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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a soil compacting device.
2. Description of the Related Art
Vibratory tampers, vibrating plates or vibrating rollers are generally used for soil compaction. Whereas tampers are displacement-excited vibratory systems with a large amplitude, vibrations in the case of vibrating plates are produced by means of force excitation. For reasons connected with the excitation of vibrations in the soil particles, guideability and to protect the operator against unwanted body vibrations, vibrating plates are often designed in such a way that they have a relatively high frequency (40 to 80 Hz) and a small amplitude of the vibrating base plate. From the category of vibrating rollers, trench rollers are generally used for soil compaction, in which vibrations are produced by rotating unbalanced weights within the facings or on the chassis forming a lower mass.
When using vibrating plates, in particular, on moist soils (what are referred to as cohesive soils with a high water content or saturated soils), such as silts and clays, that is to say fine-particle soils with little tendency toward water permeability, there is the problem that the soils can only be compacted to a limited extent by the action of vibrations. This is due to the fact that the cohesion which is often typical of cohesive soils affects the adhesion of the individual particles to one another and hence prevents repositioning of the particles. In the case of vibrating plates, the small amplitude of the vibrating base plate in conjunction with the high frequency leads to a further supersaturation of the soil with water, making the latter softer and more plastic in terms of vibration and causing its adhesive effect on the vibrating plate to increase. As a result, the vibrating plate may sink into the soft earth and no longer be capable of being moved along. In practice, this has led to vibrating plates not being used in damp weather or on saturated cohesive soils even though the soil compaction and surface quality that can be achieved by means of vibrating plates are highly regarded.
In practice, however, there is frequently the problem that, although the vibrating plates are used primarily only on non-cohesive soils, it is necessary for them at certain points to cross supersaturated cohesive soils which are likewise situated in the area to be compacted. In this case, the vibrating plates run the risk of sinking in or digging themselves in due to their natural vibration as they cross these points.
DE-B 11 68 350 has disclosed a vibration device for compacting the construction site with a vibratory plate. The vibratory plate is attached by springs to a road roller, between the front roller drum and the rear wheels. To increase the contact pressure of the vibratory plate on the ground, hydraulic cylinders are provided, these hydraulic cylinders pressing the springs and the vibratory plate against the ground and thereby increasing the spring preload. The problem described of self-propelled vibrating plates on cohesive soils does not arise with this device since the roller ensures sufficient propulsion.
Similar vehicles with attached soil compacting devices are known from DE 43 40 699 A1 and DE-A 20 46 840, where a plurality of vibratory plates or tampers are attached to a heavy travel drive.
U.S. Pat. No. 5,387,370 has disclosed an electroviscous fluid for dampers with variable damping properties, the change in damping being brought about by subjecting the electroviscous fluid to a suitable electric voltage.
U.S. Pat. No. 5,547,049 describes a construction with a magnetorheological fluid in which the damping properties of the fluid can be adjusted by varying an applied magnetic field.
OBJECTS AND SUMMARY OF THE INVENTION
The object on which the invention is based is to specify a soil compacting device in which the abovementioned problem of the device sinking in when temporarily crossing cohesive soils is avoided.
A soil compacting device according to the invention with an upper mass, a lower mass for soil compaction, a spring system coupling the upper mass and the lower mass, and with a damper system, which is arranged between the upper mass and the lower mass and interacts with the spring system, is distinguished by the fact that the damping properties of the damper system can be varied during the operation of the device. This makes it possible to vary the vibration properties and vibration behavior of the device and, for example, to adjust them in such a way that the amplitude of vibration is increased in such a way when crossing cohesive soil, for example, that the upper mass is induced to perform a resonance-type vibratory movement in order thereby to exert larger amplitudes and forces on the lower mass. The lower mass in this context is generally the actual base plate including the exciter by means of which the soil is compacted, while the upper mass is formed by the drive and the control system for the device.
By virtue of the fact that the vibration behavior can be varied during the operation of the device by means of the damping properties of a damper system provided for the partial or complete coupling of springs, the operator can cross the cohesive soil without interrupting his work. The damping properties can be adjusted manually or automatically, as defined in a number of the subsequent subclaims.
The forces on the lower mass generated by appropriate variation of the vibration properties (frequency, amplitude, direction of vibration) of the lower and the upper mass make it possible to overcome the increased sticking at the base plate caused by moist soils and associated with vibration and adhesion. The large amplitudes with an appropriately forward-directed force vector allow the device to execute a jumping movement, even on soils which are of low elasticity and are predominantly plastic.
In a particularly preferred embodiment of the invention, at least one damper of the damper system has a damping material composed of an electroviscous fluid. In the case of electroviscous fluids, the viscosity of the fluid can be varied under the action of electric voltage. This means that, depending on how the fluid is acted upon by an electric voltage, almost any viscosities and hence damping constants can be set at the damper. Dampers incorporating an electroviscous fluid are therefore particularly suitable for enabling the damping properties of the damper to be changed quickly during its operation. The response time of typical electroviscous fluids is around 3 milliseconds.
The damping properties of the damper system provided for intermittent or continuous coupling of spring systems can therefore advantageously be adjusted by subjecting the electroviscous fluid to a suitable electric voltage.
It can be particularly expedient if the electric voltage is clocked. This is particularly recommended when the vibration properties are adjusted by means of an automatic control system.
The electric voltage can additionally be adjusted to different levels.
However, it is also possible to vary the clocking, i.e. to change the lengths of time for applying voltage.
In a preferred embodiment of the invention, the electric voltage or clocking can be adjusted by means of an automatic control system. It is advantageous if the automatic control system has at least one sensor system.
It is particularly preferred if the sensor system has at least one acceleration sensor. If, namely, the base plate of the vibrating plate sinks into a soft soil or comes into contact with a soft soil, the reaction forces exerted by the soil on the plate change relative to the forces exerted by a firm underlying surface. In addition, there is a change in the frequency, amplitude and length of the jump of the lower mass and this can be detected by the acceleration sensor. When presettable limiting values are undershot, the sensor can give the signal that the contact area of the plate with soft soil is increasing at this moment or that it is already moving on said soil. This knowledge will then cause the automatic control system to alter the spring stiffness of the vibratory system and hence the vibration behavior accordingly by means of the damping constant of the damper in order to achieve the effects described above.
Instead of electroviscous fluids, it is also possible to use magnetorheological fluids, the viscosity of which changes as a function of an applied magnetic field. The magnetic field is then controlled and varied in a manner similar to the variation or clocking of the voltage in the case of electroviscous fluids.
Preferably, at least one spring of the spring system is arranged in parallel with a damper of the damper system. It can also be expedient if at least one spring of the spring system is arranged in series with a damper of the damper system. By appropriate arrangement of springs and dampers in the overall spring/damper system of the vibrating plate, it is thereby possible to define suitable spring characteristic regions within which the vibration properties can be varied. The interacting springs can have the same or different spring characteristics.
It can be particularly advantageous if the spring stiffness of the overall system is adjusted in such a way, by varying the damping constants, that the upper mass enters into resonant vibration during the operation of the device. This allows a maximum force effect at a large amplitude to be exerted on the lower mass in order to overcome the static friction with the soft underlying surface.
In a particularly preferred embodiment of the invention, at least one spring can be connected up or disconnected by means of a damper connected in series. This is possible by virtue of the fact that, at maximum stiffness, the damper completely activates the spring, while, given a correspondingly soft setting, it eliminates the effect of the spring.
The resultant direction of vibration of the upper mass can advantageously be controlled by connecting up and disconnecting one or more springs. Thus, for example, a resonant vibration of the upper mass can take place in a predetermined or controllable direction and hence expediently align the resultant force vector on the lower mass.
It is expedient if the lower mass or the upper mass is coupled to a vibration exciter by means of which the overall system has imparted to it the vibration required for soil compaction and movement of the vibrating plate.
In another embodiment of the invention, the upper mass is connected to the lower mass at four points, in each case by means of a spring/damper combination, the damping properties of the dampers being adjustable asymmetrically. Asymmetrical means that the dampers can assume different damping coefficients at each of the four points, making it possible, for example, to achieve an advantageous jumping movement of the lower mass, i.e. the base plate, for cohesive soils.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in greater detail below with reference to the accompanying figures, in which:
FIG. 1 shows the basic structure of a soil compacting device according to the invention;
FIGS. 2 and 3 show suitable arrangements of spring and damper elements.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows the basic structure of a vibrating plate according to the invention. The invention can, of course, also be employed with other soil compacting devices, e.g. with vibrating rollers or vibrating tampers.
An upper mass 1 , which essentially accommodates the drive, is coupled by a spring system 2 to a lower mass 3 representing the base plate. The lower mass 3 rests flat on the soil to be compacted.
The lower mass 3 carries one or more vibration exciters known per se (not shown), which can also be moved in opposite directions for the purpose of forming directional vibrations. Depending on the construction of the vibrating plate, the vibration exciter has one or two shafts with unbalanced weights, which are driven by the motor belonging to the upper mass 1 via V-belts or a hydraulic system, for example, and, in the process, generate centrifugal forces. These dynamic forces bring about both the forward motion of the plate and its compacting action. The centrifugal forces produced are always well above the deadweight of the vibrating plate, with the result that the entire unit is briefly raised a few millimeters above the ground and moved along every time the unbalanced weights rotate. The plate then reaccelerates back to the ground and acts with a brief, high surface pressure on the material to be compacted with the kinetic energy built up and the centrifugal force produced in the exciter.
Arranged between the upper mass 1 and the lower mass 3 there is furthermore a damper system 4 which interacts with the spring system 2 and forms an overall vibratory system with the masses 1 , 3 .
The spring system 2 comprises a plurality of springs connected in parallel or in series and composed, for example, of metal or rubber-metal elements, pneumatic springs or other flexible materials, which are connected to one another by dampers of the damper system 4 . Expedient arrangements of springs 2 and dampers 4 are illustrated in FIGS. 2 and 3.
Since the damping properties of the damper system 4 and hence of the individual dampers can be varied during the operation of the device, it is possible to set very different characteristic curves for the overall vibratory system. Assuming that the damper 4 in FIG. 2 is set so as to be extremely hard, it can be seen that the two springs 2 a, 2 b illustrated are connected in parallel and that their spring constants are added together. If, on the other hand, the damper 4 is set so as to be extremely soft, spring 2 b loses its effect in the overall vibratory system and the system is thus determined by spring 2 a alone.
Similar remarks can be made regarding the connection of spring elements in series in accordance with FIG. 3 .
The damper systems respond extremely rapidly to appropriate activation (within 3 milliseconds) and comprise reciprocating cylinders which are filled with electroviscous fluid and the damping constant of which can be varied over extremely wide ranges by clocking an applied high voltage which is, in addition, variable. The extreme states of these damper elements lie between no damping, i.e. rigid transmission of the forces introduced, to 100% damping, whereby the forces introduced are transmitted virtually not at all but instead are absorbed during the working displacement of the damper.
A sensor 5 which continuously measures the acceleration of the lower mass 3 is mounted on the lower mass 3 . When the vibrating plate is passed over a piece of ground with a tendency to adhesion or vibratory penetration, the vibration behavior changes as it approaches this piece of ground, i.e. the amplitude of the base plate, (lower mass 3 ) changes because the softer ground exerts different reaction forces on the plate than a hard underlying surface and the forward acceleration decreases. This change is detected by the acceleration sensor 5 and indicated to a control unit (not shown) which, in turn, adjusts the viscosity in the damper system 4 by suitable voltage control and/or clocking of high voltage. As a result, in accordance with the invention the resonant frequency of the vibratory system is adjusted to the range of the excitation frequency, thereby resulting in different modes of vibration, all characterized by high amplitudes, depending on the eigenform excited. The large-amplitude vibration which now results can be directed in such a way by appropriate choice of frequency and mounting of the spring and damper elements that it exerts maximum force vectors on the lower mass and thereby helps to release the lower mass 3 from the ground.
Depending on the embodiment, the automatic control system activates just one damper member in the overall system or a plurality of dampers. If a plurality of dampers are activated, they can be adjusted to the same damping constant or—if expedient in the given application—to different damping constants. The person skilled in the art can decide here what outlay is necessary and appropriate for the configuration of the automatic control system. It may be possible to achieve the desired effect according to the invention by activating just one damper.
In the control unit, the acceleration value for the base plate detected by the acceleration sensor 5 is compared with preset desired values. If it is found that the base plate does not achieve the required acceleration patterns, the control unit concludes that the vibrating plate is on a problematic underlying surface. The control unit then controls the viscosity in the connected damper elements of the damper system 4 in accordance with predetermined characteristics.
Instead of automatic control, it is possible for the operator to adjust the vibration behavior of the soil compacting device as a function of the underlying surface which is being crossed at that particular time, using control elements (not shown). Thus, for example, it is possible for a switch to be provided, which is to be actuated by the operator when he notices that the base plate is sticking on soft ground. When the switch is actuated, a corresponding damper system with electroviscous damper elements is then activated and the upper mass is adjusted to resonance of a suitable eigenform. Once the critical ground has been crossed, the operator switches the switch off again, whereupon the device reattains its normal operating state.
There is a significant advantage over the prior art in the control behavior of the vibrating plate since, previously, it was only possible to adapt or adjust the vibrating plate approximately to the ground to be compacted by configuration of the entire vibratory system of the vibrating plate and hence only by permanent presetting. In this arrangement, it was hitherto impossible to adjust the soil compacting device equally well to two different types of soil (noncohesive and moist/cohesive soils).
Examples of suitable electroviscous or electrorheological fluids are RHEOBAY® products. With these fluids, the shear stress that can be used for force transmission, and hence the dynamic viscosity, is raised within milliseconds by applying an electric field. When the voltage is switched off, the original viscosity is restored. The field strength to be applied is preferably between 0 and 3 kV/mm. Both D.C. and A.C. voltages can be applied. The voltage applied can be clocked and achieve pulse widths between 0 and 100%.
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A soil compacting device has a damping system which couples an upper mass and a lower mass together with a spring system in a vibration system. The damping properties of the damping system can be modified while the device is in operation. Therefore, when the soil compacting device passes over soils having different properties, it can constantly be adjusted in an optimal manner to the ground underneath it by acting on the vibration properties of the overall vibration system.
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FIELD OF THE INVENTION
[0001] The present invention relates to the technical sector of automatic machines for packing vials.
DESCRIPTION OF THE PRIOR ART
[0002] The prior art comprises packing machines of variously-structured vials, used in various industrial sectors, for example food, cosmetics or pharmaceutical.
SUMMARY OF THE INVENTION
[0003] The aim of the invention is that it discloses a machine for packing vials, structured such that the filling thereof which liquid solutions, and the capping of the vials are performed contemporaneously on a plurality of vials, and conformed such as to guarantee both the statistical weighing of the vials and the rejection of the vials which do not conform to predetermined requisites.
[0004] A further aim is to provide a machine which if necessary can work in a sterile environment.
[0005] A further aim of the present invention is to provide a machine for packing vials which is conformed such as not to interfere with the inserting portion of the caps, used for at least partially sealing the vials.
[0006] A further aim of the invention is to realize a machine which, while respecting the preceding aims, are at the same time reliable, functional, and require limited maintenance and enable a productivity that is comparable with that of the known machines.
[0007] The above aims are attained with a machine for packing vials as discussed further below.
[0008] In accordance with the present invention, the machine for packing vials of the invention comprises, in cascade:
[0009] a supply station of empty vials;
[0010] an Archimedes screw having a rotation axis parallel to a longitudinal development of the machine, supplied with the vials in arrival from the supply station, and destined to transfer the vials to an outlet thereof, at a predetermined step;
[0011] a first device comprising at least two cogged sectors, with an equal step to the step of the screw, which at least two cogged sectors rotate on a same axis independently of one another, and are alternatively activated in phase relation with the screw, in order to receive a predetermined number of vials from the screw;
[0012] a comb conveyor, step-moved and designed to receive the vials from one or another of the cogged sectors of the first device, consequently to a suitable phase relation between a velocity of the conveyor and a peripheral velocity of the corresponding cogged sector;
[0013] a filling station, designed for introduction of a liquid solution contemporaneously into a plurality of vials, which plurality is equal in number to the predetermined number of vials;
[0014] a statistical weighing station of the vials, arranged in proximity of the filling station, able to detect a tare and a gross weight of sample vials of the vials;
[0015] a capping station, for at least partly sealing a plurality of vials which plurality is equal to the predetermined number of vials;
[0016] a second sector device, conformed like the first device, in which at least two cogged sectors are alternatively activated in phase relation with the movement of the comb conveyor;
[0017] a star device, activated in phase relation with the movement of the cogged sector of the second device, which star device is interested by the predetermined number of vials, and exhibits a double outlet, a first outlet and a second outlet;
[0018] the star device being destined to direct conforming vials towards the first outlet, and to reject vials which do not conform to determined requisites and to convey them towards the second outlet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The characteristics of the invention will better emerge in the following description of a preferred embodiment thereof, in accordance with the contents of the claims and with the aid of the accompanying tables of drawings, in which:
[0020] FIG. 1A is a schematic perspective view of the machine for packing vials of the invention;
[0021] FIG. 1B is a view from above of the machine of FIG. 1A ;
[0022] FIG. 2 is a schematic plan view of detail H of FIGS. 1A , 1 B;
[0023] FIG. 3A schematically illustrates injection of an inert gas in the empty vial;
[0024] FIG. 3B schematically illustrates filling a vial with a liquid solution;
[0025] FIG. 3C schematically illustrates injection of an inert gas in a vial filled with a liquid solution;
[0026] FIG. 4 is a plan view schematically illustrating a possible weighing station of the vials;
[0027] FIG. 5 is a lateral view, with parts in section and others removed, of the capping station of the machine of the invention;
[0028] FIG. 5A is a large-scale view of detail K of FIG. 5 ;
[0029] FIG. 6 is a further lateral view of the capping station in an operative configuration that is different from the configuration of FIG. 5 ;
[0030] FIG. 7 is a schematic plan view of detail W of FIG. 1B ;
[0031] FIG. 8 is a view of section VIII-VIII of FIG. 7 ;
[0032] FIG. 9 is a view of section IX-IX of FIG. 7 ;
[0033] FIG. 10 is a view similar to that of FIG. 9 in a different operative situation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] The machine will be illustrated herein below with reference also to the operating steps of packing the vials, in particular in a case in which the packing of the vials is to be performed in a sterile environment.
[0035] As is known, the operating environment suitable for packing sterile vials comprises circulating a laminar flow of sterile air, forced from above in a downwards direction, with the aim of preventing inlet of any polluting particles internally of the vials. The air is then collected and purified using appropriate filters, before being newly circulated from above in a downwards direction in the operating environment.
[0036] With reference to FIGS. 1A , 1 B, M denotes the machine for packing the vials F of the invention. The machine M comprises a housing bench O for supporting the various stations and the movement means, which will be described in greater detail herein below.
[0037] The machine M comprises a first supply station 1 , in which the empty vials F, previously sterilized, are collected and arranged in reciprocal contact with each other.
[0038] The vials F are advanced using known systems, such as for example by means of use of a conveyor belt. The outlet zone of the supply station 1 comprises a longitudinal channel 2 , towards which the vials F are directed, the vials F being of such dimensions as to be arranged in a line.
[0039] The channel 2 transfers the vials F along a sliding plane (not illustrated), without obstructing advancement thereof. The vials F are then transported from the channel 2 up to the entrance of an Archimedes screw 3 , appropriately positioned, having a rotation axis thereof that is parallel to the longitudinal development of the machine M.
[0040] The screw 3 , in movement, enables advancing the vials F, supported inferiorly by the horizontal sliding plane. Further, with the aim of stabilizing the vials F during the sliding along the horizontal plane, an abutting wall E is present, which receives and guides the vials F, and is positioned perpendicularly to the plane and parallel to the rotation axis of the screw 3 .
[0041] A device 4 having sectors for transfer of the vials F is appropriately arranged such as to be supplied by the screw 3 , and is activated in phase relation therewith (see in particular FIG. 2 ). The device 4 comprises at least two distinct cogged sectors, independent of each other, which move in a step-fashion, rotating about the same vertical axis, as will be more fully described.
[0042] Each cogged sector of the device 4 comprises a determined number N of seatings on the external surface thereof; the number N of seatings corresponds to the number of vials F which are to be worked on contemporaneously. FIG. 2 illustrates a device 4 in which a first and a second cogged sector are present, each having four seatings. The seatings of each of the two cogged sectors, which have the same step as the screw 3 , are conformed such as each to receive and retain, with the aid of known technical-functional details (not illustrated), one of the vials F.
[0043] The first cogged sector of the device 4 , activated by the machine M, is arranged in such a way that when a vial F reaches the terminal part of the screw 3 it occupies one of the seatings of the first sector. The first sector then rotates by a step about the vertical axis, in a determined rotation direction S (clockwise in the figures), with the aim of predisposing a further empty seating to receive a following vial F.
[0044] Once all the seatings of the first cogged sector have each received a vial F, the first sector actuates a rotation in the predetermined direction S. At the same time the second cogged sector has undergone a rotation such as to be at the terminal part of the screw 3 ; the just-described operating cycle is then repeated.
[0045] The rotation angle of the first cogged sector in the direction S is such that the vials F, situated up to this moment in the respective seatings, engage, as will be more fully described herein below, between the tines of a comb conveyor 5 , arranged for this purpose.
[0046] The above-mentioned comb conveyor 5 develops longitudinally over the whole operating line, and is step-supplied by the sector device 4 , with which it is activated in phase relation.
[0047] The comb conveyor 5 is able to perform a plurality of movements: in the longitudinal direction from left to right (according to the development direction of the line) and vice versa, and also in a vertical direction, from above in a downwards direction and vice versa. These movements are schematically represented in FIG. 2 using arrows (from A to B, from B to C, from C to D, from D to A), in a front view.
[0048] The comb conveyor 5 , at the moment of receiving the vials F from the sector device 4 , rises from position D to position A, until it is at the position of the vials F, at the start of the line. As the cogged sector involved, for example the first sector, i.e. the one whose seatings are interacting with the vials F, has a peripheral velocity which is equal to the movement velocity of the movement of the comb conveyor 5 , the rotation in the predetermined direction S of the first sector is such that the four vials F engage between the tines of the comb conveyor 5 , which contemporaneously translates in a longitudinal direction. In this way, the first of the tines, which was at the start of the line in position A, now finds itself in position B. The distance between points A and B, reciprocally at the same height, is equal to the run comprising the four vials F moved.
[0049] Once the first run has taken place, a second centering comb 6 , superposed to the comb conveyor 5 , enters into play. The centering comb 6 has the same length as the comb conveyor minus the length of a run, and extends from the height of point B up to the end of the line.
[0050] The centering comb 6 is able to move transversally advancingly or backward, while always maintaining the same height. In FIG. 2 , arrows (from B to J and vice versa) schematically indicate the movement of the centering comb 6 in a view from above. Following the displacing from A to B of the comb conveyor 5 , the centering comb 6 , which is initially retracted, advances transversally such that the first of the tines, which was in position J, reaches position B. Thus the vials F are engaged between the tines of the centering comb 6 , which stabilizes their position. Once the stability of the vials F is ensured, the comb conveyor 5 moves from above in a downwards direction such that the first of the tines on the left passes from position B to position C. The comb conveyor 5 has therefore disengaged the vials F, which remain housed only between the tines of the centering comb 6 .
[0051] The comb conveyor 5 can displace longitudinally from right towards left, such that the first of the tines on the left thereof passes from position C to position D, in line with point A. The distance between the points C and D is thus equal to the distance between points A and B.
[0052] At this point, the comb conveyor 5 rises vertically and returns to position A, engaging the vials F received from the second sector described above, and, at the same time, the vials F retained by the centering comb 6 , previously received from the first sector. In the moment at which the comb conveyor 5 engages the vials F between the tines, the centering comb 6 disengages them, receding from B to J.
[0053] The subsequent longitudinal displacement of the comb conveyor 5 causes all the vials F to advance by an operating step. The operating step is N times the step between two consecutive vials, with N defining the predetermined number of vials F which are to be operated on contemporaneously. The movement of the vials F then step-proceeds for the whole line, as described above.
[0054] After a series of displacements of the comb conveyor 5 , the batch of vials comprising the first four vials F is at a (possible) first inert gas blower station 7 . An inert gas is injected into the empty vial F such as to replace the air, preventing oxidation of the liquid which will be injected into it. The first blower station 7 , in the preferred embodiment represented herein, comprises four immersion nozzles 71 . The nozzles 71 , moving vertically in a downwards direction up to reaching the inside of the vials F, inject the inert gas, usually helium or nitrogen. The blowing operation, schematically illustrated in FIG. 3A , is done in phase relation with the movement of the comb conveyor 5 , and comprises injection of the inert gas in the period of time in which the vials F are paused. Once the gas has been injected, the nozzles 71 move vertically in an upwards direction such as to return to the starting position.
[0055] The four vials F, then translate longitudinally according to the operating step, reach the filling station 8 , in which four immersion nozzles 81 inject a liquid solution into the vials F, operating as the blower nozzles 71 described herein above. The schematic illustration of FIG. 3B shows how the vials F are filled with the liquid solution up to a certain height which guarantees correct capping in a following step.
[0056] The full vials F are then taken to a possible second blower station 9 , in which four nozzles 91 inject inert gas into the upper part (empty) of the vials F. The nozzles 91 in this case are maintained at a height which is such as not to contact the liquid solution. This is illustrated in the schematic representation of FIG. 3C .
[0057] With the aim of guaranteeing a precise measuring of the product injected into the vials F, and the overall weight thereof when filled, the machine M of the invention further comprises a statistical weighing station 10 ( FIGS. 1A , 1 B, 4 ). The weighing station 10 is arranged adjacent to the operating line, in proximity of the filling station 8 . In the step of weighing some vials F, collected at regular intervals from the operating line of the machine M, are weighed before and after the filling station 8 , without interfering with the productive capacity of the plant. This operation is performed both such as to control with precision the quantity of product injected and such as to identify any eventual vials F that may not conform to the specifications and reject them when they arrive in proximity of the line outlet, as will be described in greater detail herein below (see patent application EP 06 003 691).
[0058] In the preferred embodiment of the invention (in accordance with document EP 1 988 018), illustrated in FIG. 4 of the drawings, the weighing station 10 of the machine M of the invention comprises a single scales 101 for weighing the vials F, situated in proximity of the operating line, on the opposite side with respect to the filling nozzles 81 . The weighing station 10 further comprises a first and a second pick-up-and-place member 102 , 103 of vials F, the first member 102 for picking up a single vial F upstream of the filling station 8 , transferring it to the weighing scales 101 and reintroducing in onto the line upstream of the filling station 8 , once the tare has been measured; the second member 103 for picking up a single vial F, the tare of which has been previously weighed downstream of the filler station 8 , transferring it to the weighing scales 101 and reintroducing it into the line once the gross weight has been measured. The above-mentioned first and second pick-up-and-place members 102 , 103 of the vials F are activated in phase relation and are operated by two respective oscillating arms 104 , 105 which constrain them to supports 106 , 107 . The supports 106 , 107 are arranged in proximity of the line on the opposite side with respect to the scales 101 , respectively before and after the filing station 8 . The supports 106 , 107 enable rotation of the oscillating arms 104 , 105 on a horizontal plane, by means of a motor organ (not illustrated), enabling displacement of the first and second pick-up and place member 102 , 103 of the vials F. Clearly, once gross weights and tares of the vials F have been taken, the net weight thereof is calculated, i.e. the weight of the liquid solution introduced.
[0059] Following their filling, the full vials F advance in order to be sealed in a capping station 11 ( FIGS. 1A , 1 B, 5 , 5 A, 6 ). In particular, the capping station 11 of the machine M is such as not to compromise the sterility of the vials F.
[0060] It is known that the most widely-used type of caps for vials F is mushroom-shaped. These caps essentially comprise a head portion (the “hat” of the mushroom) which is destined to remain outside the vial F even after capping, and an inserting portion (stalk), narrower than the head portion, conformed such as to enter the mouth of the vials F.
[0061] The capping station 11 does not comprise interaction between the means and the inserting portion of the caps, but only with the relative head portion.
[0062] It is therefore advantageous for the sterility of the vials F that the inserting portion of the caps, conformed in order at least partly to be introduced into the vials F, is not touched. In a case of filling and capping vials F for freeze-dried products, the liquid of the liquid solution containing particles in suspension is evaporated after, and for this reason the cap is inserted only partially in the mouth of the vial F. In this case, the stalk of the cap externally exhibits a groove which is sealed once the liquid has evaporated.
[0063] There follows a description in greater detail of the structure of the above-cited capping station 11 , in a preferred embodiment thereof illustrated in the accompanying figures of the drawings.
[0064] With particular reference to FIGS. 5 , 5 A and 6 , the capping station 11 comprises: a vibrator bin 110 for containing caps 200 , contacting them only in the relative head portion; conveyor means 11 supplied with the caps 200 contained in the vibrator bin 110 , conformed such as to contact only the head portions thereof; means for picking up and inserting 117 , conformed such as to contact the caps ( 200 ) only in the respective head portion, and such as to insert at least a part of an insertion portion of the cap 200 into the mouth of the vials F.
[0065] The caps 200 are predisposed in the vibrator bin 110 , facing with the inserting portion (stalk) pointing upwards, contacting the bin 110 only with the head portion thereof. The vibrator bin 110 , when activated, directs the caps 200 towards the conveyor means, comprising a specially-arranged linear vibrator 112 . The linear vibrator 112 is conformed such as to advance the caps 200 resting on the respective head portion, arranging them in a line.
[0066] The caps 200 proceed advancingly up until they reach a collecting zone 113 , in which they stop, striking against a stop surface, forming various lines, four in the present case. At this point a collecting element 114 is activated, which is destined to collect four caps 200 , i.e. the head caps, from the line. Each cap 200 collected is transferred to a housing 115 conformed such as to receive and retain the cap 200 by its head portion. The housing 115 , at the moment of receiving the cap 200 , is arranged horizontally, superposed to the collecting point ( FIG. 5A ).
[0067] The collecting element 114 comprises a lift member 116 , arranged at the collecting point, which supports a head portion of the caps 200 , once striking against the abutting surface. The lift member 116 is vertically mobile such that when it has received the caps 200 it raises them such as to insert them in the relative housings 115 . Each housing 115 , which comprises at least a through-hole, is conformed such as to receive and retain the head portion of a cap 200 by interference.
[0068] The housing 115 can therefore be brought into a release position, situated above the mouth of a vial F, engaged between the tines of the centering comb 6 . For this purpose, a transfer mechanism is included with enables the housing 115 to be moved from the first housing position to the second release position, and vice versa, describing an arched trajectory of 180 degrees. The housing 115 , during the release step, is arranged in such a way that the inserting portion of the cap 200 faces the mouth of the respective vial F.
[0069] The above-described pick-up-and-place means 117 comprise at least a presser element 118 , arranged in such a way that once activated it presses on only the head portion of a cap 200 , engaged in the housing 115 with the inserting portion facing the mouth of a vial F. The presser element 188 essentially comprises a vertically-mobile cursor 119 , having a lower end for contacting the head of the cap 200 .
[0070] When the presser element 118 is activated, the mobile cursor 119 displaces vertically from above in a downwards direction, such that the lower end exerts, on the head portion of the cap 200 , a force which is such as to separate it from the housing 115 . In this way, the inserting portion of the cap 200 enters at least partially in the mouth of the underlying vial F. This step is schematically illustrated in FIG. 6 .
[0071] The vials F, filled and capped, are transported by the comb conveyor 5 towards a second sector device 12 (see FIG. 1B ).
[0072] The sector device 12 is conformed and functions exactly like the first sector device 4 arranged between the screw 3 and the comb conveyor 5 , as previously described. In this case, the second sector device 12 is supplied by the comb conveyor 5 with which it is activated in phase relation, and is structured such as to receive the vials F in the seatings of one or the other cogged sector. At the moment in which the comb conveyor 5 translates longitudinally from left to right, a cogged sector of the sector device 12 , for example the first sector, is in a position such as to receive vials F, rotating in the direction S at the same peripheral velocity of the comb conveyor 5 , which translates contemporaneously in a longitudinal direction.
[0073] When four vials F occupy the seatings of the first cogged sector, the cogged sector performs a rotation in a clockwise direction such as to transfer the vials F to a star device 13 especially arranged (detail W of FIG. 1B and FIG. 7 ). In the meantime the second cogged sector of the device 12 has rotated such as to be at the comb conveyor 5 position.
[0074] The star device 13 has the task of conveying the vials F towards one of the two outlets provided by the line, the first outlet U 1 for conforming vials F 1 and the second outlet U 2 for defective vials F 2 . The star device 13 essentially comprises a selector disc 130 having a vertical rotation axis, which disc 130 exhibits on an external circumference thereof seatings Q conformed such as to receive the vials F. The seatings Q are connected to relative conduits 131 which can be placed under a depression by a depression source, external of the selector disc 130 , not illustrated, following a command of special intercepting organs (also not illustrated).
[0075] The selector disc 130 is combined with a first guide track P 1 of the vials F 1 classified as conforming.
[0076] The first guide track P 1 , concentric to the selector disc 130 , develops in a circular sector in rotation direction V indicated in the figures. The first guide track P 1 comprises a sliding base 132 , below the seatings Q, for receiving the vials F, and a lateral edge 133 arranged peripherally with respect to the selector disc 130 without obstructing rotation thereof. The first guide tract P 1 develops from an inlet 11 to an outlet U 1 .
[0077] A second guide tract P 2 for the vials F 2 considered defective departs tangentially to the disc 130 and to the first tract P 1 . The sliding base 134 of the second guide tract P 2 is lower than that of the tract P 1 . The lateral edge 133 of the latter is specially interrupted in the intersecting zone with the tract P 2 . The second track P 2 develops distractingly from the selector disc 130 and terminates at an outlet U 2 where the defective vials F 2 are unloaded.
[0078] The vials F which reach the selector disc 130 have been previously subjected to the appropriate checks to establish whether they are conforming or not, with respect to predetermined specifications, such as for example the weight specification. Once engaged in the seatings of the disc 130 , the vials F are already identified as conforming F 1 or defective F 2 , and the intercepting organs are able to establish whether to activate or not the source of air through the conduits 131 . In the case that a conforming vial F 1 is being transported, it is retained by the source of air depression, which retains it in suspension, releasing it only once the intersection with the track P 2 has been passed. The conforming vial F 1 thus proceeds along the sliding base 132 of the tract P 1 up to the outlet U 1 . This operation is schematically illustrated in FIGS. 8 and 9 .
[0079] In the preferred embodiment, the outlet U 1 is associated to a line arranged perpendicular to the longitudinal development direction of the machine M, such as to convey the vials considered conforming towards the back of the machine M (see FIG. 1A ).
[0080] In a case of a defective vial F 2 , however, transported by the star device 13 , the aspirating current is interrupted when the vial F is in track P 2 , releasing the defective vial F 2 (see FIG. 10 ), which distances from the disc and proceeds towards the outlet U 2 , along the sliding base 134 of the track P 2 .
[0081] The above-described machine can comprise some empty stations, arranged for example upstream of the first blower station 7 of inert gas and downstream of the second blower station 9 of inert gas, before the capping station 11 , as shown in the accompanying figures of the drawings.
[0082] The first and second blower station of inert gas can be present or not in the machine, according to operating needs.
[0083] The above has been described by way of non-limiting example, and any eventual construction variants are understood to fall within the ambit of protection of the present technical solution, as described above and claimed in the following.
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A machine (M) for packing vials (F) includes a supply station ( 1 ) of empty vials (F) and an Archimedes screw ( 3 ) having a rotation axis parallel to a longitudinal development of the machine (M), activated in phase relation with the supply station ( 1 ) from which it receives the vials (F). A first device ( 4 ) has at least two cogged sectors, rotating on a common axis independently of one another, alternatively activated in phase relation with the screw ( 3 ). The machine has a comb conveyor ( 5 ), which is step-moved and designed to receive the vials (F) from one or another of the cogged sectors of the first device ( 4 ), and a filling station ( 8 ), for introduction of a liquid solution contemporaneously into a plurality of vials (F). The machine has a statistical weighing station ( 10 ) for the vials (F), arranged in proximity to the filling station ( 8 ), able to detect a tare and a gross weight of sample vials (F). A capping station ( 11 ) is provided for at least partly sealing a plurality of vials (F). A second sector device ( 12 ), configured like the first device ( 4 ), has at least two cogged sectors alternatively activated in phase relation with the movement of the comb conveyor ( 5 ). A star device ( 13 ) is provided, exhibiting a double outlet, a first (U 1 ) and a second (U 2 ), the star device ( 13 ) directing conforming vials (F 1 ) towards the first outlet (U 1 ), and rejecting vials (F 2 ) which do not conform to determined requisites by conveying them towards the second outlet (U 2 ).
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BACKGROUND OF THE INVENTION
The invention relates to a device for shed forming whereby the position of the heddles for the warp threads in a weaving machine are individually controlled according to the open-shed principle. In such a shed-forming device the heddles for the warp threads can occupy two positions: Bottom, i.e. below the weft insertion level, and Top, i.e. above the weft insertion level. It is called a two-position open shed when each position can be reached, or be maintained, on every pick.
From the British patent publication GB 2 047 755 a shed-forming device for a weaving machine is known whereby the arcades are suspended from a pulley element. Around the wheel of this pulley element a cord is passed of which each extremity is connected to a leaf-spring-shaped hook. Each leaf-spring-shaped hook is provided on the bottom part with a nose with which it can rest on a corresponding lifting knife. The knives are brought two by two in opposite phase in an upward and downward movement. The leaf spring hooks are provided on top with a hook with which in a top position they can hook onto a fixed knife through the influence of an electromagnet which is placed between two leaf springs that work together. The nose of the bottom part of the leaf-spring-shaped hooks however always remains in the path of the ascending and descending lifting knives that work together. An unselected hook always remains on its corresponding lifting knife. The "bottom" positions for the leaf spring hooks are therefore formed by the moving lifting knives.
With this existing system the pulley device is a great disadvantage. At high weaving speed the reversing rollers of the pulley device have to rotate fast backward and forward. Heat develops through the friction which occurs in the bearing of the wheel and through slipping of the cord on the groove surface of the wheel. The cord must bendingly unwind onto the reversing roller at high frequency. This cord is subject to wear and tear and finally breaks. It also often occurs that through the dust in the weaving area the wheel will jam, through which the cord prematurely breaks through severe friction. After a time all pulley elements have to be preventively replaced when the number of pulley cord breakages becomes too great and because of this the weaving efficiency of the weaving installation will decline. The replacement of thousands of pulleys per weaving unit is time-consuming, requires specialized personnel and because of this causes an increase in running costs.
EP 0 711 856 describes an attempt at remedying these disadvantages by operating without any pulley element. This device however has the disadvantage that a preselection of the hooks must take place with the implementation of a small lift at the frequency of the weft insertion frequency. In other words the selectors and the grids on which these are mounted must perform an upward and downward movement during a weft insertion cycle. This leads to severe vibrations at high operating speed of e.g. 1,000 min. Another disadvantage is that the lifting knives must be provided with spring catch hooks which drag against the jacquard hooks. This develops heat and is the cause of considerable mechanical loss.
Another attempt according to EP 0 779 384 also has the intention of being able to operate without pulley element. The disadvantage of that technique is that a two-legged hook is required whereby the harness load in each case comes in the middle, through which the hooks are eccentrically loaded. In order to offset this eccentric loading a central guiding body has to be provided. This however causes extra friction through which this device also suffers high mechanical losses. Because of the fact that this solution rests on a two-legged hook this device takes up rather a lot of room in horizontal plane. The footprint is rather large.
Shed-forming devices are also utilized in three-position jacquard machines such as namely those employed with face-to-face double gripper weaving machines for weaving jacquard velvet and for weaving multiple pile warp thread carpets. With a double gripper weaving machine in each weft insertion cycle two wefts are simultaneously inserted. This means that the pile warp threads can occupy three positions:
Bottom: below both weft insertion means
Middle: between the two weft insertion means
Top: above both weft insertion means.
It is called a three-position open-shed jacquard machine when each position of the three positions can be reached or continue to be maintained on every pick or weft insertion cycle. Three-position open-shed jacquard machines are implemented by providing two hooks of a two-position open-shed jacquard machine with a pulley device. The importance of three-position open-shed jacquard machines for weaving jacquard velvet and multiple pile warp thread carpets is that pile weave corrections can be applied at the time of color transitions where this appears necessary in order to avoid mixed contours and double tufts on the pile side when using the two-shot weave.
From the French patent publication no. 1.225.173 a three-position jacquard machine is known with open shed for the middle and bottom position and non-open shed for the top position. This device makes use of two card-operated hooks which are connected to each other by a pulley cord, which runs around the top wheel of a pulley device, and a bottom pulley cord which is secured to a movable grid and is rerouted over the bottom wheel in order then to be connected to the harness cord(s) with the other extremity. With this device the bottom and middle position can be reached or maintained on every pick, the top position can only be reached on every second pick. The disadvantage of this device is the use of pulley cords. Through the repeated passing around and the friction of the cords on the wheels, the cords are subject to wear and tear through which they will break. A device also has to be provided in order to move the bottom pulley grid.
From the French patent publication no. 1.513.410 a three-position open-shed jacquard machine is known which makes use of two hooks of a two-position open-shed jacquard machine and one pulley element. The device makes use of two hooks: this means that for a specific number of cords with three positions, a double capacity in hooks has to be installed. The pulley cords are here again the weak element of the device. With the higher weaving speeds, which are customary at present, the pulley cords break prematurely.
From the French patent publication no. 2 466 541 a similar device is known, but with a movement reinforcement built into the pulley device. The disadvantage of this device is also here the use of twice the number of hooks and pulley cords, and the extra reversing roller which is necessary for the movement reinforcement.
From the European patent publication no. 0 399 930 a device is known which makes use of two complementary hooks, each with its own pulley and one reversing roller in order to achieve the three-position open shed. With this pulley device the pulley cords are passed around in two planes standing perpendicular to each other through which the pulley cords break through fatigue and wear and tear of the fibers in the pulley cords. Here two neighboring hooks are also necessary in order to obtain a three-position device.
These known devices all have the disadvantage that the pulley cords of the pulley device are subject to wear and tear and that the pulley cords will break, which makes premature replacement necessary. This problem becomes more serious with current weaving speeds.
This invention now has the purpose of providing a shed-forming device which prevents the deficiencies and disadvantages of the state-of-the-art, and which is suitable for being used on jacquard devices of different types, namely two-position open-shed jacquard machines and three-position open-shed jacquard machines.
SUMMARY OF THE INVENTION
For this purpose the shed-forming device according to the invention comprises hook elements which are connected to the heddles for the warp threads, and upward and downward moving knives to which the hook elements can hook onto, whereby the hook elements are provided with spring elements and whereby actuators are provided which can influence the spring elements in order to allow the hook elements selectively to hook or not hook onto the upward and downward moving knives. According to the invention each hook element is moreover provided with at least three spring elements in the form of spring legs, at least two spring elements are made as at least double laminated springs, at least two of the spring legs are provided with hooks, destined to work together with the moving knives, one or more actuators are provided which can selectively influence the various spring elements, and retaining hooks are provided for at least a part of the spring elements in a position influenced by an actuator.
According to one specific embodiment of the invention, destined for a two-position open-shed jacquard weaving device, each hook element of the shed-forming device is preferably provided with three spring legs of different lengths in the form of a triple spring element, whereby the two longer legs of a hook, destined to work together with two knives, are provided along one side of the hook element, moving in opposite phase, while each hook element comprises one actuator in order to influence at least one of the spring legs in a high position of the hook element and a second actuator for influencing one or more spring legs in a low position of the hook element, and whereby a retaining hook is provided on or nearby the second actuator which retaining hook retains the shortest of the spring legs in the position influenced by the actuator.
The problem in this embodiment is therefore namely solved by preferably providing a triple laminated hook with a long leg, and middle leg and a short leg. This hook is provided on the bottom with a projection with which the hook can rest on a fixed bottom grid when the hook is not lifted. Above this fixed grid are two knife systems which are movable upward and downward in opposite phase in order to lift the hooks. These knife systems move in the same plane alternately toward and away from each other. The hooks are made of a magnetic material such as e.g. steel. Two electromagnetic coils are provided in order to act on the hooks and to make these bend through which they cannot be engaged by the moving knives. The bottom electromagnetic coil is also provided with a projecting hook in order to be able to hold up the hook with the short leg in its top position.
According to a further characteristic of the invention the triple spring element can therefore be made in the form of a triple laminated spring element, but also in the form of a triple split spring element, or of a double laminated, partially split spring element, or similar.
According to another specific embodiment of the invention, destined for a three-position open-shed jacquard weaving device, each hook element is preferably provided with four spring legs of different lengths in the form of a double laminated, double spring element, whereby each of the two longer legs is provided with one hook destined to work together with two top knives, along one side of the hook element, moving in opposite phase, and whereby each of the two shorter legs is provided with two hooks destined to work together at different heights with two bottom knives, along one side of the hook element, moving in opposite phase, while each hook element comprises five actuators for influencing the various spring legs in different positions of the hook element.
According to a further characteristic of the invention one of the actuators can moreover comprise a locking mechanism in order to be able to retain the hook element at selected heights when one or more of the other actuators so influences the spring legs that the hooks on the corresponding spring legs do not hook onto the upward and downward moving knives.
The problems in this embodiment of the invention are therefore solved by no longer using a pulley device with pulley cords for implementing the three positions. In order to implement the three positions firstly four knife systems are provided which move in one and the same vertical plane. The knives perform a lift in opposite phase. Secondly a hook is provided with four legs, each leg works together with a respective knife. Thirdly for each leg of the hook a means is provided in order to be able to act on the leg of the hook in order to make this bend, such as e.g. an electromagnetic coil. Fourthly a holding catch is provided in order to hold the hook in middle or top position. For that purpose the hook is provided with two notches or holding noses. Fifthly on each short leg a hook is provided. Finally on the hook a nose is provided with which the hook rests in the bottom position on a fixed bottom grid.
According to a preference of the invention the actuators are more specifically electromagnetic and/or piezoelectric actuators.
The characteristics and distinctive features of the invention, and the operation thereof are further explained hereafter with reference to the attached drawings which show four preferred embodiments of the invention. It should be noted that the specific aspects of these embodiments are only described as preferred examples of what is intended in the scope of the above general specification of the invention, and may in no way be interpreted as a restriction on the scope of the invention as such and as expressed in the following claims.
BRIEF DESCRIPTION OF THE DRAWINGS
In these drawings:
FIGS. 1 through 5: are side views of a shed-forming device according to the invention, in a specific embodiment for a two-position open-shed jacquard weaving device, shown in different positions of the hook element and of the knives;
FIGS. 6 through 8: are front views of three embodiments of a hook element for a shed-forming device according to FIGS. 1-5;
FIG. 9: is a side view of a variant of the shed-forming device according to FIGS. 1-5;
FIGS. 10 through 15: are side views of a shed-forming device according to the invention, in a specific embodiment for a three-position open-shed jacquard weaving device, shown in different positions of the hook element and of the knives;
FIG. 16: is a front view of a hook element for a shed-forming device according to FIGS. 10-15.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 a shed-forming device is shown, according to a first embodiment of the invention destined for a two-position open-shed jacquard device, in a position whereby the hook h rests on the bottom grid b and the two lifting knives m 1 and m 2 are at their dead point of lifting completely apart from one another. The hook h 1 is with its top part in front of the coil S 1 , the middle hook h 2 with top part in front of coil S 2 . The long hook h 1 has a hook on the top with which it can be hooked onto the top knife m 1 . The middle hook h 2 also has a hook with which it can be hooked onto the bottom moving lifting knife m 2 . Hook h 2 works through a hole in hook h 1 . The short hook h 3 has a hole or a window opening with which this hook can be hooked onto the projecting hook on coil S 2 . See FIG. 6 with view according to arrow X in FIG. 5.
When the hook according to the pattern determined by the jacquard control has to remain down on the following pick, coil S 2 will be energized through which hook h 2 is bent away from knife m 2 so that hook h 2 comes out of reach of knife m 2 . The hook h 2 has a hole in order not to be impeded by the projecting hook on S 2 . Knife m 2 moves upward, m 1 move downward. Hook h remains standing on bottom grid b. Top knife m 1 has to move past on hook h 1 . For that purpose knife m 1 will on the bottom have a suitable form in order to press hook h 1 away mechanically. Or at this moment coil S 1 can also effectively be energized with a control provided for that purpose through which hook h 1 is bent over and is held out of reach of knife m 1 . The new position of the hook h is represented in FIG. 2.
When the hook according to the pattern determined by the jacquard control has to be up on the following pick no coil will be energized through which hook h 2 with knife m 2 is engaged so that hook h 2 comes into the top position as represented in FIG. 4. Knife m 1 in its downward movement also comes past hook h 1 which is in upward movement. Through the suitable form of knife m 1 this can mechanically press the hook h 1 away or S 1 can at this time be energized by a suitable control.
In order to bring a hook from the position as represented in FIG. 2 into the top position, no coil will be energized. Hook h 1 is not bent and will therefore move upward with knife m 1 . With this upward movement hook h 1 will have to pass by knife m 2 . This can likewise occur mechanically through a suitable form of knife m 2 or through a suitable energization of coil S 2 at this time of crossing. In hook h 2 an elongated hole is provided in order to provide passage for the hook of S 2 (See FIG. 6). The hook reaches the top position as represented in FIG. 3.
In order to hold the hook up as represented in FIG. 3, coil S 2 will be energized. The short hook h 3 is with its top part right in front of coil S 2 and the window opening of h 3 is in front of the projecting hook on coil S 2 . Because of the bending the hook h 3 is hooked onto this projecting hook and the hook will remain up during the downward movement of knife m 1 . The hook h remains in top position as represented in FIG. 4. In order to hold the hook in the position from FIG. 4 coil S 2 will again be energized, otherwise the hook just comes back down with knife m 2 .
In order to allow the hook in top position as represented in FIG. 3 to move downward into position as represented in FIG. 2, no coil will be energized. With its upward movement knife m 2 has to go past the hook h 2 and for that purpose coil S 2 will be energized at the time of the crossing. This position is illustrated in FIG. 5, direction of movement B and hooks drawn in full lines.
In order to allow the hook from above to move out of the position as represented in FIG. 4 downward into position as represented in FIG. 1, no coil will be energized. With its upward movement knife m 1 has to go past the hook h 1 and at this time coil S 1 will be energized in order to hold hook h 1 out of reach of knife m 1 . This position is illustrated in FIG. 5, direction of movement B and hooks drawn in dotted lines.
From the preceding specification it appears that each hook can be held in its position or can be moved to the other second position. The device according to the invention therefore complies with the open-shed principle. The device according to the invention works without pulley elements. Due to the multilayered hook the footprint occupied is very limited.
Instead of a multilayered hook the hook can also be formed by three flat steel strips situated next to each other in the same plane. See FIG. 7. The long hook h 1 and middle hook h 2 can also be situated next to each other and the hook h 3 can then stand against both. See FIG. 8. With this construction of the hook the projecting hook on coil S 2 can work in the path of hook h 1 and a hole in hook h 2 is no longer necessary.
As shown in FIG. 9, the device can also work with a third actuator or selection element S 3 in the form of a rotating catch which is electromagnetically or piezoelectrically controlled in order to hold the hook h in top position. This selection element can e.g. act on hook h which is provided for that purpose with a window opening, a notch or a hook. This can of course be effected with the additional cost of one selection element. The hook can then be limited to two layers h 1 and h 2 , or two hooks situated next to each other in the same plane, whereby each hook h 1 and h 2 each has a coil S 1 , respectively S 2 in its path.
In FIGS. 10-16 a shed-forming device is shown, according to an embodiment of the invention destined for a three-position open-shed jacquard device. In these figures the hook with four legs is schematically represented for the sake of simplicity with each leg situated in a different plane. The legs can also be situated next to each other two by two in the same plane (see FIG. 16), or all four can be situated next to each other in the same plane. The harness cords are attached at the bottom of the hook and a spring load constantly pulls the hook down. The knives serve to lift the hooks upward or downward against the spring load. This device is also particularly suitable for a harness-free jacquard device with three positions. The jacquard heddles through which the pile warp threads are pulled through, can be directly connected to the hook and the heddle retracting spring can possibly be partially or completely built into the shank of the hook.
In order to implement the three positions firstly four knife systems m 1 , m 2 , m 3 and m 4 are provided which move in one and the same vertical plane. See FIG. 10. The knives m 1 and m 2 perform a lift 2H in opposite phase: i.e. when m 1 is in the bottom dead point, then m 2 is in the top dead point. The knives m 3 and m 4 perform a lift H in opposite phase. Secondly a hook is provided with four legs, each leg works together with a respective knife m 1 , see FIG. 16. Thirdly for each leg of the hook a means is provided in order to be able to act on the legs of the hook in order to make this bend. This means is e.g. an electromagnetic coil S 1 . Fourthly a holding catch k with operating actuator S 5 is provided in order to hold the hook in middle or top position. For that purpose the hook is provided with two notches or holding noses situated at a distance equal to (H-2×removal play). Fifthly on each short leg h 3 and h 4 a second hook h' 3 and h' 4 is provided at a distance equal to (H-2×removal play). The removal play is the distance between the top of the knife and bottom of the hook on each leg of the hook. A removal play is necessary in order to be able to remove the leg from the knife. Finally a nose is provided on the hook with which the hook in bottom position rests on a fixed bottom grid b.
In the bottom position the hook rests on the fixed bottom grid b. In FIG. 10 this position is represented with the knives m 1 and m 3 in their bottom dead point and m 2 and m 4 in top dead point. In FIG. 11 the other position is represented. These positions are repeated cyclically every two picks or weft insertion cycles. In FIGS. 12 and 13 the hook is represented in middle position and in FIGS. 14 and 15 in top position, in each case with the respective positions of the lifting knives. A preferred embodiment of the hook is shown in FIG. 16.
When according to the prescribed pattern the hook has to remain down on a following pick, the coils S 1 and S 3 will be triggered in order to make the legs h 1 respectively h 3 bend, so that these cannot be carried by the ascending knives m 1 and m 3 . Instead of coils other means can also be provided for making the legs bend. The catch k is released by coil S 5 . The knives m 1 and m 3 move upward, and the knives m 2 and m 4 downward. At the end of this movement the bottom of the knives m 2 and m 4 will strike against the top of the legs h 2 and h 4 . In order to prevent this the bottom of the knives will be given a bevelled form, so that the top of the hooks can be mechanically pressed away by the knives. At that time the coils S 2 and S 4 can also appropriately be triggered in order to make the legs bend, so that these come out of reach of the knives, this will be referred to in what follows as an avoiding action. The hook therefore remains resting on the bottom grid b and remains in bottom position as represented in FIG. 11.
If the hook on the following pick has again to remain down, then coils S 2 and S 4 will be triggered in order to bend the legs h 2 and h 4 away from the knives m 2 and m 4 . The catch k is released by coil S 5 . At the end of their movement the bottom of the knives m 1 and m 3 will strike against the top of the legs h 1 and h 2 . In order to prevent this the bottom of the knives will be given a bevelled form, so that the top of the hooks can be mechanically pressed away. At that time an avoiding action can appropriately be performed, by triggering the coils S 1 and S 3 in order to make the legs bend, so that these come out of reach of the knives. The hook therefore remains resting on the bottom grid b and remains in bottom position as represented in FIG. 10.
When a hook according to the prescribed pattern has to move from the bottom position to the middle position this is only possible by changing from the position represented in FIG. 10 to the position in FIG. 13 or from the position represented in FIG. 11 to the position in FIG. 12, in view of the movement sequence of the knives.
In order to bring a hook from the bottom position, situation represented in FIG. 10, into the middle position, represented in FIG. 13, coil S 1 will be triggered in order to hold the top of the leg h 1 out of reach of knife m 1 . The catch k is released by coil S 5 . The hook will be carried with leg h 3 by the ascending knife m 3 over a lift equal to (H-removal play) to the middle position, where leg h 3 remains resting on knife m 3 . The knives m 2 and m 4 in their descending movement meet the tops of the ascending hooks h 2 and h 4 . In order to prevent passing strikes the bottom of the knives will be suitably bevelled and an avoiding action will be performed by triggering the coils S 2 and S 4 at that time. The hook rests with leg h 3 on the knife m 3 , see FIG. 13, and in order to be able to remove leg h' 4 from the knife m 4 , the second hook h' 4 on the leg h 4 will be placed at a distance from the top hook equal to (H-2×removal play).
In order to bring a hook from the bottom position, situation represented in FIG. 11, into the middle position, situation represented in FIG. 12, coil S 2 will be triggered in order to hold the top of the leg h 2 out of reach of knife m 2 . The catch k is released by coil S 5 . The hook will be carried with leg h 4 by the ascending knife m 4 over a lift equal to (H-removal play) to the middle position, where leg h 4 remains resting on knife m 4 . The knives m 1 and m 3 in their descending movement meet the tops of the ascending hooks h 1 and h 3 . In order to prevent a collision the bottom of the knives will be suitably bevelled and an avoiding action will be performed by triggering the coils S 1 and S 3 at that time. The hook rests with leg h 4 on the knife m 4 , see FIG. 12, and in order to be able to remove leg h' 3 from the knife m 3 , the second hook h' 3 on the leg h 3 will be placed at a distance from the top hook equal to (H-2×removal play).
The hooks can also be brought from middle position to bottom position. In order to bring a hook from middle position, in FIG. 13, to the bottom position, of FIG. 10, coil S 4 will be triggered and the catch will be released by coil S 5 . The hook h' 4 is removed from knife m 4 , the hook remains resting with the leg h 3 on the knife m 3 and will move down with this knife. The descending hook will meet the ascending knife m 2 with leg h 2 and in order to prevent engagement an avoiding action will be performed by triggering coil S 2 at that time. The hook on leg h 4 also meets knife m 4 and in order to prevent engagement an avoiding action will also be performed here by again triggering coil S 4 at that time. An avoiding action will be performed by triggering coil S 1 in order to make h 1 veer away when knife m 1 has to pass by that top with its underside. The hook comes into bottom position and rests with its nose on the bottom grid b.
In order to bring the hook from the middle position of FIG. 12 to bottom position of FIG. 11, coil S 3 will be triggered and the catch will be released by coil S 5 . The hook h' 3 is removed from knife m 3 , the hook remains resting with leg h 4 on knife m 4 and will move downward with this knife. The descending hook will meet the ascending knife m 1 with leg h 1 and in order to prevent engagement an avoiding action will be performed by triggering coil S 1 . The hook of the leg h 3 also meets knife m 3 and in order to prevent engagement an avoiding action will also be performed here by again triggering coil S 3 . The hook comes into bottom position and rests with its nose on the bottom grid b.
The hook can also remain in the middle position. In order to hold the hook in the middle position, from the position in FIG. 13 to that of FIG. 12, the coil S 4 will be triggered, through which the hook h' 4 is held out of reach of the knife m 4 , and the catch k will be made to engage in the top notch of the hook by coil S 5 . The hook descends with knife m 3 until the notch rests on the catch k. The hook remains in the middle position. Knife m 2 has to pass by the hook of leg h 2 without engaging it, for that purpose a removal action will be performed by triggering coil S 2 at that time in order to remove the hook of the leg h 2 from the knife m 2 . The knives m 1 and m 3 must respectively pass by h 1 and h' 3 , for that purpose an avoiding action will be performed by triggering the coils S 1 and S 3 .
In order to hold the hook from the middle position of FIG. 12 in the middle position in FIG. 12, coil S 3 will be triggered, through which the hook h' 3 is held out of reach of the knife m 3 , and the catch k will be made to engage in the top notch of the hook by coil S 5 . The hook descends with the knife m 4 until the notch rests on the catch k. The hook remains in the middle position. Knife m 1 has to pass by the hook of leg h 1 without engaging it, for that purpose a removal action will be performed by triggering the coil S 1 at that time in order to remove h 1 from the knife m 1 . The knives m 2 and m 4 must respectively pass by h 2 and h' 4 , for that purpose an avoiding action will be performed by triggering the coils S 2 and S 4 .
The top position can be reached from every bottom position. The transitions of the positions represented in FIG. 10 to those of FIG. 15 and those from FIG. 11 to FIG. 14 and vice versa should be demonstrated. In order to go from bottom position, as represented in FIG. 10, to the top position, as represented in FIG. 15, first no coil will be triggered. The catch is released by coil S 5 . The hook will move with knife m 1 over a lift (2H) upward into the top position. The knife m 2 has to pass by leg h 2 , for that purpose an avoiding action will be performed by triggering coil S 2 at that time. The hook h' 3 has to pass by the knife m 3 , at that time an avoiding action will be performed by triggering the coil S 3 . The knife m 4 has to pass by h 4 and h' 4 , for that purpose an avoiding action will be performed by triggering coil S 4 at that time. The hook rests on knife m 1 .
In order to go from bottom position, as represented in FIG. 11, to the top position, as represented in FIG. 14, first no coil will be triggered. The catch is released by coil S 5 . The hook will move with knife m 2 over a lift equal to (2H) upward into the top position. The knife m 1 has to pass by leg h 1 , for that purpose an avoiding action will be performed by triggering coil S 1 at that time. The knife m 3 has to pass by leg h 3 and hook h' 3 , at that time the coil S 3 will be triggered in order to perform an avoiding action. The knife m 4 has to pass by hook h' 4 , for that purpose the coil S 4 will be triggered at that time in order to perform an avoiding action. The hook now rests on knife m 2 .
In order to go from top position, as represented in FIG. 15, to the bottom position, as represented in FIG. 10, coil S 3 will be triggered, through which the hook h' 3 is removed from the knife m 3 . The catch is released by coil S 5 . The hook will move with knife m 1 over a lift equal to (2H) downward into the bottom position. The knife m 2 has to pass by the hook of leg h 2 without engaging it, for that purpose a removal action will be performed by triggering coil S 2 at that time in order to remove the hook of leg h 2 from the knife m 2 . The hook of leg h 3 has to pass by the knife m 3 , at that time a removal action will also be performed by again triggering the coil S 3 . The hook h' 4 and hook of leg h 4 have to pass by the knife m 4 without engagement movement, for that purpose a removal action will be performed by triggering the coil S 4 at that time. The hook now rests on the bottom grid b.
In order to go from top position, as represented in FIG. 14, to the bottom position, as represented in FIG. 11, coil S 4 will be triggered, through which the hook h' 4 is removed from the knife m 4 . The catch is released by coil S 5 . The hook will move with knife m 2 over a lift (2H) downward into the bottom position. The hook of the leg h 1 has to pass by knife m 1 without engagement, for that purpose a removal action will be performed by triggering coil S 1 at that time. The hook of leg h' 3 and the hook of leg h 3 has to pass by knife m 3 without engagement movement, at that time coil S 3 will be triggered in order to perform a removal action. The hook now rests on the bottom grid b.
The hook can also remain in the top position. In order to hold the hook in top position through transition from the situations in FIG. 15 to FIG. 14, no coil will be triggered and the catch k is engaged in the bottom notch of the hook by coil S 5 . The hook will rest on the catch and because of this remains in the top position. In order to hold the hook in top position through transition from FIG. 14 to FIG. 15, no coil will be triggered and the catch k is engaged by coil S 5 in the bottom notch of the hook, which will rest on the catch and because of this remains in top position. With both transitions no removal action nor any avoiding action need be performed.
The hook can be brought from the middle position to the top position and vice versa. In order to come from the middle position, as represented in FIG. 12, to the top position, as represented in FIG. 15, no coil will be triggered and the catch k is released by the coil S 5 . The hook is carried by the knife m 3 with the hook h' 3 over a lift equal to (H) and at the end of this lift the knife m 1 takes up the hook with the hook of the leg h 1 . The hook rests with the leg h 1 on the knife m 1 through which between the hook h' 3 and the knife m 3 again a removal play develops. The top of the ascending hook h 2 must avoid the descending knife m 2 , for that purpose an avoiding action will be performed by triggering coil S 2 . The hook h' 4 must avoid the knife m 4 , for that purpose an avoiding action will be performed by triggering coil S 4 .
In order to come from the middle position, as represented in FIG. 13, to the top position, as represented in FIG. 14, no coil will be triggered and the catch k is released by the coil S 5 . The hook is carried by the knife m 4 with hook h' 4 over a lift (H) and at the end of this lift the knife m 2 takes up the hook with the hook of the leg h 2 . The hook rests with the leg h 2 on the knife m 2 through which between the hook h' 4 and the knife m 4 again a removal play develops. The leg h 1 of the ascending hook must veer away for the descending knife m 1 , for that purpose an avoiding action will be performed by triggering the coil S 1 at that time. The hook h' 3 of the ascending hook must pass by the descending knife m 3 , for that purpose an avoiding action will be performed by triggering coil S 3 .
In order to bring back the hook from the top position, as represented in FIG. 15, to the middle position, as represented in FIG. 12, no coil will be triggered and the catch k is released by the coil S 5 . The hook moves with the knife m 1 downward, the support is transferred by the hook h' 3 to the knife m 3 through which the hook will perform a descent (H) with the knife m 3 . The hook of the leg h 2 may not be engaged by the knife m 2 , for that purpose a removal action will be performed by triggering the coil S 2 at that time. The hook h' 4 may not be engaged by the knife m 4 , for that purpose a removal action will be performed by triggering the coil S 4 at that time. The hook of the leg h 4 will finally hook onto the knife m 4 through which again the removal play between the hook h' 3 and the knife m 3 develops.
In order to bring back the hook from the top position, as represented in FIG. 14, to the middle position, as represented in FIG. 13, no coil will be triggered and the catch k is released by the coil S 5 . The hook moves with the knife m 2 downward, the support is transferred by the hook h' 4 to the knife m 4 through which the hook will perform a descent equal to (H) with the knife m 4 . The hook of the leg h 1 may not be engaged by the knife m 1 , for that purpose a removal action will be performed by triggering the coil S 1 at that time. The hook h' 3 may not be engaged by knife m 3 , for that purpose a removal action will be performed by triggering the coil S 3 at that time. The hook of the leg h 3 will finally hook onto the knife m 3 through which again the removal play between the hook h' 4 and the knife m 4 develops.
From the preceding specification it appears that each hook can be held in its position or can be moved to both other positions. The device therefore complies with the open-shed principle and this in fact for the three positions. The device works without pulley cords or any pulley.
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A shed-forming device for individually controlling heddles for warp threads of a weaving device has hook elements connected to the heddles for the warp threads. Upward and downward moving knives are provided to which the hook elements can hook onto. The hook elements are provided with spring elements and actuators connected to the spring elements allow the hook elements to selectively hook or not hook onto the upward and downward moving knives. Each hook element also has at least three spring elements in the form of spring legs. At least two spring elements are made as double laminated springs. At least two of the spring legs are provided with hooks for working together with the moving knives. One or more actuators are provided which selectively influence the various spring elements. Retaining hooks are provided for at least a part of the spring elements in a position determined by an actuator.
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This is a divisional of Ser. No. 07/549,756 filed Jul. 9, 1990 now U.S. Pat. No. 5,067,202.
BACKGROUND OF THE INVENTION
The invention relates to a method of maintaining a predetermined quality of a carded sliver produced in a card and/or drafted in a drawframe, the sliver being delivered into a can be a sliver delivery device in a continuous spinning mill process.
The actual spinning machine which produces the yarn end product is of course the costliest machine in the spinning process and is therefore required to operate at maximum efficiency--i.e., to have very short downtimes.
The various machines before and after the spinning machine are therefore so designed performance-wise as to overperform relative to the spinning machine so that the same does not have to wait for the feeding of its feedstock nor for subsequent processing, for example, in a winder.
The overperformance system applies to all the machines involved in the feeding of the feedstock for the spinning machine--i.e., in the blowroom of a spinning mill--viz. as will be described hereinafter with reference to drawings, any machine in the working process has a higher output than the machine immediately following it. This is how the present day machine park in spinning mills has evolved; however, if a blowroom process has to be performed by a machine considerably more expensive than a following machine (excluding the spinning machine), the previous machine may of course have a shorter downtime than the subsequent machine for the sake of economic balance.
These differences in performance can of course be compensated for by buffer stores of product which will vary in size in dependence upon the difference between the performance of the previous stage and the performance of the next stage. Clearly, large buffer stores are undesirable for purely economic reasons and in the course of spinning mill automation systems must be devised throughout from bale opening to end product either to eliminate the known manual intermediate buffer stores or at least so to organize them so that they are automatable.
SUMMARY OF THE INVENTION
The problem which the inventor had to address was therefore to optimize the performance steps in a spinning mill blowroom as to minimise the size of the buffer stores for intermediates and to facilitate automation.
To solve the problem, according to the invention, the card and/or drawframe, which each have a predetermined overproduction relative to a spinning machine associated with the process, have a predetermined temporary decrease in production which temporarily compensates correspondingly for the overproduction.
Also suggested for performing the method is a drawframe wherein the drawframe control has a computer part which at the changeover to decreased production effects the programmed slowdown and, if applicable, the stoppage and at the changeover from decreased production effects the programmed acceleration preceded, if applicable, by restarting.
Also suggested for performing the method is a combined card and drawframe system wherein the drawframe system has a supply of cans and, disposed in such supply, a can row with a can counter and the same responds to the presence of a predetermined number of cans in the row by outputting a signal.
The advantage of the invention is that it offers a basis for optimising profitability and a possibility for automation.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in greater detail hereinafter with reference to embodiments.
In the drawings:
FIG. 1 is a diagram showing the efficiency of various items of spinning mill machinery;
FIG. 2 is an illustration in graph form of the method steps according to the invention;
FIG. 3 shows a variant of FIG. 2;
FIG. 4 is a diagrammatic view of a card having a sliver delivery device, the view being in cross-section;
FIG. 5 is a diagrammatic plan view of the card of FIG. 4;
FIG. 6 is a diagrammatic plan view of a combined card and drawframe system, and
FIGS. 7 and 8 are each a view to an enlarged scale of a detail of the system shown in FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is an efficiency diagram of a number of spinning mill machines in which total or maximum efficiency is represented by a chain-dotted line W and the downtimes of the various machines are illustrated (in purely diagrammatic form) by means of spacer arrows DP, DK, DST, DF, DR and DSP.
The letters in the hatched rectangles have the following meanings:
______________________________________The letter P denotes blowroom machinesThe letter K denotes cardsThe letter ST denotes drawframesThe letter F denotes roving framesThe letter R denotes ring spinning machinesThe letter SP denotes winders______________________________________
The rectangles containing the letters P to SP are purely diagrammatic representations of machine performances or outputs, their areas being such that the area of any machine type is less than the area of the immediately previous type except for the area representing the winders, which is greater than the area representing the ring spinning machines. The aim of the diagram is to visualize the decrease in output as seen from the blowroom machines up to and including the ring spinning machine, the differences between the areas being exaggerated so that the differences can be more clearly visualized. Also, the areas shown are not in their actual relation to downtime and the latter too is shown for the sake of clarification with greater differences than are usually found in practice.
Correspondingly, in the co-ordinate system shown in FIGS. 2 and 3, efficiency is plotted along the ordinate and the steps of the method along the abscissa. As previously stated, the steps of the method are:
Blowroom=P
Card room=K
Drawframe=ST
Roving frame=F
Ring spinning machineq=R
Winding room=SP
Of the machine types P to F the card is the most complex--i.e., a machine in which a large number of technical and technological functions must co-operate if a uniform and high-quality card sliver is to be produced.
Consequently, the co-operation between the various functions does not of course lead to absolutely the same result as regards sliver quality in all the performance steps and the same assumption is made further on in the production process--i.e., in drafting and in the roving frame--so that it may be necessary to separate out the carded sliver in the event of substantial output changes.
In the method acording to the invention, to link this elimination of a sliver which cannot be used in the subsequent stages with can changing in the card, when it is required to decrease card output, the card continues to produce at its normal output until can changing becomes necessary, the card being changed over to decreased output shortly after can changing, either until stoppage of the card or until further production at a minimum output step.
The decrease in production occurs with a slowdown of the kind represented by a line 1 in FIG. 2, where the card is brought to a standstill, then restored after a controlled time T to full output represented by lines 2a, 2b, a line 3 representing this acceleration.
Chain-dotted lines 4, 5 indicate the activation times for can changing, the line 4 denoting the activation time before the slowdown 1 while the line 5 denotes the changeover time for further can changing after the acceleration 3, whereafter the silver produced on full output is delivered into the next can.
Consequently, no silver produced on decreased output can be delivered into a "good" can intended to receive only silver which has been produced on full output.
FIG. 3 shows the same principle except that output is not reduced to zero as it is in FIG. 2; instead the card continues to produce at a very low output, for example, 10% of normal output until the control instruction for acceleration back to normal output is given.
The advantage of the method shown in FIG. 3 is that cards which cannot be completely guaranteed to produce breakage-free sliver until the card stops can continue to produce on low output without a large quantity of waste sliver accumulating. The decrease in production shown in FIG. 3 is represented by a line 6. Since the other lines relate to functions substantially corresponding to the functions of FIG. 2, the latter lines have the index 1 added to their references.
FIG. 4 is a view in cross-section of a known card 10 having a known sliver delivery device 11 and, disposed between the same and the card 10, a known sliver loop sensor 12.
The card 10 is a card produced by the Applicants and sold world-wide as type C4/C1 and the facility comprising the elements 11, 12 is sold by the Applicants world-wide as type CBA.
The two combined machines were presented to the public, for example, at the 1989 American Textile Machinery Exhibition (ATME) in Greenville.
The card 10 and the device 11 operate through the agency of a control 13 which triggers the card with the necessary output-controlling signals and which imposes on the deliver device 11 a sliver delivery corresponding to card output, sliver delivery being adapted by means of the sliver loop control 12 to the alteration in card output in dependence upon the alteration thereof.
Sliver output--i.e., the weight of sliver produced per unit of time--is measured by means of a measuring roller pair 14 at the card exit and communicated by means of a measuring signal 15 to the control 13. The same deduces from the signal 15 an output-controlling signal 16 which controls the motor 17 driving the delivery device 11.
Alterations in sliver delivery after the roller pair 14 are recorded by the sensor 12 and communicated by means of a signal 18 to the control 13 so that by means of the signal 16 the motor 17 has its speed varied in accordance with the change in output.
A novel feature provided by the invention is that the control 13 has a computer attachment which is indicated in purely diagrammatic form by the reference 19 and which responds to the operation of a switch to be described hereinafter by decreasing card output in accordance with either FIG. 2 or FIG. 3, further operation of the same switch accelerating the card in the manner shown in FIGS. 2 and 3.
The decrease in output and the acceleration of the card cause a change in the position of loop 20 of the sliver 21 which the card 10 produces and which the device 11 delivers into a can 22. This change in the position of the loop 20 produces corresponding signals 18 so that the delivery device 11--i.e., motor 17 thereof-either slows down or accelerates the device 11 correspondingly. This feature provides the advantage that no additional synchronization between the card motors and the motor 17 driving the device 11 is required.
FIG. 5 is a plan view of the card 10 and delivery device 11 and also shows the sliver loop sensor 12.
Like elements in FIGS. 4 and 5 have the same references.
As previously stated, the device 11 is known from the publication. A novel feature provided by the invention is that the entering empty cans are conveyed by a conveyor belt 23 as far as an exit position M in which a displacing arm 24 of can displacer 25 moves the can into sliver delivery position N in which sliver is introduced into the can.
The can which has been filled with good sliver is moved by a second displacing arm 26 into a first removal position T on a conveyor belt 27 while a can which has been filled with a low-output sliver is moved into a second removal position Q on a conveyor belt 28. The computer part 19 controls these operations.
The arms 24, 26 can so pivot (not shown) as to be pivoted from a vertical position, in which they can be moved past the stationary cans, into a horizontal position in which they can displace the cans. The arms 24, 26 are parts of the delivery device 11.
The significance of the conveyor belts 23, 27, 28 will be described in greater detail with reference to FIG. 6.
FIG. 6 shows a number of cards 10 so disposed parallel to and adjacent one another that the conveyor belts 23, 27, 28 extend to a can conveyor 29. The cans on the conveyor belts are moved in directions indicated by arrows in FIGS. 5 and 6--i.e., the cans on the belt 23 are moved towards the can delivery and the cans on belts 27, 28 are moved towards the can conveyor 29. The cans on the belt 23 are empty cans, the cans on the belt 27 are full cans and the cans on the belt 28 are cans containing the sliver produced with the card on decreased output so that a can may have any level of filling.
So that the cans can either be pushed off the conveyor 29 on to the belt 23 or pulled off the belts 27, 28 on to the conveyor 29, the conveyor 29 has pneumatic reciprocating actuators 30, the operation of which is shown in greater detail in FIG. 8. As can be gathered therefrom, the actuators comprise a suction and shifting shoe 31 adapted to the diameter of the cans 22 and having an air-permeable but plastically deformable wall 32 which is adapted to can diameter and which covers a hollow member 33 associated with a bore 34 extending through piston rod 35 and piston 36, so that cavity 37 communicates with pressure chamber 38 of cylinder 39.
At its end near the delivery chamber, the bore 34 has a check flap 40; when the chamber 38 is maintained at a positive pressure by way of a compressed air valve 41 connected to the chamber 38, the flap 40 closes the bore 34 so that the piston 36 and, therefore, the shoe 31 can move in the direction indicated by an arrow 42.
When, however, a suction valve 43, which is also connected to the chamber 38, is open instead of the compressed air valve 41, the chamber 38 is at a negative pressure, so that the flap 40 opens and the cavity 37 is at a negative pressure. The negative pressure sucks tightly on to wall 32 of a can 22 in contact therewith which is also displaced together with the shoe 31 in the direction indicated by an arrow 44 until the hollow member 33 contacts an abutment 90 limiting this movement in the direction 44.
Sensors detecting the position of the shoe 31 for the valves 41, 43 to be changed over by means of a control (not shown) are not shown here.
The suction valve 43 is connected to a suction source 45 and the compressed air valve 41 to a compressed air source 46.
By means of a pneumatic reciprocating actuator 30, empty cans are pushed off the can conveyor 29 on to the conveyor belt 23 and full cans are pulled off the conveyor belt 27 on to the conveyor 29; the cans are also pulled off the belt 28 on to the conveyor 29.
The can conveyor 29 is movable on rails 47. A control station controlling movement of the can conveyor 29 is illustrated diagrammatically in the form of a rectangle having the reference 48; it is the subject of the Applicants' patent application No. CH 0 4410/88-1 and is not further described here.
A drawframe 50 is contiguous with the rails 47 and is disposed on a side remote from the cards of the rail oval shown in FIG. 6; the drawframe 50 takes over the cans filled by the cards 12 and processes their sliver. A drawframe of this kind is known and, for example, sold by the Applicants world-wide under the designation D1.
The drawframe includes the actual drafting unit 51 which drafts slivers 53 infed on a feed table 52.
The slivers 53 are delivered from can row 54 in which emptying cans are disposed. Can row 55, which extends parallel to row 54, consists of full cans in a reserve position. Can row 56 which is parallel to and in FIG. 6 immediately above row 55 is another full-can row but a row adapted to take up full cans from the conveyor 29.
On the bottom side of the feed table 52, looking at FIG. 6, a row of empty cans 57 stands ready parallel to the feed table 52 for transfer to the can conveyor 29.
This can arrangement just described is shown more clearly and to an enlarged scale in FIG. 7. As will be apparent, the cans of row 56 can be moved both in the conveying direction 58 and in the conveying direction 59, movement in the direction 58 being producted by discrete conveyor belts 60 disposed in adjacent end-to-end relationship to one another whereas the cans 52 can be moved in the direction 59 by reciprocating actuators 30. The same move the cans 22 from row 56 to row 55. Conveyor belts 60 are provided to move the cans 22 in the rows 55, 54 but are at a 90° offset in their conveying direction from the conveyor belts of the row 56 so that the cans are moved in the direction 59.
The cans emptied in the row 54 are moved through below the feed table 52 by means of another row of conveyor belts which move the cans so far in the direction 59 that the cans can be drawn by further actuators 30 on to the conveyor belts of the row 57. The cans move in the direction 61 on the latter belts for conveyance towards the can conveyor 29. Instead of the discrete conveyor belts of the row 57 shown in FIG. 7, a single conveyor belt (not shown) can be used.
Cans are displaced into the next row--i.e., e.g., from row 56 into row 55 and so on--when the cans in row 54 are empty, a state which is detected by a sliver sensor (not shown) on the feed table 52, for example, at the deflections 91 which deflect the sliver through 90°, and which is fed into a control 63 as a signal 92 (not completely shown). The control 63 initiates activation of whichever conveyor belts and reciprocating actuators move the cans in the direction 59--i.e., the conveyor belts 55, 54, 62 and the actuators 30 for both pushing and pulling the cans.
The control 63 is also responsible for moving the cans in the drawframe 50 in good time--i.e., changing full cans for empty cans--something which is performed in basically the same way as described with reference to the cards 12 and indicated by corresponding arrowed directions. The actual drafting unit 51 of the drawframe 50 is controlled by means of an associated computer part for both stop-start operation and low-output operation.
A can conveyor 29.1 is provided for the drawframe 50 in just the same way as for the cards 12 and has the same function as the conveyor 29 but it conveys the full and empty cans to a machine which follows the drawframe, such as one or more roving frames.
The cans previously described which contain sliver produced during low-output operation of the cards 12 and which are supplied with the sliver 28 to the can conveyor 29 are delivered thereby to a standby row 70 in which the cans are conveyed on a conveyor belt in a direction 71 so that they can be received by further means (not shown) and conveyed to a clearing station (not shown), whence empty cans return and are introduced into a standby row 72 also in the form of a conveyor belt so operated that the empty cans can be conveyed in a direction 73 towards the can conveyor 29 and delivered thereto.
The can-displacing arrangement for the drawframe 50 corresponds basically to the arrangement described for the cards 12 and so will not be described and illustrated again. Similar considerations apply to the standby position of the full and empty cans containing sliver of below normal quality so that this sliver is cleared in the clearing station.
Basically, however, output can be controlled down to zero with the drawframe 50 without any loss of quality in the drafted sliver so that the conveyor belt and the corresponding function associated with reception of the cans, similarly to the cans on the belt 28, can be omitted.
Finally, the row 56 has a can detector which by means of a signal 80 informs station 48 of the number of cans present in the row.
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The present invention is directed to a drawframe having a sliver delivery device and a computer part for maintaining a predetermined quality of sliver, wherein there is a predetermined overproduction from a card and/or a drawframe relative to a spinning machine. The arrangement temporarily decreases production to temporarily compensate for the overproductions. The sliver which is produced during the decrease in production may be delivered to a separate can.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation, under 35 U.S.C. §120, of copending international application No. PCT/EP2012/002644, filed Jun. 22, 2012, which designated the United States; this application also claims the priority, under 35 U.S.C. §119, of German patent application No. DE 10 2011 105 869.2, filed Jun. 28, 2011; the prior applications are herewith incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a method for checking the operation of a photovoltaic module of a photovoltaic power station. The photovoltaic module has a positive terminal, a negative terminal and a number of solar cells, in particular thin-layer solar cells. Furthermore, the invention relates to an associated measuring instrument.
Photovoltaic power stations generate an electrical current from solar radiation. For this, the photovoltaic power station generally has a number of photovoltaic modules, which each comprise a number of solar cells operating in a conventional manner. In the event of a certain degree of solar radiation, a characteristic electrical voltage is present at each of the solar cells depending on the materials from which the solar cells are made and depending on the combination of these materials. In order to achieve a predetermined electrical voltage and power by means of one of the photovoltaic modules, the solar cells of this photovoltaic module are interconnected in series and/or in parallel in a certain way. The photovoltaic modules in turn are electrically connected to one another in such a way that the photovoltaic power station has a certain output voltage.
The photovoltaic modules and the solar cells contained therein exhibit aging phenomena. These aging phenomena, also referred to as degradation, result in a reduction in the efficiency. In general, the efficiency declines by between 10% and 20% within 20 years owing to a change in the material within the solar cells. Furthermore, total failure of individual photovoltaic modules occasionally takes place. Preferably, defective or prematurely degraded photovoltaic modules would need to be replaced in order to maintain the power of the power station. In order to determine whether or not any such photovoltaic modules are present, the photovoltaic modules need to be checked for their operation. Generally, in order to check the operation of the photovoltaic modules, the photovoltaic modules need to be detached individually from the combined structure and checked separately, wherein said photovoltaic modules are connected to conventional current and/or voltage measuring instruments.
In the case of solar radiation on the photovoltaic power station, however, the electrical voltage, which can generally reach up to 1000V, is present at the electrical connections between the individual photovoltaic modules. In the event of disconnection of the connections, therefore, arcs can occur which damage the photovoltaic modules or other components of the photovoltaic power station or could injure or kill any person performing this activity. In addition, when disconnecting the electrical connections between the individual photovoltaic modules, the current flow through said photovoltaic modules is interrupted, with the result that no electrical current is produced or the supply is at least restricted during the checking of the power station. In any case, the photovoltaic module to be checked is not available for power generation. Therefore, it is generally uneconomical to perform a check on the operation of the photovoltaic modules of the photovoltaic power station, with the result that defective modules are not identified and replaced, which results in a reduced output of the power station.
International patent application publication WO 2010/139364 A1 describes, for monitoring a photovoltaic system comprising a plurality of photovoltaic modules, assigning a measurement system to said photovoltaic modules for the module-specific detection of the current intensity and the voltage in each case, i.e. in module-linked fashion, in order to thereby identify faulty operation and to localize such instances of faulty operation in the photovoltaic system. The large number of required measurement systems results in an undesirably high degree of complexity, however. In addition, only the measurement of the total voltage of the respective module, but not a voltage measurement at different cells (module or solar cells) of a photovoltaic module which conventionally has a plurality of cells is possible by means of the known device.
German utility model (Gebrauchsmuster) DE 20 2011 003 211 U1 describes a measuring arrangement for a photovoltaic system. The photovoltaic system comprises a photovoltaic module, which is connected to an inverter via a first energy transmission path. The inverter is connected to an electrical grid via a second energy transmission path. A sensor which is a current or voltage sensor is arranged in each energy transmission path. The inverter is monitored by means of the two sensors.
U.S. Pat. No. 6,515,215 B1 describes a photovoltaic system and a method for detecting faulty photovoltaic modules. For this purpose, the photovoltaic module has, in addition to solar cells, discrimination means which are connected in parallel or in series with a photovoltaic cell. The discrimination means have signal means, by means of which a signal is generated. The signals means emit light, for example, or generate a magnetic or electric field. In the case of the electric field, the signal means is a capacitor, whose surface charge is determined.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a method and device for checking the functionality of a photovoltaic module which overcome the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and which provides for an improved check on the operation of a photovoltaic module of a photovoltaic power station.
With the foregoing and other objects in view there is provided, in accordance with the invention, a method of checking the operation of a photovoltaic module of a photovoltaic power station, the photovoltaic module having a positive terminal, a negative terminal and a number of solar cells; when solar radiation is incident on the photovoltaic module, an electrical voltage is generated between the positive and negative terminals and an electrical current flows via the terminals; and the electrical voltage causes an electric field with a given electric field strength to be emitted by the photovoltaic module into a surrounding environment thereof;
the novel method comprises the following steps:
during an operation of the power station, measuring the electric field strength of the electric field generated as a result of the solar radiation at a given measurement location outside the photovoltaic module; and
determining the electrical voltage present between the positive terminal and the negative terminal of the photovoltaic module from the measured electric field strength.
The method is used for checking the operation and serviceability of a photovoltaic module of a photovoltaic power station. The term “photovoltaic power station” is generally understood to mean any combination of photovoltaic modules for generating electrical current, wherein the electrical interconnection of the photovoltaic modules within the photovoltaic power station is in parallel, in series or a combination of the two. In one extreme case, the photovoltaic power station can also comprise only a single photovoltaic module, however. In particular, a combination of a number of photovoltaic modules on the roof of a building or an outdoor installation in the form of a so-called solar park is referred to as a photovoltaic power station.
The, or each, photovoltaic module of the power station has a positive terminal and a negative terminal, which are each electrically connected to at least one, but preferably to a plurality of solar cells. The solar cells are in particular so-called thin-layer solar cells. The connection of the solar cells within the photovoltaic module is in parallel, in series or a combination of the two. When solar radiation is incident on the photovoltaic module, an electrical voltage and an electrical current which flows via the two terminals is generated by means of the photovoltaic module between the two terminals. As a result of the electrical voltage, an electric field is emitted by the photovoltaic module into the surrounding environment thereof.
At (at least) one exposed measurement location outside the photovoltaic module, in accordance with the method the electric field or the electric field strength is now measured. An “exposed” measurement location is in this case understood to mean a measurement location whose relative position with respect to the photovoltaic module is predetermined for the implementation of the method or is fixed according to predetermined criteria during the method. “Outside” is in this case in particular understood to mean that the measurement location is not confined to the module or that the measurement (measured value pickup) of the electric field strength is not linked to a module.
According to the method, provision can additionally be made for a number of measured values to be picked up, for example, at different measurement locations. The electrical voltage present between the two terminals is determined by means of the measured value(s). This is performed, for example, by means of a comparison of the measured values with one or more reference values.
During the measurement of the electric field or the electric field strength, contact is not made with any current-conducting material of the photovoltaic module. The measurement of the voltage therefore takes place both indirectly and in contactless fashion. In order to check the operation of the photovoltaic module, no current-conducting electrical connections need to be detached and reconnected. During the operation check, owing to the fact that the power station continues to be in operation, the way in which said power station operates is not impaired or at least is only impaired to a comparatively low extent.
In accordance with the invention, the measurement location is located outside the photovoltaic module. Thus, the measurement can be performed at a large number of photovoltaic modules and in this case using only one measuring instrument in a manner which is not confined to a module, and this measuring instrument is moved from module to module for this purpose. In addition, it is possible to perform the check on the operation in the case of an already existing photovoltaic module. The electric field strength at different module or solar cells can also be measured, which increases the measurement accuracy of the overall measurement. Expediently, in this case a position corresponding to the greatest electric field or the greatest electric field strength is selected as the measurement location. In other words, the exposed measurement location is preferably that location outside the photovoltaic module at which the absolute value of the electric field generated by said photovoltaic module or the electric field strength assumes its maximum value.
The location corresponding to the field maximum can be determined in advance prior to the actual implementation of the method and predetermined as the measurement location. Thus, given a known configuration of the photovoltaic module, the electric field can be calculated theoretically and the location associated with the field maximum can be determined. Alternatively, this location can be determined on a measurement station by means of a comparable photovoltaic module. By virtue of the fact that the measurement location, in relation to the respective photovoltaic module, is predetermined, the measurement can take place without delay at this location. It is likewise conceivable for the measurement of the electric field to take place at a location at which the value of the electric field (field strength) assumes a certain fraction at the position corresponding to the greatest electric field strength. For example, the maximum of the absolute value of the electric field outside the photovoltaic module can be determined by means of dividing the measured value by this fraction.
If the configuration of the photovoltaic module is unknown, the electric field (field strength) along the surface of the photovoltaic module is measured, and this location is determined by means of comparison of the individual respective measured values. Thus, the operation check can also be performed in the case of an already existing photovoltaic module with an unknown configuration.
Suitably, in addition to the electrical voltage present between the negative terminal and the positive terminal, the electrical current flowing through the photovoltaic module, which is at least partially generated by said photovoltaic module, is determined. For this, the magnetic field resulting from the electrical current is measured and the electrical current is calculated from the measured value by means of a formula. In particular, in the case of a known configuration, i.e. a known interconnection of the solar cells within the solar module, the electrical current is determined from a single measured value. Suitably, the measured value is multiplied by a calibration factor, which has been determined, for example, on a test station or theoretically, and is conditioned such that multiplication of the measured value by this calibration factor gives the electrical current. The calibration factor can also vary depending on certain parameters, such as, for example, the distance between the measurement and the photovoltaic module and/or the solar radiation. Corresponding values for the calibration factor can be stored in a family of characteristics.
That is the measurement of the magnetic field could be performed by means of a magnetic field sensor which is enclosed within the photovoltaic module and in particular is cast therein. During the production of the photovoltaic module, in this case the magnetic field sensor would be installed, for example, fixedly within the photovoltaic module or in a subsequent step fitted onto the photovoltaic module in a fixed location. Preferably, the magnetic field is picked up at the exposed measurement location at which the electric field (field strength) is also measured. In particular, a measuring instrument comprising a sensor for measuring the electric field and comprising a further sensor for measuring the magnetic field is provided for this purpose. Alternatively, the measuring instrument, purely for measurement purposes, can be brought into a certain position with respect to the photovoltaic module and then removed again. In this way, it is possible to check a large number of photovoltaic modules for their respective proper operation by means of only one measuring instrument, wherein this can take place in a comparatively time-saving manner at a single location owing to the measurement of both the electrical and the magnetic fields.
In a preferred embodiment of the invention, however, the magnetic field surrounding a conductor, which is connected either to the negative terminal or the positive terminal of the photovoltaic module and through which the electrical current likewise flows, is measured. In this case, the measurement is preferably only performed in a plane which runs perpendicular to the direction of the electrical current. A measurement of the magnetic field in this location is comparatively simple owing to the normally limited physical extent of the conductor in this plane. In this case, for example, the magnetic field is measured along a closed curve, which is within this plane, and added up.
In a particularly suitable embodiment, so-called calipers are used. Since generally a plurality of photovoltaic modules are interconnected in series to form a so-called string, this method is particularly advantageous, especially since, in accordance with Kirchhoff's Laws, the current needs to be measured only at one point for the entire string. With the aid of the Biot-Savart Law or Ampere's Law, the electrical current can likewise be calculated by means of these measured values.
If the position corresponding to the greatest electric field outside the photovoltaic module is selected as the measurement location and the configuration of the photovoltaic module is not known, expediently the surface of the photovoltaic module is traversed by means of the preferably mobile measuring instrument and the electric field (field strength) is measured continuously or at fixed measurement increments. In the case of a measurement of the magnetic field, it is possible to record the curve integral of the magnetic field along a curve, substantially at least in sections. In particular if the photovoltaic module is designed (for example symmetrically) in such a way that the magnetic field of a closed curve around the photovoltaic module can be calculated from at least the recorded measured values, the Biot-Savart Law or Ampere's Law can be used to calculate the electrical current.
Suitably, a power value of the photovoltaic module is set by means of the determined electrical current and the determined electrical voltage. In particular, the power value is the power generated by means of the photovoltaic module and is conventionally calculated as the product of the electrical current and the electrical voltage.
Advantageously, the power value is compared with a set point value for the power of the photovoltaic module, wherein the set point value is dependent on the present solar radiation. For this purpose, expediently, the solar radiation incident on the photovoltaic module is measured by means of a radiation sensor. In this case, the radiation sensor is subject to comparatively little aging or is renewed comparatively often, so that the measured value of the solar radiation substantially corresponds to the actual solar radiation. The radiation sensor is tied, for example, to the sensor for the magnetic field or to the sensor for the electric field. Alternatively, the radiation sensor can also be fitted fixedly to the photovoltaic power station.
