under the flange, between the flange and the back face of the block in the course below, and then between the layers of block.
The use of a pin connection to the geogrid creates a stronger structure than does the rear flange-friction connection described above. First, for the geogrid to function properly, it must positioned between two courses of blocks and then placed under tension. The geogrid is tensioned by pulling it rearwardly and staking it down. Backfill is then placed over the geogrid. Because the geogrid connection described in the Sievert patent relies solely on friction and the weight of the block on the upper course, putting the geogrids into sufficient tension is difficult to accomplish because the geogrids tend to slip through the frictional connection. Second, the connection strength of the geogrid to the wall face is, in part, a function of the extent to which the geogrid extends between the block layers. If the geogrid is not placed sufficiently close to the front face of the wall, the frictional connection is severely compromised. This problem is compounded by the tendency of the geogrids to slip back during tensioning. Third, when placed under load, the geogrids abrade against the rough texture of the concrete flange, compromising the strength of the geogrid. Finally, when placed under load through earth pressures after construction or through tensioning during construction, the geogrids place an upward pressure on the blocks where they press against the flange. This results in a tendency to rotate the back of the block upward, thereby placing the wall out of batter and compromising the wall structure.
A basic deficiency of the rear flanged retaining wall blocks of the prior art is that they do not provide the structural soundness of a pin or other mechanical connection to the geogrid used in reinforced walls. Thus, a need exists for a system employing flanged retaining wall units that can combine the advantages of a rear-flanged unit, (i.e. simplicity and ease of construction for smaller walls), with the structural advantages of a pinned retaining wall unit in situations requiring the use of a geogrid. This need is significant because many retaining walls are constructed in height ranges that require the use of geogrid layers.
Additionally, many walls may be constructed to have a variable height along their length, and as such, geogrid reinforcement may be required only along certain portions of the wall, rather than along its entire length. Thus, it would be highly desirable to have a retaining wall that can be built using a rear flanged block in some wall sections and a pin connection between courses only in portions of the wall requiring geogrid. Such a unit would also be desirable from a production and distribution view point, because the same block design could be used in multiple wall applications, thus reducing the need to produce specialty units, as well as the need to maintain separate inventories of pinned and rear flanged products.
In view of the above, a need exists for a retaining wall block that may be constructed using a rear flange connection for walls not requiring geogrid reinforcement, but which can also be constructed using pins, instead of the flange, to provide an effective connection to geogrids for walls or wall sections where soil reinforcement is required for structural soundness.
SUMMARY OF THE INVENTION
The present invention provides an improved wall block that has a removable flange positioned at the rear of the block and pin apertures incorporated into the block to accommodate a pinned connection to a geogrid or fabric. Walls formed from such blocks can be constructed using the flange for alignment and interlocking where the use of a geogrid is not required. In wall sections in which the use of geogrid layers is desired, however, the flange can be removed, and the blocks can be aligned by pins that are placed in the pin apertures. The pin apertures typically, although not necessarily, have a generally circular cross section, and are positioned to be tangential to the front surface of the flange. Such positioning allows the pins to align the blocks with the same setback as would be produced by the flange. The use of pins in connection with a removable flange also allows a mechanical connection of the blocks to geogrids without the disadvantages of the rear flange friction connection described above.
More particularly, the present invention relates to a retaining wall block having a front surface spaced apart from a rear surface, an upper surface spaced apart from a substantially parallel lower surface to define a block thickness, first and second side wall surfaces adjoining the upper and lower surfaces, and a removable flange positioned adjacent to the rear surface and extending downward from the lower surface. The flange has a rear surface that is coplanar with the rear surface of the block, a bottom flange surface, and a front flange surface which typically, although not necessarily, defines a plane that is substantially parallel to the rear surfaces of the flange and the block. Alternatively, the front flange surface may be configured at an angle other than perpendicular relative to the lower surface of the block. The block is further provided with a plurality of pin apertures that are aligned along the bottom surface of the block. The apertures are oriented such that each is located in the flange tangential to the front surface of the flange. The apertures extend past the height of the flange into the body of the block. The size of the apertures is such that when pins are placed into the apertures, a secure friction fit is established to thereby prevent the pins from falling out of the block. The invention also relates to retaining walls constructed of the blocks described above.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of one preferred embodiment of the retaining wall block in accordance with the invention.
FIG. 2 is a top plan view of the retaining wall block shown in FIG. 1.
FIG. 3 is a side elevational view of the retaining wall block shown in FIG. 1.
FIG. 4 is a bottom view of the retaining wall block shown in FIG. 1.
FIG. 5 is a section view drawn along line 5--5 from FIG. 4.
FIG. 6 is a side elevational view of the retaining wall block of FIG. 1 showing removal of the removable flange and a connection pin.
FIG. 7 is a side elevational view of the block of FIG. 6 showing the pin placed in a pin aperture.
FIG. 8 is a rear elevation of the block of FIG. 6 with pins positioned in each of the pin apertures.
FIG. 9 is a partially cut away perspective view of a wall constructed with the blocks of FIG. 1 using flanges for alignment.
FIG. 10 is a rear view of the wall of FIG. 9.
FIG. 11 is a cut away view of the wall of FIG. 9 drawn along the line 11--11.
FIG. 12 is a top view of a straight wall section using the blocks of FIG. 6.
FIG. 13 is a top view of a convex wall section using the blocks of FIG. 6.
FIG. 14 is a top view of a concave wall section using the blocks of FIG. 6.
FIG. 15 is a partially cut away perspective view of a wall showing the use of a soil reinforcing matrix.
FIG. 16 is a cut away view of the wall of FIG. 15 drawn along the line 15--15.
FIG. 17 is a top view of the wall of FIG. 15.
FIG. 18 is a rear view of the wall of FIG. 15.
FIGS. 19a-d are perspective views of various front face designs that may be used with the blocks of the present invention.
FIGS. 20a-d are perspective views of various pin designs that may be used with the blocks of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1-6, there is shown a retaining wall block 1 of the present invention. Block 1 is made of a rugged, weather resistant material, preferably pre-cast concrete. Other suitable materials are plastic, reinforced fibers, wood, metal and stone. As shown in FIG. 1, block 1 includes an upper surface 2 and a lower surface 3, spaced apart from and substantially parallel to each other by a dimension that defines the height or thickness of the block 1. The block further includes a front surface 4 and a rear surface 5 each being spaced from and substantially parallel to each other by a dimension that comprises the depth of block 1. Generally opposed first 6 and second 7 sidewalls, each being spaced from the other by a dimension defining the width of the block 1 are also present. The front surface 4, the rear surface 5 and each sidewall 6, 7 extends between the upper 2 and lower 3 surfaces.
The front surface 4 of block 1 may have various aesthetically pleasing designs such as are shown in FIG. 1 and in FIGS. 19a-19d. For example, FIG. 1 depicts a block having a three plane front face, FIG. 19a depicts a block having a convex curved front face, FIG. 19b depicts a block having a multifaceted front face, FIG. 19c depicts a block having a planar front face, and FIG. 19d depicts a block having a face which includes a plurality of vertically spaced ribs. These and other aesthetic finishes may be used with the blocks of the present invention to provide various finished appearances for walls constructed form such blocks. Further examples of a variety of face finishes may be found in U.S. Design Pat. No. Des. 296,007 (Forsberg), the teachings of which are incorporated herein by reference. It should be understood, however, that the scope of the present invention is not intended to be limited to the particular face configuration selected.
The sidewalls 6 and 7 may be configured such that sidewall 6 is substantially parallel to sidewall 7. Alternatively, and preferably, sidewall 6 and 7 may converge toward each other as they approach rear surface 5. In that embodiment, the width of the block lessens as the sidewalls 6, 7 approach the rear surface 5. This block configuration is preferred because it allows the construction of serpentine walls, shown in FIGS. 13 and 14, more readily than would blocks having parallel sidewalls.
Block 1 includes a removable flange 8 extending from the rear surface 5 downward past the lower surface 3 of the block. The flange has a front surface 9, a bottom surface 10 and a back surface 11 that extends continuously from the rear surface 5 of the block. A plurality of pin apertures 12, 13, 14, 15 are provided in the flange 8, and extend perpendicular to the lower surface 3 of the block. The apertures 12, 13, 14, 15 are generally, although not necessarily, circular in cross section, and are positioned immediately adjacent to the front surface 9 of the flange 8. Positioned in this manner, the apertures are defined herein as being substantially "tangential" or "tangentially adjacent" to the front surface 9 of the flange.
The placement of the apertures in the manner described above is one important element of the block because such placement allows the block to maintain a substantially constant setback whether the flange or the pins are used to connect adjacent courses of blocks. Thus, the apertures are placed so that when the flange 8 is removed, and a pin or pins 16 are inserted into one or more of apertures 12-15, the portion of the pin 16 closest to the front surface 4 of the block will occupy a plane that had previously been defined by the front surface 9 of the flange 8. As such, the pin is caused to tangentially intercept a plane perpendicular to bottom surface 3 and located where the front surface 9 of flange 8 intercepted the plane of the bottom surface 3.
Flange 8 may have various dimensions, depending on the desired setback for walls constructed of the blocks. In a preferred embodiment of the present invention, flange 8 extends approximately one inch past the bottom surface 3 and the flange is approximately 3/4" to one inch deep.
Pin apertures 12-15 extend beyond the flange and into the body of the block such that when the flange 8 is removed, apertures 12-15 extend about 1/3 to about 2/3 into the depth of the body of the block. In one preferred embodiment, apertures 12-15 extend about 2.5" into the block as measured from the bottom surface 3. Apertures 12-15 may be of various cross sections and diameters, however, a circular aperture having a diameter of about 3/8" is preferred. The diameter of pin 16 is approximately the same as that of the apertures so that the pins 16 may be seated firmly via a friction fit and do not fall out when the block is placed into service. The pin apertures 12-15 may be tapered such that they become narrower in diameter as they extend into the block to further encourage a tight fit between each pin and pin aperture.
As shown in FIGS. 20a-d, the pins 16 may have various configurations. Pins 16 may be hollow (FIG. 20a) or solid (FIG. 20b), and their exterior may be smooth, corrugated (FIGS. 20c, 20d), or otherwise configured to encourage a tight fit in the pin apertures. The pins 16 may be fabricated from various materials, including plastic extrusions or moldings. The dimensions of pin 16 may vary, but will correspond to the dimensions of the pin apertures such that a pin 16 may be inserted into a pin aperture and remain in position through friction or interlock. Preferred pins 16 are approximately 3/8" in diameter and approximately 3.5" long.
As shown in FIG. 6, the block 1 may be converted from use as a rear flanged retaining wall block to a pinned retaining wall block by removing flange 8. This may be accomplished in the field by striking flange 8, such as with a hammer. After the flange 8 has been removed, pins 16 are placed preferably in at least two of the pin apertures 12-15. Views of the blocks of the present invention having pins 16 positioned in each of the pin apertures 12-15 are shown in FIGS. 7 and 8. It is noted, however, that each of the pin apertures 12-15 need not be provided with a pin 16. Rather, the selection of which apertures are used will depend on whether the portion of the wall being constructed is to be straight or curved. As shown in FIGS. 12-14, a wall having a straight or a convex front surface will employ the outside pin apertures 12, 15 to maintain proper setback for the wall. In contrast, when a concave wall is to be constructed, as in FIG. 14, the inside pin apertures 13, 14 are preferred to maintain appropriate alignment.
FIGS. 9-11 depict a wall 20 constructed of the blocks of the present invention. The wall depicted is constructed using techniques well known in the field. These include the installation of a base material, preferably composed of material that is suitable for compaction, the leveling of the base material, and the installation and leveling of the first course of blocks onto the base material. Succeeding courses of blocks 1 are stacked in a running bond pattern and back fill is placed and compacted behind the blocks until the wall is of the desired height. For wall installations not requiring soil reinforcement, each block 1 is used without removing flange 8, however, to fabricate curves, portions of the flange 8 may be removed from selected blocks to maintain proper setback.
FIGS. 15-18 depict a wall 30 constructed of blocks 1 which employ pins to connect the wall to a geogrid soil reinforcement system. Typically, walls greater than about three feet in height require soil reinforcement, however, this may vary depending on block dimensions, soil characteristics, and loading conditions behind the wall. Wall 30 is constructed using similar techniques to those described above. In addition, wall 30 incorporates a geogrid 31 which is placed according to engineering design plans.
The wall is constructed as described above using a rear flange connection until the wall reaches an elevation where a geogrid layer is to be employed. The blocks in the courses below the geogrid layer are placed and the backfill is placed and compacted up to the desired elevation. The geogrid 31 is laid onto the blocks and over the backfill to the specified length. The next course of blocks are prepared for placement by removing the flange 8 and placing the pins 16 into at least two of the pin apertures 12-15. The blocks 1 are then placed over the geogrid such that pins 16 extend through apertures in the geogrid 31 and engage the back surface of the blocks in the course below. The geogrid 31 is then tensioned by pulling it in a rearward direction, generally perpendicular to the face of the wall. Once tensioned, the geogrid is secured in a tensioned state by placing a stake into the backfill through an aperture in the geogrid. The wall is then backfilled and compacted, and additional blocks are placed until the wall reaches the desired height. Depending upon the final height of the wall, it may be necessary or desirable to place additional geogrid layers at selected heights of the wall.
Equivalents
From the foregoing detailed description of specific embodiments of the invention, it should be apparent that a unique retaining wall block and retaining wall made therefrom have been described. Although particular embodiments have been disclosed herein in detail, this has been done for purposes of illustration only, and is not intended to be limiting with respect to the scope of the appended claims, which follow. In particular, it is contemplated by the inventor that various substitutions, alterations, and modifications may be made to the invention without departing from the spirit and scope of the invention as defined by the claims. For instance, the choice of materials or variations in the shape or angles at which some of the surfaces intersect are believed to be a matter of routine for a person of ordinary skill in the art with knowledge of the embodiments disclosed herein. | A retaining wall block and wall construction are disclosed. The retaining wall block is characterized in that it includes a removable flange having pin apertures which pass through the flange and into the body of the block. Such blocks allow the construction of walls having flange connections between adjacent courses of blocks or, when the flange is removed, pin connections between adjacent courses of blocks. The latter connection system is particularly well-suited for constructing walls that require soil reinforcement systems such as geogrids. | 4 |
FIELD OF THE INVENTION
The present invention relates generally to medicine and more specifically to a novel biocompatible polymer material and to a process for producing same, said material finding application in ophthalmology for making contact lenses, allodrains, biofillings, for intrastromal lenses, and other items.
BACKGROUND OF THE INVENTION
A number of diverse biocompatible materials are known to use in ophthalmological practice, which are based on collagen, i.e., fibrous protein. Collagen serves as a kind of framework performing a supporting function for other proteins, as well as for cells; it is present in all body tissues, in the skin, tendons, and bones.
A variety of techniques of collagen isolation from raw materials are widely known, by its dissolution in acids, alkalis, salts, or with the aid of enzymes, as well as its isolation in a solid undissolved fibrous state by exposing the disintegrated raw material to the effect of salts. The isolated collagen is cleaned from pigments, glycoproteins, and proteoglycans, using the commonly known methods.
One state-of-the-art biocompatible collagen-based material is known to use for making contact lenses (U.S. Pat. No. 4,268,131), said material being in fact a gel based on fibrous collagen or a mixture of fibrous collagen with collagen in a dissolved state.
In order to produce said material diverse methods are used for collagen extraction from raw stock (such as hides, tendons, skin, and others) by means of its dissolution in acids (acetic or citric) or in alkalis, followed by centrifugation of the resultant solution, washing it with water, dehydration, drying, redissolution, filtration, precipitation, and recentrifugation. To produce a lens, a 4- to 10-percent gel is prepared on the basis of collagen in an aqueous acid medium having the pH value of from 2 to 4. Resort is also made to enzymic extraction in the presence of proteolytic enzymes, such as pepsin, trypsin, protease, and others.
However, the aforesaid material cannot be used for making long-lived transplants and those having preset porosity of the material, and hence its gas permeability, since used for producing said material is a protein that features a statistical average mass of from 120 to 130 thousand D (the porosity of the material depends on the geometric dimensions of a molecule and the physicochemical characteristics of collagen by which said material is constituted).
Moreover, the material in question is not resistant to the effect of enzymes as being completely constituted by protein molecules, which are liable to undergo lysis. Thus, low porosity of the material and its low resistance to the effect of enzymes result in reduced biocompatibility of the material with the eve tissues.
Another prior-art collagen-based biological material containing ethylene-unsaturated compounds is known to use for making contact lenses (U.S. Pat. No. 4,388,428).
The material under consideration is in effect a polymerized hydrophilic composition liable to swell in water and consisting of soluble collagen and an ethylene-unsaturated monomer featured by the presence of a polymerizable double carbon-carbon bond.
The material discussed herein is produced by extracting fibrous collagen from animal's hide by enzymic extraction with the aid of pepsin. The thus-extracted and purified collagen is mixed with an aqueous solution of an ethylene-unsaturated monomer, and in the resultant mixture collagen is dissolved by acidifying said mixture with 1.0M HCl till the pH value of 3. The resultant solution is filtered, drawn in a syringe, wherein the solution is degassed, centrifugated and filled into lens moulds.
However, the material dealt with in the form of a hydrogel is featured by inadequate gas permeability and porosity accounted for by geometric dimensions of collagen molecules and of molecules of the monomer used, as well as by a low protein content, low shelf- and service life.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a material possessing high gas permeability and porosity, as well as biocompatibility, mechanical strength, and a high optical refractive index.
It is another object of the present invention to provide a process for producing the herein-proposed material.
The foregoing principal and further objects are accomplished due to the fact that proposed herein, according to the invention, is a biocompatible polymer material, which is in fact a highly porous material, i.e., the product of graft-copolymerization of a water-soluble vinyl and/or acrylate monomer with a sorption complex of polysilicic acid and collagen that has been preliminarily purified of pigments, glycoproteins, and proteoglycans, or a product obtained by way of chemical destruction, with the aid of hydrofluoric acid, of said product of graft-copolymerization, containing up to 25 weight percent of polysilicic acid (in terms of SiO 2 ), up to 12 weight percent of protein, and maximum 1 10 -6 mole/g of an anion of hydrofluorosilicic and hydrofluoric acids.
The proposed material features high gas permeability and porosity, its gas permeability being 3- to 6 times that of a known material of the charecter set forth hereinabove.
High porosity of the proposed material is responsible for its higher elasticity, which in turn adds to its biocompatiblity. Besides, products made of the proposed material are three times more biocompatible when compared to a known material (U.S. Pat. No. 4,268,131) also due to poor adhesion of the cells of the macrophagocytic series. Thus for instance, adhesion of cells in the proposed material equals 10 2 per square centimeter, whereas that in a known material (U.S. Pat. No. 4,268,131) is equal to 10 6 per square centimeter.
The proposed material is also featured by a high optical refractive index and mechanical strength, as well as by high resistance to the effect of proteolytic enzymes.
A process for producing the proposed material, according to the invention, resides in that an acid solution of collagen isolated from the eyeball sclera of farm animals and rid of pigments, glycoproteins, and proteoglycans, is mixed with an aqueous solution of an alkali polysilicate, or with polysilica gel to a pH value of from 4.5 to 6.0 to form a sorption polymer of polysilicic acid, whereupon the thus-obtained sorption polymer is cleaned from cations and subjected to graft-copolymerization with a water-soluble vinyl and/or acrylate monomer while being exposed to the effect of radiation in the dosage of 0.5 to 1.5 Mrad, followed by isolation of the end product.
Prior to isolation of the end product the thus-obtained product of graft-copolymerization may be treated with hydrofluoric acid and be electrochemically purified of cations and anions. 2-Hydroxyethylmethacrylate, or acrylamide, or else N-vinylpyrrolidone, or a mixture thereof is used preferably as a water-soluble vinyl and/or acrylate monomer.
The proposed process makes it possible to produce a novel biocompatible polymer material posessing high gas permeability, biocompatibility, mechanical strength and optical refractive index.
DETAILED DESCRIPTION OF THE INVENTION
The proposed polymer material has been tested for biocompatibility as against adhesion of the cultural cells of the fibroplastic and macrophagocytic series (on a culture of keratocytes and peritoneal macrophagocytes).
To this aim, pieces of the material measuring 20×20 mm were placed in a culture medium, whereupon a suspension of cells was introduced thereinto. It has been established, as a result of the experiments performed, that corneal fibroplastic cells adhere well (80 to 90 percent of a total amount of such cells) and spread flat on the proposed material, whereas no cells of the inflammatory series practically adhere to the surface of said material. A run of experiments was condusted, wherein the contact lenses made from the proposed material were placed onto the cornea. A total of 30 test rabbits were employed in the experiments. The state of biocompatibility was assessed by the presence of the conjuctival edema. No edematous manifestations were noticed from the instant when the lens had been placed onto the rabbit's eye. Clinical trials of the proposed material have demonstrated its good permeability to oxygen and biocompatibility.
The proposed process for producing the biocompatible polymer material of the invention is carried into effect as follows.
Collagen extraction from the raw material and its getting rid of pigments, glycoproteins and proteoglycans can be effected using any of the heretofore-known techniques.
The procedure may, e.g., be as follows. The eyeball sclera of farm animals is carefully cleaned of the internal eyeball tunics and conjunctival and muscular reqidues, whereupon the stroma is excised. Then the pigments are completely eliminated, which can be attained by concurrent mechanical or enzymic treatment, the latter procedure making it possible to completely remove the pigmental layer. The treatment is carried out as follows: pieces of the untreated sclera are placed in a weekly acidified isotonic sodium chloride solution, or in an acetic acid solution (pH being from 4.5 to 6.0), then some trypsin is added to the solution (0.01 g per gram of dry sclera) and treatment occurs at 37° C. for two hours under constant stirring. Then the sclera is removed from the solution and washed with distilled water (one gram of dry sclera per 10 to 15 l of water) under constant stirring. The pigment residues are removed mechanically and the stroma is cut into small pieces. Next the mass is thoroughly washed in distilled water till complete elimination of mechanical impurities and blood, transferred in a flask and a 10-percent sodium hydroxide solution is added thereto (500 ml of the solution per 10 kg of the tissue), whereupon the solution is allowed to stand for 48 hours at 18° to 36° C. Next the solution is poured out and the tissue is neutralized till the pH value of 6.8 to 7.0 by placing it in a 2-percent boric acid solution, while constantly stirring and regulatory changing the solution. Thereupon the tissue is washed with distilled water till complete elimination of sulfate ion from the wash liquid and a 1M acetic-acid solution is added thereto so that the final collagen concentration in the solution be in excess of one percent. Then the mass is stirred and kept in a cooler for one or two days at 4° C., after which it is homogenized, centrifugated at 3000 rpm for 30 minutes and left for 24 hours at 4° C. The resultant solution is passed through a glass filter, whereupon collagen is subjected to an additional treatment with trypsin in a 1M acetic-acid solution, the trypsin proportion being the same as in the preceding case (i.e., 0.01 g of trypsin per gram of dry sclera) and the treatment time being one hour at 37° C. The resultant solution is passed through an unglazed-porcelain filter so as to eliminate the entire trypsin and to let collagen remain in the solution, the washing-out of trypsin being carried out with the aid of an acetic acid solution. Next the collagen solution is concentrated, by passing it through an unglazed-porcelain filter, to a concentration range of from 1 to 10 weight percent. Use may be made of solutions of some other diluted acids, such as formic or hydrochloric for preparing collagen solutions.
Then the thus-prepared acid collagen solution is mixed, under constant stirring, with an aqueous alkali salt. Stirring ceases as soon as the pH value of 4.5 to 6.0 is attained and a sorption polymer of polysilicic acid is formed. The acid collagen solution can also be mixed with a preliminarily prepared gel of polysilicic acid. The resultant mixture is also stirred till the pH value of 4.5 to 6.0 is attained and said sorption polymer of polysilicic acid is established.
The thus-produced sorption polymer is allowed to stand for 24 hours at +4° C. under constant stirring, whereupon it is centrifugation-concentrated and cleaned of cations.
The resultant sorption polymer is saturated with water-soluble monomers, such as acrylamide, vinylpyrrolidone, or others, or with mixtures thereof. The saturation procedure occurs as follows. The sorption polymer is disintegrated in the monomer and kept therein for 24 hours, whereupon the surplus monomer is filtered out. The resultant mixture is cooled down to 0° C. and exposed to the effect of radiation with a dose of from 0.5 to 1.5 mrad. The radiation graft-copolymerization is carried out with a radiation dose within the aforesaid range, since the lower radiation dosage fails to yield the material having an adequately high mechanical strength. On the other hand, a dose of 1.5 mrad is an upper limit, since higher doses of radiation fail to add to the mechanical strength of the material. The end product, whenever it becomes necessary, is dried and subjected to mechanical treatment to produce optical articles therefrom, such as contact lenses. After having been treated with radiation the resultant product of graft-copolymerization may be treated with hydrofluoric acid. To this end, the thus-obtained product of graft-copolymerization is placed in a solution of chemically pure hydrofluoric acid and left therein for 24 hours, whereupon the resultant product is cleaned electrochemically of cations and anions.
The electrochemical cleaning is ceased not until complete elimination of surplus ions of F - and SiF 6 -2 from the end product, since said ions are causative, when in certain quantitative concentrations, of an inflammatory reaction within the first days following the start of application of the proposed material.
To promote understanding of the present invention given below are the following examples illustrating the various embodiments of the proposed material, of the process for its production, and of its evaluation.
EXAMPLE 1
40 g of cleaned and washed scleral stroma is placed in one liter of 0.1M acetic acid, 0.1 g of trypsin is added thereto, and the solution is allowed in incubate at 37° C. for an hour, whereupon the sclera is washed in 10 l of distilled water. The pigment residues are removed mechanically, and the stroma is cut to pieces, and added thereto is 2 l of 10-percent sodium hydroxide, whereupon the solution is kept for 48 hours at 18° to 20° C. after which the solution is poured out. The tissue is washed with a small amount of distilled water, 2 l of a 2-percent aqueous boric acid solution is added thereto and the result- and solution is subjected to agitation in a magnetic stirrer for two hours, while changing the boric acid solution two-fold. While being constantly stirred the tissue is carefully washed with 5 l of distilled water till complete elimination of the sulfate ion from the wash liquid, 700 ml of 0.5M acetic acid is added thereto, and the solution is allowed to stand for 24 hours at 4° C. Next the mass is homogenized with the aid of a mechanical tissue comminuter, centrifugated at 3000 rpm for 30 minutes and held for three days at 4° C. The resultant solution is passed through a glass filter. Then trypsin is added to the resultant collagen solution (0.1 g per 1200 ml of the solution) and the mixture is subjected to incubation for one hour, whereupon the resultant solution is passed through an unglazed-porcelain filter and doped with 10 l of 0.1M acetic acid till the collagen concentration of 4 weight percent in the solution is obtained. The thus-obtained acid collagen solution is added dropwise, under constant stirring; to a 20-percent sodium silicate (Na 2 SiO 3 ) solution that has been passed through a 0.22-filter. Then the solution is mixed till the pH value of 6.0 and the formation of a gel-like sorption polymer of polysilicic acid. The thus-obtained polymer is left to stay at 4° C. for 24 hours, then excess water is separated therefrom, and the polymer is centrifugated at 3000 rpm for 30 minutes. The resultant polymer is disintegrated in one liter of deionized water and centrifugated at 3000 rpm, the procedure being repeated sixfold. Then added to 100 g of the resultant sorption polymer is 700 g of 2-hydroxyethylmethacrylate, the sorption polymer is disintegrated in the monomer solution, and centrifugated at 3000 rpm for 30 minutes. The resultant mixture is transferred into a mould, cooled down to 4° C., exposed to the effect radiation with a dose of 1.5 Mrad, and dried. The resultant material is in effect of graft-copolymer or 2-hydroxyethylmethacrylate and the sorption complex of polysilicic acid and collagen, featuring the polysilicic acid content of 15.6 weight percent in terms of SiO 2 , and the protein content of 11.4 weight percent.
A contact lens made from the proposed material was held to the patient's corneal surface, with the result that the corneal edema on the second-third day was as low as 0.1 percent, which is indicative of good permeability of the proposed material to oxygen and of its biocompatibility.
EXAMPLE 2
The graft-copolymer of 2-hydroxyethylmethacrylate and a sorption complex of polysilicic acid and collagen is prepared in a way similar to Example 1, which graft-copolymer is then treated with a 0.4-percent hydrofluoric acid solution for 24 hours at 25° C., then placed in deionized water (10 g per liter of water) and the procedure is repeated sixor sevenfold, whereupon the material is transferred into an electrochemical bath and subjected to electrochemical purification in a 10 -3 M aqueous hydrochloric acid solution of ions of F - and SiF 6 -2 at a voltage of 300 V and a power input of 8 W. Then the material is washed off hydrochloric acid in deionized water (one gram of the material per 10 l of water), then in a phosphate buffer to obtain the material which is in fact the product of chemical destruction, with the aid of hydrofluoric acid, of the graft-copolymer of 2-hydroxyethylmethacrylate and a sorption complex of polysilicic acid and collagen, having the pore size of from 0.025 to 0.35 μm. The material is free from polysilicic acid and features the protein content of 12.0 weight percent, and that of the anion if hydrofluorosilicic and hydrofluoric acids of 1 10 -6 mole/g.
A contact lens made from the proposed material, when evaluated, exhibited the results similar to Example 1.
EXAMPLE 3
The process is conducted as in Example 1 with the sole exception that the resultant collagen solution is diafiltered with 10 l of 0.5M acetic acid till a collagen concentration of 35 weight percent. The resulting acid collagen solution is added dropwise under constant stirring to a 35-percent sodium silicate (Na 2 SiO 3 ) solution that has preliminarily been passed through a 0.22 μm filter. The solution is mixed until a gel-like sorption polymer of polysilicic acid is obtained. Then the thus-produced polymer is allowed to stand at 0° C. for 24 hours, after which the excess water is separated therefrom, and the polymer is centrifugated at 3000 rpm for 30 minutes. Next the sorption polymer is disintegrated in a microcomminuter in one liter of deionized water, the pH value being 6.5, the procedures being repeated six- to eightfold till complete elimination of the cations of metals, which is monitored on a flame photometric analyzer. Then added to 100 g of the obtained polymer is 800 g of a mixture, consisting of 600 g of acrylamide, 0.1 g of N-methylenebisacrylamide, water being the balance. The polymer is then disintegrated in a microcomminuter in a monomer solution, and the resultant pulp is centrifugated at 3000 rpm for 30 minutes. The thus-obtained mixture is transferred into a mould, cooled down to 0° C. and exposed to the effect of gamma-radiation in a dose of 0.5 Mrad. The result is a material, which is in fact the graft-copolymer of acrylamide and a sorption complex of polysilicic acid and collagen, featuring the polysilicic acid content of 24.0 weight percent in terms of SiO 2 , and the protein content of 10.2 weight percent.
An intrastromal plate made from the proposed material was implanted into the corneal layers. No response to the material was observed, the corneal layers were transparent on the second-fourth month after implantation, which was indicative of good permeability and biocompatibility of the material. No fibroplastic reaction to the implanted material was found at the corneal histological microsections.
EXAMPLE 4
The graft-copolymer of acrylamide and a sorption complex of polysilicic acid and collagen is obtained as in Example 3, which is treated with a 0.4-percent hydrofluoric acid solution for 24 hours at 25° C., then placed in deionized water (10 g per liter of water), and the procedure is repeated several fold, whereupon the material is placed in an electrochemical bath and subjected to electrochemical purification, in a 10 -3 M aqueous hydrochloric solution, of the ions of F - and SiF 6 -2 at a voltage of 300 V and a power input of 8 W for 3 hours. Next the material is washed, to get rid of hydrochloric acid, first with deionized water, then in a phosphate buffer. The result is a material, which is in fact the product of chemical destruction, with the aid of hydrofluoric acid, of the graft-copolymer of acrylamide and a sorption complex of polysilicic acid and collagen, featuring the pore size of from 0.025 to 2.0 μm, the zero content of polysilicic acid, the protein content of 10.6 weight percent, and the content of the anion of hydrofluorosilicic and hydrofluoric acids of 5 10 -7 mole/g.
A contact lens made from the proposed material, when tested, exhibited the results similar to Example 3.
EXAMPLE 5
The process is carried out similarly to Example 1, with the sole exception that the resultant acid collagen solution is diafiltered with 10 l of a 0.5M solution of hydrochloric acid till a collagen concentration of 11 weight percent is attained. The thus-obtained collagen solution is added dropwise, under constant stirring, to a 10-percent solution of sodium silicate (Na 2 SiO 3 ) that has preliminarily been passed through a 0.22 μm filter. Then the solution is mixed till the pH value of 4.5 is attained and a gel-like sorption polymer of polysilicic acid is established, and the thus-obtained polymer is allowed to stand at 4° C. for 24 hours. Next the excess water is separated and the polymer is centrifugated at 3000 rpm for 30 minutes. The sorption polymer is disintegrated in a microcomminuter in one liter of deionized water having the pH value of 6.5, the procedure is repeated six- or eightfold till the complete elimination of the cations of metals, which is monitored on a flame photometric analyzer. Then added to 100 g of the thus-produced polymer is a mixture, consisting of 300 g of 2-hydrozyethylmethacrylate and 100 g of N-vinylpyrrolidone, the polymer is disintegrated in a monomer solution and centrifugated at 3000 rpm for 30 minutes. The resultant mixture is transferred into a mould, cooled down to 0° C. and exposed to the effect of radiation in a dose of 1.0 Mrad. The obtained material is dried. The thus-produced material is in fact the graft-copolymer of 2-hydroxyethylmethacrylate and N-vinylpyrrolidone, and a sorption complex of polysilicic acid and collagen, the polysilicic acid content being 8.0 weight percent in terms of SiO 2 , and the protein content, 6.2 weight percent.
A transplant made from the proposed material in the form of a disk having a diameter of 6 mm and a thickness of 0.2 mm was implanted into the corneal layers. No response to the material was observed, the corneal layers were transparent on the second-third month after implantation, which was indicative of good permeability of the material of oxygen and glucose, as well as good biocompatibility.
EXAMPLE 6
The graft-copolymer of 2-hydroxyethylmethacrylate and N-vinylpyrrolidine and a sorption complex of polysilicic acid and collagen is produced as in Example 5, which is treated with a one-percent hydrofluoric acid solution for 24 hours at 25° to 30° C. and then placed in deionized water (10 g per liter of water), the procedure is repeated six- or seven-fold, whereupon the material is transferred into an electrochemical bath and subjected to electrochemical purification of the ions of F - and SiF 6 -2 at a voltage of 300 V and a power input of 9 W for 3 hours. Then the material is washed off hydrochloric acid in deionized water (1 g per 10 l of water), then washed with a phosphate buffer, packed and sterilized.
The result is the material, which is in fact the product of chemical destruction, with the aid of hydrofluoric acid, of the graft-copolymer of 2-hydroxyethylmethacrylate and a sorption complex of polysilicic acid and collagen, having the pore size of from 0.025 to 0.13 μm, free from polycilicic acid and featuring the protein content of 6.5 weight percent and the content of the anion of hydrofluorosilicic and hydrofluoric acids of 8 10 -7 mole/g.
An intrastromal lens made from the proposed material was implanted into the corneal layers of a test rabbit's eyeball. No response to the material was observed, the corneal layers were transparent on the second and third months after implantation, which was indicative of good permeability and biocompatibility of the material.
EXAMPLE 7
The process is carried out similarly to Example 5, the sole exception that the resultant acid acid collagen solution is diafiltered with 10 l of a 0.5M solution of hydrochloric acid till the collagen concentration of 11 weight percent is attained. The thus-obtained collagen solution is added dropwise, under constant stirring, to the polysilicic gel resulting from precipitating, with the aid of hydrochloric acid, a 20-percent aqueous sodium silicate solution. The resultant material is similar to that of Example 5.
The proposed biocompatibility polymer material possesses high gas permeability, which is three- to six-time that of the heretofore-known material. High porosity of the proposed material adds to its elasticity, which in turn renders the material more biocompatible, that is, biocompatibility of articles made from the proposed material is threefold higher than that of the heretofore-known material. The proposed material also features high optical refractive index and mechanical strength. | A biocompatible material which is the product of graft-copolymerization of a water-soluble vinyl and/or an acrylate monomer with a sorption complex of polysilicic acid and collagen that has been rid of pigments, glycoproteins and proteoglycans, or a product obtained by virtue of chemical destruction, with the aid of hydrofluoric acid, of the afore-mentioned product of graft-copolymerization, containing up to 25 mass percent of polysilicic acid (in terms of SiO 2 ), up to 12 mass percent of protein, and maximum 1 10 -6 mole/g of an anion of hydrofluoric and hydrofluoric acids, methods of making the same and products produced thereby. | 2 |
RELATED APPLICATION DATA
This application is a divisional application of U.S. patent application Ser. No. 09/621,681, filed Jul. 21, 2000, now U.S. Pat. No. 6,316,625 which is a divisional application of U.S. patent application Ser. No. 09/252,802, filed Feb. 19, 1999, now U.S. Pat. No. 6,117,999, which is a divisional application of U.S. patent application Ser. No. 08/923,947, filed Sep. 5, 1997, now U.S. Pat. No. 5,925,759, which claims benefit of priority under 35 U.S.C. §119 to U.S. Provisional Patent Application No. 60/025,515, filed Sep. 5, 1996, the disclosures of each of which are incorporated herein by reference.
This application relates to the following U.S. patent applications:
U.S. patent application No.
Filing Date
08/133,543
October 7, 1993, abandoned;
08/133,696
October 7, 1993, abandoned;
08/190,764
February 2, 1994,
now U.S. Pat. No. 5,484,926;
08/481,833
June 7, 1995,
now U.S. Pat. No. 5,846,993;
08/708,607
September 5, 1996,
now U.S. Pat. No. 5,705,647.
Each of these U.S. patents and application also is entirely incorporated herein by reference.
INTRODUCTION
Treatment of HIV-infected individuals is one of the most pressing biomedical problems of recent times. A promising new therapy has emerged as an important method for preventing or inhibiting the rapid proliferation of the virus in human tissue. HIV-protease inhibitors block a key enzymatic pathway in the virus resulting in substantially decreased viral loads, which slows the steady decay of the immune system and its resulting deleterious effects on human health. The HIV-protease inhibitor nelfinavir mesylate
has been shown to be an effective treatment for HIV-infected individuals. Nelfinavir mesylate is disclosed in U.S. Pat. No. 5,484,926, issued Jan. 16, 1996. This patent is entirely incorporated by reference into this patent application. Methods for preparing nelfinavir mesylate from nelfinavir free base are disclosed in U.S. Pat. No. 5,484,926, as well as U.S. patent appln. Ser. No. 08/708,411 of inventors M. Deason and K. Whitten, entitled “Intermediates for Making HIV-Protease Inhibitors and Methods of Making HIV-Protease Inhibitors”, filed on Sep. 5, 1996, which application is entirely incorporated herein by reference.
SUMMARY OF THE INVENTION
The present invention relates to the novel compounds illustrated below. These compounds are useful as intermediates and starting materials for the preparation of nelfinavir free base and nelfinavir mesylate.
A first compound according to this invention is a compound of formula 6, as follows:
wherein each R 3 is independently an aryl group or an alkyl group; or a pharmaceutically acceptable salt or solvate thereof.
A second compound according to this invention is a compound of formula 6a:
wherein each X is independently a halogen; or a pharmaceutically acceptable salt or solvate thereof.
A third compound according to this invention is a compound of formula 7:
wherein each R 3 is independently an aryl group or an alkyl group; or a pharmaceutically acceptable salt or solvate thereof.
A fourth compound according to this invention is a compound of formula 8:
wherein each R 3 is independently an aryl group or an alkyl group; or a pharmaceutically acceptable salt or solvate thereof.
A fifth compound according to the invention is a compound of formula 9:
wherein each R 3 is independently an aryl group or an alkyl group; or a pharmaceutically acceptable salt or solvate thereof.
A sixth compound according to this invention is a compound of formula 10:
wherein R 3 is an aryl group or an alkyl group; or a pharmaceutically acceptable salt or solvate thereof.
A seventh compound according to this invention is a compound of formula 7a:
wherein each R 3 is independently an aryl group or an alkyl group; or a pharmaceutically acceptable salt or solvate thereof.
An eighth compound according to this invention is a compound of formula 8a:
wherein R 4 is an alkyl group; or a pharmaceutically acceptable salt or solvate thereof.
A ninth compound according to this invention is a compound of formula 9a:
wherein R 4 is an alkyl group; or a pharmaceutically acceptable salt or solvate thereof.
A tenth compound according to this invention is a compound of formula 10a:
or a pharmaceutically acceptable salt or solvate thereof.
This invention further relates to processes for making and using the compounds and intermediates described above. For example, these compounds can be used to prepare nelfinavir free base and nelfinavir mesylate.
A first method according to the invention relates to a method of making a compound of formula 6:
wherein each R 3 is independently an aryl group or an alkyl group, by converting, under sufficient conditions, a compound of formula 5:
wherein each R 3 independently an aryl group or an alkyl group, to the compound of formula 6 shown above.
In a second method according to this invention, a compound of formula 6a is produced:
wherein each X is independently a halogen. In this method, the compound according to formula 5 (illustrated above) is converted, under sufficient conditions, to the compound of formula 6a.
This invention further relates to methods of making a compound of formula 7:
wherein each R 3 is independently an aryl group or an alkyl group. In one method, a compound of formula 6:
wherein each R 3 is independently an aryl group or an alkyl group, is converted, under sufficient conditions, to the compound of formula 7. In another method, a compound according to formula 6a:
wherein each X is independently a halogen, is converted, under sufficient conditions, to the compound of formula 7.
Another method according to this invention relates to a method of making a compound of formula 8:
wherein each R 3 is independently an aryl group or an alkyl group. The compound according to formula 8 is produced by converting, under sufficient conditions, a compound of formula 7:
wherein each R 3 is independently an aryl group or an alkyl group, to the compound of formula 8.
In another method according to this invention, a compound according to formula 8 (illustrated above), can be converted, under sufficient conditions, to a compound of formula 9:
wherein each R 3 is independently an aryl group or an alkyl group.
Yet another method according to this invention relates to a method of making a compound of formula 10:
wherein R 3 is an aryl group or an alkyl group. In this method, a compound of formula 9:
wherein each R 3 is independently an aryl group or an alkyl group, is converted, under sufficient conditions, to a compound of formula 10.
This invention also relates to a method of making a compound of formula 11:
by converting, under sufficient conditions, a compound of formula 10:
wherein R 3 is an aryl group or an alkyl group, to a compound of formula 11.
As mentioned above, another compound or intermediate according to this invention is a compound of formula 7a:
wherein each R 3 is independently an aryl group or an alkyl group. This material can be made, in accordance with another method of this invention, by converting, under sufficient conditions, a compound of formula 6:
wherein each R 3 is independently an aryl group or an alkyl group, to the compound of formula 7a. In an alternative method according to this invention, the compound according to formula 7a (shown above) can be produced by converting, under sufficient conditions, a compound of formula 6a:
wherein each X is independently a halogen, to the compound of formula 7a.
Another method according to this invention relates to a method of making a compound of formula 8a:
wherein R 4 is an alkyl group. This compound is produced by converting, under sufficient conditions, a compound of formula 7a:
wherein each R 3 is independently an aryl group or an alkyl group, to the compound of formula 8a.
In another method according to the invention, a compound of formula 9a:
wherein R 4 is an alkyl group, can be produced by converting, under sufficient conditions, a compound of formula 8a:
wherein R 4 is an alkyl group, to the compound of formula 9a.
Yet another method according to this invention relates to a method of making a compound of formula 10a:
by converting, under sufficient conditions, a compound of formula 9a:
wherein R 4 is an alkyl group, to the compound of formula 10a.
The compound according to formula 10a (shown above) can be used in another method of this invention to produce a compound of formula 11a:
wherein Y − is a suitable salt anion. In this method, the compound of formula 10a is converted, under sufficient conditions, to the compound of formula 11a.
The compounds and intermediates according to the invention advantageously can be used to produce nelfinavir mesylate:
In one method, a compound of formula 10:
wherein R 3 is an aryl group or an alkyl group, is converted, under sufficient conditions, to a compound of formula 11:
The compound according to formula 11 then is converted, under sufficient conditions, to a compound of formula 12:
The compound according to formula 12 is then converted to nelfinavir mesylate.
A second method according to the invention for making nelfinavir mesylate (illustrated above) includes converting, under sufficient conditions, a compound of formula 10a:
to a compound of formula 11a:
wherein Y − is a suitable salt anion. The compound of formula 11a then is converted, under sufficient conditions, to a compound of formula 12 (shown above), which then is converted, under sufficient conditions, to nelfinavir mesylate.
DESCRIPTION OF THE INVENTION
The present inventors have discovered useful novel intermediate compounds that can be used in several novel reaction schemes to make nelfinavir mesylate. More specifically, the present invention relates to new processes that have been developed to prepare nelfinavir free base, the penultimate intermediate of the raw drug nelfinavir mesylate (Schemes 1, 2 and 3). In addition to being operationally simple, these processes utilize cheap, commercially available raw materials and offer an alternative to the more expensive chloro-alcohol based chemistry that has been used for manufacture (see HIV Protease Inhibitors, Intl. Pat. No. WO 95/09843). These new processes proceed through cyclic sulfates of general structure 6 or 6a:
where R 3 is aryl or alkyl and X is a leaving group. These cyclic sulfates are novel 4-carbon electrophilic species derived from (2S,3S)-(−)tartaric acid, a substance commercially available from many suppliers. Such intermediates are new chemical entities that possess leaving group ability at 4 contiguous carbons. Such ambident electrophilicity can be selectively unmasked in the production of 4 carbon units useful in nelfinavir free base synthesis. These intermediates are general synthons for the production of 4-carbon units bearing 4 carbon-heteroatom bonds, two of which are at stereogenic centers.
Using the intermediates and compounds described in this application, as well as the methods described herein, one can prepare nelfinavir free base and nelfinavir mesylate, compounds useful as HIV-protease inhibitors. The following detailed description describes various specific examples and reaction schemes that can be used in accordance with this invention. These examples and reaction schemes should be considered as illustrating the invention and not as limiting the same.
Furthermore, in this application, Applicants describe certain theories and reaction mechanisms in an effort to explain how and why this invention works in the manner in which it works. These theories and mechanisms are set forth for informational purposes only. Applicants are not to be bound by any particular chemical, physical, or mechanical theory of operation.
Definitions
As used in the present application, the following definitions apply:
The term “alkyl” as used herein refers to substituted or unsubstituted, straight or branched chain groups, preferably, having one to eight, more preferably having one to six, and most preferably having from one to four carbon atoms. The term “C 1 -C 6 alkyl” represents a straight or branched alkyl chain having from one to six carbon atoms. Exemplary C 1 -C 6 alkyl groups include methyl, ethyl, n-propyl, isopropyl, butyl, isobutyl, sec-butyl, t-butyl, pent l, neo-pentyl, hexyl, isohexyl, and the like. The term “C 1 -C 6 alkyl” includes within its definition the term “C 1 -C 4 alkyl”.
The term “cycloalkyl” represents a substituted or unsubstituted, saturated or partially saturated, mono- or poly-carbocyclic ring, preferably having 5-14 ring carbon atoms. Exemplary cycloalkyls include monocyclic rings having from 3-7, preferably 3-6, carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and the like. An exemplary cycloalkyl is a C 5 -C 7 cycloalkyl, which is a saturated hydrocarbon ring structure containing from five to seven carbon atoms.
The term “aryl” as used herein refers to an aromatic, monovalent monocyclic, bicyclic, or tricyclic radical containing 6, 10, 14, or 18 carbon ring atoms, which may be unsubstituted or substituted, and to which may be fused one or more cycloalkyl groups, heterocycloalkyl groups, or heteroaryl groups, which themselves may be unsubstituted or substituted by one or more suitable substituents. Illustrative examples of aryl groups include, but are not limited to, phenyl, naphthyl, anthryl, phenanthryl, fluoren-2-yl, indan-5-yl, and the like.
The term “halogen” represents chlorine, fluorine, bromine or iodine. The term “halo” represents chloro, fluoro, bromo or iodo.
The term “carbocycle” represents a substituted or unsubstituted aromatic or a saturated or a partially saturated 5-14 membered monocyclic or polycyclic ring, such as a 5- to 7-membered monocyclic or 7- to 10-membered bicyclic ring, wherein all the ring members are carbon atoms.
A “heterocycloalkyl group” is intended to mean a non-aromatic, monovalent monocyclic, bicyclic, or tricyclic radical, which is saturated or unsaturated, containing 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 ring atoms, and which includes 1, 2, 3, 4, or 5 heteroatoms selected from nitrogen, oxygen and sulfur, wherein the radical is unsubstituted or substituted, and to which may be fused one or more cycloalkyl groups, aryl groups, or heteroaryl groups, which themselves may be unsubstituted or substituted. Illustrative examples of heterocycloalkyl groups include, but are not limited to, azetidinyl, pyrrolidyl, piperidyl, piperazinyl, morpholinyl, tetrahydro-2H-1,4-thiazinyl, tetrahydrofuryl, dihydrofuryl, tetrahydropyranyl, dihydropyranyl, 1,3-dioxolanyl, 1,3-dioxanyl, 1,4-dioxanyl, 1,3-oxathiolanyl, 1,3-oxathianyl, 1,3-dithianyl, azabicylo[3.2.1]octyl, azabicylo[3.3.1]nonyl, azabicylo[4.3.0]nonyl, oxabicylo[2.2.1]heptyl, 1,5,9-triazacyclododecyl, and the like.
A “heteroaryl group” is intended to mean an aromatic monovalent monocyclic, bicyclic, or tricyclic radical containing 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 ring atoms, including 1, 2, 3, 4, or 5 heteroatoms selected from nitrogen, oxygen and sulfur, which may be unsubstituted or substituted, and to which may be fused one or more cycloalkyl groups, heterocycloalkyl groups, or aryl groups, which themselves may be unsubstituted or substituted. Illustrative examples of heteroaryl groups include, but are not limited to, thienyl, pyrrolyl, imidazolyl, pyrazolyl, furyl, isothiazolyl, furazanyl, isoxazolyl, thiazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl, benzo[b]thienyl, naphtho[2,3-b]thianthrenyl, isobenzofuranyl, chromenyl, xanthenyl, phenoxathienyl, indolizinyl, isoindolyl, indolyl, indazolyl, purinyl, isoquinolyl, quinolyl, phthalazinyl, naphthyridinyl, quinoxyalinyl, quinzolinyl, benzothiazolyl, benzimidazolyl, tetrahydroquinolinyl, cinnolinyl, pteridinyl, carbazolyl, beta-carbolinyl, phenanthridinyl, acridinyl, perimidinyl, phenanthrolinyl, phenazinyl, isothiazolyl, phenothiazinyl, and phenoxazinyl.
Suitable protecting groups are recognizable to those skilled in the art. Examples of suitable protecting groups can be found in T. Green & P. Wuts, Protective Groups in Organic Synthesis (2d ed. 1991), which is incorporated herein by reference.
Suitable salt anions include, but are not limited to, inorganics such as halogens, pseudohalogens, sulfates, hydrogen sulfates, nitrates, hydroxides, phosphates, hydrogen phosphates, dihydrogen phosphates, perchloroates, and related complex inorganic anions; and organics such as carboxylates, sulfonates, bicarbonates and carbonates.
The term “DABCO” as used herein refers to the reagent 1,4-diazabicyclo[2.2.2]octane.
The term “DBN” as used herein refers to the reagent 1,5-diazabicyclo[4.3.0]non-5-ene.
The term “DBU” as used herein refers to the reagent 1,8-diazabicyclo[5.4.0]undec-7-ene.
The term “MTBE” as used herein refers to the solvent methyl t-butyl ether.
The term “arylsufonic acid” as used herein refers to substituted or unsubstituted groups of formula:
wherein Ar is an aromatic ring.
The term “leaving group” as used herein refers to any group that departs from a molecule in a substitution reaction by breakage of a bond. Examples of leaving groups include, but are not limited to, halides, arenesulfonates, alkylsulfonates, and triflates.
The term “DMF” as used herein refers to the solvent N,N-dimethylformamide.
The term “THF” as used herein refers to the solvent tetrahydrofuran.
The term “DMAC” as used herein refers to the solvent N,N-dimethylacetamide.
Examples of substituents for alkyl and aryl include mercapto, thioether, nitro (NO 2 ), amino, aryloxyl, halogen, hydroxyl, alkoxyl, and acyl, as well as aryl, cycloalkyl and saturated and partially saturated heterocycles. Examples of substituents for cycloalkyl include those listed above for alkyl and aryl, as well as aryl and alkyl.
Exemplary substituted aryls include a phenyl or naphthyl ring substituted with one or more substituents, preferably one to three substituents, independently selected from halo, hydroxy, morpholino(C 1 -C 4 )alkoxy carbonyl, pyridyl (C 1 -C 4 )alkoxycarbonyl, halo (C 1 -C 4 )alkyl, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, carboxy, C 1 -C 4 alkoxycarbonyl, carbamoyl, N—(C 1 -C 4 )alkylcarbamoyl, amino, C 1 -C 4 alkylamino, di(C 1 -C 4 )alkylamino or a group of the formula —(CH 2 ) a —R 7 where a is 1, 2, 3 or 4; and R 7 is hydroxy, C 1 -C 4 alkoxy, carboxy, C 1 -C 4 alkoxycarbonyl, amino, carbamoyl, C 1 -C 4 alkylamino or di(C 1 -C 4 )alkylamino.
Another substituted alkyl is halo(C 1 -C 4 )alkyl, which represents a straight or branched alkyl chain having from one to four carbon atoms with 1-3 halogen atoms attached to it. Exemplary halo(C 1 -C 4 )alkyl groups include chloromethyl, 2-bromoethyl, 1-chloroisopropyl, 3-fluoropropyl, 2,3-dibromobutyl, 3-chloroisobutyl, iodo-t-butyl, trifluoromethyl and the like.
Another substituted alkyl is hydroxy(C 1 -C 4 )alkyl, which represents a straight or branched alkyl chain having from one to four carbon atoms with a hydroxy group attached to it. Exemplary hydroxy(C 1 -C 4 )alkyl groups include hydroxymethyl, 2-hydroxyethyl, 3-hydroxypropyl, 2-hydroxyisopropyl, 4-hydroxybutyl and the like.
Yet another substituted alkyl is C 1 -C 4 alkylthio(C 1 -C 4 )alkyl, which is a straight or branched C 1 -C 4 alkyl group with a C 1 -C 4 alkylthio group attached to it. Exemplary C 1 -C 4 alkylthio(C 1 -C 4 )alkyl groups include methylthiomethyl, ethylthiomethyl, propylthiopropyl, sec-butylthiomethyl, and the like.
Yet another exemplary substituted alkyl is heterocycle(C 1 -C 4 )alkyl, which is a straight or branched alkyl chain having from one to four carbon atoms with a hetero-cycle attached to it. Exemplary heterocycle(C 1 -C 4 )alkyls include pyrrolylmethyl, quinolinylmethyl, 1-indolylethyl, 2-furylethyl, 3-thien-2-ylpropyl, 1-imidazolylisopropyl, 4-thiazolylbutyl and the like.
Yet another substituted alkyl is aryl(C 1 -C 4 )alkyl, which is a straight or branched alkyl chain having from one to four carbon atoms with an aryl group attached to it. Exemplary aryl(C 1 -C 4 )alkyl groups include phenylmethyl, 2-phenylethyl, 3-naphthyl-propyl, 1-naphthylisopropyl, 4-phenylbutyl and the like.
The heterocycloalkyls and heteroaryls can, for example, be substituted with 1, 2 or 3 substituents independently selected from halo, halo(C 1 -C 4 )alkyl, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, carboxy, C 1 -C 4 alkoxycarbonyl, carbamoyl, N—(C 1 -C 4 )alkylcarbamoyl, amino, C 1 -C 4 alkylamino, di(C 1 -C 4 )alkylamino or a group having the structure —(CH 2 ) a —R 7 where a is 1, 2, 3 or 4 and R 7 is hydroxy, C 1 -C 4 alkoxy, carboxy, C 1 -C 4 alkoxy carbonyl, amino, carbamoyl, C 1 -C 4 alkylamino or di(C 1 -C 4 )alkylamino.
Examples of substituted heterocycloalkyls include, but are not limited to, 3-N-t-butyl carboxamide decahydroisoquinolinyl and 6-N-t-butyl carboxamide octahydro-thieno[3,2-c]pyridinyl. Examples of substituted heteroaryls include, but are not limited to, 3-methylimidazolyl, 3-methoxypyridyl, 4-chloroquinolinyl, 4-aminothiazolyl, 8-methylquinolinyl, 6-chloroquinoxalinyl, 3-ethylpyridyl, 6-methoxybenzimidazolyl, 4-hydroxyfuryl, 4-methylisoquinolinyl, 6,8-dibromoquinolinyl, 4,8-dimethylnaphthyl, 2-methyl- 1,2,3,4-tetrahydroisoquinolinyl, N-methyl-quinolin-2-yl, 2-t-butoxycarbonyl-1,2,3,4-isoquinolin-7-yl and the like.
A “pharmaceutically acceptable solvate” is intended to mean a solvate that retains the biological effectiveness and properties of the biologically active components of the inventive compounds.
Examples of pharmaceutically acceptable solvates include, but are not limited to, compounds prepared using water, isopropanol, ethanol, methanol, DMSO, ethyl acetate, acetic acid, or ethanolamine.
In the case of solid formulations, it is understood that the inventive compounds may exist in different forms, such as stable and metastable crystalline forms and isotropic and amorphous forms, all of which are intended to be within the scope of the present invention.
A “pharmaceutically acceptable salt” is intended to mean those salts that retain the biological effectiveness and properties of the free acids and bases and that are not biologically or otherwise undesirable.
Examples of pharmaceutically acceptable salts include, but are not limited to, sulfates, pyrosulfates, bisulfates, sulfites, bisulfites, phosphates, monohydrogenphosphates, dihydrogenphosphates, metaphosphates, pyrophosphates, chlorides, bromides, iodides, acetates, propionates, decanoates, caprylates, acrylates, formates, isobutyrates, caproates, heptanoates, propiolates, oxalates, malonates, succinates, suberates, sebacates, fumarates, maleates, butyne-1,4-dioates, hexyne-1,6-dioates, benzoates, chlorobenzoates, methylbenzoates, dinitrobenzoates, hydroxybenzoates, methoxyenzoates, phthalates, sulfonates, xylenesulfonates, phenylacetates, phenylpropionates, phenylbutyrates, citrates, lactates, γ-hydroxybutyrates, glycolates, tartrates, methanesulfonates, propanesulfonates, naphthalene-1-sulfonates, naphthalene-2-sulfonates, and mandelates.
If the inventive compound is a base, the desired salt may be prepared by any suitable method known to the art, including treatment of the free base with an inorganic acid, such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid and the like, or with an organic acid, such as acetic acid, maleic acid, succinic acid, mandelic acid, fumaric acid, malonic acid, pyruvic acid, oxalic acid, glycolic acid, salicylic acid, pyranosidyl acids such as glucuronic acid and galacturonic acid, alpha-hydroxy acids such as citric acid and tartaric acid, amino acids such as aspartic acid and glutamic acid, aromatic acids such as benzoic acid and cinnamic acid, sulfonic acids such a p-toluenesulfonic acid or ethanesulfonic acid, or the like.
If the inventive compound is an acid, the desired salt may be prepared by any suitable method known to the art, including treatment of the free acid with an inorganic or organic base, such as an amine (primary, secondary or tertiary), an alkali metal or alkaline earth metal hydroxide or the like. Illustrative examples of suitable salts include organic salts derived from amino acids such as glycine and arginine, ammonia, primary, secondary and tertiary amines, and cyclic amines such as piperidine, morpholine and piperazine, and inorganic salts derived from sodium, calcium, potassium, magnesium, manganese, iron, copper, zinc, aluminum and lithium.
All inventive compounds that contain at least one chiral center may exist as single stereoisomers, racemates and/or mixtures of enantiomers and/or diastereomers. All such single stereoisomers, racemates and mixtures thereof are intended to be within the scope of the present invention. Preferably, the compounds of the present invention are used in a form that contains at least 90% of a single isomer (80% enantiomeric or diastereomeric excess), more preferably at least 95% (90% e.e. or d.e.), even more preferably at least 97.5% (95% e.e. or d.e.), and most preferably at least 99% (98% e.e. or d.e.). Compounds identified herein as single stereoisomers are meant to describe compounds used in a form that contains at least 90% of a single isomer.
The inventive compounds of general structure 6a can be made from D-tartaric acid via many permutations, as demonstrated in Scheme 1:
First, the conversion of D-tartaric acid to the intermediate of formula 2 can take different pathways. It may be first converted to the compound of formula 1 via Fisher-type esterifications (Step 2) involving refluxing any alcohol in the presence of organic acids such as alkyl or arylsulfonic acids or inorganic acids such as hydrochloric, sulfuric or nitric acids. Compounds of formula 1 are also commercially available from a number of suppliers.
Compounds of formula 1 may then be converted to the protected diester of formula 2 (Step 3) using any of a large variety of acetal or ketal protecting groups. The groups R 1 may comprise any acetal or ketal such as an acetonide, cyclohexylidene ketal, benzylidene acetal, 2-methoxyethoxyethyl acetal or a related acetal or ketal. Such groups are installed by acid-promoted condensation of the corresponding ketone or aldehyde with the compound of formula 1. These are promoted by both organic acids such as p-toluenesulfonic acid and related alkylsulfonic acids and arylsulfonic acids, trifluoroacetic acid and related organic carboxylic acids with a pK of less than 2, and inorganic acids such as sulfuric acid, hydrochloric acid, phosphoric acid, and nitric acid.
Alternatively, D-tartaric acid may be converted to compounds of formula 2 in a single reaction vessel (Step 1) by appropriate choice of the esterifying alcohol R 2 and the aldehyde or ketone component. Such reactions are modeled after those previously disclosed in the chemical literature (see Mash, E. A.; Nelson, K. A.; Van Deusen, S.; Hemperly, S. B. Org. Synth. Coil. Vol. VII, 155, 1990).
The reduction of compounds of formula 2 to compounds of formula 3 (Step 4) can be performed using a variety of reducing agents such as NaBH 4 in alcoholic media, lithium borohydride or lithium aluminum hydride and related substituted aluminum and boron hydrides in ethereal solvents like THF, diethyl ether, dioxane and MTBE.
The diols of formula 3 can be converted to compounds of formula 4 via a number of methods (Step 5). The leaving group can preferably be any halogen, alkyl or arylsulfonate. The sulfonates can be produced by reaction of the diol with 2 equivalents or greater of the corresponding sulfonyl halides such as p-toluenesulfonyl chloride, methanesulfonyl chloride in the presence of an organic amine base like triethylamine, diethylamine, diethyl isopropylamine, DABCO or related di- or trialkylamines, as well as amidine bases like DBU and DBN. The compounds where X=halogen can be prepared from such sulfonate intermediates by reaction with metal halides such as LiCl or LiBr in dipolar aprotic solvents like dimethylformamide and dimethylsulfoxide. Alternatively the halides may be made directly from the alcohols using classical reagents for this purpose such as PBr 3 and SOCl 2 .
Compounds of the formula 4 may be converted to the diol of formula 5 (Step 6) under aqueous or alcoholic acidic conditions, promoted by Lewis acids such as transition metal halides or halides of the Group 3 metals, or by protic organic acids such as p-toluenesulfonic and related alkyl and arylsulfonic acids, trifluoroacteic acid and related organic carboxylic acids with a pK of less than 6, and inorganic acids such as sulfuric, hydrochloric, phosphoric and nitric acids. Note that compounds of the formula 4 where R and R1 are methyl and R3 is p-toluenesulfonates are commercially available from the Aldrich Chemical Company (see Scheme 2, infra.).
The diol of formula 5 may be converted to the cyclic sulfates of formula 6 and formula 6a (Step 7) using a two stage procedure involving an intermediate cyclic sulfite produced by action of thionyl chloride or thionyl imidazole either neat or in most common organic solvents like halogenated methanes and ethanes, esters and ethers. The reaction may be accompanied by an organic amine base like triethylamine, diethylamine, diethyl isopropylamine, DABCO or related trialkylamines. Oxidation of the intermediate cyclic sulfite to the sulfate of formula 6 is usually performed with a Ru(III) catalyst with the ultimate oxidant being sodium periodate, or sodium or calcium hypochlorites in an aqueous-organic solvent mixture. Alternatively, diol 5 may be converted directly to cyclic sulfate 6 by use of sulfuryl chloride or sulfuryldiimidazole under the same reaction conditions as stated in this paragraph for thionyl chloride and thionyl diimidazole.
The pathways for the production of nelfinavir free base involve the sequence of intermediates shown in Schemes 2 and 3, proceeding via azido-alcohol and phthalimido alcohol intermediates, respectively. The processes both proceed through cyclic sulfate intermediates of formulas 6 and 6a. They diverge after that point and take quite different paths to nelfinavir free base.
Scheme 2 describes a reaction sequence wherein (2S,3S)-(−)tartaric acid is converted to a cyclic sulfate diaryl or dialkyl sulfonate 6 via reaction transformations such as those detailed above. This reaction scheme involves the conversion of 6 to 8 through 7, in which sodium azide attacks the more labile sulfate functionality exclusively over the primary alkyl or arylsulfonate termini to yield the azido-alcohol adduct 8 in 95% yield. In addition to sodium azide, one may use any inorganic metal azide or an organic tetralkylammonium azide. The solvents for this transformation range from aqueous solutions of polar organic solvents such as acetone, TH F, DMF (N,N-dimethylformamide), DMAC (N,N-dimethylacetamide), DMSO or N-methyl-2-pyrollidone at temperatures ranging from 25° C.-70° C., although the preferred conditions are aqueous acetone at 25° C. This reaction can be carried out in a variety of polar organic solvents. Similar chemistry has been extended to the dihalogenated analogs (6a) of 6 as well. Intermediate 6, the corresponding dihalogenated analogs (6a) and ensuing compounds that are indicated in this Scheme have been prepared for the first time and are useful to make nelfinavir free base. To the inventors' knowledge, this is the first example of a nitrogen (or any other) nucleophile selectively reacting with an internal sulfate in the presence of primary carbon centers bearing leaving groups. The sulfate 7 is hydrolyzed off using a strong inorganic protic acid. Typical ideal conditions would include use of sulfuric acid with 1-2 equivalents of water present in a solvent such as THF.
Catalytic hydrogenation of 8 to 9 can be performed with a variety of palladium catalysts such as Pd on carbon, palladium hydroxide and related Pd(II) species at pressures as low as 1 atmosphere and temperatures as low as 25° C. Suitable solvents for this reaction include alcohols of 7 carbons or less, ethyl acetate and related esters of 8 carbons or less, THF and other ethers. A strong protic acid such as HCl, HBr, sulfuric or nitric acid is used. Preferred conditions utilize a mixture of methanol and THF as solvent with 6M HCl present using 5% palladium on carbon catalyst at 1 atmosphere pressure of hydrogen.
Coupling of the amine salt with 3-acetoxy-2-methyl-benzoyl chloride (AMBCl) in the presence of base affords the oxazoline 10 in approximately 90% yield. This compound and methods of making this compound are disclosed in U.S. application Ser. No. 08/708,411, of inventors M. Deason and K. Whitten, titled “Intermediates for Making HIV-Protease Inhibitors and Methods of Making HIV-Protease Inhibitors”, filed on Sep. 5, 1996. The coupling may be performed in most common organic solvents such as THF, diethyl ether, dioxane, methyl t-butyl ether or other ethers; esters such as ethyl, methyl and isopropyl acetate, halogenated solvents such as halogenated methanes and ethanes, chlorobenzene and other halogenated benzenes, nitrites such as acetonitrile and propionitrile; lower alcohols such as ethanol, isopropanol, t-butanol and related alcohols, and polar organic solvents such as dimethylformamide, dimethylsulfoxide, N-methyl-2-pyrrollidone and related amide-containing solvents. A base is frequently used and may be any of a number of inorganic bases such as metal hydroxides, bicarbonates and carbonates or organic bases such as amines like triethylamine, diethylamine, diethyl isopropylamine, DABCO (1,4-diazabicyclo[2.2.2]octane) or related di- or trialkylamines, as well as amidine bases such as DBM (1,5-diazabicyclo[4.3.0]non-5-ene) and DBU (1,8-diazabicyclo[5.4.0]undec-7-ene). Preferred conditions have been found to be use of triethylamine in THF at 25° C. for several hours.
Subsequent treatment with base and 3S,4aR,8aR-3-N-t-butylcarboxamido-decahydroisoquinoline (PHIQ, which can be purchased from Procos SpA and NSC Technologies and which can be prepared according to the method described in U.S. Pat. No. 5,256,783, which is incorporated herein by reference) affords 11 quantitatively. Several permutations of base/solvent combinations can be applied to conduct this transformation. The base can be any metal carbonate, bicarbonate or hydroxide in an alcoholic medium such as methanol, ethanol, isopropanol or an analogous alkyl alcohol of 7 or less. The preferred temperatures of the process range from 25-70° C. or at the reflux temperature of the solvent mixture. Preferred conditions involve use of potassium carbonate in isopropanol or methanol at 60° C. for 5-10 hours.
The next step in this Scheme is the reaction of 11 with thiophenoxide which cleaves the oxazoline ring to generate nelfinavir free base. This transformation can be carried out either neat or in any polar organic solvent. Preferred solvents are ketones of greater than 5 carbons, such as cyclohexanone, methyl isobutylketone or ethers such as THF, dioxane and related cyclic or acyclic ethers. A base may be required, and acceptable bases include any methyl carbonate, bicarbonate or hydroxide. The reaction is run generally at or near the reflux temperature of the solvent. Preferred conditions involve the use of excess thiphenol in methyl isobutylketone at reflux with potassium bicarbonate as base.
Cyclic sulfate 6 serves as a common intermediate in both reaction pathways outlined in Schemes 2 and 3. Moreover, in the latter case, the phthalimido alcohol adduct 7a, obtained from the reaction of 6 with potassium phthalimide, serves both as a masked amine and a usefull precursor for the oxazoline ring formation in the next step. This transformation proceeds rapidly in aqueous acetone and DMF (N,N-dimethylformamide), while solvents such as N-methyl-2-pyrrollidone and N,N-dimethylacetamide are also acceptable. Imide bases derived from maleimide and succinimide may function as alternatives to phthalimide in the process . The reaction pathway leading to nelfinavir free base from 7a is significantly different from the azido alcohol route shown in Scheme 2. In Scheme 3, the conversion of 7a to the epoxy oxazoline 8a occurs in the presence of base/alcohol mixtures, thus delivering the two primary electrophilic sites in the 4-carbon unit with different reactivity profiles. Such base/alcohol combinations may include any alkyl alcohol and any inorganic metal carbonate, bicarbonate or hydroxide. Preferred conditions involve the use of potassium carbonate in methanol. The exact alcohol used will determine the resulting ester functionality produced. Thus, the epoxide terminus in 8a is reacted with PHIQ in the same reaction vessel to afford 9a in approximately 90% yield.
Reaction of 9a with thiophenoxide cleaves the oxazoline ring to generate intermediate 10a. This transformation can be carried out either neat or in any polar organic solvent. Preferred solvents are ketones of greater than 5 carbons such as cyclohexanone, methyl isobutylketone or ethers such as THF, dioxane and related cyclic or acyclic ethers. A base may be required, and acceptable bases include any metal carbonate, bicarbonate or hydroxide. The reaction is run generally at or near the reflux temperature of the solvent. Preferred conditions involve the use of excess thiophenol in THF at reflux with potassium carbonate as base. The resulting isoimide 10a is then hydrolyzed to the free amine of 11a with ethanolamine in 70% overall yield. One can also use hydrazine in alcoholic solvents. 11a can be either isolated as any alkyl or aromatic acid salt, although camphorsulfonic acid and benzoic acid are preferred. The salt 11a or the free base is then coupled with 3-acetoxy-2-methyl benzoyl chloride (AMBCl) to form nelfinavir free base (12). The procedure for this transformation is described in U.S. patent application Ser. No. 08/708,411 of inventors M. Deason and K. Whitten, titled “Intermediates for Making HIV-Protease Inhibitors and Methods of Making HIV-Protease Inhibitors”, filed Sep. 5, 1996, the disclosure of which is herein incorporated by reference. Compounds 7a-11a described in this scheme are novel and are useful for preparation of nelfinavir free base.
Since the phthalimido alcohol route intersects at the 11a stage with the chloroalcohol chemistry (described in U.S. patent application Ser. No. 08/708,411 of inventors M. Deason and K. Whitten, titled “Intermediates for Making HIV-Protease Inhibitors and Methods of Making HIV-Protease Inhibitors”, filed Sep. 5, 1996) wherein the expensive AMBCl is introduced in the final step, it may be cheaper than the azido alcohol process described earlier. The phthalimido alcohol route may have some advantages over the chloro alcohol route for commercial production.
Experimental Section
1. Procedures for the Tosylate / Azide Version of the Tartaric Acid Route
Chemical
MW
Density
Scale Factor
D-Tartaric Acid
150.09
1 equiv.
2,2-
104.15
.847
3.4 equiv.
dimethoxypropane
Methanol
32.14
.791
.15 equiv.
p-toluenesulfonic acid
190.22
.003 equiv.
monohydrate
Cyclohexane
84.16
.779
1 g (1)/4.5 ml
Ref: Mash. E. A.; Nelson, K. A.; Van Deusen, S.; Hemperly, S. B. Org. Synth. Coll. Vol. VII, 155 (1990).
Into a 5 L round bottom flask was placed 505 g (3.36 mol) of D-tartaric acid (Fluka, 98-99% ee), 1425 mL of 2,2-dimethoxypropane, 20 mL of methanol, 2.0 g of TsOH hydrate and 2250 mL of cyclohexane. The mixture was brought to reflux with stirring and the acetone/cyclohexane and methanol/cyclohexane azeotropes were distilled off slowly at 52-54° C. over a two day period. This was accomplished with a variable takeoff head using a reflux ratio of ca. 8:1. When the head temperature dropped off, heating was increased to distill off residual 2,2-dimethoxypropane and any remaining cyclohexane. When no more liquid was coming off, heating was stopped and the residual red-orange liquid was analyzed by 1H NMR. This consisted of almost pure 2. This material could be taken into the reduction without further purification. The 1 H NMR spectrum indicated identity with the commercial material: 1 H NMR (CDCl 3 ) δ4.8 (s 2H), 3.8 (s, 6H), 1.4 (s, 6H).
Chemical
MW
Density
Scale Factor
Grade
Compound 2
218.21
1 equiv.
Sodium
37.83
1.5 equiv.
Aldrich,98%
Borohydride
powder
Ethanol
46.07
.785
1 g(1)/10 ml
McCormick
Distilling Co.
200 proof
Absolute
Methyl t-butyl
88.15
.740
Fisher
ether
Sat'd NaCl
Reference: Takano, S.; et al; Synthesis, 1986, 811.
Procedure
In a 1 liter 3-neck flask was placed a magnetic stirrer, thermometer and dropping funnel with an Argon purge. The NaBH 4 (13.05 g, 0.345 mol) was slurried in 350 ml of ethanol and cooled to 5° C. with an ice bath. Compound 2 (50 g, 0.23 mol) was slurried in 150 ml of ethanol and added dropwise keeping the temperature less than 20° C. The mixture was then stirred at 5-10° C. for 2.5 hours. This was then concentrated on a rotovap to about a third of its volume and a solvent exchange was done with MTBE. The final volume of the solution should be about 500 ml of MTBE. This was then filtered to remove borane salts and washed with 75 ml of saturated NaCl. (The washes should be minimized because of the extreme water solubility of the product). This was then concentrated on a rotovap to give a yellow oil. 24.05 g, 65% yield. (Corrected yield was ˜82% based on the starting material containing ˜20% of the deprotected diol). This could be taken into the tosylation without further treatment. The 1 H NMR spectrum indicated identity with the commercial material: 1 H NMR (CDCl 3 ) δ4.0 (br s, 2H), 3.8 (br d, 2H), 3.7 (br d, 2H), 3.6 (br s, 2H), 1.4 (s, 6H).
Chemical
MW
Density
Scale Factor
Diol (3)
162.19
1 equiv.
p-toluenesulfonyl
190.65
2.08 equiv.
chloride
Triethylamine
101.19
.726
2.1 equiv.
Methyl t-butyl
88.15
.740
1 g (3)/5.5 ml
ether
1 N HCl
Sat'd NaCl
Reference: J. Org. Chem. 1980, 45, 2995.
Procedure
The diol (351 g, 2.16 mol) was dissolved in 2.0 L of MTBE and Et 3 N (640 ml, 466 g, 4.60 mol) was added. The TsCl (860 g, 4.51 mol, 2.08 equiv) was added as a solid in portions keeping the temperature under 40° C. The mixture was stirred for 17 hours after the end of the addition. TLC analysis can be accomplished with CH 2 Cl 2 /EtOAc (70:30) with PMA development. The diol (R f =0.10), monotosylate (R f =0.0.45) and ditosylate (R f =0.88) are easily observed during the course of the reaction. The reaction mixture was washed successively with water (2×2.0 L), 1N HCl (1×1.0 L) and brine (1×1.0 L). The layer was dried with Na 2 SO 4 and evaporated to leave an orange oil (873 g, 85%). This was analyzed by 1 H NMR and showed the ditosylate contaminated with ca 10% TsCl. This could be taken directly into the hydrolysis reaction without further purification. The 1 H NMR spectrum indicated identity with the commercial material: 1 H NMR (CDCl 3 ) δ7.8 (d, 4H), 7.4 (d, 4H), 4.2-4.0 (overlapping m, 6H), 2.4 (s, 6H), 1.2 (s, 6H).
Chemical
MW
Density
Scale Factor
Acetonide (4)
470.4
1 equiv.
95% ethanol
46.07
.785
1 g (4)/4 ml
1 M HCl
1 g (4)/1 ml
Procedure
The crude acetonide from the previous step (ca. 873 g) was dissolved in 4 volumes of 95% ethanol and 1 volume of 1M HCl was added. The mixture was heated to reflux for 3 hours. Evaporation of a small aliquot of the solution and analysis by 1 H NMR showed the reaction to be complete. Two workups may be used. The solvents may be evaporated to give the product directly which shows no other organic products by 1 H NMR except solvent. This is usually contaminated with EtOH and water, however. Alternatively, the bulk of the solvent may be removed by rotary evaporation and the remainder extracted with EtOAc (two times). The combined extracts were washed with water and brine and dried with Na 2 SO 4 . The drying agent was filtered off and the solvent removed by rotary evaporation to give 571 g of a dark tan gray solid (61% from diol-acetonide). 1 H NMR showed the ditosylate diol contaminated with a small amount of EtOAc. This was used directly in the next step. The 1 H NMR spectrum indicated identity with the commercial material: 1 H NMR (CDCl 3 ) δ7.8 (d, 4H), 7.4 (d, 4H), 4.1 (m, 4H), 3.9 (app t, 2H), 3.0 (br s, 2H), 2.4 (s, 6H).
Chemical
MW
d
Scale Factor
Grade
diol (5)
430.5
1 eq
Thionyl
118.97
1.631
2.6 eq
Aldrich 99%
Chloride
Methylene
84.93
1.325
7.5 ml/1 g of
Fisher ACS
Chloride
(5)
Procedure
In a 2 liter, 3-neck flask was placed the diol 5 (100 g, 0.23 mol) and 750 mL of methylene chloride. This was cooled to 5° C. with an ice bath and purged with argon. The thionyl chloride (71.2 g, 44 ml, 0.6 mol) was added dropwise and the mixture then allowed to warm to room temperature overnight (18 hours). Gas evolution was seen throughout. The mixture was then concentrated on a rotovap to yield 105.5 g of brown oil (96% yield). The reaction can be followed by (TLC:20% EtOAc/CH 2 Cl 2 :SiO 2 ). This material can be used as is in the next step.
Chemical
MW
d
Scale Factor
Grade
Compound
476.5
1
eq
(5a)
Ruthenium III
207.42
1
mg/5 g of 5a
Aldrich
Chloride
hydrate
Sodium
213.89
1.5
eq
Aldrich 99%
Periodate
Acetonitrile
41.05
.786
4
ml/g of (5a)
Fisher ACS
Deionized
18
1
10
ml/g of
Deionized
water
(5a)
Procedure
In a 3 liter, 3-neck flask was placed the sulfite 5a (105.5 g, 0.22 mol) with 400 mL acetonitrile and 1000 mL D. I. Water. This formed a biphasic mixture of oil and solvent. The ruthenium (III) chloride (20 mg) was added and the mixture stirred under argon. The sodium periodate (67.4 g, 0.32 mol) was added in four equal portions. No exotherm was seen after the addition. This mixture was stirred at room temperature for two hours and product slowly crystallized from the reaction mixture. This was filtered and dried overnight at 50° C in a vacuum oven. Yield: 94.6 g of tan solid (87% yield). The filtrate was extracted with methyl-t-butyl ether and concentrated to give an additional 6 g of material for an overall yield of 93%. 1 H NMR (CDCl 3 ) δ7.8 (d, 4H), 7.4 (d, 4H), 5.0 (m, 2H),4.4 (m, 4H), 3.0 (br s, 2H), 2.5 (s, 6H).
Chemical
MW
Density
Scale Factor
Cyclic Sulfate (6)
492.5
1 equiv.
Sodium azide
65.01
1.15 equiv.
Acetone
58.08
.791
1 g (6)/5 ml
D I Water
18
1
1 g (6)/.8 ml
Procedure
The cyclic sulfate (545.4 g, 1.10 moles) was dissolved in 2500 mL of acetone and 500 mL of water (no ppt present). While stirring at ambient temperature, sodium azide (1.21 moles, 1.1 equiv, 78.6 g) was added in four portions over 10 minutes. No temperature rise was observed. The reaction was followed by HPLC. After 24 hours, HPLC indicated that the reaction contained 5% starting material and a single major product. Another 5 g of NaN 3 was added and the reaction was allowed to stir another 18 hours. HPLC analysis at this time showed the starting material to be consumed resulting in an orange solution. The bulk of the solvent was removed in vacuo and a white solid crystallized from an orange oil. This water-wet cake was carefully removed from the flask and was filtered, washed with water (ca 1 L) and pressed dry on the Buchner funnel with gooch rubber. This gave 955.6 g of a wet solid (expect 613.3 g). This was used directly in the next step.
Chemical
MW
Density
Scale Factor
Azidosulfate (7)
557.54
1 equiv.
D I Water
18
1
1 equiv.
Sulfuric Acid
˜.02 ml/g (7)
Tetrahydrofuran
72.11
.889
1 g (7)/10 ml
5% Pd/C
˜.1 g/g (7)
Methanol
32.14
.791
1 g (7)/10 ml
6 N HCl
3 equiv.
Procedure
This cake was dissolved in 2200 mL of THF and 0.5 mL of concentrated sulfuric acid was added. The mixture turned slightly turbid. No precipitate and no heat evolution were noted. HPLC analysis indicated no reaction at all after 1 hour. Eight mL of conc. sulfuric acid was added and the mixture was allowed to stir for 18 hours at ambient temperature. HPLC analysis at this time showed ca 40:60 SM/hydrolysis product and about 200 mL of water had separated from the reaction which was removed. The mixture was filtered through 750 g of sodium sulfate and another 5 mL of sulfuric acid was added. After a total reaction time of 43 h, HPLC analysis showed no sulfate. Extractive workup of a small aliquot showed only the azido alcohol and no sulfate.
The solution was diluted with 2200 mL of methanol, 500 mL of 6N HCl and 50 g of 5% Pd on activated carbon in a 12 L glass reactor. Hydrogen gas was bubbled slowly through the solution for 18 hours. TLC analysis (EtOAc/CH 2 Cl 2 10:90) showed a trace of azide so the reaction was allowed to stir another 20 hours. The mixture was filtered through a bed of celite on a sintered glass funnel, and washed through with 1.5 L of THF to give a bright yellow solution. This was evaporated to provide a very wet gooey oil. This was dissolved in 3 L of EtOAc and washed with 500 mL of water and 500 mL of brine. The solution was dried with NA 2 SO 4 , and evaporated to give 464.0 g of a light brown oil. This was analyzed by 1 H NMR and determined to be contaminated with 7% EtOAc. It was assumed that the mixture contained 431 g of the amine salt. 1 H NMR (CD 3 OD) δ — 7.8 (overlapping d, 4H), 7.5 (overlapping d, 4H), 4.3 (dd, 1 H), 4.2 4.0 (overlapping m, 4H), 3.6 (m, 1 H), 2.6 (s, 6H); high resolution mass spectrum calcd for C 18 H 24 NO 7 S 2 430.0994, found 430.0983.
Chemical
MW
Density
Scale Factor
Amine salt (9)
465.96
1 equiv.
AMB-Cl
212.63
1.05 equiv.
Triethylamine
101.19
.726
10 equiv.
Tetrahydrofuran
72.11
.889
1 g (9)/7 ml
Procedure
This oil was dissolved in 3.0 L of THF and cooled to 9° C. under Ar. The AMB-Cl (206.7 9, 0.97 mol, 1.05 equiv) was added as a liquid. A solution of 1000 mL (ca 10 equiv) of Et 3 N in 600 mL of THF was added via an addition funnel slowly, observing the temperature. The internal temperature rose to 25° C. over the addition of the first 300 mL of solution (ca the first 1.5 equiv) before subsiding. The remainder of the solution was added rapidly over 20 min to give a tan solution containing a precipitate of triethylamine hydrochloride. The cooling bath was removed and the mixture was stirred at ambient temperature for 16 hours. Workup of a small aliquot of the solution showed no SM and a clean conversion to the oxazoline. The bulk of the solvent was removed in vacuo and the residue was dissolved in 2 L of EtOAc and washed successively with water, saturated aq. NaHCO 3 (1 L), water (1 L) and brine (1 L). The solution was dried with Na 2 SO 4 and evaporated to give the hydroxytosylate as an orange oil. 1 H NMR (CDCl 3 ) δ7.8 (d, 4H), 7.6 (d, 2H), 7.4 (d, 4H), 7.2 (t, 1H), 7.1 (d, 1H), 4.4-4.2 (overlapping m, 4H), 4.1 (dd, 1H), 3.m, 1H), 2.5 (s, 3), 2.4 (s, 3H), 2.3 (s, 3H); high resolution mass spectrum calcd for C 21 H 23 NO 7 S+Cs 566.0250, found 566.0275.
Chemical
MW
Density
Scale Factor
Hydroxytosylate (10)
433.48
1 equiv.
Perhydroisoquinoline
238.76
1 equiv.
Potassium carbonate
138.21
3 equiv.
Isopropanol
60.1
.785
1 g (10)/7.5 ml
Procedure
The hydroxytosylate 10 was dissolved in 175 mL of IPA along with 12.50 g (52.3 mmol of PHIQ, ca. 1.0 equiv) of PHIQ and 159 mmol (3 equiv) of K 2 CO 3 . The mixture was heated to 70° C. and stirred for 20 hours. A thick white precipitate slowly comes out of the reaction mixture. TLC analysis at this time (methylene chloride/EtOAc 70:30) does not show epoxide or hydroxytosylate, but only a baseline streak/spot. The bulk of the IPA was removed in vacuo and the residue was transferred to 300 mL of water and the pH was brought to ca 7-8 with 6N HCl. The mixture was stirred for 30 min and filtered. The resulting white solid was washed well with water and dried under vacuum to leave 19.0 g (68% from azido-sulfate) of the PHIQ adduct 11 as an off-white solid. This crude substance is identical with that produced by another route. The crude product was slurried in a mixture of 180 mL of methanol and 3675 mL of water and heated to 40° C. for 1 h. The solid was filtered at 40° C. and washed with 500 mL of water. The wet cake was recharged to the reactor and slurried with 3 L of water and 300 mL of methanol and heated to 58° C. The mixture was cooled to ca 50° C. and filtered. The filter cake was washed with 1 L of water followed by 1 L of n-BuOAc. The solid was dried at ca. 28 in Hg to give 215.7 g of 11 which 91.3% pure as assayed by HPLC. 1 H NMR (DMSOd 6 ) δ9.6 (br s, 1H), 7.4 (br s, 1H), 7.2-7.0 (overlapping m, 2H), 6.9 (d, 1H), 4.8 (br s, 1H), 4.5 (m, 1H), 4.3 (app t, 1H), 4.2 (app t, 1H), 3.8 (m, 1H), 2.9 (br d, 1H), 2.6 (br d, 1 H), 2.4-1.4 (overlapping m, 15H), 2.4 (s, 3H), 1.2 (s, 9H); 13C NMR (DMSOd 6 ) d 173.6, 164.3, 156.5, 130.1, 126.5, 125.2, 120.9, 117.3, 70.5, 70.4, 70.2, 67.9, 60.1, 59.5, 50.8, 36.5, 34.0, 31.5, 31.0, 29.8, 26.9, 26.5, 21.0, 14.0; high resolution mass spectrum calcd for C 26 H 40 N 3 O4 (M+H + ) 458.301 9, found 458.3008.
Procedure
Compound 11 (215 g, 1.0 equiv) was slurried in 1720 mL of MIBK along with KHCO 3 (94.1 g, 2.0 equiv) and thiophenol (193 mL, 4.0 equiv). The mixture was sparged with nitrogen for 2 minutes and then heated to reflux for 6.5 hours with a slow sparge. Toluene was added (1720 mL) and the mixture was refluxed for 1 hour and then slowly allowed to cool to ambient temperature over 5.5 hours. The mixture was filtered and washed with 860 mL of toluene. The solid was dried at ca. 28 in Hg and 55-60° C. overnight to give 317 g of crude compound 12. This was slurried in 2377 mL each of acetone and water and the mixture was heated to ca. 60° C. for 2.5 hours. The mixture was allowed to cool to ambient temperature slowly and filtered. The cake was washed with a mixture of 850 mL of acetone and 850 mL of water and dried at 55-60° C. for 24 hours to give 215 g of purified compound 12. The substance was assayed at 98% purity by HPLC and gave a 1 H NMR spectrum identical to material prepared via another route.
II. Procedures for the Tosylate/Phthalimide Version of the Tartaric Acid Route
Process for the Preparation of the Phthalimido alcohol (7a):
Raw Material
Source
Amount
M. wt
Mol.
Cyclic Sulfate (6)
991-116-1
1100 g
492.5
2.23
Potassium Phthalimide
Aldrich
455 g
185.2
2.46
Con. Sulfuric acid
Fisher
66 mL
—
—
Acetone
Fisher
5.5 L
—
—
Water
Stock
11 L + 198 mL
—
—
Compound 6, potassium phthalimide, acetone and 198 mL water were charged in a 22 L reactor and stirred. An exotherm was observed (35-40° C.). The mixture was stirred for 4 hours as the exotherm subsided. The mixture was checked by HPLC for reaction completion (3 drops of reaction mixture were diluted with 25 volumes of acetonitrile and 0.1M ammonium acetate solution). The mixture was warmed to 50° C. 66 mL of concentrated sulfuric acid were added over 10 minutes. The mixture was sampled to confirm completion of hydrolysis by HPLC as above. Copious amounts of precipitate (potassium sulfate) were observed.
The reaction was held at 50-55° C. for 20 minutes. 5.5 L of water were rapidly added over 5 minutes and agitation was increased. 5.5 L of more water were added over 1 hour. The temperature rose to 37° C. The product was seen falling out of solution. The product was cooled to 25° C. over 1 hour, and then held for one hour or allowed stir overnight. The solid was filtered and rinsed with water. The cake was dried in a vacuum (29 in Hg) oven at 35° C. overnight or until the water content was below 1%. The yield of 7a was 1205 g (96.6%); HPLC purity 92.9%. 1 H NMR (CDCl 3 ) δ7.87-7.83 (m, 1H), 7.79-7.74 (m, 3H), 7.70 (d, J=8.1 Hz, 2H), 7.62 (d, J=8.1 Hz, 2H), 7.26 (d, J=8.1 Hz, 2H), 7.16 (d, J=8.1 Hz, 2H), 4.63 (app t, J=9.2 Hz, 1H), 4.55-4.39 (m, 3H), 4.06 (dd, J=3.7, 10.7 Hz, 1H), 3.96 (dd, J=4.4, 10.7 Hz, 1H), 3.40 (br s,1H), 2.38 (s, 3H), 2.25 (s, 3H); high resolution mass spectrum calcd for C 26 H 25 NO 9 S 2 +Cs 692.0025, found 692.0036.
Process for the Preparation of 9a
Raw Material
Source
Amount
M. Wt.
Mol
7a (88% pure)
JDS-4-128
1000 g
559.6
1.787
Anh. Potassium carbonate
Fisher
493.9 g
138.2
3.574
Acetonitrile
Fisher
2 L
—
—
Methanol
Fisher
4 L
—
—
PHIQ
1252
425 g
238
1.787
Water
stock
10 L
—
—
Compound 7a, potassium carbonate, 2 L acetonitrile and 3 L methanol were charged in a 22 L reactor. The mixture was stirred, warmed to 50° C., held for 3 hours, then sampled for HPLC analysis (3 drops of the reaction mixture were diluted with 25 drops of 1:1 acetonitrile and 0.1M ammonium acetate solution). The profile consisted of ˜63% epoxyoxazoline intermediate 8a and <5% starting material. PHIQ dissolved in 1 L methanol was added and the batch temperature was raised to 60° C. The mixture was held at this temperature for 3 hours. HPLC analysis showed nearly 70% of product at this stage. 5 L water were added over 1-2 minutes, and the heat was removed. The batch temperature was around 40° C. 5 L water were added over 1 hour to the mixture, which was cooled to room temperature then held for 1 hour at the temperature. The reaction mixture was then filtered, and the cake was rinsed with 1.5 L water and dried in an oven at 50° C. overnight. The yield of 9a was 577 g (74%). The HPLC purity exceeded 99%.
1 H NMR (CDCl 3 ) δ7.79 (d, J=7 Hz, 1H), 7.65 (d, J=7 Hz, 1H), 7.56-7.48 (m, 2H), 5.99 (br s, 1H), 4.50-4.43 (m, 3H), 3.89 (s, 3H), 3.28 (s, 1H), 3.04 (d, J=11.4 Hz, 1H), 2.59-2.51 (m, 2H), 2.34-2.23 (m, 2H), 1.93 (app q, J=12.9 Hz, 1H), 1.87-1.59 (overlapping m, h.), 1.53-1.15 (overlapping m, 6H), 1.36 (s, 9H); high resolution mass spectrum calcd for C 27 H 39 N 3 O 5 +Cs 618.1944, found 618.1956.
Process for the Preparation of Compound 11a
Raw Material
Source
Amount
M. wt
Mol.
9a
1183-011
JDS-4-147
1000 g
485.6
2.059
Thiophenol
Aldrich
906 g (844 mL)
110.0
8.237
THF
Fisher
6 L
—
—
Anh. Potassium-
bicarbonate
Fisher
63 g
100.1
0.630
Ethanolamine
Aldrich
2.12 L
61
34.75
Methyl t-butylether
(MTBE)
Fisher
9 L
—
—
Benzoic acid
Aldrich
502 g
122
4.11
Satd. Bicarbonate soln.
5L
—
—
—
Hexanes
Fisher
2.8 L
—
—
Compound 9a, potassium bicarbonate and 6 L THF were charged in a 22 L reactor and the mixture was degased with a subsurface argon purge and stirring. Thiophenol was charged in one portion and sparging was continued for 20 minutes. The batch was brought to reflux (67° C.), held at reflux for 26 hours, then sampled for HPLC analysis. The two intermediate isoimides were produced in an ˜85:15 in ratio along with 10% unreacted starting material. All of the ethanolamine was charged in one portion, and reflux was continued for 20 hours. The batch was checked by HPLC and cooled to 45° C. 5 L of MTBE and 5 L of saturated sodium bicarbonate solution were added. The mixture was agitated for 30 minutes and allowed to settle. The layers were separated. The aqueous layer was reextracted with 3 L MTBE, and the organics were combined. The MTBE extracts were washed with 5 L sodium bicarbonate solution, and the organic layer was separated. The aqueous layer was checked by HPLC for the presence of Compound 10a. 60% of the volatiles were stripped (based on earlier experiments, full stripping of all solvents was warranted since the THF present in this concentrate severely impedes crystallization), and the concentrates were warmed to 50° C. Benzoic acid was added in one portion. The mixture was held for 1 hour. A few seed crystals were added to induce precipitation, and 2.8 L hexanes were added. The mixture was cooled to room temperature and held for 1 hour. All of the solid was filtered, and the cake was rinsed with 1 L MTBE. The mother liquor was concentrated to an oil, 2 L MTBE were added, the mixture was warmed to 50° C. temperature, and then cooled to room temperature, and the product was filtered. This process was repeated with the filtrate. All solids were combined and dried in a vacuum oven at 50° C. overnight. The filtrate still contained 15-20% Compound 10a that could not be derivatized as solid. The yield of 11a was 602 g (52%; note that a 71% yield has been achieved on a similar run conducted on a 200 g scale). The HPLC purity of the product exceeded 99%. 1 H NMR (CD 3 OD) δ7.97 (d, J=8 Hz, 2H), 7.56 (d, J=8 Hz, 2H), 7.5-7.1 (overlapping m, 6H), 3.77 (m, 2H), 3.10 (m, 1H), 2.96 (m, 2H), 2.74 (d, J=8.5 Hz, 1H), 2.51 (t, J=12.5 Hz, 1H), 2.36 (dd, J=2.5, 13 Hz, 1H), 2.26 (d, J=11.5 Hz, 1H), 2.02 (q, J=2.5, 13 Hz, 1h), 2.0-1.2 (overlapping m, 12H), 1.31 (s, 9H).
Process for the preparation of Nelfinavir Free Base:
Raw Material
Source
Amount
M. wt.
Mol.
11a
1183-016
600 g
555.4
1.08
Anh. Ethanol
Fisher
3 L
—
—
AMBCl
AB
252.6
212.6
1.19
Triethylamine
Aldrich
327.8
101.2
3.24
THF
Fisher
300 mL
—
—
50% NaOH
Fisher
432 g
40
5.40
Methanol
Fisher
600 mL
—
—
2.5% Hcl
Stock
8 L
36.5
5.47
Acetone
Fisher
9.25 L
—
—
Water
Stock
3 L
—
—
2:1 acetone water
Stock
3 L
—
—
11a was slurried in 3 L ethanol and cooled to 0° C. Triethylamine was charged in one portion, with the temperature kept below 10° C. AMBCl dissolved in 300 mL THF was charged, with the pot temperature kept below 15° C. The mixture was warmed to room temperature and checked by HPLC to confirm consumption of all of compound of the formula 11a (less than 2% of 11a remained before proceeding with the next operation). 50% NaOH was charged in one portion, and the batch was brought to reflux (75° C). 600 mL of methanol were added to dilute the mixture. The mixture was sampled by HPLC to confirm completion of hydrolysis. The batch was cooled to room temperature. The slurry was slowly fed in a 22 L reactor containing 8 L of 2.5% HCl with vigorous agitation. The pH of this slurry was adjusted to between 5 and 6. The batch was warmed to 55° C. and held at this temperature for one hour and filtered hot. The cake was rinsed with water. HPLC analysis of the filtrate indicated mostly benzoic acid with very little nelfinavir free base. The wet cake was dried in a vacuum oven at 65° C. overnight. The yield of crude nelfinavir free base was 1.45 Kg (100%; note that the batch was still 45-55% water wet and contained 1.1% benzoic acid and some inorganic salts).
Crystallization of Nelfinavir Free Base
A portion of the wet cake (˜500 g net AG 1346) was combined with 8.25 L acetone and 1.1 L water. It was heated to reflux. To this was added 1 L acetone and 1 L water. The hot mixture was filtered through celite. The filtrate was cooled to room temperature and then to 3° C. and held for one hour. The mixture was filtered and the cake was rinsed with 3 L 2:1 acetone/water. The cake was dried in a vacuum oven at 70° C. overnight. The yield of nelfinavir free base was 416 g (81%). HPLC analysis indicated the purity to be 99.4%, but still containing 0.52% benzoic acid.
Reslurry of Nelfinavir Free Base
The above solid was slurried in 4 L water (pH ˜4.92). To this was added 1.9 g of 50% NaOH (pH is now 11.8). To this was added 27 mL of 2.5% HCl to adjust the pH to between 7.5 and 8. This was heated to 60° C. and held one hour and filtered hot. The cake was rinsed with warm (40° C.) water. The cake was dried in a vacuum oven at 70° C. The yield was 386 g (98%). The filtrate contained mostly benzoic acid with very little nelfinavir free base. HPLC analysis indicated a purity of >99.9% with less than 0.1% benzoic acid. This material was spectroscopically identical to material prepared via other routes.
While the invention has been described in terms of various preferred embodiments using specific examples, those skilled in the art will recognize that various changes and modifications can be made without departing from the spirit and scope of the invention, as defined in the appended claims. | HIV protease inhibitors inhibit or block the biological activity of the HIV protease enzyme, causing the replication of the HIV virus to terminate. These compounds can be prepared by the novel methods of the present invention using the novel inventive intermediates. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to an earlier filed co-pending Provisional Patent application No. 61,366,356 filed Jul. 21, 2010 entitled Innovative Water Sprays Applications for Dust Control on Mining Machines.
FIELD OF THE INVENTION
[0002] This invention relates to mining More specifically, it relates to dust control around a continuous miner or similar mining machine through the use of water spray applications.
BACKGROUND OF THE INVENTION
[0003] Increased productivity and high out-of-coal seam dilution (25% to 30%) in the US and around the globe continue to generate dust control problems in mining areas. After a significant decrease in the number of incidents of coal worker's pneumoconiosis (CWP) over the last several decades, the number of reported cases in this decade is increasing. The primary cause of CWP is inhalation of respirable dust in a confined workplace; specifically, the inhalation of coal and quartz dust in a mine. The National Institute for Occupational Safety and Health recognizes this disease as being severely disabling, potentially lethal, and entirely preventable through respirable (less than 10 micron) dust control. The typical protocol for prevention of this disease has been monitoring mine workers for symptoms of this disease and, once a CWP diagnosis has been made, moving the miner to a low-dust exposure job. Prevention of this disease through a significant reduction in mine workers' exposure to respirable dust is a high priority. Additionally, several mines are now facing reduced dust standards due to high respirable quartz content in the dust. In underground US coal mines, miner operator (MO), haulage unit operator (HO), and roof bolting (RB) unit operator are typically overexposed to respirable dust.
[0004] The conventional approach to dust control in a mine has been the use of water sprays located on the mining machines to wet the coal. Approximately located and intuitively designed water sprays on the cutter drum and around the continuous miner chassis have been extensively used to control dust for the miner operator (MO), batch haulage unit operator (HO), haulage roadways, and material transfer points. A continuous miner or CM is extensively used for coal production in partial extraction mining areas. Typical spray systems, provided by manufacturers, have 15-45 sprays located across the top and the sides of the cutter boom ( FIGS. 1A and 1B ). In addition, under-the-boom and loading pan sprays on some miners provide water sprays to contain and wet the dust in the face area. However, there is no consensus in the art area on the type and location of sprays, volume of water and water pressure to be used in sprays. Although general guidelines have been developed by researchers based on laboratory and field studies, there is no systematic method of design or apparatus for using a spray system to meet the specific conditions to be encountered.
[0005] Several studies over the last several decades have attempted to locate the source of and have attempted a solution to the dust problems in mining environments. The conventional wisdom is that presented by Chang and Zukovich (Cheng L and Zukovich P. P. 1973. Respirable dust adhering to run-of-face bituminous coals. Pittsburgh, Pa.: U.S. Department of the Interior, Bureau of Mines, RI 7765. NTIS No. PB 221-883.) Their position was that a large amount of dust created does not become airborne and stays attached to the broken material. Therefore, spraying more water on the broken material tends to reduce dust. Adding water directly at the cutting picks that gets mixed with fragmented coal is more important than creating a shroud of water around the miner or shearer. Based on this observation, the conventional practice of mixing the water uniformly with broken coal was developed. However, this approach alone has not been effective in mine dust control.
[0006] More recently it has been observed that water can be used to control dust through the wetting of broken material and capture of airborne dust. (Kissel, F., “Handbook for Dust Control in Mining”, NIOSH, Information Circulation (IC 9465), 2003, pp. 131.) Although the methods of wetting broken material have been more uniform throughout the industry, a haphazard approach has been taken to the capture of airborne dust through the use of water sprays. This is most likely due to the problem and sometimes conflicting proposed solutions. It is suggested that a large number of smaller-volume sprays is better for dust control than smaller number of larger-volume sprays. Jayaraman and others concluded that many spray systems can create turbulent airflow in the face area that can result in rollback of dust. (Jayaraman, N, Fred N. Kissel, and W. E. Schroder (1984), “Modify Spray Heads to Reduce Dust Rollback on Miners,” Coal Age, June 1984)
[0007] However, certain research has proven valuable in the design of water spray systems. Courtney and Cheng concluded that typical water sprays operating at 100 psi do not capture more than 30% airborne dust in an open environment. (Courtney W. G. & Cheng L. 1977. Control of respirable dust by improved water sprays. In: Respirable Dust Control—Proceedings of Technology Transfer Seminars, Pittsburgh, Pa., and St. Louis, Mo., IC 8753, pp. 92-108. NTIS No. PB 272 910.) Furthermore, inappropriately designed sprays can displace dust clouds rather than wet or capture airborne dust. Reducing the water droplet size through the use of atomizing or fogging sprays may temporarily improve the airborne dust capture efficiency. However, small droplets tend to collapse/evaporate easily and release the captured dust. (McCoy J., Melcher J., Valentine J., Monaghan D., Muldoon T. & Kelly J. 1983. Evaluation of charged water sprays for dust control. Waltham, Mass.: Foster-Miller, Inc. U.S. Bureau of Mines contract no. H0212012. NTIS No. PB83-210476.) Atomizing nozzles are most efficient in airborne dust capture followed by hollow cone, full cone, and flat sprays. Hollow cone sprays are less likely to clog due to larger orifice area.
[0008] Nozzles operating at higher pressures are likely more efficient in the use of water while providing similar airborne dust capture efficiency as those operating at lower pressures. However, high-pressure sprays tend to disperse more dust. Therefore, their use is more appropriate in a relatively confined environment.
[0009] Courtney and others reported that the primary release point for dust from a CM is from under the boom when the cutter head shears down. (Courtney, W. G, N. I. Jayaraman, and P. Behum (1978), “Effect of Water Sprays for Respirable Dust Suppression with Research Continuous Mining Machine”, BuMines RI-8283, 17 pp) Thus, under-boom sprays should be considered. However, location and maintenance of under-boom sprays presents significant problems. Jankowski reported results for an alternate under-boom spray system with about 25% improved dust reduction (Jankowski, Robert A, N. I. Jayaraman, and C. A. Babbitt (1987),” Water Spray System for Reducing Quartz Dust Exposure of the continuous Miner Operator, “Proceedings of the 3 rd U.S. Mine Ventilation Symposium, Pennsylvania State University, PP 605-611.)
[0010] In spite of considerable excellent research by the U.S. Bureau of mines (USBM) and the National Institute of Occupational Safety and Health (NIOSH) over the last 40 years, there are significant limitations to the current practice. These include use of high water pressure on the chassis (100 psi or more); similar water pressure on the chassis and under-boom sprays leading to escape of airborne dust from the sides; only one point of dust control on the top of the chassis; no control on roll-back dust travel; use of only one type of sprays such as hollow-cone for all sprays; poor orientation of sprays, etc. There is a need to revisit the design concepts of sprays on continuous miners to control respirable dust (including quartz dust) in and around the mining face area.
[0011] In the industry there is a need for improving spray efficiency. A more reasoned and systematic design is needed that more effectively reduces the respirable dust around mining machinery.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 A—A top view of a continuous miner featuring an exemplary conventional spray system.
[0013] FIG. 1 B—A side view of the continuous miner of FIG. 1A .
[0014] FIG. 2 A—A top view of a continuous miner featuring an embodiment of a spray configuration, with Second Line of Defense (SLD) sprays, and Third Line of Defense (TLD) sprays.
[0015] FIG. 2 B—(a) An operator side view of the continuous miner of FIG. 2A ; (b) A scrubber side view of the continuous miner of FIG. 2A .
[0016] FIG. 2 C—A detailed view of the cutter boom of the continuous miner of FIG. 2B .
[0017] FIG. 3 A—A side view of the dust containment of an exemplary conventional spray system around the cutter boom of a continuous miner
[0018] FIG. 3 B—A side view of one embodiment of the dust containment spray system around the cutter boom of a continuous miner featuring a spray configuration including SLD sprays.
[0019] FIG. 4 A—(a) A sectional view of the side head sprays block; (b) Another sectional view of the side head sprays block.
[0020] FIG. 4 B—(a) A sectional view of the center head sprays block; (b) Another sectional view of the center head sprays block.
[0021] FIG. 4 C—A top view of the center and side head sprays blocks.
[0022] FIG. 5 —(a) A sectional view of the TLD scrubber side spray block; (b) Another sectional view of the TLD scrubber side spray block.
SUMMARY OF INVENTION
[0023] In order to revisit the sources of mine dust and to analyze how the conventional technology is failing to provide adequate control of mining dust, it is important to analyze the sources and locations of respirable dust around continuous miners in multiple environments. It is also important to identify several areas in the mine where dust control could be introduced or improved: along the roof level of the mine, at the location of the conventional spray blocks, at the sides and under the miner, and at transfer points near the last open crosscut return.
[0024] A high concentration of respirable dust occurs near and along the roof level. Location of boom sprays for the cutter drum, loading pan sprays, under-boom spray pressure, type of sprays used and high water spray pressure (˜100 psi) used can displace dust-laden air along the roof level, towards the sides, and back of the miner and results in roll-back on the miner chassis toward the miner operator and batch haulage unit operator. This dust-laden air is moving at a relatively high velocity based on water pressure used and seam height and, due to its fine size dust particles, is not captured by suction inlets of a scrubber.
[0025] Spatial location of sprays on the spray blocks and type of sprays used can typically result in significant interaction among sprays. These interactions (caused by different sprays colliding with each other) can result in droplet size increase after interaction. Conventional cutter drum head sprays are directed at the rotating drum and cutting bits at different angles in the horizontal plane so that air moves across the face and is directed in the return entry. In several cases, these sprays intercept each other upon discharge from the orifice resulting in not only larger droplets that negatively impact dust control, but also in wasted energy. Since the ability to capture dust requires that the water droplet size be near the size of the dust particle, this interaction significantly reduces the potential to wet the finer fractions of dust. Furthermore, most of the spray energy is dissipated in interactions rather than in wetting the dust.
[0026] The side sprays on the miner operator side tend to contain the dust in the face area. These sprays attempt to create a seal between the sides of the excavation and the continuous miner. However, the seals are generally incomplete due to the large distance between the sprays and the excavation sides and interactions between these side sprays and the boom and under-boom sprays. Again, dust is pushed towards the roof level, or to the sides, or underneath the miner
[0027] Most of the dust load in the scrubber is from the scrubber suction inlet at the bottom over the coal conveyor. Even if the scrubber does an excellent job of wetting the dust, the dust generated during the material discharge from the conveyor into the haulage unit significantly increases dust concentration in the last open crosscut return (LOXC). In an attempt to control dust at material discharge points, throat sprays may be located above the conveyor carrying the cut material to be discharged in the haulage unit. Since conveyor speed is very high, water discharged from throat sprays only wets the surface of coal and it is not uniformly distributed in the entire mass of the material. This results in significant dust creation when the material is dumped into the haulage unit.
[0028] Movements of batch haulage units around the face area further complicate dust concentration and turbulence in the face area and intake air flow to the face area.
[0029] In the industry there is a need for improving spray efficiency. Various embodiments of the present invention are designed for improving the dust suppression using hydraulic sprays on the continuous miner: utilizing appropriate spray pressures spatially to minimize pushing the dust toward the roof, sides, and underneath the miner; wet and surround the airborne dust to allow the scrubber to capture it; and further wet the airborne dust escaping the scrubber inlets area before it enters the area behind the miner and the LOXC.
[0030] Various embodiments of the present invention utilize spatial distribution, spray pressure and type of sprays to address the problems identified in the prior art. Principles on spray configurations include: solid-cone sprays are ideal for wetting the broken coal but not good for wetting the air-borne fine particle dust; hollow-cone sprays are more efficient for wetting the airborne dust than flat sprays; flat sprays are more efficient for creating a hydraulic curtain than wetting the dust; narrow-angle sprays at a particular pressure reach farther than wide-angle sprays; narrow angle sprays cover a small area and therefore more number of sprays is needed to cover an area; inappropriate spatial location of sprays can increase interaction among sprays that may result in increasing spray droplet size, wasted spray pressure energy, and hollow-cone behaving more like a solid cone spray; and using high pressure water sprays can decrease likelihood of contact between dust particles and water droplets and decrease residence time for wetting the dust and low water pressure results in larger droplet sizes that are not effective for wetting fine particle sizes.
Reference Numerals in Drawings
[0000]
11 Material Transfer Conveyor
12 Material Load Pan
15 Cutter Drum Hinge Point
16 Cutter Boom
21 Scrubber
22 Scrubber Suction Inlet
31 Scrubber Water Discharge Bar
32 Water Port Inlet
33 Water Supply Inlet
34 Sprays Nozzle Recess
41 SLD Sprays
42 Head Sprays Block
44 Outer Bit-ring Sprays
51 TLD Top Sprays Block
52 TLD Operator Side Sprays Block
53 TLD Scrubber Side Spray Block
61 Conventional Side Cutter-boom sprays
63 Conveyor Throat Sprays
68 Side Cutter-boom sprays
72 Center Head Sprays Block
73 Under Cutter-boom sprays
74 Existing Cutter Drum Head Sprays
75 Side Chassis Sprays
77 Conventional Throat Sprays
82 Outer Bit-ring Sprays
84 Throat Sprays
86 Cutter Drum Head Sprays
88 Material Load Pan
89 Scrubber Water Discharge Bar
90 Cutter Boom
92 Cutter Drum Hinge Point
94 Scrubber Suction Inlet
96 Material Transfer Conveyor
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0064] The primary means of dust control should be preventing the dust generated at the cutting faces from becoming airborne. Hollow-cone or flat sprays directed into the bits and the cutting face should help achieve this objective and cool the cutting bits.
[0065] Once the dust is airborne, the flooded-bed scrubber is an efficient mechanism at the face to capture the dust and wet it within the scrubber. Hence, the goal should be to maximize the amount of airborne dust that gets directed into the scrubber. To accomplish this, appropriately angled flat sprays or wide-angle hollow-cone sprays on the boom behind the first set of sprays create a shroud containing the generated dust near the face area in a restricted volume.
[0066] Similarly, flat or hollow-cone sprays underneath the cutting boom may envelope the gap between the pan and the boom and contain the airborne dust such that the central suction port of the scrubber is able to draw it inside the scrubber. Some miners have under-boom sprays that are directed away from the face toward the conveyor. However, such sprays reduce the residence time or contact time between the dust and water rather than increase it. However, spraying water toward the face area into the loading pan where it can be mixed with the entire volume of cut coal would help reduce generation during material discharge and during transport to dump point.
[0067] Under-boom sprays should be operated at a slightly lower pressure (10-20 psi lower) than the chassis sprays on the top of the cutter drum. This will allow the dust laden air to be pushed into the conveyor throat and bottom scrubber suction inlet rather than be pushed toward the roof, sides, or bottom of the miner.
[0068] Once the dust is airborne, its capture using hydraulic sprays requires sprays producing droplet sizes in the range of the respirable dust particle sizes or slightly higher. Hence, really fine, misting or atomizing sprays need to be used subject to the constraints of available water pressures and more importantly the constraints involving very small spray orifice sizes which are likely to get plugged in a typical mine environment. These sprays will be placed at the back corner of the loading pan on both sides and directed inside the pan. These sprays are introduced to allow capture of some dust (respirable and coarser than respirable) even before it actually enters the scrubber.
[0069] Despite the created shroud of sprays, some of the dust will still escape due to gaps in the shroud where the sprays do not overlap and due to the fact that at times, the cut coal traveling to the conveyor may partially obstruct the central scrubber suction port. Hence, there is a need to employ an improved line of defenses on the side of the continuous miner. This line of defense is implemented in the form of sprays on the left side of the miner located behind the left side suction ports of the scrubber. These sprays should be wide-angle, hollow-cone sprays that essentially create a seal with water curtain from the continuous miner to the left rib and to the roof top to contain the dust such that it gets an opportunity to enter the side suction port. These sprays can be located only on the left side of the miner as the prevailing air flow pattern in the face carries the escaping dust from the right side over the top of the miner and through the area between the left side of the miner and the rib.
[0070] As discussed above, dust-laden air along the roof level is moving at a relatively high velocity based on water pressure used, seam height, and rotational speed of the cutting drum. This air is not captured by suction inlets of scrubbers. To capture the dust escaping over the top of the miner, a set of misting sprays may be installed on the top of the miner directed towards the roof and angled towards the face such that the escaping dust contacts the mist and is captured. Furthermore, such sprays contain the dust in the face area and allow time for it to be sucked by the side suction inlets. These Second Line of Defense sprays (SLD sprays) are located on the top, the side, and on the top and sides of the CM chassis and spray water toward the roof and are angled toward the face. An additional set of sprays referred to herein as a Third Line of Defense (TLD) sprays generally located proximate to a set of scrubber suction inlets. Collectively or interchangeably, the SLD sprays and TLD sprays are referred to as a first set of water sprays and a second set of water sprays depending on their position and function. Due to the low inertia of the mist droplets, the mist migrates away from the face concurrently with the air and the respirable dust increasing the residence time for the dust and mist droplets to come in contact and attach resulting in the dust-droplet aggregates to drop out and fall to the ground. The SLD sprays can be small-volume misting sprays and operate at an appropriate pressure so that the resulting water curtain creates a seal against the roof. Appropriate sprays are selected that utilize orifice diameters similar to those of the conventionally used miner sprays, but which produce a very fine mist of water. Spraying Systems Company, Inc. in Chicago, Ill. produces sprays; however, this is not limiting and other fine-misting types of sprays can be substituted.
[0071] The various embodiments of the present invention are further described in reference to the figures. FIG. 2A shows a top view of one embodiment of the present invention on a CM with a new spray configuration and the TLD and SLD sprays blocks. Around the cutter boom area 90 , three sets of sprays serve to contain dust in the face area: the top of chassis sprays, including the center head spray block 72 and two side head sprays blocks 42 ; the outer bit-ring sprays 82 ; and the side cutter-boom sprays 68 . In the center head spray block 72 and the side head spray blocks 42 , the lower sprays include cutter drum head sprays 86 directed at the cutting bits of the CM drum. The SLD sprays 41 are located above the cutter drum head sprays 86 and are angled in the range of 10°-45° higher than traditional head sprays in the vertical plane to create a hydraulic seal behind the lower sprays and the immediate roof; in a preferred embodiments, the SLD sprays 41 are angled approximately 20° above traditional head sprays. The SLD sprays 41 are angled toward the roof of the mine excavation. These sprays perform several functions: the dust generated during cutting of material is contained near the face area and has a chance to be wetted and sucked in by the wet scrubber suction inlets 22 ; some of the generated dust not wetted by the head sprays gets sucked in the space between the SLD sprays 41 and the cutter drum head sprays 86 and has a chance to get wetted; the dust generated during the cutting of immediate roof material has a chance to be wetted since these sprays are located right behind the cutting drum; and the dust generated in the cutter drum area does not travel toward the mine operator or haulage unit operator (minimizing dust rollback). A sectional view of the side head sprays block 42 is shown in FIG. 4A . A sectional view of the center head spray block 72 is shown in FIG. 4B . A top view of the head sprays is shown in FIG. 4C .
[0072] The second set of sprays that contain the dust emanating from the cutter boom area 90 are the outer bit-ring sprays 82 ; these sprays are oriented differently than conventional sprays so that there is no interference between adjacent sprays. The outer bit-ring sprays 82 , as a whole, create air movement toward the face of the cutter drum to remove volatile gas and dust particles.
[0073] The third set of sprays around the cutter boom 90 are configured differently than conventional sprays. These sprays are designed to create a seal around the sides of the material loading pan 88 so that dust cannot escape and is wetted in the material loading pan 88 and sucked-in through the wet scrubber suction inlet 94 located on the top of the material transfer conveyor 96 . These sprays are oriented to establish seal along the sides of the mining excavation over as large an area as possible. Furthermore, these sprays are directed slightly inward (between 5°-20°) toward the loading pan to push the dust toward the scrubber suction inlet 94 .
[0074] On both sides of the CM behind the cutter drum, the TLD sprays prevent any dust not captured by the head sprays, the outer bit-ring sprays 82 , or the side cutter-boom sprays 68 from reaching the miner operator or haulage unit operator. The TLD top spray block 51 creates a hydraulic curtain across the excavation between the miner chassis and the roof of the excavation so that escaping dust can be wetted in this area before leaving the face area and without affecting the miner operator, haulage unit operator and other workers working on the downwind side of the miner. The TLD operator side spray block 52 and scrubber side spray block 53 create a seal between the side chassis of the miner and the sides of the excavation. The TLD top spray block 51 is located on the top of the chassis or along the sides of the chassis to ensure that roof falls will not impair their operation. The TLD top spray block 51 consists of 2-3 sprays angled horizontally and vertically in such way that the miner operator can see the mining face cutting area. The operator side spray block 52 and scrubber side spray block 53 also consist of 2-3 sprays oriented vertically and horizontally away from the chassis to create a seal between the chassis and sides of the excavation; sectional view of these spray blocks are shown in greater detail in FIG. 5 . The orientation depends upon the height of the excavation, width of the excavation and the size of the cutting drum.
[0075] One embodiment of the TLD spray system was installed in a Joy 14 CM, similar to the miner shown in FIG. 2B in order to prove the concept. The CM chassis was 36-inches high, the miner cutting drum was 11.5 ft wide and 38-inches in diameter, and the length of the CM from the front bits on the miner cutting drum to the back end of the continuous miner chassis was 35 ft. The CM was extracting a 60-inch thick coal seam with 9-12 inches of immediate floor strata and about 6-inches of immediate roof strata. Significant amount of airborne dust was produced during the cutting of the immediate roof strata. In an effort to reduce the airborne dust rollback, TLD top spray blocks 51 and TLD operator side 52 and scrubber side 53 spray blocks were installed. Two TLD top spray blocks 51 were installed on the top of the continuous miner chassis: one spray block was installed on the top of the miner chassis on the operator side of the CM approximately 42-inches behind the side scrubber suction inlet 94 and the other spray block was installed on the top of the miner chassis on the scrubber side of the CM approximately 42-inches behind the side scrubber suction inlet 94 . The TLD operator side spray block 52 and the TLD scrubber side spray block 53 were temporarily installed approximately 195 inches behind the cutting bit of the miner cutting drum; all of the sprays were directed toward the face of the continuous miner. The TLD scrubber side spray block 53 had three sprays—one oriented N 22° W, one oriented N 00° E, and one oriented N 22° E (where N=North and oriented toward the face, W=West, E=East). The TLD scrubber side spray block 53 had installed misting sprays with about an 80 degree cone angle with a capacity of 0.6 gpm at 80-psi. The TLD operator side spray block 52 consisted of only two installed misting sprays to allow the CM operator to be able to see about 33% of the cutting face and to provide good visibility of the face. The sprays were inclined about 45 degrees from the vertical. This spray system implementing the TLD sprays was tested extensively in the field and compared side-by-side with the conventional spray system. The results indicated that the TLD modified spray system design significantly improved dust control at the MO. HO, and LOXC locations 62%, 38%, and 19%, respectively. The spray orientations, spray capacity, location of the sprays, spray types, and location of the TLD spray blocks listed above are dependent on the type, configuration, and size of the CM as well as the type and configuration of the coal seam and are in no way meant to be limiting.
[0076] In FIGS. 1A and 1B , a continuous miner chassis is shown, and it can be 42-inches high and a cutting drum that is 11.5 ft wide with a diameter of 42-inch. The length of the CM from the front bits on the miner cutting drum to the back end of continuous miner chassis is about 35 ft. The continuous miner may be extracting an approximately 96-inch thick coal seam with 3-6 inches of immediate roof only. A significant amount of airborne dust can be produced during the production process due to high seam height. In order to minimize the dust rollback from the miner cutting drum, the TLD spray system can include two TLD top spray blocks 51 and TLD operator side 52 and scrubber side 53 spray blocks were installed. Two TLD top spray blocks 51 can be mounted on the top of the continuous miner chassis about 54-inches behind the right and left side scrubber suction inlets 22 . TLD operator side 52 and scrubber side 53 spray blocks can be simultaneously located about approximately 200 inches behind the cutting bit of the miner cutting drum on the CM operator side and the return side of the CM chassis, respectively. The sprays in the TLD operator side 52 and scrubber side 53 spray blocks can be directed towards the face of the CM. The TLD scrubber side spray block 53 can have three misting sprays with about approximately an 80 degree cone angle with about approximately a capacity of 0.6 gpm at 80-psi—one oriented N 22° W, one oriented N 00° E, and one oriented N 22° E. These sprays may be operated at about approximately 100 psi pressure. The TLD operator side spray block 52 can include two sprays to allow the CM operator to be able to see about 33% of the cutting face and to provide visibility of the face. The TLD operator side spray block 52 sprays may be inclined about 45 degrees from the vertical and operated at about approximately 100 psi pressure. This spray system was tested extensively in the field and compared side-by-side with a conventional spray system. The results indicated that the modified spray design significantly improved dust control in the face area by 55% at the MO location and 10% at the LOXC locations. The spray orientations, spray capacity, location of the sprays, spray types, and location of the TLD spray blocks listed above are dependent on the type, configuration, and size of the CM as well as the type and configuration of the coal seam and are in no way meant to be limiting.
[0077] FIG. 2B is a side view of the CM demonstrating the spatial orientation of the side cutter-boom sprays 68 along the cutter boom 90 . The under cutter-boom sprays 73 are placed on the underside of the cutter boom 90 behind the cutter drum and are oriented towards the floor of the mining excavation. FIG. 2C is a detailed side view of the cutter boom showing directional orientation of the sprays.
[0078] FIG. 3A shows a detailed view of conventional spray coverage and dust rollback from a cutter drum when (a) the CM is cutting the roof of the mining excavation and (b) when the CM is sumping in. In contrast, FIG. 3B illustrates one embodiment of the present invention including spray coverage and minimal dust rollback from the cutter drum of the instant invention when (a) the CM is cutting the roof of the mining excavation and (b) when the CM is sumping-in. | This invention refers to innovative water sprays applications to significantly improve coal and quartz dust control around a continuous miner Significant dust control is achieved through utilizing different types of sprays at locations on the top and sides of the miner chassis to create water curtains or shrouds of water around zones of high dust concentration and zones of high concentration dust transport. This is called “multiple lines of defense” spray system (MLD.) This invention also provides a method of reducing dust around a continuous miner by configuring a spray system, located at the top or sides of the cutter boom, thereby improving control of respirable dust. | 4 |
RELATED APPLICATION
[0001] This application contains subject matter related to copending U.S. application Ser. No. 09/826,423 of Boris Maslov et al., filed Apr. 5, 2001, copending U.S. application Ser. No. 09/826,422 of Boris Maslov et al., filed Apr. 5,2001, copending U.S. application Ser. No. 0/173,610of Boris Maslov et al., filed Jun. 19,2002, U.S. application Ser. No. 10/290,505,of Boris Maslov et al., filed Nov. 8,2002, and U.S. Application (Attorney Docket No. 57357-053), of Alexander Gladkov, filed ______, all commonly assigned with the present application. The disclosures of these applications are incorporated by reference herein.
FILED OF THE INVENTION
[0002] The present invention relates to the control of a multiphase motor, more particularly to the application of different voltages to individual phase windings of differing winding and wire gauge topologies through a succession of motor operating speed ranges.
BACKGROUND
[0003] The progressive improvement of electronic systems, such as microcontroller and microprocessor based applications for the control of motors, as well as the availability of improved portable power sources, has made the development of efficient electric motor drives for vehicles, as a viable alternative to combustion engines, a compelling challenge. Electronically controlled pulsed energization of windings of motors offers the prospect of more flexible management of motor characteristics. By control of pulse width, duty cycle, and switched application of a battery source to appropriate stator windings, functional versatility that is virtually indistinguishable from alternating current synchronous motor operation can be achieved.
[0004] The above-identified copending related U.S. patent application of Maslov et al., application Ser. No. 09/826,423, identifies and addresses the need for an improved motor amenable to simplified manufacture and capable of efficient and flexible operating characteristics. In a vehicle drive environment, it is highly desirable to attain smooth operation over a wide speed range, while maintaining a high torque output capability at minimum power consumption. The copending related U.S. application incorporates electromagnet poles as isolated magnetically permeable structures configured as segments in an annular ring, relatively thin in the radial direction, to provide advantageous effects. With this arrangement, flux can be concentrated, with virtually no loss or deleterious transformer interference effects in the electromagnet cores, as compared with prior art embodiments.
[0005] The Maslov et al. applications recognize that isolation of the electromagnet segments permits individual concentration of flux in each magnetic core segment, with virtually no flux loss or deleterious transformer interference effects from flux interaction with other core segments. Operational advantages can be gained by configuring a single pole pair as an autonomous electromagnet. Magnetic path isolation of the individual pole pair from other pole pairs eliminates a flux transformer effect on an adjacent group when the energization of the pole pair windings is switched.
[0006] The above-identified copending U.S. patent application Ser. No. 10/173,610 is directed to a control system for a multiphase motor having these structural features. A control strategy is described that compensates for individual phase circuit characteristics and offers a higher degree of precision controllability since each phase control loop is closely matched with its corresponding winding and structure. Control parameters are specifically matched with characteristics of each respective stator phase. Successive switched energization of each phase winding is governed by a controller that generates signals in accordance with the parameters associated with the stator phase component for the phase winding energized.
[0007] While the motors described in the above-identified applications provide operational advantages, these motors and prior art motors do not exhibit uniformly high efficiency at all speeds of a wide operating speed range, even with non-variable loads. For a fixed motor topology, the available magnetomotive force (MMF) is dependent upon the number of winding turns and energization current. The term “motor topology” is used herein to refer to physical motor characteristics, such as dimensions and magnetic properties of stator cores, the number of coils of stator windings and wire diameter (gauge), etc. The available magnetomotive force dictates a variable, generally inverse, relationship between torque and speed over an operating range. An applied energization current may drive the motor to a nominal operating speed. As the motor accelerates toward that speed, the torque decreases, the current drawn to drive the motor decreases accordingly, and thus efficiency increases to a maximum level. As speed increases beyond the level of peak efficiency, additional driving current is required, thereby sacrificing efficiency thereafter. Thus, efficiency is variable throughout the speed range and approaches a peak at a speed well below maximum speed.
[0008] Motors with different topologies obtain peak efficiencies at different speeds, as illustrated in FIG. 1. This figure is a plot of motor efficiency versus operating speed over a wide speed range for motors having different topologies. The topologies represented in this figure differ solely in the number of stator winding turns. Each efficiency curve approaches a peak value as the speed increases from zero to a particular speed and then decreases toward zero efficiency. Curve A, which represents the motor with the greatest number of winding turns, exhibits the steepest slope to reach peak efficiency at the earliest speed V 2 . Beyond this speed, however, the curve exhibits a similarly steep negative slope. Thus, the operating range for this motor is limited. The speed range window at which this motor operates at or above an acceptable level of efficiency, indicated as X% in FIG. 1, is relatively narrow.
[0009] Curves B through E represent motors with successively fewer winding turns. As the number of winding turns decreases, the motor operating speed for maximum efficiency increases. Curve B attains peak efficiency at speed V 3 , Curve C at V 4 , Curve D at V 5 and Curve E at V 6 . Each motor has peak efficiency at a different motor operating speed, and none has acceptable efficiency over the entire range of motor operating speeds.
[0010] In motor applications in which the motor is to be driven over a wide speed range, such as in a vehicle drive environment, FIG. 1 indicates that there is no ideal single motor topology that will provide uniformly high operating efficiency over the entire speed range. For example, at speeds above V 6 curves A and B indicate zero efficiency. At the lower end of the speed range, for example up to V 2 , curves C through E indicate significantly lower efficiency than curves A and B.
[0011] In motor vehicle drives, operation efficiency is particularly important as it is desirable to extend battery life and thus the time period beyond which it becomes necessary to recharge or replace an on-board battery. The need thus exists for motors that can operate with more uniformly high efficiency over a wider speed range than those presently in use. This need is addressed in U.S. application Ser. No. 10/290,505. The approach taken therein is to change, on a dynamic basis, the number of active coils of each stator winding for each of a plurality of speed ranges between startup and a maximum speed at which a motor can be expected to operate. The speed ranges are identified in a manner similar to that illustrated in FIG. 1 and a different number of the motor stator winding coils that are to be energized are designated for each speed range to obtain maximum efficiency for each of a plurality of operating speed ranges. The number of energized coils is changed when the speed crosses a threshold between adjacent speed ranges. Each winding comprises a plurality of individual, serially connected, coil sets separated by tap connections. Each respective tap is connected by a switch to a source of energization during a single corresponding speed range. The windings thus have a different number of energized coils for each speed range.
[0012] While this arrangement expands the speed range in which high efficiency may be obtained, the inductive characteristics of the motor windings require precisely timed connection and disconnection of the taps to and from the power source. A significant amount of electronic power circuitry and control circuitry therefor must be provided to obtain accurate functionality. Structural constraints in particular motor configurations may limit the number of taps, and thus coil sets, that are available from individual stator windings.
[0013] The need thus remains for alternative ways in which high efficiency motor operation can be obtained over extended speed ranges. This need is addressed in above-identified copending Gladkov Application (Attorney Docket 57357-053). That application describes motor structure in which each stator phase winding is configured with a topology different from the topology of each of the other phase windings. Winding topology is characterized by the total number of coil turns in each phase winding and the wire gauge of the coil in each phase winding. Each phase winding differs from each of the other phase windings by the total number of coil turns or by wire gauge, preferably in both respects. With the gauge sizes and total number of coil turns of the phase windings being in inverse relationship with respect to each other, all of the phase windings are provided with substantially the same total coil mass. Phase winding energization can be tailored to obtain maximum efficiency in each of several operating speed ranges from startup to the maximum speed at which a motor can be expected to operate.
[0014] The need exists to provide the optimal voltage to be applied to each phase winding at each operating speed range. For a machine structure that accommodates a large number of phases, it is necessary to predefine for each speed range which phase windings are to have no voltage applied as well as to identify what predefined voltage magnitude is to be applied to each of the remaining phase windings. The number of, and identity of, the phase windings that are to be energized, as well as the magnitude of the individually applied predefined voltages, may differ for each speed range. The predefined optimal voltages should be applied on a dynamic basis in accordance with the sensed speed of the motor.
[0015] While the predefined voltages for the phase windings can be derived to provide optimal efficiency over the entire motor operating speed range for a given torque, many motor applications exist which require control for variable motor speed, such as in motor vehicles. Motor output torque should be adjusted in accordance with a user's input command related to desired speed. The further need thus exists for developing applied phase winding voltages that optimize efficiency throughout the operating speed range at variable torque output in accordance with user command.
DISCLOSURE OF THE INVENTION
[0016] The present invention fulfills the above-described needs for controlling, through a plurality of operating speed ranges, a multiphase motor having a plurality of ferromagnetically isolated stator electromagnets distributed about an axis of rotation, each electromagnet having a phase winding formed on a ferromagnetic core. Successive ranges of speed during which the motor can be expected to operate are defined. A specific subset of the electromagnets is associated for each speed range, each specific subset comprising a different combination of electromagnets. Respective voltage magnitudes to be applied to each phase winding for each defined speed range are predefined. The motor speed is sensed throughout motor operation. In each defined speed range, only the electromagnets of the associated subset are energized, each of the energized electromagnets having applied thereto a different predefined voltage magnitude.
[0017] The present invention is particularly advantageous in that the different phase winding topologies of the electromagnets, wherein each phase winding has a different total number of coil turns and a different wire gauge from each of the other phase windings, permits division of the entire operating speed range into many narrow ranges in which fine adjustment for efficiency can be obtained. During operation in each defined speed range at least one of the total number of electromagnet phase windings may be deenergized.
[0018] Phase windings that are energized with specified predefined voltages during one speed range may also be energized, with different predefined voltages, during another defined speed range. The number and identity of phase windings energized during one defined speed range may be different from the number and identity of phase windings energized during another defined speed range.
[0019] A further advantage of the present invention is that the predefined voltage magnitudes for all speed ranges can be set for maximum motor torque output. Adjustment of the predefined voltage magnitudes can be made in accordance with a user torque input command to obtain optimal motor drive efficiency at other torque outputs. The user torque input command can vary through a range between zero torque and maximum torque. By relating the range of the user input to a fractional value that is variable between zero and one, the control system can multiply the predefined maximum torque voltage magnitudes for all speed ranges by the fractional value corresponding to the user input to obtain optimal motor drive efficiency at all torque outputs.
[0020] Additional advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein only the preferred embodiment of the invention is shown and described, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF DRAWINGS
[0021] The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawing and in which like reference numerals refer to similar elements and in which:
[0022] [0022]FIG. 1 is a plot of motor efficiency versus motor operating speed over a wide speed range for different conventional motors having different numbers of winding turns.
[0023] [0023]FIG. 2 is an exemplary configuration of rotor and stator elements that may be employed in the present invention.
[0024] [0024]FIG. 3 is a chart exhibiting wire gauges and total number of winding turns for each phase of a multiphase motor exemplifying the present invention.
[0025] [0025]FIG. 4 is a partial block diagram of a voltage supply circuit for the motor of FIG. 2.
[0026] [0026]FIG. 5 is an exemplary plot of voltage applied to each phase winding of the motor of FIG. 2 over the operating speed range.
[0027] [0027]FIG. 6 is a plot of motor efficiency versus motor operating speed for voltages applied in accordance with FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
[0028] [0028]FIG. 2 is an exemplary configuration of rotor and stator elements that may be employed in the present invention. Reference is made to the above identified copending Maslov et al. application Ser. No. 09/826,422 for a more detail description of the motor exemplified herein. Rotor member 20 is an annular ring structure having permanent magnets 21 spaced from each other and substantially evenly distributed along cylindrical back plate 25 . The permanent magnets are rotor poles that alternate in magnetic polarity along the inner periphery of the annular ring. The rotor surrounds a stator member 30 , the rotor and stator members being separated by an annular radial air gap. Stator 30 comprises a plurality of electromagnet core segments of uniform construction that are evenly distributed along the air gap.
[0029] The stator comprises seven core segments, each core segment formed in a generally u-shaped magnetic structure 36 with two poles having surfaces 32 facing the air gap. The legs of the pole pairs are wound with windings 38 , although the core segment may be constructed to accommodate a single winding formed on a portion linking the pole pair. Each stator electromagnet core structure is separate, and magnetically isolated, from adjacent stator core elements. Each of the core segments can be considered to represent a phase, the phase windings identified successively along the air gap by labels 38 a - 38 g. The stator elements 36 are secured to a non-magnetically permeable support structure, thereby forming an annular ring configuration. This configuration eliminates emanation of stray transformer flux effects from adjacent stator pole groups. Appropriate stator support structure, which has not been illustrated herein so that the active motor elements are more clearly visible, can be seen in the aforementioned patent application.
[0030] Windings 38 a - 38 g differ from each other in winding topology with respect to wire gauges and total number of winding coil turns. While it is preferable in this embodiment that each phase winding has a unique number of total winding turns and a unique wire gauge, two or more phase windings may have similar wire gauges or number of turns. Other embodiments may comprise a greater number of isolated core segment pole pairs. It may be preferable in such embodiments that some phase windings have the same winding topology.
[0031] [0031]FIG. 3 is a chart exemplifying phase winding topologies for a seven phase motor illustrated in FIG. 2. Each phase winding has a unique number of coil turns and is constructed of a unique wire gauge. The total copper mass of each of the phase windings is the same.
[0032] [0032]FIG. 4 is a partial block diagram of a voltage supply circuit for the motor of FIG. 2. Phase windings 38 a - 38 g are connected to d-c power supply 40 via a series connection, respectively, with voltage converters 42 a - 42 g. A control terminal of each voltage converter is coupled to controller 44 , which is also connected across power supply 40 . The controller and voltage converters are conventional devices as described more fully in the copending Maslov et al. application Ser. No. 10/173,610. The controller 44 , which may comprise a microprocessor and associated storage means, may have one or more user inputs and a plurality of inputs for motor conditions sensed during operation. For clarity of explanation of the present invention, a motor speed input is the only motor condition feedback input shown. The speed input signal may be generated by any conventional motor speed sensor. Stored in the controller is a table that identifies a voltage level to be applied to each phase winding for each of a plurality of speed ranges over the operating range. Voltage values that have been found to provide maximum operating efficiency at maximum motor torque output for each of the phase windings 38 a - 38 g in various speed ranges are identified in the table below. The efficiency of operation for each range is also set forth in the table.
TABLE Voltage Voltage Voltage Voltage Voltage Voltage Voltage for phase for phase for phase for phase for phase for phase for phase winding winding winding winding winding winding winding RPM 38a 38c 38e 38g 38b 38d 38f Efficiency 0 24.0 16.3 10.8 6.8 0.0 0.0 0.0 0.0 10 24.0 16.4 10.9 6.9 0.0 0.0 0.0 13.3 20 24.0 16.7 11.2 7.2 0.0 0.0 0.0 26.1 30 24.0 17.1 11.7 7.6 0.0 0.0 0.0 38.1 40 24.0 17.8 12.4 8.1 0.0 0.0 0.0 49.1 50 24.0 18.6 13.3 8.9 0.0 0.0 0.0 59.0 60 24.0 19.6 14.4 9.8 0.0 0.0 0.0 67.6 70 24.0 20.8 15.7 10.8 0.0 0.0 0.0 74.6 80 24.0 22.2 17.2 12.1 0.0 0.0 0.0 79.3 90 24.0 23.8 18.9 13.5 0.0 0.0 0.0 80.9 100 0.0 24.0 20.8 15.0 0.0 0.0 0.0 83.5 110 0.0 24.0 22.9 16.7 0.0 0.0 0.0 83.2 120 0.0 0.0 24.0 18.6 12.7 0.0 0.0 84.1 130 0.0 0.0 24.0 20.7 14.1 0.0 0.0 86.2 140 0.0 0.0 24.0 22.9 15.8 0.0 0.0 84.3 150 0.0 0.0 0.0 24.0 17.5 0.0 0.0 84.5 160 0.0 0.0 0.0 24.0 19.3 0.0 0.0 86.8 170 0.0 0.0 0.0 24.0 21.3 14.0 0.0 85.6 180 0.0 0.0 0.0 24.0 23.4 15.5 0.0 82.8 190 0.0 0.0 0.0 0.0 24.0 17.0 0.0 85.0 200 0.0 0.0 0.0 0.0 24.0 18.6 0.0 87.7 210 0.0 0.0 0.0 0.0 24.0 20.3 0.0 87.4 220 0.0 0.0 0.0 0.0 24.0 22.1 0.0 84.4 230 0.0 0.0 0.0 0.0 24.0 23.9 15.3 80.5 240 0.0 0.0 0.0 0.0 0.0 24.0 16.6 84.9 250 0.0 0.0 0.0 0.0 0.0 24.0 18.0 87.9 260 0.0 0.0 0.0 0.0 0.0 24.0 19.4 88.6 270 0.0 0.0 0.0 0.0 0.0 24.0 20.8 87.2 280 0.0 0.0 0.0 0.0 0.0 24.0 22.3 84.0 290 0.0 0.0 0.0 0.0 0.0 24.0 23.9 79.7 300 0.0 0.0 0.0 0.0 0.0 0.0 24.0 81.9 310 0.0 0.0 0.0 0.0 0.0 0.0 24.0 84.6 320 0.0 0.0 0.0 0.0 0.0 0.0 24.0 87.4 330 0.0 0.0 0.0 0.0 0.0 0.0 24.0 90.1 340 0.0 0.0 0.0 0.0 0.0 0.0 24.0 92.8 350 0.0 0.0 0.0 0.0 0.0 0.0 24.0 360 0.0 0.0 0.0 0.0 0.0 0.0 24.0
[0033] In operation, the controller 44 accesses data from the table to determine which phase windings are to be energized at startup and the level of voltage to be applied to each phase winding. The controller outputs the appropriate control voltages for these values to the respective voltage converters connected to the phase windings. As the motor accelerates, motor speed is repetitively sampled and fed as a signal input to the controller. In response to the received speed input signal, the controller accesses the stored table to receive voltage data for each phase winding at the speed range in which the sensed speed is located. New control signals, corresponding to the accessed data, are output to the voltage converters to change, if appropriate, the voltages applied to the phase windings. As motor load varies, the motor speed may vary accordingly. The controller, in turn, will adjust its output control voltages for these changes as provided by the table thereby to maintain optimum operation efficiency over the entire operating speed range.
[0034] The table represents a speed operating range of 360 rpm that is very finely divided for application of precisely adjusted voltage levels. This information is provided in graphic form in FIG. 5, each curve representing voltages applied to a respective phase winding throughout the range. Curve 1 represents voltages applied to phase winding 38 a; curve 2 represents voltages applied to phase winding 38 c; curve 3 represents voltages applied to phase winding 38 e; curve 4 represents voltages applied to phase winding 38 g; curve 5 represents voltages applied to phase winding 38 b; curve 6 represents voltages applied to phase winding 38 d; and curve 7 represents voltages applied to phase winding 38 f.
[0035] During different portions of the operational speed range, different combinations of phase windings will be energized. At no time are all seven phase windings energized. As evident from the table and FIG. 5, at starting, four phase windings are energized with changing voltage levels as shown up to speed of 100 rpm. For speeds between 100 and 140 rpm, three phase windings are energized with voltage levels as shown; between 140 and 160 rpm. two phase windings are energized; between 160 and 180 rpm. three phase windings are energized; between 180 and 220 rpm. two phase windings are energized; between 220 to 230 three windings are energized; between 230 and 290 two phase windings are energized; and at speeds greater than 290 only a single winding is energized. For each of these ranges, different combinations of energized phase windings are identified and are to be supplied with different energization voltages.
[0036] Motor efficiency for operation in accordance with the table over the entire speed range is illustrated graphically in FIG. 6. Comparison of this curve with the efficiency curves of conventionally operated motors, shown in FIG. 1, illustrates the improved operating efficiency of the present invention. The stator winding configuration of the present invention, when energized in accordance with the voltages indicated in the table over the motor operating range, provides a motor operating efficiency in excess of eighty per cent over approximately three quarters of the speed range.
[0037] The controller user input illustrated in FIG. 4 represents a torque command signal, such as described in the above-identified U.S. patent application Ser. No. 10/173,610. A vehicle drive application example is described therein, the user input representing desired torque indicated by the user's throttle command. The user may vary the throttle between zero and a maximum level. An increase in throttle is indicative of a command to increase speed, which is realized by an increase in torque. Description of to this point of the motor operation has focussed on control at maximum motor torque output, for which the corresponding user input represents maximum throttle.
[0038] The variable user torque input command range is related to a fractional value that is variable between zero for a zero torque input command and one for maximum torque input command. Motor speed is repetitively sampled and fed as a signal input to the controller. The controller, in response to the sensed speed signal input will access stored data stored representing the voltage magnitude values in the table and multiply these voltage magnitude values by the fractional value that corresponds to the user torque input command setting. As speed signals for different speed ranges are received, the appropriate voltage magnitude values are obtained from the table and new control signals, which are products of these voltage magnitudes and the fractional value for the user input command are produced. For the set user input command, optimal motor drive efficiency is achieved for all speed ranges. Maximum operational efficiency is similarly obtained for all set user torque inputs for all speed ranges.
[0039] In this disclosure there are shown and described only preferred embodiments of the invention and but a few examples of its versatility. It is to be understood that the invention is capable of use in various other combinations and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein. For example, as can be appreciated, motor topologies can vary significantly for different numbers of poles, pole dimensions and configurations,pole compositions, etc. Different numbers of coil sets and speed range subsets can be chosen to suit particular topologies. Instead of winding each stator core segment with wires of different gauges, the number of turns on each stator core segment can be varied with all wire being of the same gauge. The configuration of the coil sections may be varied to meet optimum efficiency curves for different topologies. Threshold levels may be adjusted to increase and/or decrease one or more speed ranges, thus setting a more even or uneven speed range subset distribution. | A multiphase motor has a plurality of ferromagnetically isolated stator electromagnets distributed about an axis of rotation. Successive ranges of speed during which the motor can be expected to operate are defined. A specific subset of the electromagnets is associated for each speed range, each specific subset comprising a different combination of electromagnets. Respective voltage magnitudes to be applied to each phase winding for each defined speed range are predefined. The motor speed is sensed throughout motor operation. In each defined speed range, only the electromagnets of the associated subset are energized, each of the energized electromagnets having applied thereto a different predefined voltage magnitude. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. patent application Ser. No. 09/520,707, filed Mar. 7, 2000, now U.S. Pat. No. 6,397,693 issued Jun. 4, 2002.
BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
This invention relates to a change speed apparatus for a tractor. More particularly, the invention relates to a change speed apparatus for a tractor having a main change speed device with a combination of gear trains mounted on a first shaft and a second shaft extending parallel to each other for producing a plurality of speeds on an output shaft, and a backward and forward drive switching device cooperable with the main change speed device to produce forward drive and backward drive in the same number of speeds.
2. Prior Art of the Invention
When carrying out a front loading operation with a tractor, switching between forward driving and backward driving has to be made frequently. To perform this operation efficiently, it is desirable that the tractor is driven forward and backward substantially at the same speed. A known change speed apparatus for a tractor that meets the above requirement includes a backward and forward drive switching device as described in Japanese Patent Laying-Open Publication H10-6792 or H11-78560, for example.
The conventional change speed apparatus for a tractor includes a main change speed device disposed in a transmission system for transmitting power from an engine to wheels. The main change speed device produces a plurality of drive speeds. A backward and forward drive switching device is disposed at an input side (upstream side) or an output side (downstream side) of the main change speed device to provide forward drive and backward drive at the same speed.
Where, as shown in FIG. 8, for example, a backward and forward drive switching device 152 is disposed at an input side of a main change speed device 151 , the power of an engine 153 is inputted to the backward and forward drive switching device 152 through a main clutch 154 , to be switched to forward drive or backward drive. The drive is then inputted to an input shaft 155 of main change speed device 151 to be changed to one of four speeds, and outputted to an output shaft 156 .
That is, the drive, whether forward or backward, is inputted to the main change speed device 151 through the same input shaft 155 . For this purpose, the backward and forward drive switching device 152 includes a pair of gear trains 158 and 159 disposed forwardly and rearwardly of a backward and forward drive switching clutch 157 . One of the gear trains is a reversing gear train 158 for providing backward rotation, and the other a back return gear train 159 for returning the backward rotation to the input shaft 155 of main change speed device 151 .
The same concept of one input shaft and one output shaft has been applied also to the construction having the backward and forward drive switching device disposed at the output side (downstream side) of the main change speed device. That is, to provide backward drive, power received from the output shaft of the main change speed device is reversed by a reversing gear train disposed forwardly of a backward and forward drive switching clutch, and thereafter returned through a back return gear train disposed rearward of the drive switching clutch, to the same shaft used for transmitting forward drive.
However, each of the conventional change speed apparatus noted above has an increased fore and aft length since the backward and forward drive switching device includes two gear trains, i.e. the reversing gear train and return gear train, forwardly and rearwardly of the switching clutch. The increased fore and aft length of the change speed apparatus results in an increased distance between front wheels and rear wheels. This impairs the small turn performance of the tractor.
A primary object of this invention, therefore, is to provide a change speed apparatus for a tractor which has a reduced fore and aft length.
SUMMARY OF THE INVENTION
The above object is fulfilled, according to this invention, by a change speed apparatus for a tractor wherein, between the main change speed device and the backward and forward drive switching device, the forward drive is transmitted through the first shaft and the backward drive is transmitted through the second shaft.
By employing this construction, the conventional backward return gear train may be dispensed with. This not only reduces the number of components but reduces the fore and aft length of the change speed apparatus. The fore and aft length of the transmission case may be reduced correspondingly, which in turn reduces the wheelbase to improve the small turn performance of the tractor.
In this way, this invention provides a compact change speed apparatus for a tractor.
Where the backward and forward drive switching device is disposed upstream of the main change speed device, the forward drive is transmitted from the backward and forward drive switching device to the main change speed device through the first shaft, and the backward drive is transmitted from the backward and forward drive switching device to the main change speed device through the second shaft.
Some conventional tractors have no backward and forward drive switching device. The tractors with and those without the backward and forward drive switching device are regarded as different in specification and design, and thus as different models. This complicates control and management in designing, manufacture and maintenance. According to this invention, the backward and forward drive switching device and the main change speed device are disposed in a transmission case, the backward and forward drive switching device is pre-assembled in a gear case fixable to the transmission case. With this construction, only by assembling to the transmission case the gear case pre-assembled with the backward and forward drive switching device, a tractor without the backward and forward drive switching device may advantageously be converted into one having the backward and forward drive switching device.
According to this invention, the transmission case may be divided by a partition into a clutch chamber for housing a main clutch for connecting and disconnecting power from an engine, and a transmission chamber for housing the main change speed device, the gear case being disposed in the clutch chamber, the main clutch being operable by a release fork disposed between the main clutch and the gear case, the release fork being curved to bulge toward the main clutch. This construction reduces the distance between the main clutch and gear case, to make the change speed apparatus compact.
A conventional backward and forward drive switching device is disposed in the transmission chamber storing a lubricant for the transmission case, is therefore remote from a control lever disposed adjacent the steering wheel. It has been difficult to connect the switching device and the control lever, and a complicated connecting mechanism has been required. It is conceivable to place the backward and forward drive switching device in the clutch chamber close to the control lever. However, the clutch chamber is a dry chamber, and it is difficult to place, in the clutch chamber, the backward and forward drive switching device which needs lubrication. In this invention, the backward and forward drive switching device and the main change speed device may be disposed in a transmission case, and the transmission case is divided by a partition into a clutch chamber for housing a main clutch for connecting and disconnecting power from an engine, and a transmission chamber for housing the main change speed device, the backward and forward drive switching device having a control lever thereof disposed on a steering wheel unit, the control lever being interlocked to the backward and forward drive switching device through an operating shaft extending vertically in the clutch chamber. By employing such a construction, the control lever and the operating shaft are disposed close to each other, and may advantageously be interconnected by a simple connecting mechanism.
Other features, functions, effects and advantages of the present invention will be appreciated upon reading the following description with reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a tractor having a change speed apparatus according to this invention.
FIG. 2 is a plan view of the tractor shown in FIG. 1 .
FIG. 3 is a sectional view of a change speed apparatus in one embodiment of this invention.
FIG. 4 is a sectional view taken on line IV—IV of FIG. 3 .
FIG. 5 is a sectional view taken on line V—V of FIG. 3 .
FIG. 6 is a plan view of a transmission case.
FIG. 7 is a schematic view of gears mounted in the change speed apparatus shown in FIG. 3 .
FIG. 8 is a schematic view of gears mounted in a conventional change speed apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of this invention will be described hereinafter with reference to the drawings.