If the power value is below the set point value by a certain percentage or a certain absolute value, this is taken as an indication of the photovoltaic module being defective or at least not functioning properly. In particular, in order to ensure efficient operation of the photovoltaic power station, such an identified photovoltaic module is replaced or repaired. A particular advantageous factor with this procedure consists in that power analysis of the photovoltaic module(s) of the photovoltaic power station takes place during operation thereof. In this way, no live plug connections need to be detached and connected to a measuring instrument, with the result that the risk associated therewith to the health of the person performing the task and possible damage to the installation owing to arcs are avoided. Furthermore, the power analysis does not result in any operational failure of the power station.
Particularly advantageously, with the invention such a high increase in the measurement speed and therefore the productivity of the measurement operation is achieved that an extensive and particularly time-saving survey on the photovoltaic module or generator or power station is possible. This in turn means a qualitative improvement in the measurement system or operation.
With the above and other objects in view there is also provided, in accordance with the invention, a measuring instrument for checking the serviceability of a photovoltaic module of a photovoltaic power station, which comprises a positive terminal and a negative terminal. The, preferably mobile, measurement instrument has a sensor for measuring the electric field emitted as a result of solar radiation by the photovoltaic module or the electric field strength. By means of the electrical sensor, the electric field (field strength) emitted by the photovoltaic module is measured at an exposed measurement location. The measuring instrument furthermore comprises a unit which is designed to calculate the electrical voltage present at the photovoltaic module between the positive terminal and the negative terminal from the measured electric field or from the measured electric field strength.
In a preferred embodiment, the measuring instrument has a conventional electric field mill as the electric sensor for measuring the electric field. The field mill comprises a rotating flywheel, which is connected to ground and which subjects a measuring electrode, which is connected electrically to ground via an ammeter, periodically to the influence of the electric field (field strength) and shields said measuring electrode from said field. The electric field (field strength) induces electrical charges on the measuring electrode which flow away via the measuring instrument during the shielding phase. This current is measured by means of the measuring instrument and, from this, the strength of the electric field (field strength) is determined.
Preferably, the measuring instrument additionally comprises a sensor for measuring the magnetic field, which is generated owing to the electrical current flowing through the photovoltaic module. The magnetic field sensor comprises in particular a Hall sensor. The sensor is particularly advantageously fitted or positioned fixed in location at the same time on a string line throughout the measurement of the electric field (E field measurement).
The sensors for measuring the electric field or the magnetic field (B field measurement) can also be positioned in a fixed location relationship with respect to one another, wherein in particular the magnetic field sensor is tied to the sensor for measuring the electric field. However, it is preferred for the magnetic field sensor and the sensor for measuring the electric field to be accommodated in two separate housings and not be in contact with one another.
Expediently, the measuring instrument has a support pole, by means of which at least one of the two sensors is positionable with respect to the photovoltaic. In particular, the sensor for measuring the electric field is brought to the exposed measurement location by means of the support pole. Preferably, the measuring instrument can be carried (by a human) by means of the support pole. Alternatively, however, the measuring instrument can also be fastened on a positioning device, in particular an articulated arm of a mobile crane or an aerial lift device, by means of the support pole. Expediently, the magnetic field which surrounds a conductor connected to one of the two terminals, which conductor conducts the electrical current, is measured. The measurement is performed in particular by means of so-called calipers, which bear the magnetic field sensor.
As an alternative to this, a robot has the measuring instrument. The robot is configured to move the measuring instrument independently along the photovoltaic module, in particular on the surface thereof. In this case, for example, the measuring instrument is fitted on the robot, which moves along a pole, a cable or a guide rail, which are each fitted in particular above the photovoltaic module, or by means of suckers on the surface of the photovoltaic module. Expediently, the magnetic and/or the electric field is/are measured during the movement of the robot or the location of the exposed measurement location which is driven by the robot substantially without delay for checking the operation of the photovoltaic module is stored in the robot. Alternatively, the magnetic field sensor can also be located in the calipers, by means of which the magnetic field is measured at a fixed location on the conductor. In this case, only the sensor for measuring the electric field is taken along the photovoltaic module by means of the robot.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a method and device for checking the operation of a photovoltaic module, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 shows a schematic view of a portable measuring instrument with a support pole; and
FIG. 2 shows a perspective view of a robot with a measuring instrument.
Mutually corresponding and functionally equivalent parts have been provided with the same reference symbols in all of the figures.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown a schematic illustration of a photovoltaic power station 2 comprising two substantially identical photovoltaic modules 4 . Each of the photovoltaic modules 4 has a positive terminal 6 and a negative terminal 8 . In this case, the positive terminal 6 of one of the photovoltaic modules 4 is electrically connected to the negative terminal 8 of the other photovoltaic module 4 . The photovoltaic power station 2 therefore has a series configuration in this case, i.e. the photovoltaic modules 4 are connected to one another in series.
Each of the photovoltaic modules 4 has a plurality of solar cells 10 , which are fitted on a rear wall 12 , for example. The solar cells 10 are preferably thin-layer solar cells. In order to protect against damage to the solar cells 10 , said solar cells are covered over their entire area by a pane of glass 14 , which substantially has the same dimensions as the rear wall 12 . In this case, the pane of glass 14 rests flush on the rear wall 12 , and the edges of the stack thus formed are covered by means of a peripheral frame 16 , for example consisting of aluminum, and are therefore protected against any damage. It would likewise be conceivable for the solar cells 10 or at least some thereof to be vapor-deposited directly onto the pane of glass 14 and/or for at least one of the photovoltaic modules 4 to comprise only a single solar cell 10 . The solar cells 10 of each of the photovoltaic modules 4 are connected in series or parallel with one another. One of the solar cells 10 of one of the photovoltaic modules 4 is electrically connected to the positive terminal 6 of said photovoltaic module and a further one of the solar cells 10 is electrically connected to the negative terminal 8 of said photovoltaic module 4 .
On the incidence of solar radiation 18 , an electrical voltage U is set between the positive terminal 6 and the negative terminal 8 of a photovoltaic module 4 by means of the solar cells 10 and an electrical current I flows. The electrical voltage U generates an electric field E, which surrounds the photovoltaic module 4 . The electrical current I brings about a magnetic field B, which surrounds the solar cells 10 . Since the electrical current I flows through an electrical conductor (line) 20 , which is connected to one of the terminals 6 , 8 of one of the two photovoltaic modules 4 , the magnetic field B likewise forms around said conductor.
By means of a measuring instrument 22 , which is in the form of a portable measuring instrument 24 , i.e. not a fixed measuring instrument, by way of example, here, the electric field E and the magnetic field B are measured. For this, the measuring instrument 22 comprises conventional calipers 26 with a Hall sensor 28 . The calipers 26 surround the conductor 20 and detect the magnetic field B surrounding the conductor 20 . With the aid of the Biot-Savart Law or Ampere's Law, the electrical current I flowing through the conductor 20 is determined from the detected value. In this case, the current I which is flowing through the conductor 20 , owing to the series circuit is equal to the current I which is flowing through the individual photovoltaic modules 4 .
The measuring instrument 22 has an electric field mill 30 , by means of which the electric field E is measured at an exposed measurement location 32 . A position 34 with respect to the photovoltaic module 4 at which the electric field surrounding this photovoltaic module 4 or the electric field strength E has the greatest value is selected as the measurement location 32 . Since the electric field or the electric field strength E decreases as the distance from the photovoltaic module 4 whose electrical voltage U generates the electric field E decreases, the position 34 is located on the surface of this photovoltaic module 4 . The field mill 30 is moved towards the position 34 by way of a support pole 36 , or rod or wand. In a known arrangement of the solar cells 10 within this photovoltaic module 4 and therefore a known propagation form of the electric field E, it is possible to move the field mill 30 directly towards the position 34 . If this should not be the case, given a substantially constant amount of incident solar radiation 18 , the field mill 30 can be brought over the surface of the photovoltaic module 4 by the support pole 36 and the electric field or the electric field strength E can be measured using the field mill 30 until the position 34 has been determined on the basis of the recorded measurement data.
The electrical voltage U is calculated from the value for the electric field or for the electric field strength E at the position 34 , wherein the functional relationship between the electric field (field strength) E at the position 34 and the electrical voltage U present between the two terminals 6 , 8 has been determined, for example, on a test station. In particular, the functional relationship is Coulomb's Law, and any coefficients specific of the photovoltaic module 4 are detected on the test station.
The value of the determined electrical current I is multiplied by the value for the determined electrical voltage U and therefore determines a power value for this photovoltaic module 4 . This power value is compared with a set point value of the power of the photovoltaic module 4 , wherein the solar radiation 18 is taken into consideration. In the case of a relatively low amount of incident solar radiation 18 , the set point value is lower than in the case of a comparatively high amount. If the power value of the photovoltaic module 4 is comparatively far below the setpoint value, this photovoltaic module 4 of the photovoltaic power station 2 is replaced.
The calculation of the power value is performed for all of the photovoltaic modules 4 of the photovoltaic power station 2 . In this case, in each case the electric field E of each photovoltaic module 4 is measured (E field measurement) and the electrical voltage U which is present at each of the photovoltaic modules 4 is determined. Since the electrical current I is constant, given a constant amount of incident solar radiation 18 and given the series circuit of photovoltaic modules 4 , only a single measurement of the magnetic field B (B field measurement) and a single determination of the electrical current I are necessary.
In practice, at the same time the magnetic field B is preferably measured with each E field measurement within or with respect to a string, but always at the same measurement location around a conductor of this string.
Referring now to FIG. 2 , there is shown a perspective view of a robot 38 with the measuring instrument 22 . The robot 38 moves automatically in the manner of a cat burglar robot over the photovoltaic modules 4 of the photovoltaic power station 2 . For example, the robot 38 is held by means of suckers on the photovoltaic modules 4 or moves along poles, cables or guide rails.
The photovoltaic power station 2 is in this case in the form of a so-called outdoor solar power station. In contrast to the photovoltaic modules 4 illustrated in FIG. 1 , these photovoltaic modules 4 do not have any frames.
By means of a positioning unit 40 , the robot 38 moves the measuring instrument 22 over one of the photovoltaic modules 4 , which is adjacent to the photovoltaic module 4 on which the robot 38 is located at that time and performs the operation check on this photovoltaic module. Therefore, the photovoltaic module 4 to be checked is only covered by the comparatively small measuring instrument 22 , which means that the power of the photovoltaic module 4 is impaired to a comparatively small extent. The measuring instrument 22 is moved towards the position 34 with respect to the photovoltaic module 4 to be checked and in particular is positioned on the photovoltaic module 4 in order to ensure a defined measurement height. In this way, the measured value recorded by means of the measuring instrument 22 is not influenced owing to a change in position of the measuring instrument 22 with respect to the photovoltaic module 4 during the measurement, as is caused, for example, by gusts of wind which can cause the positioning unit 40 to oscillate.
By means of the measuring instrument 22 , both the magnetic field B and the electric field (field strength) E are measured at the position 34 and, from these values, the electrical current I and the electrical voltage U are determined with the aid of a family of characteristics or a functional relationship explained above in connection with FIG. 1 . In addition, during the movement of the measuring instrument 22 towards the position 34 by means of the positioning unit 40 and/or during the movement of the robot 38 , the magnetic field B and/or the electric field E can be measured. In this way, more accurate values for the electrical current I or the electrical voltage U can be calculated. In a comparable manner to the measuring instrument 22 shown in FIG. 1 , the measurement of the electrical current I can be performed using the calipers 26 in this case, too. Then, it is merely necessary to move the field mill 30 over the photovoltaic module 4 by means of the positioning unit 40 .
In turn, the power value corresponding to the incident solar radiation 18 is calculated from the values for the electrical current I and the electrical voltage U in accordance with the relationship P=U×I and compared with the associated set point value. The incident solar radiation 18 is detected by way of a radiation sensor 42 , which is fitted on the measuring instrument 22 . The radiation sensor 42 can likewise also be installed fixedly on the photovoltaic power station 2 .
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A method for checking the operation of a photovoltaic module of a photovoltaic power station. The module has a positive terminal, a negative terminal and a number of solar cells, in particular thin-layer solar cells. An electric field emitted by the photovoltaic module as a result of solar radiation is measured at an exposed measurement location during the operation of the power station and the electrical voltage present between the positive terminal and the negative terminal is determined from the measured electric field. A corresponding measuring instrument has a sensor to be placed near the photovoltaic module so as to measure the electric field strength. A rod or wand may be used to position the sensor, or a robot may be configured for automatic travel on the photovoltaic module.
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FIELD OF THE INVENTION
[0001] This invention relates to the field of semiconductor device fabrication. In one aspect, the invention relates to the manufacture of a wordline stack while in another aspect, the invention relates to forming an insulating layer on the top surface of the stack. In yet another aspect, the invention relates to depositing the insulating layer on the wordline stack through the use of sputtering technology.
BACKGROUND OF THE INVENTION
[0002] Dynamic random access memory (DRAM) devices comprise, among other things, a large plurality of wordline stacks, also known as gate electrode stacks. The function of these stacks is to store a charge and when used in combination with a bit or digit line, provide an “address” for a discrete memory cell. The typical wordline stack is a layered composite of various materials, the top layer of which is typically a silicate glass, e.g., borophosphosilicate glass (BPSG).
[0003] The preparation of a DRAM device involves one or more heat annealing steps in which the temperature is such that the dopants, e.g., boron, phosphorus, arsenic, etc., of a doped material, e.g., BPSG, will migrate (or out-gas) from the doped material into the environment (i.e., into the chamber in which the heat annealing step is conducted) and into one or more adjacent layers or other components, e.g., the substrate, of the device. Since the purpose of a dopant is to enhance the conductivity of a material, migration of a dopant into a dielectric material will decrease the insulating properties of that material. If enough dopant migrates into a dielectric material, then the insulating properties of the material will be reduced to the point that a short circuit can develop between the conductive layers separated by the dielectric layer. This, of course, means that a wordline stack can lose its charge inadvertently and this, in turn, can result in a malfunction of the memory device.
[0004] To address this problem, a relatively thick, e.g., 150-300 angstroms, layer of an insulating material (also a dielectric and also known as a liner) is usually deposited adjacent to a layer of doped material. Tetraethylorthosilicate (TEOS) is a commonly used liner for this purpose. Achieving a relatively thick layer of this insulating material using conventional chemical vapor deposition (CVD) techniques is not difficult for top-level stack surfaces, but it can be problematic for the surfaces between two stacks. If the aspect ratio, i.e., the height of the stacks (the height of all of the stacks is, for all intent and purpose, essentially the same at the time a blanketing layer of insulating material is deposited) over the distance between the stacks, is relatively low, e.g., less than 3, then conventional CVD techniques will deposit a layer of insulating material of substantially the same thickness between two stacks as is deposited on the top of the stacks. However, as this aspect ratio increases, i.e., the distance between the stacks narrows, the thickness of the insulating layer deposited by conventional CVD between two stacks decreases relative to the thickness of the insulating surface deposited on the top layer of the stacks. At some point, insufficient insulating material is deposited between the two stacks to provide an effective block against the migration of dopants from a material overlying the insulating layer to a material underlying the insulating layer.
[0005] As the density of wordline stacks increase on a substrate, the space between individual stacks will inevitably decrease. As this space decreases, the need for cleaner production methods increases, including the need to block the migration of dopants from a doped material to a dielectric material during the heat annealing steps of the memory device. This increases the need for adequate deposition of liners between wordline stacks during the preparation of semiconductor memory devices and other integrated circuits.
SUMMARY OF THE INVENTION
[0006] According to this invention, a liner that is an effective block against the migration of a dopant from a doped material to a dielectric material is positioned between the two materials by sputtering. In one embodiment of this invention, an insulating material is deposited onto a gate dielectric surface separating two wordline stacks, the method comprising the steps of:
[0007] A. Forming at least two adjacent wordline stacks over a common gate dielectric, the stacks spaced apart from one another thereby forming an open surface on the gate dielectric between the stacks; and
[0008] B. Depositing by sputtering the insulating material onto the open surface of the gate dielectric separating the two wordline stacks.
[0009] In another embodiment of this invention, an insulating material is deposited onto a gate dielectric surface separating two wordline stacks, each wordline stack having a top surface, the insulating material deposited as a layer onto the dielectric surface at a thickness that is substantially the same as the thickness of the insulating layer that is deposited as a layer onto the top of the stacks, the method comprising the steps of:
[0010] A. Forming at least two adjacent wordline stacks over a common gate dielectric, the stacks spaced apart from one another thereby forming an open surface on the gate dielectric between the stacks; and
[0011] B. Depositing by sputtering the insulating material as a layer onto the top of the two stacks and the open surface of the gate dielectric separating the two wordline stacks.
[0012] In still another embodiment of this invention, an insulating material is deposited onto a gate dielectric surface separating two wordline stacks, each wordline stack having a top surface and at least one side wall, the insulating material deposited as a layer onto the dielectric surface (i) at a thickness that is substantially the same as the thickness of the insulating layer that is deposited as a layer onto the top of the stacks, and (ii) without any substantial deposition of the insulating material onto the side walls of the stacks, the method comprising the steps of:
[0013] A. Forming at least two adjacent wordline stacks over a common gate dielectric, the stacks spaced apart from one another thereby forming an open surface on the gate dielectric between the stacks; and
[0014] B. Depositing by sputtering the insulating layer onto the top of the two stacks and the open surface of the gate dielectric separating the two wordline stacks without any substantial deposition of the insulating material onto the side walls of the stacks.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Preferred embodiments of the invention are described below with reference to the following accompanying drawings, which are for illustrative purposes only. In the figures like numerals are employed to designate like parts throughout the same.
[0016] [0016]FIG. 1A is a diagrammatic cross-sectional view of a semiconductor wafer fragment bearing two adjacent but separated wordline stacks (prior art).
[0017] [0017]FIG. 1B is the diagrammatic cross-sectional view of the semiconductor wafer fragment of FIG. 1 but covered with a continuous TEOS layer deposited by LPCVD (prior art).
[0018] [0018]FIG. 1C is the diagrammatic cross-sectional view of a semiconductor wafer fragment of FIG. 1B but covered with a continuous BPSG layer (prior art).
[0019] [0019]FIG. 2A is the diagrammatic cross-sectional view of the semiconductor wafer fragment of FIG. 1A but covered with a discontinuous silicon dioxide layer deposited by sputtering, according to an embodiment of the method of the invention.
[0020] [0020]FIG. 2B is the diagrammatic cross-sectional view of the semiconductor wafer fragment of FIG. 2A but covered with a continuous BPSG layer.
[0021] [0021]FIG. 2C is the diagrammatic cross-sectional view of the semiconductor wafer fragment of FIG. 2B after a select portion of the BPSG and silicon dioxide layers are removed by an anisotropic etch.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] [0022]FIG. 1A is a diagrammatic cross-sectional view of a semiconductor wafer fragment 10 bearing two adjacent but separated wordline stacks 11 a and 11 b. Semiconductor substrate 12 typically comprises monocrystalline silicon with regions 13 a - d sufficiently doped with boron, phosphorus, arsenic or other dopant to operate efficiently as sources and drains for the stacks. Each stack is separated from substrate 12 by gate dielectric 14 , which is typically formed by oxidation of substrate 12 . Gate dielectric 14 covers essentially all of substrate 12 , and is thus common or shared by both wordline stacks.
[0023] The wordline stacks 11 a, 11 b comprise polysilicon layers 15 a - b, conductive barrier layers 16 a - b, metal layers 17 a - b, silicon dioxide layers 18 a - b, nitride cap layers 19 a - b, and spacer (i.e., side wall) nitride layers 20 a - d, respectively. Barrier layers 16 a - b are essentially impermeable to silicon and metal atoms under manufacturing and operating conditions, and can include tungsten or titanium nitride. Metal layers 17 a - b are typically a metal or alloy of aluminum, copper, tungsten, titanium, platinum, palladium, cobalt, molybdenum, nickel, rhodium and/or iridium. The cap and spacer nitride layers typically comprise silicon nitride.
[0024] The wordline stacks are constructed using conventional techniques. Typically, the materials for the polysilicon layer, the barrier layer, the metal layer, the silicon dioxide and nitride layers are alternatively deposited as blanket layers and etched to form the stacks. The wordline stacks have a height h and the open surface on the gate dielectric between the stacks has a width w, the height h and width w defining an aspect ratio of h/w of at least about 2, preferably at least about 2.5 and more preferably at least about 3. Since nitride spacers are usually components of a wordline stack, width w is usually measured from the external surface of one nitride spacer to the external surface of an opposing nitride spacer, e.g., from the external surface of 20 b to the external surface of 20 c. Height h is usually measured from the exposed surface of the gate dielectric to the exposed surface of the top layer of a stack, e.g., from the exposed surface of gate dielectric 14 to the top surface of nitride cap layer 19 a or 19 b.
[0025] Word line stacks 11 a and 11 b are designed as components for a semiconductor memory device and in this regard, are ultimately coated with a doped oxide insulator layer, typically BPSG. Because boron and phosphorus will migrate from the BPSG layer to the layers underlying it (e.g., dielectric gate 14 and/or substrate 12 ) during the beat annealing steps of the memory device manufacture, an insulation layer, typically oxide formed using TEOS, is placed between the doped oxide layer and the underlying layers. This conventional practice is illustrated in FIGS. 1B and 1C.
[0026] TEOS insulation layer or liner 21 is typically deposited upon the exposed surfaces of the semiconductor wafer of FIG. 1A such that it overlays nitride layers 19 a - b, nitride spacers 20 a - d and dielectric gate 14 . The TEOS is typically deposited by low pressure chemical vapor deposition (LPCVD) but due to the nature of LPCVD deposition and the presence of the spacer nitride on the stack side walls, the amount of TEOS deposited on the surface of dielectric gate 14 between the stacks is less than the amount of TEOS deposited upon the exposed surfaces of nitride layers 19 a - b. Referring to FIG. 1B, in terms of layer thickness, thickness t 2 < thickness t 1 , typically much less. If the thickness of the TEOS layer over the dielectric gate is inadequate, e.g., less than 150 angstroms, then the TEOS layer is likely to allow some migration of dopant from the BPSG layer into the dielectric gate layer.
[0027] Referring to FIG. 2A, insulating layers 23 a - e are deposited onto the exposed surfaces of dielectric gate 14 and nitride layers 19 a - b by any conventional sputtering technique, e.g., high density plasma (HDP) or collimated. These and other sputtering techniques (also known as physical vapor deposition) are well known in the art. Wolf and Tauber, Silicon Processing for the VLSI Era, Vol. 1, Chpt. 11, (Lattice Press 2000); Zant, Microchip Fabrication, pp.411-16 (McGraw-Hill 2000); and Aronson, “Fundamentals of Sputtering”, Microelectronics Manufacturing and Testing, January 1987. An exemplary conventional sputtering process is the sputtering of aluminum for metal interconnects.
[0028] Sputtering allows for the deposition of insulating layers 23 a - e with little, if any, deposition of insulating material on the sidewalls of the stacks. This, in turn, allows for the deposition of a layer with a more uniform thickness across the exposed surfaces of the wordline stacks and their supporting dielectric gate. As shown in FIG. 2A, thickness t 4 is substantially equal to thickness t 3 , i.e., t 4 =t 3 . Of course, the higher the aspect ratio of the space between the stacks, the more t 4 is likely to be less than t 3 . Preferably, the aspect ratio of space between the stacks is less than about 4, more preferably less than about 3.75, and most preferably less than about 3.5.
[0029] In one preferred embodiment of this invention, insulating layers 23 a - e are one of silicon dioxide (SiO 2 ) or silicon nitride (Si 3 N 4 ). Other insulators of interest include boron nitride (BN), tungsten nitride (WN), and aluminum oxide (Al 2 O 3 ). The temperature during formation of the insulting layer is sufficiently low so that little or none of the barrier and metal layers of the wordline stacks is converted to an oxide. For example, if the barrier layer comprises tungsten nitride and the metal layer comprises tungsten, then the insulating layer can be formed at a temperature in range of about 30 to about 650 C.
[0030] After insulating layers 23 a - e are applied, a doped oxide insulating layer 22 , e.g., BPSG, is applied to all the exposed surfaces of wafer 10 (FIG. 2B), and then the wafer is subjected to a standard photolithographic mask and etch process to remove insulating layers 23 a - c - e, doped oxide insulating layer 22 (except from the surface of nitride layers 19 a - b (FIG. 2C)), and the portion of gate dielectric 14 between stacks 11 a and 11 b. Subsequently, a contact (not shown) is made on substrate 12 at surface 12 a (i.e., the surface between stacks 11 a and 11 b ).
[0031] In compliance with the statute, the invention has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the invention is not limited to the specific features shown and described, since the means herein disclosed comprise preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents. Other embodiments of this invention are within the scope of the following claims.
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Insulating material is deposited onto a gate dielectric surface separating two wordline stacks, the method comprising the steps of:
A. Forming at least two adjacent wordline stacks over a common gate dielectric, the stacks spaced apart from one another thereby forming an open surface on the gate dielectric between the stacks; and
B. Depositing by sputtering the insulating material onto the open surface of the gate dielectric separating the two wordline stacks.
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BACKGROUND OF THE INVENTION
This invention relates to the field of display terminals and particularly to video screen display terminals which are vertically adjustable.
Video terminals having a screen similar in configuration to that of a television set have become very widespread in their use in office environments. With a vast number of people using display terminals, emphasis on ease and comfort has become more important. The adjustability of the position of the video screen in front of the operator for personal comfort requires the raising or lowering of the screen within limits to accommodate different preferences of the operator. The adjustability of the screen allows the operator to place the screen at a comfortable position and thus reduce or eliminate fatigue.
A significant problem in the adjustment of the video screen is the weight of the display head which typically contains the CRT, the associated electrical controls and circuits for generating the image on the CRT face and a frame and power supply associated therewith.
The weight of these combined components is a significant amount and therefore is difficult to raise and lower, particularly when working from the front of a work station or desk and having to normally reach past a keyboard or other piece of equipment in order to adjust the display head height.
With a significant weight attributed to the display head, a degree of physical strength is required. Many of the operators of data terminals are women who may not possess adequate physical strength to lift such a substantial weight at arm's length.
SUMMARY OF THE INVENTION
The data terminal display is provided with constant force springs of sufficient strength to offset the weight of the display and make it considerably easier to raise and lower the display. The display may be further mounted such that its base is capable of pivoting to accommodate viewing from several lateral positions. The mounting of the display head and its supporting frame relative to the supporting constant force springs may permit tilting of the display unit about its horizontal axis to position the display head to reduce fatigue and/or glare.
The display head is configured such that the supporting constant force springs and the uprights supporting the constant force spring assembly are containable within the housing of the display head and thus provide a contained appearance.
The movement of the head vertically with respect to the uprights is controlled such that undesired movement does not occur unless initiated by the operator due to a detenting or latching arrangement thereby preventing the head from being bumped and caused to either move or displace itself from the desired vertical positioning.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially exploded view of the display terminal with the video screen and the associated electronics removed from the housing.
FIG. 2 is a further perspective exploded of the display housing base and uprights.
FIG. 3 is a perspective exploded view of a typical upright assembly and constant force spring.
FIG. 4 is a perspective view of an alternate embodiment terminal display.
FIG. 5 illustrates the constant force spring suspendion of the terminal display head in FIG. 4.
FIG. 6 is an exploded view of the tilt mechanism for the display head illustrated in FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, the display terminal is illustrated in a partially exploded view. The base 10 is configured to provide a support for uprights 12. Uprights 12 extend parallel to each other and through apertures 14 in the floor of the bottom housing 16 which supports the chassis 48 comprising CRT 17 and associated circuitry 19. Supported on uprights 12 are constant force springs 18 which are coiled onto reels 20. The free end of the constant force springs 18 are attached to a lift plate 22. The attaching technique of attaching to lift plate 22 may involve conventional techniques or may involve an anchor device 24 which allows the constant force spring 18 to slip into the lift plate 22 and the anchor 24 then holds the constant force spring 18 against lift plate 22. Lift plate 22 is capable of riding vertically in a slot 24 best illustrated in FIGS. 2 and 3. Lift plate 22 extends through the slot and forms an attachment with bracket 28. Bracket 28 may be attached to lift plate 22 which is illustrated in its entirety in FIG. 3. Lift plate 22 includes the guiding surfaces 30 which will engage the sides of slot 26 and thus stabilize lift plate 22 in its vertical movement. The attachment of bracket 28 and lift plate 22 together with a friction shaft 32 is accomplished by a screw 44.
Bracket 28 may be tightened onto friction shaft 32 by means of screw member 45. This allows bracket 28 to be rotated with respect to lift plate 22. The tilt function is accomplished by bracket 28 pivoting about stud 32. The tilt travel is contained by slot 46 and stop 47. Slot 46 in bracket 28 provides stop surfaces for rotation friction shaft 32 and has stop 47 which contacts stop surfaces in slot 46. Tilt force is controlled by deflecting member 49 of bracket 28. Screw member 45 provides force to member 49 to cause its deflection against shaft 32. Lugs 52 which are part of stud 32 engage slots 51 which are part of lift plate 22 and prevents motion between stud 32 and lift plate 22.
Bracket 28 is engageable with and attached to the bottom cover 16 of the display station or display chassis 48. Thus, to rotate bracket 28 slightly with respect to lift plate 22 and uprights 12 will cause a slight tilting of the display station.
Release member 34 may also be configured such that the end thereof will protrude through the opening 36 in lift plate 22 and engage latching spring 38. The engagement of the latching spring 38 will be at the top end thus acting to force tabs 40 out of complimentary engaging notches 42 in the structure of upright 12. Spring 38 and tabs 40 act to prevent undesired vertical movement of lift plate 22 and bracket 28. When the tabs 40 are disengaged from the notches 42, then lift plate 22 is then free to move under external force influence. Upon the release of spring 38, the tabs 40 will reengage with notches 42 a part of upright 12, thereby locking the lift plate 22 to which spring 38 is attached in the set vertical position.
The constant force spring 18 is coiled on spool 20 which in turn is mounted on and rotates about shaft 43 of upright 12. The constant force spring's free end is fixedly attached to the anchor 24 which, as previously described, is capable of engaging the underside of lift plate 22 to provide a force upward thereto. The constant force spring 18 is configured such that it normally attempts to wrap itself about spool 20 and to maintain itself tightly coiled thereon. The force of uncoiling the spring 18 from spool 20 is the spring force of the member and, as such, will tend to be equal regardless of the extent of uncoiling accomplished.
An additional enhancement to the terminal display in FIG. 1 may be the addition of a rotational support such as that shown in FIG. 2. With the addition of the rotational support 50, the base member 10 may then be turned relative to the furniture element such as a table or desk upon which the terminal is sitting.
An alternative embodiment is illustrated in FIG. 5. The display station comprises a base 110 together with uprights 112. The bottom cover 116 is provided with apertures 114 to allow the cover to ride down over the uprights 112. Supported in the uprights 112 are guide rods 118 which serve as guide ways for the bearing block 120. Attached to the bearing block are short stub shafts extending outward from the bearing block and best observable in FIG. 6. The stub shaft 122 is hollow to permit an adjustment screw to pass therethrough. Tilt sleeve 124 is engageable with the exterior of the stub shaft 122 and will fit within the interior cylindrical surface 126 of support block 128. Support block 128 is a split block which may be tightened onto sleeve 124 by means of screw 130. Support block 128 is likewise attachable either directly or indirectly to the display case 116 in FIG. 5. Adjustment screw 132 is engageable through and coaxial with support block 128, tilt sleeve 124 and bearing block 120 to engage in a threaded fashion with break bar 134. Brake bar 134 is formed such as to engage the circumference on at least a portion of the exterior of brake sleeves 136 which may be then compressed by tightening adjustment screw 132 to limit vertical movement of bearing block 120 with respect to guide rods 118. By loosening screw 130, the support block may be tilted with respect to bearing block 120 and guide rods 118. With the attachment of the display bottom cover 116 to the support block 128, a tilting of the support block will cause a tilting of the display case and the display terminal.
Referring again to FIG. 5, uprights 112 also provide a support for the constant tension spring assemblies 140. The constant tension springs 140 extend downward are are rigidly attached at attachment points 142 either directly or indirectly to the display case 116.
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A CRT data display comprises a display head of significant weight which may be moved vertically with the aid of constant force springs and which may be tilted to adjust the position of the CRT for operator comfort. The display may be rotated about a vertical axis to permit multiple viewing positions.
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DEDICATORY CLAUSE
The invention described herein was made in the course of or under a contract or subcontract thereunder with the Government and may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to me of any royalties thereon.
BACKGROUND OF THE INVENTION
Optical reflecting telescopes are used in a majority of laser radar applications. The predominant design used as the transmitter and receiver antennas is the Cassegrain system or a modified form thereof. The Cassegrain optics achieve a relatively long effective focal length on a compact optical train. Having such a short system is an advantage when rapid slewing and accurate pointing and tracking are required.
Achieving optical isolation between the transmitted laser beam and the receiver detectors is accomplished in various ways. Very often, dual apertures are used; one for the transmitter and one for the receiver. Disadvantages with this system include the increased weight penalty of the dual aperture and the difficulties which arise in mutual alignment of the two optical axes. Systems using a single transmit-receive aperture are more compact, but switching complexities between transmit and receive modes are very costly. With the single convex secondary mirror in the single transmit-receive aperture system, the transmitted laser beam must be decollimated and focused before its entrance into the optical train. Optical isolation can be achieved using an optical switch or isolator with a somewhat increased cost penalty. However, both the decollimation and isolation problems become much more serious when using a high energy laser beam. With these obstacles in mind the described invention herein achieves a simple solution to the problems.
SUMMARY OF THE INVENTION
The dual-secondary mirror Cassegrain optical system uses a single aperture-single primary mirror. The system transmits a hollow, collimated laser beam. Received optical radiation is directed by a focusing secondary mirror through an aperture in the afocal, beam expanding secondary transmitting mirror and through the aperture in the primary mirror. The received beam is coaxial with the transmitted beam and within the hollow portion of the beam. Optical isolation is provided by spatial separation of the optical paths while continuous transmit-receive operation can be provided. In addition to dual transmit-receive operation the system can be applied as a dual-field-of-view receiver or as a dual beamwidth transmitter. By using coaxial transmit and receive optical paths, only one primary mirror and two secondary mirrors are needed. Separation of the two optical paths is in radial distance from the central optical axis.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a preferred embodiment of the dual-secondary mirror Cassegrain optical system.
FIG. 2 is a schematic diagram of the optical system used as a dual-field-of-view receiver.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings wherein like numbers represent like parts, the preferred embodiment of the optical system is shown in schematic form, in cross section in FIG. 1. Support structures are well established for optical components and, as such, are not shown since they are not related to the inventive optical system. FIG. 1 discloses the dual secondary mirror Cassegrain optical system 10 to comprise a primary mirror 12, a beam expander secondary mirror 14 and a focus secondary mirror 16. Primary mirror 12 has a concave paraboloid surface 20 and an aperture 22 in the center of the mirror. Secondary mirror 14 has a convex paraboloid surface 24 with an apertured center 26 and is located between mirrors 12 and 16. Focus secondary mirror 16 is a convex hyperboloid. The optical system axis 28 is the common axis for all the mirrors.
In a transmitter-receiver configuration, an input beam T1 enters the optical train in the form of a hollow beam at the rear of mirror 12, passing through aperture 22. The intensity distribution of the beam is a palindromic Gaussian. The hollow beam T1 provides advantage in that the transmitted optical gain is increased from that of a solid beam and no power is lost by reflection from the central zone of the secondary mirror. Additionally, the hollow portion of the beam provides a separate optical path within which received optical radiation can travel. Following the transmitted beam T1 from its entrance into the system, the collimated beam impinges on secondary mirror 14 which diverges the transmitted radiation and directs the beam toward the central zone of primary mirror 12.
The convex paraboloid surface 24 of mirror 14 coupled with the central zone of primary mirror 12 forms an afocal beam expander. The focus of both mirrors 12 and 14 are coincident. From surface 20 of mirror 12, resultant expanded beam T2 exits the telescopic optics, being transmitted along axis 28 toward the object of interest or target (not shown). The palindromic Gaussian intensity distribution is maintained.
Mirror 14 can be varied in position along the axis 28. Moving mirror 14 along the optical axis can vary the amount of transmitted beam expansion. However moving mirror 14 is limited, depending on the reception interference that can be tolerated, since mirror 14 can be moved to partially obscure the received cone of rays incoming from primary mirror 12.
The receive optics of system 10 typify a basic Cassegrain optical system. Input radiation, R1, enters the telescope and impinges first on primary 12 paraboloid mirror surface 20. The wave is converged by the mirror and is focused at point F1 on axis 28, however, before reaching F1 the converging cone of radiation intercepts and is reflected from the convex hyperboloid surface of mirror 16. Mirror 16 essentially changes the rate of convergence of the cone, increases the effective focal length of the system, and focuses the converging cone, R2 at point F2 on the focal plane. The received cone of rays may then be processed for data reduction by conventional proceedures.
The received cone of rays and the transmitted beam both pass through the aperture 22 in primary mirror 12. The degree of obscuration of secondary mirror 14 against the received cone of rays R1 is not a critical factor but should be considered, since placement of mirror 14 affects both the degree of beam expansion on transmission and the degree of receiver obscuration on reception. Thus, as mirror 14 is moved toward mirror 16 the transmitted beam is expanded more but obscuration can increase. Obviously, if obscuration appears to a be a problem with a particular mirror 14, a different mirror with a different paraboloid curved surface 24 can provide the enhanced beam expansion while allowing the mirror 14 to be more remotely located with respect to mirror 16.
The hollow beam and afocal transmitter beam expander provides an optical system capability to vary the amount of beam expansion and also diffraction limiting beamwidth in the far-field. In a laser radar this allows the transmitter to cover a greater field-of-view (floodlight) than the receiver will look into. The dual-secondary mirror system provides the isolation of a dual-aperture optical system but uses only a single aperture for transmit and receive. Optical isolation between transmit and receive is achieved without switching which allows this system the capacity to transmit while receiving.
In addition to the transmitter-receiver optical configuration, the dual-mode optical system is applicable as a dual-field-of-view receiver or as a dual beamwidth transmitter. For example, as shown in FIG. 2 optical system 10 is used as a dual-receiver. Mirror 14 is positioned to receive a portion of the incoming or received optical radiation. This radiation is directed through aperture 22 of primary 12 where it is reflected from a perforated flat mirror 30 into low power telescope 32 which provides a wide field of view. The remainder of the beam is directed, as previously set forth, from mirror 16 to focal point F2 and from there to appropriate signal processing components such as an eyepiece 34 for providing a narrow field of view.
As a dual-receiver the outer hollow beam is magnified with secondary low power telescope 32. By adjusting optical system geometrics, the system now yields a dual magnification or dual-field-of-view on the same or separate focal planes. The same duality can be applied to dual-transmitters, for providing dual-laser transmitters in both coherent and semi-coherent operation to dual-PRF designator illuminators and other similar applications.
Inputs and outputs from an optical system are well established in the art and since the invention does not involve these areas, such are not disclosed. In practice, the input beam T1 can enter the rear of the optical train after being folded by a flat perforated mirror. The received cone of light R2 will pass through a central aperture of the mirror and be focused beyond the folded path of the transmitted beam. Additionally, where a coude' focus is desired a folding flat mirror in front of the primary 12, can interrupt the cone of received light R2 and redirect the focal plane.
The system is easily adapted to pointing and tracking requirements, and transmit-receive requirements for laser radar and high energy laser beam aiming and firing. It may be used in continuous transmit-receive laser rangefinder applications. In continuous transmit-receive optical communications systems, it is very practical in handling high data rates which need continuous input and output data flow. The system can provide a continuous aim-while-illuminate capability for airborne and ground designators. In astronomical telescope built-in finder scopes, by using the hollow beam from the afocal secondary, the central part of the astronomical telescope mirror can be used in conjunction with a secondary low power telescope system to give a low power, wide field spotter scope (commonly called finder scope). The normal higher powered image would be located at the other focus of the system, as shown in FIG. 2. Using the same optical primary mirror for image formation insures good alignment between finder scope and main scope. The finder scope may then be colocated inside the main optical system eliminating the need for an "attached" finder scope mounted outside the tube.
In sighting/aiming telescopes the coarse field-of-view and fine field-of-view geometries and can be combined into a single eyepiece with a coarse and fine field shutter for providing an aiming device.
Although the present invention has been described with reference to a preferred embodiment, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the foregoing disclosure. Accordingly, the scope of the invention should be limited only by the claims appended hereto.
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The dual-secondary mirror optical system utilizes, in principle, the Cassain optical system. An apertured, single, primary mirror is coaxially aligned with two secondary mirrors to provide coaxial transmit and receive optical paths. Separation of the optical paths is in radial distance from the central optical axis. An apertured secondary mirror in conjunction with the primary mirror directs the transmitted beam, providing a hollow expanded output beam. The other secondary mirror in conjunction with the primary mirror directs received radiation coaxially within and spatially separated from the hollow transmitted beam, providing dual transmit receive operation.
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FIELD OF THE INVENTION
The present invention relates to attachments and clips for securing building components together, and more particularly to a metal attachment that can be used, for example, to secure a header to a vertical member in a wall system.
BACKGROUND OF THE INVENTION
Connecting building components in a building structure, whether they are metal or wood, present many challenges. For example, consider the concerns presented for efficiently and adequately connecting a header that extends across a window, door or throughway opening. Obviously any type of connector utilized must be able to safely carry the loads transferred to the header, which are often very substantial especially in cases where the header span is long. While it is important to provide sturdy and strong connections, it is also important that such be done in a way that generally minimizes the number of connectors or attachments used. From a cost and construction efficiency point of view, it is desirable that the connectors be relatively small and of a design that enables them to be easily installed even by individuals that are not highly skilled.
Therefore, there has been and continues to be a need for attachments that connect building components together which are structurally efficient, and which can be easily installed.
SUMMARY OF THE INVENTION
The present invention entails a metal attachment for connecting two building members together. The attachment comprises a plate for extending across a portion of the two members. At least one generally L-shaped bracket projects from the plate and includes first and second tabs or legs that are disposed at an angle with respect to each other, and which are offset with respect to the plate. The attachment can be utilized to connect various types of building members together. For example, where two members meet to form a corner, the plate portion of the attachment may extend across the aligned surfaces of the two members while the two tabs can be connected to the corner areas formed.
In another embodiment of the present invention, the attachment is provided with first and second generally L-shaped brackets. Each of the L-shaped brackets includes first and second tabs or legs that project from the plate and form an angle with respect to each other. Further, both sets of tabs are offset with respect to the plate.
Other objects and advantages of the present invention will become apparent and obvious from a study of the following description and the accompanying drawings, which are merely illustrative of such invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary perspective view of a portion of a wall showing the attachment of the present invention securing two structural members together.
FIG. 2 is a perspective view of the attachment of the present invention.
FIG. 3 is a side elevational view of the attachment.
FIG. 4 is a front elevational view of the attachment.
FIG. 5 is a top plan view of the attachment.
FIG. 6 is a fragmentary perspective view of a portion of a wall structure having the attachment incorporated therein.
FIG. 7 is a fragmentary perspective view of a portion of a wall structure showing an alternative embodiment for the attachment.
FIG. 8 is a perspective view of the alternative embodiment of the attachment.
FIG. 9 is a front elevational view of the alternative design for the attachment.
DESCRIPTION OF THE INVENTION
With further reference to the drawings, particularly FIGS. 2-5 , the attachment of the present invention is shown therein and indicated generally by the numeral 10 . As will be appreciated from subsequent portions of the disclosure, attachment 10 is designed to connect two structural members together. In FIG. 1 for example, attachment 10 connects a header 58 with a jamb 60 .
Turning to a detailed discussion of the attachment 10 , the same includes a plate indicated generally by the numeral 12 . Plate 12 is of a rectangular or square design and includes a front face 14 and a back 16 . Back 16 , in the case of the design shown in FIGS. 2-5 , will fit flush against the building members that the attachment 10 connects. Formed in the plate 12 is a pair of reinforcing ribs 11 . Plate 12 includes a series of edges that surround the same. More particularly, as shown in FIG. 2 , the edges include edge 18 A, edge 18 B, edge 18 C, and edge 18 D.
Projecting from the plate 12 is a bracket 22 . Although the bracket may assume various configurations, in the case of the present embodiments bracket 22 assumes a generally L-shape. L-shaped bracket 22 includes a first tab or leg 24 and a second tab or leg 26 . A transition line or juncture 28 extends between the tabs 24 and 26 . The angle formed by tabs 24 and 26 can vary. In this embodiment, tabs 24 and 26 form a generally right angle.
Formed in the attachment 10 in both the plate and the tabs 24 and 26 are a series of fastener openings 30 . Fastener openings 30 receive screws that effectively connect attachment 10 to adjacent building members.
Attachment 10 can be constructed in various ways utilizing various processes. In one embodiment it is contemplated that attachment 10 would be made from a single piece of material that is stamped and/or cut and formed into the configuration shown in FIG. 2 . One way of forming the attachment 10 would be to cut a single piece of material along the line generally designated by the edge 18 D. Note that the cut would only extend partially across the material. Thereafter tab 26 can be bent to an angle of approximately 90° with respect to the adjacent tab 24 . Tab 24 could be bent towards the back 16 of the plate to the position shown in FIG. 2 . In this position the plane of tab 24 would extend generally perpendicular to the plane of the plate 12 . The plane of tab 26 would extend generally perpendicular to the plane of tab 24 and also generally perpendicular to the plane of the plate 12 . It is noted that a juncture or transition line 32 , as viewed in FIG. 2 , would be formed between the plate 12 and the tab 24 . Note that the juncture or transition line 32 would generally be aligned with edge 18 D as shown again in FIG. 2 .
Attachment 10 described above is designed to be utilized in wall systems such as a metal wall system or a wood wall system. Shown in FIGS. 1 and 7 is an exemplary metal wall system. This metal wall system includes a lower track 50 and an upper track 52 . A plurality of studs 54 extend between the lower track 50 and the upper track 52 . Formed in the wall is an opening indicated generally by the numeral 56 . A header 58 extends transversely across an upper portion of the opening. A jamb or vertical member 60 also forms a part of the opening and generally extends vertically along a portion of the opening. As illustrated in FIG. 1 , the header 58 abuts against the jamb 60 so as to form a corner area underneath the header 58 and adjacent the jamb 60 , and above the header 58 and adjacent the jamb 60 .
To secure the header 58 to the jamb 60 the attachment 10 is utilized. Plate 12 is extended across a side portion of the header 58 and a flange portion 60 A of the jamb 60 . A series of fasteners 62 , such as screws, are inserted through the fastener openings 30 in the plate and on through the header 58 and jamb 60 . These fasteners 62 secure the plate 12 to both the header 58 and the jamb 60 .
Once the plate 12 is positioned adjacent the header 58 and jamb 60 , the L-shaped bracket 22 will fit in the corner area defined between the bottom of the header 58 and the web of the jamb 60 . Again, fasteners 62 such as screws, are screwed through the fastener openings 30 in both the tabs 24 and 26 . Thus, the tabs are secured to both the header 58 and the jamb 60 .
Turning to FIGS. 7-9 , a second or alternative embodiment is shown for the attachment 10 . The second embodiment is similar to the first embodiment described above with the exception that a second bracket is added to the plate 12 . More particularly, as viewed in FIG. 7 , a second bracket projects from the plate 12 and is indicated generally by the numeral 80 . Second bracket 80 assumes a generally L-shape. While the particular angle formed by the bracket can vary, just as in the case with the first embodiment, in the design illustrated herein the angle formed by the bracket 80 is generally a right angle, or an angle of approximately 90°. Similar to the bracket described above, the second bracket 80 includes a first tab or leg 82 and a second tab or leg 84 . Both tabs include fastener openings 30 . Second tab 84 is bent or otherwise disposed at an angle to the first tab 82 such that a transition line or juncture 86 is formed therebetween. See FIG. 9 . In addition, there is a juncture or transition line 88 formed between the first tab 82 and the plate 12 .
Although not required, the attachment 10 shown in FIGS. 7-9 is provided with a series of reinforcing plates 90 . In this case, a reinforcing plate is positioned on the plate 12 in a corner area adjacent one of the brackets 22 or 80 . This is particularly illustrated in FIGS. 7 and 8 .
Turning to FIG. 7 , the attachment shown in FIGS. 8 and 9 is shown therein connected between the header 58 and jamb 60 that forms a part of a wall structure. Note again that plate 12 extends across a portion of header 58 and a portion of the flange 60 A of the jamb 60 . Screws 62 are inserted through the fastener openings in the plate 12 and into the respective structural members. This connects or ties the header 58 to the jamb 60 . In addition, both brackets 22 and 80 are fastened to corner areas formed by the header 58 abutting into the jamb 60 . In this case the second bracket 80 is secured atop the header and abuts with both the top surface of the header 58 and the face or web of the jamb 60 . Again, fasteners 62 such as screws are screwed through the tabs 82 and 84 and into the adjacent or underlying structure.
From the foregoing specification and discussion, it is seen that the attachment 10 of the present invention forms a simple attachment or clip that can easily be utilized to connect two building framing members together. Because of the design and simplicity, the attachment 10 is easy to install and provides a rigid and strong connection for connecting two structural members, such as a header 58 and a jamb 60 .
The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the scope and the essential characteristics of the invention. The present embodiments are therefore to be construed in all aspects as illustrative and not restrictive and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.
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An attachment is provided for connecting two building members together such as a header and an adjoining support member. The attachment includes a plate having an engaging surface for extending across and in engagement with the two building members. At least one L-shaped bracket projects from the plate. The L-shaped bracket includes first and second tabs that form an angle of approximately 90° and which are offset with respect to the plate. The first and second tabs as well as the plate are adapted to be secured to the two building members.
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FIELD OF THE INVENTION
[0001] The present invention relates to a flow rate control valve, and more particularly, to a proportional solenoid operated valve having a shielded armature motion sensing feature.
BACKGROUND OF THE INVENTION
[0002] Solenoid valves have been conventionally used to control the flow rate of a fluid by using a solenoid to control valve activation. A conventional solenoid valve has a magnetic sensor, which is typically a Hall effect sensor, that effectively senses movement of a component and thus provides positional information for a moving component positioned in high pressure fluid in a fluid delivery device.
[0003] The Hall effect sensor used in motion sensing can offer enhanced reliability in extreme environments. A coil contained in the solenoid valve produces an electromagnetic field that may interfere with the accurate performances of the Hall effect sensor, but the prior art, such as Fukano et al., U.S. Pat. No. 6,666,429, does not have any protective mechanism to prevent external electromagnetic fields from interfering with the Hall effect sensor.
[0004] It is an object of the invention to provide a shield made of an appropriate protective material so that the performance characteristics of the Hall effect sensor are not compromised by external electromagnetic fields created by the solenoid coil.
SUMMARY OF THE INVENTION
[0005] The invention is directed to a shielded solenoid for a solenoid operated valve having a solenoid body and an annular coil of electrical wire in the solenoid body which has a central hole therethrough. A first hollow magnetic pole piece is oriented in the central hole adjacent a first axial end face of the annular coil. A second hollow magnetic pole piece is coaxially oriented with respect to the first pole piece in the central hole adjacent a second axial end face of the annular coil remote from the first axial end face and being magnetically isolated from and immovably fixed with respect to the first pole piece. An end of the second hollow pole piece has a non-magnetic plug member closing an open end thereat. An armature of magnetic material is rectilinearly movably displaceably mounted in the first and second hollow magnetic pole pieces. A non-magnetic rod part projects coaxially from at least one axially facing end thereof and is rectilinearly movable with the armature. The non-magnetic rod part has a magnet holder fastened thereto and has a permanent magnet fixedly oriented thereon. A hollow metallic shield member covers a segment of an outer periphery of the second pole piece whereat the magnet holder and the permanent magnet are oriented. The shield member is configured to shield a Hall effect sensor from any significant electromagnetic field produced by the coil when effecting rectilinear movement of the armature. The hollow shield member has a non-metallic plug closing one end thereof. The plug has the Hall effect sensor oriented therein to closely oppose the magnet on the magnet holder so that movement of the armature and resulting corresponding movement of the magnet will cause the Hall effect sensor to produce a signal indicative of movement of the armature.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Other objects and purposes of this invention will be apparent to persons acquainted with apparatus of this general type upon reading the following specification and inspecting the accompanying drawing, in which:
[0007] FIG. 1 illustrates a central, longitudinal cross sectional view of the proportional solenoid valve with a motion sensor in accordance with an embodiment of the invention; and
[0008] FIG. 2 is a fragmentary view of a modified shield member.
DETAILED DESCRIPTION
[0009] The solenoid portion 10 of a solenoid operated valve is illustrated in the drawing. The solenoid portion 10 includes a solenoid body 11 having a hollow cylindrical, non-metallic bobbin 12 on which is wound many turns of wire 13 to form an annular coil 14 .
[0010] The annular coil 14 is encased in a non-metallic synthetic resin shell 15 which has a radially outwardly extending flange 16 having a plug socket 17 formed therein so that electrical contact prongs 17 A are exposed in the socket for electrical connection to a plug not shown. The contact prongs 17 A are electrically connected to the wire 13 forming the annular coil 14 so as to facilitate the provision of electrical energy to the coil 14 .
[0011] In this particular embodiment, the shell 15 is oriented inside a steel cup 18 having a through-hole 20 in the bottom wall 19 thereof and with the flange 16 projecting through a slot 18 A in the rim of the open end of the cup 18 . The shell 15 is retained inside the steel cup 18 by press fitting a washer 18 B into the open end of the steel cup. In this particular embodiment, a compressible spring o-ring type seal 18 C is oriented between the washer 18 B and the shell 15 .
[0012] A first elongate hollow tubular magnetic pole piece 21 has an externally thread end section 21 A configured to screw into an internally threaded hole in a valve body not shown. The other end of the pole piece 21 is fixedly oriented inside the interior of the hollow bobbin 12 .
[0013] In this particular embodiment, the first pole piece 21 extends into the interior of the bobbin 12 a finite distance. A second elongate hollow tubular magnetic pole piece 22 is coaxially oriented with respect to and secured by an also coaxially oriented non-magnetic member 24 , and oriented about the mid-portion of the hollow interior of the bobbin 12 , to an end of the first pole piece 21 that is remote from the valve body. The second pole piece 22 extends a finite distance beyond the end of the bobbin 12 that is remote from the valve body and through and beyond the hole 20 in the bottom wall 19 of the steel cup 18 . It is beneficial for the clearance dimension between the inner diameter surface of the hole 20 and an outer diameter surface 23 of the pole piece 22 to be as small as is reasonable for assembly in order to optimize the magnetic shielding.
[0014] A non-magnetic, here brass, hollow plug 25 is secured to the open end of the second pole piece 22 by any convenient structure. Here, the plug 25 has a reduced diameter portion 26 receives therein the crimped open end 27 of the second pole piece 22 . In addition, the portion of the plug 25 extending axially beyond the pole piece 22 has an external thread 28 thereon, the purpose of which will be explained in more detail below. The axially facing end wall 25 A of the hollow plug 25 has a shallow centrally oriented recess 25 B therein, the purpose of which will be explained in more detail below.
[0015] A hollow armature 29 made of magnetic material is rectilinearly movably and displaceably mounted internally of the pole pieces 21 and 22 . A non-magnetic rod 31 extends through the interior of the armature 29 and is secured as by being pressed fit therein. Other forms of securement of the rod 31 to the armature 29 are to be considered as being within the scope of this invention.
[0016] In this particular embodiment, the rod 31 extends axially beyond both ends of the armature 29 . The end 32 of the rod 31 extends through the interior of the pole piece 21 and is operatively connected to a movable valve member (not illustrated) inside the valve body for controlling the flow of fluid through the valve body in a well understood way. The opposite end 33 of the rod 31 has a magnet holder 34 fixedly secured thereto and movable therewith.
[0017] In this particular embodiment, the magnet holder 34 has an opening in one end 35 into which the distal end 33 of the rod 31 is pressed fit. The opposite end 36 of the magnet holder 34 has an axially opening cup shaped opening 37 therein into which is fixedly oriented a permanent magnet 39 . In this particular embodiment, the outer diameter of the magnet holder 34 is conformed to the hollow interior of the plug 25 so as to be relatively movably and slidably received therein.
[0018] The hollow interior 30 of the armature 29 at an end from which the end 33 of the rod 31 extends is enlarged and is configured to attach to the magnet holder 34 . The attachment of the magnet holder 34 to the armature 29 can be formed by being pressed fit or by using a threaded connection. The magnet holder 34 also has a radially outwardly extending flange 38 thereon that is configured to abut against the end of the plug 25 oriented inside the pole piece 22 .
[0019] A hollow steel cylindrical shield member 40 having an internal thread 41 thereon oriented mid-length of the shield member 40 is threadedly secured to the external thread 28 on the plug 25 . The interior surface 40 A of the shield member 40 on one side of the internal thread 41 has a diameter closely conforming to the external diameter surface 23 of the second pole piece 22 so as to facilitate the interior part 42 of the shield member 40 snuggly sliding over the exterior surface 23 of the second pole piece 22 . A reduction of the clearance dimension between the outer diameter surface 23 and the inner diameter surface 40 A to as small as is reasonable for assembly is important for the purpose of optimizing the magnet shielding.
[0020] A synthetic resin plug 43 having a Hall effect sensor 47 encased therein is slidably received into an open end of the shield member 40 on a side of the internal thread 41 remote from the interior part 42 .
[0021] In this particular embodiment, the Hall effect sensor 47 is oriented at one end of the plug 43 close to an axially facing flat surface 44 of the plug 43 that opposes the shallow recess 25 B in the end wall 25 A of the plug 25 . The circumferential periphery of the plug 43 adjacent an end remote from the Hall effect sensor 47 has a reduced diameter section 45 forming a shoulder 46 onto which is provided a compressible spring 48 .
[0022] A cup shaped cap 49 having a central through-hole 50 in the bottom wall 51 through which extends the reduced diameter section 45 of the plug 43 is secured to the end of the steel shield member 40 . The segment of the bottom wall 51 surrounding the through-hole 50 serves as an abutment for the end of the compressible spring 48 that is oriented remote from the end abutting the shoulder 46 .
[0023] The compressible spring 48 initially urges the plug 43 into engagement with the shoulder 46 . However, as the internal thread 41 of the shield member 40 is threaded onto the external thread 28 of the plug 25 , the flat surface 44 of the plug 43 will abut the end face of the wall 25 A of the plug 25 in the area radially outside the shallow recess 25 B so that any forces developed during the engagement will not cause harmful mechanical stress to be applied to the Hall effect sensor 47 during assembly. A continued rotation of the shield member 40 to effect the aforesaid threaded engagement of the threads 28 and 41 will cause a relative axial movement of the shield member 40 toward the bottom wall of the steel cup 18 and a compression of the spring 48 until the shield member 40 abuts the surface of the bottom wall of the steel cup 18 . A continued rotation of the shield member 40 will cause an urging of the steel cup 18 toward the valve body (not illustrated) until the washer 15 B tightly abuts against a shoulder 21 B on the pole piece 21 . Thus, the single step of screwing the shield member 40 onto the threads 28 causes a proper orienting of the Hall effect sensor 47 with respect to the magnet 39 and a locking of the annular coil 14 in the proper position on the valve body and with respect to the pole pieces 21 and 22 .
[0024] A rubber o-ring 52 can, if desired, be provided between the shield member 40 and the bottom wall of the steel cup 18 . On the other hand, the rubber o-ring 52 can be replaced with a metal seal ring 52 A configured to wedge into contact with the shield member 40 , the bottom wall 19 of the steel cup 18 and the surface 23 of the pole piece 22 in order to optimize the magnetic shielding. In addition, a hollow or split steel ring 53 can be provided in the region of the crimped portion 27 of the pole piece 22 and configured to contact the pole piece 22 and the shield member 40 in order to enhance the magnetic shielding. The ring 53 does not need to completely encircle the aforesaid structure.
[0025] The Hall effect sensor 47 has a plurality of wires connected in a conventional way to it, and they extend through the synthetic resin plug 43 in a conventional way and exit the plug 43 in the form of a socket 53 having plural prongs 54 therein to which each respective wire is attached to facilitate the reception of a plug member (not illustrated) that can be received to connect the prongs to electrically conductive sockets provided on the plug.
[0026] The magnetic shielding for the aforesaid structure can be further enhanced by modifying the shield member 40 to include three components as shown in FIG. 2 . More specifically, the modified shield member 40 B includes a steel shield member 40 C comparable to the steel shield member 40 described above and which has the internal thread 41 thereon. Surrounding the steel shield member 40 C is a non-magnetic material 40 D which in turn is surrounded by a further steel shield member 40 E. The non-magnetic material 40 D serves to isolate the steel shield member 40 C from the steel shield member 40 E. The modified shield member 40 B combined with the hollow or split steel ring 53 and the steel seal ring 52 A and the close tolerance fit of the steel shield member 40 B to the surface 23 on the pole piece 22 and the close tolerance fit of the surface 23 on the pole piece 22 in the hole 20 provides a very effective magnetic shield isolating the effects of the magnetic field from the operating coil on the Hall effect sensor 47 .
[0027] The shield member 40 is configured to shield the Hall effect sensor 47 from any significant electromagnetic field produced by said coil 14 during periods of activation causing rectilinear movement of the armature 29 .
[0028] Although a particular preferred embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie with the scope of the present invention.
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A shielded solenoid for a solenoid operated valve having a solenoid body and an annular coil of electrical wire in the solenoid body. An armature of magnetic material is rectilinearly movable with respect to the body. A magnet holder is fastened to the armature and has a permanent magnet fixedly oriented thereon. A shield member covers the magnet holder and the permanent magnet. The shield member is configured to shield a Hall effect sensor from any significant electromagnetic field produced by the coil when effecting rectilinear movement of the armature. The hollow shield member has a non-metallic plug closing one end thereof. The plug has the Hall effect sensor oriented therein to closely oppose the magnet on the magnet holder so that movement of the armature and resulting corresponding movement of the magnet will cause the Hall effect sensor to produce a signal indicative of movement of the armature.
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FIELD OF THE INVENTION
[0001] The present invention relates to methods of making metal spheres. In particular, the present invention relates to making metal spheres from molten metal, such that the solid metal spheres achieve a very close tolerance for sphericity and size. Such metal spheres, particularly precision miniature metal spheres, have many industrial applications. For example, such spheres may be used to form Ball Grid Array (BGA) and Flip Chip (FC) arrangements in high-density integrated circuit packaging, and are also used as writing tips of ball pens.
BACKGROUND OF THE INVENTION
[0002] Conventionally, small precision metal spheres are made using a mechanical process by which a number of small metal particles are cut or punched out from fine wire or sheets. Those particles are then dropped into a tank of hot oil having a temperature that is higher than that of the melting point of the particles. In this hot oil bath, all the metal particles are melted, forming small round droplets due to surface tension of the molten metal. As the temperature of the oil cools down to below the melting point of the metal droplets, the droplets solidify into spheres. This mechanical method has intrinsic limitations that result in coarse dimensional tolerances, because each mechanical operation adds a certain amount of deviation to the size and uniformity of the particles. which together produce an unacceptable cumulative effect. Therefore, spheres are not precisely made according to this process. Further, the resulting spheres must undergo a sophisticated washing process to get rid of the oil and other surface contaminants.
[0003] Over the past two decades, many methods have been developed for generating precision molten droplets to improve the dimensional tolerances of the spheres. These new methods commonly utilize a crucible in which to melt the metal, and then cause the molten metal to flow out of the crucible through a small nozzle. Droplets are formed by shaking either the crucible or the nozzle, or by oscillating inlet gas to affect the pressure on the molten metal in the crucible. These types of vibratory disturbances that are used to generate the droplets are typically controlled by some electronic means. Due to the surface tension of the molten metal droplets, they automatically form a spherical shape while passing through a cooling medium after passing through the nozzle. However, the parameters of those processes and the environmental conditions of the electronic droplet generators are critical to the uniformity of the output. In many cases, these processes can only reach a quasi-steady-state, which limits the production throughput as well as the quality of the resulting spheres.
[0004] There is therefore a need for a process for forming metal spheres by which tolerances on the size and shape of the spheres can be kept small. Such a process must allow for a reasonable throughput and processing of the spheres such as by washing and other finishing actions should be kept to a minimum. In order to be truly useful, such a process must relatively simple, requiring few controls of parameters of the process.
SUMMARY OF THE INVENTION
[0005] It is therefore an objective of the present invention to provide a process by which precision metal spheres may be formed.
[0006] It is a further objective of the present invention to provide a process by which the degree of deviation from a perfect spherical shape of the metal spheres can be minimized.
[0007] It is an additional objective of the present invention to provide a process by which the size of the metal spheres can be determined within a small tolerance.
[0008] It is also an objective of the present invention to provide a process by which metal spheres are formed such that the metal spheres require less post-formation cleaning than do conventionally-produced metal spheres.
[0009] It is another objective of the present invention to provide a process by which fewer parameters must be controlled than when utilizing conventional processes.
[0010] It is a further objective of the present invention to provide a process by which throughput of the metal spheres is not hampered by the precision achieved in the finished product.
[0011] It is also an objective of the present invention to provide an apparatus that facilitates the process of the present invention.
[0012] The present invention is a method of forming metal spheres from molten metal in which precisely-sized droplets of the molten metal are separated from a metal mass to form the metal spheres. The droplets of the molten metal are first projected in an upward direction and buffered prior to descending through a cooling medium. Through the use of inlet gas and liquid, the cooling medium is controlled for precision solidification of the metal spheres. The solid spheres enter a liquid bath in a collection receptacle at the end of the cooling process, where they are automatically collected and separated from the liquid, which is returned to the collection receptacle for reuse.
[0013] Instead of disturbing the steady flow of the molten metal stream to create droplets, the method of the present invention utilizes a fast vibratory piston to strike each individual droplet out through a nozzle. Driven in this manner, the droplets can be shot initially upward through a cooling medium and spend more time passing through the medium before solidification of each droplet begins. Thus, a shorter cooling tower can be used, thereby saving costs related to the height of the manufacturing room, as well as reducing the amount of coolant required during the solidification process. As the piston slams a stopper or withdraws its direction of motion quickly, the resulting sudden impact transfers the energy at the piston to the molten metal and creates a droplet that shoots out through the nozzle. Control of the striking force of the piston against the stopper, and knowledge of the size of the aperture in the nozzle, allow droplets of molten metal having precisely-controlled volumes to be separated from the molten metal mass and propelled through the cooling medium, allowing for the formation of spheres of uniform size.
[0014] The structure of the apparatus of the present invention includes a buffering chamber that is designed to provide the cooling droplets with enough time to allow the internal energy to settle down before final formation and solidification. The kinetic energy within a molten droplet is usually higher than its surface tension energy right after the droplet changes dynamically in this fashion, and therefore the droplet does not acquire a spherical shape until a large percentage of this internal kinetic energy is released. When the surface tension of a droplet dominates the internal kinetic energy as the molten metal cools, the shape of the droplet becomes spherical automatically. As previously stated, the molten metal droplets are first propelled in an upward direction in the chamber, before being overcome by gravity and allowed to fall back downward. This buffering chamber has a heating system that controls the temperature of the gas inside the chamber to prevent the droplets from solidifying before the shape of the sphere is mature. The gas used is preferably an inert gas such as nitrogen, or a mixture of nitrogen and hydrogen. The temperature inside the chamber is determined empirically, depending on certain properties of the molten droplets. Typically, this temperature falls in the range between 0° C. and 100° C., depending on the size and material of the droplets.
[0015] A gas screen gate is disposed beneath the buffering chamber. This gate is a large hollow disc with two openings, one each at the centers of both top and bottom faces of the circular disc. One or more fans are disposed inside the disc along the edge of the disc wall. The fan blows in a direction tangential to the circular wall, causing the gas within the disc to flow in a circular direction within the hollow interior of the disc. This movement creates a gas barrier that slows down the heat exchange rate between the buffer chamber and the top end of the cooling tower, so that the droplets do not experience quick cooling while still in the buffering chamber. The two openings in the gate allow the droplets to pass out of the buffering chamber under the force of gravity.
[0016] Below the gas gate, a number of cooling drums are connected in a stack to form a cooling tower. Each drum has two sections formed by coaxial cylinders. The inner section of the drum is a cylinder having an open top and bottom so that the falling droplets can pass through. An outer shell forms a container with the cylindrical wall of the inner section, and is used to hold coolant or other low temperature agent such as liquid nitrogen. There are two small inlet pipes connected to the outer container of the drum. One is used to provide coolant to the outer container, and the other is used to blow a cold agent or low temperature gas around the inner section when rapid cooling is required. There are a number of small openings around the top part of the wall separating the inner section from the outer shell, to relieve pressure on the cylindrical walls and provide a passage for additional inert gas to be provided to the cooling tower.
[0017] At the bottom of the cooling tower, there is a funnel shaped collector. The collector has an outer hollow shell that is pumped into vacuum to provide good thermal insulation. The collector is filled with a liquid cooling agent such as Hexane, which has a melting point of about −100° C. The liquid agent also serves to provide a low-impact medium that stops the falling metal spheres. At the termination of the collector, there is a collecting container used to collect the mixture of solidified spheres and cooling liquid. This mixture is pumped up to above the liquid level of the collector and then flows downward into the collecting container, in which is placed a fine mash basket. The container has a pipe at the bottom end to allow the liquid to flow back to the collector after the mesh basket catches the metal spheres. The spheres that are trapped in the mesh basket can then be collected, such as by picking them out through the top opening of the container. The container opening has a gas-tight door, and the feedback pipe has a valve to prevent backflow.
[0018] In summary, a method of forming metal spheres according to the present invention includes ejecting a precisely measured droplet of molten metal from a molten metal mass, buffering the molten metal droplet to reduce the internal kinetic energy of the droplet without solidifying the droplet and cooling the buffered droplet until the droplet solidifies in the form of a metal sphere. The method may also include collecting the metal sphere.
[0019] Ejecting a droplet of molten metal may include disposing the molten metal mass in a fixed volume, providing an aperture as an outlet to the fixed volume, striking the molten metal mass with an impulse force and allowing the impulse force to propagate through the molten metal mass to cause a droplet of the molten metal mass to be ejected through the aperture. Preferably, the droplet is ejected in a generally upward direction.
[0020] Buffering the molten metal droplet may include cooling the droplet to an extent that is less than is necessary to cause the droplet to solidify, and allowing internal kinetic energy of the droplet to diminish. Further, buffering the molten metal droplet may include allowing the ejected droplet to ascend to a maximum height, and then allowing the droplet to descend through a medium having a temperature that is controlled such that the droplet is cooled but not allowed to solidify.
[0021] Cooling the buffered droplet may include allowing the droplet to descend through a medium having a temperature that is controlled to cool the droplet.
[0022] Collecting the metal sphere may include immersing the metal sphere in a liquid, and separating the metal sphere from the liquid. Separating the metal sphere from the liquid may include depositing the liquid and the metal sphere in a container having drainage holes that are smaller than the metal sphere, and draining the liquid from the container through the drainage holes.
[0023] An apparatus for fabricating metal spheres according to the present invention includes a droplet generator that generates a droplet from a molten metal mass, a buffering chamber that receives the droplet from the droplet generator, and diminishes internal kinetic energy of the droplet without solidifying the droplet, and a cooling drum that receives the droplet from the buffering chamber, and cools the droplet to the extent that the droplet solidifies into a metal sphere. The apparatus may further include a collector arrangement that receives the metal spheres from the cooling drum and makes the metal sphere available for collection.
[0024] The droplet generator may include a receptacle in which the molten metal mass is contained, wherein the receptacle includes a plurality of walls and a tube, an aperture through a first wall of the plurality of walls of the receptacle, and a piston disposed within the tube and forming a substantially fluid-tight seal with the tube. A reciprocating motion of the piston within the tube changes pressure of the molten metal mass, and an impulse force imparted by the piston on the molten metal mass within the receptacle causes a portion of the molten metal mass to eject through the aperture as a droplet. The droplet generator may also include a feed tube extending outward from the aperture; the piston abuts the first wall at an end of the reciprocating motion such that the piston closes off the aperture from the inside of the receptacle and forces a droplet of molten metal out of the feed tube. The droplet generator may be positioned such that the droplet is ejected in an upward trajectory.
[0025] The buffering chamber may include an enclosed volume having a height sufficient to allow the ejected droplet to reach a maximum unimpeded height in the upward trajectory. The buffering chamber may include an enclosed volume containing a gaseous medium, and a temperature control system that controls the temperature of the gaseous medium. The enclosed volume may include a bottom end having an opening for receiving the droplet as it descends after reaching the maximum unimpeded height in the upward trajectory.
[0026] The cooling drum may include a first cylinder, having an open top end and an open bottom end and surrounding a gaseous medium, a second cylinder; coaxial with the first cylinder and surrounding the first cylinder, and having a top end that is closed around the top end of the first cylinder, and a bottom end that is closed around the bottom end of the first cylinder, forming a reservoir between the first and second cylinders, and a system for controlling the temperature of the gaseous medium.
[0027] The system for controlling the temperature of the gaseous medium may include a first fluid inlet, disposed in an outer wall of the second cylinder, that receives a first fluid to be stored in the reservoir, and a second fluid inlet, disposed in the outer wall of the second cylinder, for receiving a second fluid to be dispersed within the first fluid in the reservoir. The system may also include a dispersal tube, connected to the second fluid inlet and surrounding the first cylinder within the reservoir, that receives the second fluid through the second fluid inlet, wherein the dispersal tube includes a plurality of holes through which the second fluid is dispersed within the first fluid. Preferably, the dispersal tube is a circular closed loop for receiving the second fluid from the second fluid inlet and for dispersing the second fluid into the first fluid, within the reservoir around the first cylinder, through the plurality of holes.
[0028] The apparatus may also include a gas screen disposed between the buffering chamber and the cooling drum, which provides temperature separation between respective media in the buffering chamber and the cooling drum. The gas screen may include a hollow disk having a top face with an opening for receiving the droplet from the buffering chamber, a bottom face with an opening for providing the droplet to the cooling drum, and circular outer wall connecting the top and bottom faces, and a fan, disposed within the hollow disk and positioned such that it blows a fluid medium within the hollow disk in a direction that is tangential to the outer wall.
[0029] The collector arrangement may include a reservoir that holds a liquid into which the metal sphere falls after passing through the cooling drum, a pipe, connected to a bottom end of the reservoir and in fluid communication with the reservoir, that receives the metal sphere and a volume of the liquid from the reservoir, and a delivery system that delivers the metal sphere to a collection basket. The reservoir may have lower sides that slope toward an opening in the pipe. The pipe may be an elbow joint having a bend in which the metal sphere settles. The delivery system may be a pump that pumps the metal sphere and the volume of the liquid to the collection basket, and the collection basket may be located at a level that is higher than a level of the liquid in the reservoir. The collector arrangement may include a holding tank in which the collection basket is disposed, and the collection basket has openings that are smaller than the metal sphere, through which the volume of liquid pass. The collector arrangement may include a return channel, in fluid communication between the holding tank and the reservoir, by which liquid passing through the openings in the collection basket is returned to the reservoir.
[0030] The cooling drum may be a plurality of cooling drums, including a first cooling drum, disposed to receive the droplet from the buffering chamber, and a last cooling drum, disposed to provide the metal sphere to the collector arrangement.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] [0031]FIG. 1 shows a sectional diagram of an exemplary apparatus of the present invention.
[0032] [0032]FIG. 2 a shows a first embodiment of a molten metal droplet generator of the present invention.
[0033] [0033]FIG. 2 b shows a second embodiment of a molten metal droplet generator of the present invention.
[0034] [0034]FIG. 3 shows an exemplary buffering chamber of the present invention.
[0035] [0035]FIG. 4 shows an exemplary gas screen of the present invention.
[0036] [0036]FIG. 5 shows an exemplary cooling drum of the present invention.
[0037] [0037]FIG. 6 shows an exemplary metal sphere collection system of the present invention.
[0038] [0038]FIG. 7 is a flow diagram of the method of the present invention.
[0039] [0039]FIG. 8 is a flow diagram of the process of forming droplets of the present invention.
[0040] [0040]FIG. 9 is a flow diagram of the process of buffering the droplets of the present invention.
[0041] [0041]FIG. 10 is a flow diagram of the process of cooling the droplets of the present invention.
[0042] [0042]FIG. 11 is a flow diagram of the process of collecting the spheres of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0043] The present invention provides a process by which metal spheres can be fabricated. As shown in FIG. 7, the process begins with the formation of molten metal droplets 71 . The droplets undergo a buffering action 72 to reduce the internal kinetic energy of the droplets prior to final cooling of the droplets to a solid form. Once the internal kinetic energy has been reduced a sufficient amount, the cooling process 73 can begin. Because the internal kinetic energy of the droplets has been reduced at this point, a droplet will form a spherical shape as it cools, due to the surface tension of the molten metal material. After cooling for a sufficient amount of time, the droplets become solid spheres 74 , and are collected 75 .
[0044] As shown in FIG. 8, the droplets are formed by providing a mass of molten metal, and exerting an impulse force to the mass of molten metal. The molten metal mass is constrained within a fixed volume 710 , which is provided with a single outlet aperture 711 . The impulse force that is applied to the molten metal mass 712 transmits through the molten metal mass. When this transmission of the impulse force reaches the surface of the molten metal mass near the aperture, the surface tension of the molten metal mass is broken there 713 . Because the surface tension is broken, a portion of the metal mass breaks away and is forced out of the volume through the aperture, in the form of a droplet 714 . The size of the droplet is determined by the size of the aperture, and the magnitude and duration of the impulse applied to the molten metal mass.
[0045] Once the droplet has been expelled through the aperture in this manner, its internal kinetic energy is high, and may even dominate the surface tension of the liquid droplet. Therefore, the buffering action takes place at this point as shown in detail in FIG. 9. Buffering takes place by slowly cooling the droplets. This is accomplished by providing an environment wherein the temperature is kept in a range that will cool the droplets but not to the extent that they will quickly solidify. Assisting in this buffering process is the motion of the droplets. When the droplet is expelled through the aperture, the force experienced by the droplet ejects the droplet at great speed. Therefore, the path of the ejected droplet is directed generally upward. The droplet is allowed to travel through the buffering medium and gradually slow down in this generally upward trajectory until stopping at a maximum height due to the effects of gravity 720 . The droplet then begins its descent due to gravity through the buffering space 721 . As described above, the space in which the droplet descends has a temperature that is controlled 722 . The droplet is allowed to fall under these controlled conditions until the internal kinetic energy of the droplets has sufficiently diminished 723 , without causing the droplets to solidify. As described previously with reference to FIG. 7, the next process will be to cool the droplets further 73 . Thus, part of the buffering process 72 preferably includes providing a gas screening action 724 between the buffering and cooling processes, to provide temperature separation as the droplets pass from the buffering stage 72 to the cooling stage 73 . This may be effected by setting up a zone between the buffering medium and the cooling medium, whereby heat exchange between the two mediums is minimized.
[0046] The droplet is then cooled by providing a cooling medium 730 through which the falling droplet continues its descent 731 . As the droplet falls through the cooling medium 731 , it gradually changes from a molten, liquid state to a solid state, in the shape of a sphere 732 . The time spent in the cooling medium must be sufficiently long to enable the spheres to harden completely. Because the droplets are falling as they cool, the length of cooling time is determined by the length of the path that the droplet is allowed to fall during the cooling process.
[0047] After the droplets have completely hardened and have become solid spheres, they must be collected. Further, because the droplets have been falling through a cooling medium during the cooling process, the motion of the falling spheres must be stopped 750 . This is accomplished by allowing the spheres to plunge into a liquid bath at the termination of the cooling path. This liquid bath is a collection medium in which a number of metal spheres are accumulated 751 . This mixture of spheres and medium is then delivered to a collection space 752 , where the spheres are separated from the collection medium 753 . The spheres can then be collected 754 , and the collection medium preferably can be returned to the liquid bath 755 . This is accomplished by pumping the liquid and sphere mixture from the bottom of the liquid bath up to a level above the level of the liquid bath. The liquid and sphere suspension is then drained such that the spheres are captured and the liquid is returned to the bath. The captured spheres may then be collected.
[0048] [0048]FIG. 1 shows an overall view of the apparatus of the present invention. The structure of the invention can be divided into four major sections. The first section is the droplet generator 1 , which produces the droplets that form the metal spheres. The second section is the buffering chamber 2 , where the propelled droplets reach a peak height before beginning the fall toward the cooling drums, while dissipating internal kinetic energy under controlled temperature conditions. The third section is the cooling drum 3 a number of which may be provided and stacked in series as necessary. The solid metal spheres are formed as the droplets cool while passing through these drums. The fourth section is the collector 4 , where the solid metal spheres end their descent and are gathered for collection.
[0049] [0049]FIG. 2 a shows an exemplary droplet generator 5 according to the present invention. This embodiment of the droplet generator is particularly advantageous for producing droplets of any size larger than approximately 0.1 mm. The molten metal is provided to the inlet 6 of a T-shaped tube 7 . The pressure of the liquid metal is controlled such that it is balanced with the surface tension of the molten metal at the top end 8 of the T-shaped tube 7 . At this top end 8 , there is a small hole that serves as a nozzle 9 . A piston 10 is mounted opposite the nozzle 9 within the bottom end 11 of the T-shaped tube 7 . The piston 10 provides a substantially airtight seal with the inner wall of the bottom end 11 of the T-shaped tube 7 . When the piston moves up and down rapidly within the bottom end 11 of the T-shaped tube 7 , it breaks the balance of forces between the surface tension and the pressure in the liquid metal. That is, the impact force of the piston on the molten metal within the T-shaped tube 7 is transmitted through the molten metal to the surface of the molten metal 12 at the top end 8 of the T-shaped tube 7 . When this occurs, the internal pressure of the molten metal at the top end 8 exceeds the surface tension, allowing a portion of the molten metal to break away. Because the nozzle 9 is the only aperture through which this portion of the molten metal can escape. each up and down cycle of the piston motion generates a droplet of the molten metal pushed through the nozzle 9 as an output of the T-shaped tube 7 . The motion of the piston 10 is preferably driven electronically, for example by an electro-mechanical transducer 13 , such as a magnetic coil or piezo crystal, so that it can be controlled for uniform speed, distance of movement, and impact force.
[0050] [0050]FIG. 2 b shows an alternative embodiment of the droplet generator 20 of the present invention. This embodiment is particularly advantageous for producing droplets of any size between approximately 0.10 mm and 2.50 mm. A stopper 21 is added at the front end of the reciprocating piston 22 motion. With each motion of the piston 22 , there is a collision between the piston 22 and stopper 21 , which closes off the proximate opening 23 in the nozzle feed tube 24 leading to the nozzle outlet 25 located at the distal end 26 of the nozzle feed tube 24 , thereby forcing a droplet of molten metal out of the nozzle outlet 25 . The piston displacement is very small and precise, and therefore causes an accurately measured amount of molten metal to be dispelled from the nozzle, which in turn becomes a droplet of predetermined size that forms a metal sphere having precisely controlled dimensions.
[0051] [0051]FIG. 3 shows the structure of a buffering chamber 30 utilized to provide a space for the droplets to propel up and then fall back downward in a temperature-controlled environment. The droplet generator 31 dispels the droplets in an upward direction, such that they follow a path 32 over a dividing wall 33 before descending over the far side of the wall 33 . In the area 34 of the chamber on the far side of the wall 33 , there is an air circulation system 35 that includes a heat exchanger 36 , which is used to control the temperature of the gas inside the area 34 . A fan 38 draws air from the area 34 into the heat exchanger 36 , where the temperature of the air is adjusted before being expelled back into the area 34 . Usually, the temperature is kept between 25° C. and 100° C. As previously explained, the air temperature is kept at a level that allows the internal kinetic energy of the droplets in the area 34 to gradually dissipate, so that the droplets are better prepared for the cooling stage that will actually solidify the droplets. This buffering stage prevents the sudden, premature cooling and solidification that can result in approximate metal spheres having dimensions with unacceptably eccentric qualities.
[0052] As shown, the chamber 30 has an opening 37 , preferably circular, at the bottom of the structure to allow the droplets drop through, leading to a gas screen. The gas screen 40 , as shown in FIG. 4, is designed to provide temperature insulation between the relatively warm buffering chamber 30 and the colder drum below. The gas screen is a hollow circular disc structure having a top face 41 adjacent the buffering chamber 30 , a bottom face 42 adjacent the cooling drum below, and a generally circular outer wall 43 . The top and bottom faces of the disc each have an opening 44 , 45 , which is preferably circular in shape. One or more fans 46 are built inside the disc to direct the gas within the gas screen 40 such that it circulates 47 about the center axis of the disc. The circular motion of the air acts to prevent heat exchange between the air in the buffering chamber 30 above the gas screen and the cooling chamber disposed below the gas screen 40 . The droplet, in its trajectory through the buffering chamber 30 , passes through the opening 37 in the bottom of the buffering chamber 30 , through the upper opening 44 in the gas screen 40 , through the lower opening 45 in the gas screen 40 , and into the cooling drum disposed below the gas screen 40 .
[0053] At least one such cooling drum 3 is located below the bottom face 42 of the gas screen 40 , and the gas screen 40 may be disposed atop a stack of such cooling drums, as shown in FIG. 1. FIG. 5 shows the structure of an individual cooling drum 50 in the stack. The number of such cooling drums 50 , if used in a stack, depends on the parameters of the particular cooling application. Such parameters include the size and material of the metal droplets, the impact of the droplet generator and attendant height reached by the propelled metal droplet, the amount of buffering time experienced by the metal droplet, and the height of each individual cooling drum 50 .
[0054] Each cooling drum 50 includes two coaxial cylinders 51 , 52 . The inner cylinder 51 is hollow and has substantially open top 53 and bottom 54 ends, so that the droplets can pass through. The outer cylinder 52 also has a hollow interior, surrounding the inner cylinder 51 , providing a chamber space 55 around the inner cylinder 51 . This chamber space 55 is closed at top 56 and bottom 57 ends. The inner cylinder 51 also has at least one and preferably multiple holes 58 in the cylinder wall separating the inner 51 and outer 52 cylinders, toward the upper end of the inner cylinder 51 . The outer cylinder 52 also has two inlet ports 58 a , 59 a , each connected to a respective feed pipe or tube 58 b , 59 b . The first inlet port and tube 58 a,b are used to add a low temperature liquid, such as liquid nitrogen, to the chamber space 55 inside the outer cylinder 52 and outside the inner cylinder 51 . The first inlet port 58 a is located at height that allows the chamber space 55 to be filled sufficiently with the liquid, which acts as the coolant for the cooling drum. The second inlet port and tube 59 a,b are used to provide a gas or gas mixture, such as 20% hydrogen in nitrogen, to a ring pipe 59 c that is connected to the second inlet tube 59 b and which encircles the inner cylinder 51 within the chamber space. The second inlet port 59 a , second inlet tube 59 b , and ring pipe 59 c are located below the first inlet port 58 a . Thus, when the chamber space 55 is sufficiently filled with the coolant liquid. the ring pipe 59 c is submersed in the liquid. After the chamber space 55 is sufficiently filled with the coolant preferably when the chamber space 55 is approximately half filled, gas is provided to the ring pipe 59 c through the second inlet port 59 a . The ring pipe 59 c has a number of small gas release holes 60 , through which gas in the ring pipe 59 c is released into the coolant liquid in the chamber space 55 . Thus, the temperature inside the cooling drum 50 is controlled by the temperature of the coolant liquid and also by the flow rate of the gas that blows through the liquid. In this manner, the temperature of the passage within the inner cylinder 51 can be maintained with a high degree of accuracy, so that a degree of control can be exercised over the solidification of the metal droplet passing through this passage. Quickly increasing the flow rate of the inlet gas can also provide rapid cooling of the passage, if necessary.
[0055] Below the cooling drum 50 , or below the bottom cooling drum 50 of the cooling tower, there is a sphere collecting arrangement 4 , as shown in FIG. 1. This arrangement 68 , as shown in detail in FIG. 6, includes a funnel-shaped reservoir 61 , an elbow pipe or tube structure 62 , a drum pump 63 , and a collection tank 64 . The reservoir 61 is located directly beneath the cooling drum 50 or tower, and contains a low freezing point liquid. such as Hexane. As a metal droplet falls from the top end of the first cooling drum to the bottom end of the last cooling drum, it solidifies into a spherical shape, and then plunges into the liquid in the reservoir 61 . The solid metal balls then make their way down the slopes of the sides of the reservoir 61 , and collect at the bottom of the elbow structure 62 . The drum pump 63 , which is connected to the other end of the elbow structure 62 . pumps the liquid and metal sphere mixture up to the collection tank 64 , such that all the metal spheres within the elbow structure 62 move with the liquid. A mesh basket 65 , which is disposed inside the collection tank 64 , receives the liquid and metal sphere mixture from the pump through a channel 66 or the like. The mesh basket 65 separates the solid spheres from the liquid. That is, the openings in the mesh walls of the basket 65 are smaller than the metal spheres, so that the liquid passes through the mesh walls of the basket 65 , leaving only the metal spheres behind. The collection tank 64 is connected to the reservoir 61 by a pipe 67 , through which the liquid flows back to the reservoir 61 after the metal spheres have been separated by the mesh basket 65 . This is possible because the collection tank 64 is located at a point that is higher in elevation than the liquid level in the reservoir 61 , so that the liquid naturally flows back to the reservoir 61 , preventing waste of the reservoir liquid. Therefore, the drum pump 63 must be able to draw the liquid and metal sphere mixture up to the level of the collection tank 64 . The entire sphere collecting arrangement 68 is preferably enclosed in a gas-tight cabinet 69 that has a closable opening 70 through which metal spheres that have accumulated in the mesh basket can be collected. Alternatively, the mesh basket 65 itself can be removed through the opening 70 , and replaced with an empty mesh basket 65 .
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A method of forming metal spheres includes ejecting a precisely measured droplet of molten metal from a molten metal mass, buffering the molten metal droplet to reduce the internal kinetic energy of the droplet without solidifying the droplet and cooling the buffered droplet until the droplet solidifies in the form of a metal sphere. An apparatus for fabricating metal spheres includes a droplet generator that generates a droplet from a molten metal mass, a buffering chamber that receives the droplet from the droplet generator, and diminishes internal kinetic energy of the droplet without solidifying the droplet, and a cooling drum that receives the droplet from the buffering chamber, and cools the droplet to the extent that the droplet solidifies into a metal sphere. The apparatus may further include a collector arrangement that receives the metal spheres from the cooling drum and makes the metal sphere available for collection.
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FIELD OF THE INVENTION
The present invention relates to the manufacture of polymers of l, d, dl or meso lactides. More particularly the present invention relates to a process for the continuous production of such polymers.
BACKGROUND OF THE INVENTION
Canadian patent 808,731 issued Mar. 18, 1969 to Ethicon Inc. discloses a process for the formation of polylactides using a catalyst of the formula R 1 MR 2 wherein R 1 and R 2 are hydrocarbyl groups having from 1 to 12 atoms and M is a divalent metal of group II of the periodic table. The patent teaches that the polymerization may be carried out as a bulk polymerization. However, the patent does not disclose a continuous process. Rather the process is a batch process.
WO 90/01521 (PCT/US89/03380) application in the name of Batelle Memorial Institute discloses a degradable thermoplastic made from lactides. The disclosure teaches at page 19, that the polymerization process may be conducted in a batch, semi-continuous or continuous manner. However, no further details of a continuous process are disclosed and all the examples use a batch process. The disclosure does not suggest a process using a chain of one preferably two or more reactors in series. The Batelle patent application gives an extensive discussion of the prior art and no prior art seems to contemplate a continuous reaction using a chain at least one, preferably two or more reactors in series.
The present seeks to provide a novel process for the continuous polymerization of polylactides in which one, preferably a chain of at least two reactors in series is
SUMMARY OF THE INVENTION
The present invention provides a continuous process for the polymerization of monomeric mixture comprising from 100 to 60 weight % of one or more monomers the formula ##STR1## wherein R 1 is a hydrogen atom or a C 1-4 alkyl radical; and R 2 is a hydrogen atom or a C 1-8 alkyl radical, provided that R 1 and R 2 cannot both be a hydrogen atom; and 0-40 weight % of one or more copolymerizable monomers which comprises:
(a) forming a melt or solution of said monomers;
(b) passing said monomeric melt or solution through at least one reactors operated at temperatures from 150° to 250° C. and at a pressure ranging from 0.5 to 5 atmospheres at a rate and for a period of time to provide not less than 75% conversion of said monomer mixture to polymer.
FIG. 1 is a schematic drawing of a reactor system which may be used in accordance with the present invention.
DETAILED DESCRIPTION
The monomers of formula I useful in accordance with the present invention may be obtained from a number of sources. Preferably the monomer is obtained from the fermentation of a relatively inexpensive feed stock such as starch derived from sugar(s) etc. However, it should be borne in mind that generally such procedures result in a racemic mixture of the d, and 1, monomer and the polymerization of such a mixture will result in a polymer having a relatively low level of crystallinity. Preferably the monomers will be selected to provide higher crystallinity polymers comprising a relatively grater amount, preferably at least 75 more preferably at least 85 weight % of the 1, monomer and up to about 25 preferably less than 15 weight % of the d monomer. Such a blend of monomers should also provide relatively higher melting polymers, having a melting temperature in the range from 130° to 170° C. However, other mixtures of the monomers may be used if melting temperature is not a significant concern as would be the case for example in blister packaging.
A particularly useful monomer of formula 1 may be a lactide, that is a alpha hydroxy lactic acid. Suitable monomers of formula 1 also include may be a C 1-8 alkyl ester of lactide. Suitable copolymerizable monomers include cyclic C 2-4 alkylene oxides such as polypropylene oxide. Other functional monomers may be included in the monomeric mixture provided they will not significantly hydrolyse the resulting polymer. Preferably, the copolymerizable monomers will be esters.
The monomeric mixture may comprise 100 weight % of one or more monomers of formula 1. Preferably, the mixture will comprise from 100 to 65 more preferably 100 to 85 weight % of one or more monomers of formula 1, and from 0 to 35 preferably not more than about 15 weight % of one or more copolymerizable monomers.
The present invention will now be described in association with FIG. 1 in which like parts have like numbers.
The monomers are fed into a prereactor 1 which is a heated vessel. The vessel may be heated by oil or steam or pressurized water maintained at initial temperature T1. The vessel is heated to above the melting point of the monomer mixture to be polymerized. Typically the temperature will be from about 125° to 150° C. The monomers may be fed to the prereactor in dry form or may be in the form of a solution or suspension. If the monomers are in the form of a solution the concentration of monomers in solvent or diluent should be as high as practicable, and preferably not less than about 85% by weight. There are a number of suitable diluents or solvents including C 6-12 aromatic solvents, C 6-12 alkanes which are unsubstituted or substituted by a C 1-4 alkyl radical, and C 1-6 alkyl ketones. Suitable aromatic diluents include ethyl benzene and toluene. Suitable C 6-12 alkanes include hexane and ethyl hexane. Suitable C 1-6 ketones include acetone. The prereactor is joined to the first reactor by a heated line 2 maintained at constant temperature. The monomer melt is pumped to the first reactor 4 by pump 3. The pump is also heated to maintain a constant temperature of at least T1. The heating means on the pump 3 and line 2, may be any suitable means such as an electric heating line steam line or hot oil and preferably controlled independently.