FIGS. 1 and 2 show a side view and a plan view of a tractor to which this invention is applied. The tractor includes a vehicle body having an engine 1 disposed in a forward portion thereof and a transmission case 2 fixed to the rear of engine 1 . The vehicle body is supported by front wheels 3 and rear wheels 4 . The engine 1 is covered by a hood 5 . An instrument panel 6 and a steering wheel unit 7 are disposed rearwardly of the hood 5 . The rear wheels 4 are covered by fenders 8 . A driver's seat 9 is disposed between the right and left fenders 8 . A PTO shaft (power takeoff shaft) 10 projects from the rear end of the vehicle body.
The transmission case 2 housing a transmission for transmitting power from the engine 1 to the rear wheels 4 , front wheels 3 and PTO shaft 10 . The transmission includes a change speed apparatus.
A clutch pedal 11 is disposed below the instrument panel 6 for engaging and disengaging a main clutch described later. The clutch pedal 11 is suspended to be pivotable forward and backward. A main shift lever 12 is disposed on an upper surface of transmission case 2 between the steering wheel unit 7 and driver's seat 9 . The steering wheel unit 7 includes a backward and forward drive switching lever 13 . An auxiliary shift lever 14 is disposed laterally of the driver's seat 9 .
FIGS. 3 through 6 show the transmission case 2 and the transmission mounted therein. The transmission case 2 is divided by a first partition 15 into a clutch chamber 16 at the front and a transmission chamber 17 at the rear. The transmission chamber 17 has oil stored at a predetermined level therein for use as lubricant and hydraulic oil. A second partition 18 is disposed rearwardly of the transmission chamber 17 .
The clutch chamber 16 includes a main clutch 19 and a gear case 20 . The gear case 20 is fixed to the first partition 15 . The gear case 20 contains a backward and forward drive switching device 21 . The gear case 20 is divided into a front case 22 and a rear case 23 .
The transmission chamber 17 contains a main change speed device 24 for providing four speeds, an auxiliary change speed device 25 for providing a high speed and a low speed, a creep change speed device 26 for providing a superlow speed, and a front wheel driving device 27 . A rear wheel driving device and a PTO change speed device, not shown, are arranged rearwardly of the transmission case 2 .
The main clutch 19 includes a flywheel 28 fixed to the rear end of a crankshaft of engine 1 , a clutch disk 30 pressed by a pressure plate 29 to an end surface of flywheel 28 , a diaphragm spring 31 for applying a pressing force to the pressure plate 29 , and a release hub 32 for releasing the pressing force of spring 31 .
The release hub 32 is mounted to be slidable fore and aft on a boss projecting from a front surface of the front case 22 .
A PTO drive shaft 33 is directly connected to an axial position of the flywheel 28 . The PTO drive shaft 33 extends rearward through the gear case 20 to be coupled to the PTO shaft 10 through the change speed device (not shown).
The main clutch 19 has a tubular driven shaft 34 extending rearward and acting also as a shuttle input shaft. The driven shaft 34 is coaxially mounted on the PTO drive shaft 33 to be rotatable relative thereto. The clutch disk 30 is fixed to the driven shaft 34 . The driven shaft 34 is relatively rotatably supported at a forward end thereof by the flywheel 28 through a bearing. The driven shaft 34 is relatively rotatably supported in a rearward position thereof by the front case 22 through a bearing. The rear end of the driven shaft 34 is located in the gear case 20 .
A clutch operating shaft 35 is supported by side walls of the clutch chamber 16 to be rotatable about an axis extending transversely of the vehicle body. A main clutch release fork 36 is fixed to the clutch operating shaft 35 . Bifurcated ends of the fork 36 are engaged with the release hub 32 . The fork 36 is disposed between the main clutch 19 and gear case 20 , and is curved to bulge toward the main clutch 19 . One end portion of the clutch operating shaft 35 projects from the clutch chamber 16 , and the clutch pedal 11 (FIG. 2) is connected to the projecting end portion through a clutch lever 37 and a clutch rod 38 .
A conventional release fork is curved to bulge rearward. With the release fork 36 curved to bulge forward, the release fork 36 does not interfere with the gear case 20 . This construction realizes a reduction in the distance between the main clutch 19 and gear case 20 . As a result, the transmission has a reduced fore and aft length.
The main clutch 19 normally transmits the power of engine 1 to the driven shaft 34 through the clutch disk 30 . To break this power transmission, the driver depresses the clutch pedal 11 . A depression of the clutch pedal 11 rotates the clutch operating shaft 35 through the clutch rod 38 and clutch lever 37 . This rotation swings the main clutch release fork 36 , which in turn moves the release hub 32 forward to push the diaphragm spring 31 , thereby canceling its pressing force. Thus, the power transmission to the clutch disk 30 is broken to place the driven shaft 34 in a free state.
The backward and forward drive switching device 21 is placed, by way of sub-assembly, inside the gear case 20 consisting of the front case 22 and rear case 23 , and then the two cases are provisionally integrated by bonding the mating surfaces thereof with an adhesive. Subsequently, the gear case 20 is fixed to the first partition 15 with common bolts 39 . This construction realizes an improved efficiency of assembly.
The backward and forward drive switching device 21 in the gear case 20 has a backward and forward drive switching clutch 40 mounted on the rear end of the driven shaft 34 of main clutch 19 . A backward drive gear 41 is freely rotatably mounted on the driven shaft 34 forwardly of the clutch 40 . A reversing intermediate gear 42 is meshed with the backward drive gear 41 . A backward drive input gear 43 is meshed with the intermediate gear 42 . The backward drive input gear 43 has a boss projecting forward. The boss is rotatably supported at an outer circumference thereof by the front case 22 through a bearing. The backward drive input gear 43 defines a splined axial bore. A backward drive input shaft 44 is removably inserted into the splined bore for spline engagement. The backward drive input shaft 44 extends parallel to the driven shaft 34 . The backward drive input shaft 44 is rotatably supported by the rear case 23 through a bearing to extend rearward and have a rear end thereof supported by the second partition 18 through a bearing.
With the backward drive input shaft 44 removably inserted into the backward drive input gear 43 , the backward and forward drive switching device 21 may be placed in the gear case 20 by way of sub-assembly.
A forward drive input shaft 45 is disposed rearwardly of the switching clutch 40 and coaxially with the driven shaft 34 and a coaxial core. The forward drive input shaft 45 is rotatably supported by the rear case 23 through a bearing. The forward drive input shaft 45 is a tubular shaft mounted on the PTO drive shaft 33 to be rotatable relative thereto.
The backward and forward drive switching clutch 40 is a synchromesh clutch as disclosed in Japanese Patent Publication H8-1221, for example. The switching clutch 40 has a hub 46 mounted on the rear end of driven shaft 34 to be rotatable therewith, a shifter 47 mounted on the hub 46 not to be rotatable but axially movable relative thereto, and synchronizing rings (not shown) disposed forwardly and rearwardly of the hub 46 . The backward drive gear 41 has an engaging portion 48 for engagement with the shifter 47 through one of the synchronizing rings. The forward drive input shaft 45 also has an engaging portion 49 for engagement with the shifter 47 through the other synchronizing ring.
The shifter 47 is engaged with the shift fork 50 . The shift fork 50 is attached, to be pivotable fore and aft, to a rod 51 fixed between the front case 22 and rear case 23 of the gear case 20 .
The front case 22 has a forwardly bulging projection 52 formed in a lower portion thereof. A shift fork operating shaft 53 is pivotably supported in vertical posture by the projection 52 and the upper wall of transmission case 2 . This operating shaft 53 is disposed rearwardly of the release fork 36 of main clutch 19 and forwardly of the shifter 47 of backward and forward drive switching device 21 . The operating shaft 53 is vertically divided into an upper shaft portion 54 and a lower shaft portion 55 separably interconnected through a coupling 56 . The lower shaft portion 55 has a yoke 57 fixed thereto in the projection 52 . The distal end of yoke 57 is engaged with the shift fork 50 . The upper shaft portion 54 has an upper end thereof projecting upward from the upper surface of transmission case 2 . The backward and forward drive switching lever 13 is connected to the projecting end through a link (not shown). An operation in the fore and aft direction of the backward and forward drive switching lever 13 attached to the steering wheel unit 7 rotates the operating shaft 53 , which forwardly or rearwardly swings the yoke 57 attached to the lower end thereof. The swing of the yoke 57 moves the shift fork 50 forward or backward, which in turn moves the shifter 47 forward or backward.
The shifter 47 has a neutral position intermediate in the fore and aft direction. When the shifter 47 is moved forward from the neutral position to engage the engaging portion 48 of backward drive gear 41 , power is transmitted from the driven shaft 34 to the backward drive input shaft 44 through the backward drive gear 41 , intermediate gear 42 and backward drive input gear 43 . Conversely when the shifter 47 is moved backward from the neutral position to engage the engaging portion 49 of forward drive input shaft 45 , power is transmitted from the driven shaft 34 to the forward drive input shaft 45 .
Since the shift fork operating shaft 53 is disposed in vertical posture, with the upper end connected to the backward and forward drive switching lever 13 , the two components may be connected through a minimum distance. Further, since the operating shaft 53 is vertically divided into two parts, the lower shaft portion 55 may be incorporated into the gear case 20 . This allows the backward and forward drive switching device 21 to form a sub-assembly with ease.
A tubular change speed output shaft 58 is relatively rotatably and coaxially mounted on the PTO drive shaft 33 in the transmission chamber 17 . The change speed output shaft 58 is rotatably supported at a forward end thereof by an inner surface of the forward drive input shaft 45 through a needle bearing. The rear end of change speed output shaft 58 is rotatably supported by the second partition 18 of transmission case 2 through a bearing.
The main change speed device 24 for providing four speeds is disposed on the forward drive input shaft 45 , backward drive input shaft 44 and change speed output shaft 58 in the transmission chamber 17 .
Specifically, the backward drive input shaft 44 has, arranged from rear to front, a first speed gear 60 and a second speed gear 61 freely rotatably mounted thereon, and a third speed gear 62 and a fourth speed gear 63 fixed to the shaft 44 . A first and second speed switching clutch 64 is disposed between the first speed gear 60 and second speed gear 61 . This clutch 64 is a synchromesh clutch as is the backward and forward drive switching clutch 40 .
The first and second speed switching clutch 64 has a hub 65 fixed to the backward drive input shaft 44 , a shifter 66 axially movably mounted on the hub 65 , and synchronizing ring (not shown) disposed forwardly and rearwardly of the hub 65 . The first and second speed gears 60 and 61 have engaging portions 67 and 68 formed on inward ends thereof, respectively, for engagement with the shifter 66 .
The change speed output shaft 24 has gears 69 and 70 fixed thereto and in constant mesh with the first and second speed gears 60 and 61 . Further, the output shaft 24 has a gear 71 relatively rotatably mounted thereon and in constant mesh with the third speed gear 62 .
The forward drive input shaft 45 has a gear 72 formed on a rear portion thereof and in constant mesh with the fourth speed gear 63 . A third and fourth speed switching clutch 73 , which is a synchromesh clutch, is disposed between the rear end of forward drive input shaft 45 and the third speed gear 71 on the change speed output shaft 58 .
The third and fourth speed switching clutch 73 has a hub 74 fixed to the change speed output shaft 58 , a shifter 75 axially movably mounted on the hub 74 , and synchronizing ring (not shown) disposed forwardly and rearwardly of the hub 74 . The rear end of forward drive input shaft 45 and the third speed gear 71 have engaging portions 76 and 77 formed on inward ends thereof, respectively, for engagement with the shifter 75 .
FIG. 7 shows a schematic view of the gears of backward and forward drive switching device 21 and main change speed device 24 described above.
As shown in FIGS. 3 and 5, the first and second speed switching shifter 66 and third and fourth speed switching shifter 75 are engaged with a first and second speed switching shift fork 78 and a third and fourth speed switching shift fork 79 , respectively. The shift forks 78 and 79 are fixed, respectively, to a first and second speed switching shift rod 80 and a third and fourth speed switching shift rod 81 extending parallel to each other and on the same horizontal plane. The shift rods 80 and 81 are parallel to the PTO drive shaft 33 . The front and rear ends of shift rods 80 and 81 are supported by the first and second partitions 15 and 18 of transmission cases 2 . The lower end of main shift lever 12 is selectively engageable with the shift forks 78 and 79 . The shift fork 78 or 79 engaged by the shift lever 12 is moved forward or rearward. fixed, respectively, to a first and second speed switching shift rod 80 and a third and fourth speed switching shift rod 81 extending parallel to each other and on the same horizontal plane. The shift rods 80 and 81 are parallel to the PTO drive shaft 33 . The front and rear ends of shift rods 80 and 81 are supported by the first and second partitions 15 and 18 of transmission cases 2 . The lower end of main shift lever 12 is selectively engageable with the shift forks 78 and 79 . The shift fork 78 or 79 engaged by the shift lever 12 is moved forward or rearward.
The first and second speed switching shifter 66 has an inside diameter larger than the outside diameter of first speed gear 60 . Thus, the shifter 66 , when shifted for the first speed, could move past the engaging portion 67 of first speed gear 60 (i.e. to be overshifted).
To prevent such an overshift of the first and second speed switching shifter 66 , as shown in FIG. 6, the first and second speed switching shift rod 80 has a cutout 82 formed in an end region thereof, and a stopper pin 83 projects from the transmission case 2 for engaging a shoulder of the cutout 82 . The stopper pin 83 is attached to the transmission case 2 as screwed into a ball receiving bore 84 formed to receive interlocking balls between the two shift rods 80 and 81 .
The change speed output shaft 58 has, arranged from rear to front, a low speed gear 85 and a high speed gear 86 rotatable with the change speed output shaft 58 .
The transmission case 2 has a propelling shaft 87 extending parallel to the change speed output shaft 58 . The propelling shaft 87 is rotatably supported at a forward end thereof by the rear case 23 of gear case 20 through a bearing, and rotatably supported in an intermediate position by the second partition 18 through a bearing. The rear end of the propelling shaft 87 is connected to a rear differential not shown).
The propelling shaft 87 has, arranged from adjacent the second partition 18 to front, a superlow speed input gear 88 , a low speed gear 89 , a high speed gear 90 and a superlow speed output gear 91 which are rotatable relative to the propelling shaft 87 . In addition, a front wheel drive gear 92 is fixed to the propelling shaft 87 forwardly of the above gears. The low speed gear 89 and high speed gear 90 on the propelling shaft 87 are in constant mesh with the low speed gear 85 and high speed gear 86 on the change speed output shaft 58 , respectively. The superlow speed input gear 88 and low speed gear 89 on the propelling shaft 87 are twin gears.
The transmission case 2 further includes an intermediate shaft 93 supported to be rotatable through bearings and extending parallel to the propelling shaft 87 . The intermediate shaft 93 has gears 94 and 95 mounted to be rotatable therewith and in constant mesh with the superlow speed input gear 88 and superlow speed output gear 91 .
The propelling shaft 87 has a high and low speed switching clutch 96 mounted thereon between the low speed gear 89 and high speed gear 90 . The high and low speed switching clutch 96 is a claw clutch having a hub 97 fixed to the propelling shaft 87 , and a shifter 98 mounted on the hub 97 not to be rotatable but axially movable relative thereto. The low speed gear 89 and high speed gear 90 have engaging portions formed on inward ends thereof for engagement with the shifter 98 .
The propelling shaft 87 has a superlow speed switching clutch 99 mounted thereon forwardly of the superlow speed output gear 91 . The superlow speed switching clutch 99 is a claw clutch having a hub 100 fixed to the propelling shaft 87 , and a shifter 101 mounted on the hub 100 not to be rotatable but axially movable relative thereto. The superlow speed output gear 91 has an engaging portion formed on an inward end thereof for engagement with the shifter 101 .
As shown in FIGS. 3 and 5, the high and low speed switching shifter 98 and superlow speed switching shifter 101 are engaged with shift forks 102 and 103 , respectively. The high and low speed switching shift fork 102 is fixed to a shift rod 102 a. The shift rod 102 a has a yoke 102 b (FIG. 1) engaged with the rear end thereof and pivotable by the auxiliary shift lever 14 as shown in FIG. 5, whereby the shift fork 102 is moved fore and aft. The superlow speed-switching fork 103 is fixed to a shift rod 103 a. The rod 103 a also is movable fore and aft by operating a control lever not shown. 102 and 103 , respectively. The high and low speed switching shift fork 102 is fixed to a shift rod 102 a . The shift rod 102 a has a yoke 102 b (FIG. 1) engaged with the rear end thereof and pivotable by the auxiliary shift lever 14 as shown in FIG. 5, whereby the shift fork 102 is moved fore and aft. The superlow speed switching fork 103 is fixed to a shift rod 103 a . The rod 103 a also is movable fore and aft by operating a the control lever not shown.
The low speed gears 85 and 89 , high speed gears 86 and 90 and high and low speed switching clutch 96 constitute the auxiliary change speed device 25 . The superlow speed gears 88 , 91 , 94 and 95 and superlow speed switching clutch 99 constitute the creep change speed device 26 .
The front wheel drive gear 92 is meshed with an output gear 105 through an intermediate gear 104 . The output gear 105 is engageable with and disengageable from an output shaft 106 through a front wheel drive clutch 107 . The output shaft 106 is connected at a forward end thereof to a front wheel driving differential not shown.
The front wheel drive gear 92 and front wheel drive clutch 107 constitute the front wheel driving device 27 .
The lubricant stored in the transmission chamber 17 is picked up by the gears in rotation to lubricate the change speed devices in the transmission chamber 17 . The lubricant is also sucked up by a hydraulic pump to be supplied as hydraulic oil to various actuators.
Returning hydraulic oil is supplied from a rearward position of change speed output shaft 58 to a gap between PTO drive shaft 33 and change speed output shaft 58 . The oil flows forward to lubricate the synchromesh clutches and the like. Then, the oil flows out from the forward end of the change speed output shaft 58 to lubricate the backward and forward drive switching clutch 40 , and is thereafter stored in the gear case 20 .
As shown in FIG. 5, the rear case 23 of gear case 20 defines an oil communicating bore 108 . Through the oil communicating bore 108 , the oil in the gear case 20 returns to the transmission chamber 17 . However, the oil communicating bore 108 is located in a higher position than the lubricant level in the transmission chamber 17 . The lubricant level in the gear case 20 is always maintained higher than the lubricant level in the transmission chamber 17 .
According to the embodiment having the above construction, the backward and forward drive switching device 21 no longer requires a backward return gear train as required in the prior art. Thus, the change speed apparatus a correspondingly reduced fore and aft length.
The change speed apparatus for a tractor according to this invention is not limited to the foregoing embodiment. The invention is applicable also to an engine power transmitting system with the backward and forward drive switching device disposed downstream, and not upstream, of the main change speed device.
According to this invention, the backward and forward drive switching device no longer requires a backward return gear train as required in the prior art. Thus, the change speed apparatus a correspondingly reduced fore and aft length. This construction provides for a reduction in the distance between the front and rear wheels, to achieve an improved small turn performance.
Further, since the backward and forward drive switching device may be sub-assembled in the gear case, an assembly operation may carried out with increased efficiency.
The backward and forward drive switching device has an operating shaft and a control lever disposed close to each other. This arrangement results in a simplified connecting mechanism between the shaft and lever. | A tractor change speed apparatus includes a manual change speed device having a combination of gear trains mounted on first and second parallel shafts and driving a change speed output shaft at various speeds. A backward and forward drive switching device is cooperable with the main change speed device for producing forward and backward drives in an equal number of speeds, wherein the forward drive is transmitted through the first shaft and the backward drive is transmitted through the second shaft. A group of gears for returning reverse drive to a forward drive transmission shaft is thereby omitted. Consequently, the backward and forward drive switching device and the entire change speed apparatus has a reduced longitudinal length. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a calender, particularly for webs of textile fabric, non-woven fabric, or synthetic fabric, with a frame and a first roll, a second roll and a third roll mounted in the frame, wherein the third roll forms during operation a single nip either with the first roll or with the second roll.
2. Description of the Related Art
A calender of the above-described type is sold by Kleinewerfers Textilmaschinen GmbH in the form of a three-roll calender with rolls arranged one above the other. The nip is in this calender formed either between the upper roll and the middle roll or between the lower roll and the middle roll. The two different pairings of rolls are necessary in order to be able to switch over as soon as possible and without major reassembly from one manner of treatment to another manner of treatment. For example, it may be necessary to treat the fabric web with different surface qualities of the upper and the lower rolls. Another situation occurs when it is desired to change the treatment temperature of the fabric web. Since the temperature change in the heated roll can be carried out only at about 1° C. to 2° C. per minute in order to avoid undue thermal stresses, a temperature change of 40° C. will take a relatively long time. On the other hand, if it is possible to change to a roll which already has the required temperature, the time required for changing between the two types of treatment is drastically shortened.
Consequently, in the known calender, the travel path of the fabric web is changed when changing from one manner of treatment to another. Thus, if the fabric web has been fed to the upper nip, i.e., the nip between the upper roll and the middle roll, the fabric web is then supplied for the changed treatment to the lower nip, i.e., the nip between the lower roll and the middle roll. The nip which is not in use remains open. A calender of the above-described type has been found acceptable in principle for different treatment possibilities of fabric webs. However, the change of one type of treatment in one nip to another type of treatment in the other nip is relatively cumbersome. In particular, the path along which the fabric web is guided must be changed. This is true for the entry side as well as the exit side. If the fabric web is a non-woven fabric which is to be bonded in the nip, for example, a supply belt on which the fabric is supplied to the nip must be pivoted. The fabric web must either travel with a different travel path through cooling rolls which as a rule are arranged at the exit of the nip, or the position of the cooling rolls must also be changed.
A calender of the above-described type is also known from DE 37 12 276 C1. In one embodiment of this calender, three rolls are arranged one above the other, wherein the middle roll can be moved either upwardly to form a nip with the upper roll, or downwardly to form a nip with the lower roll. The fabric web is supplied through a pivotable supply unit whose supply path ends either a short distance below the upper roll or a short distance above the lower roll. The fabric web leaving the respective nip is guided either from below or from above around a guide roll and leaves the calender in a slightly upwardly or downwardly inclined direction.
SUMMARY OF THE INVENTION
It is the primary object of the present invention to facilitate the change from one type of operation to another type of operation.
In accordance with the present invention, in a calender of the above-described type, the first roll is movable between a first work position in which it forms the nip with the third roll and a first parking position, and the second roll is movable between a work position in which it forms the nip with the third roll and a second parking position, wherein the two work positions coincide and the parking positions of each of the first and second rolls is distanced from the third roll by such a distance that a movement of the respectively other roll between the work position and the parking position is possible.
The statement that the two work positions coincide does not mean that they coincide in the mathematical sense. Smaller deviations are permissible as long as the nip, which is formed by the respective first or second roll which is in the work position with the third roll, produces essentially the same treatment result, independently of which roll is at a given time in the work position. Of course, this is only true if the first and second rolls are equal. However, the first and second roll will normally be of different construction. The differences may be in the surface structure or in the material if the first or second rolls or both rolls are constructed as engraved rolls. The differences may also be in the temperature or in other physical properties. A change in the type of operation from a treatment in the nip between the first and second rolls to a treatment in the nip between the second and third rolls is relatively simple. In particular, it is not necessary to change the entry travel path or the exit travel path of the fabric web. It is merely necessary to move the roll which prior to the change of the type of operation was in the work position into its parking position and to move the other roll from its parking position into the work position. Such movements can be carried out substantially simpler than the change of a travel path. It is merely a prerequisite that the roll in the parking position leaves room for the movement of the other roll from the work position into the parking position and vice versa.
In accordance with a preferred embodiment, the first roll and the second roll are each movable together with their drive and possibly supply units. Accordingly, each roll when moved takes along with it its drive and possibly its supply unit, for example, required for achieving a predetermined temperature. Accordingly, when changing from one type of operation with the first roll to another type of operation with the second roll, it is actually only necessary to move the respective roll. It is not necessary to provide new connections or to connect drives to the respective roll. The roll which is in the parking position can continue to rotate with a rate of rotation independent of the production speed, for example, for cooling the roll.
In accordance with a preferred embodiment, the first roll is mounted on the frame through a first pivoting lever and the second roll is mounted on the frame through a second pivoting lever, wherein each pivoting lever is pivotable about a pivot axis. The movement of the rolls can be carried out quickly and without problems with a pivoting movement. During the pivoting movement, the pivoting lever is secured to the pivot axis. Consequently, the pivot lever always has a defined position relative to the frame, so that the control of the movement is very simple.
Each pivoting lever can preferably be secured relative to the frame on the side of a press plane located opposite the pivot axis, wherein the press plane extends through the two roll axes of the rolls forming the nip. This takes into consideration that for treating the fabric web the third roll is pressed with a certain force against the roll located in the work position. The first or second roll located in the work position is secured through the pivot axis to the frame. However, without the additional attachment of the pivoting lever, a relatively large moment would act on the pivoting lever, wherein the moment is difficult to absorb. By attaching the pivoting lever to the frame on both sides of the press plane, this problem is eliminated. The attachment can also be carried out indirectly at least on one side.
In accordance with a preferred feature, the pivoting lever located in the work position can be locked to the pivoting lever in the parking position. This does not result in an indirect locking of the pivoting lever in the working position to the housing. Rather, the pivoting lever is locked directly through the respectively other pivoting lever. However, this type of connection forms a triangle formed by the pivot axes of the two pivot levers and the locking point between the two pivoting levers. Such a triangle provides sufficient stability for supporting the pivoting lever, or the first or second roll which may be in the work position, against the forces exerted by the third roll.
In accordance with a preferred feature, each pivoting lever has a first bore which can be aligned with a second bore in the respectively other pivoting lever, wherein a bolt can be inserted into the two bores parallel to the pivot axes. Consequently, each pivoting lever has two bores, wherein the bore of one pivoting lever is in alignment with the other bore of the other pivoting lever if the one pivoting lever is in the work position. The insertion of a bolt through the aligned bores poses no problems. The bolt can be inserted either manually or a hydraulic cylinder or another drive can be used. The arrangement of bores permits a quick and reliable locking between the levers.
Each pivoting lever preferably has an adjusting device for its work position. The adjusting device has two purposes. First, the adjusting device determines the position of the pivoting lever relative to the frame in such a way that the roll located at the respective pivoting lever is in the correct position relative to the third roll. On the other hand, the adjusting device also ensures that the first bore of the respective pivoting lever in the work position can be aligned with the respective second bore of the other lever in the parking position.
The adjusting device preferably has a first adjusting unit which cooperates with the frame. This adjusting unit is used to adjust the pivoting angle of the pivoting lever relative to the frame. In principle, the vertical position of this bore in relation to the first bore is adjusted by this adjusting unit.
The adjusting device preferably also has a second adjusting unit which interacts with the respectively other pivoting lever. The second adjusting unit has basically no influence on the position of the pivoting lever which is in the work position relative to the housing. However, the second adjusting unit forms a limit for the pivoting movement of the pivoting lever in the parking position and, thus, facilitates an adjustment of the second bore of the pivoting lever in the parking position in the horizontal direction, i.e., perpendicularly of the possible movement direction of the first bore of the pivoting lever in the work position. This makes it possible to achieve an alignment of the two bores in a relatively simple manner. The adjustment is basically only necessary during the startup and possibly during a subsequent maintenance operation. The adjustment is not changed when the pivoting lever is pivoted.
Each pivoting lever preferably has a stop for its parking position. This stop limits the movement of the pivoting lever and the load of the pivoting drive is kept small.
Each pivoting lever is preferably inclined in its parking position at most to such an extent that the other pivoting lever can be pivoted without collision relative to the first pivoting lever into its parking position. This keeps low any torque which is formed by the center of gravity of the pivoting lever in the parking position and the horizontal distance from the pivoting axis. This eliminates the load on the pivoting drive in the parking position. In the work position, the pivoting lever is already directly or indirectly supported on the frame, so that there is also no load on the pivoting drive in the work position. The pivoting drive actually has only to be used in the phases of movement between the parking position and the work position. Thus, the angle is kept as small as possible.
The pivoting levers are preferably two-arm levers, wherein the respective roll is arranged on one side of the pivoting lever and a pivoting drive acts on the other side of the lever. As a result, the pivoting drive does not impair the operation of the roll and vice versa. This means that a wide variety of pivoting drives can be used.
In accordance with an advantageous feature, each pivoting lever is constructed with two walls and surrounds both sides of bearing lug of the frame. This results in a very stable support of the pivoting lever in the frame which reliably prevents tilting of the pivoting lever relative to the housing in a direction other than the pivoting direction.
In accordance with another preferred feature, each pivoting lever has at its end facing the other pivoting lever a locking plate which can be inserted between the two walls of the other pivoting lever. Also in this case, a very stable connection is obtained when locking the levers by inserting the locking plate between the two walls of the other pivoting lever.
The rolls are advantageously releasably connected to the pivoting levers. For example, the bearings on which the rolls are rotatably mounted can be fastened through a screw connection to the pivoting levers. This simplifies the exchange of rolls which occasionally becomes necessary.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing:
FIG. 1 is a side view of a calender during operation;
FIG. 2 shows the calender of FIG. 1 during a change of the type of operation of the calender; and
FIG. 3 is a view, on a larger scale, of a locking device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 of the drawing shows a calender 1 with a frame 2 and first roll 3 , a second roll 4 , and third roll 5 mounted in the frame 2 . The third roll 5 is mounted in a carriage 6 which can be displaced in the frame 2 by means of a hydraulic cylinder 7 ; in the illustrated embodiment, the displacement of the carriage 6 is in the vertical direction. However, the hydraulic cylinder 7 not only serves for displacing the carriage 6 and the third roll 5 , but also for adjusting the third roll 5 against the first or second roll and for applying a force by the roll 5 against the first or second rolls, as will be explained below.
The first roll 3 is mounted on a first pivoting lever 8 which can be pivoted about a pivot axis 9 relative to a frame 2 . For this purpose, the first pivoting lever 8 has a pivoting drive 10 . The first pivoting lever 8 is constructed as a two-arm lever. The first roll 3 is mounted on one side of the pivot axis 9 ; in the illustrated embodiment, the first roll 3 is arranged on the right of the pivot axis 9 . The pivoting drive 10 acts on the other side, i.e., on the left in the illustrated embodiment. When the first pivoting lever 8 has been pivoted in such a way as it is illustrated in FIG. 1, the first roll 3 is in its work position, i.e., it forms with the third roll 5 a nip 11 through which a fabric web 12 can be guided and in which pressure and possibly increased temperature can be applied to the fabric web 12 .
The fabric web 12 is supplied to the nip 11 by means of a screen 13 or by means of another conveying device. This screen 13 may be stationary, i.e., the fabric web 12 is always guided through the nip 11 in the illustrated manner.
Two cooling rolls 14 , 15 are arranged at the exit side of the nip 11 ; the fabric web 12 is guided partially around each cooling roll 14 , 15 . These cooling rolls 14 , 15 also remain stationary and the fabric web 12 is always guided in the same manner around the cooling rolls 14 , 15 independently of the manner of treatment of the fabric web in the calender 1 .
The second roll 4 is mounted in a similar manner on a second pivoting lever 18 which can be pivoted about a pivot axis 19 and includes a pivoting drive 20 . As illustrated, the pivoting drives 10 , 20 are constructed as hydraulic cylinders. The pivot axes 9 , 19 are formed by bolts which are attached to the frame 2 . In FIG. 1, the second roll 4 is in the parking position.
The rolls 3 , 4 , 5 have a diameter in the order of magnitude of 400-900 mm, wherein the third roll 5 as a rule has a slightly smaller diameter than the first roll 3 or the second roll 4 .
As mentioned above, the third roll 5 is pressed by means of the cylinder 7 against the first roll 3 which is in the work position. Without additional measures, this would result in a pivoting movement of the first pivoting lever 8 . In order to prevent this, the first pivoting lever 8 is locked to the second pivoting lever 18 . This is illustrated in FIG. 2 . The first pivoting lever 8 has a first opening 21 provided in a first locking plate 22 which is arranged at the tip of the first pivoting lever 8 , i.e., at that end which is directed toward the second pivoting lever 18 when the first pivoting lever is located in the work position illustrated in FIG. 1 . In the same manner, the second pivoting lever has a first opening 23 in its locking plate 24 .
The first pivoting lever 8 has a second opening 25 . The second pivoting lever 18 has a second opening 26 . Arranged at both second openings 25 , 26 is a hydraulic cylinder 27 , 28 each which acts parallel to the pivot axes 9 , 19 , i.e., perpendicularly of the plane of the drawing in the illustrations of FIGS. 1 and 2.
When the first pivoting lever 8 has been moved into the work position and the second pivoting lever 18 has been moved into the parking position, the first opening 21 of the first pivoting lever 8 and the second opening 26 of the second pivoting lever 18 are in alignment. As can be seen in FIG. 3, the cylinder 28 can then push a bolt 29 into the openings, so that the first pivoting lever 8 and the second pivoting lever 18 are locked together. This means that the first pivoting lever 8 is indirectly secured relative to the frame 2 . The two pivot axes 9 , 19 and the locking point resulting from the bolt 29 form a triangle which is stable enough to support the first roll 3 relative to forces exerted by the cylinder 7 .
As FIG. 3 further shows, the second pivoting lever 18 is a double-walled lever (the same is true for the first pivoting lever 8 ), i.e., the pivoting lever 18 has two walls 30 , 31 between which the locking plate 22 of the first pivoting lever 8 can be inserted. In the same manner, the frame 2 is received between the two walls 30 , 31 . The frame 2 may have a smaller thickness and form a bearing lug at this location.
For ensuring the alignment of the first bores 21 , 23 with the second bores 25 , 26 of the respectively other pivoting lever after a pivoting movement has been carried out, each pivoting lever 8 , 18 has an adjusting device. The adjusting device includes a first adjusting unit 32 , 33 in the form of an adjusting screw. As can be seen in FIG. 1, the adjusting screw 32 of the first pivoting lever 8 rests in the work position against the frame 2 . By changing the length of the adjusting screw 32 , the vertical position of the opening 21 of the first pivoting lever 8 is essentially adjusted.
The adjusting device further has a second adjusting unit 34 (at the first pivoting lever) and 35 (at the second pivoting lever) which are also constructed as adjusting screws. The adjusting unit 34 at the first pivoting lever 8 limits a pivoting movement of the second pivoting lever 18 toward the first pivoting lever 8 . This essentially secures the position of the second opening 26 in the second pivoting lever 18 in the horizontal direction. Consequently, by an interaction of the two adjusting units 32 , 34 at the first pivoting lever or the two adjusting units 33 , 35 at the second pivoting lever, an alignment of the respective bores 21 , 26 and 23 , 25 can be achieved in a relatively simple manner.
When the manner of operation is to be changed, i.e., the fabric web 12 is no longer to be treated between the first roll 3 and the third roll 5 , but in a nip between the second roll 4 and the third roll 5 , initially the locking device between the first pivoting lever 8 and the second pivoting lever 18 is released by moving the bolt 29 back by means of the cylinder 28 . Next, the second pivoting lever 18 is pivoted outwardly by means of its pivoting drive 20 , as can be seen in FIG. 2 . This movement can be limited by a stop 37 in such a way that the angle of inclination of the pivoting lever relative to the vertical direction is limited to a maximum value; a corresponding stop 36 is provided for the first pivoting lever 8 . This provides sufficient space for making it possible to pivot the pivoting lever 8 past the second roll 4 into the parking position illustrated in broken lines in FIG. 2 . However, the angle remains small. As a result, the first pivoting lever 8 with its first roll 3 now has made available sufficient space for making it possible to pivot the second pivoting lever 18 in a counterclockwise direction for moving the second roll 4 into the vicinity of the third roll 5 . Since the third roll 5 has been lowered by the cylinder 7 prior to the change of operation, as a rule by 120 mm, the second roll 4 forms an open nip with the third roll 5 . Before the calender can be operated once again, the first pivoting lever is moved from the position shown in broken lines in which it rests against the stop 36 , once again back slightly in the clockwise direction in such a way that the first roll 3 is located approximately vertically above the pivot axis 9 . In this position, the first pivoting lever then rests against the second adjusting unit 35 of the second pivoting lever 18 and the openings 23 and 25 are in alignment, so that the cylinder 27 can insert a locking bolt into the aligned openings. When the cylinder 7 then moves the third roll 5 against the second roll 4 , the treatment of the fabric web 12 is then possible with the desired pressure and temperature. The arrangement is then basically mirror-symmetrical relative to the arrangement illustrated in FIG. 1 .
While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles. | A calender, particularly for webs of textile fabric, non-woven fabric or synthetic fabric, includes a frame and a first roll, a second roll and a third roll mounted on the frame. The third roll forms during operation of the calender a single nip either with the first roll or with the second roll. The first roll is movable between a work position in which it forms a nip with the third roll and a first parking position, and the second roll is movable between a work position in which it forms the nip with the third roll and a second parking position, wherein the work positions coincide and the parking position of each roll is located at such a distance from the third roll that a movement of the respectively other roll between the work position and the parking position is possible. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of and claims priority of U.S. Nonprovisional patent application Ser. No. 12/330,401 entitled “METHOD AND SYSTEM FOR CREATING AN IMAGE USING QUANTUM PROPERTIES OF LIGHT BASED UPON SPATIAL INFORMATION FROM A SECOND LIGHT BEAM WHICH DOES NOT ILLUMINATE THE SUBJECT,” by Meyers, et al., filed Dec. 8, 2008, and also claims priority of U.S. Provisional Patent Application Ser. No. 60/993,792 filed Dec. 6, 2007, both of which are incorporated herein by reference.
GOVERNMENT INTEREST
[0002] The invention described herein may be manufactured, used, and licensed by or for the United States Government.
FIELD OF THE INVENTION
[0003] This invention relates in general to a process and apparatus for quantum ghost imaging and in particular to a process using the properties of quantum ghost imaging to generate an image of an object via correlations between photons, sound or quantum particles reflected off the object and with photons, sound or quantum particles that have never interacted with the object.
BACKGROUND OF THE INVENTION
[0004] The ability to image through obscuring media remains a problem in a variety of fields. By way of example, imaging of distant objects through the obscuring media of smoke or clouds is a problem that plagues satellite imaging analysts, firefighters, drivers, oceanographers, astronomers, military personnel, and medical personnel. The ability to improve resolution in each of these exemplary instances represents an opportunity to derive more information from images and presumably the decisions made from such images. By way of example, improved resolution in x-ray or endoscopy medical imagery facilitates lower radiation dosing and diagnosis of abnormal morphologies earlier than currently possible with conventional imaging methodologies. Conventional imaging techniques have, to a large extent, arrived at the theoretical limits of image resolution owing to wavelength-limited resolution, optical element distortions, and the reflective interaction between photons and an object to be imaged.
[0005] Ghost imaging holds the prospect of improving image resolution but efforts in regard to ghost imaging have met with limited success owing to a lack of understanding of the phenomena.
[0006] Currently, quantum ghost imaging is largely dependent on the transmission of electromagnetic waves (photons) through the object to be imaged. However, in most real world applications, photonic transmission is impractical, and instead of object light reflection is the basis of image formation. Even in transmissive imaging such as x-ray imaging considerable image information occurs through consideration of reflection. Additionally, other objects can best be imaged using the fluorescence of the object when illuminated by an external light source.
[0007] The first two-photon imaging experiment was reported by Pittman et al. in “Optical Imaging by Means of Two-photon Quantum Entanglement,” Physical Review A, Vol. 52, No. 5, November 1995. According to the article, a two-photon optical imaging experiment was performed based on the quantum nature of the signal and idler photon pairs produced in spontaneous parametric down-conversion. An aperture placed in front of a fixed detector was illuminated by a signal beam through a convex lens. A sharp magnified image of the aperture was found in the coincidence counting rate when a mobile detector is scanned in the transverse plane of the idler beam at a specific distance in relation to the lens. The experiment was named “ghost imaging” due to its surprising nonlocal feature, although the original purpose of the experiment was to study and to test the two-particle EPR correlation in position and in momentum for an entangled two-photon system. The experiments of ghost imaging in Pittman, et al. “Optical Imaging by Means of Two-Photon Entanglement,” Phys. Rev. A, Rapid Comm., Vol. 52, R3429 (1995) and ghost interference by Strekalov, et al, “Observation of Two-Photon ‘Ghost’ Interference and Diffraction,” Phys. Rev. Lett., Vol. 74, 3600 (1995) together stimulated the foundation of quantum imaging in terms of multi-photon geometrical and physical optics. The prior art transmissive ghost imaging optical scheme using entangled photons of Pittman et al. is depicted in FIG. 1 .
[0008] This experiment was inspired by the theoretical work reported by Klyshko in Usp. Fiz. Nauk 154 133, Sov. Phys. Usp. 31, 74 (1988); Phys. Lett. A 132299 (1988) suggesting a non-classical two-photon interaction could exist. The Pittman experiment was immediately named “ghost imaging” due to its surprising nonlocal feature. The important physics demonstrated in that experiment, nevertheless, may not be the “ghost”. Indeed, the original purpose of the Pittman experiment was to study and to test the two-particle entanglement as originally detailed by Albert Einstein et al. (Einstein, Podolsky, Rosen) in Phys. Rev. 35 777 (1935) to determine if there was a correlation in position and in momentum for an entangled two-photon system. D'Angelo and colleagues in Phys. Rev. A 72, 013810 (2005) showed that ghost images produced by separable sources are subject to the standard statistical limitations. However, entangled states offer the possibility of overcoming such limitations to yield images that can achieve the fundamental limit through the high spatial resolution and nonlocal behavior of entangled systems.
[0009] Boto and colleagues in Phys. Rev. Lett. 85 2733 (2000) later developed an entangled multi-photon systems for sub-diffraction-limited imaging lithography and proposed a heuristic multiphoton absorption rate of a “noon” state and proved that the entangled N-photon system may improve the spatial resolution of an imaging system by a factor of N, despite the Rayleigh diffraction limit. The working principle of quantum lithography was experimentally demonstrated by D'Angelo et al. in 2001 by taking advantage of an entangled two-photon state of spontaneous parametric down-conversion as described in Phys. Rev. Lett. 87 013603.
[0010] Quantum imaging has so far demonstrated two peculiar features: (1) reproducing ghost images in a “nonlocal” manner, and (2) enhancing the spatial resolution of imaging beyond the diffraction limit. Both the nonlocal behavior observed in the ghost imaging experiment and the apparent violation of the uncertainty principle explored in the quantum lithography experiment are due to the two-photon coherent effect of entangled states, which involves the superposition of two-photon amplitudes, a nonclassical entity corresponding to different yet indistinguishable alternative ways of triggering a joint-detection event in the quantum theory of photodetection as articulated by Glauber in Phys. Rev. 130 2529 (1963); and Phys. Rev. 131 2766 (1963). The nonlocal superposition of two-photon states may never be understood classically. Classical attempts, however, have never stopped in the history of EPR studies as evidenced by Bennink et al., who demonstrated 2002 by experiment, two co-rotated laser beams produced a projection shadow of an object mask through coincidence measurements as published in Phys. Rev. Lett. 89 113601 (2002). Instead of having a superposition of a large number of two-photon amplitudes, Bennink et al. used two correlated laser beams (imagine two back to back lasers) to simulate each two-photon amplitude one at a time. If the laser beam in the object arm is blocked by the mask at a certain rotating angle, there would be no coincidence in that angle and consequently defines a corresponding “position” in the nonlocal “image” plane. The block-unblock of the correlated laser beams thus projects a shadow of the object mask in coincidences. Interestingly, this experiment has excited a number of discussions concerning certain historical realistic models of EPR (Einstein, Podolsky, Rosen). Apparently, Bennink et al. have provided experimental evidence to support the concept of classical physical reality. Perhaps, the use of a transmitting mask as the object aperture function in the historical ghost imaging experiments may have been a factor responsible for this confused wrong idea.
[0011] The classical argument seems to get more support from thermal light ghost imaging, because thermal light itself is considered as classical. Thermal light ghost imaging was proposed in 2004 by Gatti et al. in Phys. Rev. A 70 013802, Wang and co-workers in quant-ph/0404078 and quant-ph/0407065, and Cai and Zhu in Phys. Rev. E 71 056607.
[0012] Thermal light ghost imaging for thermalized photons with a single CCD camera was used by Gatti et al. The main purpose was to simulate the two-photon correlation of entangled states by a classical source. In fact, two-photon correlation of thermal radiation is not a new observation. Hanbury-Brown and Twiss (HBT) demonstrated the second-order correlation of thermal light spatially (transverse) and temporally (longitudinal) in 1956 as published in Nature 177 28, and Nature 178 1046, and Nature 178 1447. Differing from entangled states, the correlation in chaotic radiation is only “partial”, which means 50% visibility at most. Nevertheless, chaotic light is a useful candidate for ghost imaging in certain applications. Recently, a number of experiments successfully demonstrated certain interesting features of ghost imaging by using chaotic light. Representative of these experiments using chaotic light are those by A. Valencia and colleagues in Phys. Rev. Lett. 94 063601 (2005); Scarcelli and colleagues in Phys. Rev. Lett. 96 063602 (2006); Ferri and colleagues in Phys. Rev. Lett. 94 183602 (2005); and Zhang and colleagues in Opt. Lett. 30 2354 (2005). A prior art transmissive ghost imaging optical scheme using thermalized photons Meyers/Deacon “Quantum Ghost Imaging Experiments,” SPIE Proceedings Vol. 6305 (2006) is depicted in FIG. 2 .
[0013] The HBT experiment was successfully interpreted as statistical correlation of intensity fluctuations instead of two-photon coherence. A question about two-photon ghost imaging is then naturally raised: is the physics behind ghost imaging phenomenon a classical correlation of intensity fluctuations too? To answer this question, Scarcelli et al. in Phys. Rev. Lett. 96 063602 (2006) demonstrated a near-field ghost imaging of chaotic radiation. FIG. 3 is a prior art optical scheme for these experiments. In this work, Scarcelli et al. pointed out that (1) the classical interpretation leads to non-physical conclusions in the case of entangled two-photon ghost imaging; and (2) even if the classical interpretation may work for HBT, it will not work for the near-field ghost imaging of chaotic radiation. HBT correlation is measured in far-field, which is essentially a momentum-momentum self-correlation of a radiation mode. In the Scarcelli et al. experimental setup, however, the measurement is in near-field. In the near-field, for each position on the detection plane, a point photodetector receives a large number of modes in the measurement. The classical interpretation of statistical correlation of intensity fluctuations will not work in this experimental setup, as we know that different modes of chaotic light fluctuate randomly and independently. The fluctuations will cancel each other if more than one mode is involved in the measurement. On the other hand, Scarcelli et al. proved a successful alternative interpretation in terms of two-photon interference.
[0014] The experiment of Scarcelli et al. published in Phys. Rev. Lett. 98 039302 (2007) that builds on the earlier work of this group detailed above has not been able to convince Gatti et al. that ghost imaging is quantum in nature as evidenced by the publication of Gatti et al. in Phys. Rev. Lett. 98 039301. This ongoing lack of theoretical understanding of ghost imaging has hampered efforts to develop reflective ghost imaging systems for practical field uses in such fields as satellite, field, medical and research imaging.
[0015] Thus, there exists a need for a ghost imaging that is not dependent on the transmission properties of the object. Furthermore, there is a need for ghost imaging the multi-spectral properties of an object. An additional need exists for an imaging system that is tolerant of the scattering and distortion of an image as photons propagate through a distortion medium.
[0016] Ghost imaging in the prior art was dependent upon the transmission properties of an object. Accordingly, there exists a need for image creation where the transmission of light through the object is not possible or advantageous, such as when the object is opaque. Thus, there exists a need for an imaging system wherein light can be reflected from an object for subsequent image transmission.
[0017] In conventional image generation systems, a sufficient bandwidth necessary to transmit an image. There exists a need for image generation whereby the image can be generated and transmitted using minimal bandwidth, such as for example, using voltage detection readings.
[0018] Generally speaking, for the two dimensional (2D) images, there are two major graphic types: bitmap and vector image graphics. Three dimensional (3D) images are similarly formed with more complicated positional information relating to the third dimension.
[0019] A bitmap (or pixmap) image file format contains spatial information as to the location of the pixel or “bites” within the image or picture being transmitted. The term bitmap is derived from a mapped array of bits, and bitmapped and pixmap refer to the similar concept of a spatially mapped array of pixels. Both bitmapped and pixmapped formats contain spatial information. Raster graphics is the representation of images as an array of pixels.
[0020] Vector graphics are computer images that are stored and displayed in terms of vectors rather than points. Vector graphics utilizes, inter alia, points, lines, curves, and shapes or polygon(s), which are all based upon mathematical equations, to represent images in computer graphics.
[0021] Both bitmap and vector images utilize spatial information. A feature of a preferred embodiment of the present invention enables the transmission of an image without spatial information. As used herein the terminology “without spatial information” is defined as without positional information (such as that found in bitmap or pix map), or vector information such as that found in vector imaging.
SUMMARY OF THE INVENTION
[0022] A preferred embodiment of the present invention utilizes the concept that if the light generation source may be analyzed at a remote location, an image may be detected by a detector for which the output is a voltage measurement.
[0023] The source of radiation may be one of an entangled, thermal/incoherent (sun, light bulb, flame, environmental radiation), or chaotic light source. Thermal is a type of incoherent light. The present invention may be practiced using all wavelength forms of light (e.g., X-rays, visible, etc.). The photons from the light source are divided into two paths. In one path is the object to be imaged, in the other path images of the entangled, thermal, or chaotic light are measured independent of interaction with the objects. Any or all paths may pass through an obscuring medium. The measurements of the entangled, thermal, or chaotic light are then stored for future processing. The light in the object path is collected into a bucket detector and measured. The measurements of the bucket detector are then stored for future processing. A process for solving for the G (2) Glauber coherence between the two paths is provided to reconstruct the image. The G (2) Glauber coherence between the two paths is used to generate a correlation two-photon ghost image. The present invention is not limited to photons and can be conducted with any quantum particle. The principles of the present invention are not limited to light and may be practiced utilizing, e.g., using sound, electron, proton or neutron sources as the “illuminating” component of the ghost imager. Moreover, the obscuring materials may comprise foliage or vegetation in remote sensing applications and tissue in medical applications Ghost imaging may be used to achieve higher resolution than the standard Rayleigh diffraction limit using entangled or non-entangled quantum particles or other forms of radiation referenced herein.
[0024] The present invention is directed to a ghost imaging system that provides reflective object imaging with an improved sensitivity in the presence of an obscuring medium. In contrast to classical reflective object imaging, in accordance with an embodiment of the present invention, the photon ghost image is theoretically less dependent on image distortion associated with photon transit through obscuring medium and in practice there is only nominal image distortion associated with light traveling through an obscuring medium when utilizing a preferred embodiment ghost imaging system. Representative obscuring media according to the present invention illustratively include fog, an aerosol, particulate whether suspended in air, water, or vacuum media; turbulence; liquid, vegetation, foliage, tissue, sand, or frosted glass.
[0025] The present invention uses radiation from an entangled, thermal, or chaotic light source to generate ghost images. The photons from the light source are divided into two paths. In one path is the object to be imaged, in the other path images of the entangled, thermal, or chaotic light are measured independent of interaction with the objects. Any or all paths may pass through an obscuring medium. The measurements of the entangled, thermal, or chaotic light are then stored for future processing. The light in the object path is collected into a bucket detector and measured. The measurements of the bucket detector are then stored for future processing. A process for solving for the G (2) Glauber coherence of Equation 3 (provide hereafter) between the two paths is provided to reconstruct the image. This coherence between the two paths is used to generate a correlation two-photon ghost image. One or more bucket detectors are used along with a spatially addressable detector to generate images from the joint-detection correlations between the bucket detectors and the single-pixel detector(s). The resultant ghost corresponds to a convolution between the aperture function, or the amplitude distribution function, of the object and a δ-function like second-order correlation function of Glauber coherence. Furthermore, the bucket detectors may be a charged coupled device (CCD) operating as a spatially integrated detector. Alternatively, the spatially integrated detector may further comprise means for modifying sensitivity of specific pixels on the spatially integrated detector prior to producing the bucket detector signal. For example, acting as a diffraction grating of a certain order or imprinting an identification mark. Any array of detectors that covers an area or any detector that scans an area may be used in place of a CCD.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a prior art scheme depicting a quantum ghost imaging technique based on object transmission using entangled photons;
[0027] FIG. 2 is a prior art schematic depicting a quantum ghost imaging technique based on object transmission using thermalized light photons;
[0028] FIG. 3 is a prior art schematic depicting a quantum ghost imaging technique using thermalized light photons and a single CCD;
[0029] FIG. 4 is a schematic diagram of a generic inventive ghost imaging system;
[0030] FIG. 5A is a schematic of an inventive quantum ghost imaging scheme, operating with entangled or thermal photons with reflection from an object;
[0031] FIG. 5B is an actual ghost image display of an object from the scheme of FIG. 5A ;
[0032] FIG. 6 is a schematic of an inventive quantum ghost imaging scheme using a lens to focus light reflected from a remote object;
[0033] FIG. 7A is a schematic of an inventive lens-less quantum ghost imaging scheme using light reflected from an object;
[0034] FIG. 7B is single frame CCD output; the “speckles” indicate typical random photodetection events;
[0035] FIG. 7C is time averaged CCD output of a few hundred frames;
[0036] FIG. 7D is a ghost image CCD-D 1 joint detection;
[0037] FIG. 8A is an illustrative schematic indicating that a quantum ghost image can be generated if there are phase aberrations in a path, using either transmitted or reflected photons;
[0038] FIG. 8B is a perspective schematic view of quantum ghost imaging according to FIG. 8A with a partially transparent mask encoding the letters “ARL”;
[0039] FIG. 9 is a perspective schematic view of quantum ghost imaging generated with a correlated photons of a light emitting diode (LED) incoherent light source;
[0040] FIG. 10 is a perspective schematic view of the reflective ghost imaging scheme using solar light reflected from an object, depicted as a vehicle;
[0041] FIG. 11 is a diagram depicting the multiple object imaging qualities of the inventive quantum ghost imaging scheme operating with entangled or thermal photons protocol;
[0042] FIG. 12 is a set of images depicting the results of a reflection ghost imaging experiment wherein the light path to the bucket detector passes through an obscuring medium; FIG. 12A is an instantaneous image of the spatially varying intensity of light source; FIG. 12 B is an averaged image of the light source; FIG. 12C is the G (2) image of the obscured object reflection; FIG. 12D is an instantaneous image of the light source; object reflection; and FIG. 12E is an averaged image of the source; FIG. 12F is the G (2) image of object reflection. In this example the location of the obscuring medium is at position 15 of FIG. 5 . However, the inventive process compensates for obscuring medium regardless of location.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. However, this invention should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the dimensions of objects and regions may be exaggerated for clarity. Like numbers refer to like elements throughout. As used herein the term “and/or” includes any and all combinations of one or more of the associated listed items.
[0044] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the full scope of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
[0045] It will be understood that when an element such as an object, layer, region or substrate is referred to as being “on” or extending “onto” another element, it can be directly on or extend directly onto the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” or extending “directly onto” another element, there are no intervening elements present. It will also be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present.
[0046] It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. For example, when referring first and second photons in a photon pair, these terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.
[0047] Furthermore, relative terms, such as “lower” or “bottom” and “upper” or “top,” may be used herein to describe one element's relationship to other elements as illustrated in the Figures. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. For example, if the device in the Figures is turned over, elements described as being on the “lower” side of other elements would then be oriented on “upper” sides of the other elements. The exemplary term “lower”, can therefore, encompass both an orientation of “lower” and “upper,” depending of the particular orientation of the figure. Similarly, if the device in one of the figures is turned over, elements described as “below” or “beneath” other elements would then be oriented “above” the other elements. The exemplary terms “below” or “beneath” can, therefore, encompass both an orientation of above and below. Furthermore, the term “outer” may be used to refer to a surface and/or layer that is farthest away from a substrate.
[0048] Embodiments of the present invention are described herein with reference to cross-section illustrations that are schematic illustrations of idealized embodiments of the present invention. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the present invention should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, a region or object illustrated as a rectangular will, typically, have tapered, rounded or curved features. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region of a device and are not intended to limit the scope of the present invention.
[0049] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0050] It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature.
[0051] The present invention has utility as a ghost imaging system that provides reflective object imaging with an improved sensitivity in the presence of an obscuring medium. In contrast to conventional reflective object imaging, the imaging conducted in accordance with the principles of the present invention, referred to as a photon ghost image, is capable of being substantially independent of image distortion associated with photon transit through obscuring media and practically has only nominal image distortion associated with light in ghost imaging system operating in an obscuring medium constructed in accordance with the principles of the present invention. Representative obscuring media according to the present invention illustratively include fog, an aerosol, particulate whether suspended in air, water, or vacuum media; turbulence; liquid or frosted glass.
[0052] Ghost imaging may be used to achieve higher resolution than the standard Rayleigh diffraction limit using entangled or non-entangled quantum particles or other forms of radiation referenced herein.
[0053] A preferred embodiment of the present invention uses radiation from an entangled, thermal, or chaotic light source to generate ghost images. The photons from the light source are divided into two paths. This may be accomplished for example, by a beamsplitter, which is an optical component that allows part of an electromagnetic beam to pass through and reflects the rest. Beamsplitters can be, but are not restricted to, cemented right prisms or partially silvered mirrors In addition, in the case of naturally occurring sunlight, which can be divided into two different paths by other means, beam splitting is unnecessary. For example, in the embodiment shown in FIG. 5A , if the light source 12 is sunlight that radiates in multiple path directions, then the beamsplitter 28 may be omitted.
[0054] In a first path is the object to be imaged, in the second path images of the entangled, thermal, or chaotic light are measured independent of interaction with the objects. Either or both paths may pass through an obscuring medium. The measurements of the entangled, thermal, or chaotic light are then stored for future processing. The photons in the first or object path are collected by a bucket detector and measured. As used herein, the term bucket detector includes a photo sensor that collects all the light scattered and incident on it without regard to spatial information; e.g., a lens with a photodiode at the focal point of the lens. Measurements from the bucket detector are then stored for future processing. A process for solving for the G (2) Glauber coherence between the two paths is provided to reconstruct the image. The G (2) Glauber coherence between the two paths is used to generate a correlation two-photon ghost image. One or more bucket detectors are used along with a spatially addressable detector to generate images from the joint-detection correlations between the bucket detectors and the single-pixel detector(s). The resultant “ghost” corresponds to a convolution between the aperture function, or the amplitude distribution function, of the object A(ρ o ) and a δ-function like second-order correlation function G (2) (ρ o , ρ i ) as provided by Klyshko in Usp. Fiz. Nauk 154 133, Soy. Phys. Usp. 31, 74 (1988); or Phys. Lett. A 132299 (1988):
[0000]
F
(
ρ
→
i
)
=
∫
obj
ρ
→
o
A
(
ρ
→
o
)
G
(
2
)
(
ρ
→
o
,
ρ
→
i
)
≅
∫
obj
ρ
→
o
A
(
ρ
→
o
)
δ
(
ρ
→
o
-
ρ
→
i
/
m
)
o
)
(
1
)
[0000] The δ-function characterizes a perfect point-to-point relationship between the object plane and the image plane. If the image comes with a constant background the second-order correction function G (2) (ρ o , ρ i ) in Eq. (1) must be composed of two parts:
[0000] G (2) ({right arrow over (ρ)} 0 ,{right arrow over (ρ)} i )= G 0 +δ({right arrow over (ρ)} o −{right arrow over (ρ)} i /m ) (2)
[0000] where G 0 is a constant. The value of G 0 determines the visibility of the image. Examining Eq. (2), one may recognize that this Gm function can be expressed as:
[0000] G (2) ({right arrow over (ρ)} o ,{right arrow over (ρ)} i )= G 0 +δ({right arrow over (ρ)} o −{right arrow over (ρ)} i /m ) (2)
[0000] where G 0 is a constant. The value of G 0 determines the visibility of the image. Examining Eq. (2), one may recognize that this G (2) function can be expressed as:
[0000] G (2) ({right arrow over (ρ)} o ,{right arrow over (ρ)} i )= G 11 (1) ({right arrow over (ρ)} 1 , {right arrow over (ρ)} 1 ) G 22 (1) ({right arrow over (ρ)} 2 , {right arrow over (ρ)} 2 )+ G 12 (1) ({right arrow over (ρ)} 1 , {right arrow over (ρ)} 2 ) G 21 (1) ({right arrow over (ρ)} 2 , {right arrow over (ρ)} 1 ) (3)
[0000] where G 11 (1) G 22 (1) is approximately equal to G 0 and G 0 is a constant, and G 12 (1) G 21 (1) is approximately equal to δ({right arrow over (ρ)} 1 −{right arrow over (ρ)} 2 ) where δ({right arrow over (ρ)} 1 −{right arrow over (ρ)} 2 ) represents the δ-function non-local position-position correlation; and {right arrow over (ρ)} 1 and {right arrow over (ρ)} 2 are the transverse spatial coordinates of the first and second detectors respectively. Note that the superscript of the G (n) functions indicates the order (n) of the correlation of the measurements, and is not a reference or a footnote.
[0055] An imaging system according to the present invention is shown in FIGS. 4 , 5 A, 6 , 7 A, 8 A, 8 B, 9 , and 10 where like reference numerals used among the figures have like meaning. Light source 12 represents an incoherent, partially coherent or chaotic light source that is operative in an air medium as the source of the illuminating light. An object 14 receives a light source output 13 and reflects light along path 15 . The reflected light output 15 is collected by a bucket detector 16 and integrated for some exposure time. The integrated values of the intensity of output 15 are transmitted via path 17 to the two-photon correlation computation subsystem 18 . Paths 17 , 17 ′ and 23 may utilize any form of a data route, such as a wire, radio frequency (RF) transmission field, or an optical path. Output 21 from a beam splitter 28 is collected by a spatially addressable detector 22 , which may be, e.g., a CMOS, CCD (charge coupled device array and/or scanning fiber tip), that is observing the source 12 for the same exposure time at the bucket detector 16 . The spatially addressable intensity values are transmitted via path 23 to the two-photon correlation computation subsystem 18 , which may include a computer, processor, etc., and, include for example a coincidence circuit. Subsystem 18 , computes the two-photon correlation quantum ghost image in accordance with Equation 3 above, utilizing the input values from paths 17 and 23 , and displays a correlated two-photon quantum image on a monitor 25 , as shown in FIG. 4 . Additionally, one or more bucket detectors 16 ′ are optionally deployed in an inventive ghost imaging system such as those detailed with respect to FIGS. 4 , 5 A, 6 , 7 A, 8 A, 8 B, 9 , and 10 . An additional bucket detector 16 ′, positioned at a different angle, is operative to observe the object 14 with an angular distinct reflection relative to the detector 16 as illuminated by the light source or, alternatively, the additional detector 16 ′ may observe a second object illuminated by the same light source. The detector 16 ′ collects reflected light 15 reflected from object 14 and integrated values of the intensity of reflected light 15 are transmitted path 17 ′ to the two-photon correlation computation subsystem 18 . It is appreciated with angularly distinct detection of the same object by detectors 16 and 16 ′, that stereoscopic information about the object is so obtained. Furthermore, there could be a plurality of detectors, and the additional detector 16 ′ is merely illustrative of this principle of the present invention. If n quantity of detectors are looking at the same object, subsystem 18 may be modified to calculate the G (+1) correlation image to enhance or increase the contrast and/or resolution.
[0056] An object 14 , in addition to being a three-dimensional opaque object, the object 14 may also be a semi-opaque or opaque mask from which scattered and reflected entangled photons can be collected upon merging with another photon of an entangled pair which is operative as a reference photon. An example of this opaque mask is found in U.S. patent application Ser. No. 10/900,351, hereby incorporated by reference as though fully rewritten herein. The reference photon thereby acts as an ancilla which may be saved for a time period equal to that over which the reflecting or scattering photon takes to merge into the photon stream. The term ancilla as used herein refers to a unit of ancillary information utilized for an addition check or verification. The existence of the entangled photon pair in the merge stream (as shown in FIG. 5 of U.S. patent application Ser. No. 10/900,351, between elements 218 and 220) is indicative that one of the entangled photons of the pair has reflected or scattered from the object and thereby identifies the existence of the object. A significant number of entangled photon pairs provide ghost image data as to the shape of the object, which is determined from the entangled photon pair measurement according to the present invention. The present invention may also be used for encryption and coding purposes as described in the U.S. patent application Ser. No. 10/900,351, hereby incorporated by reference.
[0057] A ghost image is the result of a convolution between the aperture function (amplitude distribution function) of the object A({right arrow over (ρ)} o ) and a δ-function like second-order correlation function G (2) ({right arrow over (ρ)} o , {right arrow over (ρ)} i )
[0000] F ({right arrow over (ρ)} i )=∫ obj d{right arrow over (ρ)} o A ({right arrow over (ρ)} o ) G (2) ({right arrow over (ρ)} o ,{right arrow over (ρ)} i ), (1)
[0000] where G (2) ({right arrow over (ρ)} o , {right arrow over (ρ)} i )≅δ({right arrow over (ρ)} 0 −{right arrow over (ρ)} i /m), {right arrow over (ρ)} o and {right arrow over (ρ)} i are 2D vectors of the transverse coordinate in the object plane and the image plane, respectively, and m is the magnification factor. The term δ function as used herein relates to the Dirac delta function which is a mathematical construct representing an infinitely sharp peak bounding unit area expressed as δ(x), that has the value zero everywhere except at x=0 where its value is infinitely large in such a way that its total integral is 1. The δ function characterizes the perfect point-to-point relationship between the object plane and the image plane. If the image comes with a constant background, as in this experiment, the second-order correlation function G (2) ({right arrow over (ρ)} o , {right arrow over (ρ)} i ) in Eq. (1) must be composed of two parts
[0000] G (2) ({right arrow over (ρ)} 0 ,{right arrow over (ρ)} i )= G 0 +δ({right arrow over (ρ)} o −{right arrow over (ρ)} i /m ), (2)
[0000] where G 0 is a constant. The value of G 0 determines the visibility of the image. One may immediately connect Eq. (2) with the G (2) function of thermal radiation
[0000] G (2) =G 1 (1) G 22 (1) +|G 12 (1) | 2 , (3)
[0000] where G 11 (1) G 22 (1) ˜G 0 is a constant, and |G 12 (1) | 2 ˜δ({right arrow over (ρ)} 1 −{right arrow over (ρ)} 2 ) represents a nonlocal position-to-position correlation. Although the second-order correlation function G (2) is formally written in terms of G (1) is as shown in equation (3), the physics are completely different. As we know, G 12 (1) is usually measured by one photodetector representing the first-order coherence of the field, i.e., the ability of observing first-order interference. Here, in Eq. (3), G 12 (1) is measured by two independent photodetectors at distant space-time points and represents a nonlocal EPR correlation.
[0058] Differing from the phenomenological classical theory of intensity-intensity correlation, the quantum theory of joint photodetection, known conventionally as Glauber's theory and published in Phys. Rev. 130, 2529 (1963); and Phys. Rev. 131, 2766 (1963) dips into the physical origin of the phenomenon. The theory gives the probability of a specified joint photodetection event
[0000] G (2) =Tr[{circumflex over (ρ)}E (−) ({right arrow over (ρ)} 1 ) E (−) ({right arrow over (ρ)} 2 ) E (+) ({right arrow over (ρ)} 2 ) E (+) ({right arrow over (ρ)} 1 )], (4)
[0000] and leaves room for us to identify the superposed probability amplitudes. In Eq. (4), E (−) and E (+) are the negative and positive-frequency field operators at space-time coordinates of the photodetection event and {circumflex over (ρ)} represents the density operator describing the radiation. In Eq. (4), we have simplified the calculation to 2D.
[0059] In the photon counting regime, it is reasonable to model the thermal light in terms of single photon states for joint detection,
[0000]
ρ
^
≃
0
〉
〈
0
+
ε
4
∑
κ
->
∑
κ
->
′
a
^
†
(
κ
->
)
a
^
†
(
κ
->
′
)
0
〉
〈
0
a
^
(
κ
->
′
)
a
^
(
κ
->
)
,
(
5
)
[0000] where |ε|<<1. Basically, we model the state of thermal radiation, which results in a joint-detection event, as a statistical mixture of two photons with equal probability of having any transverse momentum {right arrow over (κ)} and {right arrow over (κ)}′.
[0060] Assuming a large number of atoms that are ready for two-level atomic transition. At most times, the atoms are in their ground state. There is, however, a small chance for each atom to be excited to a higher energy level and later release a photon during an atomic transition from the higher energy level E 2 (ΔE 2 ≠0) back to the ground state E 1 . It is reasonable to assume that each atomic transition excites the field into the following state:
[0000]
Ψ
〉
≃
0
〉
+
ε
∑
k
,
s
f
(
k
,
s
)
a
^
k
.
s
†
0
〉
,
[0000] where |ε|<<1 is the probability amplitude for the atomic transition. Within the atomic transition, f(k, s)= ψ k, s |ψ is the probability amplitude for the radiation field to be in the single-photon state of wave number k and polarization s: |ψ k, s =|1 k, s =â k, s 0 .
[0061] For this simplified two-level system, the density matrix that characterizes the state of the radiation field excited by a large number of possible atomic transitions is thus
[0000]
ρ
^
=
∏
t
0
j
{
0
〉
+
ε
∑
k
,
s
f
(
k
,
s
)
-
ω
t
0
j
a
^
k
,
s
†
0
〉
}
×
∏
t
0
k
{
〈
0
+
ε
*
∑
k
′
.
s
′
f
(
k
′
,
s
′
)
ω
′
t
0
k
〈
0
a
^
k
′
.
s
′
}
≃
{
0
〉
+
ε
[
∑
t
0
j
∑
k
,
s
f
(
k
,
s
)
-
ωt
0
j
a
^
k
,
s
†
0
〉
]
+
ε
2
[
…
]
}
×
{
〈
0
+
ε
*
⌈
∑
t
0
k
∑
k
′
,
s
′
f
(
k
′
,
s
′
)
ω
′
t
0
k
〈
0
a
^
k
′
,
s
′
⌉
+
ε
*
2
[
…
]
}
.
[0000] were e −iωt 0j is a random phase factor associated with the state |ψ j of the jth atomic transition. Summing over t 0j and t 0k by taking all possible values, we find the approximation to the fourth order of |ε|,
[0000]
ρ
^
≃
0
〉
〈
0
+
ε
2
∑
k
,
s
f
(
k
,
s
)
2
1
k
,
s
〉
〈
1
k
,
s
+
ε
4
∑
k
.
s
∑
k
′
,
s
′
f
(
k
,
s
)
2
f
(
k
′
,
s
′
)
2
1
k
.
s
1
k
′
.
s
′
〉
〈
1
k
,
s
1
k
′
,
s
′
.
[0062] The second-order transverse spatial correlation function is thus
[0000]
G
(
2
)
(
ρ
→
1
,
ρ
→
2
)
=
∑
κ
->
,
κ
->
′
〈
0
E
2
(
+
)
(
ρ
->
2
)
E
1
(
+
)
(
ρ
->
1
)
1
κ
->
1
κ
->
′
〉
2
.
(
6
)
[0063] The electric field operator, in terms of the transverse mode and coordinates, can be written as follows:
[0000]
E
j
(
+
)
(
ρ
->
j
)
∝
∑
κ
->
g
j
(
κ
->
;
ρ
->
j
)
a
^
(
κ
->
)
,
(
7
)
[0064] where â{right arrow over (κ)} is the annihilation operator for the mode corresponding to {right arrow over (κ)} and g j ({right arrow over (ρ)} j ; {right arrow over (κ)}) is the Green's function associated with the propagation of the field from the source to the jth detector [23]. Substituting the field operators into Eq. (6), we obtain
[0000]
G
(
2
)
(
ρ
->
1
,
ρ
->
2
)
=
∑
κ
->
,
κ
->
′
g
2
(
κ
->
;
ρ
->
2
)
g
1
(
κ
->
′
;
ρ
->
1
)
+
g
2
(
κ
->
′
;
ρ
->
2
)
g
1
(
κ
->
;
ρ
->
1
)
2
.
(
8
)
[0000] Eq. (8) indicates a two-photon superposition. The superposition happens between two different yet indistinguishable Feynman alternatives that lead to a joint photodetection: (1) photon {right arrow over (κ)} and photon {right arrow over (κ)}′ are annihilated at {right arrow over (ρ)} 2 and {right arrow over (ρ)} 1 , respectively, and (2) photon {right arrow over (κ)}′ and photon {right arrow over (κ)} are annihilated at {right arrow over (ρ)} 2 and {right arrow over (ρ)} 1 , respectively. The interference phenomenon is not, as in classical optics, due to the superposition of electromagnetic fields at a local point of space time. It is due to the superposition of g 2 ({right arrow over (κ)}; {right arrow over (ρ)} 2 )g 1 ({right arrow over (κ)}′; {right arrow over (ρ)} 1 ) and g 2 ({right arrow over (κ)}′; {right arrow over (ρ)} 2 )g 1 ({right arrow over (κ)}; {right arrow over (ρ)} 1 ), the so-called two-photon amplitudes.
[0065] Completing the normal square of Eq. (8), it is easy to find that the sum of the normal square terms corresponding to the constant of G 0 in Eq. (2): Σ {right arrow over (κ)} |g 1 ({right arrow over (κ)}; {right arrow over (ρ)} 1 )| 2 Σ {right arrow over (κ)}′ |g 2 ({right arrow over (κ)}′; {right arrow over (ρ)} 2 )| 2 =G 11 (1) G 22 (1) , and the cross term |Σ {right arrow over (κ)} g 1 *({right arrow over (κ)}; {right arrow over (ρ)} 1 )g 2 ({right arrow over (κ)}; {right arrow over (ρ)} 2 )| 2 =|G 12 (1) ({right arrow over (ρ)} 1 , {right arrow over (ρ)} 2 )| 2 gives the δ function of position-position correlation
[0000] |∫d{right arrow over (κ)}g 1 *({right arrow over (κ)};{right arrow over (ρ)} 1 )g 2 ({right arrow over (κ)};{right arrow over (ρ)} 2 )| 2 ≃|δ({right arrow over (ρ)} 0 +{right arrow over (ρ)} i )| 2 , (9)
[0000] where
[0000]
g
1
(
κ
->
;
ρ
->
o
)
∝
Ψ
(
κ
->
,
-
c
ω
d
A
)
κ
->
·
ρ
->
o
,
g
2
(
κ
->
;
ρ
->
i
)
∝
Ψ
(
κ
->
,
-
c
ω
d
B
)
κ
->
·
ρ
->
i
,
(
10
)
[0000] are the Green's functions propagated from the radiation source to the transverse planes of d A and d B =d A . In Eq. (11), ψ(ωd/c) is a phase factor representing the optical transfer function of the linear system under the Fresnel near-field paraxial approximation, ω is the frequency of the radiation field, and c is the speed of light.
[0066] Substituting this δ function together with the constant G 0 into Eq. (1), an equal sized lensless image of A({right arrow over (ρ)} 0 ) is observed in the joint detection between the CCD array and the photon counting detector D 1 . The visibility of the image is determined by the value of G 0 .
[0067] The inventive ghost images are thus successfully interpreted as the result of two-photon interference. The two-photon interference results in a point-point correlation between the object plane and the image plane and yields a ghost image of the object by means of joint photodetection.
[0068] An inventive imaging system is depicted generically in FIG. 4 and in exemplary actual imaging systems in FIGS. 5A , 6 , 7 A, 8 A, 8 B, 9 , and 10 where like reference numerals used among the figures have like meaning. The optional detector 16 ″ is omitted from FIGS. 5A , 6 , 7 A, 8 A, 8 B, 9 , and 10 for visual clarity. A light source 12 is provided to emit photons. A light source 12 operative in the present invention provides quantum entangled photons or thermal photons and illustratively includes sunlight, thermalized laser light (partially coherent or chaotic), an artificial incoherent light source such as an incandescent light bulb, or an entangled photon source. The present invention may be practiced with a partially coherent, chaotic, incoherent or entangled light sources. The media through which photons emitted from the light source 12 travel includes air, water, and the vacuum of space, as well as evacuated light paths produced within a laboratory. A first portion of photons 13 emitted from the light source 12 contact an object 14 to be imaged. The photons 13 are reflected from the object 14 along light path 15 . A spatially integrated detector 16 receives photons 15 for a period of time. The detector 16 integrates the received photons for the period of time to yield a bucket detector signal 17 that corresponds to integrated values of photonic intensity. The signal 17 is conveyed to a computer 18 . A second portion of photonic light emission 21 from the light source 12 is received at a second spatially addressable detector 22 aimed at the light source 12 . The second light emission portion 21 reaches the second detector 22 independent of interaction with the object. The detector 22 collects the emission 21 for a second period of time. To facilitate computation of a ghost image, preferably the integration period of time for the first detector 16 and the integration second period of time for the second detector 22 are the same. A trigger signal is conveyed from the computer 18 to initiate photon collection by the detectors, 16 and 22 and if present 16 ′. A spatially resolved signal 23 corresponding to spatially addressable intensity values for the emission 21 contacting the detector 22 are also conveyed to the computer 18 . The computer 18 computes a two-photon correlation ghost image in accordance with Eq. (3) from the bucket detector signal 17 and the spatially resolved signal 23 . A correlated two-photon quantum image is displayed on a monitor 25 .
[0069] Each of the detectors 16 or 22 is illustratively, e.g., a single photon counting detector, light intensity detector, or a charge couple device. In the instance when both detectors 16 and 22 are charge coupled devices, this affords the additional feature of being able to modify the sensitivity of specific detector pixels on the bucket detector 16 prior to producing the bucket detector signal 17 . In this way, a ghost image may be impressed by either turning off or turning on certain pixels in the shape of the object to be imaged prior to summation of the total number of photon counts impingent upon the charge couple device detector 16 . It is further appreciated that pixels may be partially or fully sensitized to provide grayscales of an image which further can be modified with artificial color to provide still additional imaging detail.
[0070] FIG. 5A is a schematic of the present invention. Radiation from a chaotic pseudothermal source 12 is divided into two paths by a nonpolarizing beam splitter 26 . In arm A, an object 14 is illuminated by the light source at a distance of d A . A bucket detector 16 is used to collect and to count the photons that are reflected from the surface of the object. In arm B, a second spatially addressable detector 22 is deployed. A detector 22 includes a two-dimensional (2D) photon counting CCD array, cooled for single-photon detection, and may optionally include a lens. The detector 22 is placed at any given distance d B . As shown in FIG. 5A , d A =d B . It is appreciated that the present invention is operative when d B does not equal d A . The detector 22 faces the light source instead of facing the object 14 . The bucket detector 16 is simulated by using a large area silicon photodiode for collecting the randomly scattered and reflected photons from the object 14 . A triggering pulse from a computer is used to synchronize the measurements at 16 and 22 for two-photon joint detection. The time window is preferably chosen to match the coherent time of the radiation to simplify computation. The light intensity is also preferably chosen for each element of the detector 22 working at a single-photon level within the period of detector element response time. The chaotic light 12 is simulated by transmitting a laser beam first through a lens to widen the beam and then through a phase screen made from rotating ground glass. Meyers and colleagues in J. Mod. Opt. 54, 2381 (2007). have shown that a large transverse sized source gives better spatial resolution of the two-photon image.
[0071] In FIG. 5A , the specific object 14 is a toy soldier. Additionally, FIG. 5A depicts electronic circuitry components of the computer 18 relative to the detectors 16 and 22 . A coincidence circuit 28 provides detection coordination between detectors 16 and 22 . A photon registration history for detector 16 is also provided at 30 and provides a temporal log for the integrated values 17 transmitted to the computer 18 . The second spatially addressable detector 22 is provided with spatially addressable output 32 that is subsequently fed to computer 18 and onto display 25 . For the optical bench schematic of FIG. 5A , the actual ghost image display on a monitor 25 is provided in FIG. 5B and is discernable as the original toy figure. It is appreciated that the image quality shown in FIG. 5B is improved by increasing photon flux along path 15 .
[0072] FIG. 6 is a schematic of a ghost imaging scheme using a lens 34 to focus reflected light 15 from the object 14 to improve ghost image quality. Elements 28 and 38 are beam splitters and the focal plane of lens 34 is depicted as 32 Q. The lens 34 is provided in the optical path such that optical path 13 (the light path of incident light to the object 14 ) and reflected light path 15 (from the object back to the beam splitter 28 A) may be coextensive. The lens 34 has a focal point spatially removed from the detector 16 by a distance d′ A and constitutes a corrective optical component. A beam splitter 38 otherwise similar to beam splitter 28 is also used to provide optical registry. The inclusion of a monochromometer 44 intermediate along the merge photon path 15 ′ allows one to determine the spectroscopic properties of an object if entangled photon pairs of differing energies are used. Such spectroscopic information is helpful in determining the chemical composition of the object surface.
[0073] FIG. 7 is a schematic of an inventive ghost imaging scheme lacking a lens yet still providing coextensive optical paths 13 and 15 where like numerals correspond to those used with respect to FIG. 6 . FIGS. 7B-7D show successive single frame output from the detector 23 ( FIG. 7B ), integrated output from detector 23 ( FIG. 7C ) and a ghost image as detected on monitor 25 upon combination of signals 17 and 23 ( FIG. 7D ). A phase screen 40 is provided as a corrective optical component intermediate between beam splitter 26 and detector 22 . A suitable phase screen 40 operative herein includes, for example, a transmissive liquid crystal display.
[0074] It is appreciated that the optical schematics of FIGS. 6 and 7A are particularly well suited for instances when the photons 21 or 13 emitted by the light source 12 represent a stimulating incident light and reflected photons 15 from the object 14 are stimulated fluorescence light. It is appreciated that the stimulated fluorescence light in such instances is of a longer wavelength than the instant photons 13 .
[0075] FIGS. 8A and 8B depict an inventive ghost imaging system in which the object is a semi-opaque mask 14 ′ providing a transmissive photon output 46 to reach the bucket detector 16 . In FIG. 8B , the mask 14 ′ is a stencil of the letters “ARL”. The detector 22 in this regime of FIGS. 8A and 8B is a two-dimensional charge couple device array that provides two-dimensional speckle data as the spatially addressable intensity values 23 to the computer 18 with gated electrical values being communicated to the computer 18 with gated exposure start and stop triggers being communicated to the detectors 16 and 22 . The object 14 ′ is located a distance d′ A from the bucket detector 16 .
[0076] In accordance with a preferred embodiment, as depicted in FIG. 8B , the laser source 12 in conjunction with the rotating phase screen diffuser 40 , emits light uncorrelated in space and time. Thus, the speckle images 23 are random distributions in space and time. The beam splitter 28 essentially “halves” the intensity of the initial speckle image from diffuser 40 and splits it into two different paths ( 21 and 13 ) as shown in FIG. 8 B. Spatially correlated means that correlations are present at any given instant of time between the two paths 13 , 21 . There will be a point to point correlation between the speckle images on each path, although paths are spatially distinct. The coincidence detection by the processor 18 is temporal; i.e. correlated at specific time intervals. “Correlation” or “Correlated,” as used in the present application, means a logical or natural association between two or more paths; i.e., an interdependence, relationship, interrelationship, correspondence, or linkage. For example, the present invention may be used in conjunction with sunlight, an incoherent light source, whereby a first and second plurality of photons are emitted from the sun at the same time. If the first detector is located on the earth (ground) receives the first plurality of photons, and the second detector located in space (such as in a satellite orbiting the earth) receives a second plurality of photons, the time intervals need to be synchronized; i.e., a first plurality of photons which strikes the ground object is correlated with a second plurality of photons detected in space at synchronized timing intervals. It can be readily appreciated by those skilled in the art that if the detected samples from the first and second plurality of photons are not part of the correlation, it will not contribute to the G (2) image as mathematically described in the above equations. Further, coincidence has to do with two measurements at the same or approximately the same time. For example, when a coincidence occurs, one must compensate for the media involved to take into account the variation in particle velocity between different media.
[0077] FIG. 9 is a perspective schematic of a reflective ghost imaging scheme according to the present invention using light emitting diodes as a representative incoherent light source in a field setting and insensitive to transmission through obscuring medium.
[0078] FIG. 10 is a perspective schematic of a reflective ghost imaging scheme according to the present invention using solar radiation as a light source. With insensitivity to obscuring medium. While FIG. 10 depicts an object 14 as a vehicle in a land setting with elevated position detectors 16 and 22 , it is appreciated that the system is operative underwater and in other configurations.
[0079] FIG. 11 is a diagram depicting multiple object imaging qualities of an inventive ghost imaging scheme operating with entangled or thermal photon protocols using solar radiation and with transmission from one or more detectors 16 or 16 ′ to only transmit event detection history indicative of movement within an observation field according to selected detection parameters such as transit speed, vehicle size, or a combination thereof.
[0080] To confirm the ability to generate a ghost image of an object through an obscuring medium, an obscuring medium of frosted glass is inserted along the optical path 15 of FIG. 5A . FIG. 12A is an instantaneous image of the light source 12 collected on the detector 22 . FIG. 12B is an averaged image of the light source 12 obtained from detector 22 on averaging of 100 such images according to FIG. 12A . FIG. 12C is a G (2) image of the object obtained by correlation to photon ghost imaging from signals 17 and 23 . The instantaneous image of the obscured reflection object 14 is provided in FIG. 12D while the averaged image of the obscured reflection object 14 is provided in FIG. 12E and substantially corresponds to that depicted in FIG. 7D .
[0081] FIG. 13 is a further description of a preferred embodiment utilizing a broadband entangled photon source 12 EP, from which light of various wavelengths is emitted in pairs. The light beam enters beam splitter 28 wherein one part of the entangled photon pair enters path 13 (to the object) and the other part of the photon pair enters path 21 to the detector 22 . The target has an influence on the photon and acts to make a measurement or partial measurement on it such that a preponderance of measurements are in one type of outcome (say for example a color) may be performed. The other reference or kept photon which enters path 21 is measured and is found to have the conjugate property (for example, a conjugate color). Besides color, polarization techniques could be utilized as described in U.S. patent application Ser. No. 10/900,351, herein incorporated by reference. The stream of such entangled photons is generated and a ghost image is formed by weighting the referenced entangled photon with the, for example color, measurements. Optionally, this system may be utilized, for example, in conjunction with a spectrometer system 35S. Assuming that the target object 14 absorbs certain wavelengths of light, and the light which is reflected back via path 15 will be missing the absorbed wavelengths. In this example, by connecting path 21 to a photo counting spectrometer system 35S, it will process coincidences between what is reflected from object 14 and that which the spectrometer system 35S detects. From this correlation, one can determine by “dips” in coincidence measurement, the wavelengths which are absorbed by the object. By determining spectrographic information relating to different objects, one can determine the nature of the object and certain properties about its chemical composition. Using this preferred embodiment, both the image and spectrographic information is obtainable. Thus, what is not received back is as informative as that which is reflected. For example, if the target is wearing an infrared absorbing uniform, the interaction of the initial light beam 13 with the target 14 may contain infrared light which is not absorbed by target 14 . One can then distinguish as whether or not a person is wearing infrared absorbing clothing from measuring the intensity of the reflected light at bucket detector 16 . Such information can be used for identification of groups of individuals. Consequently, absorption profiles of different peoples may be maintained in absorbent, florescent, or transmission spectral databases. Furthermore, a system of this type provides an easy way to generate so-called multispectral images.
[0082] A preferred embodiment of the present invention may utilize a light source emitting radiation that is one of an entangled, thermal, or chaotic light source. The photons from the light source may be divided into two paths: one path for the object to be imaged, and the other path in which images of the entangled, thermal, or chaotic light are measured independent of interaction with the objects. Any or all paths may pass through an obscuring medium. The measurements of the entangled, thermal, or chaotic light may then stored for future processing. The light in the object path is collected into a bucket detector and measured. The measurements of the bucket detector are then stored for future processing. A process for solving for the G (2) Glauber coherence between the two paths is provided to reconstruct the image. The G (2) Glauber coherence between the two paths is used to generate a correlation two-photon ghost image.
[0083] Patent documents and publications mentioned in the specification are indicative of the levels of those skilled in the art to which the invention pertains. These documents and publications are incorporated herein by reference to the same extent as if each individual document or publication was specifically and individually incorporated herein by reference.
[0084] The foregoing description is illustrative of particular embodiments of the invention, but is not meant to be a limitation upon the practice thereof. The following claims, including all equivalents thereof, are intended to define the scope of the invention. As used in the following claims, the term “processor” means one or more processing units, central processing units, processor cores, microprocessors, digital signal processors, multiprocessors, computers, and/or controllers, which may be connected together or to other circuitry in a manner known to those of ordinary skill in the art. As used in the foregoing claims, the term “subject” includes object(s), area, person(s), setting, place, mask, or scene.
[0085] The numbers in the drawing figures represent the following elements in the drawing figures.
NUMBER KEY
[0086]
[0000]
random, spatially correlated light source
12
light source output
13
Object
14
semi-opaque mask
14′
Reflected light from object (14)
15
bucket detector
16
Second bucket detector
16′
Detector (16) electrical signal
17
Detector (16′) electrical signal
17′
Computer
18
light source output
21
a spatially addressable detector
22
Detector (22) electrical signal
23
Monitor
25
beam splitter
28
lens
34
beam splitter
38
phase screen
40
monochromometer
44
transmissive photon output
46 | A preferred embodiment comprises a method and system for generating an image of a subject or area comprising a processor; at least one incoherent light source which illuminates the subject or area; a first receiver for receiving light reflected from the subject or area operatively connected to the processor; a second receiver for receiving light from at least one incoherent light source operatively connected to the processor; the first receiver collecting the amount of light reflected from the subject and transmit a value at specific intervals of time; the second receiver comprising a second detector which detects and transmits spatial information regarding the incoherent light source independent of any data concerning the subject at specific intervals of time; wherein the processor correlates the value transmitted by the first receiver with the spatial information derived from the second receiver at correlating intervals of time to create an image of the subject or area. Alternatively, sound or quantum particles may replace the incoherent light source. | 1 |
FIELD OF THE INVENTION
The present invention relates to scroll machines. More particularly, the present invention relates to scroll compressors having a non-machined anti-thrust surface located on one or both of the orbiting and non-orbiting scroll members.
BACKGROUND AND SUMMARY OF THE INVENTION
Scroll type machines are becoming more and more popular for use as compressors in both refrigeration as well as air conditioning applications due primarily to their capability for extremely efficient operation. Generally, these machines incorporate a pair of intermeshed spiral wraps, one of which is caused to orbit relative to the other so as to define one or more moving chambers which progressively decrease in size as they travel from an outer suction port toward a center discharge port. An electric motor is provided which operates to drive the orbiting scroll member via a suitable drive shaft affixed to the motor rotor. In a hermetic compressor, the bottom of the hermetic shell normally contains an oil sump for lubricating and cooling purposes.
Scroll compressors depend upon a number of seals to be created to define the moving or successive chambers. One type of seals which must be created are the seals between opposed flank surfaces of the wraps. These flank seals are created adjacent to the outer suction port and travel radially inward along the flank surface due to the orbiting movement of one scroll with respect to the other scroll. Additional sealing is required between the end plate of one scroll and the tip of the wrap of the other scroll. These tip seals have been the subject of numerous designs and developments in the scroll compressor field.
One solution to the creation of tip seals has been to machine a groove in the end surface of the wrap and insert a sealing member which can be biased away from the wrap and towards the end plate of the opposite scroll. Unfortunately, due to the complex shape of the wraps themselves, the machining of the groove, the manufacture of the sealing member and the assembly of these components, the costs associated with incorporating tip seals are excessive. Although expensive, tip seals have performed satisfactorily in creating the required sealing between the tip of the wrap and the opposing end plate.
Other designs for scroll compressors have incorporated axial biasing of one scroll with respect to the opposing scroll. The axial biasing operates to urge the tips of the scroll members against their opposing end plate in order to enhance the sealing at the tip of the wrap. The biasing of one scroll member with respect to the opposing scroll member in conjunction with dimensional control of the scroll members themselves has allowed scroll compressors to be manufactured without separate sealing members between the tip of the wrap and the opposing end plate.
The present invention provides the art with a scroll compressor which eliminates a significant amount of machining of the end plate. The end plates of the scroll members are only machined in the area which interface with the opposing scroll wrap. The remaining surface area of the end plates is left unmachined with the height of the scroll wraps being sufficient to avoid undesired contact between the two scrolls. In this manner, the scroll wraps support the entire biasing load between the two scrolls.
Other advantages and objects of the present invention will become apparent to those skilled in the art from the subsequent detailed description, appended claims and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings which illustrate the best mode presently contemplated for carrying out the present invention:
FIG. 1 is a vertical cross-sectional view through the center of a scroll type refrigeration compressor incorporating a non-machined anti-thrust surface in accordance with the present invention;
FIG. 2 is a perspective view of the non-orbiting scroll illustrated in FIG. 1 showing the non-machined anti-thrust surface;
FIG. 3 is a cross-sectional view of the non-orbiting scroll shown in FIG. 2; and
FIG. 4 is a perspective view of the orbiting scroll illustrated in FIG. 1 showing the non-machined anti-thrust surface.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in which like reference numerals designate like or corresponding parts throughout the several views, there is shown in FIG. 1 a scroll compressor which incorporates the non-machined anti-thrust surface in accordance with the present invention which is designated generally by reference numeral 10. Compressor 10 comprises a generally cylindrical hermetic shell 12 having welded at the upper end thereof a cap 14 and at the lower end thereof a base 16 having a plurality of mounting feet (not shown) integrally formed therewith. Cap 14 is provided with a refrigerant discharge fitting 18 which may have the usual discharge valve therein (not shown). Other major elements affixed to the shell include a transversely extending partition 22 which is welded about its periphery at the same point that cap 14 is welded to shell 12, a main bearing housing 24 which is suitably secured to shell 12 and a lower bearing housing 26 also having a plurality of radially outwardly extending legs each of which is also suitably secured to shell 12. A motor stator 28 which is generally square in cross-section but with the corners rounded off is press fitted into shell 12. The flats between the rounded corners on the stator provide passageways between the stator and shell, which facilitate the return flow of lubricant from the top of the shell to the bottom.
A drive shaft or crankshaft 30 having an eccentric crank pin 32 at the upper end thereof is rotatably journaled in a bearing 34 in main bearing housing 24 and a second bearing 36 in lower bearing housing 26. Crankshaft 30 has at the lower end a relatively large diameter concentric bore 38 which communicates with a radially outwardly inclined smaller diameter bore 40 extending upwardly therefrom to the top of crankshaft 30. Disposed within bore 38 is a stirrer 42. The lower portion of the interior shell 12 defines an oil sump 44 which is filled with lubricating oil to a level slightly above the lower end of a rotor 46, and bore 38 acts as a pump to pump lubricating fluid up the crankshaft 30 and into passageway 40 and ultimately to all of the various portions of the compressor which require lubrication.
Crankshaft 30 is rotatively driven by an electric motor including stator 28, windings 48 passing therethrough and rotor 46 press fitted on the crankshaft 30 and having upper and lower counterweights 50 and 52, respectively.
The upper surface of main bearing housing 24 is provided with a flat thrust bearing surface 54 on which is disposed an orbiting scroll member 56 having the usual spiral vane or wrap 58 on the upper surface thereof. Projecting downwardly from the lower surface of orbiting scroll member 56 is a cylindrical hub having a journal bearing 60 therein and in which is rotatively disposed a drive bushing 62 having an inner bore 64 in which crank pin 32 is drivingly disposed. Crank pin 32 has a flat on one surface which drivingly engages a flat surface (not shown) formed in a portion of bore 64 to provide a radially compliant driving arrangement, such as shown in assignee's U.S. Pat. No. 4,877,382, the disclosure of which is hereby incorporated herein by reference. An Oldham coupling 66 is also provided positioned between orbiting scroll member 56 and bearing housing 24 and keyed to orbiting scroll member 56 and a non-orbiting scroll member 68 to prevent rotational movement of orbiting scroll member 56. Oldham coupling 66 is preferably of the type disclosed in assignee's copending U.S. Pat. No. 5,320,506, the disclosure of which is hereby incorporated herein by reference.
Non-orbiting scroll member 68 is also provided having a wrap 70 positioned in meshing engagement with wrap 58 of orbiting scroll member 56. Non-orbiting scroll member 68 has a centrally disposed discharge passage 72 which communicates with an upwardly open recess 74 which in turn is in fluid communication with a discharge muffler chamber 76 defined by cap 14 and partition 22. An annular recess 78 is also formed in non-orbiting scroll member 68 within which is disposed a seal assembly 80. Recesses 74 and 78 and seal assembly 80 cooperate to define axial pressure biasing chambers which receive pressurized fluid being compressed by wraps 58 and 70 so as to exert an axial biasing force on non-orbiting scroll member 68 to thereby urge the tips of respective wraps 58, 70 into sealing engagement with the opposed end plate surfaces. Seal assembly 80 is preferably of the type described in greater detail in U.S. Pat. No. 5,156,539, the disclosure of which is hereby incorporated herein by reference. Non-orbiting scroll member 68 is designed to be mounted to bearing housing 24 in a suitable manner such as disclosed in the aforementioned U.S. Pat. No. 4,877,382 or U.S. Pat. No. 5,102,316, the disclosure of which is hereby incorporated herein by reference.
Referring now to FIGS. 2 and 3, non-orbiting scroll member 68 includes a housing 82 which defines a pocket 84 which creates non-orbiting scroll wrap 70. Housing 82 includes an anti-thrust surface 86 which is left in its as-cast or non-machined condition. The machining of surface 86 can be eliminated because non-orbiting scroll wrap 70 extends beyond surface 86 as shown in FIG. 3 thus enabling the tip of wrap 70 to contact the end plate of orbiting scroll member 56 without having surface 86 contact orbiting scroll member 56 as shown in FIG. 1.
Referring now to FIG. 4, orbiting scroll member 56 is shown. Orbiting scroll member 56 includes a housing 88 which includes an end plate 90 from which orbiting scroll wrap 58 extends. Housing 88 includes an anti-thrust surface 92 which is left in its as-cast or non-machined condition. The machining of the entire surface 92 can be eliminated because during the machining of orbiting scroll wrap 58, a recessed area 94 is machined into end plate 90. Recessed area 94 is configured to accept non-orbiting scroll wrap 70 of non-orbiting scroll member 68 during the orbital movement of orbiting scroll member 56 with respect to non-orbiting scroll member 68. The depth of recessed area 94 is smaller than the amount by which non-orbiting scroll wrap 70 of non-orbiting scroll member 68 extends above surface 86. In this way a gap 96 (shown in FIG. 1) is created between non-machined surface 86 and non-machined surface 92 allowing for the elimination of machining of these two surfaces. In addition, gap 96 allows for a limited amount of wear between scroll wrap 58 and the bottom of pocket 84 as well as a limited amount of wear between scroll wrap 70 and recessed area 94.
Both non-orbiting scroll member 68 and orbiting scroll member 56 are manufactured using a near-net weight manufacturing process which produces a blank or preform which requires a minimum of machining. The near-net weight process could be a powdered metal process, a die casting process, a lost foam casting process or any other process having a ability of create the near-net weight blank or preform. The near-net weight blank or preform allows the manufacturer to only machine critical areas of the blank in order to finish of the component. Thus, the overall manufacturing costs associated with the manufacturer of the component can be significantly reduced.
While the above detailed description describes the preferred embodiment of the present invention, it should be understood that the present invention is susceptible to modification, variation and alteration without deviating from the scope and fair meaning of the subjoined claims. | A scroll machine has a first scroll member and a second scroll member. The end plates of at least one of the scroll members is only machined in the area which interfaces with the wrap tip of the opposing scroll member. A clearance gap is maintained everywhere else in order to ensure sealing occurs. | 5 |
FIELD OF THE INVENTION
[0001] This invention generally relates to isotopically labeled deoxy-glucose and derivatives thereof, and uses thereof for spin hyperpolarized magnetic resonance imaging, for diagnosing of states, conditions, diseases, or disorders.
BACKGROUND OF THE INVENTION
[0002] Radioactive fluorinated deoxy-glucose ( 18 F-FDG) is being used in medical imaging diagnosis such as positron emission tomography (PET) examinations world-wide. 18 F-FDG emits paired gamma rays, allowing distribution of the tracer to be imaged by external gamma camera(s). This type of diagnostic imaging may be performed in tandem with a CT function which is part of the same PET/CT machine, to allow better localization of small-volume tissue glucose-uptake differences. About 4 million PET scans are performed annually. In these studies, a period of about an hour is given for wash-out of non-specific signals.
[0003] The limitations of the PET examination include the use of ionizing radiation and low spatial resolution. This limits the exposure in children and pregnant women and the frequency of repeated exposure for monitoring of therapeutic effects or the relapse/remission cycle of cancer, inflammatory diseases, or neurological conditions.
[0004] Yorimitsu et al. have recently shown that a deoxy-glucose analog (having 15 O labeling) has a half life of 2 min and is capable of producing images that show tissue contrast (“Synthesis and Bioimaging of Positron-Emitting 15 O-Labeled 2-Deoxy-D-glucose of Two-Minute Half-Life”, Chem. Asian J. 2007, 2, 57-65). In this study, regions of high glucose uptake or accumulation such as brain, heart, kidneys, and bladder showed high signal of [ 15 O]-DG, with a similar contrast pattern to [ 18 F]-FDG in PET. In contrast, H 2 15 O administration showed no specific contrast and a uniform distribution of the label in the body.
[0005] Both deoxy-glucose and glucose enter tissue cells using specialized proteins called transport proteins that are expressed on the plasma membrane of the cells. The types of transporters that are most efficient in transporting deoxy-glucose and glucose across the plasma membrane are generally called glucose transporters. Glucose transporters can be active or passive. Active transport occurs via co-transporters. This transport of glucose through the apical membrane of intestinal and kidney epithelial cells depends on the presence of secondary active Na+/glucose symporters, SGLT-1 and SGLT-2, which concentrate glucose inside the cells, using the energy provided by co-transport of Na+ ions down their electrochemical gradient. Passive transport of glucose occurs via the GLUTs family of transporters which mediate facilitated diffusion of glucose through the cellular membrane. These glucose carriers (protein symbol GLUT, gene symbol SLC2 for Solute Carrier Family 2) belong to a superfamily of transport facilitators (major facilitator superfamily) including organic anion and cation transporters, yeast hexose transporter, plant hexose/proton symporters, and bacterial sugar/proton symporters. Each glucose transporter isoform plays a specific role in glucose metabolism determined by its pattern of tissue expression, substrate specificity, transport kinetics, and regulated expression in different physiological conditions. The members of the GLUT/SLC2 have been divided into subclasses on the basis of sequence similarities: Class I comprises the well-characterized glucose transporters GLUT1-GLUT4′ where GLUT1 has been shown to play a critical role in glucose transport into tumor cells. Class II comprises: GLUT5 (SLC2A5)—a fructose transporter, GLUT7 (SLC2A7), which transports glucose out of the endoplasmic reticulum, GLUT9 (SLC2A9), GLUT11 (SLC2A11). Class III comprises: GLUT6 (SLC2A6), GLUT8 (SLC2A8), GLUT10 (SLC2A10), GLUT12 (SLC2A12), and the H+/myoinositol transporter HMIT (SLC2A13).
[0006] The tissue contrast obtained by radioactive deoxy-glucose reflects increased deoxy-glucose uptake, which is known in the art to be due to higher expression of glucose transporters, especially GLUT1. Several deoxy-glucose derivatives such as glucose and glucosamine (e.g. 2-Amino-2-deoxy-D-glucose chitosamine) have similar uptake characteristics (“GLUT2 is a high affinity glucosamine transporter” 2002, FEBS Letters, 524, 199-203) and can therefore serve to produce similar contrast patterns. Also, further glucosamine olefinic derivatives and esther derivatives on the glucose ring show similar uptake and cellular internalization property and may serve to produce similar contrast patterns (“Para-hydrogenated glucose derivatives as potential 13 C-hyperpolarized probes for magnetic resonance imaging”, 2010, J Am Chem Soc, 132, 7186-7193).
[0007] A previous study in humans using stable isotope labeled glucose 1-[ 13 C]glucose and 6,6-[ 2 H 2 ]glucose (“ 13 C- and 2 H-labelled glucose compared for minimal model estimates of glucose metabolism in man” Clin. Sci. 2005, 109, 513-521) used these compounds as means to monitor glucose metabolism. The metabolic products of the labeled analogs were assayed in body fluids by means of gas chromatography combined with mass spectrometry. In another study [1,6- 13 C 2 ]glucose with or without deuterium labeling (D16) was used to monitor glucose metabolism in humans by NMR spectroscopy of blood and urine samples (“Measurement of gluconeogenesis and intermediary metabolism using stable isotopes” 2007, U.S. Pat. No. 7,256,047 B2). 2-deoxy-2-fluoro-D-glucose (FDG) at natural abundance (without stable isotope labeling) had been used to study deoxy-glucose metabolism by 19 F-NMR. The main metabolites found were FDG-6 phosphate (FDG-6-P) and its epimer 2-deoxy-2 fluoro-D-mannose-6 phosphate (FDM-6-P) and their nucleoside-di-phosphate (NDP) forms NDP-FDG and NDP-FDM (“ 19 F NMR of 2-Deoxy-2-fluoro-D-glucose for tumor diagnosis in mice. An NDP-bound hexose analog as a new NMR target for imaging” NMR Biomed. 1997. 10, 35-41)
[0008] Magnetic resonance imaging and spectroscopy (MRI/MRS) has become an attractive diagnosing technique in the last three decades. Due to its non-invasive features and the fact that it does not involve the exposure of the diagnosed patient to potentially harmful ionizing radiation, MRI has become a leading diagnosing imaging procedure implemented in many fields of medicine.
[0009] The underlying principle of MRI and MRS is based on the interaction of atomic nuclei with an external magnetic field. Nuclei with spin quantum number I=½ (such as 1 H, 13 C, and 15 N) can be oriented in two possible directions: parallel (“spin up”’) or anti-parallel (“spin down”) to the external magnetic field. The net magnetization per unit volume, and thus the available nuclear magnetic resonance (NMR) signal, is proportional to the population difference between the two states. If the two populations are equal, their magnetic moments cancel, resulting in zero macroscopic magnetization, and thus no NMR signal. However, under thermal equilibrium conditions, slightly higher energy is associated with the “spin down” direction, and the number of such spins will thus be slightly smaller than the number of spins in the “spin up” state.
[0010] An artificial, non-equilibrium distribution of the nuclei can also be created by hyperpolarization NMR techniques for which the spin population differences is increased by several orders of magnitudes compared with the thermal equilibrium conditions. This significantly increases the overall polarization of the nuclei thereby amplifying the magnetic resonance signal intensity.
[0011] The enhancement of the hyperpolarized magnetic resonance signal is limited by the relatively fast decay of the hyperpolarization due to spin-lattice relaxation (termed as T 1 relaxation time). This decay, combined with the initial level of the hyperpolarized signal, determines the temporal window of ability to detect the hyperpolarized nuclei. Known techniques of enriching the proton positions with deuterium were shown to prolong the T 1 relaxation times of carbon-13 in various compounds in a manner that is dependent on the compound's conformation in solution. The prolongation of T 1 values is attributed to a decrease in dipolar interaction that a particular nucleus experiences. However, because the dipolar interaction is only one of several relaxation mechanisms that affect the overall T 1 relaxation time, it is not possible to predict the extent of this effect for a particular nucleus in specific molecule within a specific medium (for example in the blood). Moreover, prolongation of T 1 in itself at times does not allow for practical and effective in vivo magnetic resonance detection of a compound or its metabolic fate when administered to a subject, since the sensitivity of detection is limited due to the low natural abundance of 13 C nuclei, thereby yielding signals which are below the threshold of detection.
[0012] Most spin hyperpolarized MRI studies carried to date and specifically those involving dissolution DNP approach have been focused on metabolic imaging and thereby involved spectroscopic imaging, and the use of a compound that showed a chemical shift difference between its substrate form to its metabolic product.
[0013] There is a need in the field of the invention to provide non-radioactive glucose compounds capable of providing a clear, quick, and safe diagnostic tool for different states, conditions, and disorders using magnetic resonance imaging, based only on the distribution or the uptake process of these compounds.
[0014] It is known in the art that the glucose tolerance test consists of a bolus injection of a high glucose dose of 0.5 g/Kg (approximately 35 g for an average person weighing 70 Kg). The acute toxicity of intravenous injected 2-deoxy-D-glucose (2DG) was investigated in rats. No death was reported at a dose of 0.25, 0.5, and 1 g/Kg. In these doses, there was no change in heart rate or respiratory rate, but there was a mean decrease in arterial blood pressure at these doses, but not in a dose dependent manner (“Acute toxicity and cardio-respiratory effects of 2-Deoxy-D-Glucose: A promising radio sensitiser” Biomed. Environ. Sci. 2006, 19, 96-103). However, it is known in the art that molecular imaging is based on low dose administration of contrast media, whether at a nanomol level in PET examination or below 1 mmol/Kg in hyperpolarized magnetic resonance studies. The rational for this low dosing approach is 1) safety—to avoid adverse effects, and 2) the need to perturb the physiology as little as possible, as uptake and metabolism are dependent on substrate concentration.
[0015] The ability of a compound to serve as contrast media on hyperpolarized MRI is dependent to a great extent on the T 1 of its relevant 13 C nucleus or nuclei. The T 1 of glucose carbon-13 nuclei was recently found to be less than 2 s at 600 MHz in a hyperpolarized state (“Selection of endogenous 13 C substrates for observation of intracellular metabolism using the dynamic nuclear polarization technique” Jpn. J. Radiol. 2010, 28(2), 173-9) and it was concluded that glucose is not suitable for use with the DNP technique.
[0016] Therefore, there is a need in the medical imaging field for a non-radioactive imaging agent that will produce tissue contrast that is similar to that of deoxy-glucose when used as 18 F-FDG in PET examinations, thereby enabling non-radioactive imaging of different diseases such as for example oncologic, neurologic, psychiatric, and inflammatory processes. In addition, there is a need for a high signal imaging agent per se that does not utilize ionizing radiation, for imaging of blood vessels and vasculature to enable hyperpolarized MR angiography or catheter angiography.
SUMMARY OF THE INVENTION
[0017] In one of its aspects the present invention provides deoxy-glucose comprising at least one isotopically labeled carbon atom directly bonded to at least one deuterium atom (commonly marked as D or 2 H). In a further aspect the invention provides deoxy-glucose consisting of at least one isotopically labeled carbon atom directly bonded to at least one deuterium atom.
[0018] In some embodiments said deoxy-glucose comprises two isotopically labeled carbon atoms each directly bonded to at least one deuterium atom.
[0019] In other embodiments, said deoxy-glucose comprises 1 to 6 isotopically labeled carbon atoms each directly bonded to at least one deuterium atom.
[0020] In some other embodiments, said isotopically labeled carbon atom is 13 C. In other embodiments said isotopically labeled carbon atom is an sp 3 carbon atom (i.e. has an sp 3 hybridization, therefore is connected to neighboring atoms via sigma bonds). In other embodiments, said isotopically labeled carbon atom is an sp 2 carbon atom (i.e. has an sp 2 hybridization, therefore is connected to neighboring atoms via at least one pi bond).
[0021] When referring to a deoxy-glucose molecule, it should be understood to encompass any isomer (including any natural or synthetic structural isomer, any natural or synthetic stereochemical isomer or any natural or synthetic conformational isomer) of a glucose molecule wherein one of its hydroxy groups is replaced by hydrogen. Therefore, when referring to deoxy-glucose the invention encompasses any one of the following isomers: 2-deoxy-glucose, 3-deoxy glucose, 4-deoxy glucose or 6-deoxy-glucose. The present invention relates to any structural isomer of deoxy-glucose, being in a cyclic hemiacetal form or the linear aldohexose form of deoxy-glucose. Furthermore, the invention relates to all possible stereoisomers of deoxy-glucose (either in the cyclic or linear form, including D-deoxy-glucose and L-deoxy-glucose and all possible enantiomers and diastereomers in the cyclic and linear forms) and to all possible anomers of deoxy-glucose (a-deoxy-glucose or β-deoxy-glucose).
[0022] In some embodiments, a derivative of deoxy-glucose is glucose. When referring to glucose, it should be understood to encompass any isomer (including any natural or synthetic structural isomer, any natural or synthetic stereochemical isomer or any natural or synthetic conformational isomer) of 6-(hydroxymethyl)oxane-2,3,4,5-tetrol. The present invention relates to any structural isomer of glucose, being in a cyclic hemiacetal form or the linear aldohexose form of glucose. Furthermore, the invention relates to all possible stereoisomers of glucose (either in the cyclic or linear form, including D-glucose and L-glucose and all possible enantiomers and diastereomers in the cyclic and linear forms) and to all possible anomers of glucose (α-glucose or β-glucose).
[0023] The term “isotopically labeled atom” is meant to encompass an atom in a compound of the invention for which at least one of its nuclei has an atomic mass which is different than the atomic mass of the prevalent naturally abundant isotope of the same atom. Due to different number of neutrons in the nuclei, the atomic mass of isotopically labeled atoms is different. The total number of neutrons and protons in the nucleus represents its isotopic number.
[0024] In some embodiments an isotopically labeled atom is 13 C (having 7 neutrons and 6 protons in carbon nucleus). In other embodiments an isotopically labeled atom is 2 H (having 1 neutron and 1 proton in hydrogen nucleus). In further embodiments, a deoxy-glucose derivative may be labeled with 19 F (having 10 neutrons and 9 protons in fluorine nucleus) which is 100% naturally abundant, or with 18 F (having 9 neutrons and 9 protons in fluorine nucleus) which is a radionuclide that is used in combination with PET. As will be appreciated by the description below, the isotopic labeling of specific atoms in a compound of the invention is achieved by techniques known to a person skilled in the art of the invention, such as for example synthesizing compounds of the invention from isotopically labeled reactants or isotopically enriching specific nuclei of a glucose molecule or any metabolite or derivative thereof.
[0025] When referring to a deoxy-glucose and/or glucose molecule or any metabolite or derivative thereof comprising at least one isotopically labeled atom, it should be understood to encompass compounds having isotopically labeled atoms above the natural abundance of said at least one isotopically labeled atom. Thus, in some embodiments when said isotopically labeled atom is deuterium, said isotopical enrichment of said deuterium in a specific position in a compound of the invention, may be between about 0.015% to about 99.9%. Thus, in other embodiments when said isotopically labeled atom is 13 C, said isotopical enrichment of said carbon in a specific position in a compound of the invention, may be between about 1.1% to about 99.9%. Thus, in some other embodiments when said isotopically labeled atom is 18 F, said isotopical enrichment of said fluorine in a specific position in a compound of the invention, may be in between about 0.001% to about 100%. Thus, a compound or a composition of the invention may have different degrees of enrichment of isotopically labeled atoms.
[0026] In further embodiments, said deoxy-glucose of the invention has T 1 relaxation time values of 13 C nuclei of between about 2 to about 60 sec.
[0027] In other embodiments, said deoxy-glucose of the invention further comprises at least one isotopically labeled hydrogen atom. In other embodiments, said deoxy-glucose of the invention, further comprises at least one isotopically labeled carbon atom. In further embodiments of the invention, said deoxy-glucose and/or glucose molecule or any metabolite or derivative thereof further comprising at least one isotopically labeled hydrogen atom. In other embodiments, said deoxy-glucose and/or glucose molecule or any metabolite or derivative thereof further comprising at least one isotopically labeled carbon atom. In other embodiments, said deoxy-glucose molecule or any metabolite or derivative thereof, further comprises at least one isotopically labeled fluorine atom.
[0028] In other embodiments a deoxy-glucose and/or glucose molecule or any metabolite or derivative thereof of the invention further comprises at least one additional isotopically labeled carbon atom. In some embodiments said at least one additional isotopically labeled carbon atom may be directly bonded to said at least one isotopically labeled carbon atom. In other embodiments said at least one additional isotopically labeled carbon atom may be adjacent to said at least one isotopically labeled carbon atom.
[0029] In yet further embodiments of the invention said deoxy-glucose and/or glucose molecule or any metabolite or derivative thereof further comprise at least one additional isotopically labeled hydrogen atom. In some embodiments said at least one additional isotopically labeled hydrogen atom may be bonded to at least one adjacent to said at least one isotopically labeled carbon atom.
[0030] In some embodiments said deoxy-glucose and derivative of the invention are selected from the following list: [ 13 C 6 , 2 H 8 ]deoxy-glucose, [1- 13 C, 1- 2 H]deoxy-glucose, [1- 13 C, 1- 2 H]deoxy-glucose, [2- 13 C, 2- 2 H]deoxy-glucose, [3- 13 C, 3- 2 H]deoxy-glucose, [4- 13 C, 4- 2 H]deoxy-glucose, [5- 13 C, 5- 2 H]deoxy-glucose, [6- 13 C, 6- 2 H]deoxy-glucose, [1- 13 C, 1,1- 2 H 2 ]-1-deoxy-glucose, [2- 13 C, 2,2- 2 H 2 ]-2-deoxy-glucose, [3- 13 C, 3,3- 2 H 2 ]-3-deoxy-glucose, [4- 13 C, 4,4- 2 H 2 ]-4-deoxy-glucose, [5- 13 C, 5,5- 2 H 2 ]-5-deoxy-glucose, [6- 13 C, 6,6- 2 H 2 ]-6-deoxy-glucose, [6- 13 C, 6,6,6- 2 H 3 ]-6-deoxy-glucose, and any deoxy-glucose molecule in which carbon positions 1-6 maybe labeled with 13 C and any of the protons directly bonded to these carbon positions maybe isotopically labeled with 2 H and any combinations or permutations thereof;
[0031] In further embodiments of the invention, said deoxy-glucose derivative may be selected from: [ 13 C 6 , 2 H 7 ]-glucose, [1- 13 C, 1- 2 H-glucose, [1- 13 C, 1- 2 H]-glucose, [2- 13 C, 2- 2 H]-glucose, [3- 13 C, 3- 2 H]-glucose, [4- 13 C, 4- 2 H]-glucose, [5- 13 C, 5- 2 H]-glucose, [6- 13 C, 6- 2 H]-glucose, [1- 13 C, 1,1- 2 H 2 ]-1-glucose, [2- 13 C, 2,2- 2 H 2 ]-2-glucose, [3- 13 C, 3,3- 2 H 2 ]-3-glucose, [4- 13 C, 4,4- 2 H 2 ]-4-glucose, [5- 13 C, 5,5- 2 H 2 ]-5-glucose, [6- 13 C, 6,6- 2 H 2 ]-6-glucose, [6- 13 C, 6,6,6- 2 H 3 ]-6-glucose, and any glucose molecule in which carbon positions 1-6 maybe labeled with 13 C and any of the protons directly bonded to these carbon positions maybe isotopically labeled with 2 H and any combinations or permutations thereof.
[0032] In other embodiments said deoxy-glucose and/or derivative thereof is in a hyperpolarized state. In some embodiments, hyperpolarization of said deoxy-glucose and/or derivatives thereof is achieved using dynamic nuclear polarization technique or para-hydrogen induced polarization.
[0033] In a further aspect the invention provides a composition comprising at least one deoxy-glucose and/or derivative thereof, according to the invention.
[0034] In yet a further aspect the invention provides deoxy-glucose, according to any one of the embodiments of the invention or any derivative thereof, for use in diagnosing and evaluating a condition or disease.
[0035] In some embodiments of a use of the invention, said derivative of a deoxy-glucose of the invention is glucose having at least one isotopically labeled carbon atom directly bonded to at least one deuterium atom.
[0036] In some embodiments said glucose comprises two isotopically labeled carbon atoms each directly bonded to at least one deuterium atom. In other embodiments, said glucose comprises 1 to 6 isotopically labeled carbon atoms each directly bonded to at least one deuterium atom. In further embodiments, a glucose molecule of the invention may be labeled with 19 F (having 10 neutrons and 9 protons in fluorine nucleus) which is 100% naturally abundant, or with 18 F (having 9 neutrons and 9 protons in fluorine nucleus) which is a radionuclide that is used in combination with PET. In other embodiments, said glucose of the invention further comprises at least one isotopically labeled hydrogen atom. In other embodiments, said glucose of the invention, further comprises at least one isotopically labeled carbon atom. In further embodiments of the invention, said glucose molecule of the invention further comprises at least one isotopically labeled hydrogen atom. In other embodiments, said glucose further comprises at least one isotopically labeled carbon atom. In other embodiments, said glucose, further comprises at least one isotopically labeled fluorine atom.
[0037] In other embodiments a glucose molecule of the invention further comprises at least one additional isotopically labeled carbon atom. In some embodiments said at least one additional isotopically labeled carbon atom may be directly bonded to said at least one isotopically labeled carbon atom. In other embodiments said at least one additional isotopically labeled carbon atom may be adjacent to said at least one isotopically labeled carbon atom. In yet further embodiments of the invention said glucose molecule or any further comprise at least one additional isotopically labeled hydrogen atom. In some embodiments said at least one additional isotopically labeled hydrogen atom may be bonded to at least one adjacent to said at least one isotopically labeled carbon atom.
[0038] In other embodiments of the invention said diagnosis and/or evaluation of a state, condition, or disease is based on first pass or uptake imaging.
[0039] When referring to diagnosis and/or evaluation of a state, condition, or disease that is based on first pass imaging it should be understood to encompass the distribution of a hyperpolarized compound of the invention (contrast agent providing the hyperpolarized signal) in a short time frame, in some embodiments of up to 30 seconds from the moment of administration, which is shorter than the time for re-circulation, i.e. before a hyperpolarized compound of the invention (contrast agent) had reached the site of injection or an organ of target for the second time via the blood circulation through the vasculature. Any time shorter than the re-circulation time is considered first pass imaging time. For example, re-circulation of a hyperpolarized compound of the invention (contrast agent) in the brain may be visible by a second contrast peak in the brain region, when consecutive images of the brain are acquired following contrast media administration.
[0040] When referring to diagnosis and/or evaluation of a state, condition, or disease that is based on uptake it should be understood to encompass the distribution of the hyperpolarized compound of the invention (contrast agent providing the hyperpolarized signal) in the tissue of interest and surrounding tissues at any given time post administration when the signal is visible as measured by non-metabolic imaging of said deoxy-glucose and/or glucose molecule or any metabolite or derivative thereof. The differences in the signal distribution between tissues, or the tissue contrast, emanates from different uptake rates into the tissue cells where these rates of uptake or accumulation are determined by the type of transporters expressed on the tissue cell plasma membranes, on the number of these transporters in each cell, as well as on the particular cellular density. Tissue imaging of hyperpolarized deoxy-glucose or glucose uptake can be acquired for as long as the hyperpolarized signal is visible and higher than the measurement noise. The time frame for such imaging is 2 seconds to 1 to 2 minutes post-injection of the contrast media.
[0041] In yet further embodiments, said diagnosis and/or evaluation of a condition or disease is based on the uptake of deoxy-glucose of the invention or glucose of the invention.
[0042] As noted above in order to acquire an NMR signal of a particular nucleus of a compound there has to be a significant difference between the spin population energy levels of said nucleus. The strength of the NMR signal is linearly dependent on the number of nuclei at the low energy level. The difference between the population of a nucleus at high and low nuclear energy levels is the “polarization” of the nuclei, which is defined as P=CB 0 /T, where C is a nucleus specific constant, B 0 is the magnetic field strength, and T is the absolute temperature. Under thermal equilibrium conditions, the polarization is relatively low thereby resulting in a very weak signal under standard clinical MRI scanners (at body temperature of about 37° C. for a magnetic field of 1.5 T, P (for 1 H) is approximately 5×10 −6 and P (for 13 C) is approximately 1×10 −6 ).
[0043] In order to increase the polarization of a specific nucleus in a compound consequently creating an artificial, non-equilibrium distribution of the spin population of a nucleus, i.e. a “hyperpolarized” state, where the spin population difference is increased by several orders of magnitudes compared with the thermal equilibrium, the technology of ex vivo hyperpolarization by means of dynamic nuclear polarization (DNP) techniques, such as the Overhauser effect, in combination with a suitable free radical (e.g. TEMPO and its derivatives). Hyperpolarization may also be performed ex-vivo using the Para-hydrogen Induced Polarization technique, and ortho-deuterium induced polarization. Ex-vivo hyperpolarization may also be performed by interaction with a metal complex and reversible interaction with para-hydrogen without hydrogenation of the organic molecule. These techniques have been described in U.S. Pat. No. 6,466,814, U.S. Pat. No. 6,574,495, and U.S. Pat. No. 6,574,496, and in Adams R. W. et al. (Science, 323, 1708-1711, 2009), the contents of which are incorporated herein by reference.
[0044] Ex vivo hyperpolarization of a compound of the invention is performed in order to reach a level of polarization sufficient to allow a diagnostically effective contrast enhancement of said agent. In some embodiments, said level of hyperpolarization may be at least about a factor of 2 above the thermal equilibrium polarization level at the magnetic field strength at which the MRI is performed. In some embodiments, said level of hyperpolarization is at least about a factor of 10 above the thermal equilibrium polarization level at the magnetic field strength at which the MRI is performed. In other embodiments, said level of hyperpolarization is at least about a factor of 100 above the thermal equilibrium polarization level at the magnetic field strength at which the MRI is performed. In yet further embodiments, said level of hyperpolarization is a factor of at least about 1000 above the thermal equilibrium polarization level at the magnetic field strength at which the MRI is performed. In other embodiments said level of hyperpolarization is a factor of at least about 10000 above the thermal equilibrium polarization level at the magnetic field strength at which the MRI is performed. In further embodiments said level of hyperpolarization is a factor of at least 100000 above the thermal equilibrium polarization level at the magnetic field strength at which the MRI is performed.
[0045] A hyperpolarized deoxy-glucose and/or glucose molecule or any metabolite or derivative thereof according to the invention comprises nuclei capable of emitting magnetic resonance signals in a magnetic field (e.g. nuclei such as 13 C) and capable of exhibiting T 1 relaxation times between about 1 to about 60 sec (at standard MRI conditions such as for example at a field strength of 0.01-5T and a temperature in the range 20-40° C.). In some embodiments, said hyperpolarized deoxy-glucose and/or glucose molecule or any metabolite or derivative thereof according to the invention has T 2 relaxation times of 13 C nucleus of between about 10 to about 10,000 msec.
[0046] In some embodiments, said state, condition, or disease diagnosed and/or evaluated using a deoxy-glucose and glucose of the invention is selected from:
[0047] Oncologic related states, diseases or conditions including but not limited to: Tumor staging and differentiation, tumor grading, determination of tumor penetration into surrounding tissue, monitoring response to treatment, distant metastases, systemic metastasis, lymph node staging, recurrent disease, cancer imaging, radiation oncology, central nervous system tumors and cancer, head and neck cancer, brain cancer, thyroid cancer and thyroid imaging, anaplastic carcinomas of thyroid, lung cancer, non-small cell lung cancer, lymphoma and myeloma, malignant melanoma, breast cancer, esophageal cancer, colorectal carcinoma, pancreatic and hepatobiliary cancer, gynecological tumors, cervical and uterine cancers, ovarian cancer, endometrial cancer, genitourinary malignancies, sarcomas, gastrointestinal stromal tumors, neuroendocrine tumors, gastrinoma, glomus tumor, liver metastasis, astrocytoma, pilocytic astrocytoma, glioblastoma, carcinoma of unknown primary including paraneoplastic neurological syndromes, carcinoid tumor, cancer in pediatric patients, gallbladder carcinoma, hypoxia imaging, angiogenesis imaging, antiangiogenic therapeutic strategies, lymph node metastasis, Breslow's depth and thickness determination, bone lesions, bladder cancer, brown fat and hibernoma, cholangiocarcinomas, pulmonary node detection, ganglioglioma, gliomatosis cerebri, malignant degeneration of low grade glioma, prostate cancer, renal cancer, testicular cancer, genitourinary tract cancer, kidney cancer, hepatobiliary tumors, benign tumors—adrenal adenoma, and adrenal hypertrophy;
[0048] Neurologic related states, diseases or conditions including but not limited to: movement disorders, stroke, epilepsy, epilepsy in childhood, extratemporal lobe epilepsy, dementia, amphetamine induced activity, Alzheimer's disease, early onset familial Alzheimer's disease, cerebral amyloid angiopathy, dementia with Lewy bodies, frontotemporal lobal degeneration, mild cognitive impairment, Parkinson's disease, atypical parkinsonian disorders, brain development, central nervous system tumors, cerebral blood flow, interictal imaging, ictal imaging, infantile spasms, Lennox-Gastaut syndrome, normal aging imaging, cerebral oxygen metabolism, stroke, corticobasal degeneration, frontal hypometabolism, and Gilles de la Tourette syndrome;
[0049] Psychiatric related states, diseases or conditions including but not limited to: affective disorders, bipolar disorder, depression, major depressive disorder, alcohol abuse, substance abuse, cocaine abuse, anxiety disorders, personality disorders, schizophrenia, schizoaffective disorder, social fobia, post-traumatic stress disorder, and obsessive compulsive disorder;
[0050] Cardiac and vascular related states, diseases or conditions including but not limited to: evaluation of myocardial perfusion, myocardial viability, oxidative metabolism and cardiac efficiency, hypertension, myocardial neurotransmitter imaging, absolute myocardial blood flow assessment, congestive heart failure, aortic graft, arterial plasma measurement, atheroschlerosis, blood vessel formation, cardial resynchronization assessment, coronary artery disease assessment, coronary viability assessment, myocardial involvement in endocrine disorders, cardiac stem cell therapy, cardiomyopathy, pediatric cardiology, dilated cardiomyopathy, myocardial reserve assessment, dobutamine stress test, heart innervations, heart transplantation, valvular heart disease, ischemic myocardium, imaging the neovasculature, imaging of blood volume and vascular permeability;
[0051] Infection and inflammation related states, diseases or conditions including but not limited to: infection in pediatric patients, cardiorespiratory infectious processes, fever of unknown origin, focal soft tissue infections, foreign body inflammatory reaction, infection and inflammation in immune compromised patients, infection superimposed on malignancy, inflammation in children, inflammatory bowel disease (IBD), colitis, Crohn's disease, musculoskeletal inflammatory process, inflammatory joint disease, joint prosthesis infection, metallic implant infection, osteomyelitis, sarcoidosis, vascular infection, vascular graft infection, vasculitis, vulnerable atherosclerotic plaque, rheumatoid arthritis, systemic and local autoimmune diseases, AIDS infection, differentiating inflammation from malignancy, pyogenic infection, parasitic, viral infection, and bacterial infection;
[0052] Kidneys related states, diseases or conditions including but not limited to: Alport syndrome, renography, captopril renography, renal artery stenosis, and kidney transplantation;
[0053] General states, diseases or conditions including but not limited to: mapping and/or monitoring over time of abnormal metabolism, mapping of metabolic response to extrinsic or intrinsic modulation, angiography, catheter angiography, interventional radiology, neuro-interventional radiology, hemorrhagic infarction, head injuries, brain trauma conditions, and hemorrhagic stroke.
[0054] In other embodiments, said deoxy-glucose and/or any derivatives and/or metabolites thereof according to the invention may be used in drug development and therapeutic monitoring applications, which may include but are not limited to: anticancer agents, anti-angiogenic therapeutic strategies, treatment plan, determination of tumor response to treatment and medication effects, growth factor antagonists and endothelial cell signal transduction inhibitors, integrin activation inhibitors, matrix metalloproteinase inhibitors, antihypertensive therapy, anti-infective drug delivery, antioxidant therapy for smokers, antipsychotics, antipsychotics for schizophrenia, drug occupancy studies, antiapoptotic drugs, evaluation of aerobic and anaerobic glycolosis, early response determination, evaluation of post-treatment remission, pharmacokinetics evaluation, bioreductive drugs, endothelial cell proliferation inhibitors, endothelial cell signal transduction inhibitors, anti-infective drugs, and gene therapy assessment;
[0055] In some embodiments, said state, condition, or disease diagnosed and/or evaluated using a deoxy-glucose and glucose of the invention where the biomarker includes either higher or lower uptake than surrounding tissue. For example, malignant lesions are characterized by higher uptake, however, epileptic foci in the brain after seizure and area of low or null perfusion in the myocardium are characterized by lower uptake than surrounding normal counterpart tissue.
[0056] In a further aspect the invention provides a use of deoxy-glucose of the invention, and/or any derivative thereof (for example glucose according to the invention) for the manufacture of a composition for diagnosing and evaluating a condition or disease.
[0057] In other embodiments of a use of the invention said diagnosing and evaluating of a state, condition, or disease is performed using uptake, non-metabolic imaging of said glucose molecule or any metabolite or derivative thereof.
[0058] In further embodiments of a use of the invention, said deoxy-glucose derivative is glucose having at least one isotopically labeled carbon atom directly bonded to at least one deuterium atom.
[0059] In further embodiments of a use of the invention, said composition comprises said deoxy-glucose or derivative thereof in an amount of between about 0.005 g/Kg to about 0.5 g/Kg.
[0060] In another one of its aspects the invention provides a method for diagnosing and evaluating a condition or disease in a subject, said method comprising:
hyperpolarizing at least one deoxy-glucose or any derivative thereof according to the invention; administering to said subject an effective amount of hyperpolarized at least one deoxy-glucose or any derivative thereof; imaging the distribution of said hyperpolarized at least one deoxy-glucose or any derivative thereof;
[0064] thereby diagnosing said condition or disease.
[0065] In some embodiments of a method of the invention, said monitoring is performed by means of magnetic resonance imaging.
[0066] In other embodiments of a method of the invention said effective amount of hyperpolarized at least one deoxy-glucose or any derivative thereof is between about 0.005 g/Kg to about 0.5 g/Kg.
[0067] In other embodiments of a method of the invention said subject is administered with consecutive doses of said hyperpolarized deoxy-glucose or any derivative thereof.
[0068] In further embodiments of a method of the invention, said hyperpolarization is performed using dynamic nuclear polarization techniques or para-hydrogen induced polarization techniques.
[0069] In other embodiments of a method of the invention, said diagnosis and evaluation is performed during or after said subject is administered with at least one therapeutic agent.
[0070] In further embodiments of a method of the invention, said diagnosis and evaluation of said condition or disease involves a non-metabolic imaging of said deoxy-glucose or any derivative thereof
[0071] In other embodiments of a method of the invention, said state condition or disease is selected from Oncologic applications, Neurologic applications, Psychiatric disorders, Cardiac and vascular applications, Infection and inflammation applications, Drug development and therapeutic monitoring applications, Kidneys applications, and General applications, as provided in detail above.
[0072] In yet further embodiments of a method of the invention said deoxy-glucose derivative is glucose having at least one isotopically labeled carbon atom directly bonded to at least one deuterium atom.
[0073] The invention further provides a kit comprising at least one component containing at least one deoxy-glucose or any derivative thereof comprising at least one isotopically labeled carbon atom directly bonded to at least one deuterium atom, means for administering said at least one deoxy-glucose or any derivative thereof and instructions for use. In some embodiments a kit of the invention is intended for use in diagnosing and evaluating a condition or disease.
[0074] In further embodiments, a composition of the invention further comprises at least one additional (different) deoxy-glucose and/or glucose molecule or any metabolite or derivative thereof according to the invention. In another embodiment, a composition of the invention further comprises at least one fluorinated deoxy-glucose and/or glucose molecule or any metabolite or derivative thereof. In other embodiments, said fluorinated deoxy-glucose and/or glucose molecule or any metabolite or derivative thereof is labeled with 18 F.
[0075] It is noted that said composition may comprise at least one deoxy-glucose and/or glucose molecule or any metabolite or derivative thereof according to the invention in a mixture with pharmaceutically acceptable auxiliaries, and optionally other therapeutic agents. The auxiliaries must be “acceptable” in the sense of being compatible with the other ingredients of the composition and not deleterious to the recipients thereof
[0076] Compositions administrable to a subject include those suitable for oral, rectal, nasal, topical (including transdermal, buccal, and sublingual), vaginal or parenteral (including subcutaneous, intramuscular, intravenous, and intradermal) administration or administration via an implant. The compositions may be prepared by any method well known in the art of pharmacy. Such methods include the step of bringing in association a deoxy-glucose and/or glucose molecule or any metabolite or derivative thereof the invention with any auxiliary agent. The auxiliary agent(s), also named accessory ingredient(s), include those conventional in the art, such as carriers, fillers, binders, diluents, disintegrants, lubricants, colorants, flavoring agents, anti-oxidants, and wetting agents.
[0077] Compositions suitable for oral administration may be presented as discrete dosage units such as pills, tablets, dragées or capsules, or as a powder or granules, or as a solution or suspension. The active ingredient may also be presented as a bolus or paste. The compositions can further be processed into a suppository or enema for rectal administration.
[0078] The invention further includes a composition, as hereinbefore described, in combination with packaging material, including instructions for the use of the composition for a use as hereinbefore described.
[0079] For parenteral administration, suitable compositions include aqueous and non-aqueous sterile injection. The compositions may be presented in unit-dose or multi-dose containers, for example sealed vials and ampoules, and may be stored in a freeze-dried (lyophilized) condition requiring only the addition of sterile liquid carrier, for example water, prior to use. For transdermal administration, e.g. gels, patches or sprays can be contemplated. Compositions or formulations suitable for pulmonary administration e.g. by nasal inhalation include fine dusts or mists which may be generated by means of metered dose pressurized aerosols, nebulizers or insufflators.
[0080] The compounds of the invention may be administered in conjunction with other compounds, including, but not limited to physiological saline and buffers, radical residues, minute amounts of Gd-chelates such as Gd-DTPA, Gd-DOTA, Gd-EDTA, minute amount of biocompatible DNP glassing agents such as ethanol and glycerol, and other hyperpolarized compounds such as choline and pyruvate.
[0081] In some embodiments, a state, condition, or disease diagnosed and/or evaluated using a composition of the invention is selected from Oncologic applications, Neurologic applications, Psychiatric disorders, Cardiac and vascular applications, Infection and inflammation applications, Drug development and therapeutic monitoring applications, Kidneys applications, and General applications, as provided in detail above.
[0082] Additional conditions and diseases that may be diagnosed and evaluated using a method and/or composition of the invention include those commonly known to be diagnosed and evaluated using FDG-PET techniques such as for example cancer tumors. Is should be noted that since the uses and methods of the invention do not involve the use of and exposure of the subject to radioactive ionization, it is possible to use the methods and uses of the present invention in order to diagnose and evaluate states, conditions, and diseases in other populations that are usually not commonly examined by FDG-PET, such as for example children and pregnant women. Furthermore, it is possible to perform repeated examinations within a short time frame (more than 1 examination per day), fetal examinations, placental viability/perfusion examinations, repeated examination of relapse/remission cycle of inflammatory diseases such as rheumatoid arthritis and Crohn's disease, and myocardial viability examination—where specifically desired is a single examination where it is possible to image 1) cardiac output, 2) coronary angiography, and 3) perfusion. The latter may replace the CT angiography examination which is associated with high radiation doses.
[0083] Additional examinations include angiography and catheter angiography. It can be shown that hyperpolarized isotopically labeled deoxy-glucose and/or glucose of the invention can be injected at a concentration of ca. 300 mM in blood with a polarization enhancement factor of at least 1,000 for each of the 6 carbon-13, thus at a field of 3 T the expected signal level in the vasculature can reach 1980 M*ppm (taking into account 0.3 M, thermal polarization for 13 C of about 1.1 ppm, enhancement factor of 1,000, and 6 carbons per molecule). In comparison the signal level of Gd-enhanced angiography is only 990 M*ppm (taking into account 110 M concentration of water in water as an upper limit for the concentration of water in blood, thermal polarization for 1 Hof 4.5 ppm, and 2 protons per molecule). This higher signal is also accompanied by the lack of background signal in the hyperpolarized application compared to the Gd-enhanced proton-MRI angiography, which is expected to enable higher resolution and/or faster angiographic MRI applications. This presents an alternative to X-ray or CT angiography which is associated with high radiation doses for the patients, technicians, and physicians.
[0084] These applications of MRI using hyperpolarized deoxy-glucose and/or glucose of the invention, by providing an alternative to FDG-PET also reduce the need for hybrid imaging systems such as PET-CT scanners and PET-MRI scanners because the entire anatomical imaging examination and the functional/uptake/distribution examination can be performed in a conventional MRI scanner equipped with 13 C compatible hardware; this is likely to reduce the cost of such medical imaging applications.
[0085] FDG-PET had been shown to provide diagnostic benefit to neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease, however these applications are limited by the low spatial resolution of PET. MRI using hyperpolarized deoxy-glucose and/or glucose of the invention presents a means to perform similar diagnostic evaluations at higher spatial resolution and no ionizing radiation.
[0086] The use of strictly 13 C imaging as opposed to spectroscopic imaging which is usually performed in metabolic studies provides a relative increase in SNR and lowers the requirements placed on pulse sequence and reconstruction tools.
[0087] The term “diagnosing and evaluating a state, condition, or disease” is meant to encompass any process of investigating, identifying, recognizing and assessing a state, condition, disease, or disorder of the mammalian body (including its brain). A diagnosis according to the present invention using a deoxy-glucose and/or glucose molecule or any metabolite or derivative thereof according to the invention includes, but is not limited to the objective quantitative diagnosis of a condition or disease, prognosis of a condition or disease, genetic predisposition of a subject to have a condition or disease, efficacy of treatment of a therapeutic agent administered to a subject (either continually or intermittently), quantification of neuronal function, diagnosis and evaluation of a psychiatric, neurodegenerative, and neurochemical diseases and disorders, affirmation of a therapeutic agent activity, determination of drug efficacy, characterization of masses, tumors, cysts, blood vessel abnormalities, and internal organ function; quantification of brain, kidney, liver, and other organs' function; evaluation and determination of the level of anesthesia, comatose states, and the brain regions affected by stroke or trauma and their penumbra, kidney, liver, and muscle function, examination of the action, response or progress of therapy (involving medicinal and non-medicinal treatment) aimed at alleviating or curing psychiatric and neurodegenerative diseases and disorders.
[0088] The term “monitoring” as used herein is meant to encompass the quantitative and/or qualitative detection and observation of a hyperpolarized deoxy-glucose and/or glucose or any metabolite or derivative thereof according to the invention administered to said subject. Monitoring may be performed by any non-invasive or invasive imaging method, including, but not-limited to magnetic resonance spectroscopy, magnetic resonance imaging, magnetic resonance spectroscopic imaging, and PET.
[0089] In other embodiments, said magnetic resonance spectroscopy is performed using a double tuned 13 C/D RF coil. Due to possible coupling between deuterium nuclei and 13 C-nucleus, the signals 13 C-signals are split, their intensity is diminished and the signal width is broadened. In order to allow visibility of the agent's or its metabolite's signals it is sometimes necessary to improve on the line-width of this signal and increase its intensity. This may be achieved by using a double tuned 13 C/ 2 H RF coil or another combination of such coils that is capable of performing deuterium decoupling during the 13 C acquisition. Various coil design possibilities such as a saddle coil, a birdcage coil, a surface coil, or combinations thereof are suitable for this purpose.
BRIEF DESCRIPTION OF THE DRAWINGS
[0090] FIGS. 1A-1B show the effect of glucose concentration on the T 1 of glucose carbons as measured at 7 T ( FIG. 1A ) and at 11.8 T ( FIG. 1B ).
[0091] FIG. 2 shows the effect of the magnetic field strength on the T 1 of glucose carbons.
[0092] FIG. 3 shows the effect of direct bonding between carbon- 13 s on each other's T 1 in the glucose molecule.
[0093] FIG. 4 shows the simulation for the relative imaging signal of [U- 13 C 6 , 2 H 7 ]glucose compared to [1- 13 C]pyruvate hyperpolarized molecular probes.
[0094] FIGS. 5A-5C show hyperpolarized [U- 13 C 6 , 2 H 7 ]glucose in vivo images at 3 T, recorded in rats injected through the tail vein in a bolus of 12 s total duration. Images were recorded at 8 s ( FIG. 5A ), 12 s ( FIG. 5B ), and 20 s ( FIG. 5C ) from the onset of the bolus injection (i.e. during and after the bolus).
DETAILED DESCRIPTION OF EMBODIMENTS
[0095] In order to understand the invention and to see how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings.
[0096] The clinical diagnosis based on the uptake of hyperpolarized deoxy-glucose or glucose relies to a significant extent on “first pass” and uptake, due to the short term of exposure to the contrast media prior to imaging (approximately 30-60 s). This term encompasses both uptake rate at specific tissues as well as the flow rate to the tissue. High flow rate contributes to the accumulation of glucose signal in a tissue.
[0097] The effect of glucose concentration on the T 1 of its carbon positions was investigated at 7 T ( FIG. 1A ) and at 11.8 T ( FIG. 1B ) using Varian NMR spectrometers (The Netherlands). [U- 13 C 6 , 2 H 7 ]glucose was obtained from Cambridge Isotopes Laboratories (Andover, Mass., USA). The T 1 of [U- 13 C 6 , 2 H 7 ]glucose 13 C's was measured using the inversion recovery pulse sequence. The T 1 of glucose carbons was found to be longer in a physiological compatible solution (400 mM, solid gray columns) compared to a concentrated solution (4.03 M, diagonal pattern columns). The mean difference between the T 1 s of the two concentrations was 6.9 s (P=2*10 −6 , paired t-test) at 7 T. The mean difference in T 1 at 11.8 T was 4.5 s (P=4*10 −5 , paired t-test). The labels C 1 α and C 1 β ( FIG. 1-3 ) mark the two signals of the glucose carbon at position 1 in the α and β anomers. The labels C i α and C i β ( FIG. 1-3 ) mark the two signals of the glucose carbon at position i in the α and β anomers. This investigation showed that the T 1 of glucose carbons was affected by the concentration and suggested that the physiological conditions are favorable for T 1 elongation. It also suggested that hyperpolarized glucose concentration should be kept at a minimum during the transfer of the hyperpolarized media from the polarizer to the subject and during the administration to the subject.
[0098] The effect of the magnetic field strength on the T 1 of glucose carbons was investigated at 7 T ( FIG. 2 , solid gray columns) and at 11.8 T ( FIG. 2 , diagonal pattern columns). [U- 13 C 6 , 2 H 7 ]glucose T 1 at 400 mM was measured using the inversion recovery pulse sequence in the two spectrometers. The T 1 of glucose carbons was found to be longer in the lower magnetic field (7 T). The mean difference in T 1 between the two fields was 2 s (P=6*10 −4 , paired t-test). This suggests that the glucose carbons' T 1 may be longer at clinically relevant magnetic field strengths (1.5 T and 3 T). Further studies are underway to validate this suggestion.
[0099] To increase the signal of hyperpolarized deoxy-glucose and hyperpolarized glucose, stable isotope labeling by carbon-13 in all of the carbon positions was used. The effect of direct carbon-13 to carbon-13 bonding on the individual carbon-13 T 1 s was investigated to study the effect of these added dipolar interactions on T 1 relaxation times. To this end, two compounds were investigated (both from Cambridge Isotopes Laboratories): [U- 13 C 6 , 2 H 7 ]glucose ( FIG. 3 , solid gray columns) and [ 2 H 7 ]glucose ( FIG. 3 , diagonal pattern columns), both at 400 mM concentration. The T 1 at 11.8 T was measured using the inversion recovery pulse sequence. While both compounds are fully deuterated, in the [U- 13 C 6 , 2 H 7 ]glucose molecule the carbon positions are 99% occupied by 13 C nuclei. In the [ 2 H 7 ]glucose molecule, only ca. 1.1% of each of the carbon positions are occupied by 13 C nuclei (due to the natural abundance distribution of 13 C). The chance for having two directly bonded 13 C nuclei in this molecule is therefore 0.01% (negligible). Therefore this measurement was indicative of the T 1 of singly 13 C labeled glucose. It was found that the T 1 of glucose 13 Cs in a uniformly 13 C-labeled glucose was shorter by 3.3 s (P=1.4×10 −3 , paired t-test). Therefore, it was deducted that direct bonding of additional 13 C nuclei led to a decrease in glucose 13 C T 1 s, due to the additional dipolar interactions. However, as can be seen in the following, this decrease in T 1 did not prevent imaging of hyperpolarized [U- 13 C 6 , 2 H 7 ]glucose.
[0100] The fully deuterated and fully 13 C labeled [U- 13 C 6 , 2 H 7 ]glucose has two competing properties, in terms of its potential hyperpolarized signal. On one hand, it is labeled at six positions, all with similar T 1 . This property can be utilized to increase the initial hyperpolarized signal sixfold. On the other hand, the T 1 s of these carbon-13 nuclei are shorter than any hyperpolarized probe reported to date.
[0101] To gain insight into the relative imaging signal increase that would be provided by using glucose or deoxyglucose that are fully labeled with 13C and deuterium in all positions at a hyperpolarized state, a signal enhancement simulation was performed. This simulation compared the signal expected from the deoxy-glucose or glucose molecular probe ( FIG. 4 , dashed line) to that of the [1- 13 C]pyruvate molecular probe ( FIG. 4 , solid line). In this calculation the following consideration were taken: 1) pyruvate was injected at a dose of 0.2 mmol/Kg (“Real-Time Metabolic Imaging” Proc. Natl. Acad. Sci. USA, 2006, 103, 11270-11275) and glucose was injected at a dose of 1.4 mmol/Kg (which is ca. half of the dose that is safe for injection in humans, as per the glucose tolerance test); 2) the imaging signal is greater than the spectroscopic signal by an estimated factor of approximately 2.5 (in comparison to the pyruvate study described above); 3) the initial relative imaging signal is dependent both on the dose ratio and the imaging signal strength compared to that of spectroscopy; 4) the T 1 of pyruvate is 55 s; 5) the T 1 of glucose is position and anomer dependent, the individual values were determined per position and were used in this calculation (8-13 s). The glucose signal at each time point was calculated as ΣSc i , where Sc i is the individual signal for each carbon position at a particular time point. Each Sc i was calculated according to Sc i (t)=I SNR ·exp(−t/T 1 — ci ), where I BNR is the initial SNR or the initial relative imaging signal (pyruvate initial signal multiplied by the dose ratio factor and the imaging/spectroscopy signal increase factor as defined above). T 1 — ci was individually determined per carbon position (using [U- 13 C 6 , 2 H 7 ]glucose at 7 T and 400 mM, see FIG. 1 ). In this example it was assumed that the T 1 — ci of [U- 13 C 6 , 2 H 8 ]deoxy-glucose is similar to that of [U- 13 C 6 , 2 H 7 ]glucose.
[0102] Considering a duration of approximately 30 s from dissolution start for transfer and injection, this simulation suggests a temporal window for imaging of approximately 35 s more, during which the expected signal of hyperpolarized [U- 13 C 6 , 2 H 7 ]glucose is higher than that of hyperpolarized [1- 13 C]pyruvate ( FIG. 4 ). The simulation also suggests that a dramatic increase in signal may be gained using hyperpolarized [U- 13 C 6 , 2 H 7 ]glucose by minimizing the transfer and/or the injection duration.
[0103] Hyperpolarized glucose images were recorded at 3 T in vivo. As depicted in FIG. 5 , hyperpolarized [U- 13 C 6 , 2 H 7 ]glucose provided a high signal on carbon-13 images recorded in vivo. Normal rats were anesthetized, and hyperpolarized [U- 13 C 6 , 2 H 7 ]glucose was injected through the tail vein in a bolus of 12 s total duration. Images were recorded at 8, 12, and 20 s from the onset of the bolus injection (i.e. during and after the bolus).
[0104] In the image recorded at 8 s ( FIG. 5A ), the inferior vena cava and the heart are clearly visible (see indicating arrows). Arterial hyperpolarized media flow at this time is not likely, as the signal in the kidneys is not yet visible. This image, which was recorded during the bolus at a very high resolution (128×128 matrix, in-plane resolution of 1.56 mm), demonstrates the use of hyperpolarized glucose imaging in angiography. The signal from the injected hyperpolarized media is extremely high with no background signal.
[0105] At 12 s ( FIG. 5B ), at the end of the bolus injection, signal intensity in the main vasculature and the heart is still high, with substantial intensity observed in the kidneys (see indicating arrows).
[0106] At 20 s from bolus initiation ( FIG. 5C ), signal from the heart is the most intense signal in the image, about 40% higher than signal in the vasculature and 20% higher than signal in the kidneys. Still, signal in the kidneys is clearly observed, as well as signal in other tissues such as the liver (see indicating arrows and color change).
[0107] The hyperpolarized glucose signal observed in the heart at 20 s from bolus start is more intense than signal in the vasculature and the kidneys. It is thus suggested that this intense signal in the heart indicates glucose uptake in the myocardium. In the anaesthetized rat, the only tissue that is expected to actively take up glucose is the myocardium, because under anesthesia it is the only active muscle. The brain, which very actively takes up glucose in conscious subjects, as seen on clinical FDG-PET images, actually has very low glucose metabolism under anesthesia, and was therefore not imaged. It is noted that heart anatomy cannot be discerned from these hyperpolarized images since the imaging time (1 s) averaged several heart beats (approximately 6 beats). However, glucose uptake by the myocardium can be determined at short time frames of the order of 20 s using gradient de-phasing of intravoxel moving spins. Using this methodology, hyperpolarized glucose or deoxyglucose signal from capillaries are diminished, while the signal of intracellular hyperpolarized glucose or deoxyglucose are imaged and indicate the level of glucose uptake in the tissue.
[0108] The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgement or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavor to which this specification relates. | The present invention provides isotopically labeled deoxy-glucose and derivatives thereof, methods of their preparation, ration, kits comprising them and uses thereof for spin hyperpolarized magnetic resonance imaging, utilized in the quantitative and qualitative diagnosis of states, conditions, diseases, or disorders in the body of a subject. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Applicant claims priority under 35 U.S.C. §119 of German Application No. 10 2012 014 653.1 filed Jul. 24, 2012, the disclosure of which is incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a device for the treatment of skin, which device comprises a roller mounted for rotation about its longitudinal axis and comprising a number of needles protruding radially outwardly from its peripheral surface around the same, for the purpose of applying an electric potential to the skin, for example for the purpose of promoting the healing of wounds.
[0004] 2. The Prior Art
[0005] Without going into the etiology of chronic or non-healing wounds in detail, it is a fact that the main cause of a slow or discontinued healing process is an insufficient blood supply to the region of a wound. In this case, the wound is only insufficiently, or no longer, supplied with oxygen and nutrient substances. There are also other causes of bacterial and/or toxic origin that hinder or even completely suppress the proliferation of wound cleansing cells and wound repairing cells. All of these causes lead to the breakdown of cell information by chemotactic and/or electrotactic processes and prevent the proliferation of cells for the generation of new tissue. Each wound, acute or chronic, leads to a breakdown of the bioelectric potentials (trans epithelial potentials—TEPs (Foulds and Barker [1, 19] (see “Literature”), i.e. to short-circuiting thereof (Kloth [2]). Most probably, a deficiency, a pH shift, or exsiccation of the interstitial electrolyte [3, 4] additionally prevents the activity of the ion pump for the cells in the vicinity of the wound. This is always activated after an injury and serves the purpose of generating a natural electromagnetic field and activates the gene expression of transforming growth factors (TGFs) and the proliferation of fibroblasts and other cells. These deficiency manifestations suppress the generation of a natural electromagnetic field [5].
[0006] The most important prerequisites for the management of chronic wounds include four components: a) tissue management, b) inflammation and infection control, c) moisture balance, and d) epithelization. In many cases, however, the wound healing process will stop, there is often closure of the wound, but in many cases amputation of the extremities concerned is unavoidable.