In an alternate embodiment the lactide monomer may also be delivered directly to the first reactor using a dry bulk feed apparatus. Such as approach is of greater simplicity as it replaces the pre-reactor, metering pumps, associated lines, heating equipment and controls, with a simple self-contained unheated device. In addition such a feed device provides a simple process to stop the process without compromising monomer feed which otherwise would be in a melt. However, it should be noted that such a feed device should be equipped with water cooling capability to avoid premature melting of incoming monomer. Premature melting could lead to monomer feed blockage.
Reactor 1 and also the subsequent reactors may typically be a stirred vessel, such as a continuous stirred tank reactor, capable of operating at reduced and elevated pressure and temperatures up to about 250° C. The reactor configuration may be spherical, cylindrical or tubular. The agitator may be of any suitable type for the reactor including turbine, anchor, paddles and screw conveyor, or combinations thereof, such as an axial flow turbine in combination with peripheral anchor(s) or anchors in combination with peripheral a single or double helix ribbon.
In a preferred, optional, embodiment a catalyst is used to increase the rate of reaction. A wide range of catalysts are suitable to promote the rate of the reaction. The catalyst may be an acid cation exchange resin, acid clay, activated clay, bentonite, alumina, or an aluminum complex of the formula Al(O--R) 3 where R is aC 2-6 alkyl radical, talc, silicic acid, metal complexes of the formula R 1 MR 2 wherein R 1 and R 2 independently may be selected from the group consisting of C 1-18 , preferably a C 5-10 carboxy radicals, an oxygen atom, a halogen atom, and M is a group II or IV metal atom. Preferably M is selected from the group consisting of magnesium, calcium, tin and lead. Preferably, R 1 and R 2 are the same and are C 5-10 carboxyl radicals. Particularly useful catalysts include stannous octoate and the aluminum complex Al (O--R) 3 . Such aluminum complexes are disclosed in H R. Dricheldorf Macromolecules Vol. 21, No. 2 p. 286 (1988).
The catalyst may be added to the first and/or any subsequent reactor. In the drawing a catalyst vessel is shown at 5. The catalyst may be used as a dilute solution or suspension. However, preferably the catalyst is used in undilute form. The catalyst vessel is connected to the first reactor by a line 6 and a pump 7. As noted-above, the catalyst vessel need not be only connected to the first reactor. It may be connected to one or more subsequent reactors.
The monomers and optionally catalyst are fed to the first reactor 4. The first reactor 4 has a jacket 8 which may be heated by steam or hot oil or pressurized hot water to a temperature T3 . The reactor is operated at temperatures from about 150 to 225, preferably from 175 to 200, most preferably about 175° C. and at a pressure from about 0.5 to 5.0, preferably about 1.0 atmospheres pressure. Typically, the reactor is a stirred tank reactor. That is there is agitation in the reactor using typical systems as described above.
The monomers and optional catalyst are kept in the first reactor for a period of time to permit a conversion from about 35 to 85% depending on the number of reactors in the chain. Typically the conversion of monomer to polymer coming out of the first reactor should be from about 50 to 80%. The residence time in the first reactor should be from 1 to 3 hours depending on the size of the reactor and the rate of feed to the reactor.
The polymer melt is pumped from the first reactor to the second reactor 9 by a pump 10 through a heated or insulated line 17 maintain at T3. The second reactor, like the first reactor also has a jacket 11 and is maintained at T4. The second reactor is operated at temperatures from 150 to about 250, most preferably from about 185° to 200° C.
The polymer melt is held in the second reactor for a period of time from about 1 to 3 hours to bring the conversion up to from about 75 to 95, most preferably from 90 to 95%.
The polymer melt is then pumped from the second reactor by a pump 12. In the embodiment shown in the drawing the polymer melt is pumped through line 13 to reactor (or preheated) 14. The reactor is preferably a tube shell type heat exchanger. Reactor 3 may comprise a single pass tube in shell heat exchanger with static mixers for a more uniform product; or an extruder-type device if additional pressure is required. The shell enclosing the tubes through which the polymer melt passes is heated and maintained at a temperature of T3 using suitable heating means such as electric heaters, hot oil, water or steam.
The preheater is heated to temperatures up to about 250° C. More typically the preheater will be heated to from about 180 to 210 preferably from 190 to 200, most preferably about 200° C. The residence time of the polymer melt in the preheater may range from about 5 to 15 minutes. Preferably the time is kept a short as possible to minimize polymer degradation and/or depolymerization. The pressure in the preheater should range from about 0.1 to 1.5 typically about 0.5 atm.
Generally, the polymer melt exits the preheater directly into the upper end of devolatilizer 15. The devolatilizer is operated at a temperature T6 from about 150 up to about 225, preferably from about 200° to 220° C. The internal pressure in the devolatilizer is below atmospheric, typically less than about 0.02, most preferably less than about 0.01 most preferably less than about 0.005 atmospheres. While the embodiment in FIG. 1 shows only one devolatilizer the devolatilizer may comprise a series of two devolatilizers as are disclosed in a number of patents in the name of Monsanto. The devolatilizer may be a falling strand devolatilizer. That is the polymer melt falls as strands from the top to the bottom of the devolatilizer. As the polymer descends to the bottom of the devolatilizer the unreacted monomer and diluent evaporate from the polymer and are withdrawn from the devolatilizer. Depending on the polymer viscosity and the level of unreacted monomer polymer distributors may be used. For example, the polymer melt could be held in a sub atmospheric chamber for longer periods of times by using a buffer or catcher tray, such as those disclosed in U.S. Pat. application No. 271,636 in the name of Polysar Financial Services S.A. A further alternative could be to use an extruder type devolatilizer equipped with a single or multi-stage vacuum apparatus to achieve vacuum levels as low as 0.002 atomospheres. Also a suitable carrier solvent such as nitrogen, toluene, ethyl benzene etc., may be used as a nucleating agent and to aid in reducing the partial pressure of unreacted lactide monomer. This would be beneficial in trying to reduce the final level of lactide monomer in the finished product.
Yet another approach could be to use thin film (wiped-film) evaporators where the combination of shorter dwell times, high ratios of surface area to volume and reduced shear rate is of benefit to the properties of the finished product.
The volatiles from the devolatilizer pass to a condenser 16. The condenser may comprise one or more stages or zones at different temperatures to more completely condense the volatiles and to possibly separate the volatiles into different fractions. The separation may also be achieved by using thin film separators and by changing or increasing the amount of carrier diluent or solvent.
The resulting polymer may then extruded as strands and cooled and chopped into pellets which then may be moulded, extruded, blown or thermoformed into various articles.
The polymer resulting from the process of the present invention should have an intrinsic viscosity from about 0.5 to about 2.5 indicating a molecular weight from about 50,000 to about 300,000.
The process of the present invention has been described in association with two reactors. However, the chain could comprise from two to five, more typically two to three reactors.
The present invention will now be illustrated by the following non limiting example in which unless otherwise indicated parts are parts by weight.
EXAMPLE 1
A continuous polymerization of 1-lactide was carried out using a pilot plant having a single CSTR reactor in a layout as in FIG. 1. After reaching steady state in about 7 hours, the monomer was melted in a prereactor and fed into the reactor at a rate of 10 lb/hr. The reactor was operated at 178° C. The reactor was a stirred tank reactor. A catalyst comprising stannous 2-ethyl hexanoate was fed to reactor at a rate of 1-1.5 g./hr. Due to a mechanical problem the catalyst feed was 0.1% based on monomer. The target feed was 0.65% based on monomer. As a result the molecular weight of the resulting lactide polymer was low. The residence time in the first reactor was about 4 hours. The conversion in the reactor after reaching steady state was from 95.5 to 96%.
Due to the problem with catalyst feed the product exiting the reactor was sampled and conversion (gravimetric in an oven) was determined. As indicated the conversion was constant. The other variables including temperature, RPM of the stirrer, etc remained essentially constant, with in experimental error given the continuous nature of the process. The conversion result during start-up and while running are set forth in Table 1.
TABLE 1______________________________________Continuous Bulk Polylactide Process Conversion % SOLIDSDATE TIME (Oven method)______________________________________12/12/90 09:50 54.112/12/90 10:50 97.112/12/90 11:50 93.612/12/90 12:50 92.512/12/90 13:50 92.912/12/90 16:45 96.812/12/90 18:15 95.312/12/90 21:50 96.112/13/90 00:50 96.812/13/90 04:50 96.812/13/90 09:55 89.8 (*)12/13/90 12:00 95.5Onset of Continuous operation: 17:00 hours on 12/12End of Continuous operation: 13:30 hours on 12/13TOTAL Continuous operation: 20:50 hours______________________________________ (*) sample degraded during oven test.
The results show that lactide polymer may be produced by a continuous process.
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Lactide monomers and copolymers may be polymerized by a continuous process using one or more continuous stirred tank reactors. The process offers productivity and product quality advantages over the batch process of polymerization.
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REFERENCE TO RELATED APPLICATION
This application is a formal application based on and claiming the benefit of U.S. provisional patent application No. 60/410,831, filed Sep. 16, 2002.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to achieving more energy-efficient horizontal motion of a two-member knuckle boom, especially but not necessarily those which carry a tree-working tool at the distal end thereof. The term “tree-working tool” throughout this specification is intended to encompass, for example, saw heads and other devices (such as shear heads, for example), for cutting trees at the stump; tree delimbing heads; tree processing heads; wood-handling grapples for piling or loading trees or logs; and other such tools in the tree-harvesting industry. However, it is emphasized that the invention is not limited to knuckle booms used in the tree-harvesting industry.
A typical two-member knuckle boom comprises a hoist boom having a proximal end pivoted to the machine base, and a stick boom having a proximal end pivoted to the distal end of the hoist boom. In the tree-harvesting industry, a tree-working tool such as a disc saw head would be mounted on the distal end of the stick boom. Other industries of course will use other tools. A hoist cylinder is mounted between the machine base and the hoist boom, and a stick cylinder is mounted between the hoist boom and the stick boom.
2. Description of the Prior Art
The invention expands on the concepts described and claimed in Canadian patent no. 2,317,670, granted Jul. 16, 2002, and in corresponding U.S. Pat. No. 6,443,196, granted Sep. 3, 2002 (hereinafter referred to as “the prior Kurelek patents”). The prior Kurelek patents explained the concept of a hydraulic circuit for a knuckle boom which provides connecting hydraulic lines between the working ends of the hoist and stick cylinders, providing an oil flow so as to enable shunting of hydraulic oil between the working ends of the cylinders. When these cylinders are alternately extending and contracting during reaching actions with the knuckle boom, such as is always a part of tree harvesting, the circuit in that invention shunts load-supporting hydraulic oil between the cylinders rather than dumping it to tank as with previous conventional circuits. This has resulted in reduced working horsepower, i.e. fuel used and heat generation, and the ability of the operator to do reaching and tucking by operating just one lever, while continuing to do lifting and lowering with the other. This is explained in detail in the prior Kurelek patents.
In the prior Kurelek patents, there was no direct control of the shunting of hydraulic oil, for example via a valve or pump. Instead, the “reach” movement of the boom (i.e. generally horizontal extension or retraction) was controlled by an additional hydraulic cylinder, acting as a “reach” cylinder, mounted between the hoist and stick booms. In one sense, the reach cylinder in effect controlled or constrained the shunting of oil between the working ends, since the reach cylinder determined the relative positions of the hoist and stick cylinders. The reach cylinder operates one of the knuckle boom angles, usually working alongside the stick cylinder, and causes the load supporting oil to flow back and forth between the hoist and stick cylinders. The reach cylinder is required to provide the horizontal push and pull forces at the tool but normally does not do major load supporting work.
In practice, tree harvesting machines with the concepts of the prior Kurelek patents do function with benefits as described, and have already become well-accepted by users. Thus some users want to retrofit existing conventional machines to incorporate the invention, but that is difficult because the addition of a reach cylinder means that lugs for its mounting must be provided during manufacture of the machine, and on some knuckle boom structures there is insufficient physical space for a reach cylinder unless other major components are repositioned.
There is thus an ongoing need for circuits that will provide the benefits of the prior Kurelek patents without necessarily needing the major extra lugging construction and additional cylinder, and for other variations and improvements as well.
SUMMARY OF THE INVENTION
It has now been realized by the inventors, including Kurelek, that in addition to the reach cylinder used in the prior Kurelek patents, there are alternative means of controlling the shunting of oil between the working ends, to achieve the desired change of angle between the hoist and stick cylinders, and the desired reach.
Accordingly, the invention provides alternative means of producing reach, which do not involve the use of a reach cylinder as in the prior Kurelek patents.
As in the prior Kurelek patents, the invention transfers pressurized oil directly from the collapsing hoist cylinder working (pressurized, load-supporting) end to the extending cylinder working (pressurized, load-supporting) end (or vice-versa), where the oil continues to do useful load support work and thereby avoids most of the problematic heat generation. Thus the load-carrying work is separated from the reach positioning function of the knuckle boom, and is left with the hoist and stick cylinders. In the prior Kurelek patents, reaching movement was controlled by a reach cylinder. In the present invention, reaching movement is controlled by a pump connected to control transferring of the slug of pressurized hydraulic oil between the hoist and stick cylinders, or by other means as described in greater detail herein. The pump determines which cylinder receives which portion of the slug of oil, and thereby controls the angle between the booms, thereby producing reach.
The energy savings provided by this invention are very substantial, and accordingly machine size and power provided is reduced significantly, or the power saved in reaching is used in speed to gain productivity. Some embodiments of this invention will also provide even more energy savings than embodiments of the prior Kurelek patents.
Further details of the invention will be described or will become apparent in the course of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described with reference to the accompanying drawings of the preferred and alternative embodiments, by way of example only. In the drawings:
FIG. 1 (prior art) is a side elevation view showing the portions of an embodiment of the prior Kurelek patents that are pertinent to this new invention;
FIG. 2 is a side elevation view showing an embodiment of the present invention;
FIG. 3 is a schematic illustration showing a hydraulic circuit which uses hydraulic cylinders which would be mounted in the carrier and connected to work as a reach actuation pump;
FIG. 4 is a schematic illustration showing that with slightly different connections and working conditions a pump could also be installed in the rod end conduit;
FIG. 5 is a schematic illustration showing a circuit that uses a closed loop variable displacement pump for reach actuation instead of hooking on to the conventional pump with a directional control valve;
FIG. 6 is a schematic illustration showing that the hoist pump can also be a closed loop type so that the energy stored during boom lifting is recovered to the engine when the boom is lowered;
FIG. 7 is a side elevation view showing that the rod ends of the cylinders could be used instead of the base ends;
FIG. 8 shows a float valve added to a circuit for a wheeled felling or tree working machine that also keeps the tool vertical during reaching, with a tilt cylinder below the stick boom;
FIG. 9 shows a float valve added to a circuit for a wheeled felling or tree working machine that also keeps the tool vertical during lifting, with the tilt cylinder above the stick boom;
FIG. 10 shows that a float valve can also be fitted to a circuit with a reach cylinder; and
FIG. 11 is a schematic illustration showing that the concept of taking energy from a collapsing cylinder and using it to raise an extending cylinder as during reaching can be employed by computer programming two closed loop pumps to pump or remove oil at the right time.
DETAILED DESCRIPTION
Introduction
FIG. 1 (prior art) shows the portions of the an embodiment of the prior Kurelek patents that are pertinent to this new invention. There is a machine base 1 supported above vehicle tracks 2 . An operator's cab 3 is mounted on the machine base, and a diesel engine 4 is cantilevered on the back of the machine base. The knuckle boom assembly comprises a hoist boom 6 , and a stick boom 7 . The hoist boom is pivotally mounted relative to the machine base at a hoist-base pivot pin 8 on a mounting bracket 9 secured to the machine base. The stick boom is pivotally connected to the distal end of the hoist boom at a hoist-stick pivot pin 15 . The hoist boom is actuated by at least one hydraulic hoist cylinder 10 connected between the machine base and the hoist boom, at an effective angle relative to the hoist boom. The stick boom is actuated by at least one stick cylinder 11 connected between the hoist boom and the stick boom, at an effective angle relative to the stick boom. A reach cylinder 16 is also connected between the hoist boom and the stick boom, at an effective angle relative to the stick boom. A tool, such as a tree harvesting head 17 (not shown in detail), is carried at the distal end of the stick boom.
A simplified schematic superimposed on FIG. 1 shows how the hydraulic connections are made to reduce reach energy consumption with an embodiment of the prior Kurelek patents. The lift directional control valve 27 is controlled by the operator with lever 26 , getting oil from the pump 30 and tank 31 . Conduits 108 and 114 connect the base end ports of both the hoist cylinder and the stick cylinder to one of the work ports of valve 27 . Conduits 107 and 113 connect the rod end ports of both the hoist cylinder and the stick cylinder to the other work port of valve 27 . Conduit 114 in effect unites the base end volume of the hoist cylinder 10 with the base end volume of the stick cylinder 11 . That is, the hoist cylinder and stick cylinder base ends are piped together and to a valve work port with hydraulic conduit, so that they share a common load-supporting pressurized volume or “slug” of oil behind their pistons.
A reach (directional) control valve 29 has its work ports connected by means of conduits 109 and 110 to the two ports of the reach cylinder so that the operator can stroke it with lever 28 , getting oil from pump 32 . As the reach cylinder is stroked, its mechanical connection with the stick cylinder lugs forces the stick cylinder to stroke as well. When thus forced to stroke the stick cylinder must exchange oil with the hoist cylinder via lines 113 and 114 and causes it to stroke and raise or lower the hoist boom. According to the prior Kurelek patents the cylinder installation geometry is such that the oil exchanged by the hoist cylinder with the stick cylinder through the conduit 114 is the correct amount to maintain the stick boom point 13 at a nearly constant height as the reach cylinder is stroked.
When the lift valve is operated alone, i.e. while leaving the reach valve not shifted, the reach cylinder will lock the stick cylinder with it, so oil flowing in line 108 can only cause the hoist cylinder to stroke and so raise or lower the tool about pivot pin 8 .
Hence the prior Kurelek patents have established an art in hydraulic circuits for knuckle booms that saves energy by transferring load supporting pressurised oil between hoist and stick cylinders during reaching and at the same time gives the operator single lever reach control. The pressurized oil is caused to flow directly between cylinders by adding a reach cylinder to the knuckle boom.
Details of the Invention
FIG. 2 illustrates the present invention which allows energy saving benefits similar to those of the prior Kurelek patents' reach cylinder circuit and construction but does not require lugging on an extra cylinder. It too provides single lever control of reaching.
The carrier may be the same as in the prior Kurelek patents and other tree harvesting machines. The knuckle boom is different from the prior Kurelek patents in that it does not have a reach cylinder. It is hence more like a conventional tree harvesting knuckle boom. As can be seen in the superimposed circuit in FIG. 2 , the pump 30 driven by engine 203 continues to supply hydraulic oil to the lift and reach cylinders from tank 31 , and conduit lines 107 and 113 connect one work port of the lift valve to the non-working hoist and stick cylinder ends, as in the prior Kurelek patents. However line 114 no longer joins the base end (working end) ports of the hoist and stick cylinders directly as it does in the prior Kurelek patents but instead the connection is through a hydraulic pump 201 , which now does the reach actuation work that the reach cylinder does in the prior Kurelek patents.
Hydraulic motor 202 drives pump 201 when the reach control 28 is moved by the operator. In one direction the pump rotates to take oil from say the hoist cylinder and force it to flow into the stick cylinder and get the same reaching out knuckle action as was done in the prior Kurelek patents with the reach cylinder. When the operator turns the pump in the other direction the knuckle boom tucks, i.e. retracts (negative reach).
If the lift control 26 is operated and the reach control 28 is not, then the oil that is say added to the 114 A conduit will not be able to reach the 114 B side of the stopped (and hydraulically held) pump, so only boom lifting occurs. If the reach control and the lift control are both operated together a combination of reach and lift will happen, just as it does with a reach cylinder in the prior Kurelek patents' circuit.
If the cylinders and their geometry are done according to principles taught in the prior Kurelek patents the pressures in the two cylinders will be nearly equal and because both sides of the pump will be at working pressures not much power will be used to do reaching horizontally. Energy savings, engine and pump sizing, and productivity advantages of the prior Kurelek patents are retained and it is not necessary to install a reach cylinder on the knuckle boom.
This aspect of the invention thus involves flowing pressurised oil between working cylinder ends by installing an operator controlled pumping actuator in the working end connection conduit. FIG. 2 shows the actuator as a hydraulic pump, shaft-coupled to a hydraulic motor that is operator controlled with a directional control valve similar to the reach cylinder valve of the prior Kurelek patents. (In the prior Kurelek patents there is no reach actuator in the working end connecting conduit.) However, the invention is not limited to rotating pumps. FIG. 3 shows a hydraulic circuit which uses hydraulic cylinders mounted in the carrier and connected to work in effect as a reach actuation pump. These are indicated as a motor cylinder 202 ′ and a pump cylinder 201 ′. FIG. 4 shows that with slightly different connections and working conditions a pump could also be installed in the rod end conduit. This circuit subjects the pump components to less hydraulic pressure than when installed in the base end.
Further Embodiments
The use of a pump-type reach actuator different from the reach cylinder of the prior Kurelek patents allows further control and energy saving advantages. FIG. 5 shows a circuit that uses a closed loop variable displacement pump for reach actuation instead of hooking on to the conventional pump with a directional control valve. With this circuit when the operator wants to reach he moves the reach pump swash plate to pump oil in the wanted direction from one cylinder base to the other. If one cylinder happens to be loaded heavier than the other and he wants the oil to flow from the higher pressure cylinder to the lower one the closed loop pump will actually lower the pressure by being turned like a motor and transmit shaft torque back into the engine where it usually can be used to do some other work. This is scientifically better than the controlling of a reach cylinder as in FIG. 1 or a hydraulic motor as in FIG. 2 where any extra pressure energy in the oil is lost as heat at the spool of the directional control valve.
FIG. 6 shows that the hoist pump can also be a closed loop type so that the energy stored during boom lifting is recovered to the engine when the boom is lowered. Use of this type of hook-up for hoisting in combination with a reach pump is novel and inventive. The smoothness of swash plate type controls can be useful to take advantage of the higher speeds available when energy is saved with efficient reach circuits.
Additional Features
FIG. 7 illustrates that although the preceding assumes the base ends of the hoist and stick cylinders to be the working ends, it is sometimes desirable to use the rod ends under pressure. FIG. 7 thus shows use of the rod ends of the cylinders. A typical knuckle boom hydraulic cylinder necessarily has a rod end effective piston area that is only one half of its base piston area. Hence for cylinder economy size and weight and oil flow needs nearly all hydraulic boom configurations are selected with the base areas being the working ends, i.e. doing the work of supporting the boom weight and the load. Sometimes however for particular work it is desirable to have the higher cylinder force pushing/working in a particular direction on the knuckle boom. FIG. 7 thus shows that the benefit of the invention can be achieved by connecting the working ends of the hoist and stick cylinders through a pump as in FIG. 2 or FIG. 5 , even though using the rod ends of the cylinders instead. In the prior Kurelek patents, if efficient reach was wanted on this type of hoist and stick cylinder layout, the reach cylinder would be located alongside the stick cylinder.
A further variation is the possibility of a “float” capability. This means a control position where the boom is supported, but relatively free to float in terms of reach (generally horizontal extension or retraction).
There are applications of the invention, on tree working machines for example, where it is important not to hit or push the tree too hard as it is approached with a tool while the carrier is being driven. Hitting too hard could damage the bark and continued pushing could uproot the tree, but always approaching very gingerly would decrease productivity.
In addition, it is sometimes desirable to raise the head with its arms lightly embracing the tree, so that limbs are cut or scrubbed off. FIGS. 8 and 9 illustrate that there would be sufficient arcing of the head about the hoist-boom to base-pivot pin to sometimes strain the tree, particularly near the stump where the tree is stout, unless the operator also adjusted the reach as he did the lifting.
Adding a float position to the reach positioning actuator improves the situations described in the two preceding paragraphs, whether with a reach cylinder embodiment or with a pump embodiment. In the invention, it is particularly easy to have the head virtually slidable in and out by simply ceasing to restrain the reach actuator and allowing oil to flow between the already connected hoist and stick cylinders. The invention is ideal for enabling the tool to be pushed outwardly or pulled inwardly with a relatively small external force when the tool is lifted clear of the ground. The operator would choose to go into “float” mode by pushing a momentary button when the job demanded it.
In addition to showing a float valve 300 , FIG. 8 shows an automatic sender and tilt hydraulic circuit, as in the prior Kurelek patents, for the head to be kept generally vertical as reaching is done. Thus while reaching is being done to get the head to and on the tree, the operator does not need to be much concerned about the vertical attitude of the head. Once within arms' reach, the operator would put the knuckle in float and close the arms, with the head being able to snuggle up to the tree in reach float rather than the entire carrier having to readjust its position or the tree's roots being strained.
Furthermore, if the head is then lifted while the knuckle is in float the head will have a chance to follow the direction of the tree rather than being forced to arc about the hoist-boom to base-pivot pin.
If the head is to be stroked up the standing tree to remove limbs, its tilt cylinder will have to be continuously adjusted so that the head axis remains parallel to the tree. Accordingly, the tilt cylinder should be moved from beneath the stick boom to above it as in FIG. 9 and set up to hold the head near vertical when it is lifted.
FIGS. 8 and 9 show a hydraulic circuit which would be used if reach control was being done by means of the closed loop engine driven pump. Float could also be done if a reach cylinder was used, by dumping across the cylinder and to tank with a similar solenoid controlled valve, as in FIG. 10 .
FIG. 11 shows that the concept of taking energy from a collapsing cylinder and using it to raise an extending cylinder as during reaching can be employed by computer programming two closed loop pumps to pump or remove oil at the right time. In this case there is no connecting hydraulic conduit, but instead an analogous capture of mechanical energy by the engine from one pump and use of it in another.
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The knuckle boom includes a hoist boom having a proximal end pivoted to a machine base, and a stick boom having a proximal end pivoted to a distal end of the hoist boom. At least one hydraulic hoist cylinder is mounted between the machine base and the hoist boom, and at least one hydraulic stick cylinder is mounted between the hoist boom and the stick boom. A hydraulic circuit supplies hydraulic oil to the cylinders, and provides an oil flow path between working ends of the cylinders so as to transfer a slug of pressurized hydraulic oil between the working ends. In one embodiment, reaching movement is controlled by a pump connected to control transferring of the slug between the hoist and stick cylinders. The pump determines which cylinder receives which portion of the slug of oil, and thereby controls the angle between the booms, thereby producing reach.
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RELATED APPLICATIONS
This application is a non-provisional counterpart to and claims priority to U.S. Ser. No. 60/653,385, filed on Feb. 16, 2005, which is now expired, which is hereby fully incorporated by reference. The present application is a continuation of and claims priority to U.S. Ser. No. 29,236,653, now U.S. Pat. No. D526,029, filed on Aug. 19, 2005, issued Aug. 1, 2007, which is hereby fully incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to pet amusement and exercise equipment and, more particularly, to aerodynamic toys employing a fascinator capable of attracting and generating interaction with a pet animal.
2. Discussion of the Prior Art
For dogs and other animal companions, toys are not a luxury, but a necessity. Toys help fight boredom in dogs left alone, and toys can even help prevent some problem behaviors from developing. Many factors contribute to the “right” toy, and a number of them depend upon dog's size, activity level, and preferences.
Many of a dog's toys should be interactive. Interactive play is very important for a dog because it needs active “people time”— and such play also enhances the bond between the pet owner and his pet. By focusing on a specific task—such as repeatedly returning a ball or toy or playing “hide-and-seek” with treats or toys—the dog can expel pent-up mental and physical energy in a limited amount of time and space. This greatly reduces stress due to confinement, isolation, and boredom. For young, high-energy, and untrained dogs, interactive play also offers an opportunity for socialization and helps them learn about appropriate and inappropriate behavior, such as jumping up or being mouthy.
The field of aerodynamic toys includes such well-known products as the Frisbee® flying disk, which is a saucer-shaped device that can be thrown over relatively long distances. To propel the Frisbee®, one grasps its edge while flexing the wrist, and then flings the disk by extending the wrist, thereby imparting spin to the disk and launching the disk through the air. A Frisbee® is capable of remaining aloft for a relatively long time given its peripheral mass distribution and its aerodynamic structure.
Other flying toys such as the aerial disk may, for example, include outer and inner concentric deformable boundary structures, with an airfoil web joining the structures. This toy deforms in flight to form a variety of shapes.
Still other flying toys may include a hollow disk which attains a shape similar to a “flying saucer”. The spinning action of the toy causes the air scoops to direct air into the hollow regions of the toy. The shape of the toy and its aerodynamic characteristics are altered in flight and are also controlled by the method of throwing the toy.
The above-discussed toys represent only a small fraction of a variety of aerodynamic toys. Many of the toys combine a common Frisbee®-type disk with numerous toy features for added interest during play; for example, some of the aerodynamic toys feature parachuted figures, nested disks, remote-control ball drops, and illumination to the basic Frisebee®. However, none of the above-described references disclose a simple one-piece toy that combines the aerodynamic features of a disk-shaped throwable toy and the fullness of a ball or rounded toy, which can amuse a pet upon landing or simply generating a sound upon being compressed.
Accordingly, a need exists for a toy that offers at once the features of a disk-shaped aerodynamic toy and a ball operative to attract or amuse a pet.
A further need exists for the toy that permits a person to find enjoyment interacting with a pet.
Still a further need exists for the toy that combines aerodynamic, bouncing and sound characteristics that can amuse and attract the pet.
SUMMARY OF INVENTION
In accordance with the invention, a throwable toy is disclosed that combines the features of a disk-shaped flying toy with the features of a ball or rounded toy operative to produce sounds in response to applying a compression force. Specifically, the toy includes a disk-shaped portion circumscribed by a rounded rim and provided with a plurality of recesses. Two spherically shaped halves that protrude from opposite planes in an opposing fashion form the ball-like feature of the toy. Each of the halves is concentric to the circular rim of the toy, and at least one of the halves houses a fascinator operative to generate a sound in response to a compression force.
The present aerodynamic toy offers a unique play experience. It combines the ease of handling and aerodynamics experienced with a disk-shaped toy, a ball component, and a sound-generating fascinator or squeaker that invites a variety of pets to chase, catch and chew on the inventive toy. Thus, the present toy may be thrown in the known manner and kicked in the manner of a ball. Advantageously, the present toy lands in a substantially identical fashion each time it is thrown, given that each side of the ball component has a like-shaped protruding convexity. As such, one can expect perfect landings from the present toy with each throw or kick. In comparison, plain saucer-shaped flying toys may land upside-down.
The present toy may be made of any material that is sufficiently light in weight to allow an individual to throw it in the known manner. The toy may be made of a semi-rigid material such that it maintains its shape during play. The toy flexes upon impact but returns to its manufactured shape. The simplicity of its one-piece design allows for inexpensive manufacturing by known processes, such as injection molding.
The above and other features of the invention will become more readily apparent from the following detailed description accompanied by the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a preferred embodiment of the inventive toy in which the convexities protruding from the opposing planes of the circular disk are semi-spherical in shape;
FIG. 2 is a top planar view of the inventive toy of FIG. 1 ;
FIG. 3 is a side elevational view of inventive toy shown in FIG. 1 ;
FIG. 4 is a bottom planar view of the inventive toy, as shown in FIG. 2 ;
FIG. 5 is a diagrammatic side view of the inventive toy, as illustrated in FIG. 3 ; and
FIG. 6 is a cross sectional view of a preferred embodiment of the present toy in which the convexities protruding from the opposing planes of the circular disk region are semi-spherical in shape.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to several embodiments of the invention that are illustrated in the accompanying drawings. Wherever possible, same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The drawings are in simplified form and are not to precise scale. For purposes of convenience and clarity only, directional terms, such as top, bottom, left, right, up, down, over, above, below, beneath, rear, and front may be used with respect to the drawings. These and similar directional terms should not be construed to limit the scope of the invention in any manner. The words “connect,” “couple,” and similar terms with their inflectional morphemes do not necessarily denote direct and immediate connections, but also include connections through mediate elements or devices. Furthermore, such terms as “toy” and “whirling wheel toy” are used interchangeably.
In accordance with the invention, as depicted in FIGS. 1-6 , a throwable and aerodynamic toy or whirling wheel toy 10 combines a disk 12 with a centrally positioned ball, rounded component, structure 14 . Specifically, whirling wheel toy 10 comprises a one-piece molded device with flying disk 12 having a top side 13 and a bottom side 15 and circumscribed by a rounded rim 18 . In a preferred configuration, rim 18 is formed with a greater thickness than the peripheral region of flying disk 12 and, thus, protrudes outwardly from opposite sides 13 and 15 of flying disk 12 . Ball 14 includes a pair of top and bottom regions 19 , 20 , respectively, consisting of like-shaped protruding convexities or halves extending from top and bottom surfaces 13 and 15 , respectively, of disk 12 in an opposing fashion. Both convexities are centered about an axis of symmetry at the center of disk 12 and substantially perpendicular to its top and bottom surfaces 13 and 15 , respectively. In other words, the convexities are concentric to the disk.
When in flight, whirling wheel toy 10 has the appearance of a “flying saucer” or unidentified flying object, giving it added play appeal. The toy may be thrown in the manner of a Frisbee and, upon landing, may keep bouncing due to the resiliency of the ball's material. In play, whirling wheel toy 10 is thrown into the air with a spinning motion imparted thereto by grasping disk 12 with the fingers. More specifically, whirling wheel toy 10 is preferably grasped in one hand with the thumb carried on top of disk 12 and the four fingers pressing against the bottom of disk 12 . The toy is then typically projected into the air in a wrist-snapping motion. Consequently, during an airborne flight, whirling wheel toy 10 rotates about its axis of symmetry. The angle at which disk 12 is held controls the particular flight trajectory assumed by whirling wheel toy 10 . Typically, the inventive toy is propelled in an upwardly arching flight pattern so as to be held aloft aerodynamically for a time until assuming a downward trajectory toward the earth. If the trajectory of the toy's flight is correct, it typically lands on bottom half 20 of ball 14 , bounces and generates a noise a few times giving a pet time to catch it in the air.
Turning now specifically to FIG. 1 , whirling wheel toy 10 may be packaged individually to meet the individual needs of dogs classified in accordance with their respective size, which typically includes large, medium and small size dogs. In an alternative embodiment, however, more than one toy 10 can be packaged together so as to constitute a kit. One of the reasons for having the kit is that a pet may like one of the packaged toys and, for some reason, ignore the other one regardless of the size of toys 10 . Whirling wheel toy 10 is preferably a single continuous unit, which is made from a moldable material selected from a substantially rigid material, such as plastic or foam, or a flexible material, such as rubber or plastic.
As is illustrated in the embodiment of FIGS. 1 through 6 , top and bottom halves 19, 20 of ball 14 , respectively, are semi-spherically-shaped halves. However, although not shown, the ball may have a shape differing from a round ball, such as crown 21 wherein it is advantageously shaped for better bounce and/or easier deformability, and be provided with two generally conically or frustoconicaly shaped opposite halves extending from the opposite sides of flying disk 12 so as to form a substantially elliptically-shaped body.
In accordance with one of the embodiments of the invention, both semi-spherical top and bottom halves 19, 20 of ball 14 , respectively, are made from uniformly-densed polymeric material. However, in an alternative embodiment, half 20 protruding from bottom surface 15 of disk 12 may be made from a more dense material than the opposite half and, thus, be somewhat heavier. Configured in accordance with the latter embodiment, whirling wheel toy 10 may have a high probability of landing on the central region rather than wobble and land on rim 18 and, as a consequence, exhibit superior bouncing characteristics upon landing, which is particularly liked by dogs.
The disk 12 is of a substantially circular outline, and it may assume any appropriate diameter to be thrown by the pet owner. It may likewise assume any appropriate thickness defined between top surface 13 and bottom surface 15 of disk 12 . In one embodiment of the invention, as shown in FIGS. 1 through 6 , opposite top and bottom surfaces 13 and 15 , respectively, extend in parallel planes. In an alternative embodiment, which is not shown, disk 12 may be extruded so as to have the top and bottom surfaces each having a respective convex shape cumulatively defining a substantially elliptical cross-section of the disk. In particular, the thickness of disk 12 defined between its top and bottom surfaces 13 and 15 may gradually increase towards the center of the disk reaching its maximum in a region that surrounds ball 14 . In the latter embodiment, whirling wheel toy 10 may achieve high and long flight trajectories due to its better aerodynamic qualities. In any case, the thickness of disk 12 is selected so as to provide the pet owner with a comfortable grip.
Whirling wheel toy 10 may be either hollow or semi-solid, so long as surfaces 13 and 15 of disk 12 are substantially rigid to retain the shape of whirling wheel toy 10 during use and is sufficiently light in weight for throwing. Nonexclusive examples of substantially rigid materials that might form a solid whirling wheel toy 10 include foam, plastics, and rigid papers such as cardboard.
If a soft, flexible material, such as rubber, is employed to form whirling wheel toy 10 , the latter would be semi-solid and the flexible material would have sufficient rigidity such that whirling wheel toy 10 substantially retains its shape during use.
In a semi-solid toy 10 , the material, used to form toy 10 , can have a controllably different density within disk 12 . By carefully choosing the density of the material for various regions of disk 12 , inventive whirling wheel toy 10 can have different flight characteristics. For example, if whirling wheel toy 10 having the capability of sustained flight is desired, the density of the material near rim 18 will be greater than the density of the material near ball 14 .
The body of disk 12 may be continuous or provided with a plurality of spaced openings 16 extending between and through the disk's opposite top and bottom surfaces 13 and 15 , respectively. It has been found that configuring and dimensioning whirling wheel toy 10 in a specific manner may enhance its aerodynamic characteristics.
Turning to FIGS. 4 and 5 , each of openings 16 is preferably provided with an oval shape and has a ratio of a length of its major axis, Dol, to a length of its minor axis Do of between about 2 to 3 in order to provide whirling wheel toy 10 with good aerodynamic characteristics. However, the oval shape is not the only shape that may be selected for openings 16 . Other shapes, both regular and irregular, may be used as well. Empirically, it has been found that a ratio of about 2.3 to 2.7 between an inner diameter, Dbi, which is defined between opposite inner boundaries of rim 18 , which has a diameter De, and an outer diameter Dc of ball 14 may also contribute to the improved aerodynamic characteristics of whirling wheel toy 10 . Still a further feature beneficially affecting the aerodynamics of disk 12 , which has a thickness Dth, includes selecting a ratio between the disk's outer diameter, Dbo, and outer diameter, Dc, of ball 14 of about 2.8 to 3.
An interesting feature of the inventive toy includes a fascinator such as squeaker 22 ( FIG. 6 ) provided within bottom half 20 of ball 14 and operative to generate a noise upon impact with the ground. Since a material of ball 14 deforms upon impact and springs back to its original shape, the noise is produced each time bottom half 20 of ball 14 touches the ground. A configuration of squeaker 22 is known and includes an inner hollow portion 28 , perforated plastic membrane 26 , outer sleeve 24 , inner sleeve 30 and outer flange 32 with an air intake port that lies flush with the outer surface of ball 14 . Squeaker 22 is so positioned that air may be introduced into or expelled from the interior of ball 14 only through the squeaker. Upon collapsing or expanding of ball 14 , the squeaker is traversed by air stream through the air intake port so as to produce a noise that usually attracts a pet, which either tries to catch the bouncing toy or simply chews on it. Hence, each time when the animal bites ball 14 , or releases it, air passes through the squeaker producing a noise.
An optional feature is contemplated to be its illumination from within during play. Specifically, the toy 10 could be hollow and made of a translucent material, such as plastic or foam, and an illuminating means could be positioned internally in whirling wheel toy 10 .
This document describes the inventive toy for illustration purposes only. Neither the specific embodiments of the invention as a whole, nor those of its features limit the general principles underlying the invention. In particular, the invention is not limited to any specific configuration of squeaker 22 , shapes of ball 14 and rim 18 . The specific features described herein may be used in some embodiments, but not in others, without departure from the spirit and scope of the invention as set forth. Many additional modifications are intended in the foregoing disclosure, and it will be appreciated by those of ordinary skill in the art that in some instances some features of the invention will be employed in the absence of a corresponding use of other features. The illustrative examples therefore do not define the metes and bounds of the invention and the legal protection afforded the invention.
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A throwable pet toy bounces and creates an interest for a pet when impacting the ground or an object. The toy includes two domed structures, which are mounted on opposite sides of an aerodynamic base. The structures are in fluid communication with each other. A fascinator is mounted in one of the first and second domed structure to produce an interest for a pet when one of the domed structures impacts.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 11/426,466, filed Jun. 26, 2006, now U.S. Pat. No. 7,831,306, which is a continuation of U.S. application Ser. No. 10/318,741, filed Dec. 13, 2002, now U.S. Pat. No. 7,069,083, the disclosures of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present application relates generally to pain relief for spinal pain, and more generally to a system and method for electrical stimulation of the intervertebral disc to relieve pain.
BACKGROUND
[0003] The use of electrical stimulation of the spinal cord or associated nerve bundles for the reduction of bodily pain is well known in the art of pain relief. Leads containing electrodes are commonly used for such electrical stimulation and are implanted on or near a nerve bundle or the spinal cord. A pulse generator that supplies electrical pulses with predetermined characteristics is typically connected to the lead.
[0004] In a typical embodiment of the prior art, a stimulating lead incorporating multiple electrodes is constructed in a cylindrical, elongated and flexible lead configuration. The lead is then inserted into the spinal canal's epidural space and adjacent to the posterior aspect of the spinal cord. Alternatively, a lead may be inserted into the body next to or alongside the desired peripheral nerve.
[0005] A pulse generator transmits electrical pulses through two or more connecting wires within the lead to the electrodes, which by its proximity to the desired stimulation site, stimulates a certain area of the spinal cord or the peripheral nerve. In the case of spinal cord stimulation, the electrical pulse at the electrodes can negate the passage of pain sensation from peripheral areas such as a leg or arm, to the brain.
[0006] In the case of a lead inserted to lie alongside a peripheral nerve, stimulation of the nerve induces depolarization of the nerve and propagation of a nerve impulse towards the spinal cord. This also appears to negate unpleasant sensations conducted in the nerve. Various peripheral nerves have been stimulated by this latter technique including peripheral nerves to the limbs and to the cranium.
[0007] Multiple configurations of products and nerve stimulation currently exist. Papers by Holsheimer entitled “Effect of anode-cathode configuration on paresthesia coverage in spinal cord stimulation” and Hassenbusch, et. al. entitled “Long-term results of peripheral nerve stimulation for Reflex Sympathetic Dystrophy” describe various aspects of nerve stimulation and are incorporated by reference here in full.
[0008] Power to and control of such stimulating electrodes is derived from either fully implantable battery powered devices or generators, or alternatively, from radiofrequency systems, where the power is transmitted through the skin by closely applied transmitting coils. The Genesis® and Renew® systems, provided by Advanced Neuromodulation Systems, Inc. are two similar systems existing in the prior art that utilize this methodology. Such systems are further described in more detail in U.S. Pat. No. 4,793,353, which is incorporated by reference here in full.
[0009] Various configurations of leads have been designed and typically involve multiple electrodes of 2-3 mm in size, in multiples of 4 or 8. Such electrode arrays are inserted through an introducing needle into the epidural space, or in the case of a peripheral nerve are placed adjacent to the nerve either through a hollow needle or by open surgery. The power source and the electrode array are typically connected by a subcutaneous borrowed connector, which passes around the body to a suitable location such as the groin or lateral chest wall.
[0010] These products have been developed for treatment of chronic pain often where nerves have been injured or involved in surgery. Electrical stimulation provides a safe and minimally invasive means of controlling chronic pain without resorting to drugs.
[0011] The current treatment of discogenic (i.e., originating in the intervertebral disc) spinal pain is not satisfactory. Patients can be offered conservative management including physiotherapy treatment, medication and psychological techniques such as cognitive behavioral therapy. Presently, techniques exist of heating the annulus fibrosus using radiofrequency annuloplasty for painful annular tears causing discogenic low back pain.
[0012] This procedure is available for a relatively small group with only moderately degenerated discs. For a much larger group of patients with more advanced degeneration of the disc, often at multiple levels of the spine, presently, there is only surgery in the form of spinal fusion that can be offered.
[0013] Certain studies show that the results of spinal fusion are not ideal. For example, in the lumbar region only approximately 63% of patients improved, and approximately 30% experienced no improvement at all, or in some cases, worsening of the pain state.
[0014] Once a major operation such as a spinal fusion has been conducted, the anatomy of the spine is permanently changed. Secondary problems can also occur with altered mechanics of the spine, changes in nerve function and increased pressure on the discs at other spinal levels, which may need further surgery.
SUMMARY
[0015] A method for electrically stimulating an area in a spinal disc is presented. The method comprises implanting a lead with one or more electrodes in a placement site in a disc or just outside the outer confines of the disc, connecting the lead to a signal generator, and generating electrical stimulation pulses using the generator to stimulate targeted portions of the disc.
[0016] Additionally, a system for relieving pain associated with a spinal disc is presented that comprises a lead with one or more electrodes, an introducer for introducing the lead to a placement site in or just outside the confines of the disc, a removable stylet for guiding the lead to the placement site in the disc, and a generator connected to the lead for generating electrical pulses to the lead for stimulating the disc.
[0017] Finally, an insertable lead system is presented for relieving pain associated with a spinal disc that is inserted in a placement site inside or just outside the spinal disc, containing an introducer, a lead with one or more electrodes for stimulating an area in or just outside the spinal disc and an anchoring portion to anchor the lead in place either adjacent to or in the disc.
[0018] The foregoing has outlined some of the more pertinent objects and features of the present invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention as will be described. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the following Detailed Description of the Preferred Embodiment.
BRIEF DESCRIPTION OF THE DRAWING
[0019] For a more complete understanding of some embodiments, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which:
[0020] FIG. 1 shows a curved tip introducer inserted percutaneously into a lumbar intervertebral disc in accordance with one embodiment of the present;
[0021] FIGS. 2A , 2 B, and 2 C shows a system of curved tip introducer and a lead in accordance with the one embodiment of the present invention;
[0022] FIGS. 3A , 3 B, and 3 C show different embodiment configurations of a permanent lead inside with or adjacent to the intervertebral disc;
[0023] FIG. 4 shows a system of curved tip introducer and a lead in the nucleus in accordance with one embodiment of the present invention;
[0024] FIG. 5 shows a system of curved tip introducer and a lead in accordance with one embodiment of the present invention;
[0025] FIG. 6 shows a flow chart of the operation in accordance with the present invention;
[0026] FIG. 7 shows one embodiment of the present invention inserted into a patient;
[0027] FIGS. 8A and 8B shows one embodiment of the present invention during implantation of the lead at the placement site adjacent to the disc;
[0028] FIG. 9A shows a lateral view of a healthy disc and FIG. 9B shows a lateral view of a narrow degenerate disc; and
[0029] FIG. 10 shows a lateral view of a degenerate disc with one embodiment of the present invention.
DETAILED DESCRIPTION
[0030] The present invention treats the nerve-containing portion of the intervertebral disc for the indication of discogenic low back pain. The epidemiology of discogenic low back pain has been described by Deyo and Tsui-Wu in “Descriptive epidemiology of low-back pain and its related medical care in the United States,” and Schwarzer, et. al., in “The sacroiliac joint in chronic low back pain” which are incorporated by reference here in full.
[0031] Pain can be derived from degeneration or tearing of the intervertebral disc, especially in its posterior or posterolateral portions. There is innervation of the intervertebral disc near the surface of the disc and also within its outer portion, known as the annulus fibrosus. Fissures or cracks within the discs, which appear with age, mechanical trauma or disc degeneration are believed to be associated with painful symptoms. It is thought that nerve fibers grow into such painful fissures or cracks and can even reach the outer part of the disc nucleus. Electrical stimulation of the disc at a specified placement site is configured to stimulate these nerve fibers and therefore negate unpleasant sensations originating in the disc. Such a placement site may be interior or adjacent to the disc in question.
[0032] Prior treatments for such discogenic low back pain relating to disc degeneration included a technique for heating portions of the annulus fibrosus with an intradiscal radiofrequency electrode. These treatments were performed for treatment of some forms of discogenic low back pain. This method typically heats or vaporizes a portion of the disc, possibly relieving interior disc pressure, thereby possibly relieving some associated disc pain. However, this procedure leads to a burning or scaring of the nerves associated with the disc, causing the pain relief to be temporary at best.
[0033] In the present invention, electrical stimulation of the nerve fibers associated with a disc is the primary methodology for pain relief. The patterns and spread of stimulation often invariably mimic the pattern of discogenic pain. Typically, for example in the lumbar region, this involves the spread of stimulation to involve the axial spine and the buttocks. If the voltage is increased, the spread can include the lower limbs. Previous attempts to stimulate the area of the axial spine have encountered difficulties. These difficulties, that despite complex multiple electrode systems, obtaining coverage of central discogenic pain can be difficult to cover, are well known in the art. Certain dual electrode systems have been developed by Advanced Neuromodulation Systems, Inc (ANS) to address these difficulties. These dual electrode systems are typically passed into the epidural space, to lie in the dorsolumbar area.
[0034] Stimulation can be obtained in the buttock and lower limbs by classical spinal cord stimulation with epidural leads placed in the epidural space. However, central discogenic low back pain can be difficult to cover. Typically, for analgesia to occur, the stimulated area must cover the area of the pain. The present invention uses direct stimulation of the intervertebral disc providing coverage of axial pain, which can provide greater certainty of coverage of these painful areas.
[0035] There are three main risks encountered from intradiscal manipulation, including nerve injury, migration of the lead away from the placement site to involve sensitive neural structures, and disc space infection. Certain studies have shown that the risk of disc space infection is considered to be approximately one in two thousand cases. This can be reduced by the injection of antibiotic into the disc at the time of implantation. The risk of nerve injury can be greatly reduced by very careful attention to surgical technique. The risk of migration of the lead can be minimized by the use of new materials for fixation of devices in or just adjacent to the disc space. Additionally, the risk can be minimized by placing the lead at a placement site that is adjacent to the disc in question, proximal to the injury site.
[0036] To additionally minimize the risks mentioned above, one embodiment of the present invention uses a configuration of a needle introducer to approach and enter the intervertebral disc. A lead is then inserted through the introducer. This configuration helps to adequately reach the posterior and posterolateral or any other desired portions of the intervertebral disc and places the lead at the correct placement site where the desired stimulation will occur. Thus, proper placement of the lead occurs and disc disruption is minimized using this embodiment.
[0037] Another embodiment of the present invention uses a configuration of the needle introducer to approach the desired location of the disc and place the lead, inserted through the introducer, at a placement site adjacent to the disc. This configuration helps to adequately reach the proper placement site where the desired stimulation will occur, without entering the intervertebral disc. The placement site corresponds to the location where lead placement optimizes disc pain relief.
[0038] For safety, it is desirable that the surgeon has quantitative information about the placement of the introducer and the stimulating lead as it is placed near the placement site in or just outside the disc. Additionally, risk of the lead kinking within the disc or straying outside the disc, which could result in damage to the probe or injury to the patient should be taken into account when considering the placement site. One embodiment of the present invention that minimizes the risk of kinking and allows for greater flexibility of choosing a placement site retains the lead in or adjacent to the intervertebral disc and prevents its migration.
[0039] In the present invention, prior to insertion of a permanent lead into or adjacent to the disc, a trial period is typically conducted for hours, days or even sometimes weeks. Trial insertion and stimulation can be conducted at the same time as the injection of radiographic contrast material into the disc. This provides the surgeon with information on fissures or cracks within the disc (i.e. discography) and the response of the nerves to electrical stimulation.
[0040] One embodiment of the present invention envisions that each patient who is diagnosed with discogenic low back pain, often by means of Magnetic Resonance Imaging and discography, will undergo a trial period of stimulation.
[0041] In this embodiment of the present invention, a trial lead will be inserted percutaneously at the placement site in the disc via an introducer and retained for a period while stimulation is conducted. The x-ray coordinates of the position and the electrical parameters of stimulation are noted during this period before complete removal of the trial stimulating device.
[0042] It is envisaged that such a trial stimulation lead will be similar to those currently utilized for periods of trial stimulation with ANS leads in the epidural space. The period of trial implantation could be short, lasting only a few hours or days, to minimize the chance of disc space infection or may be longer depending on the needs of the procedure and patient.
[0043] After due consideration of the results of the trial stimulation, a permanent lead is inserted at the placement site in or just outside the intervertebral disc for long term stimulation purposes. As shown in FIG. 7 , lead 10 , whether trial or permanent, will be connected to either a fully implanted, battery driven, stimulating device 60 that can last many years, or alternatively to a system for passage of external electrical energy through a coil or similar device often utilizing radiofrequency current. Stimulating device 60 is coupled to lead 10 , which is place at the placement site. One embodiment of the present invention, stimulating device 60 is an implantable rechargeable device connected to the lead. Recharging of this device will be conducted by positioning of an external charging device adjacent to the implanted stimulator for a period of hours.
[0044] It is envisaged that the patient will require intermittent assessment with regard to patterns of stimulation. Different electrodes on the lead can be selected by suitable computer programming, such as that described in U.S. Pat. No. 5,938,690, which is incorporated by reference here in full. Utilizing such a program allows an optimal stimulation pattern to be obtained at minimal voltages. This ensures a longer battery life for the implanted systems. Such programming will be conducted in a similar fashion to the current method of changing parameters for ANS stimulating systems.
[0045] One embodiment of the present invention uses a curved introducer to approach the placement site of the intervertebral disc via a percutaneous insertion point in the patient. The introducer is placed in or adjacent to the disc, depending on the actual location of the placement site, and a lead is passed through the introducer and pushed to the placement site in or adjacent to the intervertebral disc space. Appropriate steering of the lead will place the device at the placement site in close proximity to the tears and fissures so that the nerves innervating these fissures can be electrically stimulated.
[0046] The stimulating lead used in the present invention has a flexible configuration and is visible under image intensifier or CT X-ray monitoring. It is envisaged that in one embodiment, the lead passes through the intervertebral foramen, to exit the skin in the lumbar region. It is connected to an internal or external stimulating device so that variations of electrode configuration and electrical stimulation can be accomplished in a trial.
[0047] Various embodiments of a permanent lead are considered. In one embodiment a lead, which can be either monopolar (unipolar) or bipolar arrangement, can be inserted surgically, preferably by an endoscopic technique. This is typically performed in a similar fashion to endoscopic sympathectomy for lower limb ischaemia or endoscopic spinal fusion. This lead will have an unexpanded and an expanded position. The lead will be either inserted into the disc or placed adjacent to the disc so that it will expand into a position preventing migration onto adjacent sensitive neural structures.
[0048] The lead can have multiple electrical contacts or a single contact. It is then connected to a stimulating device, which is either fully implanted or powered by an external radiofrequency source, in the same fashion that current ANS devices are powered. It is envisaged that the lead will be constructed of biocompatible materials and designed such that it will resist migration and yet not prevent ultimate removal, if required. Such a anti-migration design includes an inflatable miniature balloon, surgical fixation device or a device consisting of material with elastic memory, such as silicon, polymers, polyurethane materials, or Nitinol or Nitinol coated with a biocompatible material.
[0049] Alternative techniques of placement of a permanent electrode or lead are envisaged, which are performed percutaneously. Such approaches involve the lateral portion of the disc to avoid placement of the lead adjacent to a nerve root or other sensitive neural structures. Additionally, the lead may lie just adjacent to the outer confines of the disc so that nerve fibers inside the annulus fibrosis are recruited.
[0050] It is envisaged that such placements would be performed under X-ray control and possibly in the same manner that permanent leads are placed in the epidural space. Connection of the stimulating leads in the disc would then be made to either a permanent implanted power source or a coil powered by an external device.
[0051] Referring to FIG. 1 , one embodiment of the stimulating system in accordance with the present invention is generally illustrated. In this illustration, a trial lead 10 is passed across the posterior aspect of the annulus fibrosus 15 so that electrodes in the lead are near the placement site and can make contact with the requisite pain nerve fibres in the disc 20 . Lead 10 typically contains more than one electrode 5 , and often can have 8, 16 or more electrodes, which provide the direct stimulation of the nerves in the disc area during system operation.
[0052] During implantation, the introducer 30 is passed closely adjacent to the facet joint 40 of the spinal column 50 and into the outer portion 15 of the disc or the annulus. Introducer 30 can be shielded or unshielded. Shielding may be used for impedance monitoring during insertion, which assists in determine the insertion depth into the annulus.
[0053] Once the lead is properly placed at the placement site, introducer 30 is then removed. A connector 55 connects lead 10 to a power source or generator 60 , which may be either external or implanted. Introducer 30 has a curved tip 70 to facilitate placement of the lead to the placement site. The lead with stimulating electrodes can be placed both across the posterior portion of the disc or alternatively around the periphery in any configuration to allow juxtaposition of the electrodes at the placement site to the requisite nerve fibres.
[0054] In FIG. 2C , one embodiment of the components of a trial lead are illustrated. Those skilled in the art will recognize that the lead described in each of the figures, including FIGS. 2A-2C , can be either a trial lead or a permanent lead. Lead 10 with its flexible shaft 220 and connector 55 is connected to an impedance monitor and stimulation/power generator 60 . Lead 10 contains one or more electrodes 5 thereon, which provide the direct stimulation to the placement site during operation. This stimulating lead is passed down an introducer 30 with a curved tip 70 and a hub 90 to facilitate steering as shown in FIG. 2A . This is performed after the stylette 100 as shown in FIG. 2B of the introducer 30 is removed. The stylette 100 also has a connecting hub 110 .
[0055] FIGS. 3A-3C illustrate the possible placement, for certain embodiments, of a permanent implanted lead at the placement or stimulating site. It is envisaged that the introducer 30 is to be passed into the disc 20 in a more lateral position to avoid any conflict with the nerve root.
[0056] In FIGS. 3A-3C , the introducer 30 is aimed to pass into or adjacent to the anterior portion of the disc 20 so that the lead 10 curves around the annulus 15 from the anterior portion to the posterior portion of the disc. Lead 10 , as shown in FIG. 3A , contains at least one or more electrodes 5 therein, which provide the direct stimulation during operation of the lead, once connected to generator 60 . This will achieve the same juxtaposition of lead 10 and pain nerve fibres in disc 20 at the trial stimulating lead placement site as described previously in FIG. 1 . Introducer 30 for the permanent lead 10 also has a curved tip 70 and a hub 90 for steering. It is envisaged that the lead will have a central stiffening stylette 120 which will be removed in the case of the trial lead but may be partly retained in the implanted lead 10 .
[0057] The central stylette 130 will have a modification in the permanent lead 10 such that after the stylette 130 is advanced further into or around the disc 20 than lead 10 itself, then a portion of the central stylette 130 will be removed allowing the retained portion 140 to curl in upon itself and act as a locking or anchoring device for the permanent lead at the placement site in the disc. This prevents displacement and migration of the lead 10 away from the placement site. It is envisaged that lead 10 can be removed in the future if the portion of the central stylette 130 that is removed is replaced, thus straightening the retained portion of stylette 140 .
[0058] In one embodiment of the present invention, the retained portion of stylette 140 can have a metallic memory such that it can adopt a predetermined shape to anchor the lead and prevent lead migration. It is envisaged that the retained portion of stylette 140 will act as an anchor by adapting to a pre-stressed shape. Alternatively, other forms of anchoring the electrode could be utilized such as an inflatable balloon or surgical fixation.
[0059] Lead 10 is connected via an implanted connector 150 to a stimulator or generator 160 . Generator 160 may be an implantable device with an internal power source, or alternatively, a radiofrequency receiving coil which is also fully implanted. Such a receiving coil receives power transmitted through the skin.
[0060] In a further embodiment, a permanent lead could be physically separated from the power generator by a transmitting and receiving coil. This will prevent the need for direct connecting leads that exit the disc.
[0061] FIG. 4 shows one embodiment of the present invention during implantation of the lead in the nucleus. As mentioned, it is believed that nerve endings that are involved in disc pain can appear at or in the nucleus. In FIG. 4 , the introducer 30 inserts the lead 10 through the annulus 15 , and into the nucleus. Once in the nucleus, the lead is placed near the placement site and the anchor 150 is locked into position to anchor the lead in the proper location. One further reason to locate the lead in the nucleus is to ensure that the electrodes are near the proper location, should the pain sensation transmitted via the nerves near the annulus/nucleus interface or in the edge of the annulus near the nucleus interface.
[0062] FIG. 5 shows one embodiment of the present invention during implantation of the lead in the nucleus. In FIG. 5 , the introducer 30 inserts the lead 10 partially through the annulus 15 so that the lead is place in between the annulus and the nucleus. Once at the placement site in between the annulus and the nucleus, the lead is anchored by anchor 150 and locked into position to anchor the lead in the proper location. One further reason to locate the lead in the nucleus or at the nucleus/annulus interface is to ensure that the electrodes are near the proper location, should the pain be caused from nerves near the annulus/nucleus interface or in the edge of the annulus near the nucleus interface.
[0063] FIGS. 8A and 8B show another embodiment of the present invention during implantation of the lead at the placement site adjacent to the disc. Because of the proximal location of the nerve endings to the placement site exterior to the disc, placement of the lead at this location will allow the nerve endings to benefit from the stimulation effect, without having to enter into the disc. This has safety implications, by reducing the chance of disc space infections, because the leads are not interior to the disc.
[0064] In FIG. 8A , either one or two leads 10 are placed around the outside of the disc annulus 15 at the desired placement site or affected area. FIG. 8A shows a percutaneous approach from the patient's posterior side. FIG. 8B shows an endoscopic approach (from the anterior side). It is important to note that either one or both leads may be applied to either side of the affected disc, depending on the location for the desired stimulation or placement site.
[0065] FIGS. 9A , 9 B and 10 show a lateral view of an affected disc and a lead placement on the outside of such a disc. In FIG. 9A , a healthy disc is shown with a healthy disc annulus 15 . FIG. 9B shows a narrowing of a degenerated disc 20 . Fissures have narrowed the disc and there is no clear delineation between the disc annulus and the nucleus. Additionally, end plate (modic) changes have occurred. FIG. 10 , shows a lateral view of lead 10 located at the placement site in the narrowed degenerated disc. FIG. 10 could represent either lead 10 located within the disc annulus or nucleus, as described herein, or lead 10 can be located outside the disc annulus as shown in FIG. 8A or 8 B ( FIG. 10 showing a posterior placement in this case).
[0066] FIG. 6 illustrates the methodology of the present invention. In step 310 , the doctor inserts the introducer into or just adjacent to a disc. As mentioned above, the introducer has a curved tip to assist in the introduction of the lead. Next, in step 320 the doctor positions the tip of the introducer in or adjacent to the disc according to X-ray coordinates and impedance monitoring. In step 330 , the doctor inserts the flexible stimulation lead into or alongside the disc. Positioning the lead at the placement site is accomplished using the X-ray coordinates and the stimulation parameters. The stimulation parameters are determined during the trial insertion procedure to provide the optimal stimulation settings. Finally, in step 340 , the introducer is removed and the lead remains in or adjacent to the disc. The lead is then connected to the external or internal power source. The power source will have the stimulation parameters loaded into its memory. Once connected, stimulation of the disc can begin.
[0067] As such, an apparatus and method for making such apparatus is described. In view of the above detailed description of the present invention and associated drawings, other modifications and variations will now become apparent to those skilled in the art. It should also be apparent that such other modifications and variations may be effected without departing from the spirit and scope of the present invention as set forth in the claims which follow.
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In one embodiment, a method electrically stimulates an area in a spinal disc. The method comprises: implanting at least one steerable lead at a placement site for stimulating a spinal disc such that the lead is disposed exterior and immediately adjacent to and circumferentially along an annulus of the spinal disc, the at least one lead including a plurality of electrodes distributed along a majority of a circumference of the annulus; connecting the lead to a signal generator; and generating electrical stimulation pulses using the generator to stimulate targeted portions of the spinal disc, wherein the stimulation of the targeted portion of the spinal disc sufficiently stimulates nerve tissue within the spinal disc to prevent communication of pain signals originating in the spinal disc without damaging tissue of the spinal disc.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation-in-Part of U.S. patent application Ser. No. 13/322,790, entitled “Method and Apparatus for Continuous Removal of Submicron Sized Particles in a Closed Loop Liquid Flow System”, filed on Nov. 28, 2011, which is a National Stage Entry of International Patent Application PCT/US10/46421, entitled “Method and Apparatus for Continuous Removal of Submicron Sized Particles in a Closed Loop Liquid Flow System, filed on Aug. 24, 2010, which claims priority to and the benefit of U.S. Provisional Patent Application Serial No. 61/236,810, entitled “Synthesis of Oxygen Carrying, Turbulence Resistant High Density Submicron Particulates and Method for Their Continuous Retrieval from the Blood Including Submicron Size Perfluorocarbon Emulsion and PolyHb Dual-Cored Oxygen Carries (DCOC)”, filed on Aug. 25, 2009. The specification and claims thereof are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a method and apparatus for continuous removal of sub-micron sized particles from the blood or other liquids.
BACKGROUND OF THE INVENTION
[0003] The blood consists of wide ranges of cells, molecules, ions and water. But, their abnormal degradation or proliferation, their functional changes, and invasion of foreign matters or toxins into the blood call for immediate intervention. Removing unwanted materials from the blood is a solution. Embodiments of the present invention provides for a system and method to specifically remove unwanted targets in the blood by attaching the unwanted target to a high density sub-micron particle and separating the high density sub-micron particle from the blood with density dependent centrifugation. An embodiment of a device as disclosed herein will also be capable of removing specific targets from other liquids and solvents after the targets have been attached to a high density sub-micron particle functionalized to bind to the specific target.
[0004] A high density sub-micron particle as referenced herein may have intrinsic biological function, such as use as a perfluorocabon based artificial oxygen carrier (AOC). After some time, the AOC may have to be centrifugally collected from the blood and removed, by taking advantage of their density being higher than that of the blood components.
[0005] The benefits of other types of high density sub-micron particles may be found in their ability to capture the desired targets after the sub-micron high density particles are functionalized to conjugate with the specific cells, molecules and ions in the blood. The sub-micron high density particles may be able to capture the circulating tumor cells (CTC), sickle cell hemoglobin (HbS), toxins, irons etc. in the blood and then be retrieved from the circulation using the specialized centrifuge rotor described herein, after the targets bind to the binding partner located on a sub-micron high density particles.
[0006] Removing the sub-micron high density particles as described herein will be possible with aphaeresis instruments of various types already available. However, the instruments already available are tuned for separating molecules and cells found in blood which span a limited range of densities. The densities of sub-micron particles of interest are 1.9 gm/ml or higher and are significantly higher than those of the highest density component found in blood, namely 1.2 g/ml of RBC, and most synthetic organic and polymeric materials. Separating materials with such large differences in density is carried out with a rotor as described herein rather than those described for use in conventional clinical aphaeresis instruments.
[0007] An embodiment of a rotor as described herein will continuously or intermittently isolate high density sub-micron particles from blood components (for example whole blood or subfraction thereof) continuously and quickly. In one embodiment, since the separation is continuous, there will be no limits in the volume of materials to be centrifuged. In one embodiment of the rotor, the volume of rotor is no more than about 15 mls and counting the volumes of the tubes that provide flow to the rotor and the tubes that direct the liquid from the rotor through the treatment process the volume will be less than 70 mls. Thus, the volume of exo-corporeal treatment will be about 85-100 mls. In another embodiment the rotor can be used to continuously or intermittently isolate high density sub-micron particles from other biological fluids, cell lysates, macromolecule or polymer solutions etc.
SUMMARY OF THE INVENTION
[0008] One embodiment of the present invention provides for a rotor for a centrifuge used to separate a mixture of components in a fluid having different densities, the rotor comprising a rotor base having a central axis and the rotor base is rotated about the central axis when the centrifuge is in use. A first rotor element that is curved and is attached to and has an orientation extending away from the rotor base, the first rotor element having a first end and a second end; and a second rotor element that is curved and is attached to and has an orientation extending away from the rotor base, the second rotor element having a first end and a second end, the second end of the first rotor element being connected to the first end of the second rotor element to form a composite rotor element; wherein the composite rotor element is positioned on the rotor base so that the first end of the first rotor element and the second end of the second end of the second rotor element are at different distances from the central axis wherein the composite rotor element traverses 180° or less around the axis of rotation of the rotor base. The rotor base with composite rotor element mounted thereon is rotated the orientation of the composite rotor element on the rotor base and creates a density gradient that separates two components of the mixture of components that is input to the composite rotor element, where the two components have different densities, and a first of the two components moves in a first direction inside composite rotor element and is removed from the composite rotor element at the first output port while a second of the two components moves in a second, opposite direction inside the composite rotor element and is removed from the composite rotor element at the second output port.
[0009] Optionally a monitor port through the sidewall of composite rotor element can be included, the monitor port being closer to the second output port at the second end of the second rotor element than the input port is, the monitor port being used to extract a sample of the second of the two components moving toward the second output port, the sample being used to determine if the first of the two components has been separated from the second component. In addition an outwardly extending end at the first end of the first rotor segment and at the second end of the second rotor segment can be included, wherein as the rotor these two ends create a pressure pushing the first component of the mixture of components toward the first output port and pushing the second component of the mixture of components toward the second output port. A sensor can be connected to the monitor output port to monitor the sample of the second of the two components moving toward the second output port and extracted at the monitor port for the presence of any of the first of the two components, the sensor generating an output signal if any of the first of the two components is present; and electronics receiving the output signal from the sensor, the electronics causing a change in the rate at which the first of the two components is removed from the centrifuge at the first output port, and changing the rate at which the second of the two components is removed from the centrifuge at the second output port to eliminate the presence of any of the first of the two components in the sample taken at the monitor output port, thus assuring there is none of the first of the two components present with the second of the two components exiting the centrifuge at the second output port. The electronics can also cause a change in the rate at which the mixture of components is input to the composite rotor element to assure there is none of the first of the two components present with the second of the two components exiting the composite rotor element at the second output port.
[0010] Additionally, a monitor port through the sidewall of the composite rotor element, the monitor port being closer to the second output port at the second end of the second rotor element than the input port is, the monitor port being used to extract a sample of the second of the two components moving toward the second output port, the sample being used to determine if the first of the two components has been separated from the second component. Further still, an outwardly extending end at the first end of the first rotor segment and at the second end of the second rotor segment is included, wherein as the rotor turns these two ends create a pressure pushing the first component of the mixture of components toward the first output port and the second component of the mixture of components toward the second output port. The rotor base with composite rotor element mounted thereon is rotated the orientation of the composite rotor element on the rotor base creates a density gradient that separates two components of the mixture of components that is input to the centrifuge housing, where the two components have different densities, and a first of the two components moves in a first direction inside the centrifuge housing and is removed from the centrifuge housing at the first output port while a second of the two components moves in a second, opposite direction inside the centrifuge housing and is removed from the centrifuge housing at the second output port. In addition, a sensor connected to the monitor output port to monitor the sample of the second of the two components moving toward the second output port and extracted at the monitor port for the presence of any of the first of the two components, the sensor generating an output signal if any of the first of the two components is present; and electronics receiving the output signal from the sensor, the electronics causing a change in the rate at which the first of the two components is removed from the centrifuge at the first output port, and changing the rate at which the second of the two components is removed from the centrifuge at the second output port to eliminate the presence of any of the first of the two components in the sample taken at the monitor output port, thus assuring there is none of the first of the two components present with the second of the two components exiting the component rotor element at the second output port. The electronics can also causes a change in the rate at which the mixture of components is input to the component rotor element to assure there is none of the first of the two components present with the second of the two components exiting the component rotor element at the second output port.
[0011] Another embodiment provides a rotor for a centrifuge used to separate whole blood from other artificial blood having a density higher than any of the components of the whole blood, the rotor comprising a rotor base having a central axis and the rotor base is rotated about the central axis when the centrifuge is in use; a first rotor element that is curved and is attached to and has an orientation extending away from the rotor base, the first rotor element having a first end and a second end; and a second rotor element that is curved and is attached to and has an orientation extending away from the rotor base, the second rotor element having a first end and a second end, the second end of the first rotor element being connected to the first end of the second rotor element to form a composite rotor element; wherein the composite rotor element is positioned on the rotor base so that the first end of the first rotor element and the second end of the second end of the second rotor element are at different distances from the central axis wherein the composite rotor traverses about 180° around the axis of rotation of the rotor base and contains a chamber therein.
[0012] The rotor base with composite rotor element mounted thereon is rotated, and the orientation of the composite rotor element on the rotor base creates a density gradient that separates the whole blood from the artificial blood where the components of the whole blood have a lower density than the artificial blood, and a first of the whole blood moves inside the composite rotor element toward and is removed from the composite rotor element at the first output port while the artificial blood moves inside the composite rotor element and is removed from the composite rotor element at the second output port. Additionally, a monitor port through the sidewall of the component rotor element is added, the monitor port being closer to the second output port at the second end of the second rotor element than the input port is, the monitor port being used to extract a sample of the artificial blood moving toward the second output port, the sample being used to determine if the whole blood has been completely separated from the artificial blood. Further, an outwardly extending end at the first end of the first rotor segment and at the second end of the second rotor segment can be included, wherein as the rotor turns, these two ends create a pressure pushing the whole blood toward the first output port and the artificial blood toward the second output port. Further still, a sensor connected to the monitor output port to monitor the sample of the artificial blood moving toward the second output port and extracted at the monitor port to test for the presence of any whole blood components, the sensor generating an output signal if any of the whole is present; and electronics receiving the output signal from the sensor, the electronics causing a change in the rate at which the whole blood is removed from the centrifuge at the first output port, and changing the rate at which the artificial blood is removed from the centrifuge at the second output port to eliminate the presence of any of the whole blood in the sample taken at the monitor output port, thus assuring there is none of the first of the two components present with the second of the two components exiting the centrifuge at the second output port. The electronics can also causes a change in the rate at which the mixture of whole blood and artificial blood is input to the composite rotor element to assure there is none of the whole blood components present with the artificial blood exiting the composite rotor element at the second output port.
[0013] In another embodiment a method of separating components in a fluid based upon a difference in density of the components in the fluid when the components are mixed together comprising the steps of providing to a rotor as described herein the fluid containing the mixed together components to be separated based upon the difference in density of the mixed together components and continuously flowing the components in the fluid to the rotor while the rotor is spinning. The components in the fluid are separated based upon the difference in density of the mixed together components with the use of centrifugal force when the rotor is spinning. The components having a first density are collected via a first tube located at a first position on the rotor and the components having a second density are collected via a second tube located at a second position on the rotor and a the components having a third density are collected via a third tube at a third position on the rotor. The components having a first density comprise high density sub-micron particles that have a density different than the components with a second density or a third density and wherein the high density sub-micron particles are functionalized to capture a first component from the components mixed together in the fluid.
DESCRIPTION OF THE DRAWINGS
[0014] The invention will be better understood upon reading the following Detailed Description in conjunction with the drawings in which:
[0015] FIG. 1 is a perspective view of the novel centrifuge that utilizes density gradient separation to efficiently remove particulate artificial oxygen carriers from blood or other biofluids;
[0016] FIG. 2 is a top view of the novel centrifuge that better shows the novel rotor used in the centrifuge; and
[0017] FIG. 3 is a linear graphical representation of the novel rotor of the centrifuge.
DETAILED DESCRIPTION
[0018] As used herein “a” and “the” means one or more unless otherwise specified.
[0019] The term “about” as used herein is a flexible word with a meaning similar to “approximately” or “nearly”. The term “about” indicates that exactitude is not claimed, but rather a contemplated variation. Thus, as used herein, the term “about” means within 1 or 2 standard deviations from the specifically recited value, or±a range of up to 20%, up to 15%, up to 10%, up to 5%, or up to 4%, 3%, 2%, or 1% compared to the specifically recited value.
[0020] The term “comprising” as used in a claim herein is open-ended, and means that the claim must have all the features specifically recited therein, but that there is no bar on additional features that are not recited being present as well. The term “comprising” leaves the claim open for the inclusion of unspecified ingredients even in major amounts. The term “consisting essentially of” in a claim means that the invention necessarily includes the listed ingredients, and is open to unlisted ingredients that do not materially affect the basic and novel properties of the invention. A “consisting essentially of” claim occupies a middle ground between closed claims that are written in a closed “consisting of” format and fully open claims that are drafted in a “comprising' format”. These terms can be used interchangeably herein if, and when, this may become necessary. Furthermore, the use of the term “including”, as well as other related forms, such as “includes” and “included”, is not limiting.
[0021] During the continuous flow of liquid, a rotor as described herein is spinning and designed to separate the components of the liquid according to the densities of components located within the fluid and collect the components of highest, lowest and other defined densities via tubes. The blood or other fluid or solution having components to be separated will enter through a port (for example near in the middle of the rotor) and the components will be separated to high density on one end of the rotor and low density on the other end. Components with densities between the two limits will concentrate at a position between the two ends for example near in the middle of the rotor. The three different density fractions will leave through their own ports. The entering flow rate of blood or other fluid solution will often be determined by an external requirement such as the status of a patient and the desired purity of separation. The flow rate can be adjusted by a dedicated pump. In one embodiment to adjust the exit flow rates through all three exit ports only two pumps are used. The rate of each outward flow rate will be defined by the type of high-density sub-micron particles used (i.e whether or not it is surface activated to capture a target substance), the amounts of target expected to be captured by the sub-micron particles, and the source fluid. Typically, the rate of flow of a fluid such as blood entering the rotor should be in compatible with the rates of blood flows in the blood vessels of the subject, around 32 ml/min. Thus total flow rate from the three output ports should be 32 ml/min according to one embodiment of the present invention. In one embodiment, the flow rate through each tube carrying fluid to and away from the rotor will be limited by mechanism employed to ensure that the entering and exit tubes remain kink-free as the rotor spins (several methods are currently used in aphaeresis systems). The rotor and method as described according to one embodiment of the present invention distinguishes itself from other clinical aphaeresis rotors by collecting all of the naturally occurring components of blood in a single flow path, separate from materials with buoyant densities higher than 1.2 g/ml. In the event these particles are designed to attach to a specific naturally occurring blood component, then that component will also be separated along with the particles from naturally occurring components of blood. Such particles are referred to as centrifugally retrievable target activated sub-micron particles, thus rTAP and have a density higher than the density of naturally occurring components of blood. Examples of cells, molecules, and ions that can be continuously retrieved with the proposed centrifugal device from the circulating blood include circulating tumor cells, ABO type red blood cells, macrophages, sickle cell hemoglobin, AOC, antigens, antibodies, drugs, toxins, and irons but are not limited thereto.
[0022] A rotor according to one embodiment of the present invention would be able to separate continuously any particles in the flowing liquid through the rotor according to their densities when the system is exerting centrifugal force on the liquid. As the densities of targeted cells and molecules are sufficiently made higher by attaching to the retrievable high density sub-micron particles such as nanoparticles (referred to herein as high-density, retrievable sub-micron particles or rP), the target cells and molecules would establish their unique density profile of relative narrow range that can be separated with the proposed device. Retrieval of particle bound CTC, HbsS, AOC, by itself acting as high density sub-micron particles (see U.S. patent application publication US 2012/0164231 and US 2014/0008301) would offer significant benefit to the patient. The components bound to such particles will be referred to as targets and target activated rP will be referred to as rTAP, here after.
[0023] Referring now to FIG. 1 , an embodiment of the rotor is illustrated. The case of the centrifuge is not shown in FIG. 1 to make the drawing simpler so the invention can be better understood. Rotor 24 comprises a circular rotor base 25 that is mounted on an axis 27 to a motor driven shaft (not shown). As shown in FIG. 1 rotor base 25 is rotated in a counter clockwise direction for the rotor 24 configuration shown and described herein. The blood mixed with high density particles (rP or rTAP) enter at port 31 of the rotor consisting of elements 26 a and 26 b and their position on rotor base 25 , to create a density based gradient that separates RBC, of which light density plasma exits at port 29 and the high density particles (with or without targets depending on the desired outcome) exits from port 28 , while from a mixture of RBC and rTAP that is input to the centrifuge rotor at port 31 . Distances d 3 , d 4 and dr are shown in all of FIGS. 1 , 2 and 3 to better understand how the rotor is placed on the base. In one embodiment of the present invention the rotor has a width of each rotor element 26 a and 26 b of 0.5 cm, the height is 2 cm, and the length is 15 cm. In one embodiment of the present invention, the volume of the rotor will be only 15 ml. As mentioned the procedure is continuous, but actual separation of components take place within this 15 ml of fluid within the rotor when spinning. The dimensions can be changed responding to the demand, but the same principles of centrifugation apply.
[0024] Rotor 24 is made up of two curved elements 26 a and 26 b that are joined together to form a total curved element of 180 degrees or less. The curvature of element 26 b is slightly larger diameter than that of 26 a generating slightly higher centrifugal force. The rotor is similar to that of a conventional aphaeresis instrument, but unlike the rotor of a conventional aphaeresis instrument the rotor of FIG. 1 is 180 degrees of circular rotor on the base and the blood flow rate from the rotor to a receptacle such as a patient is as fast as 32 ml/min. In one embodiment, the rotor can operate at 2400 rpm of spin speed to allow the density gradient to be quickly established and maintained, since the distance between the highest (1.2) and the lowest (1.0) density will be quickly established. Even in the presence of a density as high as 1.9 g/ml, the rotor density gradient will be quickly established and maintained. The density gradient difference between the highest and lowest is still about 0.9 g/ml, but it is spread over the entire length of the rotor (15 cm) to permit subtle difference in density to be recognized with this rotor 24 . In one example, the complete blood enters from port 31 and because the rotor is off-centered from the axis of rotation, the high density components move towards the higher density, i.e. port 28 , while the low density components (e.g. blood components) move towards port 29 . Thus adjusting the relative flow rates of ports 28 and 29 , it would be possible to adjust the profile of density gradient over the entire range of the rotor. In practice, the whole blood enters port 31 under the controlled flow rate by a pump. The flow rates of ports 28 and 29 can also be adjusted with a pair of pumps and the net rates of both pumps define the out flow of blood from the port 30 , but the density of the particles at port 30 will be defined by the ratio of these two pumps. Thus, adjusting the rpm of the centrifuge, pumping rates at 31 , 28 and 29 , it would be possible to what should be the density of particles, which come out from the port 30 at the known flow rate. In practice, however, the instrument will be usually adjusted so that only the high density retrievable particles and any attached materials should appear from port 28 .
[0025] FIG. 2 is a top view of the novel centrifuge rotor 24 used in a centrifuge. As previously mentioned the different curvatures of rotor elements 26 a and 26 b and the offset of composite rotor element 26 a , 26 b on rotor base 25 are best seen in FIG. 2 . More particularly, rotor 26 a , 26 b being belt shaped in the general shape of an ellipsoid with overlapping ends. With rotor 26 a , 26 b being off centered on base 25 regions of high, medium and low centrifugal force are created depending on the distances from the axis of rotation 27 . Input 31 where the composite mixture of RBC and rTAP is input to the centrifuge rotor is offset from the junction of rotor elements 26 a and 26 b and is closer to rTAP output port 28 by a circumferential distance “dx” as shown. In one embodiment the distance d 3 is different from the distance d 4 . In one embodiment, the distance d 3 is less than d 4 .
[0026] FIG. 3 is a linear graphical representation of the novel centrifuge rotor 24 of the centrifuge. This Figure shows how the distance between the face of composite rotor elements 26 a , 26 b and the stretched form of the axis of rotation 27 of centrifuge rotor 24 changes. Thus, the magnitude of centrifugal force at different regions of centrifuge rotor 24 are depicted by the distance from the axis of rotation 27 , which is stretched and shown as the dotted line at the bottom of FIG. 2 . The distances d 3 , d 4 and dr are shown in all of FIGS. 1 , 2 and 3 to better understand how the figures relate to each other. The degree of change in distance is basically linear and in some embodiments close to flat except where rotor element 26 a meets rotor element 26 b. This is due to the fact the curvature of element 26 a is different than the curvature of element 26 b. In alternative embodiments of the invention the rate of change in distance may be uniform, and in another alternative embodiment the rate of change may be non-linear. Distances d 3 , d 4 and dr between the face of rotor element 26 a , 26 b and axis 27 are shown to link FIG. 3 with FIGS. 1 and 2 . The input port 31 and output ports 28 , 29 and 30 and their relative position with respect to the linear depiction of rotor 24 is shown according to one embodiment.
[0027] The whole blood including rTAP obtained from a person who is connected in a closed loop system with a density gradient centrifuge is input to the centrifuge rotor at input port 31 . The whole blood is separated from the rTAP because the density of the rTAPs is greater than the density of the whole blood and any of its individual components. The whole blood is output at output port 29 and port 30 and is returned to the person from whom the blood and rTAP were withdrawn or stored in a container for later use. The rTAP is released from output port 28 and disposed. In addition, at a particular location near where the rTAP exits the centrifuge via rTAP output port 28 , a small sample is removed from the density gradient centrifuge and exits the centrifuge at monitor output port 30 . The sample is input to a red blood cell sensor of a control circuit to be checked for the presence of any remaining red blood cells (RBC) with the rTAP about to exit the centrifuge rotor. If any RBC are detected control circuit adjusts the speed of the blood and retrievable particle pumps that are part of circuit shown in FIG. 4 to permit the centrifuge rotor to fully separate any remaining RBC from the rTAP before the rTAP reaches monitor output port 30 . This feedback operation assures that only rTAP exit output port 28 .
[0028] The centrifugal field generated in the density gradient centrifuge as novel centrifuge rotor 24 turns about its axis 27 ( FIGS. 1 and 2 ) creates a density gradient field that changes between output ports 28 and 29 . Depending on the shape of rotor elements 26 a and 26 b, how they are joined, and how they are positioned on rotor base 25 this density field may change uniformly or it may non-linearly. The result is that the lower density whole blood fraction is separated from the higher density rTAP fraction. In an alternative embodiment another output port may be added somewhere between output ports 28 and 29 to separate intermediate density fractions of blood. The separated whole blood and rTAP are withdrawn through their respective output ports as previously described. The whole blood collected may be subjected to further fractionation. For example, further fractionation may be used to separate platelets and white blood cells from the whole blood in a manner known in the art.
[0029] The basic design of the centrifuge rotor 26 a , 26 b is a belt shaped semicircular rotor placed slightly off-centered from the axis of rotation as shown in FIGS. 1 and 2 . FIG. 1 is a three dimensional view of the rotor 26 a , 26 b on the spinning rotor base 25 , and FIG. 2 is a top view of rotor 26 a , 26 b on the spinning rotor base 25 . In FIG. 3 the rotor 26 a , 26 b is shown stretched out in a linear configuration to help show the location of the rotor on rotor base 25 with respect to axis of rotation 27 .
[0030] With reference to FIG. 3 , as the centrifugation begins the rTAP of the input mixture 31 remain at the wall of the furthest out rotor segment 26 b, as it is the most dense material and moves towards the higher centrifugal field. This is to the right in FIG. 3 and the output is indicated as output 28 . In FIGS. 1 and 2 this is clockwise and the output is indicated as output 28 . All the blood components move toward the left in FIG. 3 toward closer rotor segment 26 a because their densities are smaller and they essentially float on top of the rTAP. In FIGS. 1 and 2 this is counterclockwise and the blood components output is indicated as output 29 .
[0031] More particularly, as the blood and rTAP continue to be injected into rotor 26 a, 26 b at input 31 (shown in FIGS. 1-3 ), the blood components move towards the lower centrifugal field while the rTAP move to the higher centrifugal field. The thickness of belt shaped rotor 24 is only 5 mm according to one embodiment. The separation of the rTAP and blood is carried out very quickly and form layers based are density of the particles. With separation being accomplished quickly it is possible maintain the rate of rTAP and blood inflow sufficiently fast to make the process “continuous-flow density separation”. As mentioned above the rTAP leave the rotor at output 28 at the end of highest centrifugal force, while the blood components move leave the rotor at output 29 at the end of lowest centrifugal force. The semicircular rotor has a small offset, bend and protrusion near the junction of segments 26 a and 26 b to make the separation of rTAP from the blood complete. In FIGS. 1 , 2 and 3 this is indicated by the number 40 , but offset 40 is best seen in FIGS. 2 and 3 . More specifically, it is possible to enhance the change of centrifugal force by creating a protrusion at the site where distinctive separation of two layers is made, since their sedimentation coefficients are predominantly a function of (1−ρ/δ), the particulates will be positioned close to the outer wall of the rotor when the density equilibrium is established.
[0032] Near at the exit port 28 of the rTAP, there is a monitor output port 30 , from which small samples are taken of the particles flowing toward its output 28 to test the purity of the rTAP. The purity of the rTAP might change slowly over time during centrifugal retrieval of the rTAP so the relative flow rates of pumps must be adjusted to maintain the purity of the rTAP output at its port 28 . Under a given revolution per minute of the rotor, to achieve the optimal removal of rTAP from the blood, using the notation in FIG. 1 , the following flow conditions must be met according to one embodiment of the present invention. F31=F28+F29+F30 wherein F stands for flow rate. Each flow rate may be controlled by the corresponding monitor/pump, except the flow rate at tube 30 (RBC). The liquid flow rate of the blood entering into the rotor through tube 31 , will be set by the pump P31 at the desired flow rate. The RBC monitors will be mounted at both tubes 28 and 29 , so that there would be little RBC going through either tube by adjusting the flow rate controlled by the pump for each tube. In short, all blood components will be collected through only tube 30 , and the plasma through tube 29 and the highest density particles through tube 28 .
[0033] According to one embodiment of the system and method of the present invention a rotor separates the components in the blood or fluid or solution according to their densities. Some of the components may be attached to high density sub-micron particles and thus they can be separated exclusively from all the blood components or the fluid or the solution. The process of separation can be done during continuous flow of the liquid through the device. The density separation is made possible with the rotor made of connecting at least two rectangular or other forms having a void within for receiving fluid or solution or blood and the forms are curved or circularly bent with two slightly different diameters of them each no longer than ¼ of the circle. The forms are mounted on the circular disc. The circular disc having a hole in the center to form a base of the rotor. A number of tubes connect to openings in the rotor such that the rotor connects fluid that flows via a tube to the rotor with one or more tubes that carry fluid that flows out of the rotor. The tubes may follow a path through the center whole and are configured so that the base will be able to continuously spin, along with the mounted rotor elements without interference from the one or more tubes. One of the tubes is connected through a port to the inner wall of the larger segment rotor and the blood or liquid will enter through the port by a pump, of which rate can be adjusted. The particles that enter the rotor will be separated according to their densities and pour out from the ports 28 and 29 . The rates of outflows will be regulated with two pumps, one pump for each port. From port 29 the lowest density matter (plasma) and port 28 the highest density matter such as rTAP bound with the target will flow out by the pumps. There is a third exit port 30 from which the particles next to the highest density particles, rTAP, such as RBC will exit. The separation will be done continuously with less than 100 ml of the samples in the rotor and feeding tubes. The entire amount of sample will be treated and collected after rising the rotor and feeding tubes.
[0034] The novel density gradient separation technique taught and claimed herein may be used to separate other mixtures of substances having different densities. It may be used to separate and remove metastatic cancer cells from circulating blood. It may also be used for retrieval of low copy mammalian, bacterial or virus cells from blood. It may also be used to remove materials added to blood to enhance tissue and organ imaging. Depending on the application, the specific design requirement of these materials in terms of their size and composition may vary, but common to all of them are the properties summarized earlier, and the tailored ability for continuous retrieval from circulating fluids.
[0035] While what has been described herein is the preferred embodiment of the invention it will be understood by those skilled in the art that numerous changes may be made without departing from the spirit and scope of the invention.
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A method and apparatus for continuous removal of sub-micron sized particles and other materials attached thereto such as cancer cells and bacteria from blood and other liquids. A centrifuge rotor having a curved shape is offset on a spinning rotor base and creates contiguous areas of low to high centrifugal force depending on the distances from the axis of the rotor base. This creates a density gradient field that separates materials of different densities input to the centrifuge that exit via different outputs. A monitor detects components of the fluid that are mixed with the particles before they exit the centrifuge. If there are any unwanted components detected with the particles logic circuitry changes the speed of rotation of the rotor, and the flow rate of pumps inputting and removing separated fluid and particles to and from the centrifuge until there are no unwanted components in the fluid exiting with the particles from the centrifuge.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation in part of co-pending U.S. application Ser. No. 799,933 filed Nov. 20, 1985 and now Pat. No. 4,730,422. This application is also related to Ser. No. 799,932 now U.S. Pat. No. 4,706,422.
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a new and improved synthetic plastic concrete forming system. The present invention also concerns a new and improved synthetic plastic concrete wall tie for use in the concrete forming system. Still another part of the invention relates to a new and improved system and method for affixing wall coverings to a modular synthetic plastic concrete form structure.
Prior to the development of the new synthetic plastic wall ties herein disclosed, metal wall ties having cones at opposite ends have been known in the art. These types of ties were laid into the form and the concrete was then poured. After the concrete had hardened, the worker would then hammer the ends of the wall tie causing the wall tie to fracture. This type of metal wall tie is called a "snap tie", and when it is struck the cone shaped ends are fractured, and then they can be removed from the formed concrete wall. Thereafter, the concrete worker will then fill the conical holes to provide a smooth finished surface. The new ties herein disclosed are of a different construction and function in a different way in that they are provided with disc shaped members which are formed integrally with the tie. Ideally these synthetic plastic discs or stops could be made of a larger diameter. It has been the further practice of concrete wall makers to use wall ties having metallic washer-like elements which would be slid onto the ends of the wall tie. The wall tie has spaced stops so that when the metal washer elements are moved into place on the wall tie that they would then be bottomed against the stops at the inside edge of the washers. The concrete functions to hold the washers in place against the stops on the tie. The new and improved wall ties herein disclosed are provided with stops that are integral and immobile and positively fixed on the tie and being made from plastic will not corrode. Also, it should be noted that the metal ties and the metal washers that were used in the past, were inferior in construction since there was a definite tendency for these metal components to breakdown and corrode thus creating a potential water leakage problem at least in certain types of wall construction.
According to certain other features of my invention, my new and improved synthetic plastic concrete wall tie has a pair of round flange-like water-stops extending radially outwardly out of an intermediate wall tie section, the water-stops serving to inhibit water flow axially or along the length of the wall tie and through a concrete wall structure where the tie is embedded, the round flange-like water-stops further serving to provide means for locating reinforcing rods extending at right angles to the wall ties when the wall ties are mounted in a concrete form.