[0007] Theoretical considerations and measurements, apparatus, and devices used in practice have shown that chronic wounds can be positively influenced by means of electrostimulation to an extent that this can cause reclosure of the wound. Falanga et al. [6] have shown in vitro that the electrostimulation up-regulates the receptors of TGF-β on human dermal fibroblasts by a factor of six compared with control fibroblasts. Other investigations have shown that cells participating in wound healing migrate to the anode or cathode of an electric field (galvanotaxis) [7-17]. Most probably, cells react to electric fields through electrophoretic motion of proteins within the plasma membrane [18]. Likewise, the migration of keratinocytes is influenced by electric fields [14, 15]. As Rowley [19] and Wolcott et al. [20] have shown, a direct current electric field has a bacteriostatic effect. As a logical consequence, other research workers have been working on the use of silver-coated anodes [21-28] and have been able to show, in vitro and in vivo, that silver cations have a bacteriostatic and antibacterial effect. Junger et al. [29] have reported on an improvement in blood flow by increasing the capillary density by means of electric fields. In the case of 15 patients with leg ulcers, following a period of many months of standard treatment, the state of the ulcers improved on application of an electric field by 43.5% on average.
[0008] The drawback of all hitherto used wound treating devices utilizing positive and negative electrodes is that it is not possible to generate exactly defined currents to, and in, the wound. The underlying causes are diverse and will only be briefly outlined here:
a fluctuating moist milieu over and in the wound, the distance of the position of the (counter) electrode from the electrode on the wound varies, the electric resistance can be influenced by fluctuating skin moisture under the counterelectrode, chronic wounds (though rarely) occurring above the heart meridian cannot be treated due to the fact that they might possibly be affected by electrical cardiac and cerebral activity.
On account of the aforementioned problems, the devices of the prior art suffer from the drawback that they frequently fail to achieve satisfactory and reproducible results as regards wound treatment.
SUMMARY OF THE INVENTION
[0013] It is thus an object of the present invention to provide a device for the treatment of skin, which makes it possible to apply, in a specific and reproducible manner, an electric field to the skin to be treated and thus to induce a flow of ions therein.
[0014] This object is successfully achieved with the device according to the invention. Preferred embodiments are described below. Accordingly, the invention relates to a device for the treatment of skin, which device comprises a roller mounted for rotation about its longitudinal axis and comprising a number of needles protruding radially outwardly from its peripheral surface around the same. Such devices in which the roller equipped with microneedles is rolled over the skin to be treated are known per se and are described in DE 10063634 A1 of the applicant. Concerning the basic construction of such a device, reference may also be made to EP 1764129 A1 of the applicant. The device described in said reference comprises a plurality of rollers equipped with needles. The needles piercing the skin during rotating of the roller(s) stimulate collagenesis and angiogenesis and promote regeneration of the skin and wound healing even in the absence of active substances. In addition, hypertrophic scars can be catabolized and atrophic scars built up. Due to the temporary formation of fine puncture channels, it is possible for active substances to be much more readily absorbed by the dermis due to easier passage thereof through the epidermal barrier.
[0015] The present invention constitutes a development of the aforementioned devices in that the latter are provided with means for making electrical contact between at least part of the needles and a voltage source. In more detail, the invention relates to a device for the treatment of skin, comprising a roller which is mounted for rotation about its longitudinal axis and on a peripheral surface of which a number of needles protrudes radially outwardly, and comprising means for establishing electrical contact between at least part of said needles and a voltage source, comprising a first terminal that is capable of being electrically connected to a first pole of said voltage source, a second terminal that is capable of being electrically connected to a second pole of said voltage source, a first contacting zone that is electrically connected to first needles, a second contacting zone that is spaced from, and electrically insulated from, said first contacting zone and that is electrically connected to second needles, said terminals and said contacting zones being configured such that when said first terminal is connected to said first contacting zone, said second terminal is connected to said second contacting zone, wherein said first and said second needles are each arranged in a row, said rows being separated from each other in a circumferential direction of said roller.
[0016] In the device of the invention for the treatment of skin—referred to below simply as “needle roller”—first and second needles are thus connected to different poles of a voltage source so as to establish an electric field between the differently polarized tips of the needles when they pierce the skin. First needles are arranged in a (first) row being distanced in a circumferential direction of the roller from the (second) row of second needles. Due to the distance of the rows and their connection with the different poles of the voltage source, an electrical field builds up between the differently polarized needles tips piercing the skin when the needle roller is passed over the skin. It has thus only to be ensured that both needle rows can penetrate the skin simultaneously when the roller is passed over it. With reference, therefore, to the arrangement relative to the peripheral surface of the roller, from which the needles protrude, the first row of needles is preferably immediately adjacent in a circumferential direction to the second row of needles. In this way it can be made sure that the distance between the first needles and the second needles in small enough for both rows to penetrate the skin simultaneously. Both needles rows suitably also extend parallel with respect to the longitudinal axis of the roller and also with respect to each other. However, also a slightly slanted arrangement, tilted with respect to the longitudinal roller axis, is principally possible.
[0017] The needles of a row are preferably arranged exactly linearly one after the other in the longitudinal direction of the roller axis, and especially preferably over the entire width of the roller. This is, however, not mandatory but it is also possible to make the rows shorter and/or to arrange the needles of a row in an offset or staggered manner as long as neighboring rows do not overlap. That is, first and second needles need not necessarily be arranged linearly but can be arranged within a strip extending over the width of the roller. The parallel longitudinal edges of the strip are then defined by the outermost needles of a row. The strip comprising the first needles and the strip comprising the second needles are arranged at a distance from each other. When the needles of the first and the second row penetrate the skin, on account of the moisture of the skin, there occurs migration of ions in the skin in the direction running from the end of the needles connected to the positive pole of the voltage source towards the end of the needles which are connected to the negative pole of the voltage source. The electromagnetic field builds up exclusively and specifically between the differently polarized needle rows and can be very precisely adjusted by suitably selecting the length of the needles and the spacing between the needles.
[0018] The device of the invention thus permits selective electrostimulation of the skin and ideally combines the positive effects that can be achieved in this way with the skin-stimulating action of a conventional needle roller. The electromagnetic field induced in the skin replaces the natural electromagnetic field that has ceased to exist following an injury, comparable to the use of a defibrillator after a cardiac arrest, and re-stimulates the flow of ions in the skin. Thus a breakdown of the bioelectric potentials (TEPs) is hindered, and the supply of blood and oxygen to the wound is restored such that the wound is again supplied with the endogenic substances required for wound healing. In all, the wound healing process is greatly accelerated and promoted, while at the same time the risk of scarring of the closing wound is reduced.
[0019] Another possible application of the device of the invention is the treatment of senescent skin. One cause of cutaneous senescence is that the peripheral supply of blood declines with increasing age. Deficiency of oxygen, decreasing cellular nourishment, and a reduced cleansing process are the causes of cutaneous senescence. In addition, there is a reduction in the proliferative capacity of the skin cells, more particularly the keratinocytes, for example as a result of intense exposure to solar radiation and the effect of exposure to UVA or UVB radiation, which likewise detracts from the appearance of the skin. In addition, such regenerative processes as decline with age can be promoted by treatment with the device of the invention, by means of which the action of an electromagnetic field re-activates cellular regeneration.
[0020] When connecting a plurality of first needles and second needles to the voltage source, this must not necessarily include all of the needles of a row. Rather, only specific needles from a row need be selected for connection to the voltage source. Preferably, electrical contact between the needles and the poles of the voltage source is established in such a manner that in the skin area pierced by the needles to which a potential is applied an electromagnetic field is produced in which a flow of ions predominates in a specific direction. If possible, this direction should not change or only insignificantly change during the course of the skin treatment using the device of the invention with, as far as possible, no chance of it reversing, since this might have a negative effect on the wound healing process or might at least retard it. By changing the polarity of adjacent rows of needles it is possible, for example, to produce a flow of ions in the treated skin area that takes place in the direction of advance of the needle roller over the skin, or contrary thereto. To this end, care must be taken to ensure that the skin is simultaneously pierced only by pairs of needle rows that are of consistently different polarity—for example always by a first row of needles, as regarded in the direction of advance, which is positively polarized while the second row of needles is negatively polarized—and that the skin is not pierced by further rows of needles exhibiting a different polarity such as might produce a reverse flow of ions in the skin. This can be basically achieved by a variety of measures.
[0021] In a very simple though not preferred variant, only two adjacent rows of needles, as regarded in the direction of the peripheral surface, are connected to the poles of the voltage source, while the remainder of the needles projecting from the peripheral surface of the roller are not connected thereto. However, in this way only a small and narrowly delimited electromagnetic field can be produced in the skin. A further possibility consists in ensuring, by careful adjustment of the lengths of the needles and of the spacing between the rows of needles, that in each case only the needles of two adjacent rows of consistent polarity can pierce the skin, while pairs of needle rows other than these two rows cannot do so. In this way, basically all of the rows of needles projecting from the roller can be connected to the voltage source. A disadvantage of this arrangement can be, however, that the pairs of needle rows that are adjacent to each other must be kept relatively far apart, which reduces the total number of needles projecting from the peripheral surface of the roller and thus weakens the effect of the needle roller, that is to say, makes it necessary to carry out a longer treatment to achieve the desired effect. In addition, the irregular intervals in the peripheral direction (smaller distance between the rows within a pair of needle rows, greater distance between adjacent pairs of rows) can possibly have a negative influence on the movement of the needle roller along the surface of the skin.
[0022] According to a further variant, the peripheral surface of the roller is provided with a plurality of pairs of rows of first needles and second needles that in each case are connected either to the first pole or to the second pole of the voltage source. These pairs of rows of needles connected to the different poles of the voltage source are however separated, in each case, by at least one row of needles not connected to the voltage source. Thus even when the needles in these rows that are not connected to the voltage source pierce the skin simultaneously with those rows of needles that are connected to the voltage source, this will not influence the flow of ions within the skin. When the rows of needles that follow on each other in the peripheral direction are connected to the different poles in a consistent manner (for example plus, minus, zero, plus, minus, zero etc.), the direction of the electromagnetic field in the skin will stay the same. It is self evident that within a row of needles not all of the needles need to be connected to a pole of a voltage source, but only some of them need be connected thereto, for example every other needle. This basically applies to all examples in which rows of needles are brought into contact with the voltage source.
[0023] In a particularly preferred embodiment of the invention, the first terminal, the second terminal, the first contacting zone, and the second contacting zone, by means of which the first needles and the second needles can be connected to the poles of the voltage source, are designed such that in each case only those first and second needles are connected to the voltage source that are currently piercing the skin. This can be achieved by designing the first terminal and the first contacting zone and also the second terminal and the second contacting zone such that they can, respectively, be releasably connected to each other. An electric contact is established, in each case, only when the corresponding needles have been moved, as a result of the rotation of the roller, to a position in which they can pierce the skin. Thus it is particularly preferred when contact can be established between the respective pair comprising a terminal and a contacting zone by means of the rotation of the roller about its longitudinal axis and subsequently released from said contact. This can be achieved, for example, when the terminals and contacting zones are in the form of sliding contacts. More specifically, the first terminal to be connected to the first pole of the voltage source is oriented relatively to the first contacting zone that is electrically connected to the first needles so that the two surfaces of contact come into contact with each other when the roller is rolled across the skin such that the first needles point in the direction towards the skin. The same applies with respect to the second terminal, the second contacting zone, and the second needles electrically connected thereto. Thus as soon as the first and second needles pierce the skin, the respective associated sliding contacts come into contact with each other, current begins to flow, and between the first needles and the second needles there is formed an electromagnetic field, which in turn induces a flow of ions between the first and second needles in the skin. Further rotation of the roller causes the first and second needles to be withdrawn from the skin, while the sliding contacts lose contact with each other and the flow of current stops. This method of establishing contact makes it possible to connect all of the rows of needles in the peripheral direction of the roller, even when these are relatively narrowly spaced from each other, without any unintentional reversals of direction occurring in the electromagnetic field induced in the skin when more than two adjacent rows of needles pierce the skin.
[0024] The first and second contacting zones serving to establish contact between the terminals connected to the voltage source and the first and second needles can basically be led out to an arbitrary site on the surface of the roller in order to make it possible to establish contact. It is particularly preferred that the first and second contacting zones be located on an end face of the roller, and more preferably they are located on opposite end faces of the roller. In this way, the two contacting zones are kept far apart from each other, and there is sufficient room for each of them to establish contact. The first and second terminals serving to provide an electrical connection between the contacting zones and the voltage source are situated so as to correspond to the positions of the associated contacting zones. If the latter are located on an end face of the roller, it is preferred that the terminals be disposed on an inside surface of a bracket holding the roller. If the first and second contacting zones are located on opposite faces of the roller, the first and second terminals will correspondingly by situated at opposite inside surfaces of the bracket. In order to ensure that a good contact is made between the associated pairs comprising terminal and contacting zone, at least one of the two paired components can be spring-biased in the direction of the other component.
[0025] In the case of the arrangement of needles in consecutive rows, as is described above, it is preferred that several or all of the first needles are connected in series with the first contacting zone and several or all of the second needles are connected in series with the second contacting zone. It is particularly preferred that each of the contactable rows of needles has both a first contacting zone for establishing contact with the first terminal and a second contacting zone for establishing contact with the second terminal. Depending on the position of the row of needles with reference to the first and the second terminal, the row of needles can for this reason function, on the one hand, as the first row of needles when it is in contact with the first pole of the voltage source, or, on the other hand, as the second row of needles, when contact is established with the second pole of the voltage source. Depending on its position, i.e. on the angular position of the roller, a row of needles can accordingly be connected either to the positive or to the negative pole of the voltage source. That is to say, the rotation of the roller changes the polarity of the needles in a row of needles from, for example, positive to negative and then to “disconnected”.
[0026] The establishment of contact between the electrically conducting interconnected parts of the device of the invention can basically take place in any desired manner, for example, with the aid of electrically conducting wires. This manner of establishing contact is advantageously used for electrically connecting the first and second terminals to the poles of the voltage source, it being preferred to lead the wire through the interior of the bracket and out through the rear end of the fork when the voltage source used is an external voltage source located away from the needle roller. However, it is basically possible to integrate the voltage source in the needle roller, for example in the form of a battery or an accumulator. In this case, the needles or rows of needles may be directly connected to the poles of the voltage source. The contacting zones are then, for example, the terminal bases of the needles (i.e. those ends of the needles that are opposite the tips of the needles projecting from the periphery of the roller). The contacting zones are in this case integral components of the needles: i.e. no separate connecting means are required for establishing electrical contact between the contacting zones and the needles. Advantageously, a switch is provided for switching the voltage source on and off when such an integrated voltage source is used, this being preferably disposed in the interior of the roller. In the case of a non-rechargeable voltage source, the device of the invention is a throw-away product, which is discarded when the energy stored in the voltage source has been consumed.
[0027] However, preference is given to devices in which the voltage source is in the form of an external voltage source situated away from the needle roller. Preferably, it is a direct current source capable of delivering either a linear and/or a pulsed direct current. Very advantageously, the voltage source is in the form of a variable voltage source allowing for adjustment of the voltage input. This will make it possible for the operator to selectively adjust, say, the size of the inputted voltage, the size of the inputted current, the type of inputted current (pulsed or linear), and also the polarity. Particularly preferred is a voltage source that is configured to deliver a direct current voltage in the two to four digit millivolt range, more particularly in the two to three digit millivolt range. The current strength will usually be in the milliampere range.
[0028] For the purpose of establishing contact between the first contacting zone and the first needles and between the second contacting zone and the second needles, use can likewise be made of any desired electrical conductor, such as wires, for example. In this case it is preferred, however, to establish the electrical contact with the aid of electrically conductive plastics materials. The electrically conductive plastics material can be a conductive adhesive, which can at the same time serve to attach the needles to the roller. More preferably, at least the rear ends of the needles below the peripheral surface of the roller can be embedded in the conductive plastics material.
[0029] As known from the conventional “non-electric” needle rollers, the needles can be embedded in needle carriers made of plastics material. In this case, use is made of, for example, needle carriers which have a substantially pie-shaped cross-section in a direction at right angles to the longitudinal axis of the roller and which in each case hold a row of needles extending in the transverse direction of the roller parallel to its longitudinal axis. A plurality of such pie-shaped needle carriers are then joined together in order to form the complete roller. Such pie-shaped needle carriers can likewise be used for the production of the electrified device of the invention. Preferably, the needle carriers then consist at least partially of a conductive plastics material that establishes electrical contact of the individual needles with each other. However, in order to prevent short circuits from occurring between the individual needle carriers and the needles embedded therein, the respective needle carriers must be insulated from each other. Preferably, this is achieved in that the needle carrier is placed in a support made of a non-conducting material, more particularly of a non-conducting plastics material, which is configured such that it prevents direct contact between the individual needle carriers. Advantageously, this support therefore has a star-shaped cross-section oriented at right angles to the longitudinal axis of the roller. The needle carriers are placed between the individual beams of the star. More preferably, this is achieved by causing the needle carriers to be held in the support merely by means of a force fit not requiring any further fixing means. Alternatively or additionally, the needle carriers may, however, be attached adhesively to the support.
[0030] If all of the needle carriers consist of an electrically conductive plastics material, it may be advantageous to insulate their surfaces that come into contact with the skin This can be achieved, for example, by applying a non-conducting coating to that surface of the needle carrier which forms the peripheral surface of the roller. In this respect, the said material may be in the form of a layer of non-conducting plastics film, for example a shrink film. If desired, those projecting regions of the needles that are directly adjacent to the peripheral surface of the roller may also be insulated, for example likewise by means of a non-conducting covering layer, so that only the extreme tips of the needles are electrically conducting and only in these regions can the electromagnetic field form in the skin. For the purpose of protection and the prevention of allergic reactions, the needles may be coated at least in those regions thereof by means of which they pierce the skin. The protective coating may be of, for example, gold, silver, titanium or some other inert metal, or mixtures thereof or alloys thereof.
[0031] As mentioned above, the device of the invention may be basically constructed in substantially the same way as the needle roller described in DE 10063634 A1. When applying the invention to the device described in EP 1764129 A1, one or more of the rollers can be provided with means for establishing electrical contact. Since the construction of the needle roller is basically known, there is no need to describe it here in detail. Thus it is only necessary to provide a brief description of some characteristics and dimensions, which are also of significance to the present invention.
[0032] Preferably, the device of the invention accordingly possesses at least one of the following characteristics:
from 8 to 30, preferably from 12 to 24 and more preferably from 16 to 20 needles in the peripheral direction of the roller, from 2 to 16, preferably from 3 to 12 and more preferably from 4 to 9 needles per row, a free length of the needles above the peripheral surface of from 0.1 to 3.0 mm, preferably from 0.2 to 2.5 mm and more preferably from 0.25 to 2.0 mm, a maximum diameter of the needles in the region thereof extending above the peripheral surface of from 0.05 to 0.3 mm and preferably from 0.08 to 0.2 mm, the needle ends are tapered towards the tips of the needles and are more particularly machine ground in the region of the tip of each needle, the distance between the tips of the first and second needles located in two adjacent rows of needles directly opposite each other is from 2.5 to 5 mm, preferably from 3.0 to 4.5 mm and more preferably from 3.5 to 4.0 mm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The invention will be explained in greater detail below with reference to an exemplary embodiment illustrated in the drawings, in which like parts are designated by like reference signs and in which:
[0039] FIG. 1 a is a schematic illustration of a side view of a device of the invention for the treatment of skin;
[0040] FIG. 1 b is a schematic top view of the device of the invention as shown in FIG. 1 a but rotated through 90°;
[0041] FIG. 2 a is a schematic top view of a device of the invention for clarification of the electrical means for establishing contact;
[0042] FIG. 2 b shows schematically the device as illustrated in FIG. 2 a but rotated through 90°;
[0043] FIG. 3 a schematically shows a side view of an end face of the roller as shown in FIG. 2 a;
[0044] FIG. 3 b schematically shows the roller as shown in FIG. 3 a but rotated through 90°;
[0045] FIG. 4 schematically shows a further top view of the end face of a roller mounted on a bracket;
[0046] FIG. 5 a schematically shows a cross-sectional view of a roller,
[0047] FIG. 5 b schematically illustrates a cross-sectional view of the support used in the roller as shown in FIG. 5 a;
[0048] FIG. 5 c schematically shows a needle carrier for the roller as shown in FIG. 5 a as a perspective view; and
[0049] FIG. 5 d schematically shows a cross-section of the needle carrier as shown in FIG. 5 a.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0050] FIGS. 1 a and 1 b show a perspective view of an exemplary embodiment of a device of the invention 1 comprising a needle roller, which is connected to a voltage source 6 . The basic construction of the needle roller is substantially the same as that of the roller that has already been described in DE 10063634 A1. The needle roller comprises a roller 3 , which is mounted on a bracket 7 for rotation about its longitudinal axis 30 . A number of needles 4 project radially outwardly from the peripheral surface 31 . In addition to the needle roller described in DE '634, the device of the invention 1 comprises means 5 for establishing electrical contact between at least two rows of the needles 4 and the voltage source 6 . The connection to the voltage source 6 is established in this case via a current lead 54 , which is guided from the roller 3 via the bracket 7 and through the handle 72 connected to the bracket 7 and out at the bottom end thereof towards the voltage source 6 . The voltage source 6 is a variable voltage source, by means of which a linear or pulsed direct current can be applied to the contacted needles 4 . The voltage strength and current strength can be adjusted by the user as desired according to the requirements necessary for the skin treatment.
[0051] The method of establishing contact between the voltage source 6 and the needles 4 is explained in greater detail below with reference to the figures. FIG. 2 a is a top view of the head region of a device of the invention 1 , more specifically a top view of the peripheral surface of a roller 3 mounted on a bracket 7 . FIG. 2 b shows the device as shown in FIG. 2 a , rotated through 90°, i.e. it is a top view of the end face of the roller 3 supported by the bracket 7 . The establishment of the electrical contact with the voltage source 6 is effected, as already discussed with reference to FIGS. 1 a and 1 b , via a current lead 54 , which is made up of a supply line 54 a connected to the positive pole of the voltage source 6 , and a supply line 54 b connected to the negative pole of the voltage source 6 . The two supply lines 54 a and 54 b are first of all guided through the handle 72 of the bracket 7 and then separated in the forked end, the wire 54 a passing in the direction of the left-hand fork end 70 , as illustrated in the figure, while the wire 54 b is guided towards the right-hand end 71 of the bracket, as illustrated in the figure. The wire 54 a is connected in the region of the fork end 70 to a first terminal 50 , which is guided outwardly towards the inside surface of the fork region 70 and comprises a surface of contact in the direction towards the roller 3 . The second wire 54 b is connected in the same manner to a terminal 51 in the region of the right-hand fork end 71 .
[0052] Via the terminal 50 there is established an electrically conducting contact with a contacting zone 52 , which outwardly projects from the left-hand end face 32 of the roller 3 , as depicted in the figure. In order to ensure that there is a sufficiently good contact between the terminal 50 and the contacting zone 52 , the terminal 50 can be mounted with a spring bias such that it is pressed against the contacting zone 52 with adequate pressure. The contacting zone 52 is the end of a contact pin projecting beyond the end face of the roller 3 , which contact pin extends through an end cap 34 , which covers the end face 32 , into the roller 3 , where it is electrically connected to an associated row of needles 4 . The same row of needles is connected in the same way to a second contacting zone 53 that protrudes beyond the right-hand end face 33 of the roller 3 , as depicted in the figure. In the embodiment shown, a row consists in each case of four needles 4 . Each of the total of 18 rows of needles possesses a first and a second contacting zone 52 , 53 . The establishment of electrical contact between the contact pins and the needles is described in greater detail below.
[0053] The making and breaking of electrical contacts between the terminal 50 and contacting zone 52 , on the one hand, and between the terminal 51 , which can also be spring-biased, and the contacting zone 53 , on the other hand, is effected by the rotation of the roller 3 about its longitudinal axis 30 . As shown in FIG. 2 b , the terminals 50 and 51 , which are located on opposite sides of the fork ends 70 and 71 , are staggered in the peripheral direction of the roller. As a result, the first terminal 50 comes into contact with a first contacting zone 52 of a first row of needles 40 , and the second terminal 51 , however, comes into contact with the second contacting zone 53 of a second row of needles 41 that is adjacent to the first row of needles 40 . The first row of needles 40 is thus positively charged, while the adjacent row of needles 41 is negatively charged. The position of the terminals 50 and 51 is chosen such that the two contacted rows of needles 40 and 41 pierce the skin when the needle roller is placed on the skin 2 (cf. FIG. 4 ). On account of the different polarities of the first and second rows of needles, a flow of ions is induced in the skin from positively charged needles 40 towards the negatively charged needles 41 to stimulate wound healing by electrostimulation.
[0054] When the device 1 is advanced along the surface of the skin (in FIG. 4 in the direction towards the left-hand side of the sheet), the roller 3 rotates about the longitudinal axis 30 in the anticlockwise direction (as indicated by the arrow). The rotation of the roller 3 causes the contacting zones 52 and 53 to move further in the anticlockwise direction and thus away from the terminals 50 and 51 which are mounted on the bracket 7 and with which they had previously been in contact. It is being assumed that the roller 3 is rotated just sufficiently as to move the first contacting zone 52 to the previous position of the second contacting zone 53 . In this way, the previously positively charged first needles 40 now become negatively charged via the second terminal 51 connected to the negative pole of the voltage source 6 . They thus become second needles 41 due to the advancement of the roller. The second row of needles previously connected to the negative pole, however, has now left the second contacting zone 53 and is therefore no longer connected to the voltage source 6 . Instead, the next—in the figure the left-hand—adjacent row of needles now moves into the region of the first terminal 50 , this row of needles now being positively charged on account of its contacting zone 52 being connected to the terminal 50 . Thus, an electromagnetic field is again induced in the skin between the adjacent and differently charged pairs of needle rows, which electromagnetic field flows in the same direction as the previous one. Thus, when the needle roller is advanced, there is no change in the direction of flow of ions in the skin, and the ion flow retains its strength and direction. There is thus produced a constant electromagnetic field in the skin irrespective of the angular position of the device of the invention. If, during a skin treatment, it should be desired to effect reorientation of this electromagnetic field, this can be achieved by reversing the polarity at the voltage source 6 ,
[0055] FIGS. 5 a to 5 d serve to illustrate the interior structure of the roller 3 and the means of establishing contact between the individual needles and the contacting zones 52 and/or 53 . As shown in FIG. 5 a , the needles 4 are embedded in individual needle carriers 8 , which have a substantially pie-shaped cross-section in the sectional view oriented at right angles to the longitudinal axis 30 of the roller 3 . Each of the needle carriers 8 extends substantially across the entire width of the roller 3 . Only the end faces are additionally covered by end caps 34 . Each of the needle carriers 8 accommodates a row of needles 4 , and, in the present embodiment, each row consists of four individual needles, which are embedded in the needle carrier and are spaced from each other at equal intervals D of in this case approximately 2 mm. The width B of the needle carrier 8 is approximately 8 mm, and the total width including the mounted end caps is approximately 10 mm. For example, the four needles 4 of a row of needles are potted in a needle carrier 8 of plastics material. Their tips project from the external periphery 31 of the needle carrier 8 or the roller 3 over a distance (length L) of, say, from 0.1 to 3 mm. The needles 4 are at least in this projecting region, outwardly tapered towards the tip 42 of the needle and are preferably provided with a machine-ground surface. The maximum diameter of the needles 4 in the region thereof projecting above the peripheral surface 31 is advantageously between 0.05 and 0.3 mm and more preferably between 0.08 and 0.2 mm. Usually, the maximum diameter of the needles in this projecting region of length L will be located in the region of the needles 4 which is directly adjacent to the peripheral surface 31 . The distance A between the tips of the needles in two directly adjacent rows of needles is approximately 3.5 mm, in the example shown.
[0056] In the case illustrated, the roller 3 comprises eighteen rows of needles and thus possesses eighteen needle carriers 8 . These are anchored in a support 9 , which is illustrated in FIG. 5 b in the cross-section oriented at right angles to the longitudinal axis 30 of the roller 3 . The support 9 is of plastics material and has a substantially star-shaped cross-section having eighteen beams 90 , between which the needle carriers 8 are individually force fitted. The needle carriers 8 are held by a force fit between two beams 90 , wherein the drop-shaped bottom regions 80 engage corresponding spherical recesses 91 in the support 9 to form a type of locking joint, thus ensuring a firm anchorage of the needle carrier 8 in the support 9 . If desired, the needle carriers 8 can alternatively be adhesively held in position in the support 9 .
[0057] There are various ways of establishing electrical contact of the needles disposed in a row and fixed in a needle carrier 8 . One such method consists in interconnecting the needles in the region of their terminal bases 43 by means of a conductive adhesive or a wire or by a similar method. In this case, however, the ability to use material for the needle carrier 8 that is conductive has been chosen. For this purpose it can be basically sufficient to produce only a sub-region of the needle carrier 8 , for example the bottom region 80 , from the conductive material. In the present case, however, the needle carrier is made entirely of a conductive plastics material, which ensures that all of the needles will be electrically interconnected and also electrically connected to the relevant contacting zones 52 and 53 . The contacting zones 52 and 53 , which, as illustrated in FIG. 3 b , for example, are located on the different end faces of every needle carrier 8 , are here in the form of contact nipples, which are guided through matching bores in the end caps 34 and are fixed, for example by adhesion, by way of their inside surfaces to a respective face of the needle carrier 8 , and are electrically connected to the electrically conductive needle carrier 8 and/or to the needles otherwise electrically interconnected. As described above, depending on the rotary position of the roller 3 about its longitudinal axis 30 , either the first contacting zone 52 will come into electrically conductive contact with the first terminal 50 or the second contacting zone 53 with the second terminal 51 . By this means, the needles 4 will be connected either to the positive pole or to the negative pole of the voltage source 6 and be charged accordingly. Short circuits between the adjacent needle carriers 8 and the rows of needles that are adjacent to each other are avoided due to the fact that the material of the support 9 is nonconductive and the individual needle carriers 8 are thus insulated from each other even when they are all made of a conductive material,
LITERATURE
[0000]
1. Foulds L., Barker A. Human skin battery potentials and their possible role in wound healing. Br J Dermatol 1983; 109:515-22.
2. L. C. Kloth, Electrical Stimulation for Wound Healing: A Review of Evidence From In Vitro Studies, Animal Experiments, and Clinical Trials. 2005 Sage Publications.
3. Jaffe L., Vanable J. Electrical fields and wound healing. Clin Dermatol 1984; 2(3):34-44.
4. Cheng K., Tarjan P., Oliveira-Gandia M., et al. Anocclusive dressing can sustain natural electrical potential of wounds. J Invest Dermatol 1995; 104(4):662-5.
5. Eltinge E., Cragoe E. Jr., Vanable J. Jr. Effects of amiloride analogues on adult Notophthalmus viridescens limb stump currents. Comp Biochem Physiol 1986; 89A:39-44.
6. Falanga V., Bourguignon G., Bourguignon L. Electrical stimulation increases the expression of fibroblast receptors for transforming growth factor-beta. J Invest Dermatol 1987; 88:488-92.
7. Orida N., Feldman J. Directional protrusive pseudopodial activity andmotility in macrophages induced by extra-cellular electric fields. Cell Motil 1982; 2:243-55.
8. Monguio J. Über die polare Wirkung des galvanischen Stromes auf Leukozyten. Z Biol 1933; 93:553-9.
9. Fukushima K., Senda N., Inui H., et al. Studies of galvanotaxis of leukocytes. Med J Osaka Univ 1953; 4(2-3):195-208.
10. Dineur E. Note sur la sensibilities des leukocytes a l′electricite. Bulletin Seances Soc Beige Microscopic (Bruxelles) 1891; 18:113-8.
11. Canaday D., Lee R. Scientific basis for clinical application of electric fields in soft tissue repair. In: Brighton C, Pollack S, editors. Electromagnetics in biology and medicine. San Francisco: San Francisco Press; 1991.
12. Erickson C., Nuccitelli R. Embryonic fibroblastmotility and orientation can be influenced by physiological electric fields. J Cell Biol 1984; 98:296-307.
13. Yang W., Onuma E., Hui S. Response of C3H/10T1/2 fibroblasts to an external steady electric field stimulation. Exp Cell Res 1984; 155:92-7.
14. Nishimura K., Isseroff R., Nuccitelli R. Human keratinocytes migrate to the negative pole in direct current electric fields comparable to those measured in mammalian wounds. J Cell Sci 1996; 109:199-207.
15. Sheridan D., Isseroff R., Nuccitelli R. Imposition of a physiologic DC electric field alters the migratory response of human keratinocytes on extracellular matrix molecules. J Invest Dermatol 1996; 106(4):642-6.
16. Min Zaho. Electrical fields in wound healing An overriding signal that directs cell migration. Elsevier 2008, page 674-680.
17. Min Zhao et al. Electrical signals control wound healing through phosphatidylinositol-3-OH kinase-Y and PTEN, Nature 2006, Vol 442/27.
18. Fang K., lonides E., Oster G., et al. Epidermal growth factor receptor relocalization and kinase activity are necessary for directional migration of keratinocytes in DC electric fields. J Cell Sci 1999; 112:1967-78.
19. Rowley B. Electrical current effects on E. coli growth rates. Proc Soc Exp Biol Med 1972; 139:929-34.
20. Wolcott L., Wheeler P., Hardwicke H., et al. Accelerated healing of skin ulcers by electrotherapy: preliminary clinical results. South Med J 1969; 62:795-801.
21. Deitch E., Marino A., Malakanok V., et al. Electrical augmentation of the antibacterial activity of silver nylon. Proceedings of the 3rd Annual BRAGS; 1983 Oct. 2-5; San Francisco.
22. Deitch E., Marino A., Gillespie T., et al. Silver nylon: a new antimicrobial agent. Antimicrobial Agents Chemother 1983; 23:356-9.
23. Marino A., Deitch E., Albright J. Electric silver antisepsis. IEEE Trans Biomed Eng 1985; 32(5):336-7.
24. Cohnano G., Edwards S., Barranco S. Activation of antibacterial silver coatings on surgical implants by direct current: preliminary studies in rabbits. Am J Vet Res 1980; 41(6):964-6.
25. Thibodeau E., Handelman S., Marquis R. Inhibition and killing of oral bacteria by silver ions generatedwith lowintensity direct current. J Dent Res 1978; 57:922-6.
26. Alvarez O., Mertz P., Smerbeck R., et al. The healing of superficial skin wounds is stimulated by external electrical current. J Invest Dermatol 1983; 81(2):144-8.
27. Falcone A., Spadero J Inhibitory effects of electrically activated silver material on cutaneous wound bacteria. Plast Reconstr Surg 1986; 77(3):445-58.
28. Becker R., Spadero J. Treatment of orthopedic infections with electrically generated silver ions. J Bone Joint Surg Am 1978; 60(7):871-81.
29. Junger M., Zuder D., Steins A., et al. Treatment of venous ulcers with low frequency pulsed current (Dermapulse): effects on cutaneous microcirculation. Der Hautarzt 1997; 18:879-903. | A skin treatment device includes a roller rotatably mounted about its longitudinal axis and having needles protruding radially outwardly from its peripheral surface, and a device for establishing electrical contact between at least part of the needles and a voltage source having first and second poles, including first and second terminals capable of being electrically connected to the first and second poles, respectively, a first contacting zone electrically connected to first needles, a second contacting zone spaced and electrically insulated from the first contacting zone and electrically connected to second needles, the terminals and the contacting zones being configured such that when the first terminal is connected to the first contacting zone, the second terminal is likewise connected to the second contacting zone. The first and the second needles are each arranged in a row, the rows being separated from each other in a circumferential direction of the roller. | 0 |
FIELD OF THE INVENTION
The invention relates to a valve means and more particularly an amplifier comprising a housing, which contains a movable switching element having two closure portions each associated with the opening of a fluid duct and engaged at two spaced points by two actuating diaphragms, which are able to be subject to fluid so that the switching element is able to be positioned in at least two switching positions in which the respectively one duct opening is closed and the respectively other duct opening is open.
BACKGROUND OF THE INVENTION
Valve means of this type are customarily employed as pneumatic amplifiers, which are in a position to influence fluid flows with a high pressure and a high rate of flow using low control pressures. As far as the assignee is aware pneumatic amplifiers so far devised are characterized by having a plunger-like switching element having two closure portions adapted to close and open the opening of a respectively associated fluid duct in a manner dependent on the switching position of the switching element. The respective switching position is set by actuating diaphragms for engaging the switching element at two axially spaced points, and which as needed are subjected to a fluid acted upon by a control pressure. The switching over of valve means, which may be termed a diaphragm amplifier, takes place as part of a linear movement of the switching element.
It is considered to be a disadvantage of the valve means of this type that a reduction of the overall size and a standardization of the geometry thereof is only possible to a limited extent. The necessary arrangement of the ducts in the interior of the housing means that a certain minimum height is more or less necessary and can not be gone below. If various different amplifier functions are to be realized, then as a rule radical changes are necessary in the structure.
OBJECTS AND SUMMARY OF THE INVENTION
One object of the present invention is to create a valve means which has more compact dimensions and whose design is more readily adaptable.
In order to achieve this aim the switching element is constituted by a switching rocking member adapted to perform a pivotal movement on switching over, whose rocking arms placed on either side of the pivotal portion are engaged respectively by one of the actuating diaphragms and on which respectively one of the closure portions is provided.
It is in this manner that a valve means is provided, which may be manufactured with an extremely low, flat form, because on the one hand the actuating diaphragm and on the other hand the closure portions may be arranged, switching over no longer involving a linear movement but rather involves a pivoting or rocking movement of the rocker-like switching element which may consequently be termed a switching rocker member. The valve means may be employed in a relatively universal manner and is suitable, given a the correct geometry, more particularly as well in micro-actuators as a principal valve stage or in conjunction with other actuators as a high speed drive for valves having a large rated aperture or lumen. Moreover, the design in accordance with the invention favors a realization of the valve means in manufacturing methods in connection with micro-technology , because same are specifically suitable for the manufacture of flat, laminated structures. Finally the design of the invention favors the manufacture of valve means having different functions, because it is particularly in the case of an amplifier that there is the possibility of clearly separating the control plane and the power plane.
Further advantageous developments of the invention are defined in the dependent claims.
The switching rocker member and the actuating diaphragms are preferably accommodated in a common interior space in the housing. The housing itself may comprise several housing parts placed together as layers or lamellas, the two actuating diaphragms being held between the same housing parts.
The necessary pivotal movement of the rocking member could be predetermined exclusively by way of its attachment to the diaphragms, but however in order to ensure an exact switching function the invention preferably contemplates a pivotal support of the switching rocker member at its pivot portion.
A structure would be possible in which the actuating diaphragms only touch the switching rocker member. Presently a design is considered to be more convenient in which the actuating diaphragms are attached not only on the housing but also on the inherently rigid switching rocker member.
Both the actuating diaphragms and also the duct openings associated with the closure portions are preferably at least approximately at the same level as each other.
In order to produce an amplifier function in a particularly advantageous fashion there is preferably a provision such that the first and second fluid ducts associated with the closure portions and furthermore a third fluid duct communicate which are common connecting chamber, by way of which the fluid may be transferred, dependent on the switching position of the switching rocker member between the third fluid duct and one of the two other fluid ducts. Each of the two actuating diaphragms in this case preferably constitutes a movable wall between the connecting chamber and a control chamber, the two control chambers being separated from one another and each communicating with a control duct, by way of which the action of fluid on them may be set. In the case of such a structure it is frequently possible to alter the manner of functioning simply by changing the arrangement of the connections of the ducts, and for instance different types of amplifiers may be realized, which normally set a closed position or normally set an open position.
The actuating diaphragms may be designed with the same or different areas and in different sizes, forms and cross sections, it being possible to provide for preset deflections in the force-free state in order to influence the switching position of the switching rocker member.
The closure portions may be integrated in the switching rocker member or be in the form of separately applied sealing bodies.
In the case of the two actuating diaphragms it may be a question of individual diaphragms. However simpler manufacture and assembly is possible if the actuating diaphragms are united together in a common integral diaphragm element.
In what follows the invention will be described in detail with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a preferred embodiment of a valve means designed in the form of a pneumatic amplifier in a longitudinal section.
FIG. 2 shows a valve means of a comparable design to that of FIG. 1 in a highly diagrammatic longitudinal sectional view, there being one amplifier of the “normally open” type, which is illustrated in the open state.
FIG. 3 shows the valve means of FIG. 2 in the closed position of the rocking member.
FIG. 4 shows a valve means of an identical design to that of FIG. 2, in the case of which however a different fluid connection arrangement is provided so that there is a “normally closed” type, which is illustrated in the closed setting.
FIG. 4 a shows a valve means of an identical design to that of FIG. 4, wherein the two actuating diaphragms have different areas.
FIG. 5 shows the valve means of FIG. 4 in the open position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Firstly the general structure of a preferred working embodiment of the valve means in accordance with the invention will be described with reference to FIG. 1 .
The valve means generally referenced 1 in the present case possesses a structure rendering possible use as a pneumatic amplifier. The valve means 1 is in this case divided up into several superposed planes functionally, that is to say in a first connection plane 2 , which is in the working example is on top, a control plane 3 arranged underneath it, a power plane 4 placed thereunder and a second connection plane 5 which is at the bottom.
The valve means 1 comprises a preferably block- or plate-like housing 6 , which is made up of a plurality of housing parts 7 , 8 and 9 arranged as layers. The division up of the housing does not have to be the same as the illustrated division into planes.
The housing 6 contains an interior space 12 , in which a moving switching element is accommodated, which owing to its rocker-like design and manner of operation is referred to as a switching rocker member 13 .
Irrespectively of the alignment of the housing 6 adopted during operation the direction of the sequence of individual planes will be termed the height direction 14 , which in FIG. 1 is marked by a chained line. The switching rocker member 13 is so arranged inside the interior space 12 of the housing that it extends athwart the height direction 14 thereof, it possible having and angled longitudinal form.
The switching rocker member 13 has a pivotal portion 15 at its longitudinal middle point in the working example, at which it is so supported on the housing 6 in an articulating manner by way of a pivotal bearing means 16 that in relation to the housing 6 it may perform a pivotal movement 17 indicated by a double arrow, as part of which movement the rocker arms 18 and 18 ′, which extend in opposite directions away from the pivotal portion, are reciprocated like a see/saw. The pivotal bearing means 16 may be a fixed component of the housing 6 or it can be constituted by one or more separate parts, which are borne between the housing 6 and the pivotal portion 15 of the switching rocker member 13 and may be for instance like balls or corrugations in shape. First and second fluid ducts 22 and 23 open into the interior space 12 of the housing and their openings 24 and 25 are aligned in the vertical direction 14 and are surrounded by an annular valve seat. The valve seats 26 may be components of separate components inserted into the respective lower housing part 9 . Such a design offers the advantage that the valve seats may be made like jets or nozzles in a simple manner. Furthermore insert parts may be employed if required which have different diameters in order to provide different flow cross sections or lumens if required as part of modular system.
The arrangement is such that each opening 24 and 25 is opposite to one of the two switching rocker arms 18 and 18 ′. In the portion opposite to the respective opening 24 and 25 each switching rocker arms 18 and 18 ′ has a closure portion 27 and 27 ′ of suitable sealing material and more particularly of plastic material having rubber-elastic properties.
As related to the height direction 14 the duct openings 24 and 25 are preferably at the same level of the housing 6 , same being placed adjacent to each other and at a distance apart athwart the height direction 14 . Since the member 13 is slightly angled so that the rocker arms 18 and 18 ′ is so set at a small angle of under 180 degrees angle that its rocking arms 18 and 18 ′ make an obtuse angle at the top longitudinal side 28 , opposite to the closure portions 27 and 27 ′ it is possible for the switching rocker member 13 to be pivoted between two positions of rocking, in which, respectively. the one closure portion 27 and, respectively, 27 ′ closes the respective duct opening 24 and respectively 25 , by engagement with the associated valve seat 26 , while simultaneously the respectively other closure portion 27 ′ and 27 is lifted clear of the associated duct opening 25 and, respectively, 24 and permits fluid passage through the respective duct opening. The switching movement takes place like the movement of a swing or see-saw.
In the second connection plane the lower housing part 9 has a third fluid duct 32 extending through it, which at a suitable point also opens into the interior space 12 of the housing, the connection being open at all times. The associated duct opening 33 is preferably also aligned in the height direction 14 and may be located between the two other duct openings 24 and 25 . In the working embodiment it is opposite to the pivotal portion 15 in the height direction 14 .
The switching rocker member 13 is located in the power plane 4 in the portion, which in the working embodiment is the bottom portion, of the interior space 12 of the housing, which space will be henceforth termed the connection chamber 34 . Dependent on the particular position of switching of the switching rocker member 13 there is a fluid connection, extending through the connecting chamber 35 , between the third fluid duct 32 and the first or second fluid division 22 and 23 .
In the portion, adjoining the switching rocker member 13 in the height direction 14 adjacent to the top longitudinal side 28 , of the interior space 12 of the housing, which represent the control plane 3 , there are two actuating diaphragms 35 and 35 ′. In the working embodiment illustrated they consist of a polymeric plastic material and have rubber-like properties. The arrangement is such that opposite to each rocking arm 18 and 18 ′ on the longitudinal side 28 opposite to the respective the closure part 27 and 27 ′, there is one of the actuating diaphragms 35 and 35 ′. Thus the two actuating diaphragms 35 and 35 ′ engage the same longitudinal section of the switching rocker member 13 , on which furthermore one of the closure parts 27 and 27 ′ is provided, only on the opposite longitudinal side of the switching rocker member 13 .
It is preferred for the two actuating diaphragms 35 and 35 ′ to be adjacent each other as related to the height direction 14 in the control plane 3 . They respectively have outer surrounding peripheral edge part 36 attached to the housing 6 in a sealing manner. In the working embodiment illustrated in FIG. 1 this is because their surrounding peripheral edge part 36 is clamped between the top housing part 7 defining the first connection plane and a middle housing part 8 defining the control plane 3 in a firm manner. The two actuating diaphragms 35 and 35 ′ are consequently fixed between the same housing parts 7 and 8 , something substantially simplifying assembly.
The surrounding peripheral edge part 36 of the actuating diaphragms 35 and 35 ′ simultaneously constitutes the seal between the top and the middle housing parts 7 and 8 . The seal between the middle and the bottom housing parts 8 and 9 is produced in the working example by an intermediately placed annular seal 37 between these housing parts in the peripheral part of the interior space 12 of the housing.
It will be clear that the division of the housing 6 may be different to that illustrated and it would be more particularly possible to provide only two housing parts, which between them define the interior space 12 of the housing and between which the actuating diaphragms 35 and 35 ′ are clamped at the edge (comparable to the designs illustrated in FIGS. 2 through 5 ).
At their central portion 38 the actuating diaphragms 35 and 35 ′ engage respectively associated rocker arms 18 and 18 ′. In this respect a plain engagement by touching would be possible, but however the physical attachment adopted in the working example is recommended, which means that a respective central diaphragm part 38 and 38 ′ is at all times only movable jointly with the associated rocker arm 18 and 18 ′ irrespectively of the direction of pivoting of the switching rocker member 13 . In order to simplify assembly and any necessary dismounting it may here be a question of a releasable type of attachment.
The desired position of switching and/or switching movement of the switching rocker member 13 may be produced by ganged fluid operation of the actuating diaphragms 35 and 35 ′. Given a suitable operation by fluid the central diaphragm portions 38 and 38 ′ are caused to move generally in the height direction 14 , such movement being transmitted to the switching rocker member 13 with a thrusting or drawing effect. Because the central diaphragm portions 38 and 38 ′ are held by way of elastic intermediate portions 42 in a flexible manner on the surrounding peripheral edge portions 36 , during the pivoting or rocking movement of the switching rocker member 13 they readily allow for the small change in direction of the movement.
It is possible to provide the valve means with a spring means 47 indicated in chained lines in FIG. 2 for example, which bears against the housing 6 and the switching rocker member 13 and biases the switching rocker member 13 in a regular manner into a switching position representing the home position of the valve means.
The actuating diaphragms 35 and 35 ′ divide up the interior housing space 12 into the above mentioned connecting chamber 34 and into two control chambers 43 and 43 ′ associated with respectively one of the actuating diaphragms 35 and 35 ′. Each actuating diaphragm 35 and 35 ′ constitutes a fluid-tight, moving wall between the connecting chamber 34 and a control chamber 43 and 43 ′ arranged on the side opposite to the switching rocker member 13 . Each of the control chambers 43 and 43 ′ communicates with its own control duct 44 and 44 ′ extending in the first connection plane 2 and, in the working example, through the top housing part 7 . The control ducts 44 and 44 ′ open like the fluid ducts 22 , 23 and 32 at their outer end at the outer face of the housing 2 , where there is the possibility of connecting up fluid ducts leading to other equipment.
In what follows a first preferred manner of operation of the valve means 1 will be described with reference to FIGS. 2 and 3, the diagrammatic drawings simultaneously indicating some possibilities of modification in the design structure of the valve means.
The fluid circuit diagram of the valve means 1 in accordance with FIGS. 2 and 3 is so selected that the first fluid duct 22 constitutes a venting duct, which is connected with a pressure sink and more particularly with the atmosphere R, whereas the second fluid duct 23 constitutes a supply duct, which is connected with a source P of pressure, which makes available a pressure medium, which is more especially gaseous and is subject to a working pressure. The third fluid duct 32 is a power duct which is able to be connected with a load A, as for instance a principal valve, which is to be controlled by the valve means 1 with a pilot function or a directly connected load. The first control duct 44 , which is associated with the first actuating diaphragm 35 cooperating with that rocker arm 18 which controls the opening of the first fluid duct 22 , constitutes a second venting duct, which like the first fluid duct 22 , is continuously connected with a pressure sink and is more particularly connected with the atmosphere, something which is indicated by the letter R′. The second control duct 44 ′ associated with the second control chamber 43 ′ and the second actuating diaphragm 35 ′. constitutes a principal control duct, which is connected with a control pressure source P s able to supply a variable control pressure, at least two pressure values being possible in the present case, on the one hand the atmospheric pressure or pressure of the surroundings and on the other hand a pressure level corresponding to the power or working pressure. The action of the pressure is controlled by means of a valve (not illustrated) associated with the second control duct 44 ′.
The valve may be operated not only with a gaseous but also with hydraulic pressure medium.
FIG. 2 shows the home position of the valve means, in the case of which it is here a question of an open position, which is produced by the application of a control pressure of zero bar to the second control duct or, respectively, principal control duct 43 ′, that is to say the second control chamber 43 ′ is vented. The balance of forces occurring at the actuating diaphragms 35 and 35 ′ and the switching rocker member 13 then means that the switching rocker 13 is pivoted into a switching position, in which the connection between the venting duct 22 and the connecting chamber 34 is closed, whereas simultaneously the supply duct 23 communicates with the connecting chamber 34 owing to the closure portion 27 ′ being moved clear of its duct opening 25 so that the pressure medium at the lower pressure level may flow into the power duct 32 and consequently to a connected load A.
In order to vent the load A a higher control pressure is applied to the principal control duct 44 , such pressure being equal to the power pressure in the working example. The balance of forces now existing results in a rocking or pivotal motion of the switching rocker member 13 into the second switching position representing the opened position as indicated in FIG. 3 . The connection between the supply duct 23 and the connecting chamber 34 is interrupted here, whereas simultaneously the pressure medium may flow off from the load A by way of the connecting chamber 34 into the venting duct 22 constituted by the first fluid duct, because the closure portion 27 associated with latter is open.
All in all the valve means 1 is able to perform a {fraction (3/2)} valve function in the working example.
While in the working embodiment of FIGS. 2 and 3 the selected fluid circuit diagram means that there is a valve means of the “normally open” type, the working example of FIGS. 4 and 5 represents a valve means of the “normally closed” type owing to its slightly modified connection arrangement.
In the case of the working embodiment of FIGS. 4 and 5 the connection of the three fluid ducts 22 , 23 and 32 of the power plane corresponds to that of the working example of the FIGS. 2 and 3. The changes in the fluid connections only relate to the control plane and, respectively, the two control ducts 44 and 44 ′.
Thus gage pressure is continuously present at the second control duct 44 ′ and accordingly in the associated second control chamber 43 ′ since there is a constant connection with a first source P′ of control pressure, the control pressure in the working example being equal to the power pressure present in the supply duct 23 . The volume of compressed air held in the control chamber 43 ′ consequently constitutes a pneumatic spring, which effects closure of the supply duct 23 as long as there is a control pressure of for example zero bar in the first control chamber 43 and, respectively, in the first control duct 44 connected with same. This is achieved because the first control duct 44 is connected with a second control pressure source P s , by way of which a control pressure with a variable pressure level may be supplied. If such control pressure is equal to the pressure of the atmosphere, the switching rocker member 13 will assume the closed position illustrated in FIG. 4, the supply duct 23 being closed and a connection being produced between the power duct 32 and the venting duct 22 . For switching over into the open position depicted in FIG. 5, the second control pressure source P s produces a gage pressure in the first control chamber 43 , which gage pressure may be equal to the power pressure, something which results in a displacement of the balance of forces so that the switching rocker member 13 is pivoted in the open position, in which the three fluid ducts 22 , 23 and 32 are connected together in the fashion already described with reference to FIG. 2 .
It will be seen that the valve means 1 renders possible a modification of the valve and amplifier functions which are possible without having perform substantial changes in design and in fact it is essentially sufficient to change the fluid connection of some valves.
FIGS. 2 through 5 furthermore serve to indicate that it is an advantage to arrange the outer duct openings of the first, second and third fluid ducts 22 , 23 and 32 , provided on the outer side of the housing 6 , at least approximately at the same level perpendicular to the height direction 14 adjacent to one another. In a similar manner it is more particularly possible to arrange for the outer openings of the control ducts 44 and 44 ′, present on the outer side of the housing 6 , to be also at least approximately at the same level perpendicularly to the height direction 14 adjacent to each other.
In the case of the working examples of FIGS. 2 and 5 the two actuating diaphragms 35 and 35 ′ are in the form of mutually separate components. On the other hand in the case of the working example of FIG. 1 they are collected together integrally in a common diaphragm element 45 , something which simplifies manufacture and assembly. In both cases the actuating diaphragms are preferably manufactured at least in part of a rubber-like elastic material, at least in the elastic intermediate portions 42 , a polymer material being preferred.
An arrangement which is particularly readily assembled is produced if the switching rocker member 13 , the actuating diaphragms 35 and 35 ′ and the closure portions 27 and 27 ′ are united as a common element.
While in the working embodiment of FIG. 1 the pivotal bearing means 16 is provided adjacent to bottom longitudinal side 29 of the switching rocker member 13 opposite to the actuating diaphragms 35 and 35 ′, in the working examples of FIGS. 2 through 5 it is located adjacent to the top longitudinal side 28 of the switching rocker member 13 facing the actuating diaphragms 35 and 35 ′. To precisely set an exact range of pivoting it would however be possible as well to provide suitable guide means on the top side and also on the bottom side. Furthermore it would be feasible to ensure the desired switching over characteristic simply by the attachment of the switching rocker member 13 on the actuating diaphragms 35 and 35 ′ and to do without an additional supporting engagement of the pivotal portion on the housing.
Changes in the switching characteristic of the valve means may also be provided by having the diaphragms not of equal area as in the working example but with different areas, forms and/or cross sections, as shown in FIG. 4 a . It is furthermore possible to so design the actuating diaphragms that in the condition free of forces they retain the deflections imparted to them.
While in the working example of FIG. 1 the closure portions 27 and 27 ′ are set in the switching rocker member 13 , so that it is possible to speak of an integral construction, the working examples of FIGS. 2 through 5 as separate sealing bodies possess closure portions 27 and 27 ′ arranged on the corresponding longitudinal side of the switching rocker member 13 .
As already noted, the housing 6 in the working embodiment of FIG. 1 is divided into three housing parts 7 , 8 and 9 , the clamping in place of the actuating diaphragms 35 and 35 ′ being between the top housing part 7 having the control ducts 44 and 44 ′ and the middle housing part 8 adjoining same. The middle housing part 8 , which may be termed an intermediate plate, ensures on the one hand a reliable sealing function between the control chambers 43 and 43 ′ and on the other hand facilitates working with different actuating diaphragms having different areas and/or being separate.
A particularly compact and flat design of the valve means 1 is more particularly ensured if the actuating diaphragms 35 and 35 ′ and the duct openings 24 and 25 controlled by the switching rocker member 13 are respectively arranged adjacent to each other in a perpendicular direction, the perpendicular direction extending athwart and more particularly at a right angle to the mutually parallel longitudinal axes 46 and 46 ′ of the duct openings 24 and 25 , such longitudinal axes being aligned in the same direction in the working example as the height direction 14 .
One advantage of the working examples is also that owing to the arrangement of the outer openings of the fluid ducts 22 , 23 and 32 on the one hand and the control ducts 44 and 44 ′ on the other hand regular or defined points of intersection may be produced, which render possible the use of the valve means as a modular component in the form of a universal “insert”. Furthermore by different connection up of the control chambers 43 and 43 ′ with line, control and atmospheric pressure it is possible to ensure a simple attainment of different valve states without further modifications of the valve means.
In accordance with a convenient further development it is possible for the output volumetric to be varied in proportion to pressure in one of the two control chambers 43 and 43 ′ so that together with a suitable actuator element an indirectly operating or regulating valve may be produced. Furthermore there is the possibility of producing amplification of pressure by having two additional diaphragms placed in the power plane and having a smaller area than the above mentioned actuating diaphragms simultaneously with the amplification of quantity or rate.
Last but not least it is to be noted that the tension state or the position of one or more diaphragms may be utilized to detect the setting quantity, this being more particularly possible in the case of use of the valve means as an amplifier. | A valve means ( 1 ) containing a switching element in the form of a switching rocker member ( 13 ). The rocking arms ( 18 and 18 ′) placed on either side of the pivotal portion ( 15 ) of the switching rocker member ( 13 ) are respectively engaged by a respective actuating diaphragm ( 35 and 35 ′) and adjacent thereto there is a closure portion ( 27 and 27 ′) associated with a duct opening ( 24 and 25 ). A valve means designed in this manner renders possible a particularly flat, planar structure with compact dimensions and a small dead volume. | 8 |
BACKGROUND OF THE INVENTION
The invention relates to a flat-bed knitting machine comprising flexible shank needles arranged in the needle channels of the needle bed, each said needle having an anterior first needle butt always projecting from the needle bed and a posterior second needle butt which sinks into the needle bed under the resilience of its own flexible shank, displacing jacks (pushers) located behind the flexible shank needles, each said jack having an operating butt and a forward end which is displaceable under the flexible shaft of the flexible shank needle for selectively lifting the second needle butt, jacquard jacks located behind and slideable on the displacing jacks and a cam system arranged symmetrically about its central longitudinal axis for selecting and operating the needles and jacks and which, in the region of the second needle butts, has at least two needle sinkers displaceable in the cam plane.
Such a flat-bed knitting machine is known for example from DE 35 23 989 C1. In this patent the displacing jacks are formed as arresting or locking jacks which allow the second needle butts to be selectively lifted into a working position for engaging with cams of the cam-system. This known flat-bed knitting machine enables the needle channels to be milled without interruption, i.e., at a single pass with a constant milling-depth, without affecting the machine's full knitting capabilities including those of transferring stitches and loops, possibly of different withdrawal depths i.e. sizes, in the same row.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a flat-bed knitting machine of the type described above with an improved and simplified cam- and knitting-system wherein the number of non-fixed cams of the cam system and the means required to control them are reduced while retaining the machine's simplicity of construction and manufacture.
This is achieved in accordance with the invention, in that
a) the displacing jack is formed as a purely displaceable lifting jack having a two-stepped forward end wherein a first top-edge serves to lift the second needle butt into a half-height working position and a contiguous second top-edge serves to lift the second needle butt into a full-height working position;
b) a control tongue rockable by the first needle butts in the plane of the cam system is provided on the central longitudinal axis of the cam system within camming range of the first needle butts;
c) in a first group of cams, the cams are arranged symmetrically about the central longitudinal axis of the cam system and are moveable perpendicularly to the cam plane, wherein
two cams are located within camming range of the first needle butts near the control tongue or within camming range of the second needle butts and
two cams are located within camming range of the second needle butts near the needle sinkers.
In a flat bed knitting machine having such a cam and knitting system, a simple to construct and operationally reliable cam system for constant needle withdrawal (i.e., for forming stitches and loops of equal size), is realised.
Preferably the flat bed knitting machine according to the invention is also arranged such that
d) the needle sinkers near the second needle butts each comprise two independently displaceable sections, of which
one section is arranged to engage those second needle butts in a half-height or a half-height and full-height working position and
the other section is arranged to engage those second needle butts in a full-height working position
e) in a second group of cams, the cams are arranged symmetrically about the central longitudinal axis of the cam system and are moveable perpendicularly to the cam plane, wherein
two cams are located within camming range of the first needle butts,
two cams are located within camming range of the second needle butts and
two cams are located within camming range of the operating butts of the lifting jacks;
f) in a third group of cams, the cams are arranged symmetrically about the central longitudinal axis of the cam system, are moveable perpendicularly to the cam plane, and are located within camming range of the operating butts of the lifting jacks.
The flat bed knitting machine according to the invention provides the full range of weaving techniques, including transfer of stitches and forming stitches of different withdrawal depths, i.e., sizes, within a same row, by means of a very simply made needle bed and a very simple, compact and operationally reliable cam system.
Preferably the first group of cams is operated as a whole by the return motion of the carriage.
In a cam system which allows various needle withdrawals to be selected, the cams of the first, second and third groups of cams are all operated together by the return motion of the carriage.
Advantageously, the lifting jack at its forward end has a first inclined cam face followed by a half-height first lifting surface and a contiguous second inclined cam face followed by a full-height second lifting surface which extends up to the operating butt.
Preferably the cams of the first group located within camming range of the first needle butts or the second needle butts are needle-withdrawing cams, while the cams of the first group located within camming range of the second needle butts have an upper part for engaging with all the selected second needle butts and a lower part for engaging only with those selected second needle butts in their full-height position.
Advantageously, in each of the halves of the cam system arranged symmetrically to the central longitudinal axis there are two selection positions for the second needle butts wherein
a first position serves for the selection of: stitch, long stitch, transfer stitch and
a second position serves for the selection of: tuck-loop, short stitch, short tuck-loop, receive stitch and stitch.
For transferring and receiving stitches, the cams of the first group of cams moveable perpendicularly to the cam plane are activated.
For forming long and short stitches, the cam of the second group of cams moveable perpendicularly to the cam plane are activated.
For forming stitches and tuck-loops and slipping stitches in three-way-operation, the cams of the third group of cams moveable perpendicularly to the cam plane are activated.
For transferring and forming stitches, the cams of the first group, the cams of the second group and the cams of the third group of cams moveable perpendicularly to the cam plane are activated together with those cams of the first group which are within camming range of the second needle butts.
For transferring stitches and forming tuck-loops, the cams of the first group and the cams of the third group of cams moveable perpendicularly to the cam plane are activated together with those cams of the first group within camming range of the second needle butts.
Finally, the control tongue rockable in the cam plane is activated by the first needle butts of the needles selected for transferring stitches.
BRIEF DESCRIPTION OF THE DRAWINGS
A number of embodiments of the invention will now be described in more detail with reference to the drawings. In the drawings:
FIG. 1 shows a flexible shank needle and a rearwardly located double-lifting jack with the second needle butt sunk out of action in the needle-bed,
FIG. 2 is a similar view to FIG. 1 but with the second needle butt in the half-raised active position,
FIG. 3 is a similar view to FIG. 1 but with the second needle butt in the fully raised active position,
FIG. 4 shows a cam system for a fixed needle withdrawal,
FIG. 5 shows a cam system for selectively variable needle withdrawals,
FIG. 6 shows the cam system of FIG. 5 adjusted for three-way operation for forming stitches and tuck-loops as well as for floating, i.e., slipping or not knitting stitches,
FIG. 7 shows the cam system of FIG. 5 arranged to produce long and short stitches,
FIG. 8 shows the cam system of FIG. 5 arranged to produce long stitches and short tuck-loops,
FIG. 9 shows the cam system of FIG. 5 arranged to transfer and receive stitches,
FIG. 10 shows a modification of the cam system of FIG. 5 adjusted for three-way operation for forming stitches and tuck-loops as well as floating,
FIG. 11 shows the cam system of FIG. 10 arranged to transfer and to receive stitches,
FIG. 12 shows the cam system of FIG. 10 arranged to transfer and to form stitches, and
FIG. 13 shows the cam system of FIG. 10 arranged to transfer stitches and to form tuck-loops.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 to 3 show a flexible shank needle N and a displaceable lifting jack H arranged one behind the other. The flexible shank needle N has a forward (anterior) butt 1 which always sticks out from the needle bed (not shown) and a rear (posterior) butt 2 which disappears into the needle bed due to the resilience of its shank. The lifting jack H has an operating butt 3 which always extends out of the needle bed so that it can be displaced.
A boss 4, formed under the second butt 2, is pressed onto the base of the needle channel by virtue of the shank's resilience as shown in FIG. 1. The second butt 2 thus remains sunk out of action in the needle bed.
The forward end of the lifting jack H has a first inclined cam face 5 which merges into a half-height first lifting surface 6 parallel to the base of the needle channel. A second inclined cam face 7 rises from the first lifting surface 6 up to a full-height second lifting surface 8 which is also parallel to the base of the needle channel and which extends to the operating butt 7 of the lifting jack H. When the needle and jack are relatively displaced from the position shown in FIG. 1, the boss 4 initially rides up the cam face 5 onto the first lifting surface 6 (FIG. 2). At this point, the needle butt 2 is in its half-height working position where it can be engaged by high contour but not intermediate contour cams of the cam system. If the needle and jack are now further displaced, the boss 4 rides up the cam face 7 onto the second lifting surface 8 (FIG. 3). In this position, the second needle butt extends fully from the needle bed into its full height working position where it can be engaged by each and every operative cam. Thus the second needle butt 2 can be lifted by the lifting jack up to two different levels and it has three possible positions:
inoperative (FIG. 1)
semi-operative (FIG. 2)
fully-operative (FIG. 3).
In the cam systems represented in FIGS. 4 to 13, fixed cams and operative cams which have been moved in a direction perpendicular to the cam plane are shown unhatched, inoperative cams and cams which are moveable perpendicularly to the cam plane are shown hatched, needle withdrawing cams and needle sinkers displaceable in the cam plane are marked with a double ended straight arrow and cams rotatable in the cam plane are marked with a double ended curved arrow. Furthermore the second needle butts located at different parts of the cam system are shown unhatched if they are sunk inoperatively in the needle bed, are marked with a cross if they are in their half-height semi-operative position and are shown in bold black if they are in their fully lifted operative position. The direction of movement of the carriage is indicated by an arrow S.
Various positions of the first needle butts 1, the second needle butts 2 and the operating butts 3 of the lifting jacks are shown in FIGS. 4 to 13. These are the positions occupied when knitting and are identified as follows:
Position 1: Basic position, needle butt 2 inoperative,
Position 2: position reached shortly after selection of: stitch, long stitch, or transfer stitch,
Position 3: second needle butt 2 in fully lifted operative position,
Positions 4 to 12: forming stitches or long stitches
Positions 13 to 15: forming stitches, long stitches or tuck-loops.
Position 16: end position,
Position 17: Basic position, needle butt 2 inoperative,
Position 18: position reached shortly after selection of: tuck-loops or short tuck-loops,
Positions 19 to 24: forming tuck-loops
Position 25: Basic position, needle butt 2 inoperative,
Position 26: position reached shortly after selection of: short stitch, or stitch,
Positions 27 to 32: forming short stitch
Positions 33 and 34: forming stitch or short tuck-loop
Positions 35 to 49: transferring stitch
Position 50: Basic position, needle butt 2 inoperative,
Position 51: position reached shortly after selection of: transfer stitch
Positions 52 to 59: receiving stitch.
FIG. 4 depicts a cam system for constant needle withdrawals with fixed cams that are shown unhatched. The cam system is essentially symmetrical about its central axis M and has two needle sinkers N2.1, N2.2, located in the neighbourhood of the second needle butts 2 and displaceable in the cam plane. A control tongue S1 rockable in the cam plane by the first needle butts 1 is located on the central longitudinal axis M of the cam system in the vicinity i.e. within camming range, of the first needle butts 1. A first group A of cams arranged symmetrically about the central longitudinal axis M of the cam system are moveable into and out of action in a direction perpendicular to the cam plane. This group consists of two cams A1.1 and A1.2 in the vicinity of the first needle butts near the control tongue S1 and two cams A2.1 and A2.2 in the vicinity of the second needle butts near the needle sinkers N2.1 and N2.2.
FIG. 5 shows a cam system wherein needle withdrawals can be selectively varied. Here a first pair of independently displaceable needle sinker sections N2.1, N2.2 are located in the neighbourhood of the second needle butts 2 for engaging the second butts 2 in their half- or their half- and full-height, working positions and a similar second pair of needle sinker sections N2.3, N2.4 are arranged for engaging the second needle butts 2 in their full-height working positions.
In addition, a second group B of cams arranged symmetrically about the central longitudinal axis of the cam system and moveable perpendicularly to the cam plane are provided. In this group B, two cams B1.1, B1.2 are located in the vicinity of the first needle butts 1, two cams B2.1, B2.1 in the vicinity of the second needle butts 2 and two cams B3.1, B3.2 in the vicinity of the operating butts 3 of the lifting jacks H.
Finally, there is provided a third group C of cams C3.1, C3.2 arranged symmetrically about the central longitudinal axis M of the cam system, moveable perpendicularly to the cam plane and located in the vicinity of the operating butts 3 of the lifting jacks H.
The first group A of cams, the second group B of cams and the third group C of cams are moved together, into and out of operation, by the return motion of the carriage.
The cams A1.1 and A1.2 of the first group A serve to control withdrawal of the needles. The cams A2.1, A2.2 of the first group A have an upper portion for engaging all of the selected second needle butts 2 and a lower portion for engaging only those second needle butts 2 which are in their fully-operative positions.
In each of the essentially symmetrical halves of the cam system, the flexible shank needles, or rather, their second needle butts 2, can be selectively placed into a first position which is used for stitches, long stitches and transfer stitches, or, into a second position which is used for tuck-loops, short stitches, short tuck-loops and for receiving stitches.
For transferring and receiving stitches, the cams of the first group A are moved perpendicularly to the cam plane into their operative positions. For forming long and short stitches, the cams of the second group B are moved perpendicularly to the cam plane into their operative positions. For forming stitches and tuck-loops during three-way-operation, the cams of the third group C are moved perpendicularly to the cam plane into their operative positions.
FIG. 6 depicts the needle and jack movements for selectively forming stitches and tuck-loops or for floating in three-way-operation using selectively variable needle withdrawal depths as per the cam system of FIG. 5. The first selectable position for cam movements from right to left is shown as position 1. The lifting jacks H, which are moved upwardly from position 1 to position 2 to reach this first selectable position, lift the second needle butts 2 into their semi-operative positions (indicated by a cross). The cams of the first group A are inoperative. By further movement of the carriage to the left, the lifting jacks H are driven-out to position 3. Consequently the needle butts 2 are lifted into their fully-operative positions. In position 4, the operative second needle butts 2 are driven-out by a fixed cam F2 into position 5. As the lifting jacks remain in position, the second needle butts 2 slide into their semi-operative positions (FIG. 2). From this position, they are driven by cam F2 into position 6. Here the first needle butts 1 are engaged by a fixed cam F3 and then brought into the stitch-clearing position 8.
In order to hold the second needle butts in their semi-operative positions, the lifting jacks must be driven-out. This is done by a fixed cam F4. From position 9, the flexible shank needles N begin their downwards movement. The first needle butts 1 are engaged by a fixed cam F5 and moved from position 9 to position 13. From this position, the flexible shank needles are drawn into the starting position required for stitch formation by means of the needle sinker N2.4 acting on the second needle butts 2. From position 15 onwards the flexible shank needles are driven-out by a fixed cam F6 acting on the first needle butts 1, into the comb-like position 16 which is similar to the starting position. The lifting jacks H move in a downward direction from position 9 onwards. In this way, the second needle butts are placed out of action in position 11, in the semi-operative state in position 12 and in the fully-operative state from position 13 onwards. In going from position 15 to position 16, the lifting jacks H are drawn-back by a fixed cam F7 into the basic position in which the second needle butts 2 are out of action.
If tuck-loops are to be formed in the same row with the same cam as in FIG. 6, then the flexible shank needles N which will be used for the even tuck-loops must be placed in their second selectable position, namely, position 18. The second needle butts 2 which were still inoperative in position 17 are brought into the semi-operative position, position 18, by the selected lifting jacks. The second needle butts 2, which were not selected in the first selectable position, position 2, slide through under the cam F2. The cams in group B are inactive. The semi-operative second needle butts 2 are engaged by a fixed cam F8 and driven-out from position 19 to position 20. In order to retain the second needle butts 2 semi-operative in position 20, the lifting jacks H are driven-out by another fixed cam F9. From position 20, the flexible shank needles N are driven-out via their first butts 1 to the receive position and, by a fixed cam F10, to the tuck position, position 21. The lifting jacks H are withdrawn from position 22 to position 23 in order then to be driven-out again by the active cam C3.2 into position 13. During this time, the second needle butts 2 move from the semi-operative to the inoperative position and then back to the active position 13 in order to be moved from there together with the stitch-forming flexible shank needles N to position 16.
FIG. 7 serves to explain the formation of long and short stitches within a knitting row. The formation of long stitches has already been described with reference to FIG. 6. The formation of short stitches commences at the second selectable position, position 26. The cams of groups A and C are inoperative while those of group B are operative. The displaceable needle sinkers N2.1, N2.3 and N2.2, N2.4 each comprise sections at two different levels, namely N2.1 and N2.3, and N2.2 and N2.4 respectively, which are driven into their withdrawal positions in different manners. The needle sinker N2.2 (shown in dashed line) engages the semi-operative second needle butts 2, while the needle sinker N2.4 engages the fully operative ones. The flexible shank needles N, which will be knitting short stitches, were selected in position 26 as described above. The second needle butts are semi-operative and are engaged by cam B2.1 and driven into position 28. In order to retain these needle butts 2 in their semi-operative positions, the lifting jacks are simultaneously driven out by cams F9 and B3.1. From position 28, the flexible shank needles N are brought into the stitch clearing position 8 by the interaction of needle butts 1 and cams B1.1 and F3, and, then from there into the comb-like position, position 13. In positions 30, 31 and 32, the second needle butts 2 of the flexible shank needles N, which will be forming short stitches, are inoperative since the lifting jacks H are withdrawn by cam F4 as indicated at position 32. While the working butts 3 of the lifting jacks H slide over a fixed cam F11, the second needle butts 2 are brought once more to their half-height position, as shown in position 33, so that they can be engaged by needle sinker N2.2 and drawn-down a little further into position 34.
The lifting jacks are moved by the flexible shank needles N into their basic position, position 34.
The movements of the flexible shaft needles N and lifting jacks H for long stitches and short tuck-loops are shown in FIG. 8. The movements are similar to those described with respect to FIG. 6 except that the cams of group C are inoperative. The needle movements correspond to those of FIG. 6 and those of the lifting jacks to FIG. 7.
A further needle and lifting jack cam-movement is necessary for transferring and receiving stitches, as shown in FIG. 9.
For transferring stitches, the first selectable position, position 2 is used. The cams of group A are operative and those of groups B and C are inoperative. Up to position 3, the process is the same as for forming stitches. As the cam section A2.1 is operative, those second needle butts 2 in the fully-operative position are engaged and moved to position 35. The lifting jacks H, which are not transported upwards therewith, permit the second needle butts 2 to slide into a half-raised position. From there a fixed cam F12 controls the further movement of the flexible shank needles N. The first needle butts 1 take the flexible shank needles 2 to position 36 in which the second needle butts 2 are fully sunk into the needle bed (FIG. 1). The flexible shank needles N are driven out by cam F12 to the transfer position, positions 38, 39, 40 and 41. From position 42, the flexible shank needles are moved by the cam frog or control tongue S1 and the cam A1.2 via position 44, where the needle butts 2 are half raised, to position 45, where the needle butts 2 are fully operative and then by means of fixed cam F13 via positions 46 and 47 to position 48. In position 16, the flexible shank needles and lifting jacks are once more in their basic positions.
For receiving stitches, the second selectable position, position 51 is used. In this position the second needle butts 2 are semi-operative. The further operation is the same as for forming tuck-loops. Needle withdrawal, which is initiated at position 15 through the co-operation of cam A1.2 and the first needle butts 1 is continued by cam F14. At position 56, the second needle butts 2 are semi-operative.
As the cams F13 and F2 as well as A2.2 and A2.1 under the horizontal line are only at half height, the second needle butts 2 slide through under the cam F13 and remain in their comb-like position. The lifting jacks H operate in the same way as described with reference to FIGS. 7 and 8 with the exception that withdrawal into the basic position is reached at position 59.
FIG. 9 shows a further variant of the cams A1.1 and A2.1, wherein these cams end at the dashed line. In this embodiment, at position 55, the receiving flexible shaft needles remain in the receiving position underneath the cam A1.2 and are only later brought into the comb-like position by the fixed cam F5.
FIGS. 10 to 13 show cam systems which differ from those shown in FIGS. 5 to 9 in that the cams A1.1 and A1.2 of the first group A of cams are arranged in the vicinity of the second needle butts 2 rather than the first needle butts 1 and in that the relative sizes of the cams are somewhat different. This provides additional combinations of needle movements.
In FIG. 10, the cams of groups A and B are inoperative while those of group C are operative. Thus, during three-way-operation it is possible to select between forming stitches and tuck-loops or clearing, as was described in connection with FIG. 6.
In FIG. 11, the cams of group A are operative while those of groups B and C are inoperative. This permits stitches to be transferred and received as was described with reference to FIG. 9. The transferring needles are drawn-down via their first needle butts 1 by the control tongue S1 and then the second needle butts 2, which have thus been activated are drawn-down by the cam A1.2.
In FIG. 12, the cams of groups A, B and C are all operative. Thus in the first selectable position, position 2, the selected needles can transfer stitches and in the second selectable position, position 26, the selected needles can form stitches.
In FIG. 13, the cams of groups A and C are operative while those of group B are inoperative. Thus in the first selectable position, position 2, the selected needles can transfer stitches, and in the second selectable position, position 18, the selected needles can form tuck-loops. By means of the operative cam C3.2, the second needle butts 2 of the tuck-loop-forming needles can be brought into operation again so that they can be engaged by the needle sinker N2.2 and the needles thus moved to the desired withdrawal depth. | A flat-bed knitting machine has sprung shank needles (N) arranged one behind the other in the needle channels of the needle beds with first and second needle ends (1, 2) and sliding lifting plates (H) with an operative end (3) and a hinge system with at least four sliding needle lowering devices (N2.1, N2.2) in the hinge region. In order to improve and simplify the construction and operation of the needle beds and hinge systems for the whole range of bonding technology, the lifting plates (H) are designed to raise the second needle ends (2) in two stages to half and full height, the hinge system has control tongue (S1) which can be swung in the hinge plane by the first needle ends (1) in the hinge system and at least one first group of hinge components (A1.1, A1.2, A2.1, A2.1) which can be engaged and disengaged perpendicularly to the hinge plane. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. Ser. No. 188,810, filed Sep. 19, 1980 now U.S. Pat. No. 4,338,242.
BACKGROUND OF THE INVENTION
In many resin applications, low viscosity and good physical properties after a minimal heat cure are necessary. Frequently, however, those objectives are antithetical. Certain polymer systems that are based on a polyglycidyl ether, such as the vinyl ester resins, have hydroxyl groups along the molecular structure. Those hydroxyl groups cause an appreciable increase in viscosity which requires extensive dilution with a monomer to permit facile fabrication.
It would be desirable to have a procedure for reducing the viscosity of hydroxyl containing polymers while at least retaining the properties of the polymer when cured.
SUMMARY OF THE INVENTION
A curable resin having improved physical and chemical properties results from the reaction of an amine-free vinyl ester of a polyglycidyl ether having secondary hydroxyl groups and an unsaturated isocyanate reacted through those hydroxyls. The resin resulting from that process has a lower viscosity than the corresponding unmodified resin. In the cured state, the increased cross-linking density provides improved heat distortion temperatures and hardness and a decrease in water and solvent sorption.
DETAILED DESCRIPTION OF THE INVENTION
Bowen in U.S. Pat. Nos. 3,066,112 and 3,179,623 describes the preparation of vinyl ester resins by esterifying acrylic or methacrylic acid with a polyepoxide. That patentee also describes the alternate procedure wherein a glycidyl acrylate or methacrylate is reacted with the sodium salt of bisphenols. Vinyl ester resins based upon epoxy novolacs are taught in U.S. Pat. No. 3,301,743.
For use herein, the vinyl ester resin can be prepared from any glycidyl polyether. Useful glycidyl ethers are those of polyhydric alcohols and phenols. Such glycidyl polyethers are commercially available or are readily prepared by reacting at least two moles of an epihalohydrin or glycerol dihalohydrin with one mole of the polyhydric alcohol or phenol together with a sufficient amount of caustic to react with the halogen of the halohydrin. The products are characterized by the presence of more than one glycidyl ether group per molecule.
The useful acids for making the vinyl ester resins are those ethylenically unsaturated monocarboxylic acids such as acrylic, methacrylic, cinnamic acids and their halogenated isomers. Also included are the hydroxyalkyl acrylate or methacrylate half esters of dicarboxylic acids as described in U.S. Pat. No. 3,367,992 wherein the hydroxyalkyl group preferably contains from 2 to 6 carbon atoms.
The glycidyl ether and the acid are reacted in about stoichiometric equivalency generally with heating in the presence of a catalyst, such as a trivalent chromium salt, as, for example, chromium trichloride. Vinyl polymerization inhibitors are also commonly included to prevent premature polymerization. For purposes of this invention, amines are contraindicated for this esterification reaction.
The isocyanate should preferably be aliphatic to achieve the optimum benefits of the invention. Typical of those isocyanates are those of saturated or unsaturated esters of acrylic or methacrylic acid, allyl ether isocyanate, vinyl isocyanate, unsaturated or saturated aliphatic isocyanates and blends or mixtures of any of those isocyanates. A preferred species is isocyanatoethyl methacrylate.
Since the vinyl ester resin is unsaturated, the isocyanate may be saturated, unsaturated or a combination thereof.
The isocyanate is employed in an amount of 0.05 to 1.00 equivalent per equivalent of hydroxyl. Less than about 0.05 equivalent imparts little observable change in the cured product. Any isocyanate in excess of 1.0 equivalent has no place to react and thus could detract from the desired properties of the cured product.
The reaction of the isocyanate with the secondary hydroxyl is conducted using known techniques. In a typical reaction, the amine-free vinyl ester resin, the reactive diluent and a catalyst, such as stannous octoate, are thoroughly mixed together and brought to a mildly elevated temperature of, for example, 50° C. The isocyanate is slowly added with stirring. Heating is maintained until absence of the isocyanate band in the infrared spectrum is attained which indicates the reaction to be complete. When the vinyl ester resin is prepared using an amine catalyst and a tin catalyst is used with the subsequent isocyanate reaction, the resulting product shows little viscosity reduction. When trivalent chromium is employed in the esterification reaction and is followed by the use of tin catalysts in the isocyanate reaction, the result is a reaction product having reduced viscosity and improved physical and chemical properties.
The potential for cross-linking in the isocyanato product can be adjusted in several ways. The amount of unsaturation in the polymer or precursor can be varied. The number of hydroxyls in that starting material can vary. The amount of unsaturated isocyanate can be adjusted to that providing the desired number of cross-links. Some of the hydroxyls can be reacted with a saturated aliphatic isocyanate.
It is commonplace in the vinyl ester resin art to adjust the viscosity of the liquid uncured resin with a reactive diluent, usually a copolymerizable monomer. Suitable monomers for this use include vinyl aromatic monomers, such as styrene and vinyltoluene, and acrylate or methacrylate esters of lower alkanols. The reactive diluent may be an amount of up to 60 weight percent of the combined resin/monomer weight.
The products have improved properties, particularly heat distortion temperature, hardness and low solvent sorption. The products find use as neat resins and in reinforced plastics. Of particular note are their use in fiberglass reinforced filament wound pipe, electrical laminates, electrical insulating varnishes and coatings, bulk and sheet molding compounds, and corrosion resistant vessels and linings for vessels.
The concept of the invention will be more apparent from the following illustrative examples wherein all parts and percentages are by weight.
EXAMPLE 1
A vinyl ester resin was made as follows. To a 1-liter resin kettle equipped with a stirrer, thermometer, temperature controller and heat lamp, were charged 495 grams tris(4-glycidylphenyl)methane (3 equivalents); 0.3 gram hydroquinone (400 ppm); and 258 grams methacrylic acid (3 equivalents). After mixing thoroughly at 80° C., 0.75 gram of a 25 percent chromium acetate solution in methanol was blended in and the temperature set to 100° C. After 20 minutes, the temperature was set to 110° C. and upon controlling for a short time to check any exotherm, the temperature was raised to 115° C. The reaction was run at this temperature until the percent acid decreased below one percent.
One hundred parts of the trimethacrylate of tris(4-glycidylphenyl)methane prepared above, 25 parts of styrene and 0.1 part stannous octoate were mixed while heating to 50° C. To that mix while stirred was slowly added 47.02 parts isocyanatoethyl methacrylate (IEM) and the temperature raised to 60° C. Heating and stirring were continued until the absence of the isocyanate band in the IR spectrum at 2280 cm -1 indicated the reaction to be complete.
To the product was added 11.75 grams styrene. The resin was cured with 1.5 parts benzoyl peroxide per 100 parts resin at a temperature schedule of 2 hours at 90° C., 4 hours at 165° C. and 16 hours at 200° C.
For comparison, the trimethacrylate with 20 percent styrene was cured in an identical manner. The samples were tested according to standard methods with the following results.
______________________________________ Nonmodified IEM Modified______________________________________Viscosity* (cstks) 11,510 7,565HDT °C. 264, psi >230 >230T.sub.g 245 266Flex. Mod., psi 9.38 × 10.sup.5 8.03 × 10.sup.5Flex. Strength, psi 17,470 9,466Barcol Hardness 41 53Gardner Color 17 17______________________________________ *Before cure
Other samples of the above-described resins were cured with 1.5 parts benzoyl peroxide at 2 hours at 90° C. and 4 hours at 165° C. The heat distortion temperature of the nonmodified resin was 203° C. and of the IEM modified resin was greater than 230° C. The Barcol Hardness of the former was 42 and of the latter was 50.
EXAMPLE 2
A resin was prepared according to the procedure and stoichiometry of Example 1 using a commercially available dimethacrylate of the diglycidyl ether of bisphenol A (sold as DERAKANE® 411-45) as the polymer and vinyltoluene as the reactive diluent.
The resin was cured with 1.5 parts benzoyl peroxide per 100 parts of resin for one-half hour at 150° C. The samples were tested according to standard procedures with the following results.
______________________________________ Nonmodified IEM Modified______________________________________Viscosity (cstks) >1,646 1,445HDT °C. 264, psi 110 137Flex. Mod., psi 4.99 × 10.sup.5 5.29 × 10.sup.5Flex. Strength, psi 21,510 17,240Tensile Strength, psi 9,100 6,46024 Hr. H.sub.2 O Boil,% Δ wt.sup.2. 1.827 1.758Barcol Hardness 45 49Gardner Color >1 1______________________________________
Similar results were observed when the vinyl ester resin was an amine-free resin prepared from a blend of 3 parts methacrylated ester of the polyglycidyl ether of a novolac having a functionality of 3.5 and 1 part of a dimethacrylate of the diglycidyl ether of bisphenol A. The viscosity of the unmodified resin was 4120 cks and of the isocyanatoethyl methacrylate modified product was 3888 cks.
Also, similar property improvements were observed when the curing system was 1.5 parts methyl ethyl ketone peroxide and 0.5 part cobalt naphthenate.
When vinyl ester resins that had been made using tris(dimethylaminomethyl)phenol as the esterification catalyst were used, there was no significant reduction in viscosity. | Curable polymeric products are the reaction product of a polymer containing secondary hydroxyl groups and an aliphatic unsaturated isocyanate. | 8 |
FIELD OF THE INVENTION
The present invention relates to a fluororubber coating composition. In particular, the present invention relates to a fluororubber coating composition which has a long pot life and provides a film with a uniform thickness.
DESCRIPTION OF THE PRIOR ART
Since a conventional fluororubber coating composition suffers from gellation within 24 hours after the addition of a crosslinking agent, its pot life is short and it has some troubles in storage and application. If the composition is not gelled, crosslinking of the fluororubber will increase a viscosity of the composition, so that a coated film has an uneven thickness depending on a coating manner (See Industrial Material (KOGYO ZAIRYO), Vol. 26, No. 12 (Dec. 1978) 46-49).
SUMMARY OF THE INVENTION
One object of the present invention is to provide a fluororubber coating composition having a long pot life.
Another object of the present invention is to provide a fluororubber coating composition which provides a film having a uniform thickness when coated.
According to the present invention, there is provided a fluororubber coating composition comprising a fluororubber, a liquid medium, a coupling agent, a crosslinking agent and a carboxylic acid.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph showing the change of the viscosity with time of the compositions prepared in Example 1 and Comparative Example 1,
FIG. 2 is a graph showing the change of the viscosity with time of the composition prepared in Example 2 containing various concentrations of formic acid, and
FIG. 3 is a graph showing the change of the viscosity with time of the composition prepared in Example 3 containing various concentrations of acetic acid.
DETAILED DESCRIPTION OF THE INVENTION
As the fluororubber contained in the coating composition of the present invention, a highly fluorinated elastomeric copolymer may be used. A preferred example of the fluororubber is an elastomeric copolymer comprising 40 to 85% of vinylidene fluoride and at least one other fluorine-containing ethylenically unsaturated monomer copolymerizable with vinylidene fluoride.
As the fluororubber, one containing iodine atoms in the polymer chain may be used. An example of the fluororubber containing iodine atoms is an elastomeric copolymer comprising 40 to 85% of vinylidene fluoride and at least one other fluorine-containing ethylenically unsaturated monomer copolymerizable with vinylidene fluoride and having 0.001 to 10% by weight, preferably 0.01 to 5% by weight of iodine atoms which are bonded to terminals of polymer chains (see Japanese Patent Kokai Publication No. 125491/1978 and U.S. Pat. No. 4,243,770).
Typical examples of the other fluorine-containing ethylenically unsaturated monomer copolymerizable with vinylidene fluoride are hexafluoropropylene, pentafluoropropylene, trifluoroethylene, trifluorochloroethylene, tetrafluoroethylene, vinyl fluoride, perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether) and the like.
Preferred examples of the fluororubber are vinylidene fluoride/hexafluoropropylene copolymers and vinylidene fluoride/tetrafluoroethylene/hexafluoropropylene terpolymers.
Examples of other fluororubber which may be used according to the present invention are tetrafluoroethylene/propylene copolymer, ethylene/hexafluoropropylene copolymer, tetrafluoroethylene/fluorovinyl ether copolymer, vinylidene fluoride/tetrafluoroethylene/hexafluoropropylene/fluorovinyl ether copolymer, vinylidene fluoride/hexafluoropropylene copolymer and the like.
To the fluororubber coating composition, a fluororesin may be added, if desired. Examples of the fluororesin are polytetrafluoroethylene, a copolymer of tetrafluoroethylene with at least other ethylenically unsaturated monomer (e.g. olefins such as ethylene and propylene; halogenated olefins such as hexafluoropropylene, vinylidene fluoride, chlorotrifluoroethylene and vinyl fluoride; perfluoro(alkyl vinyl ether), etc.), polychlorotrifluoroethylene, polyvinylidene fluoride, and the like. Among them, polytetrafluoroethylene and a copolymer of tetrafluoroethylene with at least one monomer selected from the group consisting of hexafluoropropylene, perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether) and perfluoro(propyl vinyl ether) in an amount of 40% by mole or less based on the amount of tetrafluoroethylene are preferred.
As the liquid medium, an organic solvent such as a ketone and an ester is used. As the ketone or ester, any one can be used insofar as the fluororubber is dissolved therein. Specific examples are acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexanone, methyl isobutyl ketone, 2-heptanone, diisobutyl ketone, isophorone, cyclohexanone, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, sec.-butyl acetate, pentyl acetate, isopentyl acetate, and the like.
To the fluororubber coating composition, a liquid which can be dissolved in the liquid medium, for example, alcohols (e.g. methanol, ethanol, propanol, ethylene glycol Carbitol, cellosolve, etc.), lower ethers and DMA may be added.
The coupling agent is intended to mean a compound which acts on an interface between an organic material and an inorganic material and forms a strong bridge through a chemical or physical bond between them. Usually, the coupling agent is a compound of silicon, titanium, zirconium, hafnium, thorium, tin, aluminum or magnesium having a group which bonds the organic material and the inorganic material.
Preferred examples of the coupling agent are silane coupling agents and orthoacid esters of a transition element of the IV group in the Periodic Table or their derivatives. Among them, aminosilane compounds are preferred.
A typical example of the silane coupling agent is a silane compound of the formula: ##STR1## wherein R 1 is a C 1 -C 10 alkyl group having at least one functional group selected from the group consisting of a chlorine atom, an amino group, an aminoalkyl group, a ureido group, a glycidoxy group, an epoxycyclohexyl group, an acryloyloxy group, a methacryloyloxy group, a mercapto group and a vinyl group, or a vinyl group; R 2 and R 3 are independently an atom or a group selected from the group consisting of a chlorine atom, a hydroxyl group, a C 1 -C 10 alkoxyl group, a C 2 -C 15 alkoxyl-substituted alkoxyl group, a C 2 -C 4 hydroxyalkyloxy group and a C 2 -C 15 acyloxy group; and a is 0, 1 or 2.
R 1 can be an alkyl group having a functional group. Preferred examples of such alkyl group are a β-aminoethyl group, a γ-aminopropyl group, a N-(β-aminoethyl)-γ-aminopropyl group, a γ-ureidopropyl group, γ-glycidoxypropyl group, a β-(3,4-epoxycyclohexyl)ethyl group, a γ-acryloyloxypropyl group, a γ-methacryloyloxypropyl group, a γ-mercaptopropyl group, a β-chloroethyl group, a γ-chloropropyl group, a γ-vinylpropyl group and the like. R 1 can be a vinyl group.
Preferred examples of the above silane compound are γ-aminopropyltriethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethylsilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, vinyltrichlorosilane, vinyltriacetoxysilane, N-(trimethoxysilylpropyl)ethylenediamine, N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane, β-aminoethyl-β-aminoethyl-γ-aminopropyltrimethoxysilane, and the like.
Among them, the aminosilane compounds such as γ-aminopropyltriethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, N-(trimethoxysilylpropyl)ethylenediamine, N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane, γ-ureidopropyltriethoxysilane and β-aminoethyl-β-aminoethyl-γ-aminopropyltrimethoxysilane are particularly preferred, since they act as crosslinking agents of the fluororubber, greatly contribute to the increase of adhesion of the composition to a substrate and are safely used together with the liquid medium.
As the crosslinking agent, any of conventionally used ones such as amine crosslinking agents and polyol crosslinking agents may be used.
Specific examples of the amine compound are monoamines such as ethylamine, propylamine, butylamine, benzylamine, allylamine, n-amylamine and ethanolamine; diamines such as trimethylenediamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine and 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5·5]undecane; and polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine. Among them, those having at least two terminal amino groups are preferred. In addition, a compound which has a functional group such as --NH 2 , ═NH, ═N--, ═N + ═ or ═P + ═, a dehydrogen fluoride ability and a crosslinking ability may be used.
As the carboxylic acid, a carboxylic acid having 1 to 8 carbon atoms is preferably used. Specific examples of the carboxylic acid are HCOOH, CH 3 COOH, C 2 H 5 COOH, C 7 H 13 COOH and the like.
Among them, formic acid is preferred since its boiling point is 101° C. so that it is evaporated off during heating for crosslinking and has no influence on the coated film.
The fluororubber coating composition of the present invention may be prepared by adding a pigment, an acid acceptor, a filler, etc. and optionally a surfactant to a mixture of the fluororubber, the liquid medium and optionally the fluororesin, then adding the coupling agent, the carboxylic acid and optionally the amine compound as well as optionally the pigment, the acid acceptor or the filler, and thoroughly mixing them. Thereby, a homogeneous fluororubber coating composition is prepared.
In general, a concentration of the fluororubber in the composition is from 10 to 50% by weight.
An amount of the coupling agent is usually from 1 to 50 parts by weight, preferably 1 to 20 parts by weight per 100 parts by weight of the fluororubber.
When the amine compound is optionally used, a total amount of the coupling agent and the amine compound is in the above range. A molar ratio of the coupling agent to the amine compound is from 99:1 to 1:99.
As the acid acceptor, any one that is conventionally used in the crosslinking of the fluororubber can be used. Examples of the acid acceptor are oxides or hydroxides of divalent metals. Specific examples are hydrotalcite, and oxides and hydroxides of magnesium, calcium, zinc and lead.
As the filler, silica, clay, diatomaceous earth. talc, carbon and the like are used.
The fluororubber coating composition of the present invention is coated on a substrate by a conventional method such as brush coating, dip coating and spray coating and then hardened at a temperature from room temperature to 400° C., preferably from 60° C. to 400° C. for a suitable time period to form a desired fluororubber coating film. If necessary, the coated film may be baked at a temperature of, for example, 100°to 300° C.
The fluororubber coating composition of the present invention can be used for surface modification of a gasket of an automobile or motorcycle engine head, various industrial gaskets, parts of copying machines, and other resin or rubber materials.
PREFERRED EMBODIMENTS OF THE INVENTION
The present invention will be illustrated more in detail by following Examples, in which "parts" are by weight.
EXAMPLE 1
Liquids A and B having the following compositions were prepared and mixed.
______________________________________ Parts______________________________________Liquid AFluororubber (G-501, vinylidene fluoride/ 20.8hexafluoropropylene/tetrafluoroethyleneterpolymer)Carbon black 4.1Acid acceptor (DHT-4A, hydrotalcite sold 1.0by Kyowa Chemical Co., Ltd.)Methyl ethyl ketone 73.6Formic acid 0.5Liquid BAminosilane (silane coupling agent A-1100 1.2manufactured by Nippon Unicar Co., Ltd.)Diamine (Epomate F-100 manufactured by 0.3Yuka-Shell Co., Ltd.)n-Butanol 3.5______________________________________
A viscosity of the misture was measured. The result is shown in FIG. 1.
COMPARATIVE EXAMPLE 1
Liquids A and B having the following compositions were prepared and mixed.
______________________________________ Parts______________________________________Liquid AFluororubber (G-501) 20.8Carbon black 4.16Acid acceptor (DHT-4A) 1.04Methyl ethyl ketone 74Liquid BAminosilane (silane coupling agent A-1100) 1.2Diamine (Epomate F-100) 0.3n-Butanol 3.5______________________________________
A viscosity of the mixture was measured. The result is shown in FIG. 1.
EXAMPLE 2
Liquid A consisting of the fluororubber (G-501) (20.8 parts), carbon black (4.16 parts), the acid acceptor (DHT-4A) (1.04 parts), methyl isobutyl ketone (74 parts) and formic acid (0.1, 0.3, 0.5, 0.7 or 0.9 part) was prepared and mixed with the same Liquid B as used in Example 1. Then, a viscosity of the mixture was measured. The results are shown in FIG. 2.
EXAMPLE 3
In the same manner as in Example 2 but using acetic acid in place of formic acid, a mixture was prepared and its viscosity was measured. The results are shown in FIG. 3. | A fluororubber coating composition containing a fluororubber, a liquid medium, a coupling agent, a crosslinking agent and a carboxylic acid, which has a long pot life and provides a coating film having a uniform thickness. | 2 |
FIELD OF THE INVENTION
The present invention relates to an apparatus for sensing fluid flow through a conduit and controlling a load based upon the sensing of the fluid flow. More specifically, the present invention is directed toward a fluid flow sensor and a load control circuit employing a variable time delay to control activation of an alarm circuit in a fire protection system.
BACKGROUND OF THE INVENTION
Numerous control circuits have been designed to apply a voltage or current to an electrical load after a time delay. Examples of such circuits are disclosed in U.S. Pat. No. 3,745,382 to Hoge et al., U.S. Pat. No. 3,597,632 to Vandemore, and U. S. Pat. No. 3,764,832 to Stettner. However, these and other known control circuits are relatively complicated and have numerous components, thus increasing manufacturing difficulty and costs. Further, these and other known control circuits typically provide relatively lengthy time delays, on the order of five minutes, and are unreliable when needed to be reduced to a lesser amount of time.
Control circuits are used in a variety of applications including, for example, to activate an alarm circuit in a fire protection system. Conventional fire protection systems typically include a source of water or other fire-extinguishing fluid, a detector for detecting the flow of the fire extinguishing fluid through a pipe or conduit, and an alarm circuit or other load that is activated when a sufficient flow is detected.
In such systems, the alarm is preferably not activated immediately upon detection of fluid flow in the conduit, because flow may occur due to a “water hammer” or fluid backwash within the system. If the alarm were activated immediately upon detection of a water flow, a large number of false alarms would result.
In order to reduce or eliminate such false alarms, a control circuit can delay the activation of the alarm for a predetermined time following detection of an alarm condition. Early detection and control circuits included simple mechanical devices, such as dashpots in which air was forced into and out of a chamber. The alarm would not sound until the air was completely out of the chamber, at which time a switch would close to activate the alarm.
These and other conventional detection mechanisms were designed to provide a delay in the range of 30 seconds to 90 seconds. However, these devices were unreliable and inaccurate, and were thus unsuccessful in eliminating false alarms. Accordingly, solid state electrical load control circuits were developed for fire protection systems such as the time delay circuit known as ICM/HMKS-W1104. These electrical load control circuits delay activation of the alarm until an electrical sensor or switch is rendered conductive.
It would be desirable to provide a relatively simple, reliable, and easy-to-install sensor circuit with minimal current draw, in order to detect a condition (such as fluid flow) which requires activation of a load such as an alarm. While certain flow sensing devices are known, such as those described in U.S. Pat. No. 3,749,864 to Tice, U.S. Pat. No. 4,791,254 to Polverari and U.S. Pat. Nos. 5,086,273 and 5,140,263 to Leon, these and other similar devices include relatively complex arrangements of moving parts. In addition, it would also be desirable to provide an accurate load control circuit which delays activation of a load by using an integrated circuit.
SUMMARY OF THE INVENTION
The present invention solves the foregoing problems, and provides additional advantages, by providing an apparatus for sensing fluid flow through a fluid-carrying conduit. According to exemplary embodiments of the present invention, a valve such as a flapper valve disposed within the conduit is provided with a magnetic shield. A magnet is located on one side of the magnetic shield while a sensor, associated with the valve is located on the opposite side of the magnetic shield. The valve, and hence the magnetic shield, moves to permit fluid flow. When the magnetic shield is removed from between the magnet and sensor, the magnet activates the sensor. Thus the sensor, which can be a Hall effect sensor, generates a signal when the valve is opened to permit fluid flow.
According to one aspect of the present invention, the sensor and magnet can both be encased in a tube sealed with substantially watertight material and inserted into the conduit (e.g., by threading the encased sensor through a threaded pipe opening) near the valve.
In another exemplary embodiment of the present invention, a load control circuit includes a supply terminal for receiving a supply voltage and a detector which detects a condition requiring the operation of a load. The detector causes a threshold voltage to be generated from the supply voltage, and a time delay controller controls the time required to generate the threshold voltage. A DIAC or equivalent element conducts to generate a first trigger signal once the threshold voltage is achieved, and a silicon-controlled rectifier (SCR) generates a second trigger signal in response to the first trigger signal. The load control circuit includes an opto-TRIAC and a TRIAC or similar switches which are rendered conductive by the second trigger signal to cause a voltage to be provided to the load. According to an alternate embodiment of the present invention, multiple electrically isolated loads can also be controlled.
If the supply voltage is an AC (alternating current) voltage, the load control circuit also includes a rectifying diode or equivalent element for converting the AC voltage to a DC (direct current) voltage. The time delay controller may include a potentiometer (variable resistor) to vary the delay time required to generate the threshold voltage. Additionally, the time delay controller can be implemented via a digital implementation. When digitally employed, a dip switch is used in combination with a digital control to vary the amount of time delay from zero to ninety seconds.
For implementation in a fire protection system in accordance with the present invention, the detector may be a magnet operated reed switch, or a Hall effect sensor, for detecting a threshold fluid flow in a conduit and the load is an alarm for indicating the threshold flow in the pipe.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the present invention will be more fully understood upon reading the following Detailed Description of the Preferred Embodiments in conjunction with the accompanying drawings, in which like reference indicia indicate like elements, and in which:
FIG. 1 illustrates a block diagram of the sensor circuit and load control circuit in accordance with an exemplary embodiment of the present invention;
FIG. 2 illustrates a schematic diagram showing an exemplary implementation of a fluid flow sensor of the present invention;
FIGS. 3A and 3B illustrate schematic diagrams of the fluid flow sensor and the magnetic shield in accordance with an exemplary embodiment of the present invention;
FIG. 4 illustrates a schematic diagram of a reed switch in accordance with an exemplary embodiment of the present invention;
FIG. 5 illustrates a circuit diagram illustrating the load control circuit in accordance with an exemplary embodiment of the present invention;
FIG. 6 illustrates a circuit diagram of the load control circuit with multiple loads in accordance with an exemplary embodiment of the present invention;
FIG. 7 illustrates a circuit diagram of the load control circuit implementing a digital time delay implementation in accordance with an exemplary embodiment of the present invention; and
FIG. 8 illustrates a schematic diagram of a fire protection system in which the circuit of the present invention may be implemented.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, an exemplary embodiment of an alarm circuit according to the present invention is shown. A sensor circuit 10 is implemented in a fire protection circuit. The fire protection circuit also includes a load control circuit 14 which further comprises a delay circuit for controlling the activation of a load such as an alarm circuit in a fire protection system. In such a system, the flow of water or other fire suppression fluid through the pipes of a building sprinkler system (to prevent or minimize fire damage) is detected, causing a switch to close and apply an operating voltage to the alarm circuit after a time delay to guard against false alarms.
According to the invention, sensor circuit 10 is connected as shown between a neutral wire 12 , an input of a load control circuit 14 , and a terminal 16 of a load L (e.g., an alarm, which can be embodied by one or more lights, sirens, motors, solenoids, or other loads) which is connected between a power input terminal 18 and the load control circuit 14 . The power input terminal receives an input voltage of, for example, 24-130 volts A.C. The sensor circuit 10 senses fluid flow through a pipe, and when fluid flow is sensed, the sensor circuit 10 generates an output signal and supplies this signal to the load control circuit 14 . The load control circuit 14 then operates to apply the supply voltage across the terminals 12 and 18 , thereby applying the supply voltage to the load 16 and activating the alarm. The sensor circuit 10 can be implemented using a Hall effect sensor or other suitable sensor such as a reed switch, as will be described in more detail with respect to FIGS. 2-4 below. It will be appreciated that the time delay circuit is useful for preventing false alarms.
Fluid flow can be sensed by the use of a sensor, (e.g. Hall effect sensor), a magnetic shield, and a magnet used in combination. The particular Hall effect sensor discussed above is approximately {fraction (3/16)}″×{fraction (3/16)}″×{fraction (1/16)}″, and the magnet can have a ¼″ diameter and a thickness of ⅛″. Due to the relatively small size of both the Hall Effect sensor and the magnet, each element can be inserted into a threaded tube (made of, e.g., plastic), and the tubes can be covered with epoxy or some other suitable material to provide a substantially watertight seal for the contents of the tubes. Each of the threaded tubes can then be rotated into the fluid-carrying conduit through a threaded orifice in the conduit such that the end of each tube, one containing the sensor and one containing the magnet are located in close (e.g., within approximately ⅛″) proximity to each other. Alternatively, the tubes need not be threaded. The tubes containing the sensing device and magnet can be lowered down through holes to ensure that they are correctly positioned, and tightened through the use of a nut or rubber gasket.
FIG. 2 illustrates a (not to scale) view of a tube 47 inserted into a pipe defined by pipe wall 40 , and having a check valve with a hinged clapper 42 . The pipe contains a fluid flowing in the direction indicated by the flow arrow. Threaded tubes 46 and 47 (shown in FIG. 3A) are inserted into similarly-threaded holes in pipe wall 40 and this connection is sealed by a suitable seal 46 . The tube 47 includes a Hall Effect sensor 44 and is encased in a suitable substantially water-tight material. Tube 46 (not shown in FIG. 2) includes the magnet 45 which is encased in a suitable substantially water-tight material. Hinged clapper 42 is provided with sealing portions 48 a which cooperate with corresponding portions 48 b of the pipe 40 when the clapper is in a closed position. Magnetic shield 50 is attached to the hinged clapper 42 so that the magnet is prevented from actuating the Hall Effect sensor 44 when there is no flow of water through a valve. As shown in FIGS. 2 and 3A, the magnetic shield 50 is located between the encased magnet 45 and Hall Effect sensor 44 . While the magnetic shield 50 can be made of any material that is able to shield the magnetic field of the magnet from the sensor, it is advantageous for the material to be composed of approximately 3 percent Nickel Iron to prevent oxidation of the shield.
As illustrated in FIG. 3B, when there is substantially no fluid flow in the pipe, hinged clapper valve 42 is in a closed position as its associated magnetic shield 50 is positioned between the encased Hall Effect 44 sensor and the magnet 45 to substantially neutralize the magnet 45 . When there is fluid flow within the pipe, the flapper valve 42 is moved in the direction of the flow arrow shown in FIG. 2, and the magnetic shield 50 is moved away from the Hall effect sensor 44 and magnet 45 , thereby freeing the magnet to bias the sensor such that the sensor conducts to enable the operation of the sensor circuit 10 and load control circuit 14 . The remainder of the sensor circuit 10 can consist of three additional components (such as a zener diode, a capacitor and resistor) which act as a power supply to the Hall effect sensor. These elements are described in detail in commonly assigned application Ser. No. 09/001,216, incorporated herein by reference. Additionally, the sensor circuit 10 can also include an indicator circuit also described in detail in the above-mentioned commonly assigned application.
It should be appreciated that the sensor of the sensor circuit 10 illustrated in FIG. 1 can alternatively be embodied by a reed switch associated with a magnet such that motion of the valve or other indication of fluid flow causes the reed switch to close, thereby supplying an input to the time delay circuit 14 . The reed switch is set up within the valve in the same manner as described above with respect to the Hall effect sensor. However, the manner in which the switch is activated differs slightly. As illustrated in FIG. 4, a reed switch 60 encased in tube 47 , in this embodiment, can be biased in an “on” (conductive) state by its associated magnet 45 encased in tube 46 . The reed switch 60 , as is known within the art, consists of two electrodes maintained within a glass tube. When a magnet is close to the reed switch 60 , the magnet attracts the reed switch electrodes to contact and thus provide a closed circuit. As illustrated in FIG. 4, the reed switch magnet 45 is substantially neutralized by the use of the magnetic shield 50 when the valve is in a closed (no fluid flow) state. When the magnetic shield 50 is removed from the reed switch, the magnet 45 causes the reed switch 60 to close thereby providing power to the sensor circuit 10 and load circuit 14 . This alternative has the advantage of lower cost and a reduced number of parts when compared to employing the Hall effect sensor.
It should also be appreciated that the sensor circuit 10 of the present invention can also be implemented using a push-button or pressure switch, such as in commonly used to provide interior lighting control for example, a refrigerator or automobile door. In such an embodiment, the closed clapper of the valve exerts pressure on the pressure-sensitive switch to indicate an open condition (that is, would provide no output to the delay circuit). When the valve is opened, indicating fluid flow through the pipe, the pressure exerted by the clapper on the pressure switch is reduced or eliminated and would indicate a closed condition (that is, would provide an indicator signal to the delay circuits). It should also be appreciated that alternative conventions of the reed switch can be used (i.e., the sensor switch can be a normally open or normally closed).
Referring to FIG. 5, according to another embodiment of the present invention load control circuit 14 is shown in detail. The load control circuit includes a neutral terminal 12 connected to ground and a supply terminal 18 connected to a standard A.C. power source of between 30 and 120 volts at 60 Hz. A load 70 is connected to the supply terminal 18 to receive the supply voltage. The load control circuit 14 is connected between the load 70 and the neutral terminal 12 to selectively connect the load between the supply terminal 18 and the neutral terminal 12 . In this embodiment, it is assumed that the load 70 draws a maximum of 6 amps; it will be readily appreciated that the circuit may be readily modified to accommodate loads having a current draw greater than 6 amps. The load control circuit 14 includes a switch 75 , a diode 80 , and a first capacitance 85 connected in series between the load 70 and the neutral terminal 12 . In a preferred embodiment, the diode 80 is a 1N4005 diode, and the first capacitance 85 is a 33 micro farad (MFD) capacitor rated at 160 volts D.C. (VDC). It will be appreciated that other suitable diodes and other suitable charge storing elements may be used for diode 80 and first capacitance 85 , respectively.
The first capacitor 85 is connected in parallel to a resistance 87 . A second capacitance 105 and a time delay setting circuit 90 are connected in series, in a circuit path that is in parallel with resistance 87 and in parallel with first capacitance 85 . Resistance 87 functions to discharge capacitance 85 when operation of the load control circuit is completed. Resistance 87 can be a fixed 10 kilo ohm (kΩ) resistor rated for 2 watt (W) or other suitable resistor. The second capacitance 105 may be a 47 MFD capacitor rated at 50 VDC or other suitable charge storing element.
Time delay circuit 90 includes two paths. The first path includes diode 97 while the second path includes a potentiometer 95 . The potentiometer 95 functions to adjustably control the charging rate of capacitor 105 to delay activation of the load 70 .
The time delay circuit 90 further includes a DIAC 110 . The DIAC 110 is preferably an MBS 4991 DIAC having a trigger voltage of 10 volts, though any suitable triggering element may be used. As will be appreciated by those skilled in the art, a DIAC (DIode AC switch) is a bidirectional diode which may be rendered conductive when a “breakover” or “trigger” voltage is exceeded in either direction by an applied voltage or trigger spike. Suitable DIACs are available from numerous suppliers, including Motorola Corporation.
The DIAC 110 is connected to a gate 120 a of a silicon controlled rectifier (SCR) 120 through a resistance 115 . The resistance 115 may be a fixed 690Ω resistor rated for 0.5 watts or other suitable resistance element. SCR 120 is preferably an EC103B SCR, available from numerous manufacturers, including the Teccor Corporation of Dallas, Tex. The anode 120 b of the SCR 120 is connected to the cathode of the second capacitor 105 , resistance 87 , and between the cathode of first capacitance 85 and the cathode of the diode 80 . The cathode 120 c of the SCR 120 is connected to pin 2 of an MOC3020 opto-TRIAC 125 . As a result, light emitting diode 127 connected between pins 1 and 2 of opto-TRIAC 125 is caused to emit light thereby exciting optical triac 129 connected between pins 4 and 6 of opto-TRIAC 125 . Pin 1 of the light emitting diode is connected via resistor 140 to neutral line 12 . Once optical triac 129 is excited, a trigger pulse is provided to the gate of triac 130 . The pulse is supplied via the load 70 in series with resistor 135 . Triac 130 then turns on the load 70 . Resistor 135 can be a fixed 100 ohm resistor or other suitable resistance element.
As will be appreciated by those skilled in the art, a silicon controlled rectifier (SCR) is rendered conductive when a proper signal is applied to its gate. The SCR remains conductive when the gate signal is removed, and is turned off by removing the anode voltage, reducing the anode voltage below the cathode voltage, or making the anode voltage negative, as on the alternate half-cycles of an A.C. power source. A TRIAC (TRIode AC switch) is a gate-controlled bidirectional thyristor or SCR which is rendered conductive in both directions when a proper signal is applied to its gate. TRIAC 130 is preferably a Q4006L4 TRIAC available from numerous suppliers including Teccor Corporation.
The load control circuit of FIG. 5 may be used, for example, in a fire suppression system. In such an arrangement, the switch 75 may be a Hall effect transistor in combination with a power supply circuit as described above or a magnet operated reed switch on a vane type water flow detector as discussed above with respect to FIG. 4, and the load 70 may be an alarm circuit which causes bells, horns, lights, etc., to be activated in response to a threshold fluid flow in a conduit with a reed switch. It will be appreciated that the circuit of the present invention may be used in connection with other types of switches or detectors and/or with other types of loads. Suitable reed switches are available from numerous suppliers, including the C. P. Clare Corporation of Chicago, Ill. and the Hammlin Corporation of Lake Mills, Wis.
Using the example of a fire suppression system, the operation of the load control circuit 14 of the present invention will now be described. When water or fire extinguishing fluid starts to flow through the pipes of a sprinkler system in a building to prevent fire damage, a small permanent magnet as described above is enabled to activate switch 75 to cause closure.
The closing of the switch 75 contacts applies the supply voltage potential to the rectifying diode 80 . In the embodiment of FIG. 1, the supply voltage is between 24 and 120 volts A.C. (alternating current).
The diode 80 rectifies the alternating current to provide a half wave rectified current equivalent to a D.C. (direct current) voltage which rapidly charges capacitance 85 to a voltage of about 160 volts D.C. (based on an input voltage of 120 volts A.C.). Diode 80 and capacitance 85 thus have the effect of converting the A.C. voltage source into a D.C. power source. It will be appreciated that if a D.C. power source with correct polarity is used, a rectifying function does not need to be performed, and the diode 80 is therefore unnecessary. In this case, the closing of the switch causes capacitance 85 to be rapidly charged directly by the power source.
The charge stored by capacitance 85 slowly charges the second capacitance 105 through potentiometer 95 and resistance 100 . It will be appreciated that an RC circuit is formed by second capacitance 105 , potentiometer 95 , and fixed resistor 100 , and that the RC time constant and thus the charge time of capacitance 105 may be adjusted by potentiometer 95 . According to one embodiment of the present invention, potentiometer 95 is a trim pot and allows the delay time of time delay circuit 90 to be adjustable between about zero seconds and approximately 90 seconds. A dial or other input device (such as a screw head slot, not shown) connected to the potentiometer 95 may be used to adjust the resistance and thus the time delay. Diode 93 discharges capacitor 105 when power is removed.
If not for the presence of DIAC 110 , capacitance 105 would be charged to approximately 170 volts (based on a 120 volt A.C. supply voltage). However, when the charge stored in second capacitor 105 reaches 10 volts D.C., the break over voltage of DIAC 110 is achieved, causing DIAC 110 to conduct and generate a first trigger signal. The first trigger signal is supplied to gate 120 a of SCR 120 through the resistor 115 which causes SCR 120 to conduct and generate a second trigger signal.
The SCR 120 renders a negative pulse on pin 2 of opto-TRIAC 125 . The current through LED 127 thereby renders optical triac 129 conductive. When optical triac 129 is conductive, AC voltage is supplied to the TRIAC 130 . The TRIAC 130 is rendered conductive in response to A.C. voltage generated by the closure of the optical triac 129 . When the TRIAC 130 turns on, the A.C. voltage drop across the load control circuit 14 is only about 6 volts. The signal applied to the gate of TRIAC 130 is phase controlled such that TRIAC 130 is only about 95-98% conductive. If the TRIAC were 70% conductive, the voltage drop across the TRIAC would be greater than 6 volts, and the power supplied to the load would be reduced. If the voltage drop across the TRIAC is less than about 6 volts, the TRIAC may oscillate between conductive and non-conductive states, thus impairing operation of the load control circuit. It will be appreciated that the actual voltage drop across the TRIAC is approximately 6*(1/{square root over (2)}) which equals approximately 4 volts RMS.
Because of the low voltage drop across the TRIAC, the load 70 receives a voltage substantially equal to the supply voltage potential received at terminals 12 and 18 . If the supply voltage is 120 volts A.C., the load receives approximately 114 volts A.C., which is more than sufficient to operate horns, lights, motors, solenoids or any other component in the fire alarm circuit.
When the water or fire extinguishing fluid stops flowing, the switch opens and the capacitors 85 and 105 are discharged to ground. Capacitance 85 discharges through resistor 87 and neutral terminal 12 , and capacitance 105 discharges through diode 97 and neutral terminal 12 . It will be appreciated that other suitable elements may instead be used to allow the capacitances 85 and 105 to discharge. If capacitances 85 and 105 are not provided with an effective discharge path, any remaining charge stored on the capacitances will cause the delay time to be varied during a later operation of the circuit. Once capacitances 85 and 105 are discharged, the circuit is reset and ready for another load control operation.
Referring now to FIG. 6, an alternate time delay circuit according to the present invention is shown. In the embodiment of FIG. 6, a voltage supply may be selectively applied after a time delay to a second load. The circuit includes a first circuit having substantially the same arrangement of components as in the embodiment of FIG. 5 connected between a first input terminal 18 and a first neutral line 12 , and also includes a second circuit 150 connected between second load 155 located on input terminal 154 and second neutral line 152 . Second circuit 150 includes opto-TRIAC 160 , second TRIAC 165 , and resistance 170 , which is connected as shown. Second load 155 is connected to receive a second voltage supply via input terminal 154 . In operation, once SCR 120 is rendered conductive in the manner described above, the charge stored by first capacitance 85 is discharged to provide a negative pulse to pin 2 of opto-TRIAC 160 . As a result of the discharge of first capacitance 85 , light-emitting diode (LED) 175 , connected as shown between pins 1 and 2 of opto-TRIAC 160 , is caused to emit light. The output of pin 1 of opto triac 160 is provided to pin 2 of opto TRIAC 125 as shown in FIG. 5 . Thus light emitting diodes 127 and 175 are in series thereby causing each optical TRIAC 129 and 180 between pins pins 4 and 5 of opto-TRIACs 125 and 160 , to conduct. The conduction of optical TRIACs 129 and 180 causes trigger pulses to be provided to the gates 130 g and 165 g of TRIACs 130 and 165 , thereby rendering the TRIACs 130 and 165 simultaneously conductive and causing power to be applied to both the first and second load 70 and 155 . Resistances 170 is a current-limiting resistor to limit the current applied to gate 165 g of second TRIAC 165 .
It will be appreciated that the first and second circuits in the time delay circuit of FIG. 6 are electrically isolated from one another, and therefore enable the time delay circuit to reliably control the operation of two loads. Because the first and second circuits are electrically isolated, the voltage sources connected to input terminals 18 and 154 may provide the same or different supply voltages. Alternatively, first and second neutral lines 12 and 152 may be the same neutral line. Further, input terminals 18 and 154 may be connected to the same voltage source.
Preferably, the supply voltages provided on input terminals 18 and 154 are between approximately 24 and approximately 120 volts A.C., and first and second loads 70 and 155 draw a current of no more than approximately 6 amps. Opto-TRIAC 160 can be a 3047 opto-TRIAC available from numerous suppliers, and second TRIAC 165 can be a Q4006L4 TRIAC available from numerous suppliers. Resistance 170 can be implemented by a 100Ω resistor. It will be appreciated that other suitable components can be used.
Further, it will also be appreciated that the addition of the second circuit 150 may require changes in the component values of the first circuit. In the embodiment of the circuit of FIG. 6, first capacitance 85 is a 33 microfarad capacitor rated for 160 volts D.C. Further, in the embodiment of FIG. 6, resistance 87 is preferably a 10 kΩ resistor rated for 2 watts. Additionally, capacitor 105 would be changed to a 2200 MFD capacitor rated at 16 VDC. Other component values remain the same. It will be appreciated that other suitable component values or components can be used for the time delay circuit of FIG. 6 . It will further be appreciated that operation of more than two electrically isolated loads can be controlled according to a circuit of the type shown in FIG. 2 .
In yet another exemplary embodiment of the present invention, the time delay circuit 90 employed within the load control circuits illustrated in FIGS. 5 and 6 can be implemented digitally. As illustrated in the FIG. 7 embodiment which shows a load control circuit controlling two loads, when the switch 75 is closed, AC voltage is applied to diode 80 . The diode 80 changes the alternating current to direct current and charges the capacitor 85 . The capacitor in combination with a 1N965A zener diode 205 and resistor 210 form a power supply for a programmable digital IC timer 215 . The time delay can be adjusted by use of a dip switch 220 . The dip switch 220 can comprise any multiple pole dip switch which can be set so that a wanted time delay will elapse. Also, resistance 225 and capacitance 230 on the output of the dip switch 220 and connected to the neutral node 12 , form an oscillator circuit used with IC timers. The dip switch 220 adjustably controls timing the delay in the activation of load 70 in a range from 1 to 90 seconds. Upon timeout of the delay, a trigger signal is sent to SCR 120 via resistance 115 from digital IC timer 215 . As described above, the SCR 120 receives the trigger signal and provides a path for the voltage stored in the capacitor 85 to the opto-TRIACs 125 and 160 . The opto-triac conducts AC current in both directions providing power to the load. When the valve closes, the timer 215 immediately is reset and ready to initiate another time delay upon actuation of the switch again. With the implementation of the digital control the values of capacitor 85 would be changed to a 50 MF capacitor rated at 160 VDC while the resistance would optimally be a 3 Kilo-ohm resistor rated at 2 Watts or suitable resistance component. Additionally capacitor 227 is a 0.1 Micro-Farad capacitor while resistor 225 is optimally a 27 Kilo-ohm resistor or appropriate resistance element. All remaining elements within the multiple load control circuit remain the same values discussed with respect to FIG. 6 .
The digital timer, illustrated in FIG. 7 with multiple loads, would also be able to be implemented in a load control circuit containing a single load, illustrated with analog timing in FIG. 5 . Of course, the elements would need to be modified (to the values described with respect to FIG. 5) in order to ensure proper operation.
Referring now to FIG. 8, a fire suppression system including a load control circuit 14 according to the present invention is shown. When sufficient water flow through pipe 300 is detected by switch 75 , the switch closes the load control circuit 14 and causes a load, e.g., an alarm or warning light, to be turned on after a desired time delay. The time delay reduces false alarms by avoiding registration of an alarm condition which might occur due to back flow or other temporary movement of water in the pipe. The delay period is selectable by the user or manufacturer as described above to accommodate a given fire protection system. Of course, the time delay control circuit according to the present invention may be used in other applications using household or industrial current and voltage levels. For instance, the switch 75 could detect any of a number of conditions, such as gas flow, temperature (with a thermal switch), the open or closed state of an enclosure or movement of another physical object, to name but a few.
The foregoing description, while including many specificities, is intended to be illustrative of the general nature of the invention and not limiting. It will be appreciated that those skilled in the art can, by applying current knowledge, readily modify and/or adapt the specific embodiments described above for various applications without departing from the spirit and scope of the invention, as defined by the appended claims and their legal equivalents. | A circuit and apparatus for magnetically sensing fluid flow and applying voltage to a load. A valve disposed within a conduit is provided with a magnetic shield. A magnet is located on one side of the magnetic shield while a sensor, associated with the valve is located on the opposite side of the magnetic shield. The valve, and hence the magnetic shield, moves to permit fluid flow. When the magnetic shield moves due to fluid flow, the magnet activates the sensor. A load control circuit includes a supply terminal for receiving a supply voltage and a detector which detects a condition requiring the operation of a load. The detector causes a threshold voltage to be generated from the supply voltage, and a time delay controller controls the time required to generate the threshold voltage. A DIAC or equivalent element conducts to generate a first trigger signal once the threshold voltage is achieved, and a silicon-controlled rectifier (SCR) generates a second trigger signal in response to the first trigger signal. The circuit includes an opto-TRIAC and triac which are rendered conductive by the second trigger signal to cause a voltage to be provided to the load. | 8 |
BACKGROUND OF THE INVENTION
This invention is directed to a portable electrical mechanical toy wherein the operator of the toy guides a small object, for example a race car, over a path created by a plurality of endless belts having collision obstacles on the surface of the endless belts. The path which the object must traverse is a continuously variable path because the number of and the location of the obstacles on the endless belts is such that, as the belts move, the position of any two collision obstacles in respect to one another is variable. Through a combination of the control of the speed of the belts and direction of rotation of the belts, the operator of the toy can steer or drive the object through a pathway that does not result in the collision of the object with any of the obstacles.
Presently there are two general types of mechanical apparatuses wherein an object is driven over or through a course which is painted or otherwise constructed on the surface of an endless belt. The first type of these apparatuses are used as training devices for teaching the handling and/or manipulation of an automobile or an airplane through or across a roadway or flight path which is formed on the surface of or projected from an endless belt or filmstrip mounted in the apparatus. The second class of these apparatuses is very similar to the first but is principally directed to "penny arcade" type amusement devices which require the operator of the apparatus to drive, fly or otherwise manipulate an object such as a race car or airplane through a pathway created by an endless belt or filmstrip and can include counting devices and/or penalty devices for accumulating and/or substracting scoring points. Said scoring points reflecting the ability of the operator to successfully manipulate the object across the path and/or avoid obstacles.
Both of the two types of mechanical apparatuses, however, require large consoles and/or other supports and as such are expensive to produce and maintain and their use is limited to fixed training areas or amusement centers.
There is an additional class of games that has recently become available which utilize control modules in conjunction with television sets or other cathode ray tubes. While the modules of these games are portable, the total game itself is not in that it requires the use of the television or cathode ray tube to augment the module. Further because these devices incorporate sophisticated electronics they are also expensive.
For the devices which depend solely upon mechanically based tracks or paths as opposed to sophisticated electronically generated paths, the path is normally created by an endless belt, a disc or a repeating filmstrip. Because of the space limitation of storing an endless belt or filmstrip coupled with the direct manufacturing costs associated with each particular increment of length of said belt or filmstrip, the belt or filmstrip can only be of a limited length and as such can only contain a particular finite variation of pathway on the surface of the endless belt or filmstrip. The operator of such devices is thus able to quickly memorize the pattern of these endless belts or filmstrips and thus after only a few times of operating the device, the device no longer becomes challenging to the operator and interest in the device quickly subsides.
It is considered that games utilizing endless belts have a very definite recreation value, however, in view of the above inherent properties of the prior art devices including large physical size, easily memorized travel paths, and manufacturing expenses it is considered that there exists a need for small portable raceway toys which present a variable raceway or obstacle path which must be traversed. Further these toys must be economical to manufacture, durable during repeated use and capable of maintaining the interest of a large variety of age ranges of users.
BRIEF SUMMARY OF THE INVENTION
It is an object of this invention to provide a toy having a continuously variable raceway or obstacle course and an obstacle which traverses said course in response to commands by the operator of the toy. It is a further object of this invention to provide such a toy having the above characteristics but being small and portable and inexpensive to manufacture. Additionally it is an object to provide a toy which has a continuously variable raceway and thus maintains the interest of the user for extended periods of time.
These and other objects, as will be evident in the remainder of this specification, are achieved by providing an electrical mechanical toy having a base, a drive motor mounted on said base, a drive diverter means operatively connected to said drive motor, at least one endless belt, said endless belt having a substantially continuous surface, an endless belt mounting means attached to said base, said endless belt mounted on said endless belt mounting means such that said endless belt is capable of continuously traveling about said endless belt mounting means, said drive diverter means operatively connected to said endless belt driving said endless belt about said endless belt mounting means, at least one obstacle means on the surface of said endless belt, an object member slidably mounted on said base and including an object, said object positioned over the surface of said endless belt such that said object slides back and forth over the surface of said endless belt transversely to the direction of travel of said endless belt, said object having at least one interference position with said obstacle on said endless belt, a detecting means capable of detecting when said object is in said interference position, said detecting means connected to said drive diverter means such that said detecting means causes said drive diverter means to discontinue driving said endless belt when said object is in said interference position with said obstacle, reset means for reconnecting said drive diverter means to said endless belt and restarting said drive diverter means driving said endless belt about said endless belt mounting means.
The toy can further be provided with a signaling means which is operatively connected to the detecting means and emits a signal when said object and said obstacle are in said interference position. Further the toy can be provided with a counter means for evaluating the performance of the operator of the toy such as counting the amount of orbits or laps of the endless belt and this counter can be further coupled with a timing means which allows the toy to be operated for a unit length of time and allows the operator to test his skill by accumulating as many laps on the counter means as possible within the specific unit of time.
Normally the toy will include three endless belts, a left endless, a right endless and a center endless belt. Both the left and the right endless belts each having obstacle means thereon. Preferably each having a different number of obstacle means such that as the left and right endless belts move with respect to the object, the different number of obstacle means on the left and right endless belts present a continuously variable array of obstacles which must be traversed by the object. The left and right endless belts can move both forward and backward and each independently at different speeds, the center endless belt moves independently of both the left and right endless belts and connected to the lap counter for counting the progress of the object through the obstacles on the surface of the right and left endless belts.
BRIEF DESCRIPTION OF THE FIGURES
This invention will be best understood when taken in conjunction with the drawings wherein:
FIG. 1 shows an oblique view of the toy of the invention as it is used by an operator.
FIG. 2 is a top plan view of the toy shown in FIG. 1 with the top housing removed.
FIG. 3 is a top plan view in partial section similar to FIG. 2 except that certain of the components have been removed to show other components which lie beneath them.
FIG. 4 is a side elevational view in partial section of a portion of the invention about the line 4--4 shown in FIG. 3.
FIG. 5 is a top view about the line 5--5 of the portion of the invention shown in FIG. 4.
FIG. 6 is a side elevational view in partial section of a portion of the invention about the line 6--6 of FIG. 3.
FIG. 7 is a rear elevational view in partial section of a portion of the invention about the line 7--7 of FIG. 2.
FIG. 8 is a rear elevational view in section of a portion of the invention about the line 8--8 shown in FIG. 2.
FIG. 9 is a side elevational view in partial section of a portion of the invention taken about the line 9--9 of FIG. 2.
FIG. 10 is a side elevational view in partial section of that portion of the invention shown in FIG. 5.
FIG. 11 is the same view as FIG. 10 with the exception that certain components of the invention are shown in a different spacial relationship to one another.
FIG. 12 is a top plan view of essentially the same area shown in FIG. 5 except that certain components are shown in a different spacial relationship in respect to one another.
FIG. 13 is a side elevational view in partial section of a portion of the invention taken about the line 13--13 of FIG. 2.
FIG. 14 is a side elevational view in partial section of a portion of the invention taken about the line 14--14 of FIG. 2.
FIG. 15 is the same view as FIG. 14 except that certain components of the invention are shown in a different spacial relationship in respect to one another.
FIG. 16 is a side elevational view in partial section of a portion of the invention taken about the line 16--16 of FIG. 3.
FIG. 17 is a rear elevational view in partial section about the line 17--17 of FIG. 16.
FIG. 18 is a circuit diagram for the electrical components of the invention including a diagramatic representation of several of the components of the invention.
The electrical mechanical toy shown in this specification and in the drawings utilizes certain operative principles or concepts which are set forth and defined in the appended claims which form a part of this specification. Those skilled in the art to which this specification pertains will realize that these concepts and/or principles can be applied to a number of differently appearing and differently constructed embodiments. For this reason the invention is not to be construed as limited to the precise embodiment indicated but is to be construed in light of the claims.
DETAILED DESCRIPTION
In the figures there is shown a toy 20 having a base housing 22 and an upper housing 24 which are joined together forming a case for the toy. Centered in the upper housing 24 is a view window 26 through which can be seen an object 28 which is generally depicted as the top view of a formula style racing car. Also seen through the view window 26 are two obstacles collectively identified by the numeral 30 and which are also in the form of the top view of formula style racing cars. Both the object 28 and the obstacles 30 will be outlined in greater detail below. It is the object of the game to drive the object 28 on a path such that the object 28 does not crash into, i.e. assume an interference position with, the obstacles 30. In FIG. 1 it can be seen that object 28 has crashed into the rear end of the obstacle 30 on the left side.
A control or steering wheel 32 is connected to the object 28 as will be hereinafter described and is used to move the object 28 back and forth across the width of the viewing window 26 so that the object 28 can avoid the obstacles 30. The obstacles 30 are on the surface of endless belts (which will be numbered and described hereinafter) and which cause the obstacles 30 to travel in a path parallel to the dotted line 34 shown through viewing window 26. Dotted line 34 represents the painted dashed line which is commonly used to separate two lanes of a roadway.
The game is started by pushing down the start-reset button 36 which causes the obstacles 30 to move as hereinafter described. A transmission shifting lever 38 governs the speed and the direction of the obstacles 30 as hereinafter described. A timer 40 is operatively connected to the start-reset button 36 as hereinafter described and allows the toy to run for a preset time period once the start-reset button 36 is pushed. During this period of time the skill of the operator of the toy is measured by the number of laps which can be accumulated on the lap counter 42 as hereinafter described.
Referring now to FIGS. 2 and 3, FIG. 2 generally depicts the internal mechanisms of the toy 20 as seen by removing the upper housing 24 from the base housing 22. These two housings are maintained together in the completed toy 20 by four screws (not shown) which pass through the underside of base housing 22 through four bosses collectively identified by the numeral 44 which are located near the four corners of the base housing 22. The screws screw into holes (not shown) in the upper housing 24 corresponding to the bosses 44 in the base housing 22. FIG. 3 shows the same view as FIG. 2 except certain overlaying components have been removed to show details of some of the underlying components. Within the base housing 22 is a battery pack 46 which is accessible from the underneath side of base housing 22 and which contains batteries (not shown) used to supply power to operate the toy.
A motor-timer cover plate 48 attaches to the base housing 22 by four screws collectively identified by the numeral 50. A transmission cover plate 52 attaches to the base housing 22 by a plurality of screws, collectively identified by the numeral 54, one of which is shown in FIG. 2, Mounted on the transmission cover plate 52 is a shifting member 56. Shifting member 56 is maintained on a boss 58 projecting from the surface of transmission cover plate 52 by a broad headed screw 60. The transmission-shifting lever 38 is integrally formed with and forms part of shifting member 56. On the opposite end of shifting member 56 are two opposed detent dogs collectively identified by the numeral 62. The detent dogs 62 fit into a rack 64 formed on the surface of transmission cover plate 52. The rack 64 has two opposed sets of four indents 65 each of said indents 65 defining a transmission position as is hereinafter described. Shifting member 56 has a cutout channel 66 which slides along boss 58 as the shifting member 56 is slid from one gear position to another.
The timer 40 includes a timer disc 68 having a timer hand 70 integrally formed on the surface thereof. The timer disc 68 and timer hand 70 are exposed through the surface of upper housing 24 when this housing is attached to base housing 22. This allows the operator of the game to read how much elapsed time has transpired since the operation of the game was started.
Object 28 is integrally formed with a clear plastic object supporting member 72 which in turn is attached to object supporting member base 74. This base includes a gear rack 76 which meshes with gear pinion 78. As hereinafter described, in response to rotation of steering wheel 32, gear pinion 78 engages gear rack 76 causing object supporting member base 74 to slide back and forth within base housing 22.
Three endless belts, left side belt 80, center belt 82 and right side belt 84 are mounted around a front belt spindle 86 and a rear belt spindle 88. Painted on the surface of both the right side belt 84 and the left side belt 80 are obstacles 30. All three belts 80, 82 and 84 continuously orbit around the front and rear belt spindles 86 and 88. Preferably one of the left or right side belts 80 or 84 will have two obstacles 30 painted on the surface thereof spaced on opposite points on the belt and the other of the left or right side belts 80 or 84 will have three obstacles 30 symmetrically spaced about its surface. Thus for each complete revolution on one of the belts, two obstacles will pass a particular point, such as the point directly beneath the object 28, and for each complete revolution of the other belt, three obstacles will pass this same point. This fact coupled with both the direction of rotation of the endless belts, i.e. the obstacles either move forward or backward, and the speed of the endless belts about the font and rear belt spindles 86 and 88, results in a variety of combinations of the obstacles on the left side belt 80 in respect to the obstacles on the right side belt 84, making it necessary for the operator of the toy to shift gears (as hereinafter described) in order to avoid interference of the object 28 with the obstacles 30.
The object 28 slides back and forth slightly above the surface of endless belts 80, 82 and 84. When viewed from the top, since the object support member 72 is clear plastic, the obstacles 30 can be seen beneath the object support member 72 allowing for visual overlap of the object 28 with the obstacles 30. When this visual overlap occurs, other components of the invention, as hereinafter described, are also caused to interact and a crash between the object 28 and the obstacle 30 occurs. In response to this crash, the motion of the belts cease and both a visual and an audio signal is given.
The center belt 82 has a dotted line 34 printed on its surface and when the center belt 82 is in motion this dotted line appears through view window 26 as a dividing line in a roadway. The lap counter 42 is connected to center belt 82, as hereinafter described, and each time the center belt 82 completes one full revolution or orbit around front and rear spindles 86 and 88, respectively, it is counted as one lap.
The start-reset button 36 which was shown in FIG. 1 fits into reset button housing 90 in base housing 22. Three electrical contacts 92, 94 and 96, respectively, are positioned within the reset button housing 90 and as shown in FIG. 13 contact 96 normally fits against contact 94 allowing for completion of an electrical circuit through the two contacts. When start-reset button 36 is depressed, as shown in phantom in FIG. 13, the electrical circuit between 94 and 96 is broken and a new electrical circuit between contacts 96 and 92 is formed. Start-reset button 36 (see FIG. 13) has an extension 98 which projects in the direction away from the contacts 92, 94 and 96. Normally extension 98 rests upon arm 100 of penalty reset member 102. When the start-reset button 36 is depressed, extension 98 assumes the position shown in phantom in FIG. 13. Further details of the electrical circuit associated with the penalty reset member 102 are given hereinafter.
Spaced in between front belt spindle 86 and rear belt spindle 88 and within the interior of the loop described by the endless belts 80, 82 and 84 is a flasher light housing 104 which is seen in top view in FIG. 3 and in side view in FIG. 9. This housing contains a light bulb (not shown) which lights up during a crash between the object 28 and an obstacle 30. Attached to object support member base 74 is electrical slide contact 106 which is wired to contact 94. Positioned underneath rear belt spindle 88 is left stationary contact 108 and right stationary contact 110. These contacts are placed such that slide contact 106 completes an electrical circuit through either left stationary contact 108 (as depicted in FIG. 3) or right stationary contact 110. The left stationary contact 108 and right stationary contact 110 are positioned in respect to one another such that slide contact 106 is at all times in contact with one or the other of the contacts 108 or 110.
Endless belts 80 and 84 both contain cutout portions, collectively identified by the numeral 112, extending through their surfaces. Referring to FIG. 9, it can be seen that when object 28 is overlaying an obstacle 30, a cutout portion 112 is positioned on the bottom side of the loop of left belt 80 proximal to rear spindle 88 and light housing 104. Positioned underneath light housing 104 between base housing 22 and the bottom of continuous belts 80 and 84 is a transverse electrical contact 114 which extends continuously across the width of all of the belts 80, 82 and 84. Integrally formed with left side stationary contact 108 is left spring contact 116. Integrally formed with right side stationary contact 110 is right spring contact 118. Referring to FIG. 9, it can be seen that the left spring contact 116 is biased in an upward direction and normally rests against the surface of left side belt 80. In a similar manner, right spring contact 118 rests against the surface of right side belt 84.
When any of the obstacles 30 are in a position such that if the object 28 were directly over one of them an interference position between the object 28 and that particular obstacle 30 is created. When this happens, the cutout portion 112 corresponding to the particular obstacle 30 is positioned such that either the left or right spring contact 116 or 118, depending whether the particular obstacle 30 is on the left or right side belt 80 or 84, passes upward into the cutout portion 112 in the respective belt. In so doing it contacts the transverse contact 114 theoretically completing an electrical circuit. This electrical circuit, however, can be only completed when the slide contact 106 is on the same respective, left or right side as is the particular obstacle 30 and as such is in contact with the left or right stationary contact 108 or 110 to which the respective spring contact 116 or 118 is connected to.
Motor timer cover plate 48 and transmission cover plate 52 are fixed by screws to motor and gear support housing 120 which fits within base housing 22. Housing 120 contains appropriate drillings and cutouts and together with other drillings and cutouts in motor timer cover plate 48 and transmission cover plate 52 a plurality of gear shafts and other components are supported within the housing 120. In the interest of brevity these drillings and cutouts will not be individually identified and numbered, it being deemed sufficient simply to state that the gear shafts and other components are appropriately supported or fixed in these housings and covers. A small electrical motor 122 is mounted in appropriate cutouts in housing 120 and contains a small pinion 124 on motor shaft 126.
The drive train for the timer 40 and the belts 80, 82 and 84 is shown in FIGS. 3, 4, 5 and 6. A shaft 128 is fitted with a crown gear 130 which has a pinion 132 integrally formed on its upper face. To transfer motion to the timer a spur gear 134 meshes with pinion 132 and transfers the motion of the motor 122 along shaft 136 to worm gear 138. A small spur gear 140 attached to shaft 142 meshes with worm gear 138 and transfers the motion along shaft 142 to worm gear 144 which in turn transfers the motion to gear 146 having both a spur and a pinion integrally formed thereon. Gear 146 then drives timer gear 148. Timer gear 148 has a metal contact disc 150 fixedly attached to its surface. The function of this disc will be described hereinafter. The shaft 152 to which timer gear 148 is fixedly attached contains a small slot 154. The bottom (not shown) of timer disc 68 contains a boss having a key which fits into slot 154 and maintains timer disc 68 in a fixed position with respect to shaft 152. A three lobed cam 156 is also attached to shaft 142 the function of which will described hereinafter.
Referring back to the belt drive, second pinion 158 is fixed near the bottom of shaft 128. A circular disc 160 having an upstanding bearing extension integrally formed therewith (not separately numbered) fits around shaft 128 in between crown gear 130 and pinion 158. Disc 160 is not attached to shaft 128 but is free wheeling thereon. Projecting from the underside near the edge thereof of disc 160 is an axle 162. A pinion 164 slips over axle 162 and is free to spin about axle 162. Pinion 164 meshes with pinion 158. Two ratchet teeth, upper ratchet tooth 166 and lower ratchet tooth 168, extend tangentially from the circumference of disc 160. A pawl 170, attached to an arm 172 which in turn is attached to a hinge member 174, interacts with the upper and lower ratchet teeth 166 and 168. The hinge member 174 contains an iron plate 176 on its surface and is biased about hinge pin 175 by spring 178 away from a solenoid 180. A stop 182 (see FIG. 10) is so placed such that an arm 172 rests against the bottom surface of stop 182 in response to movement of the hinge member 174 away from solenoid 180 in reaction to spring 178. In this position pawl 170 interacts with upper ratchet tooth 176 maintaining disc 160 in the position shown in FIG. 5 which places and holds axle 162 and pinion 164 against spur gear 184. In this position the rotary motion of motor 122 is transferred via pinions 158 and 164 to spur gear 184.
When solenoid 180 is energized, as hereinafter described, hinge member 174, by virtue of its having iron surface 176 attached to it which is magnetically attracted to energized solenoid 180, swings about hinge pin 175 causing arm 172 to move in a downward direction which releases pawl 170 from upper ratchet tooth 166. By virtue of the gearing described, shaft 128 is turning in a counterclockwise direction in response to rotation of motor shaft 126. The inertia of this counterclockwise spin causes disc 160 to momentarily also spin in a counterclockwise motion until pinion 164 comes in contact with gear rack 186 and engages with gear rack 186. Pinion 164 then is carried around rack 186 by the motion imparted to pinion 164 by pinion 158.
Under the influence of solenoid 180 arm 172 is held in its downward position and as soon as pinion 164 has traveled the length of rack 186 in a counterclockwise direction inertia continues to carry disc 160 in this counterclockwise direction until bottom ratchet tooth 168 engages pawl 170 which stops disc 160 in the position shown in FIG. 12. During this sequence of events it is noted that the motion of motor 122 is not transferred to spur gear 184. When pinion 164 is in the position shown in FIG. 12 and maintained therein by interaction between ratchet tooth 168 and pawl 170, pinion 164 interacts with a noise emitting clicker extension 188. Thus as pinion 164 rotates against clicker 188 the teeth of pinion 168 strike against the end of clicker 188 causing clicker 188 to emit a high pitched whine. Further discussion of the function of clicker 188 will be presented hereinafter.
When disc 160 is in the position shown in FIG. 5, i.e. upper ratchet tooth 166 is retained by pawl 170, motion of motor 122 is transferred to spur gear 184. Integrally attached to spur gear 184 is pinion 190. Transfer of motion to the endless belts 80, 82 and 84 via pinion 190 will be described in reference to FIGS. 3 and 6. A compound gear 192, having one set of crown teeth 194 on the bottom thereof, a set of spur teeth 196 around the circumference thereof, an outside set of crown teeth 198 and an inside set of crown teeth 200 on the upper surface thereof, interacts with pinion 190 via spur gear teeth 196. A shaft 202 having pinions 204 and 206 fixed on the respective ends thereof is driven by the interaction of pinion 204 with bottom crown teeth 194. A second compound gear 208 has a set of crown teeth 210 on its bottom surface and three sets, an outer 212, a middle 214 and an inner 216 set of crown teeth, on its upper surface. Compound gear 208 is rotated by interaction of bottom crown teeth 208 with pinion 206. Thus the motion of pinion 190 is also transferred to compound gear 208.
A shaft 218 having identical thrust bearings 220 and 222 attached proximal to the ends thereof, is fitted with four gears which are slid onto shaft 218 and are free to rotate about this shaft. Because of the fixed position of thrust bearings 220 and 222 on shaft 218 and placement of this shaft in housing 120 as hereinafter described, shaft 218 can slide back and forth in housing 120 within the limits defined by the placement of thrust bearings 220 and 222. The first of the four gears on shaft 218 is gear 224. It has a set of pinion teeth 226 and a set of long pinion teeth 228. The pinion teeth 226 fit up against thrust bearing 220. On the long pinion end of gear 224 is a short extension 230 having two identical notches 232 on opposite sides thereof. The second of the four gears on shaft 218 is a pinion 234 having only four teeth. An extension 236 of this gear has two ears 238 on the opposite sides thereof which fit into notches 232 and communicate any motion of gear 224 to gear 234. The third gear 240 on shaft 218 is identical to gear 224 in that it has a set of pinion teeth 242 and a set of long pinion teeth 244, however, it is oriented on shaft 218 such that the long pinion teeth 244 are directed toward gear 234. The fourth gear 246 on shaft 218 also has a set of pinion teeth 248 and a set of long pinion teeth 250 and it is positioned on shaft 218 such that long pinion teeth 250 are proximal to thrust bearing 222. In between the pinion teeth 248 and 242 on gears 244 and 240, respectively, is a thrust bearing 252. A shifting fork 254 is integrally formed with and extends from shifting member 56 and transfers the motion of shifting member 56 to shaft 218. Because gears 224, 234, 240 and 246 are maintained on shaft 218 between thrust bearings 220 and 222, these gears in respect to housing 120 slide as shaft 218 slides in housing 120 and their position with respect to housing 120 corresponds to the position of shift member 56 with respect to cover plate 52 on housing 120.
As seen in FIG. 3 a crown gear 256 meshes with long pinion teeth 228 and transfers motion along shaft 258 to pinion 260. Pinion 260 engages with spur gear 262 which transfers motion along shaft 264 to pinion 266. Pinion 266 engages with spur gear 268 which drives right side endless belt 84 as hereinafter described. Crown gear 270 engages with long pinion teeth 244. Additionally depending upon the position of shaft 218 and consequently the position of gear 234 crown gear 270 also engages with gear 234, however, even when engaged with gear 234 it still maintains its engagement with long pinion teeth 244. Motion of crown gear 270 is transferred by shaft 272 to pinion gear 274 which in turn transfers motion to spur gear 276 attached to shaft 278. Pinion gear 280 also attached to shaft 278 transfers motion to spur gear 282 which is attached to shaft 284. Shaft 284 is placed inside of the endless belts 80, 82 and 84 and conveys the rotary motion of spur gear 282 to spur gear 286. Spur gear 286 drives spur gear 288 via intermediate pinion 290. The motion of spur gear 288 is transferred to the left side belt 80 as hereinafter described. Crown gear 290 meshes with long pinion teeth 250 and transfers motion via shaft 294 to pinion 296. Pinion 296 meshes with spur gear 298 which transfers motion to center belt 82 as hereinafter described.
Front belt spindle 86 is appropriately mounted in base housing 22 by a central shaft 300 as seen in FIG. 8. Front belt spindle 86 is made up of three components the exact details of which are not necessary to the understanding of this specification and thus are not herein described in the interest of brevity, it being sufficient to note that there is a right side belt front spool 302, a center belt front spool 304 and a left side belt front spool 306 which all are capable of independently rotating about shaft 300. Integrally formed with right side belt front spool 302 is spur gear 268. Integrally formed with left side belt front spool 306 is spur gear 288. Integrally formed on right front spool 302 are right side belt drive teeth 308. Integrally formed on left side belt front spool 306 are left side belt drive teeth 310. Right and left side drive teeth 308 and 310 respectively mesh with appropriate holes collectively numbered as 312 and 314 on the right and left side belts 84 and 80 respectively as shown in FIG. 2 and transfer the motion from spur gears 268 and 288 to the right and left side belts 84 and 80 respectively.
As seen in FIG. 7 rear spindle 88 is appropriately mounted in base housing 22 by a central shaft 316. Fixed to and causing rotation thereof of rear shaft 316 is spur gear 298. On the other end of shaft 316 is a pinion gear 318 which rotates in respect to rotation of spur gear 298. Spur gear 298 is attached to a central housing 320 which is also fixed to shaft 316 and rotates in respect to shaft 316. A center rear spool 322 is keyed via key 324 to central housing 320 and thus also rotates in respect to spur gear 298. A plurality of center belt drive teeth 326 are integrally formed with rear center spool 322. These teeth 326 mesh with holes 328 as seen in FIG. 2 and drive center belt 82 in respect to rotation of spur gear 298. Right rear spool 330 and left rear spool 332 are both mounted about central housing 320 such that they are freewheeling and independent of the motion of the central housing 320. This allows right side belt 84 and left side belt 80 to freely turn about rear belt spindle 88 in response to their movement about the front belt spindle 86 previously described.
Referring back to FIG. 1, printed on upper housing 24 next to the transmission shifting lever 38 are the numerals N, 1, 2 and 3. These numerals are meant to represent the corresponding analogous gears found in a race car. In practice of the invention, the speed and the direction of the belts 80, 82 and 84 are governed by the interaction of appropriate gears. The three belts 80, 82 and 84 move in respect to one another differently, depending on what gear, i.e. position, the shifting lever is in. As was previously noted, transmission shifting lever 38 is connected to shift member 56 and on the underside of shift member 56 is shifting fork 254 which fits over thrust bearing 252. Motion of transmission shift lever 38 is therefore directly transferred to shaft 218 by interaction of shift fork 254 with thrust bearing 252.
For the purpose of describing the interaction of drive gears of the toy 20, the section of any gear closest to journal 334 will be described as the front side section of the gear and the portion of the gear closest to journal 336 will be described as the backside section of the gear. When any of the belts 80, 82 or 84 moves such that its direction when viewed through view window 26 is from the steering wheel 32 of toy 20 toward the timer 40 end of toy 20, the belt is deemed to be moving in a forward direction and when the belt moves in the opposite direction it is deemed to be moving backward.
When shifting lever 38 is in the position corresponding to the letter N (neutral) printed on the upper housing 24, shaft 218 is positioned relative to journals 334 and 336 such that thrust bearing 220 is immediately adjacent to journal 334. Pinion 226 interacts on the front side (i.e. the side toward pinion 190) of crown gear teeth 200 of compound gear 192. In response to this the right side belt 84 moves forward. Pinion teeth 242 of gear 240 mesh with middle upper crown teeth 214 of compound gear 208 which in turn drive the left side belt 80 forward. Pinion teeth 248 of gear 246 are positioned directly over the center of compound gear 208 and thus do not interact with any of the gear teeth on compound gear 208. As such center belt 82 remains stationary.