According to still other features of my invention, I have provided a new and improved synthetic plastic wall tie that has unique end formations which enable the wall tie to be easily attached with slotted form sections where the slots extend in rows along upper and lower edges of the form section.
Still other features of my invention are concerned with a new and improved synthetic plastic wall tie comprised of 20% calcium carbonate filled polypropylene of sufficient thickness to allow attachment screws to be threaded into opposite ends of the tie to anchor wall coverings to a poured concrete wall structure.
According to other important features of my invention, I have provided a new and improved synthetic plastic concrete wall tie which is totally modular in that it can be used and mounted in slots in wall sections synthetic plastic concrete forms from either edge of the tie.
According to still other important features of my invention, I have provided a new and improved synthetic plastic concrete wall tie having water-stops that can also act as reinforcing rod locating fingers which assist in providing one or more pockets for a concrete reinforcing rod to minimize movement of the reinforcing rod as concrete is poured into the form.
In the past, it will be appreciated that different types of foamed plastic concrete forming systems have been used in industry and, in this connection, attention is drawn to U.S. Pat. Nos. 3,552,0786 and 3,788,020. These patents relate generally to concrete forms formed from low density foamed plastic and polymeric material but where the forms do not possess the improvements herein described and illustrated.
SUMMARY OF THE INVENTION
A synthetic plastic wall tie of variable lengths for use with concrete forms comprising a pair of T-shaped end sections at opposite ends of the wall tie, each of the T-shaped end sections including a stem having a sufficient thickness for receiving an end of a screw in threaded engagement therewith, the T-shaped end sections having parallel cross pieces at opposite ends of the tie, an intermediate wall tie section having a pair of round flange-line water-stops extending radially outwardly out of the intermediate wall tie section and being joined therewith in integral one-piece assembly therewith, the water-stops serving to inhibit water flow axially of the wall tie and through a concrete wall structure where the tie is embedded, the round flange-like water-stops further serving to provide means for locating reinforcing rods extending at right angles to the wall ties when the wall ties are mounted in a concrete form, the cross pieces having outer faces positioned generally at right angles to a plane through the length of the wall tie enabling a screw to be screwed there through into the associated stem for attaching a wall cover thereto, the synthetic plaster ties being comprised of 20% calcium carbonate filled polypropylene which constitutes a material suitable for receiving a screw assembly therewith.
A synthetic plastic wall tie of variable lengths for use with concrete forms comprising a pair of T-shaped end sections at opposite ends of the wall tie, each of the T-shaped end sections including a stem having a sufficient thickness for receiving an end of a screw in threaded engagement therewith, the T-shaped end sections having parallel cross pieces at opposite ends of the tie, an intermediate wall tie section connecting the T-shaped end sections together, the intermediate wall tie section having a pair of round flange-like water-stops extending radially outwardly out of the intermediate wall tie section and being joined therewith in integral one-piece assembly therewith, the water-stops serving to inhibit water flow axially of the wall tie and through a concrete wall structure where the tie is embedded, the round flange-like water-stops further serving to provide means for locating reinforcing rods extending at right angles to the wall ties when the wall ties are mounted in a concrete form, the cross pieces having outer faces positioned generally at right angles to a plane through the length of the wall tie enabling a screw to be screwed there through into the associated stem for attaching a wall cover thereto.
A method of securing a wall covering to a concrete wall structure, the steps of forming synthetic plastic wall forming sections from a foamed plastic material with rows of tie slots at spaced intervals along upper and lower edges and with indicia formed on outer wall surfaces of the forming section so that the indicia and the slots are transversely aligned in pairs along the edges enabling the indicia to act as a tell tale for the slots and wall ties, securing opposite ends of synthetic plastic concrete wall ties in the slots of the wall forming sections to provide a reinforced form structure, securing transverse closure sections between the wall forming sections to provide form closures, pouring concrete in the thus formed concrete forming structure and immersing and binding the ties in the concrete, screwing fasteners through a wall covering, the panel section into the wall tie using the indicia as a blind concrete tie locator for aligning the screw with the hidden wall tie enabling the screw to be screwed into the tie to securely fasten the wall covering thereto.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an enlarged fragmentary cross-sectional view of a modular foamed plastic concrete form structure as disclosed in my parent application, U.S. Ser. No. 799,933;
FIG. 2 is an enlarged perspective view partially in section showing a concrete form structure having my new wall tie which embodies important features of my invention;
FIG. 3 is an enlarged vertical section of a concrete filled modular synthetic plastic concrete form structure embodying still further features of my invention;
FIG. 4 is an enlarged perspective view of a wall tie further illustrating the tie shown in FIGS. 2 and 3;
FIG. 5 is an exploded fragmentary vertical section of a modular synthetic plastic concrete form structure and illustrating the manner by which wall coverings can be attached thereto using my new wall tie;
FIG. 6 is an enlarged fragmentary exploded view of a modular synthetic plastic concrete form structure similar to that shown in FIG. 5 only with the components being in a more advanced stage of assembly; and
FIG. 7 is an enlarged fragmentary section taken on line 7--7 looking in the direction indicated by the arrows as seen in FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The reference numeral 10, as seen in FIG. 1, designates generally a modular foamed plastic concrete form structure. The structure that is shown in FIG. 1 is also shown in my co-pending U.S. application for patent entitled: "A PERMANENT NON-REMOVABLE INSULATING TYPE CONCRETE WALL FORMING STRUCTURE", Our Case No. 85600-2 U.S. Ser. No. 799,932 filed Nov. 20, 1985 which is co-pending with the present application. The disclosure of my co-pending application is here incorporated by reference. The present application is also a continuation in part of my co-pending U.S. application for patent entitled: "AN INSULATING NON-REMOVABLE TYPE CONCRETE WALL FORMING STRUCTURE AND DEVICE AND SYSTEM FOR ATTACHING WALL COVERINGS THERETO", our Case No. 85601-2, U.S. Ser. No. 799,933 filed Nov. 20, 1985 and now U.S. Pat. No. 4,730,422.
The structure 10 is comprised of a pair of modular concrete forming panels 11 and 12 which are spaced from one another and which when properly installed serve to act as a form into which concrete may be poured. The panels are each comprised of a series of modular concrete forming sections 13 which are all identical to one another with certain exceptions, as hereafter described. These sections are adapted to be cut and arranged so as to enable window openings 14 to be easily constructed. Cooperable with the panels 11 and 12 are end closure panels 15 which extend transversely between the forming panels 11 and 12 and between the forming sections 13 so as to confine poured concrete. It will further be seen that the window openings are also provided with closure panels 16. All of the panels 11, 12, the sections 13, the closure panels or end pieces 15, the window panels 16 and curved corner panels 17 are comprised of foamed plastic preferably an expandible polystyrene. This material has been found to have unique insulating properties and strength so as to enable concrete walls to be better insulated to impede transmission of heat through a formed wall as will be further described at another point herein.
In order to properly reinforce the concrete forming structure 10, I have developed a new and improved wall tie 19 which is comprised of 20% calcium carbonate filled polypropylene as a preferred embodiment. The improved wall tie 19 can be used in much the same way as wall tie 18 shown in FIG. 1. The wall tie 18 corresponds to the one disclosed in my parent U.S. application for patent as noted above. As a preferred construction, I have made the tie as a one piece unit. Less desirably the tie mentioned also could be made as a multiple part construction.
My thermal wall system is a whole new concept in energy efficient building technology. The building block sections of expanded polystyrene serve as a permanent form for concrete. This system of construction is for use where energy conservation and speed of construction are important.
Expanded polystyrene or EPS is a closed cell, rigid, lightweight cellular plastic, white in color, that is molded into various shaped with steam and pressure. Thermal wall system panels are made of modified polystyrene. The density of the panels range between 1.7 and 2.0. Typical physical properties of EPS insulation is given in Table 1 below. Like all organic materials, EPS is combustible and should not be exposed to flame or other ignition sources.
__________________________________________________________________________TYPICAL PHYSICAL PROPERTIES OF EPS Density (pcf)Property Units ASTM Test 10 125 15 20__________________________________________________________________________Thermal Conductivity at 25° F. BTU/(hr) C177 or 023 022 021 020K Factor at 40° F. (sq ft)(F/in) C518 024 0235 022 021 at 75° F. 026 0255 024 023Thermal Resistance at 25° F. at 1 inch 435 454 476 500Values (H) at 40° F. Thickness -- 417 425 455 476 75° F. 385 392 417 435Strength PropertiesCompressive 10% Deformation psi D1621 1014 1318 1521 533Flexural psi C203 2530 3238 4050 575Tensile psi D1623 1620 1721 1822 2327Shear psi D732 1822 2325 2632 3337Shear Modulus psi -- 280320 370410 460500 600640Modulus of Elasticity psi -- 180220 250310 320360 460500Moisture ResistanceWVT perment C355 1230 1128 0925 0615Absorption(vol) percent C272 less than less than less than less than 25 25 20 10Capillarily -- -- none none none noneCoefficient ofThermal Expansion in/(in)(F) D696 0000035 0000035 0000 0000035Maximural Service Temperature °F. --Long term 167 167 167 167Intermillent 180 180 180 180__________________________________________________________________________ All values based on data available from American Hoechst Corporation ARCO Chemical Company, and BASF Wyandolle Corporation
The basic building components of my thermal wall system are the two solid 2" panels 11 and 12 of polystyrene connected together with high impact plastic ties 18. The length of the tie 18 or 19 determines the width of the concrete wall. Each block or section 13 has castellations 20 along its top edge or surface 21 and matching castellations along its under edge 23 (FIG. 1). The blocks or sections 13 are placed one on top of the other and pressed together using simple hand pressure. The castellations mesh together creating a completely smooth surface that is interlocked. The vertical ends of the block or section 13 are tongue 24 and groove 25 (FIG. 7) and interlock as well. The blocks or sections 13 are erected directly on top of footings or on the floor slab, as design dictates. The footings must be level and flat. When placing concrete, particular care should be taken in the first lift to check the horizontal and vertical levels.
Each of the end closures 15 vertically extending alternating hooked shaped ribs and grooves generally indicated at 26 which are shaped like and complementary to book shaped ribs 27 and hooked shaped grooves 28 (FIG. 8) to enable opposite ends of the end closure 15 to be slid into interlocked assembly with the opposed sections 13, 13. The sections have the ribs 27 and grooves 28 formed integral with the associated section 13 and when set up, the ribs 27 and the grooves 28 on the opposed panels 11 and 12 confront one another.
The ties 18 or 19 are adapted to coact with upper and lower rows of T-shaped slots 29 which are formed in each of the sections 13. The slot 29 opens on an inner side so that the T-shaped slots oppose one another when two sections 13--13 are placed in opposed relation such as is shown in FIG. 2. The ties 19 are provided with T-shaped tie ends 30--30 which have a configuration that matches the shape of the slots 29 so as to be slideably engageable together when assembled with the sections. The ties 19 when engaged with the opposed sections along their upper and lower edges provide a sturdy concrete form structure.
It will be noted from comparing FIGS. 4 and 5 of my parent U.S. application Ser. No. 799,933 filed Nov. 25, 1985 that there are two different types of ties there disclosed and these ties have been identified as ties 18 and 18'. The ties 18 and 18' are essentially identical except that the tie 18' is a shorter tie and can be used where narrower concrete walls are to be formed such as having a thickness of 8". The longer ties 18 are adapted to be used in the formation of concrete walls having a thickness of 10". The length of the ties can be varied as required. The ties 19 are similar in construction to the ties 18' and the differences will be pointed out hereafter. The tie 18 here shown in FIG. 4 can be similarly varied and used.
With respect to the ties 19, each tie has an intermediate wall tie section 31', and a pair of triangular truss sections 32 are disposed on opposite ends of the mid-section 31' in integral one piece assembly therewith. The intermediate web section 31' joins the truss sections at the apexes of triangles of the triangular truss sections. As stated, the triangular truss sections 32 and 33 define triangular truss openings 34 and 35. It is these openings that have been created to enable concrete to flow freely through the ties in an unimpeded manner so that the ties will not act as dams to confine the flow of liquid concrete in the molds or forms as the concrete is poured.
The intermediate wall tie section 31 terminates in end portions 36 and 37 which in turn merge into the T-shaped tie ends 30--30. Each of the tie ends includes a cross piece portion 30a and a stem portion 30b.
The ties 19 are also provided with a pair of round flange-like water-stops 42--42 extending radially outwardly of the intermediate wall tie section 31. The stops 42 coact with the wall tie section 30 for receiving reinforcing rods 44 on either side of the stops. If desired, the rods 44 can be wired to the ties. The diameter of the rods can vary depending on the requirements of the builder. Typically, the diameter can run from 1/2" to 7/8". The water-stops 42 are preferably located a distance of 21/2 from an inner end most adjacent to the stem portion 30b as indicated at 45 in FIG. 4 to an outer face 46 on the water-stop 42. The position of the water-stops can be varied so that the water-stops can be moved closer to mold gate 47 (FIG. 4) if desired. Generally it is not practical to move the water-stops 42 closer to the end face 45 of the stem portions 30b so that sufficient space can be provided for the reinforcing rods 44. It is generally desired to not dispose the reinforcing rods 44 closer that 2< from the outer surface of the concrete wall to be poured. By providing a 2" clearance between the outer face of the concrete wall being poured and the outside face of the reinforcing rod 44, then the reinforcing rod can be sufficiently removed from the outside face of the concrete wall to minimize problems that might otherwise be generated should the rod be positioned too closely to the outside faces of the concrete wall to be poured.
In my preferred construction, the tie 19 is 12" in length and can be longer if desired. It has been found that where the ties are constructed so as to be provided with the water-stops 42 defining the notches 43 that the concrete rods 44 can be more fixedly located at the point in time when the liquid concrete is poured into the form so that the reinforcing rods will not bounce and move as the concrete C is poured thereon.
The water-stops 42 can operate to provide the notches 43 where the wall tie is disposed in either position with either side of the wall tie being positioned top side of the wall tie.
The wall tie 19 preferably has its water-stop 42 formed with a diameter of at least 1" and has a thickness of approximately 0.100". Excellent results can be achieved where my wall tie is so constructed with water-stops of the construction and dimensions as set forth above.
According to other important features of my invention, I have provided embossed I-shaped indicia 50 as seen in FIG. 5. The embossed I-shaped indicia 50 are vertically spaced in rows on an outer face adjacent to upper and lower edges of each section 13 in transverse alignment with the T-shaped slots 39 that open on the opposite surface or face of the section 13. The embossed I-shaped indicia 50 have an upstanding portion 58 that is in transverse alignment with a stem portion 29a of the notch 29 (FIG. 5).
The embossed I-shaped indicia 50 is provided on both sides of the section and opposite each row of the T-shaped slots and the spacing of the embossed I-shaped indicia may be varied as required. This spacing of the indicia may be of the order of every 6" along the length of the section.
The embossed I-shaped indicia 50 serve as a "tell tale" or as a "blind slot locator" to enable furring strips 51 to be attached by screws 52 (FIGS. 5, 7) in such a way that the screws can be screwed directly into the ties 18 and, more particularly, through the T-shaped end 30 of the tie to firmly anchor the furring strip 51 to the section 13. Thereafter, a wall covering 53 can be suitably attached to the furring strips 51 by additional screw fasteners as indicated at 54 in FIG. 6.
The ties 18 (FIG. 1) and 18' (not here shown but see parent U.S. Applications noted before) are otherwise identified as the long tie 18 and the short tie 18' are preferably constructed having the following approximated dimensions:
______________________________________ Length Height Thickness Width of Stem of Tie of Tie of Flat End of T-shaped End______________________________________Long Tie 11" 2 3/16" 3/16" 1 5/16"Short Tie 9" 2 3/16" 3/16" 11/4"______________________________________ Width of Intermediate Length Diameter Truss Section of Finger of Finger______________________________________Long Tie 1 13/16" 1/2" 3/16"Short Tie 11/4" 5/8" 3/16"______________________________________ Length of Length of Diameter of Vertical Diagonal Diagonal Truss Legs Truss Legs Truss Legs______________________________________Long Tie 13/4" 3 1/16" 3/16"Short Tie 13/4" 2 3/8" 3/16"______________________________________
The ties 19 have not been made the subject of a test study similar to the test study ran with the ties 18 but it is my belief based on my knowledge and experience with the manufacture of ties of this type that if the ties 19 were made of the same material, that comparable test results would be attainable.
The ties 18 have been tested and have been found to have the following approximated test characteristics:
__________________________________________________________________________TEST STUDY OFCALCIUM CARBONATE FILLEDPOLYPROPYLENE TIES ASTM LPP6020 LPP6030PROPERTY UNIT METHOD (20%) (30%)__________________________________________________________________________Tensile Strength at 73° F. psi D638 4,000 3,500Elongation at Break % D638 80 70Flexural Strength at 73° F. psi D790 4,800 4,950Flexural Modulus (tangent) psi × 10.sup.5 D790 2.6 2.9Flexural Modulus (1% Secant) psi × 10.sup.5 2.4 2.6Izod Impact at 73° F. Notched(1/2" × 1/4" bar) ft/lb/in. D256(1) .75 .8Izod Impact at 73° F. Unnotched(1/2" × 1/4" bar) ft-lb/in. D256 12 15Gardner Impact in-lb -- 20 30Heat Deflection Temperature,66 psi ° F. D648 210 220Specific Gravity -- D792 1.05 1.14Hardness, Shore "D" -- D2240 72 73Melt Flow g/10 min. D1238(2) 4-6 4-6Mineral Content % --(3) 20 30Mold Shrinkage in/in -- .012 .011__________________________________________________________________________ (1)Method A (2)Condition L"L (3)Burnout at 850° F. Mold Shrinkage is intended as a guide only, as specific shrinkage is affected by part design, mold design, and molding conditions. The values listed herein are to be used as guides, not as specification limits. Determination of product suitability in any given application is the responsibility of the user.
My thermal wall structure introduces a new building product made of expandable polystyrene which serves as a permanent form for concrete construction. This products main advantages are its speed of erection and the very high thermal insulation properties attained (R-Value of 20+).
Similar products have been used extensively in Switzerland, Belgium, France, Germany, Venezuela, Australia and now the United States. It has been in use for nearly 20 years. It is a simple building system: Hollow blocks made of ARCO Dylite Expandable Polystyrene, with a flame retardant additive, are erected "Lego" fashion by means of their toothed tops and grooved bottoms. Plastic ties hold the sides together and the length of the tie determines the width of the cavity or wall, the blocks are interlocked both horizontally and vertically. Once erected, concrete is poured into the cavity of the wall creating an insulated load bearing structure.
My thermal wall building blocks or sections 13 are composed of panels of EPS (Expandable Polystyrene) that are 2" thick, 12" high and 40" or 20" long. The density is nearly twice that of conventional insulation board. A whole range of exterior finishes can be applied. Scores of elastomeric coatings and stucco finishes may be used as well as siding or paneling. Interiors are finished with drywall, plaster, tile or in any other traditional manner.
My thermal wall structure is an advanced system of construction for use where energy conservation (by reduction of thermal transmission) and speed of construction (reduced labor costs) are important.
The inherent low thermal fluctuations ensure that the risk of cracking of any external rendering and internal plaster-work are non-existent. The maximum possible expansion is 0.2 mm/m.
Excellent noise and impact sound reduction is also an important advantage of the Thermal Wall System. Remembering that a difference of 10 dB almost halves the volume of noise. 350 Ka/m2 Thermal Wall 250 mm is at 49 dB.
Expandable Polystyrene does not rot and when used properly in building construction it is not subject to any other kind of deterioration while in service.
Panels of "Dylite" Expandable Polystyrene are 2" thick, 12" high and 40" or 20" long. The horizontally spaced rows of "t" or T-shaped slots 29 are disposed along the top and bottom of each section. T-shaped ends 30--30 of the ties 19 are inserted into the slots 29. These ties 19 hold the sections 13 and the panels 11 and 12 together and also determine the width of the wall. Each blocks or sections 13 have the castellations 20 along its top surface and matching castellations along the underside as previously described. The blocks 13 are placed one on top of the other and pressed together using simple pressure; the castellations mesh together creating a completely smooth surface and solid structure. The blocks are erected directly on top of footings or on a floor slab, as design dictates. The footings must be as level and flat as possible. When pouring concrete, particular care should be taken in the first three feet poured to check the horizontal and vertical levels, this is most important, as small errors and variations in the early levels will be greatly increased in height. The lightness of the blocks or sections 13 and the flexibility of them means erection can be both fast and simple.
For corners, windows, door openings and t-junctions an "endpiece" is also made of expandable polystyrene and is inserted into the end of the block. It slides into the block and acts as a bulkhead for concrete. It is held in place by surface corrugations on the insides of the block panels.
Corners of 90° are formed by interlocking blocks perpendicular to one another and inserting endpieces to bulkhead the concrete. With a 10 inch wall rounded corners are available by use of my specially made corner block or section 17.
Thermal wall blocks or sections 13 can be cut quickly and easily with any conventional hand saw. Sanding down the edge with a coarse abrasive block ensures a smooth tight fit.
The blocks or sections 13 are stacked to the desired height of 8 to 10 foot and are filled with regular concrete by means of a concrete truck and chute or with a concrete pump. A super plasticizer additive is recommended to aid in flowability of the concrete mix without detriment to the strength of the concrete. The concrete should be placed in "lifts" or layers of 4 foot, at a rate of 8 to 10 foot per hour.
Electric & Plumbing
Water supply lines and conduit for electric can be easily cut into the 2" thickness of the thermal wall, after the concrete has been poured. They are then covered with drywall or plaster. Pipes of greater diameter than 2", such as waste water pipes, should be placed in the wall cavity before the concrete is poured. Completely surrounded by concrete and thermal wall polystyrene, the pipe will be insulated and insensitive to frost even if the building is unheated.
The use of thermal wall blocks or sections 13 in construction makes possible the type of energy-efficient construction that is necessary today (and will be even more so in the future judging from the ever-increasing energy costs).
EPS (Expandable Polystyrene) panels 11 and 12 are connected together with the plastic ties 19 to form building blocks. These blocks interlock horizontally and vertically and are stacked one upon another to a desired height and filled with concrete.
The blocks remain in place after the concrete has been poured and provides the structure with an R-Value of 20.
R-Value means the resistance to heat loss and the R system is a way of rating insulation effectiveness: the higher the R-Value the greater the resistance provided against heat and cold.
T.W.S. blocks are formed from ARCO--"Dylite", a fire retardant EPS, and will not support combustion.
There are no limits to the types of wall coverings, both interior and exterior that may be applied. Generally the exterior is of a cemeticious finish and the interior is plastered or drywalled. Panels may be glued or screwed.
Some of the Advantages:
1. Rated R-20+: Stretches Energy Dollars.
2. Concrete cures under ideal conditions, down to -10 degrees C. and use of the sections 13 operates to extend the building season.
3. By using the sections 13 in block form, heating and air conditioning costs can be reduced by 50%.
4. The sections 13 and the formed blocks are fire retardant and will not support combustion.
5. Sound Proof.
6. Water Repellant.
7. Mold and mildew resistant and rot proof.
8. The sections 13 have no food value and insects cannot digest it.
9. The sections 13 are versatile and can be used both above and below grade for residential, multi-family and commercial construction, as well as high-rise construction.
10. My forms are lightweight and the interlocking procedures enable increased productivity with less construction time.
11. The sections and the formed blocks are air tight and voids and air filtration are virtually eliminated.
12. Wall thickness may vary from 6, 8 or 10" based on length of ties.
13. The rounded corner sections allow for increased design possibilities with no additional framing costs.
14. There is a complete absence of cracking of internal and external finishes and maximum possible expansion is 0.2 mm/m.
15. Use of my concrete forms enable a quicker return on Investment Dollars.
Limitations
(a) Loading:
Thermal wall panels should not be installed under surfaces subject to heavy point loading; the E.P.S. does not add structural integrity to the wall; it simply insulates it.
(b) Solvents:
E.P.S. including thermal wall panels cannot be exposed to petroleum-based solvents, fuels or coal tar products and their vapors.
(c) Ultraviolet Degredation:
Prolonged exposure to sunlite (Ultraviolet rays) will cause E.P.S. material to discolor and a dusting of the surface will occur. Wall panels must be coverd to prevent degredation.
(d) Flammability:
The E.P.S. material used in forming thermal wall panels has a flame retardant additive but it should be considered combustable when directly exposed to a constant source of flame. It should not be installed near an open flame or other source of ignition. Current model building code requirements should be met for adequate protection.
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A synthetic plastic wall tie of variable lengths for use with concrete forms. The tie has a pair of T-shaped end sections at its opposite ends. Each of the T-shaped end sections including a stem having a sufficient thickness for receiving an end of a screw in threaded engagement therewith. The T-shaped end sections have parallel cross pieces at opposite ends of the tie. An intermediate wall tie section connects the T-shaped end sections together. The intermediate wall tie section has a pair of round flange-like water-stops extending radially outwardly out of the intermediate wall tie section and are joined therewith in integral one-piece assembly therewith. The water-stops serve to inhibit water flow axially of the wall tie and through a concrete wall structure where the tie is embedded. The round flange-like water-stops further serve to provide means for locating reinforcing rods extending at right angles to the wall ties when the wall ties are mounted in a concrete form.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/977,070 filed 2 Oct. 2007, and PCT/U.S.08/77769 filed 26 Sep. 2008 which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to the field of aerosol particle sampling. In particular, the invention relates to cascade impactors for sampling pharmaceutical aerosol preparations at low flow rates.
BACKGROUND OF THE INVENTION
A cascade impactor is an aerosol-sampling device that samples and separates the aerosol according to the aerodynamic properties of the particles. The typical cascade impactor has multiple collection stages arranged in series, with each collection stage having an orifice plate and a separate, removable collection surface positioned below the orifices ( FIG. 1 ). With each successive stage, the total cross-sectional area of all of the orifices decreases in order to increase the velocity of the particle-laden air and thus the inertia of the entrained particles. The collection stages, or plates, serve as an impaction surface for the collection of the particles possessing inertia too great to be carried around the collection surface and onward to the next stage. Thus, successively smaller particles are collected on successive stages. The sizes of the particles collected on each stage, also referred to as the cut size, are primarily determined by the dimensions of the orifices above the stage and the volumetric flow rate through the impactor. Particles larger than the cut size are collected by inertial forces on the collection surface, while smaller ones remain entrained in the air stream to be collected on subsequent stages or a final collection filter. The cut size for a stage is the point of 50% collection efficiency.
Cascade impactors have been used in the pharmaceutical industry for many years (Hickey, A J. “Methods of Aerosol Particle Size Characterization” Chapter 8 in Hickey, A J ed. Pharmaceutical Inhalation Aerosol Technology, Marcel Dekker, NY 1992 pp. 219-253). The theory of operation is also known in the art (Marple, V A and Rubow, K L “Theory and Guidelines” Chapter 4 in Lodge, J P and Chan, T L eds. Cascade Impactor, Amer Indust Hygiene Assoc 1986 pp. 79-101). The pharmaceutical industry has long adapted cascade impactors designed for use in industrial and environmental sampling to characterize inhalers and devices for respiratory drug delivery (USP <601> Aerosols). These accepted pharmaceutical sampling devices are large in size and are typically operated at flow rates ranging from 28 to 100 liters per minute. At these high flow rates, numerous orifices must be used on each stage, resulting in operating conditions outside of the ideal range, and consequently non-ideal calibrations. Further, these devices have large collection surfaces requiring the collection of relatively large amounts of material to satisfy analytical method requirements. Their size also creates inaccuracies in measurement due to interstage losses of material unaccounted for in routine analysis (Marple V A, Willeke K. Inertial impactors: theory, design, and use. In: Fine Particles, Aerosol Generation, Measurement, Sampling, and Analysis. Liu BYH ed. Academic Press, NY, 1975). Further, these devices are not well suited for sampling aerosols intended for delivery to infants and children. Typical inhalation flow rates for children younger than 15 years of age range from 2 to 4 liters per minute (Coates, A. L., Tipples, G., Leung, K., Gray, M., Louca, E.; How Many Infective Viral Particles are Necessary for Successful Mass Measles Immunization by Aerosol; Vaccine; 24 (2006) 1578-1585). Infants, in particular, cannot be instructed to inhale at a rapid rate from an inhaler, and so must inhale at their normal tidal rate. Characterization of the dose and particle-size distribution from inhalation delivery devices operating at these low flow rates requires samplers, and in particular cascade impactors, operating at comparable flows.
Coating of Collection Surfaces with Adhesive Substances
To sample particles other than liquid droplets with a cascade impactor, it is generally accepted that a coating material must be placed on the collection stage. If not, the particles can bounce or be blown off or be re-entrained by the airflow, thus rendering the analysis of particle size erroneous. Typically the collection stages are coated by some means prior to sampling with a greasy, oily, or sticky substance, or a filter paper. Typically, the entire collection plate is coated by either dipping or spray or eyedropper application, and this can result in additional error for both gravimetric and quantitative chemical analysis, due to extraneous materials on the plate. Provided herein are embodiments of apparatuses and methods to apply coating material to only the small region opposite the orifices where the particles will impact, thus greatly reducing the quantity of extraneous materials required.
SUMMARY OF THE INVENTION
Compact, low flow rate impactors from which small quantities of pharmaceutical or other agents can be easily recovered are set forth in embodiments of the invention described herein.
Additional advantages of some embodiments of the invention include a reduced number of orifices compared to other cascade impactors, thus eliminating the inaccuracies due to many small holes. Another advantage of some embodiments includes the use of relatively large orifice diameters compared to currently available cascade impactors. The larger orifices allow for much easier removal of the particulate matter that may be lost in and around the orifices for analysis.
In certain embodiments, the invention comprises a cascade impactor with one or more concentrically nested stages.
In certain embodiments, the invention comprises concentric assembly of one or more impactor stages slidably coupled together to form a cascade impactor.
In certain embodiments of the invention, each impactor stage comprises a cylindrical cup further comprising an orifice-containing region and a particle collecting region.
In certain embodiments, the invention comprises one or more impactor stages wherein the orifices are located on the side walls of the stages.
In certain embodiments, the invention comprises one or more impactor stages wherein the collection surfaces are located on the side walls of the stages.
In certain embodiments, the invention comprises one or more impactor stages wherein the orifices are on the bottom surface of the stages.
In certain embodiments, the invention comprises one or more impactor stages wherein the collection surfaces are on the bottom surface of the stages.
In some embodiments of the invention the orifice containing region and the particle collecting regions are co-located.
In some embodiments of the invention, the orifice containing regions and the particle collecting regions are located on different surfaces of the impactor stages.
In some embodiments of the invention the particle collecting region is on the side wall of the stage while the orifice containing region is on the bottom surface of the stage.
In some embodiments of the invention the particle collecting region is on the bottom surface of the stage while the orifice containing region is on the side wall of the stage.
In certain embodiments, the invention comprises a cascade impactor designed to operate at between about 1 and about 10 liters per minute.
In certain embodiments, the invention comprises a cascade impactor designed to operate at between about 2 and about 8 liters per minute.
In certain embodiments, the invention comprises a cascade impactor designed to operate at between about 4 and about 6 liters per minute.
In certain embodiments, the invention comprises impactor stages designed to operate at between about 1 and about 10 liters per minute.
In certain embodiments, the invention comprises impactor stages designed to operate at between about 2 and about 8 liters per minute.
In certain embodiments, the invention comprises impactor stages designed to operate at between about 4 and about 6 liters per minute.
In certain embodiments, the invention comprises a cascade impactor for collection of particles suspended in air according to their aerodynamic properties.
In certain embodiments, the invention comprises one or more impactor stages for collection of particles suspended in air according to their aerodynamic properties.
In certain embodiments, the invention comprises a cascade impactor capable of collecting and separating aerosol particles having aerodynamic diameters between about 0.1 and about 15 micrometers.
In certain embodiments, the invention comprises a cascade impactor capable of collecting and separating aerosol particles having aerodynamic diameters between about 0.3 and about 12 micrometers.
In certain embodiments, the invention comprises a cascade impactor capable of collecting and separating aerosol particles having aerodynamic diameters between about 0.5 and about 8 micrometers.
In certain embodiments, the invention comprises impactor stages capable of collecting and separating aerosol particles having aerodynamic diameters between about 0.1 and about 15 micrometers.
In certain embodiments, the invention comprises impactor stages capable of collecting and separating aerosol particles having aerodynamic diameters between about 0.3 and about 12 micrometers.
In certain embodiments, the invention comprises impactor stages capable of collecting and separating aerosol particles having aerodynamic diameters between about 0.5 and about 8 micrometers.
In certain embodiments, the invention comprises impactor stages capable of collecting liquid aerosols in the bottom regions of stages that contain orifices and collection surfaces on the side walls.
In certain embodiments, the invention comprises a method of collecting liquid aerosols in the bottom regions of stages that contain orifices and collection surfaces on the side walls.
To improve the collection efficiency of cascade impactor stages and avoid bouncing of particles after impacting on the collecting surfaces, it is known that a coating material should be applied to the collection surfaces. Most methods involve spraying or dipping of collection plates (such as those shown schematically in FIG. 1 ) with a silicone or other coating material that will retain the particles on the surface following impaction. An apparatus and method described herein allows coating of the collection surfaces directly opposing the orifices after the impactor is assembled and ready for use. The method results in less coating material being applied and application only to the areas where it is needed. Using less coating material reduces the chances that it will interfere with the analytical methods for the pharmaceutical or test aerosol.
In certain embodiments, the invention comprises a method of applying a coating material to the collection surface of an impactor stage.
In certain embodiments, the invention comprises a method of applying a coating material simultaneously to the collection surfaces of all stages of a cascade impactor.
In certain embodiments, the invention comprises a method of applying a coating material to the collection surfaces of one or more impactor stages in the region directly opposing the orifices.
In certain embodiments of the invention, the coating material is selected from the group consisting of adhesives, greases, oils, silicone, Antifoam (Dow Corning, Midland Mich.,), glycerin, and phospholipids.
In certain embodiments, the invention comprises an apparatus for applying a coating material to the collection surfaces of a cascade impactor.
In certain embodiments, the invention comprises an apparatus for applying a coating material to the collection surfaces of a cascade impactor after it is assembled for use.
In certain embodiments of the invention, the coating material is selected from the group consisting of adhesives, greases, oils, silicone, Antifoam (Dow Corning, Midland Mich.), glycerin, and phospholipids.
In certain embodiments of the invention, the coating material is a silicone liquid.
INCORPORATION BY REFERENCE
All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:
FIG. 1 is a cross-sectional schematic view of a typical cascade impactor used for pharmaceutical aerosol sampling.
FIG. 2 is a cross-sectional view of an exemplary stage of one embodiment of the invention wherein the orifices are in the side wall of the impactor stage.
FIG. 3 is a cross-sectional view of an exemplary stage of one embodiment of the invention wherein the orifices are in the bottom of the collection stage.
FIG. 4 shows cross-sectional views of a final filter stage for holding a filter within the impactor. FIG. 4 is a longitudinal view of the stage with one impactor stage mounted therein. FIG. 4A is a transverse view through section A on FIG. 4 .
FIG. 5 is a cross-sectional view of a stage for connecting an external final filter.
FIG. 6 is a cross-sectional view of an embodiment of the invention wherein the orifices are on the side walls of the collection stages.
FIG. 7 is a cross-sectional view of an embodiment showing two assembled stages wherein the orifices are in the bottoms of the collection stages.
FIG. 8 is a cross-sectional view of an exemplary stage of one embodiment of the invention wherein the orifices are in the side wall of the collection stage with labels for dimensions referred to in some of the examples.
FIG. 9 is a schematic diagram of an apparatus for applying coating materials to the collection surfaces of an assembled cascade impactor.
FIG. 10 is a graph of the particle size generated with time derived from the equations of Mugele (Mugele, R. A and HD Evans. Droplet Size Distribution in Sprays, Indust. and Engineering Chem. 43(6):1317-1324, 1951).
FIG. 11 is a cross-sectional view of another embodiment of the invention wherein the orifices are on the side walls of the collection stages.
FIG. 12 is a graph of the size distributions for an aerosol sampled by both an Andersen cascade impactor and the embodiment described in Example 1.
FIG. 13 is a graph comparing the size distribution of an aerosol measured by the embodiments described Example 1 and in Example 5.
FIG. 14 is a graph comparing the size distribution of a liquid aerosol sampled by the embodiment described in Example 5 and a Delrin Andersen impactor.
FIG. 15 is a graph of the size distribution of a coating aerosol produced according to Example 10.
FIG. 16 is a graph comparing the size distributions of an aerosol produced and collected according to Example 11.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides embodiments for a novel cascade impactor. The stages of the impactor serve both as orifice plates and collection surfaces, thus minimizing the analytical requirements while simultaneously accounting for interstage particle losses. The orifices may be placed in the bottom surface of the collection stages, on the side walls of the collection stages, or a combination of both, depending upon the desired sampling flow rate. However, as discussed below, other configurations are also contemplated.
As used herein, the terms “comprising”, “including”, “such as”, and “for example” are used in their open, non-limiting sense.
As used herein, the term “about” is used synonymously with “approximately.” As such, values ranging between ±20% of the stated value may be considered equivalent for pressures and flow rates and ±30% for particle sizes.
As used herein, the term “aerosol” is defined as a suspension of solid particles or liquid droplets in air. Such a suspension is not required to be stable for any specific length of time, as it is recognized in the art that inhalation drug delivery devices (e.g., nebulizers, pressurized metered dose inhalers, dry powder inhalers, and the like) are capable of producing and emitting an extremely wide range of particle and droplet sizes.
As used herein, the terms atomizer and nebulizer are used interchangeably.
As used herein, the term “D 50 ” is defined as the median diameter. On an impactor stage 50% of the particles collected will be larger than the D 50 and 50% will be smaller. This is also referred to as the cutoff diameter for the stage.
As used herein, the terms “cutpoint”, “cut size”, and “cutoff diameter” refer to the median collection diameter for a given stage in the impactor.
As used herein, the term “Cunningham slip correction” refers to the correction to the particle diameter when it is close to the mean free path of the gas molecules. For particles greater than 1 micrometer, the correction is small, but becomes more significant below that size.
Calculation of the orifice diameters and corresponding flow rates to achieve desired cutoff diameters for the stages in an impactor may be accomplished using equations known in the art and presented by Marple and Willeke (Marple V A, Willeke K. Inertial impactors: theory, design, and use. In: Fine Particles, Aerosol Generation, Measurement, Sampling, and Analysis . Liu BYH ed. Academic Press, NY, 1975 pp 412-446) which is hereby incorporated by reference. Essentially, the cutoff diameter of 50% efficiency may be calculated from
Stk
50
=
4
ρ
p
QCD
50
2
9
π
n
μ
W
3
where ρ p is the particle density (assumed to be 1 for measuring aerodynamic diameters), Q is the flow rate through the stage in cm 3 /sec, C is the Cunningham slip correction, n is the number of orifices in the stage, μ is the viscosity of the sampled air (e.g., 1.81×10 −4 poise at normal temperature and pressure), W is the diameter, in cm, of a single orifice in the stage, and Stk 50 is the Stokes number at 50% collection efficiency.
This equation may be rearranged and solved for the product of the cutoff diameter times the square root of the Cunningham slip correction as follows:
C
D
50
=
9
π
μ
W
3
4
Q
*
Stk
50
For round jets operating at Reynolds numbers greater than 100, √{square root over (Stk 50 )} is approximately 0.47.
Turning now to the figures, FIG. 1 is a cross-sectional schematic view of a typical cascade impactor used for pharmaceutical aerosol sampling (Andersen Cascade Impactor, available from various manufacturers, e.g. Westech Instruments, Marietta, Ga.; Copley Scientific, Nottingham, UK; Thermo Fisher Scientific, Waltham, Mass.). Each stage has multiple orifices, ranging from 96 to 400 in number. The collection surfaces are separate metal plates that are separately inserted on supporting standoffs machined into each stage. O-rings seal each stage when the device is assembled and springs are used to compress the stages together to prevent air from leaking in between the stages during sampling.
FIG. 2 depicts an exemplary impactor stage 20 of one embodiment of the invention. One or more holes 21 are drilled or molded within the side wall of the stage. These one or more holes comprise the orifices through which the particle-laden aerosol passes before being collected on a downstream collection surface. When more than one orifice is used, the orifices may be positioned equidistant around the circumference of the stage. The inner surface 24 of the stage comprises the collection surface for the preceding stage in an assembled cascade impactor. The collection surface for the stage shown in the figure is located on the next stage in the cascade. An O-ring 23 is positioned in a groove 25 to ensure a slidable air-tight seal of the stage with the next concentric stage in the cascade.
The stage can be machined from any metal material including stainless steel, aluminum, or brass. Alternatively, a variety of plastic materials may be used, including acetal resins (e.g., DELRIN, E. I. du Pont de Nemours and Company, Wilmington, Del.), or other solid polymeric materials (e.g., NYLON, TEFLON, E. I. du Pont de Nemours and Company, Wilmington, Del.).
In some embodiments, a combination of plastic and metal materials may be used.
Also shown in FIG. 2 are three design dimensions; the orifice diameter W, the spacing S between the orifice exit and the downstream collection surface, and the thickness T of the orifice. The diameter of the holes or orifices is referred to as W in the design equations presented above.
In some embodiments of the invention, the distance from the exit of the one or more orifices to the collection surface on the next stage (S) divided by the diameter of the orifice (W), S/W, is less than or equal to about 5.
In some embodiments, the ratio of the distances S/W is less than or equal to about 2.
In some embodiments, the ratio of the distances S/W is less than or equal to about 1.
In some embodiments, the ratio of the distances S/W is less than or equal to about 0.5.
In some embodiments the ratio of the distances S/W is greater than 1.
In still other embodiments, the ratio of the distances S/W is equal to 1.
In some embodiments, ratio of the distances S/W is between 0.5 and 5.
In some embodiments, the ratio of the distances S/W is equal to about 0.5, about 1, about 1.5, about 2.0, about 2.5, about 3.0, about 3.5, about 4.0, about 4.5, or about 5.0.
In some embodiments, the ratio of the thickness of the orifice to the diameter of the orifice (T/W) is equal to about 1.
In other embodiments T/W is greater than 1.
FIG. 3 depicts an exemplary impactor stage 30 of one embodiment of the invention. One or more holes 31 are drilled or molded on the bottom surface of the stage. These holes comprise the one or more orifices through which the particle-laden aerosol passes before being collected on a downstream collection surface. The diameter of the holes is referred to as W in the design equations presented above. The inner surface 35 of the stage comprises the collection surface for the preceding stage. A raised portion 34 is machined or molded around the inside edge of the base of the stage to establish the desired distance (S) from the exit of the orifices on the preceding stage to the collection surface 35 on the illustrated stage. An O-ring 33 is positioned in a groove 36 to ensure a slidable air-tight seal of the stage with the next concentric stage in the cascade. Also shown in this figure are optional indentations 32 which are useful for assembly and disassembly of the impactor. Similar indentations may be incorporated, as needed on other embodiments and stages as presented and described herein.
In some embodiments of the invention, the distance from the exit of the one or more orifices to the collection surface on the next stage (S) divided by the diameter of the orifice (W), S/W, is less than or equal to about 5.
In some embodiments, the ratio of the distances S/W is less than or equal to about 2.
In some embodiments, the ratio of the distances S/W is less than or equal to about 1.
In some embodiments, the ratio of the distances S/W is less than or equal to about 0.5.
In some embodiments the ratio of the distances S/W is greater than 1.
In still other embodiments, the ratio of the distances S/W is equal to 1.
In some embodiments, ratio of the distances S/W is between 0.5 and 5.
In some embodiments, the ratio of the distances S/W is equal to about 0.5, about 1, about 1.5, about 2.0, about 2.5, about 3.0, about 3.5, about 4.0, about 4.5, or about 5.0.
In some embodiments, the ratio of the thickness of the orifice to the diameter of the orifice (T/W) is equal to about 1.
In other embodiments T/W is greater than 1.
The stage can be machined from any metal material including stainless steel, aluminum, or brass. Further, a variety of plastic materials may be used, including acetal resins (e.g., DELRIN, E. I. du Pont de Nemours and Company, Wilmington, Del.), or other solid polymeric materials (e.g., NYLON, TEFLON, E. I. du Pont de Nemours and Company, Wilmington, Del.).
In certain embodiments of the invention, a combination of metal and plastic materials may be used.
FIG. 4 depicts a final filter stage 40 in which a filter 44 is mounted and retained by a pressure from the nested stage 41 above and or an O-ring 42 . The filter is further supported by a mesh or screen 43 . A vacuum source is connected with an optionally threaded fitting at 45 . Also shown in FIG. 4 is the collection surface 48 for the aerosol impacted by the orifices in nested stage 41 . FIG. 4A shows a transverse section through FIG. 4 at A. Protruding portions 46 of the preceding stage may be used to apply pressure to keep the O-ring 42 and filter 44 in place. Openings 47 allow air to flow from the preceding stage to the collection filter.
The stages can be machined from any metal material including stainless steel, aluminum, or brass. Further, a variety of plastic materials may be used, including acetal resins (e.g., DELRIN, E. I. du Pont de Nemours and Company, Wilmington, Del.), or other solid polymeric materials (e.g., NYLON, TEFLON, E. I. du Pont de Nemours and Company, Wilmington, Del.). In some embodiments, a combination of metal and plastic materials may be used.
FIG. 5 depicts a final stage 500 that allows connection of a cascade impactor as described herein to an external filter holder. An optional threaded connection 503 is located in the bottom, or in the side wall, where a vacuum source may be attached. One or more protrusions 501 support the preceding stage and ensure an airflow path to the collection filter.
The stage can be machined from any metal material including stainless steel, aluminum, or brass. Further, a variety of plastic materials may be used, including acetal resins (e.g., DELRIN, E. I. du Pont de Nemours and Company, Wilmington, Del.), or other solid polymeric materials (e.g., NYLON, TEFLON, E. I. du Pont de Nemours and Company, Wilmington, Del.). In some embodiments, a combination of metal and plastic may be used.
FIG. 6 depicts a cross-sectional diagram of one embodiment of a fully assembled cascade impactor comprising 4 impaction stages and an external final filter stage. As shown, each stage is made to slidably seal with the next stage in the cascade by means of O-rings 103 , 203 , 303 , and 403 situated in grooves machined or molded into the sides of the stages. After assembly, alternating stages may be rotated to establish an angle of between approximately 30 degrees to approximately 90 degrees, to assure that the orifices are not coplanar. In usage, an inhaler or other respiratory drug delivery device, for example, is connected to the inlet 601 . Particle-laden air is pulled through the assembly by an external vacuum source connected at 503 . As particle-laden air passes through the successive stages, 100 , 200 , 300 , and 400 , it carries the particles through each stage's orifices 101 , 201 , 301 , and 401 . Particles are impacted on their respective collection surfaces 102 , 202 , 302 , and 402 downstream from the orifices as previously described according to their inertial properties. In this way, the aerosol particles are separated by aerodynamic diameter.
The stages can be machined from any metal material including stainless steel, aluminum, or brass. Further, a variety of plastic materials may be used, including acetal resins (e.g., DELRIN, E. I. du Pont de Nemours and Company, Wilmington, Del.), or other solid polymeric materials (e.g., NYLON, TEFLON, E. I. du Pont de Nemours and Company, Wilmington, Del.). In some embodiments, a combination of metal and plastic may be used.
Following collection of the sample, the impactor is disassembled and the amount of drug, or other characteristic of the particles, on each collection surface is assayed by an appropriate analytical method. The resulting particle size distribution or other descriptive parameters may be calculated from the analytical results.
If the impactor is used for environmental sampling, the inlet would remain open to the environment during sample collection and the stages would be assayed for the chemical or particle of interest.
The airflow rate through the assembled, operating cascade impactors is controlled externally with valves and or flow meters as is known in the art, and is determined from calculations of the stage parameters and the equations presented herein.
In some embodiments, the invention comprises cascade impactor comprising a series of one or more concentrically-arranged collection stages and a terminating filter or filter adapting stage, each collection stage comprising an elongated structure with a cylindrical shape, said elongated structure having a top end and a bottom end, the walls of said elongated structure having an inner surface and an outer surface and further characterized by a single inner diameter, a first outer diameter, and a second outer diameter, the top end being open and the bottom end being closed with a flat surface said elongated structure further comprising a region wherein the second outer diameter is less than the first outer diameter to form a orifice-containing region, the wall of said elongated structure further comprising at least one orifice positioned in said orifice-containing region and perpendicular to said wall and through which aerosol-containing air flows, the first outer diameter of said elongated structure being sized to fit within and slidably seal within the inner diameter of the next stage in the series.
In certain embodiments, the particles entrained in the sampled air are collected on the inner surface of the wall of the next stage in the series.
In some embodiments, orifices are placed equidistant around the circumference of the stage in the orifice-containing region.
In certain embodiments, the filter stage is further sized to receive the outer diameter of the last collection stage in said series.
In still other embodiments, the filter stage is connected externally from the series of stages.
In certain embodiments, the impactor is designed to operate at a flow rate between about 1 and about 15 lpm.
In certain embodiments, the impactor is designed to operate at a flow rate between about 1 and about 10 lpm.
In other embodiments, the impactor is designed to operate at a flow rate between about 2 and about 8 lpm.
In other embodiments, the impactor is designed to operate at a flow rate between about 4 and about 6 lpm.
In other embodiments, the impactor is designed to separate particles with sizes between about 0.1 and about 15 micrometers aerodynamic diameter.
In other embodiments, the impactor is designed to separate particles with sizes between about 0.3 and about 12 micrometers aerodynamic diameter.
In other embodiments, the impactor is designed to separate particles with sizes between about 0.5 and about 8 micrometers aerodynamic diameter.
In some embodiments of the invention, the distance from the exit of the one or more orifices to the collection surface on the next stage (S) divided by the diameter of the orifice (W), S/W, is less than or equal to about 5.
In some embodiments, the ratio of the distances S/W is less than or equal to about 2.
In some embodiments, the ratio of the distances S/W is less than or equal to about 1.
In some embodiments, the ratio of the distances S/W is less than or equal to about 0.5.
In some embodiments the ratio of the distances S/W is greater than 1.
In still other embodiments, the ratio of the distances S/W is equal to 1.
In some embodiments, ratio of the distances S/W is between 0.5 and 5.
In some embodiments, the ratio of the distances S/W is equal to about 0.5, about 1, about 1.5, about 2.0, about 2.5, about 3.0, about 3.5, about 4.0, about 4.5, or about 5.0.
In some embodiments, the ratio of the thickness of the orifice to the diameter of the orifice (T/W) is equal to about 1.
In other embodiments T/W is greater than 1.
FIG. 7 shows two nested impactor stages wherein the orifices and collection surfaces are on the bottoms of the stages. Aerosol entering the first stage passes through that stage's orifice 71 and some of the particles impact on the collection surface 72 . The remaining non-impacted aerosol continues through the orifices 75 in the next stage and onto a collection surface or filter as may be configured using the designs presented herein. O-rings 73 and 74 serve to slidably seal the stages and prevent leakage of air during sampling. A raised portion 76 and 77 is machined or molded into each stage to establish the desired spacing between the exit of the orifices and the collection surface.
Additional stages may be designed and constructed to assemble a cascade impactor covering a wide range of cut-points according to the disclosure presented herein.
In some embodiments, the invention comprises a cascade impactor comprising a series of one or more concentrically-arranged collection stages and a terminating filter stage, each collection stage comprising an elongated structure with a cylindrical shape, said elongated structure having an open top end and a bottom end containing at least one orifice through which aerosol-containing air flows, the walls of said elongated structure having an inner surface and an outer surface and further characterized by a raised portion inside said bottom end, said raised portion sized to establish an orifice-to-collection surface distance, the outer diameter of said elongated structure being sized to fit within and slidably seal within the inner diameter of the next stage in the series.
In certain embodiments, the particles entrained in the sampled air are collected on the inner surface of the bottom end of the next stage in the series.
In some embodiments, filter stage is further sized to receive the outer diameter of the last collection stage in the series.
In some embodiments, the filter stage is connected externally from the series of stages.
In certain embodiments, the impactor is designed to operate at a flow rate between about 1 and about 15 lpm.
In certain embodiments, the impactor is designed to operate at a flow rate between about 1 and about 10 lpm.
In still other embodiments, the impactor is designed to operate at a flow rate between about 2 and about 8 lpm.
In still other embodiments, the impactor is designed to operate at a flow rate between about 4 and about 6 lpm.
In certain embodiments, the impactor is designed to separate particles with sizes between about 0.1 and about 15 micrometers aerodynamic diameter.
In still other embodiments, the impactor is designed to separate particles with sizes between about 0.3 and about 12 micrometers aerodynamic diameter.
In still other embodiments, the impactor is designed to separate particles with sizes between about 0.5 and about 8 micrometers aerodynamic diameter.
In some embodiments of the invention, the distance from the exit of the one or more orifices to the collection surface on the next stage (S) divided by the diameter of the orifice (W), S/W, is less than or equal to about 5.
In some embodiments, the ratio of the distances S/W is less than or equal to about 2.
In some embodiments, the ratio of the distances S/W is less than or equal to about 1.
In some embodiments, the ratio of the distances S/W is less than or equal to about 0.5.
In some embodiments the ratio of the distances S/W is greater than 1.
In still other embodiments, the ratio of the distances S/W is equal to 1.
In some embodiments, ratio of the distances S/W is between 0.5 and 5.
In some embodiments, the ratio of the distances S/W is equal to about 0.5, about 1, about 1.5, about 2.0, about 2.5, about 3.0, about 3.5, about 4.0, about 4.5, or about 5.0.
In some embodiments, the ratio of the thickness of the orifice to the diameter of the orifice (T/W) is equal to about 1.
In other embodiments T/W is greater than 1.
FIG. 8 is a cross-sectional view of an exemplary stage of an embodiment of the invention wherein the orifices are in the side wall of the collection stage. Shown in the figure are labels for dimensions referred to in some examples presented below.
In some embodiments of the invention, the distance from the exit of the one or more orifices to the collection surface on the next stage (S) divided by the diameter of the orifice (W), S/W, is less than or equal to about 5.
In some embodiments, the ratio of the distances S/W is less than or equal to about 2.
In some embodiments, the ratio of the distances S/W is less than or equal to about 1.
In some embodiments, the ratio of the distances S/W is less than or equal to about 0.5.
In some embodiments the ratio of the distances S/W is greater than 1.
In still other embodiments, the ratio of the distances S/W is equal to 1.
In some embodiments, ratio of the distances S/W is between 0.5 and 5.
In some embodiments, the ratio of the distances S/W is equal to about 0.5, about 1, about 1.5, about 2.0, about 2.5, about 3.0, about 3.5, about 4.0, about 4.5, or about 5.0.
In some embodiments, the ratio of the thickness of the orifice to the diameter of the orifice (T/W) is equal to about 1.
In other embodiments T/W is greater than 1.
In another aspect of the invention, a novel apparatus and method has been developed to apply a suitable coating to the collection surfaces of the stages of the impactor embodiments described herein, or to the collection surfaces of other impactors as are known in the art, in the region directly opposing the orifices of the stages. The coating is deposited exactly where the aerosol to be analyzed will be impacted and deposited. The method and apparatus provide for limiting application of extraneous coating to any other part of the impactor or collection substrates. The method and apparatus serve to form an aerosol of the coating material. Subsequent sampling of the coating aerosol through the cascade impactor under normal operating conditions ensures an ample and uniform coating.
It has been discovered that a very wide aerosol size distribution of coating-material droplets is required so that each impactor stage is uniformly coated. Such an aerosol can be generated by several atomization techniques, including rotary (e.g., spinning disc), hydraulic (e.g., liquid spray under pressure), pneumatic (e.g., twin fluid atomization), electrohydrodynamic, vibrating orifice, vibrating mesh, or other atomization techniques as are known in the art. An aerosol may also be produced by dissolution or suspension of the coating material in a suitable propellant (e.g., chlorofluorocarbon, hydrogen chlorofluorocarbon, hydrocarbon, nitrogen, carbon dioxide, etc.) and generating a spray from the resulting propellant pressure.
In some embodiments, the invention comprises a method of simultaneously coating the collection surfaces of an assembled cascade impactor comprising creating an aerosol comprising droplets of a liquid coating material, drawing said aerosol into the impactor with a vacuum source, and depositing said droplets of said coating material on the collection surfaces of the impactor stages.
Production of a broad size distribution often requires variation of some property that affects atomized droplet size
In some embodiments of the invention, the method of coating the stages of the impactor comprises continually varying the viscosity of the coating material during the generation of the coating material aerosol.
In some embodiments of the invention, the method of coating the stages of the impactor comprises continually varying the density of the coating material during the generation of the coating material aerosol.
In still other embodiments of the invention, the method of coating the stages of the impactor comprises varying the input energy to the coating aerosol generator during the generation of the coating material.
The input energy to the coating aerosol generator may be varied in a number of ways depending upon the generator employed (e.g., rotational speed for a rotary atomizer, frequency of vibration for a vibrating orifice or vibrating mesh atomizer, temperature of the propellant for a propellant based atomizer, or pressure for a hydraulic or pneumatic atomizer).
In some embodiments of the invention the method of coating the impactor collection surfaces comprises varying the air pressure to a pneumatic nebulizer.
In some embodiments of the invention the method of coating the impactor collection surfaces comprises varying the air pressure to a disposable medical nebulizer.
In certain embodiments of the invention, the compressed air supply for the pneumatic nebulizer is stored in a rechargeable pressure container.
FIG. 9 is a schematic diagram of an apparatus for applying coating materials to the collection surfaces of an assembled cascade impactor. A rechargeable, pressurized air container 901 with a valve 902 is connected via a coupling 903 to a compressed air nebulizer 905 . The nebulizer is loaded with a quantity of liquid coating material 904 . Upon opening the valve 902 , the air pressure within the container is released through the nebulizer and an aerosol is produced at the outlet 906 . Initially the aerosol is comprised of small droplets, but the sizes become larger as the pressure decreases with continual release of the air from the container.
FIG. 10 shows a correlation of the particle size produced from the apparatus of FIG. 9 with time as the air pressure within the container is dissipated from about 145 psig to about 15 psig. This relationship was derived from the method of Mugele (Mugele, R. A and H D Evans. Droplet Size Distribution in Sprays, Indust. and Engineering Chem. 43(6):1317-1324, 1951; hereby incorporated by reference) using the characteristics of the nebulizer (jet-orifice diameter); the coating liquid viscosity, density, and surface tension; the gas viscosity; and the air pressure in the container. The relationship in FIG. 10 shows that the mean droplet diameter varies from about 2.5 to 18 micrometers when the coating apparatus of FIG. 9 is operated for about 15 seconds.
Air pressure is varied by charging a pressure container with compressed air, then exhausting the air supply from the pressurized container through the nebulizer. The volume of the container is selected to provide a sufficiently long operating time to aerosolize a given volume of coating material. Multiple actuations of the apparatus may used to aerosolize additional coating material. A broad size distribution of aerosol is produced as the pressure changes from high to low.
In some embodiments of the invention, the container of the apparatus is pressurized to a pressure up to approximately 10 times the recommended operating pressure of the nebulizer.
In other embodiments of the invention, the container of the apparatus is pressurized to a pressure up to approximately 5 times the recommended operating pressure of the nebulizer.
In still other embodiments of the invention, the container is pressurized to a pressure up to 2 times the recommended operating pressure of the nebulizer.
Most commercial cascade impactors are not well suited for the collection of liquid droplet aerosols. This is because the collection surfaces are often horizontal plates and excess liquid remaining in regions of high velocity airflow can be re-entrained if excessive amounts are deposited. FIG. 11 shows an assembled embodiment of the invention utilizing the stage configuration of FIG. 8 . This example embodiment has an inlet stage 1101 , 3 collection stages 1102 , 1103 , and 1104 and an adapter 1105 for a final filter (not shown). O-rings 1106 , 1107 , and 1108 create slidable seals for assembling and disassembling the impactor. After assembly, the stages are rotated from an angle between approximately 30 degrees and approximately 90 degrees so that the orifices are offset from a common vertical plane. In operation with a liquid droplet aerosol, excess liquid may drip down the sides of the collection surfaces 1109 , 1110 , and 1111 to accumulate at the bottoms of the collection stages. In order to properly account for this collected material, this embodiment of the invention creates spaces 1112 , 1113 and 1114 to accumulate the liquid at each stage without it being re-entrained by the high velocity airflow near the orifices. As shown in the figure, these spaces are created by resting the edge of one stage on the step-like portion of the next succeeding stage in the series. Further, the final stage contains an annular groove 1115 to prevent any accumulated liquid from passing onto the filter stage. This example embodiment allows for collection of significantly more liquid material than would be collectable on a horizontal flat surface, which in turn can help overcome low analytical detection limits. This embodiment is also well suited for use with dried aerosol particles.
The stages can be machined from any metal material including stainless steel, aluminum, or brass. Further, a variety of plastic materials may be used, including acetal resins (e.g., DELRIN, E. I. du Pont de Nemours and Company, Wilmington, Del.), or other solid polymeric materials (e.g., NYLON, TEFLON, E. I. du Pont de Nemours and Company, Wilmington, Del.). In some embodiments, a combination of metal and plastic may be used.
Additional stages may be designed and constructed to assemble a cascade impactor covering a wider range of cut-points according to the disclosure presented herein.
In some embodiments, the invention comprises a cascade impactor comprising a series of one or more concentrically-arranged collection stages and a terminating filter or filter adapter stage, each collection stage comprising an elongated structure with a cylindrical shape, said elongated structure having a top end and a bottom end, the walls of said elongated structure having an inner surface and an outer surface and further characterized by a first inner diameter, a second inner diameter, a first outer diameter and a second outer diameter, the top end of each stage being open and the bottom end being closed with a flat surface, said elongated structure further comprising a region wherein the second outer diameter is less than the first outer diameter to form a orifice-containing region, and a region wherein the first inner diameter is greater than the second inner diameter forming a step feature, the wall of said elongated structure further comprising one or more orifices positioned in said orifice-containing region and perpendicular to said wall and through which aerosol-containing air flows, the first outer diameter of said elongated structure being sized to fit within and slidably seal within the first inner diameter of the next stage and rest upon the step feature of said next stage in the series.
In certain embodiments with more than one orifice present, the orifices are spaced equidistant around the circumference of the stage wall.
In some embodiments, the first and second inner diameters are the same for the first stage.
In certain embodiments, the particles entrained in the sampled air are collected on the inner surface of the wall of the next stage in the series.
In some embodiments, the particles entrained in the sampled air are recovered from the bottom of the next stage in the series.
In certain embodiments, a filter stage is further sized to receive the first outer diameter of the last collection stage in said series.
In still other embodiments, a filter stage is connected externally from the series of stages.
In certain embodiments, the impactor is designed to operate at a flow rate between about 1 and about 15 lpm.
In certain embodiments, the impactor is designed to operate at a flow rate between about 1 and about 10 lpm.
In other embodiments, the impactor is designed to operate at a flow rate between about 2 and about 8 lpm.
In other embodiments, the impactor is designed to operate at a flow rate between about 4 and about 6 lpm.
In other embodiments, the impactor is designed to separate particles with sizes between about 0.1 and about 15 micrometers aerodynamic diameter.
In other embodiments, the impactor is designed to separate particles with sizes between about 0.3 and about 12 micrometers aerodynamic diameter.
In other embodiments, the impactor is designed to separate particles with sizes between about 0.5 and about 8 micrometers aerodynamic diameter.
EXAMPLES
The following examples are intended to be illustrative of various embodiments of the invention and are not intended to be limiting in nature.
Example 1
A cascade impactor with 4 collection stages and a filter stage was constructed according to the embodiment depicted in FIG. 3 and FIG. 7 and described in Table 1. This particular embodiment was designed to operate at 4 liters per minute total air flow. For the example described herein, clear plastic disks, 3.5 mil thick, were placed on each stage at the points of particle impaction in the cascade impactor to serve as particle collection substrates and allow for subsequent microscopic evaluation of the collected particles.
TABLE 1
Dimensions of one embodiment of a cascade impactor as described
herein whereby one or more orifices are on the bottom surfaces of the
impactor stages. The dimensions are
referenced to FIG. 3.
Cutoff Size
Dimensions [inches]
No.
D 50 (C) 1/2
Stage
A
B
L
W
T
S
Orifices
[micrometers]
1
0.50
0.339
1.25
0.1850
0.1850
—
1
6.95
2
0.75
0.50
1.125
0.1130
0.1130
0.370
2
4.71
3
1.00
0.75
1.00
0.1130
0.1130
0.226
1
3.36
4
1.25
1.00
1.00
0.0390
0.0390
0.226
1
1.02
Filter
1.50
1.25
1.50
—
—
0.078
—
<1.02
A = Nominal Outer Diameter [inches]
B = Nominal Inner Diameter [inches]
L = Length [inches]
W = Orifice Diameter [inches]
T = Orifice Length [inches]
S = Orifice to Collection Surface Spacing [inches]
Example 2
The apparatus of FIG. 9 was assembled. The container had a volume of about 475 ml and was pressurized to about 145 psig. A 1:100 dilution of silicone Antifoam (Dow Corning 1520) in water was added to a VixOne nebulizer (Westmed, Greenwood Village, Colo.). The valve was opened and an aerosol of the diluted silicone coating material was generated and sampled into the cascade impactor of Example 1 at a flow rate of 4 lpm. This method was repeated one more time, resulting in a total of 0.8 mg to 1.0 mg of coating material being deposited on the plastic disk collection surfaces of the impactor. The plastic disks described in Example 1 were removed and evaluated. The silicone was uniformly distributed (about 0.1 to 0.2 mg) on each collection substrate. Microscopic examination of the substrates indicated a much more uniform coating than when compared to conventional application by an eyedropper. The coating thickness was uniform and adequate for trapping particles, and the coated area opposing the orifices was about 1.5 to 2 times the diameter of the respective orifices for the stage.
Example 3
The impactor of Example 1 was once again reassembled, with clean clear plastic disks as described in Example 1. To coat the collection substrate surfaces, an aerosol of silicone Antifoam diluted 1:100 in water was produced by the apparatus depicted in FIG. 9 and the method described in Example 2. The Antifoam coating aerosol was sampled by the cascade impactor for 15 seconds with a flow rate of 4 l/min. Immediately following this, 5.1 mg of a test aerosol comprising a dry powder formulation of placebo measles vaccine was aerosolized into a spacer (Aerochamber Max, Trudell Medical, London, Ontario, Canada) and sampled into the impactor with a flow rate of 4 lpm for 30 seconds.
Example 4
After sampling the aerosol as described in Example 3, the plastic disks were removed and examined under the microscope to evaluate the size of particles collected on each stage. The results are shown in Table 2. The cut size for each stage was determined by measuring the diameters of the observed placebo vaccine aerosol particles collected on each individual substrate and estimating the median and range of the diameters. The data in Table 2 indicate that the cascade impactor separated the aerosol particles into size fractions as designed according to embodiments of the invention, with the cutoff diameter in the middle of the size range of particles collected.
TABLE 2
Microscopic Classification of the Particles Collected on the Stages
and Determination of the Cut Sizes of the Stages of the Impactor
Embodiment Described in Example 1.
Estimated
Geometric
Cut Point
Stage
Smallest
Largest
Mean
[micrometers]
1
1.5
14.4
7
6.95
2
1
6.4
5
4.71
3
1.3
4.5
3.5
3.36
4
0.7
2.8
1
1.02
Filter
<1
<1
—
—
Example 5
A cascade impactor with orifices and collection surfaces located on the side walls of the stages was constructed according to the parameters in Table 3 and single-stage embodiments shown in FIG. 2 and FIG. 8 . Clear plastic disks were placed at the points of particle impaction to serve as particle collection surfaces. To coat the collection surfaces, an aerosol of Dow Antifoam diluted 1:100 in water was produced by the apparatus depicted in FIG. 9 . The Antifoam coating aerosol was sampled by the cascade impactor for 15 seconds with a flow rate of 4 l/min. 5.1 mg of a placebo dry powder formulation of measles vaccine was aerosolized into a spacer (Aerochamber Max, Trudell Medical, London, Ontario, Canada) and sampled into the impactor with a flow rate of 4 l/min for 30 seconds.
TABLE 3
Dimensions of one embodiment of a cascade impactor as
described herein whereby one or more orifices are on the side
walls of the impactor stages. The dimensions are referenced to
FIG. 8.
Dimensions [inches]
Cutoff Size
Orifice
No.
D 50 (C) 1/2
Stage
A
B
C
W
E
F
Diameter
Orifices
[micrometers]
1
1.25
—
0.3390
0.1285
0.5960
1.1100
0.1285
3
6.96
2
1.75
1.25
1.1100
0.1015
1.3130
1.7190
0.1015
2
4.03
3
2.25
1.75
1.7190
0.0625
1.8440
2.0940
0.0625
2
1.99
4
2.50
2.25
2.0940
0.0390
2.1720
2.3280
0.0390
2
1.02
5
2.75
2.50
2.3280
0.0225
2.3730
2.4630
0.0210
4
0.66
Filter
3.00
2.75
2.4630
—
3
3
—
—
<0.66
A = Nominal outer diameter [inches]
B = Nominal inner diameter [inches]
C = Inner diameter [inches]
W = Orifice diameter [inches]
E = Outer diameter [inches]
F = Second Inner Diameter of the Next Stage [inches]
The overall height of each stage in this example is approximately 1.50 inches.
Example 6
After collection, the clear disks were examined under a microscope. The resulting sizes of particles collected on each stage confirmed the calculated cutoff diameters for the stages and showed that the embodiment containing orifices in the side walls of the stages performs comparably to the embodiment in which the orifices are in the bottoms of the stages.
Example 7
An aerosol of ammonium fluorescein was produced in a wind tunnel by nebulizing a 5% ammonium fluorescein solution with an Aeroneb nebulizer (Nectar, San Carlos, Calif.) and allowed to dry to solid particles in the wind tunnel.
Ammonium fluorescein was chosen because of its widespread and long-known use in the art as a sensitive tracer material. It is very soluble in water, forms non-hygroscopic particles, and is easily analyzed with a spectrometer or a fluorometer down to a concentration of 1 nanogram per milliliter.
The dried aerosol was sampled from the wind tunnel with the impactor of Example 1 and the mass of aerosol deposited on each stage was analyzed with a Turner Biosystems Picofluor fluorometer (Sunnyvale, Calif.). Clear plastic disks described in Example 1 were not used or needed for the collection of the fluorescein aerosol. An Andersen cascade impactor (Westech Instruments, Atlanta, Ga.) was also used to sample the aerosol from the wind tunnel and the mass collected on each stage was similarly analyzed. The size distributions as measured by both impactors were plotted and compared ( FIG. 12 ), and indicated very good agreement between the two impactors.
Example 8
A cascade impactor was constructed according to Example 5 and Table 3. An aerosol of ammonium fluorescein produced as described in Example 7 was sampled with the impactors of Examples 1 and 5. The resulting size distribution plot ( FIG. 13 ) indicates good agreement between the two impactors.
Example 9
A liquid aerosol of water and ammonium fluorescein is nebulized with a Bird Micronebulizer (Hudson RCI, Temecula Calif.). The impactor of Example 5 and a Delrin Andersen impactor (Westech Instruments, Atlanta, Ga.) specially designed for liquid aerosols are used to sample aerosol from the micronebulizer. The results are analyzed fluorometrically as in Example 7. A plot ( FIG. 14 ) of the size distributions as measured by each of the impactors shows that the impactors are similar in the measured size distribution.
Example 10
The apparatus of Example 2 was assembled. A 1:10 dilution of silicon antifoam in water with 0.01% ammonium fluorescein added as a tracer was added to a VixOne nebulizer. The apparatus was pressurized to about 145 psi. The valve was opened and the aerosol produced was sampled into the impactor of Example 4 at 4 l/min. This method was repeated five more times, and then each of the impactor stages was analyzed fluorometrically. The size distribution is shown in FIG. 15 . The mass median diameter of the grease aerosol was 3.92 micrometers, and the standard geometric deviation was 2.09. The amount of silicone grease deposited on each stage was calculated from analysis of the ammonium fluorescein tracer. Table 4 gives the approximate coverage under each impactor orifice. This aerosol was suitable for depositing a functional coating on each of the stages.
TABLE 4
Coverage of impactor stages with silicone grease
Stage
Weight Grease (mg/sq. in.)
1
20
2
98
3
260
4
250
5
69
Example 11
The apparatus of Example 2 was assembled. A 1:10 dilution of silicon antifoam in water was added to a VixOne nebulizer. The device was pressurized to about 145 psi. The valve was opened and the aerosol produced was sampled into an Andersen Cascade impactor at a flow rate of 28.3 l/min. The silicon anti-foam was allowed to dry by sampling clean, 31% relative humidity air for 12 minutes. The Andersen was then used to sample ammonium fluorescein test aerosol produced as described in Example 7. The plates were analyzed, and a size distribution of the aerosol was plotted. The same ammonium fluorescein aerosol method was used to sample into the Andersen impactor where the collection plates had been coated with grease in the traditional manner, using a dropper to cover each plate with grease, and allowing them to dry overnight. The size distribution plot ( FIG. 16 ) indicates that the two methods of coating the plates with grease produce nearly identical sampling results for the test aerosol. Further, the aerosol method was suitable for depositing a functional coating on each of the stages.
While preferred embodiments of the invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. Specific dimensions given in the above examples are for the purposes of enablement of the examples. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention, including alterations of the above stated specific dimensions. While the examples presented have a specific number of stages, it will be clear to one skilled in the art that additional collection stages may be similarly designed and added according to the teachings herein. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.
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The invention relates to low flow rate cascade impactors for sampling aerosols, notably but not limited to pharmaceutical aerosols. The impactor stages serve as both orifice plate and collecting cup, simplifying collection and analysis. The impactor is designed to operate at flow rates approximating the inspiratory flow rates of young children and infants. Also presented is a method of and apparatus for applying a coating material to the collection surface of the stages after an impactor is assembled for use. The method entails generation of a polydisperse aerosol and sampling into the impactor. The coating substance improves the trapping of particles on the stages. The apparatus and method of application limit the amount of coating material applied and confines it to the regions of particle impact opposite the stage orifices.
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[0001] This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional application Serial No. 60/289,106 for all commonly disclosed subject matter. U.S. Provisional Application Serial No. 60/289,106 is expressly incorporated herein by reference in its entirety to form a part of the present disclosure.
FIELD OF THE INVENTION
[0002] This invention relates to a security systems, and, more particularly, to a portable security system which is effective to prevent or at least slow the progress of a vehicle engaged in an attempted unauthorized entry into a facility such as a military base, power plant or other restricted access installation.
BACKGROUND OF THE INVENTION
[0003] Security at restricted access installations such as military bases, nuclear power plants and other facilities is of critical concern, particularly at facilities where personnel are housed on site, sensitive equipment is located or hazardous material is stored. One technique employed by terrorists and other groups which can have devastating results is a suicide mission where a truck or other vehicle filled with explosives is driven into the vicinity of one or more target buildings at an installation and detonated. Standard gates, fences or other obstacles deployed along the roadway leading to the installation are often ineffective to stop this type of attack, unless they are constructed to be permanent structures. In many instances, it is not desirable or feasible to install permanent barriers or other obstacles due to the temporary nature of the installation, space requirements and a variety of other factors.
SUMMARY OF THE INVENTION
[0004] It is therefore among the objectives of this invention to provide a security system which is portable, which is easy to assemble and operate and which is effective to stop or slow the progress of unauthorized vehicular traffic into restricted access areas.
[0005] These objectives are accomplished in a portable security system according to this invention which includes two security units, located on opposite sides of a roadway or other path for vehicles, which are spanned by an automatic or manually operated gate. Each security unit consists of at least two barrier devices which are generally rectangular-shaped structures formed of rigid plastic or a similar material having a top wall, a bottom wall, opposed side walls and opposed end walls which collectively form a hollow interior. At least two barriers devices are positioned side-by-side on each side of the roadway, and then they are filled with a ballast material such as water, sand, chunks of rubber or the like. Adjacent barrier devices in each group are interconnected by a first and second beams, which extend through respective fork lift openings formed in the center of the barrier devices. A gate spans the two security units, and is movable between an open position permitting the passage of vehicular traffic along the roadway and a closed position.
[0006] In one presently preferred embodiment, the gate which spans the two security units is formed of metal, fiberglass, plastic or the like, and it has a hollow interior which receives a steel cable. One end of the cable is secured to one of the beams connecting the barrier devices of one security unit located on one side of the roadway where the gate is pivotally mounted, and the other end of the cable is formed with a loop. In the closed position of the gate, the loop end of the cable is secured to a hook, shackle or similar element mounted to one or both of the beams extending between the barrier devices of the other security unit. The gate may also be provided with a tire puncture strip which extends downwardly onto the roadway with the gate in a closed position. In an alternative embodiment, the gate comprises a length of cable having one end affixed to one or both beams connecting the barrier devices of one security unit and its opposite end releasably mounted to a hook, shackle or the like carried by the beam(s) of other security unit.
[0007] In the event of an attack in which a vehicle attempts to proceed along the roadway toward a base or installation, the steel cable which forms the gate or is affixed to the gate arm is immediately engaged by the vehicle. The force of impact is transferred by the cable to each group of barrier devices within both security units which are effective to prevent or at least resist further forward movement of the vehicle. Essentially any number of barrier devices mounted side-by-side can be employed to form the two security units on either side of the roadway, each filled with a ballast material, thus providing substantial mass which would have to be dragged along by the vehicle in order for it to proceed forward once the cable is engaged. If the tire puncture strip is employed, the progress of the vehicle would be further impeded due to flat tires.
[0008] The portable security system of this invention is easily moved from one location to another by simply emptying the ballast material from the barrier devices, disconnecting the beams and removing the gate. All components can then be quickly and easily reassembled at another site as desired.
DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 is a perspective view of two security units located on either side of a roadway, with a gate arm in the closed position;
[0010] [0010]FIG. 2 is a disassembled view of the beam structure for mounting two barrier devices side-by-side;
[0011] [0011]FIG. 3 is a view similar to FIG. 2 except depicting a hook for securing one end of the gate arm to the beam structure;
[0012] [0012]FIG. 4 is a view similar to FIG. 3 wherein a cable is depicted which spans the two security units as an alternative to the gate arm of FIG. 1; and
[0013] [0013]FIG. 5 is an assembled view of the beam structure illustrating one manner of attaching an end of the cable thereto.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Referring now to FIG. 1, the portable security system of this invention comprises two security units 8 and 9 located on opposite sides of a roadway or other path for the transit of vehicles. Each security unit 8 , 9 , in turn, consists of two barrier devices 10 which are mounted side-by-side in a manner described in detail below. The construction of the barrier devices 10 shown in FIG. 1 is identical, and therefore only one is described in detail herein.
[0015] Each barrier device 10 comprises a top wall 12 , a bottom wall 14 , opposed end walls 16 , 18 , and, opposed sidewalls 20 , 22 which are interconnected to collectively define a hollow interior. In the presently preferred embodiment, each of the walls 12 - 22 are formed of a semi-rigid plastic material chosen from the group consisting of low density polyethylene, acrylonitrile or butadiene styrene, high impact styrene, polycarbonates and the like. These plastic materials are all inherently tough and exhibit good energy absorption characteristics. They will also deform and elongate, but will not fail in a brittle manner at energy inputs which cause other materials to undergo brittle failure. Additionally, materials of this type are unaffected by weather and have excellent basic resistance to weathering, leaching and biodegradation. Additives such as ultraviolet inhibitors can be added thereto, making such materials further resistant to the effects of weather. They also retain their mechanical and chemical properties at low ambient temperatures.
[0016] The hollow interior is preferably filled with a “ballast” material such as water or other liquid, or a flowable solid material such as sand, concrete and the like. For this purpose, the walls 12 - 22 of barrier device 10 have a thickness in the range of about one-eighth inch to one inch so as to perform satisfactorily in service. The barrier device 10 is preferably in the range of about six to eight feet in length, and, at the wall thickness noted above, has a weight when empty of about 80 to 140 lbs. When filled with a liquid such as water, the overall weight of the barrier is in the range of about 1400 to 2200 lbs. Flowable solid material such as sand and the like increase the weight of barrier device 10 further.
[0017] Each sidewall 20 and 22 includes a substantially vertically extending curb reveal 26 which extends from the bottom wall 14 to a horizontally extending ledge or step 28 best shown in FIG. 1. Preferably, the curb reveal 26 has a vertical height of nine inches, measured from the bottom wall 14 upwardly. The horizontal extent of the step 28 is preferably on the order of about 1½ inches measured in the direction from the outer edge of curb reveal 26 toward the hollow interior 24 of barrier device 10 .
[0018] Extending upwardly at an acute angle from the step 28 is an intermediate section 30 which terminates at a vertically extending upper section 32 . The upper section 32 , in turn, extends from the intermediate section 30 to the top wall 12 of barrier 10 which is formed with a pair of fill holes 33 preferably having a diameter in the range of about 3-4 inches. Additionally, a number of stabilizers 34 are integrally formed in the intermediate section 30 , at regularly spaced intervals between the end walls 16 , 18 .
[0019] In the presently preferred embodiment, a pair of hollow sleeves 36 are located within the hollow interior of each barrier device 10 and extend between the sidewalls 20 , 22 . For ease of illustration, only one of the sleeves 36 is shown in the Figures. A portion of each sleeve 36 is located in the intermediate section 30 of each sidewall 20 , 22 , and extends partially into the upper sections 32 thereof. The two sleeves 36 are positioned in the spaces between the three stabilizers 34 formed in the sidewalls 20 , 22 , and provide added internal support to the barrier 10 so that it retains its shape when filled with a ballast material.
[0020] Each of the sleeves 36 define a pass-through hole or channel adapted to receive the tines of a forklift truck to permit handling of the barrier devices 10 . These pass-through holes are also used to mount the beam structure for connecting to barrier devices 10 side-by-side. With reference to FIG. 2, a first beam 38 and a second beam 40 each have a reduced diameter section 42 at opposite ends which is sized to fit within the pass-through holes formed by the sleeves 36 in the barrier devices 10 . The beams 38 , 40 are preferably formed of steel or other rigid material. As best seen in FIG. 1, the reduced diameter sections 42 protrude beyond the surface of the side wall 20 of one barrier device 10 and beyond the surface of side wall 22 of the other barrier device 10 in each of the security units 8 and 9 . Each reduced diameter section 42 is positioned to mount an angle bracket 44 formed with holes 46 which align with holes 48 in the sections 42 to receive bolts 50 .
[0021] In order to provide additional stability and a platform for mounting other structure, as described below, a steel plate 52 is secured between the first and second beams 38 , 40 . Aligning bores 54 and 56 formed in the plate 52 and beams 38 , 40 , respectively, receive bolts 50 to mount same together. In one presently preferred embodiment, the plate 52 mounts one end of a gate arm 60 which spans the space between the security units 8 and 9 . See FIG. 1. The gate arm 60 is preferably formed of metal, fiberglass or plastic and carries an endless cable 62 which extends along the length of the gate arm 60 and forms a loop 64 at one end. As best shown in FIG. 3, the loop 64 of cable 62 is releasably connected to a hook 66 with the gate arm 60 in the closed position. The hook 66 , in turn, is mounted by a U-shaped connector 68 to the plate 52 . The opposite end of cable 62 is looped around the second beam 40 of the security unit 9 to secure it in place. See FIG. 1. As schematically depicted in FIG. 2, the gate arm 60 is raised and lowered by operation of a motor 70 which rotates a shaft 72 connected to the gate arm 60 . The gate arm 60 may also be manually raised and lowered, if desired. Additionally, a strip of sharp objects (not shown) capable of puncturing vehicle tires can be attached to the gate arm 60 so that it lies on the roadway with the gate arm 60 in the closed position.
[0022] In an alternative embodiment shown in FIGS. 4 and 5, the gate arm 60 is replaced by a length of cable 74 formed with loops 76 at each end. In FIG. 4, one loop 76 is releasably mounted to a hook 66 connected to the plate 52 of security unit 8 as described above in connection with a discussion of FIG. 3, and the loop 76 at the opposite end of the cable 74 is connected to a shackle 77 mounted by a connector 68 to the plate 52 of security unit 9 . Alternatively, one end of the cable 74 may be mounted to one plate 52 using a number U-shaped connectors 68 as depicted in FIG. 5, while the opposite end of cable 74 is releasably connected to a hook 66 . With the cable 74 in an extended position to block the passage of vehicles between the security units 8 , 9 , each end of the cable 74 is secured to a plate 52 . To permit the passage of vehicles between the security units 8 , 9 , one end of the cable 74 is detached from a hook 66 and the cable 74 is allowed to rest on the ground so that the vehicle can drive over it.
[0023] While the invention has been described with reference to a preferred embodiment, it should be understood by those skilled in the art that various changes may be made and equivalents substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof.
[0024] For example, only two barrier devices 10 are shown in the Figs. as comprising the security units 8 and 9 . It should be understood that essentially any number of barrier devices 10 mounted side-by-side could be employed to form the units 8 , 9 if additional mass is desired.
[0025] Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
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A portable security system comprises two security units, located on opposite sides of a roadway or other path for vehicles, each consisting of at least two hollow barrier devices filled with a ballast material such as water, sand, chunks of rubber or the like. Adjacent barrier devices in each security unit are interconnected side-by-side using first and second beams, which extend through respective fork lift openings formed in the center of the barrier devices. A gate spans the two security units, and is movable between an open position permitting the passage of vehicular traffic along the roadway and a closed position.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a non provisional application and hereby claims priority under 35 U.S.C. 119e from provisional application 60/863,416 filed on Oct. 30, 2006, the disclosure of which is hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a closet device or wardrobe whereby cross-supports to the bars for hanging clothing lead to increased stability and load capacity.
SUMMARY OF THE INVENTION
[0003] The invention relates to a closet device or wardrobe whereby cross-supports to the bars for hanging clothing lead to increased stability and load capacity. A cross-support is simply connected to the top of the frame and can be a wire with bends at its two ends and two body sections that lead to a middle section where an obtuse angle is made as the two halves of the cross-support come together. The bends hook or hang on opposite sides of the upper frame of the wardrobe. The hang bar can rest on the angled middle section of the cross support, which provides additional support to the hang bar from the usual connections of the hang bar to the frame at the hang bar's two ends. This additional support to the hang bar results in increased stability, durability, and load capacity for the wardrobe or closet device. The cross support can be in the form of a wire, a tube, a rod, a beam, or any other structural type supporting element. The cross support and also the frame can be made from any suitable material such as metal, plastic, or any other known resilient material.
[0004] In two embodiments the cross support is made of a wire metal and is called a crosswire, a cross beam or cross bar. While in the description of the drawings the term crosswire or cross bar will be used, any term for a cross supporting member can also be correctly used in describing this device. One embodiment shows a wardrobe with one main section and one crosswire or cross bar. Another embodiment shows a wardrobe or closet device with two main sections and two crosswire or cross bars.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It should be understood, however, that the drawings are designed for the purpose of illustration only and not as a definition of the limits of the invention.
[0006] In the drawings wherein similar reference characters denote similar elements throughout the several views:
[0007] FIG. 1 is a perspective view of the assembly of the bottom frame of the closet device;
[0008] FIG. 2 is a perspective view of the bottom frame of the closet device with a fabric cover stretched around the bottom frame;
[0009] FIG. 3 is a perspective view of the center portion of the frame being assembled and attached to the bottom support tubes of the closet device;
[0010] FIG. 4 is a perspective view of the assembly of the top of the frame of the closet device;
[0011] FIG. 5 is a perspective view of the assembled top portion being attached to the combined center and bottom of the frame of the closet device, with a fabric cover around the bottom frame;
[0012] FIG. 6 is a perspective view of the assembled top, center and bottom of the closet device with the fabric cover stretched over the top and bottom of the frame but with the fabric cover not being zipped shut so inside portions of the frame are still viewable;
[0013] FIG. 7 is a perspective view of the assembled closet device with the fabric cover completely stretched over the device and zipped shut;
[0014] FIG. 8 is a perspective view of the assembly of the bottom frame of another embodiment of the closet device;
[0015] FIG. 9 is a perspective view of the bottom frame of this second embodiment of the closet device with a fabric cover stretched around the bottom frame;
[0016] FIG. 10 is a perspective view of the center portion of the frame being assembled and attached to the bottom support tubes of this second embodiment of the closet device;
[0017] FIG. 11 is a perspective view of the assembly of the top of the frame of this second embodiment of the closet device;
[0018] FIG. 12 is a perspective view of the assembled top portion of the frame being attached to the combined center and bottom portions of the frame of this second embodiment of the closet device, with a fabric cover around the bottom frame;
[0019] FIG. 13 is a perspective view of the assembled top, center and bottom of this second embodiment of the closet device with the fabric cover stretched over the top and bottom of the frame but with the fabric cover not zipped shut so inside portions of the frame are still viewable;
[0020] FIG. 14 is a perspective view of this assembled second embodiment of the closet device with the fabric cover completely stretched over the device and zipped shut; and
[0021] FIG. 15 is a front view of the cross-wire of the closet devices.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Referring to the drawings, FIG. 6 shows a perspective view of the closet device 10 which is able to support a heavier load by hangers hanging onto a tube supported by an angled crosswire or cross bar 16 . FIGS. 1-7 show a step-by-step assembly of the closet device. FIG. 1 shows a perspective view of a base frame formed by bracket 2 connecting to beams 6 . Straight tubes or columns 4 can be inserted into slots 201 in the top side of bracket or corner supports 2 so that these columns 4 are directly across from and not diagonal to each other, and are vertically-oriented. Two reduced tubes forming columns 14 are inserted into the other two slots 201 on the other end of the corner supports 2 resulting in each reduced tube 14 being straight across from the reduced tube 14 connected to the opposite corner support 2 with reduced tubes 14 being vertically oriented. The end of the reduced tube 14 not connected to the bottom corner support is a male end 15 . Beams 6 which can be longer than the first set of straight tubes 4 has both ends inserted into slots 202 on the inside face of the corner supports 2 and are horizontally oriented.
[0023] FIG. 2 shows the assembled bottom portion of the closet device with a fabric cover 20 stretched around both straight tubes 4 and reduced tubes 14 . FIG. 3 shows two side connectors 18 being connected from the bottom 180 of its three openings to the top ends of straight tubes 4 . Two openings 180 and 181 on each side connector 18 are meant to be used with tubes in a vertical orientation. Each of the three openings 180 , 181 , and 182 in each side connector 18 fits tubes of equal diameter. Each end of a long straight tube 10 is inserted into a side connector 18 in the opening 182 meant to fit horizontally-oriented tubes.
[0024] FIG. 4 shows the assembly of the top of the frame. Two straight tubes forming columns 4 are inserted into two bottom openings 201 in two additional corner supports 2 so that they are directly across from each other and not diagonal to each other and are vertically oriented. Two straight tubes 12 , marginally longer than straight tubes 4 , are inserted in a vertical orientation into the two remaining bottom openings 201 at the other ends of the corner supports. The unreduced ends 120 of the straight tubes 12 allow them to act as female ends which will eventually connect with the male ends 15 of reduced tubes 14 . Two long straight tubes 6 , in addition to the two tubes 6 at the bottom of the frame, are inserted into the four outside slots 202 on the inside face of these upper corner supports 2 , resulting in these tubes 6 being horizontally oriented and parallel to each other. A straight hang bar 8 of the same length as straight tubes 6 is inserted into center slots 203 on the inside face of upper corner supports 2 . The straight hang bar 8 lies with the same horizontal orientation as straight tubes 6 forming top cross beams. After assembly of the top of the frame straight tubes 6 and straight bar 8 have no unattached ends.
[0025] FIG. 5 shows the top of the frame being inserted into the combined center and bottom of the frame. The unattached ends of straight tubes 4 insert into the remaining openings 181 of side connectors 18 . Unattached ends 120 of straight tubes 12 connect with male ends 15 of reduced tubes 14 . A floor support 22 fits snugly in between opposing bottom corner supports 2 . An angled crosswire or cross bar 16 (See FIG. 15 for greater detail) hooks onto upper straight tubes 6 and supports straight hang bar 8 . Bends 54 at the end of the angled crosswire or cross bar 16 enable it to hook onto tubes 6 . The cross bar 16 runs from each end to a middle section 58 at which both halves of the cross bar are connected at an obtuse angle. The angled middle section 58 cradles the straight hang bar 8 . FIG. 6 shows the closet device 10 with top, center, and bottom of the frame connected together and the fabric cover 20 stretched over the outside and top of the frame but not completely closed. FIG. 7 shows the finished product of the closet device 10 with cover 20 completely stretched out and zipped up. In this case the cover 20 has a closure or fastener such which can be in the form of any known fastener such as hook and loop fastener, zipper, snaps, ties, and laces.
[0026] Referring to the drawings, FIG. 13 shows a perspective view of another embodiment 100 of the closet device which also is able to support a heavier load by hangers hanging onto a bar supported by an angled cross bar 16 . Embodiment 100 is larger than closet device 10 and is bi sectioned whereas device 10 had only one main section. FIGS. 8-14 show a step-by-step assembly of this bi-sectioned variation 100 .
[0027] For example, FIG. 8 shows a perspective view of three straight tubes forming columns 32 being inserted into slots 201 in the top openings of two bottom corner supports or brackets 2 and the top opening 260 of bottom center support or bracket 26 resulting in a vertical orientation for tubes or columns 32 . These three tubes or columns 32 are inserted into the openings 201 and 260 on the same ends of support brackets 2 and 26 so a line can be formed between the three tubes or columns 32 . Three columns which can be formed by reduced tubes 38 are inserted into the slots 201 and 260 on the other end of the top face of brackets formed from the corner supports 2 and center supports 26 resulting a vertical orientation for the three columns or reduced tubes 38 . The male end 39 of each column which can be in the form of a reduced tube 38 is left unattached. Each reduced tube 38 stands opposite a straight tube 32 on its own support and in line with the other two reduced tubes 38 on the other corner supports 2 or center support 26 .
[0028] Assembly of the bottom of the frame results in six vertically-oriented tubes 32 and 38 each with one unconnected end.
[0029] Two straight tubes 36 which are longer than the straight tubes 32 but shorter than reduced tubes 38 are inserted at one end into a slot 202 on the inside face of a corner support 2 and at the other end into the side of center support 26 in a slot 261 meant for horizontally-oriented tubes. Similarly, two reduced tubes 40 of the same length as tubes 36 insert at one end into slots 202 on the inside face of a corner support 2 and with its male end 400 into slots 262 on the center support 26 meant for horizontally-oriented tubes and sized to hold male ends.
[0030] FIG. 9 shows the assembled bottom portion of the closet device with a fabric cover 50 stretched around all three sets of vertically-oriented tubes and around both sections of the bottom frame. FIG. 10 shows two side connectors 18 being connected from the bottom 180 of its three openings to the top ends of the two outside tubes of the three tubes 32 . Side connector 18 here is the same size and has openings of the same size as side connectors 18 in the previous embodiment of the closet device. The unconnected end of the middle of the three tubes 32 fits into the center connector 46 in the bottom of its two openings meant to hold tubes in a vertical orientation. Two straight tubes 34 each fit at one end into a side connector 18 at an opening 182 meant for horizontally-oriented tubes and fit at the other end into the center connector 46 at the center connector's one of two openings 462 meant to hold horizontally-oriented tubes. The bottom 460 of the center connector's two openings for vertically-oriented bars connects to the top of the straight tube 32 attached to the center support 26 .
[0031] FIG. 11 shows the assembly of the top of the frame. Six straight tubes 28 of the same length as previous reduced tubes 38 are inserted into the bottom openings 201 of two upper corner supports 2 and bottom openings 260 of uppercenter support 26 . Two long straight tubes 36 , in addition to the two tubes 36 at the bottom of the frame, are inserted at one end into the two outside slots 202 on the inside face of one of the upper corner supports 2 , and at the other end into the two outside slots 261 on the uppercenter support 26 . Each tube 36 is horizontally oriented and parallel to the other tube 36 . Similarly, two reduced tubes 40 , in addition to the two 40 at the bottom of the frame, insert at one end into slots 202 on the inside face of the opposite corner support 2 and with its male end 401 into slots 262 on the center support 26 meant for horizontally-oriented tubes and sized to hold male ends. A straight hang bar 30 of the same length as straight tubes 36 is inserted at one end into a center slot 203 on the inside face of an upper corner support 2 and at the other end into the uppercenter support 263 in a middle slot meant for horizontally-oriented bars. The straight hang bar 30 lies with the same horizontal orientation as straight tubes 36 . A reduced hang bar 42 of the same length as straight hang bar 30 is inserted at its unreduced end into a center slot 203 on the inside face of an upper corner support 2 and at its male end 41 into the uppercenter support 26 in a middle slot 264 meant for horizontally-oriented bars sized to hold male ends. After assembly of the top of the frame straight tubes 36 , reduced tubes 40 , straight hang bar 30 , and reduced hang bar 42 have no unattached ends.
[0032] FIG. 12 shows the top of the frame being inserted into the combined center and bottom of the frame. Three unattached ends of straight tubes 28 insert into the remaining top openings 181 of the two side connectors 18 and remaining opening 461 of center connector 46 . The other three unattached ends of straight tubes 28 connect with male ends 39 of reduced tubes 38 . A floor support 52 fits snugly in between opposing bottom bracket in the form of corner supports 2 and on the bottom center support 26 . An angled cross bar 16 hooks at one end on one upper straight tube 36 and at the other end to the other upper straight tube 36 and supports straight hang bar 30 . See FIG. 15 for greater detail. Straight hang bar 30 rests on cross bar 16 . A second angled cross bar 16 hooks at one end on one upper reduced tube 40 and at the other end to the other upper reduced tube 40 and supports reduced hang bar 42 . Reduced hang bar 42 rests on cross bar 16 . FIG. 13 shows the closet device 100 with top, center, and bottom of the frame connected and the fabric cover 50 stretched over the outside and top of the frame but not completely closed. FIG. 14 shows the finished product of the closet device 100 with cover 50 completely stretched out and zipped up.
[0033] FIG. 15 shows the cross bar 16 , of the closet device. Bends 54 at the ends of the wire and end sections 53 allow the cross bar to conveniently and simply attach or hook onto weight-bearing members of the frame such as straight tubes 6 , 36 or reduced tubes 40 . The body sections 56 of the cross bar run from the bends 54 to a middle section 58 . The middle section 58 forms an obtuse angle on which a hang bar such as straight hang bar 8 or 30 or reduced hang bar 42 can be cradled.
[0034] Without the cross bar 16 , the weight of items hanging in the closet are carried by the straight 30 or 8 or reduced 42 hang bar and only transferred to the rest of the frame structure through the hang bar's two connections 203 and 263 and 264 to the corner supports or bracket 2 and center support or bracket 26 . The cross bar 16 enables the weight on the hang bar 8 , 30 , or 42 to be more efficiently distributed to the rest of the frame of the closet device as it provides further means of transferring some of the load. This dramatically stabilizes the closet device, greatly increases its overall weight bearing capacity and increases the durability of the closet device. Setup of the cross bar 16 , is convenient and simple because it connects to the frame through the bends 54 in the wire and end sections 53 and the cross bar 16 , cradles the hang bar 8 , 30 , 42 .
[0035] Accordingly, while only a few embodiments of the present invention have been shown and described, it is obvious that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.
Reference Numeral List:
[0000]
2 corner support, bracket
4 straight tube or beam, column
6 straight tube or beam longer than
8 straight hang bar, middle beam
10 device, first embodiment
12 straight column or tube marginally longer than 4
14 reduced column or tube
15 male end of reduced tube or column 14
16 angled crosswire or cross beam
18 side connector or bracket
20 fabric cover
22 floor support
24 corner support or bracket—similar as 2
26 center support or bracket
28 straight tube or column
30 straight hang bar, center or middle beam
32 vertically oriented straight tube, or column
34 horizontal straight tube that connects with side connectors, or beam, such as top beam
36 straight tube longer than 32 and shorter than 38 , beam
38 column in the form of a reduced tube
39 male end of reduced tube 38
40 beam in the form of a reduced tube same length as 36
41 male end of reduced hang bar, or middle beam
42 reduced hang bar, center or middle beam
46 center connector or bracket
50 fabric cover
52 floor support
53 end section of cross bar
54 end bend of cross bar
56 body section of cross bar or crosswire
58 middle or center curve of cross bar or cross wire
100 alternative embodiment of closet
120 unreduced end of straight tube or column
180 bottom vertical opening of side connector or bracket
181 top vertical opening of side connector or bracket
182 horizontal opening of side connector or bracket
201 vertical corner support slot in a bracket
202 horizontal corner support slot in bracket
203 center horizontal corner support slot in bracket positioned lower than hole 202
204 center horizontal corner support slot in bracket positioned above hole 203
260 vertical opening of center support
261 normal-sized side slot of center support
262 male end-sized side slot of center support
263 normal-sized side slot of center support
264 male end-sized side slot of center support
400 male end of reduced tube 40
401 male end of reduced tube 40
461 top vertical opening of center connector
462 horizontal opening of center connector
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A closet device or wardrobe whereby cross-supports to the bars for hanging clothing lead to increased stability and load capacity. A cross-support is simply connected to the top of the frame and can be a wire with bends at its two ends and two body sections that lead to a middle section wherein an obtuse angle is made as the two halves of the cross-support come together. The bends hook or hang on opposite sides of the upper frame of the wardrobe . The hang bar can rest on the angled middle section of the cross support, which provides additional support to the hang bar from the usual connections of the hang bar to the frame at the hang bar's two ends. This additional support to the hang bar results in increased stability, durability and load capacity for the wardrobe or closet device. The cross support can be in the form of a wire, a tube a rod, a beam, or any other structural type supporting element. The cross support and also the frame can be made from any suitable material such as metal, plastic, or any known resilient material.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to a suspension unit having a magneto-spring unit and metal springs and, in particular but not exclusively, to a suspension unit having a spring constant of substantially zero in a predetermined range by combining a magneto-spring unit having a negative spring constant and metal springs having a positive spring constant.
[0003] 2. Description of the Related Art
[0004] In recent years, vehicle technologies including automobile technologies have been remarkably developed, and safety and riding-comfort as well as maneuverability are desired. Recently, with the practical use of permanent magnets that have a high coercive force and a high residual magnetic flux density, research is flourishing in areas such as mechanical structures and magnetic systems that utilize magnetic levitation, magnetic bearings, dampers employing a magnetic fluid, or the like. The inventors of this application have hitherto proposed suspension units in which a magneto-spring is utilized.
[0005] However, in a suspension unit having a spring constant of substantially zero in a predetermined range by combining a magneto-spring having a negative spring constant and metal springs having a positive spring constant, a large stroke results in a very large unit.
SUMMARY OF THE INVENTION
[0006] The present invention has been developed to overcome the above-described disadvantages.
[0007] It is accordingly an objective of the present invention to provide a relatively compact suspension unit that ensures a large stroke by making the amount of motion of the magneto-spring unit be smaller than that of the suspension unit.
[0008] In accomplishing the above and other objectives, the suspension unit according to the present invention includes a lower frame, an upper frame vertically movably mounted on the lower frame, and a link mechanism for connecting the lower frame and the upper frame. The suspension unit also includes a magneto-spring unit for resiliently supporting the upper frame relative to the link mechanism, and a plurality of metal springs having opposite ends hooked on the upper frame and a portion of the link mechanism, respectively.
[0009] By this construction, the amount of motion of the magneto-spring unit is made smaller than that of the suspension unit, resulting in a relatively compact suspension unit having a large stroke.
[0010] Advantageously, the link mechanism includes an X-link having two links and the magneto-spring unit includes a stationary magnet unit and a movable magnet unit. The stationary magnet unit is mounted on the upper frame and the movable magnet unit is mounted on the X-link.
[0011] The suspension unit also includes an operating member for operating the plurality of metal springs to adjust a load applied to the upper frame. The link mechanism further includes a first torsion bar that produces a lifting force of the upper frame.
[0012] Advantageously, the suspension unit includes a second torsion bar mounted on the upper frame and a contact plate secured to a portion of the link mechanism, wherein when a displacement of the upper frame relative to the lower frame is greater than a predetermined value, the second torsion bar impinges on the contact plate to thereby produce a lifting force of the upper frame.
[0013] The plurality of elastic means such as the magneto-spring unit, the plurality of metal springs, and the first and second torsion bars make it possible to provide a suspension unit having a spring constant of substantially zero with respect to a displacement in a predetermined range.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The above and other objectives and features of the present invention will become more apparent from the following description of a preferred embodiment thereof with reference to the accompanying drawings, throughout which like parts are designated by like reference numerals, and wherein:
[0015] [0015]FIG. 1 is a perspective view of a suspension unit according to the present invention;
[0016] [0016]FIG. 2 is an exploded perspective view of the suspension unit of FIG. 1;
[0017] [0017]FIG. 3A is a schematic perspective view of a magneto-spring unit mounted in the suspension unit of FIG. 1;
[0018] [0018]FIG. 3B is a front view of the magneto-spring unit of FIG. 3A;
[0019] [0019]FIG. 4 is a graph indicating the spring properties of a plurality of elastic means in the case where the load to be applied to the suspension unit of FIG. 1 has been adjusted to 70 kg;
[0020] [0020]FIG. 5 is a graph indicating the static characteristics of the suspension unit of FIG. 1; and
[0021] [0021]FIG. 6 is a graph indicating the dynamic characteristics of the suspension unit of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] This application is based on an application No. 2003-152879 filed May 29, 2003 in Japan, the content of which is herein expressly incorporated by reference in its entirety.
[0023] Referring now to the drawings and particularly to FIGS. 1 and 2, there is shown a suspension unit S embodying the present invention, which is used as a seat suspension, for example. The suspension unit S includes a generally rectangular lower frame 2 to be mounted on a vehicle floor and a generally rectangular upper frame 4 mounted on the lower frame 2 so as to be vertically movable relative thereto. A vehicle seat (not shown) is placed on the upper frame 4 .
[0024] An X-link having two links 6 , 8 rotatably connected to each other at intermediate portions thereof is disposed on each side of the suspension unit S. A front end of each link 6 is connected to a generally triangular oscillating plate 18 , while rear ends of both the links 6 are connected to each other via a cylindrical connecting shaft 12 . A front end of each link 8 is connected to a lower end of a generally rectangular oscillating plate 14 . Both the links 8 are connected to each other at respective positions apart a predetermined length rearwards from the front end thereof via a cylindrical connecting shaft 10 and at rear ends thereof via a cylindrical connecting shaft 16 . A bushing 15 rigidly secured to an upper portion of the oscillating plate 14 is rotatably connected to a front portion of the lower frame 2 via a pin 20 .
[0025] A bushing 19 rigidly secured to a lower portion of the oscillating plate 18 is rotatably connected to a front portion of the upper frame 4 via a pin 21 , and the oscillating plate 18 is joined to an end of a cylindrical connecting shaft 22 at a location forwards of the bushing 19 .
[0026] The rear connecting shaft 12 of the links 6 has a slip ring 24 mounted on each end thereof, on which a retainer ring 26 fixed to an inner surface of a side wall of the lower frame 2 is mounted for rotatably supporting the rear connecting shaft 12 . A torsion bar 28 having a square section is loosely inserted in the rear connecting shaft 12 . One end of the torsion bar 28 is secured to one end (rear end) of a lever 30 , the other end (front end) of which is secured to the side wall of the lower frame 2 . The other end of the torsion bar 28 is secured to an end of the rear connecting shaft 12 .
[0027] The rear connecting shaft 16 of the links 8 similarly has a slip ring 32 mounted on each end thereof, on which a retainer ring 34 fixed to an inner surface of a side wall of the upper frame 4 is mounted for rotatably supporting the rear connecting shaft 16 . A torsion bar 36 having a square section is loosely inserted in the rear connecting shaft 16 . One end of the torsion bar 36 is secured to one end (rear end) of a lever 38 , the other end (front end) of which is secured to the side wall of the upper frame 4 . The other end of the torsion bar 36 is secured to an end of the rear connecting shaft 16 .
[0028] A U-shaped bracket 40 is joined to the connecting shaft 22 and has an elongated opening 40 a defined in a front wall thereof. An operating shaft 44 having a knob 42 mounted on a front end thereof is loosely inserted in the elongated opening 40 a of the U-shaped bracket 40 , and a slip ring 46 is interposed between a rear end of the knob 42 and the front wall of the U-shaped bracket 40 . The operating shaft 44 has a male screw formed thereon, which is held in mesh with a female screw 48 a formed in a load adjusting shaft 48 that is located rearwards of the front wall of the U-shaped bracket 40 .
[0029] The load adjusting shaft 48 is rotatably connected to an upper portion of a spring-holding bracket 50 that is bent in the form of “U”, a lower portion of which is pivotally connected to a lower portion of the U-shaped bracket 40 . A spring-holding shaft 52 is mounted on a rear portion of the spring-holding bracket 50 , and a plurality of metal springs 54 are hooked at respective front ends on the spring-holding shaft 52 . The spring-holding bracket 50 has a load (weight) scale 56 mounted on a side portion thereof, and a pointer 58 confronting the load scale 56 is mounted on a side portion of the U-shaped bracket 40 .
[0030] The upper frame 4 has a rectangular opening 4 a defined therein and a recess 4 b formed at a location forwards of the rectangular opening 4 a . A rear spring-holding shaft 60 is received in the recess 4 b , and the plurality of metal springs 54 referred to above are hooked at respective rear ends on the rear spring-holding shaft 60 . A damper 62 is pivotally connected at a rear end (upper end) thereof to a lower surface of a rear portion of the upper frame 4 via a bracket (not shown), and is also pivotally connected at a front end (lower end) thereof to a bracket 64 that is joined to the lower frame 2 in proximity to a central portion thereof. Two torsion bars 66 bent in the form of “U” are disposed at a front portion of the upper frame 4 , and an inner end of each torsion bar 66 is secured to the upper frame 4 by means of a mounting member 68 , while an outer end of each torsion bar 66 is positioned above a contact plate 70 joined to the link 6 .
[0031] A magneto-spring unit 72 for resiliently supporting the upper frame 4 relative to the X-link 6 , 8 is disposed on each side of the damper 62 and includes a stationary magnet unit 74 and a movable magnet unit 76 .
[0032] As best shown in FIGS. 3A and 3B, the stationary magnet unit 74 includes a pair of upper permanent magnets 74 a and a pair of lower permanent magnets 74 b . The pair of upper magnets 74 a are spaced apart a predetermined distance with like magnetic poles opposed to each other. The same is true of the pair of lower magnets 74 b . The upper magnet 74 a and the lower magnet 74 b positioned on the same side are joined to each other such that unlike magnetic poles are oriented in the same direction (inwards or outwards). On the other hand, the movable magnet unit 76 has a permanent magnet positioned within an internal space in the stationary magnet unit 74 , and this permanent magnet has two magnetic poles formed on upper and lower portions thereof, respectively. The upper magnetic pole confronts the like magnetic poles of the pair of upper magnets 74 a of the stationary magnet unit 74 , and the lower magnetic pole similarly confronts the like magnetic poles of the pair of lower magnets 74 b of the stationary magnet unit 74 . As shown in FIG. 3B, a predetermined clearance is present between the stationary magnet unit 74 and the movable magnet unit 76 .
[0033] As shown in FIG. 2, each stationary magnet unit 74 is secured to an inner surface of a side wall of a metal frame 78 mounted on the upper frame 4 . The movable magnet unit 76 disposed within the internal space in the stationary magnet unit 74 has front and rear mounting members 80 formed on opposite ends thereof, which are in turn supported by brackets 82 , 84 secured to the two links 6 , 8 of the X-link, respectively.
[0034] Belt holding members 86 , 88 made of a metal are joined to a rear portion of the lower frame 2 and a rear portion of the upper frame 4 , respectively, and opposite ends of a stroke restraining belt 90 are secured to the belt holding members 86 , 88 , respectively. A cushioning member 92 made of, for example, rubber is mounted on a rear portion of the lower frame 2 .
[0035] The suspension unit S of the above-described construction operates as follows.
[0036] When a user sits on a vehicle seat placed on the upper frame 4 , the upper frame 4 moves downwards according to the load (weight of the user). The downward movement of the upper frame 4 twists the lower torsion bar 28 and the upper torsion bar 36 to produce a lifting force of the upper frame 4 according to the length of travel of the upper frame 4 . The downward movement of the upper frame 4 also expands the plurality of metal springs 54 to produce a lifting force of the upper frame 4 according to the length of travel of the upper frame 4 . On the other hand, in an unloaded condition, the outer end of each torsion bar 66 mounted on the upper frame 4 is spaced apart from the contact plate 70 joined to the link 6 . When a load greater than a predetermined value is applied to the upper frame 4 to move the upper frame 4 downwards by a length of travel greater than a predetermined value (for example, 10 mm (see FIG. 4)), the outer end of each torsion bar 66 impinges on the contact plate 70 , thereby gradually producing a lifting force of the upper frame 4 according to the length of travel of the upper frame 4 . The magneto-spring unit 72 presents a negative spring constant until a load greater than a predetermined value is applied to the upper frame 4 to move the upper frame 4 downwards by a length of travel greater than a predetermined value (for example, 25 mm (see FIG. 4)), and when the upper frame 4 further moves downwards over the predetermined value, the magneto-spring unit 72 comes to present a positive spring constant and then gradually produces a lifting force of the upper frame 4 according to the length of travel of the upper frame 4 .
[0037] The graph of FIG. 4 indicates the spring properties of the lower torsion bar 28 , upper torsion bar 36 , metal springs 54 , U-shaped torsion bars 66 , and magneto-spring unit 72 in the case where the load has been adjusted to 70 kg by rotating the knob 42 .
[0038] The graph of FIG. 4 reveals that each of the lower torsion bar 28 and the upper torsion bar 36 has a linear spring constant irrespective of the displacement (stroke), while the U-shaped torsion bars 66 have a linear spring constant with respect to a displacement greater than a predetermined value. The graph of FIG. 4 also reveals that the metal springs 54 have a spring constant close to a linear one, but present a negative spring constant, although small, with respect to a load greater than a predetermined value (20 mm in the graph of FIG. 4), and that the magneto-spring unit 72 has a negative spring constant within a predetermined range (about ±20 mm in the graph of FIG. 4), but presents a positive spring constant outside this range.
[0039] The load adjustment that is carried out by rotating the knob 42 is explained hereinafter.
[0040] Because the knob 42 is mounted on the front end of the operating shaft 44 and the male screw formed on the operating shaft 44 is in mesh with the female screw 48 a formed in the load adjusting shaft 48 , the distance between the knob 42 and the load adjusting shaft 48 varies by rotating the knob 42 . When rotation of the knob 42 causes the load adjusting shaft 48 to approach the knob 42 , the spring-holding bracket 50 pivots forwards about a lower portion thereof at which the spring-holding bracket 50 is connected to the U-shaped bracket 40 . As a result, the plurality of metal springs 54 hooked on the front spring-holding shaft 52 expand, thereby increasing the lifting force of the upper frame 4 . In contrast, when rotation of the knob 42 causes the load adjusting shaft 48 to move away from the knob 42 , the spring-holding bracket 50 pivots rearwards about the lower portion thereof, and the plurality of metal springs 54 contract, thereby reducing the lifting force of the upper frame 4 .
[0041] The user can carry out the load adjustment referred to above while watching the load scale 56 to which the pointer 58 points, and the load can be adjusted in a range of, for example, 50 kg to 130 kg.
[0042] [0042]FIG. 5 is a graph indicating the static characteristics of the suspension unit S according to the present invention where the load is 50 kg, 70 kg, 90 kg, 110 kg, and 130 kg. The graph of FIG. 5 reveals that the suspension unit S has a spring constant of substantially zero or close to zero with respect to a displacement in a predetermined range.
[0043] [0043]FIG. 6 is a graph indicating the dynamic characteristics of the suspension unit S according to the present invention. The graph of FIG. 6 reveals that the vibration transmissibility at a resonance point is restrained to be low and that both the vibration characteristics at the resonance point and the impact absorption are good and the vibration characteristics in a high frequency region is also good.
[0044] When a vibration is inputted to a vehicle frame (not shown), the damper 62 operates to attenuate the vibration. When an impact force is inputted to cause the lower frame 2 to abnormally approach the upper frame 4 , the rear connecting shaft 16 impinges on the cushioning member 92 , thereby absorbing the impact (bottom-end shock). When the lower frame 2 comes to move abnormally away from the upper frame 4 , a tension is applied to the stroke restraining belt 90 , which in turn restrains the stroke of the upper frame 4 relative to the lower frame 2 .
[0045] It is to be noted that although the above-described embodiment has been explained taking the case of the seat suspension on which a vehicle seat is mounted, the present invention is not limited to only the seat suspension, but can be used as a vibration isolator, on which an apparatus other than the vehicle seat is placed, for attenuating a vibration from outside.
[0046] Although the present invention has been fully described by way of examples with reference to the accompanying drawings, it is to be noted here that various changes and modifications will be apparent to those skilled in the art. Therefore, unless such changes and modifications otherwise depart from the spirit and scope of the present invention, they should be construed as being included therein.
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A suspension unit includes a lower frame and an upper frame vertically movably mounted on the lower frame via a link mechanism. The suspension unit also includes a magneto-spring unit for resiliently supporting the upper frame relative to the link mechanism. The amount of motion of the magneto-spring unit is smaller than that of the suspension unit, making it possible to provide a relatively compact suspension unit having a large stroke.
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BACKGROUND OF THE INVENTION
This is a division of application Ser. No 847,302, filed Apr. 2, 1986.
The present invention relates to ceramic substrates for microelectronic circuits and to a process for producing the substrates. More particularly, the invention is directed to a ceramic substrate having a specially low dielectric constant, low coefficient of thermal expansion and high mechanical strength and permitting wiring thereon with a high-melting metallic conductor, and to a process for producing such ceramic substrates.
In recent years, with the increasing integration degree of semiconductor devices, there are growing needs for circuit substrates supporting such devices to accept higher-density wiring and to have higher performance characteristics, higher reliability, and so forth. In particular, subjects important to circuit substrates for use in electronic computers and the like are high-speed signal propagation and high reliability. For these substrates, there are used, in practice, ceramics composed mainly of alumina (Al 2 O 3 ).
Desired characteristics of the ceramic to be used for such circuit substrates are generally as follows:
(1) The ceramic insulator is dense and has a hermetic nature. This matter relates to the overall reliability of the circuit substrate.
(2) The coefficient of thermal expansion of the ceramic is as close as possible to that of silicon chips. This is for the purpose of minimizing strain which will develop at the junction between the ceramic substrate and the silicon chip to prolong the joint life and enhance the reliability.
(3) The dielectric constant of the ceramic is minimized. This is for speed-up of the signal propagation.
(4) Junction of conductor metals to the ceramic substrate is strong, that is, the metallized bond strength is high. This relates to the bond strength between the circuit substrate and the output or input terminal.
(5) The ceramic has a high mechanical strength. This is necessary for handling in the process for fabricating the substrate and for mounting onto a sealing means and a cooling means to the substrate.
Thus the material to be used for the circuit substrates should satisfy the above requirements simultaneously. In particular, circuit substrates each loaded with several tens densely integrated semiconductor components for use in electronic computers will be inapplicable practically if any one of the above items is not satisfied.
Conventionally Al 2 O 3 is used for substrates of this type. Although it is satisfactory in hermetic nature, metallized bond strength and mechanical strength, it has a higher coefficient of thermal expansion of 8×10 -6 /°C. than that of silicon chips (3×10 -6 /°C.) and also has a high dielectric constant of about 10. Accordingly, Al 2 O 3 is not suitable for circuit substrates.
Known ceramic insulators having a lower coefficient of thermal expansion and dielectric constant than that of Al 2 O 3 include silica (SiO 2 , ε=ca. 4 ), cordierite crystal (5SiO 2 .2Al 2 O 3 .2MgO, ε=ca. 5.0), cordierite glass (ε=6.3), steatite (MgO.SiO 2 , ε=6.3), forsterite (2MgO.SiO 2 , ε=6.5), and mullite (3Al 2 O 3 ·2SiO 2 , ε=7).
However, the coefficient of thermal expansion of SiO 2 and cordierite crystal are very low, i.e., as low as 5×10 -7 /°C. and 1.5×10 -6 /°C., respectively and those of steatite and forsterite are 7.2 and 9.8 (room temperature -400° C.), respectively, which are nearly equal and higher than that of Al 2 O 3 . The coefficient of thermal expansion of cordierite glass is about 3.7×10 -6 /°C., which is close to that of silicon chips, but the mechanical strength of cordierite glass is as low as 100 MPa, so that the cordierite glass is impractical for circuit substrate purposes.
Mullite is somewhat unsatisfactory in dielectric constant and coefficient of thermal expansion, but it has a high mechanical strength of 350 MPa, which is thus most promising among the conventional ceramics.
However, mullite has the following inherent problems (1) and (2):
(1) Bond strength between mullite and a usual conductor metal is markedly low. This is because no chemical reaction occurs between mullite and either tungsten (W) or molybdenum (Mo), which is used commonly as a conductor metal on alumina substrates and the like, even at elevated temperatures. This property is inherent in mullite.
(2) Highly strengthening of the above-mentioned bond requires a special powder of mullite and a special sintering method which are impractical as well as expensive. That is, K. S. Mazdiyasni and L. M. Brown ["Synthesis and Mechanical Properties of Stoichiometric Aluminum Silicate (Mullite)", J. Am. Ceramic Soc., 55[11], 548-555 (1972)] obtained a sintered mullite body capable of forming a high strength by compacting a fine powder of mullite and sintering the compacted body at a temperature as high as 1800° C.
It is very difficult, however, to form such a powder in green sheets (before sintering), which are preforms of circuit substrates. Moreover, the sintering temperature of 1800° C. is much higher than those used for usual substrates, e.g., 1500° to 1650° C. This is a significant bottleneck in practicing this method in view of also the heating elements and heat insulator of the furnace.
While mullite is inherently hard to sinter, as described above, there has long been used a method referred to as "liquid phase sintering" which has been reduced into practice for producing sintered hard alloys.
The typical sintered hard alloy is composed of tungsten carbide (WC) and cobalt (Co). Although WC is difficult to sinter in single form, it can be made into a high-density sintered body when burned jointly with several percentages of cobalt. This is because cobalt is melted in the sintering step and the melted cobalt draws WC in the solid phase thereto by the surface tension thereof.
This liquid phase sintering method is also applied to the sintering of Al 2 O 3 for producing circuit substrates therefrom. That is, usual Al 2 O 3 particles of several μm in size are hard to sinter, but they can be densely sintered according to the liquid phase sintering mechanism by addition of a material (an eutectic composition of three or four components such as SiO 2 , Al 2 O 3 , MgO, and CaO) fusible at a far lower temperature than is Al 2 O 3 .
In the above two examples, both cobalt and the three- or four-component eutectic composition, which generate a liquid phase, play the role of promoting the sintering of a hardly sinterable substance. Nevertheless, the former is called a binder and the latter a sintering aid, in general.
The reason for the above is as follows: In the case of the WC-Co sintered hard alloy, WC crystal grains are strongly bonded together through metallic cobalt, and the high hardness and high toughness of this alloy can be altered optionally with the combination of hard and brittle WC and tough cobalt. Thus the binder function of cobalt is very effective.
In the case of the Al 2 O 3 circuit substrate, the sintering of Al 2 O 3 can be greatly promoted by addition of the three- or four-component eutectic composition, but the original properties of Al 2 O 3 are scarcely varied by this addition. Therefore, the three- or four-component eutectic composition is generally called a sintering aid.
From the above described point of view, studies of sintering aids for mullite have been made for the purpose of solving difficulties in sintering mullite ceramics. Of course, these studies are all intended to make denser the texture of mullite according to the liquid phase sintering mechanism by using cordierite as another sintering aid.
For instance, in Japanese Patent Laid-Open No. 139709/80 and in "Preparation and Properties of Mullite-Cordierite Composites" [B. H. Mussler and M. W. Shafer, Am. Ceram. Soc. Bull., 63, 705 (1984)], discussion is given on the use of mullite as a matrix and cordierite as a sintering aid.
From the equilibrium diagram of the SiO 2 -Al 2 O 3 -MgO system, it can be seen that the melting point of 5SiO 2 .2Al 2 O 3 .2MgO is 1490° C., which is far lower than the melting point (1830° C.) of mullite. Thus the mullite texture has been made denser by the liquid phase sintering action, yielding a sintered body of zero % water absorption.
While the sintering aid used in Japanese Patent Laid-Open No. 139709/80 and the B. H. Mussler et al article are equally referred to as cordierite, it is not clear from the former whether the cordierite is crystalline or amorphous, and B. H. Mussler et al use crystalline cordierite.
Cordierite either in a crystalline or amorphous form has a lower coefficient of thermal expansion and a lower dielectric constant than those of mullite as stated above. Accordingly, it is expected that the addition of cordierite to mullite will lower the coefficient of thermal expansion and dielectric constant of mullite as well as produce the sintering promoting effect.
In the Laid-Open No. 139709/80, a sintered body having a coefficient of thermal expansion ranging from 4.2×10 -6 to 3.8×10 -6 /°C. and dielectric constant ranging from 6.7 to 6.5 is obtained when the proportion of cordierite to mullite is altered from 3.63 to 36.2% by weight.
In the Laid-Open No. 139709/80, while cordierite is incorporated into a mullite crystal matrix, the composition range within which the above-mentioned characteristics are obtained is expressed in terms of MgO, Al 2 O 3 +SiO 2 , and the weight ratio of Al 2 O 3 /SiO 2 . Such expression of composition is obviously inappropriate for sintered bodies made denser by the liquid phase sintering mechanism and for sintered bodies all the characteristics of which are dependent on Al 2 O 3 crystal matrix It is reasonable to express the compositions of sintered mullite-cordierite bodies in terms of the proportion of cordierite to mullite.
According to the article of B. H. Mussler et al., sintered bodies having a coefficient of thermal expansion ranging from 4.5×10 -6 to 3.2×10 -6 /°C. and dielectric constant ranging from 5.7 to 4.8 are obtained when the proportion of crystalline cordierite to mullite is altered from 17.1 to 76.8% by weight.
In the two prior art examples described above, the obtained sintered bodies, when used for circuit substrates, are nearly satisfactory in air tightness, coefficient of thermal expansion and dielectric constant.
The mechanical strength of ceramics, that is, one of the characteristics required for circuit substrates is not described in the two prior art examples. Hence, it is doubtful whether these prior art ceramics are satisfactory in strength when used as circuit substrates.
Moreover, no result of investigation on metallized bond strength is described in the prior art examples. Simultaneous aggregative sintering of a conductor metal with an insulator ceramics is indispensable particularly for fabricating multilayer circuits comprising a number of substrates. Nevertheless, no description is given on the metallized bond strength in the prior art examples. It is a fatal matter in using these ceramics for circuit substrates if the metallized bonds thereof are weak.
The reason for giving no result about the metallized bond strength in the prior art examples may be that the sintering aids used in the examples have fundamental defects which affect the metallizing of mullite substrates.
Since mullite does not react chemically with any of such high-melting metals as W and Mo, the liquid phase penetration method that is applied to Al 2 O 3 substrates and the like is indispensable in order to join firmly such metals with mullite.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a ceramic circuit substrate which can overcome the above noted drawbacks of the prior art, has a dense texture, coefficient of thermal expansion closest to that of silicon, sufficiently lower dielectric constant than that of Al 2 O 3 , and high mechanical strength and can be joined firmly to such high-melting metals as W and Mo.
It is another object of the invention to provide a process for producing such ceramic substrates.
The present invention is based on the finding of a novel binder for sintering mullite which is satisfactory in any of the compacting action based on the liquid phase sintering mechanism, improvements of ceramics in properties, and strong joining of ceramics to conductor metals by the liquid phase penetrating action.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the ability of a liquid to wet a solid;
FIG. 2 shows the relation of a SiO 2 content in binder to a melting point of binder;
FIG. 3 shows the relation of a SiO 2 content in binder to a binder contact angle on mullite;
FIG. 4 shows the relation of a SiO 2 content in binder to a binder contact angle on each of W and Mo;
FIG. 5 shows the relation of a binder-to-mullite proportion to a coefficient of thermal expansion of mullite-binder sintered composition;
FIG. 6 shows the relation of a binder-to-mullite proportion to a dielectric constant of mullite-binder sintered composition;
FIG. 7 shows the relation of a SiO 2 content in binder to a dielectric constant of mullite-binder sintered composition;
FIG. 8 shows the relation of a binder-to-mullite proportion to a flexural strength of mullite-binder sintered composition;
FIG. 9 shows the relation of a SiO 2 content in binder to a flexural strength of mullite-binder sintered composition;
FIG. 10 shows the relation of a SiO 2 content in binder to a porosity of mullite-binder sintered composition;
FIG. 11 shows the relation of a sintering temperature to a flexural strength for a mullite-binder composition;
FIG. 12 is a microscopic photograph showing the fine structure of a ceramic substrate according to the present invention;
FIG. 13 is a microscopic photograph showing the fine structure of a ceramic substrate-W conductor junction according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The basic concept of the present invention will be described below. The binder to be used in the present invention needs to meet the following requirements:
(1) In order to sinter mullite densely by the liquid phase sintering mechanism, the melting point of the binder should be lower than that of mullite chemical reaction should occur slightly between mullite and the binder at suitable sintering temperatures, and mullite crystal grains should be wetted sufficiently by the molten binder.
(2) In order to join a conductor metal to mullite by the liquid phase penetrating action, the binder in a molten form mentioned in (1) above should wet sufficiently the conductor metal.
(3) Similarly to the cobalt in the WC-Co alloy, the binder should have effects of improving mullite in properties such as a coefficient of thermal expansion, dielectric constant, and mechanical strength.
To summarize the above requirements, the binder to be used in mullite-based circuit substrates needs to have a sufficiently lower melting point than does mullite, the binder in a molten form should wet sufficiently the conductor metal and mullite crystal grains, and the binder should contain much SiO 2 , in other words, the matrix of the binder should be SiO 2 which, among heat-resistant inorganic simple materials, has the lowest coefficient of thermal expansion and dielectric constant.
Now description is given on the wettability, which has an important connection with the present invention. FIG. 1 illustrates shapes of molten droplets 2 placed separately on solid plates 1. In the figure, θ is called contact angle. At θ>90° (FIG. 1(a), it is said that the plate is not wetted, and at θ<90° (FIG. 1(b) it is said that the plate is wetted. For the present invention, the conductor metals and mullite crystal grains correspond to the solid plates, and the binder corresponds to the molten droplets, in FIG. 1.
Generally, in order to densify a solid by the liquid phase sintering, the condition of θ≃90° is insufficient and the condition of θ≦50° is usually required. In consequence, the binder to be used for mullite circuit substrates is desired to exhibit θ≦50° is usually required. In consequence, the binder to be used for mullite circuit substrates is desired to exhibit θ<50°.
The present invention is illustrated in more detail with reference to the following examples.
EXAMPLE 1
FIG. 2 shows the relation of melting point to SiO 2 content (wt %) measured on the binder compositions according to the present invention for use in mullite circuit substrates. For the purpose of lowering the coefficient of thermal expansion and dielectric constant of mullite by addition of a binder, the SiO 2 content in the binder must be at least 50% by weight, but with a 100% SiO 2 content a melting point is 1740° C., which is too high to sinter materials for circuit substrates. Hence the binder of 100% SiO 2 is impractical.
The principle of melting point depression by addition of second and third elements to SiO 2 is utilized for the purpose of maintaining at least 50% SiO 2 content in a binder and putting the melting point of the binder within the usual sintering temperature range of 1550° to 1770° C. for circuit substrates metallizable with tungsten or molybdenum.
In view of the above, binders were prepared by altering the SiO 2 content from 50 to 90 wt. %, as shown in FIG. 2, the Al 2 O 3 content from 35 to 4 wt. %, and the MgO content from 15 to 1 wt. %.
Binders of these compositions were heated to 1650° C., droplets of the resulting molten binders were placed on plates of mullite sintered in a single form, and the contact angles were measured. Results thereof are shown in FIG. 3. The contact angles are up to 50° so far as the SiO 2 content in each binder lies in the range of 50 to 90 wt. %.
Further, droplets of the molten binders were placed on molybdenum and tungsten metal plates and the contact angles were measured. Results thereof are shown in FIG. 4, wherein curve 1 is on molybdenum and curve 2 on tungsten.
Comparing the results shown in FIGS. 2, 3, and 4 with the foregoing requirements for the binder to be used in mullite circuit substrates, it can be seen that among the binder compositions shown in FIG. 2, those containing 50 to 90 wt. % of SiO 2 exhibit contact angles of up to 50° on mullite and on molybdenum and tungsten metals at sintering temperatures of 1550° to 1660° C. The contact angle of a binder is desired to be as small as possible when the binder is used for sintering mullite, tungsten, or molybdenum. Therefore, it is concluded from FIGS. 3 and 4 that the preferred range of SiO 2 contents in the binder is from 60 to 80 wt. %.
In the next place, FIG. 5 shows coefficients of thermal expansion (room temperature - 500° C.) of mullite-binder sintered compositions, the coefficients having a great influence on the junction between the resulting circuit substrates and silicon chips. The coefficients of thermal expansion shown in FIG. 5 were of sintered bodies prepared by mixing mullite with various proportions of a binder having a definite composition (SiO 2 90 wt. %, Al 2 O 3 7.0 wt. %, MgO 3.0 wt. %) and sintering the mixtures at 1620° C. for 1 hour. From FIG. 5, desirable proportions of the binder to mullite are found to be from 10 to 30 wt. %.
As is clear from the above, the coefficient of thermal expansion increases with the proportion of the binder to mullite. The coefficient of the sintered body containing no binder was measured by K. S. Mazdiyasni and L. M. Brown. Such a change in coefficient of thermal expansion as shown in FIG. 5 is due to the larger coefficient of the binder than that of mullite.
It is known that the coefficient of thermal expansion of a substance generally depends on the composition and crystal structure of the substance and the coefficient of thermal expansion of a substance in a noncrystalline or amorphous form is larger than that of the substance in a crystalline form. Examination revealed that the binder used in the above-mentioned measurement of a coefficient of thermal expansion was noncrystalline and microscopically in a glass state. From these facts it may be said that binders used in the present invention are noncrystalline.
Then, coefficients of thermal expansion were measured similarly but by altering the binder composition in the range shown in FIG. 2 while constantly maintaining the mullite-to-binder ratio within a range of 75:25. The results indicated that the coefficient of thermal expansion decreased from 5.7×10 -6 /°C. to 4.8×10 -6 /°C. as the SiO 2 content was increased.
According to the prior art example, i.e., Japanese Patent Laid-Open No. 139709/80, the coefficient of thermal expansion of mullite is decreased greatly by adding cordierite as a sintering aid. This is considered to result from the extremely smaller coefficient of thermal expansion of crystalline cordierite, used as the sintering aid, than that of mullite.
It can been seen from the foregoing that the coefficient of thermal expansion of the ceramics according to the present invention is much smaller than that of the prior art Al 2 O 3 substrate and hence very effective in enhancing the reliability of junction between the circuit substrate and the Si chip.
FIG. 6 shows the measurements of dielectric constants (1 MHz) for the same mullite-binder sintered compositions as used in FIG. 5. FIG. 7 shows results of mullite-binder sintered compositions prepared by altering the binder composition as shown in FIG. 2 while constantly maintaining the mullite-to-binder ratio within a range of 75/25. From FIG. 6 it seems that desirable binder-to-mullite proportions minimize the dielectric constant; however, suitable values of said proportions are from 10 to 30 wt. % in consideration of the balance between the dielectric constant and other properties of the sintered product. While desirable binder compositions selected from FIG. 7 also seems to lower the dielectric constant, suitable SiO 2 contents for binders are from 60 to 90 wt. %. In this composition range, the dielectric constant is stable without notable variation.
As shown in FIGS. 6 and 7, the dielectric constant decreases greatly from the original value of mullite as the binder proportion and the SiO 2 content in binders are increased. Of the dielectric constant values in FIG. 6, that of the composition containing no binder is measured by K. S. Mazdiyasni and L. M. Brown.
The effect of binders in ceramic substrates of the present invention, outlined above, is slightly inferior on the coefficient of thermal expansion and dielectric constant of ceramics to the effect of sintering aid used in the two prior art examples mentioned before. This is because the present invention employs noncrystalline binders while the prior art examples employ crystalline sintering aids.
However, these slightly reduced coefficient of thermal expansion and dielectric constant do not matter in overall consideration of characteristics required for circuit substrates. That is, the most important subjects for putting a ceramic circuit substrate into practical use are the mechanical strength of the ceramic substrate and the bond strength between the ceramic substrate and the conductor metal, which are described below.
FIG. 8 shows the results of three-point bending tests for flexural strength, which is one of the characteristics required for circuit substrates, on the same samples as in FIG. 5. FIG. 9 shows the results of the above-mentioned bending tests on the same samples as in FIG. 7. Ceramics having flexural strengths of at least 15 kg/mm 2 , which is necessary for circuit substrates, are found from FIG. 8 to have binder-to-mullite proportions of 10 to 35 wt. %, preferably 15 to 30 wt. %, and are bound from FIG. 9 to have SiO 2 contents of 50 to 95 wt. %, preferably 65 to 90 wt. %, in each binder.
Decrease, as shown in FIG. 8, in flexural strength when the binder proportion exceeds 30 wt. % seems to be caused by the lower strength of the binder itself than that of mullite. Also decrease, as shown in FIG. 9, in flexural strength when the SiO 2 content in each binder exceeds 90 wt. %, seems to be caused by the inhibition of mullite compaction by the increased amounts of SiO 2 .
One of the factors controlling the flexural strength of ceramics is insufficient compaction in sintering ceramics which leaves pores in sintered bodies. It is known that the strength of sintered bodies increases with decrease in the porosity thereof. FIG. 10 shows the porosities of the same samples as in FIG. 9. As is seen from FIG. 10, the porosity is up to 5% when the SiO 2 content in each binder ranges from 60 to 90 wt. %; these results are well consistent with the flexural strengths I shown in FIG. 9. Thus, the desirable range of SiO 2 contents is from 65 to 90 wt. %. Of course, the ceramics according to the present invention are hermetic in the range of binder compositions shown in FIG. 10.
It is also known that the strength of composite materials like the ceramics according to the present invention is generally much dependent on the difference in a coefficient of thermal expansion between the matrix and the binder, besides on the above-mentioned pores remaining in the composite materials. When the coefficient of thermal expansion of the matrix is much larger than that of the binder, high tension is exerted on the binder in the cooling stage after sintering. This internal stress causes a marked decrease in the strength of the entire composite material.
Considering the strength of the ceramics according to the present invention in the light of the above mentioned mechanism of decreasing the strength, the coefficient of thermal expansion of the present binder is believed to be considerably close to that of the matrix mullite. This is due to the noncrystalline structure of the binder used in the present invention and is a natural consequence in consideration also of the foregoing example of cordierite, which indicates that the coefficient of thermal expansion of a noncrystalline substance is considerably larger than that of the crystalline substance.
Finally, explanation is made on the results of tests for the ceramic-conductor metal junction, i.e., the metallized bond strength, which is an essential requirement for circuit substrates.
Since no chemical reaction occurs between ceramic mullite and either tungsten or molybdenum even at such a high temperature as 1650° C. (in a reducing atmosphere) as stated before, some amount of a liquid phase is necessary, in other words, the liquid phase penetration mechanism must be utilized, in order to join these materials firmly.
Usually, multilayer circuit substrates have a structure in which ceramic insulative layers and conductor metal layers are superposed alternately one upon another. For substrates of such a structure, it is ideal that the composition of the liquid phase for joining the ceramic to the conductor metal is identical with the composition of the binder for sintering the ceramic densely. The foregoing results shown in FIGS. 3 and 4 reveal that the binder according to the present invention has a sufficient wettability for both mullite and tungsten or molybdenum. Green sheets of ceramics were prepared from mixtures of mullite and 28 wt. %, based on the mullite, each of binders having the same compositions as shown in FIG. 4. Marks of 2 mm square were printed on these green sheets with each of tungsten and molybdenum conductor pastes. The resulting sheets were sintered at 1630° C. for 2 hours to prepare specimens. These specimens were measured for the strength of metallized bonds. The bond strengths were 1.5 to 5 kgs for tungsten and 1.0 to 4.0 kgs for molybdenum.
The metallized bond strength of circuit substrates is generally desired to at least 1 kg. Hence, the ceramics according to the present invention are found to be sufficient for practical use. The above-mentioned high metallized bond strength is caused by nothing but the molten binder, according to the present invention, which has a small contact angle on mullite as well as on tungsten and molybdenum metals, thus fully exhibiting the liquid phase penetrating effect.
The used paste is composed of a high-melting metal such as tungsten or molybdenum, solvent, and organic vehicle. The mixing proportions of these three components vary somewhat depending upon the desired conductivity. Generally the proportions are 70 to 85 wt. % of the high-melting metal, 10 to 29 wt. % of a solvent, and 1 to 5 wt. % of an organic vehicle. Desirably the high-melting metal has an average particle size of 0.5 to 2.0 μm and a purity of at least 99.9%.
The capability of sintering simultaneously the ceramic insulator and the conductor is of great advantage in controlling a process for fabrication of electronic computer circuit substrates to be used for multilayer wiring, and in reducing production costs.
EXAMPLE 2
FIG. 11 shows the relation between flexural strength and sintering temperature examined on a mullite-based ceramic. Test specimens were prepared from a mixture of 80 wt. % of mullite and 20 wt. % of a binder composed of 90 wt. % of SiO 2 , 7 wt. % of Al 2 O 3 , and 3.0 wt. % of MgO. The specimens were sintered at different temperatures for 60 minutes in a reducing atmosphere.
As is seen from FIG. 11, ceramics according to the present invention sintered at a temperature of 1550° to 1700° C. have a flexural strength of at least 15 kg/mm 2 which is required by circuit substrates. Preferred sintering temperatures is from 1600° to 1700° C. These results are also connected to the binder-wettability of mullite and the like. It is a matter of course that the above suitable range of sintering temperatures is restricted by the melting temperature of a binder having the compositions as shown in FIG. 2 and by the contact angle of the binder on mullite at various temperatures.
EXAMPLE 3
Explanation is made below on the circuit substrates of the present invention, fabricated by the green-sheet lamination method.
A commercial mullite powder having an average particle size of 2 μm and a binder powder (having a particle size of 1-3 μm) composed of 60 wt. % of SiO 2 , 30 wt. % of Al 2 O 3 , 10 wt. % of MgO are thoroughly mixed in respective proportions of 70 wt. % and 30 wt. % by means of a wet type ball mill. An organic binder, plasticizer and dispersion medium are added as compacting aids. The organic binder is polyvinyl butyral, acrylic ester or the like; the plasticizer is phthalic ester or the like; the dispersion medium is alcohol, trichloroethylene or the like.
The slurry obtained by addition of these compacting aids is compacted by, for example, the doctor blade method. This method is carried out by coating a slurry to a uniform thickness on a base film (carrier tape), drying the coat to solid, and separating the solid coat from the base film to yield a raw material sheet for ceramics, usually called a green sheet.
The thickness of the mullite-based sheets prepared in the above method is from 0.15 to 0.25 mm so as to meet the dielectric constants required for circuit substrates. Then holes are formed by punching or other suitable ways through the green sheets for the purpose of later wiring through the multilayer substrates. These through holes are filled with a tungsten paste prepared by adding a resin and a solvent to a tungsten metal powder having an average particle size of 1 μm. The tungsten paste used herein is composed of, for example, 77.5 wt. % of a tungsten powder (a purity of at least 99.9% and average particle size of 1±0.5 μm), 20 wt. % of diethylene glycol mono-n-butyl ether acetate, 2.0 wt. % of ethyl cellulose, and 0.5 wt. % of polyvinyl butyral.
Then, intended patterns are printed with a similar tungsten paste on the green sheets for wiring of outermost circuit layers and inner circuit layers. Molybdenum also may be used in place of tungsten for the paste.
20 ceramic green sheets thus wired are super-posed one upon another, and hot-pressed under a pressure of about 50 kg/cm 2 at 110° C. to form a laminate of ceramic green sheets. This laminated body is sintered at 1580° C. for 5 hours in a humidified atmosphere of hydrogen to yield mullite-based multilayer circuit substrates wired with tungsten conductor.
The obtained circuit substrates exhibited a water absorption of zero %, coefficient of thermal expansion of 5.4×10 -6 /°C., dielectric constant of 6.1, and flexural strength of 20 kg/mm 2 . Cross sections of the substrates were observed with a microscope to examine the fine structure. As shown in FIG. 12, these substrates were found to have a structure in which mullite particles are surrounded with the binder. The characteristic and effect of the present invention were confirmed readily from FIG. 12.
EXAMPLE 4
Multilayer circuit substrates were prepared in the same manner as in Example 3 by forming green sheets from a mixture of 80 wt. % of mullite (the same powder as
used in Example 3) and 20 wt. % of a binder (SiO 2 90 wt. %, Al 2 O 3 7.0 wt. %, MgO 3.0 wt. %), forming through holes and circuit patterns, laminating 25 resulting sheets, and sintering the laminate at 1620° C. for 2 hours in a humidified atmosphere of hydrogen.
The obtained substrates exhibited a water absorption of zero %, coefficient of thermal expansion of 5.2×10 -6 /°C., dielectric constant of 5.9, and flexural strength of 25 kg/mm 2 . Cross sections of these substrates were observed with a microscope to examine internal wiring between the substrate layers It was confirmed therefrom that the ceramic layers and conductor metal layers were united completely as shown in FIG. 13. This completely united state results from the densification of mullite being performed in the sintering step by the binder added and from the tungsten layers being penetrated sufficiently with the binder.
EXAMPLE 5
Multilayer circuit substrates were prepared in the same manner as in Example 3 by forming green sheets from a mixture of 85 wt. % of mullite (the same powder as used in Example 3) and 15 wt. % of a binder (SiO 2 93 wt. %, Al 2 O 3 4 wt. %, MgO 1 wt. % , forming through holes and circuit patterns, laminating 18 resulting sintering the laminate at 1660° C. for 1 hour in a humidified atmosphere of hydrogen.
The obtained substrates exhibited a water absorption of zero %, coefficient of thermal expansion of 4.6×10 -6 /°C., dielectric constant of 5.7, and flexural strength of 21 kg/mm 2 . Input and output terminals of Kovar metal were fixed with a brazing material on the upper surface of the substrates and a tensile test was conducted so as to apply stress between the substrate and each terminal. The result showed that all breaks occurred within the ceramic substrate and the mode of breaks was similar to that of usual alumina substrates. This indicates that the substrates of this example are sufficient for practical use.
According to the present invention, it is possible to produce circuit substrates which are dense and superior in thermal and electrical properties ot conventional alumina substrates, that is, have very low coefficients of thermal expansion of 4.5 to 5.5×10 -6 /°C. and very low dielectric constants of 5.5 to 6.2, additionally have sufficient flexural strengths of 15 to 25 kg/mm 2 , and can be sintered simultaneously with a conductor metal such as W and Mo for wiring to be united therewith into a single body. Therefore, the present substrates have such distinct effects that the signal propagation speed can be increased by at least 25% as compared with conventional alumina sustrates, reliability also is hightened at the junctions between the substrate and the Si chip and between the substrate and either of input and output terminals, the economy is made better, and the process is stabilized.
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A ceramic substrate for densely integrated semiconductor arrays which is superior in a coefficient of thermal expansion, dielectric constant, strength of metallized bond, and mechanical strength, comprising a sintered body composed essentially of mullite crystals and a non-crystralline binder composed of SiO 2 , Al 2 O 3 , and MgO, is provided.
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This application is a division of U.S. patent application Ser. No. 09/709,002, filed Nov. 8, 2000, now U.S. Pat. No. 6,430,908.
The present invention relates to hitches for towed implements and more specifically a relates to self-leveling hitch and clevis arrangements adapted for being hitched to a tractor drawbar.
BACKGROUND OF THE INVENTION
Tractor drawn implements, of which a pull-type rotary cutter is one example, require the implement hitch to be coupled to the tractor drawbar in such a way as to allow for rotation in three directions (turning, twisting and pitching). To accommodate pitching, a horizontal pivot is required which in turn allows the clevis to hang down resulting in chucking and excessive clevis/drawbar wear. Chucking can also cause premature driveline failures. Two examples of designs which attempt to address these problems are respectively disclosed in U.S. Pat. No. 3,998,471 granted to Luchemeier on Dec. 21, 1976, and in U.S. Pat. No. 5,386,680 granted to Friesen on Feb. 7, 1995.
On some cutters, a link is pivotally attached between the mower deck and the clevis so as to form a parallel linkage with the hitch, thus resulting in the clevis being self-leveling as the cutter is raised and lowered, but this system does not allow for rotation during twisting or pitching except for the clearance between the drawbar pin and the slots in the clevis. With self-leveling, the clevis still rotates on the drawbar resulting in drawbar wear.
SUMMARY OF THE INVENTION
According to the present invention, there is provided an improved hitch and clevis assembly which overcomes the drawbacks associated with prior art hitch and clevis assemblies.
A object of the invention is to provide a self-leveling clevis which does not include a separate link for keeping the clevis level.
A more specific object of the invention is to provide a hitch that has separate arms that are coupled between the towed implement frame and the clevis so as to define a parallel linkage that maintains the clevis in a level attitude.
Yet another object of the invention is to provide a hitch and self-leveling clevis assembly which operates such as to permit the clevis to rotate in three directions at its connection with the drawbar.
A further specific object of the invention is to provide a hitch and self-leveling clevis assembly, as set forth in the immediately preceding object, wherein the clevis includes upper and lower halves having opposed surfaces shaped complementary to and engaging a hitch ball containing a vertical hitch pin receiving hole and a horizontal opening adapted for receiving the drawbar of a tractor, whereby the ball provides a surface on which the clevis is pivotable in three directions.
These and other objects will become apparent from a reading of the ensuing description together with the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a left side perspective view, looking slightly downwardly, of the self-leveling hitch extending between a tractor drawbar and the front of a rotary cutter deck.
FIG. 2 is a left front perspective view of the hitch.
FIG. 3 is a right side perspective view of the front end of the hitch showing the ball clevis coupled to the tractor drawbar.
FIG. 4 is a left side view of the self-leveling hitch.
FIG. 5 is a rear view of the self-leveling hitch.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, there is shown a front portion of a towed implement, here shown as a rotary cutter 10 , a drawbar 12 of a tractor (not shown) and a cutter hitch 14 coupling the cutter 10 to the drawbar 12 . Provided for transmitting power from a power take-off shaft (not shown), at a rear location of the tractor and an input shaft (not shown) of a gear box carried at a top location of a deck 16 of the rotary cutter 10 for distributing power for driving cutter blades (not shown) is a shielded, telescopic power shaft 18 .
Right- and left-hand, transversely spaced, upright hitch mounting brackets 20 and 22 , each in the form of transversely spaced parallel plates, are welded to respective upper front locations of the cutter deck 16 located equidistant from a longitudinal, vertical center plane of the rotary cutter 10 . The hitch 14 includes separate upper and lower arm sections 24 and 26 , respectively, having their respective rear ends vertically pivotally coupled to the brackets 20 and 22 , and from which the arm sections converge forwardly (see also FIG. 5) to a ball clevis 28 to which forward ends of the arm sections are individually pivotally coupled.
Specifically, referring now also to FIG. 2, it can be seen that the rear ends of the arm sections 24 and 26 are defined by respective rear connecting portions 30 and 32 , each being in the form of a pair of transversely spaced, vertical, generally triangular plates. The connecting portion 30 is received between, and has an upper rear corner pivotally connected, as by a transverse mounting pin 34 , to an upper forward location of the plates of the hitch mounting bracket 20 . Similarly, the connecting portion 32 is received between and has an upper rear corner pivotally connected, as by a transverse mounting pin 36 , to an upper forward location of the plates of the hitch mounting bracket 22 . Referring now also to FIG. 3, it can be seen that the forward ends of the arm sections 24 and 26 are defined by respective front connecting portions 38 and 40 , each of which are in the form of a pair of transversely spaced straps, with the straps of the connecting portion 38 being disposed above, and in vertical alignment with, the straps of the connecting portion 40 . The clevis 28 is made of identical, upper and lower halves 42 and 44 , respectively, having ring-like forward ends and block-like rear ends. The clevis halves 42 and 44 are clamped to each other by a pair of fore-and-aft spaced bolts 46 extending vertically through the block-like rear ends. The straps of the front connecting portion 38 of the upper arm section 24 straddle, and are pivotally coupled to the block-like rear end of the upper clevis half 42 by a horizontal pivot pin 48 located in a bore located in the clevis half 42 between the spaced bolts 46 . Similarly, the straps of the front connecting portion 40 of the lower arm section 26 straddle, and are pivotally coupled to, the block-like rear end of the lower clevis half 44 by a horizontal pivot pin 50 spaced vertically below the pivot pin 48 . It is here noted that the left-hand end of each of the pins 48 and 50 includes a head defined by a washer welded to the stem of the pin.
As can best be seen in FIG. 4, the pivot pins 34 and 36 , respectively, for coupling the rear ends of the upper and lower arm sections 24 and 26 to the hitch supports 20 and 22 , are spaced vertically from each other by the same distance that the pivot pins 48 and 50 , respectively coupling the front ends of the arm sections to the clevis halves 42 and 44 , are spaced from each other. Thus, it will be appreciated that the separate arm sections 24 and 26 form a parallel linkage which results in the clevis 28 remaining level throughout the vertical pivoting of the arm sections 24 and 26 during operation of the rotary cutter 10 over uneven terrain.
Referring once again to FIGS. 2 and 3, it can be seen that the ring-shaped forward ends of the clevis halves 42 and 44 are respectively engaged with top and bottom portions of a ball 52 . The clevis halves 42 and 44 are provided with respective spherically shaped surface portions (not shown) that are complementary to respective outer surface portions of the ball 52 so that the ball is captured by the clevis halves but is gripped loose enough that the clevis halves slide upon the ball surface. The ball 52 contains an opening 54 which is rectangular in cross section and receives the rear portion of the tractor drawbar 12 . The drawbar 12 is provided with a vertical hole which is aligned with a vertical hole 58 extending through the ball 52 , with a hitch pin 60 being received in these aligned holes so as to connect the hitch 14 to the tractor and to provide a vertical axis about which the hitch 14 may pivot.
Referring now to FIGS. 1, 2 and 5 , there is shown structure for effecting raising or lowering of the clevis 28 , for accommodating tractor drawbars of different heights, by individually inducing a force for lifting or lowering the arm sections 24 and/or 26 about the pivot pins 48 and 50 . Specifically, extending horizontally between and welded to the straps making up the connecting portion 30 of the upper hitch arm section 24 is a rod which defines a stop 62 . A bell crank 64 , in the form of a pair of parallel, generally triangular plates, has a first corner mounted for pivoting about the pivot pin 34 and includes a front corner with the plates straddling and being welded to a threaded cylindrical tube 66 , which receives a cap screw 68 having its lower end engaged with the stop 62 . A jam nut 70 is received on the screw 68 for holding the latter in a desired position of adjustment. The bell crank 64 has a lower rear corner pivotally attached to a clevis forming a forward end of a fore-and-aft extending leveling rod (not shown) having a rear end pivotally attached to a lug fixed to a transverse wheel axle (also not shown) pivotally mounted to a rear location of the deck 16 and held in a desired disposition by a hydraulic motor, or the like. Thus, it will be appreciated that, as viewed in FIG. 2, raising of the hitch 28 from its illustrated position is permitted by withdrawing the screw 68 so as to allow upward movement of the stop 62 about the pin 34 , while lowering of the hitch is permitted by advancing the screw 68 so that the stop 62 engages the screw 68 at a lower location.
Similarly, a bell crank 72 , in the form of a pair of parallel, generally triangular plates having an upper corner mounted for pivoting about the pivot pin 36 , and having a lower front corner arranged with the plates straddling and being welded to a threaded cylindrical tube 74 , which receives a cap screw 76 having its lower end engaged with a stop 78 formed by a rod extending horizontally between and welded to the plates forming the connection portion 32 of the lower arm section 26 . A jam nut 80 is received on the screw 76 and serves to retain it in a desired adjusted position. A lower rear corner of the bell crank 72 is provided with a pair of vertically spaced holes, one of which receives a pin 81 that is captured between the plates forming the bell crank 72 and pivotally attaches the bell crank to a link 82 , which is formed by a pair of parallel straps having upper ends located above the pin 81 and pinned, as at 83 , to a clevis forming a forward end of a second leveling rod (not shown) having a rear end coupled to a second lug fixed to the wheel axle at the rear of the deck 16 . It is here noted that the pin 83 is captured between the plates forming the bell crank 72 and is located at a level approximately equal to that of the connection of the lower rear end of the bell crank 64 with the leveling rod on that side. The link 82 extends downwardly from the pin 81 and has a lower end pivotally attached, as at a pin 84 , to a short link 86 that extends fore-and-aft and has its rear end received between, and pivotally attached, as by a pin 87 , to lower projections of the hitch mounting bracket 22 . Adjustment of the screw 76 results in the hitch arm section 26 , and hence the clevis 28 , being raised or lowered in a manner similar to that effected by adjustment of the screw 68 , as described above.
When it is desired to unhook the hitch 14 from the tractor drawbar 12 , a jack stand (not shown) may be mounted to the clevis 28 . For this purpose, a triangular support plate 88 , as can best be seen in FIGS. 1, 2 and 4 , is mounted to the left-hand side of the clevis 28 by the pins 48 and 50 , it being noted that the welded washers defining the heads at the left-hand ends of the pins 48 and 50 serve to retain the plate 88 in place. Welded to a rear corner location of the plate is a jack stand mounting tube 90 which is provided with a cross hole 92 that serves to receive mounting hardware of the jack stand. Of importance is the fact that, due to being mounted on the pins 48 and 50 , the plate 88 remains in a constant attitude throughout any vertical adjustments made for accommodating drawbars of different heights, with the tube 90 being oriented such that the jack stand, when coupled to it, has a substantially vertical disposition. A mounting tube 94 (see FIG. 1 ), similar in construction to the mounting tube 90 , is provided on the left-hand plate of the support bracket 22 for the purpose of providing a location for storing the jack stand, in a substantially horizontal orientation, during operation of the rotary cutter 10 .
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A rotary cutter includes a hitch comprising upper and lower arm sections which define a parallel linkage extending between the deck of the rotary cutter and a ball clevis forming a forward end of the hitch. The ball clevis includes identical upper and lower halves which include block-like rear portions that are clamped together so that a ball is releasably retained between ring-like front portions of the clevis. Leveling of the deck is accomplished by a pair of adjustable leveling mechanism respectively coupled between rear parts of the separate arm sections and the deck. Provision is made for mounting a jack stand to one side of the clevis and for storing the jack stand on the deck.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority from German Patent Application No. 10 2004 035 771.4 dated Jul. 23, 2004, the entire disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The invention relates to an apparatus at a carding machine, for example but not exclusively, a carding machine having a cylinder which has a cylindrical, clothed wall surface and at least two radial cylinder ends, and having at least one clothed and/or unclothed machine element located opposite the cylinder clothing at a spacing therefrom and two stationary side screens, on which there are mounted holding devices for work elements, for example sliding bends, stationary carding elements, cylinder coverings, which in use are subjected to heat.
[0003] The effective spacing of the tips of a clothing from a machine element located opposite the clothing is called a carding nip. The said machine element can also have a clothing but could, instead, be formed by an encasing segment having a guide surface. The carding nip is decisive for the carding quality. The size (width) of the carding nip is a fundamental machine parameter, which influences both the technology (the fibre processing) and also the running characteristics of the machine. The carding nip is set as narrow as is possible (it is measured in tenths of a millimetre) without running the risk of a “collision” between the work elements. In order to ensure that the fibres are processed evenly, the nip must be as uniform as possible over the entire working width of the machine.
[0004] The carding nip is especially influenced, on the one hand, by the machine settings and, on the other hand, by the condition of the clothing. The most important carding nip in a carding machine having a revolving card top is located in the main carding zone, that is to say between the cylinder and the revolving card top unit. At least one of the clothings bounding the work spacing is in motion, usually both. In order to increase the production of the carding machine, endeavours are made to make the speed of rotation or velocity of the moving elements, in use, as high as fibre processing technology will allow. The work spacing changes as a function of the operational conditions, the change occurring in the radial direction (starting from the axis of rotation) of the cylinder.
[0005] In carding, larger amounts of fibre material are increasingly being processed per unit time, which results in higher speeds for the work elements and higher installed capacities. Increasing fibre material throughflow (production) leads to increased generation of heat as a result of the mechanical work, even when the work surface remains constant. At the same time, however, the technological result of carding (web uniformity, degree of cleaning, reduction of neps etc.) is being continually improved, leading to more work surfaces in carding engagement and to closer settings of those work surfaces with respect to the cylinder (drum). The proportion of synthetic fibres being processed is continually increasing, with more heat, compared with cotton, being produced as a result of friction from contact with the work surfaces of the machine. The work elements of high-performance carding machines today are fully enclosed on all sides in order to meet the high safety standards, to prevent emission of particles into the spinning room environment and to minimise the maintenance requirement of the machines. Gratings or even open material-guiding surfaces, which allow an exchange of air, belong to the past. As a result of the circumstances mentioned, there is a marked increase in the input of heat into the machine whereas there is a marked decrease in the heat removed by means of convection. The resulting increase in the heating of high-performance carding machines results in greater thermoelastic deformations, which, because of the unequal temperature field distribution, influence the set spacings of the work surfaces: the spacings between the cylinder and the card top, doffer, fixed card tops and separating-off locations decrease. In extreme cases, the nip set between the work surfaces can be completely used up as a result of thermal expansion so that components in relative motion collide, causing major damage to the high-performance carding machine concerned. Additionally, it is especially possible for the generation of heat in the work region of the carding machine to result in different thermal expansions when the temperature differences between the components are too large.
[0006] In a known apparatus (EP 0 446 796 A), all parts influencing the work spacing (for example, the cylinder and the card top bars) are preferably fabricated from a material having a high elasticity modulus in order to reduce sagging over the working width. Such a material is, for example, steel or fibre-reinforced plastics material. The material selected has to ensure the desired dimensional accuracy of the part (in the case of the manufacturing procedure in question) and has to be able to maintain that in use. The material should accordingly exhibit less thermal expansion and/or greater thermal conductivity so that heat losses which occur (which are unavoidable at high production rates) do not result in disruptive deformation of the work elements. In the case of the known apparatus, the thermal expansion of the co-operating components influencing the work spacing, namely that of the cylinder (drum) and of the card top bars, is equal and homogeneous, because the components are made of the same material. Even though the material should exhibit less thermal expansion, the carding nip is reduced in undesirable manner—albeit to a small extent—which results in problems ranging from reduced carding quality to disruptions in operation. In addition, it is disadvantageous that widening of the cylinder as a result of centrifugal force cannot be reduced or avoided by the known measures.
[0007] It is an aim of the invention to provide an apparatus of the kind mentioned at the beginning that avoids or mitigates the mentioned disadvantages and that especially makes possible a carding nip or work spacing, between the cylinder clothing and the clothed and/or not clothed counterpart element, that remains constant or virtually constant when heat is generated.
SUMMARY OF THE INVENTION
[0008] The invention provides a carding machine having a carding nip and a plurality of machine elements that influence the carding nip, in which at least first and second machine elements influencing the carding nip are constructed to have thermal expansion characteristics which are such that when the first and second machine elements are subjected to heat generated in operation of the carding machine, the carding nip remains substantially constant.
[0009] In one preferred embodiment, the machine comprises first and second elements influencing the carding nip which are so constructed that, when subjected to heat generated in operation, they undergo no thermal expansion. In another preferred embodiment, at least one of said machine elements undergoes negative thermal expansion when subjected to heat in use. In a further preferred embodiment, at least one of said machine elements undergoes positive thermal expansion when subjected to heat in use.
[0010] In accordance with a first aspect of the invention, the parts influencing the carding nip (work spacing) (for example, the cylinder, the carding bars and the holding elements for the carding bars) are so constructed that they exhibit no, or virtually no, thermal expansion under the heat of operation. As a result, the carding nip does not change. In accordance with a second aspect of the invention, at least one part influencing the carding nip exhibits negative thermal expansion (contraction) so that a change in the carding nip caused, for example, by positive thermal expansion of a part influencing the carding nip is compensated. This is especially the case when the carding-nip-influencing carrying elements provided with clothings are located opposite one another and one carrying element, for example the cylinder, undergoes positive expansion as a result of heating and the other carrying element, for example the carding bars (card top bars), in contrast undergoes negative expansion, that is to say contracts and, to a certain extent, recedes. In accordance with a third aspect of the invention, at least one part influencing the carding nip exhibits positive thermal expansion (widening) so that a change in the carding nip caused, for example, by positive thermal expansion of a part influencing the carding nip is likewise compensated. This is especially the case when the carding-nip-influencing carrying elements are arranged next to one another and one carrying element, for example the cylinder, undergoes positive expansion as a result of heating and the other carrying element, for example the flexible bends, likewise undergoes positive expansion, that is to say becomes wider and as a result raises the card top bars relative to the cylinder. According to all three aspects of the invention, the carding nip remains the same or virtually the same in use.
[0011] Advantageously, a part influencing the carding nip, for example a flexible bend, is so constructed that it exhibits positive thermal expansion in use. Preferably, a part influencing the carding nip, for example a card top bar, is so constructed that it exhibits negative thermal expansion in use. Advantageously, the positive thermal expansion of a part influencing the carding nip is compensated by the negative thermal expansion of the corresponding counterpart element. Preferably, a part influencing the carding nip is so constructed that it exhibits no thermal expansion in use. Preferably, the carding nip is influenced by the cylinder and the at least one carding element. Advantageously, the carding nip is influenced by the holding device for the at least one carding element. Preferably, the holding device for the at least one carding element is formed by at least one element of the side part. Advantageously, the side part consists of a side screen and at least one guide element (flexible bend). Preferably, the side part consists of a side screen and at least one extension bend. Advantageously, the clothed machine elements are revolving card tops. Preferably, the clothed machine elements are stationary card tops. Advantageously, the cylinder is made, at least in part, of steel. Steel ensures the stability of the cylinder and has relatively high resistance to bending. Preferably, the cylinder is made, at least in part, of aluminium. Aluminium likewise ensures the stability of the cylinder and has a relatively low specific weight. Preferably, the material for the parts influencing the carding nip is, at least in part, a carbon fibre-reinforced plastics material (CFRP). Carbon has a density of 1.45 g/cm 3 . The basic material comprises carbon fibres. The latter can be produced from plastics filaments, which are heated in the absence of air and consequently “carbonised”. For example, they have a diameter of 0.007 mm. These fibres are embedded in a carrier substance (matrix) of synthetic resins. The forces acting on carbon fibres are taken up by the fibres substantially only in the line of force flux. The fibres are therefore mainly laid in parallel. If bending and torsional stresses do not come from just one direction, individual layers of fibres are advantageously placed on top of one another in different orientations. Preferably, the thermal expansion coefficient of the carbon fibre reinforced plastics material (CFRP) is adjustable. Zero adjustment means no change and negative adjustment results in contraction so that no thermal expansion or negative thermal expansion of the component(s) is produced. By that means, the materials of the cylinder and, for example, the side parts are so matched to one another that, under the heat acting on the parts influencing the carding nip in use, the carding nip remains constant. Advantageously, the cylinder of the carding machine comprises a metal cylinder and at least one circular cylindrical sheath made of carbon fibre reinforced plastics material (CFRP) surrounding the cylinder. Preferably, the flexible bend and/or the extension bend is/are made at least in part of carbon fibre reinforced plastics material (CFRP). Advantageously, the flexible bend and/or the extension bend is provided with a support (layer) of carbon fibre reinforced plastics material (CFRP). Preferably, the cylinder is made of a metallic material, for example steel, and the flexible bend and/or the extension bend is/are made at least in part of carbon fibre reinforced plastics material (CFRP). Advantageously, the card tops, for example revolving and/or stationary card tops, are made at least in part of carbon fibre reinforced plastics material (CFRP). Preferably, the side screen is made at least in part of carbon fibre reinforced plastics material (CFRP). Advantageously, at least one metal cylinder and at least one circular cylindrical sheath made of carbon fibre reinforced plastics material (CFRP) surrounding the cylinder are provided. Preferably, the metal cylinder and the sheath are mutually biased at room temperature and at operating temperature. Advantageously, the metal cylinder is subjected to compressive stresses and the sheath is subjected to tensile stresses in the circumferential direction. Preferably, the reinforcement fibres of CFRP in the sheath are oriented in the circumferential direction of the cylinder. As a result, widening of the cylinder as a result of centrifugal force is especially advantageously reduced or avoided, especially at high speeds of rotation. Advantageously, the cylinder is enclosed. Preferably, the removal of heat from the cylinder is different to that from the side parts. Advantageously, the roller is a licker-in of a flat card or roller card. Preferably, the roller is the doffer of a flat card or roller card.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a diagrammatic side view of a carding machine with an apparatus according to the invention;
[0013] FIG. 2 shows card top bars of the revolving card top of the carding machine of FIG. 1 and portions of a slideway, of the flexible bend, of the side screen and of the cylinder, and also the carding nip between the clothings of the card top bars and the cylinder clothing;
[0014] FIGS. 3 a, 3 b show sections through a roller comprising a metal cylinder and a circular cylindrical sheath made of carbon fibre reinforced plastics material surrounding the cylinder, in a front view ( FIG. 3 a ) and side view ( FIG. 3 b );
[0015] FIG. 4 is a diagrammatic section through a slideway along the line I-I in FIG. 2 together with flexible bends and side screens;
[0016] FIG. 5 is a side view of a part of a side screen and flexible bend, cylinder, extension bend, stationary carding element and revolving card top bars;
[0017] FIG. 6 is a side view of a flexible bend according to the invention;
[0018] FIG. 7 is a side view of an extension bend according to the invention in the pre-carding zone; and
[0019] FIG. 7 a shows the carding nip between the clothing of a stationary carding element according to the invention and the cylinder clothing.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0020] FIG. 1 shows a carding machine, for example a TC 03 carding machine made by Trützschler GmbH & Co. KG of Mönchengladbach, Germany, having a feed roller 1 , feed table 2 , lickers-in 3 a , 3 b , 3 c , cylinder 4 , doffer 5 , stripper roller 6 , nip rollers 7 , 8 , web-guiding element 9 , web funnel 10 , draw-off rollers 11 , 12 , revolving card top 13 having card-top-deflecting rollers 13 a , 13 b and card top bars 14 , can 15 and can coiler 16 . Curved arrows denote the directions of rotation of the rollers. Reference letter M denotes the centre (axis) of the cylinder 4 . Reference numeral 4 a denotes the clothing and reference numeral 4 b denotes the direction of rotation of the cylinder 4 . Reference letter B denotes the direction of rotation of the revolving card top 13 at the carding location and reference letter C denotes the direction in which the card top bars 14 are moved on the reverse side. Reference numerals 23 ′, 23 ″ denote stationary carding elements and reference numeral 39 denotes a cover underneath the cylinder 4 . Arrow A denotes the work direction.
[0021] In accordance with FIG. 2 , on each side of the carding machine, a flexible bend 17 having several adjustment screws is fixed laterally to the side screen 19 a, 19 b (see FIG. 4 ). The flexible bend 17 has a convex outer surface 17 a and an underside 17 b. On top of the flexible bend 17 there is a slideway 20 , for example made of low-friction plastics material, which has a convex outer surface 20 a and a concave inner surface 20 b . The concave inner surface 20 b rests on top of the convex outer surface 17 a and is able to slide thereon in the direction of arrows D, E. Each card top bar consists of a rear part 14 a and a carrying member 14 b . Each card top bar 14 has, at each of its two ends, a card top head, each of which comprises two steel pins 14 1 , 14 2 . Those portions of the steel pins 14 1 , 14 2 that extend out beyond the end faces of the carrying member 14 b slide on the convex outer surface 20 a of the slideway 20 in the direction of the arrow B. A clothing 18 is attached to the underside of the carrying member 14 b . Reference numeral 21 denotes the circle of tips of the card top clothings 18 . The cylinder 4 has on its circumference a cylinder clothing 4 a , for example a sawtooth clothing. Reference numeral 22 denotes the circle of the tips of the cylinder clothing 4 a . The spacing (carding nip) between the circle of tips 21 and the circle of tips 22 is denoted by reference letter a and is, for example, 3/1000″. The spacing between the convex outer surface 20 a and the circle of tips 22 is denoted by reference letter b. The spacing between the convex outer surface 20 a and the circle of tips 21 is denoted by reference letter c. The radius of the convex outer surface 20 a is denoted by reference letter r 1 and the radius of the circle of tips 22 is denoted by reference letter r 2 . The radii r 1 and r 2 intersect at the centre point M of the cylinder 4 . Reference numeral 19 denotes the side screen.
[0022] The high-speed roller shown in FIGS. 3 a , 3 b for a fibre-processing machine, for example a cylinder 4 of a carding machine, consists of a hollow cylindrical roller body 30 and two roller ends 31 a , 31 b at the end faces. The roller ends 31 a , 31 b advantageously are made of metal, for example steel or aluminium. Reference numeral 32 denotes a spoke, reference numeral 33 a hub and reference numeral 34 an end flange. The roller body 30 consists of an internal steel cylinder 35 and an external hardened CFRP sheath 36 . The CFRP sheath 36 has the shape of a thin-walled hollow cylinder. At operating temperature, in the biased state, compressive stresses are present in the circumferential direction in the cylindrical wall region of the steel cylinder 35 and tensile stresses in the cylindrical CFRP sheath 36 . In use, because of the centrifugal force to which the steel cylinder 35 is subjected, the compressive stresses are reduced. The thermal expansion coefficient of the cylinder material is much greater than the thermal expansion coefficient of the carbon fibre reinforced plastics material in the direction of the reinforcement fibres; for example, the thermal expansion coefficient α of steel is between 11×10 −6 1/K and 17×10 −6 1/K and that of CFRP in the fibre direction is about zero, especially between −2×10 −6 1/K and +2×10 −6 1/K. When subjected to heat in use, the internal diameter of the CFRP sheath 36 accordingly changes only very slightly, whereas the thermal expansion of the steel cylinder 35 is considerable. The thermal expansion of the CFRP-sheathed steel cylinder 35 is consequently less than the thermal expansion of a cylinder having an all-steel wall.
[0023] A roller according to the invention, comprising a metal cylinder and a composite fibre sheath, is lighter in comparison to an all-steel or all-aluminium roller, has a reduced mass inertia and exhibits linear thermal expansion which is adjustable (down to negative values) as a result of constructively arranged fibre orientation. The advantages of the roller according to the invention in use, which result from the properties of the material, are, for example, substantially improved braking values, savings in terms of drive units, energy savings, higher production rates, wider working widths and vibration-free running.
[0024] Density, specific rigidity and specific strength—the table that follows lists the density, modulus of elasticity and strength of the materials in comparison with one another:
Density Modulus of elasticity Strength Material (g/cm 3 ) (N/mm 2 ) (MPa) St 52 7.8 210 000 400 Al 2.7 70 000 350 CFRP 1.3 75 000 to 180 000 1500 GFRP* 1.9 20 000 to 40 000 1250 *Glass fibre-reinforced plastics material
[0025] In the direction of the fibres, CFRP has considerable advantages compared to steel (the latter being represented by St 52 in the above table). The individual fibres made up into a tube in the course of a winding process determine the anisotropic (directionally dependent) behaviour of such a tube.
[0026] FIG. 4 shows part of the cylinder 4 together with the cylindrical surface 4 f of its wall 4 e and the cylinder ends 4 c, 4 d (radial supporting elements). The surface 4 f is provided with a clothing 4 a , which in this example is provided in the form of wire with sawteeth. The sawtooth wire is drawn onto the cylinder 4 , that is to say is wound around the cylinder 4 in tightly adjacent turns between side flanges (not shown), in order to form a cylindrical work surface provided with tips. Fibres should be processed as evenly as possible on the work surface (clothing). The carding work is performed between the clothings 18 and 4 a located opposite one another and is substantially influenced by the position of one clothing with respect to the other and by the clothing spacing a between the tips of the teeth of the two clothings 18 and 4 a . The working width of the cylinder 4 is a determining factor for all other work elements of the carding machine, especially for the revolving card tops 14 or stationary card tops 23 ′, 23 ″ ( FIG. 1 ), which together with the cylinder 4 card the fibres evenly over the entire working width. In order to be able to perform even carding work over the entire working width, the settings of the work elements (including those of additional elements) must be maintained over that working width. The cylinder 4 itself can, however, be deformed as a result of the drawing-on of the clothing wire, as a result of centrifugal force or as a result of heat produced by the carding process. The shaft 25 of the cylinder 4 is mounted in positions (not shown) located on the stationary machine frame 24 a , 24 b . The diameter, for example 1250 mm, of the cylindrical surface 4 f , that is to say twice the radius r 3 , is an important dimension of the machine and becomes larger in use as a result of the heat of work. The side screens 19 a , 19 b are fastened to the two machine frames 24 a and 24 b , respectively. The flexible bends 17 a and 17 b are fastened to the side screens 19 a and 19 b , respectively.
[0027] When heat is produced in use in the carding nip a between the clothings 18 (or in the carding nip d between the clothings 23 ′) and the cylinder clothing 4 a as a result of carding work, especially in the case of a high production rate and/or the processing of synthetic fibres or of cotton/synthetic fibre blends, the cylinder wall 4 e undergoes expansion, that is to say the radius r 3 increases and the carding nip a (se FIG. 2 ) or d (see FIG. 7 a ) decreases. The heat is directed via the cylinder wall 4 e into the radial carrying elements, the cylinder ends 4 c and 4 d. The cylinder ends 4 c , 4 d likewise undergo expansion as a result thereof, that is to say the radius increases. The cylinder 4 is almost entirely encased (enclosed) on all sides—in a radial direction by the elements 14 , 23 , 39 (see FIG. 1 ) and to the two sides of the carding machine by the elements 17 a , 17 b , 19 a , 19 b , 24 a , 24 b . As a result, scarcely any heat is radiated from the cylinder 4 to the outside (to the atmosphere). Nevertheless, the heat of the cylinder ends 4 c, 4 d of large surface area is especially conveyed by means of radiation to the side screens 19 a , 19 b of large surface area to a considerable extent, from where the heat is radiated out to the colder atmosphere. As a result of that radiation, the expansion of the side screens 19 a, 19 b is less than that of the cylinder ends 4 c , 4 d , which results in a reduction in the carding nip a ( FIG. 2 a ) and in the carding nip d ( FIG. 7 a ) that ranges from undesirable (in terms of the result of carding) to hazardous. The carding elements (card top bars 14 ) are mounted on the flexible bends 17 a , 17 b and the fixed carding elements 23 ′, 23 ″ are mounted on the extension bends, which are in turn fixed to the side screens 19 a , 19 b . In the event of heating, the lifting of the flexible bends 17 a , 17 b —and, as a result, of the clothings 18 of the card top bars 14 —increases less, compared to the expansion of the radius r 3 of the cylinder wall 4 e —and, as a result, of the clothing 4 a of the cylinder 4 —, which results in narrowing of the carding nip a. The cylinder wall 4 e and the cylinder ends 4 c , 4 d are made of steel, for example St 37, having a linear thermal expansion coefficient of 11.5×10 −6 [1/° K]. In order then to compensate for the relative differences in the expansion of the cylinder ends 4 c , 4 d and the cylinder wall 4 e , on the one hand, and the side screens 19 a , 19 b (as a result of impeded radiation into the atmosphere because of encasing of the cylinder 4 and free radiation into the atmosphere from the side screens), the rear parts 14 a and carrying members 14 b of the card top bars are made of carbon fibre reinforced plastics material (CFRP) whose thermal expansion coefficient has been negatively adjusted. By that means, even though the expansion of the cylinder 4 remains the same because of a lack of removal of heat as a result of encasing, the card top bars 14 undergo contraction. As a result, undesirable reduction in the carding nip a and d due to thermal influences is avoided.
[0028] In the embodiment of FIG. 5 , three non-moving stationary carding elements 23 a , 23 b , 23 c and non-clothed cylinder-encasing elements 25 a , 25 b , 25 c are provided between the licker-in 3 and the card-top-deflecting roller 13 a . In accordance with FIG. 7 a , the stationary carding elements 23 have a clothing 23 ′, which is located opposite the cylinder clothing 4 a . Reference letter d denotes the carding nip between the clothing 23 ′ and the cylinder clothing 4 a . The stationary carding elements 23 , by means of screws 26 a , and the cover elements 25 (by means of screws which are not shown) are mounted on an extension bend 27 a (the extension bend 27 a on only one side of the carding machine is shown in FIG. 3 ), which is in turn fastened by means of screws 28 1 to 28 3 to the card screen 19 a and 19 b (only 19 a is shown in FIG. 5 ) on each side of the carding machine. The flexible bends 17 a , 17 b (only 17 a is shown in FIG. 5 ) are fastened to the side screens 19 a and 19 b , respectively, by means of screws 29 1 , 29 2 (see FIG. 6 ).
[0029] FIGS. 6 and 7 show, as separate components, the flexible bend 17 a and the extension bend 26 a , respectively. The flexible bend 17 a is made, for example, of GGG 30 grey cast iron, and the extension bend is made, for example, of GG 20 grey cast iron. On the convexly curved periphery of the flexible bend there is fixed a coating 37 and on that of the extension bend 26 a there is fixed a coating 38 , the two coatings 37 , 39 being made of CFRP having positively adjusted thermal expansion coefficients.
[0030] The cylinder 4 is made, for example, of steel. In order to counteract, in use, the undesirable narrowing of the carding nips a ( FIG. 2 ) and d ( FIG. 7 a ), the flexible bends 17 a , 17 b and the extension bends 26 , 26 b are respectively provided with the coating 37 ( FIG. 6 ) and 38 ( FIG. 7 ) of carbon fibre reinforced plastics material (CFRP) whose thermal expansion coefficient has been positively adjusted. As a result, even though the expansion of the cylinder 4 is unchanged, the flexible bends 17 a , 17 b and extension bends 26 a , 26 b arranged to the sides of the cylinder 4 undergo expansion, as a result of which the card top bars 14 and stationary carding segments 23 , respectively, are lifted up so that the undesirable reduction in the carding nip a and d, respectively, is avoided.
[0031] The arrangement of the flexible bends 17 a , 17 b and extension bends 26 a , 26 b shown in FIGS. 5 to 7 can advantageously be combined with the arrangement of the cylinder 4 shown in FIGS. 3 a , 3 b . In that combination, the flexible bends 17 a , 17 b and extension bends 26 a , 26 b are made at least sometimes of CFRP having a positively adjusted thermal expansion coefficient and the sheath 36 of the cylinder 4 (see FIGS. 3 a , 3 b ) is made of CFRP having a negatively adjusted thermal expansion coefficient. Where appropriate, CFRP having a thermal expansion coefficient of zero can also be selected, depending on the material of the cylinder 4 . By that means, as a result of suitable adjustment of the thermal expansion coefficients, a desired dimensional accuracy can be achieved and maintained as intended for the parts influencing the carding nip a and d in use when heat is generated.
[0032] In order to compensate for the relative differences in the expansion of the cylinder ends 4 c , 4 d and the cylinder wall 4 e , on the one hand, and the side screens 19 a , 19 b (as a result of impeded radiation into the atmosphere because of encasing of the cylinder 4 and free radiation into the atmosphere from the side screens), the sheath 36 is, in accordance with a further arrangement, made of carbon fibre reinforced plastics material (CFRP) whose thermal expansion coefficient has been negatively adjusted. By that means, expansion of the cylinder 4 because of a lack of removal of heat as a result of encasing is reduced or avoided. As a result, undesirable reduction in the carding nip a or d due to thermal influences is avoided.
[0033] Although the foregoing invention has been described in detail by way of illustration and example for purposes of understanding, it will be obvious that changes and modifications may be practised within the scope of the appended claims.
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A carding machine has a number of rollers including a cylinder and having at least one clothed and/or unclothed machine element located opposite the cylinder at a spacing therefrom. The machine may have further elements influencing the carding nip. In order to make possible a carding nip between the cylinder and the clothed and/or unclothed counterpart element that remains constant or virtually constant when heat is generated, the parts influencing the carding nip are so construed that they have thermal expansion characteristics which are such that, when subjected to the heat acting on them in use, the carding nip remains substantially constant.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a drain garbage collector. More particularly, the invention provides a drain garbage collector that can effectively collect drain garbage while preventing inundation caused by garbage jam.
[0003] 2. Description of the Related Art
[0004] Referring to FIG. 1 and FIG. 2, two perspective views illustrate the structure of a conventional drain garbage collector disclosed in the Taiwan Patent No. 197035. The known garbage collector comprises a frame structure 1 , a retainer basin 2 , and a drain cover grate 3 .
[0005] The retainer basin 2 is mounted to the frame structure 1 , and hence theassembled structure is covered by the drain cover grate 3 defining a plurality of holes 31 and placed within the drain, as shown as in FIG. 2, to collect roadside garbage. The above conventional drain garbage collector can therefore receive and contain garbage, but is not effective to filter flowing garbage in the drain itself.
[0006] Moreover, if the flowing drain garbage obstructs the lateral filter net 11 of the frame structure 1 (shown in FIG. 1), water flown into the frame structure 1 is not able to flow through the drain because of being blocked by the lateral side drain garbage, causing inundation.
SUMMARY OF THE INVENTION
[0007] It is therefore a principal object of the invention to provide a drain garbage collector that prevents inundation due to jammed drain and further enables to save the cleaning time and cost.
[0008] To accomplish the above and other objectives, a drain garbage collector of the invention comprises a frame, a top grate, a separator grate, and a collector grate, each of whom is assembled with one another. A plurality of passages are defined through the top grate to enable garbage to flow into the collector grate. The separator grate prevents garbage from flowing out of the garbage collector. Thereby, the garbage collector of the present invention is able to collect garbage and prevent inundation caused by jammed drain.
[0009] To provide a further understanding of the invention, the following detailed description illustrates embodiments and examples of the invention, this detailed description being provided only for illustration of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The drawings included herein provide a further understanding of the invention. A brief introduction of the drawings is as follows:
[0011] [0011]FIG. 1 is a perspective view showing the frame structure of a conventional drain garbage collector;
[0012] [0012]FIG. 2 is a perspective view showing an utilization of the conventional drain garbage collector;
[0013] [0013]FIG. 3 is an exploded view of a drain garbage collector according to an embodiment of the present invention;
[0014] [0014]FIG. 4 is a perspective view showing the drain garbage collector assembled according to an embodiment of the present invention;
[0015] [0015]FIG. 5 through FIG. 7 are perspective views showing the installation and manipulation of the garbage collector of the present invention while being placed in a drain; and
[0016] [0016]FIG. 8 is a front view of the garbage collector of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0017] Wherever possible in the following description, like reference numerals will refer to like elements and parts unless otherwise illustrated.
[0018] Referring to FIG. 3 through FIG. 8, various schematic views illustrate a drain garbage collector according to an embodiment of the present invention. The garbage collector comprises a frame 10 , a top grate 20 , a separator grate 30 , and a collector grate 40 . The frame 10 is L-shaped and made of metallic materials. First pivot connecting structures 11 are placed on the rear side edge of the frame 10 to connect the top grate 20 coaxially via pivot axles 12 . The top grate 20 is made of metallic materials also, and is constituted of a plurality of bars 21 that are spaced apart from one another so as to define a plurality of passages 23 there between. The bars 21 may form the top grate 20 via various methods such as soldering, hard soldering, ultra-sonic welding, or resistive welding, etc.
[0019] Second pivot connecting structures 22 , corresponding to the first pivot connecting structures 11 , are further disposed on the rear side of the top grate 20 , proximate to the rear edge thereof, to pivotably connect to the first pivot connecting structures 11 of the frame 10 . The top grate 20 is thereby assembled with the frame 10 . As shown in FIG. 4, the pivotably assembled top grate 20 can thus rotate and cover the frame 10 . Garbage can be collected through the passages 23 into the collector grate 40 (see FIG. 6).
[0020] The frame 10 internally includes two sliding slots 13 that are disposed vis-a-vis on two lateral sides of the frame 10 . The sliding slots 13 are used to slidably receive the separator grate 30 while the separator grate 30 is mounted into the frame 10 . The separator grate 30 is a metallic grate with a pulling support 31 . The pulling support 31 can be, for example, a ring or a flange that enables an operator to conveniently move the separator grate 30 along the sliding slots 13 in a slidable manner, irrespective of inserting or removing the separator grate 30 , as shown in FIG. 7. A first filter net 32 is disposed on the separator grate 30 to prevent collected roadside garbage from flowing out of the garbage collector. The collector grate 40 is further mounted to a lower side of the frame 10 . The collector grate 40 is for resting the collected roadside garbage and preventing it flowing out of the garbage collector in cooperation with the first filter net 32 and a second filter net 41 of the collector grate 40 . Retainer boards 14 are further respectively mounted onto the lateral sides of the frame 10 . The retainer boards 14 are made of metallic materials, and may be assembled with the collector grate 40 via, for example, screw assembly, as shown in FIG. 4. The retainer boards 14 support the entire structure of the frame 10 , and further prevent collected roadside garbage from flowing through the lateral sides of the frame 10 .
[0021] The lateral sides of the frame 10 are designed to be adjusted in accordance with the width of the internal part of the drain 50 , as shown in FIG. 6. With the addition of a frame mounting element 15 , the frame 10 can be fixedly mounted within the drain opening.
[0022] As described above, the garbage collector 60 of the present invention is hence composed of the frame 10 , the top grate 20 , the separator grate 30 , the collector grate 40 , and the retainer boards 14 . As shown in FIG. 5, the garbage collector 60 can be mounted within the internal part of the drain 50 to filter and collect the roadside garbage flown to the drain 50 . Via the passages 23 of the top grate 20 , roadside garbage can be collected into the garbage collector 60 , which favorably reduces the road cleaning time and costs.