When transmission shifting lever 38 is moved into the position opposite the numeral 1 (first gear) shaft 218 is shifted a first increment back from journal 334, positioning pinion teeth 226 of gear 224 in the center of compound gear 192. As such gear 224 does not move and the right side belt 84 remains stationary. In this position pinion teeth 242 of gear 240 interact on the forward side of innercrown gear teeth 216 of compound gear 208 which causes the left side belt 80 to move forward, however, at a speed slower than it moves relative to the speed of the moving when the transmission shift lever 38 was in neutral. Pinion teeth 248 of gear 246 mesh with the backside of inner crown teeth 216 of compound gear 208 resulting in center belt 82 moving backward.
When the transmission shifting lever 238 is moved to the 2 (second gear) position shaft 218 is shifted a second increment back from journal 234 and pinion teeth 226 of gear 224 now mesh with the backside of inner upper crown teeth 200 of compound gear 192 resulting in right side belt 84 moving in a backward direction. Pinion teeth 248 of gear 240 are now placed in the center of compound gear 208 and as such are not rotated by compound gear 208. However, in this position pinion 234 meshes with crown gear 270 and as such because pinion 234 is rotated by gear 224 via ear 238 and notches 232, crown gear 270 is also rotated by gear 224 meshing with compound gear 192. This results in the left side belt 80 moving in a backward direction. Pinion teeth 248 of gear 246 mesh on the backside of middle upper crown teeth 214 of compound gear 208. This causes the center belt 82 to move backward, however, since the middle crown teeth 214 are of a larger diameter than inner crown teeth 216 on compound gear 208 the speed of the center belt, when transmission shifting lever is in second gear, is faster than when it is in first gear.
When transmission shifting lever 38 is moved such that it corresponds to the numeral 3 (third gear) shaft 218 is moved the final increment back and thrust bearing 222 is now flush against journal 336. In this position pinion teeth 226 of gear 224 mesh with outer upper crown teeth 198 on the backside of compound gear 192. This results in right side belt 84 maintaining its rearward direction but increasing its speed compared to the second gear position. Pinion 234 is moved so it no longer meshes with crown gear 270 and as such does not influence the speed of left side belt 80. The speed of left side belt 80 is not controlled by pinion teeth 242 of gear 240 meshing with inner crown teeth 216 on the backside of compound gear 208. As a result left side belt 80 continues moving backward, however, its speed is faster than it was when it was in second gear. Pinion teeth 248 of gear 246 now mesh with outer crown teeth 212 on the backside of compound gear 208 resulting in center belt 82 maintaining its backward direction, however, its speed is greater than it was in second gear.
Referring to the lap counter 42 in the lower left hand portion of FIG. 2 and in part to FIG. 7 a gear support member 338 has a bearing section 340 which is freely mounted on shaft 316 and thus does not move in respect to rotation of shaft 316. A second bearing section 342 supports an axle 344 having a spur gear 346 on one end thereof and a pinion 348 proximal to the other end. Spur gear 346 meshes with pinion 318 which is fixed to shaft 316 as before noted. Thus spur gear 346 is rotated in respect to movement of shaft 316 which in turn corresponds to movement of center belt 82. This movement is transferred via axle 244 to pinion 348. The movement of center belt 82 is thus transferred to the lap counter 42 by pinion 348.
Spur gears 350 and 352 are appropriately mounted on an axle 354 which is in turn mounted on lap counter housing 356. Lap counter housing 356 is attached to base housing 22 by a screw (not numbered). Spur gear 352 is slightly larger than spur gear 350 and contains two cutout portions collectively identified by the numeral 358 which are slightly larger than pinion 348. As can be seen in FIG. 14 this allows pinion 348 to fit into one or the other of the cutout portions 358 in spur gear 352 and mesh with spur gear 350. Normally pinion 348 will rest within one of the cutouts 358 and contact spur gear 350.
The lap counter 42 contains a unit wheel 360 and a tens wheel 362. Each of these wheels are numbered around their circumference from zero to nine allowing for counting of from zero to ninety-nine laps. On the right side of unit wheel 360 are spur gear teeth 364, similarly on the right side of tens gear wheel 362 are spur gear teeth 366. Spur gear 350 meshes with spur gear teeth 364 on unit wheel 360 as seen in FIG. 2. Motion from unit wheel 360 is transferred to tens wheel 362 by the interaction of spur gear 368 which is mounted on axle 370 which in turn is mounted in the bottom-most portion of lap counter housing 356. In FIG. 17 on the left side of unit wheel 360 is a short rack of gear teeth 372. Spur gear 368 is always in contact with spur gear teeth 366 on tens wheel 362. When unit wheel 360 turns normally there is no interaction with unit wheel 360 and spur gear 368; however, when rack 372 approaches spur gear 368 it contacts spur gear 368 and meshes with it for one tenth of a revolution of unit wheel 360. This can be seen in FIG. 16. When rack 372 meshes with spur gear 368 the rotary motion of unit wheel 360 is transferred to tens wheel 362 and causes tens wheel 362 to advance one tenth of a revolution. This causes the lap counter to successfully count one through nine on the unit wheel and then advances the tens wheel one digit to count from ten to nineteen before advancing the tens wheel a second digit to count from twenty to twenty-nine and so on.
Unit wheel 360 and tens wheel 362 along with knurled knob 374 are mounted on axle 376 within lap counter housing 356. Axle 376 further extends from lap counter housing 356 to reset button housing 90 and supports penalty reset member 102. Knurled knob 374 has a slotted boss 378 extending toward tens wheel 362 and an indented boss 380 on the other side. Tens wheel 362 contains a key 382 which fits into slotted boss 378 and fixedly attaches knurled knob 374 with respect to rotation of tens wheel 362. A flexible arm 384 extends from lap counter housing 356 and has a detent ear 386 on its end. Detent ear 386 meshes with indent boss 380 as seen in FIG. 16 by fitting into any one of ten detents 388 symmetrically spaced about indent boss 380. As the tens wheel 362 is rotated the detent ear 386 tends to retain tens wheel 382 in any one of these positions which serves to center the particular numeral on the tens wheel which is visible on the lap counter 42 showing through upper housing 24.
In order to reset both the unit wheel 360 and the tens wheel 362 back to zero at the conclusion of using the toy, as seen in FIG. 16 the interior of the unit wheel 360 acts as a ratchet in that it has one ratchet tooth opening 390. This ratchet tooth opening 390 interacts with pawl 392 which is attached to pawl holding member 394 which fits around bearing 396 of tens wheel 362. Normally during counting the units wheel 360, as shown in FIG. 16, would spin in a clockwise direction and pawl 392 would not interact with the ratchet tooth opening 390. When resetting the lap counter 42 to zero the tens wheel 362 is turned clockwise via knurled knob 374 which projects through upper housing 24 and pawl 392 catches in ratchet tooth opening 390 causing the motion of the tens wheel to be transmitted to the units wheel. The ratchet tooth opening 390 and a pin 398 are positioned such that the pawl 392 slips into ratchet tooth opening 390 when the numeral zero on the tens wheel lines up with the numeral zero on the units wheel.
After a crash, as hereinafter described, reset button 36 must be depressed in order to restart any or all of the belts 80, 82 and 84 which are stopped because of the crash. As seen in FIG. 13 extension 98 on reset button 36 meshes with arm 100 on penalty reset member 102. Penalty reset member 102 swivels about axle 376. On the end of penalty reset member 102 near lap counter 42 is an extension 400. This extension can be seen in FIGS. 2 and 15 and as shown in FIG. 15 the extension fits under and is capable of lifting axle 344. This in turn swivels gear support member 338 about bearing section 340 on shaft 316. The result is pinion 348 is lifted clear of spur gear 350. This position is shown in FIG. 15. When in this position lap counter 42 is no longer connected to center belt 82 and ceases to accumulate laps in respect to movment of center belt 82.
Positioned on spur gear 352 adjacent to cutout portions 358 are two ratchet teeth collectively identified by the numeral 402. As seen in FIG. 15 the ratchet teeth 402 are positioned on the backward side of cutout portions 358 when spur gear 352 is rotating counterclockwise. On the bottom part of extension 400 is a ratchet tooth 404 which projects toward spur gear wheel 352. When reset button 36 is depressed along with lifting axle 344 the ratchet tooth 404 on extension 400 interacts with one of the ratchet teeth 402 urging this ratchet tooth upward causing spur gear 352 to rotate through several degrees in a counterclockwise direction. This causes cutout portion 358 to no longer be positioned directly in line with pinion 348 and when the reset button 36 is released extension 400 moves in a downward direction which lowers gear support member 358. A spring not shown in the figure but which attaches to the bottom of gear support member 338 and to base 22 is responsible for biasing member 338 toward base 22.
Because spur gear 352 is of a larger diameter than spur gear 350 and because cutout portions 358 are no longer in position to receive pinion 348, pinion 348 meshes with spur gear 352. Rotation of pinion 354 in respect to movement of center belt 82 is now transferred to spur gear 352 instead of spur gear 350. As a result lap counter 42 is not rotated as long as pinion 348 is not allowed to mesh with spur gear 350. Spur gear 352 turns about axle 354 for approximately 180 degrees at which time the other cutout portion 358 approaches pinion 348 and when this other cutout portion 348 is directly underneath pinion 348 pinion 348 descends through the other cutout portion 358 until it once again contacts spur gear 350 and restarts drive of lap counter 42. The net result is that whenever reset button 36 is depressed lap counter 42 is disengaged from center belt 82 for the increment of time necessary to rotate spur gear 352 through approximately 180 degrees. Since the object of the game is to accumulate as many laps as possible, the operator of the toy is penalized each time the operator pushes the start/reset button 36.
As noted previously, object 28 is moved sideways across the surface of belts 80, 82 and 84 in response to movement of steering wheel 32. As shown in FIG. 9 steering wheel 32 projects above upper housing 24. Immediately below upper housing 24 is a circular member 406 which is attached to a steering column 408. Steering wheel 32 is retained against circular member 406 by a screw (not shown) through the center of steering wheel 32. Since circular member 406 is attached to column 408, column 408 rotates in response to rotation of circular member 406. At the bottom of column 408 is a second circular member 410 which is also fixed to column 408 and rotates in response to rotation of column 408. Pinion 78 is mounted on column 408 but is free to rotate independently of column 408. In between pinion 78 and circular member 406 is a spring 412. Spring 412 is under slight compression which causes pinion 78 to frictionally fit against second circular member 410. As a result pinion 78 will normally rotate in response to rotation of second circular member 410, thus object 28 can be moved in response to steering wheel 42. If pinion 78 is at either end of rack 76, such as that shown in FIG. 2 wherein pinion 78 is at the extreme right side of rack 76, pinion 78 will no longer be free to rotate in one or the other of either a clockwise or a counterclockwise direction (in FIG. 2 pinion can no longer be rotated counterclockwise, however it can be rotated clockwise). In such a case continued movement of steering wheel 32 in the restricted direction is no longer transferred to pinion 78. By virtue of spring 412 there is a built-in frictional clutch between pinion 78 and circular member 410.
Base housing 22 contains an upstanding boss 414 which serves as a bearing for second circular member 410. Base housing 22 additionally has a rib 416 traversing across its bottom surface 418 which serves as a guide for groove 420 in object supporting member base 74. Object supporting member base 74 includes a second groove 422 which fits over upstanding boss 424 integrally formed with base 22. Object supporting member base 74 is retained on base housing 22 by a broadheaded screw 426 which screws into upstanding boss 424.
It was previously noted that timer gear 148 has a metal contact disc 150 attached to its surface. Two electrical contacts 428 and 430 respectively extend over the metal contact disc 150. One of these contacts, contact 428 is longer than the other contact 430. In the surface of metal contact disc 150 is a small cutout portion 432 which exposes a portion of the nonconducting surface of timer gear 148. As timer gear 148 turns this cutout portion 432 also turns. Contact 428 meets with and makes electrical contact with contact disc 150 near the center of contact disc 150 such that contact 428 is always in electrical contact with metal disc 150 and is not in any way effected by cutout portion 432. The shorter contact 430, however, makes contact with metal contact disc 150 near the outer edge thereof. When the timer is positioned as shown in FIG. 3, however, electrical contact between contact 430 and disc 150 is broken because cutout portion 432 now lies directly underneath the contact point of contact 430 with disc 150. This in effect breaks an electrical circuit as hereinafter described between contact 428, metal contact disc 150 and contact 430.
The position represented in FIG. 3 is the off position of the toy. When the start-reset button 36 is depressed motor 122 is energized and as previously described motion of motor 122 is transferred to timing gear 148. This causes timing gear 148 and metal contact disc 150 attached to its surface, to rotate. After rotating a few degrees the cutout portion 432 on metal contact disc 150 is no longer directly beneath contact 430 and contact 430 now contacts the surface of metal contact disc 150. This completes an electrical circuit which includes motor 122 and continues driving motor 122 independent of start-reset button 36. Motor 122 continues to rotate via this circuit until the cutout portion 432 in metal contact disc 150 has made a complete circle and again becomes positioned underneath contact 430. When this happens the circuit driving motor 122 is broken and motor 122 ceases to rotate. The time period for the cutout portion 432 to complete a full rotation is the time period allotted to the operator of the toy to accumulate as many laps as possible.
A second electrical switch similar to the timing switch just described is incorporated on the surface of disc 160. This second switch is illustrated in FIGS. 4, 5 and 12 and it serves as a bypass or alternate connection to maintain current through the "crash" electrical circuit as hereinafter described. A metal electrical contact disc 434 is attached to the surface of disc 160. Two electrical contact arms 436 and 438 extend over the surface of contact disc 434. Contact disc 434 contains a cutout portion 440 extending through a portion of the outside surface of contact disc 434 equal to approximately 90 degrees which exposes a portion of the nonconducting surface of disc 160. The two contact arms 436 and 438 are of unequal length such that contact arm 436 extends toward the center of contact disc 434 beyond the cutout portion 440 and make continuous electrical contact with contact disc 434. Contact arm 438, however, is shorter than contact arm 436 and meets contact disc 434 near its outer edge where cutout portion 440 is located. This results in contact arm 438 alternately completing a circuit between contact arm 436, contact 434 and contact arm 438 as shown in FIG. 12 and breaking this same circuit as shown in FIG. 5.
When the toy is in operation and pinion 164 is in contact with spur gear 184 transferring the rotary motion of motor 122 to the various belts 80, 82 and 84 as previously described, the circuit between contact disc 434 and contact arms 436 and 438 is open. That is it is broken by cutout portion 440. If solenoid 180 is activated resulting in arm 172 releasing upper ratchet tooth 66, disc 160 rotates as previously described. This results in cutout portion 440 of contact disc 434 also rotating allowing contact arm 438 to complete electrical contact through contact disc 434.
A lamp 442 (shown only as an electrical symbol on FIG. 18) is located in light housing 104. Additionally incorporated in the electrical lamp circuit, as hereinafter described, is a flasher switch 444 which alternately opens and closes the electrical circuit. The mechanical components of flasher switch 444 are shown in FIG. 3. An electrical contact 446 is positioned such that it fits against the surface of cam 156. As cam 156 rotates about shaft 152, as previously described, electrical contact 446 alternately makes and breaks electrical contact with a second contact (not shown in the figures) which is positioned adjacent to electrical contact 446 on support housing 448 which is mounted between base housing 22 and motor-timer cover plate 48.
The electrical circuit utilized in the toy 20 is shown in FIG. 18. In describing this circuit in relationship to the mechanical components previously described, in order to facilitate understanding of the circuit and operation of the toy, wherever appropriate the components used in the circuit will be identified by the numerals used to describe their mechanical equivalents followed by a ' (prime). Further the circuit diagram shown in FIG. 18 will generally be followed in a clockwise direction around the individual electrical circuits which together form the composite electrical circuit of the toy 20.
A first circuit or normal operation mode circuit 450 contains the start-reset button 36' wired in parallel with timer 40' and together these two components 36' and 40' are wired in series with a motor 122' and a battery pack 46'. To activate the toy start-reset button 36' is depressed connecting contact 96' with contact 92' which completes the circuit to motor 122'. The mechanical linkage between the motor 122' and the timer 40', as hereinafore described, is depicted by dotted line 452. This activates timer 40' and when disc 150' has rotated such that contact 430' is free of cutout portion 432' and completes the circuit between contact 428', disc 150' and contact 430', the circuit to the motor 122' is now completed through timer 40' and start-reset button 36' can then be released.
The endless belts are then caused to rotate by motor 122 as previously described and the operator of the toy by using a combination of changing the position of the object 28 alternately back and forth over the left and right side belts by turning steering wheel 32 and by changing the speed and direction of the belts through the use of the transmission lever 38 tries to avoid overlap of the object 28 with any of the obstacles 30.
A second circuit or crash circuit 454 contains the object obstacle interference sensor detecting switches 456 wired in parallel with the bypass or diverter switch 458. These two are then wired in series with the start-reset button 36', solenoid 180' and the battery pack 46'. Circuit 454 also contains light 442 wired in series with flasher switch 444 and together lamp 442 and switch 444 are wired in parallel with solenoid 180'.
The object obstacle interference detection switch 456 consists of contacts 106', 108', 110', 116' and 118'. The bypass of diverter switch 458 consists of disc 434' and contacts 436' and 438'. This switch 458 is mechanically and magnetically connected or linked as depicted by dotted line 460 to solenoid 180. The dotted line 460 thus represents upper and lower ratchet teeth 166, 168, and 172, pawl 170 and metal plate 176 and the other interrelated mechanical parts previously described.
As the toy is operating, contact 106' continually shifts back and forth between contacts 108' and 110' as the operator shifts the object 28 from over the surface of the left side belt 80 to the surface of the right side belt 84 by use of steering wheel 32. Further as both the left side belt 80 and the right side belt 84 rotate about the respective front and back spindles 86 and 88 contacts 116' and 118' continually open and close as the obstacles 30 and their corresponding cutouts 112 allow contact between spring contact 116 and 118 with transverse contact 114.
If the operator makes a mistake and allows the object 28 to assume an interference position with an obstacle 30 either contact 106' will close simultaneously with 108' when contact 116' closes with 114' or contact 106' will close simultaneously with 110' when contact 118' closes with contact 114'. In either case the electrical circuit through the object obstacle interference detection switches 456 will be closed and solenoid 180' will be energized. Flasher switch 444 which is alternately opening and closing in response to the rotation of cam 56 alternately opens and closes a circuit between switch 456, lamp 442 and battery pack 46'. This causes lamp 442 to flash on and off. Solenoid 180' via linkage 460 causes disc 434' to rotate until contact 438' is no longer insulated by cutout portion 440' and a circuit is completed through contact 438', disc 434' and contact 436'. Disc 160 continues rotating until it is stopped by lower ratchet teeth 168 which holds pinion 164 against clicker extension 88. This causes the toy to emit a noise which in conjunction with the flashing of lamp 442 indicates to the operator of the toy 20 that he has "crashed".
Assuming that a crash occured because of contact between contact 106' with contact 108' and contact 116' with contact 114', once this crash occurs and drive diverter 458 is activated, the operator cannot cancel the crash by simply breaking contact between contact 106' with contact 108' by moving the object 28 to the other belt. Because the circuit through solenoid 180' is now completed through the alternate circuit through diverter switch 458 the position of contact 106 with 108 or 110 no longer governs the operation of solenoid 180', lamp 442 and pinion 164. The only way the operator can restore normal operation is by depressing the start-reset button 36' therein breaking the second circuit and as previously noted this automatically deactivates the lap counter 42 for an increment of time penalizing the operator for the crash. | An electrical mechanical toy has a housing including a base. A small electrical drive motor is mounted on the base and a drive diverter-transmission operatively connects to the drive motor. Also attached to the base is an endless belt mounting member having at least one endless belt mounted thereon such that the endless belt is capable of continuously traveling or orbiting about the mounting member. The drive diverter-transmission is connected to the endless belt such that the endless belt is driven by the drive motor about the mounting member. The endless belt includes at least one obstacle on its surface. An object member is slidably mounted on the base and includes an object attached to the object member and positioned proximal to the surface of the endless belt allowing the object to slide transversely to the direction of travel of the endless belt between an interference position with the obstacle on the surface of the endless belt and a non-interference position wherein the object does not interfere with the obstacle. The toy includes a detector which detects when the object is in the interference position with the obstacle and which disconnects the drive diverter-transmission from driving the endless belt when the obstacle is in the interference position. If the drive diverter-transmission is so disconnected a manual reset is actuated to restart movement of the endless belt. | 0 |
FIELD OF THE INVENTION
[0001] This invention relates to receptor tyrosine kinase associated proteins and their uses.
BACKGROUND OF THE INVENTION
[0002] Signal transduction is a fundamental mechanism whereby external stimuli are relayed to the interior of cells. A key aspect of signal transduction involves the reversible phosphorylation of tyrosine residues on proteins. The phosphorylation state of tyrosine residues on a protein is modified through the reciprocal actions of tyrosine kinases (TKs) and tyrosine phosphatases (TPs).
[0003] For example, a variety of polypeptide growth factors and hormones mediate their cellular effects by interacting with cell surface receptors and soluble or cytoplasmic polypeptide containing molecules having tyrosine kinase enzymatic activity (for review, see Williams, et al. Cell 61:203-212 (1990); Carpenter, et al. J. Biol. Chem. 265:7709-7712 (1990)). The interaction of these ligands with their receptors induces a series of events which include receptor dimerization and stimulation of protein tyrosine kinase activity. Tyrosine autophosphorylation on multiple sites creates specific binding sites for target proteins, which bind to the activated receptor with their SH2 domains (for review, see Schlessinger and Ullrich, Neuron 9:383-391, (1992)).
[0004] SH2 (src homology 2) domains are conserved sequences of about 100 amino acids found in cytoplasmic non-receptor tyrosine kinases such as pp60src, PLC-γ, GAP and v-crk (Mayer, et al., Nature 332:272-275 (1988); Pawson, Oncogene 3:491-495 (1988)). While having distinct catalytic domains, all these molecules share conserved SH2 and SH3 (src homology 3) domains and the ability to associate with receptors with tyrosine kinase activity (Anderson, et al. Science 250:979-982 (1990)).
[0005] Tyrosine kinase activation and receptor autophosphorylation are prerequisites for the association between growth factor receptors and SH2 domain-containing proteins (Margolis, et al., Mol. Cell. Biol. 10:435-441- (1990); Kumjian et al., Proc. Natl. Acad. Sci. USA 86:6232-8239 (1989); Kazlauskas, et al., Science 247:1578-1581 (1990)). In particular, the carboxy-terminal (C-terminal) fragment of the epidermal growth factor receptor (EGFR), which contains all the known autophosphorylation sites, binds specifically to the SH2 domains of GAP and PLC-γ (see below). Hence, a major site of association exists between the SH2 domain of these substrate proteins and the tyrosine phosphorylated C-terminal tail of the EGFR.
[0006] Target proteins which bind to activated receptors have been identified by analysis of proteins that co-immunoprecipitate with growth factor receptors, or that bind to receptors attached to-immobilized matrices (Morrison, et al., Cell 58:649-657 (1989); Kazlauskas, et al., EMBO J. 9:3279-3286 (1990)).
[0007] Ohnishi et al. J. Biol. Chem. 271:25569-25574 (1996), not admitted to be prior art, described that a brain specific immunoglobulin-like molecule with tyrosine-based activation motifs, BIT, is associated with protein-tyrosine phosphatase SH-PTP2, whereby two SH2 domains of SH-PTP2 simultaneously interact with two phosphotyrosines of BIT-TAM.
[0008] Phosphotyrosine phosphatases (PTPs) are involved with negative or positive regulation of growth factor-specific cell responses such as mitosis, differentiation, migration, survival, transformation or death. For example, SHP-2 is a phosphotyrosine phosphatase which contains a SH2 domain. SHP-2 is a positive signal transducer for a number of receptor tyrosine kinases (RTKs) and cytokine receptors.
SUMMARY OF THE INVENTION
[0009] Within the scope of this invention, applicant has identified a novel mammalian protein family of at least fifteen members designated SIgnal Regulatory Proteins (SIRPs). In particular, Applicant has cloned and sequenced the coding sequences of 4 members of SIRPs, SIRP1 and SIRP4 from human, and SIRPα1 and SIRPβ1 from mouse. In this regard, the present invention relates to SIRP polypeptides, nucleic acids encoding such polypeptides, cells, tissues and animals containing such polypeptides or nucleic acids, antibodies to such polypeptides or nucleic acids, assays utilizing such polypeptides or nucleic acids, and methods relating to all of the foregoing.
[0010] SIRP family proteins play a general role in the regulation of signals that define diverse physiological and pathological processes. Thus, the present invention provides several agents and methods useful for diagnosing, treating, and preventing various diseases or conditions associated with abnormalities in these pathways as well as assay systems useful for screening for therapeutically effective agents.
[0011] In particular, SIRP polypeptides are involved in various signal transduction pathways such as the negative regulation of signals generated by receptor tyrosine kinases, including, but not limited to, receptors for EGF, insulin and platelet derived growth factor (PDGF). For example, acting like a tumor suppressor, SIRP4 exerts negative regulatory effects on growth factor and hormone induced cellular responses such as DNA synthesis. Oncogenesis may be associated with mutant SIRPs or not enough SIRPs. Restoring SIRPs to their normal levels such as by gene therapy could restore the cells to a normal growth pattern. Insulin receptor activity is also regulated by SIRPS. Overexpression of SIRPs may be involved in type II diabetes where sufficient insulin is present but insulin signaling is deficient. A compound that inhibits the negative regulation of insulin signaling by SIRPs, such as by interfering with the interaction between SIRP and SHP-2 may lead to enhanced insulin signaling.
[0012] All SIRP proteins have a receptor-like, or Immunoglubulin (Ig) like extracellular domain and a transmembrane domain. There are two subtypes of SIRPs distinguished by the presence or absence of a cytoplasmic SHP-2 binding domain. For example, SIRP4 has a cytoplasmic domain while SIRP1 doesn't. The cytoplasmic domain of SIRP4 contains two SHP-2 binding regions each having two tyrosine residues.
[0013] The growth inhibitory effect of SIRP4 depends on phosphorylation of tyrosines and is related to reduced MAP kinase activation. SIRP4 becomes a substrate of activated receptor tyrosine kinases (RTKs) upon EGF, insulin or PDGF stimulation. In its tyrosine phosphorylated form, SIRP4 binds a phosphotyrosine phosphatase, SHP-2, via SH2 interactions. Once SIRP4 binds SHP-2, it activates the catalytic activity of SHP-2 and becomes a substrate of SHP-2. This direct activation of SHP-2 could induce activation of Src or other Src family kinases. The above described interaction allows SIRP4 to participate in major signal transduction pathways involving SHP-2.
[0014] SHP-2 has two SH2 domains and is required for signaling downstream of a variety of RTKs. SHP-2 has been reported to bind directly to RTKs such as PDGF receptor, EGF receptor, and cKit in response to stimulation by their ligands. Insulin receptor substrate 1 (IRS-1) also associates with SHP-2 in response to insulin.
[0015] SIRP4 also binds SHP-1 and Grb2, both of which contain a SH-2 domain. Grb2 is an adapter molecule and one of its functions is to link growth factor receptors to downstream effector proteins. Grb2 is known to bind tyrosine-phosphorylated SHP-2 in response to PDGF stimulation.
[0016] The full length nucleic acid sequences encoding hSIRP1, hSIRP4, mSIRPα1 and mSIRPβ1 proteins are set forth respectively in SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, and SEQ ID NO: 4. The coding regions are nt 41-1237 of SEQ ID NO: 1, nt 13-1524 of SEQ ID NO: 2, nt 59-1597 of SEQ ID NO: 3, and nt 86-1261 of SEQ ID NO: 4.
[0017] The full length amino acid sequences of hSIRP1, hSIRP4, mSIRPα1 and mSIRPβ1 are set forth respectively in SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, and SEQ ID NO: 8. The first two Ig-like domains of hSIRP1 is from aa 54-227; the third Ig-like domain is from aa 250-330; the extracelluar domain next to the membrane is from aa 336-366; and the transmembrane domain is from aa 367-398. The first two Ig-like domains of hSIRP4 is from aa 1-227; the third Ig-like domain is from aa 250-336; the extracelluar domain next to the membrane, the transmembrane domain, and the cytoplasmic domain immediate next to the membrane are from aa 347-407; and the rest of the cytoplasmic domain is from aa 408-503.
[0018] Thus, in a first aspect the invention features an isolated, purified, enriched or recombinant nucleic acid encoding a SIRP polypeptide. Preferably such nucleic acid encodes a mammalian SIRP polypeptide, more preferably it encodes a human SIRP polypeptide.
[0019] By “isolated” in reference to nucleic acid is meant a polymer of 2 (preferably 21, more preferably 39, most preferably 75) or more nucleotides conjugated to each other, including DNA or RNA that is isolated from a-natural source or that is synthesized. The isolated nucleic acid of the present invention is unique in the sense that it is not found in a pure or separated state in nature. Use of the term “isolated” indicates that a naturally occurring sequence has been removed from its normal cellular environment. Thus, the sequence may be in a cell-free solution or placed in a different cellular environment. The term does not imply that the sequence is the only nucleotide chain present, but does indicate that it is the predominate sequence present (at least 10-20% more than any other nucleotide sequence) and is essentially free (about 90-95% pure at least) of non-nucleotide material naturally associated with it. Therefore, the term does not encompass an isolated chromosome encoding one or more SIRP polypeptides.
[0020] By the use of the term “enriched” in reference to nucleic acid is meant that the specific DNA or RNA sequence constitutes a significantly higher fraction (2-5 fold) of the total DNA or RNA present in the cells or solution of interest than in normal or diseased cells or in the cells from which the sequence was taken. This could be caused by a person by preferential reduction in the amount of other DNA or RNA present, or by a preferential increase in the amount of the specific DNA or RNA sequence, or by a combination of the two. However, it should be noted that enriched does not imply that there are no other DNA or RNA sequences present, just that the relative amount of the sequence of interest has been significantly increased in a useful manner and preferably separate from a sequence library. The term significant here is used to indicate that the level of increase is useful to the person making such an increase, and generally means an increase relative to other nucleic acids of about at least 2 fold, more preferably at least 5 to 10 fold or even more. The term also does not imply that there is no DNA or RNA from other sources. The other source DNA may, for example, comprise DNA from a yeast or bacterial genome, or a cloning vector such as pUC19. This term distinguishes from naturally occurring events, such as viral infection, or tumor type growths, in which the level of one mRNA may be naturally increased relative to other species of mRNA. That is, the term is meant to cover only those situations in which a person has intervened to elevate the proportion of the desired nucleic acid.
[0021] It is also advantageous for some purposes that a nucleotide sequence be in purified form. The term “purified” in reference to nucleic acid does not require absolute purity (such as a homogeneous preparation); instead, it represents an indication that the sequence is relatively purer than in the natural environment (compared to the natural level this level should be at least 2-5 fold greater, e.g., in terms of mg/ml). Individual clones isolated from a cDNA library may be purified to electrophoretic homogeneity. The claimed DNA molecules obtained from these clones could be obtained directly from total DNA or from total RNA. The cDNA clones are not naturally occurring, but rather are preferably obtained via manipulation of a partially purified naturally occurring substance (messenger RNA). The construction of a cDNA library from mRNA involves the creation of a synthetic substance (cDNA) and pure individual cDNA clones can be isolated from the synthetic library by clonal selection of the cells carrying the cDNA library. Thus, the process which includes the construction of a cDNA library from mRNA and isolation of distinct cDNA clones yields an approximately 10 6 -fold purification of the native message. Thus, purification of at least one order of magnitude, preferably two or three orders, and more preferably four or five orders of magnitude is expressly contemplated.
[0022] By “SIRP polypeptide” is meant 9 or more contiguous amino acids set forth in the full length amino acid sequence of SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, or SEQ ID NO: 8. The SIRP polypeptides can be encoded by full-length nucleic acid sequences or any portion of a full-length nucleic acid sequence, so long as a functional activity of the polypeptide is retained. Preferred functional activities include the ability to bind to a receptor tyrosine kinase or a SH-2 domain bearing protein such as SHP-2, SHP-1 or Grb-2. A non full-length SIRP polypeptide may be used to elicit an antibody against the polypeptide and the full-length polypeptide using techniques known to those skilled in the art. The present invention also encompasses deletion mutants lacking one or more isolated SIRP domains (e.g., Ig-like domain, transmembrane domain, SH2 binding domain, and tyrosine residues), and complementary sequences capable of hybridizing to full length SIRP protein under stringent hybridization conditions.
[0023] In preferred embodiments, isolated nucleic acid comprises, consists essentially of, or consists of a nucleic acid sequence set forth in the full length nucleic acid sequence SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, or SEQ ID NO: 4 or at least 27, 30, 45, 60 or 90 contiguous nucleotides thereof and the SIRP polypeptide comprises, consists essentially of, or consists of at least 9, 10, 15, 20, 30, 50, 100, 200, or 300 contiguous amino acids of a SIRP polypeptide.
[0024] By “comprising” it is meant including, but not limited to, whatever follows the word “comprising”. Thus, use of the term “comprising” indicates that the listed elements are required or mandatory, but that other elements are optional and may or may not be present. By “consisting of” is meant including, and limited to, whatever follows the phrase “consisting of”. Thus, the phrase “consisting of” indicates that the listed elements are required or mandatory, and that no other elements may be present. By “consisting essentially of” is meant including any elements listed after the phrase, and limited to other elements that do not interfere with or contribute to the activity or action specified in the disclosure for the listed elements. Thus, the phrase “consisting essentially of” indicates that the listed elements are required or mandatory, but that other elements are optional and may or may not be present depending upon whether or not they affect the activity or action of the listed elements.
[0025] Compositions and probes of the present invention may contain human nucleic acids encoding a SIRP polypeptide but are substantially free of nucleic acid not encoding SIRP polypeptide. The human nucleic acid encoding a SIRP polypeptide is at least 18 contiguous bases of the nucleotide sequence set forth in SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, or SEQ ID NO: 4 and will selectively hybridize to human genomic DNA encoding a SIRP polypeptide, or is complementary to such a sequence. The nucleic acid may be isolated from a natural source by cDNA cloning or subtractive hybridization; the natural source may be blood, semen, and tissue of various organisms including eukaryotes, mammals, birds, fish, plants, gorillas, rhesus monkeys, chimpanzees and humans; and the nucleic acid may be synthesized by the triester method or by using an automated DNA synthesizer. In yet other preferred embodiments the nucleic acid is a conserved or unique region, for example those useful for the design of hybridization probes to facilitate identification and cloning of additional polypeptides, the design of PCR probes to facilitate cloning of additional polypeptides, and obtaining antibodies to polypeptide regions.
[0026] By “conserved nucleic acid regions”, are meant regions present on two or more nucleic acids encoding a SIRP polypeptide, to which a particular nucleic acid sequence can hybridize to under lower stringency conditions. Examples of lower stringency conditions suitable for screening for nucleic acid encoding SIRP polypeptides are provided in Abe, et al. J. Biol. Chem., 19:13361 (1992) (hereby incorporated by reference herein in its entirety, including any drawings). Preferably, conserved regions differ by no more than 7 out of 20 nucleotides.
[0027] By “unique nucleic acid region” is meant a sequence present in a full length nucleic acid coding for a SIRP polypeptide that is not present in a sequence coding for any other naturally occurring polypeptide. Such regions preferably comprise 12 or 20 contiguous nucleotides present in the full length nucleic acid encoding a SIRP polypeptide.
[0028] The invention also features a nucleic acid probe for the detection of a nucleic acid encoding a SIRP polypeptide in a sample. The nucleic acid probe contains nucleic acid that will hybridize to at least one sequence set forth in SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, or SEQ ID NO: 4.
[0029] In preferred embodiments the nucleic acid probe hybridizes to nucleic acid encoding at least 12, 27, 30, 35, 40, 50, 100, 200, or 300 contiguous amino acids of the full-length sequence set forth in SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, or SEQ ID NO: 8. Various low or high stringency hybridization conditions may be used depending upon the specificity and selectivity desired.
[0030] By “high stringency hybridization conditions” is meant those hybridizing conditions that (1) employ low ionic strength and high temperature for washing, for example, 0.015 M NaCl/0.0015 M sodium citrate/0.1% SDS at 50° C.; (2) employ during hybridization a denaturing agent such as formamide, for example, 50% (vol/vol) formamide with 0.1% bovine serum albumin/0.1% Ficoll/0.1% polyvinylpyrrolidone/50 mM sodium phosphate buffer at pH 6.5 with 750 mM NaCl, 75 mM sodium citrate at 42° C.; or (3) employ 50% formamide, 5×SSC (0.75 M NaCl, 0.075 M Sodium pyrophosphate, 5×Denhardt's solution, sonicated salmon sperm DNA (50 g/ml), 0.1% SDS, and 10% dextran sulfate at 42° C., with washes at 42° C. in 0.2×SSC and 0.1% SDS. Under stringent hybridization conditions only highly complementary nucleic acid sequences hybridize. Preferably, such conditions prevent hybridization of nucleic acids having 1 or 2 mismatches out of 20 contiguous nucleotides.
[0031] Methods for using the probes include detecting the presence or amount of SIRP RNA in a sample by contacting the sample with a nucleic acid probe under conditions such that hybridization occurs and detecting the presence or amount of the probe bound to SIRP RNA. The nucleic acid duplex formed between the probe and a nucleic acid sequence coding for a SIRP polypeptide may be used in the identification of the sequence of the nucleic acid detected (for example see, Nelson et al., in Nonisotopic DNA Probe Techniques, p. 275 Academic Press, San Diego (Kricka, ed., 1992) hereby incorporated by reference herein in its entirety, including any drawings). Kits for performing such methods may be constructed to include a container means having disposed therein a nucleic acid probe.
[0032] The invention also features recombinant nucleic acid, preferably in a cell or an organism. The recombinant nucleic acid may contain a sequence (coding sequence or noncoding sequence) or a segment of sequence set forth in SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, or SEQ ID NO: 4 and a vector or a promoter effective to initiate transcription in a host cell. The recombinant nucleic acid can alternatively contain a transcriptional initiation region functional in a cell, a sequence complimentary to an RNA sequence encoding a SIRP polypeptide and a transcriptional termination region functional in a cell.
[0033] In another aspect the invention features an isolated, enriched or purified SIRP polypeptide.
[0034] By “isolated” in reference to a polypeptide is meant a polymer of 2 (preferably 7, more preferably 13, most preferably 25) or more amino acids conjugated to each other, including polypeptides that are isolated from a natural source or that are synthesized. The isolated polypeptides of the present invention are unique in the sense that they are not found in a pure or separated state in nature. Use of the term “isolated” indicates that a naturally occurring sequence has been removed from its normal cellular environment. Thus, the sequence may be in a cell-free solution or placed in a different cellular environment. The term does not imply that the sequence is the only amino acid chain present, but that it is the predominate sequence present (at least 10-20% more than any other sequence) and is essentially free (about 90-95% pure at least) of non-amino acid material naturally associated with it.
[0035] By the use of the term “enriched” in reference to a polypeptide is meant that the specific amino acid sequence constitutes a significantly higher fraction (2-5 fold) of the total of amino acids present in the cells or solution of interest than in normal or diseased cells or in the cells from which the sequence was taken. This could be caused by a person by preferential reduction in the amount of other amino acids present, or by a preferential increase in the amount of the specific amino acid sequence of interest, or by a combination of the two. However, it should be noted that enriched does not imply that there are no other amino acid sequences present, just that the relative amount of the sequence of interest has been significantly increased. The term significant here is used to indicate that the level of increase is useful to the person making such an increase, and generally means an increase relative to other amino acids of about at least 2 fold, more preferably at least 5 to 10 fold or even more. The term also does not imply that there is no amino acid from other sources. The other source amino acid may, for example, comprise amino acid encoded by a yeast or bacterial genome, or a cloning vector such as pUC19. The term is meant to cover only those situations in which man has intervened to elevate the proportion of the desired amino acid.
[0036] It is also advantageous for some purposes that an amino acid sequence be in purified form. The term “purified” in reference to a polypeptide does not require absolute purity (such as a homogeneous preparation); instead, it represents an indication that the sequence is relatively purer than in the natural environment (compared to the natural level this level should be at least 2-5 fold greater, e.g., in terms of mg/ml). Purification of at least one order of magnitude, preferably two or three orders, and more preferably four or five orders of magnitude is expressly contemplated. The substance is preferably free of contamination at a functionally significant level, for example 90%, 95%, or 99% pure.
[0037] In preferred embodiments SIRP polypeptides contain at least 9, 10, 15, 20, or 30 contiguous amino acids of the full-length sequence set forth in SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, or SEQ ID NO: 8.
[0038] In yet another aspect the invention features a purified antibody (e.g., a monoclonal or polyclonal antibody) having specific binding affinity to a SIRP polypeptide. The antibody contains a sequence of amino acids that is able to specifically bind to a SIRP polypeptide.
[0039] By “specific binding affinity” is meant that the antibody will bind to a hSIRP polypeptide at a certain detectable amount but will not bind other polypeptides to the same extent, under identical conditions. The present invention also encompasses antibodies that can distinguish hSIRP1 from hSIRP2 or hSIRP3 or can otherwise distinguish between the various SIRPs.
[0040] Antibodies having specific binding affinity to a SIRP polypeptide may be used in methods for detecting the presence and/or amount of a SIRP polypeptide is a sample by contacting the sample with the antibody under conditions such that an immunocomplex forms and detecting the presence and/or amount of the antibody conjugated to the SIRP polypeptide. Diagnostic kits for performing such methods may be constructed to include a first container means containing the antibody and a second container means having a conjugate of a binding partner of the antibody and a label.
[0041] In another aspect the invention features a hybridoma which produces an antibody having specific binding affinity to a SIRP polypeptide.
[0042] By “hybridoma” is meant an immortalized cell line which is capable of secreting an antibody, for example a SIRP antibody.
[0043] In preferred embodiments the SIRP antibody comprises a sequence of amino acids that is able to specifically bind a SIRP polypeptide.
[0044] Another aspect of the invention features a method of detecting the presence or amount of a compound capable of binding to a SIRP polypeptide. The method involves incubating the compound with a SIRP polypeptide and detecting the presence or amount of the compound bound to the SIRP polypeptide.
[0045] In preferred embodiments, the compound inhibits an activity of SIRP. The present invention also features compounds capable of binding and inhibiting SIRP polypeptide that are identified by methods described above.
[0046] In another aspect the invention features a method of screening potential agents useful for treatment of a disease or condition characterized by an abnormality in a signal transduction pathway that contains an interaction between a SIRP polypeptide and a natural binding partner (NBP). The method involves assaying potential agents for those able to promote or disrupt the interaction as an indication of a useful agent.
[0047] By “NBP” is meant a natural binding partner of a SIRP polypeptide that naturally associates with a SIRP polypeptide. The structure (primary, secondary, or tertiary) of the particular natural binding partner will influence the particular type of interaction between the SIRP polypeptide and the natural binding partner. For example, if the natural binding partner comprises a sequence of amino acids complementary to the SIRP polypeptide, covalent bonding may be a possible interaction. Similarly, other structural characteristics may allow for other corresponding interactions. The interaction is not limited to particular residues and specifically may involve phosphotyrosine, phosphoserine, or phosphothreonine residues. A broad range of sequences may be capable of interacting with SIRP polypeptides. One example of a natural binding partner may be SHP-2, which is described above. Other examples include, but are not limited to, SHP-1 and Grb2. Using techniques well known in the art, one may identify several natural binding partners for SIRP polypeptides such as by utilizing a two-hybrid screen.
[0048] By “screening” is meant investigating an organism for the presence or absence of a property. The process may include measuring or detecting various properties, including the level of signal transduction and the level of interaction between a SIRP polypeptide and a NBP.
[0049] By “disease or condition” is meant a state in an organism, e.g., a human, which is recognized as abnormal by members of the medical community. The disease or condition may be characterized by an abnormality in one or more signal transduction pathways in a cell wherein one of the components of the signal transduction pathway is either a SIRP polypeptide or a NBP. Specific diseases or disorders which might be treated or prevented, based upon the affected cells include cancers and diabetes.
[0050] In preferred embodiments, the methods described herein involve identifying a patient in need of treatment. Those skilled in the art will recognize that various techniques may be used to identify such patients.
[0051] By “abnormality” is meant an a level which is statistically different from the level observed in organisms not suffering from such A disease or condition and may be characterized as either an excess amount, intensity or duration of signal or a deficient amount, intensity or duration of signal. The abnormality in signal transduction may be realized as an abnormality in cell function, viability or differentiation state. The present invention is based in part on the determination that such abnormality in a pathway can be alleviated by action at the SHP-2-SIRP interaction site in the pathway. An abnormal interaction level may also either be greater or less than the normal level and may impair the normal performance or function of the organism. Thus, it is also possible to screen for agents that will be useful for treating a disease or condition, characterized by an abnormality in the signal transduction pathway, by testing compounds for their ability to affect the interaction between a SIRP polypeptide and SHP-2, since the complex formed by such interaction is part of the signal transduction pathway. However, the disease or condition may be characterized by an abnormality in the signal transduction pathway even if the level of interaction between the SIRP polypeptide and NBP is normal.
[0052] By “interact” is meant any physical association between polypeptides, whether covalent or non-covalent. This linkage can include many chemical mechanisms, for instance covalent binding, affinity binding, intercalation, coordinate binding and complexation. Examples of non-covalent bonds include electrostatic bonds, hydrogen bonds, and Van der Waals bonds. Furthermore, the interactions between polypeptides may either be direct or indirect. Thus, the association between two given polypeptides may be achieved with an intermediary agent, or several such agents, that connects the two proteins of interest (e.g., a SIRP polypeptide and SHP-2). Another example of an indirect interaction is the independent production, stimulation, or inhibition of both a SIRP polypeptide and SHP-2 by a regulatory agent. Depending upon the type of interaction present, various methods may be used to measure the level of interaction. For example, the strengths of covalent bonds are often measured in terms of the energy required to break a certain number of bonds (i.e., kcal/mol) Non-covalent interactions are often described as above, and also in terms of the distance between the interacting molecules. Indirect interactions may be described in a number of ways, including the number of intermediary agents involved, or the degree of control exercised over the SIRP polypeptide relative to the control exercised over SHP-2 or another NBP.
[0053] By “disrupt” is meant that the interaction between the SIRP polypeptide and SHP-2 or a NBP is reduced either by preventing expression of the SIRP polypeptide, or by preventing expression of SHP-2 or NBP, or by specifically preventing interaction of the naturally synthesized proteins or by interfering with the interaction of the proteins.
[0054] By “promote” is meant that the interaction between a SIRP polypeptide and SHP-2 or NBP is increased either by increasing expression of a SIRP polypeptide, or by increasing expression of SHP-2 or a NBP, or by decreasing the dephosphorylating activity of the corresponding regulatory PTP (or other phosphatase acting on other phosphorylated signaling components) by promoting interaction of the SIRP polypeptide and SHP-2 or NBP or by prolonging the duration of the interaction. Covalent binding can be promoted either by direct condensation of existing side chains or by the incorporation of external bridging molecules. Many bivalent or polyvalent linking agents are useful in coupling polypeptides, such as an antibody, to other molecules. For example, representative coupling agents can include organic compounds such as thioesters, carbodiimides, succinimide esters, diisocyanates, glutaraldehydes, diazobenzenes and hexamethylene diamines. This listing is not intended to be exhaustive of the various classes of coupling agents known in the art but, rather, is exemplary of the more common coupling agents. (See Killen and Lindstrom 1984, J. Immunol. 133:1335-2549; Jansen, F. K., et al., 1982, Immunological Rev. 62:185-216; and Vitetta et al., supra).
[0055] By “signal transduction pathway” is meant the sequence of events that involves the transmission of a message from an extracellular protein to the cytoplasm through a cell membrane. The signal ultimately will cause the cell to perform a particular function, for example, to uncontrollably proliferate and therefore cause cancer. Various mechanisms for the signal transduction pathway (Fry et al., Protein Science., 2:1785-1797, 1993) provide possible methods for measuring the amount or intensity of a given signal. Depending upon the particular disease associated with the abnormality in a signal transduction pathway, various symptoms may be detected. Those skilled in the art recognize those symptoms that are associated with the various other diseases described herein. Furthermore, since some adapter molecules recruit secondary signal transducer proteins towards the membrane, one measure of signal transduction is the concentration and localization of various proteins and complexes. In addition, conformational changes that are involved in the transmission of a signal may be observed using circular dichroism and fluorescence studies.
[0056] In another aspect the invention features a method of diagnosis of an organism for a disease or condition characterized by an abnormality in a signal transduction pathway that contains an interaction between a SIRP polypeptide and SHP-2 or a NBP. The method involves detecting the level of interaction as an indication of said disease or condition.
[0057] By “organism” is meant any living creature. The term includes mammals, and specifically humans. Preferred organisms include mice, as the ability to treat or diagnose mice is often predictive of the ability to function in other organisms such as humans.
[0058] By “diagnosis” is meant any method of identifying a symptom normally associated with a given disease or condition. Thus, an initial diagnosis may be conclusively established as correct by the use of additional confirmatory evidence such as the presence of other symptoms. Current classification of various diseases and conditions is constantly changing as more is learned about the mechanisms causing the diseases or conditions. Thus, the detection of an important symptom, such as the detection of an abnormal level of interaction between SIRP polypeptides and SHP-2 or NBPs may form the basis to define and diagnose a newly named disease or condition. For example, conventional cancers are classified according to the presence of a particular set of symptoms. However, a subset of these symptoms may both be associated with an abnormality in a particular signaling pathway, such as the ras 21 pathway and in the future these diseases may be reclassified as ras 21 pathway diseases regardless of the particular symptoms observed.
[0059] Yet another aspect of the invention features a method for treatment of an organism having a disease or condition characterized by an abnormality in a signal transduction pathway. The signal transduction pathway contains an interaction between a SIRP polypeptide and SHP-2 or a NBP and the method involves promoting or disrupting the interaction, including methods that target the SIRP:NBP interaction directly, as well as methods that target other points along the pathway.
[0060] By “dominant negative mutant protein” is meant a mutant protein that interferes with the normal signal transduction pathway. The dominant negative mutant protein contains the domain of interest (e.g., an SIRP polypeptide or SHP-2 or a NBP), but has a mutation preventing proper signaling, for example by preventing binding of a second domain from the same protein. One example of a dominant negative protein is described in Millauer et al., Nature Feb. 10, 1994. The agent is preferably a peptide which blocks or promotes interaction of the SIRP polypeptide and SHP-2 or another NBP. The peptide may be recombinant, purified, or placed in a pharmaceutically acceptable carrier or diluent.
[0061] An EC 50 or IC 50 of less than or equal to 100 μM is preferable, and even more preferably less than or equal to 50 μM, and most preferably less that or equal to 20 μM. Such lower EC 50 's or IC 50 's are advantageous since they allow lower concentrations of molecules to be used in vivo or in vitro for therapy or diagnosis. The discovery of molecules with such low EC 50 's and IC 50 's enables the design and synthesis of additional molecules having similar potency and effectiveness. In addition, the molecule may have an EC 50 or IC 50 less than or equal to 100 μM at one or more, but not all cells chosen from the group consisting of parathyroid cell, bone osteoclast, juxtaglomerular kidney cell, proximal tubule kidney cell, distal tubule kidney cell, cell of the thick ascending limb of Henle's loop and/or collecting duct, central nervous system cell, keratinocyte in the epidermis, parafollicular cell in the thyroid (C-cell), intestinal cell, trophoblast in the placenta, platelet, vascular smooth muscle cell, cardiac atrial cell, gastrin-secreting cell, glucagon-secreting cell, kidney mesangial cell, mammary cell, beta cell, fat/adipose cell, immune cell and GI tract cell.
[0062] By “therapeutically effective amount” is meant an amount of a pharmaceutical composition having a therapeutically relevant effect. A therapeutically relevant effect relieves to some extent one or more symptoms of the disease or condition in the patient; or returns to normal either partially or completely one or more physiological or biochemical parameters associated with or causative of the disease or condition. Generally, a therapeutically effective amount is between about 1 nmole and 1 μmole of the molecule, depending on its EC 50 or IC 50 and on the age and size of the patient, and the disease associated with the patient.
[0063] In another aspect, the invention describes a polypeptide comprising a recombinant SIRP polypeptide or a unique fragment thereof. By “unique fragment,” is meant an amino acid sequence present in a full-length SIRP polypeptide that is not present in any other naturally occurring polypeptide. Preferably, such a sequence comprises 6 contiguous amino acids present in the full sequence. More preferably, such a sequence comprises 12 contiguous amino acids present in the full sequence. Even more preferably, such a sequence comprises 18 contiguous amino acids present in the full sequence.
[0064] By “recombinant SIRP polypeptide” is meant to include a polypeptide produced by recombinant DNA techniques such that it is distinct from a naturally occurring polypeptide either in its location (e.g., present in a different cell or tissue than found in nature), purity or structure. Generally, such a recombinant polypeptide will be present in a cell in an amount different from that normally observed in nature.
[0065] In another aspect, the invention describes a recombinant cell or tissue containing a purified nucleic acid coding for a SIRP polypeptide. In such cells, the nucleic acid may be under the control of its genomic regulatory elements, or may be under the control of exogenous regulatory elements including an exogenous promoter. By “exogenous” it is meant a promoter that is not normally coupled in vivo transcriptionally to the coding sequence for the SIRP polypeptide.
[0066] In another aspect, the invention features a SIRP polypeptide binding agent able to bind to a SIRP polypeptide. The binding agent is preferably a purified antibody which recognizes an epitope present on a SIRP polypeptide. Other binding agents include molecules which bind to the SIRP polypeptide and analogous molecules which bind to a SIRP polypeptide.
[0067] By “purified” in reference to an antibody is meant that the antibody is distinct from naturally occurring antibody, such as in a purified form. Preferably, the antibody is provided as a homogeneous preparation by standard techniques. Uses of antibodies to the cloned polypeptide include those to be used as therapeutics, or as diagnostic tools.
[0068] In another aspect, the invention provides a nucleic acid molecule comprising a nucleotide sequence that encodes a polypeptide having the full length amino acid sequence set forth in SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, or SEQ ID NO: 8 except that it lacks at least one of the domains selected from the group consisting of the extracellular Ig like domain, the transmembrane domain, and the SHP-2 binding domains. Such deletion mutants are useful in the design of assays for protein inhibitors. The nucleic acid molecules described above may be, for example, cDNA or genomic DNA and may be placed in a recombinant vector or expression vector. In such a vector, the nucleic acid preferably is operatively associated with the regulatory nucleotide sequence containing transcriptional and translational regulatory information that controls expression of the nucleotide sequence in a host cell.
[0069] Thus, the invention also provides a genetically engineered host cell containing any of the nucleotide sequences described herein and the nucleic acid preferably is operatively associated with the regulatory nucleotide sequence containing transcriptional and translational regulatory information that controls expression of the nucleotide sequence in a host cell. Such host cells may obviously be either prokaryotic or eukaryotic.
[0070] Other features and advantages of the invention will be apparent from the following description of the preferred embodiments thereof, and from the claims.
BRIEF DESCRIPTION OF THE FIGURES
[0071] [0071]FIG. 1 shows the deduced amino acid sequences of SIRP4 and SIRP1. Identical amino acids are boxed. The putative signal sequence and transmembrane region are indicated by thin and thick overlines, respectively. Three Ig-like domains are indicated by stippled overlines. Potential tyrosine phosphorylation sites are shown in bold, the C-terminal proline rich region is shaded. The location of oligonucleotides flanking the Ex region is indicated by stars.
[0072] [0072]FIG. 2 shows the alignment of extracellular regions including the first Ig-like domain of 15 SIRP family members. Ex1 shows amino acids encoded by the initial PCR fragment that was used for screening and GST-fusion protein construction. Ex2-11 are derived from PCR and cDNA sequences, Ex12-15 from genomic isolates. Numbering is according to FIG. 1.
[0073] [0073]FIG. 3 shows the alignment of amino acid sequences of human SIRP4, mouse SIRP1, human SIRPα1 and mouse SIRPβ1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0074] The present invention relates to SIRP polypeptides, nucleic acids encoding such polypeptides, cells, tissues and animals containing such nucleic acids, antibodies to such polypeptides, assays utilizing such polypeptides, and methods relating to all of the foregoing. Those skilled in the art will recognize that many of the methods described below in relation to SIRP1, SIRP4, SHP-2, SHP-1 and Grb2 could also be utilized with respect to the other members of this group.
[0075] Various other features and aspects of the invention are: Nucleic Acid Encoding A SIRP Polypeptide; A Nucleic Acid Probe for the Detection of SIRP; Probe Based Method And Kit For Detecting SIRP; DNA Constructs Comprising a SIRP Nucleic Acid Molecule and Cells Containing These Constructs; Purified SIRP Polypeptides; SIRP Antibody And Hybridoma; An Antibody Based Method And Kit For Detecting SIRP; Isolation of Compounds Which Interact With SIRP; Compositions; Disruption of Protein Complexes; Antibodies to Complexes; Pharmaceutical Formulations and Modes of Administration; Identification of Agents; Purification and Production of Complexes; Derivatives of Complexes; and Evaluation of Disorders.
[0076] All of these aspects and features are explained in detail with respect to another protein involved with signal transduction, PYK-2, in PCT publication WO 96/18738, which is incorporated herein by reference in its entirety, including any drawings. Those skilled in the art will readily appreciate that such description can be easily adapted to SIRP as well, and is equally applicable to the present invention.
EXAMPLES
[0077] The examples below are non-limiting and are merely representative of various aspects and features of the procedures used to identify the full-length nucleic acid and amino acid sequences of a series of SIRP proteins. Experiments demonstrating SIRP expression, interaction and signaling activities are also provided.
[0078] Material and Methods
[0079] Cell Culture and Transient Expression
[0080] MM5/C1, Rat1-IR, A431 or human fibroblast cells were grown until confluency, starved for 18 hours in serum-free medium, and either left untreated or were POV—(1 mM sodium orthovanadate, 3 mM H 2 O 2 ), insulin—(100 nM), EGF—(1 nM), or PDGF—(100 pM) stimulated for different time intervals as indicated. SIRP4, SHP-2 (Vogel, et al., Science 259:1611-1614 (1994)) or SHP-2C463A mutant (Stein-Gerlach, et al. J. Biol. Chem. 270:24635-24637 (1995)) cDNAs were transiently cotransfected in BHK-IR, BHK-EGFR or BHK-βPDGFR cells using the calcium precipitation method (Chen, et al. Mol. Cell. Biol. 7:2745-2752 (1987)). After stimulation, cells were lysed in buffer containing 50 mM HEPES, pH 7.5, 150 mM NaCl, 1% Triton X-100, 10% glycerol, 1 mM POV, 1 mM EDTA, 1 mM PMSF, 1 mg/ml leupeptin, 1 mg/ml aprotinin.
[0081] Immunoprecipitation and Western Blotting
[0082] SHP-2 immunoprecipitations were performed with polyclonal anti-SHP-2 antibodies (Vogel, et al., Science 259:1611-1614 (1994)). Overexpressed SIRP4 or endogenous SIRP4-like proteins were immunoprecipitated by polyclonal anti-Ex1 antibodies raised by immunizing rabbits with a GST-fusion protein containing the Ex1 fragment (FIG. 2). Western blots were labeled with monoclonal anti-phosphotyrosine antibodies 5E2 (Fendly, et al., Cancer Res. 50:1550-1558 (1990)), and after stripping, reprobed with monoclonal anti-SHP-2 antibodies (Transduction Laboratories), or polyclonal anti-SIRP4-CT antibodies, raised against a GST-fusion protein containing the C-terminal part of SIRP4 (amino acids 336-503). For immunolabeling goat anti-mouse or -rabbit horseradish peroxidase conjugates (Bio-Rad) and the ECL detection system (Amersham) were used.
[0083] To obtain 293 cells stably expressing SIRP4 (293/SIRP4), cells were transfected with SIRP4 cDNA in pLXSN (Miller, et al. Biotechniques 7:980-988 (1989)) using the calcium precipitation method, followed by selection with G418 (1 mg/ml). SIRP4 was immunoprecipitated from quiescent or POV-stimulated (1 mM) 293/SIRP4 cells with polyclonal anti-Ex1 antibodies. Subsequently, crude lysates of [ 35 S]-methionine labeled 293 cells expressing different SH2 domain containing proteins were added to the affinity matrix and incubated for 2 h at 4° C. The is immunocomplexes were washed, separated by SDS-PAGE and analyzed by autoradiography.
[0084] Enzymatic Deglycosylation
[0085] To perform in vitro deglycosylation SHP-2 immunocomplexes or the 110 kDa protein preparation were first denatured in the presence of 1% SDS at 100° C. for 5 min. Deglycosylation was done in potassium phosphate buffer (40 mM, pH 7.0), containing 20 mM EDTA, 1% b-mercaptoethanol, 1% Triton X-100 and 0.5 Unit of Endoglycosidase F/N-Glycosidase F (Boehringer Mannheim) at 37° C. for 16 hours.
[0086] Protein Purification
[0087] Approximately 10 10 Rat1-IR cells were used to purify the 110 kDa protein. Starved Rat1-IR cells were insulin-stimulated (100 nM) for 10 min, washed briefly with ice-cold hypotonic buffer containing 20 mM HEPES, pH 7.5, 1 mM POV, 1 mM EDTA, 1 mM PMSF, 1 mg/ml leupeptin, 1 mg/ml aprotinin, scraped into the same buffer and homogenized. Obtained cell extracts were pelleted at 1000 rpm for 15 min, and supernatants were spun at 48.000 g for 1 hour. Membranes were solubilized in lysis buffer as described above. hIR was depleted from membrane extracts using an affinity column with monoclonal anti-hIR antibody 83-14 (Redemann et al., Mol. Cell. Biol. 12:491-498 (1992)), covalently coupled to Protein A-Sepharose beads (Pharmacia). Depleted extracts were applied onto a WGA-agarose 6 MB column (Sigma), and glycoproteins were eluted with 0.3 M N-acetyl-glucosamine in HNTG (20 mM HEPES (pH 7.5), 150 mM NaCl, 0.1% Triton X-100, 10% glycerol, 1 mM POV). After concentration protein extracts were applied onto an anti-phosphotyrosine antibody column (Sigma). Bound proteins were eluted with 20 mM phosphotyrosine in HNTG. The eluate was subjected to SDS-PAGE, proteins were transferred to a PVDF membrane (Millipore) and stained with Coomassie blue. The protein of 110 kD apparent molecular weight was microsequenced. The following five tryptic peptides were obtained: PIYSFIGGEHFPR, IVEPDTEIK, YGFSPR, IKEVAHVNLEVR, VAAGDSAT.
[0088] Biological Assays
[0089] To produce retroviruses expressing pLXSN, wild type SIRP4 and mutated SIRP4 constructs, BOSC 23 cells were transiently transfected by expression plasmids as described (Pear, et al. Proc. Natl. Acad. Sci. 90:8392-8396 (1993)). To obtain NIH3T3 cells stably expressing wild type SIRP4, SIRP4-4Y or SIRP4-DCT mutants subconfluent NIH3T3 cells (10 5 cells per 6 cm dish) were incubated with supernatants of transfected BOSC 23 cells for 4 h in the presence of Polybrene (4 mg/ml), followed by selection with G418 (1 mg/ml).
[0090] To perform focus formation assays cell lines 3T3/pLXSN, 3T3/SIRP4, 3T3/SIRP4-4Y or 3T3/SIRP4-DCT were superinfected for 4 hours with equal volumes of v-fms-virus supernatant (10 5 cells/6 cm dish). Cells were cultivated for 14 days in 4% FCS with medium change every second day. Cell foci were stained with Crystal violet (0.1% crystal violet, 30% methanol).
Example 1
Identification and Cloning of Signal Regulatory Proteins
[0091] Western blot of mammalian cells with anti-phosphotyrosine antibodies and anti-SHP-2 antibodies was used to identify tyrosine phosphorylated SHP-2 associated proteins.
[0092] Western blots containing anti-SHP-2 immunoprecipitates from starved or POV-treated mouse MM5/C1 mammary carcinoma, rat fibroblast Rat1-IR or human epidermal carcinoma A431 cells were incubated with anti-phosphotyrosine antibodies or anti-SHP-2 antibodies. Samples were deglycosylated with or treated without Endoglycosidase F/N-Glycosidase F (Endo.F/F). As a control, insulin-stimulated Rat1-IR cell lysates were immunoprecipitated with preimmune rabbit serum (aNS).
[0093] Samples from each purification step (i.e., solubilized crude membrane extract, hIR-depleted extracts, concentrated eluate from WGA-agarose beads, and eluate from anti-phosphotyrosine antibody column) were analyzed by 10% SDS-PAGE and visualized by silver staining and in Western blots using monoclonal anti-phosphotyrosine antibodies.
[0094] A major tyrosine phosphorylated protein was revealed in analysis of anti-SHP-2 immunoprecipitates from both pervanadate (POV) and growth factor stimulated cells. This phosphoprotein migrated at 120 kDa, 110 kDa and 90 kDa positions in mouse mammary tumor (MM5/C1) cells, Rat1 cells overexpressing the human insulin receptor (Rat1-IR), and human epidermoid carcinoma (A431) cells, respectively.
[0095] Upon in vitro deglycosylation, this glycoprotein was reduced to 65 kDa apparent molecular weight (MW) in all cases. This indicated that the same SHP-2 binding protein of 65 kDa was differentially glycosylated in a species specific manner.
[0096] In some cell lines such as A431, other tyrosine phosphorylated proteins in the 90-120 kDa range remained unaffected by the deglycosylation treatment. These proteins may represent Gab1 and/or the human homologue of the Drosophila DOS protein.
[0097] Insulin treated Rat1-IR were used to purify the 110 kDa SHP-2 binding glycoprotein using standard chromatography procedures. Approximately 4 mg of the glycoprotein that copurified with SHP-2 were obtained and subject to microsequence analysis. This yielded five peptide sequences: PIYSFIGGEHFPR, IVEPDTEIK, YGFSPR, IKEVAHVNLEVR, VAAGDSAT. Computer aided search in the EST database led to the identification of a 305 bp rat sequence (accession Nr.: H31804) and subsequent human cDNA fragment of 2 kb (EMBL databank, accession Nr.: U6701) containing matching and homologous sequences, respectively.
[0098] Specific primers flanking the very 5′ portion of this sequence were used to amplify a 360 bp human DNA fragment (encoding Ex1 in FIG. 2) which was used to screen a human placenta cDNA library.
[0099] Several positive clones were isolated. One clone of 2.4 kb encoded a polypeptide of 503 amino acids designated SIRP4 (for SIgnal Regulating Protein 4) with a calculated mass of 57,000. The deduced sequence identifies SIRP4 as a transmembrane protein with three Ig-like domains and a cytoplasmic portion containing four potential tyrosine phosphorylation sites and one proline-rich region.
[0100] A second cDNA clone, SIRP1, is also identified. This protein is highly homologous to SIRP4 within the Ig-like domains (Ig-1: 83%; Ig-2: 88%; Ig-3: 83%), but displays striking sequence divergence at the amino terminus and upstream of the transmembrane domain which gives rise to a shorter protein that still contains a transmembrane-like region but lacks the cytoplasmic C-terminal portion.
[0101] SIRP4 and SIRP1 are members of a novel protein family. This protein family has a variety of distinct sequence isoforms as evidenced by comparison of fifteen cDNA and genomic sequences within the first Ig-like domain (FIG. 2). Two major classes exist in SIRP family distinguished by the presence or absence of a cytoplasmic SHP-2 binding domain.
Example 2
Analyzing the Functions of SIRP4
[0102] SIRP4 Binds to SHP-2 and Serves as a Substrate for SHP-2, IR, EGFR, and βPDGFR
[0103] The identity of SIRP4 as SHP-2 binding protein and substrate was confirmed by expression of the SIRP4 cDNA either alone or in combination with SHP-2 or an enzymatically inactive mutant SHP-2C463A in BHK cells. BHK cells stably express human EGF-, insulin- or βPDGF receptors.
[0104] Immunoprecipitations were performed with a polyclonal antibody raised against a GST-fusion protein containing the extracellular Ex1 region (FIG. 2).
[0105] Western blots containing anti-SIRP4 immunoprecipitations from quiescent or ligand-stimulated BHK-IR, BHK-EGFR or BHK-βPDGF cells were labeled with anti-phosphotyrosine, anti-SHP-2 and anti-SIRP4 antibodies, respectively.
[0106] Anti-SIRP4 immunoprecipitation revealed a tyrosine phosphorylated protein of 85-90 kDa upon ligand stimulation which associated with SHP-2.
[0107] The results suggested SIRP4 to be a direct substrate of SHP-2 since expression of the SHP-2 mutant SHP-2C463A led to a significant increase in its phosphotyrosine content (even in starved cells) while coexpression of wt SHP-2 resulted in dephosphorylation. The MW of overexpressed SIRP4 matches that of the endogenous protein detected in SHP-2 immunoprecipitates from A431 cells.
[0108] Endogenous SIRP4-like proteins were immunoprecipitated from untreated or EGF-stimulated A431 cells, from quiescent or PDGF-treated human fibroblasts, or from starved or insulin-stimulated HBL-100 cells. As a control, ligand-stimulated cell lysates were immunoprecipitated with preimmune rabbit serum (aNS). Immunoblots were probed with monoclonal anti-phosphotyrosine and monoclonal anti-SHP-2 antibodies.
[0109] Polyclonal anti-Ex1 antibodies immunoprecipitate a protein of 85-90 kDa apparent MW from A431, HBL-100 tumor cells and human fibroblasts. This protein was tyrosine phosphorylated upon EGF, insulin or PDGF stimulation, respectively, and coprecipitated with SHP-2 in a ligand dependent manner.
[0110] These data indicate the existence of SIRP4 in several human cell lines where SIRP4 serves as a substrate for insulin-, EGF- and βPDGF receptors, binds SHP-2 in its tyrosine phosphorylated form and serves as a substrate for the phosphatase activity of SHP-2. The interaction of SHP-2 with SIRP4 likely involves one or both SH2 domains of SHP-2 as suggested by the requirement of phosphotyrosine residues and the abrogation of detectable association by mutation of critical residues in SHP-2 SH2 domains.
[0111] In vitro binding assays were performed to determine whether SIRP4 is able to interact with other SH2 domain-containing proteins. SIRP4-associated [ 35 S]-Methionine labeled proteins were resolved on SDS-PAGE and detected by autoradiography. The result shows that SIRP4 associates with both SHP-1 and Grb2 but not p85, Shc, Grb7, PLC-g, c-src, Nck, Vav, GAP, or ISGF-3.
[0112] A catalytically inactive SHP-1 mutant has recently been shown to bind an as yet unidentified tyrosine phosphorylated protein of 90-95-kDa in human 293 cells. This tyrosine phosphorylated protein is likely to be SIRP4 or one of its family members.
[0113] Effects of SIRP4 on Cell Growth and Transformation
[0114] To investigate the biological function of SIRP4, three stable transfectants of NIH3T3 cells were constructed to express wild type SIRP4 or SIRP4 mutants carrying either point mutations of the putative SHP-2 tyrosine binding sites (SIRP4-4Y) or a deletion of most of the cytoplasmic region (SIRP4-DCT).
[0115] Ligand-stimulated [ 3 H]-thymidine incorporation of NIH3T3 cells expressing empty vector (3T3/pLXSN), wild type SIRP4 (3T3/SIRP4), SIRP4-4Y (3T3/SIRP4-4Y) or SIRP4-DCT (3T3/SIRP4-DCT, amino acids 402-503 are deleted) mutants. Cells were grown to confluence in 24-well dishes (Nunc), starved for 24 h in DMEM/0.5% FCS, stimulated with different concentrations of insulin or EGF for 18 h, then incubated with 0.5 mCi [ 3 H]-thymidine per well for 4 h. Incorporation into DNA was determined as described (Redemann, et al. Mol. Cell. Biol. 12:491-498 (1992)).
[0116] Upon stimulation of cells with insulin, EGF and PDGF, control cells showed growth factor-induced DNA synthesis as measured by [ 3 H]-thymidine incorporation. Overexpression of SIRP4 led to a decrease of [ 3 H]-thymidine incorporation. In contrast, both SIRP4 mutants had nearly no effect on DNA synthesis. The observed inhibitory effect on DNA synthesis must be connected to SIRP4 tyrosine phosphorylation and/or its association with SHP-2 since wt SIRP4 became tyrosine phosphorylated and bound to SHP-2 upon ligand stimulation, and SIRP4 mutants did not.
[0117] SIRP4 effected growth inhibition upon insulin or EGF stimulation is correlated with reduced MAP kinase activation in 3T3/SIRP4 cells. 3T3/pLXSN, 3T3/SIRP4 or 3T3/SIRP4-4Y cells were starved for 18 hours in DMEM/0.5% FCS and stimulated with insulin or EGF for the time indicated. MAP kinase was detected in Western blots by using polyclonal erk1 and erk2 antibodies (Santa Cruz). In contrast, expression of SIRP4 mutants defective in SHP-2 binding had no effect on MAP kinase activation. Similar observations were made upon stimulation of the cells with PDGF.
[0118] These data strongly indicate that SIRP4 represents a novel regulatory-element in the pathway that leads to MAP kinase activation.
[0119] We next determined the consequence of SIRP4 overexpression on oncogene mediated transformation of NIH3T3 cells. To examine the ability of SIRP4 to influence the formation of cell foci, subconfluent 3T3/pLXSN, 3T3/SIRP4, 3T3/SIRP4-4Y or 3T3/SIRP4-DCT cells were infected with v-fms virus supernatants. As measured by focus formation, transformation by a v-fms retrovirus was significantly suppressed in cells overexpressing wt SIRP4 but not in cells expressing mutant SIRP4.
[0120] Previous reports have described certain SHP-2 binding proteins of 110-130 kDa apparent MW in mouse, rat or hamster cells. Tyrosine hyperphosphorylation of these proteins was observed when an enzymatically inactive SHP-2 mutant was overexpressed. In addition, disruption of SHP-2 function induced a variety of negative effects on growth factor-induced cellular signals. Our experiments strongly indicate that these proteins belong to the SIRP family and that the biological effects previously observed are due to the function of these SIRP proteins.
[0121] Without being bound by any theory, applicant proposes that tyrosine docking sites on SIRP proteins for either SHP-2 and/or other SH2 proteins such as SHP-1 or Grb2 play a significant role since the inhibitory effect of SIRP4 on NIH3T3 cell proliferation and transformation depends on phosphorylation of tyrosines.
[0122] One or both of the SHP phosphatases may tightly regulate the SIRP4 phosphorylation state.
[0123] SIRP4 may also act in its phosphorylated state as a “trapping” protein that sequesters SHP-2 from activated RTKs. The sequestion makes SHP-2 unavailable for other positive regulatory functions such as an adapter which recruits the Grb2-SOS complex to activated receptors. Such a function is supported by the observation that SHP-2 has higher affinity to the tyrosine phosphorylated form of SIRP4 than to autophosphorylated insulin and EGF receptors (Yamauchi, et al., J. Biol. Chem. 270:17716-17722, Yamauchi, et al. J. Biol. Chem. 270:14871-14874 (1995)).
[0124] A third possibility is based on the membrane-spanning structural features of the SIRP4 variant. The high degree of sequence diversity within the Ig-domains is reminiscent of immunoglobulin variable regions and suggests a role of extracellular determinants in the SIRP related signal transduction. Structurally defined interaction of SIRP with specific receptors, soluble ligands, extracellular matrix components or other factors may result in specific regulatory consequences for intracellular signaling events.
[0125] All publications referenced are incorporated by reference herein, including the nucleotide sequences, amino acid sequences, drawings and tables in each publication. All the compounds disclosed and referred to in the publications mentioned above are incorporated by reference herein, including those compounds disclosed and referred to in articles cited by the publications mentioned above.
[0126] Other embodiments of this invention are disclosed in the following claims. As will be obvious to those skilled in the art, may variations and modifications may be made without departing from the spirit and scope of the invention.
1
26
1
3804
DNA
Homo sapiens
1
cacagacgtt tggacagagc aggctcctaa ggtctccaga atgcccgtgc cagcctcctg 60
gccccacctt cctagtcctt tcctgctgat gacgctactg ctggggagac tcacaggagt 120
ggcaggtgag gacgagctac aggtgattca gcctgaaaag tccgtatcag ttgcagctgg 180
agagtcggcc actctgcgct gtgctatgac gtccctgatc cctgtggggc ccatcatgtg 240
gtttagagga gctggagcag gccgggaatt aatctacaat cagaaagaag gccacttccc 300
acgggtaaca actgtttcag aactcacaaa gagaaacaac ctgaactttt ccatcagcat 360
cagtaacatc accccagcag acgccggcac ctactactgt gtgaagttcc ggaaagggag 420
ccctgacgac gtggagttta agtctggagc aggcactgag ctgtctgtgc gcgccaaacc 480
ctctgccccc gtggtatcgg gccctgcggt gagggccaca cctgagcaca cagtgagctt 540
cacctgcgag tcccatggct tctctcccag agacatcacc ctgaaatggt tcaaaaatgg 600
gaatgagctc tcagacttcc agaccaacgt ggaccccgca ggagacagtg tgtcctacag 660
catccacagc acagccaggg tggtgctgac ccgtggggac gttcactctc aagtcatctg 720
cgagatggcc cacatcacct tgcaggggga ccctcttcgt gggactgcca acttgtctga 780
ggccatccga gttccaccca ccttggaggt tactcaacag cccatgaggg cagagaacca 840
ggcaaacgtc acctgccagg tgagcaattt ctacccccgg ggactacagc tgacctggtt 900
ggagaatgga aatgtgtccc ggacagaaac agcttcgacc ctcatagaga acaaggatgg 960
cacctacaac tggatgagct ggctcctggt gaacacctgt gcccacaggg acgatgtggt 1020
gctcacctgt caggtggagc atgatgggca gcaagcagtc agcaaaagct atgccctgga 1080
gatctcagca caccagaagg agcacggctc agatatcacc catgaaccag cgctggctcc 1140
tactgctcca ctcctcgtag ctctcctcct gggccccaag ctgctactgg tggttggtgt 1200
ctctgccatc tacatctgct ggaaacagaa ggcctgactg accctcagtc tctgctgcct 1260
cctcctttct tgagaagctc agcctgagag aaggagctgg cgagaacctt ccccacactc 1320
agctccaaac gcctcctctc ccaggtcatc tgcctgccca cacgctcctg ttccaccttc 1380
acaagaccat gatgccccaa agcagtgtct ctattcacgg tcctgagcag gggccatggg 1440
attgggctct gggcactgac tcatggcacc tccctagaag gtgagaaaca ctccaaatct 1500
aaacacacca ggacttctcc catccgtcgc cttgggactg gccataaacc acagactctc 1560
tccaggctct caagagttat cctgtcttct ggattcctgc ctaccccaac tcccccagcc 1620
ttgttgaggt tctctactgc ctcctgaata cacatgaacc cctataccaa ttttaagaaa 1680
aaaatgattc tctttcctct ttgtccaagc atcctatccc tcaaacccaa aaagaaagaa 1740
gctctccctt ctctctctgt gatggagaca gtatttcttc tagtatcctg cagccttccc 1800
agtcctgctg cttgtggtag aaattgctgc cacagcccaa cattgaggag ccctcgatga 1860
ctgcccttta caactcatat tcagttctgc ctccaaaatg catgtgtcca cttacatgag 1920
atggtaaatg tttaacaatg gactttctga aagggaaaaa ccaaaagctg ttttgcagtg 1980
cttgccaatt tctctagtgt aataactccc aacctgacca atttcagcac tgccaacagt 2040
taaacaacca gattcgaaga ttcctgaaat ttaacaattg gttttcaggg cccagtccaa 2100
gcctgctgct ggaaacctca gagttaaatc cctattctcc acacctctca cctccaccac 2160
ccctccctgt cccagccagc atcatctctt tggggaccac tcctctggct ttcatttttc 2220
agccacagtg attctttgga aaagtcaaat catatcactt ctctgcttct tccccaacac 2280
agctgcatgg tcccgctctc cctccttcaa gtctctgctc aatgtcactt cattaaaggc 2340
ggccttctat aaactacctt gtataaaata ttatttattt tctctatccc ggcattctaa 2400
tttctcttat cctaattaat ttttctttag cccttatttt gatgagtatt atgccgaata 2460
caggcagccc tcacttttca tggccagtgc aagattgcaa aaagactgtg caacctgaaa 2520
cccaggaaag cagtctccat agtcaatcag aaaaacaatg atcattctgt gacctttacc 2580
attttttgtc aaaatattag aaactctcac actctcagtt acaaatgtag aggacaatga 2640
aaatataatg aaataaatat ttatttgtgc actacaattc aaagcattag aaacattgaa 2700
gtcaatggcg tttcttgtaa atgtatccag atgaggttgg aagagtgctt gacctttttg 2760
tatatttcta atatggagtg atatagtttg gctctgtgtc tccatccaaa tctcatctta 2820
aattgtaatc tgcatgtgtt gtgggaatgg gacctaggta ggaggtgact gaatacatgg 2880
gggcggactt cccccttgct gttcttgtga tagtgagttc tcataagatc tcagtgagtt 2940
ctcatgagat ctggtttttt gaaagtgtgt ggcaagtccc ccttcgctct ctctctctct 3000
ctccctcctg ccaccatgtg aagaaggtgc ctgcttcctt ttctccttcc accatggttg 3060
taagtttcct gaggcctccc agtcatgctt cctgttaagc ctgtggaact gtgagtccaa 3120
ttaaacctct tttattcata aaatatccag tttctggtag ttctttatag cagtgtgaga 3180
atgggctaat acacggagca agcatcgttc tttcattttt atttatttta ttttttgaga 3240
tggagtttca ccttattccc aggctggagt gcaatgtcgt gatcttggct cactgcaacc 3300
cccgcctcca gggttcaagt gattctcctg cctcagcctc ctgagtagct gggattacag 3360
gcatgtacca ccacacccag ctaattttgt atttttagta gagatggggt ttctccatgt 3420
tgatcagact agtcttgaac tcccgacctc aggtgatcca cctgtcttgg cctcccaaag 3480
tgctgggatt acaggcatga gccaccatgc ctagccagca agcatcattt ctattatacc 3540
ttggtgtttg cctctttcta agtttggact agcttccaac atcttatccc ttgaattttc 3600
aatattgtgg aatcactcca gaagatcctt tcatgtgaag ttttttgctg gcatttcaac 3660
ctttgggaca tcttcagccc ttttattacc actcctctcc catttgtggc agtttgcgtt 3720
tactacctcc ctctggctgc ctatctgaag ttcctgcatc agggtctaca ttgccacagt 3780
caactatttg tacttctaga attc 3804
2
2433
DNA
Homo sapiens
2
cagccgcggc ccatggagcc cgccggcccg gcccccggcc gcctcgggcc gctgctctgc 60
ctgctgctcg ccgcgtcctg cgcctggtca ggagtggcgg gtgaggagga gctgcaggtg 120
attcagcctg acaagtccgt atcagttgca gctggagagt cggccattct gcactgcact 180
gtgacctccc tgatccctgt ggggcccatc cagtggttca gaggagctgg accagcccgg 240
gaattaatct acaatcaaaa agaaggccac ttcccccggg taacaactgt ttcagagtcc 300
acaaagagag aaaacatgga cttttccatc agcatcagta acatcacccc agcagatgcc 360
ggcacctact actgtgtgaa gttccggaaa gggagccctg acacggagtt taagtctgga 420
gcaggcactg agctgtctgt gcgtgccaaa ccctctgccc ccgtggtatc gggccctgcg 480
gcgagggcca cacctcagca cacagtgagc ttcacctgcg agtcccacgg cttctcaccc 540
agagacatca ccctgaaatg gttcaaaaat gggaatgagc tctcagactt ccagaccaac 600
gtggaccccg taggagagag cgtgtcctac agcatccaca gcacagccaa ggtggtgctg 660
acccgcgagg acgttcactc tcaagtcatc tgcgaggtgg cccacgtcac cttgcagggg 720
gaccctcttc gtgggactgc caacttgtct gagaccatcc gagttccacc caccttggag 780
gttactcaac agcccgtgag ggcagagaac caggtgaatg tcacctgcca ggtgaggaag 840
ttctaccccc agagactaca gctgacctgg ttggagaatg gaaacgtgtc ccggacagaa 900
acggcctcaa ccgttacaga gaacaaggat ggtacctaca actggatgag ctggctcctg 960
gtgaatgtat ctgcccacag ggatgatgtg aagctcacct gccaggtgga gcatgacggg 1020
cagccagcgg tcagcaaaag ccatgacctg aaggtctcag cccacccgaa ggagcagggc 1080
tcaaataccg ccgctgagaa cactggatct aatgaacgga acatctatat tgtggtgggt 1140
gtggtgtgca ccttgctggt ggccctactg atggcggccc tctacctcgt ccgaatcaga 1200
cagaagaaag cccagggctc cacttcttct acaaggttgc atgagcccga gaagaatgcc 1260
agagaaataa cacaggacac aaatgatatc acatatgcag acctgaacct gcccaagggg 1320
aagaagcctg ctccccaggc tgcggagccc aacaaccaca cggagtatgc cagcattcag 1380
accagcccgc agcccgcgtc ggaggacacc ctcacctatg ctgacctgga catggtccac 1440
ctcaaccgga cccccaagca gccggccccc aagcctgagc cgtccttctc agagtacgcc 1500
agcgtccagg tcccgaggaa gtgaatggga ccgtggtttg ctctagcacc catctctacg 1560
cgctttcttg tcccacaggg agccgccgtg atgagcacag ccaacccagt tcccggaggg 1620
ctggggcggt gcaggctctg ggacccaggg gccagggtgg ctcttctctc cccacccctc 1680
cttggctctc cagcacttcc tgggcagcca cggccccctc ccccaacatt gccacacacc 1740
tggaggctga cgttgccaaa ccagccaggg aaccaacctg ggaagtggcc agaactgcct 1800
ggggtccaag aactcttgtg cctccgtcca tcaccatgtg ggttttgaag accctcgact 1860
gcctccccga tgctccgaag cctgatcttc cagggtgggg aggagaaaat cccacctccc 1920
ctgacctcca ccacctccac caccaccacc accaccacca ccaccactac caccaccacc 1980
caactggggc tagagtgggg aagatttccc ctttagatca aactgcccct tccatggaaa 2040
agctggaaaa aaactctgga acccatatcc aggcttggtg aggttgctgc caacagtcct 2100
ggcctccccc atccctaggc aaagagccat gagtcctgga ggaggagagg acccctccca 2160
aaggactgga agcaaaaccc tctgcttcct tgggtccctc caagactccc tggggcccaa 2220
ctgtgttgct ccacccggac ccatctctcc cttctagacc tgagcttgcc cctccagcta 2280
gcactaagca acatctcgct gtaagcgcct gtaaattact gtgaaatgtg aaacgtgcaa 2340
tcttgaaact gaggtgttag aaaacttgat ctgtggtgtt ttgttttgtt ttttttctta 2400
aaacaacagc aacgtgaaaa aaaaaaaaaa aaa 2433
3
3645
DNA
Mus sp.
3
gcccgcctgc cgagcgcgct caccgccgct ctccctcctt gctctgcagc cgcggcccat 60
ggagcccgcc ggcgcccctg gccgcctagg gccgctgctg ctctgcctgc tgctctccgc 120
gtcctgtttc tgtacaggag tcacggggaa agaactgaag gtgactcagc ctgagaaatc 180
agtgtctgtt gctgctgggg attcgaccgt tctgaactgc actttgacct ccttgttgcc 240
ggtgggaccc attaagtggt acagaggagt aggcaaagcc ggctgtttga tctacagttt 300
cacaggagaa cactttcctc gagttacaaa tgtttcagat gctactaaga gaaacaatat 360
ggacttttcc atccgtatca gtaatgtcac cccagaagat gccggtacct actactgtgt 420
gaagttccag aaaggaccat cagagcctga cacagaaata caatctggag ggggaacaga 480
ggtctatgta ctcgccaaac cttctccacc ggaggatccc cccaggagac aggggcatac 540
tgaccagaaa gtgaacttca cctgcaagtc tcatggcttc tctccccgga atatcaccct 600
gaagtggttc aaagatgggc aagaactcca ccccttggag accaccgtga accctagtgg 660
aaagaatgtc tcctacaaca tctccagcac agtcagggtg gtactaaact ccatggatgt 720
tcattctaag gtcatctgcg aggtagccca catcaccttg gatagaagcc ctcttcgtgg 780
gattgctaac ctgtctaact tcatccgagt ttcacccacc gtgaaggtca cccaacagtc 840
cccgacgtca atgaaccagg tgaacctcac ctgccgggat gagaggttct accccgagga 900
tctccagctg atctggctgg agaatggaaa cgtatcacgg aatgacacgc ccaagaatct 960
cacaaagaac acggatggga cctataatta cacaagcttg ttcctggtga actcatctgc 1020
tcatagagag gacgtggtgt tcacgtgcca ggtgaagcac gaccaacagc cagcgatcac 1080
ccgaaaccat accgtgctgg gacttgccca ctcgagtgat caagggagca tgcaaacctt 1140
ccctggtaat aatgctaccc acaactggaa tgtcttcatc ggtgtgggcg tggcgtgtgc 1200
tttgctcgta gtcctgctga tggctgctct ctacctcctc cggatcaaac agaagaaagc 1260
caaggggtca acatcttcca cacggttgca cgagcccgag aagaacgcca gggaaataac 1320
ccaggtacag tctttgatcc aggacacaaa tgacatcaac gacatcacat acgcagacct 1380
gaatctccca aagagaagga agcccgcacc cggctccctt gagttcctta acaaccacac 1440
agaatatgca agcattgaga caggcaaagt gcctaggcca gaggataccc tcacctatgc 1500
tgacctggac atggtccacc tcagccgggc acagccagcc cccaagcctg agccatcttt 1560
ctcagagtat gctagtgtcc aggtccagag gaagtgaatg gggctgtggt ctgtactagg 1620
ccccatcccc acaagttttc ttgtcctaca tggagtggcc atgacgagga catccagcca 1680
gccaatcctg tccccagaag gccaggtggc acgggtccta ggaccagggg taagggtggc 1740
ctttgtcttc cctccgtggc tcttcaacac ctcttgggca ccacgtcccc ttcttccgga 1800
ggctgggtct tgcagaacca gagggcgaac tggagaaatc tgcctggaat ccaagaagtg 1860
ttgtgcctcg gcccatcact cgtgggctcg gatcctggtc ttggcaaccc caggttgcgt 1920
ccttgatgtt ccagagcttg gtcttctgtg tggagaagag ctcaccatct ctacccaact 1980
tgagctttgg gaccagactc cctttagatc aaaccgcccc atctgtggaa gaactacacc 2040
agaagtcgac aagttttcag ccaacagtgt ctggcctccc cacctcccag gctgactagc 2100
ctggggagaa ggaaccctct cctcctagac cagcagagac tccctgggca tgttcagtgt 2160
ggccccacct cccttccagt cccagcttgc ttcctccagc tagcactaac tcagcagcat 2220
cgctctgtgg acgcctgtaa attattgaga aatgtgaact gtgcagtctt aaagctaagg 2280
tgttagaaaa tttgatttat gctgtttagt tgttgttggg tttcttttct ttttaatttc 2340
tttttctttt ttgatttttt ttctttccct taaaacaaca gcagccagca tcttggctct 2400
ttgtcatgtg ttgaatggtt gggtcttgtg aagtctgagg tctaacagtt tattgtcctg 2460
gaaggatttt cttacagcag aaacagattt ttttcaaatt cccagaatcc tgaggaccaa 2520
gaaggatccc tcagctgcta cttccagcac gcagcgtcac tgggacgaac caggccctgt 2580
tcttacaagg ccacatggcg ggcctttgcc tccatggcta ctgtggtaag tgcagccttg 2640
tctgacccaa tgctgaccta atgttggcca ttccacattg aggggacaag gtcagtgatg 2700
ccccccttgg ctcacaagca cttcagaggc atgcagagag aagggacact cgtccagctc 2760
tctgaggtaa tcagtgcaag gaggagtccg ttttttgcca gcaaacctca gcaggatcac 2820
actggaacag aacctggtca tacctgtgac aacacagctg tgagccaggg caaaccaccc 2880
actgtcactg gctcgagagt ctgggagagc tctgacccga caccctttaa actggatgcc 2940
ggggcctggc tgggcaatgc caagtggtta tggcaaccct gactatctgg tcttaacatg 3000
tagctcagga agtggaggcg ctaatgtccc caatccctgg ggattcctga ttccagctat 3060
tcatgtaagc agagccaacc tgcctatttc tgtagggtgc gactgggatg ttaggagcac 3120
agcaaggacc cagctctgta gggctggtga cctgatacct tctcataatg gcatctagaa 3180
gttaggctga gttgcctcac tggcccagca aaccagaact tgtctttggc cgggccatgt 3240
tcttgggctg tcttctaatt ccaaagggtt ggttggtaaa gctccacccc cttctcctct 3300
gcctaaagac ataacatgtg tatacacaca cgggtgtata gatgagttaa aagaatgtcc 3360
tcgctggcat cctaattttg tcttaagttt ttttggaggg agaaaggaac aaggcaaggg 3420
aagatgtgta gctttggctt taaccaggca gcctgggggc tcccaagcct atggaaccct 3480
ggtacaaaga agagaacaga agcgccctgt gaggagtggg atttgttttt ctgtagacca 3540
gatgagaagg aaacaggccc tgttttgtac atagttgcaa cttaaaattt ttggcttgca 3600
aaatattttt gtaataaaga tttctgggta acaataaaaa aaaaa 3645
4
2020
DNA
Mus sp.
4
ccctcactaa agggaacaaa agctggagct ccaccgcggt ggcggccgct ctagaactag 60
tggatccccc gggctgcagg caaccatgct tctcctagat gcctggaccc acattcctca 120
ctgtgtcctg ctgttgatcc tgcttctggg acttaaagga gcagctatga gagagctgaa 180
ggtgatccaa cctgttaaat cattttttgt tggtgctgga gggtcagcca ctctgaactg 240
cacagtgaca tctctcctcc ctgtggggcc catgaggtgg tacaggggta taggacaaag 300
tcgactcttg atatactcgt tcacaggaga aggcttcccc agaataacaa atacttcaga 360
tactacaaag agaaacaaca tggacttttc catccgtatc agtaatgtca ctcctgctga 420
ttcgggtacc tactactgtg tgaagttcca gagaggacca tcagactttt acactgagat 480
tcagtctgga ggtggcactg agttgtcagt acttgctaaa ccatcttcac ctatggtctc 540
cggtcctgca gccagagctg tccctcagca gacagtgacc tttacatgca gatcccatgg 600
attctttccg cggaacctca cgctgaagtg gttcaagaat ggagatgaga tctctcactt 660
ggaaacttct gtggaaccgg aagaaacaag tgtctcctat agagtttcca gcacagtcca 720
ggtggtgttg gaacctaggg atgtccgctc tcagatcatc tgtgaagtgg atcatgtcac 780
tttagatcga gcccctctca gagggattgc tcacatctct gagttcattc aagttccacc 840
caccctggag atccgccagc agccaacaat ggtttggaat gtgataaatg ttacctgcca 900
aatacagaag ttctatcctc caagttttca gttgacctgg ttagagaatg gaaatatatc 960
ccggagagaa gtacctttta cacttacagt aaacaaggat ggaacttaca actggatcag 1020
ctgtctcttg gtgaacatat ctgcccttga ggagaacatg gtagtgacat gccaggttga 1080
gcatgatgga caagcagaag tcattgaaac ccatactgtg gtggtcactg aacatcagag 1140
agtgaaaggt actgctacca agtctggtga ggtcttcacc ccacccttat gtctaaatgt 1200
aaattgggct ttatttttta tgtataaggt aacattcttg attattgtag cattatcctg 1260
acaactacaa agtaaaatgt taacgtcata tttcattccc aacttctcac acgtctcaca 1320
tatctttcca ctaatagatt aaatagttaa gaatggaagg tatcatcaaa ttccagtatc 1380
ttgccccttc cctgttttac ctaacatttg tgaacatcct tatgctcatg tgtttccttt 1440
accatatctt tactgactcc attacatttt agatatttcc taaatatagt gtcctaatgg 1500
agtgaaattt caacgggtca cctgacaacc tgtttgtaca cacacacaca cacacacaca 1560
cacacacaca cacacagcat atgatctgga ctaatgaaat aaaggaaaat caaatgtcca 1620
ttggagcact gctatcacta aggtataagg aaaacttgct agcaaagtat ttcttttcaa 1680
cttgttacga tgctagcagt tagtttgcat tagattggac ccatttatgt gaatatcttt 1740
ttccttctct taaaacaaca aaaaagatcc tcaactccag tgacttttga aaaactcatg 1800
ttccttggca tccctccttt gctgtgagtt cattggctgg ataaacactg ggtcgcctaa 1860
ttatctataa atatgccagt taaaaatgtc aaggttagaa agcatcagtc catacagtgc 1920
aaatatagtc cacagtgggt gctcaggtaa atcatgatat tttcatttaa aatatacatt 1980
caataaaatt aactgtagtt caaaaaaaaa aaaaaaaaaa 2020
5
398
PRT
Homo sapiens
5
Met Pro Val Pro Ala Ser Trp Pro His Leu Pro Ser Pro Phe Leu Leu
1 5 10 15
Met Thr Leu Leu Leu Gly Arg Leu Thr Gly Val Ala Gly Glu Asp Glu
20 25 30
Leu Gln Val Ile Gln Pro Glu Lys Ser Val Ser Val Ala Ala Gly Glu
35 40 45
Ser Ala Thr Leu Arg Cys Ala Met Thr Ser Leu Ile Pro Val Gly Pro
50 55 60
Ile Met Trp Phe Arg Gly Ala Gly Ala Gly Arg Glu Leu Ile Tyr Asn
65 70 75 80
Gln Lys Glu Gly His Phe Pro Arg Val Thr Thr Val Ser Glu Leu Thr
85 90 95
Lys Arg Asn Asn Leu Asn Phe Ser Ile Ser Ile Ser Asn Ile Thr Pro
100 105 110
Ala Asp Ala Gly Thr Tyr Tyr Cys Val Lys Phe Arg Lys Gly Ser Pro
115 120 125
Asp Asp Val Glu Phe Lys Ser Gly Ala Gly Thr Glu Leu Ser Val Arg
130 135 140
Ala Lys Pro Ser Ala Pro Val Val Ser Gly Pro Ala Val Arg Ala Thr
145 150 155 160
Pro Glu His Thr Val Ser Phe Thr Cys Glu Ser His Gly Phe Ser Pro
165 170 175
Arg Asp Ile Thr Leu Lys Trp Phe Lys Asn Gly Asn Glu Leu Ser Asp
180 185 190
Phe Gln Thr Asn Val Asp Pro Ala Gly Asp Ser Val Ser Tyr Ser Ile
195 200 205
His Ser Thr Ala Arg Val Val Leu Thr Arg Gly Asp Val His Ser Gln
210 215 220
Val Ile Cys Glu Met Ala His Ile Thr Leu Gln Gly Asp Pro Leu Arg
225 230 235 240
Gly Thr Ala Asn Leu Ser Glu Ala Ile Arg Val Pro Pro Thr Leu Glu
245 250 255
Val Thr Gln Gln Pro Met Arg Ala Glu Asn Gln Ala Asn Val Thr Cys
260 265 270
Gln Val Ser Asn Phe Tyr Pro Arg Gly Leu Gln Leu Thr Trp Leu Glu
275 280 285
Asn Gly Asn Val Ser Arg Thr Glu Thr Ala Ser Thr Leu Ile Glu Asn
290 295 300
Lys Asp Gly Thr Tyr Asn Trp Met Ser Trp Leu Leu Val Asn Thr Cys
305 310 315 320
Ala His Arg Asp Asp Val Val Leu Thr Cys Gln Val Glu His Asp Gly
325 330 335
Gln Gln Ala Val Ser Lys Ser Tyr Ala Leu Glu Ile Ser Ala His Gln
340 345 350
Lys Glu His Gly Ser Asp Ile Thr His Glu Pro Ala Leu Ala Pro Thr
355 360 365
Ala Pro Leu Leu Val Ala Leu Leu Leu Gly Pro Lys Leu Leu Leu Val
370 375 380
Val Gly Val Ser Ala Ile Tyr Ile Cys Trp Lys Gln Lys Ala
385 390 395
6
503
PRT
Homo sapiens
6
Met Glu Pro Ala Gly Pro Ala Pro Gly Arg Leu Gly Pro Leu Leu Cys
1 5 10 15
Leu Leu Leu Ala Ala Ser Cys Ala Trp Ser Gly Val Ala Gly Glu Glu
20 25 30
Glu Leu Gln Val Ile Gln Pro Asp Lys Ser Val Ser Val Ala Ala Gly
35 40 45
Glu Ser Ala Ile Leu His Cys Thr Val Thr Ser Leu Ile Pro Val Gly
50 55 60
Pro Ile Gln Trp Phe Arg Gly Ala Gly Pro Ala Arg Glu Leu Ile Tyr
65 70 75 80
Asn Gln Lys Glu Gly His Phe Pro Arg Val Thr Thr Val Ser Glu Ser
85 90 95
Thr Lys Arg Glu Asn Met Asp Phe Ser Ile Ser Ile Ser Asn Ile Thr
100 105 110
Pro Ala Asp Ala Gly Thr Tyr Tyr Cys Val Lys Phe Arg Lys Gly Ser
115 120 125
Pro Asp Thr Glu Phe Lys Ser Gly Ala Gly Thr Glu Leu Ser Val Arg
130 135 140
Ala Lys Pro Ser Ala Pro Val Val Ser Gly Pro Ala Ala Arg Ala Thr
145 150 155 160
Pro Gln His Thr Val Ser Phe Thr Cys Glu Ser His Gly Phe Ser Pro
165 170 175
Arg Asp Ile Thr Leu Lys Trp Phe Lys Asn Gly Asn Glu Leu Ser Asp
180 185 190
Phe Gln Thr Asn Val Asp Pro Val Gly Glu Ser Val Ser Tyr Ser Ile
195 200 205
His Ser Thr Ala Lys Val Val Leu Thr Arg Glu Asp Val His Ser Gln
210 215 220
Val Ile Cys Glu Val Ala His Val Thr Leu Gln Gly Asp Pro Leu Arg
225 230 235 240
Gly Thr Ala Asn Leu Ser Glu Thr Ile Arg Val Pro Pro Thr Leu Glu
245 250 255
Val Thr Gln Gln Pro Val Arg Ala Glu Asn Gln Val Asn Val Thr Cys
260 265 270
Gln Val Arg Lys Phe Tyr Pro Gln Arg Leu Gln Leu Thr Trp Leu Glu
275 280 285
Asn Gly Asn Val Ser Arg Thr Glu Thr Ala Ser Thr Val Thr Glu Asn
290 295 300
Lys Asp Gly Thr Tyr Asn Trp Met Ser Trp Leu Leu Val Asn Val Ser
305 310 315 320
Ala His Arg Asp Asp Val Lys Leu Thr Cys Gln Val Glu His Asp Gly
325 330 335
Gln Pro Ala Val Ser Lys Ser His Asp Leu Lys Val Ser Ala His Pro
340 345 350
Lys Glu Gln Gly Ser Asn Thr Ala Ala Glu Asn Thr Gly Ser Asn Glu
355 360 365
Arg Asn Ile Tyr Ile Val Val Gly Val Val Cys Thr Leu Leu Val Ala
370 375 380
Leu Leu Met Ala Ala Leu Tyr Leu Val Arg Ile Arg Gln Lys Lys Ala
385 390 395 400
Gln Gly Ser Thr Ser Ser Thr Arg Leu His Glu Pro Glu Lys Asn Ala
405 410 415
Arg Glu Ile Thr Gln Asp Thr Asn Asp Ile Thr Tyr Ala Asp Leu Asn
420 425 430
Leu Pro Lys Gly Lys Lys Pro Ala Pro Gln Ala Ala Glu Pro Asn Asn
435 440 445
His Thr Glu Tyr Ala Ser Ile Gln Thr Ser Pro Gln Pro Ala Ser Glu
450 455 460
Asp Thr Leu Thr Tyr Ala Asp Leu Asp Met Val His Leu Asn Arg Thr
465 470 475 480
Pro Lys Gln Pro Ala Pro Lys Pro Glu Pro Ser Phe Ser Glu Tyr Ala
485 490 495
Ser Val Gln Val Pro Arg Lys
500
7
512
PRT
Mus sp.
7
Met Glu Pro Ala Gly Ala Pro Gly Arg Leu Gly Pro Leu Leu Leu Cys
1 5 10 15
Leu Leu Leu Ser Ala Ser Cys Phe Cys Thr Gly Val Thr Gly Lys Glu
20 25 30
Leu Lys Val Thr Gln Pro Glu Lys Ser Val Ser Val Ala Ala Gly Asp
35 40 45
Ser Thr Val Leu Asn Cys Thr Leu Thr Ser Leu Leu Pro Val Gly Pro
50 55 60
Ile Lys Trp Tyr Arg Gly Val Gly Lys Ala Gly Cys Leu Ile Tyr Ser
65 70 75 80
Phe Thr Gly Glu His Phe Pro Arg Val Thr Asn Val Ser Asp Ala Thr
85 90 95
Lys Arg Asn Asn Met Asp Phe Ser Ile Arg Ile Ser Asn Val Thr Pro
100 105 110
Glu Asp Ala Gly Thr Tyr Tyr Cys Val Lys Phe Gln Lys Gly Pro Ser
115 120 125
Glu Pro Asp Thr Glu Ile Gln Ser Gly Gly Gly Thr Glu Val Tyr Val
130 135 140
Leu Ala Lys Pro Ser Pro Pro Glu Asp Pro Pro Arg Arg Gln Gly His
145 150 155 160
Thr Asp Gln Lys Val Asn Phe Thr Cys Lys Ser His Gly Phe Ser Pro
165 170 175
Arg Asn Ile Thr Leu Lys Trp Phe Lys Asp Gly Gln Glu Leu His Pro
180 185 190
Leu Glu Thr Thr Val Asn Pro Ser Gly Lys Asn Val Ser Tyr Asn Ile
195 200 205
Ser Ser Thr Val Arg Val Val Leu Asn Ser Met Asp Val His Ser Lys
210 215 220
Val Ile Cys Glu Val Ala His Ile Thr Leu Asp Arg Ser Pro Leu Arg
225 230 235 240
Gly Ile Ala Asn Leu Ser Asn Phe Ile Arg Val Ser Pro Thr Val Lys
245 250 255
Val Thr Gln Gln Ser Pro Thr Ser Met Asn Gln Val Asn Leu Thr Cys
260 265 270
Arg Asp Glu Arg Phe Tyr Pro Glu Asp Leu Gln Leu Ile Trp Leu Glu
275 280 285
Asn Gly Asn Val Ser Arg Asn Asp Thr Pro Lys Asn Leu Thr Lys Asn
290 295 300
Thr Asp Gly Thr Tyr Asn Tyr Thr Ser Leu Phe Leu Val Asn Ser Ser
305 310 315 320
Ala His Arg Glu Asp Val Val Phe Thr Cys Gln Val Lys His Asp Gln
325 330 335
Gln Pro Ala Ile Thr Arg Asn His Thr Val Leu Gly Leu Ala His Ser
340 345 350
Ser Asp Gln Gly Ser Met Gln Thr Phe Pro Gly Asn Asn Ala Thr His
355 360 365
Asn Trp Asn Val Phe Ile Gly Val Gly Val Ala Cys Ala Leu Leu Val
370 375 380
Val Leu Leu Met Ala Ala Leu Tyr Leu Leu Arg Ile Lys Gln Lys Lys
385 390 395 400
Ala Lys Gly Ser Thr Ser Ser Thr Arg Leu His Glu Pro Glu Lys Asn
405 410 415
Ala Arg Glu Ile Thr Gln Val Gln Ser Leu Ile Gln Asp Thr Asn Asp
420 425 430
Ile Asn Asp Ile Thr Tyr Ala Asp Leu Asn Leu Pro Lys Arg Arg Lys
435 440 445
Pro Ala Pro Gly Ser Leu Glu Phe Leu Asn Asn His Thr Glu Tyr Ala
450 455 460
Ser Ile Glu Thr Gly Lys Val Pro Arg Pro Glu Asp Thr Leu Thr Tyr
465 470 475 480
Ala Asp Leu Asp Met Val His Leu Ser Arg Ala Gln Pro Ala Pro Lys
485 490 495
Pro Glu Pro Ser Phe Ser Glu Tyr Ala Ser Val Gln Val Gln Arg Lys
500 505 510
8
391
PRT
Mus sp.
8
Met Leu Leu Leu Asp Ala Trp Thr His Ile Pro His Cys Val Leu Leu
1 5 10 15
Leu Ile Leu Leu Leu Gly Leu Lys Gly Ala Ala Met Arg Glu Leu Lys
20 25 30
Val Ile Gln Pro Val Lys Ser Phe Phe Val Gly Ala Gly Gly Ser Ala
35 40 45
Thr Leu Asn Cys Thr Val Thr Ser Leu Leu Pro Val Gly Pro Met Arg
50 55 60
Trp Tyr Arg Gly Ile Gly Gln Ser Arg Leu Leu Ile Tyr Ser Phe Thr
65 70 75 80
Gly Glu Gly Phe Pro Arg Ile Thr Asn Thr Ser Asp Thr Thr Lys Arg
85 90 95
Asn Asn Met Asp Phe Ser Ile Arg Ile Ser Asn Val Thr Pro Ala Asp
100 105 110
Ser Gly Thr Tyr Tyr Cys Val Lys Phe Gln Arg Gly Pro Ser Asp Phe
115 120 125
Tyr Thr Glu Ile Gln Ser Gly Gly Gly Thr Glu Leu Ser Val Leu Ala
130 135 140
Lys Pro Ser Ser Pro Met Val Ser Gly Pro Ala Ala Arg Ala Val Pro
145 150 155 160
Gln Gln Thr Val Thr Phe Thr Cys Arg Ser His Gly Phe Phe Pro Arg
165 170 175
Asn Leu Thr Leu Lys Trp Phe Lys Asn Gly Asp Glu Ile Ser His Leu
180 185 190
Glu Thr Ser Val Glu Pro Glu Glu Thr Ser Val Ser Tyr Arg Val Ser
195 200 205
Ser Thr Val Gln Val Val Leu Glu Pro Arg Asp Val Arg Ser Gln Ile
210 215 220
Ile Cys Glu Val Asp His Val Thr Leu Asp Arg Ala Pro Leu Arg Gly
225 230 235 240
Ile Ala His Ile Ser Glu Phe Ile Gln Val Pro Pro Thr Leu Glu Ile
245 250 255
Arg Gln Gln Pro Thr Met Val Trp Asn Val Ile Asn Val Thr Cys Gln
260 265 270
Ile Gln Lys Phe Tyr Pro Pro Ser Phe Gln Leu Thr Trp Leu Glu Asn
275 280 285
Gly Asn Ile Ser Arg Arg Glu Val Pro Phe Thr Leu Thr Val Asn Lys
290 295 300
Asp Gly Thr Tyr Asn Trp Ile Ser Cys Leu Leu Val Asn Ile Ser Ala
305 310 315 320
Leu Glu Glu Asn Met Val Val Thr Cys Gln Val Glu His Asp Gly Gln
325 330 335
Ala Glu Val Ile Glu Thr His Thr Val Val Val Thr Glu His Gln Arg
340 345 350
Val Lys Gly Thr Ala Thr Lys Ser Gly Glu Val Phe Thr Pro Pro Leu
355 360 365
Cys Leu Asn Val Asn Trp Ala Leu Phe Phe Met Tyr Lys Val Thr Phe
370 375 380
Leu Ile Ile Val Ala Leu Ser
385 390
9
13
PRT
Rattus sp.
9
Pro Ile Tyr Ser Phe Ile Gly Gly Glu His Phe Pro Arg
1 5 10
10
9
PRT
Rattus sp.
10
Ile Val Glu Pro Asp Thr Glu Ile Lys
1 5
11
6
PRT
Rattus sp.
11
Tyr Gly Phe Ser Pro Arg
1 5
12
12
PRT
Rattus sp.
12
Ile Lys Glu Val Ala His Val Asn Leu Glu Val Arg
1 5 10
13
8
PRT
Rattus sp.
13
Val Ala Ala Gly Asp Ser Ala Thr
1 5
14
107
PRT
Unknown Organism
Description of Unknown Organism Mus sp. or
Homosapiens
14
Asp Glu Leu Gln Val Ile Gln Pro Glu Lys Ser Val Ser Val Ala Ala
1 5 10 15
Gly Glu Ser Ala Thr Leu Arg Cys Ala Met Thr Ser Leu Ile Pro Val
20 25 30
Gly Pro Ile Met Trp Phe Arg Gly Ala Gly Ala Gly Arg Glu Leu Ile
35 40 45
Tyr Asn Gln Lys Glu Gly His Phe Pro Arg Val Thr Thr Val Ser Glu
50 55 60
Leu Thr Lys Arg Asn Asn Leu Asp Phe Ser Ile Ser Ile Ser Asn Ile
65 70 75 80
Thr Pro Ala Asp Ala Gly Thr Tyr Tyr Cys Val Lys Phe Arg Glu Gly
85 90 95
Ser Pro Asp Asp Val Glu Phe Lys Ser Gly Ala
100 105
15
107
PRT
Unknown Organism
Description of Unknown Organism Mus sp. or
Homosapiens
15
Asp Glu Leu Gln Val Ile Gln Pro Glu Lys Ser Val Ser Val Ala Ala
1 5 10 15
Gly Glu Ser Ala Thr Leu Arg Cys Ala Met Thr Ser Leu Ile Pro Val
20 25 30
Gly Pro Ile Met Trp Phe Arg Gly Ala Gly Ala Gly Arg Glu Leu Ile
35 40 45
Tyr Asn Gln Lys Glu Gly His Phe Pro Arg Val Thr Thr Val Ser Glu
50 55 60
Leu Thr Lys Arg Asn Asn Leu Asp Phe Ser Ile Ser Ile Ser Asn Ile
65 70 75 80
Thr Pro Ala Asp Ala Gly Thr Tyr Tyr Cys Val Lys Phe Arg Lys Gly
85 90 95
Ser Pro Asp Asp Val Glu Phe Lys Ser Gly Ala
100 105
16
107
PRT
Unknown Organism
Description of Unknown Organism Mus sp. or
Homosapiens
16
Glu Glu Leu Gln Val Ile Gln Pro Glu Lys Ser Val Leu Val Ala Ala
1 5 10 15
Gly Glu Thr Ala Thr Leu Arg Cys Thr Ala Thr Ser Leu Ile Pro Val
20 25 30
Gly Pro Ile Met Trp Phe Arg Gly Ala Gly Ala Gly Arg Glu Leu Ile
35 40 45
Tyr Asn Gln Lys Glu Gly His Phe Pro Arg Val Thr Thr Val Ser Asp
50 55 60
Leu Thr Lys Arg Asn Asn Met Asp Phe Ser Ile Arg Ile Gly Asn Ile
65 70 75 80
Thr Pro Ala Asp Ala Gly Thr Tyr Tyr Cys Val Lys Phe Arg Lys Gly
85 90 95
Ser Pro Asp Asp Val Glu Phe Lys Ser Gly Ala
100 105
17
107
PRT
Unknown Organism
Description of Unknown Organism Mus sp. or
Homosapiens
17
Glu Glu Leu Gln Val Ile Gln Pro Asp Lys Ser Val Ser Val Ala Pro
1 5 10 15
Gly Glu Ser Ala Ile Leu His Cys Thr Val Thr Ser Leu Ile Pro Val
20 25 30
Gly Pro Ile Gln Trp Phe Arg Gly Ala Gly Pro Ala Arg Glu Leu Ile
35 40 45
Tyr Asn Gln Lys Glu Gly His Phe Pro Arg Val Thr Thr Val Ser Glu
50 55 60
Ser Thr Lys Arg Glu Asn Met Asn Phe Ser Ile Ser Ile Ser Asn Ile
65 70 75 80
Thr Pro Ala Asp Ala Gly Thr Tyr Tyr Cys Val Lys Phe Arg Lys Gly
85 90 95
Ser Pro Asp Asp Val Glu Phe Lys Ser Gly Ala
100 105
18
107
PRT
Unknown Organism
Description of Unknown Organism Mus sp. or
Homosapiens
18
Asp Glu Leu Gln Val Ile Gln Pro Asp Lys Ser Val Ser Val Ala Ala
1 5 10 15
Gly Glu Ser Ala Thr Leu Arg Cys Ala Met Thr Ser Leu Ile Pro Val
20 25 30
Gly Pro Ile Met Trp Phe Arg Gly Ala Gly Ala Gly Arg Glu Leu Ile
35 40 45
Ser Asn Gln Lys Glu Gly His Phe Pro Arg Val Thr Thr Val Ser Glu
50 55 60
Ser Thr Lys Arg Glu Asn Met Asp Phe Ser Ile Ser Ile Ser Asn Ile
65 70 75 80
Thr Pro Ala Asp Ala Gly Thr Tyr Tyr Cys Val Lys Phe Arg Lys Gly
85 90 95
Ser Pro Asp Asp Val Glu Phe Lys Ser Gly Ala
100 105
19
107
PRT
Unknown Organism
Description of Unknown Organism Mus sp. or
Homosapiens
19
Asp Glu Leu Gln Val Ile Gln Pro Glu Lys Ser Val Ser Val Ala Pro
1 5 10 15
Gly Glu Ser Ala Thr Leu Arg Cys Ala Met Thr Ser Leu Ile Pro Val
20 25 30
Gly Pro Ile Met Trp Phe Arg Gly Ala Gly Ala Gly Arg Glu Leu Ile
35 40 45
Ser Asn Gln Lys Glu Gly His Phe Pro Arg Val Thr Thr Val Ser Glu
50 55 60
Leu Thr Lys Arg Asn Asn Leu Asp Phe Ser Ile Ser Ile Ser Asn Ile
65 70 75 80
Thr Pro Ala Asp Ala Gly Thr Tyr Tyr Cys Val Lys Phe Arg Lys Gly
85 90 95
Ser Pro Asp Asp Val Glu Phe Lys Ser Gly Ala
100 105
20
106
PRT
Unknown Organism
Description of Unknown Organism Mus sp. or
Homosapiens
20
Glu Glu Leu Gln Val Ile Gln Pro Asp Lys Ser Val Ser Val Ala Pro
1 5 10 15
Gly Glu Ser Ala Ile Leu His Cys Thr Val Thr Ser Leu Ile Pro Val
20 25 30
Gly Pro Ile Gln Trp Phe Arg Gly Ala Gly Pro Ala Arg Glu Leu Ile
35 40 45
Tyr Asn Gln Lys Glu Gly His Phe Pro Arg Val Thr Thr Val Ser Asp
50 55 60
Leu Thr Lys Arg Asn Asn Leu Asp Phe Ser Ile Ser Ile Ser Asn Ile
65 70 75 80
Thr Pro Ala Asp Ala Gly Thr Tyr Tyr Cys Val Lys Phe Arg Lys Gly
85 90 95
Ser Pro Asp Val Glu Phe Lys Ser Gly Ala
100 105
21
106
PRT
Unknown Organism
Description of Unknown Organism Mus sp. or
Homosapiens
21
Glu Glu Leu Gln Val Ile Gln Pro Asp Lys Ser Val Ser Val Ala Pro
1 5 10 15
Gly Glu Ser Ala Ile Leu His Cys Thr Val Thr Ser Leu Ile Pro Val
20 25 30
Gly Pro Ile Gln Trp Phe Arg Gly Ala Gly Pro Ala Arg Glu Leu Ile
35 40 45
Tyr Asn Gln Lys Glu Gly His Phe Pro Arg Val Thr Thr Val Ser Glu
50 55 60
Ser Thr Lys Arg Glu Asn Leu Asp Phe Ser Ile Ser Ile Ser Asn Ile
65 70 75 80
Thr Pro Ala Asp Ala Gly Thr Tyr Tyr Cys Val Lys Phe Arg Lys Gly
85 90 95
Ser Pro Asp Val Glu Phe Lys Ser Gly Ala
100 105
22
107
PRT
Unknown Organism
Description of Unknown Organism Mus sp. or
Homosapiens
22
Asp Glu Leu Gln Val Ile Gln Ser Glu Lys Ser Val Ser Val Ala Ala
1 5 10 15
Gly Glu Ser Ala Ala Leu His Cys Ala Met Thr Ser Leu Ile Pro Val
20 25 30
Gly Pro Ile Met Trp Phe Arg Gly Ala Gly Ala Gly Arg Glu Leu Ile
35 40 45
Tyr Asn Gln Lys Glu Gly His Phe Pro Arg Val Thr Thr Val Ser Glu
50 55 60
Leu Thr Lys Arg Asn Asn Leu Asp Phe Ser Ile Ser Ile Ser Asn Ile
65 70 75 80
Thr Pro Ala Asp Ala Gly Thr Tyr Tyr Cys Val Lys Phe Arg Lys Gly
85 90 95
Ser Pro Asp Asp Val Glu Phe Lys Ser Gly Ala
100 105
23
107
PRT
Unknown Organism
Description of Unknown Organism Mus sp. or
Homosapiens
23
Asp Glu Leu Gln Val Ile Gln Pro Glu Lys Ser Val Ser Val Ala Ala
1 5 10 15
Gly Glu Ser Ala Thr Leu Arg Cys Ala Met Thr Ser Leu Ile Pro Val
20 25 30
Gly Pro Ile Met Trp Phe Arg Gly Ala Gly Ala Gly Arg Glu Leu Ile
35 40 45
Tyr Asn Gln Lys Glu Gly His Phe Pro Arg Val Thr Thr Val Ser Glu
50 55 60
Leu Thr Lys Arg Asn Asn Leu Asp Phe Ser Ile Arg Ile Ser Asn Ile
65 70 75 80
Thr Pro Ala Asp Ala Gly Thr Tyr Tyr Cys Val Lys Phe Arg Lys Gly
85 90 95
Ser Pro Asp Asp Val Glu Phe Lys Ser Gly Ala
100 105
24
107
PRT
Unknown Organism
Description of Unknown Organism Mus sp. or
Homosapiens
24
Asp Glu Leu Gln Val Ile Gln Pro Glu Ala Phe Val Ser Val Ala Ala
1 5 10 15
Gly Glu Met Ala Thr Leu Asn Cys Thr Val Thr Ser Leu Leu Pro Val
20 25 30
Gly Pro Ile Gln Trp Phe Arg Gly Ala Cys Pro Gly Gln Lys Leu Ile
35 40 45
Tyr Ser Pro Lys Arg Cys His Ser Pro Arg Val Thr Thr Ile Ser Asp
50 55 60
Gln Arg Lys Arg Asn Ser Thr Asp Tyr Ser Ile Arg Ile Ser Ser Ile
65 70 75 80
Thr Leu Glu Asp Ala Gly Thr Tyr Tyr Cys Met Lys Leu Arg Arg Ala
85 90 95
Ile Pro Ala Asn Val Glu Ile Lys Ser Gly Thr
100 105
25
107
PRT
Unknown Organism
Description of Unknown Organism Mus sp. or
Homosapiens
25
Glu Glu Leu Gln Met Ile Gln Pro Glu Lys Leu Leu Leu Val Thr Val
1 5 10 15
Gly Lys Thr Ala Thr Leu His Cys Thr Val Thr Ser Leu Leu Pro Val
20 25 30
Gly Pro Val Leu Trp Phe Arg Gly Val Gly Pro Gly Arg Glu Leu Ile
35 40 45
Tyr Asn Gln Lys Glu Gly His Phe Pro Arg Val Thr Arg Val Ser Asp
50 55 60
Leu Thr Lys Arg Asn Asn Met Asp Phe Ser Ile Arg Ile Ser Ser Ile
65 70 75 80
Thr Pro Ala Val Val Gly Thr Tyr Tyr Cys Val Lys Phe Arg Lys Gly
85 90 95
Ser Pro Glu Asn Val Glu Phe Lys Ser Gly Pro
100 105
26
106
PRT
Unknown Organism
Description of Unknown Organism Mus sp. or
Homosapiens
26
Glu Glu Leu Gln Val Ile Gln Pro Glu Lys Ser Val Ser Val Ala Ala
1 5 10 15
Gly Glu Ser Ala Ala Leu Gln Cys Thr Val Thr Ser Leu Asn Pro Val
20 25 30
Gly Pro Ile Gln Arg Phe Arg Gly Ala Gly Pro Gly Arg Lys Leu Ile
35 40 45
Tyr His Gln Lys Glu Gly His Phe Pro Arg Val Thr Thr Val Ser Asp
50 55 60
Leu Thr Lys Arg Thr Asn Met Asp Phe Ser Ile Cys Ile Ser Asn Ile
65 70 75 80
Thr Pro Ala Asp Ala Gly Thr Tyr Tyr Cys Val Lys Phe Gln Lys Gly
85 90 95
Ser Pro Asp Val Glu Leu Lys Ser Gly Ala
100 105 | The present invention features isolated, purified, or enriched nucleic acid encoding a SIRP polypeptide and isolated, purified, or enriched SIRP polypeptide and uses thereof. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to hydrophobic peptides and/or peptidomimetics capable of forming a (nanofibrous) hydrogel and hydrogels comprising said hydrophobic peptides and/or peptidomimetics and to various uses, such as in regenerative medicine, injectable therapies, delivery of bioactive moieties, wound healing, 2D and 3D synthetic cell culture substrate, biosensor development, biofunctionalized surfaces, and biofabrication.
BACKGROUND OF THE INVENTION
[0002] Self-assembly is an elegant and expedient “bottom-up” approach towards designing ordered, three-dimensional and biocompatible nanobiomaterials. Reproducible macromolecular nanostructures can be obtained due to the highly specific interactions between the building blocks. These intermolecular associations organize the supramolecular architecture and are mainly non-covalent electrostatic interactions, hydrogen bonds, van der Waals forces, etc. Supramolecular chemistry or biology gathers a vast body of two or three dimensional complex structures and entities formed by association of chemical or biological species. These associations are governed by the principles of molecular complementarity or molecular recognition and self-assembly. The knowledge of the rules of intermolecular association can be used to design polymolecular assemblies in form of membranes, films, layers, micelles, tubules, gels for a variety of biomedical or technological applications (J.-M. Lehn, Science, 295, 2400-2403, 2002).
[0003] Peptides are versatile building blocks for fabricating supramolecular architectures. Their ability to adopt specific secondary structures, as prescribed by amino acid sequence, provides a unique platform for the design of self-assembling biomaterials with hierarchical three-dimensional (3D) macromolecular architectures, nanoscale features and tuneable physical properties (S. Zhang, Nature Biotechnology, 21, 1171-1178, 2003). Peptides are for instance able to assemble into nanotubes (U.S. Pat. No. 7,179,784) or into supramolecular hydrogels consisting of three dimensional scaffolds with a large amount of around 98-99% immobilized water or aqueous solution. The peptide-based biomaterials are powerful tools for potential applications in biotechnology, medicine and even technical applications. Depending on the individual properties these peptide-based hydrogels are thought to serve in the development of new materials for tissue engineering, regenerative medicine, as drug and vaccine delivery vehicles or as peptide chips for pharmaceutical research and diagnosis (E. Place et al., Nature Materials, 8, 457-470, 2009). There is also a strong interest to use peptide-based self-assembled biomaterial such as gels for the development of molecular electronic devices (A. R. Hirst et al. Angew. Chem. Int. Ed., 47, 8002-8018, 2008).
[0004] A variety of “smart peptide hydrogels” have been generated that reaction external manipulations such as temperature, pH, mechanical influences or other stimuli with a dynamic behavior of swelling, shrinking or decomposing. Nevertheless, these biomaterials are still not “advanced” enough to mimic the biological variability of natural tissues as for example the extracellular matrix (ECM) or cartilage tissue or others. The challenge for a meaningful use of peptide hydrogels is to mimic the replacing natural tissues not only as “space filler” or mechanical scaffold, but to understand and cope with the biochemical signals and physiological requirements that keep the containing cells in the right place and under “in vivo” conditions (R. Fairman and K. Akerfeldt, Current Opinion in Structural Biology, 15, 453-463, 2005).
[0005] Much effort has been undertaken to understand and control the relationship between peptide sequence and structure for a rational design of suitable hydrogels. In general hydrogels contain macroscopic structures such as fibers that entangle and form meshes. Most of the peptide-based hydrogels utilize 0-pleated sheets which assemble to fibers as building blocks (S. Zhang et al., PNAS, 90, 3334-3338, 1993: A. Aggeli et al., Nature, 386, 259-262, 1997, etc.). It is also possible to obtain self-assembled hydrogels from α-helical peptides besides 0-sheet structure-based materials (W. A. Petka et al., Science, 281, 389-392, 1998; C. Wang et al., Nature, 397, 417-420, 1999; C. Gribbon et al., Biochemistry, 47, 10365-10371, 2008; E. Banwell et al., Nature Materials, 8, 596-600, 2009, etc.).
[0006] Nevertheless, the currently known peptide hydrogels are in most of the cases associated with low rigidity, sometimes unfavourable physiological properties and/or complexity and the requirement of substantial processing thereof which leads to high production costs. There is therefore a widely recognized need for peptide hydrogels that are easily formed, non-toxic and have a sufficiently high rigidity for standard applications. The hydrogels should also be suitable for the delivery of bioactive moieties (such as nucleic acids, small molecule therapeutics, cosmetic and anti-microbial agents) and/or for use as biomimetic scaffolds that support the in vivo and in vitro growth of cells and facilitate the regeneration of native tissue and/or for use in 2D and/or 3D biofabrication.
[0007] “Biofabrication” utilizes techniques such as additive manufacturing (i.e. printing) and moulding to create 2D and 3D structures from biomaterial building blocks. During the fabrication process, bioactive moieties and cells can be incorporated in a precise fashion. In the specific example of “bio-printing”, a computer-aided device is used to precisely deposit the biomaterial building block (ink), using a layer-by-layer approach, into the pre-determined, prescribed 3D geometry. The size of these structures range from the micro-scale to larger structures. Additives such as growth factors, cytokines, vitamins, minerals, oligonucleotides, small molecule drugs, and other bioactive moieties, and various cell types can also be accurately deposited concurrently or subsequently. Bio-inert components can be utilized as supports or fillers to create open inner spaces to mimic biological tissue. Such biological constructs can be subsequently implanted or used to investigate the interactions between cells and/or biomaterials, as well as to develop 3D disease models. In the specific example of “moulding”, the biomaterial building block is deposited into a template of specific shape and dimensions, together with relevant bioactive moieties and cells (Malda J., et al. Engineering Hydrogels for Biofabrication. Adv. Mater. (2013); Murphy S. V., et al. Evaluation of Hydrogels for Bio-printing Applications. J. of Biomed. Mater. Res. (2012)).
SUMMARY OF THE INVENTION
[0008] It is therefore desirable to provide a biocompatible compound that is capable of forming a hydrogel, that meets at least some of the above requirements to a higher extent than currently available hydrogels and that is not restricted by the above mentioned limitations.
[0009] The objects of the present invention are solved by a hydrophobic peptide and/or peptidomimetic capable of forming a (nanofibrous) hydrogel, the hydrophobic peptide and/or peptidoinimetic having the general formula II:
[0000] Z—(X) a —Z′ b II
wherein Z is an N-terminal protecting group; X is a hydrophobic amino acid sequence of aliphatic amino acids, which, at each occurrence, are independently selected from the group consisting of aliphatic amino acids and aliphatic amino acid derivatives; a is an integer selected from 2 to 6, preferably 2 to 5; Z′ is a C-terminal group; and b is 0 or 1.
[0016] The inventors have found that said aliphatic amino acids and aliphatic amino acid derivatives need to exhibit an overall decrease in hydrophobicity from the N-terminus to the C-terminus of said peptide and/or peptidomimetic in order to form nanofibrous hydrogels.
[0017] The terms “peptoid” and “peptidomimetic” are used herein interchangeably and refer to molecules designed to mimic a peptide. Peptoids or peptidomimetics can arise either from modification of an existing peptide, or by designing similar systems that mimic peptides. These modifications involve changes to the peptide that will not occur naturally (such as altered backbones and/or the incorporation of non-natural amino acids).
[0018] In particular, peptoids are a subclass of peptidomimetics. In peptoids, the side chains are connected to the nitrogen of the peptide backbone, differently to normal peptides. Peptidomitnetics can have a regular peptide backbone where only the normally occurring amino acids are exchanged with a chemically different but similar amino acids, such as leucine to norleucine. In the present disclosure, the terms are used interchangeably.
[0019] In one embodiment, said aliphatic amino acids and aliphatic amino acid derivatives are either D-amino acids or L-amino acids.
[0020] In one embodiment, said aliphatic amino acids are selected from the group consisting of alanine (Ala, A), homoallylglycine, homopropargylglycine, isoleucine (Ile, I), norleucine, leucine (Leu, L), valine (Val, V) and glycine (Gly, G), preferably from the group consisting of alanine (Ala, A), isoleucine (Ile, I), leucine (Leu, L), valine (Val, V) and glycine (Gly, G).
[0021] In one embodiment, all or a portion of said aliphatic amino acids are arranged in an order of decreasing amino acid size in the direction from N- to C-terminus, wherein the size of the aliphatic amino acids is defined as I=L>V>A>G.
[0022] In one embodiment, said aliphatic amino acids arranged in an order of decreasing amino acid size have a sequence which is a non-repetitive sequence.
[0023] In one embodiment, the very first N-terminal amino acid of said aliphatic amino acids is less crucial (it can be G, V or A). The inventors found that this specific first amino acid has not a dominant on this otherwise mandatory requirement of decreasing hydrophobicity from N- to C-terminus.
[0024] In one embodiment, the first N-terminal amino acid of said aliphatic amino acids is G, V or A.
[0025] In one embodiment, said aliphatic amino acids have a sequence selected from
[0000] (SEQ ID NO: 1) ILVAG (SEQ ID NO: 2) LIVAG, (SEQ ID NO: 3) IVAG, (SEQ ID NO: 4) LVAG, (SEQ ID NO: 5) ILVA, (SEQ ID NO: 6) LIVA, (SEQ ID NO: 13) IVG, (SEQ ID NO: 14) VIG, (SEQ ID NO: 15) IVA, (SEQ ID NO: 16) VIA, (SEQ ID NO: 17) VI and (SEQ ID NO: 18) IV,
wherein, optionally, there is an G, V or A preceding such sequence at the N-terminus, such as
[0000]
(SEQ ID NO. 7)
AIVAG,
(SEQ ID NO. 8)
GIVAG,
(SEQ ID NO. 9)
VIVAG,
(SEQ ID NO. 10)
ALVAG,
(SEQ ID NO. 11)
GLVAG,
(SEQ ID NO. 12)
VLVAG.
[0026] In one embodiment, (X) a has a sequence selected from the group consisting of SEQ ID NOs. 1 to 18,
[0000] preferably the sequence with SEQ ID NO: 1 and SEQ ID NO: 2.
[0027] In one embodiment, all or a portion of the aliphatic amino acids are arranged in an order of identical amino acid size, preferably wherein said aliphatic amino acids arranged in order of identical amino acid size have a sequence with a length of 2 to 4 amino acids.
[0028] For example, said aliphatic amino acids arranged in an order of identical size have a sequence selected from LLLL, LLL, LL, IIII, III, II, VVVV, VVV, VV, AAAA, AAA, AA, GGGG, GGG, and GG.
[0029] In one embodiment, said N-terminal protecting group Z has the general formula —C(O)—R,
[0000] wherein R is selected from the group consisting of H, unsubstituted or substituted alkyls, and unsubstituted or substituted aryls,
wherein R is preferably selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl and isobutyl.
[0030] In one embodiment, said N-terminal protecting group Z is an acetyl group.
[0031] In one embodiment, said N-terminal protecting group Z is a peptidomimetic molecule, including natural and synthetic amino acid derivatives, wherein the N-terminus of said peptidomimetic molecule may be modified with a functional group selected from the group consisting of carboxylic acid, amide, alcohol, aldehyde, amine, imine, nitrile, an urea analog, phosphate, carbonate, sulfate, nitrate, maleimide, vinyl sulfone, azide, alkyne, alkene, carbohydrate, imide, peroxide, ester, aryl, ketone, sulphite, nitrite, phosphonate, and silane.
[0032] In one embodiment, said C-terminal group Z′ is a non-amino acid, preferably selected from the group of small molecules, functional groups and linkers. Such C-terminal groups Z′ can be polar or non-polar moieties used to functionalize the peptide and/or peptidomimetic of the invention.
[0033] In one embodiment, said C-terminal group Z′ is selected from
functional groups, such as polar or non-polar functional groups,
such as (but not limited to)
—COOH, —COOR, —COR, —CONHR or —CONRR′ with R and R′ being selected from the group consisting of H, unsubstituted or substituted alkyls, and unsubstituted or substituted aryls, —NH 2 , —OH, —SH, —CHO, maleimide, imidoester, carbodiimide ester, isocyanate;
small molecules,
such as (but not limited to) sugars, alcohols, hydroxy acids, amino acids, vitamins, biotin;
linkers terminating in a polar functional group,
such as (but not limited to) ethylenediamine, PEG, carbodiimide ester, imidoester;
linkers coupled to small molecules or vitamins,
such as biotin, sugars, hydroxy acids,
[0044] In one embodiment, wherein said C-terminal group Z′ can be used for chemical conjugation or coupling of at least one compound selected from
bioactive molecules or moieties,
such as growth factors, cytokines, lipids, cell receptor ligands, hormones, prodrugs, drugs, vitamins, antigens, antibodies, antibody fragments, oligonucleotides (including but not limited to DNA, messenger RNA, short hairpin RNA, small interfering RNA, microRNA, peptide nucleic acids, aptamers), saccharides;
label(s), dye(s),
such as fluorescent or radioactive label(s), imaging contrast agents;
pathogens,
such as viruses, bacteria and parasites;
micro- and nanoparticles or combinations thereof
wherein said chemical conjugation can be carried out before or after self-assembly of the peptide and/or peptidomimetic.
[0053] In one embodiment, the C-terminus of the peptide and/or peptidomimetic is functionalized (without the use of a C-terminal group or linker), such as by chemical conjugation or coupling of at least one compound selected from
bioactive molecules or moieties,
such as growth factors, cytokines, lipids, cell receptor ligands, hormones, prodrugs, drugs, vitamins, antigens, antibodies, antibody fragments, oligonucleotides (including but not limited to DNA, messenger RNA, short hairpin RNA, small interfering RNA, microRNA, peptide nucleic acids, aptamers), saccharides;
label(s), dye(s),
such as fluorescent or radioactive label(s), imaging contrast agents;
pathogens,
such as viruses, bacteria and parasites;
micro- and nanoparticles or combinations thereof
wherein said chemical conjugation can be carried out before or after self-assembly of the peptide and/or peptidomimetic.
[0062] In one embodiment, said C-terminal group Z′ is a peptidomimetic molecule, including natural and synthetic amino acid derivatives, wherein the C-terminus of said peptidomimetic molecule may be modified with a functional group selected from the group consisting of carboxylic acid, amide, alcohol, aldehyde, amine, imine, nitrile, an urea analog, phosphate, carbonate, sulfate, nitrate, maleimide, vinyl sulfone, azide, alkyne, alkene, carbohydrate, imide, peroxide, ester, aryl, ketone, sulphite, nitrite, phosphonate, and silane.
[0063] In one embodiment, the hydrophobic peptide and/or peptidomimetic according to the invention is being stable in aqueous solution at physiological conditions at ambient temperature for a period of time in the range from 1 day to at least 6 months, preferably to at least 8 months more preferably to at least 12 months.
[0064] In one embodiment, the hydrophobic peptide and/or peptidomimetic according to the invention is being stable in aqueous solution at physiological conditions, at a temperature up to 90° C., for at least 1 hour.
[0065] The objects of the present invention are solved by a composition or mixture comprising
[0000] (a) at least one hydrophobic peptide and/or peptidomimetic of the present invention, and
(b) at least one hydrophobic peptide and/or peptidomimetic capable of forming a hydrogel, the hydrophobic peptide and/or peptidomimetic having the general formula:
[0000] Z—(X) a —N′ b
wherein Z is as defined herein for the hydrophobic peptide and/or peptidomimetic of the present invention; X is as defined herein for the hydrophobic peptide and/or peptidomimetic of the present invention; a is as defined herein for the hydrophobic peptide and/or peptidomimetic of the present invention; N′ is a non-polar C-terminal group which differs from Z′, the polar C-terminal group as defined herein for the hydrophobic peptide and/or peptidomimetic of the present invention;
and is preferably carboxylic acid, amide, alcohol, biotin, inaleimide, sugars, and hydroxyacids,
and b is 0 or 1.
[0074] The objects of the present invention are solved by a hydrogel comprising the hydrophobic peptide and/or peptidomimetic of the present invention.
[0075] In one embodiment, the hydrogel is stable in aqueous solution at ambient temperature for a period of at least 7 days, preferably at least 2 to 4 weeks, more preferably at least 1 to 6 months.
[0076] In one embodiment, the hydrogel is characterized by a storage modulus G′ to loss modulus G″ ratio that is greater than 2.
[0077] In one embodiment, the hydrogel is characterized by a storage modulus G′ from 100 Pa to 80,000 Pa at a frequency in the range of from 0.02 Hz to 16 Hz.
[0078] In one embodiment, the hydrogel has a higher mechanical strength than collagen or its hydrolyzed form (gelatin).
[0079] The objects of the present invention are solved by a hydrogel comprising
[0000] (a) at least one hydrophobic peptide and/or peptidomimetic of the present invention, and
(b) at least one hydrophobic peptide and/or peptidomimetic with a non-polar head group.
[0080] Said at least one “hydrophobic peptide and/or peptidomimetic with a non-polar head group” is capable of forming a hydrogel and has the general formula:
[0000] Z—(X) a —N′ b
wherein Z, X and a are as defined herein for the hydrophobic peptide and/or peptidomimetic of the present invention; N′ is a non-polar C-terminal group which differs from Z′, the polar C-terminal group as defined herein for the hydrophobic peptide and/or peptidomimetic of the present invention;
and is preferably carboxylic acid, amide, alcohol, biotin, maleimide, sugars, and hydroxyacids,
and b is 0 or 1.
[0087] In one embodiment, the hydrogel comprises fibers of the hydrophobic peptide and/or peptidomimetic of the invention or fibers of the hydrophobic peptide and/or peptidomimetic with a non-polar head group as defined above, said fibers defining a network that is capable of entrapping at least one of a microorganism, a virus particle, a peptide, a peptoid, a protein, a nucleic acid, an oligosaccharide, a polysaccharide, a vitamin, an inorganic molecule, a synthetic polymer, a small organic molecule, a micro- or nanoparticle or a pharmaceutically active compound.
[0088] In one embodiment, the hydrogel comprises at least one of a microorganism, a virus particle, a peptide, a peptoid, a protein, a nucleic acid, an oligosaccharide, a polysaccharide, a vitamin, an inorganic molecule, a synthetic polymer, a small organic molecule, a micro- or nanoparticle or a pharmaceutically active compound entrapped by the network of fibers of the hydrophobic polymer.
[0089] In one embodiment, the fibers of the hydrophobic polymer are coupled to the at least one of a microorganism, a virus particle, a peptide, a peptoid, a protein, a nucleic acid, an oligosaccharide, a polysaccharide, a vitamin, an inorganic molecule, a synthetic polymer, a small organic molecule, a micro- or nanoparticle or a pharmaceutically active compound entrapped by the network of fibers of the amphiphilic polymer.
[0090] In one embodiment, the hydrogel is comprised in at least one of a fuel cell, a solar cell, an electronic cell, a biosensing device, a medical device, an implant, a pharmaceutical composition and a cosmetic composition.
[0091] In one embodiment, the hydrogel is injectable.
[0092] The objects of the present invention are solved by the use of the hydrogel according to the present invention in at least one of the following:
release of a pharmaceutically active compound and/or delivery of bioactive moieties, medical tool kit, a fuel cell, a solar cell, an electronic cell, regenerative medicine and tissue regeneration, wound healing, 2D and 3D synthetic cell culture substrate, stem cell therapy, injectable therapies, biosensor development, biofunctionalized surfaces, biofabrication, such as bio-printing, and gene therapy.
[0107] For the uses, we also refer to the uses in biofabrication described in the inventors' parallel application “Self-assembling peptides, peptidomimetics and peptidic conjugates as building blocks for biofabrication and printing”, having the same filing date as the present application, and the subsequent embodiments and methods described therein, which also apply to the hydrophobic peptides and/or peptidomimetics of this invention.
[0108] The objects of the present invention are solved by a method of preparing a hydrogel, the method comprising dissolving a hydrophobic peptide and/or peptidomimetic according to the present invention in an aqueous solution.
[0109] In one embodiment, the dissolved hydrophobic peptide and/or peptidomimetic in aqueous solution is further exposed to temperature, wherein the temperature is in the range from 20° C. to 90° C., preferably from 20° C. to 70° C.
[0110] In one embodiment, the hydrophobic peptide and/or peptidomimetic is dissolved at a concentration from 0.01 μg/ml to 100 mg/ml, preferably at a concentration from 1 mg/ml to 50 mg/ml, more preferably at a concentration from about 1 mg/ml to about 20 mg/ml.
[0111] The objects of the present invention are solved by a method of preparing a hydrogel, the method comprising dissolving a hydrophobic peptide and/or peptidomimetic according to the present invention and a hydrophobic peptide and/or peptidomimetic with a non-polar head group as defined herein in an aqueous solution.
[0112] The objects of the present invention are solved by a wound dressing or wound healing agent comprising a hydrogel according to the invention.
[0113] The objects of the present invention are solved by a surgical implant, or stent, the surgical implant or stent comprising a peptide and/or peptidomimetic scaffold, wherein the peptide and/or peptidomimetic scaffold is formed by a hydrogel according to the invention.
[0114] The objects of the present invention are solved by a pharmaceutical and/or cosmetic composition and/or a biomedical device and/or electronic device comprising the hydrophobic peptide and/or peptidomimetic according to the invention.
[0115] The objects of the present invention are solved by a pharmaceutical and/or cosmetic composition and/or a biomedical device and/or electronic device comprising the hydrophobic peptide and/or peptidomimetic of the present invention and the hydrophobic peptide and/or peptidomimetic with a non-polar head group as defined herein.
[0116] In one embodiment, the pharmaceutical and/or cosmetic composition and/or the biomedical device, and/or the electronic devices further comprises a pharmaceutically active compound.
[0117] In one embodiment, the pharmaceutical and/or cosmetic composition is provided in the form of a topical gel or cream, a spray, a powder, or a sheet, patch or membrane, or wherein the pharmaceutical and/or cosmetic composition is provided in the form of an injectable solution.
[0118] In one embodiment, the pharmaceutical and/or cosmetic composition further comprises a pharmaceutically acceptable carrier.
[0119] The objects of the present invention are solved by a kit of parts, the kit comprising a first container with a hydrophobic peptide and/or peptidomimetic according to the invention and a second container with an aqueous solution.
[0120] In one embodiment, the kit further comprises a third container with a hydrophobic peptide and/or peptidomimetic with a non-polar head group as defined herein.
[0121] In one embodiment, the aqueous solution of the second container further comprises a pharmaceutically active compound.
[0000] and/or wherein the first and/or third container with a hydrophobic peptide and/or peptidomimetic further comprises a pharmaceutically active compound.
[0122] The objects of the present invention are solved by an in vitro or in vivo method of tissue regeneration comprising the steps:
(a) providing a hydrogel according to the invention, (b) exposing said hydrogel to cells which are to fonn regenerated tissue, (c) allowing said cells to grow on said hydrogel.
[0126] In one embodiment, wherein the method is performed in vivo, in step a), said hydrogel is provided at a place in a body where tissue regeneration is intended,
[0000] wherein said step a) is preferably performed by injecting said hydrogel at a place in the body where tissue regeneration is intended.
[0127] The objects of the present invention are solved by a method of treatment of a wound and for wound healing, said method comprising the step of
applying an effective amount of a hydrogel according to the invention or a pharmaceutical composition according to the invention to a wound.
[0129] The objects of the present invention are solved by a bioimaging device comprising a hydrogel according to the invention for in vitro and/or in vivo use,
[0000] preferably for oral application, for injection and/or for topical application.
[0130] The objects of the present invention are solved by a 2D or 3D cell culture substrate comprising a hydrogel according to the invention.
[0131] The peptides, peptidomimetics and peptoids disclosed herein are suitable as ink(s) or (biomaterial) building block(s) in biofabrication, including bioprinting, (bio)moulding.
[0132] “Biofabrication” as used herein refers to the use of techniques, such as additive manufacturing (i.e. bio-printing) and moulding to create 2D and 3D structures or biological constructs from biomaterial building blocks (i.e. the peptides and/or peptoids according to the invention). During the fabrication process, bioactive moieties and cells can be incorporated in a precise fashion. In the specific example of “bio-printing”, a computer-aided device is used to precisely deposit the biomaterial building block (ink), using a layer-by-layer approach, into the pre-determined, prescribed 3D geometry. The size of these structures range from the micro-scale to larger structures. Additives such as growth factors, cytokines, vitamins, minerals, oligonucleotides, small molecule drugs, and other bioactive moieties, and various cell types can also be accurately deposited concurrently or subsequently. Bio-inert components can be utilized as supports or fillers to create open inner spaces to mimic biological tissue. Such biological constructs can be subsequently implanted or used to investigate the interactions between cells and/or biomaterials, as well as to develop 3D disease models. In the specific example of “moulding”, the biomaterial building block is deposited into a template of specific shape and dimensions, together with relevant bioactive moieties and cells.
[0000] (see Malda J., et al. Engineering Hydrogels for Biofabrication. Adv. Mater. (2013); Murphy S. V., et al. Evaluation of Hydrogels for Bio-printing Applications. J. of Biomed. Mater. Res. (2012)).
[0133] “Bioprinting” is part of the field tissue engineering which is the use of a combination of cells, engineering and materials methods, and suitable biochemical and physio-chemical factors to improve or replace biological functions.
[0134] Tissue engineering is used to repair or replace portions of or whole tissues (i.e., bone, cartilage, blood vessels, bladder, skin, muscle etc.). Often, the tissues involved require certain mechanical and structural properties for proper functioning.
[0135] The term “bioprinting” as used herein also comprises a process of making a tissue analog by depositing scaffolding or ink material (the peptides/peptoids of the invention or hydrogels thereof) alone, or mixed with cells, based on computer driven mimicking of a texture and a structure of a naturally occurring tissue.
[0136] An “ink” or “bio-ink” for bioprinting as used herein refers to the biomaterial building block that is sequentially deposited to build a macromolecular scaffold.
[0137] In one embodiment, the C-terminal amino acid is further functionalized.
[0138] In one embodiment, the polar functional group(s) can be used for chemical conjugation or coupling of at least one compound selected from
bioactive molecules or moieties,
such as growth factors, cytokines, lipids, cell receptor ligands, hormones, prodrugs, drugs, vitamins, antigens, antibodies, antibody fragments, oligonucleotides (including but not limited to DNA, messenger RNA, short hairpin RNA, small interfering RNA, microRNA, peptide nucleic acids, aptamers), saccharides;
label(s), dye(s),
such as imaging contrast agents;
pathogens,
such as viruses, bacteria and parasites;
micro- and nanoparticles or combinations thereof
wherein said chemical conjugation can be carried out before or after self-assembly of the peptide and/or peptoid.
[0147] In one embodiment, the use according to the invention comprises a conformational change of the peptide(s) and/or peptoid(s) during self-assembly,
[0000] preferably a conformational change from a random coil conformation to a helical intermediate structure (such as α-helical fibrils) to a final beta turn or cross beta conformation, such as fibrils which further aggregate and/or condense into nanofibers (which make up a network), wherein, preferably, the conformational change is dependent on the peptide concentration, ionic environment, pH and temperature.
[0148] In one embodiment, at least one peptide and/or peptoid as herein defined forms a hydrogel.
[0149] The hydrogel is formed by self-assembly of the peptide and/or peptiod, as explained in further detail below.
[0150] In one embodiment, different peptide(s) and/or peptoid(s) as defined herein are used to form the hydrogel.
[0151] Preferably, different peptide(s) and/or peptoid(s) refers to peptide(s) and/or peptoid(s) that differ in their amino acid sequence, C-terminal group(s), conjugated/coupled compounds (such as different labels, bioactive molecules etc) or combinations thereof.
[0152] In one embodiment, at least one peptide and/or peptoid as defined herein is dissolved in water and wherein the solution obtained can be dispensed through needles and print heads.
[0153] In one embodiment, the use according to the invention comprises conjugation or coupling of further compound(s) to the peptides and/or peptoid, preferably to C-terminal group(s), post-assembly,
wherein said further compound(s) can be selected from
bioactive molecules or moieties,
such as growth factors, cytokines, lipids, cell receptor ligands, hormones, prodrugs, drugs, vitamins, antigens, antibodies, antibody fragments, oligonucleotides (including but not limited to DNA, messenger RNA, short hairpin RNA, small interfering RNA, microRNA, peptide nucleic acids, aptamers), saccharides;
label(s), dye(s),
such as imaging contrast agents;
pathogens,
such as viruses, bacteria and parasites;
micro- and nanoparticles or combinations thereof.
[0163] In one embodiment, the peptide and/or peptoid is present at a concentration in the range of from 0.1% to 30% (w/w), preferably 0.1% to 20% (w/w), more preferably 0.1% to 10% (w/w), more preferably 0.1% to 5% (w/w), even more preferably 0.1% to 3% (w/w), with respect to the total weight of said hydrogel.
[0164] In one embodiment, the use according to the invention comprises the addition or mixing of cells prior or during gelation, which are encapsulated by the hydrogel,
wherein said cells can be stem cells (mesenchymal, progenitor, embryonic and induced pluripotent stem cells), transdifferentiated progenitor cells and primary cells isolated from patient samples (fibroblasts, nucleus pulposus).
preferably comprising the addition of further compound(s) prior or during gelation, which are co-encapsulated by the hydrogel.
[0166] In one embodiment, the use according to the invention comprises the addition of cells onto the printed hydrogel, wherein said cells can be stem cells (adult, progenitor, embryonic and induced pluripotent stein cells), transdifferentiated progenitor cells, and primary cells (isolated from patients) and cell lines (such as epithelial, neuronal, hematopoietic and cancer cells).
[0167] In one embodiment, the use according to the invention comprises
[0000] (1) the addition or mixing of cells prior or during gelation, which are encapsulated by the hydrogel, and
(2) subsequently comprising the addition of cells onto the printed hydrogel, wherein said cells of (1) and (2) are the same or different,
and can be stem cells (adult, progenitor, embryonic and induced pluripotent stein cells), transdifferentiated progenitor cells, and primary cells (isolated from patients) and cell lines (such as epithelial, neuronal, hematopoietic and cancer cells).
[0168] In one embodiment, the use according to the invention comprises the addition of cross-linkers to the peptide(s) and/or peptoid(s),
[0000] wherein said cross-linkers preferably include short linkers, linear and branched polymers, polymers conjugated with bioactive molecules or moieties.
[0169] The objects of the present invention are solved by a method of preparing a hydrogel, the method comprising dissolving at least one peptide and/or peptoid as defined herein in an aqueous solution, such as water, or in a polar solvent, such as ethanol.
[0170] In one embodiment, the method of the invention comprises stimuli-responsive gelation of the at least one peptide and/or peptoid as defined herein,
[0000] wherein said stimulus/stimuli or gelation condition(s) is/are selected from pH, salt concentration and/or temperature.