[0023] Referring to FIG. 5 through FIG. 7, when garbage within the drain 50 flows into the garbage collector 60 , garbage of greater size is collected by the collector grate 40 while garbage of smaller size is flown out of the garbage collector 60 via the first filter net 32 of the separator grate 30 . To maintain fluid flowing in the drain 50 , the cleaning operator only has to regularly remove the garbage accumulated in the garbage collector 60 , as shown in FIG. 8.
[0024] During rain and storm seasons, the waterflow in the drain 50 may be substantially huge. For preventing inundation, the operator slidably removes the separator grate 30 from the frame 10 via pulling the pulling support 31 . Drainage through the garbage collector 60 is hence facilitated. Inundation due to jammed garbage in the garbage collector 60 can be thereby prevented.
[0025] In conclusion, the invention provides a garbage collector that, installed within a drain, can prevent the drainage jam and reduces the cleaning time and costs. Thus, the risks of inundation are thus favorably reduced.
[0026] It should be apparent to those skilled in the art that the above description is only illustrative of specific embodiments and examples of the invention. The invention should therefore cover various modifications and variations made to the herein-described structure and operations of the invention, provided they fall within the scope of the invention as defined in the following appended claims.
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A drain garbage collector of the invention includes a frame, a top grate, a separator grate, and a collector grate. A plurality of passages are defined through the top grate let the roadside garbage pass through. The separator grate prevents garbage from flowing out of the garbage collector via filtering wastewater flow. Thereby, the garbage collector collects garbage and the collected garbage can be cleaned regularly to prevent inundation caused by jammed drain.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to systems and methods for crash energy management and, more specifically, relates to systems and methods for energy absorption in automotive applications utilizing a taper and flare energy absorption system.
[0003] 2. Description of the Background
[0004] The design for crashworthiness is an extremely important aspect of vehicle and structural design. The primary aspect of crashworthiness design is providing a means to dissipate kinetic energy through the work of deformation within the vehicle structure. In the current energy absorption design systems, such as axially collapsed or inverted crush tubes, highly ductile material is critically important due to the severe strain states experienced during the deformation. Also, the amount of energy absorption is very sensitive to the quality and controls of the material. The available materials that meet these requirements, especially for non-ferrous metals, may be limited, and the resulting product cost may be significantly increased.
[0005] A typical prior art application may utilize an axial folding collapse technique, wherein a pre-dented hollow tube 100 is crushed lengthwise into a regular pattern 110 (see, FIG. 1). These triangular or other-shaped dents (not shown) force the crush tube to collapse into the “natural mode” which can then produce expected results. Typically, these prior art crush tubes 100 are made of aluminum alloys, but many other materials are also used. Some conventional crush tube assemblies may not contain any dents.
[0006] These conventional crush tubes are typically installed behind the front bumper section of an automobile or truck. The tube is affixed at one end to a rail on the chassis of the automobile and at the other end to the bumper. Hence, the force of a resulting collision that is perpendicular to the front face of the bumper will cause an axial compressive force on the installed crush tube, causing it to collapse. These tubes may also be installed in the rear bumper of automobiles or in any other orientation or system in which a spatially-confined absorption of an abrupt axial load is desired.
[0007] The conventional crush tube applications may suffer from one or more drawbacks that prevent their controlled use in many applications. For example, because of the intense crushing action, the tube must be made of a ductile metal, such as a special aluminum alloy. Such highly ductile metals are typically more expensive than less ductile materials. If materials with lower ductility are used, they may crack or split and therefore lose some or all of their energy absorption capacity.
[0008] Also, as seen in FIG. 1, the “crush zone” 110 into which the tube 100 is compacted does not extend throughout the entire length of the crush tube 100 . Hence, the uncrushed portions of the crush tube 100 are wasted in terms of energy absorption. Testing has shown that the conventional crush tube application may crush only approximately 70%-75% of the length of the crush tube.
[0009] Because of the intense and structured way in which the conventional application is crushed in a natural mode pattern, these crush tubes are typically made pursuant to very tight tolerances. Even small variations in the thickness of the material of the crush tube may cause a large variation in energy absorption during a crash event. For example, a weakness in one area of the tube may cause the tube to buckle in that area with a result that the tube does not perform as designed and may not absorb the requisite amount of energy for its intended application.
[0010] Even during normal operation, these conventional crush tube applications are not ideal. For example, the force dissipated by the “collapsing” process oscillates around the mean force dissipation of the system. Therefore, high peaks of force are created by the conventional methods. These peak loads may cause a “jerking” sensation to the passengers of the vehicle and may require that the backup structure be reinforced, thereby increasing the peak loads when crushing the backup structure. This may reduce passenger safety.
[0011] Also, because the existing technologies typically utilize only about 70% of the original crush tube length for energy absorption, high loads are needed to absorb the required energy in a given space. Therefore, in the case of automobiles, the accelerations imparted to the passengers are correspondingly high which may also adversely affect passenger safety.
[0012] These various limitations to the current implementation of axially loaded crush tube absorption systems are preferably addressed by one or more embodiments of the present invention.
SUMMARY OF THE INVENTION
[0013] In accordance with the present invention, there is provided an energy absorption system and method generally comprised of a crush tube, a taper component, and a flare component. The crush tube is inserted into a matching hole in the taper component. As the taper and flare components are moved over the crush tube, the taper component decreases the diameter of the crush tube and the flare component splits the crush tube into a plurality of petals. When mounted with the longitudinal axis of the crush tube parallel to an axis of an impact, the present invention is capable of absorbing some or all of the crash event by dissipating energy by the tapering, flaring, friction, and other methods.
[0014] The crush tube may include a plurality of initiator slits to aid in the flaring process, and the crush tube may have a circular, oval, square, rectangular, hexagonal, or other cross-sectional profile. The taper and flare components are preferably adapted to accept one or more of these crush tube orientations.
[0015] The present invention may utilize materials that are not acceptable for use with conventional axial crush absorption systems. For example, a material with less ductility may be used.
[0016] In at least one presently preferred embodiment, the invention is installed in a car, truck or other vehicle to partially or wholly absorb the shock of a crash event. For example, the energy absorption system may be mounted between a rail on the chassis or frame of the car and a bumper. Because the present absorption system generally dissipates energy along a single impact axis, two or more of the present absorption systems may be installed in a plurality of locations and orientations in a vehicle to absorb crash shocks from various impact angles and locations. The present invention may also be used in other axial load applications such as trains, barriers, elevators, carriers, and the like.
[0017] These and other features and advantages of the present invention will become readily apparent to persons skilled in the art from the following detailed description of the invention, the abstract, and the attached claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] For the present invention to be clearly understood and readily practiced, the present invention will be described in conjunction with the following figures, wherein like reference characters designate the same or similar elements, which figures are incorporated into and constitute a part of the specification, wherein:
[0019] [0019]FIG. 1 shows a conventional crush tube after partial deformation;
[0020] [0020]FIG. 2 details one presently preferred embodiment of an energy absorption assembly;
[0021] [0021]FIG. 3 shows a sectional view of a taper and flare energy absorption system;
[0022] [0022]FIG. 4 shows a perspective view of a taper and flare energy absorption system after a crash event; and
[0023] [0023]FIG. 5 shows a graph of the crush load versus crush distance for an exemplary embodiment of the present invention and a conventional axial collapsing crush tube.
DETAILED DESCRIPTION OF THE INVENTION
[0024] It is to be understood that the figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the invention, while eliminating, for purposes of clarity, other elements that may be well known. Those of ordinary skill in the art will recognize that other elements are desirable and/or required in order to implement the present invention. However, because such elements are well known in the art, and because they do not facilitate a better understanding of the invention, a discussion of such elements is not provided herein. The detailed description will be provided hereinbelow with reference to the attached drawings.
[0025] In at least one presently preferred embodiment of the invention, there is provided an energy absorption system comprising a taper component, a flare component, and a crush tube component. An axial load is initially absorbed by the crush tube as it is compressed by the taper component and thereafter as it is split apart by the flare component. The taper component and flare component may be combined into a single “taper and flare component.” The present invention preferably combines the advantages of tapering and flaring of crush tubes into a single energy absorption system.
[0026] [0026]FIG. 2 details one presently preferred embodiment of an energy absorption assembly 200 according to the present invention. In FIG. 2, a cast, machined or fabricated taper and flare component 205 is oriented to accept the end of a crush tube 210 which is shown broken because it is generally longer than that shown in FIG. 2. The crush tube 210 is depicted as a circular profile cylinder, but the tube may be made in other orientations and profile shapes as described below. When an impacting body imparts an axial load (a load parallel to the longitudinal axis of the crush tube 210 ) on the taper and flare assembly 200 (i.e., a “crash event”), the taper and flare component 205 slides over the crush tube 210 and tapers the tube (compresses the radial diameter of the tube).
[0027] As the taper and flare component 205 continues down the crush tube 210 because of a continuous or additional axial load, the tapered portion of the tube becomes split (“flared”) into multiple pieces (“petals”). The taper and flare component 205 continues to move down the crush tube 210 until all of the energy from the crash event is absorbed or until the end of the crush tube 210 is reached.
[0028] More specifically, FIG. 3 shows a sectional view of a preferred taper and flare assembly 300 cut parallel to the longitudinal axis of the crush tube 310 . The crush tube 310 enters the taper and flare component 305 through an opening 315 , which is preferably just slightly larger than the profile of the crush tube 310 . As the taper and flare component 305 is forced down over the crush tube 310 (or similarly as the crush tube is forced up into the taper and flare component), the crush tube enters the “tapering” section 320 of the taper and flare component 305 which is generally a gradual decrease in the size of the profile of the crush tube 310 .
[0029] For example, if the crush tube 310 was a circular profile cylinder with a diameter of X millimeters, the taper and flare opening 315 may be a circular opening with a diameter of just greater than X millimeters, and the taper component 320 may gradually reduce this diameter to approximately X-Y millimeters. This tapering absorbs energy through the deformation of the crush tube (described in greater detail below).
[0030] As shown in FIG. 2, the crush tube 210 is preferably initiated with small slots 215 (shown as triangles in FIG. 2) placed at various locations around the end of the tube 210 that enters the taper and flare component 205 . Forcing the split end of the crush tube 210 onto the “cone” 325 (FIG. 3) of the flaring component causes the tube to split into separate segments or “petals” 330 . These petals 330 then flare out away from the central axis of the crush tube 310 . In other words, as the taper and flare component 305 continues to be forced down over the crush tube 310 , the “tapered” and split part of the tube will begin to flare into a number of pieces 330 (dictated by the number of initiators 215 cut into the tube). Preferably, no other guidance of the flares 330 is necessary, but a guide slot 220 or other guiding mechanism may be used in certain applications to better control the properties of the flared crush tube.
[0031] For purposes of clarification, the small segments 313 shown between the taper and flare components correspond to the small amount of material between adjacent guide slots 220 . If the FIG. 3 cross section is rotated slightly along the longitudinal axis (so that the cross section is taken through the guide slots 220 ), these segments 313 would not be present. The taper and flare components are shown as one piece 305 in FIG. 3, but these components may also be manufactured as two or more separate pieces that are then bolted or otherwise attached together.
[0032] Preferred measurements for the initiator slots 215 may be approximately 6 millimeters deep and 2 millimeters wide each. As the taper and flare component 305 continues to push down over the crush tube 310 and the flaring continues, the flared petals 330 will generally fold back over themselves (“curl”) as the natural (unguided) mode of deformation. The guide slots 220 in the flare portion of the taper and flare component 305 may provide merely a window or hole for the flared petals 330 to curl, but the petals may be directed in any fashion to increase the resulting friction (and therefore the resulting energy dissipation). The radial compression of the tube 310 due to the taper component preferably keeps the “split” from passing down into the non-tapered portion of the crush tube and causing a failure or reduced energy absorption in the system.
[0033] [0033]FIG. 4 shows a perspective view of one embodiment of a taper and flare energy absorption system 400 after a crash event. The taper and flare component 405 has been forced down over the majority of the crush tube 410 , and the various petals 430 (in this case four) can be seen curled back over the taper and flare assembly. From the outside of the assembly, the free end of the crush tube and the resulting tapered and flared “ends” 430 of the crush tube can be seen. The energy dissipated by the system includes, among other sources, all of the energy used to deform the cylinder between these two states (from tube 410 to split petals 430 ).
[0034] From a more technical point of view, the taper and flare energy absorption system of the present invention is preferably able to dissipate the energy from a crash event in a variety of different manners. For example, during the tapering process, the largest amount of energy is absorbed due to the reduction in the crush tube's diameter. The amount of energy dissipated in the taper is generally based on the decrease in the diameter of the tube during compression and the plastic flow stress of the tube material. The resulting crush tube will generally have a reduced diameter, an increased thickness, and a decreased length.
[0035] Additionally, the flaring of the crush tube into multiple petals generally dissipates work by way of friction and metal fracture or tearing. There is friction involved as the tube is forced over the flaring apparatus. Energy is also dissipated by the tearing of the material.
[0036] The present invention preferably allows the use of a much higher percentage of the original length of the crush tube for energy absorption, relative to conventional axial compression technology. Testing has shown that the length utilization may be approximately 90% instead of 70% for the existing technologies described above. Given a specified space, for example between a vehicle bumper and the frame, the present invention preferably provides equal energy absorption with lower peak loads and therefore provides better safety to the passengers in the vehicle. In addition to the higher safety potential, this invention allows the use of materials that have a much lower ductility than those required for the conventional technologies. Therefore, the cost of the present system may be decreased, and the reliability of the present system may be increased.
[0037] [0037]FIG. 5 shows a graph of the energy absorption (the crush load) versus crush distance in a taper and flare energy absorption system according to the present invention as compared to the conventional axial collapsing energy absorption system. FIG. 5 shows that the displacement of the crush tube through the taper assembly is generally linearly related to the force applied to the tube down its longitudinal axis. At the point where the compressed end of the tube leaves the taper apparatus, the crush tube displacement will proceed at an approximately steady level of force (steady state). Since the assembly process preferably accounts for the initial portion of the load curve which is due to tapering only, the crush load experienced in an impact is initially approximately equal to the steady state crush load. Therefore, high energy absorption efficiency is achieved with lower peak load requirements in the crush rail and supporting structure. This results in improved passenger safety due to reduced peak decelerations.
[0038] The highest point on the FIG. 5 curves is the peak load of the energy absorption systems. Because it takes a greater initial load to begin the crushing of the conventional system, the conventional system has a greater peak load than the present invention. In the FIG. 5 example, the peak load for the crush tube and backup structure of the present invention is shown to be approximately 15% less than the conventional assembly. These lower peak loads preferably result in an automobile passenger “feeling” less deceleration during a crash event, thereby increasing passenger safety at lower vehicle speeds.
[0039] The steady state crush load for the present invention is also significantly higher than that of the conventional energy absorption systems. As seen in FIG. 5, after the “pre-loading” of the taper component of the present invention (described more fully below), the systems reach a steady state crush load throughout much of the length of the crush tube. The conventional assembly has comparatively wide oscillations with a mean steady state crush load that is approximately 35-50% lower than the present invention. Therefore, the present invention may be capable of absorbing more energy per unit of displacement than the prior art. A higher total crush load absorption may be further amplified because a greater percentage of the length of the crush tube may be utilized with the present invention when compared to conventional systems.
[0040] The prior art systems' ability to absorb loads is typically based on the materials used, the geometry of the tubes, and the thickness of the tubes. Preferably, the present invention may be used with a wider variety of materials. Specifically, the present invention may be used with the 6000 series aluminum alloys, such as 6260 and 6063-T6 temper. Many of these alloys are commonly available and are among the cheapest metal alloys of this type available. The present invention may also be used with steel. The taper or the taper and flare components both may be made of steel, aluminum, magnesium or other materials.
[0041] In one preferred embodiment of the present invention, the taper and flare energy absorption assembly is installed behind the bumper of a vehicle. Specifically, the crush tube and taper and flare component are welded or otherwise affixed between a rail of the vehicle chassis and the bumper of the vehicle. The taper and flare component(s) may be oriented immediately behind the bumper or between the crush rail and backup structure (the interior of the vehicle frame). A “preloading” step of installation for the taper and flare system involves inserting the end of the crush tube into the taper component to the point just before flaring. In the vehicle, the crush tube is preferably subassembled to the taper component by simply pushing the tube into the taper. This pre-insertion increases the energy capacity of the system (see, FIG. 5).
[0042] In typical energy absorption systems, material fracture is an undesirable event, but with the present concept, the fracture is limited to the free end of the tube because the compressive stress field created by the taper component does not allow the fracture to propagate past the taper. The taper component provides the structural connection between the tube and the rest of the structure. Therefore, the structural integrity is maintained throughout the crash event.
[0043] Although the examples of the present disclosure have involved the use of a hollow circular crush tube, it is also possible to utilize other crush tube profiles such as oval, square, rectangular, hexagonal, octagonal, etc. The taper and flare component may be adapted to accept these various crush tube profiles. Specifically, different taper and flare components may be designed with different openings to accept different crush tube profiles. These “alternative crush tubes” may also utilize common aluminum alloys like air quenched 6063-T6 and 6060-T6 for primary energy absorbing members or materials other than aluminum. The taper and flare system has the potential to allow the use of more common alloys, which may therefore improve the cost and supply base issues.
[0044] In addition to the alloy-related issues, the existing energy absorption technology typically utilizes 70-75% of the original member length for energy absorption. Therefore, due to the increased average crush load capability and crush length efficiency, the present taper and flare concept has the potential to significantly improve vehicle crashworthiness by absorbing more energy with less intrusion into passenger compartments.
[0045] In the design concepts that utilize castings for the taper and flare component, it is estimated that Advanced Green Sand Casting (AGSC) or permanent mold castings will be best suited due to the size, thickness and alloys available. Also, since the joints connecting the taper, flare and crush tube are preferably mechanical joints, it may be feasible to use any combination of the design and materials of each component (e.g., a steel tube and steel flare may be used with a cast taper) This added flexibility is not generally available in the conventional energy absorption system because of the design constraints described above.
[0046] An exemplary taper and flare component length may be approximately 400 mm. The fracture initiators in the end of the crush tube may be made by simple saw cuts approximately 6 mm deep and as wide as the saw blade. In a preferred embodiment, the number of initiators is four, however, a greater or lesser number of initiators may be used for various applications and design requirements. An isometric view of the exemplary initiators is shown in FIG. 2.
[0047] The number of initiator slits may be adapted over a wide range of values. Generally speaking, an increase in the number of slits will increase the stability of the system during a crash event. However, an increased number of slits may also decrease the amount of energy that may be absorbed by the system. Hence, depending on the desired performance of the taper and flare energy absorption system in accordance with the present invention, the number, size and orientation of the slits may be altered.
[0048] The present invention may be adaptable in a variety of others ways. For example, due to the coefficient of static friction between the tube and the taper component, significant surface galling may occur on the taper and flare assembly which causes the crush load to increase as the crash event progresses. This may cause the tube to eventually collapse in an axial folding mode. However, the surface galling may be eliminated by applying a common hard anodize coating to the crush tube and taper and flare components. It should be noted that the coating may affect the coefficient of friction thus changing the crush loads. Although the anodize coating may not be preferred, it demonstrates design alterations that may not be feasible in the prior art which depends more on material consistency and uniformity.
[0049] Because of the high efficiency of the energy absorption system of the present invention, the taper and flare system may preferably be used in other applications in addition to the conventional front bumper orientation. For example, the present invention may be used behind the instrument panels or in other confined areas of the vehicle. Because of the adjustability and high value of energy absorption, the present invention may be used in higher inertial applications such as in trains or in elevators as emergency braking apparatuses. The present invention may also be less sensitive to tolerances in manufacture than conventional applications.
[0050] Nothing in the above description is meant to limit the present invention to any specific materials, geometry, or orientation of parts. Many part/orientation substitutions are contemplated within the scope of the present invention. The embodiments described herein were presented by way of example only and should not be used to limit the scope of the invention.
[0051] Although the invention has been described in terms of particular embodiments in an application, one of ordinary skill in the art, in light of the teachings herein, can generate additional embodiments and modifications without departing from the spirit of, or exceeding the scope of, the claimed invention. Accordingly, it is understood that the drawings and the descriptions herein are proffered by way of example only to facilitate comprehension of the invention and should not be construed to limit the scope thereof.
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An energy absorption system and method comprised of a crush tube, a taper component, and a flare component. The crush tube is inserted into a matching hole in the taper component. As the taper and flare components are moved down over the crush tube, the taper component decreases the diameter of the crush tube and the flare component splits the crush tube in a plurality of petals. The crush tube may include a plurality of initiator slits to aid in the flaring process. When mounted with the longitudinal axis of the crush tube parallel to an axis of an impact, the present invention is capable of absorbing some or all of the crash event by dissipating energy by the tapering, flaring, friction, and other methods.
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BACKGROUND OF THE INVENTION
(i) Field of the Invention
This invention relates to systems for minimizing heat loss from buildings. More particularly, it is directed to systems for selectively insulating large transparent exterior walls, e.g., the roofs and walls of greenhouses and other structures., e.g., swimming pool covers.
(ii) Description of General Problem
There are in the United States and Canada commercial greenhouses totalling over 250 million square feet. Over two-thirds of this total is in the northern United States and Canada, where greenhouses must be heated during at least some of the year. The greenhouse heating cost exceeds $120 million annually.
Most of the fuel used to heat greenhouses is expended at night. It is thought that night-time heating accounts for as much as 80% of the total heating bill. Recent increases in fuel cost, coupled with severe shortages of fuels, have faced greenhouse owners with a major problem. They must cut their total fuel consumption drastically if they wish to remain competitively viable.
The energy requirements of commercial greenhouses for heating are so high at present as to exclude economic operation of many greenhouses. One way to cut fuel consumption is to reduce the heat loss through the greenhouse walls and roof, especially at night. Insulating the walls or roof can significantly reduce heating requirements, but itself presents several potentially serious problems. An insulating system should not significantly reduce the amount of sunlight that can enter the house during the day. The insulating system may take up valuable growing space within the greenhouse. North walls and part of roofs have been insulated, but these reduce effective growing area and the production per plant because of poor light, to the point where the structure is not economic. The radiant heat loss at night can be minimized by using cloth or polyethylene screens inside the structure and these have been attempted. They fail in cold climates (i.e., below -18° C.) because the moisture-laden air creeps around the screen and forms frost on the inside cover of the greenhouse. Often this falls off when the sun warms the roof and walls, thereby damaging the plants as well as creating a hazard for workers. If it does not, the resulting chill from the cold air above the screen reduces the crop yield significantly (e.g., 10 to 15%). Outside shutters have also been tried but wind problems and economics exclude this type of arrangement in commercial greenhouses although feasible in back yard greenhouses. Accordingly, an insulating system should be readily adaptable for use with greenhouses of widely varying size and construction, and should cover a large area rather than requiring many small systems installed between each pair of obstructing greenhouse supports.
(iii) Description of the Prior Art
Many systems have been proposed to control the temperature within greenhouses. Thus, French Patent No. 371,926 dated Mar. 19, 1907 provides a system in which shades are provided which can be rolled up or down the exterior arched transparent walls of greenhouse structures.
Italian Patent No. 695,829 dated Sept. 27, 1965 provides a system in which shades are drawn within the inside of the greenhouse structure, the shades being in the form of a movable horizontal ceiling.
Italian Patent No. 717,643 dated Oct. 15, 1966 provides a system in which shades are drawn across the transparent portion of the greenhouse parallel to the sloping roof thereof to provide an internal, dropped shielding ceiling.
Canadian Patent No. 982,426 issued Jan. 27, 1976 to R. Delano et al provides a method of protecting greenhouses involving coating the inside transparent surfaces of the greenhouses with a coating which is translucent, so that the amount of light permitted therethrough is controlled by the thickness and density of the coating and which, when wet, becomes almost transparent, permitting the passage of considerably more light therethrough than when dry. The humidity of the interior of the greenhouse, which was alleged to vary from high on cloudy days to low on sunny days, was said automatically to control the amount of light entering the greenhouse.
Canadian Patent No. 1,003,641 issued Jan. 18, 1977 to H. Grossman et al provided a shade-providing system including at least one powered track on which a drape or shade cloth was supported for covering an area. The powered track included a self-contained motor means having a track guiding means for drawing the shade cloth between a gathered stored position and to an extended position for shading a selective area. The shade system could also include suspension tracks spaced from the powered track means for maintaining the shade cloth or panel elevated above the benches. The suspension tracks were said to be devoid of any actuating means and served merely as a support and guide for the shade cloth.
U.S. Pat. No. 4,064,648 issued Dec. 27, 1977 to C. L. Cary provided an insulating system for reducing heat loss from a structure during one part of the day and for permitting light to enter the structure during another part of the day. This system included a roll mounted within the structure, a flexible sheet of material wound around the roll, a structure for supporting the roll immediate its length and engaging portions of the wound sheet, and means both for unwinding the sheet from the roll and deploying it in a plane and for rotating the roll to rewind the sheet therearound.
Canadian Patent No. 1,043,070 issued Nov. 28, 1978 to M. Dube provided a system of filling double-glazed building panels with insulating light-weight granular material for the purpose of providing insulating shading or privacy and for evacuating such material therefrom when light transmission was to be restored. The system included a container for the material, a header for through-flow of gas-conveyed granular material into and from the space between the double-glazed unit, and blower means and controls therefor for conveying the granular material into the space and for retaining it therein by gaseous pressure.
U.S. Pat. No. 4,067,347 issued Jan. 10, 1978 to Lipinski provided a portable solar-heated shelter comprising at least one fixed roof layer and a second mechanically supported roof layer which can be selectively employed to vary the thermal characteristics of the shelter. The second roof layer was adapted to be unwound from a storage spool and drawn into a take-up spool, passing over the first roof layer, by a cranking action. The second roof layer included a first sunshade portion and a series connected heat insulative portion of opaque material which may be selectively deployed to control the thermal characteristics of the enclosure.
Canadian Patent No. 1,054,081 issued May 8, 1979 to D. M. Fraioll provided a double wall fabric panel unit supported by pressurized air pumped into the interior thereof, with insulation provided in the double walled panels by including a plastic coated fabric panel and a thermal liner panel, with said edge strips being discontinuous to provide spaced air passageways to vent air from between the panels as the unit is rolled.
While the teachings of U.S. Pat. Nos. 4,067,347 (Lipinski) and 4,064,648 (Cary), described above, provided a movable insulation to allow entrance of light in day and provide insulation at night, the Lipinski and Cary approaches are uneconomical because of their complexity and have one basic failing, namely, that they do not protect against formation of frost or ice within the structure but outside of the insulating layer.
Moreover, Cary does not provide a movable insulation outside the usable space. The system taught by Cary is very difficult and expensive to install. Installed within a greenhouse, it will be extremely difficult to overcome the infiltration of warm, moist air above the flexible material at night which will freeze on the mechanism or the roof. In cold climates (e.g., as in Canada and the northern United States), this system will not prevent the freezing problem, and in addition, it will create a cold mass of air above the blanket that will fall once the blanket is withdrawn, and result in chilling that will impede the growth of greenhouse crops. Cary attempts to overcome the icing and snow accumulation on the outside of the roof by automatically retracting the blanket.
Lipinski provides for the placement of the insulating barrier between unpressurized flexible roof layers. The system, however, will fail in cold freezing climates since any small hole (either accidental or otherwise) will allow the warm moist air to penetrate into the space between his roofs, freeze onto the mechanism, tear the walls and immobilize the blanket. Its very nature only allows it to be used on structures of short length, i.e., movable shelters.
SUMMARY OF THE INVENTION
(i) Aims of the Invention
Accordingly, a broad object of this invention is to provide a system which has great economic significance for the greenhouse industry, is practical, economical and immediately usable.
Another object of this invention is to provide such a system which is simple and hence which has a very high potential in the market place for all countries with cold climates.
Another object of this invention is to provide such a system which includes an automatic retraction device.
Still another object of this invention is to provide such a system whereby snow on the greenhouse is caused to melt or fall off naturally by retracting the blanket and by inflation and/or mechanical pulsations.
(ii) Statement of Invention
This invention provides a structure comprising: (A) an enclosure having an outer light-transparent wall and an inner light-transparent wall spaced apart from that outer wall: (B) means for charging the space between the outer wall and the inner wall with air upper pressure, the air having a dew point so selected that it will not allow condensation to take place under pressure; (C) and an insulating layer disposed in, and bathed on both its side faces by the pressurized air in the space between the outer wall and the inner wall, the insulating layer comprising an insulating blanket which is situated in the pressurized air space which exists between the outer wall and the inner wall the insulating blanket having a leading edge and a trailing portion and being movable between an extended covering position and a retracted stored position within an enclosed storage area; (D) means connected to the leading edge of the insulating blanket and positively operable to move the leading edge from its retracted stored position to its extended covering position; and (E) means operatively associated with the trailing portion of the insulating blanket and adapted to draw the insulating blanket from its extended covering position to its retracted stored position.
(iii) Other Features of the Invention
The pressurized air space may be disposed only in a horizontal or approximately horizontal position, in which case the insulating blanket is drawn across the horizontal area by carrier cables from an accordion-folded retracted stored position to an extended covering position, and vice versa, and with the leading edge at any selected position between extended and retracted.
The horizontal-type situation would be, for example, on a gutter-connected, pillow-type open greenhouse.
By such feature, the greenhouse of the gutter-connected pillow-type, open-type includes a roof of a plurality of inflated double-walled polyethylene pillows.
By another feature thereof, the insulating blanket is supported at spaced-apart locations throughout its length by carrier cables, the carrier cables being movable in both directions under constant tension to extend or to retract the insulation blanket.
Another situation where the insulating blanket is drawn across a roof structure is when it is disposed in a metal arch gutter-connected greenhouse. The insulating blanket would move in a generally one-half sinusoidal path.
By yet another feature, the greenhouse of the metal arch gutter-connected type includes an inner transparent layer of polyethylene resting on the metal arched frames and separated from the outer polyethylene arch by the outside air under pressure.
By a feature thereof, the insulating blanket is supported by three longitudinally extending cables, which are under tension to enable movement of the blanket, but which, when relaxed, allow the insulation blanket to rest on the inner polyethylene layer to provide the covering insulation.
By a further feature thereof, the blanket is provided with carrier cables, the carrier cables being movable transverse of and within the arches in both directions under constant tension to extend or to retract the insulation blanket.
If the greenhouse is a steep roof type or quonset hut type, the trailing edge is provided with a ballast weight or tension device, e.g., an electric tension cord to draw the blanket into a lower storage box. The storage box may or may not be insulated.
If the greenhouse is of the flat roof type, the insulating blanket is controlled by a two-rope constant-tension system. The insulation may be one extensive width or be of a plurality of butted batts of insulating blankets.
By another feature, the greenhouse is of the very flat roof hoop-type, and includes a plurality of such butted batts of insulation blankets, with extension and retraction being accomplished by a rope secured at one end to the leading edge of the insulation blanket and at its other end wrapped in one direction on a rotatable shaft, and a second rope wrapped in an opposite direction to the rotatable shaft and trained around a lower pulley and secured to a lower pull bar on the insulation blanket.
By yet another feature, in a very flat roof type greenhouse, a pair of rollers are provided engaging opposite faces of the insulation blanket to hold the insulation blanket to the vertical wall.
By yet another feature, the greenhouse is of the quonset hut type and the extension and retraction of the insulation blanket is accomplished by a continuous rope, entraining a plurality of pulleys within the greenhouse, wound around a rotatable winding shaft and each end connected to the leading edge of the insulation blanket.
By another feature, the operating means comprises a motor manually actuatable to move the insulating blanket to a selected position between its extended covering position and its retracted stored position, and to hold the blanket at that selected position.
By another feature, the operating means comprises a motor automatically actuatable in response to a preselected cycle automatically to move the insulating blanket in response to predetermined positions of the sun with respect to the greenhouse.
By a further feature thereof, one longitudinal half of the greenhouse has its insulating blanket in its extended covering position while the other longitudinal half of the greenhouse has its insulating blanket in its retracted stored position.
By another feature, one longitudinal half of the greenhouse has its insulating blanket movable between its extended covering position to its retracted stored position, while the other longitudinal half of the greenhouse has its insulating blanket movable between its retracted stored position and its extended covering position.
By a further feature, the greenhouse is of the hoop-type and includes an arched framework, an outer light-transparent covering thereover, a spaced-apart, inner, light-transparent membrane thereover, and fan means for inflating the space between the outer covering and the inner membrane with outside air.
By yet another feature, the fan means introduces air into one of the storage boxes or above the boxes, or at any other convenient location.
By still another feature, the fan means introduces air into a header disposed at the apex crest of the arched structure, between the outer covering and the inner membrane.
By yet another feature of such greenhouse, the outer covering and the inner membrane each comprise a polyethylene sheet.
By another feature, the greenhouse is of the rigid transparent type, e.g., glass plates and an outer skin of flexible transparent plastic sheet disposed in spaced-apart relation from the rigid transparent, e.g., glass plates between the base of the structure and the apex of the roof thereof, and includes fan means for introducing the outside air under pressure between the rigid transparent, e.g, glass plates and the transparent skin to provide a double walled unit.
By another feature, the rigid transparent plates are, e.g., flat or corrugated sheet material made of glass fibers.
By another feature thereof, the fan means pressurizes the space of the storage boxes or above the boxes or at any other convenient location under conditions of zero or approaching zero flow, in order to minimize heat transfer and minimize fan power.
By another feature, the insulating blanket includes a pair of sealing skins with a filling of insulating material therebetween.
By a further feature thereof, one skin is formed of a pliable waterproof material, e.g., polyethylene or polyvinyl plastic.
By another feature, one skin is formed of an aluminized material.
By a further feature, the filling of insulating material is formed of a structurally integral glass fiber blanket.
By yet another feature, the insulating blanket includes a further portion comprising a mesh material to provide shading to restrict the amount of light entering the greenhouse.
(iv) Generalized Description of the Invention
Accordingly, this invention addresses itself to several critical problems, namely, reduction of light by north wall insulation, the formation of ice on the structure covering and morning chill of crop, and wind problems and the economics, and substantially overcomes such problems by a movable layer of flexible insulation placed between the two spaced-apart walls of the greenhouse which are charged with pressurized air, depending on light and temperature conditions, to minimize heating requirements. The inside cover of the insulation is preferably covered with a light-reflecting material, e.g., reinforced aluminized material, to enhance light conditions when partially covered.
The provision of the pressurized zone of gas between the outer and inner walls has the following advantages:
(1) It substantially eliminates any freezing problem in the space containing the insulation since outdoor air entering into the structure is dry and substantially prevents moisture penetration into the space from the interior.
(2) Because of the pressurization, a space is provided which is free of structure, that easily accommodates thick or thin insulation (up to 3" or more in thickness) and provides a space for a suitable windup mechanism. It can accommodate any length of greenhouse. The standard 100' greenhouse could thus use two 50' systems or any number of smaller sizes modular systems. (3) The complicated storage device is eliminated. In one embodiment, the insulation folds under the action of gravity, which effectively eliminates the lower roller.
(4) The system can be installed on an existing greenhouse structure with minor modifications.
(5) The system can preferably be automated so that the insulation covers the greenhouse as night comes and lowers at dawn.
(6) The inflated layer contains dry air since the inflation is accomplished with outdoor air and no significant frost formation can occur.
The insulation is protected from the wind since it rests on the inner wall in a smooth channel free of obstructions so that a movable insulating blanket may be drawn up at night and let down in the day. The insulation is preferably a flexible glass fiber insulation with a reinforced light reflection backing which allows pulling of the flexible blanket.
Maximum effective light for growing with minimum heating is achieved by drawing the insulating blanket part way up during early morning or late afternoon.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings,
FIG. 1 is a perspective view of the greenhouse of one embodiment of the present invention;
FIG. 2 is a transverse cross section through the embodiment of FIG. 1;
FIG. 3 is a transverse cross section through a greenhouse of a second embodiment of this invention;
FIG. 4 is a transverse cross section through a greenhouse of a third embodiment of this invention;
FIG. 5 is a front elevational view of a gutter-connected pillow-type open greenhouse of another embodiment of this invention;
FIG. 6 is a side elevational view of the embodiment of FIG. 5;
FIG. 7 is a detail of the embodiment of FIG. 5 showing the disposition of the insulating blanket and the extension and retraction thereof;
FIG. 8 is a front elevational view of a metal arch gutter-connected greenhouse of yet another embodiment of this invention;
FIG. 9 is a detail of an arch of the embodiment of FIG. 8, showing the disposition of the insulation blanket;
FIG. 10 is a perspective view of a greenhouse of still another embodiment of this invention which is a variation of the embodiment of FIG. 1;
FIG. 11 is a perspective detail view showing the extension and retraction of the insulation blanket;
FIG. 12 is a transverse cross section through the embodiment of FIG. 10;
FIG. 13 is a transverse cross section through yet another embodiment of this invention which is another variation of the embodiment of FIG. 1; and
FIG. 14 is a cross section through a typical insulating blanket used in the greenhouse of embodiments of this invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
(i) Description of FIGS. 1 and 2
As seen in FIGS. 1 and 2, the greenhouse structure 10 includes an arched framework 11 supporting an outer transparent covering 12 e.g., of polyethylene film or rigid preformed glass or polyethylene sheet and an inner transparent membrane 13 e.g., of polyethylene film or rigid preformed glass or polyethylene sheet. A fan 14 fills the space between outer covering 12 and inner transparent membrane 13 with pressurized air, e.g., dry outdoor air drawn in through end wall inlets to a header 14a, which air may be heated air in order to heat the greenhouse in winter. Alternatively, the fan 14 may drawn in outside ambient air through a vaned aperture at the base of storage box 21.
The insulation system 20 of an embodiment of this invention includes a storage box 21 (which may or may not be insulated) at the base 22 of the greenhouse 10 and a longitudinal roller 23 at the crest of the greenhouse 10. A reversing motor 24 is provided having a sprocket 25 thereon driving a sprocket 26 on the roller 23 by means of a chain 27 or alternatively by a direct drive to the roller 23. Secured and entrained on roller 23 is a plurality of ropes 28 whose free ends 29 are secured to the upper edge 30 of an insulation blanket 31. The lower edge 32 of the insulation blanket 31 is secured to the bottom 33 of the storage box 21 (which may or may not be insulated) and is also provided with a longitudinally extending lower ballast weight 34. Ballast weight 34 should be located about 3 feet above the ground level 33 in order to pull the blanket 31 in its initial stages.
(ii) Operation of Embodiment of FIGS. 1 and 2
In operation, rotation of the motor 24 in one direction causes the ropes 28 to wind up on the roller 23, thereby drawing the insulation blanket 31 up to its extended covering position against the force exerted by the weight of the blanket 31 and the weight of the ballast 34. Rotation of the motor 24 in the reverse direction allows the blanket 31 to be drawn down by its own weight and the weight of the ballast 34 into the storage box 21 (which may or may not be insulated) in a natural accordion-type fold to its retracted stored position.
While the description of the operation has referred to rolling and unrolling the insulation blanket, such operation may embody several options. The motor may be manually actuatable to move the insulating blanket to a selected position between its extended position and its retracted stored position, and to hold the insulating blanket at that selected position. The motor may be automatically actuatable in response to a preselected cycle automatically to move the insulating blanket in response to predetermined positions of the sun with respect to the structure. In its operation, one longitudinal half of the structure may have its insulating blanket in its extended covering position while at the same time the other longitudinal half of the structure has its insulating blanket in its retracted position. Finally, in its operation, one longitudinal half of the structure may have its insulating blanket at an intermediate position between its extended covering position and its retracted stored position, while at the same time the other longitudinal half of the greenhouse has its insulating blanket at an intermediate position between its retracted stored position and its extended covering position.
(iii) Description of FIG. 3
As seen in FIG. 3, the greenhouse 310 includes an arched framework 311 supporting an outer transparent covering 312 and an inner membrane 313. The outer transparent covering 312 and the inner membrane 313 may be made of the same material as described for members 12 and 13 in FIG. 1. A fan 314 fills the space between outer coverings 312 and inner membrane 313 with outside air through an inlet 314a at the bottom 322 of the storage box 321 (which may or may not be insulated), which air may be heated air in order to heat the greenhouse 310 in winter.
The insulation system 320 of an embodiment of this invention includes a storage box 321 (which may or may not be insulated) at the base 322 of the greenhouse 310 and a longitudinal roller 323 at the crest of the greenhouse 310. A reversing motor 324 is provided having a sprocket 325 thereon driving a sprocket 326 on the roller 323. In another alternative, a pullcord (not shown) may be used for manual operation. The roller 323 may be located either between the covering layers 312 and 313, or outside the inner layer of the greenhouse 310. Secured and entrained on roller 323 is a plurality of ropes 328 whose free ends 329 are secured to the upper edge 330 of an insulation blanket 331. The lower edge 332 of the insulation blanket 331 is secured to the bottom 322 of the storage box 321 (which may or may not be insulated) and is also provided with a longitudinally extending lower ballast 334.
(iv) Operation of Embodiment of FIG. 3
In operation, rotation of the motor 324 in one direction causes the ropes 328 to wind up on the roller 323, thereby drawing the insulation blanket 331 up to its extended covering position against the force exerted by the weight of the blanket 331 and the weight of the ballast 334. Rotation of the motor 324 in the reverse direction allows the blanket 331 to be drawn down by its own weight and the weight of the ballast into the storage box 321 (which may or may not be insulated) in a natural accordion-type fold to its retracted storage position. As shown, however, the greenhouse 310 is so fitted with two rollers that one longitudinal half has its blanket in the lower retracted stored position to allow early morning sun to enter the greenhouse, while the other longitudinal half has its insulation blanket in its upper extended covering position. The blankets are switched in their dispositions as the day progresses.
The blanket falls within the storage box 321 (which may or may not be insulated) due to its own weight and the weight of the ballast 334. It may be guided by means of tracks (not shown) at the ends of or in the greenhouse.
While not specifically shown here, the blanket may include an extension of a mesh material to provide shading to restrict the amount of light (and thus heat) entering the greenhouse. Thus, the blanket system may be useful for cooling as well as for retaining heat.
(v) Description of FIG. 4
As seen in FIG. 4, the greenhouse 410 includes a standard glass framed greenhouse 411 including an inner rigid series of panels 412 (which may be either of glass or of transparent plastic). It is modified by an outer transparent covering 413 of polyethylene sheet, joined to the storage box 421 (which may or may not be insulated) at its lower end, and to the apex 450 of the greenhouse 410 at its upper end. A fan 414 fills the space between inner coverings 412 and outer membrane or membranes 413 through an inlet 414a at the bottom 422 of the storage box 421 (which may or may not be insulated), which air may be heated air in order to heat the greenhouse 410 in winter.
The insulation system 420 of an embodiment of this invention includes a storage box 421 (which may or may not be insulated) at the base 422 of the greenhouse 410 and a longitudinal roller 423 at the crest of the greenhouse 410. A reversing motor 424 is provided having a sprocket 425 thereon driving a sprocket 426 on the roller 423 by means of a chain 427 or alternatively by direct drive to the roller 423. Secured and entrained on roller 423 is a plurality of ropes 428 whose free ends 429 are secured to the upper edge 430 of an insulation blanket 431. The lower edge 432 of the insulation blanket 431 is secured to the bottom 422 of the storage box 421 (which may or may not be insulated) and is also provided with a longitudinally extending lower ballast 434.
(vi) Operation of Embodiment of FIG. 4
In operation, rotation of the motor 424 in one direction causes the ropes 428 to wind up on the roller 423, thereby drawing the insulation blanket 431 up to its extended covering position against the force exerted by the weight of the blanket 431 and the weight of the ballast 434. Rotation of the motor 424 in the reverse direction allows the blanket 431 to be drawn down by its own weight and the weight of the ballast 434 into the insulated storage box 421 (which may or may not be insulated) in a natural accordion-type fold to its retracted stored position. The insulation takeup can be either accordion fold (as described) or on a roller (not shown). As shown, however, the greenhouse 410 is so fitted with two rollers that one longitudinal half has its blanket in the lower retracted stored position to allow early morning sun to enter the greenhouse, while the other longitudinal half, on a second roller, has its insulating blanket in its upper extended covering position. The insulating blankets are switched in their dispositions as the day progresses.
The insulating blanket 431 falls within the storage box 421 (which may or may not be insulated) due to its own weight and the weight of the ballast 434. It may be guided by means of tracks at the ends and rollers 451 at the sides of the greenhouse.
(vii) Description of FIGS. 5, 6 and 7
The greenhouse 510 of FIGS. 5, 6 and 7 includes a plurality of upright columns supporting gutters 511a which, in turn, support a plurality of inflated pillow polyethylene covers comprising an outer skin 512 and inner skin 513. A fan 514 within a header house or non-greenhouse structure 514a fills the space between outer skin 512 and inner skin 513 with outside air, which air may be heated air in order to heat the greenhouse 510 in winter.
The insulation system of an embodiment of this invention includes a horizontal storage box 521 above the header house 514a. An insulation blanket 531 extends across the inflated pillow covers. Three ropes or cables 540, 541, 542 which extend longitudinally of the greenhouse and are anchored to a cross-brace at both ends of the greenhouse 510 (not shown) to support the insulation blanket 531 with grommets 543 for vertical movement between a tensed condition, (in which the inflated pillow is not covered by the insulation blanket 531 for insulation purposes) and a relaxed condition (in which the insulation blanket 531 is resting on the inner skin 513 for insulation purposes). One such cable tensioning device may be a hydraulic cylinder whose rod end is provided with a pulley entrained by the cable. Another cable 544 may be a moving device.
(viii) Operation of Embodiment of FIGS. 5, 6 and 7
The insulation blanket 531 may be retracted to the accordion folded condition shown in FIG. 6 by drawing a clamp (not shown) at the leading end of the respective cable from the forward end of the greenhouse 510 to the storage end at the storage box 521.
(ix) Description of FIGS. 8 and 9
The embodiment of greenhouse 810 shown in FIGS. 8 and 9 is virtually the same as that shown in FIGS. 5, 6 and 7 and so the same parts will be designated on the drawings by the same reference numeral in the "800" series rather than the "500" series but will not be described in detail. The only significant difference between the "500" embodiment and the "800" embodiment is that the metal arch gutter-connected greenhouse of FIGS. 8 and 9 includes a metal arch framework 811b interconnecting the gutters 811a resting atop the gutter support columns 811. The outer skin 812 is fixed to the gutters 811a spaced away from the metal arch framework 811b, while the inner skin 813 rests on the metal arch 811b.
(x) Operation of Embodiment of FIGS. 8 and 9
The construction and operation of the insulation blanket 831 is the same as in the embodiment of FIGS. 5, 6 and 7.
(xi) Description of FIGS. 10, 11 and 12
The embodiment shown in FIGS. 10, 11 and 12 is virtually the same as the embodiment shown in FIG. 1 and hence the same parts will be designated on the drawings by the same reference numeral in the "1000" series rather than in the "10" series, but will not be otherwise described. Because the greenhouse 1010 is a very flat roof quonset hut type greenhouse, a different extension-retraction system is used.
The greenhouse 1010 shown in FIGS. 10-12 comprises a framework in the form of a plurality of spaced apart "A" frame members 1011 connected together at their apices by a longitudinally extending ridgeboard 1050. The inner transparent membrane 1013 may be formed of light-transmitting polyethylene film or it may be formed of thin but rigid glass. The outer transparent covering 1012 may be formed of a polyethylene film, but preferably is of a rigid light-transmitting material, e.g., glass or preformed polyethylene sheets. The lower portion at each base of the frames 1011 define the storage box 1021.
A fan 1014 draws in dry air and discharges it under pressure into the space between inner membrane 1013 and outer transparent covering 1012, via portion 1014a. The air may be dry ambient air drawn from outdoors, or from a source of dry heated air (not shown).
The insulation blanket 1031 is provided as a plurality of narrow edge butted batts 1031a, 1031b, 1031c, etc. and are extended and retracted by a two-rope system. One rope 1041 is connected to the leading edge 1030 of insulation blanket batt 1031a and extends to a pulley 1026a, mounted on the ridgeboard 1050 and then is wound on a winding shaft 1023 driven by a reversing motor 1024 via drive pulley 1025 entraining a driven pulley secured in winding shaft 1023 by a belt 1027. A second rope 1042 is wound on winding shaft 1023 in an opposite direction and extends within the inner polyethylene or glass membrane 1013 guided by pulleys 1043 (supported on membrane 1013) to the storage box 1021 where it is guided by pulley 1044 and 1045 within the pressurized air layer to be secured to the leading edge 1030 of the insulating blanket batt 1031a.
As also seen in FIG. 12 at the junction of the roof and the wall, the insulation blanket batts 1031a, etc. pass on the outside of roller 1046 and on the inside of roller 1047 in order to hold the insulation 1031a, etc. tight to the wall. An alternative retraction system is a tension device (e.g., a stretchable rope) 1047 pulled tight on raising the insulation 1031.
(xii) Operation of the Embodiment of FIGS. 10, 11 and 12
Thus, rotation of the winding shaft 1023 in one direction results in extension of the insulation blanket batt 1031a to its covering position, while rotation of the winding shaft 1023 in an opposite direction results in retracting the insulation blanket batt 1031a within storage box 1021 in accordion folded form. The ropes 1041 and 1042 are maintained under constant tension to facilitate accurate operation. The other insulation blanket batts 1031b, 1031c, etc. are operated in a like fashion.
(xiii) Description of FIG. 13
The embodiment shown in FIG. 13 is virtually identical to the embodiment shown in FIG. 1 and hence the same parts will be designated on the drawings by the same reference numeral in the "1300" series rather than the "10" series, but will not be otherwise described. Because the greenhouse 1310 is a very flat roof quonset hut type greenhouse, a different extension-retraction system is used.
The greenhouse 1310 shown in FIG. 13 comprises a framework in the form of a plurality of arched frames 1311, each having a lower vertical segment which are transversely spaced apart. The arched frames 1311 are connected at their apices by a longitudinally split, longitudinally extending ridgeboard 1339. The inner transparent membrane 1313 may be formed of light-transmitting polyethylene film or it may be formed of thin rigid glass or polyethylene plate. The outer transparent covering 1312 may be formed of polyethylene film, in which case it is supported above the inner membrane 1313 by pressurized air, or it may be preformed rigid glass or polyethylene sheet. The lower portion at each base of the frames 1311 define the storage box 1321.
A fan 1314 draws in dry air and discharges it under pressure into the space between inner membrane 1313 and outer covering 1312, via port 1314a. The air may be dry ambient air drawn from outdoors, or from a source of dry heated air (not shown).
The insulation blanket 1331 is extended and retracted by a continuous rope system. The rope 1340 is secured to the inside edge 1330a of the leading edge 1330 of the insulation blanket 1331. It then passes a pulley 1347 in the pressurized air space above the ridgeboard 1339, then passes through a longitudinal slot (not shown) in the ridgeboard 1339 to the greenhouse space proper where it is wound on winding drive shaft 1323 driven by a motor as previously described. Now within the interior of the greenhouse 1310, the rope 1340 is guided by pulleys 1342-1345 to the bottom interior of the greenhouse 1310. Then it passes through the inner membrane 1313 to the pressurized air space and into the storage box 1321 where it is guided by pulley 1346. The rope 1340 fits between the insulation blanket batts 1331 and the outer covering 1312 in the pressurized air space and is secured to the outside edge 1330b of the leading edge 1330 of the insulation blanket. The leading edge 1330 is preferably a pull bar.
The rope 1340 is preferably a woven band (e.g., a 2"×1/16") which minimizes wear on the polyethylene and rolls on the shaft without sideways movement.
(xiv) Operation of the Embodiment of FIG. 13
Thus, rotation of the winding shaft 1323 in one direction results in extension of the insulation blanket batt 1331, while rotation of the winding shaft 1323 in the opposite direction results in retracting the insulation blanket batt 1331 within the storage box 1321 in accordion folded form.
(xv) Description of FIG. 14
As seen in FIG. 14, a typical blanket 1431 includes one skin 1441 of a pliable waterproof material, e.g., polyethylene or polyvinyl plastic film, and another skin 1442 of aluminized material. Between the skins is the insulation material, preferably a self-sustaining flexible pad of glass fibers. The ballast weight 1434 at the bottom but which is preferably about 3 feet off the ground 1433 is also shown.
SUMMARY OF ADVANTAGES OF THE INVENTION
The economics of the system of this invention projected from the cost of the present systems is about $28,000 per acre, while saving $24,000 per year in natural gas fuel bills, (at Western Canada prices). At the present price of oil, the cost of the system would be repaid in less than one year.
The disposition of the insulation outside the greenhouse structure proper in a pressurized zone rather than in the unpressurized zone described by Cary provides a significant advance over the prior art. The improvement can be used with greenhouses with inflated polyethylene outer layers or existing glasshouses with inflated layers added to reduce heating to 1/3 or less the present uninsulated or uncovered structure heating costs. In addition, the advantages of the pressurized system are so great (especially low cost) that the present invention has the potential of developing into a standard system for commercial, backyard greenhouses, swimming pools and any structure requiring sunshine or the benefits of solar energy. It can also be used in implement storage areas to provide a warm dry environment by the double layers of polyethylene. On cloudy days or at night the insulation blanket could be used.
SUMMARY
From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. Consequently, such changes and modifications are properly, equitably, and "intended" to be, within the full range of equivalence of the following claims.
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An improved building, e.g., a greenhouse structure, is provided herein. It consists of an enclosure having a pair of spaced-apart walls, e.g., an outer light transparent covering and an inner light transparent membrane spaced apart from the outer covering. A fan is provided for charging the space between the covering and the membrane with air, under pressure having a dew point so selected that it will not allow condensation to take place, e.g., outdoor air, or, preferably, heated air. An insulating layer is disposed in the pressurized air space between the outer covering and the inner membrane so that it is bathed, on both its faces, with the low dew point air under pressure. The insulating layer includes an insulating blanket disposed between the outer covering and the inner membrane, and is positively movable between an extended covering position and a retracted stored position. Operating structure is connected to a leading edge of the blanket and this structure is adapted to move the leading edge from its retracted stored position to its extended covering position. Cooperative structure is provided operatively associated with the trailing portion of the blanket. This structure is adapted to draw the blanket from its extended covering position to its retracted stored position. This provides a system in which heat loss from within the structure is minimized at night and yet does not result in excessive condensation within the structure.
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CROSS REFERENCES TO RELATED APPLICATIONS
[0001] Applicant claims priority under 35 USC 119 c to provisional application 61/212,169 filing date Apr. 8, 2009.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
[0002] Not Applicable
BRIEF DESCRIPTION OF THE PRIOR ART
[0003] It is known to provide shade for people in the water by providing inflatable floatation devices with shade. These are typically very small and intended for individual use. U.S. Pat. No. 4,248,255 is an example. The result is very limited shade that does not even cover one entire person. The shade further requires that the person remain on the floatation device.
[0004] Patent application 2003/0046755 discloses a somewhat larger arrangement but the shade is very confining. A person has to remain laying down. Also the shade takes up a large area so that others in the pool have little space to move around and enjoy the pool.
[0005] U.S. Pat. No. 5,505,645 discloses a one pole sun shade with a drink holder and anchor 13. This patent allows for greater movement but still provides a small area of shade and is very prone to blow over in a strong wind.
[0006] As can be seen, there is a need for an improved system for providing shade for people in the water.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to a free floating canopy shade system for use in a pool comprising a canopy having four legs each leg supported by a float. Each float has an outer cylindrical wall and an inner cylindrical wall, the inner cylindrical wall being sized to receive a leg. An attachment to attach each leg to the float, the float being water tight and open at the top. Wherein an open shaded area is created beneath the canopy bounded only on four corners by each float.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 shows a view of the present invention in use,
[0009] FIG. 2 shows details of a portion of the invention,
[0010] FIG. 3 shows details of a portion of the invention;
[0011] FIG. 4 shows an alternate embodiment of the invention;
[0012] FIG. 5 shows an overhead view.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] In accordance with the present invention, FIG. 1 shows a view of the portable canopy shade system 100 in use. The canopy shade system 100 includes a frame 102 with four legs 104 and a canopy 106 stretched on the frame 102 . The canopy system 100 also includes four corner floats 110 each cylindrical corner float 110 supports a leg 104 . As can be seen the canopy system 100 can float in a pool 120 . The light weight canopy system 100 will weigh less than 100 pounds so that the corner floats 110 can take up less than one square foot of pool surface area per supported leg 104 and less than one cubic foot of pool water is displaced by each float. Many commercially available four leg canopies are less than 50 pounds. The result is a canopy 106 that can provide a large area of shade perhaps 8 ft by 8 ft (64 square feet) while taking up a very small area of the surface of the pool (less than 4 square feet) for example. Further because the sides are open the canopy system 100 provides uninterrupted, unobstructed access to the pool in and out of the shaded area. The system 100 floats with the corner floats 110 nearly on top of the water line WL. The system 100 is designed so that it can use a conventional shade canopy 106 that are available for use now on patios. The canopy frame 102 might bolt together or fold up. The system 100 can be installed by first assembling the canopy 106 and legs 104 like it would be used on a patio. Then moving one person gets in the water with the 4 floats 110 . The person on the edge of the pool 120 can move the canopy 106 so that the first 2 legs 104 hang down into the pool 120 . Corner floats 110 are placed on these legs 104 then the first two legs can be floated out into the pool 120 until the person in the water can place corner floats 110 on the other two legs 104 . The canopy system 100 can be removed from the pool 120 by reversing the process. Alternatively the floats 110 can be attached to the legs 104 , using ties or clips to retain the corner floats 110 on the legs 104 while it is placed in the pool 120 .
[0014] FIG. 2 shows details of a corner float 110 with a leg 104 in place. The float 110 includes a cylindrical wall 150 shown partially cut away to show the inside of the corner float 110 . The float 110 includes a solid bottom 152 and an open top 154 . The cylindrical side wall 150 can be slightly tapered from top to bottom to allow the floats 110 to nest together for shipping for example the open top can have a 10 inch diameter and the bottom 152 can have a diameter of 9 inches. A float 110 includes an attachment point such as an eye 160 on the bottom surface 152 such that an anchor weight can be attached if desired.
[0015] FIG. 2 shows that the inside of the corner float 110 includes an inner cylinder 170 that is generally concentric with the outer wall 150 and that includes an opening in the top 172 ( FIG. 3 ) sized to receive leg 104 . The inner cylinder 170 can include molded support walls 174 . The corner float 110 can be molded in one piece or the inner cylinder 170 and supports can be assembled into the float 110 . Each corner float 110 can include an attachment such as a tie 180 that allows the float 110 to be tied to the leg 104 or some other point on the canopy 102 . The float 110 can be retained on the leg 104 if the leg fits tight in the inner cylinder 170 .
[0016] FIG. 3 shows the corner float 110 interior with the leg 104 removed. The outer wall 150 , bottom 152 and radial supports walls 174 can form 4 pie shaped sections 190 . The pie shaped sections 190 can be water tight such that a section 190 can be used to contain items such as drinks or personal items such as a shirt, watch or billfold. It is also possible to fill one or several pie sections with water, sand or other material such that the canopy system 100 has more weight such as might be required on a windy day or if the canopy system 100 were to be used at the beach. The float 110 can also be filled with ice and used as a cooler so it is possible to have one corner float 110 for a cooler and another of the four floats for dry storage.
[0017] FIG. 4 shows an alternate embodiment of the corner float 210 where the float 210 is a closed container. The closed container float 210 also includes an opening 220 which can be the top of a closed cylinder sized to receive the leg 104 within the float 210 . The closed corner float 210 includes a side wall 222 , a top 224 and a bottom surface 226 . A top attachment point 230 allows the float 210 to be tied to a leg 104 and a bottom attachment point 232 allows for the attachment of an anchor. A third embodiment of the corner float could be achieved by leaving off the bottom surface 226 and simply allowing the float to float on air trapped in the float by the wall 222 and top 224 . The top 224 can include a recess 226 such as a drink holder.
[0018] FIG. 5 shows a plan view of the pool 120 with the area (S) shaded by the canopy 106 indicated by dashed lines L. As can be seen the corner floats 110 provide access for a person to move in and out of the shades area S with unobstructed movement. The open lines L between the corner floats 110 allow for the pool 120 to be used in any way that it could without the canopy system 100 in place. The floats 110 take up only about ½-2% of the area contained between the floats 110 .
[0019] Although the description above contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. As such, it is understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the claims.
[0020] It will be obvious to those skilled in the art that modifications may be made to the embodiments described above without departing from the scope of the invention. Thus the scope of the invention should be determined by the claims in the formal application and their legal equivalents, rather than by the examples given.
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A free floating canopy shade system for use in a pool or at a beach. The canopy has four legs each leg supported by an open top float, each float having an outer tapered cylindrical wall and an inner cylindrical wall, the inner cylindrical wall being sized to receive a leg, an attachment to attach the leg to the float. The float being water tight and open at the top. Wherein an open shaded area is created beneath the canopy bounded only on four corners by each float.
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FIELD OF THE INVENTION
The present invention relates generally to orthopedic treatment devices, particularly to an ankle brace, and more particularly to a pliant ankle brace providing both compression and stability to the entire ankle joint region.
BACKGROUND OF THE INVENTION
In the treatment of soft tissue or skeletal injuries to the ankle joint, it is preferable to stabilize the ankle joint as well as portions of the foot and leg in the region of the ankle joint. At the outset, when the injury is in the acute rehabilitation phase, stabilization of the ankle joint generally comprises compression and significant mobility restriction thereof to reduce swelling and facilitate healing. As treatment progresses and the injury enters the return to activity phase, stabilization of the ankle joint generally requires lesser, yet still somewhat significant, mobility restriction thereof.
In the past, stabilization of the injury during the acute rehabilitation phase has required casting of the ankle joint, thereby immobilizing it. Removable ankle braces became available which could subsequently be used to stabilize the injury during the return to activity phase. Once the ankle joint was fully rehabilitated, a removable ankle brace could also be worn as a prophylaxis on the healthy ankle joint to minimize the risk of re-injury during activity. More recently, removable ankle braces have been developed which can even be employed during the acute rehabilitation phase of the injury in the place of a cast.
It is apparent that each phase of the injury has different performance requirements for the ankle brace. While presently-available ankle braces have specific utility for a given injury phase, no one ankle brace is sufficiently versatile to be useful throughout treatment of the ankle joint injury and thereafter when the ankle joint is fully rehabilitated. Thus, known ankle braces are found to exhibit at least one of the following deficiencies lack of compression, incomplete protection of the injury, discomfort when worn with a shoe, and cumbersome when engaging in activity. As such, a need exists for an ankle brace that overcomes these deficiencies and provides effective stabilization of the ankle joint during various stages of treatment or activity.
It is an object of the present invention to provide an orthopedic ankle brace that is sufficiently versatile to have utility in the acute and return to activity phases of an injury, as well as having utility as a prophylaxis for a healthy ankle joint. It is also an object of the present invention to provide an ankle brace that is capable of providing compression to the ankle joint while adequately restricting mobility of the ankle joint during the acute phase of the injury. It is further an object of the present invention to provide an ankle brace that is capable of being comfortably worn under a shoe and which is not cumbersome to wear during activity.
SUMMARY OF THE INVENTION
The present invention is an orthopedic ankle brace for stabilizing the ankle joint as well as the foot and lower leg in the region of the ankle joint. The brace has specific utility for the treatment of ankle joint injuries, including both bone and soft tissue injuries. The brace is particularly effective during the acute rehabilitation phase immediately following the injury, or thereafter during the return to activity phase of the injury. The brace also has utility as a prophylaxis for healthy ankle joints to prevent new injuries or the reoccurrence of old injuries during activity. Accordingly, the brace is described hereafter in the context of its useful environment and in reference to those parts of the body with which the brace aligns and interacts.
The brace of the present invention comprises a pliant boot that wraps around and conforms to the contours of the ankle joint, thereby substantially enclosing the joint. When in place about the ankle joint, the boot has a proximal segment extending vertically and encircling the lower leg immediately above the ankle joint in the region of the distal tibia. The boot also has a distal segment extending horizontally and encircling the foot immediately below the ankle joint in the region of the plantar vault. The two segments intersect at the ankle joint, to provide a unitary boot.
The boot has a proximal opening through which the lower leg extends into the boot and a distal opening through which the distal end of the foot extends from the boot. A posterior opening is also provided at the base of the boot through which the tuberosity of the calcaneus extends, thereby serving as a heel lock for the brace when it is in position about the ankle joint. In a first embodiment, the brace further has an anterior opening extending the length of the boot which enables application of the brace onto the ankle joint and adjacent leg and foot.
A pair of flaps are provided across the anterior opening of the first embodiment, extending from one side of the boot to the opposite side thereof, and being releasably fastenable by means of releasable fasteners on each flap. The first flap is positioned on the proximal segment of the boot and the second flap is positioned below it on the distal segment. Unfastening of the flaps enables ready application of the boot to the ankle joint or ready removal therefrom, while fastening of the flaps secures the boot thereto. The releasable fasteners further enable adjustable tension of the fastened flaps, thereby enabling compression adjustment of the boot around the ankle joint.
Integral with each side of the proximal segment is a stiffening member which is formed from a more rigid material than that of the boot. The stiffening member is an elongated element extending vertically along the length of the proximal segment and terminating above the malleolus of the ankle joint. The stiffening member imparts a higher degree of stiffness to the side of the proximal segment than the pliant boot material.
Further provided integral with each side of the proximal segment is a retention member that is of intermediate rigidity relative to the pliant boot and stiffener members. The retention member is positioned immediately distal each stiffening member on the proximal segment of the boot at its intersection with the distal segment. In this position, the retaining member fits around the malleolus in abutment therewith, forming a malleolus pocket to isolate the malleolus from the stiffening member for the comfort of the wearer.
Affixed to the boot are a pair of tension straps which enhance the stabilizing effect of the brace on the ankle joint when the straps are in place. The first tension strap is anterior relative to the second tension strap and permits variable tension control of forefoot inversion and, to a lesser degree, variable tension control of internal rotation. This first, or anterior, tension strap has two ends and attachment means provided at each end for attaching the ends to the boot. More specifically, one end of the anterior tension strap is attached to the distal segment on one side of the boot and the other end of the anterior tension strap is attached to the proximal segment on the opposite side of the boot.
In the above-described configuration, the anterior tension strap extends from its point of attachment on the distal segment of the boot around the bottom of the distal segment abutting the plantar vault to the point of attachment at the proximal segment on the opposite side of the boot. Guides may be provided integral with the boot to maintain the position of the anterior tension strap relative to the boot. Furthermore, at least one of the attachment means permits removable attachment of a strap end, thereby enabling one to vary the tension in the strap by modifying the point of attachment along the end of the strap.
The second, or posterior, tension strap permits variable tension control of rearfoot inversion. The posterior tension strap, like the anterior tension strap, has two ends and attachment means provided at each end for attaching the ends to the boot. Both ends of the posterior tension strap are attached to the same side of the proximal segment. The strap extends from its first point of attachment on the proximal segment around the posterior thereof abutting the achilles tendon to the distal segment. The strap continues around the bottom of the distal segment abutting the calcaneus back to its second point of attachment on the same side of the proximal segment.
As with the anterior tension strap, guides may be provided integral with the boot to maintain the position of the posterior tension strap relative to the boot. Also, at least one of the attachment means permits removable attachment of a strap end, thereby enabling one to vary the tension in the strap by modifying the point of attachment along the end of the strap.
Finally, a pair of retention straps are provided which encircle the lower leg and proximal segment to retain the two tension straps as well the proximal flap in their respective positions. The first retention strap is proximally located on the proximal segment above the distally located second retention strap. The first, or proximal, retention strap wraps around the boot at this point to secure the boot on the lower leg. The proximal retention strap also overlaps the adjacent proximal ends of the two tension straps and the proximal flap to further secure them in attachment with the boot.
The second, or distal, retention strap wraps around the boot, but without overlapping the adjacent proximal ends of the tension straps. Instead, the distal retention strap overlaps the posterior tension strap as it extends around the posterior of the proximal segment to retain its desired alignment. An auxiliary strap is, however, provided in conjunction with the distal retention strap which overlaps the adjacent proximal ends of the tension straps and is removably attachable to the distal retention strap to additionally secure attachment of the tension straps to the boot.
An alternate embodiment of the present invention is provided which is substantially identical to the abovedescribed embodiment with the exception of the means by which the boot applies compression to the ankle joint and further with some variations in the configuration of the retention straps. Specifically, the anterior opening is omitted from the alternate embodiment such that the boot is continuous across the anterior. Two parallelly aligned vertical flaps are provided on opposite sides of the boot which have parallel rows of eyelets formed therein. A lace is further provided which is threadable through the eyelets of alternate rows back and forth across the anterior of the boot, thereby providing means for adjustable compression of the boot against the ankle joint when the lace is tightened and tied at its ends.
The alternate embodiment is provided with only a single retention strap that wraps around the proximal segment to secure the boot to the lower leg. This retention strap differs, however, from the previous embodiment in that it simultaneously overlaps the adjacent proximal ends of the anterior and posterior tension straps and the extension of the posterior tension strap around the proximal segment. Thus, a single retention strap secures the adjacent ends of both tension straps in attachment with the boot and retains the posterior tension strap in its desired alignment.
It is apparent from the foregoing description of the ankle brace that particular advantages are realized therewith. As a device for acute rehabilitation, the ankle brace of the present invention is capable of applying adjustable compression and stability to the entire region of the ankle joint even as post-trauma swelling diminishes. Further, the present device can achieve a desirable degree of compression and stability without wearing a shoe in conjunction with the brace.
The present device also offers performance advantages during the return to activity phase of the injury. The brace fits easily within a shoe so that the wearer may engage in mobil activities while wearing the brace. The brace is sufficiently pliant to be comfortable within the shoe, yet sufficiently rigid to provide effective protection and stability to the ankle joint. Finally, as a prophylaxis, the device offers a preferred alternative to conventional taping of the ankle in that it is easy to apply and remove and is tension adjustable even when positioned within a shoe without necessitating removal of the shoe.
The present invention will be further understood, both as to its structure and operation, from the accompanying drawings, taken in conjunction with the accompanying description in which similar reference characters refer to similar parts.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a medial perspective view of the ankle brace of the present invention positioned on the ankle of a user.
FIG. 2 is a lateral perspective view of the ankle brace as shown in FIG. 1.
FIG. 3 is an posterior elevational view of the ankle brace as shown in FIG. 1.
FIG. 4 is an exploded lateral perspective view of the ankle brace of the present invention.
FIG. 5 is a medial perspective view of another embodiment of the ankle brace of the present invention positioned on the ankle of a user.
FIG. 6 is a lateral perspective view of the ankle brace as shown in FIG. 5.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
A first embodiment of the ankle brace of the present invention is described below with reference initially to FIG. 1, wherein a left ankle brace is shown and generally designated 10. It is understood that the foregoing description of a left ankle brace 10 can be adapted to a right ankle brace as well simply by reversing the elements of brace 10 in a manner readily determinable by one skilled in the art from the disclosure provided herein.
Ankle brace 10 comprises a boot 12 substantially enclosing the ankle joint 14. Boot 12 has a proximal segment 16 encircling the lower leg 18 adjacent the ankle joint 14 and a distal segment 20 encircling the foot 22 adjacent the ankle joint 14. Boot 12 is formed from a pliant material that for acute applications is preferably elastic to apply compression to the soft tissue of the ankle joint 14 and the surrounding lower leg 18 and foot 22. A suitable elastic material is a laminate of elasticized nylon fabric and neoprene, such as is well known for use in wetsuits. For prophylactic applications wherein compression is not required, the pliant material of boot 12 may be non-elastic such as a fabric or synthetic leather. Boot 12, as shown in FIG. 1, is preferably formed from a single piece of material that is cut out from a sheet according to a pattern and sewn together at its base to provide it with a tubular configuration.
A proximal opening 24 is provided in proximal segment 16 through which the lower leg 18 enters boot 12. A distal opening 26 is further provided through which foot 22 exits boot 12. Boot 12 also has a posterior opening 28 at the intersection of proximal and distal segments 16 and 20 through which the tuberosity of the calcaneus 30 protrudes to lock the boot 12 in place and prevent migration of the boot 12 along the lower leg 18 or foot 22.
An anterior opening 32 extends the length of boot 12. However, when boot 12 is in place about the ankle joint 14 as shown in FIG. 1, anterior opening 32 is substantially closed except for a small uncovered portion at ankle joint 14. Closure of anterior opening 32 is provided by a proximal flap 34 extending from, and integral with, the lateral face 36 of proximal segment 16. A conventional hook and loop fastener coupling 38, commonly termed VELCRO, is stitched onto the proximal flap 34 and the medial face 40 of proximal segment 16 to enable releasable and adjustable fastening of proximal flap 34 to medial face 40 when flap 34 is pulled across anterior opening 32.
Distal closure of anterior opening 32 is provided by a distal flap 42 extending from, and integral with, the lateral face 36 of distal segment 20. As in the case of proximal flap 34 and proximal segment 16, a conventional hook and loop fastener coupling 44, commonly termed VELCRO, is stitched onto the distal flap 42 and the medial face 40 of distal segment 20 to enable releasable and adjustable fastening of distal flap 42 to medial face 40 when flap 42 is pulled across anterior opening 32.
Ankle brace 10 further comprises a pair of tension straps 46 and 48 formed from a pliant, yet relatively inelastic, material such as an inelastic nylon fabric. The first, or anterior, tension strap 46 is so termed because of its anterior position relative to the second, or posterior, tension strap 48. Anterior tension strap 46 is fixedly attached at its medial end 50 to distal segment 20 by medial stitching 52 and passes under distal segment 20 abutting the plantar vault 54 to releasably connect at its other end not shown with the lateral face 36 of boot 12 in a manner described hereafter.
Posterior tension strap 48 likewise has two ends, but neither are shown in FIG. 1, both being connected to the lateral face 36 of boot 12 in a manner described hereafter. Strap 48 is shown passing under distal segment 20 abutting the calcaneus 56 and passing posteriorly behind distal segment 20 abutting the achilles tendon 58. A medial guide sleeve 60 is integrally provided on distal segment 20 by stitching it thereto, through which strap 48 is slidably retained in a desired orientation relative to the ankle joint 14. Guide sleeve 60 is formed from a pliant, yet relatively inelastic, material such as synthetic leather or inelastic nylon fabric.
Ankle brace 10 is further shown to comprise a pair of retention straps 62 and 64 which may be formed from substantially the same material as tension straps 46, 48. The first, or proximal, retention strap 62 is so termed because of its proximal position relative to the second, or distal, retention strap 64. Proximal retention strap 62 is fixedly attached by stitching at one of its ends 66 to proximal flap 34 and extends around proximal segment 16 abutting the lower leg 18. Strap 62 is releasably and adjustably fastened onto itself at its opposite end 68 by means of a hook and loop fastener coupling 70 after reversing end 68 through rigid loop 72. Proximal retention strap 62 is shown to retain the closure of proximal flap 34 and to apply compression to lower leg 18 across proximal segment 16. Other functions of proximal retention strap 62 are described hereafter.
Distal retention strap 64 is also fixedly attached by stitching at one of its ends 74 to proximal flap 34 and extends around proximal segment 16 abutting the lower leg 18, but below proximal retention strap 62. Strap 64 is releasably and adjustably fastened onto itself at its opposite end 76 by means of a hook and loop fastener coupling 78 after reversing end 76 through rigid loop 80. Distal retention strap 64 is shown to further retain the closure of proximal flap 34 and to apply compression to lower leg 18 across proximal segment 16. Finally, a smaller auxiliary retention strap 82 is positioned on distal retention strap 64 with one end 84 fixedly attached thereto and the other end (not shown) releasably attached which functions in cooperation with distal retention strap 64 as described hereafter.
Further shown in FIG. 1 are a malleolus pocket 86a and a stiffener pocket 88a which are sheaths formed from a pliant inelastic material, such as synthetic leather or inelastic nylon fabric, integrally stitched into the medial face 40 of proximal segment 16. Malleolus pocket 86a retains a retention member and stiffener pocket 88a retains a stiffener member which are described hereafter. Pockets substantially identical to pockets 86a, 88a are provided on the lateral face 36 of proximal segment 16.
Referring now to FIG. 2, the lateral face 36 of brace 10 is shown. Therein it is seen that anterior and posterior tension straps 46, 48 extend from under distal segment 20 and up the lateral face 36 of boot 12. The lateral end 90 of anterior tension strap 46 and a first lateral end 92 of posterior tension strap 48 are releasably and adjustably fastened to the lateral face 36 of proximal segment 16 adjacent to one another by a hook and loop fastener coupling 94 mounted in part on stiffener pocket 88b.
It is noted that proximal retention strap 62 overlaps anterior and posterior tension straps 46, 48, thereby securing the attachment of ends 90, 92 to proximal segment 16, whereas distal retention strap 64 passes underneath tension straps 46, 48. Auxiliary retention strap 82, however, is provided to overlap tension straps 46, 48 and has an end 96 opposite end 84 that is releasably fastened to distal retention strap 64 to further secure straps 46, 48. Finally, lateral guide sleeves 98, 100 similar to medial guide sleeve 60 are provided to slidably retain tension straps 46, 48 in a desired orientation relative to the ankle joint 14.
The orientation of posterior tension strap 48 and its cooperation with distal retention strap 64 is more clearly seen with reference to FIG. 3. Posterior tension strap 48 has a second lateral end 102 fixably attached to proximal segment 16 beneath distal retention strap 64. As tension strap 48 extends posteriorly across proximal segment 16 in abutment with achilles tendon 58, the overlapping distal retention strap 64 retains strap 48 in a desired orientation relative to the ankle joint 14.
Referring now to FIG. 4, stiffener members 104a, 104b and retention members 106a, 106b are shown outside of malleolus pockets 86a, 86b and stiffener pockets 88a, 88b, respectively. Each stiffener member 104 is a substantially planar sheet of a semi-rigid material, such as a high-strength plastic, which is capable of elastic flex when subjected to sufficient stress. The stiffener member 104 is essentially rectangular except for the distal edge 108 which is curved to conform to the shape of the arcuate retention member 106. Retention member 106 has an arcuate profile and is thicker than stiffener member 104. Retention member 106 is formed from a material which is more pliant than that of the stiffener member 104, yet less pliant than that of the boot 12. A preferred material is felt or a foam.
The stiffener members 104a, 104b and retention members 106a, 106b are incorporated onto the lateral and medial faces 36, 40 of the proximal segment 16 by stitching three sides 110a, 110b, 110c of a patch 112 of appropriate material onto each face, and leaving the proximal side 110d unstitched. The distal side 110b of patch 112 defines the malleolus pocket 86 and the anterior and posterior sides 110a, 110c define the stiffener pocket 88. A retention member 106 is inserted into the malleolus pocket 86 and positioned such that it is downwardly curved to fit around the top edge of the malleolus. Retention member 106 is then sewn into this fixed position by stitches 114. Thereafter, a stiffener member 104 is inserted into the stiffener pocket 88 with the distal edge 108 resting against the crown 116 of the retention member 106. Finally, the proximal edge 110d is stitched shut to retain the stiffener member 104 in the stiffener pocket 88.
With this assembly of boot 12, the stiffener member 104 functions to provide a stable base for the cooperation of straps 46, 48, 62, 64 with boot 12. The retention member 106 functions to prevent the stiffener member 104 from riding too low and rubbing against the malleolus. Accordingly, user discomfort is obviated while wearing the brace 10 and the stiffener members 104a, 104b are retained in their most effective position.
An alternate embodiment of the ankle brace of the present invention is described hereafter with reference to FIGS. 5 and 6. The alternate ankle brace is generally designated 210 in FIG. 5. Ankle brace 210 is substantially the same as ankle brace 10 shown in FIGS. 1-4 except that the boot 212 of ankle brace 210 has no anterior opening and, thus, the proximal and distal flaps are omitted from ankle brace 210. To apply compression to the ankle joint 14, the boot 212 is continuous around the ankle joint 14 and anterior and posterior segments 402 and 404 are integrally provided in boot 212.
Anterior and posterior segments 402, 404 are formed from an elastic material such as elasticized nylon fabric. The remainder of boot 212 may likewise be formed from an elastic material or alternatively be formed from a relatively inelastic material, such as synthetic leather or inelastic nylon fabric. Bordering the opposite sides of anterior segment 402 are two parallelly aligned vertical flaps 406, 408 respectively, which have parallel rows of eyelets 410, 412 formed therein. A lace 414 is threaded through alternate rows 410, 412 back and forth across anterior segment 402, thereby providing adjustable compression of boot 212 against the entire ankle joint region when lace 414 is tightened through eyelet rows 410, 412 and tied at lace ends 416a, 416b.
As with the previous embodiment, ankle brace 210 stabilizes the ankle joint 14 by means of anterior and posterior tension straps 246 and 248 shown in FIGS. 5 and 6. Malleolus and stiffener pockets 286, 288 are further provided containing stiffener and retention members (not shown) to cooperate with tension straps 246, 248 for inversion resistance and internal rotation resistance in the same manner as the previous embodiment.
Ankle brace 210 further differs from the previous embodiment in that it has only a single retention strap 264. Retention strap 264 wraps around the boot 212 to secure it to the lower leg 18 while laterally overlapping the anterior and posterior tension straps 246, 248. The retention strap 264 simultaneously posteriorly overlaps the posterior tension strap 248. Thus, retention strap 264 laterally secures both tension straps 246, 248 in attachment with boot 212 and posteriorly retains the posterior tension strap 248 in its desired alignment.
While the particular ankle brace as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages hereinbefore stated, it is to be understood that the brace is merely illustrative of the presently preferred embodiments of the invention and that other embodiments are possible within the scope of the present invention.
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An orthopedic ankle brace is provided having a pliant boot that surrounds the ankle joint, as well as the foot and lower leg in the region thereof. The boot may incorporate means of applying compression to the ankle joint. Attached to the boot are a pair of adjustable tension straps vertically disposed about the ankle joint for restricting the mobility thereof. Integral with the boot are pair of stiffening members positioned about the ankle joint to cooperate with the tension straps in the performance of their mobility restricting function Further provided integral with the boot are retention members that isolate the malleoli from the stiffening members for the comfort of the wearer. Finally, one or more retention straps are provided to maintain the stability of the brace.
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BACKGROUND OF THE INVENTION
The present invention relates to adducts of tetrasubstituted pyrophosphato titanates with phosphites and/or amines. The pyrophosphato titanate adducts of the present invention are useful in controlling the viscosity, flow and the conductivity of many filled resins. They improve the physical and chemical properties of many filled resins thereby permitting more valuable and more stringent usage with maintained ease of processing. They also serve as acid catalysts in various applications and inhibit water/salt caused corrosion in treated substrates.
The titanates of the present invention differ from the pyrophosphato titanates disclosed in U.S. Pat. Nos. 4,122,062 and 4,087,402 primarily by the controlled reactivity of the titanates presently mentioned which permits long term storage of said titanates and of the treated filler/pigment resin at ambient to moderately elevated temperatures, and a very specific initiation of functional rates of activity to occur at controlled temperatures depending upon the specific adduct ligand employed. Other advantages conferred upon pyrophosphato titanates by adduction as taught in the present invention include a substantially reduced tendency for such adducts to crystallize as compared to their non-adducted analogs thereby permitting greater ease of dispersion in more vehicles and decreased acidity. In addition, many of the nitrogeneous adducts are water soluble, thereby permitting use of aqueous vehicles in conjunction with fillers and pigments which were heretofore incompatible in water as well as the incorporation of water as a diluent in organic systems which were previously incapable of accepting significant water dilution.
SUMMARY OF THE INVENTION
The pyrophosphato titanate adducts of the present invention may be represented by the following formula:
X.sub.c Ti[OP(O)(OR.sup.1)OP(O)(OR.sup.2)(OR.sup.3)].sub.4-c (NR.sup.4 R.sup.5 R.sup.6).sub.d [P(OR.sup.7)(OR.sup.8)(OR.sup.9)].sub.e I
In Formula I, c is 1 or 2; d is 0, 1 or 2; and e is 0, 1 or 2, with the proviso that d plus e must be 1 or 2. When c is 2, X is either RO- or a group which taken together with the Ti to which it is attached forms a ring having the following Formula (VI): ##STR1## when c is 1, however, X must be RO--. In Formula VI, each of f, g, h and i is O or 1, with the proviso that at least one of g, h and i is 1 and that the sum of f, g, h and i is 2 or 3. Each R is independently chosen from among 1 to 10 carbon alkyl groups, 3 to 10 carbon alkenyl groups, 7 to 10 carbon aralkyl groups, 2 to 10 carbon oxyalkylene groups and 3 to 10 carbon dioxyalkylene groups. R 1 , R 2 , R 4 , R 7 , each R 10 and R 11 are independently chosen from among hydrogen, 6 to 10 carbon aryl groups, 7 to 20 carbon aralkyl groups, 1 to 20 carbon alkyl groups, 3 to 20 carbon alkenyl groups, 2 to 20 carbon oxyalkylene groups and 3 to 20 carbon oligooxyalkylene groups, except that one and only one of R 1 and R 2 must be hydrogen. R 5 , R 6 , R 8 and R 9 are independently chosen from the same groups as R 1 , R 2 , R 4 , R 7 , R 10 and R 11 except that R 5 , R 6 , R 8 and R 9 may not be hydrogen. R 5 and R 6 may also be independently chosen from among 1 to 10 carbon alkyl, 3 to 10 carbon alkenyl, 6 to 10 carbon aryl and 7 to 10 carbon aralkyl groups. These last four groups optionally have from 1 to 3 carboxylate groups or from 1 to 3 carboxamide groups as substituents. Each such substituent may be saturated or unsaturated and have from 1 to 5 carbon atoms. R 5 and R 6 may also be independently chosen from among 1 to 10 carbon alkanols, 2 to 6 carbon alkadiols or 7 to 10 carbon aralkanols. When aromatic carbons are present in R, R 2 , R 4 , R 7 , R 10 and R 11 groups, each of said carbons is optionally substituted by 1 or 2 independently selected halogen atoms (for example, fluorine, chlorine, bromine or iodine).
The present invention also relates to the use of such adducts for treating particulate fillers, including pigments, the compositions of fillers and the aforesaid adducts with thermoplastics, thermosets and coating or casting resins, and the use of such adducts in conjunction with coating and casting resin compositions in the absence of particulates.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The aforementioned alkyl and alkenyl groups, and alkyl and alkylene portions of the other aforementioned groups may be straight chain, branched chain or cyclic. Examples of alkyl groups are methyl, hexyl and decyl. Examples of cyclic alkyl groups are cyclohexyl and cyclooctyl. Allyl and crotyl are examples of alkenyl groups. Oxyalkylene groups are exemplified by methoxymethyl and methoxyethyl. Aralkyl groups are exemplified by benzyl and beta naphthyl methyl. Examples of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 and R 11 are likewise numerous. In addition to the above mentioned groups cited as examples of R, these groups are also exemplified by higher carbon analogs of the above such as octadecatrienyl and 2,4,6-trimethyl-1-cyclohexyl as well as by naphthyl and biphenyl aralkyl groups such as 2-phenethyl, 2-chloro, 4-bromophenyl or naphthyl. In addition to the above, R 5 and R 6 are exemplified by such groups as 3-methacrylpropyl, and 2-acrylamidoethyl hydroxy methyl and dihydroxy octyl.
The inorganic materials that may be treated with the titanate adducts of the present invention may be particulate or fibrous and of any shape or particle size, the surfaces of which are reactive with the hydrolyzable group of the organo-titanium compound by means of hydroxyl groups, or absorbed water, or both. Examples of such reactive inorganic materials are the metal oxides of zinc, magnesium, lead, and calcium and aluminum, iron filings and turnings, and sulfur. Examples of inorganic materials that are reinforcing materials are metals, clay, carbon black, calcium carbonate, barium sulfate, silica, mica, glass and asbestos. Examples of such inorganic materials that are pigments are titanium dioxide, iron oxides, zinc chromate and ultramarine blue. As a practical matter, it is preferable that the particle size of the inorganic material should not be greater than 1 mm, preferably from 1 micron to 500 microns.
It is imperative that the titanate adduct be properly admixed with the inorganic material so as to permit the surface of the latter to react sufficiently. The optimum amount of the titanate to be used is dependent on the effect to be achieved, the available surface area of and the bonded water in the inorganic material.
Reaction is facilitated by admixing under the proper conditions. Optimum results depend on the properties of the titanate, namely, whether it is a liquid or solid, and its decomposition and flash point. The particle size, the geometry of the particles, the specific gravity and the chemical composition, among other things, must be considered. Additionally, the treated inorganic material must be thoroughly admixed with the polymeric medium. The appropriate mixing conditions depend on the type of polymer, for example, whether it is thermoplastic or thermosetting, and its chemical structure, as will be readily understood by those skilled in the art.
Where the inorganic material is pretreated with the titanate adduct, it may be admixed in any convenient type of intensive mixer, such as a Henschel (trademark of Prodex) or Hobart (trademark of Hobart Corporation) mixer or a Waring (trademark of Dynamics Corporation of America) blender. Even hand mixing may be employed. The optimum time and temperature is determined so as to obtain substantial reaction between the inorganic material and the organic titanate. Mixing is performed under conditions at which the organic titanate is in the liquid phase, at temperatures below the decomposition temperature. While it is desirable that the bulk of the hydrolyzable groups be reacted in this step, this is not essential where the materials are later admixed with a polymer, since substantial completion of the reaction may take place in this latter mixing step.
Polymer processing, e.g., high shear mixing, is generally performed at a temperature well above the second order transition temperature of the polymer, preferably at a temperature where the polymer will have a low melt viscosity. For example, low density polyethylene is best processed at a temperature range of 177° to 232° C.; high density polyethylene from 204° to 246° C.; and polystyrene from 232° to 260° C. Temperatures for mixing other polymers are known to those skilled in the art and may be determined by reference to existing literature. A variety of mixing equipment may be used, e.g., two-roll mills, Banbury (trademark of Farrel Corporation) mixers, double concentric screws, counter or corotating twin screws and ZSK type of Werner and Pfleiderer (trademark of Werner & Pfleiderer) and Bussex (trademark of Bussex Corp.) mixers.
When the titanate adduct and the inorganic materials are dry-blended, thorough mixing and/or reaction is not readily achieved and the reaction may be substantially completed when the treated filler is admixed with the polymer. In this latter step, the titanate adduct may also react with the polymeric material if one or more of the groups on the titanate adduct is reactive with the polymer.
The ratio of pyrophosphato titanate to adducting agents is preferably 1:1 or 1:2, with the latter ratio most preferred. Each adducting ligand may be the same or different. In those formulations in which either the phosphorus based or the nitrogen based adducting agents are different, the product obtained is usually a mix of possible adducts including mixed as well as identical ligands. In those adducts wherein combinations of nitrogen and phosphorus are employed, it is often possible by control of stoichiometry and mode of addition to maintain an almost complete dispersity of product, if so desired.
When used in conjunction with particulates, the adducts of the present invention are employed at levels of at least 0.01 parts by weight, preferably from 0.1 to 5 parts by weight, and most preferably from 0.2 to 2 parts by weight, per 100 parts by weight of inorganic solid. The portion of adduct actually chosen by one skilled in the art is a function of the inorganic solid, its surface area and the particular titanium adduct selected. Upon reaction between the titanate and the surface of the inorganic solid, the titanate becomes chemically bonded to at least a portion of the inorganic solid, thereby modifying the surface considerably. The modified inorganic solid is generally far more easily dispersed in organic media than is the untreated solid. For treatment purposes, the titanate may be added to a suitable vehicle, such as water or a resin to be filled depending upon the investigator's desire and/or the nature of the titanate being employed. This addition is followed by appropriate shear to create an adequate level of dispersion. The treated particulate, in addition to being more effectively coated, will almost certainly have substantially valuable additional properties, such as the ability to act as a catalyst, improved adhesion to substrate, and/or the ability to activate a cross-linking agent in appropriate vehicle systems, primarily due to the availability or organo-functionality added by attached titanate molecules.
The amount of treated filler added to a resin generally ranges from about 1% to about 15% for a pigment and from about 1% to about 500% for an extender (all percentages are % by weight based on the weight of the resin). A wide variety of resins may be filled with fillers that are treated with the titanate adducts of the present invention. Examples of such resins are coating resins, casting resins, thermoplastic resins and thermosetting resins. Examples of all of the foregoing may be found in the reference Modern Plastics Encyclopedia.
In many instances, it is advantageous to dilute the titanate with an appropriately compatible fluid before the titanate is introduced into resin vehicles or before it is mixed with an inorganic particulate. Examples of appropriate inert fluids are aromatic hydrocarbons, ethers and glycol ethers. In many applications involving the use of nitrogeneous adducts of pyrophosphato titanates, water may also be utilized as a solubilizing inert vehicle, particularly in applications involving subsequent use in aqueous systems, such as latex products.
The compounds of the present invention may be prepared by numerous routes. Among the synthetic routes which have proven successful are the addition of appropriate phosphites (Formula II) and/or amines (Formula III) to the corresponding pyrophosphato titanates (Formula IV) described in U.S. Pat. No. 4,122,062 and U.S. Pat. No. 4,087,402. The reaction of tetraalkyl titanate phosphite adducts (Formula V), preparation of which is described in U.S. Pat. No. 4,080,353 with addition of an appropriate pyrophosphate, an amine and/or a phosphite and/or a chelating agent may also be utilized, as may processes employing titanium tetrachloride in place of tetraalkyl titanates. The aforementioned formulae are shown below:
Formula II
P(OR.sup.7)(OR.sup.8)(OR.sup.9)
Formula III
NR.sup.4 R.sup.5 R.sup.6
Formula IV
X.sub.c Ti[OP(O)(OR.sup.1)OP(O)(OR.sup.2)(OR.sup.3)].sub.4-c
Formula V
(RO).sub.4 Ti(P)(OR.sup.7)(OR.sup.8)(OR.sup.9).sub.d
In Formulae II, III, IV and V, the various notations and functional groups have the definitions given above for Formula I.
Another synthetic route found useful for the preparation of the phosphite adducts of the present invention wherein the adduct ligands are homogeneous is the reaction of tetraalkyl titanate with an admixture of disubstituted pyrophosphoric acid and the phosphite ligand(s). This last technique is the preferred one for the preparation of mono and di- phosphite adducts of such pyrophosphato titanates. Variations of the aforementioned synthetic routes will be apparent to those skilled in the art.