[0171] In one embodiment, the at least one peptide and/or peptoid comprises as the polar head group basic amino acid(s), such as lysine or lysine-mimetic molecules, preferably ainidated basic amino acid(s),
[0000] and gelation is carried out in the presence of salt at physiological conditions (such as PBS or 0.9% saline and PBS) and/or at a pH above physiological pH, preferably pH 7 to 10 (such as by adding NaOH).
[0172] In one embodiment, the at least one peptide and/or peptoid comprises as the polar head group acidic amino acid(s),
[0000] and gelation is carried out at a pH below physiological pH 7, preferably pH 2 to 6.
[0173] In one embodiment, the dissolved peptide and/or peptoid is further warmed or heated, wherein the temperature is in the range from 20° C. to 90° C., preferably from about 30° C. to 70° C., more preferably from about 37° C. to 70° C.
[0174] In one embodiment, the at least one peptide and/or peptoid is dissolved at a concentration from 0.01 μg/ml to 100 mg/ml, preferably at a concentration from 1 mg/ml to 50 mg/ml, more preferably at a concentration from about 1 mg/ml to about 20 mg/ml.
[0175] The objects of the present invention are solved by a method of preparing continuous fibres, the method comprising
dissolving at least one peptide and/or peptoid as defined herein in an aqueous solution, such as water, and dispensing the solution obtained through needles, print heads, fine tubings and/or microfluidic devices into a buffered solution, such as PBS.
[0178] In one embodiment, the method comprises the addition of further compound(s) prior or during gelation/self-assembly, which are encapsulated by the hydrogel,
wherein said further compound(s) can be selected from
bioactive molecules or moieties,
such as growth factors, cytokines, lipids, cell receptor ligands, hormones, prodrugs, drugs, vitamins, antigens, antibodies, antibody fragments, oligonucleotides (including but not limited to DNA, messenger RNA, short hairpin RNA, small interfering RNA, microRNA, peptide nucleic acids, aptamers), saccharides;
label(s), dye(s),
such as imaging contrast agents;
pathogens,
such as viruses, bacteria and parasites;
quantum dots, nano- and microparticles, or combinations thereof.
[0188] In one embodiment, the method comprises the addition or mixing of cells prior or during gelation/self-assembly, which are encapsulated by the hydrogel,
wherein said cells can be stein cells (mesenchymal, progenitor, embryonic and induced pluripotent stem cells), transdifferentiated progenitor cells and primary cells isolated from patient samples (fibroblasts, nucleus pulposus).
preferably comprising the addition of further compound(s) prior or during gelation (such as defined herein), which are co-encapsulated by the hydrogel.
[0190] In one embodiment, the method comprises the addition of cells onto the printed hydrogel, wherein said cells can be stem cells (adult, progenitor, embryonic and induced pluripotent stem cells), transdifferentiated progenitor cells, and primary cells (isolated from patients) and cell lines (such as epithelial, neuronal, hematopoietic and cancer cells).
[0191] In one embodiment, the method comprises the following steps:
[0000] (1) the addition or mixing of cells prior or during gelation, which are encapsulated by the hydrogel, and
(2) subsequently the addition of cells onto the printed hydrogel,
wherein said cells of (1) and (2) are the same or different,
and can be stem cells (adult, progenitor, embryonic and induced pluripotent stem cells), transdifferentiated progenitor cells, and primary cells (isolated from patients) and cell lines (such as epithelial, neuronal, hematopoietic and cancer cells).
[0192] In one embodiment, the method comprises the addition of cross-linkers to the peptide(s) and/or peptoid(s) prior, during or after gelation/self-assembly,
[0000] wherein said cross-linkers preferably include short linkers, linear and branched polymers, polymers conjugated with bioactive molecules or moieties (such as defined herein), wherein, preferably, said cross-linkers interact electrostatically with the peptides and/or peptoid(s) during self-assembly.
[0193] In one embodiment, the method comprises the use of different peptide(s) and/or peptoid(s).
[0194] Preferably, different peptide(s) and/or peptoid(s) refers to peptide(s) and/or peptoid(s) that differ in their amino acid sequence, C-terminal group(s), conjugated/coupled compounds (such as different labels, bioactive molecules etc) or combinations thereof.
[0195] The objects of the present invention are solved by the use of a hydrogel obtained by a method (for preparing a hydrogel and/or for preparing continuous fibers) according to the invention for substrate-mediated gene delivery,
[0000] wherein oligonucleotides are encapsulated in the hydrogel and cells are co-encapsulated or seeded onto said hydrogel.
[0196] The objects of the present invention are solved by the use (of a peptide and/or peptoid for biofabrication) according to the invention or the use of a hydrogel obtained by a method (for preparing a hydrogel and/or for preparing continuous fibers) according to the invention, for obtaining 2D mini-hydrogel arrays,
[0000] preferably comprising using printers, pintools and micro-contact printing.
[0197] Preferably, a microarray of the invention comprises hydrogels that encapsulate different biomolecules, drugs, compounds, cells etc.
[0198] In one embodiment, said use comprises printing the 2D mini-hydrogels onto electrical circuits or piezoelectric surfaces that conduct current.
[0199] The objects of the present invention are solved by the use (of a peptide and/or peptidomimetic for biofabrication) according to the invention or the use of a hydrogel obtained by a method (for preparing a hydrogel and/or for preparing continuous fibers) according to the invention, as injectable or for injectable therapies,
[0000] such as for the treatment of degenerative disc disease.
[0200] An injectable is preferably an injectable scaffold or an injectable implant or an implantable scaffold.
[0201] By virtue of their self-assembling properties, the stimuli-responsive ultrashort peptides of the present invention are ideal candidates for injectable scaffolds. Such scaffolds can be injected as semi-viscous solutions that complete assembly in situ. Irregular-shaped defects can be fully filled, facilitating scaffold integration with native tissue. These injectable formulations offer significant advantages over ex vivo techniques of preparing nanofibrous scaffolds, such as electrospinning, which have to be surgically implanted. During the process of in situ gelation, the ability to modulate gelation rate enables the clinician to sculpt the hydrogel construct into the desired shape for applications such as dermal fillers. Furthermore, the bio compatibility and in vivo stability bodes well for implants that need to persist for several months. Taking into consideration the stiffness and tunable mechanical properties, we are particularly interested in developing injectable therapies and implantable scaffolds that fulfill mechanically supportive roles.
[0202] The objects of the present invention are solved by the use (of a peptide and/or peptoid for biofabrication) according to the invention or the use of a hydrogel obtained by a method (for preparing a hydrogel and/or for preparing continuous fibers) according to the invention, comprising bioprinting, such as 3D microdroplet printing, and biomoulding.
[0203] In one embodiment, said use is for obtaining 3D organoid structures or 3D macromolecular biological constructs.
[0204] An organoid structure is a structure resembling an organe.
[0205] The term “3D organoid structures” or “3D macromolecular biological constructs” refers to samples in which various cell types are integrated in a 3D scaffold containing various biochemical cues, in a fashion which resembles native tissue. These constructs can potentially be used as implants, disease models and models to study cell-cell and cell-substrate interactions.
[0206] In one embodiment, said use comprises the use of moulds (such as of siliconde) to pattern the hydrogels in 3D.
[0207] In one embodiment, said use is for obtaining multi-cellular constructs,
[0000] which comprise different cells/cell types,
which preferably comprise co-encapsulated further compound(s) (such as defined herein) and/or cross-linkers (such as defined herein).
[0208] In one embodiment, said use is for obtaining 3D cellular constructs or scaffolds comprising encapsulated cells and cells deposited or printed onto the surface of the printed/fabricated scaffold.
[0209] In one embodiment, said use is for
preparation of cell based assays,
preferably for identifying patient specimens, more preferably for identifying patient specimens containing pathogens (e.g. dengue, malaria, norovirus), which do not infect primary cells that have lost their native phenotype;
recovery of infected cells to identify and expand pathogen(s) of interest,
preferably for elucidating mechanism(s) of infection and/or enabling the design of molecules that inhibit pathogen infection and/or replication.
[0214] The objects of the present invention are solved by a method for obtaining a multi-cellular construct, comprising
preparing a hydrogel by the method (for preparing a hydrogel and/or for preparing continuous fibers) according to the invention, comprising the addition or mixing of different cells or cell types prior or during gelation/self-assembly, which are encapsulated by the hydrogel,
wherein said cells can be stem cells (mesenchymal, progenitor, embryonic and induced pluripotent stem cells), transdifferentiated progenitor cells and primary cells isolated from patient samples (fibroblasts, nucleus pulposus).
preferably comprising the addition of further compound(s) (such as defined herein) prior or during gelation, which are co-encapsulated by the hydrogel, optionally comprising the addition of cross-linkers (such as defined herein) to the peptide(s) and/or peptoid(s) prior or during gelation/self-assembly, obtaining the multi-cellular construct.
[0222] The objects of the present invention are solved by a method for obtaining a multi-cellular construct, comprising
preparing a hydrogel by the method (for preparing a hydrogel and/or for preparing continuous fibers) according to the invention, comprising the following steps: (1) the addition or mixing of cells prior or during gelation, which are encapsulated by the hydrogel, and (2) subsequently the addition of cells onto the printed hydrogel, wherein said cells of (1) and (2) are different, and can be stem cells (adult, progenitor, embryonic and induced pluripotent stein cells), transdifferentiated progenitor cells, and primary cells (isolated from patients) and cell lines (such as epithelial, neuronal, hernatopoietic and cancer cells), preferably comprising the addition of further compound(s) (such as defined herein) prior or during gelation, which are co-encapsulated by the hydrogel, optionally comprising the addition of cross-linkers (such as defined herein) to the peptide(s) and/or peptidomimetic(s) prior or during gelation/self-assembly, obtaining the multi-cellular construct.
[0232] In one embodiment, the multi-cellular construct obtained is formed in a mould (such as of silicone).
[0233] The objects of the present invention are solved by a multi-cellular construct obtained according to the methods for obtaining a multi-cellular construct according to the invention and as described herein above,
preferably comprising micro-domains.
[0235] The objects of the present invention are solved by the use of a 3D biological construct obtained by a method (for obtaining a 3D biological construct) according to the invention or of a multi-cellular construct obtained according to the method (for obtaining a multi-cellular construct) according to the invention as:
organoid model for screening biomolecule libraries, studying cell behavior, infectivity of pathogens and disease progression, screening infected patient samples, evaluating drug efficacy and toxicity, tissue-engineered implant for regenerative medicine, and/or in vitro disease model.
[0239] In one embodiment, said use is for
preparation of cell based assays,
preferably for identifying patient specimens, more preferably for identifying patient specimens containing pathogens (e.g. dengue, malaria, norovirus), which do not infect primary cells that have lost their native phenotype;
recovery of infected cells to identify and expand pathogen(s) of interest,
preferably for elucidating mechanism(s) of infection and/or enabling the design of molecules that inhibit pathogen infection and/or replication.
BRIEF DESCRIPTION OF THE DRAWINGS
[0244] Reference is now made to the figures, wherein:
[0245] FIG. 1 . Self-assembly of ultrashort peptides/peptidomimetics into macromolecular nanofibrous hydrogels.
[0246] (A) These amphiphilic peptides have the characteristic motif, wherein the aliphatic amino acids are arranged in decreasing hydrophobicity from N-terminus. During self-assembly, the peptides are hypothesized to associate in an anti-parallel fashion, giving rise to α-helical intermediate structures detected by circular dichroism. (B) As the peptide concentration increases, conformational changes from random coil (black line) to α-helical intermediates (red line) to β-fibrils (blue line) are observed. The insert better illustrates the latter conformations. This phenomenon is observed for hexamers and trimers, though the transition concentration to β-fibrils is higher for the trimer. The peptide dimers subsequently stack in fibrils that aggregate into nanofibers and sheets, which entrap water to form hydrogels. (C) The nanofibrous architecture, as observed using field emission scanning microscopy, resembles extracellular matrix. The fibers extend into the millimeter range. The nanofibers of hexamers readily condense into sheets, while individual fibers are more easily observed for trimers. The fibers form interconnected three-dimensional scaffolds which are porous.
[0247] FIG. 2 . Examples of subclasses of peptides/peptidomimetics that demonstrate stimuli-responsive gelation. (refers to the inventors' parallel application “Self-assembling peptides, peptidomimetics and peptidic conjugates as building blocks for biofabrication and printing”, having the same filing date as the present application)
[0248] FIG. 3 . Stimuli-responsive gelation of amidated peptides/peptidomimetics containing primary amine groups. (refers to the inventors' parallel application “Self-assembling peptides, peptidomimetics and peptidic conjugates as building blocks for biofabrication and printing”, having the same filing date as the present application)
[0249] (A) A subclass of ultrashort peptides with lysine as the polar residue at the C-terminus, form hydrogels more readily in salt solutions—the minimum gelation concentration is significantly lowered and the gelation kinetics are accelerated. Ac-LIVAGK-NH 2 forms hydrogels at 20 mg/mL in water, 12 mg/mL in saline, 7.5 ing/mL in PBS, and 10 mg/mL in 10 mM NaOH. (B) The rigidity, as represented by the storage modulus (G′), of 20 mg/mL Ac-LIVAGK-NH 2 hydrogels increases by one order of magnitude to 10 kPa when dissolved in normal saline (NaCl) as compared to water at 1 kPa. In phosphate buffered saline (PBS), G′ increases to 40 kPa. The stiffness also increases with peptide concentration. (C) The addition of sodium hydroxide (NaOH) enhances the rigidity of 20 mg/mL Ac-LIVAGK-NH 2 hydrogel from 1 kPa in water to 80 kPa. The rigidity increases with NaOH concentration. (D) Hydrogel droplet arrays of various dimensions can be obtained by mixing equivolumes of peptide solution (such as 10 mg/mL Ac-ILNAGK-NH 2 ) and PBS containing small molecules. Bioactive moieties can also be encapsulated; 1 μL droplets with green food colouring and 488 nm emission quantum dots, 2 μL droplets with red food colouring and 568 nm emission fluorophore conjugated to a secondary antibody, and 5 μL droplets with methylene blue and DAPI. (E) Hydrogel “noodles” are obtained by extruding 5 mg/mL peptide solution through a 27 gauge needle into a concentrated salt bath.
[0250] FIG. 4 . Cells can be encapsulated and immobilized within the peptide hydrogels for various applications such as induction of differentiation and screening assays.
[0251] (A) Human mesenchymal stem cells encapsulated within 2 μL droplets of 5 mg/mL peptide hydrogels. (Ai) Photograph of mini-hydrogels on a 25 mm cover slip. (Aii) The cells encapsulated visualised using fluorescent microscopy of a single mini-hydrogel, wherein the cells are stained with Phalliodin-FITC (cytoskeleton is stained green) and Dapi (nuclei stained blue). (Aiii) The encapsulated cells adopt an elongated morphology as demonstrated in this 2D projection image at 10× magnification. The cells are located on different focal planes. (Aiv) Higher magnification image (63×) showing the focal adhesions (in red). (B) Human mesenchymal stem cells cultured on hydrogel films also adopt an elongated morphology compared to those cultured on (C) glass cover slips.
[0252] FIG. 5 . Oligonucleotides such as DNA, mRNA, siRNA can be encapsulated in the hydrogels for substrate mediated gene delivery. Cells can subsequently be co-encapsulated or seeded onto these hydrogels.
[0253] (A) Hydrogels protect the oligonucleotide from nuclease degradation. (B) Hydrogels slowly release the encapsulated DNA over time. (C) Cells cultured on hydrogels encapsulating GFP mRNA express the protein of interest (GFP) after 2 days.
[0254] FIG. 6 . 2D mini-hydrogel arrays for various applications.
[0255] Such 2D arrays can be generated using existing technology such as printers, pintools and Micro-contact printing. (A) The array could be subject to electrical or magnetic stimuli, such as a electric field or point stimuli. The mini-hydrogels can also be printed onto electrical circuits or piezoelectric surfaces to conduct current. (B) Different small molecules or oligonucleotides can be encapsulated to create a biochemical gradient. (C) Different cells can be encapsulated in different mini-hydrogels and treated with the same drug/bioactive molecule dissolved in the bulk media. Alternatively, different drugs or biochemical cues can be incorporated to alter gene expression of the encapsulated cells.
[0256] FIG. 7 . The stability and mechanical properties of mini-hydrogels can also be further enhanced through the addition of cross-linkers, including short linkers, linear and branched polymers.
[0257] Such composite polymer-peptide hydrogels are produced by incorporating (A) linear and (B) branched polymers that can interact electrostatically with ultrashort peptides during self-assembly. The resulting hydrogels have better mechanical properties (due to cross-linking and increased elasticity) and (C) offer opportunities to incorporate bioactive functionalities to modulate the immune and physiological response.
[0258] FIG. 8 . 3D bio printingor moulding techniques to create biological constructs with distinct, multi-functional micro-niches.
[0259] Multi-cellular constructs can also be obtained as the hydrogel can spatially confine different cell types.
[0260] FIG. 9 . A novel class of hydrophobic peptides which self-assemble into hydrogels.
[0261] (A) These hydrophobic peptides have the characteristic motif, wherein the aliphatic amino acids are arranged in decreasing hydrophobicity from N-terminus, as exemplified by Ac-ILVAG. (B) A hydrogel comprising of peptide Ac-ILVAG (at 5 mg/mL), which has a carboxylic acid as a polar functional group at the C-terminus.
[0262] FIG. 10 . C-terminus functionalization of the hydrophobic peptides.
[0263] (A) The characteristic peptidic motif that drives self-assembly can be coupled to other functional groups, linkers and small molecules to obtain conjugates that self-assemble. (B) FESEM images of Ac-ILVAG-biotin reveal its nanofibrous architecture, confirming that functionalization at the C-terminus does not disrupt the nanofibrous architecture.
DETAILED DESCRIPTION OF THE INVENTION
Further Definitions
[0264] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
[0265] Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are described.
[0266] The terms “peptoid” and “peptidomimetic” are used herein interchangeably and refer to molecules designed to mimic a peptide. Peptoids or peptidomimetics can arise either from modification of an existing peptide, or by designing similar systems that mimic peptides. These modifications involve changes to the peptide that will not occur naturally (such as altered backbones and/or the incorporation of non-natural amino acids). See above.
[0267] The term “amino acid” includes compounds in which the carboxylic acid group is shielded by a protecting group in the form of an ester (including an ortho ester), a silyl ester, an amide, a hydrazide, an oxazole, an 1,3-oxazoline or a 5-oxo-1,3,-oxazolidine. The term “amino acid” also includes compounds in which an amino group of the form —NH 2 or —NHR′ (supra) is shielded by a protecting group. Suitable amino protecting groups include, but are not limited to, a carbamate, an amide, a sulfonamide, an imine, an imide, histidine, a N-2,5,-dimethylpyrrole, an N-1,1,4,4-tetramethyldisilylazacyclopentane adduct, an N-1,1,3,3-tetramethyl-1,3-disilisoindoline, an N-diphenylsilyldiethylene, an 1,3,5-dioxazine, a N-[2-(trimethylsilyl)ethoxy]methylamine, a N-(5,5-dimethyl-3-oxo-1-cyclohexenyl)amine, a N-4,4,4-trifluoro-3-oxo-1-butenylamine, a N-9-borabicyclononane and a nitroamine. A protecting group may also be present that shields both the amino and the carboxylic group such as e.g. in the form of a 2,2-dimethyl-4-alkyl-2-sila-5-oxo-1,3-oxazolidine. The alpha carbon atom of the amino acid typically further carries a hydrogen atom. The so called “side chain” attached to the alpha carbon atom, which is in fact the continuing main chain of the carboxylic acid, is an aliphatic moiety that may be linear or branched. The term “side chain” refers to the presence of the amino acid in a peptide (supra), where a backbone is formed by coupling a plurality of amino acids. An aliphatic moiety bonded to the α carbon atom of an amino acid included in such a peptide then defines a side chain relative to the backbone. As explained above, the same applies to an aliphatic moiety bonded to the amino group of the amino acid, which likewise defines a side chain relative to the backbone of a peptoid.
[0268] The term “aliphatic” means, unless otherwise stated, a straight or branched hydrocarbon chain, which may be saturated or mono- or poly-unsaturated and include heteroatoms. The term “heteroatom” as used herein means an atom of any element other than carbon or hydrogen. An unsaturated aliphatic group contains one or more double and/or triple bonds (alkenyl or alkynyl moieties). The branches of the hydrocarbon chain may include linear chains as well as non-aromatic cyclic elements. The hydrocarbon chain, which may, unless otherwise stated, be of any length, and contain any number of branches. Typically, the hydrocarbon (main) chain includes 1 to 5, to 10, to 15 or to 20 carbon atoms. Examples of alkenyl radicals are straight-chain or branched hydrocarbon radicals which contain one or more double bonds. Alkenyl radicals generally contain about two to about twenty carbon atoms and one or more, for instance two, double bonds, such as about two to about ten carbon atoms, and one double bond. Alkynyl radicals normally contain about two to about twenty carbon atoms and one or more, for example two, triple bonds, preferably such as two to ten carbon atoms, and one triple bond. Examples of alkynyl radicals are straight-chain or branched hydrocarbon radicals which contain one or more triple bonds. Examples of alkyl groups are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, the n isomers of these radicals, isopropyl, isobutyl, isopentyl, sec-butyl, tert-butyl, neopentyl, 3,3 dimethylbutyl. Both the main chain as well as the branches may furthermore contain heteroatoms as for instance N, O, S, Se or Si or carbon atoms may be replaced by these heteroatoms.
[0269] An aliphatic moiety may be substituted or unsubstituted with one or more functional groups. Substituents may be any functional group, as for example, but not limited to, amino, amido, azido, carbonyl, carboxyl, keto, cyano, isocyano, dithiane, halogen, hydroxyl, nitro, organometal, organoboron, seleno, silyl, silano, sulfonyl, thio, thiocyano, trifluoromethyl sulfonyl, p-toluenesulfonyl, bromobenzenesulfonyl, nitrobenzenesulfonyl, and methanesulfonyl.
[0270] As should be apparent from the above, the side chain of an amino acid in a peptide/peptoid described herein may be of a length of 0 to about 5, to about 10, to about 15 or to about 20 carbon atoms. It may be branched and include unsaturated carbon-carbon bonds. In some embodiments one or more natural amino acids are included in the peptide or peptoid. Such a natural amino acid may be one of the 20 building blocks of naturally occurring proteins.
[0271] In a peptide or peptoid, including a peptide/peptoid disclosed herein individual amino acids are covalently coupled via amide bonds between a carboxylic group of a first and an amino group of a second amino acid.
[0272] The term hydrophobic refers to a compound that is soluble in non-polar fluids. The hydrophobic properties of the peptide and/or peptoid are due to the presence of non-polar moieties within the same peptide and/or peptoid. Besides the hydrophobic peptide sequemce part there is a C-terminal —COOH moiety included that can occur in free, unprotected form, or in protected form. Non-polar moieties of a peptide or peptoid include a hydrocarbon chain that does not carry a functional group.
[0273] The non-polar moiety includes an amino acid, generally at least two amino acids, with a hydrocarbon chain that does not carry a functional group. The respective side chain, coupled to the α-carbon atom of the amino acid (supra), may have a main chain that includes 0 to about 20 or 1 to about 20, including 0 to about 15, 1 to about 15, 0 to about 10, 1 to about 10, 1 to about 5 or 0 to about 5 carbon atoms. The non-polar moiety may thus include an amino acid without side chain, i.e. glycine. The peptide and/or peptoid side chain may be branched (supra) and include one or more double or triple bonds (supra). Examples of peptide and/or peptoid side chains include, but are not limited to, methyl, ethyl, propyl, isopropyl, propenyl, propinyl, butyl, butenyl, sec-butyl, tert-butyl, isobutyl, pentyl, neopentyl, isopentyl, pentenyl, hexyl, 3,3 dimethylbutyl, heptyl, octyl, nonyl or decyl groups. As a few illustrative examples, the non-polar moiety may include an amino acid of alanine, valine, leucine, isoleucine, norleucine, norvaline, 2-(methylamino)-isobutyric acid, 2-amino-5-hexynoic acid. Such an amino acid may be present in any desired configuration. Bonded to the non-polar moiety may also be the C-terminus or the N-terminus of the peptide/peptoid. Typically the C-terminus or the N-terminus is in such a case shielded by a protecting group (supra).
[0274] In some embodiments the non-polar moiety includes a sequence of amino acids that is arranged in decreasing or increasing size. Hence, a portion of the amino acids of the non-polar moiety may be arranged in a general sequence of decreasing or increasing size. Relative to the direction from N- to C-terminus or from C- to N-terminus this general sequence can thus be taken to be of decreasing size. By the term “general sequence” of decreasing or increasing size is meant that embodiments are included in which adjacent amino acids are of about the same size as long as there is a general decrease or increase in size. Within a general sequence of decreasing size the size of adjacent amino acids of the non-polar moiety is accordingly identical or smaller in the direction of the general sequence of decreasing size. In some embodiments the general sequence of decreasing or increasing size is a non-repetitive sequence.
[0275] As an illustrative example, where a respective portion of amino acids is a sequence of five amino acids, the first amino acid may have a 3,4-dimethyl-hexyl side chain. The second amino acid may have a neopentyl side chain. The third amino acid may have a pentyl side chain. The fourth amino acid may have a butyl side chain. The fifth amino acid may be glycine, i.e. have no side chain. Although a neopentyl and a pentyl side chain are of the same size, the general sequence of such a non-polar peptide portion is decreasing in size. As a further illustrative example of a general sequence of decreasing size in a non-polar moiety the respective non-polar portion may be a sequence of three amino acids. The first amino acid may have an n-nonyl side chain. The second amino acid may have a 3-ethyl-2-methyl-pentyl side chain. The third amino acid may have a tert-butyl side chain. As yet a further illustrative example of a general sequence of decreasing size in a non-polar moiety, the non-polar moiety may be a sequence of nine amino acids. The first amino acid may have a 4-propyl-nonyl side chain. The second amino acid may have an n-dodecyl side chain. The third amino acid may have a 6,6-diethyl-3-octenyl side chain. An n-dodecyl side chain and a 6,6-diethyl-3-octenyl side chain both have 12 carbon atoms and thus again have a comparable size, Nevertheless, the 6,6-diethyl-3-octenyl group includes an unsaturated carbon-carbon bond and is thus of slightly smaller size than the dodecyl group. The fourth amino acid may have a 2-methyl-nonyl side chain. The fifth amino acid may have a 3-propyl-hexyl side chain. The sixth amino acid may have an n-hexyl side chain. The seventh amino acid may have a 2-butynyl side chain. The 8th amino acid may have an isopropyl side chain. The ninth amino acid may have a methyl side chain.
[0276] Where a portion of the amino acids of the non-polar moiety arranged in a general sequence of decreasing (or increasing) size only contains naturally occurring amino acids (whether in the D- or the L-form), it may for example have a length of five amino acids, such as the sequence leucine-isoleucine-valine-alanine-glycine or isoleucine-leucine-valine-alanine-glycine, A general sequence of decreasing size of only natural amino acids may also have a length of four amino acids. Illustrative examples include the sequences isoleucine-leucine-valine-alanine, leucine-isoleucine-valine-alanine, isoleucine-valine-alanine-glycine, leucine-valine-alanine-glycine, leucine-isoleucine-alanine-glycine, leucine-isoleucine-valine-glycine, isoleucine-leucine-alanine-glycine or isoleucine-leucine-valine-glycine. A general sequence of decreasing size of only natural amino acids may also have a length of three amino acids. Illustrative examples include the sequences isoleucine-valine-alanine, leucine-valine-alanine, isoleucine-valine-glycine, leucine-valine-glycine, leucine-alanine-glycine, isoleucine-alanine-glycine or isoleucine-leucine-alanine. A general sequence of decreasing size of only natural amino acids may also have a length of two amino acids. Illustrative examples include the sequences isoleucine-valine, leucine-valine, isoleucine-alanine, leucine-alanine, leucine-glycine, isoleucine-glycine, valine-alanine, valine-glycine or alanine-glycine.
[0277] In some embodiments the direction of decreasing size of the above defined general sequence of decreasing size is the direction toward the C-terminus of the hydrophobic linear sequence. Accordingly, in such embodiments the size of adjacent amino acids within this portion of the non-polar moiety is accordingly identical or smaller in the direction of the C-terminus. Hence, as a general trend in such an embodiment, the closer to the polar moiety of the amphiphilic linear sequence, the smaller is the overall size of a peptide and/or peptoid side chain throughout the respective general sequence of decreasing size.
[0278] In some embodiments the entire non-polar moiety of the hydrophobic linear peptide and/or peptoid or the hydrophobic linear sequence, respectively, consists of the general sequence of decreasing (or increasing) size. In such an embodiment the general sequence of decreasing (or increasing) size may have a length of n−m amino acids (cf. above). In some embodiments the general sequence of decreasing or increasing size is flanked by further non-polar side chains of the peptide/peptoid. In one embodiment the general sequence of decreasing (or increasing) size has a length of n−m−1 amino acids. In this embodiment there is one further amino acid included in the peptide/peptoid, providing a non-polar peptide/peptoid side chain. This amino acid may be positioned between the general sequence of decreasing (or increasing) size and the C-terminus, the C-terminus may be positioned between this additional non-polar amino acid and the general sequence of decreasing (or increasing) size or the general sequence of decreasing (or increasing) size may be positioned between the C-terminus and this additional non-polar amino acid. Typically the general sequence of decreasing (or increasing) size is positioned between the C-terminus and this additional non-polar amino acid. The additional non-polar amino acid may for example define the N-terminus of the peptide/peptoid, which may be shielded by a protecting group such as an amide, e.g. a propionic acyl or an acetyl group. Together with the general sequence of decreasing (or increasing) size as defined above it may define the non-polar portion of the peptide/peptoid. The polar amino acid may define the C-terminus of the peptide/peptoid. In this example the general sequence of decreasing (or increasing) size is thus flanked by the polar amino acid on one side and by the additional non-polar amino acid on the other side. In one embodiment where embodiment the general sequence of decreasing (or increasing) size has a length of n−m−1 amino acids, the remaining non-polar amino acid of the non-polar moiety of n−m amino acids is one of alanine and glycine.
[0279] As explained above, the polar moiety of the linear sequence may in some embodiments be defined by two or three consecutive amino acids. The polar moiety includes in aliphatic amino acids. Each of the in aliphatic amino acids is independently selected and carries an independently selected polar group. The symbol in represents an integer selected from 1, 2 and 3. The at least essentially non-polar moiety (supra) accordingly has a number of n−m, i.e. n−1, n−2 or n−3 amino acids. In some embodiments n is equal to or larger than m+2. In such an embodiment m may thus represent a number of n−2 or smaller.
[0280] In an embodiment where the entire non-polar moiety of the linear peptide and/or peptoid consists of the general sequence of decreasing (or increasing) size (supra), this non-polar moiety may thus have a length of n−2 or n−3 amino acids. In an embodiment where the linear peptide and/or peptoid has a further non-polar side chain in addition to the non-polar moiety of decreasing (or increasing) size, this additional non-polar side chain may be included in an amino acid that is directly bonded to an amino acid of the general sequence of decreasing (or increasing) size. The non-polar moiety may thus be defined by the non-polar moiety of decreasing (or increasing) size and the respective further amino acid with a non-polar side chain. In one such an embodiment where m=1, the non-polar moiety may thus have a length of n−2 amino acids, of which the non-polar moiety of decreasing (or increasing) size has a length of n−3 amino acids. The general sequence of decreasing (or increasing) size may be positioned between the two polar amino acids and this additional non-polar amino acid, or the additional non-polar amino acid may be positioned between the general sequence of decreasing (or increasing) size and the two polar amino acids. Typically the general sequence of decreasing (or increasing) size is positioned between the two polar amino acids and this additional non-polar amino acid. As mentioned above, one of the two polar amino acids may define the C-terminus of the peptide/peptoid. In this example the general sequence of decreasing (or increasing) size may thus be flanked by the two consecutive polar amino acids on one side and by the additional non-polar amino acid on the other side. Again, in some embodiments where m=1 the two consecutive polar amino acids may also be positioned between the general sequence of decreasing (or increasing) size and the additional non-polar amino acid, in which case the non-polar moiety has a first portion with a length of n−3 amino acids and a further portion of one amino acid.
[0281] Electrostatic forces, hydrogen bonding and van der Waals forces between hydrophobic linear sequences as defined above, including hydrophobic linear peptides and/or peptoids, result in these hydrophobic linear sequences to be coupled to each other. Without being bound by theory, thereby a cross-linking effect occurs that allows the formation of a hydrogel. In this regard the inventors have observed the formation of fibers based on helical structures.
[0282] The fibers formed of hydrophobic linear sequences of hydrophobic peptides and/or peptoids disclosed herein typically show high mechanical strength, which renders them particularly useful in tissue regeneration applications, for instance the replacement of damaged tissue. Hydrophobic peptides and/or peptoids disclosed herein have been observed to generally assemble into a fiber structure that resembles collagen fibers. Collagen, a component of soft tissue in the animal and human body, is a fibrous protein that provides most of the tensile strength of tissue. The mechanical strength of fibers of hydrophobic peptides and/or peptoids disclosed herein has been found to typically be much higher than that of collagen (cf. e.g. Figures) of gelatine, the hydrolysed form of collagen. An hydrophobic peptide and/or peptoid disclosed herein may thus be included in a hydrogel that is used as permanent or temporary prosthetic replacement for damaged or diseased tissue.
[0283] The hydrophobic linear sequence of the peptide/peptoid, which may represent the entire hydrophobic peptide/peptoid (supra) has been found to show remarkable stability at physiological conditions, even at elevated temperatures. It is in some embodiments stable in aqueous solution at physiological conditions at ambient temperature for a period of time in the range from 1 day to 1 month or more. It may in some embodiments be stable in aqueous solution at physiological conditions at 90° C. for at least 1 hour, at least 2 hours, at least 3 hours, at least 4 hours or at least 5 hours An hydrophobic linear sequence of an hydrophobic peptide and/or peptoid including an hydrophobic linear peptide and/or peptoid, is capable of providing a self assembling α-helical fiber in aqueous solution under physiological conditions. The peptides/peptoids (typically 3-7-mers) in the L- or D-form can self assemble into supramolecular helical fibers which are organized into mesh-like structures mimicking biological substances such as collagen. It has previously been observed in X-ray crystallography that peptides of a length of 3 to 6 amino acids with repetitive alanine containing sequences and an acetylated C-terminus take a helical conformation (Hatakeyama, Y, et al, Angew. Chem. Int. Ed. (2009) 8695-8698). Using peptides with an hydrophobic sequence, Ac-LD 6 (L), the formation of aggregates has for example been observed already at 0.1 mg/ml. As the concentration of peptide is increased to 1 mg/ml, the peptide monomers were found to align to form fibrous structures. With a formation of fibers occurring under physiological conditions at concentrations below 2 mM a peptide/peptoid is well suited as an injectable hydrogel material that can form a hydrogel under physiological conditions. Also disclosed herein is an hydrophobic linear peptide and/or peptoid as defined above for tissue engineering as well as to a tissue engineering method that involves applying, including injecting a respective hydrophobic linear peptide and/or peptoid.
[0284] A hydrogel is typically characterized by a remarkable rigidity and are generally biocompatible and non-toxic. Depending on the selected peptide/peptoid sequence these hydrogels can show thermoresponsive or thixotropic character. Reliant on the peptide/peptoid assembling conditions the fibers differ in thickness and length. Generally rigid hydrogels are obtained that are well suited for cultivation of a variety of primary human cells, providing peptide/peptoid scaffolds that can be useful in the repair and replacement of various tissues. Disclosed is also a process of preparing these hydrogels. The exemplary usage of these hydrogels in applications such as cell culture, tissue engineering, plastic surgery, drug delivery, oral applications, cosmetics, packaging and the like is described, as well as for technical applications, as for example for use in electronic devices which might include solar or fuel cells.
[0285] As an hydrophobic linear sequence of the peptide/peptoid, a hydrogel shows high stability at physiological conditions, even at elevated temperatures. In some embodiments such a hydrogel is stable in aqueous solution at ambient temperature for a period of at least 7 days, at least 14 days, at least a month or more, such as at least 1 to about 6 months.
[0286] In some embodiments a hydrogel disclosed herein is coupled to a molecule or a particle, including a quantum dot, with characteristic spectral or fluorometric properties, such as a marker, including a fluorescent dye. A respective molecule may for instance allow monitoring the fate, position and/or the integrity of the hydrogel.
[0287] In some embodiments a hydrogel disclosed herein is coupled to a molecule with binding affinity for a selected target molecule, such as a microorganism, a virus particle, a peptide, a peptoid, a protein, a nucleic acid, a peptide, an oligosaccharide, a polysaccharide, an inorganic molecule, a synthetic polymer, a small organic molecule or a drug.
[0288] The term “nucleic acid molecule” as used herein refers to any nucleic acid in any possible configuration, such as single stranded, double stranded or a combination thereof. Nucleic acids include for instance DNA molecules (e.g., cDNA or genomic DNA), RNA molecules (e.g., mRNA), analogues of the DNA or RNA generated using nucleotide analogues or using nucleic acid chemistry, locked nucleic acid molecules (LNA), and protein nucleic acids molecules (PNA). DNA or RNA may be of genomic or synthetic origin and may be single or double stranded. In the present method of an embodiment of the invention typically, but not necessarily, an RNA or a DNA molecule will be used. Such nucleic acid can be e.g. mRNA, cRNA, synthetic RNA, genomic DNA, cDNA synthetic DNA, a copolymer of DNA and RNA, oligonucleotides, etc. A respective nucleic acid may furthermore contain non-natural nucleotide analogues and/or be linked to an affinity tag or a label. In some embodiments the nucleic acid molecule may be isolated, enriched, or purified. The nucleic acid molecule may for instance be isolated from a natural source by cDNA cloning or by subtractive hybridization. The natural source may be mammalian, such as human, blood, semen, or tissue. The nucleic acid may also be synthesized, e.g. by the triester method or by using an automated DNA synthesizer.
[0289] Many nucleotide analogues are known and can be used in nucleic acids and oligonucleotides used in the methods of exemplary embodiments of the invention. A nucleotide analogue is a nucleotide containing a modification at for instance the base, sugar, or phosphate moieties. Modifications at the base moiety include natural and synthetic modifications of A, C, G, and T/U, different purine or pyrimidine bases, such as uracil-5-yl, hypoxanthin-9-yl, and 2-aminoadenin-9-yl, as well as non-purine or non-pyrimidine nucleotide bases. Other nucleotide analogues serve as universal bases. Universal bases include 3-nitropyrrole and 5-nitroindole. Universal bases are able to form a base pair with any other base. Base modifications often can be combined with for example a sugar modification, such as for instance 2′-O-methoxyethyl, e.g. to achieve unique properties such as increased duplex stability.
[0290] A peptide may be of synthetic origin or isolated from a natural source by methods well-known in the art. The natural source may be mammalian, such as human, blood, semen, or tissue. A peptide, including a polypeptide may for instance be synthesized using an automated polypeptide synthesizer. Illustrative examples of polypeptides are an antibody, a fragment thereof and a proteinaceous binding molecule with antibody-like functions. Examples of (recombinant) antibody fragments are Fab fragments, Fv fragments, single-chain Fv fragments (scFv), diabodies, triabodies (Iliades, P., et al., FEBS Lett (1997) 409, 437-441), decabodies (Stone, E., et al., Journal of Immunological Methods (2007) 318, 88-94) and other domain antibodies (Holt, L. J., et al., Trends Biotechnol. (2003), 21, 11, 484-490). An example of a proteinaceous binding molecule with antibody-like functions is a mutein based on a polypeptide of the lipocalin family (WO 03/029462, Beste et al., Proc. Natl. Acad. Sci. U.S.A. (1999) 96, 1898-1903). Lipocalins, such as the bilin binding protein, the human neutrophil gelatinase-associated lipocalin, human Apolipoprotein D or glycodelin, posses natural ligand-binding sites that can be modified so that they bind to selected small protein regions known as haptens. Examples of other proteinaceous binding molecules are the so-called glubodies (see e.g. internation patent application WO 96/23879), proteins based on the ankyrin scaffold (Mosavi, L. K., et al., Protein Science (2004) 13, 6, 1435-1448) or crystalline scaffold (e.g. internation patent application WO 01/04144) the proteins described in Skerra, J. Mol. Recognit. (2000) 13, 167-187, AdNectins, tetranectins and avimers. Avimers contain so called A-domains that occur as strings of multiple domains in several cell surface receptors (Silverman, J., et al., Nature Biotechnology (2005) 23, 1556-1561). Adnectins, derived from a domain of human fibronectin, contain three loops that can be engineered for immunoglobulin-like binding to targets (Gill, D. S. & Damle, N. K., Current Opinion in Biotechnology (2006) 17, 653-658). Tetranectins, derived from the respective human homotrimeric protein, likewise contain loop regions in a C-type lectin domain that can be engineered for desired binding (ibid.). Where desired, a modifying agent may be used that further increases the affinity of the respective moiety for any or a certain form, class etc. of target matter.
[0291] An example of a nucleic acid molecule with antibody-like functions is an aptamer. An aptamer folds into a defined three-dimensional motif and shows high affinity for a given target structure. Using standard techniques of the art such as solid-phase synthesis an aptamer with affinity to a certain target can accordingly be formed and immobilized on a hollow particle of an embodiment of the invention.
[0292] As a further illustrative example, a linking moiety such as an affinity tag may be used to immobilise the respective molecule. Such a linking moiety may be a molecule, e.g. a hydrocarbon-based (including polymeric) molecule that includes nitrogen-, phosphorus-, sulphur-, carben-, halogen- or pseudohalogen groups, or a portion thereof. As an illustrative example, the peptide/peptoid included in the hydrogel may include functional groups, for instance on a side chain of the peptide/peptoid, that allow for the covalent attachment of a biomolecule, for example a molecule such as a protein, a nucleic acid molecule, a polysaccharide or any combination thereof. A respective functional group may be provided in shielded form, protected by a protecting group that can be released under desired conditions. Examples of a respective functional group include, but are not limited to, an amino group, an aldehyde group, a thiol group, a carboxy group, an ester, an anhydride, a sulphonate, a sulphonate ester, an imido ester, a silyl halide, an epoxide, an aziridine, a phosphoramidite and a diazoalkane.
[0293] Examples of an affinity tag include, but are not limited to, biotin, dinitrophenol or digoxigenin, oligohistidine, polyhistidine, an immunoglobulin domain, maltose-binding protein, glutathione-S-transferase (GST), calmodulin binding peptide (CBP), FLAG′-peptide, the T7 epitope (Ala-Ser-Met-Thr-Gly-Gly-Gln-Gln-Met-Gly), maltose binding protein (MBP), the HSV epitope of the sequence Gln-Pro-Glu-Leu-Ala-Pro-Glu-Asp-Pro-Glu-Asp of herpes simplex virus glycoprotein D, the hemagglutinin (HA) epitope of the sequence Tyr-Pro-Tyr-Asp-Val-Pro-Asp-Tyr-Ala, the “myc” epitope of the transcription factor c-myc of the sequence Glu-Gln-Lys-Leu-Ile-Ser-Glu-Glu-Asp-Leu, or an oligonucleotide tag. Such an oligonucleotide tag may for instance be used to hybridise to an immobilised oligonucleotide with a complementary sequence. A further example of a linking moiety is an antibody, a fragment thereof or a proteinaceous binding molecule with antibody-like functions (see also above).
[0294] A further example of linking moiety is a cucurbituril or a moiety capable of forming a complex with a cucurbituril. A cucurbituril is a macrocyclic compound that includes glycoluril units, typically self-assembled from an acid catalyzed condensation reaction of glycoluril and formaldehyde. A cucurbit[n]uril, (CB[n]), that includes n glycoluril units, typically has two portals with polar ureido carbonyl groups. Via these ureido carbonyl groups cucurbiturils can bind ions and molecules of interest. As an illustrative example cucurbit[7]uril (CB[7]) can form a strong complex with ferrocenemethylammonium or adatnantylarnmonium ions. Either the cucurbit[7]uril or e.g. ferrocenemethylammonium may be attached to a biomolecule, while the remaining binding partner (e.g. ferrocenemethylammonium or cucurbit[7]uril respectively) can be bound to a selected surface. Contacting the biomolecule with the surface will then lead to an immobilisation of the biomolecule. Functionalised CB[7] units bound to a gold surface via alkanethiolates have for instance been shown to cause an immobilisation of a protein carrying a ferrocenemethylammonium unit (Hwang, I., et al., J. Am. Chem. Soc. (2007) 129, 4170-4171).
[0295] Further examples of a linking moiety include, but are not limited to an oligosaccharide, an oligopeptide, biotin, dinitrophenol, digoxigenin and a metal chelator (cf. also below). As an illustrative example, a respective metal chelator, such as ethylenediamine, ethylenediamine-tetraacetic acid (EDTA), ethylene glycol tetraacetic acid (EGTA), diethylenetriaminepentaacetic acid (DTPA), N,N-bis(carboxymethyl)glycine (also called nitrilotriacetic acid, NTA), 1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA), 2,3-dimercapto-1-propanol (dimercaprol), porphine or heme may be used in cases where the target molecule is a metal ion. As an example, EDTA forms a complex with most monovalent, divalent, trivalent and tetravalent metal ions, such as e.g. silver (Ag + ), calcium (Ca 2+ ), manganese (Mn 2+ ), copper (Cu 2+ ), iron (Fe 2+ ), cobalt (Co 3+ ) and zirconium (Zr 4+ ), while BAPTA is specific for Ca 2+ . In some embodiments a respective metal chelator in a complex with a respective metal ion or metal ions defines the linking moiety. Such a complex is for example a receptor molecule for a peptide of a defined sequence, which may also be included in a protein. As an illustrative example, a standard method used in the art is the formation of a complex between an oligohistidine tag and copper (Cu 2+ ), nickel (Ni 2+ ), cobalt (Co 2+ ), or zink (Zn 2+ ) ions, which are presented by means of the chelator nitrilotriacetic acid (NTA).
[0296] Avidin or streptavidin may for instance be employed to immobilise a biotinylated nucleic acid, or a biotin containing monolayer of gold may be employed (Shumaker-Parry, J. S., et al., Anal. Chem. (2004) 76, 918). As yet another illustrative example, the biomolecule may be locally deposited, e.g. by scanning electrochemical microscopy, for instance via pyrrole-oligonucleotide patterns (e.g. Fortin, E., et al., Electroanalysis (2005) 17, 495). In other embodiments, in particular where the biomolecule is a nucleic acid, the biomolecule may be directly synthesised on the surface of the immobilisation unit, for example using photoactivation and deactivation. As an illustrative example, the synthesis of nucleic acids or oligonucleotides on selected surface areas (so called “solid phase” synthesis) may be carried out using electrochemical reactions using electrodes. An electrochemical deblocking step as described by Egeland & Southern (Nucleic Acids Research (2005) 33, 14, e125) may for instance be employed for this purpose. A suitable electrochemical synthesis has also been disclosed in US patent application US 2006/0275927. In some embodiments light-directed synthesis of a biomolecule, in particular of a nucleic acid molecule, including UV-linking or light dependent 5′-deprotection, may be carried out.
[0297] The molecule that has a binding affinity for a selected target molecule may be immobilised on the nanocrystals by any means. As an illustrative example, an oligo- or polypeptide, including a respective moiety, may be covalently linked to the surface of nanocrystals via a thio-ether-bond, for example by using ω functionalized thiols. Any suitable molecule that is capable of linking a nanocrystal of an embodiment of the invention to a molecule having a selected binding affinity may be used to immobilise the same on a nanocrystal. For instance a (bifunctional) linking agent such as ethyl-3-dimethylaminocarbodiimide, N-(3-aminopropyl) 3-mercapto-benzamide, 3-aminopropyl-trimethoxysilane, 3-mercaptopropyl-trimethoxysilane, 3-(trimethoxysilyl) propyl-maleimide, or 3-(trimethoxysilyl) propyl-hydrazide may be used. Prior to reaction with the linking agent, the surface of the nanocrystals can be modified, for example by treatment with glacial mercaptoacetic acid, in order to generate free mercaptoacetic groups which can then employed for covalently coupling with an analyte binding partner via linking agents.
[0298] Embodiments of the present invention also include a hydrogel, which can be taken to be a water-swollen water-insoluble polymeric material. The hydrogel includes, including contains and consists of a peptide and/or peptoid as defined above. Since a hydrogel maintains a three-dimensional structure, a hydrogel of an embodiment of the invention may be used for a variety of applications. Since the hydrogel has a high water content and includes amino acids, it is typically of excellent biocompatibility.
[0299] A hydrogel according to an embodiment of the invention is formed by self-assembly. The inventors have observed that the peptides/peptoids assemble into fibers that form mesh-like structures. Without being bound by theory hydrophobic interaction between non-polar portions of peptides/peptoids are contemplated to assist such self-assembly process.
[0300] The method of forming the hydrogel includes dissolving the peptide/peptoid in aqueous solution. Agitation, including mixing such as stirring, and/or sonication may be employed to facilitate dissolving the peptide/peptoid. In some embodiments the aqueous solution with the peptide/peptoid therein is exposed to a temperature below ambient temperature, such as a temperature selected from about 2° C. to about 15° C. In some embodiments the aqueous solution with the peptide/peptoid therein is exposed to an elevated temperature, i.e. a temperature above ambient temperature. Typically the aqueous solution is allowed to attain the temperature to which it is exposed. The aqueous solution may for example be exposed to a temperature from about 25° C. to about 85° C. or higher, such as from about 25° C. to about 75° C., from about 25° C. to about 70° C., from about 30° C. to about 70° C., from about 35° C. to about 70° C., from about 25° C. to about 60° C., from about 30° C. to about 60° C., from about 25° C. to about 50° C., from about 30° C. to about 50° C. or from about 40° C. to about 65° C., such as e.g. a temperature of about 40° C., about 45° C., about 50° C., about 55° C., about 60° C. or about 65° C. The aqueous solution with the peptide/peptoid therein may be maintained at this temperature for a period of about 5 min to about 10 hours or more, such as about 10 min to about 6 hours, about 10 min to about 4 hours, about 10 min to about 2.5 hours, about 5 min to about 2.5 hours, about 10 min to about 1.5 hours or about 10 min to about 1 hour, such as about 15 min, about 20 min, about 25 min, about 30 min, about 35 min or about 40 min.
[0301] In some embodiments a hydrogel disclosed herein is a biocompatible, including a pharmaceutically acceptable hydrogel. The term “biocompatible” (which also can be referred to as “tissue compatible”), as used herein, is a hydrogel that produces little if any adverse biological response when used in vivo. The term thus generally refers to the inability of a hydrogel to promote a measurably adverse biological response in a cell, including in the body of an animal, including a human. A biocompatible hydrogel can have one or more of the following properties: non-toxic, non-mutagenic, non-allergenic, non-carcinogenic, and/or non-irritating. A biocompatible hydrogel, in the least, can be innocuous and tolerated by the respective cell and/or body. A biocompatible hydrogel, by itself, may also improve one or more functions in the body.
[0302] Depending on the amino acids that are included in the peptide/peptoid that is included in a hydrogel, a respective hydrogel may be biodegradable. A biodegradable hydrogel gradually disintegrates or is absorbed in vivo over a period of time, e.g., within months or years. Disintegration may for instance occur via hydrolysis, may be catalysed by an enzyme and may be assisted by conditions to which the hydrogel is exposed in a human or animal body, including a tissue, a blood vessel or a cell thereof. Where a peptide is made up entirely of natural amino acids, a respective peptide can usually be degraded by enzymes of the human/animal body.
[0303] A hydrogel according to an embodiment of the invention may also serve as a depot for a pharmaceutically active compound such as a drug. A hydrogel according to an embodiment of the invention may be designed to mimic the natural extracellular matrix of an organism such as the human or animal body. A fiber formed from the peptide/peptoid of an embodiment of the invention, including a respective hydrogel, may serve as a biological scaffold. A hydrogel of an embodiment of the invention may be included in an implant, in a contact lens or may be used in tissue engineering. In one embodiment, the peptides consist typically of 3-7 amino acids and are able to self-assemble into complex fibrous scaffolds which are seen as hydrogels, when dissolved in water or aqueous solution. These hydrogels can retain water up to 99.9% and possess sufficiently high mechanical strength. Thus, these hydrogels can act as artificial substitutes for a variety of natural tissues without the risk of immunogenicity. The hydrogels in accordance with the present invention may be used for cultivating suitable primary cells and thus establish an injectable cell-matrix compound in order to implant or reimplant the newly formed cell-matrix in vivo. Therefore, the hydrogels in accordance with the present invention are particularly useful for tissue regeneration or tissue engineering applications. As used herein, a reference to an “implant” or “implantation” refers to uses and applications of/for surgical or arthroscopic implantation of a hydrogel containing device into a human or animal, e.g. mammalian, body or limb. Arthroscopic techniques are taken herein as a subset of surgical techniques, and any reference to surgery, surgical, etc., includes arthroscopic techniques, methods and devices. A surgical implant that includes a hydrogel according to an embodiment of the invention may include a peptide and/or peptoid scaffold. This the peptide and/or peptoid scaffold may be defined by the respective hydrogel. A hydrogel of an embodiment of the invention may also be included in a wound cover such as gauze or a sheet, serving in maintaining the wound in a moist state to promote healing.
[0304] Depending on the amino acid sequence used in the peptide/peptoid the hydrogel may be temperature-sensitive. It may for instance have a lower critical solution temperature or a temperature range corresponding to such lower critical solution temperature, beyond which the gel collapses as hydrogen bonds by water molecules are released as water molecules are released from the gel.
[0305] The disclosed subject matter also provides improved chiral hydrophobic natural-based peptides and/or peptoids that assemble to peptide/peptoid hydrogels with very favorable material properties. The advantage of these peptide/peptoid hydrogels is that they are accepted by a variety of different primary human cells, thus providing peptide scaffolds that can be useful in the repair and replacement of various tissues. Depending on the chirality of the peptide monomer the character of the hydrogels can be designed to be more stable and less prone to degradation though still biocompatible.
[0306] A hydrogel and/or a peptide/peptoid described herein can be administered to an organism, including a human patient per se, or in pharmaceutical compositions where it may include or be mixed with pharmaceutically active ingredients or suitable carriers or excipient(s). Techniques for formulation and administration of respective hydrogels or peptides/peptoids resemble or are identical to those of low molecular weight compounds well established in the art. Exemplary routes include, but are not limited to, oral, transdermal, and parenteral delivery. A hydrogel or a peptide/peptoid may be used to fill a capsule or tube, or may be provided in compressed form as a pellet. The peptide/peptoid or the hydrogel may also be used in injectable or sprayable form, for instance as a suspension of a respective peptide/peptoid.
[0307] A hydrogel of an embodiment of the invention may for instance be applied onto the skin or onto a wound. Further suitable routes of administration may, for example, include depot, oral, rectal, transmucosal, or intestinal administration; parenteral delivery, including intramuscular, subcutaneous, intravenous, intramedullary injections, as well as intrathecal, direct intraventricular, intraperitoneal, intranasal, or intraocular injections. It is noted in this regard that for administering microparticles a surgical procedure is not required. Where the microparticles include a biodegradable polymer there is no need for device removal after release of the anti-cancer agent. Nevertheless the microparticles may be included in or on a scaffold, a coating, a patch, composite material, a gel or a plaster.
[0308] In some embodiments one may administer a hydrogel and/or a peptide/peptoid in a local rather than systemic manner, for example, via injection.
[0309] Pharmaceutical compositions that include a hydrogel and/or a peptide/peptoid of an embodiment of the present invention may be manufactured in a manner that is itself known, e. g., by means of conventional mixing, dissolving, granulating, dragee-making, levigating, emulsifying, encapsulating, entrapping or lyophilizing processes.
[0310] Pharmaceutical compositions for use in accordance with an embodiment of the present invention thus may be formulated in conventional manner using one or more physiologically acceptable carriers including excipients and auxiliaries that facilitate processing of the hydrogel and/or peptide/peptoid into preparations that can be used pharmaceutically. Proper formulation is dependent upon the route of administration chosen.
[0311] For injection, the peptide/peptoid of an embodiment of the invention may be formulated in aqueous solutions, for instance in physiologically compatible buffers such as Hanks's solution, Ringer's solution, or physiological saline buffer. For transmucosal administration, penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are generally known in the art.
[0312] For oral administration, the hydrogel and/or peptide/peptoid can be formulated readily by combining them with pharmaceutically acceptable carriers well known in the art. Such carriers enable the hydrogel and/or peptide/peptoid, as well as a pharmaceutically active compound, to be formulated as tablets, pills, dragees, capsules, liquids, gels, syrups, slurries, suspensions and the like, for oral ingestion by a patient to be treated. Pharmaceutical preparations for oral use can be obtained by adding a solid excipient, optionally grinding a resulting mixture, and processing the mixture of granules, after adding suitable auxiliaries, if desired, to obtain tablets or dragee cores. Suitable excipients are, in particular, fillers such as sugars, including lactose, sucrose, mannitol, or sorbitol; cellulose preparations such as, for example, maize starch, wheat starch, rice starch, potato starch, gelatine, gum tragacanth, methyl cellulose, hydroxypropylmethyl-cellulose, sodium carboxymethylcellulose, and/or polyvinylpyrrolidone (PVP). If desired, disintegrating agents may be added, such as the cross-linked polyvinyl pyrrolidone, agar, or alginic acid or a salt thereof such as sodium alginate.
[0313] Dragee cores are provided with suitable coatings. For this purpose, concentrated sugar solutions may be used, which may optionally contain gum arabic, talc, polyvinyl pyrrolidone, carbopol gel, polyethylene glycol, and/or titanium dioxide, lacquer solutions, and suitable organic solvents or solvent mixtures. Dyestuffs or pigments may be added to the tablets or dragee coatings for identification or to characterize different combinations of active compound doses.
[0314] Pharmaceutical preparations that can be used orally include push-fit capsules made of gelatine, as well as soft, sealed capsules made of gelatine and a plasticizer, such as glycerol or sorbitol. The push-fit capsules can contain the active ingredients in admixture with filler such as lactose, binders such as starches, and/or lubricants such as talc or magnesium stearate and, optionally, stabilizers. In soft capsules, the peptides/peptoids may be suspended in suitable liquids, such as fatty oils, liquid paraffin, or liquid polyethylene glycols. In addition, stabilizers may be added. All formulations for oral administration should be in dosages suitable for such administration. For buccal administration, the compositions may take the form of tablets or lozenges formulated in conventional manner.
[0315] The hydrogel and/or peptide/peptoid may be formulated for parenteral administration by injection, e.g., by intramuscular injections or bolus injection or continuous infusion. Formulations for injection may be presented in unit dosage form, e. g., in ampules or in multi-dose containers, with an added preservative. The respective compositions may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulatory agents such as suspending, stabilizing and/or dispersing agents.
[0316] The hydrogel and/or peptide/peptoid may be formulated for other drug delivery systems like implants, or trandermal patches or stents.
[0317] The present invention provides a novel class of hydrogel-forming hydrophobic peptides/peptidomimetics.
[0318] The inventors have found advantages and properties that the absence of a polar head group, such as hydrophilic amino acid(s), is giving to small peptides consisting solely of hydrophobic amino acids.
[0319] The absence of a polar group at the C-terminus gives rise to a new class of self-assembling peptides with different properties to the so far disclosed class of ultrashort peptides. It is not evident for a person aware of the state-of-the-art that a solely hydrophobic sequence of amino acids will be able to self-assemble to fibrous scaffolds, ending up in hydrogels. The so far explored assembly process of the currently explored type of ultrashort peptides was thought to be solely depending on amphiphilic sequences. The absence of a polar head group would have been more likely predicted to generate micelle-like structures, but not soft solid material. In addition, the absence of a polar head group leads to new material properties and gives so far unexplored possibilities to create novel smart biomaterial.
[0320] New advantages in material properties can be designed by the functionalization via the conjugation of non-amino acids such as small molecules, functional groups and short linkers.
[0321] These small molecule/functional group/short linkers bestow new material properties such as bio-adhesiveness and receptor-targeting. The new peptide sequence characteristics enables the development of new (and different to the one developed so far) applications. It also simplifies the purification of the desired compound. Compared to the peptide itself, the presence of the functional group/short linker at the C-terminus enhances ease of functionalization and the ability to chemically conjugate multiple bioactive molecules (such as cytokines, prodrugs etc) to a single peptidomimetic/peptidic conjugate. We can also eliminate undesired side reactions and non-specific interactions between the peptidomimetic/peptidic conjugate and bioactive molecules of interest.
[0322] In a further aspect, the present invention provides the use of said hydrophobic peptides/peptidomimetics in biofabrication.
[0323] Peptide self-assembly is an elegant and expedient “bottom-up” approach towards designing ordered, three-dimensional nanobiomaterials. Reproducible macromolecular nanostructures can be obtained due to the highly specific interactions that govern self-assembly. The amino acid sequence determines peptide secondary structure and interactions with other molecules, which in turn dictates the higher order macromolecular architecture.
[0324] Self-assembled nanofibrillar peptide scaffolds are of great interest for applications in regenerative medicine. As their nanofibrous topography resembles the extracellular matrix, they have been extensively applied as biomimetic scaffolds, providing spatial and temporal cues to regulate cell growth and behavior. Spatially defined, large-scale three-dimensional scaffolds, incorporating cells and other biochemical cues, can be obtained by 3D microdroplet bio-printing and moulding techniques. Self-assembling peptides, peptidomimetics and peptidic conjugates can serve as building blocks for printing or moulding of biocompatible macromolecular scaffolds that support the growth of encapsulated cells.
[0325] This disclosure describes a novel class of ultrashort peptides/peptidomimetics/conjugates, with a characteristic motif that facilitates self-assembly in aqueous conditions, forming porous, nanofibrous scaffolds that are biocompatible ( FIG. 1 ). Several subclasses demonstrate stimuli-responsive gelation ( FIG. 2 ) and can be used to for bio-printing of mini-hydrogel arrays and 3D organotypic biological constructs. The stimuli-responsive nature can also be exploited to produce hydrogel fibers or “noodles” through extrusion into salt solution baths. The resulting fibers can potentially be collected and used to create woven and aligned fibrous scaffolds.
[0326] The characteristic motif that drives self-assembly consists of a N-terminus “tail” of 2 to 7 natural aliphatic amino acids, arranged in decreasing hydrophobicity towards the C-terminus ( FIG. 10 ). The C-terminus can be functionalized, such as with a functional group (e.g. carboxylic acid, amine, ester, alcohol, aldehyde, ketone, maleimide), small molecules (e.g. sugars, alcohols, vitamins, hydroxyl-acids, amino acids) or short polar linkers.
[0327] Self-assembly in aqueous conditions occurs when the amino acids pair and subsequently stack into α-helical fibrils ( FIG. 1 ). Hydrogels are obtained when further aggregation of the fibrils into 3D networks of nanofibers entrap water ( FIG. 3A ).
[0328] The presence of functional groups enables to perform chemical modifications pre- and post-assembly. For instance, bioactive moieties such as growth factors, lipids, cell-receptor ligands, hormones and drugs can be conjugated to the scaffold post-assembly, giving rise to functionalized hydrogels.
[0329] Several subclasses of these peptides/peptidomimetics/conjugates demonstrate stimuli-responsive gelation ( FIG. 2 ). In particular, a subclass of peptides with lysine or lysine-mimetic molecules as the polar head group exhibit enhanced gelation and rigidity in the presence of salts and elevated pH ( FIGS. 3A , B and C). The gelation duration can be tuned by titrating the peptide and salt concentration. This opens avenues for the development of bio-printing, wherein gelation can be controlled and limited to desired areas through the co-injection of salt solutions.
[0330] Furthermore, the gelation process is slightly endodermic, which adds an element of temperature-sensitivity and eliminates the possibility of thermal damage to encapsulated cells. During the process of gelation, the ability to modulate gelation duration enables to sculpt the hydrogel construct into the desired shape for applications in regenerative medicine. The mechanical properties of this subclass of peptide hydrogels are enhanced by increasing salt concentration and pH. The stiffness and tunable mechanical properties render this subclass of amidated peptides hydrogels as ideal candidates for developing biological constructs that fulfill mechanically supportive roles. Through the judicious addition of ionic buffers and bases, less peptide can be used to attain equivalent mechanical stiffness while maintaining the porosity for supporting cell migration. The ability to modulate the mechanical properties and porosity is integral to creating organotypic constructs with mechanical properties comparable to that of the native tissue. In comparison, other peptide hydrogels, based on self-assembling α-helices, β-hairpins (G′≦2 kPa) and β-sheets (G′≦2 kPa), cannot attain such high rigidity. (References: α-helices:
Banwell, E. F. et al. Rational design and application of responsive alpha-helical peptide hydrogels. Nat Mater 8, 596-600 (2009). Yan, C. & Pochan, D. J. Rheological properties of peptide-based hydrogels for biomedical and other applications. Chem Soc Rev 39, 3528-3540 (2010).
β-Hairpins:
[0000]
Yan, C. et al. Injectable solid hydrogel: mechanism of shear-thinning and immediate recovery of injectable β-hairpin peptide hydrogels. Soft Matter 6, 5143 (2010).
Schneider, J. P. et al. Responsive hydrogels from the intramolecular folding and self-assembly of a designed peptide. J Am Chem Soc 124, 15030-15037 (2002).
References: β-Sheets:
[0000]
Zhang, S., Holmes, T., Lockshin, C. & Rich, A. Spontaneous assembly of a self-complementary oligopeptide to form a stable macroscopic membrane. Proc. Natl. Acad. Sci. USA 90, 3334-3338 (1993).
Liu, J., Zhang, L., Yang, Z. & Zhao, X. Controlled release of paclitaxel from a self-assembling peptide hydrogel formed in situ and antitumor study in vitro. Int J Nanomedicine 6, 2143-2153 (2011).
Aggeli, A. et al. Responsive gels formed by the spontaneous self-assembly of peptides into polymeric beta-sheet tapes. Nature 386, 259-262 (1997).)
[0338] As a proof-of-concept, this subclass of peptides was used to demonstrate the feasibility of bio-printing to develop mini-hydrogel arrays and 3D organoid structures for screening and regenerative medicine. This subclass of peptides demonstrates good solubility in water, forming solutions with low viscosity. This facilitates the printing and prevents the clogging of the needle/printer. Upon interacting with a physiological salt solution (such as phosphate buffered saline, PBS), the peptide solution gels instantaneously. As shown in FIG. 3D , arrays of microdroplets will form mini-hydrogels that adhere to a glass or polystyrene surface upon washing with PBS.
[0339] The peptides/peptidomimetics are biocompatible. Stem cells (mesenchymal, progenitor, embryonic and induced pluripotent stem cells) and primary cells isolated from patient samples (fibroblasts, nucleus pulposus) can be mixed with the peptide during the dispensing process ( FIG. 4 ). Following gelation, the cells are immobilized to the drop. Nanoparticles, small molecule drugs, oligonucleotides, and proteins can be similarly co-encapsulated ( FIGS. 4 and 5 ).
[0340] Coupled with the advent of high-throughput histological screening using slide scanners, this technology can be used to evaluate different test compounds using minimal cell numbers on a single microscope slide ( FIG. 6 ).
[0341] By incorporating cross-linkers, we can improve the mechanical stability of these mini-hydrogels. Bioactive functionalities can be also incorporated through mixing or cross-linking with polymers ( FIG. 7 ).
[0342] We can mix different peptides/peptidomimetics/conjugates without compromising their propensity for self-assembly. This allows us to combine different compounds to access different functional groups for conjugation and vary the bulk properties.
[0343] Extending the technology towards 3D microdroplet printing and moulding, biological, organotypic constructs with distinct, multi-functional micro-niches can be obtained ( FIG. 8 ). Multi-cellular constructs can also be obtained as the hydrogel can spatially confine different cell types during the printing process. The peptide/peptidomimetic/conjugate scaffold will provide the co-encapsulated cells with mechanical stability. Genes, small molecules and growth factors can be co-delivered to enhance cell survival, promote stem cell differentiation and modulate the host immune response. The resulting 3D biological constructs can be used as organoid models for screening drugs, studying cell behavior and disease progression, as well as tissue-engineered implants for regenerative medicine.
[0344] In addition to microdroplets, also obtain fibres (“noodles”) can be obtained by extruding the peptidic solution into a high concentration salt solution ( FIG. 3E ). Co-encapsulation of cells and bioactive moieties can be performed. The fibrous microenvironment can give rise to new applications such as woven scaffolds, aligned scaffolds and 3D patterned co-culture scaffolds.
Key Features:
[0000]
A novel class of peptides/peptidomimetics/conjugates which only consists of 2 to 7 amino acids which can self-assemble into nanofibrous scaffolds. The significantly shorter sequence implies a lower cost and ease of synthesis and purification compared to other self-assembling peptide/conjugate technologies.
An interesting mechanism of self-assembly into nanofibrous scaffolds in aqueous conditions and polar solvents. Such scaffolds can provide mechanical cues for cellular and tissue regeneration (biomimetic scaffold).
A versatile material which can be formulated in different ways. Some subclasses are stimuli-responsive, which facilitates the development of bio-printing technologies. Several subclasses demonstrate stimuli-responsive behavior which can be exploited for various applications.
A subclass of peptides demonstrates salt and pH-responsive gelation. In particular, instantaneous gelation can be obtained upon exposure to a physiologically compatible salt solution.
When dissolved in water, the peptidic solution has low viscosity and can be easily dispensed through needles and print-heads. This minimizes the possibility of clogging.
The stimuli-responsiveness can also be exploited to generate hydrogel fibers/′ noodles′. These fibers can subsequently be aligned or woven to create innovative scaffolds for tissue engineering and disease models.
On a macroscale, we can also use moulds (such as those made of silicone) to pattern the hydrogels in a 3D fashion.
The hydrogels are biocompatible and can be used to encapsulate cells. Upon gelation, the resulting hydrogel is stable and not easily dissociated. Therefore, encapsulated cells cannot escape.
Bioactive moieties, such as oligonucleotides, proteins and small molecule drugs, as well as nano- and microparticles, can be co-encapsulated to influence cell behavior. Drug release can also be modulated by porosity and various molecular interactions.
Post-assembly modifications are feasible due to the presence of functional groups. Large proteins such as growth factors can also be conjugated to the peptidic backbone or functional groups on the conjugate to modulate biological behavior.
Examples
[0355] Experiments have been performed to illustrate the technical aspects of exemplary embodiments of the present invention. The following examples are described in the Experimental Methods and Results. The skilled artisan will readily recognize that the examples are intended to be illustrative and are not intended to limit the scope of the present invention.
Experimental Methods and Results
Circular Dichroism (CD) Spectroscopy
[0356] Secondary peptide structures were analyzed by measuring ellipticity spectra using the Aviv Circular Dichroism Spectrometer, model 410. CD samples were prepared by diluting stock peptides solutions (5-10 mg/ml) in water. The diluted peptide solutions were filled in to a cuvette with 1 mm path length and spectra were acquired. As a blank reference water was used and the reference was subtracted from the raw data before molar ellipticity was calculated. The calculation was based on the formula: [θ] λ =θ obs ×1/(10 Lcn), where [θ] λ□ is the molar ellipticity at λ in deg cm 2 d/mol, is the observed ellipticity at □λ in mdeg, L is the path length in cm, c is the concentration of the peptide in M, and n is the number of amino acids in the peptide. Secondary structure analysis was done using CDNN software.
Environmental Scanning Electron Microscopy (ESEM)
[0357] Samples were placed onto a sample holder of FEI Quanta 200 Environmental Scanning Electron Microscopy. The surface of interest was then examined using accelerating voltage of 10 kV at a temperature of 4° C.
Field Emission Scanning Electron Microscopy (FESEM)
[0358] Samples were frozen at −20° C. and subsequently to −80° C. Frozen samples were further freeze dried. Freeze dried samples were fixed onto a sample holder using conductive tape and sputtered with platinum from both the top and the sides in a JEOL JFC-1600 High Resolution Sputter Coater. The coating current used was 30 mA and the process lasted for 60 sec. The surface of interest was then examined with a JEOL JSM-7400F Field Emission Scanning Electron Microscopy system using an accelerating voltage of 5-10 kV.
Preparation of Hydrogel Droplets
[0359] We obtained hydrogel arrays by simply dispensing small volume droplets (0.5, 1, 2, 5, 10 and 20 μL) of peptide solution and subsequently mixing or washing with PBS. The viscosity and rigidity increases significantly upon gelation, conferring high shape fidelity, which enables us to localize the hydrogel droplets to the site of deposition, control the internal composition and suspend encapsulated cells or bioactive moieties, two important criteria for bioinks. To date, we have generated hydrogel droplet arrays of various volumes, encapsulating small molecules, DNA, mRNA, nanoparticles, proteins and cells.
Encapsulation of Human Mesenchymal Stem Cells
[0360] Human mesenchymal stem cells were obtained from Lonza (Basel, Switzerland) and cultured in α-MEM medium with 20% fetal bovine serum, 2% L-glutamine and 1% penicillin-streptomycin. Upon trypsinization, the cells were suspended in PBS and subsequently added into or onto peptide solutions (in PBS). The constructs were then allowed to gel at 37° C. for 15 minutes before media was added.
[0000] Hydrophobic Peptides which Self-Assemble into Nanofibrous Hydrogels
[0361] Materials.
[0362] All peptides used in this study were manually synthesized by American Peptide Company (Sunnyvale, Calif.) using solid phase peptide synthesis and purified to >95% via HPLC. Amino acid and peptide content analysis were performed.
[0363] Preparation of Hydrogels.
[0364] To prepare the peptide hydrogels, the lyophilized peptide powders were first dissolved in milliQ water and mixed by vortexing for 30 seconds to obtain a homogenous solution. The gelation occurred between minutes to overnight, depending on the peptide concentration. Gelation can be facilitated by sonication or heating.
[0365] Functionalization of C-Terminus.
[0366] To functionalize the C-terminus, biotin and L-DOPA was incorporated during solid phase peptide synthesis by first reacting the Fmoc protected precursor to the Wang or Rink-amide resin. The final product was purified using HPLC/MS, lyophilized and evaluated for gelation.
[0367] Field Emission Scanning Electron Microscopy.
[0368] Hydrogel samples were flash frozen in liquid nitrogen and subsequently freeze-dried. Lyophilized samples were sputtered with platinum in a JEOL JFC-1600 High Resolution Sputter Coater. Three rounds of coating were performed at different angles to ensure complete coating. The coated sample was then examined with a JEOL JSM-7400F FESEM system using an accelerating voltage of 2-5 kV.
[0369] The listing or discussion of a previously published document in this specification should not necessarily be taken as an acknowledgement that the document is part of the state of the art or is common general knowledge. All documents listed are hereby incorporated herein by reference in their entirety for all purposes.
[0370] Exemplary embodiments of the invention illustratively described herein may suitably be practiced in the absence of any element or elements, limitation or limitations, not specifically disclosed herein. Thus, for example, the terms “comprising”, “including,” containing”, etc. shall be read expansively and without limitation. Additionally, the terms and expressions employed herein have been used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding 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 invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by exemplary embodiments and optional features, modification and variation of the inventions embodied therein herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention.
[0371] The invention has been described broadly and generically herein. Each of the narrower species and subgeneric groupings falling within the generic disclosure also form part of the invention. This includes the generic description of the invention with a proviso or negative limitation removing any subject matter from the genus, regardless of whether or not the excised material is specifically recited herein.
[0372] Other embodiments are within the following claims. In addition, where features or aspects of the invention are described in terms of Markush groups, those skilled in the art will recognize that the invention is also thereby described in terms of any individual member or subgroup of members of the Markush group. | The present invention relates to hydrophobic peptides and/or peptidomimetics capable of forming a (nanofibrous) hydrogel and hydrogels comprising said hydrophobic peptides and/or peptidomimetics and to various uses, such as in regenerative medicine, injectable therapies, delivery of bioactive moieties, wound healing, 2D and 3D synthetic cell culture substrate, biosensor development, biofunctionalized surfaces, and biofabrication. | 2 |
CROSS REFERENCE TO RELATED APPLICATION
The following application filed on even date relates to a method and tool for removing a metalic plug from a tube: Ser. No. 08/203,631, entitled METHOD AND TOOL FOR REMOVING A METALIC PLUG FROM A TUBE, by David J. Fink, James W. Everett, Paul Boone, Annette M. Costlow and James J. Roberts, now U.S. Pat. No. 5,465,483.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to tools for removing a plug from a conduit, and, more particularly, to a pneumatic tool for removal of a plug from a heat exchanger tube mounted in a tube sheet of a nuclear powered steam generator by simultaneously applying a static pull force and a repetitive impulse to the plug.
2. Description of the Prior Art
Damaged or corroded heat exchanger tubes in nuclear powered steam generators have, in the past, been removed from service by plugging them with metallic plugs. Recent technological advances have made it possible to refurbish some marginally corroded or damaged tubes to put them back in service, thereby increasing the power producing capacity of the steam generator. Therefore it is desirable to be able to remove a plug, inspect the tube from which it is removed, and refurbish the tube or replug it depending upon the outcome of the inspection.
The plugs typically used for plugging heat exchanger tubes in nuclear powered steam generators are formed from a tubular shell fabricated of a nickel alloy, such as, Inconel®. The shell is open at an end near an open end of the conduit, or tube, near a face of a tube sheet in the steam generator, and closed at its opposite end distal from the tube opening. One common type of plug, described in commonly owned U.S. Pat. No. 4,390,042, to Kucherer, includes an internally threaded plug skirt at the open end and a tapered, cork-shaped expander member contained completely in the interior of the shell. Before fixing the plug to the tube, the larger, circular end of the expander member is in abutment with the inner surface of the closed end of the plug shell. The shell inner surface is slightly tapered from the closed end to an axial position near the threaded plug skirt. When the cork-shaped expander member is forcefully drawn from the closed end towards the open end of the shell by a hydraulic ram, it radially expands the plug into sealing engagement with the interior surface of the tube by a wedging action. The forceful pulling of the cork-shaped expander member along the longitudinal axis of the shell further applies an extruding force to the metallic walls of the shell. A plurality of annular lands circumscribing the outer walls of the shell become sealingly engaged against the interior surface of the heat exchanger tube.
The traditional method for removing mechanical plugs, such as the plug described above, includes the steps of first pushing back the internal expander with a push-rod, and then pulling the plug with a hydraulic puller. Typically, the threads of the plug skirt are used for attachment of the puller to the plug. This method of pushing the expander back and pulling has severe problems. First, and most limiting, is that the bottom of the plug (the plug skirt) often breaks off before the plug dislodges. This is particularly undesirable since the only remaining recovery method, drilling, is now made difficult by a loose expander. When a plug is pulled successfully, the inner surface of the tube is often deeply scored by the pulling process. This scoring usually dictates a reaming process if the tube is to be replugged at a later date and may be severe enough to prevent a tube from being put back in service.
Another method for removing such plugs is described in commonly owned U.S. Pat. No. 4,903,392, to Stickel, et al. According to this method, the plug is heated with an electrically conductive push-rod by ohmic heating to a temperature that lowers its tensile yield strength, and an axial force is applied to the plug to elongate it, thereby radially contracting the plug and relaxing the engagement between the plug and the inner surface of the tube. After cooling, the plug may then be pulled out of the tube. This heat relaxation method requires a complex tooling system and also has some severe limitations. The plug shell can tear, or separate, during the step of pushing back the expander or elongating the plug shell. In this event, the tube will most likely need to be reamed and replugged. U.S. Pat. No. 4,800,637, to Overbay, also describes a method by which the plug shell is mechanically elongated, but without the heating step.
Another method for removing such plugs from heat exchanger tubes is disclosed in commonly owned U.S. Pat. No. 4,829,660, to Everett et al. The expander element is pushed back out of engagement with the tapered inner surface of the plug and forced through the closed end of the plug shell. A TIG torch is then used to create beads along the longitudinal axis of the plug shell to relax the engagement between the shell and the tube. This method also requires a complex tooling system. Further, if the plug shell separates during the expander push-back, a TIG burn will be made in the tube wall, likely requiring reaming and replugging of the tube.
Plug drilling, such as disclosed in commonly owned U.S. Pat. No. 4,734,972, to Hawkins, is another method of plug removal but is usually undesirable because of the complexity of the process and the risk of damaging the tube sheet and the tubes. Drilling is also very slow and impractical for large numbers of plugs. Further, drilling can create activated debris in the steam generator that is difficult and hazardous to remove.
Alternative methods of plug removal have not been forthcoming because of the limitation of the breakage of the bottom of the plug and the difficulty in finding an alternate place to apply a removal force. Therefore, there is a need for a new method for removing plugs from heat exchanger tubes and similar conduits that does not suffer the disadvantages of the prior art methods.
SUMMARY OF THE INVENTION
These needs and others are satisfied with the present invention for a tool and method for removing a metallic plug that has been radially expanded into engagement with an inner surface of a conduit, or tube. According to the invention, the plug is removed with preferably repeated pulling impulses on the plug, preferably applied to the plug in conjunction with a static pull force.
The tool includes a pneumatic cylinder defining an interior, cylindrical chamber, a first end distal from the plug defining an anvil at a surface of the chamber distal from the plug, and a cylindrical slug, or hammer, sealingly slidable within the chamber in response to a pressure difference between a hammer surface proximal the plug and a hammer surface distal the plug. (Throughout the remainder of this specification, the terms "distal" and "proximal" shall be defined in relation to the plug unless otherwise specified.) The cylinder is rigidly connected to the plug by a mandrel that is preferably fabricated from a solid member. A pulling impulse is provided by first moving the hammer away from the anvil by pneumatically creating a pressure difference in the chamber between the proximal end of the chamber on a proximal side of the hammer and the distal end of the chamber on a distal side of the hammer, then quickly venting the pressure in the distal end of the chamber while maintaining a positive pressure in the proximal end to allow the hammer to strike against the anvil at speed. The tool and the method of using the tool are particularly suited for and easily adapted to removing a plug from a heat exchanger tube in a nuclear powered steam generator.
According to another aspect of the invention, the cylinder is oriented so as to hang from the plug by the mandrel, the weight of the cylinder and any components supported by the cylinder providing the static pull force.
According to another aspect of the invention, a pneumatic system connected to the top and bottom ends of the chamber provide controlled pressure to the proximal end and to the distal end of the chamber, respectively. The pressure to each of the proximal and distal ends is preferably independently sourced and controlled by first and second pneumatic systems, respectively. The tool can also include a distal vent system for venting the distal end of the chamber. To create a pulling impulse, the hammer is first moved away from the anvil by the steps of closing the vent, and then providing positive pressure with each of the pneumatic systems so as to apply a greater force to the distal side of the hammer than to the proximal side of the hammer. Then, by opening the vent to quickly release the positive pressure in the distal end of the chamber, the force on the distal side of the hammer is rapidly reduced to a magnitude that is less than the magnitude of the force applied to the proximal side of the hammer. The positive pressure in the proximal end of the chamber, preferably acting in conjunction with gravity, applies a force moving the hammer against the anvil at speed. The plug can be removed by applying repeated pulling impulses.
According to another aspect of the invention, a position feedback system, capable of sensing movement of the plug due to a first pulling impulse, can adjust the magnitude of a subsequent pulling impulse based upon the magnitude of movement of the plug due to the first pulling impulse. The position feedback system can also be used for determining when the plug is removed from the tube and for stopping the impulses is response to a predetermined condition, for example, if the plug is removed, or if the plug does not move after applying repeated pulling impulses.
According to another aspect of the invention, the tool is adapted for displacing an expander member in a metalic plug, such as that described in U.S. Pat. No 4,390,042 and discussed hereinbefore, prior to removing the plug, by applying a displacement impulse to the expander member. Repeated displacement impulses can be applied if a first impulse does not displace the plug. A push-back mandrel rigidly connects the cylinder and the plug, a distal end of the push-back mandrel connecting to the proximal end of the cylinder. An elongated push-rod is slidable a predetermined distance within an axially extending bore of the push-back mandrel, and extends beyond the proximal and distal ends thereof. The proximal end of the push-rod is adapted for pushing on the expander member.
Before starting to displace an expander member, the push-rod is positioned distal from the plug such that the distal end of the push-rod extends through an axial hole in the cylinder into the proximal end of the chamber, and a proximal end of the push-rod can abut the expander member. Applying the displacement impulse includes several steps. First, the pressure control means applies positive pneumatic pressure to each end of the chamber. The pressure applied to the distal end of the chamber is preferably 15-30 psi greater than the pressure applied to the proximal end of the chamber. The distal end of the chamber is then vented by opening the distal vent. The pressure on the proximal surface of the hammer, which is preferably minimal for this purpose, thereby moves the hammer towards the anvil. A pressure difference between the ends of the chamber is quickly created by closing the distal vent and then quickly venting the proximal end of the chamber with a proximal vent provided for that purpose, thereby applying a net force on the hammer moving it towards the proximal end of the chamber so as to strike the distal end of the push-rod at speed, and thereby transfering the displacement impulse to the expander member. To apply a repeated displacement impulse, the proximal vent is closed and the distal vent opened to move the hammer to the distal end of the chamber, and the steps of closing the distal vent and then quickly opening the proximal vent are repeated.
An object of this invention is to provide a method and tool for removing a plug from a conduit, or tube, that reduces the likelihood of scoring the conduit during the removal process.
Another object of this invention is to provide a method and tool for removing a plug, formed by a plug shell having a threaded plug skirt, from a conduit that reduces the likelihood of breaking off the plug skirt or tearing the plug shell during the removal process.
Another object of this invention is to provide a method and tool for removing a plug from a conduit that does not require that a high current be applied to the plug.
Another object of this invention is to provide a method and tool for removing a plug from a conduit that does not require that a high heat source be applied to the plug.
Another object of this invention is to provide a method and tool for removing a plug from a conduit wherein the static pulling force applied to the plug is significantly smaller than the force applied using prior art methods.
Another object of this invention is to provide a more reliable method and tool for removing a plug from a conduit, or tube, than provided by prior art methods.
Another object of this invention is to provide a method and tool for removing a plug from a heat exchanger tube in a nuclear powered steam generator that creates less debris than prior art methods.
Another object of this invention is to provide a method and a tool that are especially suitable for removing a plug used to plug a heat exchanger tube of a nuclear powered steam generator.
These and other objects of the present invention will be more fully understood from the following description of the invention with reference to the illustrations appended hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal section of a plug lodged in a tube, wherein an expander member is engaged with a tapered inner surface of the plug shell.
FIG. 2 is a similar view of the plug of FIG. 1, wherein the expander member is pushed back out of engagement with the tapered inner surface of the plug shell.
FIGS. 3a and 3b are longitudinal section views of a plug removal tool of this invention with, respectively, a puller mandrel and a push-back mandrel attaching the pneumatic cylinder to a plug.
FIG. 4 is plan view of a preferred embodiment of the pneumatic cylinder.
FIG. 5 is a section through line 5--5 of FIG. 4.
FIG. 6 is a bottom plan view of the pneumatic cylinder of FIG. 4.
FIG. 7 is a section view through line 7--7 of FIG. 4.
FIG. 8 is an elevation view of a preferred embodiment of a puller mandrel adapted for the pneumatic cylinder of FIG. 4.
FIG. 9 is an elevation view of a second preferred embodiment of a puller mandrel including a tap.
FIG. 10 is a longitudinal section view of a push-back mandrel.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the figures, and in particular to FIGS. 1 and 2, a plug 1 of the type commonly used to seal a heat exchanger tube in a nuclear powered steam generator is illustrated in cross section within such tube 3. Plug 1 is formed of a generally cylindrical, hollow, plug shell 5 about 3/4 inch (1.91-2.22 cm) in diameter and a few inches long. Plug shell 5 is made of a nickel alloy, such as Inconel®, as is heat exchanger tube 3. An open end 7 of plug shell 5 is near the opening 9 of heat exchanger tube 3, and a closed end 11 is distal from opening 9. A plug skirt 13 at open end 7 is tapped with threads 15 so that a pulling tool (not shown) with mating threads can be attached for gripping plug shell 5. An inner surface 17 of plug shell 5 is tapered down towards plug skirt 13. An expander member 19 inside plug shell 5 is also tapered towards plug skirt 13 for engaging tapered inner surface 17 when pulled down by a ram.
FIG. 1 shows the plug 1 with expander member 19 in the engaged position with tapered inner surface 17 of plug shell 5. As expander member 19 is pulled down into tapered inner surface 17, wall 21 of plug shell 5 is expanded radially outward and engages inner surface 23 of tube 3. Annular lands 25 formed on outer wall 21 provide a secure seal. FIG. 2 shows plug 1 after expander member 19 has been pushed back out of engagement with tapered inner surface 17 by, for example, a push-rod (not shown).
Referring now also to FIGS. 3a and 3b, a tool 31 of this invention for extracting heat exchanger plug 1 is schematically illustrated in longitudinal cross section. Similar structures common to each figure will be referenced by the same reference numbers throughout this specification for simplicity of exposition. Heat exchanger tube 3 is shown emplaced within a tube sheet 33 of a heat exchanger (not shown). Tool 31, which can have a high degree of structural symmetry about a cylindrical axis aligned with the longitudinal axes of tube 3 and plug 1 as illustrated in the figure, utilizes the weight of pneumatic cylinder 35 and a second cylinder 63 to provide a static pull force to the plug 1. Experience has shown that using an axial pull force alone to pull plugs will often exceed the tensile strength of plug skirt 11, causing plug skirt 11 to break off. This invention permits use of a smaller static pull force than prior art methods of plug removal, thus avoiding the skirt breakage problem.
The tool 31 is adapted for applying repeated pulling impulses to the plug 1 to extract plug 1, and is also adapted for applying repeated displacement impulses to the expander member 19 to disengage it from the tapered inner surface 17 of plug shell 5. The tool 31 transmits the static force and each type of impulse directly through solid members. This is necessary in order to achieve the full effect of the impulses.
The tool 31 is connected to the plug 1 with a mandrel, referred to hereinafter generically by reference character 37. Mandrel 37 can be adapted for applying pulling impulses or for applying displacement impulses. Tool 31 illustrated in FIG. 3a transfers the static pull force and pulling impulses to plug shell 5 via a puller mandrel 131 that preferably engages threads 15 of plug skirt 13 with mating threads 39 at a proximal end. The other, distal end of mandrel 37 is rigidly connected to the pneumatic cylinder 35, for example, by screw threads 41 screwed into tapped threads 113 in the proximal end of the cylinder 41. FIG. 3b illustrates a tool 31 adapted for displacing an expander member 19 using a push-back mandrel 161 similarly connecting the cylinder 35 to the plug 1. A push-rod 165 transfers displacement impulses to the expander member 19.
Pneumatic cylinder 35 includes a cylindrical internal chamber 43 that is divided into a proximal end 45 and a distal end 47 by a generally cylindrical slug, or hammer 49 sealingly slideable within the chamber 43 in response to a pressure differential between the proximal end 45 of the chamber and the distal end 47 of the chamber. A lubricated o-ring 51 seated in o-ring groove 53 provides a slidable seal between the hammer 49 and the cylindrical surface 55 of the chamber 43. O-ring 51 is preferably lubricated with a non-fluid lubricant, such as 10W-NR lubricant. Proximate pneumatic channels 57 and distal pneumatic channels 59 are provided for pressurizing and depressurizing the proximal end 45 of the chamber and the distal end 47 of the chamber, respectively. A distal surface of the chamber 43 defines an anvil 61 for absorbing impacts from the hammer 49.
Substantially surrounding the pneumatic cylinder 35 is the second cylinder 63 which can preferably be carried by a free end of a robotic arm (not shown) having a base plate at a fixed end secured to the tubesheet 33. The second cylinder 63 can move axially on seals located between the pneumatic cylinder 35 and the second cylinder 63. The seals are preferably provided by a proximal o-ring 65 and a distal o-ring 67 that cooperatively define a proximal plenum 69 and a distal plenum 71 between the two cylinders. Each o-ring is preferably lubricated. Channels 57 communicate between the proximal plenum 69 and the proximal end 45 of the chamber. Channels 59 communicate between the distal plenum 71 and the distal end 47 of the chamber. The second cylinder 63 also includes a proximal pneumatic connector 73 for connecting to a first source of pneumatic air 74 and a distal pneumatic connector 75 for connecting the distal plenum 71 to a second source of pneumatic air 76. The first source of pneumatic air preferably includes a proximal vent mechanism 78, preferably solenoid actuated, for quickly reducing pressure in the proximal plenum 69, and thereby also in the proximal end 45 of the chamber.
A shutter arrangement 77 is used for quickly reducing pressure, or venting, the distal plenum 71 and thereby also venting the distal end 47 of the chamber 43. The shutter arrangement 77 preferably includes an annular, moveable shutter 79 concentrically aligned outside the second cylinder 63. Near the distal of the second cylinder are a plurality of distal plenum vents 81 facing the shutter. The shutter 79 is moveable in a direction indicated by arrows between a closed position (shown in the figure) and an open position (not shown). In the closed position, first and second seals, preferably provided by resilient o-rings 83 and 85, provide seals between the shutter 79 and the sidewall 87 of the cylinder 63, and between a distal edge 89 of the shutter 79 and a radially extending flange 91 at the distal of the second cylinder 63. First and second pneumatic actuators 93, 95 are mechanically connected to the shutter 79 to rapidly raise and lower the shutter 79. O-ring 85 is secured to an o-ring groove 96 in flange 91 by a glue to prevent its displacement in cycling the shutter 79 open and closed.
Referring now to FIGS. 4 through 6, which show details of the pneumatic cylinder 35, the pneumatic cylinder includes a body 101 and an end plug 103 each fabricated from a hardened stainless steel material, and joined by, for example, a threaded connection secured with a liquid sealant, after insertion of the hammer 49. O-rings 65 and 67 are seated in annular bushings 1O5 and 107 respectively, that are attached to the body 101 of cylinder 35 by fasteners, such as screws 109. The upper end of the body 101 is adapted for rigidly securing a mandrel 37 for attachment to the plug 1. A central bore 111 preferably extends from a proximal face 113 into the proximal end 45 of the chamber 43. The bore 111 includes screw threads 115 along a middle portion of its length for screwing in a distal end of a mandrel. The mandrel is further secured to the pneumatic cylinder 35 by a plurality of set screws (not shown), threaded into angularly extending threaded holes 117 transverse to the mandrel.
A preferred embodiment of a mandrel 37 for pulling a plug is illustrated in FIG. 8. The puller mandrel 131 is preferably fabricated of a solid piece of stainless steel. A distal end 133 includes screw threads 41 adapted for screwing into the internal threads 115 at the proximal end of the pneumatic cylinder 35. A proximal end 137 includes a centering post 139 and external screw threads 39 for screwing into the skirt threads 15 of the plug 1. A middle section 143 is adapted, for example with flats 145, for grasping and turning with turning tools (not shown). Means resisting loosening of the mandrel 131 from the cylinder 35 are provided by angled, longitudinally extending notches 147 cooperating with set screws (not shown) threaded into the angularly extending threaded holes 117 transverse to the mandrel.
A second embodiment of a puller mandrel 151 is illustrated in FIG. 9. Similar to the puller mandrel 131 illustrated in FIG. 8, puller mandrel 151 includes a distal section 133 that is threaded for screwing into the pneumatic cylinder 35, a middle section 143 adapted for grasping and turning with turning tools and for resisting loosening of the puller mandrel 151, and a proximal section 137 having a centering post 139 and screw threads 39 adapted for attachment to the skirt threads 15 of a plug 1. In addition, the proximal section 137 includes tap threads 153 for tapping into and further rigid attachment to the tapered inner surface 17 of a plug that is potentially cracked above the skirt threads 15.
A mandrel 37 adapted for disengaging the expander member 19 is illustrated in FIG. 10 in longitudinal cross-section. Push-back mandrel 161 includes a distal threaded section 133 for screwing into the pneumatic cylinder 35 and a proximal section 137 having threads 39 for screwing securely to the plug 1, and a middle section 143 having a surface adapted, for example with flats 145 for holding and grasping with a turning tool. Grooved notches 147 resist loosening of the push-back mandrel 161 from the cylinder 35. The push-back mandrel 161 also includes a central, axially extending bore 163. A push-rod 165 is slideably moveable within the bore 163 and extends beyond the proximal end 137 and distal end 133 of the push-back mandrel 161. A push-rod anvil 167 caps the distal end of the push-rod 165. An annular shoulder 169 in the bore 163 provides a stop surface of the push-rod anvil to prevent the push-rod 165 from extending too far into a plug 1. The proximal end of the push-rod includes a centering post 171 and a radially extending surface 173 for pushing against the expander member 19. Push-back mandrel 161 can be used for both pushing the expander member 19 out of position in the plug 1, and also for pulling a plug 1. However, because the push-back mandrel 161 is not a solid member and may break or deform due to the stresses applied and by the tool 31, it is generally preferable to use a solid mandrel 37, such as those illustrated in FIGS. 8 and 9 for plug pulling.
To remove a plug, a push-back mandrel 161 having a push-rod member 165 is first secured to the pneumatic cylinder 35. The tool 31 is positioned directly beneath a plug 1 using visual aids and leveling devices (not shown) and the push-back mandrel is screwed into the plug 1 by turning the pneumatic cylinder 35. At this stage the push-rod 165 is in a lowered position (see FIG. 3a) and the chamber 43 is not pressurized until the push-back mandrel 161 is rigidly secured to both the plug 1 and the pneumatic cylinder 35. With both the shutter 79 and the proximal vent mechanism 78 open, the chamber is open to ambient pressure and the hammer 49 rests against the anvil 61. Keeping the shutter 79 open, the proximal vent mechanism 78 is closed with pneumatic pressure turned on from each of the first and second sources of pressurized air 74, 76. Quickly closing the shutter 79 and opening the proximal vent mechanism 78 at the same time creates a pressure differential that provides a force to drive the hammer 49 up against the push-rod anvil 167 at speed, thereby communicating an impulsive force to the expander member 19. The cycle is repeated by first closing the proximal vent mechanism 78 while opening the shutter 79. This causes the hammer 49 to move towards the anvil 61. Another impulse is delivered by again quickly closing the shutter 79 and opening the proximal vent mechanism 78.
The pneumatic pressure from the first source of pressurized air 74 is preferably just enough to move the hammer 49 towards the anvil 61 during the recovery period of the expander push-back procedure and will generally differ for different hammer 49 and cylinder 35 designs. A typical pressure is about 15 psi. The pneumatic pressure from the second source of pressurized air 76 is typically about 15-40 psi greater than that from the first source of pressurized air 74. Thus, the displacement impulses are produced by operation of the shutter 79 and the proximal vent mechanism 78 while the first and second sources of pressurized air 74, 76 are kept open.
Referring now also to FIG. 7, an indicator pin 181 is slideably moveable in a bore axially extending through the proximal end of pneumatic cylinder 35. O-ring 183 in o-ring groove 185 provides a pneumatic seal for pin 181. Pin 181 is used as a visual indicator when impulsively displacing the expander member 19 out of position with push-rod 165. At the start of the operation of displacing the expander member 19, the indicator pin 181 is in a lowered position having a distal end extending down into the proximal end 45 of chamber 43. If no movement of the pin 181 is seen, the pressure in the distal end 47 of the chamber 43 is increased, thereby increasing the energy of the displacement impulses, until some substantial movement is noticed. When the hammer 49 pushes the push-rod member 165 high enough to displace the expander member 19, the hammer 49 also strikes the distal end of the indicator pin 181 and moves it up as a visual indicator that the procedure is finished. The push-rod member 165 moves to a full stop position with the push-rod anvil 167 against the shoulder 169. It should be noted that during this operation the pneumatic cylinder 35 is resting against the distal of the second cylinder 63 so as not to transfer any impulsive force to the second cylinder 63.
After the expanded member is pushed out of position by the push-rod member 165, the push-back mandrel 161 is removed from the plug 1 and then removed from the pneumatic cylinder 35. A puller mandrel, such as puller mandrel 131, is then rigidly secured to the pneumatic cylinder 35 and to the plug 1 using screw threads for attachment to each. With the shutter 79 and the proximal vent mechanism 78 each in the closed position, both the proximal end 45 and the distal end 47 of the chamber 43 are pressurized. The pressure in the distal end 47 is greater than the pressure in the proximal end 45 so that the hammer 49 is raised to the proximal end of the chamber 43. While continuing to provide pneumatic pressure to both the proximal end 45 and the distal end 47 of the chamber 43, the shutter 79 is quickly opened with the pneumatic actuators 93, 95, thereby venting the distal end 47 of the chamber to channels 59 and thence 81. Since a positive pressure is maintained above the hammer 49 in the proximal end 45 of the chamber, the hammer 49 is driven against the anvil 61 at speed by the pressure head in the proximal end 45 of the chamber and by gravity. This transfers an impulsive energy via the pneumatic cylinder 35 and the puller mandrel 131 that may cause a displacement of the plug. It is important that the opening of the shutter 79 be performed quickly in order that the hammer 49 accelerate quickly.
For the plug pulling operation, the pneumatic cylinder 35 is positioned at the proximal end of the second cylinder, leaving a gap of about 1/2 inch between the distal plug 103 and the second cylinder 63 in order that the pulling impulses are not transferred to the second cylinder 63.
The energy of the pulling impulse will depend upon the mass of the hammer 49, its travel distance in the chamber 43 before impacting the anvil 61, the surface areas of the proximal and distal sides of the hammer 49, the rapidity of venting the distal end 47 of the chamber 43, and the pneumatic pressure in the proximal end 45 of the chamber. Typically, both the regulated supply pressure to the proximal end 45 and to the distal end 47 of the chamber 43 are varied in unison during the pulling operation, the difference between them being held constant, the distal end pressure supply being greater than that of the proximal side pressure supply. The pressure difference should be sufficient to move the hammer 49 to the proximal end 45 of the chamber 43 in a reasonable time between pulling impulses when the shutter 79 is closed, typically about 15 psi.
The impulsive energy applied to the plug should be at least sufficient to move the plug. This can only be determined in the field. Controlled laboratory tests have shown that about 30 ft-lbs of energy is sufficient to pull most plugs of the type described hereinabove. However, it is prudent to start at a significantly lower pulling impulse energy and slowly increase the energy if there is insufficient plug travel. A feedback mechanism (not shown) can be used to sense movement of the plug and adjust the pressure in the proximal end 45 of the chamber 43 to increase the impulsive energy if necessary. The process of raising the cylinder 49 and driving it against the anvil 61 is repeated until the plug is removed.
In conjunction with the impulsive pulling force provided by the hammering action of the tool 31, a static pull force can also preferably be applied to the plug 1. This can be provided most simply by the weight of the first cylinder 35 hanging from the plug 1 and by the mandrel 37. As illustrated in FIG. 3a, the second cylinder 63 is supported by the pneumatic cylinder 35 and also contributes its weight to the static pull force. A typical total weight applying the static pull force is in a range of 10-20 pounds. This is significantly less than the static pulling force applied by hydraulic plug pullers.
Whereas particular embodiments of the present invention have been described above for purposes of illustration, it will be appreciated by those skilled in the art that numerous variations of the details may be made without departing from the invention as described in the appended claims. | A tool for removing a metal plug from a tube with repeated pulling impulses includes a pneumatic cylinder defining an interior, cylindrical chamber. A distal end surface of the cylinder defines an anvil. A cylindrical slug, or hammer, is sealingly slidable within the chamber in response to a pressure difference above and below the hammer within the chamber. The cylinder is rigidly connected to the plug so as to hang therefrom, the weight of the cylinder providing a static pull force working in conjunction with the pulling impulses. A pulling impulse is provided by first raising the hammer above the anvil by pneumatically creating a first pressure difference wherein the pressure below the hammer is greater than the pressure above the hammer, then creating a second pressure difference wherein the pressure below the hammer is no greater than the pressure above the hammer in order to drive the hammer against the anvil at speed. The tool is also adapted for disengaging an expander member engaged in a tapered plug shell with a mandrel that includes a push-rod having an end extending into the top of the chamber proximate the plug. Repeated displacement impulses are applied to the expander member by applying a different sequence of forces to the hammer so as to cause it to repeatedly strike the push-rod against the expander member. The tool and a method of using the tool are particularly suited to removing a plug from a heat exchanger tube in a nuclear powered steam generator. | 8 |
CROSS REFERENCE TO RELATED APPLICATION
This is a continuation of international application PCT/EP01/12063, filed Oct. 18, 2001, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to a false twist texturing machine for texturing a plurality of thermoplastic multifilament yarns.
A false twist texturing machine of this general type is disclosed, for example, in U.S. Pat. No. 5,644,908. The false twist texturing machine as described in that patent comprises a plurality of processing stations, each of which produces a crimped yarn from a fed flat yarn. To this end, a first feed system withdraws the yarn from a feed yarn package and advances it into a false twist zone. The false twist zone includes a heating device, a cooling device, and a false twist unit mounted in series. Within the false twist zone, the yarn undergoes a drawing and setting. The false twist unit produces a twist, which extends opposite to the direction of the advancing yarn, so that within the cooling device and the heating device, in which the yarn undergoes thermal treatment, the yarn exhibits a false twist, which is removed at the outlet of the false twist unit.
For a thermal aftertreatment, a second feed system advances the yarn through a second heater as well as to a takeup device, which winds the yarn to a package. Since after removing the false twist, a greater or lesser residual twist remains in the yarn as a function of the process, the known texturing machine includes a countertwist device in the form of an entanglement nozzle upstream of the takeup device. The countertwist device leads to a twist treatment, which removes the residual twist in the yarn.
Whether or not, and the extent a twist treatment by the countertwist device is needed, depends both on the polymer type of the yarn and on the adjusted process parameters, for example, the yarn speed.
Furthermore, for increasing the effectiveness of the twist treatment, it is known from WO99/09239 and corresponding U.S. Pat. No. 6,301,870 to arrange the countertwist device directly in the outlet region of the second heating device, so as to enable a well defined setting of the yarn in the heating device and, with that, a destruction of the residual twist. However, in so doing, one should consider that such heating devices, as disclosed, for example, in EP 0 595 086 B1 and corresponding U.S. Pat. No. 5,431,002, often cooperate with a guide tube for a thermal adjustment or for threading the yarn. Thus, for threading the yarn, the guide tube is connected to an injector, so that the yarn is taken in by suction at the inlet of the heating device, and so that it is advanced via the guide tube to a predetermined position within the machine.
It is therefore an object of the invention to provide the initially described false twist texturing machine with a countertwist device, which is easy to use when a twist treatment is needed, and which does not interfere with a pneumatic threading of the yarn at the beginning of a process.
SUMMARY OF THE INVENTION
In accordance with the invention, the above and other objects and advantages of the invention are achieved by the provision of a yarn false twist texturing machine of the described type and wherein a yarn countertwist device is positioned in the yarn path of travel between the second heating device and the winding device, with the countertwist device comprising a twist imparting member that cooperates with a yarn guide means.
The invention distinguishes itself in that it permits adapting the guidance of the yarn in the countertwist device to respective needs. In this connection, the invention offers a first variant, in which the position of the yarn advance is variable, and a second variant, in which the position of the yarn advance remains unchanged. In the first variant, a twist imparting member of the countertwist device cooperates with a guide means which guides the advancing yarn, and which is adapted for reciprocating between an idle position and an operating position. In the idle position, the yarn is guided in such a manner that it is separated from the twist imparting member and undergoes no twist treatment. This position is thus also well suited for threading the yarn. Only when the guide means is in its operating position, will the twisting device treat the yarn.
In the second variant, which is based on the same fundamental concept, the yarn advance within the machine remains substantially unchanged. To this end, the countertwist device includes a movable twist imparting member, which is likewise adapted for reciprocal movement between an idle position and an operating position. In the idle position, the yarn undergoes no twist treatment. Only when the twist imparting member is moved to its operating position, will it be possible to treat the yarn by twisting it.
As a twist imparting member, it is possible to use, for example, rolls or guide edges, over which the yarn advances obliquely for receiving a twist treatment. It is especially preferred to realize the twist imparting member as an entanglement nozzle. In this instance, the entanglement nozzle comprises a yarn channel for guiding the yarn. In this channel, a tangentially entering air flow produces the twist on the yarn. The yarn channel communications with a continuous threading slot, which permits inserting the yarn from the outside into the yarn channel. With that, it is possible to advance the yarn both by the guide means and by the entanglement nozzle itself, inside the yarn channel in the operating position and outside the yarn channel in the idle position.
In a particularly advantageous further development of the invention, the entanglement nozzle comprises a piston that is movable transversely to the yarn advance, and adjustable within a housing between the idle position and the operating position. In the transverse direction of its longitudinal axis, the piston includes both the yarn channel with the threading slot and a nozzle bore terminating in the yarn channel. The housing includes a yarn inlet, and a yarn outlet opposite thereto, as well as a compressed air connection. In the operating position of the piston, the yarn channel interconnects the yarn inlet and the yarn outlet. Likewise, the nozzle bore is coupled with the compressed air connection, so that a twist treatment on the yarn occurs within the yarn channel.
To interrupt the treatment of the yarn, or to enable a threading of the yarn through the yarn inlet and yarn outlet, it is especially advantageous to construct the threading slot that connects to the yarn channel, with a V-shaped cross section at one front end of the piston. Thus, the movement of the piston between the operating position and the idle position makes it possible to guide the yarn advancing between the yarn inlet and the yarn outlet, automatically through the threading slot into or out of the yarn channel.
To interrupt the supply of compressed air to the entanglement nozzle, an advantageous further development of the invention proposes to close the compressed air connection in the housing by a control surface of the piston. In so doing, the control surface of the piston is guided by the movement of the piston to the idle position in the region of the compressed air connection.
Another preferred further development of the invention is especially suited for automatically threading the yarn. In this development, both the yarn inlet of the housing and the yarn outlet of the housing each mount a guide tube. For threading the yarn, it is possible to connect an injector to one of the guide tubes, so that the yarn can be pneumatically threaded in a simple manner, while the piston is in its idle position. Advantageously, the guide tube arranged at the yarn inlet of the entanglement nozzle is coupled directly with the outlet of a set heater.
The movement of the guide means or the movement of the twist imparting member is preferably controlled by an actuator. The actuator may be activated directly by an operator or via a control device.
In the false twist texturing machine, the false twist unit may impart to the yarn a so-called Z-twist or an S-twist. To be able to use the countertwist device arranged upstream of the takeup device both for the Z-twist and for the S-twist, it will be of particular advantage, when the twist imparting member is made exchangeable, so as to enable a twist treatment that is selectively applied against the S-twist or against the Z-twist.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, two embodiments of the yarn false twist texturing machine according to the invention are described in greater detail with reference to the attached drawings, in which:
FIG. 1 is a schematic view of a yarn false twist texturing machine which embodies the invention;
FIG. 2 is a longitudinally sectioned view parallel to the direction of movement of the yarn showing the countertwist device of the false twist texturing machine shown in FIG. 1 in its operating position;
FIG. 3 is a sectional view transverse to the direction of movement of the yarn showing the countertwist device of the false twist texturing machine shown in FIG. 1 in its operating position;
FIG. 4 is a longitudinally sectioned view parallel to the direction of movement of the yarn showing the countertwist device of the false twist machine shown in FIG. 1 in its idle position;
FIG. 5 is a sectional view transverse to the direction of movement of the yarn showing the countertwist device of the false twist texturing machine shown in FIG. 1 in its idle position;
FIG. 6 is a longitudinally sectioned view parallel to the yarn advance showing a further embodiment of an entanglement nozzle; and
FIG. 7 is a sectional view transverse to the yarn advance showing an entanglement nozzle of FIG. 6 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 schematically illustrates an embodiment of a yarn false twist texturing machine according to the invention. The yarn false twist texturing machine comprises a creel frame 2 , a processing frame 3 , and a takeup frame 1 . A service aisle 5 is formed between the processing frame 3 and the takeup frame 1 . On the side of the takeup frame 1 opposite to the service aisle 5 , the creel frame 2 extends in spaced relationship with the takeup frame 1 . Between the takeup frame 1 and the creel frame 2 , a doffing aisle 6 is formed. The takeup frame 1 accommodates three takeup devices 9 , one overlying the other, which are part of each processing station of the machine. In each processing station, a first delivery system 13 withdraws, via a yarn guide 12 and a first deflection roll 11 . 1 , a yarn 4 from a supply yarn package 7 arranged in the creel frame 2 . From the first delivery system 13 , the yarn advances into a false twist zone, which comprises a heating device 8 , a cooling device 10 , a second deflection roll 11 . 2 , and a false twist unit 14 . Subsequently, a second delivery system 15 withdraws the yarn 4 from the false twist zone and advances it to a second heating device 16 . In this process, the speed of the yarn is adjusted by a third delivery system 18 downstream of the second heating device 16 .
A countertwist device 17 is arranged between the second heating device 16 , herein referred to as a set heater, and the third delivery system 18 . For guiding the yarn, the countertwist device 17 mounts on its inlet side and its outlet side respectively a first guide tube 25 and a second guide tube 26 . Upstream of the countertwist device 17 , the first guide tube 25 is coupled with the outlet of the set heater 16 . An injector 27 connects to the second guide tube 26 , which extends below a platform 23 of the service aisle 5 . The second guide tube 26 ends directly upstream of the third feed system 18 .
The third delivery system 18 advances the yarn 4 to the takeup device 9 via a third deflection roll 11 . 3 . The takeup device 9 comprises a friction roll 19 for driving a package 20 while being wound, a yarn traversing device 24 upstream of the friction roll 19 , a storage 21 serving to receive full packages, as well as a tube magazine 22 . In the takeup device 9 , the yarn 4 is wound to a package 20 .
In the embodiment of the false twist texturing machine as shown in FIG. 1 , the delivery system 13 withdraws the yarn 4 from the supply yarn package 7 and advances it into the false twist zone. The false twist is imparted to the yarn 4 by the false twist unit 14 . The thus-produced false twist returns against the direction of the advancing yarn to the first delivery system 13 or the first deflection roll 11 . 1 , which could be constructed as a twist stop roll. Thus, the yarn advances in a false twisted condition through the first heating device 8 into the cooling device 10 . In its twisted condition, the yarn is drawn and set in the heating device 8 , which leads to a setting of the twist and thus to a satisfactory crimp result in the yarn 4 .
After the yarn 4 has left the false twist zone, it exhibits a greater or lesser residual twist. Such a residual twist, which causes the yarn 4 to turn about itself, however, is undesired for a subsequent further processing. Consequently, the countertwist device 17 imparts to the yarn a countertwist, which is opposite in its direction to that of the false twist. This countertwist propagates as far back as the second feed system 15 . Since the countertwist acts against the residual twist, the setting and the relaxation treatment in set heater 16 lead to a twistfree yarn 4 . In this process, the countertwist device is in an operating position, as is described in greater detail in the following.
The countertwist device 17 is schematically illustrated in FIGS. 2-5 . While FIGS. 2 and 3 show the countertwist 17 in an operating position, FIGS. 4 and 5 show it in an idle position. The following description will apply to FIGS. 2-5 , unless express reference is made to one of the Figures.
FIGS. 2 and 3 show the countertwist device in its operating position, with the countertwist device being shown in a longitudinally sectioned view parallel to the yarn advance (FIG. 2 ), and in a cross sectional view transverse to the yarn advance (FIG. 3 ). As a twist imparting member, the countertwist device includes an entanglement nozzle 28 . To this end, the entanglement nozzle 28 comprises a piston 29 , which extends in a cylindrical housing 30 in the transverse direction of the yarn advance. In a plane of the advancing yarn, the housing 30 has on its one side a yarn inlet 31 and on its opposite side a yarn outlet 32 . The yarn inlet 31 and yarn outlet 32 include respectively an inlet yarn guide 44 . 1 and an outlet yarn guide 44 . 2 . In concentric relationship with the yarn inlet 31 , the housing mounts on its outside the first guide tube 25 . On the opposite side, the second guide tube 26 connects to the housing 30 at the height of the yarn outlet 32 . Between the yarn inlet 31 and the yarn outlet 32 , the piston 29 extends in the housing 30 .
In the transverse direction of its longitudinal axis, the piston 29 includes a continuous yarn channel 33 , which connects the yarn inlet 31 to the yarn outlet 32 . The yarn channel 33 includes a continuous threading slot 34 , which has a V-shaped opening cross section in the direction of movement of the piston 29 . To this end, the threading slot 34 is provided in the lower front end of the piston 29 . At its opposite front end, the piston 29 connects to an actuator 36 .
In a transverse direction of the yarn channel 33 , the piston 29 is provided with a nozzle bore 35 , which terminates with its one end in the yarn channel 33 and connects with its other end to a pressure line 38 , which is joined to the housing 30 via a compressed-air connection 37 .
In FIGS. 2 and 3 , the entanglement nozzle 28 is shown in its operating position. In this situation, the piston 29 is held in its position by the actuator 36 and a spring 39 , which is operative on the lower front end of the piston 29 , and which is supported on the base of the closed housing 30 . The yarn 4 enters the yarn channel 33 via yarn inlet 31 . Inside the yarn channel 33 , compressed air enters in a substantially tangential relationship through the nozzle bore 35 , and acts upon the yarn 4 to produce a countertwist. This countertwist propagates as far back as the feed system 15 . The yarn 4 leaves the entanglement nozzle 28 via the yarn outlet 32 , and advances through the second guide tube 26 to the third feed system 18 .
In cases wherein no twist treatment of the yarn 4 by the countertwist device 17 is desired, the actuator 36 is activated for moving the piston 29 . Subsequently, the piston 29 is moved in the transverse direction of the yarn advance, to its idle position within the housing 30 . This situation is shown in FIGS. 4 and 5 . In this connection, FIG. 4 is a longitudinally sectioned view of the entanglement nozzle 28 parallel to the plane of the advancing yarn, and FIG. 5 is a cross sectional view thereof in the transverse direction of the yarn advance. In this situation, the piston 29 is displaced such that the yarn inlet 31 and the yarn outlet 32 are interconnected via a large opening cross section of the threading slot 34 . The yarn channel 33 is removed from the advancing yarn. At the same time, a control surface of the piston 29 closes the compressed-air connection 37 , note FIG. 5 , thereby preventing additional compressed air from entering the interior of the housing 30 . In the idle position, the piston 29 is held by the actuator 36 and spring 39 .
The situation of the entanglement nozzle 28 shown in FIGS. 4 and 5 , is in particular also suited for enabling an automatic threading of the yarn 4 . As previously shown in FIG. 1 , the outlet of set heater 16 connects to the first 25 and the second guide tube 26 . The first guide tube 25 and the second guide tube 26 surround respectively the yarn inlet 31 and the yarn outlet 32 . Connected to the second guide tube 26 is the injector 27 , which is biased with compressed air for threading the yarn 4 . In this process, a vacuum for taking in the yarn 4 by suction is generated both in the tube section upstream of the injector 27 and in the set heater 16 . This makes it possible to guide the yarn through the set heater 16 , into the first guide tube 25 , to the yarn inlet 31 of the entanglement nozzle 28 . Based on the large opening cross section within the entanglement nozzle 28 , the yarn is sucked into the second guide tube 26 directly via the yarn outlet 32 . Subsequently, it is possible to take over the yarn at the outlet of the second guide tube 26 , a short distance upstream of the third feed system 18 .
After the yarn 4 has been threaded in the machine, it will be possible to guide the piston 29 by means of the actuator 36 to the operating position within the housing 30 , when a treatment by the countertwist device is needed.
In this process, the yarn 4 advancing between the yarn inlet 31 and the yarn outlet 32 , automatically slides via the threading slot 34 into the yarn channel 33 . At the same time, the nozzle bore 35 is coupled with the lateral compressed-air connection 37 . Compressed air is allowed to enter, so that it is possible to perform a corresponding treatment of the yarn 4 .
FIGS. 6 and 7 illustrate a further embodiment of a countertwist device, which is used in particular in false twist texturing machines, wherein a manual operation is performed.
In this embodiment of the countertwist device, an entanglement nozzle 28 is provided as the twist imparting member. FIG. 6 illustrates a longitudinally sectioned view of the entanglement nozzle parallel to the yarn advance, and FIG. 7 is a cross sectional view thereof in the transverse direction of the yarn advance. The following description will apply to both Figures.
The entanglement nozzle 28 includes a continuous yarn channel 33 . Toward one side, the yarn channel 33 connects without interruption to a threading slot 34 . The threading slot 34 has a V-shaped opening cross section. In the transverse direction of the yarn channel 33 , a nozzle bore 35 is provided, which connects to a pressure line 38 .
A guide means 40 is associated with the entanglement nozzle 28 . The guide means 40 comprises a support 43 as well as a first yarn guide 41 in the yarn path upstream of the yarn channel 33 and a second yarn guide 42 in the yarn path downstream of the yarn channel 33 . These two yarn guides 41 , 42 are mounted to the support 43 . The guide means 40 connects to an actuator 36 . The actuator permits adjusting the guide means 40 in its location between an operating position as shown, and an idle position not shown. In the operating position, the yarn guides 41 and 42 guide the yarn 4 through the yarn channel 33 . In this situation, the yarn 4 undergoes a twist treatment.
In the case that no twist treatment is desired, the actuator 36 will be activated, so that the guide means 40 is moved such that the yarn guides 41 and 42 are guided into the region of the threading slot 34 . In so doing, the yarn 4 is automatically removed from the yarn channel 33 .
In the case of the countertwist device shown in FIGS. 6 and 7 , the twist imparting member could also be formed by a roll, which extends in oblique relationship with the advancing yarn. In this connection, the guide means 40 would establish a contact between the yarn 4 and the roll in the operating situation. In the case that no treatment is desired, the guide means may be moved to discontinue the contact between the yarn 4 and the roll. | A yarn false twist texturing machine for texturing multifilament synthetic yarns ( 4 ), wherein a heating device and a false twist unit are arranged within a false twist zone. An aftertreatment zone accommodates a second heating device and a countertwist device. The countertwist device is used to remove any residual twist that is left in the yarn by the false twist unit. To be able to perform a selective treatment by the countertwist device, a first embodiment provides for a twist imparting member yarn guide means for guiding the yarn ( 4 ) and being adapted for reciprocal movement between an idle position for not treating the yarn ( 4 ) or for threading it and an operating position for treating the yarn ( 4 ). In a second embodiment, the countertwist device comprises a movable twist imparting member ( 28, 29 ), which is adapted for reciprocal movement between an idle position for not treating or for threading the yarn ( 4 ) and an operating position for treating the yarn ( 4 ) by twisting it. | 3 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a control apparatus for a vehicular internal combustion engine, and particularly to a control apparatus for a vehicular internal combustion engine, which controls torque generated by an internal combustion engine by directly injecting fuel into a cylinder of the internal combustion engine.
[0003] 2. Description of the Related Art
[0004] In recent years, in an internal combustion engine mounted in an automobile, in order to improve fuel consumption or the like, a direct-injection internal combustion engine in which fuel is directly injected into a combustion chamber of a cylinder by an injector is proposed and is put to practical use. In the direct-injection internal combustion engine, because of restrictions of pressure in a cylinder, a fuel injection period, a fuel atomization period and the like, fuel pressure is set to be higher than that of a conventional port injection internal combustion engine. The injector to inject the high pressure fuel has a large drive current and requires a drive circuit to control the large current.
[0005] In this type of conventional apparatus, an injector drive circuit is provided separately from an internal combustion engine control apparatus, an injector drive signal is transmitted from the internal combustion engine control apparatus to the injector drive circuit, and the, driving of the injector is controlled by the injector drive circuit in accordance with the injector drive signal. Besides, in accordance with a request for the practice of self diagnosis in an internal combustion engine control system, it is detected whether a drive current flows to an injector in synchronization with an injector drive signal, and failure of a fuel injection system is diagnosed based on the detection result (see, for example, patent document 1: JP-A-2000-73840 (pages 1 to 5, FIGS. 1 to 7).
[0006] In this conventional apparatus, in order to avoid such a problem that in a case where a signal line to transmit an abnormality diagnosis signal goes wrong (opened or shorted), although fuel injection can be normally carried out, it is judged that a fuel injection system goes wrong, and vehicle traveling is carelessly stopped, the internal combustion engine control apparatus detects the existence of a misfire at every cylinder, and in the case where the misfire is not detected although the abnormality diagnosis signal to indicate the abnormality of the fuel injection system is outputted, an energization signal to each cylinder is continuously outputted, and the fuel injection is continued.
[0007] However, according to the conventional apparatus as stated above, in the case where the abnormality of the fuel injection system is detected, and a fuel supply stop processing against the abnormality is carried out, since the judgment is made using the misfire judgment, in the case where the misfire judgment is carried out in a periodic measurement system, the reliability is low at the time of a period variation or in a low rotation region, and in the case where it is carried out in an ion detection system, an increase in cost is caused. Further, an increase in calculation load of the internal combustion engine control apparatus due to the misfire judgment processing is also conceivable.
[0008] Besides, the misfire is not necessarily generated by injector drive abnormality. In general, the connection from the injector drive circuit to the injector is such that the power supply side to the injector is common to group cylinders, and the GND side is independent in each cylinder. Thus, for example, in the case of a four-cylinder internal combustion engine having a first to a fourth cylinders, in the case where the ground (hereinafter referred to as GND) side harness of the third injector for the third cylinder is GND-shorted, since the power supply side is common to the second and the third injectors for the second and the third cylinders, at the time of driving the normal second injector, current flows to the third injector. Thus, the third injector is also driven at the same time as the second injector, and the second cylinder at the normal drive timing injects fuel, for example, in the intake stroke to cause normal combustion, while the third injector for the third cylinder injects fuel into the third cylinder in the expansion stroke. In the third cylinder, since the injection of the fuel occurs in the expansion stroke, a misfire signal is not detected, however, there arises a problem that the combustion is delayed, or the fuel flows out to the exhaust system.
SUMMARY OF THE INVENTION
[0009] In view of the problems of the conventional apparatus as stated above, the invention provides a control apparatus for a vehicular internal combustion engine in which in a case where abnormality of a fuel injection system occurs, only an injector drive confirmation signal is used, and it is judged whether driving of an injector is abnormal or the injector drive confirmation signal is abnormal, and in the case where the injector drive confirmation signal is abnormal, it is avoided that fuel supply is carelessly stopped, and in the case where the driving of the injector is abnormal, a problem that combustion is delayed or fuel flows out to an exhaust system can be avoided.
[0010] A control apparatus for a vehicular internal combustion engine of this invention includes plural injectors which are provided correspondingly to plural cylinders of an internal combustion engine and are driven by drive currents to inject fuel into the corresponding cylinders, an injector drive circuit to supply the drive currents to the plural, injectors, an injector control unit to supply injector drive signals, which control the drive currents, to the injector drive circuit, an injector drive detection unit to generate injector drive confirmation signals corresponding to drivings of the plural injectors, and an injector drive abnormality judgment unit to judge, based on the injector drive confirmation signal, a drive abnormality of the injector corresponding to the injector drive confirmation signal, and the injector drive abnormality judgment unit judges an abnormality of the injector drive confirmation signals based on a state of the injector drive confirmation signals.
[0011] Besides, the control apparatus for the vehicular internal combustion engine according to the invention is constructed such that the injector drive abnormality judgment unit judges the state of the injector drive confirmation signals based on existence of a past injector drive signal corresponding to the injector drive signal generated from the injector control unit, and judges the abnormality of the injector drive confirmation signals.
[0012] Further, the control apparatus for the vehicular internal combustion engine according to the invention is constructed such that the injector drive detection unit outputs the injector drive confirmation signal in synchronization with the injector drive signal by the injector control unit.
[0013] Further, the control apparatus for the vehicular internal combustion engine according to the invention is constructed such that the injector drive detection unit generates the injector drive confirmation signal based on a serge voltage at a time of stop of the drive current supplied to the injector by the injector drive circuit.
[0014] Besides, the control apparatus for the vehicular internal combustion engine according to the invention is constructed such that the injector drive abnormality judgment unit judges that when the injector drive confirmation signal is missed, the injector corresponding to the injector drive confirmation signal is abnormal in driving, and judges that when all the injector drive confirmation signals corresponding to the plural injectors are missed, the injector drive confirmation signals are abnormal.
[0015] Further, the control apparatus for the vehicular internal combustion engine according to the invention is constructed such that the injector drive signal from the injector control unit is stopped to stop fuel supply to the target cylinder of the injector judged to be abnormal in driving by the injector drive abnormality judgment unit, and the injector drive signal from the injector control unit is continued and fuel supply to the cylinder is continued when it is judged that the injector drive confirmation signals are abnormal.
[0016] Furthermore, the control apparatus of the vehicular internal combustion engine according to the invention is constructed such that when it is judged by the injector drive abnormality judgment unit that the injector is abnormal in driving, the injector control unit stops output of the injector drive signal of the cylinder of a group to which the target cylinder of the injector judged to be abnormal in driving belongs.
[0017] As described above, the control apparatus for the vehicular internal combustion engine according to the invention includes the plural injectors which are provided correspondingly to the plural cylinders of the internal combustion engine and are driven by the drive currents to inject the fuel into the corresponding cylinders, the injector drive circuit to supply the drive currents to the plural injectors, the injector control unit to supply the injector drive signals, which control the drive currents, to the injector drive circuit, the injector drive detection unit to generate the injector drive confirmation signals corresponding to the drivings of the plural injectors, and the injector drive abnormality judgment unit to judge, based on the injector drive confirmation signal, the drive abnormality of the injector corresponding to the injector drive confirmation signal. The injector drive abnormality judgment unit judges the abnormality of the injector drive confirmation signals based on the state of the injector drive confirmation signals, and therefore, the detection of the drive abnormality of the injector and/or the abnormality of the injector drive confirmation signals can be easily judged by using only the injector drive confirmation signals indicating the drive states of the injectors.
[0018] Besides, the control apparatus for the vehicular internal combustion engine according to the invention is constructed such that the injector drive abnormality judgment unit judges the state of the injector drive confirmation signals based on the existence of the past injector drive signal corresponding to the injector drive signal generated from the injector control unit, and judges the abnormality of the injector drive confirmation signals, and therefore, the abnormality of the injector drive confirmation signals can be certainly and easily judged.
[0019] Further, the control apparatus for the vehicular internal combustion engine according to the invention is constructed such that the injector drive detection unit outputs the injector drive confirmation signal in synchronization with the injector drive signal by the injector control unit, and therefore, the target cylinder can be certainly specified from the injector drive confirmation signal.
[0020] Further, the control apparatus for the vehicular internal combustion engine according to the invention is constructed such that the injector drive detection unit generates the injector drive confirmation signal based on the serge voltage at the time of stop of the drive current supplied to the injector by the injector drive circuit, and therefore, the injector drive confirmation signal accurately corresponding to the drive state of the injector can be obtained.
[0021] Besides, the control apparatus for the vehicular internal combustion engine according to the inventions is constructed such that the injector drive abnormality judgment unit judges that when the injector drive confirmation signal is missed, the injector corresponding to the injector drive confirmation signal is abnormal in driving, and judges that when all the injector drive confirmation signals corresponding to the plural injectors are missed, the injector drive confirmation signals are abnormal, and therefore, the drive abnormality of the injector and the abnormality of the injector drive confirmation signals can be certainly judged by only the injector drive confirmation signals.
[0022] Further, the control apparatus for the vehicular internal combustion engine according to the invention is constructed such that the injector drive signal from the injector control unit is stopped to stop the fuel supply to the target cylinder of the injector judged to be abnormal in driving by the injector drive abnormality judgment unit, and the injector drive signal from the injector control unit is continued and the fuel supply to the cylinder is continued when it is judged that the injector drive confirmation signals are abnormal, and therefore, in the case where the injector drive confirmation signals are abnormal, it is avoided that the fuel supply is carelessly stopped, and in the case where the injector is abnormal in driving, the fuel supply to the target cylinder of the injector is stopped, and it is possible to avoid the problem that the combustion is delayed or the fuel flows out to the exhaust system.
[0023] Furthermore, the control apparatus of the vehicular internal combustion engine according to the invention is constructed such that when it is judged by the injector drive abnormality judgment unit that the injector is abnormal in driving, the injector control unit stops the output of the injector drive signal of the cylinder of the group to which the target cylinder of the injector judged to be abnormal in driving belongs, and therefore, it is possible to avoid simultaneous fuel injection of the group cylinder, and the safe internal combustion engine control apparatus can be obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a structural view showing a control apparatus for a vehicular internal combustion engine according to embodiment 1 of the invention.
[0025] FIG. 2 is a structural view of a main part of the control apparatus for the vehicular internal combustion engine according to embodiment 1 of the invention.
[0026] FIG. 3 is a timing chart showing an injector drive confirmation signal of the control apparatus for the vehicular internal combustion engine according to embodiment 1 of the invention.
[0027] FIG. 4 is a timing chart showing a state of the injector drive confirmation signal, at the time of drive abnormality of an injector, of the control apparatus for the vehicular internal combustion engine according to embodiment 1 of the invention.
[0028] FIG. 5 is an explanatory view showing a failure state between an injector and an injector drive circuit of the control apparatus for the vehicular internal combustion engine according to embodiment 1 of the invention.
[0029] FIG. 6 is a timing chart showing respective signals at the time of failure between the injector and the injector drive circuit of the control apparatus for the vehicular internal combustion engine according to embodiment 1 of the invention.
[0030] FIG. 7A and FIG. 7B are flowchart charts for explaining an abnormality judgment operation by an injector drive abnormality judgment unit of the control apparatus for the vehicular internal combustion engine according to embodiment 1 of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment 1
[0031] FIGS. 1 to 7 A and 7 B show a control apparatus for a vehicular internal combustion engine according to embodiment 1 of the invention, FIG. 1 is a structural view, FIG. 2 is a structural view of its main part. FIG. 3 is a timing chart showing an injector drive confirmation signal, FIG. 4 is a timing chart showing a state of the injector drive confirmation signal at the time of drive abnormality of an injector, FIG. 5 is an explanatory view showing a failure state between an injector and an injector drive circuit, FIG. 6 is a timing chart showing respective signals at the time of failure between the injector and the injector drive circuit, and FIG. 7 is a flowchart chart for explaining an abnormality judgment operation by an injector drive abnormality judgment unit.
[0032] In FIG. 1 , first to fourth cylinders (not shown) of a four-cylinder internal combustion engine are provided with first to fourth injectors 101 , 102 , 103 and 104 to directly inject fuel into the respective cylinders, and these injectors 101 , 102 , 103 and 104 are connected to a common fuel pipe 2 . The common fuel pipe 2 has a function to store pressurized fuel supplied from a high pressure fuel pump 3 and to distribute the fuel to the respective injectors 101 to 104 . During the operation of the internal combustion engine, the pressure of fuel in a fuel tank 4 is raised to a specific pressure by a low pressure feed pump 5 , and is supplied to the high pressure fuel pump 3 through a low pressure pipe 6 . The high pressure fuel pump 3 is driven by a pump drive cam 8 , and pressure-sends the fuel to the common fuel pipe 2 through a high pressure pipe 7 . The high pressure fuel supplied to the fuel pipe 2 is injected into the respective cylinders by the respective injectors 101 to 104 .
[0033] Signals from various sensors 10 to indicate a load state of the internal combustion engine and states of the internal combustion engine, and a signal from a fuel pressure sensor 11 to detect fuel pressure in the common fuel pipe 2 are inputted to an internal combustion engine control apparatus 9 to control the internal combustion engine. A crank angle sensor 14 is placed in the vicinity of a crank angle detection member 13 provided on a crank shaft 12 of the internal combustion engine, and the crank angle sensor 14 generates a reference pulse signal when the crank shaft 12 is located at a reference rotation position, and generates a rotation pulse signal corresponding to the rotation angle of the crank shaft 12 .
[0034] The reference pulse signal and the rotation pulse signal generated by the crank angle sensor 14 are inputted to the internal combustion engine control apparatus 9 . Further, a cam angle sensor 17 is placed in the vicinity of a cam angle detecting member 16 provided on a cam shaft 15 , and the cam angle sensor 17 generates the cam pulse each time the cam shaft 15 is located at the reference rotation position. The cam pulse signal generated by the cam angle sensor 17 is inputted to the internal combustion engine control apparatus 9 .
[0035] The internal combustion engine control apparatus 9 performs cylinder discrimination based on the reference pulse signal and the rotation pulse signal inputted from the crank angle sensor 14 and the cam pulse signal from the cam angle sensor 17 , and further, calculates control amounts to control the internal combustion engine based on the input signals of the other respective sensors, and controls the injectors or not-shown ignition coils, and respective actuators such as throttles, so that the driving of the internal combustion engine is carried out.
[0036] In FIG. 2 showing the structure of the internal combustion engine control apparatus 9 , the structure includes an internal combustion engine control unit 201 which calculates the control amounts to control the combustion engine based on the signals inputted from the respective sensors and controls the actuators, and an injector drive unit 202 to control the driving of the injectors.
[0037] The internal combustion engine control unit 201 includes a well-known CPU, ROM, RAM, backup RAM, input/output interface and the like. Besides, there is included an injector control unit 203 to calculate drive times and drive timings of the injectors 101 , 102 , 103 and 104 based on the signals inputted from the respective sensors. The injector control unit 203 outputs injector drive signals S 1 , S 2 , S 3 and S 4 to an injector drive circuit 204 of the injector drive unit 202 based on the calculated result.
[0038] The injector drive circuit 204 included in the injector drive unit 202 controls drive currents of the corresponding injectors 101 , 102 , 103 and 104 based on the injector drive signals S 1 , S 2 , S 3 and S 4 from the injector control unit 203 and drives the respective injectors. In the internal combustion engine of this embodiment, the combustion stroke advances in the order of the first cylinder→third cylinder→fourth cylinder→second cylinder, and with respect to group cylinders, there are two groups, that is, the group of the first cylinder and the fourth cylinder and the group of the second cylinder and the third cylinder. In the drawing, #1 to #4 are respectively attached to the first cylinder to the fourth cylinder as targets.
[0039] The connection between the injector drive circuit 204 and the injectors 101 , 102 , 103 and 104 is constructed in such a form that the power supply side is common to the first injector 101 and the fourth injector 104 , and the GND side is independent in the respective cylinders. Similarly, the power supply side is common to the second injector 102 and the third injector 103 , and the GND side is independent in the respective cylinders.
[0040] Further, the injector drive unit 202 includes an injector drive detection unit 205 which judges whether driving of the respective injectors 101 , 102 , 103 and 104 by the injector drive circuit 204 is normally performed and outputs an injector drive confirmation signal K in the case where it is normally performed. The injector drive detection unit 205 in this embodiment outputs the injector drive confirmation signal K by an off surge voltage generated when the drive current of each of the injectors 101 , 102 , 103 and 104 is turned off by the injector drive circuit 204 .
[0041] Specifically, a terminal voltage at the time when a GND side injector driving transistor (not shown), which is included in the injector drive circuit 204 and controls the injector of each cylinder, is turned off is compared with a specified threshold, and in the case where the terminal voltage exceeds the threshold, a rectangular wave is outputted as the injector drive confirmation signal K. Incidentally, the injector drive circuit may be a well-known circuit as shown in, for example, FIG. 2 of patent document 1.
[0042] In a chart of output timing of the injector drive confirmation signal K shown in FIG. 3 , the injector drive signals S 1 , S 2 , S 3 and S 4 are outputted to the injector drive circuit 204 for the respective cylinders by the injector control unit 203 , and when each of the signals does not drive the injector, the signal becomes high level H, and when driving the injector, the signal becomes low level L. Injector drive currents I 1 , I 2 , I 3 and I 4 are outputted to the injectors 101 , 102 , 103 and 104 by the injector drive circuit 204 , and drive the respective injectors. The injector drive confirmation signal K is outputted by the injector drive detection unit 205 .
[0043] In the injector drive confirmation signal K, in the case where an off surge voltage V, which is generated when the passage of current to each of the injectors 101 , 102 , 103 and 104 is stopped, is generated, the signal is made the low level L, and in the other case, the high level H is outputted. Accordingly, as shown in FIG. 4 , for example, in the case where the off surge voltage is not generated when the injector drive signal S 3 of the third injector 103 is changed from the low level L to the high level H and the driving is turned off, that is, in the case where the driving of the third injector 103 is not normally performed, the injector drive confirmation signal K remains at the high level H at the end of the driving of the third cylinder, and there occurs a state where the signal of the low level L is missed.
[0044] Here, a failure mode in which the signal of the low level L of the injector drive confirmation signal K is missed will be described.
[0045] The failure mode in which the signal of the low level L is missed has following four items.
[0046] (1) Missing of the injector drive signal due to disconnection or the like.
[0047] (2) Disconnection of a power supply side harness between the injector drive circuit and the injector, or disconnection of a GND side harness between the injector and the injector drive circuit.
[0048] (3) GND short of the GND side harness between the injector and the injector drive circuit
[0049] (4) Disconnection or short of the signal line to transmit the injector drive confirmation signal.
[0050] Among these items, in the item (1), there occurs a state in which at least one of the injector drive signals S 1 , S 2 , S 3 and S 4 is not inputted to the injector drive circuit 204 , and in the item (2), the injector drive current to the injector relating to the disconnection can not be controlled. Thus, both the items (1) and (2) become the failure state in which fuel can not be injected from the injector.
[0051] Next, the case of the item (3) will be described with reference to FIGS. 5 and 6 . FIG. 5 shows a state in which the GND side harness between the third injector 103 and the injector drive circuit 204 is GND-shorted and goes wrong. In the case where this failure occurs, when the second injector 102 is driven, the injector drive current flows also to the third injector 103 sharing the common power side, and the third injector 103 operates at the same time as the second injector 102 .
[0052] FIG. 6 is a chart showing the injector drive signals S 1 , S 2 , S 3 and S 4 , the injector drive confirmation signal K, and the states of fuel injection of the injectors 101 , 102 , 103 and 104 at the time when the GND harness between the third injector 103 and the injector drive circuit 204 is GND-shorted and goes wrong. As shown in FIG. 6 , with respect to the normal injectors 101 , 102 and 104 , as the injector drive confirmation signal K, a signal is outputted which becomes the low level at the time point when the low level of each of the injector drive signals S 1 , S 2 and S 4 comes to an end. However, at the time point of the driving end of the third injector 103 , since the GND side harness is GND-shorted, the off surge voltage V is not detected, and accordingly, the injector drive confirmation signal K remains at the high level, and a low level signal is not outputted.
[0053] In the failure state of the item (3), since the third injector 103 is also driven at the timing when the normal second injector 102 is driven, when the intake stroke of the internal combustion engine is performed at the normal injection timing, the third injector 103 makes injection in the expansion stroke, and the combustion is delayed, or the fuel flows out to the exhaust system, and the disadvantageous state occurs.
[0054] With respect to the failure of the item (4), the injector drive confirmation signal K always becomes the high level or the low level. The fuel injection by the injector in this failure state is normally carried out as long as a double failure including another failure state does not occur.
[0055] In order to judge the abnormal state of the injector driving based on the injector drive confirmation signal K from the injector drive detection unit 205 , the internal combustion engine control unit 201 includes an injector drive abnormality judgment unit 206 . The injector drive abnormality judgment unit 206 detects the existence of switching from the high level to the low level of the injector drive confirmation signal K, and judges whether the injector driving is in a normal state or an abnormal state.
[0056] Specifically, at each timing when the injector control unit 203 outputs the injector drive signals S 1 , S 2 , S 3 and S 4 , the injector drive abnormality judgment unit 206 detects whether level switching from high to low occurs in the injector drive confirmation signal K from the injector drive detection unit 205 during a period from the last output of the injector drive signal to this output of the injector drive signal. That is, now, in FIG. 6 , when attention is paid to the first injector 101 , when S 1 t 1 is outputted as the injector drive signal S 1 at this time, it is confirmed that KS 10 is generated as the injector drive confirmation signal K during the period from the last output of S 1 t 0 to this output of S 1 t 1 , and the injector drive abnormality judgment unit 206 judges that the first injector 101 is normally driven.
[0057] Next, when attention is paid to the third injector 103 , when S 3 t 1 is outputted as the injector drive signal S 3 at this time, it is confirmed that KS 30 , which originally should be generated as the injector drive confirmation signal K, is not generated during the period from the last output of S 3 t 0 to this output of S 3 t 1 , the injector drive abnormality judgment unit 206 judges that the third injector 103 is not normally driven, and the driving is abnormal.
[0058] Also with respect to the fourth injector 104 and the second injector 102 , when an injector drive signal S 4 t 1 at this time and an injector drive signal S 2 t 1 (not shown) are outputted, similarly, it is confirmed whether the injector drive confirmation signal K are generated as KS 40 and KS 20 , and the injector drive abnormality judgment unit 506 judges, based on the existence thereof, whether the drivings of the fourth injector 104 and the second injector 102 are abnormal.
[0059] In the case where the injector drive abnormality judgment unit 206 detects the missing of the injector drive confirmation signal corresponding to all the first to fourth cylinders, it is judged that the injector drive confirmation signal K is abnormal, that is, the signal line to transmit the injector drive confirmation signal K is broken or shorted.
[0060] When it is judged by the injector drive abnormality judgment unit 206 that driving of one of the injectors is abnormal, the injector control unit 203 stops the injector drive signals of the injector judged to be abnormal in driving and the other injector corresponding to the group cylinder of the target cylinder. By this, at the time of the failure state of the item (3), it becomes possible to avoid the disadvantage that fuel injection into the group cylinder is simultaneously performed.
[0061] Besides, in the case where the injector drive abnormality judgment unit 206 detects the missing of the injector drive confirmation signal corresponding to all the first to fourth cylinders, or in the case where it is judged that the injector drive confirmation signal K is abnormal, that is, the signal line to transmit the injector drive confirmation signal K is broken or shorted, the injector control unit 203 continues the output of the injector drive signals S 1 to S 4 , and stores the abnormal state of the injector drive confirmation signal K as failure information.
[0062] Next, an abnormal judgment operation using the injector drive confirmation signal, which is carried out by the injector drive abnormality judgment unit 206 , will be described with reference toga flowchart of FIG. 7A and FIG. 7B . As described above, the injector drive abnormality judgment unit 206 carries out the injector drive abnormality judgment processing in synchronization with the timing when the injector control unit 203 outputs the injector drive signals S 1 , S 2 , S 3 and S 4 .
[0063] First, in the process of steps S 701 to S 708 , it is judged that the injector drive confirmation signal from the injector drive detection unit 205 indicates the drive state of the injector for which cylinder. That is, at step S 701 , it is confirmed whether there is output of the injector drive signal for the former cylinder, and in the case where there is output, advance is made to step S 705 , and it is judged that the target cylinder of the injector drive confirmation signal is the former cylinder. In the case where it is confirmed at step S 701 that there is no output of the injector drive signal for the former cylinder, advance is made to step S 702 , and it is confirmed whether there is output of the injector drive signal for the cylinder two cylinders before. In the case where there is output, advance is made to step S 706 , and it is judged that the target cylinder of the injector drive confirmation signal is the cylinder two cylinders before.
[0064] In the case where it is confirmed at step S 702 that there is no output of the injector drive signal for the cylinder two cylinders before, advance is made to step S 703 , and it is confirmed whether there is output of the injector drive signal for the cylinder three cylinders before. In the case where there is output, advance is made to step S 707 , and it is judged that the target cylinder of the injector drive confirmation signal is the cylinder three cylinders before. In the case where it is confirmed that there is no output of the injector drive signal for the cylinder three cylinders before, advance is made to step S 704 , and it is confirmed whether there is output of the injector drive signal for the cylinder four cylinders before. In the case where there is output, advance is made to step S 708 , and it is judged that the target cylinder of the injector drive confirmation signal is this cylinder, that is, its own cylinder. In the case where it is confirmed that there is no output of the injector drive signal for the cylinder four cylinders before, the injector drive abnormality judgment processing is ended.
[0065] Now, when the combustion order of the internal combustion engine is the first cylinder→third cylinder→fourth cylinder→second cylinder, the judgment processing of the target cylinder at steps S 701 to S 708 is specifically as follows. That is, in FIG. 6 , in case the output of the injector drive signal at this time is S 4 t 1 for the fourth cylinder, when there is output of the last injector drive signal S 3 t 1 , it is meant that the injector drive confirmation signal is KS 31 indicating the drive state of the third injector 103 for the third cylinder, and the target cylinder becomes the third cylinder. When there is no output of the last injector drive signal and there is output of the last but one injector drive signal S 1 t 1 , it is meant that the injector drive confirmation signal is KS 11 indicating the drive state of the first injector for the first cylinder, and the target cylinder becomes the first cylinder.
[0066] Similarly, when there is no output of the last but one injector drive signal and there is output of the last but two injector drive signal S 2 t 0 , it is meant that the injector drive confirmation signal is KS 20 indicating the drive state of the second injector for the second cylinder, and the target cylinder becomes the second cylinder. When there is no output of the last but two injector drive signal and there is output of the last but three injector drive signal S 4 t 0 , it is meant that the injector drive confirmation signal is KS 40 indicating the drive state of the fourth injector for the fourth cylinder, that is, its own cylinder, and the target cylinder becomes the fourth cylinder, that is, its own cylinder. In the case where it is judged at step S 704 that there is no output of injector drive signal for the last but three cylinder, since it is meant that an all-cylinder fuel drive stop state occurs, the injector drive abnormality judgment processing is not performed.
[0067] After the judgment of the target cylinder at step S 701 to S 708 , advance is made to step S 709 , and it is confirmed whether there is switching of level of the injector drive confirmation signal. In the case where there is switching, it is meant that driving of the injector is normally performed, advance is made to step S 710 , and an abnormality counter of the target cylinder is reset to 0. In the case where there is no switching, it is meant that injector driving is abnormal, advance is made to step S 711 , and the abnormality counter of the target cylinder is incremented. With respect to the judgment of the existence of the switching, for example, the existence of input of a signal falling edge from high to low of the injector drive confirmation signal is confirmed after the last injector drive signal is outputted.
[0068] Next, advance is made to step S 712 , and it is judged whether the abnormality counter of the target cylinder has a specified value or more. When it does not have the specified value or more, the abnormality judgment is not made, and the injector drive abnormality judgment processing is ended. In the case where it is judged at step S 712 that the abnormality counter has the specified value or more, in order to make a distinction from the abnormality of the injector drive confirmation signal, advance is made to step S 713 . At step S 713 , it is confirmed whether one of abnormal counters of the other cylinders is 0. That the one of the abnormal counters of the other cylinders is 0 means that the information that the one of the cylinders normally carries out injector driving can be judged based on the injector drive confirmation signal. That is, the injector drive confirmation signal can output signals of the high level H and the low level L, and it can be judged that the injector drive confirmation signal is not abnormal.
[0069] At step S 713 , when it is confirmed that one of the abnormality counters of the other cylinders is 0, advance is made to step S 714 , and it is judged that the injector of the target cylinder is abnormal in driving. In the case where it is judged at step S 713 that the abnormality counters of any cylinders are not 0, advance is made to step S 715 , and it is judged that the injector drive confirmation signal is abnormal.
[0070] According to embodiment 1 described above in detail, the drive abnormality of the injector, or the abnormality of the injector drive confirmation signal can be judged by using only the injector drive confirmation signal indicating the drive state of the injector. Further, at the time of drive abnormality of the injector, it is possible to avoid simultaneous fuel injection of the group cylinder, and the safe internal combustion engine control apparatus can be obtained.
[0071] Besides, although the invention is applied to the direct-injection gasoline internal combustion engine, the invention can also be applied to a port injection gasoline internal combustion engine, a diesel internal combustion engine or the like. Further, although the description has been given to the case where the internal combustion engine control unit and the injector drive unit are separate bodies, even when these are integrated in the same unit, the invention can be similarly applied. | In a case where fuel injection system abnormality is detected, and fuel supply stop processing is carried out against the abnormality, since a judgment is made using a misfire judgment, in a case where the misfire judgment is carried out in a periodic measurement system, the reliability is low at the time of a periodic variation or in a low rotation region, and in a case where it is carried out in an ion detection system, the cost increases, and the calculation load of an internal combustion engine control apparatus by the misfire judgment processing increases. A control apparatus for a vehicular internal combustion engine of the invention includes an injector drive abnormality judgment unit to judge, based on an injector drive confirmation signal, drive abnormality of an injector corresponding to the injector drive confirmation signal, and the injector drive abnormality judgment unit judges abnormality of the injector drive confirmation signal based on a state of the injector drive confirmation signal. | 5 |
This application is a continuation of application Ser. No. 08/449,782 filed on May 24, 1995, now abandoned.
BACKGROUND
1. Field of the Invention
The present invention relates to high-voltage insulators made from ceramic materials having a shank and ends where the ends are at least 1.05 times as thick as the shank. Caps are shrink-fit around the ends of the insulators to provide a tight seal.
2. Description of Related Art
High voltage insulators of ceramic materials are mainly used in outdoor switching stations and outdoor lines. They comprise an elongated insulation body which is equipped with shields for the formation of a leakage path which is matched, to the atmospheric conditions. The shields are moulded on the insulator shank whose thickness is determined by the mechanical requirements. At the ends of the insulation body or the insulator shank there are located metal caps via which the force transmission from the insulator shank to components leading further takes place. High voltage insulators are usually configured so as to have rotational symmetry, if the asymmetry of the caps, for example, as a result of individual links is ignored; the insulator caps concentrically surround the ends of the insulator shank. The mechanical loadability is determined not only by the shank diameter of the insulator, but also by the configuration of the shank ends, the manner in which the metal caps are fixed to the shank and the configuration and the material of the metal caps and also the type of mechanical stresses, which can, in principle, be tensile forces, compressive forces, flexurel forces and torsional forces or combinations of these forces. The constructions of the metal caps therefore depend on the type of stress prevailing in the particular case.
In the case of the known high voltage insulators, solid or hollow, the metal caps are slipped onto the insulator end to be reinforced and the gap between the insulator shank and the metal cap is filled with a setting filler material, such as various types of cement, lead or casting resin. The ends of the insulator body are here configured differently. Thus, the ends of tensile-stressed series path stabilizers (suspended insulators) have a conical configuration and are glazed and are frequently fixed in the metal cap by means of cast lead. In the case of post insulators subjected to flexural and/or torsional stresses, the insulation bodies are usually provided with cylindrical ends. The ends can here be made rough in various ways, e.g. fluted, spread with grit or corrugated. Portland cement is mainly used as filler material. The flexural strength of post insulators is strongly dependent on the ratio of filler depth to insulator shank diameter. Metal caps for suspended and post insulators usually comprise galvanized cast iron, because in the case of these insulators no great accuracy is required for the external dimensions. Where high demands are placed on the accuracy of the external dimensions of the insulators, the metal caps usually comprise aluminum alloys which have to be very accurately machined and require no additional corrosion protection after machining. To achieve the necessary precision of the insulator dimensions during cementing of the caps, efforts have to be made to relieve stresses in the positioning of the caps.
DE-A-36 43 651 discloses the shrink-fitting of the metal caps onto the ends of spherical-headed ceramic insulators. According to this method, the components are heated together, joined and cooled together, so that the ceramic workpiece is not damaged. This type of joining technique is very complicated for insulators, since hollow insulators in particular can have dimensions in the meter range. The invention is to provide a solution here.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a high tension insulator of ceramic material which has precise dimensions and also keeps them, is simple and quick to reinforce and in which no chemical reactions occur between the material components. Furthermore, the mechanical strength of the insulator material should be fully exploited for as small as possible an insertion length of the insulator ends into the metal caps.
This object is achieved by means of a rotationally symmetric high voltage insulator of ceramic material having shrink caps fitted to the ends, wherein the ends of the insulator in the region of the joining surfaces are configured so as to be at least 1.05 times as thick as the shank diameter and these thickened ends are, after firing, machined cylindrically and on the end faces.