The preparation of phosphite adducts of corresponding pyrophosphato titanates may be accomplished under adiabatic conditions (since minimal heat evolution occurs) at any convenient temperature between approximately -20° C. and approximately 150° C. The addition of the phosphite to the pyrophosphato titanate in either direct or reverse order of addition will, in general produce minimal visual or thermal indication of reaction. However, typically, a bathochromic shift of the absorption maximum toward, and, occasionally even into the visual absorption range, will generally be observed. Additionally, the melting point will be depressed below that of the corresponding unadducted precursor. Solubility of the resulting titanate in hydrocarbon media will generally be increased at the expense of the dispersibility in water. By contrast, those adducts produced by the addition of appropriately substituted amines to pyrophosphato titanates or their phosphite adducts will generally provide substantial exotherms of formation together with displacement of stoichiometric proportions of phosphite, if present, and will produce products of considerably enhanced water solubility as compared to the parent pyrophosphato titanate. Techniques employing the addition of dibasic pyrophosphates to tetrasubstituted titanate adducts of phosphite and/or amines will also generate substantial exotherms of formation and in both of these latter two synthetic approaches, temperatures should be kept within the range of approximately 0° C. to approximately 150° C. by external cooling in order to minmize product degradation and/or by-product formation. Examples 1 through 4 below, are illustrative of the above mentioned techniques in the order indicated above for the preparation of pyrophosphato organo titanate adducts of the present invention. Subsequent examples 5 through 17 are illustrative of the utility of the materials of the present invention for a variety of applications, such as corrosion control, pigment/filler dispersion, catalyst activity control and impact improvement. Preferred methods of incorporation of the titanate adducts of the present invention into filled resin systems and their uses both in the presence and in the absence of fillers, for purposes other that those listed above are also illustrated.
EXAMPLE 1
Preparation of Di(butyl,methyl) pyrophosphato ethylene titanate di(dioctyl phosphite)
This example illustrates the sequential addition mode of phosphite adduct formation.
206 g of dimethyl acid pyrophosphate (1 mole) and 296 g of dibutyl acid pyrophosphate (1 mole) were charged into a 2 liter stainless steel and glass assembly comprising a mechanically stirred 2 liter glass vessel equipped with a thermometer, addition funnel, and a water cooled jacket. 285 g of tetraisopropyl titanate (1 mole) was added via the addition funnel over a period of 1 hour. Cooling sufficient to prevent the reactionmass temperature from exceeding 150° C. was maintained throughout the addition period. After 20 minutes of further mixing, 62 g of ethylene glycol (1 mole) were added over a period of about 20 minutes, at an addition rate and at a cooling rate such that the temperature of the reaction mass was kept between 42° and 46° C. 612 g dioctyl phosphite (2 moles) were then added, all at once. The resulting mass was transferred to a 2 liter flask equipped for vacuum distillation and was distilled from a water bath to give a pot residue having a boiling point of 80° C. 231 g of isopropyl alcohol (3.85 moles, GLC assay greaterthan 98%) were recovered as a distillate via liquid nitrogen cooling of volatiles. Product recovery was 1246 g (100% yield). The product was a pale yellow low viscosity liquid which crystallized slowly from a 40% solution in n-hexane at -20° C. to give light amber platelike crystals having a melting point of 48°±3° C. Recovery was1014 g (81%). The omission of byproduct isopropanol removal lowered productrecovery on crystallization to 63%, but otherwise gave unchanged results.
EXAMPLE 2
Preparation of Di(butyl, methyl) pyrophosphato ethylene titanate di(dioctylphosphite)
This example illustrates the preparation of the example adduct in situ.
The procedures, reaction conditions and materials examplified in Example 1 were employed except that the dioctylphosphite was introduced with the pyrophosphates prior to titanate addition. The nature of the crude productproduced and its yield (1248 g, 100%) were essentially unchanged, but this order of addition was found to provide several operating advantages. Amongthe advantages were lower and more uniform exotherms of tetraisopropyl titanate addition (possibly due to the larger mass in the pot "heat sink",and/or to the more efficient cooling made possible by the reaction mass' considerably lower viscosity) and virtual freedom from the formation of crystalline intermediates of undetermined nature which formed copiously during the procedure given in Example 1, unless the dispersion of tetraisopropyl titanate added was extremely efficient.
It should be noted that other tetraalkyl titanates, e.g., methyl, n-butyl, t-butyl, or sec-octyl may be substituted for the tetraisopropyl titanate used in the illustration. However, the use of n-alkyl titanates frequentlyresults in ligand exchange with the pyrophosphate moiety and may therefore result in complex product mixtures, especially via the procedure outlined in Example 1. Furthermore, the removal of higher boiling by-product alkanols, if desired, usually proved more difficult than the removal of the more volatile lower alkanols. The removal of by-product alcohol is optional and is not required for the preparation of the products of the present invention. Said removal merely facilitates product purification and/or may eliminate side reactions in alcohol sensitive substrates such as polyesters and urethanes and/or may provide decreased product flammability.
EXAMPLE 3
Preparation of Di(butyl,methyl) pyrophosphato, ethylene titanate di(dioctylphosphite)
Tetraisopropyl titanate di(dioctylphosphite), 901 g (1 mole), was charged to a 2 liter stainless steel vessel equipped with an efficient agitator and external cooling. Temperature was maintained at or below 45° C.during the sequential addition of 206 g (1 mole) of dimethyl acid pyrophosphate followed by 296 g (1 mole) of dibutyl acid pryophosphate over a period of approximately one hour each. Ethylene glycol 62 g (1 mole) was then added. The reaction mixture was then transferred to a Pyrex(trademark of Corning Glass for heat resistant borosilicate glass) glass system equipped for simple vacuum distillation and was distilled to give 1238 g (99% yield) of pale yellow oil having a boiling point of greater than 90° C. which slowly crystallized to produce a white waxy crystalline mass having a melting point of 49°±4° C.
This procedure was not as satisfactory as that of Example 1, because it suffered from the formation of localized gels during pyrophosphate addition. These gels made mixing difficult.
EXAMPLE 4
Numerous examples of chelated pyrophosphato titanate adducts prepared via the procedure given in Examples 1 to 3 are given in Table 1. Each titanateadduct is identified by a symbol in the extreme left hand column that similarly identifies the adduct in the Examples that follow.
TABLE 1__________________________________________________________________________ Method of Melting CalculatedPyrophosphato Titanate Adduct Preparation Point °C. % P/Found % P__________________________________________________________________________(A) ethylene di(butyl, octyl)pyro- 1,2,3 <0 16.4/16.1 phosphato titanate di(tris- ethylphosphite)(B) 1-oxo-1,3-propylene di(bis- 2,3 42 ± 5 15.0/14.8 phenyl)pyrophosphato titanate dilaurylphosphite(C) 1-oxo-2-phenylethylene, di(2- 1,2,3 54 ± 3 11.3/11.2 chloro-p-cresyl, methyl)pyro- phosphato titanate, triphenyl phosphite(D) neopentenyl, di(bisoctadecyl) 1,3 27 ± 6 9.74/9.5 pyrophosphato titanate di(butyl, propyl phosphite)(E) 1,3 propylene, di(bisoctadecyl) 1 <0 9.26/9.3 pyrophosphato titanate di(di- benzyl phosphite)(F) oxoethylene di(butyl, methoxy- 1,2 <0 9.46/9.3 ethoxyethyl) pyrophosphato titanate dimethoxethylphosphite(G) ethylene di(methyl, 11, 14-hexa- 1,2,3 34 ± 6 16.2/16.1 decadienyl) pyrophosphato titanate di(bismethyl phosphite)(H) 1,2-propenyl, di bis(2-bromo-3- 1,3 64 ± 2 12.5/12.6 chloro-4-t-butylphenyl) pyro- phosphato titanate di(bishexa- decyl phosphite)(I) ethylene di(butyl,methyl) pyro- 1,2,3 73 ± 4 16.9/16.8 phosphato titanate di(tris- ethylamine)(J) oxoethylene di(butyl, octyl) 1 42 ± 5 13.3/12.9 pyrophosphato titanate 2-di- methylaminoisobutanol(K) ethylene di(bisoctyl)pyrophos- 1,3 82 ± 4 9.65/9.9 phato titanate di(3-dimethyl- aminopropylmethacrylamide(L) benzylethylene di(phenyl, lauryl) 1 76 ± 4 9.57/9.7 pyrophosphato titanate di(ethyl- aminoethyl acrylate(M) ethylene, di(butyl, methyl) pyro- 1 not isolated* phosphato titanate di(bisoctyl) phosphite(N) oxoethylene di(butyl, octyl)pyro- 1 not isolated* phosphato titanate diphenyl phos- phite(O) 2-methyl-2,4-butenyl di(di-p- 1 not isolated* chlorobenzyl)pyrophosphato titanate di(butoxyethyl, methyl phosphite(P) oxoethylene, di(benzyl, 2- 1,2 not isolated* pentenyl)pyrophosphato titanate di(2-dimethylamino) isobutanol(Q) 2,3-butenyl di(bis-4-methoxy- 1 not isolated* phenyl)pyrophosphato titanate diethylamine(R) 2,3-dimethyl-2,3-butenyl di(bis- 1 not isolated* methyl)pyrophosphato titanate triethylamine, dibutyl phosphite(S) oxoethylene di(p-bromobenzyl) 1 not isolated* pyrophosphato titanate methyl- aminoethanol(T) 1-oxoprop-1,3-enyl di(butoxy- 1 not isolated* methoxyethyl, isobutyl)pyro- phosphato titanate di(bistridecyl) phosphite(U) methoxyethylene di(bispropyl) 1 not isolated* pyrophosphato titanate di propylamino ethyl methacrylate(V) isopropyl, tri(butyl,methyl) 1,2,3 <0 17.0/16.8 pyrophosphato titanate di(bis- octyl phosphite)(W) isopropyl, tri(bisoctyl)pyro- 1,2, 16 ± 5 12.9/12.8 phosphato titanate triethanol- amine(X) isooctyl, tri(bismethyl)pyro- 1,2,3 not isolated* phosphato titanate tripropyl phosphite(Y) ethoxytriglycolyl, tri(4-bromo- 1 14 ± 6 15.3/15.1 phenyl,methyl)pyrophosphato titanate di(methoxyethyl) phosphite(Z) 4-ethoxybenzyl tri(di-alphanaph- 1 64 ± 5 10.4/10.1 thyl) pyrophosphato titanate di (di-ethylaminoethyl(methacrylate)(AA) t-butyl, tri(bisbutyl) pyro- 1 12 ± 4 17.2/17.0 phosphato titanate tri-methyl phosphite, dimethylaminoethanol(AB) methyl,tri(bis-4-chlorophenyl) 1 48 ± 3 15.8/15.5 pyrophosphato titanate dioctyl phosphite, dimethylaminoethyl formamide(AC) allyl, tri(allyl,methyl)pyro- 1,3 23 ± 3 20.2/19.9 phosphato titanate trimethyl phosphite, dioctyl phosphite(AD) (2,2-diallyloxymethyl)ethyl 1,2 38 ± 4 11.9/11.7 tri(bisbutyl)pyrophosphato titanate di(trisphenyl phosphite)(AE) 1-(2-butenyl)tri(methyl, octyl) 1 31 ± 3 13.1/12.9 pyrophosphato titanate, tri- ethylamine, dioctyl phospite__________________________________________________________________________*by-product alcohol not removed, reaction mixture used as such.
EXAMPLE 5
This example illustrates the utility of various titanate adducts of the present invention as corrosion retardants.
Xylene degreased 20 mil panels of cold rolled steel were dip coated with a 1 weight percent solution of additive in toluene followed by a toluene wash and were then oven dried at 150° C. in a nitrogen atmosphere. The dried panels were cooled, weighed, subjected to 100 hours of 100% humidity at 40° C. exposure in an environmental cabinet, re-dried, cooled, and re-weighed. The corrosion rate in mils per year was calculatedfrom the following equation:
______________________________________Corrosion rate =(weight loss/panel weight) (20 mils) (8670 hours/year/100______________________________________hours)
The results of a study of selected examples of the titanates of the presentinvention are given in Table 2.
TABLE 2______________________________________ Indicated %Adduct Corrosion Rate (mils/yr) of Control______________________________________None (control) 172 100A 38 22B 26 15C 69 40D 81 47E 24 14F 13 8G 32 19H 19 11I 20 12J 31 18K 38 22L 35 20X 17 10Y 20 12AB 26 15AC 18 10AD 41 24AE 38 22______________________________________
In each instance, the materials of the present invention improved humidity resistance of cold rolled steel by at least two-fold and in the case of the F material, the improvement was twelve-fold.
EXAMPLE 6
Titanate adducts M through U, identified above, were compounded into an alkyl-melamine baking enamel having a brown color as indicated below. The resultant formulations were each oven baked at 100° C. for a periodadequate to provide a film pencil hardness (Society of Coatings Technology Test) of F-H at 1.3±0.2 mils dry film thickness. The results of this study are given in Table 3.
The following materials were premixed, on a high shear disperser, at ambient temperature for fifteen minutes:
______________________________________Material Kilograms Liters______________________________________soya alkyd short oil, 172 174Cook #S-157-A-2 (trademark ofCook Paint and Varnish Co.)pyrophosphato titanate adduct 0.397 0.33titanium dioxide, DuPont #R-960 21 5.08(trademark of E.I. DuPontde Nemours, Co.)magnesium silicate 32 12.0lamp black 0.9 0.512red iron oxide 3.2 0.648yellow iron oxide 15 3.72bentonite clay 1.1 0.633fumed silica 1.1 0.523soya lecithin 1.4 1.42______________________________________
Tetraoctyltitanate di(dioctyl)phosphite (0.188 kilograms, 0.20 liters) was added to the above mixture and the mixture was further mixed on a sand mill until the particle size was Hegman 6.5 grind guage. The resulting blend was added to the following Material Letdown Solution and was mixed at ambient temperature.
______________________________________Material Letdown Solution Kilograms Liters______________________________________xylene 41.8 48.5Butyl Cellosolve (trademark of Union 10.2 11Carbide Corporation)triethylamine 2.0 2.73n-butanol 0.90 1.1250% melamine formaldehyde resin, 74.5 76Cargil #2218 (trademark ofCargill Inc.)6% Cobalt naphthenate 0.90 0.95______________________________________
The resulting paint composition had the following properties:
______________________________________weight per liter 1.05viscosity (#2 Zahn ± 6 sec.) 28.0volume solids (%) 32.0weight solids (%) 49.0thickness dry film 1.0-1.75pencil hardness F-Hgloss (±5°) 55.0letdown solution to grind ratio 5:1______________________________________
The bake time at 93° C. required to achieve specification hardness was determined for several titanate adducts of the present invention. The results are shown in Table 3.
TABLE 3______________________________________ Bake Time at 93° C. Time required toPyrophosphato Titanate achieve specificationAdduct Employed hardness (+ 2 minutes)______________________________________None (control) 117M 43N 41O 57P 84F 21Q 39R 48S 83T 42U 38______________________________________
The reduction in bake time required in order to achieve specification properties is clearly shown to be substantial for all members of the classtested. A considerable reduction in cost results from the savings in both time and energy expended during backing.
EXAMPLE 7
This example illustrates the utility of certain pyrophosphato titanate adducts in the simultaneous control of viscosity and pot life of polyestercasting resins.
Polyester resin composites were prepared by thoroughly admixing in the following order, 100 g of polyester resin (#30001, trademark of Reichold Chemical Co.), 0.5 g of pyrophosphato titanate adduct, 100 g of talc (#42,trademark of Englehard Mineral & Chemical Co.), and 1 g of 6% cobalt naphthenate. The resultant dispersions were deaerated by mixing in vacuo to eliminate variable air entrainment. The viscosities of the dispersions were then measured employing a Brookfield RVF viscosimeter (trademark of Brookfield Corp., Stoughton, Mass.). Thereafter, 0.5 g of methyl ethyl ketone peroxide was added to 100 g aliquots of deaerated dispersion and pot life was measured (time to achieve 2 million cps viscosity) at 21° C. The results are given in Table 4.
TABLE 4______________________________________ Viscosity of CompositeAdduct Employed (thousands of poise) Minutes______________________________________None 2.7 33N 1.6 109O 1.3 127F 0.8 18T 1.4 142U 0.6 14V 3.7 37W 5.2 35______________________________________
The data show that the phosphite adducts N, O and T retard the increase of viscosity due to premature gellation, thereby providing substantially increased useful working pot life, whereas the unsaturated nitrogen based adducts F and U act as accelerators, useful where rapid cure is desired. Furthermore, all of the adducts tested, other than V and W, provided the bonus of lower composite viscosities useful in many low energy applicationsituations. Adducts V and W acted as thixotropes without material effect onpot life, a characteristic not shared by conventional thixotropes such as fumed silica and asbestos which, normally, markedly slow peroxide cures.
EXAMPLE 8
This example illustrates the use of various pyrophosphato titanate adducts to improve the scrubbability of a latex coating.
Test batches of latex paint were prepared by mixing 25 g of titanium dioxide (DuPont #R931, trademark of E. I. DuPont de Nemours) in 20 g of ethylene glycol monobutyl ether containing 0.25 g of pyrophosphato titanate adduct on a high shear disperser (at constant torque) to a Hegmangrind gauge of minus 6. This was followed by letdown (dilution) with 100 g of acrylic latex (Ucar 4550, trademark of Union Carbide Corp.). Test panels were then prepared as 3 mil wet (about 2 mil dry) drawdowns on toluene degreased mild steel and the resultant films were dried at 25° C. for 48 hours prior to scrub testing. The scrub tester employed was a 1/8" wide, 10 micron silica impregnated phenolic grinding wheel rotated at 10 RPM. Grinding was continued in each case until magnetic dust was detected. Results are given in Table 5.
TABLE 5______________________________________ Grind Time (minutes)Adduct Required for -6(Hegman) Scrub Cycles______________________________________Control 22 38B 14 57C 12 83D 13 71E 9 46Q 14 143G 15 71H 12 62I 14 49J 13 53K 15 168______________________________________
These data show that the use of the adducts of the present invention markedly improved both the grinding efficacy and the scrub resistance in those formulations in which they were employed and that in several cases (C, F and K) the improvements in scrub resistance were twofold or higher.
EXAMPLE 9
This example illustrates the utility of pyrophosphato titanium adducts of the present invention for the improvement of epoxy polyamide coatings.
The coating components A and B were prepared separately by mixing the ingredients listed in Tables 6A and 6B, respectively, in the order indicated at 33° C. to 45° C., using a Cowles dissolver (trademark of Moorhouse Cowles Co.). Components A and B were admixed at ambient temperature using the same equipment. Q-panels (trademark of Q-Panel Corp.) of cold rolled steel were coated with portions of the test coating to provide a film one mil dry thickness. The coatings were aged for one week at ambient temperature before testing. Test results are givenin Table 6C.
TABLE 6A______________________________________Component A BLSC Control Silica SystemIngredient Parts by weight Parts by weight______________________________________epoxy resin (Araldite 210 210571CX80, trademarkof Ciba-Geigy Corp.)basic lead silicochromate 480 None(BLSC)titanium dioxide 30 30red iron oxide 15 15fumed silica 6.4 6.4talc 235 235amorphous silica None 400xylene 193 193diacetone alcohol 96 96urea formaldehyde resin 10.5 10.5(Beetle 216-8, trademarkof America Cyanamid Corp.)chelated pyrophosphato None 3.3titanate adductparts by weight 1276 1199______________________________________
TABLE 6B______________________________________Component B BLSC Control Silica SystemIngredient Parts by weight Parts by weight______________________________________polyamide curative 105 105(Araldite 820, trademarkof Ciba-Geigy Corp.)xylene 24 24butanol 12 12parts by weight 141 141______________________________________
The cost per gallon of the Component A BLSC Control was $1.35; the cost pergallon of the Component A titanate adduct formulation was about $0.66.
TABLE 6C______________________________________ Rusting Stripped after 1000 panel rust- hour salt ing after Initial Four Month fog expo- 500 hours, viscosity viscosity sure at 100% humid-Adduct KU* KU 27° C. ity at 27° C.______________________________________BLSC(Control) 192 216 M (moderate) S (severe)B 112 126 Sl (slight) SlC 103 104 Sl MD 106 118 Sl SlE 102 104 Sl SlQ 116 109 Sl MG 109 111 M MH 113 115 Sl SlI 96 100 M SlJ 101 107 Sl Sl______________________________________*Krebs units
Note that as compared with the BLSC Control, each of the pyrophosphato titanate adducts of the present invention provided improved protection against corrosion at a cost considerably lower than that of the BLSC Control without the employment of environmentally damaging heavy metals asrequired by the best previously available technology. Also demonstrated arethe massive viscosity reduction achieved via the use of the products of thepresent invention as a major contributing capability to the functional utility of the silica system since control viscosity would otherwise prevent effective application coverage.
EXAMPLE 10
This example illustrates the utility of pyrophosphato titanium adducts of the present invention as adhesion promoters for polymer laminates.
The titanate adducts listed in Table 7 below were compounded into virgin low density polyethylene (LDPE). Thirty mil sheets of the LDPE were extrusion laminated onto preformed 50 mil Surlin (trademark of DuPont de Nemours for metalated polyolefin) ionomer sheets at 107° C., employing a 24:1 vented National Plastics Machinery (trademark) extruder. The peel strength of each laminate was measured with a constant speed motor and a strain gauge at 27° C. after 24 hours at ambient temperature and pressure. The results are given below in Table 7. The formuations contained 0.2 weight percent of the indicated chelated pyrophosphato titanium adduct on LDPE.
TABLE 7______________________________________Adduct Peel Strength, kg/cm.sup.2______________________________________Control 4.8A 9.0B 19C 20D 17E 20G 17H 16I 24Z 13______________________________________
Note that in each instance, the use of the adducts improved peel strength (bonding) between the dissimilar polymer layers.
EXAMPLE 11
This example illustrates the utility of pyrophosphato titanium adducts of the present invention in enhancing the tensile and elongation properties of cellulosics (cross-linked low density polyethylene filled with cotton linters).
One hundred parts by weight of low density cross-linkable polyethylene, 20 parts cotton linters (chopped to 20-45 micron length, 0.5 parts dicumyl peroxide and 0.2 parts of pyrophosphato titanate adduct were compounded ona two roll mill at 93°±6° C. (all parts given are parts byweight). Samples were then press cured at 149° C. for 20 minutes. The samples were equilibrated at 21° C. for 24 hours prior to testing on an Instron (trademark of Instron Corporation) tensile tester atan extention rate of 0.2 inches/min. The results are given below in Table 8.
TABLE 8______________________________________Adduct Tensile Strength, kg/cm.sup.2 Elongation at Break, %______________________________________Control 6.11 × 10.sup.3 80A 6.53 × 10.sup.3 90D 7.95 × 10.sup.3 170Q 10.9 × 10.sup.3 230K 8.80 × 10.sup.3 210______________________________________
EXAMPLE 12
This example illustrates the use of pyrophosphato titanate adducts as viscosity control agents and/or dispersants in dissimilar media (for example, water and mineral oil).
In each instance, the indicated titanate was precoated at 0.5 weight percent on HiSil 223 (trademark of PPG Industries) in a household type blender prior to dispersion in the liquid vehicle (water or mineral oil) at 70 weight percent HiSil using a Hochmeyer disperser (trademark of Hochmeyer Corp.). The resulting dispersions were evaluated at 27° C. using a Brookfield RVF viscometer (trademark). The results are given inTable 9.
TABLE 9______________________________________ Aqueous dispersion visco- Mineral Oil dispersionAdditive sity MCPS (10.sup.3 centipoise) viscosity MCPS______________________________________Control 152 23A 130 28B 37 56C 52 72D 168 22E 182 18Q 154 21G 172 19H 41 62I 227 separates rapidlyJ 47 62K 164 18Z 194 17Y 184 18AD 171______________________________________
This example demonstrates the wide range of viscosity control available in vehicles as diverse as water and mineral oil via the employment of small proportions of pyrophosphato titanium adducts in conjunction with a single(silica) particulate.
EXAMPLE 13
This example illustrates the utility of pyrophosphato titanium adducts as promoters of conductivity in metal filled polymer composites. In each instance, the metal indicated was precoated with the specified adduct by admixture in a household type blender prior to incorporation into the polymer base on a laboratory two roll mill. The formulations were press cured and formed as 6 inch×6 inch×100 mil sheets for 20 minutes at 170° C. and stress relieved at 27° C. for 24 hours, prior to evaluation. Resistivities were measured using a field effect transistor type ohmeter equipped with a decade runup box of 10 1 to 10 9 ohms range on a through the sample basis. The resultsare given in Table 10 (Tables 10a, 10b and 10c).
TABLE 10______________________________________TABLE 10aFormulation (in parts by weight): nickel (1 micron nomimal pow-der, manufactured by Potter Industries), 87.5; Geon 103EP(trademark of B.F. Goodrich Co. for PVC resin), 7; dioctylphthalate, 4.5; mixed barium, cadmium and zinc oxalate stabilizer,0.05, epoxidized soybean oil, 0.5; pyrophosphato titanateadduct, 0.25. Resistance ResistanceAdduct ohm/cm Nickel ohm/cm Tin______________________________________Control 1.3 × 10.sup.6 3.9 × 10.sup.6B 16 6.2 × 10.sup.2C 28 4.8 × 10.sup.2Q 45 87E 63 1.1 × 10.sup.2K 1.1 × 10.sup.2 96______________________________________
TABLE 10b______________________________________Formulation (in parts by weight): nickel (1 micron nominal pow-der), 75; SWS (trademark of Stauffer Chemichal Co. for siliconeresin), 24; dicumyl peroxide, 1.0; pyrophosphato titanium adduct,0.25.Adducts Resistance ohm/cm______________________________________Control 1.6 × 10.sup.8B 2.0 × 10.sup.4C 1.4 × 10.sup.4E 4.7 × 10.sup.2Q 6 × 10.sup.2K 1.7 × 10.sup.2Y 5.7 × 10.sup.5Z 6.2 × 10.sup.3AA 4.1 × 10.sup.3AB 8.1 × 10.sup.1AD 6.2 × 10.sup.2AE 3.8 × 10.sup.2______________________________________
TABLE 10c______________________________________Formulation (in parts by weight): Viton E430 (trademark of E.I.duPont de Nemours for fluoroelastomer), 24; calcium hydroxidepowder, regent grade (manufactured by J.T. Baker ChemicalCompany), 1.28; nickel (1 micron nominal powder), 75;pyrophosphato titanium adduct, 0.25.Adduct Resistance ohm/cm______________________________________Control 9 × 10.sup.8B 5 × 10.sup.5C 7 × 10.sup.4E 1.8 × 10.sup.2Q 38K 61F 6.1 × 10.sup.6M 5 × 10.sup.3P 8 × 10.sup.3AB 3.4 × 10.sup.2______________________________________
In each and every instance the use of pyrophosphato titanate adduct provided for substantial conductivity enhancement versus the control, despite the gross variation in polymer binders employed; (i.e. the silicone and Viton (trademark) are grossly differing thermosets, and the PVC is a thermoplastic).
EXAMPLE 14
This example illustrates the use of selected pyrophosphato titanium adductsas insulation value enhancers in hard clay filled flexible polyvinyl chloride.
SP-33 Clay (trademark of Burgess Pigment Co.), 20 parts by weight; dioctyl phthalate, 50; and pyrophosphato titanium adduct, 0.01; were admixed in a household type blender. The resulting mixture was added to polyvinyl chloride resin (Geon 103EP, trademark of B. F. Goodrich Co.), 100; epoxidized soybean oil, 3; powdered lead diphthalate, 3; and stearic acid,0.3, all quantities are in parts by weight. The mix was compounded on a laboratory two-roll mill at 135° C. and press-formed for 10 minutesat 160° C. prior to evaluation of resistance of a sheet having a cross-section of about 100 mils by employing a mehohm Bridge coupled to a 10 4 -10 5 ohm decade box assembly. The results are shown in Table
TABLE 11______________________________________Adduct Resistance ohms/cm______________________________________Control 5 × 10.sup.12B 2 × 10.sup.13C 3 × 10.sup.13D 8 × 10.sup.12Q 7 × 10.sup.12J 1 × 10.sup.13______________________________________
These data show that significant resistivity increases result from the employment of pyrophosphato titanate adducts in vinyl based insulation.
EXAMPLE 15
This example illustrates the advantages in terms of shelf stability resulting from the adduction of pyrophosphato titanates with certain typesof amines and/or phosphites.
Test formulations containing 40 weight percent Bakelite CK-1634 phenolic resin (trademark of Union Carbide Corp.) and 10 weight percent of powderedcoal (Carbofil #1--Shamokin Filler Co.), together with 0.2 weight percent of pyrophosphato titanate (as shown) in xylene were coated on aluminum Q-pannels (trademark of Q-Pannel Corp.) to a wet film thickness of 5 mils and placed in a 150° C. forced draft oven until the resultant film showed a pencil hardness of 3 H. A second sample of each formulation was shelf aged in a closed container, at 25°±3° C. to determine package stability. The test results are shown in Table 12.
TABLE 12______________________________________Pryophosphato Titanate Shelf Life (days).sup.(1) Cure Time Min.______________________________________Control (none) 60 ± 3 25 ± 3A 55 ± 5 16 ± 2non-adducted A.sup.(2) 22 ± 2 15 ± 2B >120 14 ± 2non-adducted B 20 ± 3 15 ± 2J >120 17 ± 2non-adducted J 20 ± 3 16 ± 2(same as A)K >120 20 ± 2non-adducted K 28 ± 3 19 ± 2Q >120 16 ± 2non-adducted Q 22 ± 3 15 ± 2(same as A)AA 74 ± 5 11 ± 2non-adducted AA 18 ± 3 10 ± 2AE 82 ± 5 12 ± 2non-adducted AE 16 ± 4 12 ± 2______________________________________ .sup.(1) Time to 100% Brookfield (trademark) viscosity increase .sup.(2) Prepared as disclosed in U.S. Pat. No. 4,122,062 or 4,087,402
This example shows that while both adducted and non-adducted pyrophosphato titanates decrease cure time with consequent reduction in energy requirements when employed in conjunction with phenolic resins, the non-adducted analogs negatively effect formulation shelf life whereas their adducted analogs either effect shelf life positively or negligibly compared to the control. This example also shows that the choice of adducting agent also has a substantial effect on the properties of the resulting adduct.
EXAMPLE 16
This example shows the advantages of appropriate adduction of pyrophosphatotitanates for purposes of melting point depression and ease of dispersion. One gram of the specified adducts of the present invention and, separately, their non-adducted analogs were added to separate 200 mil portions of water. 100 grams of Optiwhite Calcined Clay (trademark of Burgess Corp.) was then dispersed at 30°±5° C. using a Hochmeyer disperser and the viscosity of each dispersion measured immediately and after boiling for two hours at 30°±1° C. using a Brookfield RVF viscometer (trademark of Brookfield Corp.). The results are shown in Table 13.
TABLE 13______________________________________Pyrophosphato Initial 30° C. Boiled dispersionTitanate Employed viscosity (cps) 30° C. viscosity (cps)______________________________________Control 4.3 × 10.sup.5 >10.sup. 7I 6.7 × 10.sup.3 >10.sup.7non-adducted I 4.1 × 10.sup.5 >10.sup.7J 3.9 × 10.sup.3 5.2 × 10.sup.4non-adducted J 4.5 × 10.sup.5 >10.sup.7K 6.3 × 10.sup.4 4.7 × 10.sup.4non-adducted K 5.0 × 10.sup.5 >10.sup.7L 3.9 × 10.sup.3 8.4 × 10.sup.3non-adducted L 4.0 × 10.sup.5 >10.sup.7W 6.1 × 10.sup.3 >10.sup.7non-adducted W 4.2 × 10.sup.5 `10.sup.7Z 4.8 × 10.sup.5 5.2 × 10.sup.5non-adducted Z 4.5 × 10.sup.5 >10.sup.7AB 2.9 × 10.sup.2 >10.sup.7non-adducted AB 4.5 × 10.sup.5 >10.sup.7AE 8.2 × 10.sup.4 9.5 × 10.sup.5non-adducted AE 4.1 × 10.sup.5 >10.sup.7______________________________________
This example shows that pyrophosphato titanate adducts of the present invention may be utilized to achieve controlled viscosity reduction of aqueous clay dispersions at ambient temperature with or without controlledviscosity lowering after boiling whereas their non-adducted analogs give essentially negligible response in comparable formulations.
EXAMPLE 17
This example shows the utility of adduction of pyrophosphato titanates withamines of Formula III and/or phosphites of Formula II with respect to melting point reduction and with respect to solubility enhancement in selected media.
The indicated phosphato titanates, prepared according to the procedures described in U.S. Pat. Nos. 4,122,062 or 4,087,402, were converted to the indicated adducts via the procedure outlined in Example 1 and solubility (as weight percent) at 25°±3° C. was measured in n-hexane(Hexane sol.). Melting points of the phosphato titanate were determined before and after adduction. The results are given in Table 14.
TABLE 14______________________________________Pyrosphos- Pyrophos- Melt-phato non- Hexane phato ing Hexaneadducted Melting sol. wt. Titanate Point sol. wt.Titanate Point °C. % adduct °C. %______________________________________I dec 182 <0.5 I 73 ± 4 7V 171-174 <0.5 V <0 >25AA 158-161 1 AA 12 ± 4 >25AC 179-184 <0.5 AC 23 ± 3 >25AE 129-134 3 AE 31 ± 3 12______________________________________
This example shows the improvement in hexane solubility and melting point lowering effected upon prior art phosphato titanates via the practice of adduction as described in the present invention.
EXAMPLE 18
This example shows the utility of pyrophosphato titanate adducts as thermally activated catalysts in the controlled interconversion of esters,i.e., the transesterification of ethyl propionate with methyl butyrate in solutions containing ethyl acetate.
In a 2 liter pyrex flask equipped with facilities for mechanical agitation,pot and head thermometers, innert gas inlet, fractionating column (30 theoretical plates), automatic reflux-takeoff assembly, vacuum receivers, external heat and vacuum sources was placed 3 M each of ethyl (acetate, ethyl propionate and methyl butyrate, together with 1.0 g of the indicatedcatalyst. Vacuum and reflux ratios were adjusted to 25 mm and 25:1, respectively, and the pot contents distilled to recover 97±1% of the feed overhead. Analysis of the distillate(s) was performed by gas liquid chromatography results are given in Table 15.
TABLE 15__________________________________________________________________________Catalyst % Yield Byproduct % Recovery % Yield % Recovery % RecoveryEmployed Methyl Acetate Ethyl Acetate Methyl Propionate Ethyl Propionate Methyl Butyrate__________________________________________________________________________SulfuricAcid 97 2 <1 95 <1AluminumChloride 94 5 4 97 <1B 13 85 84 13 3Non adducted B 89 9 8 90 3H 7 91 90 8 1Non adducted H 91 8 5 92 2I <1 99+ 94 5 3Non adducted I 87 11 10 88 2J 2 96 93 5 2Non adducted J 94 4 5 95 1__________________________________________________________________________ .sup.a All numerical data in mole %.?
Note that both conventional acid catalysts and nonadducted pyrophosphato titanates, when employed in the above system, produce substantial proportions of byproduct methyl acetate due to preferential volatilizationof same once formed, whereas the adducts of the instant invention, having little catalytic activity until temperatures in excess of 50° C., permitted recovery by vacuum distillation of the bulk of the ethyl acetateprior to onset of catalytic transesterification.
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Adducts of tetrasubstituted pyrophosphato titanates and/or amines, having the formula
X.sub.c Ti[OP(O)(OR.sup.1)OP(O)(OR.sup.2)OR.sup.3)].sub.4-c (NR.sup.4
R 5 R 6 )d[P(OR 7 )(OR 8 )(OR 9 )]e,
are useful in improving the physical and chemical properties of many filled resins.
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CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims priority from U.S. provisional patent application No. 60/645,154, which was filed on Jan. 19, 2005, and which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the use of electromagnetic energy to subject heavy crude oil to mild thermal cracking conditions, thereby lowering the viscosity, pour point, and specific gravity of the oil and rendering it easier to recover and handle. More particularly, this invention relates to methods for applying electromagnetic energy to heavy oils in the reservoir to promote in situ upgrading and facilitate recovery. This invention also relates to systems to apply electromagnetic energy to heavy oils in situ.
BACKGROUND OF THE INVENTION
[0003] Heavy crude oil presents problems in oil recovery and production. Crude oils of low API gravity and crude oils having a high pour point present production problems both in and out of the reservoir. Extracting and refining such oils is difficult and expensive. In particular, it is difficult to pump heavy crude oil or move it via pipelines.
[0004] Various methods to ameliorate the disadvantages of heavy crude oil are used today. For example, the oil industry reduces surface handling problems by blending heavy crude oil with light oils and liquid proprane gas to make them easily handled in pipelines and storage facilities. This method has drawbacks, however, as it does not assist in the initial recovery of the oil, and it is expensive.
[0005] A process called “visbreaking,” or mild thermal cracking, may also be used to reduce the viscosity of heavy crude oil. “Visbreaking” is an oil refinery process for increasing the pumpability of heavy crudes. It typically is accomplished by heating heavy crude oil in a furnace. The process is characterized by mild decomposition, minimum coke formation and the retention of the cracked product in the original feed stock. The resultant mixture has viscosity, pour point, and specific gravity values that are lower than the original oil. However, ask applied today, visbreaking cannot be used on oil in situ.
[0006] The present invention applies visbreaking new contexts and for new purposes, and proposes improved methods for the application of visbreaking. In the present invention, visbreaking is accomplished using electromagnetic energy to heat the heavy crude oil, rather than heating it in a furnace. Furthermore, the present invention is suitable for use in the treatment of oil in situ. Such treatment permits the upgrade of the oil in reservoir and assists in the recovery of the oil.
BRIEF SUMMARY OF THE INVENTION
[0007] The present invention utilizes the ability of electromagnetic energy at the appropriate frequency to selectively deposit thermal energy in the heavy oil for precise control of cracking temperature throughout a given volume of material. Selective electromagnetic energy absorption in the heavy crude oil provides energy efficient transfer of heat at the molecular level and thereby insures precise temperature control throughout the treatment volume. This allows for optimization of the visbreaking process using electromagnetic energy.
[0008] Proper selection of frequency and power duration results in the rapid cracking of heavy hydrocarbons to any degree desired by electromagnetic energy absorption. When the desired degree of cracking is reached, the hot oil matrix provides a significantly different set of electrical properties which can be measured on the surface during the “electromagnetic visbreaking process.” (EVP) to insure precise down hole temperature and power control.
[0009] This proposed EVP provides efficient energy absorption and control of thermal cracking of heavy oils for in-situ upgrading. The application of low power (a few ten's of kilowatts) electromagnetic energy to the formation for visbreaking will provide mild decomposition of the heavy oil, minimum coke formation and the retention of the cracked product in the original feedstock. The resultant mixture has viscosity, pour point, and specific gravity values which are lower than those of the original oil.
[0010] The present invention several promising applications. It can be used to upgrade heavy crude oil in situ. It can also assist in the recovery of heavy crude oil from reservoirs. Further, the present invention can be used to more efficiently recovery hydrocarbons from oil shale, such as that present in the Western United States.
[0011] In one embodiment of the invention, a system may be provided for use in treating heavy crude oil underground. The system may comprise a borehole in an area in which crude oil exists in the ground, an electromagnetic energy applicator positioned within the borehole in the vicinity of the heavy crude oil to be treated, a cable attached to the electromagnetic energy applicator to supply electromagnetic energy to the applicator, an electromagnetic energy generator attached to the cable to generate electromagnetic energy to be supplied to the applicator, and a product return pipe running through the borehole, the product return pipe comprised of a distal end positioned in the vicinity of the electromagnetic energy applicator through which oil or other products may be recovered and a proximal end on or near the surface of the ground.
[0012] In another embodiment of the invention, a method for treating heavy crude oil underground is provided. The method comprises the steps of positioning an electromagnetic energy applicator in a borehole in the vicinity of heavy crude oil, generating electromagnetic energy, applying the electromagnetic energy to the heavy crude oil with the applicator to achieve thermal cracking, and recovering heavy crude oil through a product return pipe.
[0013] While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. As will be realized, the invention is capable of modifications in various obvious aspects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective view of a single borehole radiation type applicator.
[0015] FIG. 2 is a close up view of a portion of the applicator system.
[0016] FIG. 3 is a perspective view of a portion of another configuration of a single borehole applicator.
[0017] FIG. 4 is a perspective view of a wellhead for use with the applicator system.
[0018] FIG. 5 shows a sample of the absorption data from experiments on the application of electromagnetic energy to large oil molecules in oil shale.
DETAILED DESCRIPTION
[0019] A variety of different types of down hole electromagnetic structures may be employed to apply electromagnetic energy to heavy crude oil in situ. The proper structure for any particular application depends on a variety of factors, including depth, heat uniformity, and minimizing the degree of coking and production of unsaturated hydrocarbons.
[0020] FIG. 1 is a perspective view of a single borehole radiation type applicator. Applicator system 10 is positioned within borehole 12 . Borehole 12 is supported by casing 14 . Applicator system 10 is then used to apply electromagnetic energy to heavy crude oil in the vicinity of borehole 12 .
[0021] Applicator structure 20 is a transmission line retort. For a point of reference, a typical applicator 20 may be approximately 70 feet long. In a typical configuration, the applicator 20 may be positioned from between 100 to 600 feet underground in borehole 12 . Radiofrequency (“RF”) energy is supplied to applicator 20 by an RF generator (not shown). The RF generator is connected to applicator 20 via a portion of flexible coaxial cable 30 . In turn, the flexible coaxial cable 30 is connected to a portion of rigid coaxial cable 32 . The coaxial cable may or may not be supported by ceramic beads, which are desirable at higher temperatures. By this means, the RF generator supplies RF energy to applicator 20 , which in turn applies RF energy to the target volume to achieve visbreaking. This allows in situ upgrading of the heavy crude oil and assists in recovery.
[0022] Recovery of the oil and related products is achieved by means of production pipe 40 . This non-metallic pipe runs from the production area of borehole 12 through the borehole to surface 16 . At the surface, production pipe 40 is connected via a product return line to a storage or processing facility (no shown).
[0023] Production pipe 40 provides a firm mounting base for the RF hardware of applicator system 10 . Coaxial cables 30 and 32 can be attached directly to production pipe 40 using connectors 42 . Applicator 20 also attaches to production pipe 40 .
[0024] FIG. 2 is a close up view of a portion of the applicator system. Applicator structure 20 , rigid coaxial cable 32 , and production pipe 40 are all positioned within borehole 12 . Typical dimensions for such a system are shown in FIG. 2 . Ceramic support beads 34 support rigid coaxial cable 32 . Further, ceramic pressure window 36 is placed at the tope of applicator 20 .
[0025] FIG. 3 is a perspective view of a portion of another configuration of a single borehole applicator. In this configuration, a dipole feed is used. Coaxial feed 38 surrounds production pipe 40 . Ceramic window 36 is placed at the bottom of coaxial feed 38 .
[0026] Although specific examples of applicator structures are given, it is understood that other arrangements known in the art could be used as well. Uniform heating may be achieved using antenna array techniques, such as those disclosed in U.S. Pat. No. 5,065,819. Such techniques can be used to minimize coking conditions at the applicator borehole and avoid excessive electrode voltage gradients at high power. Arrays reduce excessive voltage gradients at the borehole by means of mutual coupling. The ability to separately measure reflected power from each applicator borehole containing radiator and mutual impedance coupling between any pair of applicator boreholes insures precise temperature control of the heated volume.
[0027] Other variations are possible, including non-radiation structures such as those proposed in J. Bridges, et al., “RF Heating of Utah Tar Sands,” Final Report, IIT Research Institute. However, such structures are sensitive to high voltage breakdown and require extensive drilling which is not economical.
[0028] A special wellhead may be used in conjunction with applicator system 10 . Properly designed, the wellhead can be used to provide safe and efficient delivery of RF energy to the applicator.
[0029] FIG. 4 is a perspective view of a wellhead for use with the applicator system. The weight of the down hole applicator (not shown) rests on a special bellows 46 within the wellhead. This insures that any heat induced mechanical movements of the down hole apparatus during energy transfer do not interrupt power flow. An input opening 44 permits nitrogen to be introduced into the interior of the wellhead and borehole, further ensuring the safe application of RF energy. Insulators 45 are positioned above the bellows 46 , and a center conductor expansion joint is positioned on top of that. At the top of the wellhead, where coaxial cable 30 exits and runs to RF generator 28 , a coaxial line seal and vertical alignment clamp 26 secure the cable to the wellhead. Product return line 41 carries the product recovered through the system to a storage or processing facility (not shown), and water extraction line 43 permits the removal of water from borehole 12 .
[0030] The present invention also has application in oil shale fields, such as those present in the Western United States. Large oil molecules that exist in such oil shale have been heated in a series of experiments to evaluate the dielectric frequency response with temperature. The response at low temperatures is always dictated by the connate water until this water is removed as a vapor. Following the water vapor state, the minerals control the degree of energy absorption until temperatures of about 300-350 degrees centigrade are reached. In this temperature range, the electromagnetic energy begins to be preferentially absorbed by the heavy oil. The onset of this selective absorption is rapid and requires power control to insure that excessive temperatures with attendant coking do not occur. FIG. 5 shows a sample of the absorption data from such experiments.
[0031] Because of the high temperature selective energy absorption capability of heavy oil, it is therefore possible to very carefully control the bulk temperature of down hole crude oil heated by electromagnetic energy. The energy requirement is minimized once the connate water is removed by steaming. It takes much less energy to reach mild cracking temperatures with electromagnetic energy than any other thermal means to provide visbreaking.
[0032] Kasevich has published a molecular theory that relates to the specific heating of heavy of oil molecules. He found that by comparing cable insulating oils with kerogen (oil) from oil shale, a statistical distribution of relaxation times in the kerogen dielectric gave the best theoretical description of how electromagnetic energy is absorbed in oil through dielectric properties. With higher temperatures and lowering of potential energy barriers within the molecular complex a rapid rise in selective energy absorption occurs.
[0033] In use, a user of an embodiment of the present invention would position an applicator system in a borehole in an area in which heavy crude oil exists. The user would position the applicator structure itself in the borehole in the target area for application of RF energy. The user would connect the applicator structure to an RF generator via coaxial cable. A production pipe would run from the area of production to the surface, and from there to a storage or processing facility. The user would then apply RF energy using the RF generator to the applicator, thereby applying the RF energy to the heavy crude oil in situ. The RF energy would be controlled to minimize coking and achieve the desired cracking and upgrading of the heavy crude oil. The resulting products would then be recovered via the production pipe and transferred to a storage or processing facility.
[0034] Although the present invention has been described with reference to preferred embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
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The present invention utilizes the ability of electromagnetic energy at the appropriate frequency to selectively deposit thermal energy in the heavy oil for precise control of cracking temperature throughout a given volume of material. Selective electromagnetic energy absorption in the heavy crude oil provides energy efficient transfer of heat at the molecular level and thereby insures precise temperature control throughout the treatment volume. This allows for optimization of the visbreaking process using electromagnetic energy.
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TECHNICAL FIELD
[0001] The field to which the disclosure generally relates includes bipolar plates for fuel cells and methods of making and using the same.
BACKGROUND
[0002] Heretofore bipolar plates for fuel cells have been known to include at least one reaction gas flow path defined in a surface of a bipolar plate by a plurality of lanes and at least one channel. To reduce contact resistance between a diffusion media layer and a bipolar plate, the surface defining the reaction gas flow path of the bipolar plate has heretofore been coated with gold.
SUMMARY OF EXEMPLARY EMBODIMENTS OF THE INVENTION
[0003] One exemplary embodiment of the invention includes a method including providing a bipolar plate including at least one reacting gas flow path defined in a surface of the bipolar plate by a plurality of lands and at least one channel, selectively electroplating an electrically conductive coating over a plurality of first locations on the lands, and so that a plurality of second locations on the lands are free of the electrically conductive coating, and so that the channels are substantially free of the electrically conductive coating. In one exemplary embodiment the electrically conductive coating may include gold.
[0004] Other exemplary embodiments of the invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while disclosing exemplary embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Exemplary embodiments of the invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0006] FIG. 1 illustrates an electroplating system useful in a method according to one exemplary embodiment of the invention.
[0007] FIG. 2 is a plan view of a sponge having a plurality of through-holes useful in a method according to one exemplary embodiment.
[0008] FIG. 2A is an enlarged view of a portion 2 A of FIG. 2 .
[0009] FIG. 3 is a sectional view of a bipolar plate including a first substrate and a second substrate onto which an electrically conductive coating may be selectively electroplated according to one embodiment of the invention.
[0010] FIG. 4 illustrates an alternative embodiment of a fuel cell bipolar plate onto which an electrically conductive coating may be selectively electroplated according to one embodiment of the invention.
[0011] FIG. 5 is an enlarged, partial, plan view of a surface of a fuel cell bipolar plate including a plurality of lands and a reacting gas flow channel, and wherein an electrically conductive coating has been electroplated selectively on portions of the lands leaving portions of the lands uncoated, as well as the channels uncoated according to one exemplary embodiment.
[0012] FIG. 6 illustrates an alternative method of electroplating selected portions of the lands of a fuel cell bipolar plate utilizing a sponge having a plurality of raised features or projections for contact with portions of the lands of the fuel cell bipolar plate according to one exemplary embodiment.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0013] The following description of the embodiment(s) is merely exemplary (illustrative) in nature and is in no way intended to limit the invention, its application, or uses.
[0014] Referring now to FIG. 1-2A , one embodiment of the invention may include a method including providing an electroplating system 10 including a container 12 which may include sidewalls 14 , a top 16 and a bottom 18 each of which may be an insulative material such as a polymeric material. The bottom 18 may be a polymeric sheet including a plurality of through-holes 21 best seen in FIG. 2A . The through-holes 21 may each be of and arranged in a variety of designs. In one embodiment, the through-hole may have a cross-sectional area ranging from 1 nm to 100 nm, and may be spaced apart a distance from center-to-center ranging from 1 nm to 100 nm. A material for slowing the flow of the electrolyte solution through the through-holes 21 , such as, but not limited to, a sponge 20 may be provided in the container overlying the bottom 18 . A positive electrode (anode) 22 may be provided in the container and connected to an electrical source such as a battery 28 . The positive electrode 22 may be made from any of a variety of electrically conductive materials, such as but not limited to low contact resistant materials. A suitable low contact resistant material or coating may include, but is not limited to, gold, palladium, platinum, iridium, ruthenium, silver, alloys or mixtures thereof may be suitable for the positive electrode 22 . An electrolytic solution 24 may be provided in the container which is complementary to the positive electrode 22 . A charge pipe 26 may be provided and connected to the container 12 to replenish the electrolytic solution from a reservoir.
[0015] At least a first substrate 30 for a fuel cell bipolar plate may be positioned under the bottom 18 and connected to the electrical source (battery) 28 . The first substrate 30 includes a first face 31 having a fuel cell reactant gas flow field defined therein by a plurality of lands 32 and channels 34 . The first substrate 30 may also include a second opposite face 33 which may include a plurality of portions of a coolant fluid channel 40 defined therein. When the first substrate 30 and the positive electrode 22 are connected to the battery 28 electrons flow from the first substrate 30 to the positive electrode 22 and so that material from the positive electrode enters the electrolytic solution and travels through the plurality of through-holes 36 in the bottom 18 to be selectively electroplated on portions of the lands 32 of the first substrate leaving portions of the lands uncovered.
[0016] FIG. 3 illustrates an alternative embodiment showing a first substrate 30 including a first face 31 defining a plurality of lands 32 and channels 34 . A second substrate 38 which includes a first face 37 also defining a plurality of lands 32 and channels 34 is joined to the first substrate 30 . A plurality of coolant fluid flow channels 40 may be defined between the first substrate 30 and second substrate 38 . The first substrate 30 may have a second face 33 which also defines a plurality of lands and channels. Likewise, the second substrate 38 may have a second face 39 defining a plurality of lands and channels. FIG. 4 illustrates an alternative embodiment of a fuel cell bipolar plate wherein the first substrate 30 and second substrate 38 may be substantially thicker.
[0017] FIG. 5 is an enlarged, partial, plan view of a portion of the first face 31 of a first substrate 30 of a fuel cell bipolar plate. The first face 31 includes at least one reacting gas flow channel 34 defined by a plurality of lands 32 . An electrically conductive material 42 is selectively deposited over portions of the lands 32 leaving portions 44 uncovered by the electrically conductive material. Furthermore, the channels 40 may be substantially free of the electrically conductive material 42 .
[0018] Referring now to FIG. 6 , in another embodiment of the invention, the container 12 may be modified to remove the bottom 18 and the sponge 20 may be provided with a plurality of raised features or projections 46 extending downwardly with the adjacent projections 46 spaced apart by a recess 48 so that the projections 46 selectively contact portions of the lands 32 to electrically plate the electrically conductive material thereon.
[0019] In one embodiment electrically conductive coating is a gold alloy having up to 90 Wt % gold and the balance including an unstable metal. The unstable metal can be zinc, magnesium, aluminum or mixtures thereof. In one embodiment the alloy may include a reactive component, and the reactive component may be dissolved in an acid such as sulfuric acid or a base such as sodium or potassium hydroxide leaving behind gold islands on the lands. The above described designs may be constructed and arranged and operated so that less than 30% of the area of the lands is electroplated.
[0020] The above description of embodiments of the invention is merely exemplary in nature and, thus, variations thereof are not to be regarded as a departure from the spirit and scope of the invention.
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One exemplary embodiment includes a method of selectively electroplating an electrically conductive coating on selected portions of lands of a bipolar plate leaving portions of the lands uncoated by the electrically conductive coating. Thus, allowing for reducing cost of bipolar plates for PEM fuel cells considerably.
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FIELD OF THE INVENTION
The present invention relates to an ignition system and more particularly to a continuous plasma ignition system for a gas turbine engine.
BACKGROUND OF THE INVENTION
An ignition system for a gas turbine engine may include a plasma igniter. A plasma arc is generated across an air gap between two electrodes to light fuel in a combustion chamber. The size of the air gap between the two electrodes is a problematic in igniter design. Larger air gaps provide plasma arcs with higher energy but require higher breakdown voltages which can lead to failure in other locations such as at lead connections. Smaller gaps are subject to short circuit if carbon accumulates in the gap.
Therefore, there is a need for an improved plasma igniters.
SUMMARY OF THE INVENTION
One object of the present invention is to provide an improved plasma igniter for gas turbine engines.
In accordance with one aspect of the present invention, there is a variable arc gap plasma igniter element which comprises a first electrode and a second electrode defining a gap therebetween, adapted to generate a plasma arc extending through the gap when an electric voltage is applied across the electrodes. There are means provided for moving the second electrode relative to the first electrode during arcing, from a first position to a second position. The second position increases the gap size relative to the first position.
In accordance with another aspect of the present invention, there is a variable arc gap plasma igniter element provided for gas turbine engines, which comprises a first electrode having an end exposed to a cavity, a second electrode moveable relative to the first electrode and spaced apart therefrom to define a variable-sized gap between the end of the first electrode and an end of the second electrode, and an apparatus adapted to move at least the second electrode to thereby vary the arc size during arcing.
In accordance with a further aspect of the present invention, there is a method provided for operating a variable arc gap plasma igniter element for gas turbine engines, which comprises setting first and second electrodes of a plasma igniter element in a close relationship to define a small arc gap therebetween, applying an electric voltage across the electrodes to initiate a plasma arc across the arc gap, increasing the arc gap size, and injecting a fuel flow adjacent the plasma arc to ignite the fuel.
The present invention advantageously provides extremely long plasma arcs with relatively low breakdown voltages, thereby reducing failure modes. This and other features and advantages of the present invention will be better understood with reference to that which is described hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference will now be made to the accompanying drawings in which:
FIG. 1 is a schematic cross-sectional view of a turbofan gas turbine engine, as an example showing an application of the present invention;
FIG. 2 is a schematic cross-sectional view of a plasma igniter element having a variable arc gap according to one embodiment of the present invention;
FIG. 3 is a schematic cross-sectional view of a plasma igniter element in a first phase for plasma arc ignition according to another embodiment of the present invention;
FIG. 4 is a schematic cross-sectional view, showing the plasma igniter element in a second phase to initiate the torch ignition process according to the embodiment of the present invention illustrated in FIG. 3 ; and
FIG. 5 is a schematic cross-sectional view, showing the plasma igniter element in a third phase to withdraw the moving electrode from the combustion area according to the embodiment of the present invention illustrated in FIG. 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A typical application of the present invention for turbofan engines illustrated schematically in FIG. 1 , incorporates an embodiment of the present invention presented as an example of the application of the present invention, and includes a housing or nacelle 10 , a low pressure spool assembly seen generally at 12 which includes a fan 14 , low pressure compressor 16 and low pressure turbine 18 , a high pressure spool assembly seen generally at 20 which includes a high pressure compressor 22 and a high pressure turbine 24 . There is provided a burner seen generally at 25 which includes an annular combustor 26 and a plurality of fuel injectors 28 for mixing liquid fuel with air and injecting the mixed fuel/air flow into the annular combustor 26 for combustion.
A continuous plasma ignition system generally indicated by numeral 32 is provided in one location of the annular combustor 26 downstream of one of the fuel injectors 28 , for initiating a torch ignition process to start the combustion process. The continuous plasma ignition system 32 according to the present invention is adapted to vary the air gap between the electrodes in order to change the energy level of the generated plasma arc therebetween.
It should be noted that similar components of the different embodiments shown in FIGS. 2-5 are indicated by similar numerals for convenience of description of the present invention. Only those components different in one embodiment from the other will be separately described with reference to additional numerals.
Referring to FIG. 2 , a continuous plasma ignition system 32 includes an igniter body 34 defining a cavity 36 therein. The cavity 36 is in fluid communication with a chamber of the annular combustor 26 of FIG. 1 , or may be a part of the chamber of the annular combustor 26 when the igniter body 34 is a structural part of the combustor 26 . One fuel injector 28 is adapted to inject fuel into the cavity 36 . The fuel injector 28 is preferably affixed to the igniter body 34 but can also be otherwise attached to other structures of the engine, provided that the fuel injector 28 can inject fuel into the cavity 36 to a predetermined location.
A spark plug 38 which is connected to an electrical high voltage source such as an exciter, is affixed to the igniter body 34 at one side thereof. The spark plug 38 includes an electrode 40 having an end 42 thereof exposed to the cavity 36 .
A cylinder 44 is affixed to the igniter body 34 at an opposed side thereof, accommodating a slidable piston 46 therein. A solenoid 48 is attached to the cylinder 44 either inside thereof (as shown in this embodiment) or outside thereof. Piston 46 is connected at one side thereof to the solenoid 48 by a piston rod 50 . A spring 52 is provided within the cylinder 44 . The spring 52 is attached at one end thereof to the piston 46 and the other end is affixed to the cylinder 44 such that the piston 46 , when moving leftwards or rightwards, will cause the spring 52 to be pulled or pressed. An electrode 54 is attached to the piston at the opposed side thereof and extends across the cavity 36 towards electrode 40 . The electrode 54 is grounded in an electric circuit (not shown) supplying electric voltage to the spark plug 38 . The cylinder 44 is substantially aligned with the plug 38 therefore the electrodes 40 and 54 are aligned with each other.
The electrode 54 , piston 46 , piston rod 50 and the solenoid 48 are dimensioned and positioned to achieve the following operation of electrode 54 . In a first position, the solenoid 48 is activated, and moves the combination of electrode 54 , piston 46 and piston rod 50 towards the electrode 40 until an end 56 of the electrode 54 is in a proximity of the end 42 of the electrode 40 (the two ends of the respective electrodes preferably almost touch each other). Therefore, the air gap (not indicated) formed between the two ends 42 and 56 of the respective electrodes 40 , 54 has a reduced resistance which requires a relatively low breakdown voltage to be applied to the spark plug 38 in order to initiate a plasma arc to extend through the air gap.
When the plasma arc is initiated, the solenoid 48 is deactivated. Because the spring 52 was pulled to extend when the piston 46 was driven leftwards to the first position by the solenoid 48 , the resilient force of the extended spring 52 now pulls the combination of electrode 54 , piston 46 and piston rod 50 to move rightwards, back to a neutral position which is referred to as a second position. During the movement of the electrode 54 from the first position to the second position, the plasma arc across the minimum air gap between the ends 42 , 56 when the electrode 54 is in the first position, will follow the movement of the electrode 54 and extend because the initial ionization path established across the air gap between the ends 42 and 56 is still the preferred electrical route. In this manner, extremely long plasma arcs that would normally require extremely high breakdown voltages can be established using lower breakdown voltage levels. As the air gap between the end 42 and 56 of the respective electrodes 40 , 54 increases, the resistance also increases. Therefore, the longer plasma arc extending through the air gap carries a high level electric energy compared to the initial plasma arc across the minimum air gap between the ends 42 , 56 when the electrode 54 is in the first position.
Adequately determining the neutral position of the spring 52 (the second position of the electrode 54 ) can achieve generation of a plasma arc between the ends 42 , 56 of the respective electrodes 40 , 54 with a desired electric energy level for initiating a torch ignition process. The resilient properties of the spring 52 should also be adequately determined in order to assure controllable movement of the electrode 54 such that the plasma arc will follow and is maintained during the movement.
When the electrode 54 is in the second position and a longer plasma arc carrying a high electric energy level is established, the fuel injector 28 injects fuel into the cavity 36 . The injected fuel is lit by the plasma arc extending between the ends 42 , 56 of the respective electrodes 40 , 54 , thereby initiating a torch ignition process. Once the torch ignition process is initiated, all fuel injectors 28 of FIG. 1 inject fuel continuously into the annular combustor 26 to start and maintain a combustion process. When the ambient air temperature and pressure increase to a certain level during the combustion process, the piston 46 is moved by hot air pressure further rightwards against the resilient force of the spring 52 , thereby moving the electrode 54 away from the combustion area in the cavity 36 . When the engine stops operation and the hot air pressure within the cavity 36 no longer exists, the spring 52 under its resilient force, moves from the compressed condition to regain the neutral position thereof, thereby moving the combination of the electrode 54 , piston 46 and the piston rod 50 , back to the second position thereof.
Referring to FIGS. 3-5 , the continuous plasma ignition system 32 ′ according to another embodiment of the present invention incorporates a cooling system (not indicated) thereinto. Similar to the embodiment of FIG. 2 , the system 32 ′ includes the igniter body 34 which defines the cavity 36 in a middle portion thereof. The cavity 36 further includes a ceramic liner 58 attached to the inner surface thereof. The body 34 further defines a cylindrical chamber 60 at one side thereof and a cylindrical chamber 62 at an opposed side thereof. A spark plug 38 affixed within the cylindrical chamber 60 includes the electrode 40 , and is electrically connected to a high voltage source. The cylindrical chamber 62 receives the piston member 46 slidably movable therein. The solenoid 48 is affixed to the igniter body 34 at the outside of the cylindrical chamber 62 .
The piston rod 50 extends through the solenoid 48 and is attached at an end opposed of the piston 46 , to an end member 64 . The piston rod 50 can be actuated to move to and remain in the first position as shown in FIG. 3 , when the solenoid 48 is activated. In this position, the end member 64 compresses the spring 52 to store a resilient energy therewith. The spring 52 is affixed at one end thereof to the igniter body 34 and connected at the other end thereof to the end member 64 . The piston rod 50 is free to move through the solenoid 48 from the first position of FIG. 3 to the second position of FIG. 4 when the solenoid 48 is deactivated and the spring 52 returns to its neutral position, thereby moving the end member 64 outwards.
The piston rod 50 can be further moved through the solenoid 48 from the second position of FIG. 4 to a third position shown in FIG. 5 when the solenoid 48 is deactivated and the piston 46 is pressed by an air pressure differential which will be further discussed below. In this third position, the spring 52 is forced to be extended thereby storing energy in a resilient deformation thereof. When the air pressure differential does not exist, the stored energy of the extended spring 52 will pull the end member 64 and thus the entire combination of electrode 54 , piston 46 and piston rod 50 , back to the second position of FIG. 4 . The electrode 54 connected to the piston 46 thus has three operative positions, which will be further described with reference to an ignition sequence below.
A cooling air circuit (not shown) is provided to the continuous plasma ignition system 32 and is preferably connected to a pressure air source such as the compressor air of the engine. A fluid passage 66 is provided in the igniter body 34 , for fluid communication between the cylindrical chamber 60 and the cooling air circuit. Fluid passages 68 and 70 are provided in the igniter body 34 for fluid communication between the cylindrical chamber 62 and the cooling air circuit. The fluid passages 68 , 70 are positioned both at the righthand side of the piston 46 in the first position as shown in FIG. 3 , and positioned at the opposite sides of the piston 46 when in the second and third positions as shown in FIGS. 4 and 5 . The electrode 40 with the spark plug 38 , is affixed within the cylindrical chamber 60 of the igniter body 34 and is positioned such that the end 42 of the electrode 40 is exposed to the cavity 36 but does not protrude thereinto, in order to reduce the potential damage of the end 42 of the electrode 40 caused by the high temperature of combustion in the cavity 36 .
The electrode 54 with its associated components is designed to meet the following requirements: in the first position as shown in FIG. 3 , the end 56 of the electrode 54 is in close proximity with the end 42 of electrode 40 ; in the second position as shown in FIG. 4 , the end 56 of the electrode 54 is located in a predetermined position for generating a plasma arc between the two electrodes 40 , 54 , having an electric energy level predetermined for initiating a torch ignition process; and in the third position as shown in FIG. 5 , the electrode 54 is withdrawn from the cavity 36 , and the end 56 of electrode 54 does not protrude into the cavity 36 .
The ignition sequence of a gas turbine engine using the continuous plasma ignition system 32 ′ includes three phases. At the initiation of the ignition sequence which is the first phase, the solenoid 48 is activated thereby moving the combination of the electrode 54 , piston 46 , piston rod 50 and end member 64 against the spring 52 inwardly towards the fixed high voltage electrode 40 until the ends 42 , 56 of the respective electrodes 40 , 54 almost touch each other. This results in a dependable low power ionization path development across the electrodes 40 , 54 when a relatively low breakdown voltage is applied over the electrodes, regardless of the insulation around the cavity 36 or the electrodes 40 , 54 . An initial plasma arc is thus generated, as shown in FIG. 3 .
When the initial plasma arc is generated the ignition sequence enters the second phase as shown in FIG. 4 . In this second phase, the solenoid 48 is deactivated and the retracting forces of the compressed spring 48 , pulls the ground connected electrode 54 away from the high voltage electrode 40 with the initial plasma arc following the movement of the electrode 54 . The resistance of the air gap between the ends 42 , 56 of the respective electrodes 40 , 54 increases as does the electric energy input into the extending plasma arc. The length of the air gap may be much longer than could be crossed by a plasma arc from a static condition, because the ionization path developed in the initial small air gap helps establish the initial arc and promotes its further growth. Once the spring 52 reaches its neutral position, the electrode 54 reaches a predetermined position at which the working air gap is set. Fuel is then injected from the fuel injector 28 into the plasma arc in order to initiate the torch ignition process. Once the torch ignition is initiated, a stable combustion process is started and maintained in a combustion area 72 within the cavity 36 , provided that all fuel injectors 28 of the engine continuously inject fuel into the annular combustor 26 of FIG. 1 .
The engine ignition sequence is part of an engine starting process. Prior to and during the first and second phases of the engine ignition sequence as shown in FIGS. 3 and 4 , the engine high pressure compressor 22 of FIG. 1 is rotated by a starter (not shown). Therefore pressure air is generated and introduced through the fluid passage 66 , 68 into the respective cylindrical chambers 60 , 62 to cool the respective electrodes 40 and 54 . In the first phase as shown in FIG. 3 , the pressure air enters the cylindrical chamber 62 from the fluid passage 68 and exits from the fluid passage 70 , having little pressure effect on the piston 46 . In the second phase of the ignition sequence as shown in FIG. 4 , piston 64 moves to the middle of the cylindrical chamber 62 , thereby blocking the cooling air path from the passage 68 to 70 through the cylindrical chamber 62 . Thus, the pressure air entering the left side of the cylindrical chamber 62 through the fluid passage 68 builds up a pressure differential over the opposed sides of the piston 46 . Nevertheless, at this stage, the high pressure compressor 22 of FIG. 1 is driven by an engine starter at a limited speed and cannot generate high pressure air. Therefore, the air pressure differential over the opposed sides of piston 46 is not enough to significantly move the piston 46 outwardly against the resilient force of the spring 52 .
Once the torch ignition is initiated and the combustion process is started, the electrical voltage applied over the electrodes 40 , 54 is withdrawn and no plasma arc further exists between the ends 42 , 56 of the respective electrodes 40 , 54 . In the third phase of the ignition sequence as shown in FIG. 5 , the combustion in the annular combustor 26 of the engine of FIG. 1 is stable and the engine reaches a certain power level, which results in the capability of the high pressure compressor 22 of FIG. 1 to generate compressor air at a predetermined pressure level. At this stage, the air pressure differential built over the opposed sides of the piston 46 is enough to overcome the resilient forces of the spring 52 , thereby moving the piston 46 to the third position as shown in FIG. 5 . In this position the piston 46 abuts a stop shoulder (not indicated) of the cylindrical chamber 62 and the end 56 of the electrode 54 does not protrude into the cavity 36 , thereby being protected from the high temperature of the combustion area 72 within the cavity 36 . In this way, both electrodes 40 , 54 are withdrawn from direct exposure to fuel and combustion gases, thereby increasing the life of the electrodes. The electrode 54 remains withdrawn until the air pressure differential over the opposed sides of the piston 46 falls and the extended spring 52 returns the combination of the electrode 54 , piston 46 , piston rod 50 , back to the neutral position which is the second position shown in FIG. 4 .
It is preferable to include in the electric circuit of the continuous plasma ignition system 32 ′, means (not shown) for detecting the absence of electrical current in the ground circuit resulting from plasma arc process failure due to electrode deterioration. When such a situation is detected a warning signal is generated and sent to the engine display panel.
The present invention advantageously provides the apparatus for a standard method for a continuous plasma ignition system for gas turbine engines, which requires lower electrical insulation for dependable plasma arc initiation, and which provides a, higher power plasma arc than the conventionally available plasma arc from conventional static electrodes. In accordance with the present invention, a variable arc gap plasma ignition system can be operated under severe operative conditions. For example, a plasma arc can be initiated with adequate breakdown voltages even when the air gap is flooded with liquid fuel or water because the flooded gap can be adjusted to a minimum to reduce the resistance between the electrodes. The present invention further advantageously provides longer electrode life for plasma ignition systems.
By moving the electrodes close together to initiate the process, the minimum air gap becomes the lowest resistance path and an initial arc will arise there, even under conditions which would cause plasma arc initiation failure of conventional plasma igniters, as discussed in the background of the invention. Once the initial plasma arc is started, the electrodes move away from each other and the plasma arc will follow because the initial ionization path is still the preferred electrical route.
It should be noted that the above-described embodiments are merely part of an ignition system of gas turbine engines, and especially addresses the problem associated with the failure to ignite a plasma arc between electrodes in those systems. Therefore, the present invention is applicable to any continuous plasma ignition system, and is not limited to the above-described embodiments. The present invention is also applicable to any type of gas turbine engine, not being limited to the turbofan engine taken as an example to illustrate the application of the present invention. The particular motive and biasing systems disclosed for moving the electrode(s) are but of a multitude of possibilities which will become apparent to the skilled reader, and thus is intended to be merely exemplary, and the motive and biasing means need not be separated, either. Likewise the cooling system disclosed is merely one of many possibilities now within the ordinary skill in the art in light of this description. Although described as 3 distinct phases, it will be understood that the phases may overlap or occur more or less at the same time. For example, the second and third phases ( FIGS. 4 and 5 may be integrated into a single step, such that the second phase is rather an element of phase three. Although the embodiments described include a fixed electrode and a moveable electrode, both may be moved if desired.
Still other modifications to the above-described embodiments of the present invention will be apparent to those skilled in the art without departing form the principles disclosed. For example, the solenoid and spring in the above-described embodiments can be replaced by linear actuators of any type, such as a linear electric motor, linear hydraulic motor, or a motor with gears and racks, etc. Therefore, the foregoing description is intended to be exemplary rather than limiting. The scope of the present invention is therefore intended to be limited solely by the scope of the appended claims.
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A variable arc gap plasma igniter element includes electrodes moveable relative to each other. The electrodes are preferably set to define a smaller air gap to initiate a plasma arc and later extended to obtain longer plasma arc.
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BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
This invention relates to instrument heaters, and more particularly, to an apparatus for heating a instrument used in surgery, such as laparoscopic surgery.
2. Description of Related Art
Various delicate and small instruments are used in surgery. One of the most important instruments utilized by surgeons is an optical scope. An optical scope is essentially a telescope which normally has a camera for inserting through a small incision into a human body to view the interior of the body, such as the stomach. The optical scope includes a long thin cylindrical probe having a lens at one end and a fiber optic line that connects a camera to the lens. Wires connect the camera to a display used for viewing by a surgeon. The long thin portion of the probe is small enough and long enough to enter through the small incision. The use of the optical scope provides a very useful means for viewing the interior of the human body, without opening the cavity of a body to major surgery (e.g., large incisions).
Although the optical probe is very useful in surgery, there is a problem associated with using the optical scope. When the optical scope is initially inserted through the small incision into the interior of the body, the lens at the tip of the optical scope fogs up. The optical scope's lens fogs up because of the differential in temperature between the initial temperature of the probe and the interior of the human body. The optical scope is much cooler than the warm and moist interior of the human body. This temperature differential produces a moist film on the lens of the optical scope, resulting in the clouding of the lens.
When the lens fogs up, a surgeon must wait several minutes, with the optical scope being inserted into the interior of the body, until the temperature of the optical scope is equalized with the temperature of the interior of the body. This is a waste of precious time and prolongs the length of the surgery. Therefore, a simple, safe, sterile and inexpensive method and apparatus is needed to prevent the lens of the optical scope from fogging up. The present invention provides such a device.
One known prior art teaching of a solution to the aforementioned deficiency and shortcoming is to coat the lens of the optical scope with an anti-fogging material prior to inserting the scope into the incision. To date, the results from this prior art technique have been marginal at best. Other prior art references that discuss subject matter that bears some relation to matters discussed herein are U.S. Pat. No. 5,207,213 to Auhll et al. (Auhll), U.S. Pat. No. 4,279,246 to Chikama (Chikama), U.S. Pat. No. 5,400,767 to Murdoch (Murdoch), U.S. Pat. No. 5,549,543 to Kim (Kim), and U.S. Pat. No. 5,647,840 to D'Amelio et al. (D'Amelio).
Auhll discloses a laparoscope for performing laparoscopic surgery. The laparoscope includes a rigid elongated sheath tube having a distal section and a proximal section. The distal section has a distal tip with a lens. The lens has an exterior surface located at the distal tip. The laparoscope includes a fluid flow channel which terminates in a nozzle located at the distal tip for directing a fluid flow across the exterior surface of the lens. The laparoscope further includes a first channel which terminates in an orifice which is capable of directing a flow of irrigation fluid along a selected path. Auhll does not teach or suggest a simple method for preventing the formation of moisture film on the lens of an optical scope. Auhll merely discloses a complicated apparatus for removing the moisture film by directing a fluid over the optical scope.
Chikama disclose a device for preventing the clouding of an observing window of an optical scope using heat rays from a light source. A converter is provided for changing light into heat and transmitting optical bundles. A portion of the light is changed into heat by the converter causing the observing window to be warmed, thereby preventing the clouding. Although Chikama discloses a method and apparatus for heating the lens of an optical scope. Chikama does not use a simple, disposable sheath to warm the optical scope. Chikama utilizes a complicated device having a light source, to generate the necessary heat. Murdoch discloses a device for cleaning the lens of an optical scope within removing the scope from the body cavity. The device includes a tube, an inner diameter of the tube accepting the shaft of the optical scope. On the inner circumference, near to or at one end of the tube, is a ridge that can direct a flow of fluid within the tube onto the lens of the optical scope. During operation, whenever the lens becomes obscured, a fluid is injected into the device to clean the lens. Murdoch does not teach or suggest a device to prevent the formation of a moisture film on the lens of the optical scope. Murdoch merely discloses a device to remove a film obscuring the lens of the optical scope.
Kim discloses a laparoscopic defogging apparatus used to regulate and maintain the temperature of a lens at an end portion of the laparoscope. The apparatus utilizes a receptacle containing a first sterile fluid in which the lens is placed within. Additionally, a container is provided into which the receptacle is placed, the container being adapted to receive and contain a second sterile fluid at a sufficient depth to provide thermal contact with at least a part of the receptacle side wall portion. Kim also includes a heating device which provides heat to the sterile fluids whereby the laparoscope is maintained at a constant desired temperature. Although Kim discloses a device which warms the lens of an optical scope, Kim does not teach or suggest a simple method for heating the lens. Rather, Kim utilizes a complicated device using fluids to maintain the lens of the optical scope at the desired temperature.
D'Amelio discloses an endoscope having a distally heated lens for performing laparoscopic surgery. The laparoscope includes a rigid elongated sheath tube which encloses means defining a fiber optic light caring bundle. The fiber optic bundle has a proximal end which is adapted to be operatively coupled to a light source having light energy including infrared radiation and a distal end which is located in the distal section of the sheath tube contiguous the distal lens. The lens is heated by the light source. D'Amelio does not teach or suggest a device which can be simply and effectively used on an existing optical scope. D'Amelio merely discloses designing an entirely new and more complicated optical scope to prevent the formation of an film obscuring the lens of the optical scope.
Additionally, other methods have been used to solve the problem of moisture film formation. One such method involves applying alcohol wipes to the lens prior to use within the interior of the body. However, the alcohol wipes do not prevent the formation of the moisture film. Since the alcohol is cool, the lens remains cool, resulting in the formation of the unwanted film.
Thus, it would be a distinct advantage to have a method and apparatus for heating an optical instrument to prevent the fogging of the lens of the optical instrument. It is an object of the present invention to provide such a method and apparatus.
SUMMARY OF THE INVENTION
The present invention is an instrument heater for heating an optical scope used in laparoscopic surgery. The instrument heater may also be used to heat other surgical instruments. The instrument heater includes a sheath surrounding the instrument. The sheath has an inner wall forming a bore for receiving the instrument and an outer wall forming a void between the inner wall and the outer wall. Between the inner and outer walls of the sheath is a chemical solution, such as food grade sodium acetate and water, which is reactive to a chemical substance for generating heat. On one end of the sheath is a closed-ended tip. The tip includes an activator disk having a substance, such as garnet powder, attached to the activator disk. When the activator disk is flexed, the chemical substance is ejected from the activator disk which mixes with the chemical solution. The interaction of the chemical solution and the chemical substance results in an exothermic reaction which generates heat within the sheath. On the opposite end of the sheath is an opening for receiving the optical scope within the bore. The instrument is inserted within the opening into the bore, being surrounded by the inner wall of the sheath. When the instrument requires heating, the activator disk is flexed causing the generation of heat within the sheath, which is then transmitted to the instrument.
The invention includes a method of heating an instrument used in laparoscopic surgery. The method begins by flexing an activator disk located on an end of a sheath of the instrument heater. Next, the sheath forming a bore is placed on the instrument heater. The flexing of the activator disk causes an exothermic reaction in the sheath having a chemical solution. The resulting exothermic reaction generates heat within the sheath. Next, the optical scope is heated by the sheath. The instrument heater is then removed from the instrument.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective view of an optical scope used in laparoscopic surgery;
FIG. 2 is a side perspective view of an instrument heater according to the teachings of the present invention;
FIG. 3 is a cut-away perspective view of the instrument heater according to the teachings of the present invention;
FIG. 4 is a side view of the activator disk according to the teachings of the present invention;
FIG. 5 is a greatly enlarged graphically illustrative view of a portion of the surface of the activator disk according to the teachings of the present invention;
FIG. 6 is a perspective view of the instrument heater positioned on the optical scope according to the teachings of the present invention; and
FIG. 7 is a flow chart illustrating the steps of heating an optical scope according to the teachings of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
The present invention is a method and apparatus for heating a surgical instrument, such as an optical scope used in laparoscopic surgery.
FIG. 1 is a front perspective view of an optical scope 1 used in laparoscopic surgery. The optical scope 1 includes a long cylindrical probe 3. The probe 3 is very thin and typically has a length of several inches. At one end of the probe 3 is a lens 5. The lens 5 is constructed of a clear material. On an opposite end of the probe 3 is a camera 7 used in televising the image received from the lens 5. Normally, a fiber optic cable (not shown) is utilized to connect the camera 7 to the lens 5. The camera 7 is attached to a monitor 9 by a cable 11. The monitor 9 is used to display the images received by the camera 7. The optical scope 1 may be a laparoscope, endoscope, coeloscope or similar telescope.
In operating the optical scope 1, a small incision is made through the skin of a human body. The probe 3 is inserted several inches into the interior of the body. The camera 7 remains outside of the body. The lens 5 is position for viewing a specific area desired by the surgeon. The images received by the lens 5 are then transmitted to the camera 7 and displayed on the monitor 9.
Prior to entering the body, the probe 3 is normally at room temperature, which is several degrees cooler than the temperature of a human body. When the probe 3 is inserted into the body, the probe 3 normally is obscured by a moisture film which develops upon the lens 5. The moisture film develops because the temperature of the probe 3 is several degrees cooler than the body. Additionally, the interior of a human body is very moist, causing moisture to develop on the cooler surface of the lens 5. This moisture film remains on the lens 5 until the probe 3 and its lens 5 warm to a temperature near that of the interior of the body. This temperature equalization process normally takes several minutes. Precious time is lost in waiting for the lens 5 of the optical scope 1 to clear.
FIG. 2 is a side perspective view of an instrument heater 21 according to the teachings of the present invention. The instrument heater 21 is cylindrically-shaped. The instrument heater 21 includes a sheath 23. The sheath 23 has an inner wall 25 and an outer wall 27 running across the entire length of the sheath 23. The inner wall 25 and the outer wall 27 form an essentially circular bore (not shown in FIG. 1) through the center of the sheath 23. At one end of the sheath 23 is an opening 29 which serves as the beginning of the bore. At an opposite end of the sheath 23 is a tip 31. The tip 31 is closed-ended and essentially dome-shaped.
The inner wall 25 and the outer wall 27 are constructed of a flexible nonporous material allowing for the insulation of heat. In the disclosed embodiment, the material is chip board which is a thin cardboard type material which insulates the heat within the interior of the sheath 23. However, any flexible and nonporous material capable of being sterilized may be used.
Between the inner wall 25 and the outer wall 27 is a chemical solution used in forming an exothermic reaction to create heat. In the disclosed invention, a food grade sodium acetate and water solution is utilized. Other chemical solutions may be used such as calcium chloride and water to produce the desired heat. The mixed chemical solution runs between the inner wall 25 and the outer wall 27 across the entire length of the sheath 23. Additionally, the chemical solution is present at the tip 31. The inner wall 25 and the outer wall 27 retain the chemical solution within the sheath 23.
FIG. 3 is a cut-away perspective view of the instrument heater 21 according to the teachings of the present invention. Between the inner wall 25 and the outer wall 27 at the tip 31 is an activator disk 41. The activator disk 41 is described in U.S. Pat. No. 4,872,442 to Manker and is hereby incorporated herein by reference. The activator disk 41 is located between inner wall 25 and the outer wall 27 at the tip 31 and surrounded by the chemical solution.
FIG. 4 is a side view of the activator disk 41 according to the teachings of the present invention. FIG. 5 is a greatly enlarged graphically illustrative view of a portion of the surface of the activator disk 41 according to the teachings of the present invention. The activator disk has a plurality of slits (not shown) in a flexible metal article. The opposing sides of the slits are in contact along at least a part of the length of the slit, and by an eroded and roughened surface on the metal article which includes a number of minute metal nodules attached to and protruding from the surface. The nodules are adapted to be detached or broken-off upon flexing of the activator disk 41. Such flexing is believed to cause a metal-to-metal contact between the adjacent sides to release one or more minute particles of metal, such as garnet powder, from the roughened surface which acts as a nesting side for a crystal deposited from the solution, thereby destabilizing the chemical solution and causing it to progress rapidly from a liquid to crystalline state with a resultant generation of heat. In the disclosed invention, sodium acetate and water forms the chemical solution which is present in the sheath 23. The amount and mix of the sodium acetate with the water and its interaction with the activator disk 41 determines the amount of heat produced. The preferred temperature is approximately 104 degrees Fahrenheit. However, a temperature range of 97 to 108 degrees Fahrenheit may be utilized with the instrument heater 21. The higher end of the temperature range is necessary because any hotter of a temperature may result in damage to any portion of the body which comes in contact with the probe 3. The lower end of the temperature range is the lowest temperature in which the instrument heater 21 can be useful in preventing the formation of a moisture film upon the lens 5.
FIG. 6 is a perspective view of the instrument heater 21 positioned on the optical scope 1 according to the teachings of the present invention. Referring to FIGS. 1-6, the operation of the instrument heater 21 will now be explained. The instrument heater 21 is sterilized prior to use. Normally, the sterilization of the instrument heater 21 is accomplished by bombarding the instrument heater 21 with Gamma-rays. The instrument heater 21 is then vacuumed sealed and wrapped in a sterile wrap very similar to syringe packaging.
The instrument heater 21 is activated by pinching the tip 31, thereby bending the activator disk 41. Next, the instrument heater 21 is placed over the probe 3, covering several inches (approximately 4 to 6 inches) of the probe 3 as well as the lens 5. Upon flexing the activator disk 41, the activator disk 41 releases metal nodules which react with the sodium acetate to cause an exothermic reaction at approximately 104 degrees Fahrenheit. This exothermic reaction heats the sheath 23 which transmits the heat to the probe 3 and the lens 5. The sheath 23 may be massaged to induce a faster reaction by mixing more metal nodules into the chemical solution throughout the length of the sheath 23.
The instrument heater 21 remains in place on the probe 3 for several minutes until the probe 3 and its lens 5 are at a temperature approximately equal to the interior of a human body. Once this temperature is reached, the instrument heater 21 is removed from the probe 3 and discarded. The probe 3 and the lens 5 are then inserted into the body for examination of the interior of the body.
The sheath 23 runs approximately 4 to 6 inches to cover most of the probe 3 and lens 5. The probe 3 as well as the lens 5 should both be heated. If the lens 5 was only heated, the cool probe 3 may cool the lens 5 back to a lower temperature, resulting in the formation of a moisture film upon the lens 5.
In alternate embodiments of the present invention, the instrument heater 21 may be used to heat other surgical instruments such as clamp, forceps, or scalpels.
FIG. 7 is a flow chart illustrating the steps of heating an optical scope 1 according to the teachings of the present invention. The method starts with step 51 where the instrument heater 21 is sterilized. Sterlization normally occurs by bombarding the instrument heater 21 with Gamma-rays. Next, in step 53, the activator disk 41 is bent, releasing metal nodules into the chemical solution (food grade sodium acetate in the disclosed invention) contained in the sheath 23. The activator disk 41 is bent by pinching the tip 31. In step 55, the instrument heater 21 is placed on the probe 3 with the sheath 23 covering the lens 5 and several inches of the probe 3.
Next, in step 57, the interaction of the metal nodules with the chemical solution initiates an exothermic reaction which radiates heat throughout the sheath 23. In step 59, the radiated heat in the sheath 23 is transmitted to the probe 3 and the lens 5. In step 61, when the desired temperature for the probe 3 and lens 5 is reached, the instrument heater 21 is removed and may be disposed. In step 63, the heated probe 3 and lens 5 is then inserted into a body. Since the lens 5 has the same or nearly the same temperature as within the body, a moisture film will not form over the lens 5. Therefore, viewing of the desired area within the body's interior can start immediately.
In alternate embodiments, the present invention may be used in dentistry for such tools as an extended mirror and in veterinary medicine with surgical tools used on animals.
The instrument heater 21 offers many advantages. The instrument heater is a simple, inexpensive, and disposable means for solving the problem of the formation of a moisture film upon the lens of the optical scope. The instrument heater provides an effective means for heating the optical scope without modifying an existing optical scope. Additionally, sterilization of the instrument heater is maintained easily by initially sterilizing the instrument heater with Gamma-rays and vacuum sealing the instrument heater in a sterile wrap. After use, the instrument heater can be discarded, thereby removing the problem of having to re-sterilize the instrument heater.
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An instrument heater for heating a surgical instrument. The instrument heater includes a sheath having an inner and outer wall. The inner wall forms a bore through which the optical scope is inserted. A chemical solution fills the space between the inner and outer wall of the sheath. At one end of the sheath is an activator disk having a chemical substance attached to its surface. When the activator disk is flexed, it ejects the chemical substance and interacts with the chemical solution to initiate an exothermic reaction. The exothermic reaction results in the generation of heat within the sheath, which is transmitted to the surgical instrument. Once the surgical instrument is sufficiently heated to a temperature close to the temperature of a body, the optical scope is inserted into the body. A natural tendency for the instrument to fog up is prevented by the equalizing the temperature of the instrument with the body.
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RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 12/525,801, which is a national stage application of PCT/SE2008/050129, filed Feb. 1, 2008, which claims benefit of SE 0700289-2 filed Feb. 5, 2007, the disclosures of each of which are incorporated herein by reference in their entirety.
TECHNICAL FIELD
The concepts described herein may relate to methods and arrangements in a network. In particular, the concepts described herein may relate to methods and arrangements for providing load measurements and resource management in a network.
BACKGROUND
Under the Third Generation Partnership Project (3GPP) release 99 framework, a radio network controller (RNC) may control resources and user mobility. Resource control may include admission control, congestion control, and channel type switching. Uplink data may be allocated to an Enhanced Dedicated Channel (E-DCH), which may include an Enhanced Dedicated Physical Control Channel (E-DPCCH) for data control and an Enhanced Dedicated Physical Data Channel (E-DPDCH) for data. The E-DPCCH and the E-DPDCH may be discontinuous and may be transmitted only when there is uplink data to be sent. Additionally, uplink data may be transmitted on a continuous Dedicated Physical Data Channel (DPDCH). A radio base station (RBS) may include an uplink scheduler that determines which transport formats each subscriber may use over the E-DPDCH.
As previously mentioned, the RNC may be responsible for admission control and congestion control. For example, the RNC may monitor and control the load in the RBS. The RNC may perform these operations based on Iub interface measurements from the RBS. The Iub measurements related to the uplink may include received total wideband power (RTWP) (i.e., the total received power at the uplink receiver), reference received total wideband power (RRTWP) (i.e., the thermal noise contribution to the RTWP), and received scheduled E-DCH power share (RSEPS) (i.e., the received power from resources controlled by an enhanced uplink (EUL) scheduler (e.g., the E-DPCCH and the E-DPDCH) relative to the RTWP). In one implementation, the Iub measurements may be transmitted to the RNC by the RBS in a Node B Application Part (NBAP) report. In some instances, the NBAP report may include both the RSEPS and the RTWP for the same time interval to enable direct comparisons.
FIG. 1 illustrates an exemplary uplink stack 100 that includes exemplary uplink interference contributions. As illustrated in FIG. 1 , total uplink interference (I-total) 140 may include background noise interference 105 , other-cell interference 110 , DPDCH interference 115 , DPCCH interference 120 , non-scheduled interference 125 and scheduled interference 130 . Non-scheduled interference 125 may include interference from the E-DPCCH, the E-DPDCH, and a High Speed Dedicated Physical Control Channel (HS-DPCCH). The HS-DPCCH may be employed for uplink acknowledgements relating to downlink data transmitted over a High Speed Downlink Shared Channel (HS-DSCH). Scheduled interference 130 may include interference from the E-DPCCH and the E-DPDCH. The interference contribution of scheduled interference is further illustrated by uplink scheduled interference (I_sch) 135 .
Based on measurements over the Iub interface, the following may be estimated according to the following expressions:
Uplink noise rise as = RTWP/RRTWP;
Uplink relative load as L nr =1−(1/ )=1−( RRTWP/RTWP ); and
Non-scheduled load as L non-sched =L nr −RSEPS.
In such an instance, the non-scheduled load estimate may include the load due to inter-cell interference from other cells. Additionally, E-DCH may yield a non-scheduled load because the DPCCH of the E-DCH may be considered non-scheduled.
When balancing scheduled and non-scheduled loads, the non-scheduled load may be used as input to the admission control of the RNC to ensure that there is sufficient headroom for scheduled data. This reallocatable resource intended for scheduled E-DCH is referred to as the scheduling headroom. This may be expressed as:
L sched, headroom =L nr, max −L non-sched ,
where L nr, max is the maximum uplink relative load of the cell based on, for example, a coverage or power control stability metric.
For a target scheduling headroom, a target non-scheduled load, L non-sched, target of the cell may be derived, to which an estimated current, non-scheduled load may be compared. In such a comparison, an admitted load, L adm , from recently admitted connections that are still inactive may be included. Consequently, a user may be admitted if the following expression is met:
L non-sched +L adm +L new potential connection ≦L non-sched, target .
Margins considered by, for example, a load estimation algorithm (LEA) and/or a scheduler may affect the available scheduling headroom. For example, the RNC may employ a LEA for purposes of admission and/or congestion control. Additionally, or alternatively, the RBS may employ a LEA for scheduling, and/or assign grants to subscribers based on the scheduler. The LEA may calculate the load contribution from non-scheduled connections in their own cell, L non-sched, own , and may maintain an estimate of other-cell load contribution, L other (i.e., the other-cell received power share). For example, the other-cell load contribution may equate to a ratio between received powers from other cells and the RTWP. In this regard, the scheduler may consider the scheduling headroom according to the following expression:
L sched, headroom =L nr, max −L non-sched, own −L other .
Further, in order to maintain a margin for inter-cell interference, and to be robust to estimation errors of the other-cell load contribution, the other-cell load contribution may be limited from below by a minimum other-cell load contribution L other min . In one implementation, L other min may be a static value. Thus, the scheduler may consider the scheduling headroom according to the following expression:
L sched, headroom =L nr, max −L non-sched, own −max ( L other , L other min ).
Such a margin, which is not always active, may not be accounted for in the Iub measurements. Additionally, there may be other margins utilized by the LEA and/or the scheduler that may not be accounted for in the Iub measurements, but reduce the scheduling headroom considered by the RBS. Consequently, such margins may not be known by the RNC and correspondingly may not be taken into account.
Additionally, multi-user detector schemes and/or interference cancellation schemes may be adopted by the RBS to cancel intra-cell interference. One approach to such schemes includes regenerating the interfering signal from detected connections and subtracting the regenerated interfering signal from the received signal. Thus, the effective interference power from an E-DCH may be less than the actual received power. Therefore, the RSEPS may not reflect the actual balance between the E-DCH and a DCH.
SUMMARY
It is an object to obviate at least some of the above disadvantages and to improve the operation of a network.
According to one aspect, a method may include determining whether a discrepancy exists between scheduling headroom computable by a first device and scheduling headroom computable by a second device, determining one or more load measurements that the second device bases its computation of the scheduling headroom if it is determined that the discrepancy exists, modifying the one or more load measurements, and calculating the scheduling headroom based on the modified one or more load measurements.
Additionally, the modifying may include modifying, by the first device, the one or more load measurements, and the method may further include transmitting, by the first device, the modified one or more load measurements to the second device.
Additionally, the method may further include transmitting, by the first device, the one or more load measurements together with additional information about the scheduling headroom discrepancy to the second device, and where the modifying may include modifying, by the second device, the one or more load measurements based on the additional information about the scheduling headroom discrepancy.