The end of the metal cap facing the insulator body can project over the thickened insulator end and have, on its end face, a stop which rests on the end face of the insulator. A glazed groove can be provided between the metal cap and the insulator shank and a phase having a height of at least 1.5 mm, preferably a height of 2-5 mm, can be provided on the end faces of the insulator. The use of glaze is to prevent pollution from adhering to the surface of the insulator surface and to provide a smooth surface. The thickened, machined insulator end and the inner surfaces of the metal caps can have a roughness R a of 0.5-100 μm, preferably 0.8-30 μm, particularly preferably 1-10 μm and the groove can be filled with a sealant, e.g. silicone rubber. The metal caps can be provided with flanges which have a groove for accommodating a seal. Metal caps can comprise cast aluminum, wrought aluminum alloys, corrosion-resistant steel materials or steel and cast materials having corrosion-protective surface coatings. Suitable ceramic materials are, in particular, porcelains, ceramics containing aluminum oxide, zirconium silicate, cordierite and steatite materials.
The advantages of the invention are essentially in the simple joining technique, the dimensional accuracy and the reproducibility of the mechanical loading values of the high voltage insulators, in particular for hollow insulators. For the latter, there is the advantage of simpler sealability.
The invention is illustrated below with the aid of the figures.
BRIEF DESCRIPTION OF THE DRAWINGS
In the figures:
FIG. 1 shows a test specimen for tensile tests, partially sectioned;
FIG. 2 shows a test specimen for flexural tests, partially sectioned;
FIG. 3 shows the relationship between radial stress and flexural strength;
FIG. 4 shows, in section, part of a hollow post insulator and
FIG. 5 shows a variant to FIG. 4.
DETAILED DESCRIPTION
Glazed, rotationally symmetric test specimens 1 having thickened, machined ends 3, so-called shoulder rods, were produced from aluminous porcelain. The rod diameter d was 75 mm, the diameter D of the ends 3 was 95 mm. The metal caps 2 comprised a wrought aluminum alloy. The ends 3 of the rods 1 were machined after firing on the circumference and on the end faces and had a roughness R a of 1.3-2.5 μm. The roughness R a of the metal caps 2 in the recess 6 was 1.2-1.5 μm. The diameter of the recess 6 was smaller than the diameter D of the ends 3; their height H was 65 mm and the height h of the ends 3 was 60 mm, resulting in formation of a groove 7 between cap and rod. The metal caps were heated to 250° C. then slipped onto the ends of the rods and cooled to 25° C., which resulted in formation of a metal-ceramic connection by shrinkage. Depending on the cap dimensions, a radial stress results in the ceramic, which stress can be calculated.
According to FIG. 1, the test specimens were subjected to an ultimate tensile strength test, with the tensile forces F T being applied in the direction of the arrows. T-shaped elements 14 are jaw elements used to draw test specimen 1 with the corresponding forces F T to determine the tensile strength. Fracture values between 190 and 230 kN were obtained, which corresponds to a tensile strength of the ceramic material of 43-52 N/mm 2 . Fracture of these test specimens always occurred in the region of the groove 7, i.e. in the region of the transition from the shank 8 to the thickened shank end 3.
According to FIG. 2, the test specimens were subjected to a flexural strength test, with the flexural forces F F being applied in the direction of the arrow, giving the relationship between radial stress and flexural strength shown in FIG. 3. The strength values between 50 and 100 N/mm 2 are obtained from test specimens whose fracture point is in the region of the shoulder 5 of the groove 7. The low strength values (<20 N/mm 2 ) are attributable to circular fractures within the metal cap 2.
FIG. 3 shows a clear relationship between flexural strength and radial stress in the region of the point of connection, without the occurrence of scatter as observed according to the prior art. FIG. 3 also shows that radial stresses of>40 N/mm 2 are required for industrially interesting flexural strengths at ambient temperatures of 23° C. to 26° C. Tests in the temperature range from -25° C. to +125° C., i.e. in a temperature interval of 150°, confirm the reproducibility of the measured points in FIG. 3, with the radial stress not falling below 60 N/mm 2 . It was thus able to be shown that metal caps shrink-fitted to the ends of high tension insulators according to the features of the invention can also be used outdoors where temperature differences in regions of extreme climate can be expected to be up to 100° C.
In the hollow insulator of porcelain shown in FIG. 4, the shank 8 is provided with molded shields 4. The end 3 of the insulation body has a greater diameter D than the diameter d of the shank 8. By machining the outer circumferential surface of the end 3 and the end face of the end 3, the length of the insulation body can be made to conform to a predetermined value, and the surface roughness also can be adjusted to a predetermined value. The metal cap 2, preferably comprising an aluminum alloy or stainless steel, is arranged under radial stress on the machined end 3 of the insulation body. The metal cap 2 can be provided with a circumferential stop 9 which during the reinforcement of the insulation body rests on the end face of the end 3 of the insulation body. In this way, a precise dimension of the connection of the insulator is achieved. The mounting of the metal caps 2 is very simple. The heated metal caps are simply pushed onto the ends of the insulation body and then in a few seconds cool sufficiently for the insulator to be able to be handled immediately. After only about 30 minutes, the insulator can be mechanically tested without settling of the metal caps occurring.
The roughnesses of the joining surfaces of the shrink seat are of great importance, since the pulling off of the cap as a result of mechanical stressing depends not only on the radial stress in the shrink seat, but also on the coefficient of friction between the joining surfaces. It has been found that a roughness R a of 1-10 μm is particularly advantageous for the pairing aluminum/porcelain. Of great importance in hollow insulators is also the sealing to components which are fixed to the hollow insulator of porcelain. It has been found that roughnesses of the pairing aluminum/porcelain of 1-10 μm are impermeable to water and gas, so that seals 10 can also be arranged in a groove 13 in the flange 11 of the metal cap 2 (FIG. 4). If the joint is permeable however, seals 10 can also, as shown in FIG. 5, be arranged on the end face of the end 3 of the insulation body. That is, when the roughness of the aluminum and porcelain pairings are such that the joint between them is impermeable to water and gas, the seal does not have to placed at the joint of these two surfaces. Rather, the seal can be placed in groove 13 in flange 11 of the metal cap, as shown in FIG. 4. On the other hand, if the joint is permeable to water and gas, then the seal would be placed at the end face of end 3 of the insulation body, as shown in FIG. 5.
For the joining process, it is advantageous, as shown in FIG. 5, to provide the end 3 of the insulation body with a chamfer 12 having a height of at least 1.5 mm and an included angle of 2-45 degrees, in particular 5-30 degrees, with the insulator axis. It will be appreciated that a cylinder that has no chamfer on its front end can only be inserted with great difficulty into a tube with an inside diameter that is slightly larger than the diameter of the cylinder. A chamfer at the front end of a cylinder reduces the diameter of the cylinder at the end and gives it a slight tapered shape which substantially facilitates installation.
The detailed studies on the shrink connection with the insulator end have shown that any movement between the insulator and the metal cap has to be avoided under any circumstances. To meet this condition even for the region where the point of highest mechanical stress for the insulation material is located, namely in the transition region from end 3 to shank 8, it is advantageous to select the height H of the cap 2 so as to be greater than the height h of the end 3 of the insulation body. The groove 7 formed in this way can be filled with a single-component silicone rubber to avoid formation of pools of water. Silicone rubbers based on acetoxyacetic acid have excellent adhesion to aluminum and glazed porcelain.
The glazed groove 7 forms a preferential point of fracture under high mechanical stress owing to its notch effect. Since the position of the preferential point of fracture depends of the projecting length of the cap 2, it is advantageous to make the groove 7 as flat as possible and to provide it with a radius on the insulator shank.
The invention has been illustrated for the example of the hollow insulator, because it can be applied most advantageously here. Of course, high voltage insulators according to the invention can also be configured as solid post insulators or as suspended insulators. Other applications of the invention for components of very high precision, e.g. for switching and actuator rods for electrical high voltage installations are possible. | The invention relates to a high voltage insulator of ceramic material, which includes a longitudinal shank having molded sheds and to whose ends of the shank metal caps are shrink-fitted. The ends of the longitudinal shank are enlarged so that the diameter of the enlarged ends is at least 1.05 times the diameter of the longitudinal shank. The cylindrical surface, and the end face of the enlarged ends of the longitudinal shank are machined. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to the earthboring arts. More particularly, the invention relates to methods and devices for severing drill pipe, casing and other massive tubular structures by the remote detonation of an explosive cutting charge.
[0003] 2. Description of Related Art
[0004] Deep well earthboring for gas, crude petroleum, minerals and even water or steam requires tubes of massive size and wall thickness. Tubular drill strings may be suspended into a borehole that penetrates the earth's crust several miles beneath the drilling platform at the earth's surface. To further complicate matters, the borehole may be turned to a more horizontal course to follow a stratification plane.
[0005] The operational circumstances of such industrial enterprise occasionally presents a driller with a catastrophe that requires him to sever his pipe string at a point deep within the wellbore. For example, a great length of wellbore sidewall may collapse against the drill string causing it to wedge tightly in the well bore. The drill string cannot be pulled from the well bore and in many cases, cannot even be rotated. A typical response for salvaging the borehole investment is to sever the drill string above the obstruction, withdraw the freed drill string above the obstruction and return with a “fishing” tool to free and remove the wedged portion of drill string.
[0006] When an operational event such as a “stuck” drill string occurs, the driller may use wireline suspended instrumentation that is lowered within the central, drill pipe flow bore to locate and measure the depth position of the obstruction. This information may be used to thereafter position an explosive severing tool within the drill pipe flow bore.
[0007] Typically, an explosive drill pipe severing tool comprises a significant quantity, 800 to 1,500 grams for example, of high order explosive such as RDX, HMX or HNS. The explosive powder is compacted into high density “pellets” of about 22.7 to about 38 grams each. The pellet density is compacted to about 1.6 to about 1.65 gms/cm 3 to achieve a shock wave velocity greater than about 30,000 ft/sec, for example. A shock wave of such magnitude provides a pulse of pressure in the order of 4×10 6 psi. It is the pressure pulse that severs the pipe.
[0008] In one form, the pellets are compacted at a production facility into a cylindrical shape for serial, juxtaposed loading at the jobsite as a column in a cylindrical barrel of a tool cartridge. Due to weight variations within an acceptable range of tolerance between individual pellets, the axial length of explosive pellets fluctuates within a known tolerance range. Furthermore, the diameter-to-axial length ratio of the pellets is such that allows some pellets to wedge in the tool cartridge barrel when loaded. For this reason, a go-no-go type of plug gauge is used by the prior art at the end of a barrel to verify the number of pellets in the tool barrel. In the frequent event that the tool must be disarmed, the pellets may also wedge in the barrel upon removal. A non-sparking depth-rod is inserted down the tool barrel to verify removal of all pellets.
[0009] Extreme well depth is often accompanied by extreme hydrostatic pressure. Hence, the drill string severing operation may need to be executed at 10,000 to 20,000 psi. Such high hydrostatic pressures tend to attenuate and suppress the pressure of an explosive pulse to such degree as to prevent separation.
[0010] One prior effort by the industry to enhance the pipe severing pressure pulse and overcome high hydrostatic pressure suppression has been to detonate the explosive pellet column at both ends simultaneously. Theoretically, simultaneous detonations at opposite ends of the pellet column will provide a shock front from one end colliding with the shock front from the opposite end within the pellet column at the center of the column length. On collision, the pressure is multiplied, at the point of collision, by about 4 to 5 times the normal pressure cited above. To achieve this result, however, the detonation process, particularly the simultaneous firing of the detonators, must be timed precisily in order to assure collision within the explosive column at the center.
[0011] Such precise timing is typically provided by means of mild detonating fuse and special boosters. However, if fuse length is not accurate or problems exist in the booster/detonator connections, the collision may not be realized at all and the device will operate as a “non-colliding” tool with substantially reduced severing pressures.
[0012] The reliability of state-of-the-art severing tools is further compromised by complex assembly and arming procedures required at the well site. With those designs, regulations require that explosive components (detonator, pellets, etc.) must be shipped separately from the tool body. Complete assembly must then take place at the well site under often unfavorable working conditions.
[0013] Finally, the electric detonators utilized by state-of-the-art severing tools are not as safe from the electric stray currents and RF energy points of view, further complicating the safety procedures that must be observed at the well site.
SUMMARY OF THE INVENTION
[0014] The pipe severing tool of the present invention comprises an outer housing that is a thin wall metallic tube of such outside diameter that is compatible with the drill pipe flow bore diameter intended for use. The upper end of the housing tube is sealed with a threaded plug having insulated electrical connectors along an axial aperture. The housing upper end plug is externally prepared to receive the intended suspension string such as an electrically conductive wireline bail or a continuous tubing connecting sub.
[0015] The lower end of the outer housing tube is closed with a tubular assembly that includes a stab fit nose plug. The nose plug assembly includes a relatively short length of heavy wall tube extending axially out from an internal bore plug. The bore plug penetrates the barrel of the housing tube end whereas the tubular portion of the nose plug extends from the lower end of the housing tube. The bore plug is perimeter sealed by high pressure O-rings and secured by a plurality of set screws around the outside diameter of the outer housing tube.
[0016] The tubular portion of the nose plug provides a closed chamber space for enclosing electrical conductors. The bore plug includes a tubular aperture along the nose plug axis that is a load rod alignment guide. Laterally of the load rod alignment guide is a socket for an exploding bridge wire (EBW) detonator or an exploding foil initiator (EFI).
[0017] Within the upper end of the outer housing barrel is an inner tubular housing for a electronic detonation cartridge having a relatively high discharge voltage, 5,000 v or more, for example. Below the inner tubular housing is a cylindrical, upper detonator housing. The upper detonator housing is resiliently separated from the lower end of the inner tubular housing by a suitable spring. The upper detonator housing includes a receptacle socket 31 for an exploding bridge wire (EBW) detonator. The axis for the upper detonator receptacle socket is laterally offset from the outer housing barrel axis.
[0018] Preferably, the severing tool structure is transported to a working location in a primed condition with upper and lower EBW detonators connected for firing but having no high explosive pellets placed between the EBW detonators. At the appropriate moment, the nose plug assembly is removed from the bottom end of the outer housing and a load rod therein removed. The upper distal end of the load rod includes a circumferential collar such as a snap ring. The opposite end of the load rod is visually marked to designate maximum and minimum quantities of explosive aligned along the load rod.
[0019] Explosive pellets for the invention are formed as solid cylinder sections having an axial aperture. The individual pellets are stacked along the load rod with the load rod penetrating the axial aperture. The upper distal end collar serves as a stop limit for the pellets which are serially aligned along the rod until the lower face of the lowermost pellet coincides with the max/min indicia marking. A restriction collar such as a resilient O-ring is placed around the loading rod and tightly against the bottom face of the lowermost explosive pellet.
[0020] The rod and pellet assembly are inserted into the outer housing barrel until the uppermost pellet face contiguously engages the upper detonator housing. The rod guide aperture in the nose plug is then assembled over the lower distal end of the load rod and the lower detonator brought into contiguous engagement with the lowermost pellet face. The assembly is then further compressed against the loading spring between the inner tubular housing and the upper detonator housing until abutment between the nose plug shoulder and the lower distal end of the outer housing tube.
[0021] In the event that the invention severing tool must be disarmed, all pellets may be removed from the housing barrel as a singular unit about the load rod. This is accomplished by removing the lower nose plug which exposes the lower end of the load rod. By grasping and pulling the load rod from the housing barrel, all pellets that are pinned along the load rod below the upper distal end collar are drawn out of the housing tube with the rod.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Relative to the drawings wherein like reference characters designate like or similar elements or steps through the several figures of the drawings:
[0023] [0023]FIG. 1 is a sectional view of the invention as assembled without an explosive charge for transport;
[0024] [0024]FIG. 2 is a sectional view of the invention with the bottom nose piece detached from the main assembly housing;
[0025] [0025]FIG. 3 is a sectional view of an assembled, explosive pellet unit;
[0026] [0026]FIG. 4 is a sectional view of the invention with the explosive pellet unit combined with the main assembly housing but the bottom nose piece detached therefrom;
[0027] [0027]FIG. 5 is a sectional view of the invention in operative assembly with an explosive pellet unit.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] Referring to the FIG. 1 cross-sectional view of the invention 10 , a tubular outer housing 12 having an internal bore 14 is sealed at an upper end by a plug 16 . The plug 16 includes an axial bore 18 and an electrical connector 20 for routing detonation signal leads 22 . A boss 17 , projecting from the base of the plug, is externally threaded for the attachment of the desired suspension string such as an electrical wireline or service tubing.
[0029] An inner housing tube 24 is secured to and extends from the upper end plug 16 into the internal bore 14 of the outer housing 12 . The inner housing tube 24 encloses a capacitive firing cartridge 26 . Below the inner housing 24 is an upper detonator housing 28 . A coil spring 30 links the upper detonator housing 28 to the inner housing tube 24 . An exploding bridge wire (EBW) detonator or exploding foil initiator (EFI) 32 is seated within a receptacle socket formed in the upper detonator housing 28 laterally of the housing axis. Electrical conduits 34 connect the capacitive firing cartridge 26 to to the EBW detonator or EFI 32 .
[0030] An exploding bridge wire (EBW) detonator comprises a small quantity of moderate to high order explosive that is detonated by the explosive vaporization of a metal filament or foil (EFI) due to a high voltage surge imposed upon the filament. A capacitive firing cartridge is basically an electrical capacitator discharge circuit that functions to to abruptly discharge with a high threshold voltage. Significantly, the EBW detonator or EFI is relatively insensitive to static or RF frequency voltages. Consequently, the capacitive firing circuit and EBW or EFI function cooperatively to provide a substantial safety advantage. An unusually high voltage surge is required to detonate the EBW detonator (or EFI) and the capacitive firing cartridge delivers the high voltage surge in a precisely controlled manner. The system is relatively impervious to static discharges, stray electrical fields and radio frequency emissions. Since the EBW and EFI detonation systems are, functionally, the same, hereafter and in the attached invention claims, reference to an EBW detonator is intended to include and encompass an EFI.
[0031] The lower end of the outer housing tube 12 is operatively opened and closed by a nose plug 40 . The nose plug 40 comprises a plug base 42 having an O-ring fitting within the lower end of the outer housing bore 14 . The plug base 42 may be secured to the outer housing tube 12 by shear pins or screws 44 to accomodate a straight push assembly. Projecting from the interior end of the plug base is a guide tube boss 46 having an axial throughbore 48 and a receptacle socket 50 for a detonator cap 66 .
[0032] Projecting from the exterior end of the plug base 42 is a heavy wall nose tube 52 having a nose cap 54 . The nose cap 54 may be disassembled from the nose tube 52 for manual access into the interior bore 56 of the nose tube 52 . Detonation signal conductor leads 58 are routed from the firing cartridge 26 , through the upper detonator housing and along the wall of housing bore 14 . A conductor channel 60 routes the leads 58 through the nose plug base 42 into the nose tube interior 56 . This nose tube interior provides environmental protection for electrical connections 62 with conductor leads 64 from the lower EBW detonator 66 .
[0033] Although the electrical connections of both EBW detonators 32 and 66 are field accessible, it is a design intent for the invention to obviate the need for field connections. Without explosive pellet material in the outer housing bore 14 , EBW detonators 32 and 66 are the only explosive material in the assembly. Moreover, the separation distance between the EBW detonators 32 and 66 essentially eliminates the possibility of a sympathetic detonation of the two detonators. Consequently, without explosive material in the tubing bore 14 , the assembly as illustrated by FIG. 1 is safe for transport with the EBW detonators 32 and 66 connected in place.
[0034] The significance of having a severing tool that requires no detonator connections at the well site for arming cannot be minimized. Severing tools are loaded with high explosive at the well site of use. Often, this is not an environment that contributes to the focused, intellectual concentration that the hazardous task requires. Exacerbating the physical discomfort is the emotional distraction arising from the apprehension of intimately manipulating a deadly quantity of highly explosive material. Hence, the well site arming procedure should be as simple and error-proof as possible. Complete elimination of all electrical connection steps is most desirable.
[0035] The load rod 70 , best illustrated by FIGS. 2, 3 and 4 , is preferably a stiff, slender shaft having an end retainer 72 such as a “C” clip or snap ring. Preferably, the shaft is fabricated from a non-sparking material such as wood, glass composite or non-ferrous metal. Individual high explosive “pellets” 74 are cylindrically formed with a substantially uniform outer perimeter OD and a substantially uniform ID center bore. The term “pellets” as used herein is intended to encompass all appropriate forms of explosive material regardless of the descriptive label applied such as “cookies”, “wafers”, or “charges”. The axial length of the pellets may vary within known limits, depending on the exact weight quantity allocated to a specific pellet. The pellets are assembled as a serial column over the rod 70 which penetrates the pellet center bore. A prior calculation has determined the maximum and minimum cumulative column length depending on the the known weight variations. This maximum and minimum column length is translated onto the rod 70 as an indicia band 76 . The maximum and minimum length dimensions are measured from the rod end retainer 72 . The OD of the end retainer 72 is selected to be substantially greater than the ID of the pellet center bore. Hence the pellets cannot pass over the end retainer and can slide along the rod 70 length no further than the end retainer. When loading the tool with explosive in the field, the correct quantity of explosive 74 will terminate with a lower end plane that coincides within the indicia band 76 . An elastomer O-ring 78 constricted about the shaft of rod 70 compactly confines the pellet assembly along the rod length.
[0036] A lower distal end portion 79 of the rod extends beyond the indicia band 76 to penetrate the guide bore 48 of the bore plug base 42 when the bottom nose plug 40 is replaced after an explosive charge has been positioned. This rod extension allows the high explosive to be manually manipulated as a singular, integrated unit. In full visual field, the explosive charge is assembled by a columned alignment of the pellets over the penetrating length of the rod. When the outside surface plane of the last pellet in the column aligns within the indicia band 76 , the lower end retainer 78 is positioned over the rod and against the last pellet surface plane to hold the column in tight, serial assembly. Using the rod extension 79 as a handle, the explosive assembly is axially inserted into the housing bore 14 until contiguous contact is made with the lower face of the upper detonator housing 28 .
[0037] One of the synergistic advantages to the unitary rod loading system of the invention is use of lighter, axially shorter pellets, i.e. 22.7 gms. These lighter weight pellets enjoy a more favoraable shipping classification (UN 1.4S) than that imposed on heavier, 38 gm pellets (UN 1.4D). In a prior art severing tool, the lighter weight pellets would be avoided due to “cocking” in the tool barrel 14 during loading. The loading rod system of the present invention substantially eliminates the “cocking” problem, regardless of how thin the pelleet is.
[0038] With the explosive assembly in place, the lower end of the housing is closed by placement of the nose plug 40 into the open end of the housing. The rod end projection 79 penetrates the guide bore 48 as the plug base 42 is pushed to an internal seal with the housing bore 14 . To assure intimate contact of the opposite end EBW detonators 32 and 66 with the respective adjacent ends of the explosive assembly, the upper detonator housing 28 is displaced against the spring 30 to accommodate the specified length of the explosive column. Accordingly, when the nose plug 40 is seated against the end of the outer housing tube 12 , both EBW detonators are in oppositely mutual compression as is illustrated by FIG. 5. The severing tool is now prepared for lowering into a well for the pipe cutting objective
[0039] Presently applied Explosive Safety Recommendations require the severing tool 10 to be electrically connected to the suspension string i.e. wireline, etc., before arming ballistically. Ballistic arming with respect to the present invention means the insertion of the explosive Pellets 24 into the housing bore 14 .
[0040] On those occasions when the severing tool must be disarmed without discharge, it is only necessary to remove the nose plug 40 and by grasping the rod extension 79 , draw the pellets 74 from the tube bore 14 as a single, integrated item.
[0041] Numerous modifications and variations may be made of the structures and methods described and illustrated herein without departing from the scope and spirit of the the invention disclosed. Accordingly, it should be understood that the embodiments described and illustrated herein are only representative of the invention and are not to be considered as limitations upon the invention as hereafter claimed. | A pipe severing tool is arranged to align a plurality of high explosive pellets along a unitizing support structure whereby all explosive pellets are inserted within or extracted from a tubular housing as a singular unit. Electrically initiated exploding wire detonators (EBW) are positioned at opposite ends of the tubular housing for simultaneous detonation by a capacitive firing device. The housing assembly includes a detachable bottom nose that permits the tool to be armed and disarmed without disconnecting the detonation circuitry. Because the tool is not sensitive to stray electrical fields, it may be transported, loaded and unloaded with the EBW detonators in place and connected. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/599,864, filed Aug. 10, 2004, incorporated herein by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] None.
BACKGROUND OF THE INVENTION
[0003] Many humidifiers that are currently manufactured for patient respiratory disorders such as Obstructive Sleep Apnea (OSA) are large, bulky, and have large water reserves to treat most medical-related ailments such as dryness that may be caused by mouth leaks for example. Mouth leaks or any leaks for that matter release humidified gases to the atmosphere and bypasses the patient's airways where it is required. These heavy requirements including those medical conditions requiring high levels of continuous humidification may require humidifier devices with reserves as high as 600 mL of water. This increases the overall size and bulk of the Continuous Positive Airway Pressure (CPAP) Apparatus, ventilator, patient breathing air system, or gas supply system.
[0004] Where patients do not exhibit these inadvertent leaks or are only seeking lower levels of humidification, they are likely to be left with an unnecessarily oversized reservoir of remaining water at the end of a treatment session.
[0005] Furthermore, there are a substantial number of patients that only require relatively smaller amounts of humidification to marginally improve comfort to an acceptable level for a typical patient. These patients for example may include those that only use their conventional humidifiers (ResMed HumidAire™ or Fisher & Paykel HC100) during the cooler months in winter for small but substantial gain in comfort by adding warmth and/or moisture to the airways that may dry due to the flow of air through the patient airways.
[0006] Current humidifiers are generally designed to fulfill the worst ailments and therefore require substantial humidification requirements. These systems could be regarded as ‘overkill’ for a substantial population of OSA patients who are only looking for a ‘comfortable’ level of improvement to undesirable dry and cool air.
[0007] Current and conventional humidification systems generally supply a continuous level of humidification as set by the user and dependent on the ambient temperature and humidity level. There are also systems that may modify humidification levels using a number of sensor arrays such as temperature sensors and/or humidity or flow sensors in aid to maximize efficiency and/or synchronize with pressure or airflow. These conventional systems can maximize the performance of the humidifier by being able to deliver the maximum amount of humidity whilst reducing or eliminating condensation (e.g. cooler air can carry less moisture), also known in the art as “rain-out”. However, these types of sensor systems are complex and costly and still consume large amounts of water.
[0008] Accordingly, a need has developed in the art to address at least one of the shortcomings of the prior art humidifiers described above.
BRIEF SUMMARY OF THE INVENTION
[0009] One aspect of the invention to ameliorate the size and design constraints of the conventional humidifier whilst delivering an adequate and comfortable level of humidification whilst consuming/delivering the fluid (e.g. water, core gas vapor, etc.) in an efficient manner (requiring lower liquid reservoir volumes) and delivered according to the patient's needs, which may also be a manually selectable and/or programmable, semi-automated and/or automated delivery profile.
[0010] Another aspect of the invention relates to assisting patients looking for limited improvement to breathing comfort. However, the intention is not to replace conventional, continuously heated humidifiers, but rather to provide an additional choice more suitable for certain patients.
[0011] Another aspect of the invention provides profiled delivery of humidified gas to a patient.
[0012] Another aspect of the invention reduces water or fluid volume required by maximizing efficient use of water, which is a form of ‘rationing’.
[0013] Another aspect of the invention aims to improve breathing comfort according to patient selectable profiles in one embodiment.
[0014] These and other aspects will be described in or apparent from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a schematic view of a blower according to an embodiment of the present invention;
[0016] FIGS. 2 and 3 illustrate sample humidity profiles for a patient's treatment session; and
[0017] FIG. 4 schematically illustrates an alternative embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] FIG. 1 schematically illustrates a blower 10 according to an embodiment of the present invention. Blower 10 typically includes a housing 12 to support a blower motor 14 that pressurizes breathable gas for delivery to a patient interface 16 (e.g., a mask) via an air delivery conduit 18 that is connected to an outlet conduit 20 of blower 10 . Blower 10 includes a control panel 22 with one or more buttons and preferably a display. Blower 10 includes a pressure sensor 24 to provide a signal to a controller 26 (e.g., CPU) for control of blower motor 14 , in accordance with one or more control algorithms commercially available from ResMed, Inc.
[0019] Blower 10 is optionally provided with a selectively attachable and detachable humidifier unit 28 that includes a tub 30 and one or more conduits 32 , 34 that communicate with blower 10 . Humidifier unit 28 may include structure as detailed in U.S. Published Patent Application No. 2004/0055597A1, incorporated by reference in its entirety. Humidifier unit 28 is in communication with controller 26 , e.g., when conduits 32 , 34 are attached to blower 10 .
[0020] In one embodiment, the operation and/or performance of the humidifier unit 28 is tailored or profiled to suit the patient's specific humidification requirements. This in turn results in more efficient water usage, and allows the capacity of the tub 30 to be reduced. For example, the capacity of the tub 30 can be less than 400 mL, e.g., from 20 mL-400 mL or more preferably between 50 mL-200 mL. Of course, the volume capacity can be greater or less, depending on application. This reduced volume allows the overall size of the blower humidifier and/or assembly to be reduced, thereby removing design constraints and facilitating transport of the blower, e.g., during travel of the patient.
[0021] Profiling may be intermittent or profiled in accordance to a patient selectable profile or according to a selectable or semi/automated profile typical of the treatment session's ambient environment conditions.
[0022] Another embodiment may modify the delivery profile according to temperature of room over the course of a treatment session. The device may measure temperature versus time and predict what adjustments in profile are desirable to maintain efficient fluid/water use.
[0023] In another embodiment the profile may change over a set time period of treatment. For example, during an eight-hour treatment session, the profile begins at start of treatment and continues on to either end of session or a set time period on the device.
[0024] The above can obviously be used in combination with other embodiments such as watching average room temperature or even monitoring temperature changes over a period of hours, days, weeks, or months, and can modify the profile accordingly.
[0025] A profile may, for example, recognize that a typical bedroom tends to cool until the early hours of the morning where the temperature tends to stabilize before warming again by sunrise. Another profile that may be used may gradually reduce the humidity level during the course of the night in one simple form of the invention.
[0026] In embodiments, the invention may also postpone delivery until a period of the sleep session has passed. For example, a patient in the case of CPAP does not tend to go to sleep (beginning of treatment session) with dry airways. Their airways are probably going to dry later, say one hour into the night. Compared to conventional humidifiers used in OSA over eight-hour sessions, this feature alone can reduce humidification water volumes by one-eighth.
[0027] When implementing the delay feature, valves 35 a and 35 b can be used to divert the path of the air so as to by-pass the humidifier unit 28 via a by-pass conduit 35 c . The air path is schematically illustrated in FIG. 1 with a broken arrow 36 . When shut, valves 35 a and 35 b form part of the respective walls of gas conduits within blower 10 .
[0028] The invention in one preferred embodiment may cycle between switch on and off during the course of the night. These cycles can be regular, irregular, or otherwise controlled for numerous intervals and various durations using some smart electronic control. The switching off does not necessarily need to completely switch off, but may reduce in temperature during periods where less humidification is required. As mentioned, this reduces water usage but may also lead to reduced energy (power) consumption and/or reduced running costs. For example, humidifier unit 28 may include a heater element to heat the volume of water. Heater element can be controlled via controller 26 .
[0029] A user's manually selectable version is also possible. For example, as shown in FIGS. 2 and 3 , a patient may set the humidifier device from a menu including, e.g., a Square wave or a Sinusoidal wave which may be integrated into blower 10 or humidifier unit 28 in the form of a symbol on a dial or push button. The device then humidifies the air to a level according to these changing profiles over a treatment session. In the case of a Sinusoidal wave setting where the cycle starts as a ‘rise’, the humidifier level increases gradually to a maximum during the middle of a treatment session and gradually reduces to the end of the treatment session. The profile can be symmetrical or asymmetrical. Also, the delay feature described above can be used in conjunction with the Square and/or Sinusoidal wave, so that humidity is added only after treatment has commenced.
[0030] If the humidifier provides instantaneous humidification on demand, this profile may also be adapted on a patient breath-by-breath basis rather than over a full treatment session.
[0031] These profiles mentioned above can be any combination or variation of a wave/curve and/or stepped. It may also be automated to learn the ambient environmental conditions. For example, a temperature sensor 40 ( FIG. 1 ) may monitor room temperature changes over the annual seasons and modify the profile further to gain maximum water/fluid use and efficiency. For example, during cooler months, the humidification profile may allow for longer humidification periods (during the switch on or higher heat cycle) but not allow as high a level so as to reduce condensation and maximize comfort for the patient.
[0032] Another embodiment may include a ‘fuzzy logic’ version where the user, with the assistance of the device's intelligence, provides an optimum humidification profile, which provides optimal comfort to the patient whilst maintaining efficient fluid/water usage. In this example, the patient may wake up and press one of three buttons, or select a dial setting, to indicate whether the level of humidification was “okay”, “too little” or “too much”. The device can then re-profile the delivery according to the patient's perceived comfort level. In this case, much of the actual profiling is automated.
[0033] Another embodiment of the invention considers two positive aspects of humidification and provides additional benefits. Current technology warms the patient breathing air. Warm air is considered more comfortable to breathe especially if the ambient temperature is relatively low. Secondly, humidifiers add moisture to the breathing air. The invention may profile the humidity level at a different rate to that of the air temperature. For example, according to the Sinusoidal wave setting example mentioned earlier, the device may maintain warm breathing air with minimal increased requirement at the middle of the treatment session. The humidity however may increase at an independent level relative to the temperature; for example, the humidity may increase much more than the temperature at the peak of the wave profile. This can again be selected by a patient according to their comfort requirements.
[0034] Any of the embodiments mentioned above may have an ability to transfer any ‘learned’ logic by memory storage media, or wireless communication (e.g. “Blue tooth” technology) so that the logic could be utilized by a physician, another user, or else simply because the patient intends to replace the device or upgrade to a newer model. Controller 26 may include a memory 26 a to facilitate data storage/transfer.
[0035] In a more mechanized embodiment of the invention, a simple valve that controls the humidified air entering the mainstream breathing air may be controlled by mechanical links. For example, as shown in FIG. 4 , a rotating cam 42 that is profiled to control a valve 46 via mechanical linkage 48 , thus producing staged delivery of humidified gas through a conduit 49 (which may be conduit 34 in FIG. 1 ). The cam profile can be such that the peak of the cam's lobe translates to largest valve opening and therefore greatest humidification level. The cam 42 could be designed to turn one revolution in one treatment session. The shape of the cam lobe determines the delivery profile. A bimetallic spring may also be added to modify lift (generally reduce lift to reduce humidification as temperature decreases) and therefore forms a type of mechanical temperature compensation.
[0036] Further to the above embodiment, the profile could be mechanically adjustable by a user. For example, a number of selectable pins around the perimeter of a cam lobe could be push in or out to modify at what period of the session and by how much to lift the valve.
[0037] In another embodiment, the invention may also incorporate a switch or sensor device that switches off the humidifier should the treatment session be interrupted. For example, an OSA patient may get up in the middle of the night to go to the bathroom. This feature is designed to reduce water consumption further and also prevent condensation in the air delivery pipe, especially if the flow generator has stopped (ResMed's Smart Stop™ feature). It may also prevent the patient breathing in condensate when they return to bed, which in turn improves patient comfort.
[0038] Yet another embodiment of the invention includes a mask “rain-out” sensor 50 ( FIG. 1 ) that does not require the use of humidity sensor like the prior art. An infrared emitter and detector in communication with controller 26 , e.g., are placed at the bottom of the mask interface or location where condensation is likely to bead or pool. The mask frame wall in front of the side-by-side emitter/detector is transparent to infrared light. Under normal conditions, the detector does not see any infrared light. If significant water droplets develop (condensation) in front of the emitter/detector, the light reflects back to the detector and signifies condensation. The device may also use another type of visible or non-visible light emitter/detector combination.
[0039] The above feature applied to the invention may either reduce humidification or heating in response to “rain-out”, or otherwise it may modify the humidification delivery profiles as described earlier to improve patient comfort. Also by identifying “rain-out”, this may provide intelligence to the device's control that the ambient temperature is falling or the heating of the delivered air is too low to carry the current level of moisture.
[0040] One or more of the following advantages may be realized in accordance with preferred embodiments of the invention:
Humidifier that is smaller, easier to store or travel with. A device that can be tailored (profiled) or set by a user to suit their circumstances, needs or desires for comfort. A profile humidifier may bridge the gap between inefficient “Passover” (non-heated) humidifiers and fully featured heated humidifiers that treat most dry airway ailments. Potentially less complaints of “rain-out” or condensation as patients may have adjusted their device to a high setting, only to find that a cooling room creates increased condensation. Ability to control, modify and fine-tune their patient's therapy. By minimizing humidity delivery when it is not necessary reduces water usage and reservoir volume required, therefore reducing device size. Alleviates the size constraints on engineers for the OSA market that is trending towards fewer design compromises to meet comfort expectations. Flow generators have already been reduced in size, whereas the humidifier is about the same size as next generation flow generators, if not larger. This concept gives users the perception of even more compact dimension that is potentially lighter and easier to transport.
[0049] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention. For example, the above described preferred embodiments of the invention may be adapted to any humidification device whether to treat OSA or used in any gas breathing system. | A method and apparatus for delivering breathable gas to a user includes a humidifying unit that is controllable to humidify the gas in accordance with a variable humidity profile such that the gas is delivered to the user at variable humidity levels, e.g., during a treatment session. | 0 |
This application is a division of application Ser. No. 640,326 filed on Aug. 13, 1984, now U.S. Pat. No. 4,615,911.
BACKGROUND OF THE INVENTION
Prior U.S. Pat. No. 3,911,160, which was granted to co-inventor William B. Neuberg, describes a method for curing solvent free inks by the application of a powder resin to a freshly printed surface. The printed surface then cured, such as by passing it throuoh a heating apparatus, wherein the resin melts, curing the ink.
The prior patent suggests mechanically leveling the printed surface following curing to produce a high gloss. Applicants have found that in some instances such mechanical leveling causes a smearing of the ink and molten powder resin coating, particularly on printed surfaces using half-tone dots. Such mechanical leveling can cause a smearing of the half-tone dots to an oval or teardrop shape without producing a uniform coating surface.
The present invention is an improved method of using resin powders to cure solvent free inks and provides a process wherein high gloss can be achieved with a half-tone printing process and without the use of a mechanically leveling apparatus that would produce smearing of the half-tone dots. The process permits replication of the high gloss or matte caulstock, or other release surfaces described herein, and eliminates the problem of smearing of the molten powder resin coating or half-tone dots experienced in the earlier patent.
SUMMARY OF THE INVENTION
In accordance with the present invention the process for curing solvent free ink wherein resin powder is applied to a printed surface on a web and cured, is improved by applying a caulstock laminate having a release agent to the powdered, printed surface of the web and wherein the web and the caulstock are passed together over a first, heated roller and pressed between the first roller and a second roller. Thereafter the web and the caulstock are passed over at least a third cooled roller and the caulstock is peeled from the web.
The caulstock may have an aluminum foil surface which is applied against the printed surface or a thermoset resin surface which is applied against the printed surface. The second roller is preferably heated and there may be provided additional cooling rollers to cool the web and the caulstock prior to separation. The caulstock laminate can be re-used by winding on a take-up spool, or by using an endless caulstock laminate which is returned to be reapplied to the web. The process can be used to simultaneously cure printing on both sides of the web by applying a second caulstock to the reverse side of the printed web.
In accordance with the invention there is provided the product of the process and also an apparatus for carrying out the process.
For a better understanding of the present invention together with other and further objects, reference is made to the following description, taken in conjunction with the accompanying drawings and its scope will be pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram illustrating a printed web undergoing the process of the present invention and the apparatus for carrying out the process of printing on the upper surface of the web only.
FIG. 2 is a simplified drawing illustrating another embodiment of the apparatus for carrying out the present invention.
DESCRIPTION OF THE INVENTION
The first embodiment of the present invention will be described with reference to the simplified apparatus and process drawing of FIG. 1. In FIG. 1 there is shown a simplified side view of an apparatus for processing a web 10 with printing on its upper surface to which there has been applied a resin powder in accordance with the techniques of the invention described in the referenced prior patent to co-inventor Neuberg. The web 10 consists of a paper, polymeric film, or foil material on which, by conventional printing processes, there has been deposited a solvent-free ink, the ink being one of the types listed in the referenced Neuberg patent. Following application of ink, the upper printed surface of web 10 has applied thereto a resin oowder of one of the types listed in the referenced Neuberg patent, and excess powder has been removed from the surfaced by means of an air knife, as described in the prior Neuberg patent. In a preferred embodiment of the invention, the resin and ink have not been cured by heating or other means, but the invention may also be used in cases where the surface has been pre-cured.
As shown in FIG. 1 the upper printed surface of web 10 is mated with a caulstock 11, which is shown as a dotted line for clarity in the illustration. Caulstock 11 is provided from a feed soool 12 and mated with web 10 at idler roller 14. The combined caulstock and web are thereafter received by a driven heated roller 15.
Caulstock 11 consists of a laminate of aluminum foil approximately 0.3 milliliters thick which is laminated to paper, such as 60 pound lithostock. The foil surface may be either high gloss or matt, according to the desired finished of the printed surface on web 10. Caulstock of the required characteristics can be obtained commercially, such as from Gum Products Company. The foil surface of the caulstock is not treated with the usually provided stearic acid release agent, but it is treated with a release agent, wherein the fusion or boiling temperature of the release agent is higher than the operating temperature of the invention. The foil surface is preferably treated with silicone or polyvinyl alcohol based release agents. Other suitable release agents such as lecithin may be employed which permit release of the fused powder caulstock. Experiments have indicated that a release agent marketed under the trade name "Frekote Exitt" mold release which was sprayed onto the foil is suitable for the process. As an alternate to the use of a foil laminate, other casting papers or films and laminated webs such as a thermoset resin, coated paper or polymeric film caulstock can be used for the process of the invention. The surface of all systems may require the application of an approved release media. Certain thermoset silicone resin papers or casting papers may be used without application of external release media.
As illustrated in FIG. 1, the combined web 10 and caulstock 11 are received around heated roller 15, which is driven at a speed to takeup the material as it comes from the press. The material is heated as it passes around roller 15 to achieve curing of the ink and powder as described in the prior Neuberq patent. The web and caulstock then passes onto a second roller 16, which in the preferred embodiment is also heated. Roller 16 bears against roller 15 with the web and caulstock between to effectively nip the printed surface against the caulstock while the resin is in a heated condition. For this purpose the clearance between the rollers should be 0.005 inches for a web and caulstock having a combined thickness of 0.0055 inches. The inventors believe that this process causes a continuous resin bead to be maintained at the pressure point to yield a result which provides a continuous resin film over the printed surface. In the case of half-tone printing the resin film must be continuous to provide a smooth matt or high gloss finish, as contrasted to a dull finish which results from merely heat curing a half-tone printed surface according to the process of the prior patent. When the prior process is applied to half-tones, the space between half-tone dots has no resin finish, and therefore the overall surface appears to have a dull rough texture.
The rollers 15 and 16 are heated above the curing temperature of the resin, but not to a level which would cause discoloration of the paper. A temperature of 275° to 300° F. has been found suitable, but it is expected that temperatures above 400° F. would cause paper discoloration at slow line speed. The temperature level of the rollers depends on the number of rollers which are heated and the speed of the web movement. At high speed it would be appropriate to either use one or more of the following: a preheater oven, more rollers, larger diameter rollers or higher roll temperatures to maintain sufficient roller contact time to heat the resin to curing temperature prior to nipping the surface between the heated rollers. It is appropriate that both rollers 15 and 16 be mechanically driven in coordination with the press speed. However, if the copy being produced does not require a nip pressure to achieve leveling of the powderset material, the heating rolls may be free idler rolls.
From roller 16 the combined web and caulstock passes onto cooling roll or rollers, in the case of FIG. 1 a single roller 17. The cooling roller can be water cooled with water at temperature of approximately 55° F., and a sufficient amount of cooling contact should be provided to cool the web and caulstock to 90° F. prior to separation.
In the apparatus of FIG. 1 the caulstock is separated from the web at idler roller 18, and is thereafter passed over roller 24 and taken-up on spool 26. The printed and cured web passes over rollers 20 and 22 and thereafter is provided to other processing, such as a takeup spool or cutting apparatus.
FIG. 2 illustrates a minor variation of the apparatus and process of the present invention. In the FIG. 2 embodiment the caulstock 11 is in the form of an endless belt which passes from separating roller 18 over rollers 28 and 30 and is reapplied to the web by roller 14. The FIG. 2 embodiment also shows and additional cooling roller 32.
While there has been described what is believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such embodiments as fall within the true scope of the invention. | An improved process for curing solvent free inks using resin powder makes use of a caulstock laminate which is applied against a printed surface bearing ink and resin powder. The printed material and the caulstock are heated, pressed together and then cooled. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a 35 USC 371 application of PCT/EP 2006/062119 filed on May 8, 2006.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is based on a high-pressure fuel pump for a fuel injection system of an internal combustion engine, and more particularly to such a pump having a pump housing in which a drive shaft is supported by a first bearing and a second bearing; having at least one pump element disposed radially relative to the drive shaft; having a fuel feed line, with a prefeed pump that pumps fuel into the fuel feed line; having a fuel return line; having a metering unit for regulating the pump capacity of the pump element or elements; and having a pressure regulating valve.
2. Description of the Prior Art
In these high-pressure fuel pumps known from the prior art, the pressure regulating valve serves to regulate the pressure in the low-pressure circuit of the high-pressure fuel pump. The pump capacity of the prefeed pump is typically split into three partial flows. A first partial flow flows through the metering unit to the intake side of the pump element or elements. The second partial flow as a rule flows through the pump housing via a lubricating throttle restriction and serves there to cool and lubricate the pump. From the pump housing, the second partial flow reaches the fuel return line of the fuel injection system. A third partial flow flows through the pressure regulating valve, which may also be embodied as an overflow valve, and likewise reaches the fuel return line.
With increasing injection pressures, the mechanical and thermal loads on both the drive shaft and the bearing of the drive shaft in the pump housing also increase. Conventional high-pressure fuel pumps are not capable of withstanding these increasing loads.
The object of the invention is to furnish a high-pressure fuel pump for a fuel injection system that makes do with the same installation space as conventional high-pressure fuel pumps and nevertheless is superior with regard to thermal and mechanical bearing capacity, to the high-pressure fuel pumps known from the prior art. Moreover, the high-pressure fuel pump of the invention should be simple in construction and capable of being produced economically.
In a high-pressure fuel pump for a fuel injection system of an internal combustion engine, having a pump housing, having a drive shaft with the drive shaft supported in the pump housing by a first bearing and a second bearing, having at least one pump element disposed radially relative to the drive shaft, having a fuel feed line, where a prefeed pump pumps fuel into the fuel feed line, having a fuel return line, having a metering unit for regulating the pump capacity of the pump element or elements, and having a pressure regulating valve, this object is attained in that the pressure regulating valve is disposed in the fuel return line.
SUMMARY AND ADVANTAGES OF THE INVENTION
Because according to the invention the pressure regulating valve is disposed in the fuel return line, it is attained among other advantages that the majority of the fuel pumped by the prefeed pump flows through the pump housing and as a result contributes to improved cooling of the pump housing and of the drive shaft. Moreover, the pressure in the pump housing is elevated compared to conventional constructions, which reduces the tendency to cavitation in the interior of the pump housing. Finally, the formation of vapor bubbles and local overheating (so-called hot spots) is effectively prevented.
In the high-pressure fuel pump of the invention, a lubricating throttle restriction between the prefeed pump and the pump housing can be dispensed with, so that despite the advantages cited, the high-pressure fuel pump of the invention is constructed even more simply than conventional high-pressure fuel pumps.
In an advantageous embodiment of the invention, it is provided that the first bearing is lubricated by fuel under pressure; and that the first bearing is in hydraulic communication with both the fuel feed line and the fuel return line. This means that on one side of the first bearing, approximately the same pressure prevails as on the compression side of the prefeed pump, while the other side of the first bearing is in pressure equilibrium with the virtually pressureless fuel return line. As a result, the first bearing necessarily experiences a flow through it of fuel, and thus adequate lubrication and cooling of the first bearing is assured at all operating points.
In a further advantageous feature of the invention, a first flow limiting device is provided, which is connected in series with the first bearing.
The first flow limiting device serves to keep the fuel flow, which flows through the first bearing, within predetermined limits. In mass production of high-pressure fuel pumps, it can happen, because of production variations and wear at the first bearing, that the thickness of the lubrication gap and hence the fuel flow through the bearing and its bearing capacity will vary within very wide limits. This means that if the tolerance situation is unfavorable, the bearing capacity of the first bearing and its cooling and lubrication by the fuel are not adequate at all operating points. If the first flow limiting device according to the invention is now connected in series with the first bearing, it is possible because of the very narrow production tolerance with which the first flow limiting device can be produced to adjust the fuel flow by means of the first bearing. As a result, the aforementioned production variations have only a slight effect on the bearing capacity, so that even given an unfavorable tolerance situation, the bearing capacity of the first bearing is assured at all operating points of the high-pressure fuel pump.
The flow limiting device limits the fuel flow that flows through the bearing. As a result, in unfavorable tolerance situations of the bearing, the demands made of the prefeed pump are reduced.
The object stated at the outset is attained, in a high-pressure fuel pump for a fuel injection system of an internal combustion engine, having a pump housing, having a drive shaft with the drive shaft supported in the pump housing by a first bearing and a second bearing, having at least one pump element disposed radially relative to the drive shaft, having a fuel feed line, where a prefeed pump pumps fuel into the fuel feed line, having a fuel return line, having a metering unit for regulating the pump capacity of the pump element or elements, and having a pressure regulating valve, in that the first bearing is lubricated by fuel under pressure; that the first bearing is in hydraulic communication with both the fuel feed line and the fuel return line; a first flow limiting device is provided; that the first flow limiting device is connected in series with the first bearing; and that between the pump housing and the fuel return line, a bypass throttle restriction is provided.
In this exemplary embodiment of a high-pressure fuel pump of the invention, it is possible by the suitable adaptation of the first flow limiting device and the bypass throttle restriction to assure in a simple and effective way that an adequate quantity of fuel will flow through the first bearing, thus assuring the cooling and lubrication of this bearing at all operating points.
In the high-pressure fuel pumps of the invention, the metering unit can alternatively be disposed either between the prefeed pump and the high-pressure fuel pump in the fuel feed line, or between the pressure regulating valve and the high-pressure fuel pump in the fuel return line. Both arrangements have specific advantages, which should be weighed against one another in an individual case.
A factor in favor of disposing the metering unit between the prefeed pump and the high-pressure fuel pump in the fuel feed line is that with this arrangement, the fuel flowing into the high-pressure region of the high-pressure fuel pump will not have first flowed through the pump housing, so that any chips or other particles may be present there cannot get into the high-pressure fuel region.
An advantage of disposing the metering unit in the fuel return line is that the entire fuel quantity pumped by the prefeed pump is available at every operating point for cooling and lubricating the pump housing or the drive shaft of the high-pressure fuel pump as well as the associated bearings. As a result, the bearing capacity of the low-pressure region of the high-pressure fuel pump of the invention is increased still further.
Alternatively, it is possible to dispose the first flow limiting device either upstream or downstream of the first bearing. Which disposition will be preferred in an individual case depends on the circumstances and peripheral conditions of the individual case.
In a further augmentation of the high-pressure fuel pumps of the invention, it may furthermore be provided that the second bearing is lubricated by fuel under pressure, and that the second bearing is in hydraulic communication with both the fuel feed line and the fuel return line.
Moreover, a second flow limiting device may be provided, which is disposed upstream or downstream of the second bearing. The advantages of the forced lubrication of the second bearing and of the second flow limiting device correspond essentially to the advantages mentioned above, in conjunction with the first bearing and the first flow limiting device.
The first flow limiting device and/or the second flow limiting device may be embodied as a throttle restriction, diaphragm, or flow regulating valve. Which of these alternatives will be preferred in the individual case depends on the ranges of tolerance of the various components, the loads, and of course commercial reasons and must be decided in the individual case.
An especially advantageous feature of the invention provides that the second bearing is supplied with fuel under pressure by a leak fuel line of the prefeed pump. This is especially advantageous whenever the prefeed pump is embodied for instance as a vane cell pump, external gear-wheel pump, or internal gear-wheel pump. In vane cell pumps or gear pumps, leakage that must be carried away through a leak fuel line occurs at the interface with the drive shaft, in the gap between the vane wheel or gear wheel and the housing. If this leak fuel line is now used for lubricating and cooling the second bearing, then firstly the lubrication and cooling of the second bearing can be assured under all operating conditions, and secondly, because of the counterpressure, the leak fuel quantity from the prefeed pump is reduced. This leads to improved hydraulic efficiency of the prefeed pump.
It is especially advantageous if the first bearing and/or the second bearing is embodied as a slide bearing. Then, by the provision according to the invention of fuel under pressure to the bearing, a stable hydrostatic film of lubrication is formed, which assures a very high bearing capacity of the bearings in the most various rpm ranges.
Advantageously, the fuel connection discharges into an interior of the pump housing.
BRIEF DESCRIPTION OF THE DRAWINGS
Further advantages and advantageous features of the invention can be learned from the description contained herein below, taken in conjunction with the drawings, in which:
FIG. 1 shows a first exemplary embodiment of a high-pressure fuel pump 1 of the invention in a block circuit diagram and
FIGS. 2 through 7 are views similar to FIG. 1 showing alternative embodiments of the Invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The high-pressure fuel pump 1 is part of a fuel injection system that essentially comprises a tank 3 , a prefeed pump 5 , a filter 7 , a rail 9 , and a pressure limiting valve 11 . The injectors, which are connected to the rail 9 , are not shown in the drawings. The pressure limiting valve 11 discharges into a return line 13 , into which the leak fuel quantities from the injectors are also carried away. The return line 13 , in this first exemplary embodiment, discharges into the tank 3 , where it drives a jet pump (not identifiedby reference numeral).
In the interior of the high-pressure fuel pump 1 , there is a temperature sensor T. The high-pressure fuel pump 1 communicates hydraulically with the tank 3 via a fuel feed line 15 , the filter 7 , and the prefeed pump 5 .
Inside the high-pressure fuel pump 1 , a first branch line 17 , in which a metering unit 19 is disposed, branches off from the fuel feed line 15 . The metering unit 19 serves to control the quantity of fuel aspirated by pump elements 21 of the high-pressure fuel pump, and thus also to control the pump capacity thereof. To that end, the intake sides of the pump elements 21 communicate hydraulically with the outlet of the metering unit 19 via a distribution line 23 .
The pump elements 21 essentially comprise suction valves 25 , check valves 27 on the high-pressure side, and a piston 29 that oscillates in a cylinder bore (not identified by reference numeral). The pistons 29 of the pump elements 21 are driven via roller tappets 31 by cams 33 of a drive shaft 35 . The pump elements 21 pump fuel, which is at high pressure, into the rail 9 via a high-pressure line 37 .
The cams 33 are part of a drive shaft 35 that is supported rotatably on both sides of the cams 33 in a first bearing and in a second bearing in a pump housing (not shown). The drive shaft 35 is disposed in the interior 38 of the pump housing. The bearings of the drive shaft 35 are shown as throttle restrictions in the block circuit diagram in FIG. 1 . In FIG. 1 , the first bearing is identified by reference numeral 39 , while the second bearing has been provided with reference numeral 41 .
A fuel return line 43 acts as a hydraulic communication between the interior 38 of the pump housing and the return line 13 . A pressure regulating valve 45 is disposed in the fuel return line 43 . Various throttle restrictions (not shown) may be integrated with the pressure regulating valve 45 .
In the exemplary embodiment, shown in FIG. 1 , of a high-pressure fuel pump according to the invention, the pressure regulating valve 45 is disposed downstream of the interior 38 of the high-pressure fuel pump 1 . This means that in the interior 38 , virtually the same pressure as on the compression side of the prefeed pump 5 prevails. As a rule, the pressure on the compression side of the prefeed pump 5 and thus in the interior 38 amounts to approximately 3 bar to approximately 6 bar.
This pressure prevailing in the interior 38 leads to a lessening of the tendency to cavitation, and thus to suppression of vapor bubbles, especially at high rotary speeds. Moreover, the elevated internal pressure in the interior 38 of the pump housing causes fuel to be forced through the first bearing 39 and the second bearing 41 . As a result, depending on the pressure prevailing in the interior 38 , the viscosity of the fuel, and the flow resistance of the first bearing 39 and the second bearing 41 , a defined quantity of fuel is forced through the bearings 39 and 41 . This leads to a marked increase in the bearing capacity of both the first bearing 39 and the second bearing 41 .
Since the first bearing 39 and the second bearing 41 are as a rule embodied as slide bearings, the forced flow through the bearings 39 and 41 leads to the development of a hydrostatic lubrication wedge in the bearings 39 and/or 41 . As a result, the bearing capacity of the first bearing 39 and second bearing 41 increases considerably, and at the same time the heat dissipation from the first bearing 39 and the second bearing 41 is improved.
To reduce the variation in the fuel quantity that flows through the first bearing 39 , and thus also to reduce the variation in the bearing capacity of the first bearing, a first optional flow limiting device 47 is disposed in series with the first bearing 39 . This first flow limiting device may, as indicated in FIG. 1 , be embodied as a throttle restriction. Alternatively, it may be embodied as a diaphragm or as a flow regulating valve.
In experiments, it has been found that because of the production tolerances, for instance in the diameter of the bearing journal (not shown) of the drive shaft 35 for the first bearing 39 and the associated bearing plate (not shown) in the pump housing, given an unfavorable tolerance situation, the quantity of fuel that flows through the first bearing 39 can vary considerably within one series of high-pressure fuel pumps 1 . This unwanted effect is reduced, if necessary, to a non-critical amount by the first flow limiting device 47 according to the invention.
Because of the serial connection of the first bearing 39 and the first flow limiting device, it can be assured that the quantity of fuel that flows through the first bearing 39 can be kept within a relatively narrow range. This can be ascribed above all to the fact that the flow resistance of the first flow limiting device 47 can be adjusted with very high precision. By a suitable adaptation of the flow resistance of the first flow limiting device 47 and the pressure prevailing in the interior 38 , it is possible in the high-pressure fuel pump 1 of the invention to keep the fuel quantity flowing through the first bearing 39 within a predetermined range under all tolerance conditions that occur in mass production.
If needed, a suitable second flow limiting device (not shown) may also be provided for the second bearing 41 .
In FIG. 1 , a filter is provided in the fuel feed line 15 ; this filter also takes on the function of a damping device 49 . Thus any pressure fluctuations in the low-pressure region can be damped. Alternatively, the damping device 49 may be embodied with a gas cushion, or may be omitted.
The high-pressure fuel pump 1 of the invention has the following advantages, among others:
Because of the disposition of the pressure regulating valve 45 in the fuel return line 43 , the pressure level prevailing in the interior 38 of the pump housing is increased, which reduces the danger of cavitation and the danger of vapor bubble formation.
Moreover, both the first bearing 39 and the second bearing 41 as a result necessarily experience a flow through them of fuel, which markedly increases their bearing capacity with regard to both mechanical and thermal stresses.
Any fluctuations in the flow quantity that may occur between various examples of mass-produced high-pressure fuel pumps 1 according to the invention can be reduced by means of a series-connected first flow limiting device 47 and/or a second flow limiting device.
The quantity of fuel flowing through the pump housing and the bearings 39 and 41 for lubricating and cooling purposes is increased sharply.
A lubricating throttle restriction for adjusting a defined quantity of lubricant can be omitted. Because of the high lubrication quantities, any particles that may be present are rapidly floated out of the interior.
The pumping capacity of the prefeed pump can often be reduced, which improves the efficiency of the injection system.
In FIGS. 2 through 7 further exemplary embodiments of high-pressure fuel pumps according to the invention and fuel injection systems according to the invention are shown, also in the form of block circuit diagrams. Only the essential differences will now be explained. Identical components are provided with the same reference numerals, and what has been said for the exemplary embodiment above applies accordingly. In FIGS. 2 through 7 , for the sake of simplicity, not all the components are provided with the reference numerals of FIG. 1 , and with respect to these components, reference is made to what is said in conjunction with the first exemplary embodiment.
The essential distinction between the first exemplary embodiment of FIG. 1 and the second exemplary embodiment of FIG. 2 is that the first branch line 17 in the second exemplary embodiment branches off from the fuel return line 43 . This means that the entire amount of fuel pumped by the prefeed pump 5 through the fuel feed line 15 reaches the interior 38 of the high-pressure fuel pump first and branches off only after that. As a result, an even better flow through the high-pressure fuel pump 1 and even better pump cooling are attained.
To damp any pressure fluctuations that occur in the low-pressure region, a damping device 49 is provided in the fuel return line 43 . The damping device 49 is disposed upstream of the pressure regulating valve 45 and the metering unit 19 . In FIG. 2 , the damping device 49 is embodied as a filter with an increased flow resistance if needed (not shown). Alternatively, the damping device 49 may be embodied as a damper with a gas cushion.
The third exemplary embodiment in FIG. 3 corresponds in wide areas to the second exemplary embodiment of FIG. 2 . An essential distinction is that, unlike in the preceding exemplary embodiments, the prefeed pump 5 is driven not by an electric motor (not shown) but rather directly by the engine. The details of this drive mechanism are not shown in FIG. 3 .
Upstream of the prefeed pump 5 , namely between the filter 7 and the prefeed pump 5 , a suction throttle restriction 51 is provided, which limits the pump capacity of the prefeed pump 5 , above all at high rotary speeds.
The prefeed pump 5 may be embodied as a vane cell pump, external gear-wheel pump or internal gear-wheel pump, and in particular as a Gerotor pump. In these pumps, there is a gap that causes leakage losses between the rotating components and the pump housing. This gap is represented in FIG. 3 by the symbol for a throttle restriction (see reference numeral 53 ).
The leak fuel quantity flowing out through the gap is carried away through a leak fuel line 55 .
In the third exemplary embodiment, a diversion line 56 is provided, which begins at the pressure regulating valve 45 and discharges into the fuel feed line 15 upstream of the suction throttle restriction 51 . Via the diversion line 56 , the excess fuel quantity from the pressure regulation is carried away into the feed line 15 .
The first bearing 39 is supplied with fuel from the interior 38 . From the leak fuel line 55 , a second branch line 57 branches off, which discharges into the fuel return line 43 . Through the second branch line 57 , the quantity of lubricant in the first bearing 39 is also carried away. A bypass throttle restriction 59 may be provided in the second branch line 57 .
In FIG. 4 , fourth exemplary embodiment of a high-pressure fuel pump 1 of the invention is shown that has many parallels with the third exemplary embodiment of FIG. 3 . In this exemplary embodiment as well, a leak fuel line 55 is located at the prefeed pump 5 .
In this exemplary embodiment as well, the first bearing 39 is supplied with fuel from the interior 38 . From the leak fuel line 55 , a second branch line 57 branches off, which discharges into the fuel return line 43 . Through the second branch line 57 , the quantity of lubricant in the first bearing 39 is also carried away. A bypass throttle restriction 59 may be provided in the second branch line 57 . In this exemplary embodiment, the metering unit 19 is disposed in the fuel feed line 15 , as is also the case in the first exemplary embodiment of FIG. 1 .
In the exemplary embodiment of FIG. 4 , the fuel return line 43 is returned not to the tank 3 , as in the exemplary embodiments of Figs. 1 and 2 , but rather into the fuel return line 15 as in the third exemplary embodiment, specifically upstream of the suction throttle restriction 51 .
The essential distinction of the fifth exemplary embodiment of FIG. 5 compared with the fourth exemplary embodiment of FIG. 4 is that in the fifth exemplary embodiment, the metering unit 19 and the optional damping device 49 are disposed in the fuel return line 43 . The pressure relief for the motion of the piston of the pressure regulating valve 45 can be selectively connected into the fuel feed line 15 or the fuel return line 43 .
In addition, the pressure regulating valve 45 has a separate diversion line 56 , which, similarly to the third exemplary embodiment, discharges into the fuel feed line 15 upstream of the suction throttle restriction 51 .
In this exemplary embodiment, the fuel return line 43 is returned to the tank 3 via the return line 13 . In a third branch line 63 , which connects the interior 38 of the high-pressure fuel pump 1 to the fuel return line 43 , there is a second bypass throttle restriction 61 . In series with the second bypass throttle restriction 61 , a pressure limiting valve 65 is also provided in the third branch line 63 . The pressure limiting valve 65 assures that if a predetermined pressure difference between the pressure in the interior 38 of the high-pressure fuel pump 1 and the fuel return line 43 is exceeded, the third branch line 63 is opened, and thus the excess fuel can flow out of the interior 38 .
In the sixth exemplary embodiment of FIG. 6 , the leak fuel line 55 discharges into the interior 38 of the pump housing. The first bearing 39 is supplied with fuel under pressure from the interior 38 of the pump housing, and this fuel then flows through the first flow limiting device 47 and then reaches the fuel return line 43 . In this exemplary embodiment as well, the fuel metering unit 19 is disposed on the side toward the fuel return line 43 , with the advantages already mentioned several times; however, it may also be disposed on the side of the fuel feed line 15 .
In the exemplary embodiment of FIG. 7 , the prefeed pump 5 is embodied as a fuel pump which is driven by an electric motor and is disposed in the vicinity of the tank 3 . The metering unit 19 is disposed on the fuel feed line side 15 of the high-pressure fuel pump 1 . The pressure regulating valve 45 is connected on the inlet side to the fuel feed line 15 . The outlet side of the pressure regulating valve 45 discharges into the fuel return line 43 . Also discharging into the fuel return line 43 is the third branch line 63 , in which there is not only a second bypass throttle restriction but also a damping device 49 , such as filter. Also in the fuel return line 43 , the fuel that flows through the first bearing 39 and the first flow limiting device 47 is carried away. The same applies to the second bearing 41 , which in the exemplary embodiment of FIG. 7 is provided with a second flow limiting device 67 , whose mode of operation corresponds to that of the first flow limiting device 47 .
The foregoing relates to a preferred exemplary embodiment 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. | The invention relates to a high-pressure fuel pump comprising a drive shaft supported by bearings, and fuel flows through the bearings in a forced manner in such a way that the mechanical and thermal load-carrying capacity of the bearings, and thus the entire high-pressure fuel pump, is significantly increased. | 5 |
This is a division, of application Ser. No. 09,184,521, filed Nov. 2, 1998, now the U.S. Pat. No. 6,161,622, such prior application being incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
The present invention relates generally to operations performed in subterranean wells and, in an embodiment described herein, more particularly provides a remotely actuatable plug apparatus.
It is common practice for plugs in subterranean wells to be serviced via intervention into the wells. For example, a plugging device may be latched in an internal profile of a tubular string using a slickline, wireline, coiled tubing, etc. The plugging device may then be retrieved also using a slickline, wireline, coiled tubing, etc.
However, it would be more convenient, and at times less expensive, to be able to remotely actuate a plugging device. For example, instead of mobilizing a slickline, wireline or coiled tubing rig, ceasing production if necessary, and entering the tubing string with equipment for retrieving a plugging device, it would be far more convenient and economical to merely apply fluid pressure to open a plug apparatus and thereby permit fluid flow through a portion of the tubing string. It would, therefore, be desirable to provide a plug apparatus which is remotely actuated.
SUMMARY OF THE INVENTION
In carrying out the principles of the present invention, in accordance with an embodiment thereof, a remotely actuated plug apparatus is provided which permits actuation of the apparatus by application of fluid pressure thereto. Methods of using a remotely actuated plug apparatus are also provided.
In broad terms, a plug apparatus is provided which includes an expendable plug member. The plug member initially blocks fluid flow through one of two flow passages of the plug apparatus. The plug member may be expended by applying a predetermined fluid pressure to one of the two flow passages.
In one aspect of the present invention, a flow passage is isolated from fluid communication with a portion of the plug member by a fluid barrier or a flow blocking member. Application of the predetermined fluid pressure to the flow passage, or another flow passage, ruptures the fluid barrier or displaces the flow blocking member, thereby permitting fluid communication between one or both of the flow passages and the plug member portion. In various representative embodiments of the invention, the flow passages may or may not be placed in fluid communication with each other, and either of the flow passages may by placed in fluid communication with the plug member portion.
In another aspect of the present invention, fluid may be delivered to the plug member portion by a fluid source located within the well, or at the earth's surface. The fluid source may be interconnected to the plug apparatus by a line extending externally to the tubing string in which the plug apparatus is connected. The line may also extend through a well tool interconnected in the tubing string between the fluid source and the plug apparatus.
These and other features, advantages, benefits and objects of the present invention will become apparent to one of ordinary skill in the art upon careful consideration of the detailed description of representative embodiments of the invention hereinbelow and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A&1B are cross-sectional views of successive axial portions of a first plug apparatus embodying principles of the present invention;
FIGS. 2A&2B are cross-sectional views of successive axial portions of a second plug apparatus embodying principles of the present invention;
FIGS. 3A&3B are cross-sectional views of successive axial portions of a third plug apparatus embodying principles of the present invention;
FIG. 4 is a schematicized view of a first method of using a remote actuated plug apparatus, the method embodying principles of the present invention; and
FIG. 5 is a schematicized view of a second method of using a remote actuated plug apparatus, the method embodying principles of the present invention.
DETAILED DESCRIPTION
Representatively illustrated in FIGS. 1A&1B is a plug apparatus 10 which embodies principles of the present invention. In the following description of the plug apparatus 10 and other apparatus and methods described herein, directional terms, such as “above”, “below”, “upper”, “lower”, etc., are used for convenience in referring to the accompanying drawings. Additionally, it is to be understood that the various embodiments of the present invention described herein may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., without departing from the principles of the present invention.
The plug apparatus 10 is similar in some respects to plug apparatus described in U.S. Pat. Nos. 5,479,986 and 5,765,641, the disclosures of which are incorporated herein by this reference. Specifically, the plug apparatus 10 includes a generally tubular housing assembly 12 configured for interconnection in a tubing string, a flow passage 14 extending generally axially through the housing assembly, and a plug member 16 which blocks fluid flow through the flow passage, but which is expendable upon contact between a fluid and a portion 18 of the plug member. As used herein, the term “expend” means to dispense with or to make no longer functional. For example, the plug member portion 18 , or a portion thereof, may be dissolvable in the fluid, may otherwise react with the fluid, etc., so that the plug member portion is no longer able to block fluid flow through the flow passage 14 . In the embodiment representatively illustrated in FIGS. 1A&1B, the plug member portion 18 is a compressed mixture of salt and sand which is isolated from contact with fluid in the flow passage 14 by elastomeric end closures 20 , but it is to be clearly understood that the plug member portion may be made of any other material and may be otherwise configured without departing from the principles of the present invention.
A fluid passage 22 is formed in the housing assembly 12 for providing fluid communication between a port 24 positioned externally on the housing assembly and the plug member portion 18 . When fluid is delivered through the fluid passage 22 to the plug member portion 18 , in a manner described more fully below, the plug member portion becomes weakened, so that the plug member 16 is no longer able to block fluid flow through the flow passage 14 . A conventional rupture disk 26 or other fluid barrier may be installed between the port 24 and the fluid passage 22 , so that a predetermined fluid pressure must be applied to the port 24 to rupture the rupture disk and permit fluid communication between the port and the plug member portion 18 through the fluid passage 22 .
Note that the port 24 is formed in a conventional tubing connector 28 which also retains the rupture disk 26 and is threadedly installed externally in the housing assembly 12 . It is to be clearly understood that the connector 28 is not necessary in a plug apparatus constructed in accordance with the principles of the present invention, for example, the port 24 could be formed directly on the housing assembly 12 and the rupture disk 26 could be eliminated or otherwise retained relative to the housing assembly.
The connector 28 is configured for connection of an external flow passage or line thereto for application of a predetermined fluid pressure to the rupture disk 26 to rupture it and deliver fluid to the plug member portion 18 , as described more fully below. However, the flow passage or line could also extend internally within the housing assembly 12 , or be placed in fluid communication with the fluid passage 22 via an appropriately designed connection between the plug apparatus 10 and an external fluid source. Thus, it may be readily appreciated that it is not necessary for the fluid passage 22 to be in fluid communication with a line or flow passage external to the housing assembly 12 .
When the plug member 16 is expended, permitting fluid flow through the flow passage 14 , note that the flow passage 14 will be placed in fluid communication with the fluid passage 22 . This may be desirable in some instances, such as when it is desired to inject fluid into the flow passage 14 via the fluid passage 22 after the plug member 16 has been expended. A check valve (not shown) could be installed to prevent fluid flow from the flow passage 14 into the line or other flow passage connected to the port 24 . However, it is not necessary for the flow passage 14 and fluid passage 22 to be placed in fluid communication after the plug member 16 is expended, in keeping with the principles of the present invention. Representatively illustrated in FIGS. 2A&2B is another plug apparatus 30 embodying principles of the present invention. Elements of the plug apparatus 30 which are similar to elements previously described are indicated in FIGS. 2A&2B using the same reference numbers, with an added suffix “a”.
In the plug apparatus 30 , the port 24 a is formed directly externally in the outer housing assembly 12 a , and no rupture disk 26 is utilized to block fluid communication between the port 24 a and the fluid passage 22 a . However, a tubing connector 28 could be installed in the outer housing assembly 12 a , and a rupture disk 26 or other fluid barrier could be utilized, without departing from the principles of the present invention.
Instead of the rupture disk 26 , the plug apparatus 30 utilizes a sleeve 32 sealingly and reciprocably disposed within the housing assembly 12 a to isolate the fluid passage 22 a from fluid delivery thereto. As viewed in FIG. 2A, the sleeve 32 is in an upwardly disposed position relative to the housing assembly 12 a , in which the sleeve prevents fluid flow between the fluid passage 22 a and the port 24 a , and between the fluid passage 22 a and the flow passage 14 a . The sleeve 32 is releasably secured in this position by shear pins 34 .
When a predetermined fluid pressure is applied to the port 24 a , the shear pins 34 will shear, and the fluid pressure will downwardly displace the sleeve 32 relative to the housing assembly 12 a . Such downward displacement of the sleeve 32 places openings 36 formed through the sleeve in fluid communication with openings 38 formed in the housing assembly 12 a , thereby permitting fluid communication between the flow passage 14 a and the fluid passage 22 a . Fluid in the flow passage 14 a may then flow through the openings 36 , 38 and through the fluid passage 22 a to the plug member portion 18 a.
Note that, in the plug apparatus 30 , the fluid passage 22 a is placed in fluid communication with the flow passage 14 a when fluid is delivered to the plug member portion 18 a . Additionally, the port 24 a is not placed in fluid communication with the fluid passage 22 a . Thus, although the predetermined fluid pressure is applied to the port 24 a to expend the plug member 16 , it is the flow passage 14 a which is placed in fluid communication with the plug member portion 18 a . However, the port 24 a could be placed in fluid communication with the flow passage 14 a and/or fluid passage 22 a without departing from the principles of the present invention. For example, one or more seals providing sealing engagement between the sleeve 32 and the housing assembly 12 a could be disengaged from sealing engagement with the sleeve and/or the housing assembly when the sleeve 32 is displaced downwardly.
Referring additionally now to FIGS. 3A&3B, a plug apparatus 40 embodying principles of the present invention is representatively illustrated. Elements of the plug apparatus 40 which are similar to elements previously described are indicated in FIGS. 3A&3B using the same reference numbers, with an added suffix “b”.
The plug apparatus 40 is similar in many respects to the plug apparatus 30 described above, in that a predetermined fluid pressure may be applied to the port 24 b to shear the shear pins 34 b and thereby downwardly displace a sleeve 42 within the housing assembly 12 b , permitting fluid communication between the flow passage 14 b and the fluid passage 22 b . However, in the plug apparatus 40 , a predetermined fluid pressure may also be applied to the flow passage 14 b to shear the shear pins 34 b and downwardly displace the sleeve 42 .
Note that the sleeve 42 of the plug apparatus 40 , unlike the sleeve 32 of the plug apparatus 30 , presents an upwardly facing piston area 44 in fluid communication with the openings 38 b . Thus, when fluid pressure is applied to the flow passage 14 b , that fluid pressure also biases the sleeve 42 downward. The predetermined fluid pressure which may be applied to the flow passage 14 b to shear the shear pins 34 b may be the same as, or different from, the predetermined fluid pressure which may be applied to the port 24 b to shear the shear pins, depending upon the respective piston areas on the sleeve 42 .
When a predetermined fluid pressure is applied to the port 24 b or flow passage 14 b , the shear pins 34 b will shear, and the fluid pressure will downwardly displace the sleeve 42 relative to the housing assembly 12 b . Such downward displacement of the sleeve 42 places the openings formed through the sleeve in which the shear pins 34 b are installed in fluid communication with the openings 38 b , thereby permitting fluid communication between the flow passage 14 b and the fluid passage 22 b . Fluid in the flow passage 14 b may then flow through the openings 38 b and through the fluid passage 22 b to the plug member portion 18 b.
Note that, in the plug apparatus 40 , the fluid passage 22 b is placed in fluid communication with the flow passage 14 b after fluid is delivered to the plug member portion 18 b . Additionally, the port 24 b is not placed in fluid communication with the fluid passage 22 b . Thus, although a predetermined fluid pressure is applied to the port 24 b or the flow passage 14 b to expend the plug member 16 b , it is the flow passage 14 b which is placed in fluid communication with the plug member portion 18 b . However, the port 24 b could be placed in fluid communication with the flow passage 14 b and/or fluid passage 22 b without departing from the principles of the present invention. For example, one or more seals providing sealing engagement between the sleeve 42 and the housing assembly 12 b could be disengaged from sealing engagement with the sleeve and/or the housing assembly when the sleeve 42 is displaced downwardly.
Referring additionally now to FIG. 4, a method 50 of utilizing a remote actuated plug apparatus is representatively illustrated. In the method 50 , a remote actuated plug apparatus 52 is interconnected as a part of a tubular string 54 installed in a subterranean well. The plug apparatus 52 may be similar to one of the above-described plug apparatus 10 , 30 , 40 , or it may be another type of remote actuated plug apparatus.
Another well tool 56 may be interconnected in the tubular string 54 . In the method 50 as depicted in FIG. 4, the well tool 56 is a hydraulically settable packer of the type well known to those skilled in the art. The packer 56 is positioned between the plug apparatus 52 and the earth's surface. It is to be clearly understood, however, that the well tool 56 may be a tool or item of equipment other than a packer, and it may be otherwise positioned in the well, without departing from the principles of the present invention.
A control line or other type of flow passage 58 is connected to a conventional fluid source, such as a pump (not shown), at the earth's surface. The term “fluid source” as used herein means a device or apparatus which forcibly transmits fluid, such as a pump, a pressurized accumulator or another fluid pressurizing device. The line 58 extends downwardly from the earth's surface, extends through the packer 56 , and connects externally to the plug apparatus 52 , such as at the ports 24 , 24 a , 24 b described above. Of course, the line 58 or other type of flow passage could be internally disposed relative to the tubular string 54 , could be formed in a sidewall of the tubular string, etc., without departing from the principles of the present invention. For example, in the packer 56 , the flow passage 58 could be formed in a sidewall of a mandrel of the packer.
With the plug apparatus 52 initially preventing fluid flow through the tubular string 54 , fluid pressure may be applied to the tubular string to set the packer 56 in the well, and then fluid pressure may be applied to the line 58 to open the plug apparatus to fluid flow therethrough. If the plug apparatus 52 , like the plug apparatus 40 described above, is actuatable by application of fluid pressure to the tubular string 54 , the line 58 may not be necessary, and the plug apparatus may be set up so that the predetermined fluid pressure needed to open the plug apparatus is greater than the fluid pressure needed to set the packer 56 . Alternatively, the packer 56 could be settable by application of fluid pressure to the line 58 , and the plug apparatus 56 could be actuated by application of fluid pressure to the line greater than that needed to set the packer. As another alternative, the packer 56 could be settable by fluid pressure in the line 58 , and the plug apparatus 52 could be actuatable by fluid pressure in the tubular string 54 . Thus, it will be readily appreciated that the plug apparatus 52 permits increased versatility in wellsite operations, without requiring intervention into the well for its actuation.
Referring additionally now to FIG. 5, another method 60 embodying principles of the present invention is representatively illustrated. Elements shown in FIG. 5 which are similar to elements previously described are indicated in FIG. 5 using the same reference numbers, with an added suffix “c”.
Note that, in the method 60 , the line 58 c does not extend to a fluid source at the earth's surface. Instead, the line 58 c extends to a fluid source 62 installed in the well as a part of the tubular string 54 c . The fluid source 62 may be a pump, hydraulic accumulator or differential pressure-driven piston of the type well known to those skilled in the art. Additionally, the fluid source 62 may apply fluid pressure to the line 58 c in response to receipt of a signal transmitted thereto from the earth's surface or other remote location, such as another location within the well.
The fluid source 62 could include a pump or other fluid pressurizing device coupled with the tubular string 54 c for supplying the predetermined fluid pressure to actuate the plug apparatus 52 c . For example, a slickline, wireline, coiled tubing, or otherwise-conveyable fluid pressurizing device could be positioned in the tubular string 54 c and coupled therewith. An example of such a fluid pressurizing device is described in U.S. Pat. No. 5,492,173. Another fluid pressurizing device is the model DPU available from Halliburton Energy Services, Inc. of Dallas, Tex. The DPU or other fluid pressurizing device may be engaged with the tubular string 54 c , such as via an internal latching profile, to form the fluid source 62 and to place the DPU in fluid communication with the line 58 c . The DPU could then be actuated to provide pressurized fluid, which is then delivered to the plug apparatus 52 c via the line 58 c.
Of course, many modifications, additions, deletions, substitutions and other changes may be made to the various embodiments of the present invention described herein, which would be obvious to a person skilled in the art, and these changes are contemplated by the principles of the present invention. For example, in the method 60 , the fluid source 62 could be positioned between the packer 56 c and the plug apparatus 52 c , and could be attached directly to the plug apparatus. Accordingly, the foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims. | Apparatus and associated methods are provided for remotely actuating a plug apparatus in a subterranean well. In a described embodiment, a plug apparatus has a plug member blocking fluid flow through one of two flow passages of the plug apparatus. A predetermined fluid pressure applied to one of the flow passages permits the plug member to be expended from the plug apparatus. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a biocompatible bilayer porous matrix, more particularly to a porous matrix used for cell culture.
[0003] 2. Description of the Prior Art
[0004] Clinically, the burned patient with large-area burn shall be saved by the skin graft operation, or the rehabilitation after operation shall be conducted. Theoretically, it is hoped that the patient can use his own normal skin for autograft, in order to resume the function of wound skin, and avoid other side effects caused by the graft. However, during the therapy process, the major problem is the normal skin for autograft is very limited, and new wound will be generated for the patient, so it is necessary to use other auxiliary materials.
[0005] At present, there are three methods to substitute the autograft of skin, such as the allograft by using the skin of dead body, the xenograft by using the skin of animal, and the method by using the artificial synthetic dressing (namely artificial skin). But these methods can be used as temporary protection only, the epidermis of autograft has to be used for the replacement later. In addition, the skin of allograft or xenograft will usually be rejected by the autoimmune function of patient, and infected by the germ, or the inflammation of patient may be induced. So it can be used as the temporary wound dressing only, and it has to rely on the medicine to control the immune rejection. Clinically, the allograft or artificial skin is usually used to protect the wound from the bacterial infection or avoid the loss of body fluid during the convalescent time of patient. After the dermis layer of patient is recovered, the artificial skin can be removed, and the formal autograft can be conducted. These methods are standard therapy procedure to treat the burned patient with large-area burn, but it is very expensive, and the operation is labor intensive.
[0006] The research of tissue engineering provides a direction of solving the above-mentioned problems. At present, there are a lot of researches associated with large-scale in vitro keratinocyte culture. But most of these cell culture substances only have monolayer epidermal structure, which lack the support of the connective tissue, and do not possess the elasticity or mechanical property of skin. Other in vitro cell culture methods only increase the fibroblast, but because the characteristics of different skin cells are quite different, different environment is required for the growth of cultivated cell, so there is still no artificial skin substitute with satisfactory effect.
[0007] Upon inquiring the patent database of Taiwan Intellectual Property Office, the Taiwanese Patent No. I265035 “Type II Collagen/Glycosaminoglycan/Hyaluronic Acid Porous Carrier And Preparation Thereof” disclosed a porous carrier used in the tissue engineering. But the prepared porous carrier is used for the cartilage cell culture, which is only used for the transplant substitute of cartilage tissue, and type II collagen can not meet the skin demand of burned patient. The dermis of skin is composed of type I collagen, not composed of type II collagen.
[0008] In order to overcome the foresaid drawbacks in the prior arts, the present invention provides a biocompatible bilayer porous matrix.
SUMMARY OF THE INVENTION
[0009] Therefore, the present invention uses the tissue-engineering technique to develop a skin-like equivalent for promoting the repair and regeneration of the skin, in order to help the patient who requires the skin graft operation for large-area burn, or the wound is difficult to be closed, i.e. diabetes foot ulcers.
[0010] It is an aspect of the present invention to provide a biocompatible bilayer porous matrix, including a first porous matrix and a second porous matrix. The first porous matrix and the second porous matrix are composed of cross-linked gelatin, chondroitin 6 sulfate, and hyaluronic acid.
[0011] Preferably, the pore size of the first porous matrix is 10 to 50 μm, and the matrix thickness is 80 to 120 μm thereof, and the pore size of the second porous matrix is 50 to 180 μm, and the matrix thickness is 500 to 900 μm thereof.
[0012] More preferably, the pore size is 20 to 40 μm, and the matrix thickness is 90 to 110 μm for the first porous matrix.
[0013] More preferably, the pore size is 75 to 150 μm, and the matrix thickness is 600 to 800 μm for the second porous matrix.
[0014] It is another aspect of the present invention to provide a biocompatible bilayer porous matrix and preparation thereof, its steps include: first, (a) prepare an aqueous solution with gelatin, chondroitin 6 sulfate, and hyaluronic acid; (b) pour the aqueous solution into a mold, and freeze it quickly to form a first porous matrix; then, (c) apply the aqueous solution on the surface of the first porous matrix, and freeze it slowly to form a second porous matrix; and finally, (d) add a cross-linking agent to initiate the cross-linkage of the porous matrixes.
[0015] According to a preferred embodiment of the present invention, the preparation of the aqueous solution is to dissolve gelatin in water at room temperature, and then add chondroitin 6 sulfate and hyaluronic acid, respectively.
[0016] Preferably, the composition of the aqueous solution is 5 to 10 wt % of gelatin, 0.5 to 2.5 wt % of chondroitin 6 sulfate, and 0.3 to 0.5 wt % of hyaluronic acid.
[0017] According to another preferred embodiment of the present invention, the porous matrixes are fabricated through different freezing temperatures and time durations to form the pores with different size and density.
[0018] Preferably, the aqueous solution is frozen quickly to the temperature of −196° C. for 1 to 2 min to form the first porous matrix layer.
[0019] Preferably, the aqueous solution is frozen to the temperature of −80° C. for 180 min to form the second porous matrix layer.
[0020] According to another preferred embodiment of the present invention, the step (c) further includes step (c1): lyophilize the porous matrix at −70° C.
[0021] According to another preferred embodiment of the present invention, the cross-linking agent is carbodiimide.
[0022] Preferably, the cross-linking agent is 0.5 to 1 wt % of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC).
[0023] Preferably, the cross-linking agent is 0.25 wt % of N-hydroxysuccinimide solution, which is reacted at pH 5.75 and 4° C.
[0024] According to another preferred embodiment of the present invention, after the cross-linking reaction, the porous matrix is rinsed by disodium phosphate solution to remove residual carbodiimide.
[0025] Preferably, after rinsing, the porous matrix is frozen at −80° C. followed by lyophilizing at −70° C.
[0026] It is another aspect of the present invention to provide a method of animal cell culture using the bilayer porous matrix according to the present invention, wherein the first porous matrix and the second porous matrix are used to cultivate different cells, respectively.
[0027] According to a preferred embodiment of the present invention, the first porous matrix is used to cultivate epidermal keratinocytes, and the second porous matrix is used to cultivate dermal fibroblasts.
[0028] Preferably, the animal cell is human cell.
[0029] The term “matrix” described in the present invention is also called a “substrate” or “scaffold”, which is used for cell growth and adhesion, and it mainly imitates the composition and content of extracellular matrix (ECM) of animals.
[0030] The term “gelatin” described in the present invention means a collagen molecule or fragment without three-dimensional structures, which can be refined or synthesized from animal tissue. The molecular structure of gelatin still reserves the domain for cell contact, proliferation, or differentiation. In addition, the gelatin is a biocompatible, nontoxic material, which is used for wound therapy widely.
[0031] The term chondroitin 6 sulfate (C6S) described in the present invention means the molecule derived from hexuronic acid (vitamin C) and hexosamine. Upon adding chondroitin 6 sulfate into gelatin solution, it can increase the resistance of gelatin solution to collagenase, improve the stability of structure, and increase the elasticity and porosity. The addition of chondroitin 6 sulfate can also improve the construction of skin basal membrane.
[0032] The term hyaluronic acid (HA) described in the present invention is a transparent colloid substance found in the connective tissue and dermal layer commonly. It is a polysaccharide composed of Glucuronic acid and N-acetylglucosamine. The hyaluronic acid possesses many characteristics such as biological absorbability, biocompatibility, viscous property, water retaining property etc., which has already been used in biomedical application generally.
[0033] The present invention provides a bilayer porous matrix and preparation thereof, which is fabricated successfully using different freezing temperatures and followed by lyophilization. It can be used as a scaffold of artificial skin for cell culture. In the first porous matrix (upper layer, prepared at −196° C.), the pore is smaller and denser, the preferred pore size is 20 to 40 μm, and the porosity is 30 to 40%, which is suitable for the attachment and proliferation of epidermal keratinocytes. In the second porous matrix (lower layer, prepared at −80° C.), the pore is larger and sparse, the preferred pore size is 75 to 150 μm, and the porosity is 70 to 80%, which is suitable for the migration and growth of dermal fibroblasts. The interconnected pores between two layers can provide the interaction opportunities for released cytokines and growth factors by dermal fibroblasts and epidermal keratinocytes, to accelerate the growth and differentiation process of skin tissues.
[0034] The above aspects and advantages of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which:.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 is a flowchart schematically illustrating the preparation for bilayer porous matrix according to the present invention;
[0036] FIG. 2 is diagram schematically illustrating the structure for bilayer porous matrix according to the present invention; and
[0037] FIG. 3 is a diagram schematically illustrating the scanning electron microscopy image for bilayer porous matrix according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0038] The invention is described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this invention are presented herein for the purpose of illustration and description only; it is not intended to be exhaustive or to be limited to the precise form disclosed.
[0039] In order to provide a skin-like equivalent, it is necessary to develop a suitable matrix used for skin scaffolds. In order to simulate the composition of extracellular matrix, the present invention selects gelatin, chondroitin 6 sulfate, and hyaluronic acid as basal materials, and uses the lyophilization to fabricate the matrix membrane with bilayer porous structure at different freezing temperatures. The carbodiimide is used as the cross-linking agent to improve the mechanical property of bilayer porous matrix membrane.
[0040] According to the method of the present invention, after the bilayer porous matrix is prepared, it can be used to cultivate the skin cell. After it is cultivated for 3 to 4 weeks, the keratinocyte can be differentiated from the basal layer to the suprabasal layer and cornified squamous layer upwards. Meantime, the dermal fibroblasts start to secrete their own extracellular matrix to substitute the original bilayer porous matrix gradually and develop a derma-like structure.
EMBODIMENT 1: PREPARATION OF THE BILAYER POROUS MATRIX
[0041] Referring to step 101 shown in FIG. 1 , a solution of gelatin, chondroitin 6 sulfate, and hyaluronic acid is prepared first. At room temperature, 5 to 10 wt % of gelatin (Cat. No. G-2500, purchased from Sigma Chemical, USA) is dissolved in distilled water. The powder of chondroitin 6 sulfate (Cat. No. C-4384, purchased from Sigma Chemical, USA) and hyaluronic acid (Cat. No. H-5388, purchased from Sigma Chemical, USA) are added to the gelatin solution with the final concentration of 0.5 to 2.5 wt % of chondroitin 6 sulfate and 0.3 to 0.5 wt % of hyaluronic acid, respectively. The solution is then well mixed at 37° C. for an hour.
[0042] As step 102 shown in FIG. 1 , a first layer of the porous matrix is prepared. The 0.5 ml of gelatin, chondroitin 6 sulfate, and hyaluronic acid solution prepared above is poured into a circular stainless mold (1.5 cm in diameter). For the preparation of smaller pore size matrix, the solution/mold is put in liquid nitrogen and frozen quickly to the temperature of −196° C. for 1 to 2 min, to form the first layer of the porous matrix. As the first porous matrix 21 shown in FIG. 2 , it possesses a plurality of smaller first pore 201 .
[0043] As step 103 shown in FIG. 1 , a second layer of the porous matrix is prepared. To prepare the second layer of the porous matrix, another 0.5 ml of gelatin, chondroitin 6 sulfate, and hyaluronic acid solution prepared above is applied onto the surface of the first porous matrix 21 , and is then frozen at −80° C. for 3 h, to form the second layer of the porous matrix. As the second porous matrix 22 shown in FIG. 2 , it possesses a plurality of larger second pore 202 . The first porous matrix 21 and the second porous matrix are combined to the bilayer porous matrix 20 .
[0044] As step 104 shown in FIG. 1 , the bilayer porous matrix is prepared. The bilayer porous matrix 20 frozen at −80° C. is taken out and is then frozen at −70° C., preferably for several hours.
[0045] As step 105 shown in FIG. 1 , add a cross-linking agent to the prepared bilayer porous matrix 20 to react at 4° C. for several hours preferably. The cross-linking agent is the solution of 0.5 to 1 wt % 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC) with pH 5.75 and 0.25 wt % N-hydroxysuccinimide.
[0046] As step 106 shown in FIG. 1 , after the reaction is completed, the prepared bilayer porous matrix 20 is immersed in a disodium phosphate solution, sonicated 5 times in distilled water to remove residual carbodiimide.
[0047] Finally, as step 107 shown in FIG. 1 , the rinsed bilayer porous matrix 20 is frozen at −80° C. for 3 h followed by lyophilizing at −70° C. FIG. 3 is the scanning electron microscope image of the prepared bilayer porous matrix, the level and pore size change of porous matrix can be seen clearly.
EMBODIMENT 2: THE UTILIZATION OF BILAYER POROUS MATRIX FOR CELL CULTURE
[0048] The prepared bilayer porous matrix 20 is used as the scaffold for cell culture. The spinner flask is used to cultivate dermal fibroblasts (FB) to achieve the advantages of high cultivation efficiency and uniform cell distribution. In the second porous matrix 22 (lower layer, prepared at −80° C.) of the bilayer porous matrix 20 , the pore is larger (75 to 150 μm) and sparse (70 to 80% in porosity), which is suitable for the migration and growth of dermal fibroblasts.
[0049] The epidermal keratinocyte (K) is cultivated on the dermal equivalent with cultivated dermal fibroblast. In the first porous matrix 21 (upper layer, prepared at −196° C.), the pore is smaller (20 to 40 μm) and denser (30 to 40% in porosity), which is suitable for the attachment and proliferation of epidermal keratinocytes. The interconnected pores between two layers can provide the interaction opportunities for released cytokines and growth factors by dermal fibroblasts and epidermal keratinocytes, to speed the quick growth and differentiation of skin tissue.
[0050] Then, immerse the skin equivalent under the culture medium for some time, and move it to air-liquid interface to mature and differentiate skin tissues. After cultivated for 3 to 4 weeks, the keratinocytes can be differentiated from the basal layer to the suprabasal layer and cornified squamous layer upwards. Meantime, the dermal fibroblasts start to secrete their own extracellular matrix to substitute the original bilayer porous matrix gradually and develop a derma-like structure.
[0051] The present invention uses different freezing rates and lyophilization to prepare the matrix with bilayer porous structures, which can be used as the scaffold of artificial skin. The scaffold has good physical-chemical property and biocompatibility. After in vitro culture, the scaffold will be degraded gradually and substituted by new extracellular matrix secreted from the cell. After several weeks, new skin-like tissue structure including epidermal layer and dermal layer can be grown preliminarily. After the animal experiment, it is found that it not only can promote the repair and regeneration of wound, but also can provide suitable mechanical strength to newly grown skin tissue. It will have great potential on clinical application in the future. It can help the patient who requires the skin graft operation for large-area burn, or the wound is difficult to be closed, i.e. diabetes foot ulcers.
[0052] While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures. | The present invention provides a biocompatible bilayer porous matrix and preparation thereof. The bilayer porous matrix is composed of gelatin, chondroitin 6 sulfate, and hyaluronic acid, also, prepared through freeze-drying technique at different temperature and time duration to form varied pore sizes on each layer. The present invention also provides a method of cell culture using the bilayer porous matrix. | 2 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a closing device consisting of a plastic material for applying to a closed container consisting of a plastic film material, wherein said closing device comprises a lower part with a cylindrical outlet and a flange for attaching same to the container and a screw cap which is screwably fixed to the lower part. Said closing device further comprises a cylindrical perforator having external thread, which is open to both sides in the axial direction and travels in the outlet of the lower part, in the internal thread thereof, wherein means are located in the screw cap, which move the perforator downwards in a helical manner during the initial unscrewing movement of said screw cap and wherein said cylindrical perforator has cutting teeth on the cylindrical wall thereof at the end which is directed towards the container wall.
[0002] Closing devices of the type previously mentioned have to date only been applied to containers produced from laminated film material. These laminated films comprise at least three layers of different types of material. First of all, such a film consists of a cardboard layer, which provides the container with the necessary rigidity, an aluminum layer serving as an aroma barrier and a plastic layer which ensures the required denseness. In order to separate these three layers, the corresponding perforator of the aforementioned closing device must fulfill various functions. A plurality of saw teeth are often recommended for separating the cardboard layer, wherein a raised tooth cuts through the aluminum layer with a forward cutting edge and wherein a perforating tooth breaks through the plastic layer before the aforementioned cutting edge can continue to cut the plastic film. In the case of these containers consisting of laminated film material, the separation of the cardboard material generally represents a problem. Particularly if the partial press cut, which serves as a support and at least separates the cardboard layer to some extent, does not exactly correspond to the cutting line of the perforator, the teeth are then either too weak or in the case of a considerable number of teeth, the cardboard material comes between the teeth and said teeth can thereafter hardly produce a perforating effect.
SUMMARY OF THE INVENTION
[0003] The present invention relates, however, to a closing device, which is applied to a pure plastic film material. Such tubular receptacles, mostly referred to as pouches in the technical language, have not been opened to date by means of the aforementioned closing devices. On the contrary, an opening was already punched out and a closure including the outlet thereof was welded on the pouches so as to be correctly positioned or was shrink-wrapped between two film layers. Because the shelf-life of the filled food material or beverage is thereby solely dependent upon the impermeability of the closure, such closures were virtually used only in unproblematic areas, particularly in the area of cosmetics.
[0004] When using a closing device of the kind mentioned at the beginning of the application, the container pouch remains completely closed until the point of first being opened. An increased shelf-life is thereby provided. In addition, the plastic film in such applications according to the invention is substantially more robust and is designed having a greater wall thickness than the very thin plastic film layer in the case of a laminated film. This in turn gives rise to other demands being placed on the closing device. Initial trials with closing devices from prior art did not produce any reliable results.
[0005] Perforators as, for example, from the American patent publications U.S. Pat. No. 5,020,690 or U.S. Pat. No. 5,141,133 comprise a plurality of teeth. These teeth abutting one another basically form the shape of an annular saw blade. Such solutions have either led to a rondelle being completely cut out of the plastic film and falling into the container or as a result of the toughness of the film to individual teeth being broken off and falling into the container. Because the containers involved here typically relate to containers for beverages, this is totally unacceptable.
[0006] It has been assumed up until now that a plurality of teeth is advantageous because a plurality of perforations thereby arise. It has, however, actually been determined that a plurality of perforations do not provide an advantage per se. It has in fact been shown, that a plurality of teeth automatically leads to these teeth having to be relatively weak. This leads to the disadvantage previously mentioned above.
[0007] Based on this realization, further developments have accordingly been put into place, in which on the one hand the number of teeth was reduced and on the other hand the shape of the teeth was variably configured. A solution is therefore known, for example, from the European patent publication EP-A-1415926 having equally high teeth, which, however, are distributed over the periphery in a non-uniform manner. In addition, a closing device of the type mentioned at the beginning of the application is known from the American patent publication U.S. Pat. No. 6,279,779 having a perforator which comprises only a single tooth. This tooth is designed in a suitably strong manner and has different surfaces with a different effect. The one-tooth version has definitely not proven its worth. The procedures for severing the film as well as the perforation thereof, the subsequent cutting of the complete material and finally the folding away of the cut-out part have not been able to be optimized in a single element. The applicant therefore conducted trials with a perforator according to the WIPO patent publication WO2007/030965, wherein three teeth are present, which are distributed over the periphery and are minimally offset from a uniform distribution. Even though perforators of this type have proven their worth in many instances, cases frequently occur in which either the film is completely cut out and the corresponding rondelle fell into the receptacle or in other cases the films were cut only at three locations to an approximately equal width and the film remained hanging in an occluding manner over the opening. Based on these realizations, the applicant undertook elaborate trials to find an optimal solution, which reliably implements an opening incision in such a way that a flap-like rondelle, which stays in contact with the receptacle, remains hanging, said rondelle also being pushed out of the open area of the perforator by the teeth.
[0008] A closing device of the kind mentioned at the beginning of the application meets this aim, wherein said device is characterized by having exactly two equally high teeth which are arranged in an angular region of between 70° and 120° of the circumference. This has the effect that the plastic film to be cut open is pre-tightened by the two teeth and that said teeth subsequently begin to perforate and cut the film. After a short distance, the subsequent tooth then extends into the cutting area of the previous tooth and is thereby rendered inoperative. If the perforation of the film occurs virtually immediately upon first contact, the film still cannot completely be annularly cut out and consequently a plastic film rondelle does not fall into the container. If the perforation and the following incision occur relatively late, a sufficiently long incision is still produced, which ensures that the section of the subsequent tooth runs into the area of the section of the previous tooth and as a result a section is still achieved, which extends more than 180°; thus enabling the film to be cut open sufficiently wide to achieve a sufficient flow rate.
[0009] As previously mentioned, the closing device according to the invention is applied to a container consisting of a pure plastic film material. This one or multiple layer plastic film is substantially thicker than the plastic film which is used as an impermeability layer in the composite film consisting of diverse materials.
[0010] Whereas in the case of the thin film, wherein the perforation must foremost be done to ensure a reliable opening on account of the high elasticity of said film, this appears to no longer play a central role in the case of the film now being used. Experiments observed at a strong magnification have shown that apparently the film is slit open while forming swarf.
[0011] In light of this evidence, it is therefore an additional aim of the present invention to equip the teeth with swarf control means as in the case of a steel processing cutting plate. In solutions from prior art, this swarf has actually accumulated on the tooth tip and the torque output applied by means of said prior art was thus substantially higher than is the case with the now present solution.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] A preferred exemplary embodiment of the subject matter of the invention is depicted in the drawings and subsequently described. In the drawings:
[0013] FIG. 1 shows the closed plastic closure prior to initial use in a side view and
[0014] FIG. 2 shows the same in a diametral vertical section
[0015] FIG. 3 shows in a simplified depiction the perforator from below with a view of the edge having the two cutting teeth
[0016] FIG. 4 shows the perforator and the lower part with a flange as a one-piece subassembly prior to assembly, again in a diametral vertical section and
[0017] FIG. 5 the same view rotated 180°.
[0018] FIG. 6 a - 6 c show various sectional views.
[0019] FIG. 7 shows a perforator suitable for harder plastic films comprising two teeth which are offset at an angle and have different cutting characteristics and
[0020] FIG. 8 shows the same perforator rotated 120°.
[0021] FIG. 9 shows a load-time diagram for the perforator according to the FIGS. 7 and 8 , whereas
[0022] FIG. 10 shows such a load-time diagram for the perforator having the tooth configuration according to the FIGS. 4 and 5 .
DETAILED DESCRIPTION
[0023] The plastic closing device is denoted in its entirety with the numeral 1 . Said device comprises three components, of which two can be produced as one piece resulting from the manufacturing processes thereof, as is subsequently described in FIGS. 4 and 5 . Said plastic closing device 1 comprises a screw cap 4 , on the lower edge of which a tamper evidence band 7 is molded via predetermined breaking point bridges so as to align with the jacket wall of the screw cap. In the side view according to FIG. 1 , only a flange 3 , which is a part of the lower part 2 , of the closing device 1 can be seen.
[0024] In the cross-sectional view according to FIG. 2 , it can be seen that the screw cap 4 has a jacket wall 9 as well as a top surface 10 . Said screw cap 4 has internal screw thread 11 which is designed as fine-pitch-pitch thread. The lower part 2 including the flange 3 thereof, which serves as a welded or glued connection to the container, comprises a cylindrical outlet 6 , which is tubular and open to both sides. This outlet 6 has external thread 12 which is also designed as fine-pitch thread and meshes with the internal thread 11 of said screw cap 4 when said screw cap 4 is screwed on and off. The fine-pitch thread 11 , 12 is preferably designed as a double-start thread. The fine-pitch thread has the advantage of easy assembly due to the internal thread of the said screw cap being able to be pushed over the external thread 12 of the outlet 6 in a ratchet-like manner. This allows for assembly without a relative rotation of the parts with respect to one another. Two driving elements 13 diametrically opposed to one another are located in said screw cap 4 , wherein said driving elements are integrally formed with the bottom side of the top surface 10 of said screw cap 4 . Said driving elements 13 act together with the driving element 14 in the perforator 5 . Said perforator 5 is subsequently described in detail with the aid of FIGS. 4 and 5 .
[0025] As previously described, the perforator 5 and the lower part 2 are manufactured as one piece, just as is depicted in FIG. 4 . In this case, said lower part 2 and said perforator 5 together form a subassembly, which can be manufactured using a single injection mold. During assembly, said lower part 2 and said perforator 5 can simply be pushed together. In so doing, said perforator 5 comes to rest completely within the cylindrical outlet 6 . In this position, said perforator 5 is integrally formed as a subassembly on the upper edge of the outlet 6 via predetermined breaking points. Said perforator 5 consists of a cylindrical pipe section 16 , which has course thread 17 on the outside. Said course thread 17 having a large pitch meshes with a correspondingly adapted trapezoidal thread 18 on the inside of the outlet 6 . Said perforator 5 additionally comprises two entraining ribs 19 which are diametrically opposed to one another and on which the aforementioned driving elements 13 of the screw cap 4 make contact during the respective screwing movement. Two cutting teeth are integrally formed on the lower edge of said perforator 5 . Both of said teeth can be seen in FIG. 2 , whereas in FIG. 5 only the subsequent tooth can be seen while the leading tooth has been cut away. Said leading tooth is denoted with the reference numeral 20 and said subsequent tooth with the reference numeral 21 . Both teeth 20 , 21 have the same length l. This length designates the vertical distance from the lower edge 22 of the cylindrical pipe section 16 to the tip of the corresponding cutting tooth.
[0026] In the assembled state as is shown in FIG. 2 , the perforator 5 completely lies within the cylindrical outlet 6 . The tip or rather the two tips of the cutting teeth 20 , 21 lies at the height of the lower edge of the flange 3 of the lower part 2 . When the screw cap 4 is unscrewed, said perforator 5 moves axially in the opposite direction, wherein said perforator carries out a substantially larger translational vertical travel per rotation than said screw cap 4 in the opposite direction. Said perforator 5 actually carries out maximally a rotary motion of around approximately 330°, whereas said screw cap goes through one or several turns until being completely unscrewed.
[0027] Depending upon strength, elasticity and other factors, in particular with regard to the pre-tightening force on the plastic film of the pouch receptacle, the plastic film is sooner or later perforated. Said film is practically always perforated simultaneously by the cutting teeth 20 , 21 . The sectional views as depicted in FIGS. 6 a to c thus arise. In FIG. 6 a , the partial sections of the subsequent tooth have not yet advanced into the section of the leading (previous) tooth. On the other hand in FIG. 6B , this has already happened. This figure shows the cutting line obtained in the worst case, which lies in the magnitude of 200 to 240°. Were this the end position, the leading (previous) tooth would basically push the flap-like part L downwards so that also in this case, the passage is open more than 50%. The cutting line normally extends about a partial circle of around 330°. This situation is depicted in FIG. 6 c.
[0028] In FIG. 3 , the perforator 5 is depicted in a simplified form with a view of the teeth in the direction of the rotational axis of the cylindrical pipe section 16 . If radii are drawn from tooth tips to the center of the longitudinal axis, an angle α is then formed between them. Said angle α must be within an angular range between 70° and 120°. In addition, it is advantageous if the steepness of the external thread of the perforator 5 and the internal thread 18 of the outlet 6 are selected in such a way that during the unscrewing movement of the screw cap 4 , the cutting teeth 20 , 21 travel through a maximum cutting distance of 210° in the cutting direction from the point of contact on the plastic film of the container to be severed up until said unscrewing movement of said screw cap 4 has completely ended. If the maximum angle, which the leading tooth 20 and the subsequent cutting tooth 21 enclose together, namely an angle of 120°, is now added to the 210°, this then results in a maximum cutting line which extends over 330°. A sufficient connection between the plastic film of the container and the aforementioned flap L thereby remains. If the worst case is assumed, that the perforation of the film first occurs after a quarter turn, i.e. after 90°, and the angle between the two cutting teeth amounts to only 70°, said leading tooth still implements a minimum cutting line of 120° while said subsequent tooth 21 travels through the additional 70°; thus enabling a cutting line of over 180° also to be formed in the worst case.
[0029] Because the resulting forces on the cutting teeth are substantially greater in this version than in the case of a plurality of small teeth, it is advantageous for the wall thickness of the cutting teeth 20 , 21 to be selected to be larger than the wall thickness of the cylindrical pipe section 16 of the perforator. This can be seen most clearly in FIG. 5 . This does not appear to be the case in FIG. 4 ; however, this is merely due to the fact that the cutting line travels in this instance through the entraining ribs 19 .
[0030] It is known that plastic films can be obtained in many different qualities. Said films differ not only in the selection of the plastic materials used but also in thickness, stiffness, hardness, etc. With regard to the production of pouch receptacles, which are to have a comparable strength to those consisting of multilayered laminates comprising cardboard, such plastic films cannot be reliably opened with the plastic closing devices known to date. The stronger the film being used was, the greater the thickness of the teeth had to be, and in doing so the films could hardly be opened without too high of a torque being required for the operation, which then users could not be expected to produce. The pouch receptacles were in fact entirely manufactured from this relatively thick and hard material, wherein, however, an opening was press cut and sealed with a film section, which was substantially softer and could be cut with the usual plastic closing devices known until that time. The plastic closing device was in turn welded to the film section.
[0031] The trend is to move away from this technology and it has been shown that this is possible if the leading as well as the subsequent tooth is designed in the manner depicted in FIGS. 7 and 8 . Whereas emphasis was especially placed on a perforation of the film when using the teeth from prior art, weight is now placed on the cutting of the film. In the case of the softer plastic films, a much stronger stretching occurs and accordingly it was essential for the two teeth to make contact at approximately the same time and thereby to tighten the film so that a perforation takes place. After that, the film itself could subsequently be cut practically without resistance along the cutting edge of the corresponding teeth. This process is, for example, depicted in the time-load diagram according to FIG. 10 . FIG. 9 , on the other hand, shows the load-time diagram of the perforator according to FIGS. 7 and 8 comprising the new tooth configuration. Both curves cannot be directly compared when considering the fact that a thin, substantially more elastic film is cut in the case depicted in FIG. 10 whereas a thicker film, which is substantially harder but less elastic, has been cut in the diagram according to FIG. 9 .
[0032] It can be seen in FIG. 10 that the torque increases more slowly up until the point in time of the perforation by a first of the two teeth, whereupon the torque immediately drops until the second tooth begins to have an effect and then subsequently falls very sharply.
[0033] In contrast thereto, when severing the thicker film using the perforator comprising the newly designed teeth shapes, the load which has to be applied increases faster until the maximum pressure occurs on the film and the cutting action begins. The load now continuously decreases until the first succeeding tooth begins to have an effect and the additional effect of the further succeeding teeth can then additionally be seen in the region where the drop in load occurs. Despite the substantially harder film, the required force output remains practically the same. This astonishing result is due to the fact that the thicker film hardly ever tears but has accordingly to be cut much more, wherein the cutting characteristics resemble a cutting plate of a lathe tool. It can be microscopically determined that swarf forms at the same time the plastic is cut, and this swarf must be able to be routed into an area away from the teeth in order to prevent said swarf from moving in front of the actual cutting point of the teeth and thereby substantially increasing the torque.
[0034] A preferred exemplary embodiment of these newly configured teeth of a perforator is explained below with the aid of FIGS. 7 and 8 . The perforator in its entirety is denoted with the reference numeral 5 . This too comprises a cylindrical pipe section 16 , on the outside of which a coarse thread 17 is molded. The trapezoidal thread 18 then engages in said coarse thread 17 in the cylindrical outlet 6 . The cylindrical section 16 is equipped on the inside with entraining ribs 19 . In this option, the cylindrical section 16 is reduced in diameter in the lower cutting region 26 by approximately the depth of said coarse thread 17 . Provision is made in turn at the lower edge of this tapered cutting region 26 for a leading cutting tooth 20 and a subsequent cutting tooth 21 . Whereas in the previously described option of this cutting tooth, a straight, relatively steep cutting surface is present in the leading position in the cutting direction, this leading cutting edge is in this case tiered; and there is a plurality of succeeding teeth 24 , which are tiered at different heights, arranged in a staggered manner. Depending upon the penetration depth, said succeeding teeth 24 are employed one after the other A swarf receiving space 25 , which runs approximately arcuately, is situated between in each case the foremost leading and subsequent cutting tooth 20 , 21 and the cutting tooth 24 disposed in the leading position in the cutting direction. Such a swarf receiving space 25 is also in each case situated between two succeeding teeth 24 arranged adjacently in each case. This can be seen most clearly in FIG. 7 .
[0035] In contrast to the solution first shown, wherein the teeth perform practically only a perforating action by means of a perforating tip 23 and thereafter the leading cutting edge 28 comes into operation, the two main teeth, namely the leading cutting tooth 20 and the subsequent cutting tooth 21 , as well as the staggered succeeding teeth 24 all work in this case the same and have altogether a swarf-removing cutting effect. After the leading tooth and the subsequent tooth 20 , 21 have come through the film, a succeeding tooth 24 must therefore take on their function. Said succeeding teeth are therefore disposed according to height in a descending step-like succession on account of the perforator 5 penetrating ever deeper into the container to be cut open during the screwing action. Said succeeding teeth also operate in a swarf-removing manner and thus said succeeding teeth are also equipped in each case with a respective swarf receiving space 25 . It is appropriate for the swarf receiving spaces 25 which operate first to be larger that the swarf receiving spaces that subsequently become operative. | The invention relates to a closing device ( 1 ) consisting of a plastic material for applying to a closed container consisting of a plastic film material. Only two cutting teeth ( 20, 21 ) of the same height are to be applied to the cylindrical perforator ( 5 ) of said device, said teeth being arranged in an angular region of between 70° and 120° of the circumference. In this way, the section of the subsequent tooth extends into the section of the previous tooth, enabling a secure opening, without the risk of cutting an entire rondelle out of the plastic film of the container. The creation of only two partial sections without producing an opening in the container is also prevented. | 1 |
TECHNICAL FIELD
[0001] The present invention generally relates to power device packaging and, more particularly, to an improved packaging structure and heat sink for a power device.
BACKGROUND OF THE INVENTION
[0002] As seen in FIG. 1 , one example of a conventional power device package, which is seen generally at 10 , comprises a flip chip 12 affixed to a printed wire board 14 . Such power device packages may be used in a variety of applications such as consumer-, medical-, military-, or automotive-related fields. If applied in an automotive-related field, such power device packages 10 may be implemented in a power-train control module, an engine control module, a transmission control module, a braking control module, a steering control module, or the like.
[0003] The flip chip 12 is typically affixed to the printed wire board 14 by high temperature solder balls 16 and an underfilling epoxy resin 18 . The top, non-active side of the package, which is generally seen at 20 , includes a heat spreader, which is generally seen at 22 . The heat spreader 22 typically comprises a heat sinkable material, such as, for example, copper. The bottom active side of the package, which is seen generally at 24 , includes a plurality of low temperature solder balls 26 that will reflow at lower temperatures when attached to the circuit board (not shown). Although seen from a cross-sectional view as illustrated in FIG. 1 , the layout of the low temperature solder balls 26 may be in any desirable pattern, such as for example, a ball grid array (BGA) pattern, which essentially, defines a BGA power device package.
[0004] A thermally conductive adhesive, which is seen generally at 28 , is intermediately located between the flip chip 12 and the heat spreader 22 . The thermally conductive adhesive 28 may typically include a silver epoxy. The heat spreader 22 is carried by a support ring 30 that encompasses the flip chip 12 and is positioned adjacent to the printed wire board 14 . Typically, similar in design to the heat spreader 22 , the support ring 30 comprises a heat sinkable material, such as, or example, copper. The heat spreader 22 is secured to the support ring 30 by an upper layer of epoxy resin adhesive 32 .
[0005] Although adequate for most applications, the power device package 10 includes multiple thermal interfaces. The thermal interfaces are located at the thermally conductive adhesive 28 , the upper layer of epoxy resin 32 , and at the top side 20 where a product heat sink (not shown) sinks the heat out to a product case (not shown). In design, the multiple thermal interfaces adequately sinks the heat from the power device package 10 , however, the additional structure, including the heat spreader 22 , adds to the cost of the power device package 10 .
[0006] Other conventional power device packages not including multiple thermal interfaces do not provide an optimal heat sink path for flip chips. More specifically, such power device packages sink most of the heat through the circuit board, which results in poor removal of the heat from the applied integrated circuit and overall system. The circuit board is typically chosen as the heat sink out of design convenience and comprises a laminate material made out of epoxy glass, which, conversely, is an insulator and a relatively poor thermal conductor.
[0007] As seen in FIG. 2 , another conventional power device package, which is seen generally at 100 , include chip and wire devices. The power device package 100 is typically referred to as a chip and wire quad-flat non-leaded package (QFN) that includes a copper lead frame 102 and a silicon integrated circuit (IC) 104 . The power device package 100 is further defined to include a copper lead frame wire bond input-output (I/O) 106 connected to the silicon IC 104 by a gold or aluminum wire 108 and a gold ball bond 110 . As illustrated, the power device package 100 is overmolded with a thermoset epoxy resin 112 . Chip and wire QFN packages 100 are typically used more often than the flip chip BGA packages 10 because the chip and wire QFN package 100 does not include the multiple thermal interfaces. However, the chip and wire QFN package 100 undesirably includes the I/O and heat sink on the same surface, which is the bottom side of the package, which is seen generally at 114 .
[0008] Although the power device package 10 illustrated in FIG. 1 includes a single flip chip 12 , defining a single chip module (SCM), power device packages 10 may include multiple flip chips 12 , defining a multi-chip module (MCM). If MCMs are manufactured, height variances (i.e. a tolerance stack up) of the power device package 10 may occur, effecting the manufacturing consistency height of the packages. For example, upon reflowing, the collapse heights of the high temperature solder balls 16 may vary from approximately 3.0-3.5 mils. Even further, chips thicknesses vary from approximately 17-29 mils. Therefore, as a result, a need exists for a power device package that results in consistent manufacturing in the event of encountering tolerance stack up.
[0009] Accordingly, it is therefore desirable to provide a power device package including an improved heat sink structure and manufacturing consistency of the overall package.
SUMMARY OF THE INVENTION
[0010] The present invention relates to a heat sinkable package. Accordingly, one embodiment of the invention is directed to a heat sinkable package that includes a power device package including an active side and a non-active side. The non-active side includes a heat sinkable surface positioned adjacent to a product case. Another embodiment of the invention is directed to a method for manufacturing a heat sinkable package. The method comprises the steps of placing at least one flip chip over a flexible circuit within a mold tool; compensating for height variances of the flip chips; and positioning an input/output on an active side of the power device package opposite a non-active side of the power device package.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
[0012] FIG. 1 illustrates a conventional power device package;
[0013] FIG. 2 illustrates another conventional power device package;
[0014] FIG. 3 illustrates an assembly layout of the power device package according to one embodiment of the invention;
[0015] FIG. 4 illustrates a side view of an assembled power device package according to FIG. 3 ;
[0016] FIG. 5 illustrates a bottom view of the power device package according to FIG. 4 ;
[0017] FIG. 6 illustrates a side view of a power device package according to another embodiment of the invention;
[0018] FIG. 7 illustrates a bottom view of the power device package according to FIG. 6 ;
[0019] FIG. 8 illustrates a side view of a power device package according to another embodiment of the invention;
[0020] FIG. 9 illustrates a bottom view of a power device package according to another embodiment of the invention;
[0021] FIG. 10 illustrates a side view of a power device package according to FIG. 9 ; and
[0022] FIG. 11 illustrates a side view of the power device packages according to FIGS. 4 and 9 applied to a product case and circuit board.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] The above described disadvantages are overcome and a number of advantages are realized by the inventive power device packages, which are generally illustrated at 200 , 300 , 400 , and 500 in FIGS. 5, 7 , 9 , and 11 , respectively. It is contemplated that the power device packages may include either a SCM or a MCM packaging, including any desirable amount of chips. The inventive power device packages include a low thermal resistance IC junction to the product case that essentially provides a single thermal interface for the power device packages. Even further, if a flip chip is implemented in the power device package, consistent manufacturing of each power device package is ensured in view of associated tolerance stack up issues described above.
[0024] Referring initially to FIGS. 3-5 , the power device package 200 generally includes a BGA of low temperature solder balls 202 ( FIGS. 4-5 ) and flip chips 204 a , 204 b with high temperature solder balls 206 ( FIGS. 3-4 ). The power device package 200 further includes a flexible circuit 208 , which may comprise any desirable material, such as copper, polyimide, or a thin FR-4 Core Material, that is laminated to a ring carrier 210 . Upon being properly aligned in a mold tool ( FIG. 3 ), a thermoset epoxy mold compound 212 ( FIG. 4 ) fills the mold cavity, encasing and protecting the flip chips 204 a , 204 b . The flexible circuit 208 may include a thickness approximately 3-6 mils and the ring carrier may include a thickness of approximately 20-40 mils.
[0025] As seen in FIG. 3 , the power device package 200 is manufactured by first placing at least one flip chip, being flip chips 204 a , 204 b over the flexible circuit 208 within the mold tool defined by upper and lower mold halves 201 , 203 . The mold tool also includes a punch 205 that facilitates cutting of a Teflon film 207 dispensed from rollers 209 about the upper mold half 201 and lower mold half 203 . The Teflon film 207 may be secured to the upper and lower mold halves 201 , 203 by a vacuum or adhesive. According to one aspect of the invention, an MCM including flip chips 204 a , 204 b of varying heights may be consistently manufactured. More specifically, as seen in then illustrated embodiment, the flip chip 204 a includes a height, H 1 , that is greater than a height, H 2 , of flip chip 204 b . Upon closing of the upper mold 201 upon the lower mold 203 , the thermoset epoxy mold compound 212 is injected about the flexible circuit 208 and the flip chips 204 a , 204 b.
[0026] Referring to FIGS. 3 and 5 , central passages 214 and perimeter passages 216 in the flexible circuit 208 permits the thermoset epoxy mold compound 212 to fill the entire mold cavity about the flip chips 204 a , 204 b . More specifically, the thermoset epoxy resin 212 flows through the central passages 214 to underfill the high temperature solder balls 206 underneath the flip chips 204 a , 204 b as the thermoset epoxy mold compound 212 also flows through the perimeter passages 216 to overmold the flips chips 204 a 204 b . Besides allowing the simultaneous overmolding of the flip chips 204 a , 204 b while being underfilled, the absence of the material about the passages 216 also increases the elasticity of the flexible circuit 208 when the mold tool is closed.
[0027] The mold tool is closed with approximately 75 tons of force, the mold compound filling/packing pressure is 350-1000 psi. As seen in FIG. 4 , the closing of the mold tool and underfilling of the thermoset epoxy resin 212 about the passages 214 , 216 results in a deformed, flexed portion, F, of the flexible circuit 208 . The flexed portion, F, is displaced downwardly in the direction of the arrow, D, such that the top of the flip chip 204 a is level with the top of the flip chip 204 b that generally rests on an unflexed portion, U, of the flexible circuit 208 . Essentially, the upper mold half 201 pushed down on the top of the flip chips 204 a , 204 b as the thermoset epoxy resin 212 pushes upwardly from the bottom of the flip chips 204 a , 204 b.
[0028] Once the thermoset epoxy resin has cured, the power device package is removed from the mold tool so that Teflon film 207 may be removed from the non-active side, N, and the active side, A, of the power device package 200 . Although not required, the Teflon film advantageously prevents the thermoset epoxy resin 212 from sticking to the upper and lower mold halves 201 , 203 while also acting as a release film such that the molded power device package 200 may be easily removed from the mold tool. Then, after removal from the mold tool, an array of low temperature solder balls 202 are attached to the bottom side of the power device package 200 and positioned opposite through-hole via 208 extending from flexible circuit 208 and attached to each low temperature solder ball 202 . If desired, a gold film may be adhered to the non-active side, N, to provide a solderable surface for an enhanced thermal interface when attaching the power device package to the product case. Although the illustrated embodiment of the invention shows an MCM power device package 200 , it is contemplated that the same procedure may be applied to a SCM power device package 200 .
[0029] Referring now to FIGS. 6 and 7 , a power device package according to another embodiment of the invention is shown generally at reference numeral 300 . The power device package 300 is a QFN package is generally manufactured the sane as the BGA power device package 200 as described above with respect to the molding operation. The QFN power device package includes flip chips 304 a , 304 b that are placed over a flexible circuit 308 , which includes central passages 314 and perimeter passages 316 , laminated to a ring carrier 310 , and a bottom portion 311 . As seen more clearly in FIG. 7 , the bottom portion 311 includes a plurality of QFN connector pads 312 that are electrically coupled to the flexible circuit 308 , which is defined by a dashed line perimeter. The bottom portion 311 including the connector pads 312 may be integral with the ring carrier 310 , including a sheet of material, such as copper, that is sheared after the molding operation to form the connector pads 312 . Alternatively, the sheet defining the bottom portion 311 may be stamped and subsequently adhered to the ring carrier 310 .
[0030] Referring now to FIG. 8 , a power device package according to another embodiment of the invention is shown generally at reference numeral 400 . The power device package 400 is another BGA package is generally manufactured in the same respect as the BGA power device package 200 in a molding operation, however, the power device package 400 does not include a flexible circuit. As illustrated, the power device package 400 includes flip chips 404 a , 404 b that are pre-underfilled to an exposed active-side silicon layer 402 . The underfilling material may be a thermoset epoxy resin, which is generally seen at reference numeral 406 , and, in the molding operation, the overmolding material, which is seen generally at reference numeral 408 , may also be a thermoset epoxy resin.
[0031] In this embodiment of the invention, the tolerance stack up is compensated for by the Teflon film applied from the rollers 209 . As seen, flip chip 404 b has a greater height than flip chip 404 a such that the top of the flip chip 404 b extends from the overmolded material 408 . The Teflon film may be any desirable thickness, such as, for example, approximately 5 mils thick and is compressible up to any desirable thickness, such as, for example, approximately 2 mils such that upon removal of the Teflon, flip chips having a tolerance stack up may slightly extend from the overmolded material 408 , such as the flip chip 404 b . Upon removal of the Teflon film, the low temperature solder balls 410 are added in a subsequent application.
[0032] Referring now to FIGS. 9 and 10 , a power device package according to another embodiment of the invention is shown generally at reference numeral 500 . The power device package 500 is a QFN package that is generally manufactured the same as the BGA power device package 200 as described above with respect to the molding operation. The QFN power device package 500 differs from the QFN power device package 300 in that the power device package 500 does not include a flip chip. As illustrated, the QFN power device package 500 includes a copper lead frame 502 , a silicon IC 504 , a copper lead frame wire bond I/O 506 connected to the silicon IC 504 by a gold or aluminum wire 508 and a gold ball bond 510 overmolded with a thermoset epoxy resin 512 . Similar in design to the QFN power device package 300 , the copper lead frame wire bond I/O 506 may integrally include connector pads 514 , or alternatively, the connector pads 514 may extend from a sheet of material, such as copper, that is sheared before or after the molding operation.
[0033] Referring now to FIG. 11 , a product case, C, including a product case thermal interface, T, is shown. The thermal interface, T, is adjacent to non-active side heat sinks 250 , 550 of the power device packages 200 , 500 , respectively. The thermal interface, T, may be any desirable material such as, for example, a metallic solder, a thermally conductive adhesive, a thermally conductive grease, a thermal film, or the like. The low temperature solder balls 202 and printed solder 516 connects the power device packages 200 , 500 to a device, D. The product case, C, may be any type of desirable metal, such as, for example, aluminum or copper. In general, approximately 90-95% of the heat generated by the power device package is evacuated to the thermal interface, T, and out towards the product case, C.
[0034] Accordingly, the inventive power device packages includes heat sinks that are directly adjacent to the product case, C, which efficiently permits heat to evacuate the power device packages. Even further, because the heat sinks may be located opposite the I/O at the solder balls (i.e. in a BGA implementation) and printed solder (i.e. in a QFN implementation), heat generated by the power device packages is directed away from the device, D, thus, advantageously lowering the device's operating temperature. Another advantage associated with the inventive power device packages is that the thermal interface, T, is the only thermal interface applied to the power device packages; essentially, the power device packages do not include additional thermally conductive layers and provides a single direct path for heat evacuation.
[0035] The present invention has been described with reference to certain exemplary embodiments thereof. However, it will be readily apparent to those skilled in the art that it is possible to embody the invention in specific forms other than those of the exemplary embodiments described above. This may be done without departing from the spirit of the invention. The exemplary embodiments are merely illustrative and should not be considered restrictive in any way. The scope of the invention is defined by the appended claims and their equivalents, rather than by the preceding description. | A heat sinkable package that includes a power device package including an active side and a non-active side is disclosed. The non-active side includes a heat sinkable surface positioned adjacent to a product case. Another embodiment of the invention is directed to a method for manufacturing a heat sinkable package. The method comprises the steps of placing at least one flip chip over a flexible circuit within a mold tool; compensating for height variances of the flip chips; and positioning an input/output on an active side of the power device package opposite a non-active side of the power device package. | 7 |
FIELD OF THE INVENTION
THIS INVENTION relates to the production of Fischer-Tropsch synthesis produced wax. It relates in particular to a process for producing a clean wax product, and to the use of a cobalt slurry phase Fischer-Tropsch synthesis catalyst in such a process.
BACKGROUND OF THE INVENTION
It is known from the prior art that clean wax products, ie wax products containing less than 50 mass ppm total cobalt, can be obtained during slurry phase Fischer-Tropsch synthesis involving contacting a synthesis gas comprising hydrogen and carbon monoxide at elevated temperature and pressure with a particulate supported cobalt Fischer-Tropsch synthesis catalyst, to produce the clean wax products. The clean wax product can be defined as being the filtrate of the liquid Fischer-Tropsch synthesis product (ie reactor wax) continuously extracted directly from the reactor slurry phase through an in-situ primary filtration process. The particulate supported cobalt slurry phase Fischer-Tropsch synthesis catalysts are sufficiently strong so that little break-up thereof during extended slurry phase Fischer-Tropsch synthesis runs takes place, and cobalt crystallites are sufficiently anchored to the catalyst support to prevent cobalt from readily dislodging and washing out of the cobalt catalyst during such extended slurry phase Fischer-Tropsch synthesis runs conducted at realistic conditions, also implying catalyst stability in the associated hydrothermal environment.
This objective is successfully achieved in the prior art through the introduction, during production of a catalyst precursor from which the catalyst is obtained, of additional processing step(s) to modify an already pre-shaped catalyst support, such as Al 2 O 3 , MgO or TiO 2 , thus producing a modified catalyst support, wherein the cobalt crystallites are sufficiently anchored to the selected catalyst support to prevent cobalt from readily dislodging and washing out of the resultant cobalt catalyst during the extended slurry phase Fischer-Tropsch synthesis runs. Such a catalyst is preferably prepared through the aqueous phase impregnation of the modified catalyst support with cobalt.
SUMMARY OF THE INVENTION
The known slurry phase Fischer-Tropsch synthesis processes involving the use of the cobalt slurry phase Fischer-Tropsch synthesis catalysts hereinbefore described, suffer from the drawback that additional processing steps are required to modify the already pre-shaped catalyst supports. It is hence an object of this invention to provide a process for producing a clean wax product, ie a wax product having less than 50 mass ppm total cobalt, whereby this drawback is eliminated or at least reduced.
Thus, according to a first aspect of the invention, there is provided a process for producing a clean wax product, which process includes contacting, at an elevated temperature between 180° C. and 250° C. and at an elevated pressure between 10 bar and 40 bar, a synthesis gas comprising hydrogen and carbon monoxide with a cobalt slurry phase Fischer-Tropsch synthesis catalyst obtained from a successful catalyst support, in a slurry phase Fischer-Tropsch synthesis reaction, to produce a clean wax product containing less than 50 mass ppm submicron particulates of cobalt.
In this specification, ‘a successful catalyst support’ is defined as a catalyst support obtained by means of a catalyst support preparation step into which is integrated a catalyst support modification step and a pre-shaping step, ie the catalyst support modification step and the catalyst pre-shaping step both take place during preparation of the catalyst support. In other words, the catalyst support modification is not effected as a separate step after the preparation of the catalyst support has been completed.
In the preparation of the successful catalyst support, a modifying component Mc, where Mc is any element of the Periodic Table that increases the inertness of a catalyst support towards dissolution in an aqueous environment during cobalt impregnation or hydrothermal attack during Fischer-Tropsch synthesis, is introduced onto the catalyst support, followed by calcination of the thus modified catalyst support. The cobalt slurry phase Fischer-Tropsch synthesis catalyst is then produced from the successful catalyst support by impregnating the successful catalyst support with an aqueous solution of a cobalt salt, to form an impregnated support; partially drying the impregnated support; calcining the partially dried impregnated support, to obtain a catalyst precursor; and reducing the catalyst precursor to form the cobalt slurry phase Fisher-Tropsch synthesis catalyst.
The modifying component, Mc, is preferably selected from (i) Si, Co, Ce, Cu, Zn, Ba, Ni, Na, K, Ca, Sn, Cr, Fe, Li, Tl, Sr, Ga, Sb, V, Hf, Th, Ge, U, Nb, Ta, W, La and mixtures thereof; and/or from (ii) Ti in combination with at least one of Si, Co, Ce, Cu, Zn, Ba, Ni, Na, K, Ca, Sn, Cr, Fe, Li, Tl, Sr, Ga, Sb, V, Hf, Th, Ge, U, Nb, Ta, W, and La.
The modifying component, Mc, that is present in the successful catalyst support thus serves to render the catalyst support, eg Al 2 O 3 , TiO 2 , MgO or ZnO, which is normally partially soluble in an acid aqueous solution and/or in a neutral aqueous solution, less soluble or more inert in the acid aqueous solution and/or in the neutral aqueous solution.
The introduction of the modifying component, Mc, onto the catalyst support may be effected by incorporating the modifying component into a precursor of the catalyst support. This may include contacting a precursor of the modifying component, Mc, with the catalyst support precursor, for example, by means of doping, co-gelling or precipitation. The modifying component precursor may be a salt or an alkoxide of the modifying component or components. Examples of alumina catalyst support precursors are boehmite, gibbsite, bayerite, sodium aluminate, aluminium nitrate, and aluminium tributoxide. Examples of titania catalyst support precursors are titanium tert-butoxide and hydrated titanium hydroxide (TiO(OH) or TiO 2 .H 2 O). Examples of magnesia support precursors are magnesium hydroxide (Mg(OH) 2 ) and magnesium carbonate. Examples of zinc oxide support precursors are ZnSO 4 and ZnCl 2 .
In one embodiment of the invention, the successful catalyst support may be prepared in accordance with the process for manufacture of alumina silicates as described in DE 3839580, which is hence incorporated herein by reference. Thus, it may be prepared by hydrolyzing an aluminium alkoxide, obtained from an alkoxide process, eg the Ziegler ALFOL process or the Sasol Chemie (formerly Condea) “o n-purpose” proprietary process, as described in German Patent No. DE 3244972, at about 90° C. Thereafter, a dilute solution of orthosilicic acid may be added to the stirred mixture. This slurry can then be spray dried at 300° C. to 600° C. to obtain a product known as Siral (trademark), which can be tailored through calcination, to obtain a product known as Siralox (trademark), which is a successful catalyst support. Siral and Siralox are proprietary products of Sasol Germany GmbH.
In another embodiment of the invention, the precursor of the modifying component may be an inorganic cobalt compound so that the modifying component is cobalt (Co). The inorganic cobalt precursor, when used, may be a cobalt salt, eg Co(NO 3 ) 2 .6H 2 O, which can be mixed into a slurry, eg a boehmite slurry obtained from the alkoxide process, gelled by the addition of nitric acid, and spray dried.
The modified catalyst support may then be calcined at a temperature of from 400° C. to 900° C., preferably from 600° C. to 800° C., and for a period of from 1 minute to 12 hours, preferably from 1 hour to 4 hours.
The method of forming the catalyst precursor may be in accordance with that described in U.S. Pat. No. 5,733,839, WO 99/42214, and/or WO 00/20116, which are thus incorporated herein by reference. Thus, the impregnation of the successful catalyst support with the active catalyst component, ie the cobalt, or its precursor aqueous solution, may comprise subjecting a slurry of the catalyst support, water and the active catalyst component or its precursor to a sub-atmospheric pressure environment, drying the resultant impregnated carrier under a sub-atmospheric pressure environment, and calcining the dried impregnated carrier, to obtain the catalyst precursor.
If a higher catalyst cobalt loading is required, then a second or even a third impregnation, drying, and calcination step may thereafter be carried out after the first impregnation, drying, and calcination step hereinbefore described.
During the slurry phase cobalt impregnation step(s), a water soluble precursor salt of Pt or Pd, or mixtures of such salts, may be added, as a dopant capable of enhancing the reducibility of the active component. The mass proportion of this dopant, when used, to cobalt may be between 0.01:100 and 0.3:100.
The process may include subjecting the wax product that is produced, to primary separation to separate the wax product from the catalyst. A serious problem that may arise when utilizing a cobalt slurry phase Fischer-Tropsch synthesis catalyst, not being a cobalt slurry phase Fischer-Tropsch synthesis catalyst prepared according to the invention, as observed during larger scale pilot plant slurry phase Fischer-Tropsch synthesis runs, is the undesired high cobalt (submicron particulates of cobalt) content of the wax product. Typically, the wax product may contain contamination levels of such cobalt in excess of 50 mass ppm, even after secondary ex-situ filtration through a Whatman no. 42 (trademark) filter paper (the product of such filtration is hereinafter referred to as ‘secondary filtered reactor wax’). Due to the high cost of cobalt and the contamination and poisoning of downstream hydroconversion processes, this is a highly undesirable problem which has thus been solved, or at least alleviated, with this invention. Also, the use of extensive and expensive polishing steps of the primary filtered wax product is not necessary. The said Al 2 O 3 , TiO 2 , MgO or ZnO based catalyst supports are thus modified and pre-shaped during the catalyst support preparation step, a process that may include spray-drying and calcination, in order to increase inertness of the catalyst support in an aqueous (neutral or acidic) environment during the cobalt nitrate impregnation step, and thus prevent the formation of cobalt-rich ultra fine or submicron particulates during slurry phase Fischer-Tropsch synthesis.
During the primary separation, separation of catalyst particles, which have sizes in the order of between 10-200 micron, from the wax product, is effected to produce primary filtered wax. The process is thus characterized thereby that it does not include any, or any significant, separation of particles of submicron size from the wax product.
The clean wax product, ie the hydrocarbons produced by the slurry hydrocarbon synthesis process of the invention, may typically be upgraded to more valuable products, by subjecting all or a portion of the clean wax product to fractionation and/or conversion. By ‘conversion’ is meant one or more operations in which the molecular structure of at least a portion of the hydrocarbon is changed and includes both non-catalytic processing (eg steam cracking), and catalytic processing (eg catalytic cracking) in which a fraction is contacted with a suitable catalyst. If hydrogen is present as a reactant, such process steps are typically referred to as hydroconversion and include, for example, hydroisomerization, hydrocracking, hydrodewaxing, hydrorefining and hydrotreating, all conducted at conditions well known in the literature for hydroconversion of hydrocarbon feeds, including hydrocarbon feeds rich in paraffins. Illustrative, but non-limiting, examples of more valuable products formed by conversion include one or more of synthetic crude oils, liquid fuel, olefins, solvents, lubricating, industrial or medicinal oils, waxy hydrocarbons, nitrogen and oxygen containing hydrocarbon compounds, and the like. Liquid fuel includes one or more of motor gasoline, diesel fuel, jet fuel, and kerosene, while lubricating oil includes, for example, automotive, jet, turbine and metal working oils. Industrial oils includes well drilling fluids, agricultural oils, heat transfer fluids and the like.
According to a second aspect of the invention, there is provided the use of a cobalt slurry phase Fischer-Tropsch synthesis catalyst obtained from a successful catalyst support, in a process for producing a clean wax product, by contacting, at an elevated temperature between 180° C. and 250° C. and at an elevated pressure of between 10 bar and 40 bar, a synthesis gas comprising hydrogen and carbon monoxide with the catalyst, in a slurry phase Fischer-Tropsch synthesis reaction, to produce a clean wax product containing less then 50 mass ppm submicron particulates of cobalt.
The invention will now be described in more detail with reference to the following non-limiting examples and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows cumulative dissolution profiles of a pure pre-shaped alumina catalyst support (Puralox SCCa) and a silica modified catalyst support (Siralox 1.5 support), at a solids concentration of 2% (w/w);
FIG. 2 depicts the cobalt contamination level of secondary filtered wax product as a function of Fischer-Tropsch slurry phase synthesis time on stream, as observed on Pilot Plant scale. Cobalt supported Fischer-Tropsch synthesis catalysts were compared with catalysts supported as follows: (i) a pure pre-shaped alumina particulate catalyst support known by the trademark: Puralox SCCa, as supplied by SASOL Germany GmbH, (catalyst B), and (ii) a pre-shaped silica modified alumina catalyst support known by the trademark: Siralox 1.5, as supplied by SASOL Germany GmbH (catalyst A), which is in accordance with the invention;
FIG. 3 shows cumulative dissolution profiles of a pure pre-shaped alumina catalyst support (Puralox SCCa) and doped alumina catalyst supports, A, B, C and D, at a solids concentration of 2% (w/w). Modified support A is an alumina modified support doped with 1.5 m % WO 3 . Modified support B is an alumina modified support doped with a mixture of 1.5 m % TiO 2 and 1.5 m % SiO 2 . Modified support C is an alumina modified support doped with 1.5 m % BaO. Modified support D is an alumina modified support doped with 4 m % Ce.
FIG. 4 shows cumulative dissolution profiles of various pure catalyst supports at a solids concentration of 2% (w/w); and
FIG. 5 shows cumulative dissolution profiles of a pure unmodified pre-shaped titania catalyst support (Degussa Titania P25 (trademark)) and a silica modified titania catalyst support, at a solids concentration of 2% (w/w)
DETAILED DESCRIPTION
EXAMPLE 1
In the example, two catalyst supports, and supported cobalt slurry phase Fischer-Tropsch synthesis catalysts obtained therefrom, are compared:
Puralox Catalyst
support: This catalyst support is that obtainable under the trademark Puralox SCCa 2/150 from SASOL Germany GmbH of Üb erseering 40, 22297, Hamburg, Germany. It is a pure gamma-alumina support, and is prepared by calcination of boehmite (AlO(OH)) at 750° C.
Siralox 1.5 Catalyst
support: A successful catalyst support was prepared by hydrolyzing an aluminium alkoxide, obtained from the alkoxide process eg the Ziegler ALFOL process or the Sasol Chemie (formerly Condea) “o n-purpose” proprietary process as described in German Patent No. DE 3244972, at 90° C. Thereafter, a dilute solution of orthosilicic acid was added to the stirred mixture. This slurry was then spray dried at 300° C. to 600° C. to obtain the trademark product: Siral, which was tailored through calcination at between 600° C. and 1100° C., to obtain the trademark product: Siralox, which is a Sasol Germany GmbH proprietary product. The composition of Siralox 1.5 is 1.5 SiO 2 /100 Al 2 O 3 (m/m).
1.1 Conductivity Measurements
Alumina dissolves in an aqueous medium at low pH. The dissolution of alumina results in the formation of aluminium ions. As more alumina dissolves, the concentration of aluminium ions increases with time. The increase of aluminium ions with time was monitored by measuring conductivity at a constant pH of 2. The pH was kept constant by automated addition of a 10% nitric acid solution. The results are set out in FIG. 1 .
In FIG. 1 , the cumulative mg Al dissolved per m 2 fresh catalyst support is plotted against time. It can be seen that the unprotected pure alumina (Puralox catalyst support) dissolves faster than the successful silica modified alumina (Siralox 1.5 catalyst support).
1.2 Catalyst Preparation
Catalyst A
A supported cobalt catalyst precursor was prepared on the Siralox 1.5 successful catalyst support with a porosity of 0.46 ml/g, as catalyst support material. A solution of 17.4 kg of Co(NO 3 ) 2 .6H 2 O, 9.6 g of (NH 3 ) 4 Pt(NO 3 ) 2 , and 11 kg of distilled water was mixed with 20.0 kg of the Siralox 1.5 successful catalyst support, by adding the successful catalyst support to the solution. The slurry was added to a conical vacuum drier and continuously mixed. The temperature of this slurry was increased to 60° C. after which a pressure of 20 kPa (a) was applied. During the first 3 hours of the drying step which commenced when the pressure of 20 kPa(a) was applied, the temperature was increased slowly and reached 95° C. after the 3 hours. After the 3 hours the pressure was decreased to 3-15 kPa(a), and a drying rate of 2.5 m %/h at the point of incipient wetness was used. The complete impregnation and drying step took 9 hours, after which the impregnated and dried catalyst support was immediately and directly loaded into a fluidized bed calciner. The temperature of the dried impregnated catalyst support was about 75° C. at the time of loading into the calciner. The loading took about 1 to 2 minutes, and the temperature inside the calciner remained at its set point of about 75° C. The impregnated and dried material was heated from 75° C. to 250° C., using a heating rate of 0.5° C./min and an air space velocity of 1.0 m 3 n /kg Co(NO 3 ) 2 .6H 2 O/h, and kept at 250° C. for 6 hours. To obtain a catalyst with a cobalt loading of 30 g Co/100 g Al 2 O 3 , a second impregnation/drying/calcination step was performed. A solution of 9.4 kg of Co(NO 3 ) 2 .6H 2 O, 15.7 g of (NH 3 ) 4 Pt(NO 3 ) 2 , and 15.1 kg of distilled water was mixed with 20.0 kg of the ex first impregnation and calcination intermediate material, by adding this material to the solution. The slurry was added to a conical vacuum drier and continuously mixed. The temperature of this slurry was increased to 60° C. after which a pressure of 20 kPa(a) was applied. During the first 3 hours of the drying step, the temperature was increased slowly and reached 95° C. after 3 hours. After 3 hours the pressure was decreased to 3-15 kPa(a), and a drying rate of 2.5 m %/h at the point of incipient wetness was used. The complete impregnation and drying step took 9 hours, after which the impregnated and dried intermediate material was immediately and directly loaded into the fluidized bed calciner. The temperature of the dried impregnated intermediate material was about 75° C. at the time of loading into the calciner. The loading took about 1 to 2 minutes, and the temperature inside the calciner remained at its set point of about 75° C. The impregnated and dried intermediate material was heated from 75° C. to 250° C., using a heating rate of 0.5° C./min and an air space velocity of 1.0 m 3 n /kg Co(NO 3 ) 2 .6H 2 O/h, and kept at 250° C. for 6 hours. The resultant 30 g Co/100 g Al 2 O 3 catalyst precursor was activated, ie reduced in a pure hydrogen environment in an atmospheric pressure fluidized bed at an elevated temperature of 425° C., to obtain a cobalt slurry phase Fischer-Tropsch synthesis catalyst (catalyst A).
Catalyst B
A supported cobalt catalyst precursor was prepared in a similar manner to that described for catalyst A, except that the catalyst precursor was prepared on the pure alumina pre-shaped support, Puralox SCCa 2/150. The resultant catalyst precursor was also reduced in a pure hydrogen environment in an atmospheric pressure fluidized bed at an elevated temperature of 425° C., to obtain the cobalt slurry phase Fischer-Tropsch synthesis catalyst (catalyst B).
1.3 Pilot Plant Slurry Phase Fischer-Tropsch Synthesis Test
During a confidential Pilot Plant slurry phase Fischer-Tropsch synthesis test run, using 5 kg of the catalyst prepared on unmodified alumina, ie catalyst B, in a 11 m high bubble column reactor with an external recycle, the secondary filtered reactor wax product turned grey after about 10 days on-line and the cobalt content increased to 350 mass ppm after 25 days on line, as shown in FIG. 2 . Pilot Plant scale Fischer-Tropsch synthesis test runs were performed under realistic conditions:
Reactor temperature:
230° C.
Reactor pressure:
20 Bar
% (H 2 + CO) conversion:
50–70%
Feed gas composition:
H 2 :
about (‘ca’) 50 vol %
CO:
ca 25 vol %
Balance:
Ar, N 2 , CH 4 and/or CO 2
A similar confidential Pilot Plant slurry phase Fischer-Tropsch synthesis test run was also performed on catalyst A, and showed a substantial improvement with respect to the submicron cobalt particulate contamination in the secondary filtered reactor wax product ( FIG. 2 ). After 38 days on stream, the cobalt contamination level of the secondary filtered reactor wax product was still within the specification of <50 mass ppm.
From the Pilot Plant slurry phase Fischer-Tropsch synthesis tests, it can be seen that the improvement of the inertness of the alumina catalyst support by modifying it with silica, as shown by conductivity measurements, also prevented the formation of sub-micron cobalt rich particulates during slurry phase Fischer-Tropsch synthesis in the absence of catalyst break-up.
1.4 Laboratory Slurry Phase Fischer-Tropsch Synthesis
The cobalt catalyst precursors were reduced (as hereinbefore described) prior to Fischer-Tropsch synthesis in a tubular reactor at a hydrogen space velocity of 200 ml hydrogen/(g catalyst.h) and atmospheric pressure. The temperature was increased to 425° C. at 1° C./min, after which isothermal conditions were maintained for 16 hours.
Between 10 g and 30 g of the resultant particulate catalyst, with the catalyst particles ranging from 38 μm to 150 μm, was suspended in 300 ml molten wax and loaded in a CSTR with an internal volume of 500 ml. The feed gas comprised hydrogen and carbon monoxide in a H 2 /CO molar ratio of from 1.5/1 to 2.3/1. This reactor was electrically heated and sufficiently high stirrer speeds were employed so as to eliminate any gas-liquid mass transfer limitation. The feed flow was controlled by means of Brooks mass flow controllers, and space velocities ranging from 2 to 4 m 3 n /(kg cat hr) were used. GC analyses of the permanent gases as well as the volatile overhead hydrocarbons were used in order to characterize the product spectra.
The catalysts, ie the reduced, or activated precursors, were tested under realistic Fischer-Tropsch synthesis conditions:
Reactor temperature:
220° C.
Reactor pressure:
20 Bar
% (H 2 + CO) conversion:
50–70%
Feed gas composition:
H 2 :
ca 50 vol %
CO:
ca 25 vol %
Balance:
Ar, N 2 , CH 4 and/or CO 2
Having applied a reported cobalt based Fischer-Tropsch kinetic equation, such as:
r FT =( k FT P H2 P CO )/(1 +KP CO ) 2
the Arrhenius derived pre-exponential factor of k FT was estimated for each of the reported runs. By defining the relative intrinsic Fischer-Tropsch activity as (pre-exponential factor of catalyst X after reduction test)/(pre-exponential factor of the baseline catalyst B), where X is catalyst A or B, the intrinsic Fischer-Tropsch activities of the cobalt catalysts could be compared. The relative intrinsic Fischer-Tropsch activity is determined after 15 hours on stream (Table 1). It is clear that support modification did not influence the intrinsic Fischer-Tropsch performance characteristics when compared to the pure alumina supported cobalt catalyst, Catalyst B.
TABLE 1
Laboratory CSTR Fischer-Tropsch synthesis performance
comparison between catalysts prepared on a pure alumina catalyst
support (catalyst B) and a Siralox 1.5 successful catalyst support
(catalyst A).
Catalyst A
Catalyst B
Run Number
163F
130$
Synthesis conditions:
Calcined catalyst mass (g)
20.5
20.6
Reactor temp (° C.)
219.3
221.0
Reactor pressure (bar)
20.0
20.0
Time on stream (h)
15.5
15.0
Feed gas composition:
H 2 (vol %)
53.2
52.2
CO (vol %)
27.2
26.4
(Balance = Ar, CH 4 + CO 2 )
Syngas (H 2 + CO) space velocity
3.8
3.0
(m; n /(kg cat hr))
Reactor partial pressures (bar)
H 2
5.7
4.5
CO
3.1
2.5
H 2 O
4.2
4.8
CO 2
0.2
0.3
Synthesis performance
Conversion: % syngas
60.1
68.3
Relative intrinsic FT activity
1.1
1.0
% CO of total amount of CO converted
1.5
3.1
to CO 2
% C-atom CH 4 selectivity
4.0
4.3
EXAMPLE 2
The following modified or successful alumina supports were prepared by Sasol Germany GmbH of Üb erseering 40, 22297, Hamburg, Germany by doping of an alumina precursor (boehmite, ie AlO(OH)) before spraydrying (shaping). The modified supports were then calcined in a furnace at 750° C.:
Modified support A: doped with 1.5 m % WO 3 . Modified support B: doped with a mixture of 1.5 m % TiO 2 and 1.5 m % SiO 2 . Modified support C: doped with 1.5 m % BaO. Modified support D: doped with 4 m % Ce.
Conductivity measurements were performed on these samples under similar conditions as described in Example 1. The results are shown in FIG. 3 , is clearly demonstrating that the modification of alumina, as a catalyst support, with W, a mixture of Ti and Si, Ba and Ce effects an alumina dissolution suppression similar to that of Si as a proved successful alumina support modifier.
EXAMPLE 3
The more preferred catalyst supports for cobalt based Fischer-Tropsch synthesis catalysts are alumina, titania, magnesium oxide and zinc oxide.
Particulate titanium dioxide (Degussa P25 (trademark)) support was spraydried and calcined for 16 hours at 650° C. The support had a surface area of 45 m 2 /g. A magnesium oxide support, as supplied by MERCK, had a surface area of 88 m 2 /g. Zinc oxide pellets, as supplied by Süd Chemie, were crushed and sieved to obtain a fraction between 38 and 150 μm. The resultant zinc oxide support had a surface area of 50 m 2 /g.
The dissolution profiles of these supports were determined, and are shown in FIG. 4 .
MgO and ZnO completely dissolved in the aqueous/acidic solution during the dissolution test, as indicated by the levelling off of the dissolution profile after 1 hour on-line. Both conductivity solutions after the test did not contain any solid residue and the solutions were clear. The TiO 2 catalyst support only partially dissolved. These experiments show that the use of pure or unmodified catalyst supports in an aqeuous acidic solution will result in the dissolution thereof.
EXAMPLE 4
2 kg of a particulate TiO 2 support (obtainable from Degussa AG, under the trademark ‘P25’) was redispersed in 10 kg water and 220 g of a silica precursor, TEOS (tetra ethoxy silane), was added to the mixture, and this mixture was homogenised for 30 minutes. Thereafter the mixture was spraydried and calcined at 800° C. for 2 hours, and resulted in a doped silica modified or successful titania support. The silica modified titania support had a surface area of 46 m 2 /g. Conductivity measurements were performed on the sample as described in Example 1 and the dissolution profile compared to the dissolution profile of a pure titania support (Degussa Titania P 25).
In FIG. 5 , the cumulative mg Ti dissolved per m 2 fresh support is plotted against time. It can be seen that the unprotected and unmodified titania. support dissolved faster than the silica modified titania support, ie the successful catalyst support. | A process for preparing and using a cobalt slurry phase Fischer-Tropsch synthesis catalyst includes introducing a modifying component Mc into a catalyst support precursor, followed by shaping and calcination, to obtain a catalyst support. The catalyst support is impregnated with an aqueous solution of a cobalt salt, to form an impregnated support which is partially dried and calcined, to obtain a catalyst precursor. The catalyst precursor is reduced to form a cobalt slurry phase Fischer-Tropsch synthesis catalyst. A synthesis gas is contacted with this catalyst in a slurry phase Fischer-Tropsch synthesis reaction at elevated temperature and elevated pressure, and a clean wax product that contains less than 50 mass ppm submicron particulates of cobalt is obtained. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/423,722 filed Dec. 16, 2010, which application is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention broadly relates to torque converters, more specifically to leaf springs for setting the position of a piston in a torque converter, and even more particularly to a device for preventing the buckling of leaf springs in a torque converter.
BACKGROUND OF THE INVENTION
[0003] Torque converters are well known in the art. Torque converters often include a piston that is axially moveable for engaging a clutch. Leaf springs may be included for transferring torque (directly or indirectly) from the cover of the torque converter to the piston. The leaf springs enable the transfer of torque through the leaf springs to the piston while also being able to flex to enable the piston to move axially with respect to the torque converter cover or a drive plate for the leaf springs. For example of one type of leaf spring arrangement, see United States Patent Publication No. 2008/0190723 (Heck et al.) which Patent Publication is hereby incorporated by reference in its entirety. Typically, the leaf springs are arranged so that in a normal drive mode of operation of the torque converter, the leaf springs are subjected to only tensile forces. Since the springs are, for example, thin plate-like members, they have good tensile strength.
[0004] While coasting in an automobile, however, the forces are reversed so that the leaf springs are subjected to compression forces. By coasting, it is meant generally that the engine is idling, but the vehicle is moving, including the components of the torque converter. The compression forces on the leaf springs are a result of resistance of the engine that is coupled to the torque converter. The compression forces create a risk that the leaf springs will buckle, and become permanently bent or deformed. The engine resistance is sometimes referred to as providing “engine braking ” Basically, the torque converter and other elements are still rotating when the automobile is coasting, but the engine is not (or only to some marginal degree while idling), so the torque converter components generally act to rotate the engine while the engine is idling, instead of the other way around. The engines of many automobiles, such as typical passenger cars, do not usually exhibit engine resistance large enough to make buckling of the leaf springs a substantial risk. However, the engines of some automobiles, such as semitrailers, are arranged to strongly resist rotation while coasting, and provide a large amount of engine braking, which is exerted as compression forces on opposite ends of the leaf springs. As a result, in these vehicles there is a very real risk that the leaf springs will buckle when coasting.
BRIEF SUMMARY OF THE INVENTION
[0005] The present invention broadly comprises a buckling prevention device including a first rotational element, a second rotational element, a leaf spring arranged for transferring torque between the first and second rotational elements while enabling relative axial movement between the first rotational element and the second rotational element, a connection member fixedly connecting the leaf spring to the second rotational element, wherein the connection member extends axially through a hole in the first rotational element, wherein a gap is formed between the connection member and an edge of the hole when the leaf spring is not experiencing an overly high compression force, and wherein the connection member is operatively arranged to close the gap and engage with the first member when the spring is experiencing an overly high compression force for preventing the leaf spring from buckling and at least partially transferring the torque directly between the first and second rotational elements. In one embodiment, the first rotational element is a drive plate for the leaf spring. In one embodiment, the second rotational element is a piston for engaging a clutch. In one embodiment, the connection member is a retainer rivet having a head for engaging against the first rotational element for limiting axial movement between the first rotational element and the second rotational element in one axial direction.
[0006] The current invention also broadly comprises a torque converter including the buckling prevention device described above. In one embodiment, the second rotational element is a piston for engaging a clutch. In one embodiment, the leaf spring is operatively arranged to hold the piston in an open position with respect to the clutch. In one embodiment, the first rotational element is at least coupled mechanically to a torsional input to the torque converter. In one embodiment, the first rotational element is a drive plate for the leaf spring, and the drive plate is connected to a cover for the torque converter, and wherein the cover is connected to the torsional input. In one embodiment, the overly high compression force is a result of resistance in the torsional input, while the torsional input is idling, opposing a rotation of the cover of the torque converter. In one embodiment, the clutch is a lock-up clutch for mechanically coupling a damper of the torque converter to a cover of the torque converter.
[0007] These and other objects and advantages of the present invention will be readily appreciable from the following description of preferred embodiments of the invention and from the accompanying drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The nature and mode of operation of the present invention will now be more fully described in the following detailed description of the invention taken with the accompanying drawing figures, in which:
[0009] FIG. 1 is a cross-sectional view of a torque converter;
[0010] FIG. 2 is a front view of a leaf spring arrangement for a piston;
[0011] FIG. 3 is a cross-sectional view of the leaf spring arrangement taken generally along line 3 - 3 in FIG. 2 ;
[0012] FIG. 4 is a cross-sectional view of the leaf spring arrangement taken generally along line 4 - 4 in FIG. 2 ; and,
[0013] FIG. 5 is an enlarged view of a buckling stop device for the leaf spring arrangement of FIG. 4 .
DETAILED DESCRIPTION OF THE INVENTION
[0014] At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements of the invention. While the present invention is described with respect to what is presently considered to be the preferred aspects, it is to be understood that the invention as claimed is not limited to the disclosed aspects.
[0015] Furthermore, it is understood that this invention is not limited to the particular methodology, materials and modifications described and as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present invention, which is limited only by the appended claims.
[0016] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the preferred methods, devices, and materials are now described.
[0017] Referring now to the figures, FIG. 1 shows torque converter 10 . Torque converter 10 includes cover 12 , impeller 14 , turbine 16 , stator 18 , and vibration damper 20 for transferring torque from an engine (not shown) to an input shaft for a transmission (not shown).
[0018] Cover 12 , impeller 14 , turbine 16 , stator 18 , and vibration damper 20 could generally take any form known in the art, and the illustrated embodiment is for explanation purposes only.
[0019] In the embodiment shown throughout FIGS. 1-5 , torque is transferred from an engine into drive plate 22 , which is then transferred to cover 12 via rivets 24 . The torque is then transferred to leaf spring drive plate 26 via rivets 28 . Retainer rivet 30 is provided between leaf spring drive plate 26 and piston 32 , but it is not arranged for transferring torque directly between plate 26 and piston 32 under normal operating conditions, as there is some play or looseness in the leaf spring drive plate around the retainer rivet. Thus, retainer rivet 30 and plate 26 are moveable with respect to each other to some degree. The retainer rivet is limited with respect to plate 26 on one side due to enlarged head 31 on rivet 30 for setting an axial limit for piston 32 while the piston transitions into an open position, as will be described in more detail below.
[0020] Torque is transferred from plate 26 to piston 32 via leaf springs 36 . Specifically, as shown in FIGS. 4 and 5 , the leaf spring is fixed to plate 26 via rivet 38 and to piston 32 via retainer rivet 30 . Thus, torque is not transferred from drive plate 26 to piston 32 directly via retainer rivet 30 , but instead torque is transferred from plate 26 to rivet 38 to leaf springs 36 to retainer rivet 30 and finally to piston 32 . Typically, a plurality of leaf springs is provided about the outer perimeter of the leaf spring drive plate. Piston 32 has two axial positions, namely, an open position and a closed position, for engaging or enabling disengagement of clutch 34 , respectively. That is, surface 35 of piston 32 is brought into engagement with clutch 34 for locking damper 20 to cover 12 , or surface 35 is brought away from clutch 34 to enable the clutch to disengage.
[0021] In FIG. 1 , piston 32 is shown in the open position. The piston can be moved into the closed position, for example, by pressurizing and/or depressurizing the various chambers of the torque converter. When the pressure is released or equalized on both axial sides of the piston, the piston returns to the open position, for example, due to the pressure forces and/or slightly urged by the leaf springs, as generally shown in FIG. 1 . During this transition from the closed position to the open position, the piston in some prior art torque converters will tend to collide with other components of the torque converter, such the damper, for example, due to flexing or shifting of the components. In order to prevent piston 32 from axially moving too far away from clutch 34 and colliding with damper 20 , for example, head 31 is provided on retainer rivet 30 for providing a retaining function for piston 32 . That is, rivet 30 is rigidly secured to piston 32 at one end, with the other end moveable with respect to drive plate 26 . However movement between rivet 30 and plate 26 is limited by head 31 , which acts as a stop to limit how far rivet 30 , and therefore piston 32 , can axially move in the direction toward damper 20 . In this way, rivet 30 can be provided as a positive stop for setting a limit for the open position of piston 32 . It should be appreciated that the ability of the piston to engage clutch 34 is not compromised because rivet 30 is not secured to plate 26 , and head 31 of retainer rivet 30 does not limit the axial movement of the piston in both axial directions.
[0022] Advantageously, leaf springs 36 can flex to enable axial movement of the piston with respect to plate 26 while also enabling the transfer of torque through the springs. Typically, when the engine is being driven, the engine is transferring torque through the leaf spring such that rivets 30 and 38 are pulling on the leaf spring in opposite directions, resulting in tensile forces in the leaf spring. For example, as illustrated in FIG. 5 , rivet 30 results in tensile force component F t1 on the leaf spring, while rivet 38 results in tensile force component F t2 on the leaf spring. Since the leaf spring is essentially a thin plate-like member, it has good tensile strength and forces F t1 and F t2 will not easily damage the leaf spring.
[0023] However, when the engine is idling and the vehicle is moving, the torque converter is still rotating in the drive direction, but the engine will not. Instead, as mentioned supra, the engine will resist the rotation, so that cover 12 actually transfers torque back to the engine. That is, while coasting, the engine is idling and instead of driving the torque converter cover, the engine is rotated by the torque converter cover. Again, frictional forces in the engine oppose this rotation while the engine is idling. As a result, rivets 30 and 38 will exert forces on the leaf spring towards each other. That is, rivet 30 will exert force F c1 on the leaf spring toward rivet 38 , while rivet 38 exerts opposing force F c2 on the leaf spring in the direction of rivet 30 . If the torque, and therefore force, is high enough, then these compressive forces can exceed a critical level, resulting in buckling of the leaf springs, which would generally cause the leaf spring to bend, bringing rivets 38 and 30 closer together. Springs are used primarily because they demonstrate good elastic properties, namely, they return to their original shape after an applied force is removed. Under too much compressive force, however, the buckling will cause the springs to yield and become plastically deformed.
[0024] Retainer rivet 30 is also arranged with leaf spring drive plate 26 to prevent buckling of leaf springs 36 . As mentioned previously, there is some play or looseness between rivet 30 and drive plate 26 . Specifically, as can be seen in FIG. 4 and the enlarged view of FIG. 5 , gap 40 is provided between the body of rivet 30 and drive plate 26 . Specifically, rivet 30 extends axially through hole 42 in drive plate 26 . Gap 40 could be formed, for example, by making hole 42 in drive plate 26 greater in diameter than rivet 30 , or by making hole 42 ellipsoidal or some other shape. Gap 40 is positioned such that if leaf spring 36 begins to buckle, rivet 30 will shift toward drive plate 26 in the direction of force F c1 and close the gap. With enough deformation of leaf spring 36 , gap 40 will close completely, and rivet 30 will engage against plate 26 at the edge of hole 42 . Once the gap is closed and rivet 30 is pressed firmly against drive plate 26 , rivet 30 will prevent further buckling of the leaf spring by acting as a stop against the edge of the hole in drive plate 26 . Additionally, torque from piston 32 to drive plate 26 will be at least partially transferred directly through rivet 30 . That is, drive plate 26 and rivet 30 act to provide a hard stop for limiting the compression or buckling experienced by the leaf springs. Accordingly, the leaf springs are only able to buckle a distance approximately equal to gap 40 .
[0025] The leaf springs are provided so that there is not a hard mechanical link to the piston, such as by a rivet, because such a link may cause a rattling or other performance issues. By creating this hard mechanical link only when necessary, that is, to prevent buckling of the leaf springs, performance is not decreased and the longevity of the system, the leaf springs in particular, is greatly improved. In this way, the size of gap 40 and/or hole 42 can be altered to achieve a balance between the amount of buckling allowed in the leaf springs and how often the rivet will engage with the drive plate.
[0026] It should be appreciated that while rivets are disclosed as the preferred connection means for connecting the various components of the torque converter together, other connecting members could be used in lieu of rivets. For example, bolts could be used in a similar fashion as any of the rivets, and including a head for a retaining function similar to head 31 .
[0027] Thus, it is seen that the objects of the present invention are efficiently obtained, although modifications and changes to the invention should be readily apparent to those having ordinary skill in the art, which modifications are intended to be within the spirit and scope of the invention as claimed. It also is understood that the foregoing description is illustrative of the present invention and should not be considered as limiting. Therefore, other embodiments of the present invention are possible without departing from the spirit and scope of the present invention. | A buckling prevention device including a first rotational element, a second rotational element, a leaf spring arranged for transferring torque between the first and second rotational elements while enabling relative axial movement between the first rotational element and the second rotational element, a connection member fixedly connecting the leaf spring to the second rotational element, wherein the connection member extends axially through a hole in the first rotational element, wherein a gap is formed between the connection member and an edge of the hole when the leaf spring is not experiencing an overly high compression force, and wherein the connection member is operatively arranged to close the gap and engage with the first member when the spring is experiencing an overly high compression force for preventing the leaf spring from buckling and at least partially transferring the torque directly between the first and second rotational elements. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 10/914,939, filed Aug. 9, 2004, which is a continuation of U.S. patent application Ser. No. 10/102,276, filed Mar. 20, 2002, the entire contents of each of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to bedding products (including but not limited to mattresses) and in particular to edge support systems used to stiffen the perimeter of a bedding product.
[0004] 2. Description of the Related Art
[0005] A traditional bedding or seating product has an inner spring core comprising a plurality of identically configured coil springs arranged in linear columns and rows. If such a spring core is used in a bedding product, the spring core is covered with a mattress pad or covering materials and an upholstered covering surrounds and encases the spring core and mattress pad. Sometimes, an additional padding layer, known as a “topper” is attached to the top sleeping surface. The topper may also be attached to the bottom sleeping surface as well, so that the mattress can be flipped.
[0006] Traditional bedding or seating products typically have one degree of firmness throughout because all of the springs of the spring core are identical.
[0007] Alternatively, bedding and seating systems may have a resilient foam core. This foam core may be surrounded by perimeter bolsters, located around the edges of the sleeping surface, i.e., at the head, foot, or sides of the mattress as those terms are known in the art. Foam core mattresses may also include toppers, in addition to mattress pads and covers.
[0008] Also known in the art are bedding or seating products that have increased firmness about their perimeter edge portions, primarily to prevent collapse of the side edges of the bedding or seating product when a person sits on the side edges. The well-known border wires found in almost all mattresses and seating products are one such device. These edge reinforcements also prevent loss of resiliency of the perimeter edge of the bedding or seating product as a result of persons repeated getting on and off the product or by sitting or leaning on one edge of the bedding or seating product.
[0009] Most of these edge supports enhances the firmness by locating firmness enhancing materials or devices between the upper and lower border wires of the product. This limits the effectiveness of the edge support and subjects the border wires to excessive bending forces.
[0010] What is needed is an edge support for a bedding or seating product which enhances the firmness of the edge of the product while preventing the border wire from being repeatedly flexed and possibly permanently bent due to a user sitting on the edge of the bedding or seating product.
SUMMARY
[0011] A stiffening system for the perimeter edges of a foam core mattress comprising a coil spring (or other spring-based) structure disposed along one or more perimeter edges (e.g., one or both side edges, the foot, the head, or a combinations thereof including the foot and both side edges) of a mattress having a foam sleeping area. The perimeter spring-based structure is rectangular or square in cross-section and provides sufficient stiffness for comfortable seating on the edges of the mattress, while the sleep area defined within the perimeter spring structure provides the softness and other salutary effects of a foam sleeping surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present disclosure may be better understood and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings.
[0013] FIG. 1 is an isometric view of a bedding product according to one embodiment of the invention.
[0014] FIG. 2 is a cross-section view at AA of FIG. 1 .
[0015] FIG. 3 is an alternate embodiment of the invention, shown in cross-section view at AA.
[0016] FIGS. 4A, 4B , and 4 C are plan views of a bedding product according to several alternate embodiments of the invention.
[0017] The use of the same reference symbols in different drawings indicates similar or identical items.
DETAILED DESCRIPTION
[0018] FIG. 1 illustrates, in an isometric view, a bedding product generally and in particular a mattress 10 manufactured according to one embodiment of this invention. Mattress 10 consists of a top sleeping surface 12 , a bottom sleeping surface 14 , a head 15 , a foot 16 , and two side edges 17 . Top sleeping surface 12 and bottom sleeping surface 14 may include within them, or have attached to them, a topper (not shown). The topper may contain one of more layers of fabric, batting, ticking, foam, and/or coiled springs. When present, the foam layer(s) of the topper may include latex and/or synthetic foam, including but not limited to polyurethane foam.
[0019] Although omitted for clarity, the topper may be either permanently or removably attached to sleeping surface 12 and 14 . Examples of permanently attached topper, seen in the art, are those that are sewn or bonded onto the mattress cover or those that are encased within a sealed pocket in the mattress cover, yet disposed on the surface of the mattress. Removable toppers are typically attached with a temporary fastener, such as a zipper or hook-and-loop fastener in one or more locations. Either attachment method may be used, or no topper may be supplied.
[0020] Mattress 10 also includes foam core 20 and perimeter element 25 . Foam core 20 is, in some embodiments, a single, monolithic block of a single type of resilient foam selected from foams having a range of densities (themselves well-known in the art) for supporting one or more occupants during sleep. In one embodiment, foam core 20 is made of any industry-standard natural and/or synthetic foams, such as (but not limited to) latex, polyurethane, or other foam products commonly known and used in the bedding and seating arts having a density of 1.9 and a 22 ILD (also known as “192 foam”). Although a specific foam composition is described, those skilled in the art will realize that foam compositions other than one having this specific density and ILD can be used. For example, foams of various types, densities, and ILDs may be desirable in order to provide a range of comfort parameters to the buyer.
[0021] In an alternative embodiment, foam core 20 may comprise one or more horizontal layers of multiple types of foams arranged in a sandwich arrangement. This sandwich of different foams, laminated together, may be substituted for a homogeneous foam block of a single density and/or ILD. Accordingly, the invention is not limited to any particular type of foam density or ILD or even to a homogenous density/ILD throughout foam core 20 .
[0022] In a further embodiment, foam core 20 may comprise one or more vertical regions of different foam compositions (including vertical regions having multiple horizontal layers), where the different foams are arranged to provide different amounts of support (also referred to as “firmness” in the art) in different regions of the sleeping surface.
[0023] Perimeter element 25 is an array of coil springs 32 of substantially the same height as foam core 20 is thick, as shown in FIG. 2 . FIG. 2 is a cross-section view at AA of FIG. 1 and illustrates the relative placement of perimeter element 25 abutting side edges 17 . The term “perimeter element” is used herein to denote the entire perimeter spring array, whether it abuts one or more than one edge of foam core 20 . Accordingly, while FIG. 1 shows a perimeter element 25 that abuts three edges of foam core 20 (to wit, foot 16 and two sides 17 ), the definition of the term “perimeter element,” and the invention in general, are not limited to the configurations illustrated herein.
[0024] Springs 32 are of a conventional helical or semi-helical type known and used in the art today. Springs 32 may also be encased in a fabric pocket, either individually, in groups, or pocketed in strings joined by fabric, all of which are well-known in the bedding art.
[0025] Note also that the mattress drawn in FIG. 1 is not drawn to scale: the perimeter element 25 is generally about two to six inches wide (measured from the sleeping surface outward to the ultimate edge of the mattress), while the overall mattress dimensions typically fall into the ranges commonly found in the trade and referred to, for example, as Twin, Full, King, Queen, Double, etc.
[0026] Returning to FIG. 2 , border wires 40 of a type and construction well-known in the art are placed at the outer vertices of perimeter element 25 . Alternatively, to supply even more stiffness at the mattress edges, an additional set of border wires 40 may be placed at the inner vertices 35 of perimeter element 25 (see FIG. 3 ). All of these border wires 40 may be used as attachment points for securing springs 32 within perimeter element 25 , as with the clips or metal “hog ring” attachment devices currently known and used in the bedding art today.
[0027] Although hog ring or clip attachment means are described, those skilled in the art will realize that attachment devices other than hog rings, such as plastic snap fasteners, locking cable ties, wire twists, lacing, or cord can be used. Accordingly, the invention is not limited to any particular type of attachment means for securing coils 32 to border wires 40 .
[0028] In some embodiments, border wires 40 may also be omitted, along with the hog ring/clip attachment means in order to reduce cost and/or manufacturing complexity.
[0029] Perimeter element 25 and foam core 20 are attached one to the other by planar elements 50 . Each planar element 50 is a textile material, including but not limited to a tape or webbing or open-weave material, non-woven fibers, or a coated fabric capable of heat lamination (fusion, i.e., a “fusible fabric”) to and with both foam core 20 and perimeter 25 . Alternatively, planar elements 50 may be attached by means of gluing, stitching, quilting, riveting, or welding, or by other attachment means currently known or afterwards discovered for attaching fabric-like, planar materials to both foam and metallic elements (i.e., the perimeter element's array of springs), whether or not the perimeter element consists of fabric-pocketed coils and whether or not the perimeter element is encased in a covering.
[0030] In one embodiment, planar elements 50 consist of strips of Weblon® or Duong brand ticking. Duon is a polyethylene or polypropylene fiber (an olefin, generally) manufactured by Phillips Fiber Corp.
[0031] Planar elements 50 , which may consist of a single piece of material cut or otherwise formed to span all foam core/perimeter element interfaces or multiple strips of material that abut or overlap when they intersect, is typically about three to six inches wide, though the exact width is not critical. ( FIG. 1 , by way of example and not limitation, shows planar elements 50 as three strips of material overlapping at two intersections.) Planar elements 50 are placed on the sleeping surface of mattress 10 substantially as shown in FIG. 2 , roughly centered on the joint formed by the abutting components and overlapping portions of both foam core 20 and perimeter element 25 prior to attachment to both. Alternatively, planar element(s) 50 may be first attached to foam core 20 before the core is brought into abutment with perimeter element 25 , in order to aid handling and manufacturing. Such an arrangement creates a foam core with a “flange” of planar element material around it.
Alternate Embodiments
[0032] FIG. 3 is an alternate embodiment of mattress 10 , shown in a cross-section view at AA (referring to FIG. 1 ), illustrating an alternate embodiment having two sets of border wires 40 .
[0033] In some embodiments, planar elements 50 may be omitted entirely. In these embodiments, a perimeter element 25 consisting of pocketed coils may be glued directly to foam core 20 .
[0034] FIG. 4A illustrates, in plan view, a further alternate embodiment of the invention, in which perimeter elements 25 extend around all four sides of foam core 20 . Such an embodiment is useful, for example, in bedding products for use without a headboard or footboard or when it is desirable to be able to flip the mattress from head to foot to extend the lifetime of the sleeping surfaces. Other embodiments, in which perimeter element 25 is placed on only one or only two sides or on the head or foot alone, are equally within the scope and spirit of this invention and are shown in FIGS. 4B and 4C .
[0035] The order in which the steps of the present method are performed is purely illustrative in nature. In fact, the steps can be performed in any order or in parallel, unless otherwise indicated by the present disclosure.
[0036] In particular, as an aid to manufacturing, the planar elements may be first attached to the foam core to form a soft “flange” prior to placing the perimeter elements in abutment with the foam core (or vice-versa). Once abutting, the “flange” (unattached) portion of the planar element can be laminated or otherwise bonded to the perimeter element.
[0037] While particular embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspect and, therefore, the appended claims are to encompass within their scope all such changes and modifications as fall within the true spirit of this invention. | A stiffening system for the perimeter edges of a foam core mattress comprising a coil spring (or other spring-based) structure disposed along one or more perimeter edges (e.g., one or both side edges, the foot, the head, or a combinations thereof including the foot and both side edges) of a mattress having a foam sleeping area. The perimeter spring structure is rectangular or square in cross-section and provides sufficient stiffness for comfortable seating on the edges of the mattress and is joined to the foam core by planar fabric elements that span the joint between them and are attached to both. The sleep area provides the softness and other salutary effects of a foam sleeping surface while the stiffer spring perimeter element provides the rigidity need for comfortable seating and wear resistance. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the detection of covert communication signals. More particularly, this invention relates to a novel circuit for detecting the presence of signals which typically are received at very low signal to interference and noise ratios.
2. Description of the Prior Art
The general class of signals to which the present invention is directed are commonly referred to as periodically keyed random modulated signals. For example, communications intelligence is often transmitted in coded form. One form or way of denying data access to the enemy is to transmit the data stream in direct sequence spread spectrum format. It is extremely difficult to detect data signals embedded or encoded in such spread spectrum format because the signal to noise ratio is so low as to make detection difficult.
Before it is possible to attempt to decode direct sequence spread spectrum coded data signals, it is necessary to determine that such coded signals are actually being transmitted. This invention is directed to the problem of detecting that such coded signals are being transmitted and is not directed to the problem of decoding such signals.
It has been suggested that radiometers or power signal detection devices be employed to determine if periodically keyed random modulated signals are being transmitted. When such signals are received at a receiver it is often impossible to distinguish them from the receiver noise, thermal background noise, other transmitted signals and interfering emission signals. It is possible that the power level of the signals which are to be detected do not exceed the background noise and interference signals mentioned above. Thus, it is often impossible to employ radiometers and power detection devices to detect the presence of low power periodically keyed random modulated signals.
When a radiometer is employed to detect the presence of a signal, then the threshold of the detector must be set very close to the signal levels. Changes in either the interference levels or the threshold levels will affect the sensitivity of the receiver which results in false alarms or reduced sensitivity. For example, if a threshold of a radiometer is set to detect the desired signal at a -20 db signal to noise ratio, then a one percent increase in interference level will cause a false alarm.
It has been suggested that since periodically keyed random modulated signals by definition change symbols at a fixed rate, it may be possible to detect the periodic repetition as a clock signal even though the data signal is not discernible.
One prior art attempt to recover the inherent clock in a periodically keyed modulated signal was to pass the received signal through a filter and then through a non-linear detector to provide power concentrated as a spectral line at the clock frequency. The output from the non-linear detector was then passed through a narrow bandpass filter tuned to the known clock frequency and that output was enveloped detected to provide an indication of the signal amplitude level as an output from the narrow bandpass filter. If the amplitude level output from the envelope detector exceeded the predetermined noise and interference reference threshold level then there is a high likelihood that a periodically keyed random modulated signal was being received.
These prior art devices have been found to require wide band filters to achieve desirable sensitivity. It is well-known that wide band width filters in such clock recovery circuits will also pass more high energy spectral lines, narrow band width signals and other noise which will be confused with the desired clock signal.
If narrow band width filters could be employed in clock recovery circuits, some of the aforementioned problems could be eliminated. Accordingly, it would be desirable to be able to detect the inherent keyed clock signal present in low signal to noise ratio periodically keyed random modulated signals employing narrow band width filters.
SUMMARY OF THE INVENTION
It is a principal object of the present invention to provide a novel clock recovery circuit for periodically keyed random modulated signals.
It is another principal object of the present invention to provide a dual channel clock recovery circuit for low signal to noise ratio periodically keyed random modulated signals.
It is another principal object of the present invention to provide a dual channel clock recovery circuit for low signal to noise ratio periodically keyed random modulated signals.
It is another object of the present invention to provide a circuit having dual channels comprising narrow bandpass filters to recover a clock signal from a periodically keyed random modulated signal.
It is another object of the present invention to provide means for adjusting and changing the frequency of the clock signal recovered to enable a search for an unknown clock frequency.
It is another object of the present invention to provide means for automatically generating a threshold reference voltage for establishing the background noise and interference level which is to be compared with the clock.
It is yet another object of the present invention to provide a new and more reliable circuit for detecting the absence or presence of periodically keyed random modulated signals.
According to these and other objects of the present invention there is provided a circuit for detecting the presence or absence of a periodically keyed random modulated signal which includes a power splitter adapted to supply two separate and distinct channels with the source of periodically keyed modulated signals. The separate channels contain narrow bandpass filters. One is tuned to a frequency higher than the expected center frequency of the periodically keyed random modulated signals and the other bandpass filter is tuned to a frequency lower than the expected center frequency. The distance between centers of the narrow bandpass filters is approximately the clock frequency to be detected. The output from the narrow bandpass filters is connected to a mixer to provide an output signal representative of a clock having a frequency equal to said periodically keyed random modulated signals. The output of the mixer is then analyzed so as to determine the presence or absence of the inherent clock signal which would indicate that periodically keyed random modulated signals are being transmitted.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a prior art radiometer for use in measuring power in selected frequency bands;
FIG. 2 is a power spectral plot showing a typical periodically keyed random modulated signal of the type to be detected;
FIG. 3 is a block diagram showing a prior art single channel circuit for recovering the clock signal from a randomly modulated intermediate frequency signal;
FIG. 4 is a block diagram showing the present invention dual channel circuit for recovering the clock signal from a periodically keyed random modulated signal;
FIG. 5 is a diagram of input and output signal frequency spectrums for the circuit of FIG. 4;
FIG. 6 is a diagram of performance versus bandwith for the circuits of FIGS. 3 and 4 employing single pole I.F. filters;
FIG. 7 is a diagram of performance versus bandwidth for the circuits of FIGS. 3 and 4 employing rectangular I.F. filters;
FIG. 8 is a block diagram of the present invention showing a modified dual channel circuit embodiment for recovering the clock signal from a randomly modulated intermediate frequency signal;
FIG. 9 is a diagram of the input signal frequency spectrum for the circuit of FIG. 8;
FIG. 10 is a diagram of the output signal frequency spectrums for the circuit of FIG. 8; and
FIG. 11 is a diagram showing the probability of narrow band interference generating a false alarm in the circuits of FIGS. 1, 3, 4 and 8.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Refer to FIG. 1 showing in block diagram form the components of the prior art radiometer 10. An input signal on line 11 contains the intermediate frequency signal which is to be searched for the absence or presence of a periodically keyed randomly modulated signal. The intermediate frequency signal on line 11 is applied to the broad bandpass filter 12 which removes the frequency componants on either side of the band which is being searched. The output from bandpass filter 12 on line 13 is then detected in a square law detector 14 to provide an output on line 15 which is a measure of the power of the signal being passed through filter 12. The power signal on line 15 is passed through a narrow low pass filter 16 to smooth the power output signal on line 15. The smoothed power measurement is applied via line 17 to a comparator 18 which is provided with a voltage threshold reference on line 19. When the power level on input line 17 exceeds the predetermined voltage threshold level on line 19 a signal is provided on output line 21 which indicates that more power is being received at line 11 than can be accounted for by the background noise and interference signals. The problem with this prior art device is that it does not give a positive indication that a periodically keyed random modulated signal is being received.
Refer now to FIG. 2 showing a power spectral plot of a typically periodically keyed random modulated signal of the type to be detected. The main lobe 22 has an abscissa or X axis frequency base plotted versus the watts per hertz as the Y axis. The spectral plot shows side lobes 23 which are not to be detected by the present invention. The center frequency of the main lobe 22 is designated by F if which is the intermediate frequency of the signals being received at the input to the filter 12. The frequency response of a typical broad bandpass filter is shown in phantom lines at 24. The filter frequency response 24 is superimposed on main lobe 22 at the same frequency and as a function of the gain from input to output of the filter. Thus, if the filter 12 of FIG. 1 has the same bandpass as the filter frequency response 24, then the output signal on line 13 will be restricted to the frequency shown. When high energy interference signals or noise appear in the frequency spectrum embraced by the filter frequency response 24 of the broad bandpass filter 12, then the signal may exceed the reference voltage on line 19 and cause an output on line 21 which is a false signal.
Refer to FIG. 3 showing a prior art single channel clock recovery circuit. The intermediate frequency signal to be detected is shown being applied via line 25 to a broad bandpass filter 26 similar to filter 12. The output on line 27 is applied to a square law detector 28 similar to detector 14. The output from square law detector 28 on line 29 is applied to a narrow bandpass filter 31 to remove the interference and noise signals close to the clock frequency spectral line. The output or tone signal from the narrow bandpass filter 31 on line 32 is applied to the envelope detector 33 to provide an amplitude output signal on line 34 indicative of the tone signal being enveloped detected. The amplitude signal on line 34 is applied to the threshold comparator 35 which is also supplied with a reference voltage threshold input via line 36. When the amplitude signal on input line 34 exceeds the reference voltage on line 36 the threshold comparator 35 produces an output signal on line 37 indicative of the presence of a periodically keyed random modulated signal being present at the input line 25. As explained herein above, with reference to FIGS. 1 and 2 it is not desirable to have to employ broad bandpass filters 12 and 26 in order to detect the main lobe of the signal to be detected. When such broad bandpass filters are employed the incidents of false indications increases substantially.
Refer now to FIG. 4 showing a block diagram of the present invention employing dual channel circuits with narrow bandpass filters to recover the clock signal from a periodically keyed random modulated signal. The clock recovery circuit 30 is shown having an antenna 38 connected via line 39 to a down converter 41 of the type which modulates the incoming signal to provide an intermediate frequency signal on line 42. The signal on line 42 is divided in power splitter 43 to provide identical signals on lines 44 and 45 which are applied to the narrow bandpass filters 46 and 47. The narrow bandpass filter 46 is tuned to provide an intermediate frequency plus half of the clock frequency on output line 48. The narrow bandpass filter 47 is tuned to provide the intermediate frequency minus half the clock frequency on output line 49. The signals on lines 48 and 49 are applied to mixer 51 to produce an output on line 52 which is representative of the inherent clock frequency of the periodically keyed random modulated signal if such signal is present. If the periodically keyed random modulated signal is not present at the input line 42 then the only signal present on line 52 is the noise and interference signals. Assuming that a periodically keyed random modulated signal was present then there is a clock signal on line 52 which is applied to the wide low pass filter 53 to provide the different frequencies from the mixer 51 as an output on line 54. The difference frequency on line 54 is applied to mixer 55. A tuneable oscillator 56 is connected to mixer 55 via line 57 to provide an output on line 58 representative of a clock frequency which has been changed slightly by the tuneable oscillator 56. The tuneable oscillator 56 permits the circuit 30 to be employed to search for unknown clock frequencies over a range approximate equal to the range of the passband of the bandpass filters 46 and 47. The modified clock signal on line 58 is applied to the narrow bandpass filter 59. Narrow bandpass filter 59 is tuned to the center frequency of the clock signal on line 58 whereas the center frequency of the aforementioned narrow bandpass filters 46 and 47 is tuned to the center frequency of the intermediate frequency plus or minus half of the clock frequency. Assuming that the frequency of the clock on line 59 is tuned to the center of the narrow bandpass filter 59 an output on line 61 is produced which is a high amplitude signal assuming that the periodically keyed random modulated signal is present. The high amplitude signal on line 61 is applied to the square law detector 62 to provide a signal on line 63 which is proportional to the power of the bandpass filter 59. The signal on line 63 is applied to the comparator 64 which is also provided with a reference voltage threshold signal on line 65. When the signal on line 63 exceeds the voltage threshold level on line 65 an output signal will be produced on line 66 which is indicative of the presence of a clock signal thus indicating that a periodically keyed random modulated signal was also present at the input IF line 42.
Another feature of the present invention is the provision for generating an automatic voltage threshold reference level. The line 58 on which the modified clock signal appears is also applied to a reference bandpass filter 67 to produce an output on line 68. The reference bandpass filter 67 is tuned to a portion of the frequency spectrum which does not contain the modified clock frequency on line 58 thus the output on lines 68 is indicative of the noise background and interference level being produced. The background noise and threshold level on line 68 is applied to a square law detector 69 to produce a power output signal on line 71 which is applied to a narrow low pass filter 72 which smooths the input signal on line 71 and provides the desired referenced voltage on line 65 which is applied to the comparator 64.
Refer now to FIG. 5 which is a diagram showing the input signal frequency spectrum and the output signal frequency spectrum for the circuit of FIG. 4. The X axes of FIGS. 5a and 5b are frequency based and the Y axis is the signal strength and watts per hertz. In FIG. 5a the center of the frequency spectrum of this curve is the intermediate frequency shown at point 73. This point is representative of the frequency of this signal being applied at line 42 to power splitter 43. The filter response curve 74 is indicative of filter 46 which has its frequency tuned to the center of a frequency indicated by the intermediate frequency plus half of the clock frequency. The response curve 75 is indicative of filter 47 which has its center frequency tuned to the intermediate frequency minus half the clock frequency.
In the preferred embodiment of the present invention the center of the frequency response curves 74 and 75 are separated by the clock frequency F CL . If the frequency response curves 74 and 75 are either closer together or further apart than the separation shown by the clock frequency the power in the clock line which is available at line 52 is degraded. The input power spectrum at line 42 is shown as curve 76. It will be noted that any reasonable operable combination of narrow bandpass filters will produce an overlap of the two response curves 74, 75 at the intermediate frequency point 73. This overlap will cause a DC power component to appear in the output of mixer 51 on line 52 and is preferably made as small as possible.
Refer now to FIG. 5b showing the output freqency spectrum. At the zero frequency point a spectral line or DC component 77 is shown which is indicative of the total power in the overlapping region of the filter response curve 74, 75. The keying clock spectral line 78 is shown at the clock frequency F CL and its magnitude is shown greater than the DC spectral line 77. However, since there is no interference noise component on the spectral line 78 it is entirely possible that the DC spectral line 77 may be greater in magnitude than the keying clock spectral line 78. The waveforms 79 represents the residual power spectrum due to the interference signals noise and background etc. and appears at the output of mixer 51 on line 52. It will be noted that the narrow bandpass filter 59 is employed to filter out as much of this residual power spectrum 79 as possible. Waveform 81 which represents the sum frequency power spectrum also appears on output line 52. The power spectrum waveform 81 is removed by the wide low pass filter 53. Having explained the waveforms associated with FIGS. 5a and 5b it will be recognized that the filter response curve 74 and 75 may be made very narrow so as to eliminate the interference spectral lines which will be explained in more detail hereinafter.
Spectral line 82 is representative of the spectral line which will appear at twice the intermediate frequencies for some forms of transmission such as when the signal is bi-phased shift keyed.
FIG. 6 is a curve which is adapted to illustrate that the degradation of the input power to the clock recovery circuit 30 of FIG. 4 is much less than the degradation of the input power to the prior art clock recovery circuit 20 of FIG. 3 for low values of the bandwidth of the filters employed in the respective circuits. Curve 83 represents the degradation of the input power when the clock recovery circuit FIG. 4 is employed. It will be noted that the curve 83 drops substantially to one decibel and does not exceed three decibels until the noise equivalent bandwidth is exceeding approximately one and a half times the clock frequency. It will be noted that the curve 84 which is associated with the degradation of power input to FIG. 3 stays substantially higher than curve 84 until it reaches the noise equivalent bandwidth of approximately one and a half times the clock frequency. Thus, it will be appreciated that the curves of FIG. 6 show that the degradation of the improved clock recovery circuit is much less than the prior art clock recovery circuits over the desired operable IF bandwidths. The curves 83, 84 of FIG. 6 were derived assuming that a single pole bandpass filter was employed in the respective circuits.
Refer now to FIG. 7 which is a diagram of the performance versus the bandwidth for the circuits of FIGS. 3 and 4 when rectangular IF filters are employed in the respective circuits. Curve 85 represents the degradation of the input power signal of the present invention circuit 30 of FIG. 4. It will be noted that the degradation of the signal is less than one decibel at the operating frequency of approximately one times the clock frequency and does not exceed three decibels degradation until approximately one and one half times the clock frequency. However, when employing the rectangular filters in the prior art circuit 20 shown in FIG. 3 the degradation of the input signal at one times the clock frequency shown in curve 86 is over three decibels and does not reduce to a point below one decibel until after one and a half times the clock frequency is obtained. FIG. 7 illustrates the ability to achieve acceptable noise performance results employing very narrow intermediate frequency bandwidth filters and also shows that the prior art clock recovery circuits require relatively broad bandpass filters to achieve equivalent white noise sensitivity. Stated differently, this diagram of curves in FIG. 7 shows that the same amount of power is obtained by the new circuit of FIG. 4 without broadening the bandpass filter spectrum which would also permit the introduction of extraneous spectral lines and noise in the output being detected.
Refer now to FIG. 8 showing another form of the present invention. The block diagram of FIG. 8 is a modification of the novel clock recovery circuit of FIG. 4. FIG. 4 employed two bandpass filters in a single dual channel arrangement whereas FIG. 8 illustrates a plurality of dual channels. The down converted intermediate frequency signal to be detected is present on input line 87 and is applied to power splitter or divider 88. The output on lines 89, 91 is applied to a first pair of bandpass filters 92, 93 which operate in an identical manner as explained hereinbefore with respect to the narrow bandpass filters 46, 47 of FIG. 4. The output from the narrow bandpass filters 92, 93 on lines 94, 95 is applied to the first mixer 96. The recovered clock signal on line 97 is applied to a first spectrum analyzer 98 which analyzes the output frequency spectrum similar to that explained with regard to FIG. 5b. The output of the spectrum analyzer 98 on line 99 is applied to a threshold detector 101 to produce a signal output on line 102 when the input signal on line 99 exceeds the referened voltage on line 103.
Output lines 104 and 105 from power splitter 88 are applied to a second pair of narrow bandpass filters 106, 107 to produce filtered outputs on lines 108, 109 which are applied to the second mixer 111. The output of the second mixer 111 on line 112 is representative of an output frequency spectrum similar to that explained with regards to FIG. 5b. The output of the second spectrum analyzer 113 on line 114 is applied to the threshold detector 115 to produce an output on line 116 when the input on line 114 exceeds the referenced voltage on line 117. The outputs of the threshold detectors 101 and 115 are applied to AND gate 118 to produce an output on line 119 when signals are present on both lines 102 and 116. The output from AND gate 118 on line 119 is employed to set the flip-flop 121 to produce an output on line 122. Flip-flop 121 is representative of any type of device which will sample and hold the signal on line 119. Thus it will be understood that flip-flop 121 may be a monostable flip-flop or it may be reset by means not shown. The bandpass filters 92, 93 are similar to those explained hereinbefore with reference to FIG. 4. Similarly, the bandpass filters 106, 107 are tuned to different frequency from the frequency of the bandpass filters 92, 93 and operate in a manner similar to that explained with regards to FIG. 4.
Refer now to FIG. 9 for an explanation of the operation of the narrow bandpass filters employed in FIG. 8. FIG. 9 is a diagram of the input signal frequency spectrum for the circuit of FIG. 8. The filter response curve 123 is representative of the output from narrow bandpass filter 92. The filter response curve 124 is representative of the output from narrow bandpass filter 93. The filter response curve 125 is representative of the output of narrow bandpass filter 106 and the filter response curve 126 is representative of the output narrow bandpass filter 107. It will be understood by examination of FIG. 9 that the narrow bandpass filters of the circuit of FIG. 8 are all tuned to a frequency which is very close to the intermediate frequency 127 and that the separation of the respective pairs of filters 123, 124 and 125, 126 are separated by the clock frequency shown as F CL . The filter response curves 123, 124, 125 and 126 illustrate clearly that the narrow bandpass filters 92, 93, 106 and 107 may all be operably placed within the main lobe of the input power spectrum 128. Superimposed on FIG. 9 there are shown spectral lines which are representative of narrow band interferers. The interferers 129, 132, 131, etc. are representative of very narrow band signals which occur at different frequencies close to the intermediate frequency. By employing the very narrow band filters in the FIG. 8 embodiment it is possible to eliminate the coincidence of these narrow band interferers with the filter response curves. While it is not possible to eliminate the coincidence of narrow band interferers in every incident, it is possible to eliminate a majority of such interferers. It will be noted that the interferers illustrated in FIG. 9 are random and completely independent of the filter response curves. These interferers may be fixed or may be transient. Thus, using two or more sets of filters it is possible to eliminate false alarms because the random interferers do not occur in both sets of filters simultaneously.
Refer now to FIGS. 10a and 10b showing a diagram of the output signal frequency spectrums for the circuit of FIG. 8. The spectral lines interferers 133, 134, 135, etc. are the spectral lines which are appearing at the output of spectrum analyzer 98 on line 99. It will be understood that the magnitude of the spectral lines may have reached the point where they will exceed the reference threshold voltage at line 103 and produce a false clock indication on output line 102. A clock spectral line 136 is shown appearing in FIG. 10a at the exact coincident frequency of the clock which is shown at frequency line 137.
The spectral lines 138, 139 and 141 are shown as interferers or spectral lines which appear at the output of spectrum analyzer 113 on line 114. These spectral lines are shown being large enough to create a false alarm output from the threshold detector 115 on line 116. Further, the clock spectral line 142 is shown being coincident with the frequency line 137. By combining the outputs from the threshold detectors 101 and 115 in AND gate 118 it is possible to isolate the clock spectral lines 136 and 142 from the interfering spectral lines 133 to 135 and 138 to 141. Thus, it will be appeciated that the random interfering spectral lines do not appear coincident with each other in normal operation and the probability of their occurring simultaneously is very low, thus, the number of false alarms produced at the output line 122 are substantially reduced by employing two or more dual channels as shown in FIG. 8.
Refer now to FIG. 11 showing a diagram of the probability of the narrow band interferers generating a false alarm. Curve 143 of FIG. 11 shows the probability of generating an interference false alarm when the radiometer circuit 10 of FIG. 1 is employed. It will be understood that any narrow band interferer which passes through the radiometer circuit of FIG. 1 and is of sufficient magnitude to produce an output will also produce a false alarm.
Curve 144 shows the probability of the clock recovery circuits associated with FIGS. 3 and 4 producing a false alarm. When two interferers of sufficient magnitude occur and are separated by the clock frequency an interference false alarm can be produced with the clock recovery circuits of FIG. 3 and 4.
Curve 145 shows the probability of producing an interference false alarm when employing the novel circuit of FIG. 8. This assumes that at the FIG. 8 spectrum analyzers 98 and 113 are basically single bandpass filters in their mode of operation. When the spectrum analyzers 98 and 113 are replaced with a more complex and expensive multipoint spectrum analyzer, the curve 146 is more representative of the probability of interference of false alarms being produced.
Having explained a simplified preferred embodiment dual channel narrow bandpass filter clock recovery circuit it will be appreciated that more expensive forms of bandpass filters may be employed in the circuits shown. Further, it is to be understood that FIG. 8 is designed to show that a plurality of dual narrow band filter channels may be employed and the present invention is not restricted to only two pairs of narrow bandpass filters. It is entirely possible that hundreds of pairs of narrow bandpass filters may be employed if the hardware implementation demands the improved performance. | Apparatus is provided for detecting the presence of a periodically keyed random modulated signal source. Received signals are stepped down to an intermediate frequency and then applied to pairs of narrow bandpass filters. The output from pairs of the narrow bandpass filters are applied to mixers to provide difference frequency signals occurring at the clock rate of the periodically keyed random modulated signal. The clock signal is processed through recovery circuits including a detector and a comparator A signal is generated at the output of the comparator when the clock signal is detected above the background noise and interference, thus, indicating the presence of a periodically keyed random modulated signal source. | 7 |
INTRODUCTION
This application is a continuation-in-part of copending application Ser. No. 842,521, filed Oct. 17, 1977, now U.S. Pat. No. 4,180,717, the disclosure of which is incorporated herein by reference as fully as if set forth in its entirety.
The present invention concerns an inductively heated godet of improved design having means for mounting the induction coil of such a godet about the laminated pack of the magnetic core element including cooling means to prevent internal overheating.
BACKGROUND OF THE INVENTION
Inductively heated godets are widely used for guiding or conveying continuous synthetic fiber yarns and the like and are particularly useful in stretching and texturizing devices for the treatment and processing of such yarns. In operation, the yarns are generally wound several times about the outer circumference of the driven outer shell or casing of the godet and heat is thereby conducted to the yarn for the purpose of, for example, plastic deformation or fixation.
Godets of this general type are characterized by an induction coil being mounted in a stationary coaxial position about a laminated magnetic core which is composed of a ferromagnetic material and which is rigidly connected to the frame of the device. A drive shaft extends coaxially through the center of the laminated pack and the rotatable casing which surrounds the induction coil and laminated pack assembly is secured to the end of this drive shaft. An example of such a godet is shown in U.S. Pat. No. 3,487,187 issued Dec. 30, 1969, the disclosure of which is incorporated herein by reference.
One significant problem in these godets has been their inability to function well at high thread treating temperatures on the order of 250° C. together with high yarn speeds. With a thread contact temperature of about 250° C. on the outer casing surface, the temperature in the winding and along the inside of the hollow shell or casing rises to 300° C. or more, and the heat developed internally of the godet causes severe damage to the laminated core pack and especially to the bearings where lubricant may be completely evaporated. Therefore, these high working temperatures have been avoided with inductively heated godets, and correspondingly low thread speeds have been required to achieve a satisfactory thermal treatment.
Another significant problem encountered with such godets, has been the loosening of the induction coil from the iron core of the laminated pack in operation. This problem is caused by the differing coefficients of thermal expansion of the material used for the coil (e.g. tin, aluminum, or copper) and the material used for the laminated pack (e.g. iron). This problem is particularly acute at high operating speeds where the yarn is conveyed at speeds of 4,000 m/min. and more. At such high speeds, slight vibrations created in the godet become significant and may result in an axial shift and wear of the coil.
SUMMARY OF THE INVENTION
It is the primary object of the present invention to overcome these problems so as to permit the use of high yarn or thread speeds above about 4,000 m/min. and correspondingly high treatment temperatures of about 250°-300° C. A specific object of the invention is to provide a secure mounting of the laminated core pack while also surrounding it with an effective cooling means to rapidly draw off heat generated in the shell or casing and preventing passage of this heat through the core pack into the shaft and bearings of the godet. Yet another object is to provide satisfactory means for securing the induction coil of such godets about the magnetic core in such a manner that thermal expansion of these elements and vibration will not cause the coil to loosen during operation of the device.
The problem of overheating has been solved, in accordance with the invention by providing a cooling means in the form of at least one hose-like cooling tube having inlet and outlet ends for conducting a fluid coolant therethrough, this tube being located between the laminated core pack and the induction coil as a layer of side by side windings wrapped around and on the laminated core pack. Suitable means are included to supply a fluid coolant under sufficient pressure at the inlet end of the cooling tube to circulate the fluid coolant as a heat-exchange medium. In a preferred embodiment, two hose-like cooling tubes are guided side by side in the layered winding. The tubes are best mounted or positioned in one or more radially recessed circumferential grooves of the laminated core pack. These individual grooves at spaced axially positions are separated by a radially projecting bar or separator means which is preferably an integral part of the laminated core pack. The depth of each circumferential groove in this laminated pack is preferably approximately equal to the radially measured width of the layered tube winding.
These fluid-conducting tubes may have a circular or preferably a rectangular cross-section and should be made of a material resistant to the required high temperatures on the order of 300° C. The use of a flexible hose material is expecially favorable, e.g. a fluorinated elastomer resistant to such high temperatures, especially polyvinyl hexafluoropropylene.
It is also advantageous for purposes of the invention to place an elastic intermediate piece between the induction coil and the laminated pack in order to compensate for any unequal thermal expansion of these elements. In assembly, the coil is slipped onto the elastic intermediate piece which is positioned about the laminated pack as a part of the cooling means, and the coil is then secured against axial shifting. As a result, the coil is sufficiently secured, such that, even when heat expansion of the elements occurs during operation of the device and without any further compensating measures, there is no longer any danger of damaging the coil. Furthermore, the elastic intermediate piece when associated with the cooling means, serves partly as an insulator to reduce the amount of heat passed to the godet bearings due to heat loss through the coil, thereby increasing the service life of these bearings.
Assembly and disassembly of the induction coil may be significantly simplified by providing an elastic intermediate member that can be externally expanded by the radial expansion of the flexible hose-like cooling tube or tubes. These tubes may be separate from or integral with the elastic intermediate member. Such construction makes it possible to easily replace the coil without danger of damaging any component parts for such purposes as, for example, changing the installed heating output.
Constructing the elastic intermediate member as a separate sleeve or circumferential layer around the cooling tube or tubes permits a number of advantageous design variations. This elastic member may also be introduced as a molded elastomer in and/or around the cooling tube or tubes at selected circumferential positions sufficient to firmly hold the coil during heat expansion or contraction. In another embodiment, the induction coil can be radially supported directly on the projections or support bars which define the grooves of the laminated pack, preferably using end support members such as annular rings at either end of the coil to prevent axial movement of the coil.
In each embodiment of the invention, the individual hose-like cooling tubes are connected to a coolant circuit which is under pressure sufficient to circulate the fluid coolant, preferably water. Thus, in this simple manner, the godet bearings are effectively protected against the deleterious effects of heat while at the same time the coil is reliably secured to the laminated pack during operation of the device.
THE DRAWINGS
The invention is illustrated by the accompanying drawings in which:
FIG. 1 illustrates a schematic longitudinal section through an inductively heated godet constructed from the fewest number of elements capable of yielding the improvement of the present invention;
FIG. 2 is a schematic longitudinal section taken vertically through the axis of a preferred godet according to the invention, the induction coil being omitted to illustrate the use of two cooling tubes arranged in a series of grooves axially spaced along the laminated core pack;
FIG. 3 is a partial bottom plan view of the godet of FIG. 2 to illustrate the arrangement of the cooling tubes in the grooves;
FIG. 4 is a schematic longitudinal section taken through another preferred godet of the invention illustrating a separate insertion of one or more elastic intermediate members as an outer layer or sleeve over the cooling tubes; and
FIG. 5 is a schematic longitudinal section of the upper segment of another godet similar to the structure of FIG. 4 but with deeper grooves to create an air-insulating gap between the cooling tubes and the induction coil.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, in the generally required arrangement for a cooled godet of the invention according to FIG. 1, the godet drive shaft 1 rests in two ball bearing assemblies 2 and 2' mounted in the frame 3 of the machine. It is also possible to support this godet drive shaft 1 in a bearing housing or in a universal ball joint which is then secured to the machine frame 3.
The end of godet shaft 1 within machine frame 3 is driven by a motor (not shown) and the other front, free end of the shaft carries the godet shell or casing 4 upon which a synthetic fiber thread or yarn may be wound. A secondary induction coil in the form of a copper bushing 4a is secured to the inner surface of the hollow casing 4 to regulate the development of heat over the surface of the godet. Mounted between rotatable casing 4 and drive shaft 1 are a primary coil 5 and laminated pack 6, these members being firmly secured to a carrier 8 which is fixed on the machine housing 3. The elastic intermediate member 7 of the invention, which in this case is a flexible, elastomeric, helically wound cooling tube, is located between coil 5 and laminated pack 6. Coil 5 is supported here solely by the elastic intermediate member 7.
In mounting the induction coil 5, which is supplied as a unitary, finished package, upon the laminated pack 6, the intermediate elastic member 7 is compressed and coil 5 is then pushed over it. The inward pressure on the intermediate member is then relieved and it expands to secure the coil upon the laminated pack.
During operation of the godet, the coil and laminated pack will expand due to the inductive heating of the assembly. The coil and laminated pack are made of different materials so that their expansion due to heating will also be different. Since the coil is solely supported upon laminated pack 6 by the elastic intermediate member 7, this intermediate member will completely compensate for differences in expansion so as to secure the coil to the laminated pack at all times without play.
In this first disclosed embodiment of the invention, the elastic intermediate member 7 is constructed of a hose-like hollow chamber rather than a solidly formed elastic body. In such an embodiment, the hose is expanded under pressure when filled with a coolant in order to secure the coil about the laminated pack. The assembly is connected to a coolant circuit as indicated by the two valves V so that circulation therethrough is maintained. This construction is advantageous because the heat transfer to the godet drive shaft 1 is blocked, or at least sharply restricted, thereby substantially reducing the amount of heat carried to the shaft bearings 2 and 2'. This makes it possible to move the bearing 2' outwardly toward the free end of the shaft so as to reduce the length of shaft projecting beyond this bearing. In this manner, the godet assembly is made more resistant to vibration and the load demands on the bearings are also significantly reduced.
An especially preferred arrangement of two cooling tubes wound side by side is illustrated in FIGS. 2 and 3 where the individual hollow tubes have a square or rectangular cross-section and act as elastic supporting members for the induction coil (not shown). In this case, the carrier 8 is connected to the machine frame 3 shown partly in FIG. 3 so as to hold the laminated pack 9 in a fixed position with the two hollow cooling tubes 10 and 11 wound thereon. The inlet ends 10i and 11i of these two cooling tubes enter from the machine frame 3 into a deeply recessed axial groove 12 of the laminated pack 9 so as to extend up to the forward or outer projecting end of this pack and are then helically coiled back over these inlet ends in a layer of tube windings positioned in the circumferential grooves 14a, 14b, 14c and 14d. These four circumferential grooves of the laminated pack are separated from each other by the projections or bars 15, each having an oblique opening 16 in its circumference to guide the pair of tubes from one groove to the next. These openings are advantageously filled with a heat-resistant silicone rubber which may also be used to fill in other open spaces around the tubes, thereby assisting in holding the tubes in place and preventing movement or play on the laminated pack. The exit or outlet ends 10x and 11x of the hollow tubes return from the inner end of the pack through the machine frame, and coolant such as water is continuously circulated in direct contact with the laminated pack 9.
In FIGS. 2 and 3, the square or rectangular tubes 10 and 11 project just slightly beyond the outer circumferential portions 15 of the laminated pack 9 (exaggerated in FIGS. 2 and 3) so as to be in direct supporting contact with an induction coil which can be slipped thereon when the tubes have been drained of coolant. Once the induction coil is in place, the coolant is introduced and circulated under sufficient pressure to slightly expand the tubes and firmly grip the interior circumferential portion of the induction coil.
The embodiment of FIG. 4 provides another example of winding two side by side hollow cooling tubes. In this case the tubes 17 and 18 have a circular cross-section but are introduced and wound in the same type of axial groove 12 and circumferential grooves 14 as shown in FIG. 2. The width or radial thickness of the layer of helically wound tubes is approximately equal to the depth of the circumferential grooves 14 as defined by the projections 15. Two intermediate elastic sleeves 19 and 20 are drawn over the laminated pack and the hollow tubes nested in their grooves so as to form a protective insulating and elastic supporting layer which prevents axial and radial play of the induction coil 5 mounted thereon as the godet is heated to high temperatures. The coil 5 may also be positioned by the use of the annular end members 21 and 22, for example, to permit coils of different lengths to be inserted, the outer end 21 preferably being fixed in place by a locking washer 23 or the like.
The carrier 8 in FIG. 4 is fixed to a circular mounting plate 24 which in turn is readily bolted to the machine frame at a number of bolt positions 25 while providing a suitable opening 26 for the inlet and outlet ends of the cooling tubes. This opening 26 may also receive a wedge-shaped member 27 replacing a small segment of the laminated pack and having set screw 27a which pushes against the annular end member 22 bearing thin rubber faces 22a and 22b with enough force to prevent any axial movement of the coil 5. The key lock 27b of wedge 27 fits into plate 24 to position and brace the wedge against the screw pressure. Again, any empty spaces in or around the tubes can be filled with silicone rubber 16 or the like.
The embodiment of FIG. 5 illustrates another preferred variation similar to FIG. 4 but with the paired hollow tubes 17 and 18 being set into deeper circumferential recesses 28 in the laminated pack 9, thereby providing an insulating air gap 29 between these tubes and the induction coil 5. The coil 5 is supported directly on the projections 15 of the laminated pack, and axial movement of the coil 5 is prevented in a satisfactory manner by the rubber or elastic faced end member 22. Such end members when wedged or compressed in place are generally very satisfactory means of preventing both axial and radial play of the coil.
Alternatively, the circumferential air gap spaces 29 between the pack and the coil as shown in FIG. 5 can receive individual elastic sleeves, for example using a narrow sleeve band only near the inner and outer ends of the grooved pack. All of these sleeves, bands, or other elastic intermediate members used for tensioning or gripping the induction coil during operation of the godet are preferably made of one of conventional rubber or elastomeric materials known to be very heat-resistant.
The flexible hoses used as hollow tubes are preferably composed of a fluoro-substituted elastomer such as polyvinyl hexafluoropropylene, e.g. obtainable under the trademark "Viton". However, other heat-resistant materials may also be used, especially in the embodiments of FIGS. 4 and 5 where the tubes are not used to provide the main support for the induction coil. Also, in place of intermediate elastic sleeves or hose-like supports, it is possible to cast or pour a moldable and curable elastomeric compound such as a silicone polymer into and around the individual hoses or tubes, thereby preventing any loosening or undesirable axial and radial play at high temperatures.
While several particular embodiments of the present invention have been shown and described, it should be understood that various obvious changes and modifications thereto may be made by those skilled in the art, and it is therefore intended in the following claims to include all such changes and modifications as may fall within the spirit and scope of this invention. | An improved means for mounting the induction coil of an inductively heated, rotatable godet about the magnetic core thereof so as to prevent internal overheating and preferably also to avoid any movement or play between the core and the coil as caused by heat expansion and vibration during operation of the godet. The improvement comprises cooling means for cooling the laminated pack acting as the magnetic core and for thermally isolating the pack from the coil and outer godet shell or casing, said cooling means including at least one hose-like tube wound around the laminated pack with means to conduct a fluid coolant therethrough. An elastic intermediate member is preferably introduced at some point between the coil and magnetic core in order to compensate for any unequal thermal expansion of these elements in the axial and/or radial directions. | 3 |
RELATED APPLICATIONS
[0001] This present application claims priority to currently pending application Ser. No. 10/686,940 filed on Oct. 15, 2003 entitled “Signal Processor with Fast Field Reconfigurable Data Path, Data Address Unit and Program Sequencer”, by Kenneth Garey which in turn claims priority to application Ser. No. 09/408,825 filed on Sep. 29, 1999 entitled “Signal Processor with Fast Field Reconfigurable Data Path, Data Address Unit and Program Sequencer” by Kenneth Garey which was pending at the time application Ser. No. 10/686,940 was filed.
BACKGROUND OF THE INVENTION
[0002] Conventional systems that perform data processing do not possess the ability to adapt to various data types on which a data processor must operate. Specific application specific integrated circuitry or other processing circuitry geared and designed to execute specific and limited applications do provide for extremely fast processing, but at a cost of significantly limited functionality. In addition, present signal processors do not provide hardware oriented solutions. For each computational operations within modern signal processors, the signal processor performs multiple functions including a program random access memory (RAM) or a program read only memory (ROM). The conventional signal processor ‘must also employ a data random access memory (RAM) or a plurality of data registers, several address buses and data buses, a data address unit, and a predetermined data path.
[0003] Conventional signal processors that employ hardware directed solutions typically provide a limited functionality to a plurality of input data and drive that plurality of input data to a next function. In other words, conventional hardware solutions are geared primarily to perform a very limited number of functions. Limitations of general purpose signal processors employing conventional techniques are numerous; however, a main limitation is an inability to perform a substantially wide variety of operations to accommodate various pluralities of input data. To perform a wide variety of functions, conventional signal processors typically need to perform a large number of gate toggles with each operation.
SUMMARY OF THE INVENTION
[0004] The present invention comprises a method for processing data in a reconfigurable manner. According to one example method, data is processed by receiving input data, selecting a logic configuration according to the input data to processing the input data using the selected logic configuration. According to one alternative illustrative method, input data that is received is subject to a “type” determination. A logic selection indicator is then generated according to be determined type. The logic selection indicator can then be used to select a configuration map. Accordingly, the configuration map may then be used to configure a reconfigurable logic circuit.
[0005] According to one alternative method, a configuration map comprises a configuration for at least one of an addressing unit, and instruction decoder, an instruction sequencer and an arithmetic unit. Accordingly, various functional aspects of processing data may be modified according to the type of data being processed a particular instant in time. Generally, a first configuration map is used to create a logic function during a first data period. A second logic function is created using a second configuration map during a second data period. Accordingly, with each subsequent data a different configuration map may be selected according to the input data.
[0006] According to yet another alternative illustrative method, selection of a logic configuration comprises generation of a parallel configuration word. The parallel configuration word, which is based in whole or in part on the input data, is used to configure a plurality logic element substantially in one data period.
[0007] According to one illustrative aspect of the present method, a first logic element is configured according to a first input data. The first input data is then processed using the first logic element. A second logic element is configured according to the first input data substantially while the first logic element is reconfigured according to a subsequent input data. The once-processed first input data is then processed using the second logic element substantially while the subsequent input data is processed by the reconfigured first logic element. This method provides for “pipelining” of data with selective reconfiguration of logic elements as data moves from one logic element to the next.
[0008] According to yet another alternative method, the amount of power required to process input data using the selected logic configuration is determined. If the amount of power required exceeds a pre-established threshold, a new logic configuration is selected.
[0009] The present invention further comprises a data processing unit. According to one embodiment that illustrates the present invention, a data processing unit comprises an input unit that receives data. A reconfigurable logic circuit is also included in the data processing unit. The reconfigurable logic circuit processes the input data. The reconfigurable logic circuit is configured by a configuration circuit that is also included in the data processing unit. The configuration circuit reconfigures a logic circuit according to a portion of the input data.
[0010] According to one alternative example embodiment, the configuration circuit comprises a data monitor. The data monitor is capable of determining a type for the input data. The configuration circuit of this alternative example embodiment further comprises a configuration memory that is capable of storing a plurality of configuration maps. The configuration circuit selects a particular configuration map according to the determined type of the input data. According to yet another alternative example embodiment, the data monitor is capable of generating a configuration selection signal according to a portion of the input data. The configuration map is selected from the configuration memory using the configuration selection signal. According to yet another alternative example embodiment, the configuration memory includes a configuration map for at least one of an addressing unit, an instruction decoder, an instruction sequencer and an arithmetic unit. According to yet another alternative embodiment, the configuration memory generates a parallel configuration word. The parallel configuration word may be used to configure a plurality of logic elements substantially in one data period.
[0011] According to one alternative illustrative embodiment, the configuration circuit comprises an active configuration unit and a loading configuration unit. According to this illustrative embodiment, the active configuration unit configures the reconfigurable logic circuit during a first data period. The loading configuration unit typically receives a new configuration map while the active configuration unit is configuring the reconfigurable logic circuit. The loading configuration unit is then used to configure the reconfigurable logic circuit during a second data period.
[0012] According to yet another alternative example embodiment, the reconfigurable logic circuit comprises a first logic element and a second logic element. According to this alternative embodiment, the first logic element processes a first input data according to a first configuration. The second logic element processes the output of the first logic element (i.e. a once-processed first data) while the first logic element processes a subsequent data according to a subsequent configuration.
[0013] According to one alternative embodiment, a data processing unit further comprises a power monitor. According to this alternative embodiment, the power monitor determines the power consumed by the reconfigurable logic circuit. The configuration circuit selects a different configuration map when the determined power exceeds a pre-established threshold.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present invention will hereinafter be described in conjunction with the appended drawings and figures, wherein like numerals denote like elements, and in which:
[0015] FIG. 1 is a system diagram illustrating a signal processor built in accordance with the invention having a processing circuitry that contains a re-configurable circuitry;
[0016] FIG. 2 is a system diagram illustrating a signal processor built in accordance with the invention having a re-configurable logic circuitry governed by a configuration control circuitry;
[0017] FIG. 3 is a system diagram illustrating a signal processor built in accordance with the invention having a plurality of reconfigurable components;
[0018] FIG. 4 is a system diagram illustrating a signal processor built in accordance with the invention that selects at least one configuration option to program a programmable logic array circuitry;
[0019] FIG. 5 is a system diagram illustrating a signal processor built in accordance with the invention that selects at least one area configuration to program at least one area of a programmable logic array circuitry;
[0020] FIG. 6 is a system diagram illustrating a signal processor built in accordance with the invention that performs recursive updating of a programmable logic configuration circuitry and a programmable logic array circuitry; and
[0021] FIG. 7 is a functional block diagram illustrating a method performed in accordance with the invention that reconfigures a logic array circuitry.
DETAILED DESCRIPTION
[0022] The present invention presents a solution that provides operation within a signal processor with a significantly reduced number of gate toggles for a given operation. A relatively complex data path is generated for a plurality of input data to reduce the number of gate toggles required to perform operation on the plurality of data. In certain embodiments of the invention, the complex data path is a 64 bit deeply pipelined parallel serial data path with rich interconnects between the pipeline levels and the adjacent data paths within the signal processor. In other embodiments of the invention, the data path provides interconnects capable of allowing multiple 8 bit, 16 bit, or 32 bit parallel operations to occur in parallel. Serial operations including up to ‘n’X 16 bit serial multiples with adjacent signal summing is also provided within various embodiments of the invention. Control of the depth of the deeply pipelined parallel serial data path and a clock signal's gating is also provided within the invention.
[0023] Similar programmability is also provided within a data addressing unit in other embodiments of the invention. This programmability facilitates content addressable data and coordinates re-mapping address support within the signal processor. A program sequencer employs re-configuration to allow flexible control over the data path and the addressing unit. Wide word access is provided to allow rapid re-configuration of a programmable logic circuitry. A hardwired, or default, logic configuration is provided for multiple components within the signal processor. In addition, re-configuration is provided for the multiple components within the signal processor using direct memory access (DMA) logic having wide word read only memory (ROM) and random access memory (RAM).
[0024] FIG. 1 is a system diagram illustrating a signal processor 100 built in accordance with the invention having a processing circuitry 140 that contains a re-configurable circuitry 105 . The processing circuitry 140 of the signal processor 100 contains the re-configurable circuitry 105 to perform at least a portion of its total signal processing. The re-configurable circuitry 105 contains, among other things, a programmable logic circuitry 110 , a processing power consumption analysis circuitry 120 , and a programmable logic configuration circuitry 130 . The programmable logic configuration circuitry 130 itself contains, among other things, a default configuration circuitry 132 , an adaptive configuration circuitry 134 , an active configuration circuitry 136 , and a loading configuration circuitry (buffer) 138 . The programmable logic configuration circuitry 130 selects a predetermined logic configuration from among a predetermined plurality of default logic configurations contained within the default configuration circuitry 132 . The programmable logic configuration circuitry 130 programs the programmable logic circuitry 110 to perform at least one predetermined function within the signal processor 100 .
[0025] In certain embodiments of the invention, the programmable logic configuration circuitry 130 selects an alternative logic configuration using the adaptive configuration circuitry 134 . The adaptive configuration circuitry 134 selects the alternative logic configuration in response to a number of factors including, among other things, a plurality of input data that is given to the signal processor 100 . In other embodiments of the invention, the adaptive configuration circuitry 134 selects the alternative logic configuration in response to the amount of power being consumed by the signal processor 100 . This determination of the amount of power being consumed is made using the processing power consumption analysis circuitry 120 . Regardless of what specific parameters are used to identify and select an appropriate logic configuration, the programmable logic configuration circuitry 130 programs the programmable logic circuitry 110 to perform the predetermined functionality of the signal processor 100 .
[0026] The active configuration circuitry 136 of the programmable logic configuration circuitry 130 is the actual configuration that is presently being employed by the signal processor 100 . That is to say, the active configuration circuitry 136 performs the actual logic configuration of the signal processor 100 during real time operation. If desired in certain embodiments of the invention, the loading configuration circuitry (buffer) 138 is simultaneously loading another logic configuration into the programmable logic configuration circuitry 130 while the active configuration circuitry 136 is busy configuring the programmable logic configuration circuitry 130 using either the default configuration circuitry 132 or the adaptive configuration circuitry 134 , depending on the specific application. The implementation of both the active configuration circuitry 136 and the loading configuration circuitry (buffer) 138 is performed in a “ping-pong”style operation known to those having skill in the art of logic configuring, data management, and data processing, among other things.
[0027] In this embodiment, the programmable logic configuration circuitry 130 employs the active configuration circuitry 136 to perform the actual logic configuration of the signal processor 100 while the loading configuration circuitry (buffer) 138 is loading a logic configuration to be used next. Then, after the present logic configuration of the programmable logic configuration circuitry 130 has been loaded by the active configuration circuitry 136 to process a first plurality of input data, the next logic configuration that was just previously contained within the loading configuration circuitry (buffer) 138 is then passed to the active configuration circuitry 136 to perform processing on a next plurality of input data. If desired, various logic configurations are used to perform processing on the same plurality of input data, and in such a case, the present and the next logic configurations are used to configure the programmable logic configuration circuitry 130 at various phases within the processing of the same plurality of input data. The simultaneous operation of the programming of one logic configuration to the programmable logic configuration circuitry 130 using the active configuration circuitry 136 while another logic configuration is being loaded into the loading configuration circuitry (buffer) 138 provides for faster, overall operation of the signal processor 100 , given that a next logic configuration is immediately ready for the programmable logic configuration circuitry 130 after the processing of the plurality of input data.
[0028] FIG. 2 is a system diagram illustrating a signal processor 200 built in accordance with the invention having a re-configurable logic circuitry 250 governed by a configuration control circuitry 210 . The signal processor 200 operates to convert a plurality of input data 220 into a plurality of output data 240 . The configuration control circuitry 210 operates cooperatively with a programmable logic configuration circuitry 230 to program the re-configurable logic circuitry 250 . The programmable logic configuration circuitry 230 itself contains, among other things, a read only memory (ROM) 232 and a random access memory (RAM) 234 . The re-configurable logic circuitry 250 itself contains, among other things, an input programmable logic circuitry 252 , a main programmable logic circuitry 254 , and an output programmable logic circuitry 256 . The read only memory (ROM) 232 and the random access memory (RAM) 234 store a predetermined number of logic configurations that are used to program the re-configurable logic circuitry 250 . If desired, the read only memory (ROM) 232 store a predetermined number of fixed logic configurations for the re-configurable logic circuitry 250 . The fixed logic configurations includes at least one default logic configuration for the re-configurable logic circuitry 250 that is loaded during startup of the signal processor 200 or, alternatively, during any power cycle or reset operations that the signal processor 200 undergoes. In addition, the random access memory (RAM) 234 operates within the signal processor 200 to determine a more appropriate logic configuration for the re-configurable logic circuitry 250 through adaptive techniques employed by the programmable logic configuration circuitry 230 . The programmable logic configuration circuitry 230 analyzes various parameters to determine an appropriate logic configuration for the signal processor 200 .
[0029] The programmable logic configuration circuitry 230 provides the proper logic configuration to the re-configurable logic circuitry 250 . Irrespective of whether the programmable logic configuration circuitry 230 loads a predetermined logic configuration from the read only memory (ROM) 232 or an adaptively selected logic configuration from the random access memory (RAM) 234 , the programmable logic configuration circuitry 230 performs the programming of the re-configurable logic circuitry 250 so that the re-configurable logic circuitry 250 operates properly on the plurality of input data 220 . The programming of the programmable logic configuration circuitry 230 operates to program the logic configuration for at least one of the input programmable logic circuitry 252 , the main programmable logic circuitry 254 , and the output programmable logic circuitry. 256 . In certain embodiments of the invention, all of the input programmable logic circuitry 252 , the main programmable logic circuitry 254 , and the output programmable logic circuitry 256 are provided with a logic configuration. In other embodiments of the invention, only one of the input programmable logic circuitry 252 , the main programmable logic circuitry 254 , and the output programmable logic circuitry 256 is provided with a modified logic configuration to perform processing on the plurality of input data 220 . For example, when the signal processor 200 performs updating of new logic configurations during each passing of a clock signal's cycle of the signal processor 200 , the logic configurations of each of the input programmable logic circuitry 252 , the main programmable logic circuitry 254 , and the output programmable logic circuitry 256 is analyzed to determine if the present logic configuration is appropriate for the particular segment of the plurality of input data 220 on which the signal processor 200 is operating. If it is determined that existing logic configuration for at least one of the input programmable logic circuitry 252 , the main programmable logic circuitry 254 , and the output programmable logic circuitry 256 is appropriate for the plurality of input data 220 within the given clock signal's cycle, then that particular logic configuration is maintained. Alternatively, the logic configurations of the input programmable logic circuitry 252 , the main programmable logic circuitry 254 , and the output programmable logic circuitry 256 that need to be modified are indeed modified, as required and governed by the plurality of input data 220 . The signal processor 200 then utilizes the logic configurations to generate the plurality of output data 240 .
[0030] Those having skill in the art of data processing will recognize that the various portions of the re-configurable logic circuitry 250 are re-configurable to accommodate various types of the plurality of input data 220 . If desired, the signal processor 200 operates into a low power consumption mode wherein default logic configurations are loaded into each of the input programmable logic circuitry 252 , the main programmable logic circuitry 254 , and the output programmable logic circuitry 256 . Various intelligence is employed in the programmable logic configuration circuitry 230 to determine, in various low power consumption modes, whether it is more power efficient to switch to a new logic configuration for at least one of the input programmable logic circuitry 252 , the main programmable logic circuitry 254 , and the output programmable logic circuitry 256 within the re-configurable logic circuitry 250 or to remain with a default logic configuration. In addition, those having skill in the art of data processing will recognize that various permutations of the modification of the logic configuration of the reconfigurable logic circuitry 250 is performed depending on various operational considerations of the signal processor 200 .
[0031] FIG. 3 is a system diagram illustrating a signal processor 300 built in accordance with the invention having a plurality of reconfigurable components. A programmable logic configuration circuitry 330 is operable to provide configuration to each of a data memory 310 , a data addressing unit 320 , a program memory 340 , an arithmetic logic unit 350 , and an instruction decode & sequencing unit 360 ; the programmable logic configuration circuitry 330 is operable to provide updated configuration for each of the above mentioned reconfigurable components. The programmable logic configuration circuitry 330 itself contains, among other things, a read only memory (ROM) 332 and a random access memory (RAM) 334 . As described above and similar to the various embodiments of the invention including the signal processor 100 and the signal processor 200 , the signal processor 300 is operable using the programmable logic configuration circuitry 330 to perform both default and adaptive configuration of the various reconfigurable components contained within the signal processor 300 .
[0032] The data memory 310 itself contains, among other things, a word width 312 , an addressing logic circuitry 314 , and a random access memory (RAM) 316 . The data addressing unit 320 itself contains, among other things, a plurality of addressing modes 322 wherein the plurality of addressing modes 322 include, among other addressing modes, an indirect addressing mode 323 , an indexed addressing mode 324 , a based offset addressing mode 325 , a first in/first out (FIFO) addressing mode 326 , and a stack addressing mode 327 . The program memory 340 itself contains, among other things, a read only memory (ROM) 346 . The program memory 340 provides a plurality of immediate data 370 that is stored in the program memory 340 to the arithmetic logic unit 350 , and the instruction decode & sequencing unit 360 . The arithmetic logic unit 350 itself contains, among other things, a word width 352 and an addressing logic circuitry 354 . The various data addressing mode functionality of the data addressing unit 320 are known to those having skill in the art of data processing. Any appropriate data addressing mode is used within the invention without departing from the scope and spirit thereof. The word width 312 of the data memory 310 and the word width 352 of the arithmetic logic unit 350 correspond to a word width in which each of the data memory 310 and the arithmetic logic unit 350 is configured within one given updating logic configuration step. When the programmable logic configuration circuitry 330 operates to modify the logic configuration of each of the data memory 310 , the data addressing unit 320 , the program memory 340 , the arithmetic logic unit 350 , and the instruction decode & sequencing unit 360 , a wide word width that is loaded in parallel is used so that all of the configuration of the above mentioned reconfigurable components are re-configured simultaneously, if desired. In certain embodiments of the invention, only a subset of the data memory 310 , the data addressing unit 320 , the program memory 340 , the arithmetic logic unit 350 , and the instruction decode & sequencing unit 360 is updated with a new logic configuration in any given logic configuration updating performed by the programmable logic configuration circuitry 330 of the signal processor 300 . The variations of the invention, as described above in the embodiments of the signal processor 100 of FIG. 1 and the signal processor 200 of FIG. 2 , wherein only various elements of the signal processor 300 receive a modified logic configuration in a clock signal's cycle.
[0033] The addressing logic circuitry 314 of the data memory 310 and the addressing logic circuitry 354 of the arithmetic logic unit 350 operate to perform the addressing' of modified and updated logic configurations within the signal processor 300 as required by various parameters including characteristics of a plurality of input data, similar to the embodiment shown above and described within the signal processor 200 of FIG. 2 .
[0034] FIG. 4 is a system diagram illustrating a signal processor 400 built in accordance with the invention that selects at least one configuration option to program a programmable logic array circuitry 440 . The signal processor 400 contains, among other things, a memory 410 , an ‘n’ bit word width bus that performs parallel configuration loading 420 , a logic configuration selection circuitry 430 , and the programmable logic array circuitry 440 . The memory 410 contains, among other things, a configuration option # 1 412 , a configuration option # 2 414 , and a configuration option #‘n’ 416 . The logic configuration selection circuitry 430 , that itself contains, among other things, a data monitoring circuitry 432 , provides information to the memory 410 to determine which logic configuration is appropriate for a given portion of data. The given portion of data is a plurality of input data, as described above in the various embodiments of the invention shown in FIGS. 2 and 3 . The data monitoring circuitry 432 is operable to identify characteristics of the plurality of input data and to provide information to the logic configuration selection circuitry 430 so that it operates to perform selection of a logic configuration that is most appropriate. The logic configuration selection circuitry 430 cooperates with the memory 410 , selecting from among the configuration option # 1 412 , the configuration option # 2 414 , and the configuration option #‘n’ 416 to identify an appropriate logic configuration for the plurality of input data. As described above in various embodiments of the invention, the selection of the appropriate logic configuration is made using various indicia in accordance with the invention. Examples of such indicia and parameters include power consumption within the signal processor 400 , the characteristics of the plurality of input data provided to the signal processor 400 , and other parameters.
[0035] The selected logic configuration, selected from among the configuration option # 1 412 , the configuration option # 2 414 , and the configuration option #‘n’ 416 contained within the memory 410 , is transported to the programmable logic array circuitry 440 via the ‘n’ bit word width bus that performs parallel configuration loading 420 . The ‘n’ bit word width of the ‘n’ bit word width bus that performs parallel configuration loading 420 provides very fast loading and configuration of the programmable logic array circuitry 440 . For example, for embodiments of the invention where the width of the programmable logic array circuitry 440 is also ‘n’ bits, the entirety of the programmable logic array circuitry 440 is programmable with a modified logic configuration within a given, clock signal's cycle, i.e., all of the logic elements of the programmable logic array circuitry 440 are re-programmable in one given step. The programmable logic array circuitry 440 itself contains, among other things, a plurality of logic elements including a logic element # 1 , 1 441 , a logic element # 1 , 2 442 , a logic element # 1 , ‘n’ 443 , a logic element # 2 , 1 444 , a logic element # 2 , 2 445 , a logic element # 2 , ‘n’ 446 , a logic element #‘n’, 1 447 , a logic element #‘n’, 2 448 , and a logic element #‘n’, ‘n’ 449 .
[0036] In other embodiments of the invention, the width of the programmable logic array circuitry 440 is ‘n’ bits that is different than the ‘n’ bit word width of the ‘n’ bit word width bus that performs parallel configuration loading 420 and only a predetermined portion of the individual logic elements of the programmable logic array circuitry 440 is programmed with a modified logic configuration in the given clock signal's cycle. Additional clock signal cycles are required to modify the logic configuration of the remainder of the programmable logic array circuitry 440 .
[0037] FIG. 5 is a system diagram illustrating a signal processor 500 built in accordance with the invention that selects at least one area configuration to program at least one area of a programmable logic array circuitry. The signal processor 500 contains, among other things, a memory 510 , an ‘n’ bit word width bus that performs parallel configuration loading 520 , a logic configuration selection circuitry 530 , and a programmable logic array circuitry 540 . The memory 510 contains, among other things, a configuration option # 1 512 , a configuration option # 2 514 , and a configuration option #‘n’ 516 . The logic configuration selection circuitry 530 , that itself contains, among other things, a data monitoring circuitry 532 , provides information to the memory 510 to determine which logic configuration is appropriate for a given portion of data. Similar to the embodiment of the invention described above in the signal processor 400 of FIG. 4 , the given portion of data is a plurality of input data, as described above in the various embodiments of the invention shown in FIGS. 2 and 3 . The data monitoring circuitry 532 is operable to identify characteristics of the plurality of input data and to provide information to the logic configuration selection circuitry 530 so that it operates to perform selection of a logic configuration that is most appropriate. The logic configuration selection circuitry 530 cooperates with the memory 510 , selecting from among the configuration option # 1 512 , the configuration option # 2 514 , and the configuration option #‘n’ 516 to identify an appropriate logic configuration for the plurality of input data. As described above in various embodiments of the invention, the selection of the appropriate logic configuration is made using various indicia in accordance with the invention. Examples of such indicia and parameters include power consumption within the signal processor 500 , the characteristics of the plurality of input data provided to the signal processor 500 , and other parameters.
[0038] The selected logic configuration, selected from among the configuration option # 1 512 , the configuration option # 2 514 , and the configuration option #‘n’ 516 contained within the memory 510 , is transported to the programmable logic array circuitry 540 via the ‘n’ bit word width bus that performs parallel configuration loading 520 . The ‘n’ bit word width of the ‘n’ bit word width bus that performs parallel configuration loading 520 provides very fast loading and configuration of the programmable logic array circuitry 540 . For example, for embodiments of the invention where the width of the programmable logic array circuitry 540 is also ‘n’ bits, the entirety of the programmable logic array circuitry 540 is programmable with a modified logic configuration within a given clock signal's cycle, i.e., all of the logic elements of the programmable logic array circuitry 540 are re-programmable in one given step. The programmable logic array circuitry 540 itself contains, among other things, a plurality of logic elements including a logic element # 1 , 1 541 , a logic element # 1 , 2 542 , a logic element #l,’n’ 543 , a logic element # 2 , 1 544 , a logic element # 2 , 2 545 , a logic element # 2 ,’n’ 546 , a logic element #‘n’, 1 547 , a logic element #‘n’, 2 548 , and a logic element #‘n’, ’n’ 549 .
[0039] In the specific embodiment of the signal processor 500 , the programmable logic array circuitry 540 is not only partitioned into the logic element # 1 , 1 541 , the logic element # 1 , 2 542 , the logic element # 1 , ‘n’ 543 , the logic element # 2 , 1 544 , the logic element # 2 , 2 545 , the logic element # 2 , ‘n’ 546 , the logic element #‘n’, 1 547 , the logic element #‘n’, 2 548 , and the logic element #‘n’, ‘n’ 549 , but the programmable logic array circuitry 540 is further organized into an area # 1 552 , an area # 2 554 , and an area #‘n’ 556 . The area # 1 552 contains the logic element # 1 , 1 541 , the logic element # 1 , 2 542 , the logic element # 2 , 1 544 , and the logic element # 2 , 2 545 ; the area # 2 554 contains the logic element #‘n’, 1 547 and the logic element #‘n’, 2 548 ; the area #‘n’ 556 contains the logic element #‘n’, ‘n’ 549 . The signal processor 500 is operable to provide various logic configurations to each of the area # 1 552 , the area # 2 554 , and the area #‘n’ 556 as required by the specific application. For example, in a given instance, for a given plurality of input data, only the area # 1 552 and the area # 2 554 need to be provided a modified logic configuration whereas the logic configuration of the area #‘n’ 556 is appropriate for the given application. Those having skill in the art of data processing will recognize that the logic element # 1 , ‘n’ and the logic element # 2 , ‘n’ may be organized into another area in certain embodiments of the invention. The logic element # 1 , 1 541 , the logic element # 1 , 2 542 , the logic element # 1 , ‘n’ 543 , the logic element # 2 , 1 544 , the logic element # 2 , 2 545 , the logic element # 2 , ‘n’ 546 , the logic element #‘n’, 1 547 , the logic element #‘n’, 2 548 , and the logic element #‘n’, ‘n’ 549 is operable to be organized into any number of individual areas such that predetermined logic configurations are loaded into the various areas of the programmable logic array circuitry 540 for processing within the signal processor 500 .
[0040] FIG. 6 is a system diagram illustrating a signal processor 600 built in accordance with the invention that performs recursive updating of a programmable logic configuration circuitry 630 and a programmable logic array circuitry 640 . The signal processor 600 contains, among other things, a logic configuration selection circuitry 650 that is coupled to a programmable logic configuration circuitry 630 , and a programmable logic array circuitry 640 . The programmable logic configuration circuitry 630 and the programmable logic array circuitry 640 are additionally coupled to one another via an ‘n’ bit word width bus that performs parallel configuration loading 620 . The logic configuration selection circuitry 650 selects from the programmable logic configuration circuitry 630 a logic configuration that is appropriate for the signal processor 600 . In performing this selection, the signal processor 600 utilizes information of the existing logic configuration programmed in the programmable logic array circuitry 640 . In addition, in the selection of an appropriate logic configuration, selected from the programmable logic configuration circuitry 630 , and the updating of the selected logic configuration into the programmable logic array circuitry 640 are each performed using a recursive updating circuitry 690 and a recursive updating circuitry 692 , respectively. That is to say, adaptive logic configuration is supportable within the programmable logic configuration circuitry 630 using the recursive updating circuitry 690 as required by the specific application of the signal processor 600 . For example, a “new” logic configuration is achieved within the programmable logic configuration circuitry 630 , even if it is not originally loaded into the programmable logic configuration circuitry 630 at the inception of the operation of the signal processor 600 . That is to say, the “new” logic configuration is generated in real time, operation of the signal processor 600 to accommodate an immediate logic configuration within the programmable logic array circuitry 640 . The “new” logic configuration is adaptively generated specifically for the plurality of input data that is fed into the signal processor 600 . As required by a number of parameters including a plurality of input data, the power consumption of the signal processor 600 , or other parameters, the “new” logic configuration of the signal processor 600 is appropriately chosen for the present application.
[0041] In certain embodiments of the invention, the recursive updating circuitry 690 and the recursive updating circuitry 692 operate cooperatively to perform recursive updating of the programmable logic configuration circuitry 630 and the programmable logic array circuitry 640 . Alternatively, the recursive updating circuitry 690 and the recursive updating circuitry 692 operate independently to perform recursive updating of the programmable logic configuration circuitry 630 and the programmable logic array circuitry 640 based upon various parameters including, among other things, the type of incoming data on which the signal processor 600 will operate and a most efficient logic array configuration that is identified by the logic configuration selection circuitry 650 .
[0042] FIG. 7 is a functional block diagram illustrating a method 700 performed in accordance with the invention that reconfigures a logic array circuitry. In a block 710 , a default logic configuration is selected from among a plurality of predetermined logic configurations. In a block 720 , a logic array circuitry is programmed using the default logic configuration that is selected in the block 710 . In a block 730 , a plurality of input data in analyzed to determine if the default logic configuration that is selected in the block 710 is appropriate. In an alternative process block 735 , a power consumption of a signal processor is analyzed to perform the determination whether the default logic configuration that is selected in the block 710 is appropriate. Subsequently and irrespective of which of the block 730 and the alternative process block 735 is performed, an alternative logic configuration is selected in a block 740 . In certain applications of the invention, the already selected default logic configuration selected in the block 710 is appropriate. In such an instance, the alternative logic configuration need not be selected in the block 740 .
[0043] However, if the already selected default logic configuration selected in the block 710 is inappropriate or if the processing of a signal processor is improved as determined by the analysis of the plurality of input data in the block 730 or the analysis of the power consumption in the alternative process block 735 , an alternative logic configuration is selected in the block 740 that is more appropriately geared for the plurality of input data that is analyzed in the block 730 or more appropriately geared for the power consumption that is analyzed in the block 735 . Finally, in a block 750 , the logic array circuitry is re-programmed using the alternative logic configuration that is selected in the block 740 . As described above, if it is determined that an alternative logic configuration is not needed in the block 740 , then no re-programming is performed in the block 750 . However, in those instances where re-programming is required as determined by the selection of an alternative logic configuration in the block 740 , the reprogramming of the logic array circuitry is performed in the block 750 .
[0044] While this invention has been described in terms of several alternative methods and exemplary embodiments, it is contemplated that alternatives, modifications, permutations, and equivalents thereof will become apparent to those skilled in the art upon a reading of the specification and study of the drawings. It is therefore intended that the true spirit and scope of the present invention include all such alternatives, modifications, permutations, and equivalents. | Processor architecture adapts to input data. With each incoming data, the processor adapts in real-time. The structure of the processors is adapted by configuring a reconfigurable logic element. Reconfiguration occurs based on a portion of the input data to select a configuration map. The configuration map parallel loads the reconfigurable logic element, thus avoiding latency associated with reconfiguration. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to an optical disc drive which can effectively reduce the vibration and noise produced by a drive unit thereof.
[0003] 2. Description of Related Art
[0004] Optical disc drives are widely used in personal computers and in entertainment equipment such as DVD (Digital Video Disc) players. Generally, an optical disc received inside an optical disc drive is rotated by a drive unit, and an optical pick-up device moves along the radial direction of the optical disc to read a data stream recorded therein. If the optical disc does not rotate evenly, the optical disc drive is liable to vibrate and generate noise. Excessive vibration may even interfere with the correct operation of the optical pick-up. Therefore, measures must be taken to efficiently reduce the vibration of the drive unit.
[0005] A typical example of a vibration-reducing configuration is disclosed in U.S. Pat. No. 4,922,478. Supporting elements are provided and arranged to reduce vibration of the drive unit in an optical disc drive. The supporting elements have helical springs. The springs elastically support the drive unit, reduce the vibration of the drive unit, and reduce noise accordingly. However, the supporting elements are only used to reduce vibration in vertical directions, and are not capable of reducing vibration in horizontal directions. The drive unit is liable to vibrate in horizontal directions. This not only produces noise, but may even lead to the optical disc being damaged.
SUMMARY OF THE INVENTION
[0006] Accordingly, an object of the present invention is to provide an optical disc drive which can reduce vibration of a drive unit thereof in horizontal directions, and thereby effectively reduce or eliminate associated noise.
[0007] Another object of the invention is to provide an optical disc drive which reduces vibration between a subframe and a frame thereof, especially during loading and unloading of an optical disc.
[0008] In order to achieve the objects set out above, an optical disc drive of the present invention comprises: a frame; a U-shaped subframe pivotably mounted on the frame; a slider slidably mounted on the frame for making the subframe pivot; a drive unit comprising a spindle motor for rotating an optical disc, an optical pickup, and a feeding mechanism adapted to move the optical pickup for reading/recording information; and a pair of elastic elements located between the subframe and the drive unit for reducing vibration thereof.
[0009] Other objects, advantages and novel features of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is an exploded, isometric view of an optical disc drive in accordance with the present invention;
[0011] FIG. 2 is similar to FIG. 1 , but viewed from another aspect;
[0012] FIG. 3 is a further exploded view of FIG. 2 , but not showing a tray of the optical disc drive;
[0013] FIG. 4 is an enlarged view of a circled portion IV of FIG. 3 ;
[0014] FIG. 5 is similar to FIG. 3 , but viewed from another aspect; and
[0015] FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0016] Reference will now be made to the drawing figures to describe the preferred embodiment of the present invention in detail.
[0017] As shown in FIG. 1 , an optical disc drive 99 in accordance with the present invention includes a tray 1 , a frame 2 , a slider 3 , a U-shaped subframe 4 , a drive unit 5 and four dampers 6 . The tray 1 can slide into and out from the frame 2 .
[0018] Referring to FIGS. 2 and 3 , the drive unit 5 has a supporting plate 51 , a spindle motor 52 , an optical pickup 53 and a feeding mechanism 54 . An optical disc (not labeled) is rotated by the spindle motor 52 , and the optical pickup 53 is driven by the feeding mechanism 54 to move along the radial direction of the optical disc so that it reads information recorded in the disc. Four open mounting holes 511 are defined in four comers of the supporting plate 51 respectively.
[0019] Referring also to FIGS. 5 and 6 , the frame 2 is rectangular and hollow. The frame 2 comprises a pair of opposite side walls 21 , which are interconnected by a front beam 22 and by a back beam 23 . A U-shaped recess 211 is defined in a middle of each side wall 21 . An elastic arm 212 is formed on each side wall 21 at each recess 211 . The elastic arm 212 extends from an outer side of the recess 211 into the recess 211 . The elastic arm 212 comprises a fixed portion 213 and a movable portion 214 . The movable portion 214 comprises a claw 215 at an upper end thereof. A first elastic sponge 25 is fixed at each of junctions of the front beam 22 and the two side walls 21 (see especially FIG. 4 ). A platform 24 is formed at each of junctions of the back beam 23 and the two side walls 21 . A screw hole 241 is defined in each platform 24 .
[0020] The slider 3 is movably mounted on the front beam 22 of the frame 2 . Two parallel Z-shaped slots 31 are defined in the front beam 22 . Each Z-shaped slot 31 comprises a higher slot portion 311 , a lower slot portion 312 , and a slant slot portion 313 intercommunicating between the higher slot portion 311 and the lower slot portion 312 .
[0021] The U-shaped subframe 4 comprises a crossbeam 41 , two parallel side beams 42 connecting with opposite ends of the crossbeam 41 respectively, and two extended ends 43 extending perpendicularly outwardly from the free ends of the side beams 42 respectively. The extended ends 43 are accommodated in the recesses 211 . Each extended end 43 comprises a cylindrical pivot portion 431 , and a cylindrical clamping portion 432 at a distal end of the pivot portion 431 . A cross section of the clamping portion 432 is larger than that of the pivot portion 431 . Two guide pins 411 extend from an outside surface of the crossbeam 41 , for being slidably received in the Z-shaped slots 31 of the slider 3 . A platform 44 is formed at each of junctions of the crossbeam 23 and the two side beams 42 . A screw hole 441 is defined in each platform 44 . A second elastic sponge 45 is fixed on an inside surface of each side beam 42 .
[0022] The dampers 6 are made of elastic rubber. Each damper 6 defines a central through hole 62 , and an external annular groove 61 . The annular groove 61 enables the damper 6 to be deformably accommodated in a corresponding mounting hole 511 .
[0023] In assembly of the optical disc drive 99 , the guide pins 411 of the U-shaped subframe 4 are inserted into the Z-shaped slots 31 . The extended ends 43 of the U-shaped subframe 4 are pivotably mounted to the frame 2 . In particular, the pivot portions 431 of the extended ends 43 are received in the recesses 211 , and the claws 215 of the elastic arms 212 hold the extended ends 43 and prevent the extended ends 43 from accidentally coming out from the recesses 211 . Further, the elastic arms 212 clamp the clamping portions 432 , thereby preventing the U-shaped subframe 4 from moving in directions parallel to the crossbeam 41 . The dampers 6 are deformably engaged in the mounting holes 511 of the supporting plate 51 . Four screw bolts 7 are respectively passed through the through holes 62 of the dampers 6 and engaged in the screw holes 441 of the U-shaped subframe 4 and the screw holes 241 of the frame 2 . Thus, the front of the drive unit 5 is fixed on the platforms 44 of the U-shaped subframe 4 , and the back of the drive unit 5 is fixed on the platforms 24 of the frame 2 . As a result, the drive unit 5 is located between the second sponges 45 of the side beams 42 . Lastly, the tray is inserted into the frame 2 .
[0024] In operation, the slider 3 slides left/right along the front beam 22 as the tray 1 slides into/out from the frame 2 . When the slider 3 slides to the left end of the front beam 22 (as viewed from a front of the optical disc drive 99 ), the pins 411 of the U-shaped subframe 4 are in the lower slot portions 312 . Conversely, when the slider 3 slides to the right end of the front beam 22 (as viewed from the front of the optical disc drive 99 ), the guide pins 411 of the U-shaped subframe 4 slide along the Z-shaped slots 31 into the higher slot portions 311 . As the slider 3 moves from left to right and from right to left, the U-shaped subframe 4 can pivot about the extended ends 43 correspondingly. That is, the drive unit 5 can rise or fall together with the U-shaped subframe 4 . The first elastic sponges 25 at the junctions of the front beam 22 and the side walls 21 reduce the clearance between the U-shaped subframe 4 and the frame 2 . The first elastic sponges 25 thus reduce any vibration of the U-shaped subframe 4 , especially during loading and unloading of the optical disc. The dampers 6 can reduce the vibration of the drive unit 5 in vertical directions. The second elastic sponges 45 can reduce the vibration amplitude of the drive unit 5 in horizontal directions, thus reducing any noise caused by vibration of the drive unit 5 .
[0025] In alternative embodiments, the first elastic sponges 25 can instead be attached on the U-shaped subframe 4 . As long as the first elastic sponges 25 are placed between the U-shaped subframe 4 and the frame 2 , vibration occurring during loading and unloading of the optical disc can be reduced. Similarly, the second elastic sponges 45 can instead be attached on side surfaces of the drive unit 5 . As long as the second elastic sponges 45 are placed between the U-shaped subframe 4 and the drive unit 5 , vibration of the drive unit 5 can be reduced. Furthermore, the first elastic sponges 25 and the second elastic sponges 45 can be devices or materials other than elastic rubber. For example, the first and second elastic sponges 25 , 45 may instead be springs, or may comprise another kind of elastic material such as an elastomer.
[0026] Although the present invention has been described with reference to specific embodiments, it should be noted that the described embodiments are not necessarily exclusive, and that various changes and modifications may be made to the described embodiments without departing from the scope of the invention as defined by the appended claims. | An optical disc drive ( 99 ) includes a frame ( 2 ); a U-shaped subframe ( 4 ) pivotably mounted on the frame; a slider ( 3 ) slidably mounted on the frame for making the subframe pivot; a drive unit ( 5 ) including a spindle motor ( 52 ) for rotating an optical disc, an optical pickup ( 53 ), and a feeding mechanism ( 54 ) adapted to move the optical pickup for reading/recording information; and a pair of elastic elements ( 45 ) located between the subframe and the drive unit for reducing vibration thereof. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cassette tape slack-preventing apparatus which is adapted for use in a magnetic recording/reproducing apparatus, such as a video tape recorder (VTR), wherein a capstan motor drives both a front loading mechanism and a tape-driving mechanism.
2. Description of the Related Art
As is well known, a helical scan VTR is provided with both a front loading mechanism and a tape-loading mechanism. When a video tape cassette containing a video tape is horizontally inserted into the cassette insertion port formed in the front face of the VTR, the front loading mechanism receives the cassette by means of a cassette holder and draws the cassette inside together with the cassette holder, and then lowers the cassette until it comes to the predetermined cassette-loading position. When the cassette is being lowered, its cover is opened, and the tape-pulling members of the tape-loading mechanism are inserted into the cassette and brought into contact with the inner side of the tape. Next, the tape-loading mechanism causes the tape-pulling members to pull the tape out of the cassette placed at the cassette-loading position and guides the tape such that it is in contact with about half of the circumference of the rotating cylinder. After the tape-loading mechanism sets the tape along the tape feed path in this way, various operation modes, such as recording, play, freeze (i.e., still image reproduction), slow play, fast-forward play, fast-rewind play, fast forward, and fast rewind, are selectively established with a mode-establishing mechanism and its associated circuits. If an eject key is operated, the tape-loading mechanism draws the tape back into the cassette, and the front loading mechanism returns the cassette from the cassette-loading position to the cassette insertion port.
With the recent trend toward miniaturization, it is demanded that the structural components of this type of magnetic recording/reproducing apparatus be simplified and reduced in both number and weight, without adversely affecting the ability to control the operation with high accuracy.
In a conventional VTR, the front loading mechanism for moving a tape cassette to the predetermined tape-loading position, the tape-loading mechanism for pulling the tape out of the tape cassette and bringing the tape into contact with the cylinder, and the tape-driving mechanism for driving the loaded tape are all driven or controlled by use of different motors specially designed for their respective purposes. Since each of these specially-designed motors can be controlled with high accuracy independently of the others, the operation of the driven-components of the VTR can be controlled with high accuracy. Due to the use of the specially-designed motors, however, the construction of the conventional VTR cannot be easily reduced in size or weight. It is therefore to difficult to manufacture a simple, light-in-weight VTR which meets the recent trend toward miniaturization.
Under the circumstances, it is thought to combine the front loading mechanism, the tape-loading mechanism and the tape-driving mechanism together in such a way that they can be driven or controlled by the same motor. If these mechanisms are combined in this way, the number of structural components can be reduced, so that a small-sized, light-in-weight VTR can be obtained.
Among various VTRs actually developed to date, there is a type wherein the capstan motor is used for driving both the front loading mechanism and the tape-driving mechanism (which includes not only a capstan shaft but also reel bases, etc.). This type of VTR operates as follows. The front loading mechanism moves the cassette to the predetermined loading position by utilization of the torque transmitted thereto from the capstan motor. Next, the tape-loading mechanism (which is driven by a motor different from the capstan motor, i.e., by a loading motor used for rotating mode cams) pulls the tape out of the cassette. Thereafter, the torque of the capstan motor is transmitted to the tape-driving mechanism (e.g., reel bases) in accordance with the user's operation.
In this type of VTR, the torque of the capstan motor is transmitted to the tape-driving mechanism (particularly, to the reel bases) whenever a driving force is transmitted to the front loading mechanism. This means that the tape take-up real of the real bases is rotated in the tape-winding direction when the front loading mechanism is operating. When the cassette has been loaded at the predetermined loading position (i.e., when the reel shaft-engaging hoes of the cassette have been brought into engagement with the reel shafts standing on the reel bases), the capstan motor is stopped, whereby the VTR is set in a standby condition, waiting for the user's next operation.
In the first state of the VTR (the first state being a state immediately after the cassette is loaded to the predetermined loading position), the tape take-up reel side of the cassette immediately stops since the capstan motor which drives the tape take-up reel is applied with a braking force during the first state. However, the tape-supply reel side of the cassette continues to rotate for some time, due to the moment of inertia, so that the tape is fed more than necessary, causing tape slack.
If tape slack is caused, the tape disengages from the slanted post and guide roller of the tape-pulling members, and thus drops. If the tape is pulled out of the cassette in this condition, it may happen that the tape will be brought into contact with the flanges of the slanted post and the guide roller, resulting in damage to the tape. It may also happen that the tape will fall in the gap between the chassis and the base member (by which the slanted post and the guide roller are supported), with the result that the tape may be stained with grease or cut. If the tape is stained with grease, this grease may attach also to the components of the tape-driving system, disabling the tape-driving system.
When, in the above-mentioned first state, the cassette is raised to return it to the cassette insertion port, the torque of the capstan motor is transmitted to the tape-supply reel in such a manner as to rotate the tape-supply reel in the tape-rewinding direction. If the tape is wound around the tape take-up reel at the time, the tape may slacken and overlap at the portions located inside the cover of the cassette.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a cassette tape slack-preventing apparatus which prevents a tape from slackening when the cassette of the tape engages with the reel shafts or disengages therefrom.
This object is achieved by a cassette tape slack-preventing apparatus for preventing slack of a cassette tape used in a magnetic recording/reproducing apparatus. The magnetic recording/reproducing apparatus comprises: a capstan motor; supply and take-up reel bases having reel shafts adapted for engagement with reel-engaging holes of a tape cassette; a front loading mechanism for transporting the tape cassette and bringing the reel-engaging holes of the tape cassette into engagement with the reel shafts of the reel bases, and for disengaging the tape cassette from the reel shafts of the reel bases and transporting the tape cassette back to an original position; a clutch mechanism for selectively transmitting torque of the capstan motor to the front loading mechanism; and a tape-driving mechanism for selectively transmitting the torque of the capstan motor to one of the supply and take-up reel bases. The cassette tape slack-preventing apparatus comprises: detection means for detecting an operating condition of the front loading mechanism; and a braking mechanism for braking at least one of the supply and take-up reel bases when the detection means detects the operating condition of the front loading mechanism, whereby the cassette tape is prevented from slackening in both first and second states, the first state being a state immediately after the reel-engaging holes of the tape cassette are brought into engagement with the reel shafts of the reel bases and the second state being a state when the reel-engaging holes are disengaged from the reel shafts.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.
FIGS. 1A-1C are top, side and bottom views, respectively, of a VTR (i.e., a magnetic recording/reproducing apparatus) to which a tape slack-preventing apparatus according to the first embodiment of the present invention is applied;
FIG. 2 is a sectional view of a clutch gear mechanism;
FIG. 3 is a perspective view of a switching mechanism;
FIGS. 4A and 4B are top and bottom views, respectively, illustrating both a pulley and a vertically-movable gear;
FIGS. 5A and 5B are top and bottom views, respectively, illustrating a tape-loading mechanism;
FIG. 6 is a block circuit diagram of the electric circuit of the VTR;
FIG. 7 is a view illustrating a slack cassette tape;
FIG. 8 is a view illustrating the construction of the cassette tape slack-preventing apparatus of the first embodiment; and
FIG. 9 is a view illustrating the construction of a cassette tape slack-preventing apparatus according to the second embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
One embodiment of the present invention will now be described, with reference to the accompanying drawings.
FIGS. 1A, 1B and 1C are top, side and bottom views, respectively, of a VTR to which a cassette tape slack-preventing mechanism of the present invention is applied. Referring to the Figures, frame member 11 is coupled to one end of main chassis 10. Cassette holder 12 is supported by frame member 11 such that it is movable in the directions indicated by arrows A, B and D (the direction indicated by arrow D is perpendicular to the directions indicated by arrows A and B). Cassette holder 12 is adapted to receive cassette C (which is not shown in FIGS. 1A, 1B and 1C, for simplicity) when it is located at the cassette insertion port. In response to the insertion of cassette C into cassette holder 12, front loading mechanism 13 is automatically driven. This front loading mechanism moves cassette holder 12 in direction B, together with cassette C inserted therein, until cassette holder 12 reaches a predetermined position. Then, front loading mechanism 13 moves cassette holder 12 in direction D. As a result, cassette C is fitted on supply and take-up reel bases 14 and 15, which are parts of a tape-driving mechanism.
Gears 14a and 15a are coupled to reel bases 14 and 15, respectively. Driving gear 16 constituting part of the tape-driving mechanism is located between gears 14a and 15a. This driving gear 16 is supported by one end of swing member 17.
As is shown in FIG. 2, gear 18, which is in mesh with driving gear 16, is attached to the other end of swing member 17. First clutch gear 19, which is part of a clutch gear mechanism, is arranged coaxial with gear 18. Second clutch gear 21, which is also part of the clutch gear mechanism, is stacked upon first clutch gear 19, with friction member 20 interposed therebetween. Clutch-switching gear 22 is arranged in such a manner as to face both gears 19 and 21. Clutch-switching gear 22 can be brought into contact with the first and second clutch gears 19 and 21, and can be moved away from them. Clutch-switching gear 22 is swung by change-over lever 23 (which interlocks with an operation mode-switching mechanism), such that it is selectively brought into mesh with both clutch gears 19 and 21. Pulley 24 is arranged coaxial with second clutch gear 21, and driving belt 25 is wound around pulley 24.
As is shown in FIG. 1C, driving belt 25 is wound around driving pulley 26. This driving pulley 26 is fitted on the rotating shaft of capstan motor 27. Therefore, the driving force of capstan motor 27 is transmitted first to pulley 24 via driving belt 25, and then to second clutch gear 21. Capstan shaft 28 is arranged coaxial with capstan motor 27.
A clutch mechanism is provided for capstan motor 27 mentioned above. The clutch mechanism serves to selectively transmit the torque of capstan motor 2 to front loading mechanism 13. More specifically, driving gear 29 is fitted around the periphery of the rotating member of capstan motor 27, as is shown in FIG. 3. Vertically-movable gear 30 is arranged such that it faces driving gear 29. As will be detailed later, vertically-movable gear 30 is designed to transmit its torque to front loading mechanism 13. First end 31a of vertically-swingable switch lever 31 is in contact with the upper side of vertically-movable gear 30. Second end 31b of the switch lever 31 engageable with one side of first mode-switching cam 32a, which is one of the mode-switching cams coaxial with the operation mode-switching mechanism.
First mode-switching cam 32a has step portion 32b which is in the form of a circular arc having predetermined size. Slanted portion 32c is formed in that end of step portion 32b which is located downstream with reference to the rotating direction of first mode-switching cam 32a. Slanted portion 32c is formed in such a manner that step portion 32b is smoothly connected to surface 32d of first mode-switching cam 32a.
With this construction, second end 31b of switch lever 31 engages with one of step portion 32b, slanted portion 32c and surface 32d of first mode-switching cam 32a in accordance with the rotation of this cam 32a. As a result of this engagement, first end 31a of switch lever 31 swings in the axial direction of vertically-movable gear 30, with rotatable shaft 31c as a center of swing.
As is shown in FIGS. 4A and 4B, vertically-movable gear 30 is coaxial with pulley 33, and this pulley 33 is coupled to main chassis 10 such that it is rotatable around shaft 33a. Vertically-movable gear 30 is located around pulley 33 and is urged toward pulley 33 in the axial direction of shaft 33a by spring 30a. The rotation of vertically-movable gear 30 is transmitted to pulley 33 through stop members 33b. That is, vertically-movable gear 30 and pulley 33 are rotatable in the same direction.
Driving belt 34 is wound around both pulley 33 and pulley 35. As is shown in FIG. 1C, pulley 35 is coaxial with worm 36 of front loading mechanism 13.
At the time of loading tape cassette C, second end 31b of switch lever 31 engages with step portion 32b, due to the rotation of first mode-switching cam 32a. Therefore, first end 31a of switch lever 31 is separated from vertically-movable gear 30. As a result, vertically-movable gear 30 is raised (in the direction E) by the urging force of spring 30a and brought into mesh with driving gear 29. Thus, the rotation of capstan motor 27 is transmitted to front driving mechanism 13 through vertically-movable gear 30, pulley 33, driving belt 34, pulley 35 and worm 36, whereby front driving mechanism 13 performs the loading of cassette holder 12.
When the loading of cassette C is completed, first mode-switching cam 32a is rotated, and second end 31b of switch lever 31 engages with surface 32d after sliding along slanted portion 32c. Therefore, first end 31a of switch lever 31 contacts vertically-movable gear 30 and pushes this gear downward. As a result, vertically-movable gear 30 is moved downward in the direction F in spite of the urging force of spring 30a. Thus, the rotation of pulley 33 is stopped, and the loading of cassette holder 12 is stopped, accordingly.
Loading motor 32 is designed to drive not only first mode-switching cam 32a mentioned above but also the other mode-switching cams.
As is shown in FIG. 1A, helical scan type cylinder 37 having magnetic heads (not shown) is rotatably coupled to main chassis 10 mentioned above. Around this cylinder 37, first and second guide holes 38a and 38b (which are parts of a tape-loading mechanism) are provided such that the two guide holes correspond in location to the tape inlet and outlet sides, respectively.
As is shown in FIG. 5A, first and second tape-pulling members 39a and 39b are fitted in first and second guide holes 38a and 38b, respectively, such that they are movable within the guide holes. Slanted post 40a substantially parallel to cylinder 37 and guide roller 41a substantially perpendicular to main chassis 10 are provided for first tape-pulling member 39a such that they are located side by side with reference to each other. Likewise, slanted post 40b substantially parallel to cylinder 37 and guide roller 41b substantially perpendicular to main chassis 10 are provided for second tape-pulling member 39b such that they are located side by side with reference to each other.
As is shown in FIG. 5B, the one-end portions of first and second links 42a and 42b are coupled to the proximal ends of first and second tape-pulling members 39a and 39b, respectively. The other-end portions of first and second links 42a and 42b are supported by first and second driving gears 43a and 43b, respectively, which are in mesh with each other. Half-gear 44 is arranged coaxial with second driving gear 43b. Sectorial gear 45a formed at one end of driving lever 45 is in mesh with half-gear 44. An intermediate point of driving lever 45 is swingably supported by main chassis 10 by means of shaft 46. Pin 45b located at the other end of driving lever 45 engages with cam groove 32f formed in second mode-switching cam 32e, and this cam 32e is rotated within a predetermined angular range by loading motor 32. Therefore, driving lever 45 is driven by the movement of second mode-switching cam 32e, and transmits the driving force to first and second tape-pulling members 39a and 39b, through half-gear 44, first and second driving gears 43a and 43b, and first and second links 42a and 42b, whereby performing tape loading.
As is shown in FIG. 1A, pinch roller 47, which is part of the tape-driving mechanism, is arranged on main chassis 10 such that it is located in the neighborhood of capstan shaft 28 mentioned above. Pinch roller 47 is swingably supported by one end of pinch lever 48. Pinch lever 48 is swung in association with the above-mentioned mode-switching cams by a linking mechanism (not shown). As a result of the swing of pinch lever 48, pinch roller 47 supported at one end of lever 48 is pressed against capstan shaft 28, with tape T interposed.
First and second mode-switching cams 32a and 32e mentioned above are coaxial with the other mode-switching cams (not shown). All these mode-switching cams are rotated within the same angular range by loading motor 32, and their angles of rotation are determined in accordance with the operation modes of the VTR. As is shown in FIG. 6, loading motor 32 is driven by motor driver 49 under the control of controller 50. In accordance with the user's operation of control panel 51, controller 50 determines an operation mode of the VTR. Controller 50 causes the mode-switching cams to be rotated by the angle corresponding to the determined operation mode. Further, controller 50 controls motor driver 52 in accordance with the determined operation mode, to thereby drive capstan motor 27. The torque of capstan motor 27 is selectively transmitted to capstan shaft 28, reel base 14 located on the tape supply side, reel base 15 located on the tape take-up side, etc. Still further, controller 50 controls motor driver 53 in accordance with the determined operation mode, to thereby drive cylinder motor 54 to rotate cylinder 37.
In the VTR having the above-mentioned construction, loading motor 32 is driven and first mode-switching cam 32a is rotated, in response to the insertion of tape cassette C into cassette holder 12. First mode-switching cam 32a actuates switch lever 31 in such a manner that vertically-movable gear 30 is brought into mesh with driving gear 29. After first mode-switching cam 32a is rotated by a first predetermined angle, loading motor 32 is stopped, with the mesh between vertically-movable gear 30 and driving gear 29 maintained. Simultaneous with this, capstan motor 27 is driven, and the driving force of this motor is transmitted to front loading mechanism 13 through driving gear 29, vertically-movable gear 30, pulley 33, driving belt 34, pulley 35, and worm 36, as mentioned above. Thus, tape cassette C is mounted on reel bases 14 and 15.
After the cassette loading is completed in the above manner, loading motor 32 is driven again, and first mode-switching cam 32a is rotated by a second predetermined angle. In accordance with this rotation, switch lever 31 is swung in the reverse direction E, causing vertically-movable gear 30 to separate from driving gear 29. Simultaneous with this, second mode-switching cam 32e coaxial with first mode-switching cam 32a is also rotated by the second predetermined angle, whereby first and second tape-pulling members 39a and 39b are driven to perform tape loading.
Thereafter, first and second mode-switching cams 32a and 32e, and other mode-switching cams (not shown) which are coaxial with first and second mode-switching cams 32a and 32e are rotated by the angle corresponding to a desirable operating mode. In accordance with this rotation of the cams, an operating mode-switching mechanism (not shown) is driven such that the tape-driving mechanism is selectively switched into one of the operating modes, such as the play mode, fast-forward mode, fast-rewind mode, etc.
As mentioned above, vertically-movable gear 30 is moved in the axial direction thereof, with reference to driving gear 29 driven by capstan motor 27, and the movement of gear 30 is controlled by switch lever 31 which is moved in association with the driving of first mode-switching cam 32a. In this manner, the driving force of driving gear 29 is selectively transmitted to front loading mechanism 13 through vertically-movable gear 30. Thus, the cassette-loading operation can be controlled with high accuracy by utilization of the driving force of capstan motor 27. Since the number of structural components of the VTR can be reduced while maintaining the highly-accurate operation of the front loading mechanism, the size and weight of the VTR can be reduced to the possible degree.
As is shown in FIGS. 1C and 3, capstan motor 27 is constantly connected to either reel base 14 or reel base 15 through such a clutch mechanism as is shown in FIG. 2. Due to this, the VTR may be faced with the problem mentioned above if it does not employ the cassette tape slack-preventing apparatus of the present invention. Specifically, in the first state of the VTR (i.e., the state immediately after tape cassette C is loaded at the predetermined loading position, in other words, the state immediately after reel shaft-engaging holes 55 and 56 of cassette C engage with reel shafts 14b and 15b of reel bases 14 and 15), tape T may be fed from cassette C, due to the rotation of tape-supply reel base 14 caused by the moment of inertia, and thus slackens, as is indicated by the solid lines in FIG. 7. Further, in the second state of the VTR (i.e., the state where cassette C in the first state has just been raised to return it to the cassette insertion port), tape T may be fed from cassette C, due to the rotation of tape take-up reel base 15 caused by the moment of inertia, and thus slackens. However, the cassette tape slack-preventing apparatus incorporated in the VTR prevents tape T from slacking in both the first and second states and maintains tape T in the condition indicated by the one-dot-chain lines in FIG. 7. A detailed description will now be given of this cassette tape slack-preventing mechanism.
FIG. 8 shows the manner in which the cassette tape slack-preventing apparatus of the first embodiment of the present invention is applied to tape take-up reel base 15 of the VTR. Referring to FIG. 8, pinch lever 48 is coupled to main chassis 10 by means of shaft 57. This pinch lever 48 includes a plurality of arm portions 48a, 48b and 48c extending in different directions. Pinch roller 47 mentioned above is supported by the upper side of the tip end of arm portion 48a. The first end of coupling lever 58 engages with the tip end of arm portion 48b, while the second end of coupling lever 58 engages with the tip end of cam 59 whose rotational position is varied in accordance with the rotation of third mode-switching cam 32g. Cam 59 is rotatable, with immovable support shaft 60 as the center of rotation. Cam 59 includes pin 59a which is in engagement with cam section 32h formed in third mode-switching cam 32g. Third mode-switching cam 32g is arranged coaxial with both first and second mode-switching cams 32a and 32e. Loading motor 32 rotates these mode-switching cams by the same angle in accordance with the operating mode of the VTR, as mentioned above.
Arm portion 48c of pinch lever 48 extends toward brake member 61 of reel base 15. Brake member 61 includes arm portions 61a, 61b and 61c and is swingably supported by immovable shaft 62. Reel base 15 is rotated in the direction indicated by arrow G in FIG. 8 when the VTR is in the play, recording, or fast forward mode, while it is rotated in the opposite direction indicated by arrow H when the VTR is in the fast rewind mode. Reverse brake pad 61e attached to arm portion 61b of brake member 61 is located in opposition to the circumferential brake face of reel base 15. Spring 63 is coupled to arm portion 61a of brake member 61. Normally, brake member 61 is pulled by spring 63, so that reverse brake pad 61e attached to arm portion 61b is elastically pressed against the circumferential brake face of reel base 15.
Arm portion 61c of brake member 61 is provided with brake pad 64 at the tip end thereof. Brake pad 64 is located in opposition to the circumferential face of gear 15a. Boss 61d is formed at arm portion 61c, and arm portion 48c of pinch lever 48 is located in opposition to boss 61d.
In the state shown in FIG. 8, pinch roller 47 is located away from capstan shaft 28. In this state, reverse brake pad 61e of brake member 61 is in slight contact with reel base 15.
When pinch roller 47 is pressed against capstan shaft 28 (e.g., at the time of the play or the recording mode of the VTR), pinch lever 48 swings in direction I indicated in FIG. 8, whereby its arm portion 48c allows arm portion 61c of brake member 61 to swing in direction J indicated in FIG. 8. Therefore, brake member 61 is pulled by spring 63, and reverse brake pad 61e is pressed against reel base 15. In this state, reel base 15 can be smoothly rotated in the tape winding direction, but is applied with a great braking force in the reverse direction (i.e., in the tape-rewinding direction).
When the front loading mechanism is operating, third mode-switching cam 32g is rotated in direction K indicated in FIG. 8. Therefore, cam 59 is rotated in direction L, and pinch lever 48 swings in direction M. Accordingly, arm portion 48c of pinch lever 48 is pressed tightly against boss 61d of brake member 61, causing brake member 61 to swing in direction N.
Due to the operation mentioned above, brake pad 64 is forcibly pressed against gear 15a of reel base 15 when the front loading mechanism is operating. Since the rotation of reel base 15 of the tape take-up side is prevented, tape T is prevented from undesirably feeding from tape-supply reel base 14 when cassette C is fitted on reel bases 14 and 15.
The cassette tape slack-preventing apparatus of the first embodiment employs a brake mechanism which forcibly applies a braking force to tape take-up reel base 15 when the front loading mechanism is operating. However, the braking force may be forcibly applied to tape-supply reel base 14. In other words, the brake mechanism may be provided for tape-supply reel base 14.
FIG. 9 illustrates the construction of a cassette tape slack-preventing apparatus according to the second embodiment of the present invention. This apparatus is designed to forcibly apply a braking force to tape-supply reel base 14. Referring to FIG. 9, tension lever 65 for applying tension to tape T is arranged between first guide hole 38a and reel base 14. One end of tension lever 65 is swingably attached to main chassis 10 by means of shaft 67, while the other end has tension pole 68 standing upright thereon. The state shown in FIG. 9 is a state where the front loading has been completed or where tape T has been returned into the interior of cassette C by tape unloading. When tape T is pulled out of cassette C and brought into contact with cylinder 37, tension lever 65 swings to the position indicated by the one-dot-chain lines in FIG. 9, with shaft 67 as a center. Tension lever 65 is driven by a mode-switching mechanism (not shown) to which a driving force is transmitted from a mode-switching cam. Simultaneous with the swing of tension lever 65, first tape-pulling member 39a moves along first guide hole 38a to the position indicated by one-dot-chain lines in FIG. 9. Accordingly, tape T is brought into contact with the circumference of cylinder 37. When tape T is unloaded, the opposite operation to that mentioned above is performed. Specifically, first tape-pulling member 39a is returned to the position indicated by the solid lines in FIG. 9; likewise, tension lever 65 is returned to the position indicated by the solid lines in FIG. 9.
In the second embodiment, first tape-pulling member 39a is designed to operate on tension lever 65. As can be understood from the state shown in FIG. 9, first tape-pulling member 39a continues to forcibly push and swing tension lever in direction O, immediately before the tape loading is performed.
The operation of tension lever 65 is related with that of brake band 69 wound around the circumferential face of reel base 14. More specifically, even when tape T is not applied with tension, tension lever 65 pulls end 69a of brake band 69, to thereby tighten brake band 69 around reel base 14. Thus, reel base 14 is kept applied with a great braking force until the tape loading illustrated in FIG. 9 is performed, i.e., until the end of the front loading. Therefore, tape T prevented from slackening when the slot-in operation has just been performed.
The primary function of tension lever 65 is to maintain the tape tension at a constant value and control the movement of reel base 14. Specifically, tension lever 65 applies tension to tape T when it is located at the position indicated by the one-dot-chain lines in FIG. 9. If, in this condition, the rotation of reel base 14 becomes faster and tape T is fed more than necessary, tension lever 65 swings in direction P, due to the elastic force of a spring or the like. Thus, the tape tension is maintained at a constant value. Simultaneous with the swing of tension lever 65, brake band 69 is pulled, whereby reel base 14 is applied with a braking force. In the second embodiment, tension lever 65 having this primary function is also designed such that it can forcibly apply a braking force to reel base 14 by utilization of the movement of tape-pulling member 39a.
As mentioned above, the cassette tape slack-preventing apparatus of the invention is employed in a magnetic recording/reproducing apparatus of a type wherein the capstan motor is used for driving the front loading mechanism and for rotating the reel bases, and comprises a braking mechanism which forcibly arrests the rotation of the reel bases when the front loading mechanism is operating. Due to the action of the braking mechanism, the rotation of the reel bases is arrested during the slot-in operation, and tape T is prevented from being undesirably fed immediately after the completion of the slot-in operation (i.e., immediately after reel shaft-engaging holes 55 and 56 of cassette C are fitted around reel shafts 14b and 15b of reel bases 14 and 15, respectively).
The braking mechanism of the present invention may be embodied in various manners. Any type of braking mechanism can be employed as long as it can forcibly apply a braking force to the reel bases during the operation of the front loading mechanism. In addition, a braking force may be applied to one or both of the take-up and supply reel bases.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative devices, and illustrated examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. | A cassette tape slack-preventing apparatus to prevent magnetic tape from becoming slack when inserted into a video tape recorder in which the capstan motor drives the reel bases as well as the cassette loading machanism. Mode switching cams are used to detect if a front loading mechanism is in operating and keeps the reel bases from rotating through linkages to the cams. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to communication networks. In particular, the invention relates to providing a default subscription profile for controlling a roaming terminal device in a packet data based mobile communication network in a novel way.
2. Description of the Related Art
Recently also mobile communication networks have started to support transmission of packet switched data or packet data in addition to traditional circuit switched data transmission.
An example of a technique allowing packet data transmission for mobile communication networks is General Packet Radio Service (GPRS). GPRS is designed to support e.g. digital mobile telecommunication networks based on the Global System for Mobile Communications (GSM) standard. However, GPRS is not restricted to only GSM networks but may support for example 3 rd Generation Partnership Project (3GPP) based digital mobile telecommunication networks. Other examples of packet data based mobile communication networks are Wireless Local Area Network (WLAN) based mobile communication networks, Code Division Multiple Access (CDMA) based mobile communication networks, Wideband Code Division Multiple Access (WCDMA) based mobile communication networks, and Enhanced Data Rates for Global Evolution (EDGE) based mobile communication networks.
A GPRS based mobile communication network comprises supplementary network elements or nodes in addition to existing network elements. These include a Serving GPRS Support Node (SGSN) and a Gateway GPRS Support Node (GGSN). A Serving GPRS Support Node typically delivers packets to and from GPRS enabled terminal devices within its service area. A Gateway GPRS Support Node is typically used as an interface to external IP networks such as the Internet, other mobile service providers' GPRS services, or enterprise intranets.
The introduction of packet data based mobile communication networks has resulted in various value-added subscriber services being provided for these packet data based mobile communication networks. Examples of such subscriber services are packet data based voice, email, content downloading, browsing, streaming and rich calls. Furthermore, packet data based mobile communication networks typically offer network services to support the usage of subscriber services. Such network services include e.g. rerouting, barring, accounting, content proxy services, content blocking services, firewall services, virus scanning services, performance enhancement proxy services, Virtual Private Network (VPN) services, various Quality of Service (QoS) related services and various charging related services for both online and offline charging.
A recent trend is to provide the various subscriber and network services for packet data based mobile communication networks in a subscriber specific manner. To allow this, one or more subscription profiles are generated for each subscriber. The subscription profile comprises subscriber specifically customized subscription data that will be utilized in providing the various subscriber and network services to the terminal device of the subscriber. The subscription data may comprise e.g. authorization information about which access points in the mobile communication network the subscriber is allowed to access, and which services are allowed within each allowed access point. The subscription data may further comprise e.g. information about charging attributes or rules, Quality of Service attributes or rules, and service chaining attributes such as attributes or rules for chained service selection and chained service component specific attributes or rules. An access point may be e.g. a Gateway GPRS Support Node of a General Packet Radio Service based mobile communication network, or a Packet Data Gateway of a Wireless Local Area Network based mobile communication network.
Prior art teaches storing the generated subscription profile in a subscriber database of a home network of the subscriber. As is known in the art, in the context of mobile communication networks, when a subscriber connects via a service area that is managed by an operator other than the one with whom the subscriber originally registered with, the subscriber is said to be ‘roaming’. In contrast, when the subscriber connects via a service area that is managed by the operator with whom the subscriber originally registered with, the subscriber is said to be at ‘home’. The mobile communication network managed by the operator with whom the subscriber originally registered with is called the home network of the subscriber. The subscriber database may be, for example, a Home Location Register in a General Packet Radio Service based mobile communication network.
The prior art solution of storing the generated subscription profile in the subscriber database of the home network of the subscriber works reasonably well while the subscriber is at home.
However, problems arise when the subscriber is roaming. When the terminal device of the subscriber roams into a visited network and requests to use a gateway of the visited network, the gateway needs to acquire the subscription profile of the roaming terminal device. Prior art teaches ways of acquiring the subscription profile. A way involves the gateway of the visited network directly contacting the subscriber database of the home network of the roaming terminal device and requesting the subscription profile of the roaming terminal device. Another way involves the gateway of the visited network first contacting a session control means of the home network of the roaming terminal device and requesting the subscription profile of the roaming terminal device. The session control means in turn contacts the subscriber database of the home network of the roaming terminal device, requests the subscription profile of the roaming terminal device, and forwards relevant parts of the subscription profile to the gateway of the visited network. Yet another way involves the gateway of the visited network contacting the session control means of the visited network, and the session control means of the visited network contacting the subscriber database of the home network and requesting the subscription profile of the roaming terminal device. The session control means is sometimes also referred to as Internet Protocol Session Control, a Policy Decision Function (PDF), a Charging Rules Function (CRF) or a Policy and Charging Control Node (PCCN)
Thus, in prior art, when the terminal device is roaming and its subscription profile is required, the subscription profile will always have to be transmitted from one network to another, i.e. from the home network to the visited network. This, however, is not desirable. Transmitting the subscription profile from one network to another requires real-time signaling which in turn causes delay. In today's highly loaded mobile communication networks real-time signaling and its associated delay is to be avoided whenever possible. Furthermore, transmitting the subscription profile from one network to another may not even be possible at all times due to e.g. some connection problem between the two networks.
Prior art further includes U.S. Ser. No. 09/774998, now U.S. Pat. No. 7,231,028, which discloses a method and system for the management of subscriber functions in a digital telephone exchange. The functions for default subscribers are stored in and read from default records common to the subscribers, and only the functions for special subscribers are stored in and read from subscriber-specific records.
Therefore, the object of the present invention is to alleviate the problems described above and to introduce a mechanism that allows providing a default subscription profile for controlling a roaming terminal device in a packet data based mobile communication network in order to avoid having to transmit the subscription profile of the roaming terminal device from the home network of the roaming terminal device to the visited network.
SUMMARY OF THE INVENTION
A first aspect of the present invention is a method of providing a default subscription profile for a roaming terminal device in a packet data based mobile communication network.
A terminal device roaming in a packet data based mobile network requesting to use a gateway of the mobile communication network is detected. As the terminal device is roaming in the mobile communication network, this mobile communication network is not a home network of the terminal device.
In response to the detection, a request for a subscription profile for the roaming terminal device is sent from the gateway.
In response to the received request, a default subscription profile stored in a network element of the mobile communication network is sent to the gateway. The default subscription profile comprises default subscription data to be utilized in providing services to the roaming terminal device.
The term ‘service’ herein refers to both the value-added subscriber services and the network services supporting them, as described above.
The term ‘default’ herein refers to the fact that the default subscription data comprised in the default subscription profile is not subscriber specifically customized subscription data, as is the case with the prior art subscription profile stored in the home network of the roaming terminal device. Rather, the default subscription profile is stored in the visited network instead of the home network, and one default subscription profile may be used for multiple subscribers roaming in the visited network or even all the subscribers roaming in the visited network.
A second aspect of the present invention is a method of generating a subscription profile for a roaming terminal device in a packet data based mobile communication network.
At least one default subscription profile comprising default subscription data is generated. The generated at least one default subscription profile is stored in a network element of a packet data based mobile communication network. The default subscription data is to be utilized in providing services to a terminal device roaming in the mobile communication network.
A third aspect of the present invention is a system of providing a default subscription profile for a roaming terminal device in a packet data based mobile communication network. The system comprises a packet data based mobile communication network.
The system further comprises a default subscription profile generator, in the mobile communication network, for generating at least one default subscription profile comprising default subscription data to be utilized in providing services to a terminal device roaming in the mobile communication network.
The system further comprises a default subscription profile storage, in the mobile communication network, for storing the at least one generated default subscription profile. The system further comprises a gateway, in the mobile communication network, for requesting the stored default subscription profile in response to detecting a terminal device roaming in the mobile communication network requesting to use the gateway.
A fourth aspect of the present invention is a system of providing a default subscription profile for a roaming terminal device in a packet data based mobile communication network. The system comprises a packet data based mobile communication network.
The system further comprises a default subscription profile generating means, in the mobile communication network, for generating at least one default subscription profile comprising default subscription data to be utilized in providing services to a terminal device roaming in the mobile communication network.
The system further comprises a default subscription profile storing means, in the mobile communication network, for storing the at least one generated default subscription profile. The system further comprises a gateway means, in the mobile communication network, for requesting the stored default subscription profile in response to detecting a terminal device roaming in the mobile communication network requesting to use the gateway means.
A fifth aspect of the present invention is a network element of a packet data based mobile communication network. The network element comprises a default subscription profile generator for generating at least one default subscription profile comprising default subscription data to be utilized in providing services to a terminal device roaming in the mobile communication network.
A sixth aspect of the present invention is a network element of a packet data based mobile communication network. The network element comprises a default subscription profile storage for storing at least one default subscription profile comprising default subscription data to be utilized in providing services to a terminal device roaming in the mobile communication network.
A seventh aspect of the present invention is a network element of a packet data based mobile communication network. The network element comprises a selector for selecting a default subscription profile out of multiple default subscription profiles for a terminal device roaming in the mobile communication network according to a predetermined selection criterion. The multiple default subscription profiles are stored in a network element of the mobile communication network. Each profile comprises at least partially different default subscription data to be utilized in providing services to the roaming terminal device.
An eight aspect of the present invention is a computer program embodied on a computer readable medium for providing a default subscription profile for a roaming terminal device in a packet data based mobile communication network. The computer program controls a data-processing device to perform the steps of: detecting a terminal device roaming in a packet data based mobile communication network requesting to use a gateway of the mobile communication network; sending, from the gateway, a request for a subscription profile for the roaming terminal device; and sending, to the gateway, a default subscription profile stored in a network element of the mobile communication network, the default subscription profile comprising default subscription data to be utilized in providing services to the roaming terminal device.
A ninth aspect of the present invention is a computer program embodied on a computer readable medium for generating a default subscription profile for a roaming terminal device in a packet data based mobile communication network. The computer program controls a data-processing device to perform the steps of: generating at least one default subscription profile comprising default subscription data; and storing the generated at least one default subscription profile in a network element of a packet data based mobile communication network, the default subscription data to be utilized in providing services to a terminal device roaming in the mobile communication network.
In an embodiment of the invention, multiple default subscription profiles are generated and stored in a network element of the mobile communication network. Each profile comprises at least partially different default subscription data. One default subscription profile out of the multiple stored profiles is selected for a given roaming terminal device according to a predetermined selection criterion.
In an embodiment of the invention, the default subscription profile out of the multiple stored profiles is selected according to a predetermined selection criterion comprising at least one of: access network type, time of day, network load, and a group of the roaming terminal device.
In an embodiment of the invention, the default subscription data comprises at least one of: allowed access points in the mobile communication network, allowed services within each allowed access point, charging attributes, Quality of Service attributes, and service chaining attributes.
In an embodiment of the invention, the default subscription profile generator is comprised in at least one of: the gateway, a session control means of the mobile communication network, and a subscriber database of the mobile communication network.
In an embodiment of the invention, the default subscription profile storage is comprised in at least one of: the gateway, a session control means of the mobile communication network, and a subscriber database of the mobile communication network.
The invention allows avoiding the need to transmit the subscription profile of the roaming terminal device from the home network of the roaming terminal device to the visited network. Rather, a default subscription profile stored in the visited network is used. Thus real-time signaling and its associated delay are decreased. Furthermore, the subscription profile is accessible even when there are connection problems between the home network and the visited network.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further understanding of the invention and constitute a part of this specification, illustrate embodiments of the invention and together with the description help to explain the principles of the invention. In the drawings:
FIG. 1 a is a graphical representation illustrating a method according to an embodiment of the present invention,
FIG. 1 b is a flow diagram illustrating another method according to an embodiment of the present invention, and
FIG. 2 is a block diagram illustrating a system according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the embodiments of the invention, examples of which are illustrated in the accompanying drawings.
FIG. 1 a illustrates an exemplary embodiment of the method of the present invention relating to providing a default subscription profile for a roaming terminal device in a packet data based mobile communication network. In the exemplary embodiment of FIG. 1 a the packet data based mobile communication network 103 comprises a General Packet Radio Service based mobile communication network the packet data transmission of which is based on Internet Protocol (IP). However, the present invention applies as well to e.g. Wireless Local Area Network based mobile communication networks, Code Division Multiple Access based mobile communication networks, Wideband Code Division Multiple Access based mobile communication networks, and Enhanced Data Rates for Global Evolution based mobile communication networks.
At step 110 , a terminal device 100 roaming in the packet data based mobile network 103 sends a request to use a gateway 101 of the packet data based mobile communication network 103 , and the gateway 101 detects the request. The request may be a request for bearer establishment or modification, such as a request for e.g. Packet Data Protocol context activation or modification or a request for tunnel establishment or modification, or the request may be a packet of a service flow.
In response to the detection, at step 111 , the gateway 101 sends a request for a subscription profile for the roaming terminal device. The subscription profile request is sent to a network element 102 of the packet data based mobile communication network 103 .
In the exemplary embodiment of FIG. 1 a, the network element 102 comprises multiple default subscription profiles stored therein. Each stored default subscription profile comprises default subscription data. The default subscription data is to be utilized by the gateway 101 in providing services to the roaming terminal device 100 , and the default subscription data may comprise e.g. allowed access points in the packet data based mobile communication network 103 , allowed services within each allowed access point, charging attributes, Quality of Service attributes, and/or service chaining attributes. In other words, the default subscription data may comprise at least partially same subscription attributes as the prior art subscription profile customized specifically for the subscriber of the terminal device 100 and located typically in a subscriber database of a home network of the terminal device 100 . However, the values of the subscription attributes of the default subscription data are default values as opposed to the subscriber specifically customized values of the prior art subscription attributes of the prior art subscription profile. Thus, if e.g. the set of allowed services is limited in the visited network compared to the home network, the default subscription profile of the present invention allows indicating which access points and services are allowed in the visited network. Likewise, the present invention allows setting such rules for charging, Quality of Service, and service chaining purposes, that are specific to the visited network but still common to all the roaming terminal devices in the visited network or to a group of all the roaming terminal devices in the visited network.
If there are multiple stored default subscription profiles, as is the case with the exemplary embodiment of FIG. 1 a, each stored default subscription profile comprises default subscription data that is at least partially different from each other.
At step 112 , one default subscription profile out of the stored multiple default subscription profiles is selected at the network element 102 for the roaming terminal device 100 according to a predetermined selection criterion. The selection criterion may be e.g. access network type, time of day, network load, or a group of the roaming terminal device 100 .
Thus, the present invention allows using a given default subscription profile for all roaming subscribers or for a group of roaming subscribers. Correspondingly, a first default subscription profile may be used for a first group of subscribers, and a second default subscription profile may be used for a second group of subscribers. A first group of subscribers may be e.g. the roaming subscribers of a first network operator, whereas a second group of subscribers may be e.g. the roaming subscribers of a second network operator. To allow this, subscriber identification of the roaming terminal device, such as e.g. International Mobile Subscriber Identifier (IMSI), may be analyzed in order to determine to which group a given roaming terminal device belongs.
Furthermore, the present invention allows e.g. using a first default subscription profile for a first access network type of the roaming terminal device, such as e.g. General Packet Radio Service, and a second default subscription profile for a second access network type of the roaming terminal device, such as e.g. Wireless Local Area Network.
Furthermore, the present invention allows e.g. using a first default subscription profile comprising a more limited set of allowed services during busy hours of the visited network, and a second default subscription profile comprising a less limited set of allowed services during non-busy hours. Furthermore, the present invention allows e.g. using a first default subscription profile comprising more limited rules for Quality of Service during high network load of the visited network, and a second default subscription profile comprising less limited rules for Quality of Service during low network load.
In response to the received subscription profile request, at step 113 , the selected default subscription profile is sent from the network element 102 to the gateway 101 .
FIG. 1 b illustrates an exemplary embodiment of the method of the present invention relating to generating a subscription profile for a roaming terminal device in a packet data based mobile communication network. At step 120 , at least one default subscription profile comprising default subscription data is generated. At step 130 , the generated at least one default subscription profile is stored in a network element of a packet data based mobile communication network. The default subscription data is to be utilized in providing services to a terminal device roaming in the same packet data based mobile communication network in which the generated at least one default subscription profile is stored.
FIG. 2 illustrates an exemplary embodiment of the system of the present invention relating to providing a default subscription profile for a roaming terminal device in a packet data based mobile communication network. The system comprises a packet data based mobile communication network 200 . In the exemplary embodiment of FIG. 2 the packet data based mobile communication network 200 comprises a General Packet Radio Service based mobile communication network. However, the present invention applies as well to e.g. Wireless Local Area Network based mobile communication networks, Code Division Multiple Access based mobile communication networks, Wideband Code Division Multiple Access based mobile communication networks, and Enhanced Data Rates for Global Evolution based mobile communication networks.
FIG. 2 also illustrates a terminal device 201 which is roaming in the packet data based mobile communication network 200 . Thus the packet data based mobile communication network 200 is a visited network from the point of view of the terminal device 201 . For the sake of clarity, FIG. 2 also illustrates a home network 250 of the terminal device 201 which may be another packet data based mobile communication network, and a home subscriber database 251 located in the home network 250 . The home subscriber database 251 may comprise a prior art subscription profile specifically customized for the subscriber of the terminal device 201 . FIG. 2 further illustrates a network element 203 comprised in the packet data based mobile communication network 200 .
The system further comprises a default subscription profile generator 210 , in the mobile communication network 200 , for generating at least one default subscription profile comprising default subscription data to be utilized in providing services to the terminal device 201 roaming in the mobile communication network 200 . In the exemplary embodiment of FIG. 2 , the default subscription profile generator 210 is configured to generate multiple default subscription profiles, each profile comprising at least partially different default subscription data.
The system further comprises a default subscription profile storage 220 , in the mobile communication network 200 , for storing the generated default subscription profiles. The system further comprises a gateway 202 , in the mobile communication network 200 , for requesting one of the stored default subscription profiles in response to detecting the terminal device 201 roaming in the mobile communication network 200 and requesting to use the gateway 202 . In the exemplary embodiment of FIG. 2 , the gateway 202 is a Gateway GPRS Support Node. However, if the mobile communication network 200 comprises a Wireless Local Area Network based mobile communication network, the gateway 202 may be e.g. a Packet Data Gateway.
The system further comprises a selector 230 , in the mobile communication network 200 , for selecting one default subscription profile out of the stored multiple profiles for the roaming terminal device 201 according to a predetermined selection criterion. The selection criterion may be e.g. access network type, time of day, network load, or a group to which the roaming terminal device 201 belongs.
The default subscription profile generator 210 , the default subscription profile storage 220 , and the selector 230 may, as illustrated in FIG. 2 , be implemented in the network element 203 which is a new dedicated network element of the mobile communication network 200 . However, the default subscription profile generator 210 , the default subscription profile storage 220 , and the selector 230 may alternatively be implemented in one or more already existing network elements of the mobile communication network 200 , such as the gateway 202 , a session control means (not illustrated in FIG. 2 ) of the mobile communication network 200 , or a subscriber database (not illustrated in FIG. 2 ) of the mobile communication network 200 . Naturally, the default subscription profile generator 210 , the default subscription profile storage 220 , and the selector 230 may also be distributed between various network elements of the mobile communication network 200 . Furthermore, the default subscription profile generator 210 , the default subscription profile storage 220 , and the selector 230 may be implemented by software, hardware or a combination thereof.
The present invention illustrated in FIG. 2 allows acquiring the subscription profile needed in order to provide services for the roaming terminal device 201 from inside the visited network 200 rather than from the home subscriber database 251 in the home network 250 , as is the case with prior art. Thus real-time signaling between the mobile communication networks 200 and 250 is decreased. Thus delay associated with the real-time signaling is decreased.
It is obvious to a person skilled in the art that with the advancement of technology, the basic idea of the invention may be implemented in various ways. The invention and its embodiments are thus not limited to the examples described above, instead they may vary within the scope of the claims. | The invention concerns providing a default subscription profile for controlling a roaming terminal device in a packet data based mobile communication network. A roaming terminal device requesting to use a gateway is detected. A request for a subscription profile for the roaming terminal device is sent from the gateway. A default subscription profile stored in a network element of the mobile communication network is sent to the gateway. The invention allows avoiding the need to transmit the subscription profile of the roaming terminal device from a home network of the roaming terminal device to the visited network. Thus real-time signaling and its associated delay are decreased. Furthermore, the subscription profile is accessible even when there are connection problems between the home network and the visited network. | 7 |
BACKGROUND OF THE INVENTION
The invention relates to a dismantlable facade scaffold and to a method for the assembly and dismantling of such a facade scaffold.
Such facade scaffolds, in which the vertical support consists of support elements which can be separated from one another (CH-A-658878; GB-A-0276487), are used extensively for erection at the facade of a building in order to carry out external work there, for example applying a coat of paint.
Such facade scaffolds are generally assembled by successively erecting the individual scaffold planes, with the individual support elements of the, vertical supports of a first scaffold plane ending as a rule in each case just above a floor plate belonging to a second scaffold plane lying above it. This upper end of the support elements is then coupled by the installer to the lower end of the support elements for the second scaffold plane, in particular by means of a plug connection.
Thereafter, one or more substantially horizontally extending railing elements are mounted on the support elements in that scaffold plane (the second plane), in which the installer was present during the last discussed working step. These railing elements serve to reduce the danger of falling.
Once all the railing elements for the second scaffold plane have been installed, the floor plates belonging to the third scaffold plane lying above the second scaffold plane are coup led by the installer above his head with the previously installed support elements.
Finally, the scaffold is additionally stabilized during of the individual planes with transverse and/or diagonal struts.
In known facade scaffolds of the named kind it is a disadvantage that the installer has to work both during the erection of the support elements for the next scaffold plane and also during the installation of the railing elements for this next scaffold plane without any form of side protection, or without any form of side railing. This causes a considerable accident danger.
In order to counter this, it has already become known (FR-A-2336532) to install the railings of a new story to be erected from the already finished story and only then to place the floor plate belonging to the next story onto the already finished part of the scaffold, so that a worker treading on the new floor plate is already protected against falling by the previously installed railing. The pre-installation of the railing of the next story makes it necessary for vertical struts to extend downwardly from both sides of the railing which must first be connected to the already finished part of the scaffold and later also to the support elements of the following story.
In a further known dismantlable scaffold (FR-A-2516141) of the same kind, downwardly projecting struts are provided at one end of the railing by means of which the railing which is suspended at the other end of a vertical support can thus be swung upwardly to the next story and then secured to an already previously erected vertical support element.
The known solutions thus require additional downwardly extending vertical supports in order to move a railing element up to the next story and to secure it to the vertical support elements of the scaffold.
SUMMARY OF THE INVENTION
The object of the invention is to make available a dismantlable facade scaffold and also a method of assembling and dismantling such a facade scaffold of the initially named kind, in which not only the danger of an accident during the assembling or dismantling is reduced to a minimum, but rather the assembly/dismantling can be carried out economically in a simple manner.
Thus, in accordance with the invention, the railing elements which are pivotally connected at one end to an already installed support element are coupled at the other end to a not yet installed further support element, whereupon the further support element is lifted up, with a pivoting of the railing element into a horizontal position, and is set onto the associated support element of the already finished story. Thus, no additional vertical supports are required for the vertical pivoting of the railing element, but rather the support element which later forms a component of the scaffold is itself used.
Since, with facade scaffolds, several vertical units are as a rule erected alongside one another, with their floor plates adjacent to one another in a plane, it is sensible to design the coupling between the railing elements and the support elements so that two railing elements can be secured at one end of a support element and can then respectively extend horizontally in opposite directions.
A particularly simple coupling between railing elements and support elements results when the railing elements can be hung into the fastening positions of the support element provided for this purpose. In this respect it is again of advantage when the suspended connection is equipped with a security device against unintentional release in order to ensure, in this manner, that the railing element is reliably connected to the support element when a horizontally directed force is exerted on a railing element, such as for example occurs when an installer leans against the railing element.
The said securing device is preferably so designed that it is achieved solely by the coupling of the railing element and the support element, without special devices having to be actuated for this purpose or without the installer having to carry out additional manual actions.
The suspended connection is preferably realized by a projection element which extends substantially perpendicular to the support element and is fixedly connected to the latter, and also by a lug provided at the end region of the railing element and which can be coupled to the projection element. It is an advantage of this embodiment that moveable parts do not need to be provided either at the railing element or at the support element.
The projection element is preferably executed as a stamped part, which can for example be welded onto the support element. Thus, the manufacturing costs can be restricted to a minimum because the stamping procedure can be carried out at low cost.
The projection element can, for example, be made substantially areal or flat, with it naturally having to have a certain thickness in order to be able to withstand the forces which arise.
In one possible embodiment of the projection element, the latter is provided with at least two mutually displaced projections at its upper and lower sides in each case. In this case the lug of the railing element can be threaded onto the projection element while executing pivotal movements when the railing element is aligned perpendicular to the support element, with the lug being moved over one projection of the projection element during each pivotal movement. Through sequential, opposite pivotal movements the lug is thereby alternatively moved over the projections provided at the upper and lower side of the projection element.
It is preferred when the lug is executed as an elongate slot which extends in the longitudinal direction of the railing elements, since in this case the lug can be pushed onto the projection element while executing a substantially linear movement, when the support element and the railing element include an angle, which is for example smaller than 45°. The support element and the railing element include an angle of this kind at the stage of the erection or dismantling in which the railing element has a free end, i.e. an end which is not coupled to a support element, and the other end is connected to a support element or to be released from such an element.
In this case the coupling position between the support element and the railing element stands, for example, approximately three meters above the floor plate, on which the installer is actually standing, so that it is of advantage when the corresponding coupling can be easily produced or cancelled by a simple linear movement.
In a preferred embodiment of the invention two fastening positions, in each case for a separate railing element, are provided with an erected scaffold above the fastening position of this support element provided for the floor plate. Thus, two railing elements can be provided at different spacings from the floor plate which is subsequently to be installed, whereby the side protection to be brought about is increased.
The distance between the fastening position provided for the second railing element and the fastening position provided for the floor plate amounts, by way of example, to between 30 cm and 70 cm, in particular to approximately 50 cm. It is consequently possible to provide, for example, two railing elements at a distance of 50 cm and 100 cm from the floor plate.
The number of parts which have to be moved during erection and dismantling can in the latter case be reduced if the two railing elements belonging to a support element are pivotally connected together. This pivotal connection makes it possible for the two railing elements to be jointly swung upwardly in the manner already described above into their horizontal position. Instead of two individual railing elements, it is, however, only necessary to move one part which embraces the two railing elements and an additional stabilization of the overall scaffold is achieved by the said hinged connection of the two railing elements.
The effective total length of a support element with an erected scaffold can amount to between 180 cm and 220 cm, in particular to approximately 200 cm.
The effective total length in the erected scaffold of a support element which can be inserted into the lowermost scaffold plane can amount to between 280 cm and 330 cm, in particular to approximately 300 cm, and a support element of this kind can have two fastening positions for two base plates which are to be arranged in different scaffold planes. With support elements dimensioned in this way a situation is avoided in the lowermost scaffold plane in which a joint position or coupling position already has to be provided in this scaffold plane between two support elements arranged above one another, which would form a weak point of the overall scaffold as a result of the high forces which act in the lowermost plane.
The number of the parts which have to be moved during installation and dismantling can be additionally reduced in that two support elements aligned parallel to one another, and which come to lie at the narrow side of a floor plate, in particular when the scaffold is erected, are fixedly connected to one another via a transverse brace. In this case an at least approximately H-shape results for the two support elements connected to one another.
Since scaffolds erected in front of facades frequently only require railing elements at one side, it is sufficient with support elements which are connected to one another in the described manner when only one of these two support elements has at least one fastening position for a railing element.
In the context of the support elements connected to one another, it is possible to connect two support elements to one another which have different lengths, or substantially the same length, but are displaced relative to one another in the vertical direction.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a facade scaffold in accordance with the invention in the course of being built up,
FIGS. 2 a - 2 f show a schematic illustration of a total of six working steps which have to be completed when building up a facade scaffold in accordance with the invention,
FIGS. 3 a - 3 c show different individual elements of a facade scaffold in accordance with the invention,
FIGS. 4 a , 4 b show two variants for the coupling of support elements which respectively extend parallel to one another,
FIGS. 5 a - 5 c show an example for the design of the fastening device for the attachment of a railing element to a support element, and
FIGS. 6 a , 6 b show two further alternatives with respect to the fastening device of FIG. 5 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with FIG. 1, a facade scaffold is in the course of being erected at a building 1 . Four support elements 3 are braced against the ground 2 to form vertical supports in an arrangement with a rectangular base surface, with the longer side of the rectangular base surface extending parallel to the front side of the building 1 .
The support elements 3 associated with the lowermost scaffold plane are supported at the base side via vertically adjustable spindle arrangements 4 and are completed by transverse beams 5 and diagonal struts 6 into a load carrying base frame 7 . This base frame 7 is continued to the right in FIG. 1 in a corresponding manner which is not, however, illustrated for reasons of clarity.
Further support elements which are partly braced together are pushed onto two rear vertical support projections 8 of the base frame 7 arranged behind one another at a small spacing in order to form vertical supports. In the story A, which directly adjoins the base frame 7 , an intermediate piece 9 , a connection piece 10 and also an end frame 11 are provided as support elements, with the end frame 11 consisting of two support elements extending parallel to one another and fixedly connected together via transverse strut or brace.
For the further stories B to F, which follow the story A, further connection pieces 10 and end frames 11 are pushed onto the support elements or onto the connection piece and the end frame 11 of the story A. The shape of an end frame 11 can be particularly well seen for the end frame 11 provided for the story E, which is actually being held by an installer 12 in the erection step shown in FIG. 1 .
The joints between the base frame 7 , intermediate pieces 9 , connection pieces 10 and end frame 11 , at which respective plug connections are provided, are characterized for the end regions of the overall scaffold in FIG. 1 by short horizontal lines.
The assembly scheme for the vertical supports of FIG. 1 will be described once again in the following with an explanation of FIG. 4 b.
Provided along the building 1 at uniform intervals there are a total of seven vertical support arrangements consisting of intermediate pieces 9 , connection pieces 10 and end frames 11 put together vertically above one another.
Respective rectangular floor plates 14 are held between two vertical support arrangements arranged in series along the building 1 and ultimately form the different working planes for the individual stories A to F.
The facade scaffold has furthermore two forwardly projecting auxiliary scaffolds 15 and 16 respectively.
In order to secure the people 12 , 17 working on the floor plates 14 , railing elements 18 are provided at a suitable height at the front sides of the end frames 11 . The installation of these railing elements takes place in a manner in accordance with the invention in that in each case first the railing elements 18 of one story are installed, and only then the floor plate 14 belonging to this story.
In the embodiment of the invention shown in FIG. 1, the railing elements 18 are first secured at the fastening positions 19 of the end frame 11 ′ by the installer 12 . Thereafter, the end frame 11 ″ is connected at the fastening positions 20 to the end of the railing elements 18 remote from the fastening positions 19 , so that the two end frames 11 ′, 11 ″ jointly form a parallelogram with the two railing elements 18 . It is of importance that the railing elements
18 are hingedly mounted on the end frames 11 ′, 11 ″ so that it is possible for the installer 12 to grasp the entire arrangement at the end frame 11 ″ and swing it upwardly in the direction of the arrow in order to subsequently enable the end frame 11 ″ to be plugged onto the lower lying end frame 11 and the lower lying connection piece 10 respectively.
Through the above-described working step the railing 18 for the story E has already been installed before the introduction of the floor plate provided for the story E. As a consequence, it is ensured that at the time at which the floor plate 14 is secured to the story E, a side protection in the form of the railing elements 18 already exists so that the danger of an installer working on the story E falling is already reduced from the outset to a considerable degree.
End railings 21 are respectively provided at the ends of the total scaffold in addition to the railing elements 18 .
Curb strips 22 are releasably secured, in particular to the side of the floor plates 14 remote from the building 1 and, if necessary, also at the side adjacent the building 1 and at the end sides, and are intended to prevent tools which lie on the floor plates 14 being pushed sideways over the edge of the floor plates 14 when walking on them and thus to prevent the tools being able to fall downwardly from the facade scaffold.
The scaffold has four already finished stories A, B, C and D and two which are already under construction, E and F respectively.
FIG. 2 shows individual working steps during the erection of a facade scaffold in accordance with the invention.
In the working step of FIG. 2 a the installer 12 is standing on a floor plate 14 which is associated with the story A. The installer 12 is secured during this by at least one railing element 18 , which is coupled at the fastening positions 19 to vertically extending support elements 3 .
In the working step of FIG. 2 b the installer 12 is placing a further support element 3 ′ on the support element 3 , with the joint 23 between the support elements 3 , 3 ′ being realized by a plug connection.
Subsequently, in accordance with FIG. 2 c , a further railing element 18 ′ is suspended at one end at a fastening position of the support element 3 ′ provided for this purpose. After this railing element 18 ′ has been coupled at its other end to a further support element 3 ″, the railing element 18 ′ is swung upwardly together with the support element 3 ″ in accordance with FIG. 2 d in the direction of the arrow, whereupon, in accordance with FIG. 2 e , the support element 3 ″ is plugged onto the lower lying support element 3 at 23 ′.
In this position shown in FIG. 2 e , the railing element 18 is consequently already erected for the story B lying above the story A before the floor plate 14 ′ required for the story B was secured.
In accordance with FIG. 2 f the floor plate 14 ′ for the story B is finally attached to the fastening positions 24 of the support elements 3 ′, 3 ″ provided for this purpose. Thereafter, the story B can be walked on for the first time by the installer 12 and at this point in time the railing 18 ′ is, however, already installed so that a side protection exists for the installer.
It should be remarked that the floor plates 14 , 14 ′ in accordance with the invention can basically be secured either directly to the support elements 3 , 3 ′, 3 ″ or also indirectly, for example via transverse struts which are connected to the support elements 3 , 3 ′, 3 ″.
FIG. 3 shows different vertical support elements which can be used in the context of the invention for the erection of a scaffold.
FIG. 3 a shows two support elements which are approximately three meters long which are intended for use in the lowermost plane of the scaffold.
At the lower end and also at a height of approximately two meters, the support elements 25 have respective fastening positions 24 for floor plates 14 , 14 ′. Thus two floor plates 14 , 14 ′ for two different scaffold planes can be secured to the support elements 25 .
Approximately 50 cm above and also approximately 100 cm above the two fastening positions 24 for the floor plates 14 , 14 ′ there are fastening positions 19 for railing elements, which are not shown in FIG. 3 .
At least one of the two support elements 25 thus has fastening positions 19 for railing elements of two scaffold planes lying above one another.
The embodiment of FIG. 3 a of support elements 25 for the lowermost scaffold plane is of advantage, because in this manner no joint positions or plug connections are present in the lowermost plane, which impair the stability of the overall scaffold.
In FIG. 3 b there is shown a support element 3 which can be used for all scaffold planes which follow the support elements 25 . This support element 3 can be plugged at its lower end onto the upper end of the support element 25 of FIG. 3 a.
In accordance with the invention, two fastening positions 19 of the support element 3 intended for railing elements are located above a fastening position 24 provided for a floor plate.
The effective overall length of the support element in accordance with FIG. 3 b amounts to approximately two meters.
In the lower region of FIG. 3 b the fastening position 24 , which is formed as a rose, is shown in plan view and has apertures for the hanging into place of the floor plates.
FIG. 3 c shows a special embodiment of a support element 26 , which can be used in the context of the invention and which only has one fastening position 24 for a floor plate at its upper end. A support element 26 of this kind can, for example, be used in the uppermost scaffold plane in which, in certain applications, the vertical supports adjacent the building are located beneath a roof projection so that care can be taken here by means of the short support element 26 of FIG. 3 c that the roof projection and the support element do not collide with one another.
In the embodiment of FIG. 3 the vertical supports are built up exclusively of individual supports, with any eventual connections between adjacent support elements being produced exclusively via releasable connections.
In contrast to this, FIG. 4 a illustrates how two support elements 3 are fixedly connected to one another via a transverse brace 27 to form an end frame. The overall arrangement of a support element 3 and transverse brace 27 thereby forms an H-like structure.
Just above the transverse brace 27 are fastening positions 24 for a floor plate 14 , which is shown in broken lines. Alternatively, the fastening position 24 could also be spared in this case if the transverse brace is used as a support and thus as a fastening position for the floor plate 14 .
Further fastening positions 19 for railing elements not shown in FIG. 4 a are provided approximately one meter above the fastening positions 24 .
Individual end frames in accordance with FIG. 4 a can be plugged into one another via plug connections 23 .
Through this embodiment the number of parts which have to be moved during erection and dismantling are reduced, since in each case two support elements 3 are combined together to a single element via the transverse brace 27 .
An alternative embodiment is shown in FIG. 4 b . This embodiment corresponds to the embodiment in accordance with FIG. 1 .
Here, the two support elements 3 which are to be connected together via the transverse brace 27 have different lengths. As one support element 3 is shortened relative to the embodiment of FIG. 4 a , the total weight of the end frame 3 , 27 can be reduced in this way. However, allowance must be made for the fact that the individual end frames have to be coupled.
It should be expressly mentioned at this point that for the additional reduction of the number of parts which have to be moved, the railing elements in all embodiments in accordance with FIGS. 3 and 4 can also be fixedly hinged to the fastening positions 19 provided for this, so that a fixed but hinged connection is already present in the support elements 3 and the railing elements 18 prior to the installation.
FIG. 5 shows the manner in which railing elements 18 can be coupled to the support elements 3 .
With the illustrated way of coupling, this is essentially a suspended connection, which is realized by a projection element 28 extending substantially perpendicular to the support element 3 and also by a lug 29 provided in the end region of a railing element 18 and capable of being coupled to the projection element 28 . The projection element 28 is fixedly connected to the support element 3 , and is in particular welded to it at 32 .
The projection element 28 has, at its upper side and lower side, displaced relative to one another, in each case two projections 30 .
The transverse dimension q of the aperture 31 of the lug 29 is so selected that the railing element 18 can also be threaded onto the projection element 18 while executing alternating pivotal movements. In this respect the dimension q is precisely selected such that threading on is possible unhindered but cannot, however, be brought about by means of a linear movement of the railing element 18 or of the lug 29 , when the railing element 18 and the support element 3 are aligned approximately perpendicular to one another.
The fact that the pivotal or threading movement is necessary to secure the railing element 18 to the support element 3 ensures that the railing element 18 cannot be released in unintentional manner by the action of horizontally directed forces from the support element 3 . This security is, moreover, favored by the fact that the abutment surface of the projection 30 of the projection element 28 disposed closest to the support element 3 extends vertically and thus parallel to the support element 3 .
The further abutment surfaces of the projections 30 can, for example, be obliquely executed in order to facilitate the threading on of the lug 29 in this way.
The spacing d between the abutment surfaces of the projections 30 facing the support elements 3 and the support element 3 is so selected that the lugs 29 of two railing elements 18 extending in opposite directions can be threaded onto a single projection element 28 .
On attachment of the first end of one railing element 18 to the projection element 28 , the railing element 18 has the position relative to the projection element 28 , which is for example shown in FIG. 2 (see also FIG. 2 c ).
The angle a enclosed between the sup,port element 3 and the railing element 18 is in this case smaller than 60° and preferably smaller than 45°.
As a result of the aperture 31 of the lug 29 , which is formed as an elongate slot with the length 1 , a plugging of the railing element 18 onto the projection element 28 is possible in this position by the execution of a purely linear movement. Thereafter, the railing element 18 is then swung in the direction of the arrow A upwardly about the projection element 28 into a horizontal position shown in FIG. 5 c.
In this position it is no longer the longitudinal dimension 1 of the aperture 31 but rather its transverse dimension q which is the determining factor, with respect to the cooperation between the lug 29 and the projection element 28 .
As a result of the already described dimensioning of q, a situation is effectively prevented in the position of FIG. 5 c in which the railing element 18 could be released from the projection element 28 by a purely linear movement. A release of this kind is only possible by the intentional execution of several sequential pivotal movements.
In the context of the system of the invention, the first end of the railing element 18 is coupled to the support element 3 in the manner shown in FIGS. 5 b and 5 c , while the other end is threaded onto the second support element 3 by executing pivotal movements.
FIG. 6 shows alternative embodiments of the projection element of FIG. 5 .
In FIG. 6 a the projection element is formed by two part elements 33 , 34 arranged above one another, with the lower part element 34 having two upwardly extending projections 30 , and the upper part element having two recesses 35 at its lower side aligned with the projections 30 .
The operating principle corresponds here to the operating principle of FIG. 5, with the lug 29 being threaded over the lower part element 34 .
FIG. 6 b shows an embodiment corresponding to that of FIG. 6 a , only with projections 30 and recesses 35 being arranged in reversed manner on the upper and lower part elements 33 ′, 34 ′ respectively.
The invention is not restricted to the above-described embodiments. Many other variants can be realized within the context of the disclosure. | A dismantlable, multi-story facade scaffold is formed of at least four vertical support elements and floor plates and railing elements which are mounted thereto. An additional scaffold story is erected by coupling an additional vertical support element to an already existing one and pivotally attaching one end of a railing element thereto at a location above where the floor plate for the next story will be placed. The other end of that railing element is pivotally attached to another vertical support element. This other vertical support element is then raised, thereby pivotally moving the rail element relative to the respective vertical support element until the rail element is in a horizontal position and the vertical support element is in the vertical position. The other vertical support element is now attached to the upper end of a corresponding vertical support of the lower scaffold story. Thereafter the floor plate for the additional scaffold story is installed so that a worker stepping on the floor plate of the higher story is protected from the very beginning against falling off. The connections between the ends of the railing and the respective vertical support elements are disengageable when they are in relatively inclined positions and become locked when the railing is perpendicular to the support elements. The scaffold is dismantled by reversing this procedure. | 4 |
STATEMENT REGARDING COPYRIGHTED MATERIAL
Portions of the disclosure of this patent document contain material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office file or records, but otherwise reserves all copyright rights whatsoever.
FIELD OF INVENTION
This invention generally relates to Light Emitting Diodes (LED) lighting systems, and more specifically to a method and apparatus of controlling one or more LED lights in order to provide different colors, and still more precisely to provide different colors, achievable by the system, to the individual LED or combination thereof by digital programming and a time sensitive on-off switching method.
BACKGROUND OF THE INVENTION
LEDs are commonly used in lighting applications, and have in many areas superseded conventional lighting, including decorative elements, indicators etc. LEDs have various advantages: they are cost effective, easy to implement and typically consume very little power. Furthermore, LEDs may be employed to produce a lighting system with a varying color scheme, which is often desired for applications such as lamps, back light sources, traffic signals, display boards, illuminating switches and commercial lighting. LEDs provide the best option for these applications as they are easily available in basic colors Red, Green and Blue (RGB) and any other colors can be produced by manipulating the intensity of these basic colors RGB.
U.S. Patent publication number US 2004/0207334 discusses a system for a color changing bulb for the instrument panel of a vehicle, which is made as a bulb and directly installable in a bulb seat of the instrument panel. The color changing bulb includes a bulb housing defining a receiving space for receiving a light emitting diode and a circuit board. The LED includes three LED chips for generating red, blue and green light components. A controlling circuit is disposed on the circuit board and connected with the LED for driving the three-color LED chips to emit light. By use of a brightness adjustment switch on the instrument panel or a headlight switch, at least seven combinations of colors of light can variably emitted. This patent provides a memory unit to store or count the number of times the headlight switch is switched to create additional signal indicating which color the LED system should produce. This system is further using stabilizing unit and a digital cycle outputting unit, which makes it limited to only cyclic color changes and does not provide with an option for selecting a single color and the system can not be programmed for selecting flashing or steady state color mode.
In another US Patent publication, number US 2002/0047628, a system is discussed which is more complicated and requires a more complex infrastructure to control and use the system, making it both bulky and costly. This art is used in larger applications such as in decorating retail, commercial and residential places; thus limiting this system to outdoor environments. It is not cost-effective in smaller applications.
In another U.S. Pat. No. 5,420,482, a color display apparatus is disclosed in which each of the three color LED in the circuit are driven by transistor biasing. In this system, each transistor base is coupled to a respective latch resistor. As the three latches are connected to a single data bus, it becomes impossible to change the color of all the three LED's at a very high speed. Also, the biasing of the transistor was changed by simply changing the grounding resistor of the potential divider which may vary from piece to piece due to component tolerance.
U.S. Pat. No. 6,016,038 to Mueller, et al. discloses a pulse width modulated current control for an LED lighting assembly, where each current-controlled unit is uniquely addressable and capable of receiving illumination color information on a computer lighting network. The light module is adapted to be conveniently interchanged with other light modules having programmable current and hence maximum light intensity, ratings. The pulse width modulated LED lighting assembly of this invention however necessitates the use of a computer controller to operate the system.
U.S. Pat. No. 6,150,774, also to Mueller, et al. discloses a similar pulse width modulated current control for an LED lighting assembly wherein each current-controlled unit is uniquely addressable and capable of receiving illumination color information on a computer lighting network. This patent anticipates the use of a manual control for an LED lighting assembly, however there is no method for manually programming an LED light source with such a method.
U.S. Pat. No. 6,211,626 to Lys, et al. discloses a light module, comprising an LED system for generating a range of colors within a color spectrum, a processor for controlling the amount of electrical current supplied to the plurality of light emitting diodes, so that a particular amount of current supplied thereto generates a corresponding color within the color spectrum, a housing within which the LED system is positioned, and a heat spreader plate in contact with the housing for dissipating heat from the housing; wherein the LED system includes a thermal connection to the heat spreader plate. This invention fails to provide for a manual, switched color or color array setting mode.
U.S. Pat. No. 6,340,868 to Lys, et al. discloses a light module having a plurality of light emitting diodes for generating light of a range of colors within a color spectrum, a processor for controlling the amount of electrical current supplied to each light emitting diode such that a particular amount of current supplied to the light module generates a corresponding color within the color spectrum, and a power module for providing electrical current from a power source to the light module, the power module including a connector for removably and replacably connecting the power module to the light module. However, this invention contemplates a computer controlled multicolored lighting network, rather than individual lighting units which may be programmed to multiple modes in a series by a manual switch.
U.S. Pat. No. 6,528,954 to Lys, et al. also relates to LED lighting assemblies, however this patent claims the use of a processor to control current through the LEDs, rather than a technique to control pre-programmed modes through a manual switch.
U.S. Pat. No. 6,806,659 to Mueller, et al. discloses a pulse width modulated current control for an LED lighting assembly, wherein each current-controlled unit is uniquely addressable and capable of receiving illumination color information on a computer lighting network. In a further embodiment, the invention includes a binary tree network configuration of lighting units (nodes). In another embodiment, the present invention comprises a heat dissipating housing, made out of a heat-conductive material, for housing the lighting assembly. The heat dissipating housing contains two stacked circuit boards holding respectively the power module and the light module. The light module is adapted to be conveniently interchanged with other light modules having programmable current, and hence maximum light intensity, ratings. Like the other background references, this invention doesn't contemplate an LED lighting assembly, wherein the ON/OFF switch is also the color control.
The above mentioned prior art does not provide choice of selection of cyclic or steady state color modes. Although several instances of the prior art have the capability of generating a variety of combinations, they lack the ability to make color changes without large, costly, complex controllers, and are not suitable for use in small applications. Furthermore, these arts do not provide any memory means to store a mode of operation and color or color combination when they are switched off, to restore a variety of predetermined settings at the time of the next restart.
OBJECT OF THE INVENTION
Therefore it is one object of the invention is to provide a light emitting diode system.
It is a further object of the present invention to provide choices of flashing or steady state color selection of lighting of LEDs.
A further object of the present invention is to reduce the complexity of the system, and to make the system comparatively cost effective, small, intelligent and efficient.
Yet another object of this invention is to simplify the selection process of flashing or steady state light operation, within a stipulated time limit, so that anyone, irrespective of age or knowledge, can use the system effectively.
Still another object of the present invention is to provide with a memory means to store the system's mode of operation and display color, and to restore a variety of predetermined settings at the time of a subsequent system restart.
SUMMARY OF THE INVENTION
The present invention comprises a system and method for color changing lighting, having a pre-programmed controller with driver circuit, single or combination of LEDs and an OFF/ON switch which is used for making a mode of operation selection as well as switching the system on and off. The brightness of the LED or combination of LEDs is changed using pulse width modulation.
This system is capable of working on a regulated or unregulated power supply and the drive circuit of the system is provided with an external resistor to set the drive current for different LED arrays and it keeps equal current in each leg of LEDs in varying forward voltage with the help of transistors. The LED's are selectively activated by programmed variable pulses to generate the desired color mixing effect. The controller controls the lighting mode and color of said LEDs, it uses 8 bits of data in the presented embodiment, to provide maximum of 256 intensity levels per LED, thereby giving a smooth transition from one color to other.
The controller uses an external crystal which allows all light modules in the system to be synchronized, and is capable of storing the mode and color (or combination of colors) at the time it is switched off. In an alternate embodiment, an internal oscillator may be used for synchronization; however the preferred mode uses an external crystal for accuracy. The system provides options for selecting one mode of two different modes of operation; namely rotating color mode and fixed color mode.
When the system is initially powered on, a user may select from a variety of color modes. A user can switch from mode to mode by turning the power off and on within a first predetermined time, called the “switching time.” In the present embodiment, for purposes of illustration, a period of 5 or less is proposed. All mode switching operations must be completed within a second predetermined time, called the “synchronize time.” For purposes of illustration, a period of 10 seconds is proposed. Each time the power is turned off and on in under five seconds, from the first time the power is turned on until the end of the synchronize time at ten seconds, it starts in a new mode. To select a mode, a user simply leaves the system on until the end of the synchronize time.
Each mode is characterized by either a changing, selectable or static light pattern of one or a variety of colors, and each mode has a corresponding indicator pattern that is displayed by the LEDs of the system during the synchronize time. When the synchronize time ends, the LEDs go from displaying the indicator pattern to either a color changing cycle or static color of the mode selected.
For instance, in a system with standard red green and blue LEDs, when the power is initially switched on, a green LED may blink to indicate a first (default) mode. If the power is turned off for less than five seconds and back on again, a red blinking LED may be used to indicate that the system has switched to a second mode. If the power is then turned off a third time and back on within five seconds, the system goes into a third mode, reflected perhaps by a blue LED indicator.
If the mode is switched again after the last selectable mode, it cycles back to the first (default) mode. At the end of the synchronize time, the system goes into the mode selected. If the power is switched off and on in under five seconds once the synchronize time is over and the system has switched into a particular mode, the system restarts at the beginning of a new synchronize time in the first (default) mode.
The number of modes is only limited by the possible combinations of static or blinking colors or combinations of colors of LEDs, and each mode may be characterized by different characteristics, such as a constantly changing color pallet, a changing color pallet that remembers the final color selected and stays there, or a pallet that moves between two selected colors, etc.
If a mode is selected that is characterized by a static color, That color will be displayed each time the system is turned on, as long as the interval between powering off and back on is more than the switching time (in the present embodiment, 5 seconds). If the system is turned off and on in less than the switching time, it reverts to the first default mode and a new synchronize time starts. If a color changing mode is selected, once the synchronize time ends, the system goes into that mode's color changing cycle.
A color changing cycle cycles through all or a range of the system's possible colors in a predetermined time. In one embodiment, it may take 60 seconds to cycle through all of the colors of a system. The range of possible colors in a particular cycle depends on the characteristics of the mode. For instance, one color changing mode may cycle through all possible colors. A second color changing mode may be limited to colors between orange and purple, etc. The number of modes is limited only by the number of combinations of colors, and blinking rates possible in the LED array. While not infinite, a very large number of modes are possible in any given system.
Color changing modes may be either continuous, or selectable. A continuous color changing mode constantly cycles through its range of colors. When the system is powered off for a period greater than the switching time (5 seconds in the present embodiment), once it is powered on again, the color continues to cycle starting from any predetermined position, including the last color displayed before the power was turned off.
By contrast, a selectable color cycle cycles through a range of colors just like a continuous cycle. However, when a selectable cycle is powered off for a period greater than the switching time, it retains the last displayed color as a static color once it is powered on again, and retains that color until the system is reset by powering off and on in a period less than the switching time.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 shows a basic block diagram of the presented work.
FIG. 2 shows a simple block diagram of the circuit.
FIG. 3 shows circuit diagram of color changing system.
FIG. 4 shows the electrical circuit for LED board.
FIG. 5 shows a simple block diagram of the flow of the program in the presented system.
FIGS. 6A-6C show the flow chart of the program work.
REFERENCE NUMERALS
1 . . . User Interface
3 . . . Microcontroller
5 . . . LED Drivers Geen, Red and Blue
7 . . . Single or Combination of Green, Red, Blue LEDs
9 . . . Ground
11 . . . Power Supply Block
13 . . . User Interface Block
15 . . . Power Regulator Block
17 . . . Controller Block
19 . . . LED Board
21 . . . Power ON Test Block
23 . . . Selection (synchronize time or switching option mode) Block
25 . . . Cyclic/rotating Color Mode Block
27 . . . Fixed Color Mode Block
60 . . . Input Supply
62 . . . Bridge Rectifier
64 . . . Switching Regulator
66 . . . Linear Regulator
68 . . . Voltage Detector
70 . . . Microcontroller
72 . . . Crystal
74 . . . LED Driver
76 . . . Schottky Diode
78 . . . Inductor
80 . . . Ground Node
82 . . . Electrolytic Capacitor
84 . . . Resistor
86 . . . Transistor
88 . . . Diode
90 . . . Ceramic Capacitor
DETAILED DESCRIPTION
A further understanding of the present invention may be obtained with reference to the following description taken in conjunction with the accompanying drawings. However, the embodiments used for describing the invention are illustrative only and no way limiting scope of the invention. A person skilled in the art will appreciate that many more embodiments of the invention are possible without deviating from the basic concept of the invention any such embodiment will fall under the scope of the invention and is a subject matter of protection.
FIG. 1 shows a basic block diagram of the presented work, the user interface 1 gets the ON/OFF input and sends it to the micro-controller 3 which drives the LED Drivers 5 . The driver circuit drives single or combination of red, blue and green lighting devices or LED's 7 , which are used as the light source, and according to the inputs and micro-controllers signals, the LED's emit light.
FIG. 2 shows a simple block diagram of the circuit presented which consists of power supply 11 , user interface 13 , power regulator block 15 , controller block 17 and LED board 19 . When the power supply 11 is on and there is an input at user interface 13 , the controller block 17 sends control signals to the LED board 19 according to the function selected. The LED board 19 receives the regulated power from the power regulator block 15 for the proper LED output.
FIG. 3 shows a circuit diagram of the present invention which is designed to operate on low voltage. It contains a power supply unit (PSU) 30 with a 2 point connector that receives the 12 V AC input from the step down transformer (not shown in the figure). The bridge assembly consisting of rectifier diodes D 8 , D 9 , D 10 , D 11 which convert the AC into a pulsating DC signal. This signal is then fed to the power regulator section which regulates the voltage to 5 V LED driver circuit. Although a 5 V LED driver circuit is contemplated in this example, the present invention also contemplates a range of line voltages from any regulated or unregulated power supply.
Filter capacitors C 1 , C 2 , C 3 , C 4 and linear 5 V regulators (REGs) 38 and 34 (LM7805 and LM 2576 in the present example) are used for high current application. The pulsating DC signal is applied to the user interface which senses the switch ON/OFF time period and changes the state of the light accordingly. The Zener diode D 7 keeps the input signal to the voltage detector (VD) 49 , MCP100, at fixed level when power is on at 5.1 V. The output of the voltage detector (VD) 49 , MCP100, changes to low as soon as the power is off, and provides active low switch input for the micro-controller (μC) 42 . The user interface provides input to the micro-controller (μC) 42 , PIC12F629. The micro-controller (μC) 42 communicates with the user using pin number 4 to detect a power fail. The micro-controller (μC) 42 runs at 8 bits so that 256 possible voltage levels for can be achieved. Thus 256 current values and equivalent levels of intensity per LED are achieved. An external crystal Y 1 provided with the micro-controller (μC) 42 synchronizes all light modules.
The digital signal from pins 5 , 6 , 7 control the intensity of R,G,B LEDs (LED diodes) 36 respectively by turning on and off LED drivers 35 A, 35 B, and 35 C chips, using transistors Q 1 , Q 2 and Q 3 . An external resistor allows the circuit designer to set the drive current for different LED arrays. It also supplies constant current for varying input voltage. External resistors R 4 , R 5 , R 6 allow current to be set, upto 350 mA of each leg of distinct color LEDs (LED diodes). The control card which uses IC's (for LED drivers 35 A, 35 B, and 35 C) numbered NUD 4001 connects with the LED board where the color changing LED diodes 36 or combination of LEDs (LED diodes) are connected.
In FIG. 3 , PSU 30 includes line L 1 connected to a bridge rectifier 32 between an anode of diode D 8 and a cathode of diode D 9 and a second line L 2 connected between a cathode of diode D 1 O and anode of diode D 11 . Line L 3 is coupled between cathodes of diodes D 8 and D 11 to an anode of diode D 31 . The anode of diode D 31 is coupled to node N 1 in line L 3 . The cathode of diode D 31 is coupled to REG 38 . Node N 2 is placed between REG 38 and the cathode of diode D 31 . Line L 4 is coupled to bridge rectifier 32 between anodes of diodes D 9 and D 10 . Line L 4 includes a node N 5 , where node N 5 is connected to ground G. Node N 5 is hereinafter referred to as a “ground node N 5 .”
Line L 5 extends between node N 2 and line L 4 . An anode of capacitor C 1 is connected to node N 2 and a cathode of capacitor C 1 is connected to line L 4 and, hence, ground node N 5 . Line L 6 connects to and extends between REG 34 and node N 2 .
Line L 7 is coupled to an anode of diode D 32 and REG 38 . A cathode of diode D 32 is coupled to node N 3 in line L 8 . Line L 9 extends between node N 3 and line L 4 . An anode of capacitor C 2 is coupled to node N 3 . A cathode of capacitor C 2 is connected line L 4 and, hence to ground node N 5 . Line L 8 extends between the cathode of diode D 32 and node N 4 . Line L 10 extends between node N 4 and line L 4 . Line L 10 includes capacitor C 3 having one side connected to line L 4 and, hence, ground node N 5 . The other side of capacitor C 3 is connected to node N 4 . REG 38 is also coupled to an anode of diode D 33 . The cathode of diode D 33 is coupled to line L 4 at ground node N 5 in line L 4 .
At voltage regulator kEG 34 , two additional leads or lines on an input side of REG 34 are coupled to ground G. Lines L 11 and L 13 are shown as extending from an output side of REG 34 . Line L 11 includes inductor L 100 . Between REG 34 and one side of inductor L 100 is node N 6 . A cathode of a Schottky diode D 40 is coupled to node N 6 , where node N 6 is between kEG 34 and inductor L 100 . The anode of Schottky diode D 40 is coupled to ground G. Line L 13 extends from REG 34 to the other side of the inductor L 100 at node N 7 . Line L 12 has node N 8 . Node N 8 has an anode of capacitor C 4 coupled thereto. The cathode of capacitor C 4 is coupled to ground G.
Line L 12 also includes node N 9 . Node N 9 has the collectors C of transistors Q 1 , Q 2 and Q 3 coupled thereto through resistors RQ 1 , RQ 2 , RQ 3 , respectively, in the collector paths of transistors Q 1 , Q 2 and Q 3 . The emitters E of transistors Q 1 , Q 2 and Q 3 are coupled to ground G. The collectors C of transistors Q 1 , Q 2 and Q 3 are also coupled to a respective different one LED Driver 35 A, 35 B and 35 C via lines LQ 1 , LQ 2 and LQ 3 where LQ 1 , LQ 2 and LQ 3 are coupled to one side of the resistors RQ 1 , RQ 2 , RQ 3 , respectively. The other side of each of the resistors RQ 1 , RQ 2 , RQ 3 is coupled node N 9 . From node N 9 extends line L 13 . From line L 13 extends line LL 1 A to the LED Driver 35 A; line LL 1 B to LED Driver 35 B; and line LL 1 C to LED Driver 35 C. From Line L 13 extends a line to the LED Driver 35 A having resistor R 4 ; a line to LED Driver 35 B having resistor R 5 ; and a line to LED Driver 35 C having resistor R 6 .
The other side of each of LED Driver 35 A, LED Driver 35 B, and LED Driver 35 C is coupled to a respective different one of the LED diodes 36 , where the LED diodes 36 are coupled to ground G. Returning again to the bases of transistors Q 1 , Q 2 and Q 3 , base B 1 of transistor Q 1 has one side of resistor RB 2 coupled thereto; base B 2 of transistor Q 2 has one side of resistor RIB 2 coupled thereto; and base B 3 of transistor Q 3 has one side of resistor RB 3 coupled thereto. The other side of each resistor RB 1 , RB 2 , RB 3 is coupled to a respective different one of first, second and third outputs of micro-controller 42 .
A plurality of resistors 3 R 1 , 3 R 2 and 3 R 3 all have one side thereof coupled to ground G. The other side of resistor 3 R 1 is coupled to said other side of resistor RB 1 between resistor RB 1 and the first output of micro-controller 42 . The other side of resistor 3 R 2 is coupled to said other side of resistor RB 2 between resistor RB 2 and the second output of micro-controller 42 . The other side of resistor 3 R 3 is coupled to said other side of resistor RB 3 between resistor RB 3 and the third output of micro-controller 42 .
The micro-controller 42 is coupled to ground G. The micro-controller 42 is coupled to one side of crystal Y 1 at node N 20 and the other side of crystal Y 1 at node N 21 . Nodes N 20 and N 21 are connected to micro-controller 42 . One side of capacitor C 1 Y is coupled to one side of capacitor C 2 Y. The other side of capacitor C 1 Y is coupled to node N 20 . The other side of capacitor C 2 Y is coupled to node N 21 .
Voltage detector (VD) 49 has an input side and an output side. The output side of VD 49 has a lead coupled to the micro-controller 42 . The VD 49 is coupled to ground G. Additionally, another line L 20 from the input side of VD 49 is coupled to a cathode of Zener diode D 7 at node N 22 . The anode of Zener diode D 7 is coupled to ground G. Between node N 22 and VD 49 is node N 23 . Capacitor C 31 has one end coupled to ground G and the other end coupled to node N 23 . Line L 21 extends from node N 22 to node N 1 in line L 3 . In the path of line L 21 is resistor R 35 .
FIG. 4 shows the electrical circuit of the LED boards used in the present embodiment. In the circuit diagram, one LED each of red, blue and green or an array 50 of green, blue and red LED's are used as the light source. This LED board design is such that despite variations in forward voltage from different LEDs, the current remains equal in each LED or LED array 50 with the help of the transistors 52 a, 52 b, 52 c and 52 d in the LED board 19 .
FIG. 4 illustrates an array 50 with four transistors 52 a, 52 b, 52 c and 52 d . The base B 4 of each transistor 52 a, 52 b, 52 c and 52 d is coupled to each other. The emitter E 4 of each transistor 52 a, 52 b, 52 c and 52 d is coupled to ground 54 . Each collector C 41 has coupled thereto a different pair of series coupled LED diodes 51 . Node 41 receives an input to LED diodes 51 .
FIG. 5 shows a simple block diagram of the flow of the program in the presented system. Power on test is performed at Block 21 . At Block 21 , when the power is on for the first time, the first (default) mode LED will blink or flash, and the system goes into synchronize time. At Block 23 , during synchronize time a user has the option of switching modes. The selection block 23 checks for the user's selection of the mode for running on the system for a fixed time and accordingly switches to the respective block rotating color mode 25 or block fixed color mode 27 . These respective blocks 25 or 27 run the mode until the user interface supplies some other input to return to a subsequent instance of synchronize time. When system is switched off after use, the mode of operation and color or color combinations are stored and the settings are restored until the next restart.
FIGS. 6A-6C show a flow chart of the program of the system. The system starts at block 41 , followed by power on test at block 43 and a selection block 45 if system is powered on, these steps of operation are named as “synchronize” or “switching option mode” with a predetermined cycle time. Here, block 47 checks for switching operation by the user. If switching is done, the mode is changed depicted by the block 49 , and a time check is performed in block 51 , if the predetermined synchronize time limit is not over, the control goes to the block 47 again otherwise a check is performed for mode of operation selection in block 53 .
If the mode is set to rotating color, the operation starts with the block 61 and the indicator LED for the mode starts blinking, depicting the rotating color mode of operation. Block 63 checks for the switching operation if switch is pressed control goes to block 65 where the program stores the last color and mode of operation of the system, and in the next control block 67 , checks for the time lag of the switching. In the present example, if switching is more than 5 seconds, the system starts at block 68 with the last mode selected and starts at a predetermined position from block 61 , otherwise the control goes back to block 45 via block 69 where a save option takes place.
If the mode of operation selected is fixed color mode, the indicator LED for that mode starts indicating the fixed color mode of operation. In this mode, the system starts with a rotating color cycle at block 71 , which allows the user to select from the available choices. Block 73 checks for the switching operation. If the switch is pressed, control goes to the next block 75 where the system saves the last color and mode of operation. A check is performed in block 77 to determine if the time between pressing the switch is more than 5 seconds, if it is, the system reinstates the last color position at block 78 and control goes back to block 73 . If it is not, control goes to block 79 where the system saves the color and mode of operation and control goes to block 45 .
Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. For example, the present invention can be utilized in other contexts such as military installations or in-house corporate departments without departing from the spirit or intent of the invention. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.
Any element in a claim that does not explicitly state “means for” performing a specific function, or “step for” performing a specific function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C. § 112, paragraph 6. In particular, the use of “step of” in the claims herein is not intended to invoke the provisions of 35 U.S.C. § 112, paragraph 6. | A system and method for color changing lighting comprising a pre-programmed controller along with driver circuit, a single or combination of LEDs and an OFF/ON switch which is used for making selection of mode of operation as well as switching the system ON/OFF. Brightness is changed using pulse width modulation. The LED's are selectively activated by programmed variable pulse to generate desired color mixing effect. The resulting illumination may be controlled by a computer/micro-controller program to provide pre-designed complex patterns of light in virtually any environment. | 8 |
FIELD OF INVENTION
The present invention relates to the control of cigarette rod formation, more particularly to the utilization of the recycle of trimmed tobacco as a control mechanism.
BACKGROUND OF THE INVENTION
In the manufacture of cigarettes, cut tobacco is metered from a reservoir or hopper of tobacco to provide a metered flow, a vertically-moving thin shower of tobacco particles is formed from the metered flow, a tobaco filler rod is formed from the shower of tobacco particles, and a paper web is wrapped around the tobacco filler rod.
Since there is a tendency for the tobacco filler rod to have variable quantities of tobacco at various locations along its length, giving rise to a variable thickness, there is usually first formed from the shower of tobacco particles a rod of tobacco particles containing a greater quantity in the cross-section thereof over that ultimately required in the tobacco filler rod, and excess tobacco is trimmed from the rod of tobacco particles to provide the tobacco filler rod for wrapping and trimmed tobacco. This procedure of overfeeding and then trimming ensures that all locations along the length of the rod have the thickness of tobacco required to form the cigarette.
Trimmed tobacco usually is recycled to the hopper of tobacco from which the metered flow is formed. The metered flow of tobacco from which the tobacco shower is formed generally is provided from a tobacco hopper with some form of refuser mechanism, such as carding drums, to control and meter the quantity of tobacco which passes to the rod-forming operation from the hopper. Such refuser mechanisms, which may also involve recycle of tobacco to the hopper, result in degradation of tobacco, thereby impairing the filling power of the tobacco.
In most cigarette-making machines, the feeder speed, i.e. the refuser roll metering, is not normally continuously controlled but rather is preset to a desired average flow rate and, as a result of variations in density, the mosture content of the tobacco, particle size and similar variations, variable flow rates of tobacco occur, leading to variations in quantities of tobacco trimmed. Any tobacco which is trimmed becomes degraded, thereby impairing its filling power, and hence it is desirable to control the amount of trimming to take into account the variations noted above.
Prior attempts have been made to use trimmed tobacco as a rod-formation control. In U.S. Pat. No. 3,431,914, there is described a procedure in which trimmed tobacco is fed to a storage vessel, tobacco from the storage vessel is returned to the rod of tobacco particles formed from the shower, and the amount of tobacco withdrawn from the storage vessel and recycled is regulated in accordance with testing the quantity of tobacco in the filler rod after trimming or the rod of tobacco particles before trimming. In addition, the amount of trimmed tobacco in the storage vessel is sensed, with the amount of rising and falling dependent on the amount of excess tobacco trimmed. If the amount of tobacco in the storage vessel is sensed to be too great, then the mechanism for forming the vertically-moving tobacco shower is regulated to decrease the tobacco feed rate. The rate of removal of the tobacco from the trimmed tobacco storage vessel, however, is controlled by measurements conducted on the rod prior to or after trimming. Two independent measurements are made and two different operational controls result from these measurements.
U.S. Pat. No. 4,095,604 describes a tobacco metering device which comprises a generally vertically-extending thin and laterally-wide channel in which tobacco particles fed from a hopper by a carding drum and picker combination pile up to form a carpet between the front and rear wall of the channel. One of the walls of the channels is movable to permit the carpet of tobacco to be fed downwards through the channel and a conveyor is provided at the lower end of the channel for forwarding the carpet towards the formation of the vertically-moving shower.
In one embodiment of this prior art device, trimmed tobacco is fed into the upper end of the channel across one part of the width of the channel while new tobacco from the hopper is fed across the remainder of the width of the channel, so that the carpet of tobacco in the channel is formed of side-by-side portions of new tobacco and recycled trimmed tobacco. Provided at the lower end of the channel are a pair of independently-operated carding rollers, so as to feed tobacco independently from the side-by-side portions of the carpet. The height of tobacco in the side-by-side portions of the carpet is independently sensed and such sensings are used to control independently the speed of the carding rollers to maintain the levels of the side-by-side portions within predetermined levels.
In this prior art device, therefore, recycled trimmed and new tobacco are provided side-by-side in a carpet confined between vertical front and rear walls, the height of the respective portions is sensed and the flow rate of tobacco from the respective portions is independently controlled as a result of independent measurements.
As far as the applicant is aware, there has been no published attempt to use the feed rate of recycled trimmed tobacco as the control mechanism for the metering of cut tobacco from a reservoir thereof to form a metered flow.
SUMMARY OF INVENTION
In accordance with the present invention, the recycle of trimmed tobacco is used to control the rate of feed of tobacco to the rod-formation procedure. The feed rate control which is achieved in the present invention can be used to avoid the necessity for the utilization of refuser mechanisms and the tobacco degradation that results therefrom. In the present invention, the only tobacco recycled within the rod-forming procedure is the tobacco which is trimmed from the rod. In addition, the present invention avoids the necessity to make multiple measurements of tobacco reservoir levels and independent changes in flow rates of different streams based upon such measurements.
Accordingly, the present invention provides an improvement in a method of forming a tobacco filler rod suitable for formation of cigarettes therefrom wherein cut tobacco is metered from a reservoir thereof to provide a metered flow, a vertically-moving shower of tobacco particles is formed from the metered flow, a rod of tobacco particlaes is formed from the shower and contains a greater quantity of tobacco in the cross-section thereof than is required in the tobacco filler rod, excess tobacco is trimmed from the rod of tobacco particles to provide the tobacco filler rod and trimmed tobacco, and the trimmed tobacco is recycled to the reservoir of cut tobacco.
The improvement of the present invention resides in a combination of features. Firstly, the reservoir of cut tobacco is divided into two physically-separate zones which are out of communication one with another, the trimmed tobacco is recycled to one only of the reservoir zones and fresh cut tobacco is fed only to the other of the reservoir zones. Secondly, tobacco is metered continuously from both reservoir zones at the same rate per unit width of reservoir zone to provide the metered flow and the level of recycled trimmed tobacco in the one reservoir zone is continuously monitored. Thirdly, the rate of metering of tobacco from the reservoir is controlled so as to maintain the level of recycled trimmed tobacco in the one reservoir zone between predetermined levels by decreasing the rate of metering for sensed trimmed tobacco levels above a predetermined upper level and by increasing the rate of the metering for sensed trimmed tobacco levels below a predetermined lower level.
In this way, the sensed level of recycled trimmed tobacco is the sole control parameter for the feed of tobacco to the rod-forming procedure and the necessity to make measurements on the tobacco filler rod, before or after trimming, or of reservoir levels for new cut tobacco, as suggested in the prior art, is avoided. A novel and much simplified tobacco flow rate control procedure is provided thereby.
The present invention also includes a novel cut tobacco hopper device for use in conjunction with a cigarette-making machine, which comprises a reservoir vessel having an upper inlet for tobacco and a lower outlet and having divider means located therein separating the interior of the reservoir vessel into side-by-side vertically-extending physically-separate reservoir chambers, and common metering and feeding means located in operative relationship with the lower outlet for metering and feeding tobacco from the reservoir chambers at the same rate per unit reservoir zone width.
The reservoir vessel, therefore, is divided vertically into two chambers, the one usually narrow and the other usually wide, recycled trimmed tobacco is fed to a narrow chamber, the height of tobacco in the narrow chamber is sensed, and the flow rate of tobacco per unit width of resevoir from both chambers is speeded up or slowed down in response to predetermined "too-low" or "too-high" levels in the narrow chamber. In addition, the width of the narrow chamber in relation to the width of the wide chamber may be used to determine the degree of trimming.
Control of the rod-forming operation in accordance with the present invention is simple yet very effective. As noted earlier, in most machines the feeder speed (i.e. refuser roll metering) is not normally continuously controlled and, as a result of variations in density, the moisture content of the tobacco, particle size etc., variable flow rates of tobacco occur, leading to variations in quantities of tobacco trimmed. By controlling the flow rate in absolute terms by monitoring the amount of tobacco trimmed and recycled, these prior art problems are overcome.
BRIEF DESCRIPTION OF DRAWINGS
The accompanying drawing is a schematic representation of one embodiment of a cigarette-making apparatus embodying the principles of the invention.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring to the drawing, there is illustrated therein a cigarette-making machine 10 constructed in accordance with one embodiment of the invention. In the illustrated embodiment, a tobacco feed is provided for a filler rod-forming mechanism 12, wherein a tobacco filler rod 14 is formed from substreams of tobacco by layering of the same one on another on the periphery of a vacuum wheel 16. The substreams are formed on vacuum wheels 18 from a falling stream or shower 20 of separated tobacco particles. The rod-forming mechanism 12 is fully described in U.S. Pat. No. 3,980,088 and reference may be made thereto for details of the construction and operation. The rod-forming mechanism 12 is provided with a trimmer 22 to remove excess tobacco from the rod 14.
While the present invention is illustrated and described with reference to the filler rod-forming mechanism 12, the principles of the manner of formation of the tobacco feed for the rod former and its manner of control are applicable to any rod-forming procedure wherein a tobacco filler rod is formed, directly or indirectly, from a falling or rising stream or shower of substantially-separated tobacco particles.
The falling tobacco shower 20 is formed by permitting tobacco to fall from the end of a conveyor 24 on which is conveyed a thin carpet 26 of opened tobacco particles. A conventional winnowing operation usually is carried out on the thin carpet 26 as the shower 20 is formed to remove heavy tobacco particles. Details of the winnowing have been omitted for clarity.
The tobacco carpet 26 is formed by discharge from a hopper or reservoir device 28 of novel construction. The reservoir device 28 and its principles of construction and operation constitute one aspect of this invention.
The reservoir device 28 has a generally rectangular cross-sectioned tobacco receiving zone which is divided internally into two physically-separate chambers 30 and 32 by a baffle 34. The chamber 32 is of relatively narrow width as compared with the chamber 30. The width of the chamber 32 in comparison with that of the chamber 30 determines and controls the degree of trimming of the tobacco rod 14, as will become apparent from the further description below.
A tobacco separation and discharge device 36 is provided at the upper end of the reservoir device 28 in communication with the wide chamber 30 for receiving cut tobacco conveyed through feed pipe 38 by the application of vacuum by line 40, for separation of the tobacco from the conveying air by a suitable screen 42 and for feeding charges of tobacco so separated from the conveying air by the screen 42 intermittently into the chamber 30.
The discontinuous discharge device 36 may be replaced, if desired, by a continuous discharge device, whereby tobacco fed by feed pipe 38 is continuously discharged into the chamber 30. For this purpose, the interior of the reservoir device 28 is maintained under vacuum and a continuous air lock is required to be included in the structure of the reservoir device 28 to enable tobacco to be continuously discharged from the reservoir chamber 30 to the external atmospheric conditions without loss of the internal vacuum. One suitable structure is illustrated in U.S. Pat. No. 4,446,876 and reference may be had thereto for details of the construction and operation. Alternatively, the discontinuous discharge device 36 may be replaced by a rotary air lock located at the upper end of the device 28, which enables tobacco to be discharged continuously or discontinuously from the feed pipe 38 to the chamber 30, without breaking the internal vacuum. In this alternative, the chamber 30 is at atmospheric pressure. A further alternative is to feed cut tobacco manually to the wide chamber 30.
The feed of tobacco to the chamber 30, either on a discontinuous or continuous basis, using the devices described above, results in the provision of a reservoir of tobacco 44 in the reservoir chamber 30.
A separate tobacco separation and discharge device 46 is provided at the upper end of the reservoir device 28 in communication with the narrow chamber 32 for receiving a recycle feed of tobacco trimmed from the filler rod 14 by the trimmer device 22. The recycle of trimmed tobacco is effected in the illustrated embodiment by air drawn through recycle line 48. Any other convenient feed means may be employed, for example, a conveyor.
In the separation and discharge device 46, which is in the form of a cyclone separator in the illustrated embodiment, tobacco is separated from the conveying air stream and is continuously discharged to the hopper or chamber 32 by a rotary air lock 50 which maintains the vacuum conditions within the device 46 while permitting the tobacco to be discharged to the ambient atmospheric pressure conditions of the chamber 32. Depending on the manner of provision of the conveying air stream in line 48, the rotary air lock 50 may be omitted. Any other suitable separation and tobacco discharge device may be used.
Since tobacco is continuously trimmed from the filler rod 14 by the trimmer 22, and, as described below, the quantity of trimmed tobacco in the chamber 32 is employed as the control parameter, as a practical consideration, the recycle of trimmed tobacco and its discharge to the narrow chamber 32 should be effected continuously, as illustrated.
The recycled trimmed tobacco discharged to the narrow chamber 32 forms a reservoir of tobacco 52 in the narrow chamber 32. Sensors 53 and 54 are provided in association with the narrow chamber 32 to sense "too-high" and "too-low" conditions respectively of the tobacco in the reservoir 52. The tobacco reservoir 52 in the narrow chamber 32 and the tobacco reservoir 44 in the wide chamber 30 provide the sources of tobacco from which the tobacco carpet 26 is formed on the conveyor 24.
At the lower end of the reservoir device 28, there is provided a tobacco metering and opening device 56, which comprises a pair of counter-rotating metering rollers 58 which extend across the width of the reservoir device 28 in communication with the tobacco reservoirs 44 and 52 in both of the chambers 30 and 32. The counter-rotating rollers 58 have a plurality of radially-directed pins 60 which cooperate with each other to meter a desired amount of tobacco from both the reservoirs 44 and 52 simultaneously. The rate of rotation of the pair of rollers 58 determines the amount of tobacco discharged from the reservoir device 28 to the conveyor 26. Since the metering rollers 58 extend across the whole width of the reservoir device 28 and meter tobacco from both chambers 30 and 32, the rate of feed of tobacco from the chambers 30 and 32 is the same per unit width.
The tobacco metering and opening device 56 also includes a third roller 62 generally equidistantly positioned with respect to the pair of rollers 58. The third roller 62 is provided with projecting pins 64 which interdigitate with and cooperate with the pins 60 on the rollers 58 to separate the tobacco metered by the pair of rollers 58 from the reservoirs or sources 44 and 52 into individual tobacco particles which are discharged onto the upper surface of the conveyor 24 to provide the tobacco carpet 26.
The thickness of the carpet 26 on the conveyor 24 and hence the amount of tobacco forming the tobacco shower 20 from which the filler rod 14 is formed is determined by the speed of the conveyor surface 24 and the rate of rotation of the pair of rollers 58. Usually, the speed of the conveyor 24 is maintained constant and the tobacco flow rate then is controlled by the operation of the metering and opening device 56.
As may be seen from the foregoing description, the only tobacco recycled in this system is trimmed tobacco and no refuser mechanism is required or utilized. The tobacco which forms the carpet 26 is positively metered and then discharged in an opened condition from the reservoir device 28 by the tobacco metering and opening device 56 and is in the amount required for rod formation. Tobacco degradation introduced by refuser and metering mechanisms such as are employed in conventional cigarette-making machines is eliminated. The utilization of the hopper 28 not only enables fully-opened relatively-undamaged tobacco to be fed to rod formation but also results in considerable simplification in the elements of construction of a cigarette-making machine.
In the present invention, the recycle of trimmed tobacco by line 48 is used to control the operation of the rod-forming device 12. The rate of feed of tobacco by the metering and opening device 56 from the chambers 30 and 32 is controlled so as to maintain a substantially constant level of the tobacco 52 in the narrow chamber 32.
If the quantity of tobacco in the narrow chamber 32 rises, then the quantity of tobacco being trimmed has risen and, therefore, the cigarette-making machine is operating with an excess of the tobacco required. In response to a rise in the quantity of tobacco in the narrow chamber 32, the feed rate of tobacco from the reservoir device 28 is decreased by slowing down the rate of operation of the metering and opening device 56 until the desired level of recycled tobacco in the narrow chamber 32 is restored.
Similarly, if the quantity of tobacco in the narrow chamber 32 falls, then the quantity of tobacco being trimmed has fallen and, therefore, the cigarette-making machine is operating with a deficiency of tobacco. The feed rate of tobacco from the reservoir device 28 is speeded up to compensate for the inadequate feed rate until the desired level of recycled tobacco in the narrow chamber is restored.
The level of tobacco in the narrow chamber 32 may be sensed in any desired manner, for example, by using optical sensors 53 and 54, and usually variations in tobacco level within a predetermined range, as determined by the spacing of the sensors 53 and 54, are permitted. Through appropriate circuitry, a "too-high" or "too-low" signal may be used to trigger appropriate variation in the speed control 64 for the drive motor 66 for the device 56, which appropriately speeds up or slows down the rate of tobacco feed from the reservoirs 44 and 52.
Using the level of recycled tobacco in the narrow chamber 32 to control the rate of metered tobacco supplied to the rod-forming operation to ensure that the correct quantity of tobaco is present in the filler rod 14, is a very simple yet extremely functional operation. Overfeeding and trimming are required to be effected in cigarette filler rod formation for the reasons discussed above and it is necessary to recycle the trimmed tobacco to ensure economic use of tobacco. The present invention has used these prior art operations in a unique and useful manner, to control the rod-forming operation.
The recycle of trimmed tobacco also has been uniquely combined into a procedure of forming the feed to filler rod formation which does not involve any refuser mechanism and/or recycle procedure, other than the recycle of trimmed tobacco, and so the present invention has eliminated the tobacco degradation which results during conventional feed-forming procedures.
The degree of trimming of tobacco from the filler rod 14 also may be controlled, in accordance with one embodiment of the invention. The degree to which trimming of a filler rod 14 is required to be effected to remove the variations in tobacco thickness along the length of the rod depends on a number of factors, including the nature of the rod-forming operation.
In this embodiment of the invention, the degree of trimming is controlled by the width of the narrow chamber 32. As the transverse dimension of the chamber 32 is narrowed, less tobacco is required to maintain the desired level of tobacco 52 in the narrow chamber 32 and hence a lesser amount of tobacco needs to be recycled by line 48. Similarly, as the transverse dimension of the chamber 32 is widened, more tobacco is needed to maintain the desired level of tobacco 52 in the narrow chamber 32 and hence a greater amount of tobacco is required to be recycled by line 48.
The width of chamber 32, therefore, is preset to the desired degree of trimming having regard to the predetermined speed of operation of the cigarette rod-forming procedure and then that degree of trimming is maintained by maintaining the predetermined level of recycled trimmed tobacco 52 in the narrow chamber 32.
In the illustrated embodiment, the trimmed tobacco is positioned adjacent the rod-forming surface of the wheel 16. It is also possible and preferred to arrange the apparatus 10 to provide the recycled trimmed tobacco on the exterior surface of the filler rod 14 and hence on the side of the filler rod opposite to the rod-forming surface of the wheel 16. In this way, the already-trimmed tobacco once again is trimmed and overall tobacco degradation thereby is minimized and an improved distribution of shorts across the width of the filler rod is achieved, since the increased quantity of shorts in the trimmed tobacco offsets the normal concentration of shorts towards the rod-forming surface.
SUMMARY OF DISCLOSURE
In summary of this disclosure, the present invention provides a novel manner of controlling cigarette filler rod-forming procedures by controlling the rate of recycle of trimmed tobacco. This recycle operation preferably is combined with and renders effective a novel tobacco feeding procedure which enables a feed for a filler rod-forming operation to be provided without resulting in tobacco degradation from refuser and recycle operations. The degree of trimming may also be controlled by this invention. Modifications are possible within the scope of this invention. | Tobacco trimmed from a filler rod is recycled and used in the control of the rod-forming operation. A reservoir vessel is divided into physically-separate chambers, a narrow one of which receives the recycled trimmed tobacco and a wider one of which receives cut tobacco. Tobacco is simultaneously fed from both chambers by a common feeding device to form a metered flow from which the filler rod is ultimately formed. The level of tobacco in the narrow chamber is sensed and the operation of the common feeding device is controlled in response to sensed levels outside a predetermined range. If the sensed level is too high, then the tobacco is being fed too fast to the rod formation and the common feeding device then is slowed down, thereby slowing the tobacco feed rate, while, if the sensed level is too low, then the tobacco is being fed too slowly to the rod formation and the common feeding device then is speeded up, thereby speeding up the tobacco feed rate. | 8 |
BACKGROUND OF THE INVENTION
This invention relates generally to a steam generating system having a coal or oil fired boiler and a regenerative air preheater. More particularly, the present invention relates to a steam generating system having a boiler and a rotary regenerative air preheater.
During the combustion process in the boiler, the sulfur in the fuel is oxidized to SO 2 . After the combustion process, some amount of SO 2 is further oxidized to SO 3 , with typical amounts on the order of 1 to 2% going to SO 3 . The presence of iron oxide, vanadium and other metals at the proper temperature range produces this oxidation. Selective catalytic reduction (SCR) is also widely known to oxidize a portion of the SO 2 in the flue gas to SO 3 . The catalyst formulation (primarily the amount of vanadium in catalyst) impacts the amount of oxidation, with rates ranging from 0.5% to over 1.5%. Most typical is around 1%. Therefore plants firing a high sulfur coal with a new SCR can see a large increase in the SO 3 emissions, which produce a visible plume, local acidic ground level problems and other environmental issues.
Regenerative air preheaters condense or trap a portion of the SO 3 in the flue gas. The SO 3 is condensed as sulfuric acid at temperatures typically below 300° F. Cold end acidic fouling of regenerative air preheaters creates a gradual increase in pressure drop. Sootblowing is generally utilized to reduce the rate of pressure drop build-up, but after some period of operation the air preheater must be cleaned by water washing. This is most typically accomplished by having an outage and shutting down the boiler. The maximum amount of pressure drop increase which is acceptable depends on the limitations of the existing fans, either the forced draft (air side), or induced draft (gas side) fans. The maximum acceptable pressure drop across the air preheater imposes limits on the design of the air preheater, principally limiting the number and type of heat exchange elements, thereby limiting the thermal efficiency of the air preheater.
SUMMARY OF THE INVENTION
Briefly stated, the invention in a preferred form is a method for increasing the efficiency of a steam generator system including a boiler producing a flow of flue gas containing SO 3 . An air preheater includes an air inlet and a flue gas outlet defining a cold end and a flue gas inlet and an air outlet defining a hot end. The flow of flue gas is received by the flue gas inlet, carried through heat exchange element basket assemblies, and discharged from the flue gas outlet, such that the flow of flue gas creates a pressure drop across the air preheater. A portion of the SO 3 carried in the flue gas forms an acid which accumulates in the cold end of the air preheater, with the rate of acid accumulation depending on the amount of SO 3 carried in the flue gas. The accumulating acid causes the pressure drop across the air preheater to increase from a maximum allowable clean condition pressure drop to a maximum allowable dirty condition pressure drop over the operating cycle of the steam generator system. The method comprises the steps of determining a reduced rate of acid accumulation which may be achieved by injecting an SO 3 neutralizing or SO 3 reactant additive material into the flue gas. A new maximum allowable clean condition pressure drop is calculated based on the reduced rate of acid accumulation. Modified heat exchange element baskets are created. The modified baskets have an increased heat transfer efficiency, compared to the conventional heat exchange element basket assembly, and a maximum allowable clean condition pressure drop substantially equal to the calculated new maximum allowable clean condition pressure drop. The conventional heat exchange element basket assemblies are replaced with modified heat exchange element basket assemblies. When the boiler is operating, the additive material is added to the flue gas.
Creating a modified heat exchange element basket includes identifying how the conventional heat exchange element basket assemblies may be modified to increase the heat transfer surface area and heat transfer. The cost of effecting each identified modification is determined. Finally, it is determined which of the identified modifications will most cost effectively produce the new maximum allowable clean condition pressure drop to provide the increased efficiency desired.
The steam generator system also generally includes fans for pushing and pulling the flue gas through the boiler. The maximum output of the limiting fan determines the maximum allowable dirty condition pressure drop (ΔP max ). The new maximum allowable clean condition pressure drop may be determined by calculating the increase in the pressure drop over the operating cycle attributable to the reduced rate of acid accumulation and subtracting the increase in the pressure drop over the operating cycle from the maximum allowable dirty condition pressure drop. Alternatively, the new maximum allowable clean condition pressure drop may be determined by calculating the increase percent decrease in acid accumulation over the operating cycle attributable to the reduced rate of acid accumulation (% ΔP) and determining the maximum allowable dirty condition pressure drop with the formula ΔP max /(1+% ΔP).
It is an object of the invention to provide a cost effective steam generating system in which a large percentage of SO 3 emitted by the boiler is removed in the installed regenerative air preheater.
It is also an object of the invention to provide a steam generating system in which fouling and corrosion problems associated with SO 3 removal are minimized.
Other objects and advantages of the invention will become apparent from the drawings and specification.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawings in which:
FIG. 1 is a perspective view, partially broken away, of a rotary regenerative air preheater;
FIG. 2 is a schematic diagram of a system in accordance with the invention;
FIG. 3 is a flow diagram of a method for increasing the efficiency of the air preheater of FIG. 1; and
FIG. 4 is a perspective view of portions of three heat exchange elements of a heat exchange element basket assembly of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The majority of steam generating systems utilize regenerative air preheaters to increase the boiler efficiency, with the largest portion being a rotary regenerative air preheater. This type of air preheater features rotating heat exchange elements. A different type of regenerative air preheater utilizes fixed heat exchange elements and internally rotating hoods or ductwork fixed to the rigid air and gas ducts. The subject invention relates to boiler systems equipped with either type of regenerative air preheater. To facilitate discussion, the inventive arrangement will be discussed in combination with a rotary regenerative air preheater.
With reference to FIG. 1 of the drawings, a conventional rotary regenerative preheater is generally designated by the numerical identifier 10 . The air preheater 10 has a rotor 12 rotatably mounted in a housing 14 . The rotor 12 is formed of diaphragms or partitions 16 extending radially from a rotor post 18 to the outer periphery of the rotor 12 . The partitions 16 define compartments 20 therebetween for containing heat exchange element basket assemblies 22 .
In a typical rotary regenerative heat exchanger 10 , the hot flue gas stream 28 and the combustion air stream 34 enter the rotor 12 from opposite ends and pass in opposite directions over the heat exchange elements 42 housed within the heat exchange element basket assemblies 22 . Consequently, the cold air inlet 30 and the cooled flue gas outlet 26 are at one end of the heat exchanger, referred to as the cold end 44 , and the hot flue gas inlet 24 and the heated air outlet 32 are at the opposite end of the air preheater 10 , referred to as the hot end 46 . Sector plates 36 extend across the housing 14 adjacent the upper and lower faces of the rotor 12 . The sector plates 36 divide the air preheater 10 into an air sector 38 and a flue gas sector 40 . The arrows of FIG. 1 indicate the direction of the flue gas stream 28 and the air stream 34 through the rotor 12 . The hot flue gas stream 28 entering through the flue gas inlet duct 24 transfers heat to the heat exchange elements 42 in the heat exchange element basket assemblies 22 mounted in the compartments 20 positioned in the flue gas sector 40 . The heated heat exchange element basket assembles 22 are then rotated to the air sector 38 of the air preheater 10 . The stored heat of the heat exchange element basket assemblies 22 is then transferred to the air stream 34 entering through the air inlet duct 30 . The cold flue gas stream exits the preheater 10 through the flue gas outlet duct 26 and the heated air stream exits the preheater 10 through the air outlet duct 32 .
Regenerative air preheaters 10 condense or trap a portion of the SO 3 carried in the flue gas. Acidic fouling of the cold end 44 of the air preheater 10 creates a gradual increase in pressure drop across the air preheater 10 . Sootblowing is generally utilized to reduce the rate of pressure drop build-up, but after some period of operation the air preheater 10 must cleaned by water washing. This is most typically accomplished during an annual outage when the boiler 48 is shut down.
The amount of pressure drop increase which is acceptable depends on the most limiting of either the forced draft (air side) fan(s) 49 , or induced draft (gas side) fan(s) 50 . The design of the heat exchange element basket assemblies 22 must account for the increase in pressure drop over the twelve month period between outages. That is, the number, size, and/or type of heat exchange elements 42 carried in the basket assemblies 22 is in part set by the value of the pressure drop across the air preheater 10 in the clean condition. For example, if a maximum pressure drop of 8 inches is allowed by the limiting fan 49 or 50 and the acidic fouling will cause the pressure drop to double over the twelve month period, the maximum allowable pressure drop of the air preheater 10 in the clean condition is 4 inches. A heat exchange element basket assembly 22 for such an air preheater 10 will include fewer heat exchange elements 42 and/or heat exchange elements 42 which are less efficient in transferring heat than a heat exchange element basket assembly 22 which may sustain a greater pressure drop in the clean condition.
In a system for increasing efficiency of steam generator system having a regenerative air preheater 10 , an additive material 52 is injected into the hot flue gas stream 28 to remove or significantly reduce the amount of SO 3 prior to the cold end 44 . The SO 3 reaction may occur prior to the hot end 46 , or during the temperature reduction within the heat exchange elements 42 (but prior to the heat exchange elements 42 reaching the acidic condensation temperature), or some combination of the two. Such additive materials 52 include solutions containing a bisulfite, or a sulfite. Alternatively, the additive material 52 may be an alkaline sorbent such as magnesium oxide or calcium oxide.
Reducing the amount of SO 3 reduces the rate of cold end acidic fouling, thereby reducing the rate of increase in the pressure drop and consequently reducing the pressure drop across the air preheater 10 at the end of the twelve month period (or any desired design time period) of the operating cycle. The limiting fan 49 or 50 will therefore have additional capacity which can be used to allow a revision in the heat exchange elements 42 that increases the efficiency of such elements 42 while increasing the pressure drop attributable to the heat exchange elements 42 . Addition of the additive material 52 produces a significant reduction in the rate of pressure drop increase, for example by at least by 25%.
The efficiency of the air preheater 10 is increased, thereby increasing the efficiency of the entire steam generator system, by replacing some or all of the existing heat exchange elements 42 with new, more efficient, heat exchange elements 42 ′. As explained above, the new heat exchange elements 42 ′ generate a greater pressure drop in the air/gas flow. Accordingly, the total increase in the pressure drop attributable to the new heat exchange elements 42 ′ is set to be equal to or less than the reduction in pressure drop attributable to the reduction in acidic fouling of the cold end 44 . In this manner, the total pressure drop across the air preheater 10 at the end of the design period between steam generator system outages will be the same as the total pressure drop for a conventional steam generator system having equivalent pressure drop limitations.
For example, if the additive material 52 injected into the hot flue gas steam 28 produces a twenty-five percent (25%) reduction in acidic fouling of the cold end 44 of an air preheater 10 having a 4 inch pressure drop in the clean condition, the increase in pressure drop over the operating cycle will be 3 inches (25% less than the 4 inch increase discussed above), providing a total pressure drop across the air preheater 10 at the end of the operating cycle of 7 inches. Accordingly, more efficient heat exchange elements 42 ′ may be substituted for the conventional heat exchange elements 42 . The allowable clean condition pressure drop of the “improved” air preheater 10 may be determined by the following formula:
Δ P max /(1+% Δ P increase)
Where ΔP max is the maximum allowable pressure drop at the end of the operating cycle and % ΔP increase is the percentage increase in pressure drop over the operating cycle after addition of the additive material 52 . For the example above, the allowable clean condition pressure drop would therefore be
8 inches/(1+0.75)=4.57 inches
With an initial, clean condition pressure drop of 4.57 inches, a pressure drop increase of seventy-five percent (75%) over twelve months produces 8 inches of pressure drop, leaving no excess fan capacity.
The efficiency of a heat exchange element basket assembly 22 may be increased in a number of ways. The area of the surface available for transferring heat may be increased by increasing the depth or flow length 54 of the heat exchange elements 42 ′ (FIG. 4) within a basket assembly 22 by using a special basket design that provides a greater total depth 54 for the heat exchange elements 42 ′ by reducing the space occupied by supports and/or handling bars. The spacing 56 between the heat exchange elements 42 ′ may be reduced and/or the thickness 58 of the sheet material forming the heat exchange elements 42 ′ may be reduced to allow the basket assembly 22 to contain a greater number of heat exchange elements 42 ′. Heat exchange elements 42 ′ may be used which have a larger length factor. Although costly, the rotor 12 may be modified to provide for a greater depth 54 for the heat exchange elements 42 ′. The design of the rotor 12 may also be modified to reduce the number of layers of heat exchange element basket assemblies 22 , thereby reducing the number of support bars and also reducing rotor volume attributable to clearance gaps.
The efficiency may also be increased by increasing the heat transfer coefficient of the heat exchange element basket assemblies 22 . The heat transfer coefficient of a basket assembly 22 may be increased by lowering the porosity, for example by increasing the number of heat exchange elements 42 ′. Increasing the number of heat exchange elements 42 ′ in a basket assembly 22 not only increases the total surface for heat exchange, it decreases the total flow area 60 resulting in a higher flow velocity and a higher heat transfer coefficient. The heat exchange elements 42 ′ may have a rougher heat transfer surface to produce turbulence in the flow. Heat exchange element features such as indentations 62 on notches, a greater undulation height 64 , or a steeper undulation angle 66 may be used to roughen the surface. Alternatively, the heat exchange elements 42 ′ may include flow interrupters or boundary layer trips (e.g. punched tabs or expanded metal) to produce turbulence in the flow.
It should be appreciated that reducing the thickness 58 of the sheet material from which the heat exchange elements 42 ′ are manufactured will increase the porosity of the basket assembly 22 in the absence other changes to the basket assembly design. That is, the thinner heat exchange elements 42 ′ create a larger flow area 60 , producing a lower flow velocity.
In summary, the efficiency of a regenerative air preheater 10 may be increased by first determining 68 the reduction in the rate of cold end fouling which may be achieved by injecting an additive material 52 into the hot flue gas stream 28 that reduces the amount of SO 3 which may be retained in the cold end 44 of the air preheater 10 (FIG. 3 ). For a given reduction in the rate of fouling, a new allowable clean condition pressure drop is calculated 70 . The various ways of increasing the heat transfer surface area and the heat transfer coefficient for the particular preheater design are evaluated to determine 72 which modifications to the heat exchange element basket assembly design will most cost effectively produce the calculated clean condition pressure drop and thereby increase the heat transfer efficiency. Heat exchange element basket assemblies 22 ′ incorporating the selected modifications are installed 74 in the air preheater 10 . During operation of the steam generating system, additive material 52 is injected 76 into the flue gas stream 28 proximate to the flue gas inlet duct 24 . The additive material 52 reacts 78 with the SO 3 present in the flue gas stream 28 such that the amount of acid produced and deposited in the cold end 44 is substantially equal to the amount calculated in step 68 .
While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation. | A method for increasing the efficiency of a steam generator system including a boiler and a regenerative air preheater. The method including determining a reduced rate of acid accumulation in the preheater which may be achieved by injecting an SO 3 neutralizing additive material into flue gas generated by the boiler. A new maximum allowable clean condition pressure drop is calculated based on the reduced rate of acid accumulation. Modified heat exchange element baskets are created having an increased heat transfer efficiency, compared to conventional heat exchange element basket assemblies, and a maximum allowable clean condition pressure drop substantially equal to the calculated new maximum allowable clean condition pressure drop. The conventional heat exchange element basket assemblies are replaced with modified heat exchange element basket assemblies. When the boiler is operating, the additive material is added to the flue gas. | 8 |
BACKGROUND OF THE INVENTION
The automobile industry includes manufacturers of products that allow owners to customize the look and functionality of their vehicles. In particular, the disclosed invention concerns the class of customizing products referred to as guards or deflectors. These products are typically mounted to a vehicle with the purpose of protecting a vulnerable part of the vehicle from impacts with road debris, brush, rocks, shopping carts, or other hazards. Vehicle parts which are often particularly vulnerable are the plastic or glass lenses of the various lights including the headlights and taillights. In modern vehicles, these lens assemblies are typically mounted at the 4 corners of a vehicle where they are vulnerable from 2 sides. Additionally, these lens assemblies may be complex in shape and integrated into the overall appearance and aesthetics of the vehicle which often makes them very expensive to replace.
The typical brush guard is fabricated from metal and mounted to the vehicle via one or more brackets which are attached to the vehicle body or directly to the part being protected. Attachment is typically accomplished by drilling new holes or by utilizing existing attachment points. Existing attachment points are typically accessed by disassembling a portion of the vehicle. Both drilling new attachment points and utilizing existing ones have distinct disadvantages. Drilling can cause disruption of a vehicles corrosion protection and must be repaired if the guard assembly is later removed. Disassembling the vehicle also has disadvantages. A disassembled part may be damaged during disassembly and then reassembly. A skilled service person usually must perform the operation, often using specialized tools. Reassembly must be carefully performed to avoid misalignment, especially with headlights.
The shape of modern lens assemblies is often complex with multiple light sources. Any guard must protect the lens but minimize light obstruction. The complex shape of the lens is often a result of the lens being formed to match or continue the contours of the vehicle body. A guard will have greater consumer acceptance if it does not interfere with the overall vehicle aesthetic. To minimize this impact, a guard should be low profile and as form-fitting as possible. This is often very difficult with systems incorporating brackets since the brackets can often be seen and can cause the guard to appear to be sticking out from the vehicle.
Other methods of attachment are available for affixing components to a vehicle exterior. One common method for attaching decorative molding and small accent pieces is by using double sided adhesive tape. This tape typically has a pressure sensitive adhesive on both sides of a plastic film. A popular product uses acrylic foam as the center film and is produced by numerous adhesive film manufacturers like 3M or Avery Dennison. The use of foam is intended to fill small voids between the surfaces of a rigid part being applied and the rigid vehicle body. The foam is not generally intended to provide any significant shock isolation. The use of two sided adhesive tape has the advantage that the attachment device is substantially hidden from view. In addition, no special tools are necessary and no vehicle modification need be performed by skilled workers. Finally, it is often possible to remove taped-on parts with minimum damage to the vehicle and often the part itself.
What is needed is a system for attaching a protective guard onto or around a vulnerable vehicle component which can be installed by any vehicle owner, without special tools, and without drilling or disassembling the vehicle. The guard should have a low profile and complement the overall vehicle aesthetics.
SUMMARY OF THE INVENTION
The disclosed invention describes a protective guard and system of attachment consisting of an aesthetically attractive, low profile, grill structure adapted to the shape of and attached directly to a vehicle component, such as a headlight lens, using an attachment device consisting of layers of adhesive and energy absorbing/dissipating material. In general the disclosed invention is ideally suited for protecting plastic or glass lens assemblies on motor vehicles from accidental damage. The system could also be used to protect other vulnerable parts.
The protection system consists of two major components. The first is the guard assembly which is a cage or grid of metal ribs attached to a flat frame. The frame is typically adapted to a shape which closely matches the perimeter of the vehicle lens to be protected. The frame has a contacting surface which is substantially parallel to the surface of the lens. The metal ribs of the grid are also formed to match the shape of the lens; however, the grid is offset in a direction away from the lens so that a gap exists between the grid and the lens such that any impact energy imparted to the grid will be transferred to the frame instead of the lens.
The second component is the energy absorbing attachment system which affixes the frame to the perimeter of the lens. The attachment system is a multi-layer strip consisting of two adhesive layers on each face of the strip and one or more inner layers consisting of a structural energy absorbing material such as rubber, urethane, or other plastics. Additional layers may also be present between the adhesive layers and the energy absorbing layers. These additional layers could be of materials designed to transfer heat such as aluminum foil or of materials designed to present a color.
The disclosed invention can be used to affix a guard directly to the surface of a lens or it could also be used to affix a guard to a surrounding surface, such as the vehicle body, such that the component to be protected is under the guard.
The spacing of the ribs within the protective grid is determined by its intended use. The factors contributing to the grid spacing and rib placement include the size of the debris to be deflected, the position of the light sources within the lens assembly, and the position of any fasteners used to hold the lens to the vehicle. A unique set of guard assemblies are typically required for every vehicle model.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings in which like reference numbers represent corresponding parts throughout:
FIG. 1 is the left rear view of a light duty truck showing the left taillight with the guard of the disclosed invention mounted in place.
FIG. 2 is a front right view of a light duty truck showing the right headlight with the guard of the disclosed invention mounted in place.
FIG. 3 is a cross section of the energy absorbing material of the current invention showing the embodiment which includes two outer adhesive layers
FIG. 4 is a cross-section of an alternate embodiment of the energy absorbing material showing one adhesive layer and prior direct bonding to the protective guard.
FIG. 5 is a cross-section of an alternate embodiment of the energy absorbing material showing an additional pair of layers that are connected to each other over one of the edges of the material thereby covering any interstitial layers and providing a means to insert an color accent or move heat.
FIG. 6 is a guard assembly showing one possible orientation of ribs and a frame.
DETAILED DESCRIPTION
In the following description of the preferred embodiment, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration one or more embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.
Overview
The disclosed invention describes a system for attaching an aesthetically attractive protective guard to a vehicle. The guard is a low profile grill structure adapted to the shape of an underlying vehicle component. It is typically attached directly to a vehicle component, such as a headlight lens, using an attachment device consisting of layers of adhesive and energy absorbing/dissipating material. The device is well suited for the “do-it-yourself” market and is also very attractive to vehicle customizers because it typically can be installed using no tools, does not require the disassembly or modification of the vehicle, and has a visual impact consistent with the original vehicle aesthetic.
Specifics of the Invention
The disclosed invention describes a protective guard and system of attachment. The guard is an attractive grill structure which is adapted in shape to conform to a specific vehicle or family of vehicles. The guard is primarily intended to protect vulnerable vehicle body assemblies such as plastic or glass lens assemblies containing headlights 16 , taillights 12 , brake lights, and/or marker lights, although it could be adapted to protect other vehicle features or assemblies.
FIGS. 1 and 2 show a typical installation of the guard system on a light duty truck. FIG. 1 shows a taillight guard 10 in position over the left rear taillight assembly 12 . FIG. 2 shows a headlight guard 14 over a front right headlight assembly 16 .
The invention is an improvement over the existing methods of attaching guards. It creates a very low profile, form-fitting guard which integrates well into the existing vehicle aesthetics. The guard attaches directly to the face of a lens assembly, FIGS. 1 , 2 , or alternately it could be mounted outside the perimeter of a lens assembly with the lens assembly beneath the guard.
FIG. 6 shows a guard assembly which is comprised of a grid or ladder structure made up of ribs of flat metal 20 . Said ribs are oriented such that a force normal to the protected lens assembly would strike a flat rib 20 on its outward facing edge. The ribs 20 are oriented in this manner to provide the greatest strength while presenting the lowest cross section to the light coming from the protected lens assembly. The ribs, in the form of a grid or ladder, are attached to a frame 2 which makes up the perimeter of the guard and is adapted to match the vehicle surface to which it will be attached. Force applied to the protective portion of the guard is transferred through the ribs to the frame where it is more widely distributed. While FIG. 6 shows a guard with a ladder arrangement of ribs 20 , a guard with vertical or intersecting ribs is also anticipated.
The guard is affixed to the vehicle through strips of energy absorbing material which also includes adhesives on its surfaces. The energy absorbing material is positioned between the guard frame 2 and the surface of the vehicle 4 at the attachment point of the guard. Forces which have been transferred into the guard frame are further transferred into the energy absorbing layers 6 where they are more widely dispersed and absorbed before the force is finally transmitted to the vehicle itself.
Each guard assembly is adapted to fit a specific vehicle. Rib position and orientation depend on the shape of the underlying lens assembly and the location of the light sources within the assembly. The ribs 20 of the guard assembly are perpendicular to the surface of the protected vehicle assembly and are oriented to generally minimize any intrusion into the light path of headlights or taillights.
FIGS. 3 , 4 , and 5 show three possible embodiments of the energy absorbing material in cross section. The energy absorbing attachment strip is formed from one or more layers with the center layer 6 being an energy absorbing layer of rubber, urethane, closed cell foam, or other elastic material which is both compressibly elastic and rigid enough to hold the guard to the vehicle. The two outer surfaces of the attachment strip are coated with an adhesive 8 to bond the attachment strip to the guard frame 2 on one side and the vehicle 4 on the other. An adhesive layer 8 is accomplished by applying glue or by the use of a double-sided tape. Since the product is intended for sales in packaged sets, any glue surfaces or double sided tape surfaces would necessarily be provided with a peel-off backing strip which is not shown in the figures. Additional layers of material, not indicated in the drawings, could also be incorporated such as metal foils or Mylar for the purpose of isolating elastic layers from heat generated by light bulb.
FIG. 5 shows an additional embodiment that includes an optional layer 9 that wraps around one or both edges of the attachment strip to provide a color edge or to extend the heat-dissipating layer from the vehicle side to the guard side.
The energy absorbing attachment strip can be manufactured as a linear strip and then bent to conform to the shape of the guard frame. In an alternate embodiment, the energy absorbing attachment strip can be cut or punched from one or more sheets of material to create one or more pre-shaped gasket-like assemblies.
A tradeoff between manufacturing complexity and consumer cost would suggest two typical forms of delivery to the consumer. A first form would be for the guard to be shipped without the energy absorbing attachment system affixed to the guard. In this form the attachment system would have pressure sensitive adhesive tape or other consumer usable adhesive 8 on both outer surfaces as indicated in FIG. 3 .
In an alternate embodiment, shown in FIG. 4 , the energy absorbing attachment system would be pre-installed onto the back of the guard frame 2 during manufacture. This has the advantage of ensuring proper alignment of the guard onto the attachment strip. Additionally, this second embodiment allows the use of industrially applied adhesives to bond the guard frame to the attachment strip resulting in a more consistent fit and finish of the final installation.
The disclosed invention is typically used to affix the guard directly to the surface of a lens assembly. No special tools are required; however, proper cleaning of the contacting surfaces should be performed. An alternate embodiment is to affix the guard to the vehicle body. In this case, the protected vehicle assembly would be partially or completely surrounded buy the guard frame. This embodiment is appropriate for smaller or recessed assemblies such as side marker lights.
The foregoing description of the preferred embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. | A protective guard mounting system that provides a shock absorbing and dissipating means of attachment for vehicle exterior components or protective devices. The protective guards are adapted to protect vehicle components such as headlights, taillights, signal/corner and/or driving lights, or painted/non-painted steel/plastic body parts. | 1 |
FIELD
[0001] This disclosure relates generally to a Wheelbarrow Attachment.
BACKGROUND
[0002] Gardeners, construction workers, farmers, and other wheelbarrow users must often transport various items in addition to the load contained in their wheelbarrow bin. These items may include tools such as shovels, rakes, and picks, for example. The size, weight, and shape of these items may preclude them from fitting securely inside of the bin. As a result, the items may fall, cause the wheelbarrow to tip, damage nearby property, or injure people or livestock.
SUMMARY
[0003] The following presents a simplified summary of the disclosure to provide a basic understanding to the reader. This summary is not an extensive overview of the disclosure, nor does it identify key or critical elements of the claimed subject matter, or define its scope. Its sole purpose is to present some concepts disclosed in a simplified form as a precursor to the more detailed description that is later presented.
[0004] The instant application discloses, among other things, a Wheelbarrow Attachment. In one embodiment, a Wheelbarrow Attachment may comprise a rack which may attach to the side of a wheelbarrow bin. Wheelbarrow Attachment may include a plurality of holders designed to secure various items, for example, gardening tools. In this embodiment, the holders may be arranged so as to allow elongated handles of tools such as shovels, rakes, and picks, for instance, to rest horizontally along the side of the bin. Wheelbarrow Attachment may also include a handle which a user may pull upward to disconnect the rack from the wheelbarrow bin and to carry the items away.
[0005] In another embodiment, the Wheelbarrow Attachment may include holders comprised of hooks, belts, buckles, hook and loop fasteners such as Velcro, adhesives, magnets, or any other holding means.
[0006] A person skilled in the art will understand that a Wheelbarrow Attachment may be made into various shapes, sizes, and colors. It may also be made of various materials, such as wood, plastic, rubber, metal, or carbon fiber, for example.
[0007] Many of the attendant features may be more readily appreciated as they become better understood by reference to the following detailed description considered in connection with the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a front perspective view of a Wheelbarrow Attachment, according to one embodiment.
[0009] FIG. 2 is a front view of a Wheelbarrow Attachment connected to the outer side of wheelbarrow bin, according to the first embodiment.
[0010] FIG. 3 is a front perspective view of a Wheelbarrow
[0011] Attachment according to another embodiment.
DETAILED DESCRIPTION
[0012] FIG. 1 is a front perspective view of a Wheelbarrow Attachment, according to one embodiment. In this example, Wheelbarrow Attachment 100 may be attached to any part of a wheelbarrow, for instance, to the outer side of a wheelbarrow bin. Wheelbarrow Attachment 100 may be made into various shapes, sizes and colors, and may be made of various materials, such as wood, plastic, rubber, metal, or carbon fiber, for example.
[0013] Wheelbarrow Attachment 100 may be secured to the wheelbarrow by Attachment Means 110 , which may comprise a clip that uses tension to hold Wheelbarrow Attachment 100 securely in place. Attachment Means 110 may also comprise a hook, adhesive, magnet, or any other attachment means. Wheelbarrow Attachment may include a Handle 120 at the top portion of the rack, for example. A user may grasp and lift Handle 120 in order to disconnect Wheelbarrow Attachment 100 from the wheelbarrow. Handle 120 may have a grip designed to enhance traction or comfort, for example. A grip on Handle 120 may be made of one of a variety of materials, including, for example rubber, foam, silicone, gel, plastic, leather, or a combination of two or more materials.
[0014] Wheelbarrow Attachment 100 may include a plurality of Holders 130 designed to hold items such as gardening, farming, or construction tools, for example. Holders 130 may be comprised of U-shaped cavities that are tapered on its outer ends to help keep items placed inside Holders 130 securely in place. Holders 130 may be arranged so as to allow elongated handles of tools such as shovels, rakes, and picks, for instance, to rest horizontally along the side of the wheelbarrow bin. Holders 130 may also comprise any other means of securing objects, including but not limited to any type or combination of clips, spring-loaded clips, hook and loop fasteners such as Velcro, adhesives, magnets, S-hooks, snap hooks, bolt plates, anchor plates, j-hooks, flat hooks, ratchet fasteners, over-center fasteners, slide buckles, snap buckles, and containers, for example. Holders 130 may adjust position by sliding in Track 150 , and may be held in place by friction, a tightening fastener, or other means.
[0015] Wheelbarrow Attachment 100 may also include one or a plurality of Cross Bar 140 in order to support or distribute the weight of items placed on the rack.
[0016] FIG. 2 is a front view of a Wheelbarrow Attachment 100 connected to the outer side of wheelbarrow bin, according to one embodiment. In this example, Wheelbarrow Attachment 100 may be secured to the outer side of Wheelbarrow Bin 210 . Wheelbarrow Attachment 100 may also attach to any other part of a wheelbarrow, including the outer side of the back of Wheelbarrow Bin 210 , or the outer side of the front of Wheelbarrow Bin 210 , for example.
[0017] FIG. 3 is a front perspective view of a Wheelbarrow
[0018] Attachment according to another embodiment. In this example, Wheelbarrow Attachment 300 may comprise a rack with an Attachment Means 310 that comprises a clip. It may also include a Handle 320 at the top portion of the rack, which a user may pull upward to remove Wheelbarrow Attachment 300 from Wheelbarrow Bin 210 , and a Cross Bar 340 to support and distribute weight on the rack. In this embodiment, Holders 330 may be made of adjustable straps which may be made in any colors, shapes, sizes, and textures, and of any material such as nylon, polypropylene, polyester, webbing, mesh, cotton, spandex, rubber, silicone, plastic, rope, or cable, for example. Holders 330 may also be comprised of any other holding means including, but not limited to clips, spring-loaded clips, hook and loop fasteners such as Velcro, adhesives, magnets, S-hooks, snap hooks, bolt plates, anchor plates, j-hooks, flat hooks, ratchet fasteners, over-center fasteners, slide buckles, snap buckles, and containers, for example. | The instant application discloses, among other things, a wheelbarrow attachment. In one embodiment, a wheelbarrow attachment may attach to any part of a wheelbarrow. A wheelbarrow attachment may include a plurality of holders designed to secure various items, such as gardening, construction, or farming tools. | 1 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/710,704 filed Oct. 6, 2012, which is incorporated herein by reference in its entirety as if fully set forth herein.
FIELD OF THE INVENTION
[0002] The invention involves concentrating autologously-derived plasma, using the concentrated plasma fluid to dilute the patient's cells and applying the combination of concentrated fluid with cells at a site of pathology.
BACKGROUND OF THE INVENTION
[0003] Plasma protein concentrate (PPC) was investigated as a potential improvement for cell delivery in regenerative therapies. Blood plasma contains useful proteins for cell adhesion/retention including fibrinogen, fibronectin, and vitronectin. It is hypothesized that enriching these proteins' concentrations will enhance cell retention on biological substrates or at tissues injected with autologous cells. A second potential benefit of PPC is improved clotting. It has been clinically observed that bone marrow aspirate and bone marrow concentrate from a percentage of patients does not sufficiently clot when combined with a coagulation agent. PPC may increase fibrinogen and prothrombin concentrations to or above normal levels in deficient patients. For normal patients, increased fibrinogen and prothrombin is believed to result in more robust clots to minimize lost cells and fluid. PPC also contains growth factors, including platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF), which nourish cell functions at a higher concentration that normal plasma.
[0004] Plasma derived from blood or bone marrow contains many proteins with specific functions. Table 1 describes the most prevalent proteins found in plasma. Fibrinogen, fibronectin, vitronectin, and prothrombin are associated with natural wound repair mechanisms. Plasma also contains buffering and immune system proteins to maintain homeostasis of the circulating blood. Many growth factors (PDGF, VEGF, TGF-beta, and FGF) are responsible for cell recruitment and proliferation.
[0000]
TABLE 1
Normal
Plasma
Concen-
Molecular
tration
Regenerative
Weight
Protein
(mg/mL)
Function
Application
(kDa)
Total
65-80
Fibrinogen
2.0-4.5
Clotting
Faster clotting
340
time, stronger
“bone logs”
Fibronectin
0.3
Cell
Enhanced cell
440
migration/
retention;
adhesion,
Faster healing
Wound closure
time
Vitronectin
0.2
Cell adhesion
Enhanced cell
75
retention
Prothrombin
0.05-0.1
Clotting
Clotting rate
72
control
Albumin
35-50
Hormone
Buffer acidity
67
transport,
from carrier
pH Buffer
breakdown
Immuno-
10-15
Immune
150 (IgG)-
globulins
recognition
900 (IgM)
VEGF
0.0008
Angiogenesis,
Faster blood
40
Endothelial
vessel growth
cell migration
into graft site
PDGF
0.003
Cell growth,
Stem cell
31
angiogenesis
replication,
faster blood
vessel growth
TGF-β1
0.01
Cell growth/
Stem cell
25
differentia-
replication,
tion
faster tissue
regeneration
FGF
0.0001
Cell growth,
Stem cell
20
angiogenesis,
replication,
Wound healing
faster blood
vessel growth
SDF-1
0.0009
Cell
Endogenous
8
recruitment/
cell
migration
recruitment
RANTES
0.002
Cell recruit-
Endogenous
8
ment to
cell
inflammation
recruitment
site
[0005] Clotting is a natural mechanism for wound closure and repair. Briefly, biomolecules signaling tissue damage are released by cells and platelets after injury. These molecules react with calcium to transform several clotting factors, culminating in the conversion of prothrombin to thrombin. Active thrombin cleaves portions of fibrinogen to form fibrin molecules, which are polymerized to form a fibrin clot. After clotting or coagulation, the wound undergoes stages of inflammation (restricted blood flow, recruitment of macrophages to remove foreign bodies and debris), proliferation (generation of new blood vessels, proliferation of cells, creation of new tissue, and contraction of the wound), and remodeling (cells convert fibrous tissue to a more mature and functional tissue).
SUMMARY OF THE INVENTION
[0006] There is a problem with the delivery of regenerative cells and the environment in which they are applied, injected, sprayed or otherwise presented to a patient. Without taking special precautions, autologous regenerative cells might not remain at the site of application or treatment, thereby reducing their therapeutic potential. Standard approaches for retaining regenerative cells include allowing a cell preparation to soak into a bone void filler, usually in the form of granules (also can be used with block-shaped bone void fillers), but bone void fillers are not appropriate for all indications, especially those involving soft tissue pathologies. Another approach is to inject the cell preparation directly into a tissue pathology, e.g., into the capsular space of a joint like the knee, but there is no way to ensure that the cells will be retained on the articular surfaces. The invention addresses the need to improve delivery of cells for all kinds of pathologies, including bony and soft tissue pathologies. The invention involves concentrating autologously-derived plasma (from whole blood, bone marrow, etc.), using the concentrated plasma fluid to dilute the patient's cells and injecting or otherwise applying the combination of concentrated fluid with cells at a site of pathology. Alternatively, the concentrated fluid can be applied prior to the treatment with the patient's own cells, which will serve to coat the affected surfaces with proteins from the concentrated fluid, thereby improving the adherence of the cell preparation to the coated surfaces. There is a specific need to improve the retention by bone void fillers of autologous cells in order to improve the transfer of the cells into spinal fusion treatment sites in a patient. The invention specifically enhances cell retention of bone void fillers due to the formation of a clot within the particles of the bone void filler when placed into contact with the cell preparation and thrombin/CaCl 2 . Improved clotting also will play a role in other pathologies, including the treatment of burns and topical wounds, in general, due to the formation of a clot containing cells and concentrated proteins and growth factors that coats the wound or burn site.
[0007] PPC may be used to “coat” biological substrates or carriers prior to the addition of cells in order to increase cell adhesion to those materials. It may also be used to “pre-coat” a tissue to be injected with cells for the same reason. In many instances, PPC may be co-delivered with cells. The PPC or PPC+cells also may be combined with a coagulation agent, such as thrombin or calcium chloride, to form a clot in situ or at the site of deposition. Delivery could be achieved through a syringe for applications such as disc or joint injections. Delivery could be achieved by spraying the solutions onto a surface for applications such as the treatment of skin burns. Increased cell retention and function is beneficial with most cell therapies including skeletal fractures, spinal fusion, intervertebral disc injections, joint injections, plantar fasciitis, torn cartilage, ligaments or tendons, wounds, burns, or ulcers of the skin, surgical closure of soft tissues, or internal organs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 shows the fibrinogen deposition on tricalcium phosphate granules as measured by ELISA assay; and
[0009] FIGS. 2A and 2B show bone logs prepared with PPP that maintain their shape; and
[0010] FIG. 3 shows the cell retention by granular bone void fillers under several conditions.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0011] In the broadest sense, the invention relates to the use of concentrated plasma (plasma protein concentrate, or PPC) as a diluent for suspending cells, and/or to coat tissue surfaces prior to cell application. More specifically, the invention relates to the concentration of autologous plasma (platelet-rich plasma or platelet-poor plasma) derived from peripheral blood or bone marrow aspirate and, subsequently, combining the concentrated autologous fluid preparation with autologous regenerative cells. PPC may be prepared from a patient's plasma by several methods including filtration, ultracentrifugation, cold precipitation, or lyophilization. The autologous regenerative cells may be derived from bone, bone marrow, adipose, dermis, or any combination thereof. Regenerative cells include mesenchymal stem cells, hematopoietic stem cells, stromal cells, pericytes, and endothelial progenitor cells, among others. PPC is enriched in plasma proteins including, but not limited to, fibrinogen, fibronectin, and vitronectin; and growth factors including, but not limited to, platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF). Use of an enriched autologous plasma-derived fluid may promote greater cell retention or adhesion, cell proliferation, cell migration for co-delivered cells, as well as chemotaxis and angiogenesis by local endogenous tissues, among other beneficial effects. Once the cells are combined with PPC, they may be delivered to a degenerated, injured, or diseased tissue for the purpose of tissue regeneration and/or modulation of inflammatory factors. Examples of these tissues include, among others, pathologies in bone voids, bone fractures, spinal fusions, intervertebral discs (restoration of disc height and rehydration), cartilage, ligaments, tendons, dermis, epidermis, skeletal muscle, cardiac muscle, lungs, liver, pancreas, kidneys, bladder. The invention may also be used to treat arthritis in cases where the tissue is not necessarily degenerated, injured, or diseased. The PPC may be applied to the pathologic sites in conjunction with and/or prior to treatment with autologous, regenerative cells. PPC may be applied in several ways, including injection through a needle, spraying onto a surface, or soaking onto a wound dressing or biomaterial. The PPC may be combined with a coagulant to form a fibrin matrix for increased cell retention. Examples of coagulants are thrombin (autologous, recombinant human, bovine, or porcine; concentration range 500-5000 units/mL, preferably 1000 units/mL) and a divalent cationic salt such as calcium chloride or calcium carbonate (concentration range 10-80 mM, preferably 20 mM).
[0012] PPC is prepared in several methods from platelet-poor plasma (PPP) derived from bone marrow aspirate. These methods included filtration through porous hollow microfibers (with and without a priming step) and ultrafiltration with centrifugation. The fibrinogen concentration was measured before concentration (PPP) and after concentration (PPC) in a hollow microfiber device.
[0013] The analysis also revealed substantial variability in plasma fibrinogen concentration from patient to patient. 20 unique plasma samples were analyzed from peripheral blood and bone marrow aspirate. Fibrinogen concentration ranged from 0.9 to 6.0 mg/mL with a standard deviation of 1.6. This wide variation could be responsible for insufficient clotting occasionally observed in the clinical setting. In the PPC, fibrinogen concentrations ranged from 8.0 to 13.4 mg/mL, indicating that even the most fibrinogen-deficient PPP sample had been enriched above the highest unconcentrated level.
[0014] Next, the deposition of fibrinogen was examined as a model plasma protein, onto the surface of a tricalcium phosphate substrate (CymbiCyte, Celling Biosciences, Austin, Tex.). Briefly, 1 mL of substrate was coated with 1 mL of PPP or PPC for 10 minutes at 4° C. After incubation, the PPP or PPC was removed and the granules were washed with 1 mL saline to remove unbound proteins from the substrate. Fibrinogen deposition was measured for three PPP and PPC samples and the results are provided in FIG. 1 . PPC deposited approximately three times as much fibrinogen onto the substrate than PPP. This increased protein deposition is hypothesized to promote higher cell adhesion and retention onto coated substrates and tissues.
[0015] Next, PPP or PPC was mixed with CymbiCyte in vitro and combined with coagulation agents (thrombin (bovine, 1000 units/mL) and calcium chloride (20 mM)) in situ in plastic molds. After 60 seconds, the formed “bone logs” were removed from the mold to evaluate sturdiness, handling properties, and unretained fluid. A representation of the bone logs are illustrated in FIGS. 2A and 2B .
[0016] The interaction of PPC, bone void fillers (CymbiCyte and cancellous bone chips) and cultured cells was assessed. Cells were combined with the bone void fillers in the absence of PPC, after a PPP coating period, after a PPC coating period and finally with the cells mixed with the PPC before being combined with the bone void fillers. Retention of cells by the bone void fillers was highest for the PPC+Cell premixture, followed by PPC coating, PPP coating and with no coating having the lowest retention level. The cell retention values for the conditions are shown in FIG. 3 .
[0017] PPC-Cell co-injection was demonstrated using PPC derived from peripheral blood plasma. Briefly, 2 mL of PPP or PPC was loaded into a 10 mL syringe. In a separate 1 mL syringe, 0.2 mL thrombin and calcium chloride mixture was drawn. The syringes were joined by a Y-connector and expelled through needles for joint (approximately 4 cm) or disc (approximately 10 cm) injections. Within approximately 30 seconds after injection, all PPC samples had formed a stable gel, while some PPP gels took 60 to 90 seconds to stabilize. Final gels of PPC were more firm, opaque, and lost less fluid than PPP gels. It is hypothesized that this will result in greater cell retention at the injection site using PPC compared to unconcentrated plasma, blood, or bone marrow.
WORKING EXAMPLES
[0018] The below examples show the use of PPC with regenerative cells.
Example 1
Protein and Growth Factor Enrichment
[0019] Plasma proteins and growth factors may be enriched for increased dose when co-injected with cells. PPC was prepared by concentrated 30 mL PPP to 5 mL using hollow fiber tangential flow filters of two pore sizes. Protein and growth factor concentrations were measured by enzyme-linked immunosorbent assay (ELISA). The percentage of enrichment of beneficial plasma proteins above baseline (PPP) values using the two filters is listed in Table 2. Due to the smaller pore size of the 30 kDa unit, more proteins and growth factors were retained in the PPC compared to that prepared using the 60 kDa filter. Platelet-derived growth factor-AB/BB (PDGF-AB/BB), Transforming growth factor-beta 1 (TGF-b1), and Basic fibroblast growth factor (FGF-2) have been widely demonstrated in the literature to promote cell proliferation, migration, and differentiation that may be beneficial to the therapeutic effect when PPC is co-injected with regenerative cells.
[0020] Table 2 shows the percent increase in protein concentration of PPC prepared by 30 kDa and 60 kDa hollow fiber tangential flow filters compared to original PPP.
[0000]
TABLE 2
30 kDa Pore Size
65 kDa Pore Size
Fibrinogen
254%
172%
PDGF-AB/BB
447%
180%
TGF-b1
420%
260%
FGF-2
130%
128%
Example 2
Fibrinogen Coating of Biomaterial Substrates and Cell Retention
[0021] Coating biological substrates with adhesion proteins (fibrinogen, fibronectin, vitronectin) from plasma has advantages for cell adhesion/retention, providing molecular targets for cell binding. Five unique PPP and corresponding PPC samples (1 mL) each were used to coat 1 gram of a 60:40 hydroxyapatite-tricalcium phosphate (HA-TCP) granular substrate. Fibrinogen deposition onto the tricalcium phosphate granules was measured by ELISA assay (results shown in FIG. 1 ). On average, at least 3 times the mass of fibrinogen was deposited onto the biomaterial from an equal volume of PPC compared to PPP from the same donor blood sample.
[0022] The benefit of pre-coating or co-delivering cells with PPC was demonstrated by observing cell retention on common orthopedic bone graft substrates in vitro. Cancellous bone chips or tricalcium phosphate granules (0.5 mL each) were untreated or pre-coated with 0.5 mL PPP or PPC for 15 minutes. After coating, the PPP or PPC was drained from the substrates and a solution of 700,000 bone marrow mesenchymal cells in 1 mL of buffered medium was applied. A fourth experimental group consisted of co-delivering the cell solution with an equal volume to PPC to uncoated bone chips or tricalcium phosphate granules. Each variable was tested in triplicate (n=3). After a 15 minute adhesion period, the cell solution was removed from each sample and the cells were counted. The average number retained cells and standard error are reported in Table 3. There is a statistically significant increase in retained cells on both types of substrates by using PPC as a coating or co-delivery agent compared to uncoated or PPP-coated materials.
[0000]
TABLE 3
Tricalcium Phosphate
Cancellous Bone Chips
Granules
Number of Cells
Fold
Number of Cells
Fold
Condition
Retained
Increase
Retained
Increase
No Coating
2.37
1.0
2.70
1.0
(±0.56) × 10 4
(±0.65) × 10 4
PPP
4.27
1.80
4.73
1.75
Pre-coating
(±0.30) × 10 4
(±0.24) × 10 4
PPC
6.95
2.94
7.52
2.78
Pre-coating
(±0.44) × 10 4
(±0.93) × 10 4
PPC
8.43
3.56
8.30
3.07
Co-Delivery
(±0.10) × 10 4
(±0.16) × 10 4
Example 3
Clot Stability
[0023] BMC, PRP, or PPP activated with 10% calcium chloride and/or thrombin forms a clot that is usually unstable and without mechanical strength sufficient to resist deformation under stress. Sample of PPP and PPC from matching donors were activated with 10% calcium chloride and thrombin by mixing through a dual syringe and “Y” connector to form 1 cc spherical clots. Clots formed from PRP were partially transparent and released approximately 20% of their fluid volume under mild compression. Conversely, clots formed from PPC were opaque (indicating a denser network of proteins) and lost no more than 5% of their fluid volume under mild compression. The loss of fluid is analogous to a loss of regenerative cells in vivo after injection.
Example 4
Injection of Autologous PPC and Regenerative Cells for Osteoarthritis Treatment And Articular Cartilage and Meniscus Repair
[0024] To increase cell retention at the site of injection by means of increased protein content, autologous regenerative cells were prepared at the point-of-care and mixed with autologous PPC for percutaneous injection into arthritic or damaged tissues. In one instance, 5 mL bone marrow concentrate (BMC) prepared from 60 mL bone marrow aspirate (BMA) and 5 mL PPC prepared from 30 mL PPP were co-injected into arthritic knee and hip joints for the cumulative and synergistic benefits of BMC, platelets, and plasma proteins and growth factors. In a different application, articular cartilage damage and osteoarthritis of the knee was treated with a combination of mononuclear cells harvested from the patient's bone marrow (4 mL) and stromal vascular fraction of adipose (4 mL) were injected bilaterally into the knee capsule after injection of PPC (6 mL) to wash the joint and coat the cartilage surfaces with proteins. For treatment of partially torn meniscus, 5 mL autologous BMC was mixed with 5 mL PPC and activated with 1 mL 10% calcium chloride and thrombin prior to arthroscopic injection into the damaged site. In each of these cases, surgeons indicated improved patient outcomes compared to the conventional standard of care for the respective orthopedic applications.
Example 5
PPC as a Carrier for Cellular Injection Therapy for Degenerative Disc Disease
[0025] Degenerative disc disease describes pain associated with damaged, dehydrated/desiccated, herniated, or depressed intervertebral discs. Current treatment options include rest, steroid or anti-inflammatory injections, discectomy, and/or spinal fusion surgery. In the case of tears or herniation, fluid from the nucleus pulposus may escape the disc and contact a nerve or the spinal cord, resulting in severe back pain. In a pilot study, 3 mL autologous BMC and PPC was prepared from 60 mL BMA and injected into degenerated lumbar intervertebral discs of patients were fusion surgery candidates. Intervertebral disc injection with BMC resulted in an average reduction of pain scores of 57% (ODI) and 65% (VAS) at 3 months post-therapy, 58% (ODI) and 72% (VAS) at 6 months, and 62% (ODI) and 63% (VAS) at 12 months compared to pre-injection pain scores. PPC provided growth factors for cell proliferation and bioactivity and aided in the repair of annular tears.
Example 6
Spinal Fusion Graft Preparation
[0026] In spinal fusion surgeries, graft materials are implanted to regenerate bone to fuse adjacent vertebral bodies. For many biomaterial substrates, their physical properties are not sufficient to form moldable grafts for interbody or posterolateral fusion. Many ortho-biologic graft materials do not possess favorable surface characteristics for cell adhesion/retention, growth, and differentiation. Surgeons often form grafts as “bone logs” using particles or granules glued together by soaking the materials in and clotting the patient's PRP or bone marrow. Because approximately 1 in 8 patients are deficient in clotting proteins, it is not always possible to form these types of grafts. Two popular graft materials (cancellous bone chips and tricalcium phosphate granules) were formed into bone logs using PRP and PPC in an in vitro setting. In the PRP-soaked bone logs, 7 of 12 grafts maintained their shape after two minutes. Bone logs prepared with PPP maintained their shape after two minutes in 11 of 12 grafts ( FIG. 2 ). In posterolateral spinal fusion surgery, grafts were prepared with tricalcium phosphate and hydroxyapatite granules (10 mL) and PPC (5 mL) derived from the patients BMA. After activation with 1 mL 10% calcium chloride and thrombin, sturdy bone logs were formed and implanted for successful spinal fusion.
[0027] FIG. 2A shows bone grafts that are formed with cancellous bone chips or tricalcium phosphate granules and PPC. FIG. 2B shows that PPC-based bone grafts hold together and retain their shape. PPC bone grafts are more robust than grafts formed with PRP and retain their shape under stress with greater frequency than PRP-based grafts.
Example 7
Rotator Cuff Surgery
[0028] Rotator cuff injuries include tears and detachments of muscles and ligaments in the shoulder joint. Many surgeons wish to augment the standard clinical treatment methods with regenerative cells but lack an appropriate carrier to delivery the cells. In one instance, a partially torn rotator cuff may be treated by percutaneous injection of cells mixed with PPC and activated by a clotting agent such as calcium chloride and/or thrombin. Upon injection, the PPC acts as a biologic glue to bridge the tear and retain the cells. In another instance, rotator cuff repair surgery may utilize regenerative cells by gluing the cells at the tendon insertion site after surgically fixing the tendon to the bone by anchor, screw, suture, or another implant. | The invention is directed to concentrating autologously-derived plasma, using the concentrated plasma fluid to dilute the patient's cells and applying the combination of concentrated fluid with cells at a site of pathology or mixing the combination of concentrated fluid with cells with a particulate material like a bone void filler prior to placing the mixture at a site of pathology. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to the fields of data networks and communication systems; more specifically, to mobile communication service providers that deploy push-to-talk applications for subscribers.
BACKGROUND OF THE INVENTION
[0002] Push-to-talk (PTT) is a two-way communication service that works like a walkie-talkie. A normal cell phone call is full-duplex, meaning both parties can hear each other at the same time. PTT is half-duplex, meaning communication can only travel in one direction at any given moment. A token-based model of operation, in which a person must be first granted access to the floor by a floor control mechanism before he may speak to other session participants, typically governs most PTT sessions. For instance, a PTT-enabled handset typically requires that a caller press and hold a button while talking, and then release the button when they are done. Any listener may then press their button in a similar manner to request access to the floor in order to respond.
[0003] PTT applications have been utilized in the radio and microwave communication industries for many years. A variety of different applications are ubiquitous today. For example, dispatch services such as police and fire departments, paramedic units, and security teams routinely use PTT applications for field communications. More recently, mobile service providers have begun to provide enhanced PTT services based on Internet Protocol (IP) based solutions. For instance, push-to-talk over cellular (PoC) applications are actively being pursued by mobile service providers in the Open Mobile Alliance (OMA) standards body for use in chatting with families, buddies and in certain business applications, such as dispatch services, security services and various government agencies (e.g., fire, ambulance, police, FEMA, etc.). The OMA PoC approach is based on the session initiation protocol (SIP), a widely-used signalling protocol for voice over IP (VoIP) communications in which transfer of packets is done using the real-time transport protocol (RTP). RTP is a known protocol for transmitting real-time data such as audio or video streams. The RTP control protocol (RTCP) is an associated protocol useful for maintaining RTP session quality. The talk burst control protocol (TBCP) is a known protocol that uses extension features of RTCP to invoke floor control within a PoC environment.
[0004] By way of further background, a system and method for controlling the transmission of talk bursts using a talk burst control protocol is described in U.S. Patent Publication No. 2006/0034336. A system for providing media services in voice over IP (VoIP) telephony in which audio is transmitted in packet streams such as RTP/RTCP packets is disclosed in U.S. Pat. No. 6,947,417. U.S. Pat. No. 6,044,081 teaches a communications system and multimedia system that allows private network signaling to be routed over a packet network.
[0005] One of the problems with providing enhanced PTT services is that many legacy communication systems that accommodate PTT based radio communication devices are often incompatible with each other. This can make it difficult to integrate different PTT services in situations where endpoint communication devices must share the same logical floor and arbitrate across different applications. Many times, with disparate applications there arises a need to provide different floor control characteristics applicable to these different application scenarios.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The present invention will be understood more fully from the detailed description that follows and from the accompanying drawings, which however, should not be taken to limit the invention to the specific embodiments shown, but are for explanation and understanding only.
[0007] FIG. 1 is a high-level conceptual diagram of a PTT system architecture in accordance with one embodiment of the present invention.
[0008] FIG. 2 is a PTT system architecture diagram in accordance with another embodiment of the present invention.
[0009] FIG. 3 is a flowchart diagram that illustrates a method of operation according to one embodiment of the present invention.
[0010] FIG. 4 illustrates a user interface window associated with an application running on a PC of a user in accordance with one embodiment of the present invention.
[0011] FIG. 5 is a meta language code listing of an exemplary template in accordance with one embodiment of the present invention.
[0012] FIG. 6 illustrates a display window of a telephone device with a user interface that may be utilized to select a particular floor control template in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION
[0013] A framework for enhanced floor control in a PTT conference session is described. In the following description specific details are set forth, such as device types, system configurations, protocols, methods, etc., in order to provide a thorough understanding of the present invention. However, persons having ordinary skill in the relevant arts will appreciate that these specific details may not be needed to practice the present invention.
[0014] According to one embodiment of the present invention, a mechanism defines several different templates or algorithms for floor control for various types of PTT applications. The initiator or moderator/administrator of the PTT group session may apply any of the available templates to the current session. Different groups can have different templates applied. Each floor control template corresponds to a different floor control algorithm (thus, the terms “template” and “algorithm” are used interchangeably in context of the present application). When a group session is initiated, a first (i.e., default) floor control algorithm or template in the form of executable code is loaded and applied (i.e., the code is executed) on the PTT server(s) responsible for handling floor control for the PTT session. For example, the template code may be downloaded via a network connection, or, alternatively, fetched from a memory associated with the PTT server(s). Each template, as well as the computer-executable routine used for selecting a new floor control template, may also be embodied in a variety of different forms, e.g., software, hardware, firmware, computer program products, etc.
[0015] The initial floor control algorithm continues to apply to the PTT session until the template is switched or changed. That is, a participant, session moderator or an administrator with an appropriate privilege grant can dynamically change the template during the course of the session. Various privilege levels governing who may change the floor control template may be assigned based on the particular application. For example, in an emergency response situation application, the privilege to change the current template and apply a new floor control algorithm may only be granted to unit commanders (i.e., a police chief, a fire chief, etc.).
[0016] As will be described in more detail below, in a specific implementation, a user interface may be employed by a user/moderator/administrator to select a new floor control to be applied to the current PTT session. A graphical user interface (GUI), a telephony user interface (TUI), or a voice user interface (VUI) may be used. For example, a user may utilize an interactive voice response (IVR) system associated with the PTT server, wherein the user may press a special key code, e.g., “#9”, in order to invoke a menu that allows the user to select one of a number of different floor control algorithms or templates to be applied to the current PTT session. In the case where the user is communicating via an IP phone, a special “floor control template” softkey button may display a selection menu and instantiate one or more softkey buttons allowing the user to make his selection from the menu listing. An exemplary user interface in accordance with this later embodiment is described in more detail below in connection with FIG. 6 .
[0017] In yet another embodiment, a user/moderator can use a web-based or native graphical user interface (GUI) running on a personal computer (PC) to selectively change the floor control template applied to the current PTT session. The GUI may be generated by software (i.e., code) running the user's PC. In other cases, the GUI may comprise a collaborative web-based application that is accessed by the browser software running on the user's PC. In other instances, the GUI may comprise a downloaded application, or other forms of computer-executable code that may be loaded or accessed by a user's PC.
[0018] By way of example, the GUI may list the entire set of available templates, optionally including a detailed text description of the operational features offered by each template and situational examples where application of the template is most useful. When the user selects a particular floor control template for the session, the GUI outputs a signal via an external interface of the PC to the PTT server that causes the server to immediately change the floor control algorithm is use. In other words, in response to the selection of the user/moderator, the PTT server changes the way it arbitrates requests from users to talk and/or the conditions associated with the talk bursts of each participant. PTT.
[0019] Practitioners will appreciate that the present invention is not limited to any specific types of floor control algorithms or to any particular set of templates. In other words, the various types of algorithms used to control the PTT floor described below is not intended to be exclusive or exhaustive of the different types of control algorithms that may be employed. Rather, the framework and overlaying mechanism for selecting a particular template is largely independent of the particular floor control templates used to populate the list from which the user makes his selection.
[0020] In accordance with one embodiment of the present invention, when a new floor control template has been selected and applied to the current PTT session, the PTT server may notify each of the participants of the change via a brief audio tone (e.g., two short “beep” tones) or a pre-recorded message sent to their communication device. In the latter case, for example, the server may play a message (e.g., “Priority-based floor control is now in use” or “Buffered talk bursts are now in use”) that provides adequate notification of the change in floor control to all persons participating in the PTT session. Depending on the capabilities of the particular endpoint devices being used, various participants may also be notified via other media channels (e.g., text messaging, or some combination of text and audio messaging).
[0021] It is appreciated that the media path for the session participants may include audio (voice) transmissions across a variety of different networks (e.g., Internet, intranet, PSTN, radio or microwave frequency communication networks, etc.), different protocols (e.g., IP, Asynchronous Transfer Mode (ATM), Point-to-Point Protocol (PPP)), with connections that span across multiple services, systems, and devices (e.g., handsets, cellphones, IP phones, softphones, emergency response communication systems, etc.). Alternative embodiments of the present invention may be implemented in PBX, telephony, telephone, and other telecommunications systems.
[0022] FIG. 1 is an architectural diagram of a system 10 in accordance with one embodiment of the present invention which includes a PTT server 12 that manages or controls a logical “floor” 13 wherein one of a plurality of participants 16 is permitted to speak at a time via corresponding endpoint devices 16 . PTT server 12 and floor 13 are grouped together as a logical entity shown by dashed line 11 . When a participant wishes to speak during the session he transmits, via his corresponding endpoint device 16 , a talk burst request message to server 12 . PTT server 12 may utilize the TBCP or some other protocol to arbitrate control of floor 13 amongst all of the participants 16 in accordance with a particular floor control algorithm. Practitioners in the arts will understand that PTT server 12 may be implemented by hardware, firmware, or software component elements that implement the various functions described herein.
[0023] A number of different floor control algorithms or templates may be designed for use in accordance with the present invention. For example, in a “Priority-based” floor control template different subscribers or participants are assigned to different weights or priority values. Participants having higher weights assigned to the name, i.e., a higher priority, therefore have a better chance to capturing the floor in an arbitration contest with another participant having a lower priority weight. By way of example, in an emergency response or natural disaster situation, a Police Chief for Fire Chief may be granted the highest priority such that he will gain access to the floor every time he wants to communicate instructions to his subordinates via the PTT group session.
[0024] Another template that may be used in accordance with the present invention is a “Barge-In” floor control algorithm. Here, the idea is to grant a specially designated person(s) permission to barge-in and capture the floor from someone else anytime they want or need to speak to the group. Typically, 911 operators, command center operators/dispatchers, and the like, are persons that might appropriately be conferred with barge-in privileges. Once the barge-in floor control template is applied—either as a general policy or as an overlapping policy on top of another floor control algorithm—any participant that has been granted barge-in privileges is free to take over the floor from anyone who already has the floor and who may be in the middle of speaking.
[0025] A “Groups-based” relative priority floor control template can be used where there are different groups of people participating. Each group can be assigned different priority levels. Groups can also be divided into sub-groups, with each of the subgroups being assigned sub-priorities. For example, as among different groups such as fire-fighters policemen, paramedics, and emergency management administrative personnel, it may be desirable to give the highest priority to the people in the field closest to the unfolding emergency situation. Thus, for example, in certain emergency or disaster scenarios it may be desirable to define the fire-fighter group as having a higher priority relative to other groups.
[0026] Yet another template that may be used in accordance with the present invention is a “Distributed” floor control template or algorithm. FIG. 2 illustrates a PTT system 20 with a distributed, hierarchical architecture in accordance with one embodiment of the present invention. Distributed PTT servers 21 , 23 , 25 , and 27 are each connected to a central PTT server 30 . In the example of FIG. 2 , PTT server 21 is also shown connected with a group of participants 22 ; PTT server 23 is shown connected with a group of participants 24 ; PTT server 25 is connected with a group of participants 26 ; and PTT server 27 is connected with a group of participants 28 .
[0027] In the architecture of FIG. 2 , applying the distributed floor control template to PTT server 30 has the effect of distributing the floor control to each of servers 21 , 23 , 25 , and 27 . In other words, instead of having server 30 arbitrate requests from all of the groups of participants 22 , 24 , 26 , and 28 , the distributed floor control template distributes most of the arbitration among the participants so that it is done locally, i.e., before it reaches central PTT server 30 , which then arbitrates the final winner. In this sense, the distributed floor control template is more of an overlay template since server 30 still arbitrates to grant the floor (according to some selected or predetermined algorithm) as among the local arbitration winners.
[0028] Persons of skill in the arts will appreciate that the distributed floor control template provides scalability and speed for large PTT groups. It also provides significant savings in bandwidth, since most of the arbitration is performed locally, rather than at central PTT server 30 .
[0029] In a specific implementation, a GUI/TUI may be defined to enable different floor control templates for different groups. In other words, instead of applying a floor control template on a per session basis, the template can be applied on a per group basis, with the algorithm controlling a particular group being independent from that utilized to manage/control floor behavior in another group.
[0030] For instance, each group can be access a floor control GUI from a secure web page so that templates may be applied to that group (associated server). Alternately, a TUI can be defined to apply the different templates. For example, the TUI may connect to an interactive voice response (IVR) system server to provide various configuration parameters for changing the floor behavior. The user may be prompted by the IVR with a menu listing of different template options and respond accordingly (e.g., “Press or say ‘1’ to select the priority-based, template; press or say ‘2’ to select the barge-in template”, and so on.). In cases where intelligent endpoint devices are used, the template can be managed directly from the endpoint device via a GUI rather than from a TUI.
[0031] Another template that can be selected and applied in accordance with the present invention is the “Buffered Talk Burst” floor control template, which basically allows an open floor. And that is, anyone is free to speak at any time. All requests are time-stamped, buffered and played out in the order that they were generated.
[0032] Still another template that can be selected and applied in accordance with the present invention is the “Round Robin Talk Burst” allocation template. In this algorithm, the floor is granted to each participant for a predetermined time burst (e.g., 5-10 seconds) in a round-robin fashion. This is typically useful for polling or introduction type situations.
[0033] A “Variable-sized Talk Burst” floor control template can be selected by a user for application in situations where it is necessary or desired to assign different individuals with different talk burst times. For instance, at times it may be important to assign a substantially longer talk burst time to a particular individual relative to other participants or subscribers to the PTT group session. For example, a person who possesses certain expert knowledge in a particular area or subject matter may be assigned a substantially longer talk burst time (e.g., 30 seconds) relative to others (e.g., 5 seconds) in order to explain something of significance to the group when he is called upon to speak or offer his expert knowledge.
[0034] Yet another example of a floor control template that may be selected by a user and applied to a PTT group session in accordance with one embodiment of the present invention is a “Weighted-Fair Queue” template. In this algorithm, floor requests that lose out (i.e., requests that are denied as part of the arbitration process, thereby resulting in the participant being unable to speak) are placed in a weighted-fair queue based on the relative priority of the losing participant (or some other weight) of each request. When the floor once again becomes available, a floor grant indication can be sent to the participant who is currently occupying the top (i.e., highest priority) position in the queue.
[0035] FIG. 3 is a flowchart diagram that illustrates a basic method of operation according to one embodiment of the present invention. The process begins with the PTT group session being initiated by a user, e.g., a moderator or administrator (block 31 ). At the time that the PTT group session is initiated, a default and floor control algorithm or template may be loaded and applied to the appropriate PTT server(s). Alternately, the user (or moderator/administrator) who initiated the PTT session may invoke a user interface (e.g., GUI or TUI) to select an initial floor control algorithm for the PTT session (block 32 ). Once the user has made his selection, the template is either downloaded or retrieved from memory and then applied to the PTT server performing the floor control function for the PTT group session (block 33 ). At any point during the PTT session in the user may change the current for control template in use via the GUI or TUI (block 34 ).
[0036] Note that in the embodiment of FIG. 3 , there is no limitation as to the number of times that the user can change the template being applied to control the floor in the PTT session. Furthermore, in certain embodiments, more than one template may be applied at a given time to control arbitration of requests made to the PTT server. For example, in a distributed architecture with a hierarchical arrangement of PTT servers, a user may select a distributed a floor control template in order to distribute most of the arbitration to the local servers, while utilizing another template for final arbitration at the central PTT server.
[0037] It should be further understood that, in certain embodiments, selection of the particular floor control template to be applied to the PTT server may be automated, based on policy rules, particular system configurations, or other considerations. For example, the system may be configured such that for a PTT session initiated by a person associated with a certain group (e.g., fire-fighters), a priority-based template is initially applied by default. Later, if during the session, persons from other groups join in and participate in the session, the system may automatically change the template to a “Groups-based” floor control template, or some other control algorithm. If a Fire Chief or Police Chief participates in the session, a “Barge-in” template may be overlaid onto the existing floor control algorithm. In other words, changing of the templates may be automated in accordance with the changing dynamics and conditions of the PTT session as monitored and determined by the PTT server. An optional override privilege may be granted to certain users or to the session moderator/administrator to override the automatic template selection and/or disable the automatic template selection mechanism.
[0038] FIG. 4 is an example that illustrates a graphical user interface (GUI) 41 associated with an application running on a PC of a moderator or participant in accordance with one embodiment of the present invention. As can be seen, GUI 41 includes respective display windows 42 and 43 that list the available floor control algorithms may be selected from and the floor control. In this example, window 42 lists seven different floor control templates that may be applied to a PTT group session (i.e., Priority-based, Barge-In, Groups-based, Distributed, Buffered Talk Bursts, Variable-Sized Talk Bursts, and Weighted-Fair Queue). The floor control algorithm currently in use (window 43 ) is the priority-based floor control algorithm. According to one implementation, when the user or moderator wants to change the floor control template he may do so by clicking (i.e., selecting) on one of the template names listed in window 42 and dragging/dropping it into window 43 . Alternatively, the moderator may “double-click” on the template name to select that template and have it applied at the PTT server. In this latter case, “double-clicking” on a selected template results in the user interface being immediately moving that template into window 43 , and moving the template name that was previously in window 43 back into the listing shown in window 42 .
[0039] FIG. 5 is a meta language code listing of one possible implementation of a priority-based floor control template in accordance with one embodiment of the present invention. The example shown in FIG. 5 is a simple Extensible Mark-Up Language (XML)-based listing that defines relative priorities of two individuals (i.e., Bob and Alice) who are designated as participants in the “Fire-fighters” group. Note that in this example, Bob is assigned a priority level “1”, having an associated talk burst time defined by the variable “x”. Similarly, Alice is assigned a priority level “2”, with an associated talk burst-time defined by the variable “y”. Practitioners in the art will appreciate that the listing in FIG. 5 can easily translate into corresponding bits in the TBCP protocol (e.g., TBCP floor request message: 32 bytes=SSRC; 8 bytes=priority; 32 bytes=talk burst-time).
[0040] FIG. 6 illustrates a display screen 60 of an IP phone (e.g., a VoIP phone) according to one embodiment of the present invention. Display screen 60 comprises a specialized user interface useful in displaying various floor control algorithms or templates that may be selected for use during the PTT session. The user interface shown in FIG. 6 may be generated by software (i.e., code) running on the user's phone. In this case, the IP phone may be equipped with a special “softkey” assignment button that can be used to invoke the floor control algorithm selection display screen shown. The icon for this softkey button can be instantiated once the user joins the PTT session (with appropriate moderator or administrator rights), or simply be located under a main conferencing menu on the telephone device. For example, to initiate display screen 60 , which provides the user with the ability to dynamically select a particular floor control algorithm or template, the user of the IP phone can simply the press the “Floor Control” softkey button on his IP phone, resulting in the display screen 60 being presented as shown in FIG. 6 .
[0041] Note that in the example of FIG. 6 , the cursor arrow 63 is currently shown positioned by the “Buffered Talk Bursts” floor control algorithm. The user has the option of moving cursor arrow 63 up or down by pressing scrolling buttons 61 or 62 , respectfully. A selection of a particular floor control algorithm or template may be made by pressing softkey 67 , which corresponds to icon 65 (“SELECT”) on display screen 60 . When the user is finished making his selection, he may exit the selection screen by pressing softkey button 66 , which corresponds to icon 64 (“EXIT”) on display screen 60 . Exiting the floor control algorithm selection display screen terminates the ability of the user to change the floor control algorithm currently in use via the user interface. The user, of course, may re-invoke the user interface at a later time during the session.
[0042] It should be understood that once a particular floor control algorithm or template has been selected, the user/moderator/administrator may change his selection as the conditions of the session change. For example, initially the person moderating a PTT session may select a “Round Robin Talk Burst” template that allows each participant to introduce himself to the other participants in attendance. Afterward, the “Buffered Talk Burst” floor control template may be selected, where any participant is free to request the floor and speak at any time. Later, if the dialogue deteriorates, e.g., due to a large number of participants trying to speak at once or if the discussions become unproductive, the moderator might appropriately select a “Priority-Based” or “Variable-Sized Talk Burst” floor control template. In other words, the user interface of FIG. 6 permits changes to the floor control algorithm on an ad hoc basis depending on current need and session communication dynamics.
[0043] It should be understood that elements of the present invention may also be provided as a computer program product which may include a machine-readable medium having stored thereon instructions which may be used to program a computer (e.g., a processor or other electronic device) to perform a sequence of operations. Alternatively, the operations may be performed by a combination of hardware and software. The machine-readable medium may include, but is not limited to, floppy diskettes, optical disks, CD-ROMs, and magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, magnet or optical cards, propagation media or other type of media/machine-readable medium suitable for storing electronic instructions. For example, elements of the present invention may be downloaded as a computer program product, wherein the program may be transferred from a remote computer or telephonic device to a requesting process by way of data signals embodied in a carrier wave or other propagation medium via a communication link (e.g., a modem or network connection).
[0044] Additionally, although the present invention has been described in conjunction with specific embodiments, numerous modifications and alterations are well within the scope of the present invention. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. | A processor-implemented method of operation for managing a push-to-talk (PTT) session involving a plurality of participants includes applying a first floor control algorithm at a PTT server. The first floor control algorithm being selected from a plurality of algorithms that arbitrate among talk requests received from the participants. The method further includes changing, during the PTT session, from the first floor control algorithm to a second floor control algorithm at the PPT server. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72( b ). | 7 |
BACKGROUND OF THE INVENTION
This invention relates to a new and improved apparatus for testing the non-conductance of rubber matting under the application of high voltage.
Where electrical repairs are made in areas that have good conductive substances such as steel or metal, it is necessary to provide a mat that is relatively thin and lightweight on which the repairman may stand. Such mat must be portable so that it can be rolled out for use in a prescribed area and thence rerolled and carried to the next location or packed conveniently for moving to the next location. It is necessary that such matting withstand high voltage. Heretofore, such matting would be manually unrolled and small sections of the matting would be tested for its resistance to the application of a high voltage. After one section or a portion of the roll is tested, the roll is manually manipulated such as to position a new section for testing. Such process is slow and tedious. Such matting is also very useful in areas such as ship decks where there are control panels and switch gears to provide proper insulation of power stations. The present invention provides means for automatically winding and unwinding the matting to expose a predetermined length of the matting to high voltage charge. After exposure to such charge, the matting is rolled up while another length of the matting is positioned for testing.
SUMMARY OF THE INVENTION
The present invention contemplates an apparatus for applying a high voltage charge in seriatim order to successive adjacent portions of an electrical non-conductive matting such as a rubber as it unwound from a supply roll to a take-up roll. Provisions are made to overlap the testing of the successive strips or portions of the matting to assure a testing of the full length of the matting.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side-elevational view of the mat testing apparatus.
FIG. 2 is a plan view of the mat testing apparatus.
FIG. 3 is an enlarged cross sectional view of the high voltage testing chamber taken on line 3--3 of FIG. 2.
FIG. 4 is an enlarged fragmentary view of the high voltage testing chamber taken on line 4--4 of FIG. 3.
FIG. 5 is an enlarged side elevational view of the mat tester taken on line 5--5 of FIG. 2.
FIG. 6 is a fragmentary end view of the mat tester on line 6--6 of FIG. 5.
DETAILED DESCRIPTION
Referring to the drawings, wherein like reference numerals designate like or corresponding parts throughout the several views, there is shown in FIG. 1 a plurality of vertical supports 10 supporting brackets 11 which in turn supports cross braces 12 and channel beams 13. Mounted on one of the cross braces 12 is a pair of spaced brackets 14 journaling for rotation a guide roller 15 over which matting 16 is guided. Side guide rollers 17--17 cooperate with the guide roller 15 to guide the matting as it passes from the supply roll 20 to the high voltage testing chamber to be described. Supply roll 20 is supported by a pair of spaced idler rollers 21-22 to facilitate the unwinding of the matting as it is advanced in a manner to be described.
Suitably mounted on channel beams 13 is a lower plate member 31 supporting transparent side windows 32,33 and transparent end windows 34-35 such as clear polycarbonate. The upper ends of windows 32,33 34 and 35 are supported by an upper plate member 36. Plate members 31 and 36 cooperate with windows 32 through 35 to define a high voltage testing chamber 37. Plate members 31 and 36 are held in spaced relationship by suitable plates (FIGS. 1, 3 and 4). Lower plate member 31 and upper plate member 36 are made of electrical non-conductive material. Lower plate member 31 supports an electrical conductive plate or lower electrode platen or plate 40 which is grounded as by conductive member 41. A plurality of pneumatic cylinders 42 have their cylinder ends suitably connected to the upper plate member 36. The respective piston rods 43 of cylinders 42 are connected to an upper platen or electrical conductive plate 44. A suitable electrical power source for supplying a high voltage is connected to upper electrode platen or plate 44 via conductor 45. A control switch 46 is operatively connected to an adjustable abutment 47 on piston rod 43 to facilitate the sensing and control of the platen's movement. An adjustable stop 48 is mounted on upper platen 44 in alignment with a stop 49, mounted on upper plate member 36.
Lower plate member 31 has an electrically conductive bracket 50 and 51 mounted on the respective forward and rearward edge end portions thereof. Each bracket 50 and 51 supports upwardly extending metallic bristles 52. The lower portions of the respective end windows 34 and 35 have brackets 55 and 56 which support downwardly extending metallic bristles 57 which form a brush. The respective brackets 50,51,55 and 56 are grounded to prevent any static charge from building up on the matting. A beveled plate 60 and 61 (FIG. 3) is suitably mounted at the forward and rearward end portions of the test chamber 37 adjacent to end windows 34 and 35 respectively to guide the matting as it enters and leaves the test chamber 37 for guidance to the clearance space provided between platens 40 and 44. The respective end windows 34 and 35 are suitably recessed to permit the passage of matting therethrough.
Suitably mounted on brackets 11 adjacent to the discharge end of high voltage testing chamber 37 is a pair of journals 65 and 66 which receive the shaft 67 journaling for rotation roller 68. Also mounted on brackets 11 at the rearwardmost end portion of the support frame are a pair of journals 70 and 71 supporting idler roller 72. Trained about rollers 68 and 72 is an endless belt 74 to facilitate the movement of the matting for windup.
Suitably mounted on the bottom framework of the apparatus described is a pneumatic cylinder 75, having its output piston rod connected to a gear rack 76 guided by guideways 77. Rack 76 meshes with a gear 78 suitably journaled on shaft 79 supported by the apparatus framework. Keyed to shaft 79 is a sprocket 80 in vertical alignment with a sprocket 81 (FIG. 5) keyed to the same shaft on which roller 68 is mounted. Sprockets 80 and 81 are interconnected by a sprocket chain 82.
Journaled on shaft 67 for pivotal movement are a pair of L-shaped spaced lever arm members 85 whose leg portions 86 support a housing member 87 on which is mounted pneumatic cylinders 88 and 89 that are operative to actuate chuck means to release or mount a shaft 90 that supports a core around which the mating is wound. The respective ends of leg portions 86 are interconnected by a rod 91. The rear of leg portions 86 adjacent to lever arm members 85 is connected to a bracket 93 which in turn is connected to a piston rod 94 of pneumatic cylinder 95. Cylinder 95 is pivotally connected to braces 96 such that energization of head end of cylinder 95 pivots lever arm members 85 counter-clockwise about shaft 67 as seen in FIG. 1, which lifts the matting roll 92 (FIG. 1) wound around the core on shaft 90 upwardly out of contact with the belt 74 and roller 72; whereas exhausting of the head end of cylinder 95 allows the matting being wound about the core on shaft 90 to rest on the belt 74 in contact with the roller 72. The windup of the matting onto the core on shaft 90 would automatically compensate for its increase in diameter to provide a constant peripheral speed.
Pivotally mounted as at 96 on the spaced brackets 11 adjacent to one cross channel beam 13 is a pair of spaced lever arm members 97 which support for rotation a roller 98. A pair of spaced pneumatic cylinder 100 has their respective head ends pivotally secured as at 101 to supporting brackets 11. The respective piston rods 102 of cylinder 100 are pivotally connected to the intermediate portion of lever arm members 97 for raising and lowering lever arm members 97 and idler roller 98 supported therebetween.
In the operation of the mat tester, a roll of matting on a roller is placed between rollers 21 and 22 with the leader therefrom extending over roller 15 and fed through the test chamber between platens 40 and 44, thence between rollers 68 and 98 for attachment to the core supported by the shaft 90 on leg portions 86 of arm members 85. The apparatus is now in a condition to test the insulating factor of the mat material. The head end of cylinders 42 are actuated to lower the upper platen into contact with the mat material. A voltage such as 15,000 volts A.C. is applied from a suitable source to the upper platen. If the mat material is defective a current will flow through the material to the grounded lower platen 40 which condition will be observed on the ammeter connected to the respective lower and upper platens. Where no current flow is indicated after the prescribed time lapse, the rod end of pneumatic cylinders 42 are actuated which lifts the electrode plate 44 out of contact with the matting in the test chamber, permitting its advancement such that a new section of matting is brought into position underneath the plate 44 with a slight overlap of the section already tested to assure that the entire length of matting will be tested. This is accomplished by adjusting the stroke of cylinder 75. Pneumatic cylinder 75 is then actuated to extend the piston rod and rotate gear 78, which in turn rotates sprockets 80 and 81, roller 68 and endless belt 74. The mat material resting between rollers 68 and 98 will be advanced the length of the stroke of cylinder 75. The matting as it is advanced will be wound up onto roll 92 since roll 92 is frictionally resting on roller 72, to be rotated thereby. The operation will proceed as described above until the entire roll of matting from roller 20 is expended; however, a second roll of matting is placed onto the rollers 21 and 22 and spliced to the trailing end of the prior matting roll to facilitate uninterrupted passage through the test chamber 37.
Various modifications are contemplated and may obviously be resorted to by those skilled in the art without departing from the described invention, as hereinafter defined by the appended claims, as only a preferred embodiment thereof has been disclosed. | A mat testing apparatus having an enclosed test chamber with a moveable electrode platen that is cooperative with a stationary electrode platen to define a clearance space therebetween to receive a portion of a mat for testing its non-conductivity to a high electrical charge. Feed means are provided to index a predetermined length of matting that is cooperative with a let-off means and a take-up roll. The take-up feed is adjusted to its increasing size to provide for change in diameter size. | 6 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a national phase of PCT/HU90/00050 filed Jul. 20, 1990 and based upon Hungarian national application A3736/89 filed Jul. 25, 1989 and modified Jul. 3, 1990, under the International Convention.
FIELD OF THE INVENTION
The present invention is directed to a process for the preparation of quinoline derivatives of the formula (I) ##STR3## wherein R 1 stands for hydrogen or a group of the formula (II) ##STR4## by reacting a halogen quinoline derivative of the formula (III) ##STR5## wherein X stands for chlorine or bromine with picoline oxide of the formula (IV) ##STR6## in the presence of alkali-t-alkylate, preferably potassium-t-butylate or b) oxidizing a compound of the formula (V). ##STR7## The definition of the substituents is as follows: R 1 stands for hydrogen or a group of the formula (II)
X stands for chlorine or bromine.
The novel compounds according to the present invention are important intermediates for the preparation of pharmaceutically active compounds. Thus, for instance the novel compounds are valuable intermediates of erythro-alpha-2-piperidyl-2,8-bis(trifluoro-methyl)-quinoline-4-methanol-hydrochloride (meflokin) or mefloquin. This latter active ingredient can be successfully used in pharmaceutically active compositions against malaria.
BACKGROUND OF THE INVENTION
Meflokin has been first prepared (see J. Med. Chem. 14, 926 (1971)) by reacting a 2,8-bis(trifluoro-methyl)-quinoline-4-carboxylic acid synthesized in three steps with 2-lithio-pyridine and by hydrating the obtained 2-pyridyl-2,8-bis(trifluor-methyl)-quinolyl-ketone ("Ketone") above Adams-catalyst. From the above quinoline carboxylic acid intermediate the ketone was obtained also by reacting it with 2-bromo-magnesiumpyridine (DOS 29 40443), and by hydrogenating the "ketone" analogously to meflokin above a platina charcoal catalyst. The unisolated intermediate of the reduction step (2-pyridyl)-2,8-bis(trifluor-methyl)-quinoline-4-methanol is referred to hereinafter as "Oxy-methane". This compound can be obtained also by reacting 4-lithio-quinoline derivatives obtained from 2,8-bis(trifluoro-methyl)-4-bromo-quinoline by lithiation with 2-pyridine-aldehyde (DOS 28066909). According to a newer technical solution the metallation step is eliminated and thereby a less expensive starting material can be used compared to the so far known quinoline intermediates. When reacting 2,8-bis(trifluoro-methyl)-4-chloro-quinoline with 2-pyridyl-acetonitrile or with 2-pyridyl-methyl-phosphonium salt the obtained intermediate results in ketone by oxidation. According to the authors in these cases in order to subject the halogen of the quinoline in 4-position to nucleophilic substitution the pyridine reactant has to contain on the methyl group an electron withdrawing substituent (see the above mentioned carbonitrile or phosphonium group) (EP0049776).
In EPA 0049 776 in Example 1 the aromatic nucleophilic substitution of 2-methyl-pyridine-N-oxide has been mentioned and was carried out with sodium amide in dimethoxy-ethane, but the structure of the obtained product has not been determined, no physical-chemical data were given and the reference was cancelled from the granted patent.
The above mentioned processes have several disadvantages, such as the already mentioned metallation steps or the expensive quinoline intermediates (such as 2,8-bis(trifluoro-methyl)-4-bromo-quinoline or the corresponding quinoline-4-carboxylic acid) and the pyridine derivatives are expensive and not easily accessible.
These disadvantages could be successfully eliminated by using a quinoline intermediate of the formula (III) and 2-methyl-pyridine-N-oxide. The quinoline intermediate of the formula (III) is prepared by our method disclosed in U.S. Pat. No. 4,599,345 and U.S. Pat. No. 4,659,834 which is also suitable for the industrial synthesis of 2,8-bis(trifluoro-methyl)-4-chloro-quinoline. We have now found that as opposed to the teaching of EP 0 049 776 the electron withdrawing substituent is not necessary on the methyl group of picoline as the cheaper and more easily accessible 2-methyl-pyridine-N-oxide can be reacted without the electron withdrawing substituent as well.
DESCRIPTION OF THE INVENTION
According to the present invention di(2,8-bis(trifluoro-methyl)-quinoline-4-yl)-N-oxy-2-pyridyl-methane can also be prepared depending on the circumstances. This compound is novel. By using the suitable condensating agent or an excess of 2-methyl-pyridine-N-oxide depending on the solvent and/or by using a dilute reaction mixture substantially only mono-quinolyl-derivative is obtained.
According to process a. of the present invention one may preferably proceed by reacting a halogen-quinoline-derivative of the formula (III) with 2-methyl-pyridine-N-oxide in the presence of potassium tertiary-butylate using as the reaction medium tertiary alcohols or inert solvents, such as aromatic hyrocarbons, cyclic or acyclic ethers, dimethyl-formamide, dimethyl-sulphoxide preferably toluene or tetrahydrofuran.
According to the process variant b. one may preferably oxidize a compound of the formula (V) with per acids, preferably with peracetic acid or hydrogen-peroxide.
The starting material of process variant b. is the compound of the formula (V) or salts thereof which compounds are new. The compound of the formula (V) can be prepared from the derivatives of the formula (VI) ##STR8## by eliminating the nitrile or ═O group.
The elimination of the nitrile group can be performed in an acid medium, such as sulphuric acid by heating in the presence of water.
The product can be obtained after neutralizing the reaction mixture by purification in a solvent in a crystalline form.
The elimination of the oxygen from the ketone derivative can be performed by catalytic reduction with hydrogen or transfer hydrogenolysis, preferably by a treatment with ammonium-formiate in the presence of a metal catalyst or formic acid.
The present invention also extends to the novel compounds of the formula (I), to the novel compound of the formula (V) and salts thereof.
The novel compounds according to the invention can be isolated from the reaction mixture as outlined in the following examples. If the compounds have to be converted to oxymethane by rearranging, then isolation from the reaction medium is not necessary, if the rearrangment is carried out by the method of our copending Hungarian patent application No. 3736/89 (see PCT/HU90/00049 corresponding to the concurrently filed U.S. application Ser. No. 671,917).
SPECIFIC EXAMPLES
The details of the present invention are shown in the following examples.
EXAMPLE 1
12.73 g of potassium-tert.-butylate and 6.20 g of 2-methyl-pyridine-N-oxide and 50 ml of tetrahydrofuran are mixed and to the mixture 3 g of 2,8-bis(trifluoro-methyl)-4-chloro-quinoline are added at 60° C. The mixture is allowed to cool to room temperature and 5 ml of glacial acetic acid is added dropwise under aqueous cooling to the mixture and the precipitated inorganic salt is filtered and washed with 2×20 ml ether. The organic layer is evaporated to dryness and the residual 9.31 g of product is admixed with an 1:1 mixture of ice and methanol, it is filtered, washed with water and dried. 3.42 g of N-oxy-2-pyridyl)-2,8-bis(trifluoro-methyl)-quinoline-4-methane are obtained. M.p.: 156°-158° C. An analytically pure sample is recrystallized twice from ethanol, m.p.: 162°-162.5° C.
EXAMPLE 2
16 g of potassium are dissolved in hot tertiary-butanol and the obtained potassium-tert.-butylate is suspended in 350 ml of toluene. To the suspension 21.8 g 2-methyl-pyridine-N-oxide and 24.1 g 2,8-bis(trifluoro-methyl)-4-bromo-quinoline are added at 45° C. The mixture is cooled to 20° C. and under external cooling 125 ml of 10% hydrochloric acid are added, the aqueous layer is separated and extracted with toluene. The organic layer is dried, clarified with active charcoal and evaporated to 150 g at reduced pressure. The mixture is cooled and the precipitated crystalline product is filtered. 20.12 g of (N-oxy-2-pyridyl)-2,8-bis(trifluoro-methyl)-quinoline-4-methane are obtained. Mp.: 157°-158° C.
EXAMPLE 3
To 100 ml of a 25% solution of potassium-tert.-pentylate in toluene 6 g of 2-methyl-pyridine-N-oxide and 3.44 g of 2,8-bis(trifluoro-methyl)-4-bromo-quinoline are added according to Example 1. 3.57 g of (N-oxi-2-pyridyl)-2,8-bis(trifluro-methyl)-quinoline-4-methane are obtained. M.p.: 155°-157° C.
EXAMPLE 4
To a solution prepared from 3.21 g of potassium metal and 80 ml of anhydrous tert.-butanol 4.4 g of 2-methyl-pyridine-N-oxide are added, the mixture is heated to 70° C. and 4.2 g of 2,8-bis(trifluoro-methyl)-4-chloroquinoline are added. When the reaction is terminated the pH is adjusted to 6 by adding concentrated hydrochloric acid solution, the mixture is stirred for 10 minutes at 25° C., the precipitated substance is filtered and covered with 10 ml of tert.-butanol. The mixture is concentrated by suction, dissolved in 100 ml of water and the insoluble part is filtered off and dried. 1.14 g of the product is obtained. Mp.: 264°-265° C. After recrystallization from methanol: Mp.: 271°-272° C. According to MS 1 H- and 13 C-NMR the product is di(2,8-bis(trifluoro-methyl)-4-quinolyl)-(N-oxy-2-pyridyl)-methane. From the aqueous tert-butanolic mother lye the tert.-butanol is distilled off and the residue is diluted with 100 ml of water, extracted with 3×50 ml chloroform, dried above sodium-sulphate and evaporated. After recrystallization of the residue 3.46 g of (N-oxy-2-pyridyl)-2,8-bis(trifluoro-methyl)-quinoline-4-methane are obtained. Mp.: 159°-161° C.
EXAMPLE 5
At 10° C. 350 ml of potassium-tert.-butylate are admixed in 2250 ml of hexane and 100 g of 2-methylpyridine-N-oxide are added. At this temperature the mixture is stirred for 1 hour, whereafter 100 g of 2,8-bis(trifluoro-methyl)-4-chloro-quinoline are added dropwise dissolved in 200 ml of hexane and after 6 hours of stirring at a temperature below 20° C. the mixture is neutralized by acetic acid. After 90 minutes the precipitated substance is filtered, washed with hexane, dried, admixed with 1000 ml of water and the insoluble raw product is filtered, washed with water and dried. 102.5 g of (N-oxy-2-pyridyl)-2,8-bis(trifluoro-methyl)-quinoline-4-methane are obtained. Mp.: 152°-154° C. Active ingredient content according to HPLC 83.2%.
EXAMPLE 6
To a mixture of 2250 ml of toluene and 250 g of potassium-tert-butylate of a temperature 0°-5° C. 70 g of freshly distilled 2-methyl-pyridine-N-oxide are added.
After stirring for 10 minutes 100 g of 2,8-bis(trifluoro-methyl)-4-chloro-quinoline are added dropwise in 150 ml of toluene within 60 minutes. After 90 minutes stirring the reaction mixture neutralized with glacial acetic acid is extracted with water. The residual toluene solution is clarified, filtered, evaporated and cooled. The precipitated crystalline product is filtered, covered with some toluene and dried. 89.9 g of (N-oxy-2-pyridyl)-2,8-bis(trifluoro-methyl)-quinoline-4-methane are obtained. Mp.: 157°-159° C. The product is of 95.6% purity according to HPLC.
EXAMPLE 7
125.0 g of potassium-tert.-butylate are dissolved in 2250 ml of abs. tetrahydrofuran, the mixture is cooled to 0°-5° C. and after adding 50.0 g of 2-methyl-pyridine-N-oxide 100 g of 2,8-bis(trifluoro-methyl)-4-chloro-quinoline dissolved in 150 ml of tetrahydrofuran are added dropwise. The solution is neutralized with acetic acid at a temperature below 20° C., the precipitated salt is filtered, and washed with tetrahydrofuran. The tetrahydrofuran solution is evaporated to a 1/10 volume and the precipitated product is filtered, washed with water and dried. 95.6 g of (N-oxy-2-pyridyl)-2,8-bis(trifluoro-methyl)-quinoline-4-methane are obtained.
M.p.: 159°-161° C.
The purity of the product according to HPLC=96.3%
EXAMPLE 8
1.0 g 2-pyridyl-2,8-bis(trifluoro-methyl)-quinoline-4-methane is dissolved in 10 ml of glacial acetic acid, and after adding 1.0 ml of 30% hydrogen peroxide the mixture is maintained at 80° C. for 90 minutes. The reaction mixture is poured on ice and extracted with chloroform. The organic layer is dried above sodium sulphate, evaporated and after recrystallization of the residue from 10 ml of ethanol 1 g of (N-oxy-2-pyridyl)-2,8-bis(trifluoro-methyl)-quinoline-4-methane is obtained.
EXAMPLE 9
10 g of 2-pyridyl-2,8-bis(trifluoro-methyl)-quinoline-4-acetonitrile are boiled under reflux for 5 hours in 70% sulfuric acid, the mixture is allowed to stand overnight, poured on ice and alkalized with concentrated ammonia to pH 9-10. The mixture is extracted with dichloroethane and the extract is dried above sodium sulphate and evaporated. The residue is crystallized from hexane and 6.47 of 2-pyridyl-2,8-bis(trifluoro-methyl)-quinoline-4-methane are obtained. Mp.: 62°-63° C.
EXAMPLE 10
Under vigorous stirring 5 g of 2-pyridyl-2,8-bis(trifluoro-methyl)-4-quinoline-ketone are maintained at 60° C. in 50 ml of 98% formic acid in the presence of 2 g of 10% Pd/C catalyst. In small portions 0.85 g of ammonium formiate are added. When the reaction is completed the catalyst is filtered off and the reaction mixture is evaporated. The residue is poured on ice and the mixture is worked up according to Example 9. 4 g of 2-pyridyl-2,8-bis(trifluoro-methyl)-quinoline-4-methane are obtained and the product melts after recrystallization from hexane at 57°-58° C. | The invention relates to a processes for the preparation of quinoline derivatives of the general formula (I) ##STR1## wherein R 1 stands for hydrogen or a group of the formula (II) ##STR2## which are intermediates for pharmaceutically active compounds. | 2 |
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