Additionally, the method may include determining effective interference cancellation associated with enhanced dedicated channels, where the effective interference cancellation associated with the enhanced dedicated channels corresponds to the additional information.
Additionally, the determining the effective interference cancellation associated with the enhanced dedicated channels may include determining an interference from the scheduled enhanced dedicated channels before an interference cancellation process is employed, determining an interference from the scheduled enhanced dedicated channels after an interference cancellation process is employed, and determining the effective interference cancellation associated with the enhanced dedicated channels based on a difference between the interference determined before the interference cancellation process and the interference determined after the interference cancellation process.
Additionally, the determining may include calculating an other-cell load.
Additionally, the calculating may include determining whether a difference value between the other-cell load and a minimum other-cell load yields a non-zero value.
Additionally, the modifying may include modifying the one or more load measurements relating to an Iub interface if the difference value yields the non-zero value.
Additionally, the method may include performing, by the first device, interference cancellation, and determining an effective interference corresponding to an interference power that remains.
Additionally, the modifying may include modifying the one or more load measurements corresponding to a received scheduled enhanced dedicated channel power share (RSEPS) based on the effective interference associated with a received scheduled power and a received non-scheduled power.
Additionally, the method may include transmitting, by the first device, a modified received total wideband power (RTWP) measurement and a modified RSEPS measurement to the second device.
Additionally, the method may further include calculating, by the second device, at least one of admission control or congestion control parameters based on at least one of the modified RTWP measurement or the modified RSEPS measurement
According to another aspect, a device may include a memory to store instructions, and a processor to execute the instructions. The processor may execute instructions to determine whether a discrepancy relating to scheduling headroom exists between the device and another device, modify a power measurement associated with an interface shared between the device and the other device if it is determined that the discrepancy exists, and provide the other device with a modified power measurement.
Additionally, when determining whether the discrepancy relating to scheduling headroom exists, the processor may be configured to calculate an other-cell load based on inter-cell interference.
Additionally, when calculating the other-cell load, the processor may be configured to determine whether a minimum other-cell load exceeds the other-cell load.
Additionally, when modifying the power measurement, the processor may be configured to compute at least one of a modified RTWP measurement, a modified reference received total wideband power (RRTWP) measurement, or a modified RSEPS measurement if it is determined that the discrepancy exists.
Additionally, the interface may include an Iub interface.
Additionally, when computing the processor may be configured to compute the at least one of the modified RTWP measurement or the modified RSEPS measurement based on a difference value, the difference value being equal to a difference between a minimum other-cell load and an other-cell load.
Additionally, the processor may further execute instructions to determine an effective interference after interference cancellation is performed.
Additionally, when modifying the power measurement, the processor may be configured to compute at least one of a modified RTWP measurement or a modified RSEPS measurement based on the effective interference.
Additionally, when providing the other device with the modified power measurement, the processor may be configured to provide the modified RTWP measurement and the modified RSEPS measurement to the other device, and provide an unmodified RTWP measurement to the other device.
Additionally, when determining the effective interference, the processor may be configured to determine connections subject to interference cancellation and connections not subject to interference cancellation.
Additionally, the device may include a radio base station and the other device may include a radio network controller.
According to still another aspect, a computer-readable medium may include instructions executable by a radio base station, the computer-readable medium may include one or more instructions for determining whether a discrepancy relating to a non-scheduling load exists between the radio base station and a radio network controller, one or more instructions for modifying one or more interface measurements if the non-scheduling load discrepancy exists, and one or more instructions for sending a modified one or more interface measurements to the radio base station controller.
Additionally, the one or more instructions for determining may include one or more instructions for calculating whether a minimum other-cell load value exceeds an other-cell load value.
Additionally, the one or more instructions for calculating may include one or more instructions for generating a difference value, the difference value being a quantity by which the minimum other-cell load value exceeds the other-cell load value.
Additionally, the one or more interface measurements may include a RSEPS measurement, and the one or more instructions for modifying may include one or more instructions for subtracting the difference value from the RSEPS measurement.
Additionally, the one or more instructions for modifying may include one or more instructions for modifying the one or more interface measurements based on the difference value.
Additionally, the one or more interface measurements include at least one of a RTWP measurement, a RRTWP measurement, or a RSEPS measurement.
Additionally, the one or more interface measurements may relate to an Iub interface.
Additionally, the computer-readable medium may further include one or more instructions for determining an interference power after an interference cancellation scheme is performed.
Additionally, the computer-readable medium may further include one or more instructions for calculating one or more modified interface measurements based on the interference power.
Additionally, the modified one or more interface measurements based on the interference power may include a modified RTWP measurement.
Additionally, the modified one or more interface measurements based on the interference power may include a modified RSEPS measurement.
According to still another aspect, a device may include a memory to store instructions, and a processor to execute the instructions. The processor may execute instructions to receive one or more load measurements and effective cancellation interference information associated with a scheduling headroom discrepancy determination, modify the one or more load measurements based on the effective cancellation interference information, and calculate a scheduling headroom based on the modified one or more load measurements.
Additionally, the effective interference information may correspond to effective cancellation interference information associated with scheduled enhanced dedicated channels.
Additionally, when calculating the scheduled headroom, the processor may be further configured to calculate a received scheduled enhanced dedicated channel power (RSEP) based on the one or more load measurements, where the one or more load measurements include a received total wideband power (RTWP) measurement and a received scheduled enhanced dedicated channel power share (RSEPS) measurement, calculate a total cancelled interference, modify the RSEP and the RTWP based on the calculation of the total cancelled interference, and modify the RSEPS based on the modified RSEP and the modified RTWP.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 . is a diagram illustrating exemplary uplink interference contributions;
FIG. 2 is a diagram illustrating an exemplary wireless network environment;
FIG. 3 is a diagram illustrating exemplary components that may correspond to one or more of the devices of the exemplary wireless network environment depicted in FIG. 2 ;
FIG. 4 is a diagram illustrating an exemplary component associated with the RBS depicted in FIG. 2 ;
FIG. 5 is a diagram illustrating relations between defined load quantities; and
FIGS. 6 , 7 and 8 are flow diagrams related to processes associated with the concepts described herein.
DETAILED DESCRIPTION
The following detailed description refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements. Also, the following description does not limit the invention. The term “component,” as used herein, is intended to be broadly interpreted to include software, hardware, or a combination of hardware and software.
FIG. 2 illustrates an exemplary wireless network 200 . As illustrated, wireless network 200 may include a core network (CN) 202 , a radio access network (RAN) 204 , radio network subsystems 206 - 1 and 206 - 2 (collectively referred to as RNS 206 ), radio network controllers (RNCs) 208 - 1 and 208 - 2 (collectively referred to as RNC 208 ), radio base stations (RBSs) 210 - 1 , 210 - 2 , 210 - 3 , and 210 - 4 (collectively referred to as RBS 210 ), user equipment (UE) 212 - 1 , 212 - 2 , 212 - 3 , and 212 - 4 (collectively referred to as UE 212 ), Iu interfaces 214 - 1 and 214 - 2 (collectively referred to as Iu interface 214 ), Iub interfaces 218 - 1 , 218 - 2 , 218 - 3 , and 218 - 4 (collectively referred to as Iub interface 218 ), and Uu interfaces 220 - 1 , 220 - 2 , 220 - 3 , and 220 - 4 (collectively referred to as Uu interface 220 ). In one implementation, wireless network 200 may correspond to a wideband code division multiple access (WCDMA)-based network. In other implementations, wireless network 200 may correspond to a network other than a WCDMA-based network.
CN 202 may be, for example, a network that includes circuit switched and packet switched domains that provide various services to UE 212 subscribers. For example, although not illustrated, the circuit switched domain may include mobile switching centers (MSCs), visitor location registers (VLRs), and gateways. The packet switched domains may include, for example, serving general packet radio service (GPRS) support nodes (SGSN) and gateway GPRS support nodes (GGSNs). CN 202 may also include home location registers (HLRs), authentication centers (AUCs), equipment identity registers (EIR), etc.
RAN 204 may be a part of wireless network 200 that is responsible for the radio transmission and control of a radio connection between UE 212 and CN 202 . In one embodiment, RAN 204 may include one or more RNSs 206 . RNS 206 may manage resource allocations of a radio link to a subscriber. Each RNS 206 may include an RNC 208 and a group of RBSs 210 .
RNC 208 may control radio resource management and radio connectivity within a set of cells. For example, RNC 208 may manage radio access bearers for user data transfer (e.g., between CN 202 and UE 212 ), manage and optimize radio network resources (e.g., outer-loop power control and admission and congestion control), and/or control mobility, including soft handovers. RNC 208 may determine load information for purposes of admission and congestion control, as further described below.
RNC 208 may control RBS 210 via Iub interface 218 . RNC 208 may also connect RAN 204 to CN 202 via Iu interface 214 . RNC 208 may include a controlling RNC and a serving RNC. For example, RNC 208 - 1 may be the controlling RNC, and RNC 208 - 2 may be the serving RNC. The controlling RNC may have overall control of a particular set of cells and their associated RBS 210 . In instances, for example, when UE 212 may need to utilize resources in a cell not controlled by its serving RNC, the serving RNC (e.g., RNC 208 - 2 ) may issue a request to the controlling RNC (e.g., RNC 208 - 1 ) for such resources via Iur interface 216 .
RBS 210 (sometimes referred to as Node B) may handle radio transmission and reception within one or more cells. Each cell may be identified by a unique identifier, which may be broadcast in the cell. In some instances, there may be more than one cell covering the same geographical area. RBS 210 may perform various functions, such as calculations of timing advance, measurements in the uplink direction, scheduling headroom, channel coding, encryption, decryption, frequency hopping, inner-loop power control, softer handover combining and splitting, and operation and maintenance.
UE 212 may include a mobile terminal by which subscribers may access services by maintaining a radio link with one or more cells in RAN 204 . UE 212 may include a mobile phone, a personal digital assistant (PDA), a mobile computer, a laptop, and/or another type of handset or communication device. In other instances, UE 212 may include a vehicle-mounted terminal.
Iu interface 214 may connect CN 202 with RAN 204 . Iur interface 216 and Iub interface 218 may connect the different nodes in RAN 204 , as illustrated in FIG. 1 . Uu interface 220 may connect UE 212 to RBS 144 . User data may be transported on transport bearers on these interfaces. Depending on the transport network employed, the transport bearers may be mapped to, for example, Asynchronous Transfer Mode (ATM) adaptation layer type 2 (AAL2) connections for an ATM based transport network, or User Datagram Protocol (UDP) connections for an Internet Protocol (IP) based transport network.
Although FIG. 1 illustrates an exemplary wireless network 200 , in other implementations, fewer, additional, or different devices may be employed. Additionally, or alternatively, one or more devices of wireless network 200 may perform one or more functions described as being performed by one or more other devices of wireless network 200 .
FIG. 3 is a diagram illustrating exemplary components of a device 300 that may correspond to one or more of the devices depicted in FIG. 1 . For example, device 300 may correspond to RNC 208 , RBS 210 , and/or UE 212 . As illustrated, device 300 may include a bus 310 , a processor 320 , a memory component 330 , a storage component 340 , an input component 350 , an output component 360 , and/or a communication interface 370 .
Bus 310 may include a path that permits communication among the components of device 300 . For example, bus 310 may include a system bus, an address bus, a data bus, and/or a control bus. Bus 310 may also include bus drivers, bus arbiters, bus interfaces, and/or clocks.
Processor 320 may include a general-purpose processor, a microprocessor, a data processor, a co-processor, a network processor, an application specific integrated circuit (ASIC), a controller, a programmable logic device, a chipset, a field programmable gate array (FPGA), or any other component or group of components that may interpret and execute instructions.
Memory component 330 may include any type of component that stores data and instructions related to the operation and use of device 300 . For example, memory component 330 may include a storing component, such as a random access memory (RAM), a dynamic random access memory (DRAM), a static random access memory (SRAM), a synchronous dynamic random access memory (SDRAM), a ferroelectric random access memory (FRAM), a read only memory (ROM), a programmable read only memory (PROM), an erasable programmable read only memory (EPROM), an electrically erasable programmable read only memory (EEPROM), and/or a flash memory.
Storage component 340 may include a storing component, such as a hard disk (e.g., a magnetic disk, an optical disk, a magneto-optic disk, etc.), a compact disc (CD), a digital versatile disc (DVD), a floppy disk, a cartridge, a magnetic tape, another type of storage medium, or another type of computer-readable medium, along with a corresponding drive.
Memory component 330 and/or storage component 340 may also include a storing component external to and/or removable from device 300 , such as a Universal Serial Bus (USB) memory stick, a hard disk, a Subscriber Identity Module (SIM), etc.
Input component 350 may include a mechanism that permits a user to input information to device 300 , such as a keyboard, a keypad, a mouse, a button, a switch, voice recognition, etc. Output component 360 may include a mechanism that outputs information to a user, such as a display, a speaker, one or more light emitting diodes (LEDs), etc.
Communication interface 370 may include any transceiver-like mechanism that enables device 300 to communicate with other devices and/or systems. For example, communication interface 370 may include an Ethernet interface, an optical interface, a coaxial interface, a radio interface, or the like. Communication interface 330 may allow for wired and/or wireless communication.
Communication interface 330 may implement industry promulgated protocol standards, such as transmission control protocol/Internet protocol (TCP/IP), Asynchronous Transport Mode (ATM), digital subscriber line (DSL), integrated services digital network (ISDN), fiber channel, synchronous optical network (SONET), Ethernet, Institute of Electrical and Electronic Engineers (IEEE) 802 standards, etc. Additionally, or alternatively, communication interface 330 may implement non-standard, proprietary, and/or customized interface protocols. Communication interface 330 may contain a plurality of communication interfaces to handle multiple traffic flows.
As will be described in detail below, device 300 may perform certain operations relating to the system and services described herein. Device 300 may perform these operations in response to processor 320 executing software instructions contained in a computer-readable medium, such as memory component 330 . A computer-readable medium may be defined as a physical or a logical memory device.
The software instructions may be read into memory component 330 from another computer-readable medium or from another device via communication interface 370 . The software instructions contained in memory component 330 may cause processor 320 to perform processes that will be described later. Alternatively, hardwired circuitry may be used in place of or in combination with software instructions to implement processes described herein. Thus, implementations described herein are not limited to any specific combination of hardware circuitry and software.
Although, FIG. 3 illustrates exemplary components of device 300 , in other implementations, device 300 may include fewer, additional, and/or different components than those depicted in FIG. 3 . In still other implementations, one or more components of device 300 may perform one or more other tasks described as being performed by one or more other components of device 300 .
FIG. 4 is a diagram of an exemplary component of RBS 210 that may perform calculations for modifying Iub 218 measurements. For purposes of discussion, the component will be referred to as an Iub measurement modifier 405 . Iub measurement modifier 405 may modify Iub 218 measurement values, such as the RTWP, the RRTWP, and/or the RSEPS, according to the expressions provided below. In one implementation, Iub measurement modifier 405 may implemented as software stored in storage component 340 . In another implementation, Iub measurement modifier 405 may be implemented as hardware, such as processor 320 . In still other implementations, Iub measurement modifier 405 may include a combination of hardware and software.
Although FIG. 4 illustrates an exemplary component of RBS 210 , in other implementations, Iub measurement modifier 405 may be a component of a device other than RBS 210 . Additionally, or alternatively, the functionality associated with Iub measurement modifier 405 , as to be described more fully below, may be employed in a distributed fashion between or among more than one device, including or excluding RBS 210 .
FIG. 5 is a diagram illustrating exemplary load contributions. As illustrated, load information may include a L_scheduled portion 505 (i.e., a scheduled load), a L_non-scheduled portion 510 that may include a L_non-scheduled load, own, and an other-cell load (L_other), and a L_other, min 515 that may include a load corresponding to Δ, as described below. Further, FIG. 5 illustrates a L_nr 520 and a L_nr, max 525 that correspond to a relative load and a maximum relative load, respectively.
Referring to FIG. 5 , the non-scheduling load L non-sched may be separated into non-scheduled load from the own cell L non-sched, own and load from other-cells L other as discussed above. Thus, in one implementation, the scheduling headroom may be expressed as:
L sched, headroom =L nr, max −L non-sched, own −max ( L other , L other min )= L nr, max −L non-sched, own −L other −max (0, L other min −L other ). (1)
In some instances, the scheduling headroom considered in RBS 210 may be (artificially) reduced according to the following expression:
Δ=max (0, L other min −L other ), (2)
in order to be robust to the inter-cell interference contribution as described above. However, when Δ is greater than zero, there may be a discrepancy between the scheduling headroom calculated by RBS 210 and the scheduled headroom that can be estimated in RNC 208 . That is, in instances where L other min is greater than L other , Δ may have a value greater than zero. For example, as illustrated in FIG. 5 , the value of L_other, min 515 may exceed L_other. Thus, as indicated in expression (2) above, Δ may have a value greater than zero.
Based on the load contribution illustrated in FIG. 5 , the LEA of RNC 208 may need to consider the non-scheduled load according to the following expression:
L non-sched =L non-sched, own +L other +Δ. (3)
Since, however, RNC 208 may compute the non-scheduled load according to the following expression:
L non-sched =L nr −RSEPS, (4)
the impact or effect from a non-zero Δ may be accounted for by modifying either RSEPS or L nr . That is, Iub measurement modifier 405 may modify either RSEPS or L nr . As previously described above, L nr may be expressed as:
L nr =1−( RRTWP/RTWP ).
Thus, L nr may be computed from RRTWP and RTWP. Accordingly, the impact or effect from a non-zero Δ may be accounted for by modifying either of RSEPS, RTWP, or RRTWP.
Based on expressions (3) and (4), the RSEPS may be modified according to the following expression:
RSEPS_mod=RSEPS−Δ. (5)
In this regard, increasing the used load margin by reducing the used scheduled load measurement may appear to be an illogical approach. However, the rationale to this approach is that this measurement may be used to compute the non-scheduled load, which is increased as a consequence.
Based on expressions (3) and (4), (L nr — mod)=L nr +Δ, thus
1
-
RRTWP_mod
RTWP
=
1
-
RRTWP
RTWP
+
Δ
=
1
-
RRTWP
-
Δ
·
RTWP
RTWP
.
(
6
)
Hence, the RRTWP may be modified according to the following expression:
RRTWP _mod= RRTWP−Δ*RTWP. (7)
As noted from expression (6) above, the RTWP may be modified according to the following expression:
RRTWP
RTWP_mod
=
RRTWP
-
Δ
·
RTWP
RTWP
⇔
RTWP_mod
=
RTWP
1
-
Δ
·
RTWP
/
RRTWP
.
(
8
)
In one implementation, Iub 218 measurement of the RRTWP may be reported by RBS 210 infrequently to RNC 208 since the RRTWP may not change frequently. Additionally, or alternatively, the RRTWP measurement may be updated based on an event-trigger so that reporting occurs only when there is a change of the RRTWP.
On the other hand, measurement modifications to the RSEPS or the RTWP may be considered. For example, a modified RTWP may be reported in the same report as the modified RSEPS. Also, a non-modified RTWP may be reported in a separate message. In either instance, modifications to the Iub 218 measurements may be utilized and reported to RNC 208 so that RNC 208 may be informed about the margins affecting RBS 210 scheduling headroom.
Further, in instances when RBS 210 employs a multi-user detector or an interference cancellation receiver, the effective interference measurement may be modified. For example, the effective interference may be determined after detection, signal regeneration and subtraction has been carried out. RBS 210 may then determine the efficiency of the cancellation, and consider the effective interference in the calculations of the RTWP and the RSEPS. For example, RBS 210 may separate the received scheduled power I sched and non-scheduled power I non-sched into powers from connections subject to interference cancellation, I sched IC and I non-sched IC , and not subject to cancellation, I sched notIC and I non-sched notIC , according to the following expressions:
I sched =I sched IC +I sched notIC (9)
I non-sched =I non-sched IC +I non-sched notIC . (10)
Further, RBS 210 may define the effective interference from connections subject to interference cancellation as I sched ICeff and I non-sched ICeff respectively. That is, I sched ICeff and I non-sched ICeff may correspond to the interference power that remains after a last step of an interference cancellation scheme. In such an instance, the measured interference values may be adjusted according to the following expressions:
I _mod sched =I sched +I sched ICeff −I sched IC . (11)
I _mod non-sched =I non-sched +I non-sched ICeff −I non-sched IC . (12)
Hence, as noted from expressions (9), (10), (11), and (12) above, the RTWP may be modified according to the following expression:
RTWP _mod= RTWP+I sched ICeff −I sched IC +I non-sched ICeff −I non-sched IC . (13)
Further, as noted from expressions (9), (10), (11), (12), and (13) above, the RSEPS may be modified according to the following expression:
RSEPS_mod
=
(
I
sched
+
I
sched
ICeff
-
I
sched
IC
)
/
RTWP_mod
=
(
I
sched
notIC
+
I
sched
ICeff
)
/
RTWP_mod
.
(
14
)
Again, it may be beneficial to use the combined RSEPS and RTWP measurement report to provide the modified measurements, while the dedicated RTWP measurement report may include the unmodified measurement since this may be of specific interest for coverage determination.
Alternatively, measurement modifications may be determined by RNC 208 based on additional information received over Iub 218 together with RTWP and/or RSEPS measurements. For example, the additional information may include cancelled scheduled E-DCH interference and cancelled non-scheduled E-DCH interference, which may be expressed according to the following expressions:
I sched,canc =I sched ICeff −I sched IC . (15)
I non-sched,canc =I sched ICeff −I sched IC . (16)
Then, RNC 208 may be able to modify RSEPS based on the following exemplary procedure. For example, RNC 208 may calculate the received scheduled E-DCH power (RSEP) using the RSEPS and RTWP measurements according to the following expression:
RSEP=RSEPS*RTWP. (17)
RNC 208 may calculate cancelled interference in total according to the following expression:
I canc =I sched,canc +I non-sched,canc (18)
RNC 208 may modify RSEP and RTWP based on the information related to cancelled interference according to the following expressions:
RTWP _mod= RTWP−I canc (19)
RSEP _mod= RSEP−I sched,canc (20)
RNC 208 may calculate a modified RSEPS according to the following expression:
RSEPS _mod= RSEP _mod/ RTWP _mod (21)
In another embodiment, interference cancellation may never be employed to connections other than scheduled E-DCH connections in which case only cancelled scheduled E-DCH interference may be reported. Similarly, the cancelled interference from connections other than scheduled E-DCH connections may be neglected and/or treated as being negligible.
FIG. 6 is a diagram illustrating an exemplary process 600 that may be employed when calculating the scheduled headroom load. In one implementation, Iub measurement modifier 405 of RBS 210 may perform one or more of the operations of process 600 . In other implementations, process 600 may be performed by another device or group of devices including or excluding RBS 210 .
Process 600 may begin with calculating the other-cell load (block 605 ). As described in reference to expression (1), when calculating the scheduled headroom load, other-cell load may be considered. In some instances, RBS 210 may provide a margin for inter-cell interference corresponding to expression (2). For example, as indicated in expression (2), RBS 210 may calculate the other-cell load based on a delta margin.
A determination whether the delta margin is non-zero may be made (block 610 ). For example, based on expression (2), the delta margin may yield a zero or non-zero value, as illustrated in FIG. 5 . If the delta margin is non-zero (block 610 —YES), then the measurements of at least one of the RSEPS, RRTWP, or the RTWP may be modified (block 615 ). For example, the RSEPS measurement may be modified based on expression (5), the RRTWP measurement may be modified based on expressions (6) and (7), and the RTWP measurement may be modified based on expression (8).
The modified RWTP and the RSEPS measurement report may be transmitted (block 620 ). In one implementation, the modifications of the RWTP and the RSEPS measurements may be transmitted to, for example, RNC 208 , in the same measurement report. In other implementations, the modified RRTWP may be transmitted to, for example, RNC 208 , in a measurement report. Additionally, or alternatively, a non-modified RTWP measurement may be reported in the same or different message than the modified RTWP and RSEPS.
If the delta margin is zero (block 610 —NO), then the process may end. For example, the scheduled headroom may be calculated without modifying measurements associated with Iub 218 measurements.
Although FIG. 6 illustrates an exemplary process 600 , in other implementation, fewer, different, or additional operations may be performed.
FIG. 7 is a diagram illustrating an exemplary process 700 that may be employed when calculating the effective interference. In one implementation, Iub measurement modifier 405 of RBS 210 may perform one or more of the operations of process 700 . In other implementations, process 700 may be performed by another device or group of devices including or excluding RBS 210 .
Process 700 may begin with determining connections to which interference cancellation may be performed (block 705 ). For example, as described in connection to expressions (9) and (10), flows may be separated into scheduled flows and non-scheduled flows. Additionally, flows may be separated into scheduled flows subject to interference cancellation and scheduled flows not subject to interference cancellation. Further, non-scheduled flows may be separated into non-scheduled flows subject to interference cancellation and non-scheduled flows not subject to interference cancellation.
The interference power before interference cancellation is performed may be determined (block 710 ). For example, in one implementation, received schedule power and non-scheduled power may each be determined before an interference scheme is employed based on power connections subject to interference cancellation and connections not subject to interference cancellation. In one implementation, the interference power may be determined based on expressions (9) and (10).
The effective interference for connections subject to interference cancellation may be determined (block 715 ). For example, RBS 210 may determine the effective interference for connections subject to interference cancellation after an interference cancellation scheme is employed. In one implementation, the measured effective interference may be based on expressions (11) and (12).
The measurement of the RTWP may be modified (block 720 ). For example, the RTWP may be modified based on expression (13).
The measurement of the RSEPS may be modified (block 725 ). For example, the RSEPS may be modified based on expression (14).
The modified RWTP and RSEPS measurement report may be transmitted (block 730 ). In one implementation, the modifications of the RWTP and the RSEPS may be transmitted to, for example, RNC 208 , in the same measurement report. Additionally, or alternatively, a non-modified RTWP measurement may be reported in the same or different message than the modified RTWP and RSEPS.
Although FIG. 7 illustrates an exemplary process 700 , in other implementation, fewer, different, or additional operations may be performed.
FIG. 8 is a diagram illustrating an exemplary process 800 that may be employed when calculating the effective interference.
Process 800 may begin determining connections to which interference cancellation may be performed (block 805 ). For example, as described in connection to expressions (9) and (10), flows may be separated into scheduled flows and non-scheduled flows. Additionally, flows may be separated into scheduled flows subject to interference cancellation and scheduled flows not subject to interference cancellation. Further, non-scheduled flows may be separated into non-scheduled flows subject to interference cancellation and non-scheduled flows not subject to interference cancellation.
The interference power before interference cancellation is performed may be determined (block 810 ). For example, in one implementation, received schedule power and non-scheduled power may each be determined before an interference scheme is employed based on power connections subject to interference cancellation and connections not subject to interference cancellation. In one implementation, the interference power may be determined based on expressions (9) and (10).
The effective interference for connections subject to interference cancellation may be determined (block 815 ). For example, RBS 210 may determine the effective interference for connections subject to interference cancellation after an interference cancellation scheme is employed. In one implementation, the measured effective interference may be based on expressions (11) and (12).
The effective interference for E-DCH connections subject to interference cancellation may be determined (block 820 ). For example, RBS 210 may determine the effective interference for connections subject to interference cancellation after an interference cancellation scheme is employed. In one implementation, the measured effective interference may be based on expressions (15) and (16).
A measurement report and the effective interference for E-DCH connections may be transmitted (block 825 ). For example, RBS 210 may transmit the measurement report and the effective interference associated with E-DCH connections to RNC 208 .
Measurements of the RTWP and the RSEPS may be modified (block 830 ). For example, RNC 208 may modify the RTWP and the RSEPS measurements based on expressions (17), (18), (19), (20), and (21).
Although FIG. 8 illustrates an exemplary process 800 , in other implementation, fewer, different, or additional operations may be performed. For example, as previously described above, in some instances, interference cancellation may not be employed to connections other than scheduled E-DCH connections. In such instances, process 800 may be modified to where only cancelled E-DCH interference may reported.
In contrast to other implementations where the scheduled headroom may be smaller than what is reflected by Iub 218 measurements (e.g., the RTWP, the RRTWP, and the RSEPS), the concepts described herein may provide that RNC 208 and RBS 210 have the same view of the scheduled headroom, as well as the effective interference (e.g., the actual balance between the E-DCH and the DCH). That is, given the margin information provided from, for example, the LEA, the scheduler, interference cancellation performance of the receiver, and/or knowledge about how RNC 208 calculates the non-scheduled load, RBS 210 may recognize discrepancies (in terms of view) and modify the Iub 218 measurements, as well as effective interference measurements so that RNC 208 and RBS 210 may have a corresponding network state view. As a result, a variety of advantages may be realized. For example, admission control decisions by RNC 208 may be more accurate based on the modified Iub 218 measurements, which may prevent a scenario where too many subscribers may be admitted. For example, in instances when there are too many subscribers admitted, a significant portion of the uplink resources may be utilized based on the continuous transmission over the DPCCH, which may lead to excessive non-scheduled load. Additionally, or alternatively, admission control by RNC 208 may provide for sufficient headroom for scheduled data since the estimation of the non-scheduled load may be more accurate. Additionally, or alternatively, congestion control of RNC 208 may be improved. Additionally, or alternatively, DCH Radio Resource Management (RRM) may be more efficiently managed.
Conclusion
The foregoing description of implementations provides illustration, but is not intended to be exhaustive or to limit the implementations to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the teachings. For example, the concepts described herein may be applied to any type of network where a functional split exists (e.g., a base station and a base station controller) so that discrepancies of one or more network states (e.g., headroom) between respective devices may be mitigated. More generally, even a single device or node that includes a functional split (e.g., a scheduling component and an admission component) may benefit from the concepts described herein.
In addition, while series of blocks have been described with regard to processes illustrated in FIG. 6 and FIG. 7 , the order of the blocks may be modified in other implementations. Further, non-dependent blocks may be performed in parallel. Further one or more blocks may be omitted.
It will be apparent that aspects described herein may be implemented in many different forms of software, firmware, and hardware in the implementations illustrated in the figures. The actual software code or specialized control hardware used to implement aspects does not limit the invention. Thus, the operation and behavior of the aspects were described without reference to the specific software code—it being understood that software and control hardware can be designed to implement the aspects based on the description herein.
Even though particular combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to limit the invention. In fact, many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification.
It should be emphasized that the term “comprises” or “comprising” when used in the specification is taken to specify the presence of stated features, integers, steps, or components but does not preclude the presence or addition of one or more other features, integers, steps, components, or groups thereof.
No element, act, or instruction used in the present application should be construed as critical or essential to the implementations described herein unless explicitly described as such. Also, as used herein, the article “a” and “an” are intended to include one or more items. Where only one item is intended, the term “one” or similar language is used. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. As used herein, the term “and/or” includes any and all combinations of one or more of the associated list items.
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A method may include determining whether a discrepancy exists between scheduling headroom computable by a first device and scheduling headroom computable by a second device, determining one or more load measurements that the second device bases its computation of the scheduling headroom if it is determined that the discrepancy exists, modifying the one or more load measurements, and calculating the scheduling headroom based on the modified one or more load measurements.
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[0001] The invention concerns a method for evaporation of liquids with assistance of a heat pump, both for production of evaporated liquids for industrial and other technical purposes, as well as for distillation.
KNOWN TECHNOLOGY
[0002] Evaporation of liquids is required in many processes. Both for distribution of energy—were a typical example is production of steam, or in distillation processes were the most common is production of ethanol from a fermented sugar and water solution.
[0003] Steam from water is used for a variety of purposes due to the waters thermal properties with a relatively high heat capacity in all three phases, as well as a relatively high melting and vaporization heat rate (enthalpy of melting and vaporization). This last property is also one of the problems with production of steam. A lot of energy is used to evaporate water. Traditionally this has been done by heating water in boilers by the use of traditional energy sources as oil and gas, coal or electricity. Earlier, as in the first steam locomotives wood were also used.
[0004] By use of a heat pump large amount of energy can be obtained from vast energy reservoirs like rivers, lakes, ocean, air, sun or the ground. The problem is to obtain a sufficiently high temperature to make water evaporate. The waters boiling temperature is a 100° C. by 1 atm. or 101.3 kPa.
SHORT DESCRIPTION OF THE INVENTION
[0005] The invention is to use the low temperature heat produced by the heat pumps condenser to evaporate liquids under low pressure, and thereby low temperature. If as an example one reduces the pressure water is evaporated under to 10 kPa (appr. 0.1 atm) the evaporating temperature will drop to 45.8° C. Most refrigerants on the market today have a maximum condensation temperature under or just above 100° C. This is to low to evaporate water by atmospheric pressure.
[0006] By reducing the evaporation pressure it is as an example possible to use a heat pump to evaporate water under low pressure. To make steam at higher pressure and temperature require it to be compressed by a compressor after evaporation. The advantage with the invention is that one uses energy from a natural energy reservoir for the most energy intensive part of the steam production—which is the phase transition from liquid to gas.
[0007] The same problems as described above will also arise by evaporation of liquids for distillation. Typical is the production of alcohol in various forms, and also for the production of pure ethanol based on the fermentation of sugar dissolved in water.
[0008] Also for other distillation processes, or processes for separation of liquids can the invention be used. Typical for this last processes are separation of oil products from tar- or oil- sand.
DESCRIPTION OF FIGURES
[0009] FIG. 1 ) is an embodiment of the invention where the method is exemplified with a process to extract to distilled products from a liquid.
[0010] FIG. 2 ) is a detail for a possible design of a regulation device ( 17 ) for the control of the level of the liquids in the evaporator ( 4 ′).
DETAILED DESCRIPTION OF THE INVENTION
[0000]
1 ) Energy reservoir for the heat pump. This can be rivers, lakes, sea water, air, sun or ground heat. (Illustrated in FIG. 1 as the cross section of a river.)
2 ) The heat pumps evaporator. This is the heat pumps low pressure side where the refrigerant is heated and evaporated by the heat reservoir.
3 ) The heat pumps compressor. Here the refrigerant is compressed to a higher pressure and temperature. This to enable the water or liquid to evaporate in the next stage.
4 ) The heat pumps condenser. (see item 4 ′) This is the heat pumps high pressure side of a heat exchanger where the refrigerant is cooled off and recondensed by the water or liquids that are to be evaporated.
5 a,b , . . . )The heat pumps possible extra heat exchangers for extra cooling of the refrigerant. (see item 5 ′ a,b , . . .) Dependent on the operation of the system and the refrigerant's thermal properties, it may be possible to utilize the refrigerant's energy in condensated state on the heat pump's high pressure side to preheat the water or liquids that are to be evaporated. For best to utilize this energy the preheating can be performed in multiple stages. Alternatively the energy can be used for other purposes.
6 ) The heat pumps pressure reduction valve. This valve reduces the pressure from the heat pump's high pressure side to its low pressure side. This alters the refrigerant's evaporation- /saturation-temperature and will bring the refrigerant to evaporate again on the low pressure side.
7 ) Device for supply of water or liquids to be evaporated This is the water intake or inlet of liquids to be evaporated, alternatively tank(s) or container(s) with the same.
8 ) Possible supply pump or feeding device for water or liquids. This device may be required if there by various reasons are large drops of pressure on the supply side, or it is required to measure out the supply of water or liquids.
5 ′ a,b , . . . )Heat exchangers for preheating of water or liquids to be evaporated. (see item 5 a,b , . . . ) Dependent on the operation of the system and the refrigerant's thermal properties, it may be possible to utilize the refrigerant's energy also in condensated state on the heat pump's high pressure side to preheat the water or liquids that are to be evaporated. For best to utilize this energy the preheating can be performed in multiple stages.
9 ) Possible pressure reduction valve or device to control the evaporation pressure for the water or liquid that is to be evaporated. To obtain the pressure required to evaporate the water or liquids, a valve or other device may be required on the supply side. Alternatively can a high column (riser) be used, where the density and gravity of the water or liquids helps reducing the pressure. Or a combination of those two methods can be used.
4 ′) The evaporator. (see item 4 ) This is the heat exchanger were the water or other liquids are evaporated by the heat from the refrigerant on the heat pump's high pressure side. The water or liquids that are to be evaporated are already preheated to evaporation temperature or higher in ( 5 ′ a,b , . . . ) or will be so in the first part of the heat exchanger. The evaporation takes place under sufficiently low pressure.
10 ) Steam compressor. This is the device that creates the low evaporation pressure in the evaporator ( 4 ′), as well as compressing the steam or evaporated liquids to the required pressure for further use. This compressor will act as a first stage in a distillation process.
10 ′) Steam compressor for multiple stages in a distillation process. This compressor will compress the evaporated liquids to the next heat exchanger to extract the next distilled product. Dependent on how many components there are to extract this stage will be repeated the required number of times in order to separate all the distilled components.
11 ) Intermediate heat exchanger. (see item 16 ) This is the first of possible multiple stages of heat exchangers to either heat the steam further, or recondensate one component after another in a series of distilled products.
11 ′) Intermediate heat exchanger. (see item 16 ′) This is the possible second stage of heat exchangers. Normally this will be one of possible more stages in a distillation process.
11 ″) Intermediate heat exchanger. (see item 16 ″) This is possibly the next stage in a multiple distillation process. The remaining evaporated liquids are directed to a new compression stage, or when all distilled products are extracted the remaining residuals are directed to outlet ( 20 ). Dependent on how many components there are to extract, this stage together with steam compressor for multiple stages ( 10 ′) will be repeated the required number of times in order to separate all the distilled components.
12 ) Drainage device for remaining not evaporated products. This is a possible outlet or drainage for those products that are not to be evaporated in a distillation process. If the liquid to be distilled is saltwater this device also must be able to remove salt and other solids.
12 ′) Drainage device for evaporated and then recondensated residuals. This is a possible outlet or drainage for those liquids that are partially evaporated in the evaporator ( 4 ′) but not wanted as distilled products. Normally this one is not used. Another way is to design the intermediate heat exchanger ( 11 ) in a way so that these recondensated residuals will flow back to the evaporator ( 4 ′) and be drained by the possible drainage device or outlet ( 12 ).
12 ″) Drainage device for distilled products. This is where the first distilled product is drawn off.
12 ″′) Drainage device for distilled products. This is where the next distilled product is drawn off. Dependent on how many components there are to extract this stage together with steam compressor for multiple stages ( 10 ′) and intermediate heat exchanger ( 11 ″) will be repeated the required number of times in order to separate all the distilled components.
13 ) Pump for not evaporated residuals in a distillation process. It is necessary with a pump or other device to remove residuals from the process in order to maintain the necessary low evaporation pressure.
13 ′) Pump for evaporated and then recondensated residuals. If drainage device for evaporated and then recondensated residuals ( 12 ′) is installed as part of the intermediate heat exchanger ( 11 ) it will be necessary with a pump or other device to remove residuals from the process in order to maintain the necessary low evaporation pressure.
13 ″) Pump for distilled products. It is necessary with a pump to draw off the first distilled product from the process in order to maintain the correct pressure true the distillation process.
13 ″′) Pump for distilled products. It is necessary with a pump to draw off the next distilled product from the process in order to maintain the correct pressure true the distillation process. Dependent on how many components there are to extract, this stage together with steam compressor for multiple stages ( 10 ′), intermediate heat exchanger ( 11 ″) and drainage device for distilled products ( 12 ″′) will be repeated the required number of times in order to separate all the distilled components.
14 ) Valve. This one is used if the possible pump and or drainage device ( 12 and 13 ) are not able to measure out accurately enough the drainage of residuals in order to maintain correct evaporation pressure in the evaporator ( 4 ′).
14 ′) Valve. This one is used if the possible pump and or drainage device ( 12 ′ and 13 ′) are not able to measure out accurately enough the drainage of residuals in order to maintain correct evaporation pressure in the evaporator ( 4 ′).
14 ″) Valve. This one is used if the possible pump and or drainage device ( 12 ″ and 13 ″) are not able to measure out accurately enough the distilled products in order to maintain correct recondensation pressure in the intermediate heat exchanger ( 11 ′).
14 ″′) Valve. This one is used if the possible pump and or drainage device ( 12 ′″and 13 ′″) are not able to measure out accurately enough the distilled products in order to maintain correct r condensation pressure in the intermediate heat exchanger ( 11 ″). Dependent on how many components there are to extract this stage together with steam compressor for multiple stages ( 10 ′), intermediate heat exchanger ( 11 ″), drainage device for distilled products ( 12 ′″) and pump for distilled products ( 13 ′″) will be repeated the required number of times in order to separate all the distilled components.
15 ) Drainage device or tank for residuals. (see item 21 ) If the residuals from a distillation process have to be collected or processed further, it will be necessary to collect them in a tank. Otherwise these are directed to a waste outlet.
15 ′) Container or tank for distilled products. (see item 21 ′) Here the first distilled product is collected.
15 ″) Container or tank for distilled products. (see item 21 ′) Here the next distilled product is collected. Dependent on how many components there are to extract this stage, together with steam compressor for multiple stages ( 10 ′), intermediate heat exchanger ( 11 ″), drainage device for distilled products ( 12 ″′), pump for distilled products ( 13 ′) and possible valve ( 14 ′″) will be repeated the required number of times in order to separate all the distilled components.
16 ) Cooling or heater element for intermediate heat exchanger. (see item 11 ) This is a cooling or heater element for a possible intermediate heat exchanger ( 11 ). Dependent on the use of such a system this element is either the first stage of the heat pump's condenser ( 4 ) in order to utilize the refrigerants temperature after compression. In this case the heat exchanger ( 11 ) will help to increase the steam temperature in order to reduce the amount of saturation of the steam. Alternatively the element can have its own circuit for cooling or heating of the evaporated liquid. The latter will be the case in a distillation process, where intermediate heat exchanger ( 11 ) will be one of more stages in the process. In this configuration the element could be connected with heat exchanger ( 4 ),( 5 a, 5 b , . . . ) to contribute to heating of the liquids in possible pre-heaters ( 5 ′ a , 5 ′ b , . . . ) and evaporator ( 4 ′), or form a separate circuit with one or more of these. It is also possible to connect the element to external heat exchangers for other use.
16 ′) Cooling or heater element for intermediate heat exchanger. (see item 11 ′) This is a cooling or heater element for a possible intermediate heat exchanger ( 11 ′). Dependent on the use of such a system this element can have its own circuit for cooling or heating of the evaporated liquid, or be connected with cooling or heater element for intermediate heat exchanger ( 16 ). If this element has its own circuit, this one could also be connected as described for the circuit of element ( 16 ).
16 ″) Cooling or heater element for intermediate heat exchanger. (see item 11 ″) This is a cooling or heater element for a possible intermediate heat exchanger ( 11 ″). Dependent on the use of such a system this element can have its own circuit for cooling or heating of the evaporated liquid, or be connected with cooling or heater elements for intermediate heat exchangers ( 16 and 16 ′). The elements ( 16 , 16 ′, 16 ″, . . . ) can either be connected in series or parallel configuration, or any combination suitable. If this element has its own circuit, this one could also be connected as described for the circuit of element ( 16 ). Dependent on how many components there are to extract this stage will have to be repeated the same number of times as intermediate heat exchanger ( 11 ″) in order to extract all the distilled products.
17 ) Device for regulating level of liquid in evaporator. (see item 4 ′). In order to evaporate all liquid components that are to be separated by distillation it may be required to use some form of level regulation in the evaporator. This can be made by installing some form of device on the outlet for residuals ( 12 ). It may be a flotation device in a chamber that is designed to regulate the amount of liquid. (See detail as illustrated in FIG. 2 .) This device shall not be limited to a float in a chamber, but can be designed in any practical form or shape. As an example in its simplest form it can be to position the outlet or drainage device ( 12 ) in a specific position in the evaporator ( 4 ′).
18 ) Chamber for a float used for regulating level of liquid. (see item 17 ) As a possible device to regulate the level of liquid in the evaporator ( 4 ′), one can use a chamber with one or more holes to allow liquid to flow freely. The dimensions of the chamber must be designed to fit with the float ( 19 ) in such a way that the float can move freely with the variations of the level of liquids in the evaporator ( 4 ′).
19 ) Flotation device for regulating level of liquid. (see item 17 ) As a possible device to regulate the level of liquid in the evaporator ( 4 ′) a float inside a chamber ( 18 ), can be used to regulate the amount drawn off from drainage device for remaining not evaporated products ( 12 ). By ensuring the right weight and thereby density of the float compared to the liquids, one can ensure that all components to be separated in a distillation process will be evaporated in the evaporator ( 4 ′).
20 ) Outlet for steam or evaporated residuals from a distillation process. For steam production this is the stage where the steam has reached final state for use in industrial or other processes. The steam will be directed to whatever use it is intended for. In a distillation process this is where the still evaporated residuals that have no use will be let out or drawn off. For freshwater production from saltwater this stage will not be used.
21 ) Cooling element to container or supply-pipes for residuals. (see item 15 ) This is the cooling element for residuals from a distillation process. It is used to extract the heat added to the residuals in the evaporator ( 4 ′). This element can either be connected with heat exchangers ( 4 ), ( 5 a, 5 b , . . . ) to contribute to the heating of the liquids in possible pre-heaters ( 5 ′ a , 5 ′ b , . . . ) and/or evaporator ( 4 ′). It is also possible to connect the element to external heat exchangers for other use.
21 ′) Cooling element to container or supply-pipes for distilled products. (see item 15 ′) This is the cooling element for the first distilled product from a distillation process. It is used to extract the heat left after recondensation in intermediate heat exchanger ( 11 ′). This element can either be connected with heat exchangers ( 4 ), ( 5 a, 5 b , . . . ) to contribute to the heating of the liquids in possible pre-heaters ( 5 ′ a , 5 ′ b , . . . ) and/or evaporator ( 4 ′). It is also possible to connect the element to external heat exchangers for other use.
21 ″) Cooling element to container or supply-pipes for distilled products. (see item 15 ″) This is the cooling element for the next distilled product from a distillation process. It is used to extract the heat left after recondensation in intermediate heat exchanger ( 11 ″). This element can either be connected with heat exchangers ( 4 ), ( 5 a, 5 b , . . . ) to contribute to the heating of the liquids in possible pre-heaters ( 5 ′ a , 5 ′ b , . . . ) and/or evaporator ( 4 ′). It is also possible to connect the element to external heat exchangers for other use. Dependent on how many components there are to extract this stage will have to be repeated the same number of times as container or tank for distilled products ( 15 ″) in order to extract all the distilled products.
Configuration of the Invention for Three Typical Operations Based on the Example in FIG. 1:
[0000]
A) Steam production from water. For steam production from water the heat pump will be as described by item ( 1 ), ( 2 ), ( 3 ), ( 4 ), ( 5 a ), possibly ( 5 b )—to utilize the heat-energy to the optimum, and ( 6 ). The water intake ( 7 ) will normally be from a reservoir or a water-pipeline. Dependent on the supply of water a water-pump ( 8 ) may or may not be required. To preheat the water a pre-heater ( 5 ′ a ) and possibly ( 5 ′ b ) will be used. Dependent on the height from the water-intake ( 7 ) or the water-pump ( 8 ) to the evaporator ( 4 ′) a pressure reduction valve ( 9 ) may or may not be required to ensure a low evaporation pressure. The evaporator ( 4 ′) is where the water is evaporated. An intermediate heat-exchanger ( 11 ) together with a heater element ( 16 ) can be used to reduce the saturation of the steam before the steam compressor ( 10 ). The steam will then go to outlet ( 20 ) for use in other processes.
B) Distillation of ethanol from a fermented sugar solution with water. For distillation of ethanol the heat pump will be as described by item ( 1 ), ( 2 ), ( 3 ), ( 4 ), ( 5 a ), possibly ( 5 b )—to utilize the heat-energy to the optimum, and ( 6 ). The intake of liquid ( 7 ) will be from a tank with the fermented sugar solution. Dependent on the supply a pump ( 8 ) may or may not be required. To preheat the liquid a pre-heater ( 5 ′ a ) and possibly ( 5 ′ b ) will be used. Dependent on the height from the intake ( 7 ) or the supply pump ( 8 ) to the evaporator ( 4 ′) a pressure reduction valve ( 9 ) may or may not be required to ensure a low evaporation pressure. The evaporator ( 4 ′) is where the ethanol is evaporated. Normally a device for control with the level of liquid ( 17 ) in the evaporator ( 4 ′) will be used to regulate the drainage of the residual liquids thru an outlet or other drainage device ( 12 ). The residual liquids are pumped with a pump ( 13 ) alternatively thru a valve ( 14 ) to an outlet or container or tank for the residual liquids ( 15 ). The evaporated ethanol is led thru a intermediate heat exchanger ( 11 ) together with a cooling element ( 16 ) that is used to recondensate whatever water and other heavier distillates than ethanol that has been evaporated together with the ethanol in the evaporator ( 4 ′). These recondensated liquids are drained thru outlet ( 12 ′), with pump ( 13 ′) alternatively thru valve ( 14 ′) to outlet or container or tank ( 15 ). Cooling element ( 21 ) can be used to utilize these residual liquids heat to preheat the fermented sugar solution thru pre-heater ( 5 a, 5 a ′) and possibly ( 5 b, 5 b ′). The evaporated ethanol together with other lighter distillates will be compressed with compressor ( 10 ) to another intermediate heat exchanger ( 11 ′) with a cooling element ( 16 ′) that is used to recondensate the ethanol. The ethanol is drained thru outlet ( 12 ″) and possibly pumped with pump ( 13 ″) thru a possible valve ( 14 ″) to container or tank ( 15 ′). The lighter distillates left will go to outlet ( 20 ). In cases where these elements cause pollution problems they can be collected for further processing.
C) Production of freshwater from saltwater. For production of freshwater from saltwater the heat pump will be as described by item ( 1 ), ( 2 ), ( 3 ), ( 4 ), ( 5 a ), possibly ( 5 b )—to utilize the heat-energy to the optimum, and ( 6 ). The saltwater intake ( 7 ) will normally be from the sea. Dependent on the supply a water-pump ( 8 ) may or may not be required. To preheat the saltwater a pre-heater ( 5 ′ a ) and possibly ( 5 ′ b ) will be used. Dependent on the height from the water-intake ( 7 ) or the water-pump ( 8 ) to the evaporator ( 4 ′) a pressure reduction valve ( 9 ) may or may not be required to ensure a low evaporation pressure. The evaporator ( 4 ′) is where the water is evaporated. Normally a device for control with the liquid level in the evaporator ( 17 ) will be used to regulate the drainage of the salt thru an outlet or other device ( 12 ). The salt will be pumped with a pump ( 13 ) alternatively thru a valve ( 14 ) to an outlet or container or tank ( 15 ). The steam will be compressed with steam-compressor ( 10 ) to an intermediate heat exchanger ( 11 ′) with a cooling element ( 16 ′) that is used to recondensate the water. The heat collected in cooling element ( 16 ) is used to preheat the saltwater in pre-heater ( 5 a - 5 ′ a , 5 b - 5 ′ b , . . . ) and possibly evaporator ( 4 ′). The water is drained thru outlet ( 12 ″) and possibly pumped with pump ( 13 ″) thru a possible valve ( 14 ″) to a tank or freshwater pipeline ( 15 ′). Cooling element ( 21 ′) will be used in parallel to cooling element ( 16 ′) to utilize the recondensated water's heat to preheat and maybe partly evaporate the saltwater.
[0055] The method for evaporate and possibly distillation of liquids with assistance of a heat pump can be utilized by most processes where evaporation of liquids and the usage of these are integrated. Other examples are the paper and pulp industry, production of gypsum boards, extraction of oil-products from tar- or oil- sand, as well as many other industries.
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The invention concerns a method for evaporation and possibly distillation of liquids by means of a heat pump. By using a heat pump ( 2 ), energy is taken from energy reservoirs ( 1 ) such as rivers, lakes, sea water, air, sun or ground heat. It is however difficult to obtain temperatures to evaporate water at atmospheric conditions. According to the invention, low temperature heat is utilized by means of a heat pump by using the condenser (high pressure part) of the heat pump to evaporate liquids in an evaporator ( 4′ ) at a pressure lower than the atmospheric pressure, and thus at a lower evaporation temperature. A pump or a compressor ( 10 ) after the evaporator ( 4′ ) together with a pressure reducing device ( 9 ) at the inlet of the evaporator ( 41 ) ensures lower evaporation pressure. To fully utilize the heat energy from the heat pump, the liquids may be preheated in heat exchangers ( 5 ) before the pressure reducing means, or as part of the same means. To achieve higher temperature and pressure of the evaporated liquids, said liquids are further compressed by means of compressors ( 10 ), or alternatively by heating in intermediate heat exchangers ( 11 ) in order to achieve the desired temperature level. In the case of distillation, one stage will be required for each distillate. In addition to compressors ( 10 ), intermediate heat exchangers ( 11 ) and draining devices ( 12 ), pumps ( 13 ) are required to maintain desired recondensation pressure, possibly also valves ( 14 ) to insure correct dosing of residual products and distillates to collecting devices ( 15 ).
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FIELD OF THE INVENTION
[0001] The subject matter of the present application relates to tool assembly, particularly for heavy duty parting-off applications, comprising a solid cutting insert having a single cutting edge, a tool, and a clamp for securing the insert to a rigid insert seat of the tool.
BACKGROUND OF THE INVENTION
[0002] Cutting inserts were traditionally held to rigid insert seats with a clamp. A clamp according to the specification and claims meaning a member having a head and a shank of either a threaded type, e.g. a screw, or a non-threaded type, e.g. a pin. An example of a clamp with a non-threaded shank is disclosed in U.S. Pat. No. 9,033,621, assigned to the present applicant.
[0003] It was discovered that, particularly for parting-off, an improved design without the need for a clamp was feasible (e.g. the assembly disclosed in U.S. Pat. No. 7,326,007, assigned to the present applicant). In such design, instead of utilizing a clamp, a single-cutting-edged solid insert (“single-cutting-edged” or stated differently “non-indexable”; “solid” or stated differently “devoid of a clamping hole”) is resiliently retained to a seat of tool by elasticity of opposing portions of the insert seat. A notable advantage of such clamp-less design is the relatively narrow machining width enabled, since the insert and the tool widths do not need to accommodate a clamp.
[0004] Yet a further design utilizing a single-cutting-edged solid insert, but with a dual resilient insert seat and clamp (called a “threaded fastener” therein), is shown in U.S. Pat. No. 7,578,640, also assigned to the present applicant. On the one hand, the construction is more complicated due to the presence of the additional component, i.e. the clamp, on the other since the resilient seat also clamps the insert a relatively narrow clamp can be utilized, thereby retaining at least some of the relatively narrow machining width benefit.
SUMMARY OF THE INVENTION
[0005] In accordance with a first aspect of the subject matter of the present application, there is provided a tool assembly comprising: an insert, tool and clamp configured to secure the insert to the tool; the insert being circumferentially divisible into first, second, third and fourth corner regions, and comprising: a first corner region comprising: an insert upper abutment surface formed at a peripheral upper sub-surface and extending forward of a peripheral rear sub-surface; and an insert rear abutment surface formed at the peripheral rear sub-surface and extending downward of the peripheral upper sub-surface; a second corner region comprising: a cutting edge connecting the insert side surfaces and being wider than adjacent portions of the peripheral upper surface and a peripheral front sub-surface; a third corner region comprising: an insert first lower abutment surface formed at a peripheral lower sub-surface and extending rearward of the peripheral front sub-surface; an insert second lower abutment surface formed at the peripheral lower sub-surface and extending downward of the insert first lower abutment surface; the tool comprising: a rigid insert seat along a tool peripheral surface; the insert seat comprising: a rearwardly extending tool first lower abutment surface; a tool second lower abutment surface extending downward of the tool first lower abutment surface; a downwardly extending tool rear abutment surface; and a tool relief sub-surface extending between the tool second lower abutment surface and the tool rear abutment surface; the clamp comprising: a shank; and a clamp head extending from the shank and comprising a clamp-insert abutment surface; wherein, the insert is clamped to the tool by the following abutment configuration: the clamp-insert abutment surface abutting the insert upper abutment surface; the tool first lower abutment surface abutting the insert first lower abutment surface; the tool second lower abutment surface abutting the insert second lower abutment surface; and the tool rear abutment surface abutting the insert rear abutment surface.
[0006] In accordance with a second aspect of the subject matter of the present application, there is provided a tool assembly comprising, in combination: an insert, tool and clamp configured to secure the insert to the tool; the insert comprising: opposite insert first and second side surfaces; an insert plane parallel with and located midway between the insert side surfaces; an insert peripheral surface connecting the insert side surfaces; a first corner region located in an upper-rear portion of the cutting insert; a second corner region located in an upper-front portion of the cutting insert; a third corner region located in an lower-front portion of the cutting insert; and a fourth corner region located in an lower-rear portion of the cutting insert; the insert peripheral surface comprising: a peripheral upper sub-surface extending from the first corner region to the second corner region; a peripheral front sub-surface extending from the second corner region to the third corner region; a peripheral lower sub-surface extending from the third corner region to the fourth corner region; and a peripheral rear sub-surface extending from the fourth corner region to the first corner region; the first corner region comprising: an insert upper abutment surface formed at the peripheral upper sub-surface and extending forward of the peripheral rear sub-surface; and an insert rear abutment surface formed at the peripheral rear sub-surface and extending downward of the peripheral upper sub-surface; the second corner region comprising: a cutting edge connecting the insert side surfaces and being wider than adjacent portions of the peripheral upper and front sub-surfaces; the third corner region comprising: an insert first lower abutment surface formed at the peripheral lower sub-surface and extending rearward of the peripheral front sub-surface; and an insert second lower abutment surface formed at the peripheral lower sub-surface and extending downward of the insert first lower abutment surface;
[0007] the tool comprising a tool corner which in turn comprises: opposite tool first and second side surfaces; a tool plane parallel with and located midway between the tool side surfaces; a tool peripheral surface connecting the tool side surfaces; and a rigid insert seat formed at an intersection of the tool peripheral surface and tool first and second side surfaces; the tool peripheral surface at the tool corner further comprising: a tool upper sub-surface extending rearward of the insert seat; and a tool front sub-surface extending downward of the insert seat; the insert seat, along the tool peripheral surface, comprising: a tool first lower abutment surface extending rearward of the tool front sub-surface; a tool second lower abutment surface extending downward of the tool first lower abutment surface; a tool rear abutment surface extending downward of the tool upper sub-surface; and a tool relief sub-surface extending between the tool second lower abutment surface and the tool rear abutment surface; the clamp comprising: a shank; and a clamp head extending from the shank and comprising a clamp-insert abutment surface; wherein the insert is clamped to the tool by the following abutment configuration: the clamp-insert abutment surface abutting the insert upper abutment surface; the tool first lower abutment surface abutting the insert first lower abutment surface; the tool second lower abutment surface abutting the insert second lower abutment surface; and the tool rear abutment surface abutting the insert rear abutment surface.
[0008] In accordance with a third aspect of the subject matter of the present application, there is provided a tool assembly comprising, in combination: an insert, a tool, and a clamp configured to secure the insert to the tool; the insert comprising: opposite insert first and second side surfaces;
[0009] an insert plane parallel with and located midway between the insert side surfaces; an insert peripheral surface connecting the insert side surfaces; a first corner region located in an upper-rear portion of the cutting insert; a second corner region located in an upper-front portion of the cutting insert; a third corner region located in an lower-front portion of the cutting insert; and a fourth corner region located in an lower-rear portion of the cutting insert; the insert peripheral surface comprising: a peripheral upper sub-surface extending from the first corner region to the second corner region; a peripheral front sub-surface extending from the second corner region to the third corner region; a peripheral lower sub-surface extending from the third corner region to the fourth corner region; and a peripheral rear sub-surface extending from the fourth corner region to the first corner region; the first corner region comprising: an insert upper abutment surface formed at the peripheral upper sub-surface and extending forward of the peripheral rear sub-surface; and an insert rear abutment surface formed at the peripheral rear sub-surface and extending downward of the peripheral upper sub-surface; the second corner region comprising: a cutting edge connecting the insert side surfaces and being wider than adjacent portions of the peripheral upper and front sub-surfaces; the third corner region comprising: an insert first lower abutment surface formed at the peripheral lower sub-surface and extending rearward of the peripheral front sub-surface; and an insert second lower abutment surface formed at the peripheral lower sub-surface and extending downward of the insert first lower abutment surface; the tool comprising a tool corner which in turn comprises: opposite tool first and second side surfaces; a tool plane parallel with and located midway between the tool side surfaces; a tool peripheral surface connecting the tool side surfaces; and a rigid insert seat formed at an intersection of the tool peripheral surface and tool first and second side surfaces; the tool peripheral surface at the tool corner further comprising: a tool upper sub-surface extending rearward of the insert seat; and a tool front sub-surface extending downward of the insert seat; the insert seat, along the tool peripheral surface, comprising: a tool first lower abutment surface extending rearward of the tool front sub-surface; a tool second lower abutment surface extending downward of the tool first lower abutment surface; a tool rear abutment surface extending downward of the tool upper sub-surface; and a tool relief sub-surface extending between the tool second lower abutment surface and the tool rear abutment surface; the clamp comprising: a shank; and a clamp head extending from the shank and comprising a clamp-insert abutment surface; wherein, the insert is clamped to the tool by the following abutment configuration: the clamp-insert abutment surface abutting the insert upper abutment surface; the tool first lower abutment surface abutting the insert first lower abutment surface; the tool second lower abutment surface abutting the insert second lower abutment surface; and the tool rear abutment surface abutting the insert rear abutment surface; wherein: the insert's fourth corner region comprises a rearwardly facing insert rear non-abutment surface which is located adjacent to and below the insert rear abutment surface; the tool relief sub-surface comprising a forwardly facing tool rear non-abutment surface which is located adjacent to and below the tool rear abutment surface; a rear relief gap separates the insert rear non-abutment surface and the tool rear non-abutment surface.
[0010] In accordance with a fourth aspect of the subject matter of the present application, there is provided a tool assembly comprising an insert, tool and clamp according to any of the aspects below.
[0011] Heavy duty machining is characterized by particularly high machining forces, accordingly, each of the following features, alone or in combination with any one of the above aspects, can improve performance of a tool assembly during heavy duty machining:
A clamping force F 1 caused by the clamp-insert abutment surface abutting the insert upper abutment surface can be directed in a downward direction which is rearward of the insert's peripheral front sub-surface. Without being bound to theory, it is believed directing said clamping force towards the insert's peripheral front sub-surface can cause instability of the insert. A clamping force F 3 caused by the tool second lower abutment surface abutting the insert second lower abutment surface can be directed in a rearward direction which is lower than the location towards a region below where the tool rear abutment surface abuts the insert rear abutment surface. Stated differently, the insert second lower abutment surface is directed in a rearward direction towards a region below where the tool rear abutment surface abuts the insert rear abutment surface. Without being bound to theory, it is believed that if said clamping force would be directed to another abutment point, a resilient-like mounting arrangement would be achieved. Such resilient mounting being detrimental to longevity of the tool, since elastic components can be worn relatively quickly down during heavy duty machining. Such arrangement is also believed to provide a superior force-arrangement for stability of the insert when mounted. A way to achieve this is by providing a rear relief gap at said location. An insert in a mounted-unclamped position in the insert seat can be freely removable (i.e. not resiliently mounted). For heavy duty machining the perceived benefit of the present arrangement (e.g. such as longevity of the tool, superior stability) is believed to outweigh benefits of resilient mounting. The clamp can merely ensures that the insert remains in a desired position, but the arrangement described ensures that cutting forces are applied to the tool alone and not the clamp.
[0016] To summarize the above, as will be understood, each of the features above can, individually and in combination, contribute to an insert mounting arrangement which is superior for heavy duty machining. Summarized differently, the features above result in the machining forces on the insert are applied to the tool and not the clamp, the clamp force application direction providing increased insert stability, the lack of opposing tool abutment areas providing insert stability and also increases tool longevity.
[0017] Generally speaking, in the specification and claims, where it is stated that the insert is clamped by an “abutment configuration” it should be understood that additional abutments are excluded.
[0018] It will be understood that an insert, according to any of the aspects, is configured to be held in a mounted position in an insert seat by having a clamping force simultaneously applied on, and only on, the insert upper abutment surface, the insert first lower abutment surface; the insert second lower abutment surface, and the insert rear abutment surface.
[0019] In accordance with a fifth aspect of the subject matter of the present application, there is provided an insert being circumferentially divisible into first, second, third and fourth corner regions; the first corner region comprising: an insert upper abutment surface formed at a peripheral upper sub-surface and extending forward of a peripheral rear sub-surface; and an insert rear abutment surface formed at the peripheral rear sub-surface and extending downward of the peripheral upper sub-surface; the second corner region comprising: a cutting edge connecting the insert side surfaces and being wider than adjacent portions of the peripheral upper surface and a peripheral front sub-surface; the third corner region comprising: an insert first lower abutment surface formed at a peripheral lower sub-surface and extending rearward of the peripheral front sub-surface; and an insert second lower abutment surface formed at the peripheral lower sub-surface and extending downward of the insert first lower abutment surface.
[0020] In accordance with a sixth aspect of the subject matter of the present application, there is provided a single-cutting-edged solid cutting insert comprising: opposite insert first and second side surfaces; an insert plane parallel with and located midway between the insert side surfaces; an insert peripheral surface connecting the insert side surfaces; a first corner region located in an upper-rear portion of the cutting insert; a second corner region located in an upper-front portion of the cutting insert; a third corner region located in an lower-front portion of the cutting insert; and a fourth corner region located in an lower-rear portion of the cutting insert; the insert peripheral surface comprising: a peripheral upper sub-surface extending from the first corner region to the second corner region; a peripheral front sub-surface extending from the second corner region to the third corner region; a peripheral lower sub-surface extending from the third corner region to the fourth corner region; and a peripheral rear sub-surface extending from the fourth corner region to the first corner region; the first corner region comprising: an insert upper abutment surface formed at the peripheral upper sub-surface and extending forward of the peripheral rear sub-surface; and an insert rear abutment surface formed at the peripheral rear sub-surface and extending downward of the peripheral upper sub-surface; the second corner region comprising: a cutting edge connecting the insert side surfaces and being wider than adjacent portions of the peripheral upper and front sub-surfaces; the third corner comprising: an insert first lower abutment surface formed at the peripheral lower sub-surface and extending rearward of the peripheral front sub-surface; and an insert second lower abutment surface formed at the peripheral lower sub-surface and extending downward of the insert first lower abutment surface.
[0021] In accordance with a seventh aspect of the subject matter of the present application, there is provided an insert being circumferentially divisible into first, second, third and fourth corner regions; the first corner region comprising: an insert upper abutment surface formed at a peripheral upper sub-surface and extending forward of a peripheral rear sub-surface; and an insert rear abutment surface formed at the peripheral rear sub-surface and extending downward of the peripheral upper sub-surface; the second corner region comprising: a cutting edge connecting the insert side surfaces and being wider than adjacent portions of the peripheral upper surface and a peripheral front sub-surface; the third corner region comprising: an insert first lower abutment surface formed at a peripheral lower sub-surface and extending rearward of the peripheral front sub-surface; and an insert second lower abutment surface formed at the peripheral lower sub-surface and extending downward of the insert first lower abutment surface; the insert being configured to be held in a mounted position in an insert seat by having a clamping force simultaneously applied on, and only on, the insert upper abutment surface, the insert first lower abutment surface; the insert second lower abutment surface, and the insert rear abutment surface.
[0022] A heavy duty cutting insert according to any of the aspects above can comprise one or a combination of the following features, each of which can improve performance during heavy duty machining (in accordance with the seating stability/tool longevity advantages described above, although additional specific advantages are stated below):
Only one of the insert abutment surfaces comprises an insert lateral securing arrangement comprising, e.g., insert first and second inward slanted surfaces. This can reduce the precision needed during manufacture of an insert for a rigid insert seat. The lateral securing arrangement can preferably be at a location, e.g. the insert second lower abutment surface, which does not directly oppose the primary cutting forces. It will be understood by the figures that the non-lateral cutting forces are opposed by the insert first lower abutment and rear abutment surfaces. Similarly, it will be understood that an applied force on the insert upper abutment surface can be for ensuring the lateral securing arrangement is secured against an insert pocket. This way the insert upper rear abutment surface and lateral securing arrangement can be protected from the larger machining forces which are countered by the more massive tool. Stated differently, it can be advantageous to have a cutting insert where a first corner (the second corner region) receives the primary machining forces but diverts them to the adjacent corners (the first and third corner regions) since the forth corner region is not abutted by the tool. Advantageously, an insert lateral securing arrangement can be positioned where it does not oppose the primary machining forces. The insert upper abutment surface faces away from the peripheral lower sub-surface without facing away from the peripheral front sub-surface. This can allow a clamping force to be directed in a downward direction which is rearward of the insert's peripheral front sub-surface. The insert second lower abutment surface extends lower than the insert rear abutment surface. The insert second lower abutment surface extends lower than the peripheral rear sub-surface. The peripheral front sub-surface extends lower than the insert rear abutment surface. The peripheral front sub-surface extends lower than the peripheral rear sub-surface. Each of the two latter points can assist in avoiding opposing abutment areas providing insert stability and also increases tool longevity Insert height and depth differs by less than 40%, preferably less than 25%. The insert second lower abutment surface has an insert second lower abutment surface length which is less than one-third of a height of the insert, preferably less than one-sixth, measurable from the peripheral upper sub-surface to the peripheral lower sub-surface.
[0032] Each of the two latter points can reduce the depth that a corresponding tool relief sub-surface of a corresponding insert seat needs to extend, thereby allowing adjacent portions of the insert seat to be more rigid.
[0033] In accordance with a eighth aspect of the subject matter of the present application, there is provided a tool comprising a tool corner which in turn comprises: opposite tool first and second side surfaces; a tool plane parallel with and located midway between the tool side surfaces; a tool peripheral surface connecting the tool side surfaces; and a rigid insert seat formed at an intersection of the tool peripheral surface and tool first and second side surfaces; the tool peripheral surface comprising: a tool upper sub-surface extending rearward of the insert seat; and a tool front sub-surface extending downward of the insert seat; the insert seat, along the tool peripheral surface, comprising: a tool first lower abutment surface extending rearward of the tool front sub-surface; a tool second lower abutment surface extending downward of the tool first lower abutment surface; a tool rear abutment surface extending downward of the tool upper sub-surface; and a tool relief sub-surface extending between the tool second lower abutment surface and the tool rear abutment surface.
[0034] In accordance with an ninth aspect of the subject matter of the present application, there is provided a tool comprising a tool corner which in turn comprises: opposite tool first and second side surfaces; a tool plane parallel with and located midway between the tool side surfaces; a tool peripheral surface connecting the tool side surfaces; and a rigid insert seat formed at an intersection of the tool peripheral surface and tool first and second side surfaces; the tool peripheral surface comprising: a tool upper sub-surface extending rearward of the insert seat; and a tool front sub-surface extending downward of the insert seat; the insert seat, along the tool peripheral surface, comprising: a tool first lower abutment surface extending rearward of the tool front sub-surface; a tool second lower abutment surface extending downward of the tool first lower abutment surface; a tool rear abutment surface extending downward of the tool upper sub-surface; and a tool relief sub-surface extending between the tool second lower abutment surface and the tool rear abutment surface.
[0035] A tool according to any of the aspects above can comprise one or a combination of the following features, each of which can improve performance during heavy duty machining (in accordance with the seating stability/tool longevity advantages described above, although additional specific advantages may be stated below):
Only one of the tool abutment surfaces comprises a tool lateral securing arrangement comprising e.g. tool first and second inward slanted surfaces. This can reduce the precision needed during manufacture of a tool having a rigid insert seat. The tool second lower abutment surface extends lower than the tool rear abutment surface. The tool first lower abutment surface extends lower than the tool rear abutment surface.
[0039] Each of the two latter points can assist in avoiding opposing abutment areas providing insert stability and also increases tool longevity
The tool second lower abutment surface has a tool second lower abutment surface length which is less than one-third of a seat height, preferably less than one-sixth. Seat height and depth differ by less than 40%, preferably less than 25%.
[0042] Each of the two latter points can reduce the depth that a corresponding tool relief sub-surface of a corresponding insert seat needs to extend, thereby allowing adjacent portions of the insert seat to be more rigid. It will be understood that the term “rigid” is not meant to limit the material used for the tool or insert seat thereof, which may be made of materials such as steel. Rather that the geometrical structure of the insert seat is not designed to accommodate an insert designed to push apart opposing surfaces of the insert seat to cause a resilient clamping effect on the insert.
[0043] While an insert seat with a relatively large tool relief recess could also theoretically function as a rigid insert seat, since resilient clamping is also dependent on the insert geometry, geometrical features such as minimizing the tool relief gap size can still be beneficial.
[0044] In accordance with a tenth aspect of the subject matter of the present application, there is provided a clamp comprising: a shank; and a clamp head extending from the shank and comprising a clamp-insert abutment surface.
[0045] The clamp can comprise one or a combination of the following features, each of which can improve performance during heavy duty machining:
A clamp rear head portion can extend rearward of the shank. This can allow a clamp-tool abutment surface to abut an adjacent tool-clamp abutment surface and counter a moment caused by clamping of the insert via the clamp-insert abutment surface. A clamp rear head portion can have a clamp rear surface which is planar shaped. The rear surface can be perpendicular to a central longitudinal plane of the clamp head. This can allow a clamp to be rotationally-oriented correctly when clamping an insert. At least a clamp rear head portion's clamp upper surface can be provided with a ridge (i.e. having at least one non-orthogonal surface extending to an apex, or, e.g., two inwardly slanted surfaces meeting at an apex). This can allow movement of the tool holding the clamp (particularly when the tool has a correspondingly shaped upper surface, such as a parting-off blade with a slanted ridge shape) when held by a tool holder. The ridge can be a longitudinally extending ridge.
[0049] Generally speaking, directions used throughout the specification and claims are relative to other parts of an object or group of objects being described. As will be clear from reading the text in view of the drawings, when a direction is mentioned it is meant “generally”. Therefore, for example, if a first surface is said to be, e.g., extending “rearward” of a second surface, it is not necessary that the first surface be orthogonal with the second surface, rather it should be understood the first surface extends in a “generally rearward direction”. Stated differently, if a first surface is said to extend rearwardly, this is to be interpreted as the first surface extending more in the rearward direction than any other orthogonal direction, e.g. upwardly or downwardly (i.e. it extends in the defined direction within a tolerance of ±45° thereof).
[0050] It will be understood that the above-said is a summary, and that any of the aspects above may further comprise any of the features described hereinbelow. Specifically, the following features, either alone or in combination, may be applicable to any of the above aspects:
[0000] i. A tool assembly can comprise an insert, tool and clamp configured to secure the insert to the tool.
ii. An insert can comprise a single-cutting edge only.
iii. An insert can be solid, i.e. devoid of a clamping hole. Such construction may be particularly useful against impact forces incurred during heavy-duty applications.
iv. The insert first and second surfaces can be devoid of a clamping construction (e.g. a clamping hole or recess).
v. An insert can comprise opposite insert first and second side surfaces, and an insert peripheral surface connecting the insert side surfaces.
vi. An insert plane can be parallel with and located midway between insert side surfaces.
[0051] The insert can be mirror-symmetric on opposing sides of the insert plane
[0000] vii. An insert can have an insert height and an insert depth. The insert height can be measurable from the peripheral upper sub-surface to the peripheral lower sub-surface. The insert depth can be measurable from the peripheral rear sub-surface to the peripheral front sub-surface. The insert height and depth can differ by less than 40% (e.g. if the overall height is 10 mm the depth will be greater than 6 mm or less than 14 mm). Preferably the insert height and depth differ by less than 25%.
viii. An insert front-lower height can be smaller than 40% of an insert height, preferably smaller than 30%. Preferably the insert front-lower height can be greater than 10% of the insert height.
ix. An insert second lower abutment length can be smaller than 40% of an insert height, preferably smaller than 30%,. Preferably the insert second lower abutment length can be greater than 10% of the insert height.
x. An insert can be circumferentially divisible into, and comprise, first, second, third and fourth corner regions. To elaborate: a first corner region can be located in an upper-rear portion of the insert; a second corner region can be located in an upper-front portion of the insert; a third corner region can be located in an lower-front portion of the insert; and a fourth corner region can be located in an lower-rear portion of the cutting insert.
xi. An insert peripheral surface can comprise: a peripheral upper sub-surface extending from the first corner region to the second corner region; a peripheral front sub-surface extending from the second corner region to the third corner region; a peripheral lower sub-surface extending from the third corner region to the fourth corner region; and a peripheral rear sub-surface extending from the fourth corner region to the first corner region.
xii. A peripheral front sub-surface can extend lower than a peripheral rear sub-surface.
xiii. A first corner region can comprise an insert upper abutment surface. The insert upper abutment surface can be formed at a peripheral upper sub-surface. The insert upper abutment surface can extend forward of a peripheral rear sub-surface. The insert upper abutment surface can faces away from the peripheral lower sub-surface without facing away from the peripheral front sub-surface. Stated differently, an imaginary normal line extending downward from the insert upper abutment surface can be rearward of the insert's peripheral front sub-surface.
xiv. A first corner region can comprise an insert rear abutment surface. The insert rear abutment surface can be formed at a peripheral rear sub-surface. The insert rear abutment surface can extend downward of a peripheral upper sub-surface.
xv. A second corner region can comprise a cutting edge connecting the insert side surfaces. The cutting edge can be wider than adjacent portions of the peripheral upper surface and a peripheral front sub-surface. The cutting edge can extend rearward along an intersection of an insert peripheral surface and one or both insert side surfaces.
xvi. A rake surface can extend rearward of a cutting edge, along the insert peripheral surface. The rake surface can be formed with a chip-control arrangement.
xvii. An insert relief surface can extend downward-rearward of a cutting edge, along the insert peripheral surface.
xviii. A third corner region can comprise an insert first lower abutment surface. The insert first lower abutment surface can be formed at a peripheral lower sub-surface. The insert first lower abutment surface can extend rearward of a peripheral front sub-surface.
xix. A third corner region can comprise an insert second lower abutment surface. The insert second lower abutment surface can be formed at the peripheral lower sub-surface. The insert second lower abutment surface can extend downward of an insert first lower abutment surface. The insert second lower abutment surface can extend lower than the peripheral rear sub-surface. The insert second lower abutment surface has an insert second lower abutment surface length (the linear portion of which is measured). The insert second lower abutment surface length can be less than one-third of a height of the insert, preferably less than one-sixth.
xx. At a fourth corner region the insert can be devoid of, or not subjected to, clamping forces.
xxi. An insert can comprise a rearwardly facing insert rear non-abutment surface. The rear non-abutment surface can be located adjacent to and below the insert rear abutment surface. A fourth corner region can comprise the rear non-abutment surface.
xxii. A tool relief sub-surface can comprise a forwardly facing tool rear non-abutment surface. The tool rear non-abutment surface can be located adjacent to and below the tool rear abutment surface.
xxiii. A rear relief gap can separate an insert rear non-abutment surface and a tool rear non-abutment surface. A rear relief gap can be located rearward of an insert and can separate the insert's fourth corner region and the tool relief sub-surface.
xxiv. A tool relief recess can separate an insert's peripheral lower sub-surface and a tool relief sub-surface. A tool relief recess can be located downward of an insert and can separate the insert's fourth corner region and the tool relief sub-surface. Preferably, a tool relief recess can be made to correspond to the size of an insert intended to be received therein (of course being slightly larger so as to provide relief). Such sizing (or, stated differently, minimizing of the size of the tool relief recess) can assist in providing additional rigidity of an insert pocket.
xxv. A rear relief gap can be contiguous with a tool relief recess.
xxvi. An insert abutment surface can comprise an insert lateral securing arrangement. The insert lateral securing arrangement can comprise e.g., insert first and second inward slanted surfaces. Preferably only one of the insert abutment surfaces comprises the insert lateral securing arrangement. Most preferably the insert second lower abutment surface of the third corner region comprises the insert lateral securing arrangement. Without being bound to theory, it is believed that the insert lateral securing arrangement being formed at the insert second lower abutment surface provides the most stable insert seating arrangement. Preferably the insert first and second inward slanted surfaces form a concave shape rather than a convex or ridge shape.
xxvii. A tool can be a parting-off blade. The tool can have an insert seat at each of two diagonally opposed corners thereof. The insert seats can be identical. The tool can be 180° rotationally symmetric about a tool axis extending through the center of tool first and second sides.
xxviii. A tool corner, or an entire tool, can comprise opposite tool first and second side surfaces and a tool peripheral surface connecting the tool side surfaces.
xxix. A tool corner, or an entire tool, can comprise a tool plane parallel with and located midway between tool side surfaces.
xxx. A tool corner can comprise a rigid insert seat or a plurality of rigid insert seats. Each insert seat can be a rigid insert seat. Each insert seat can be formed at an intersection of a tool peripheral surface and tool first and second side surfaces.
xxxi. An insert seat can be located along the tool peripheral surface.
xxxii. An insert seat can comprise a tool first lower abutment surface, a tool second lower abutment surface, a tool rear abutment surface and a tool relief sub-surface.
xxxiii. A seat can have a seat height and a seat depth. The seat height can be measurable from an imaginary extension line of a tool upper sub-surface to a lowermost point of a tool relief sub-surface. A seat depth can be measurable from a tool rear abutment surface to an imaginary extension line of a tool front sub-surface. The seat height and depth can differ by less than 40%. Preferably the seat height and depth differ by less than 25%.
xxxiv. A cutting edge of the insert can be wider than at least a corner of the tool comprising an insert seat, and can be wider than a remainder of the entire tool.
xxxv. A tool first lower abutment surface can extend rearward of a tool front sub-surface.
xxxvi. A tool first lower abutment surface can extend lower than the tool rear abutment surface.
xxxvii. A tool second lower abutment surface can extend downward of a tool first lower abutment surface.
xxxviii. A tool second lower abutment surface can extend lower than a tool rear sub-surface. The tool second lower abutment surface can have a tool second lower abutment surface length (the linear portion of which is measured). The tool second lower abutment surface length can be less than one-third of a seat height, preferably less than one-sixth.
xxxix. A tool rear abutment surface can extend downward of a tool upper sub-surface.
xl. A tool relief sub-surface can extend between a tool second lower abutment surface and a tool rear abutment surface.
xli. A tool peripheral surface can comprise a tool upper sub-surface. The tool upper sub-surface can extend rearward of an insert seat. The tool upper sub-surface can extend the entire length of the tool. The tool upper sub-surface can be can be ridge shaped (i.e. having at least one non-orthogonal surface extending to an apex, or, e.g., two inwardly slanted surfaces meeting at an apex). The tool lower sub-surface can be can be ridge shaped (i.e. having at least one non-orthogonal surface extending to an apex, or, e.g., two inwardly slanted surfaces meeting at an apex).
xlii. A tool peripheral surface can comprise a tool front sub-surface. The tool front sub-surface can extend downward of an insert seat.
xliii. A tool corner can comprise a clamp hole.
xliv. A tool peripheral surface can comprise a clamp hole.
xlv. A clamp hole can be located along the tool upper sub-surface and adjacent to the tool rear abutment surface. The tool peripheral surface can further comprise a tool-clamp abutment surface. The tool-clamp abutment surface can extend upwardly and facing towards the insert seat, from the clamp hole and the tool upper sub-surface.
xlvi. A clamp hole can be, or have a clamp axis A c , slanted in a downward-rearward direction.
xlvii. A tool peripheral surface can comprise a locking screw hole. The locking screw hole can be threaded. The locking screw hole can be located at an opposite side of an insert seat from a clamp hole. The locking screw hole can be located along a tool front sub-surface downward of the tool first lower abutment surface.
xlviii. A clamp hole and locking screw hole can intersect. A locking screw hole and clamp hole can surround an insert seat.
xlix. A clamp's shank can be unthreaded, a locking screw can occupy a locking screw hole formed in the tool front sub-surface; and the locking screw can engage a front recess formed in the clamp.
l. A tool abutment surface can comprise a tool lateral securing arrangement. The tool lateral securing arrangement can comprise, e.g., tool first and second inward slanted surfaces. Preferably only one of the tool abutment surfaces comprises the tool lateral securing arrangement. Most preferably the tool second lower abutment surface comprises the tool lateral securing arrangement. Without being bound to theory, it is believed that the tool lateral securing arrangement being formed at the tool second lower abutment surface provides the most stable insert seating arrangement. Preferably the tool first and second inward slanted surfaces form a convex or ridge shape rather than a concave shape.
li. A clamp can comprise a shank and a clamp head extending from the shank and comprising a clamp-insert abutment surface.
lii. A shank can be non-threaded.
liii. A clamp head can comprise a clamp upper surface, a clamp lower surface and a clamp peripheral surface connecting the clamp upper and lower surfaces.
liv. A clamp head can comprise a clamp front head portion, a clamp rear head portion and a clamp intermediary head portion.
lv. A clamp front head portion can comprise a downwardly directed clamp-insert abutment surface. Stated differently the clamp-insert abutment surface can be located at the clamp front head portion's lower surface.
lvi. A clamp intermediary head portion can be connected to a shank which extends therefrom in a downward direction. Stated differently the shank can be located at the clamp intermediary head portion's lower surface.
lvii. A clamp rear head portion can comprise a clamp-tool abutment surface located at the clamp peripheral surface. A clamp rear head portion can extend rearward of the shank. This can allow the clamp-tool abutment surface to abut an adjacent tool-clamp abutment surface and counter a moment caused by clamping of the insert via a clamp-insert abutment surface.
lviii. A clamp-tool abutment surface can be planar shaped. The clamp-tool abutment surface can be perpendicular to a central longitudinal plane of the clamp head (i.e. the clamp head being elongated in a transverse direction to the shank). This can allow a clamp to be rotationally-oriented about a shank axis correctly for clamping an insert.
lix. At least a clamp rear head portion's clamp upper surface can be ridge shaped (i.e. having at least one non-orthogonal surface extending to an apex, or, e.g., two inwardly slanted surfaces meeting at an apex). This can allow movement of the tool holding the clamp (particularly when the tool has a correspondingly shaped upper surface, such as a parting-off blade with a slanted ridge shape) when held by a tool holder.
lx. An insert can be clamped to the tool by the following abutment configuration: a clamp-insert abutment surface abutting an insert upper abutment surface; a tool first lower abutment surface abutting an insert first lower abutment surface; a tool second lower abutment surface abutting an insert second lower abutment surface; and a tool rear abutment surface abutting an insert rear abutment surface.
lxi. A clamp's clamp-insert abutment surface can simultaneously abut an insert upper abutment surface and the clamp's clamp-tool abutment surface can abut a tool-clamp abutment surface.
lxii. An insert in a mounted-unclamped position in the insert seat can be freely removable.
lxiii. A clamping force caused by a clamp-insert abutment surface abutting an insert upper abutment surface can be directed in a downward direction which is rearward of the insert's peripheral front sub-surface. Preferably the resultant clamping force can be directed rearward of the tool first lower abutment surface.
lxiv. A clamping force caused by a tool second lower abutment surface abutting an insert second lower abutment surface can be directed in a rearward direction towards a region below where the tool rear abutment surface abuts the insert rear abutment surface. A rear relief gap can be located between an insert's peripheral rear sub-surface, below an insert rear abutment surface, and a tool relief sub-surface. At least a portion of the rear relief gap can extend rearward of a tool rear abutment surface. As will be understood, the above-said also excludes the possibility of an additional rear clamping abutment location below where the clamping force is directed.
lxv. An insert can be configured to be held in a mounted position in an insert seat by having a clamping force simultaneously applied on, and only on, the insert upper abutment surface, the insert first lower abutment surface; the insert second lower abutment surface, and the insert rear abutment surface. Stated differently, an insert can be configured to be held in a mounted position in an insert seat by having abutment on, and only on, the insert upper abutment surface, the insert first lower abutment surface; the insert second lower abutment surface, and the insert rear abutment surface.
lxvi. A tool or tool assembly can be configured to hold an insert in a mounted position in an insert seat by having a clamping force simultaneously applied on, and only on, the insert upper abutment surface, the insert first lower abutment surface; the insert second lower abutment surface, and the insert rear abutment surface. Stated differently, a tool or tool assembly can be configured to hold an insert in a mounted position in an insert seat by simultaneously abutment on, and only on, the insert upper abutment surface, the insert first lower abutment surface; the insert second lower abutment surface, and the insert rear abutment surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0052] For a better understanding of the subject matter of the present application, and to show how the same may be carried out in practice, reference will now be made to the accompanying drawings, in which:
[0053] FIG. 1A is a partial side view of a tool assembly and a partial view of a workpiece;
[0054] FIG. 1B is a front view of the tool assembly in FIG. 1A ;
[0055] FIG. 1C is a perspective exploded view of the tool assembly in FIG. 1A ;
[0056] FIG. 2A is an upper perspective view of the cutting insert of the tool assembly in FIG. 1A ;
[0057] FIG. 2B is a lower perspective view of the cutting insert in FIG. 2A ;
[0058] FIG. 2C is a top view of the cutting insert in FIG. 2A ;
[0059] FIG. 2D is a side view of the cutting insert in FIG. 2A , which, unlike the cutting insert views in FIGS. 2A to 2C , is devoid of curvature lines;
[0060] FIG. 2E is a front view of the cutting insert in FIG. 2A ;
[0061] FIG. 2F is a section view taken along line 2 F- 2 F in FIG. 2D ;
[0062] FIG. 2G is a section view taken along line 2 G- 2 G in FIG. 2E ;
[0063] FIG. 3A is a front view of a clamp of the tool assembly in FIG. 1A ;
[0064] FIG. 3B is a section view taken along mid-line 3 B- 3 B in FIG. 3A ;
[0065] FIG. 3C is a partial view of the clamp taken in the direction of the arrow designated 3 C in FIG. 1A ;
[0066] FIG. 4A is a side perspective view of a tool corner portion of the tool in FIGS. 1A to 1C ;
[0067] FIG. 4B is another side perspective view of the tool corner portion in FIG. 4A ;
[0068] FIG. 4C is a front view of the tool corner portion in FIG. 4A ;
[0069] FIG. 4D is a section view taken along mid-line 4 D- 4 D in FIG. 4C ;
[0070] FIG. 5A is a section view taken along line 5 A- 5 A in FIG. 1B ; and
[0071] FIG. 5B is a section view taken along mid-line 5 B- 5 B in FIG. 1B .
DETAILED DESCRIPTION
[0072] Referring to FIGS. 1A and 1B , illustrated is an exemplary tool assembly 10 comprising an insert 12 , a tool 14 and a clamp 16 for securing the insert 12 to the tool 14 in the mounted-clamped position shown.
[0073] The tool assembly 10 can be configured for parting-off a portion of a cylindrical rotating workpiece 18 , when moved in a forward direction D F towards the workpiece 18 . The exemplary tool assembly shown is designed for being held in a parting-off block (not shown).
[0074] Referring also to FIG. 1C , the clamp 16 can be part of a clamp mechanism 20 , comprising a locking screw 22 , anti-fallout member 24 , and clamp-spring 26 . It will be understood that while this is a preferred clamping arrangement, other arrangements such as the clamp having a threaded screw shank and/or only some of the above mentioned clamp assembly elements may be used.
[0075] The locking screw 22 can comprise a tool-receiving configuration 22 A (e.g. a Torx® configuration) at a proximal end, a conical abutment surface 22 B at an opposing distal end, and an external thread 22 C therebetween.
[0076] The anti-fallout member 24 can comprise a tool-receiving configuration 24 A (e.g. a Torx® configuration) at one end and an external thread 24 B extending therefrom.
[0077] Drawing attention to FIGS. 2A to 2D , the insert 12 is shown in detail.
[0078] The insert 12 is for metal machining operations and can be typically made of extremely hard and wear-resistant material such as cemented carbide. Advantageously, the insert 12 can be pressed to final dimensions as per the example described herein. It will be understood that different chip-control arrangements may warrant a grinding step, but that even less ground surfaces on a cutting insert is still advantageous.
[0079] The insert 12 is a solid insert comprising opposite insert first and second side surfaces 28 A, 28 B and an insert peripheral surface 30 connecting the insert side surfaces 28 A, 28 B.
[0080] The insert peripheral surface 30 can comprise a peripheral upper sub-surface 30 A, a peripheral front sub-surface 30 B, a peripheral lower sub-surface 30 C, and a peripheral rear sub-surface 30 D.
[0081] Insert forward, rearward, upward and downward directions D IF , D IR , D IU , D ID are shown for the purposes of explanation. These directions are not meant in absolute terms but only as reference to relative positions of other portions of the insert 12 .
[0082] Also shown in FIG. 2C are insert first and second width directions D IW1 , D IW2 which are parallel, but not necessarily coaxial with an insert center axis A I extending perpendicular to the insert side surfaces 28 A, 28 B (noting that functional portions in an exemplified second region R 2 described hereinafter, is not taken into account for the overall orientation of the side surfaces 28 A, 28 B). Additionally, an insert plane P I is shown which is parallel with and located midway between the insert side surfaces 28 A, 28 B.
[0083] As shown in FIG. 2D , an insert center axis A I can be used to divide the insert (theoretically) into first, second, third and fourth corner regions R 1 , R 2 , R 3 , R 4 using a vertically extending height plane P H containing the insert center axis A I and extending perpendicular to the insert first and second surfaces 28 A, 28 B and a horizontally extending depth plane P D orthogonal thereto and also containing the insert center axis A I . As this theoretical division is merely to assist understanding of the relative locations of various components, it will be understood that the description below does not rely on exact boundary positions of the corner regions being defined and that terms vertical and horizontal are relative to the insert and are not meant to restrict orientation of an insert relative to the foolr.
[0084] Using the relative directions, the first corner region R 1 is in an upper-rear portion of the insert 12 , the second corner region R 2 in an upper-front portion thereof, the third corner region R 3 in a lower-front portion thereof, and the fourth corner region R 4 in a lower-rear portion thereof.
[0085] The first corner region R 1 can be recessed as shown. This can reduce upward projection of the clamp 16 , such upward projection being undesired as it can impede chip flow (not shown).
[0086] The first corner region R 1 can comprise an insert upper abutment surface 32 A and an insert rear abutment surface 32 B.
[0087] The insert rear abutment surface 32 B can comprise rear projection portions 32 B 1 , 32 B 2 separated by a rear recess 32 B 3 to assist precision insert positioning, even without the abutment surfaces being ground. It will be understood that such positioning construction is preferred (i.e., two projections separated by a recess), even though other constructions are possible.
[0088] Notably, the insert upper abutment surface 32 A can be planar shaped (i.e. free of a projection-recess arrangement) since preferably, only abutment surfaces intended to contact an insert seat 92 A are intended for positioning of the insert.
[0089] A second corner region R 2 can comprise a cutting edge 34 , rake surface 36 formed, e.g., with a chip-control arrangement 38 , which in this example takes the form of a recess ( FIG. 2A ), and a rearwardly tapering insert relief surface 37 ( FIG. 2D ).
[0090] The cutting edge 34 , in this example comprises a central portion 34 A which connects the insert side surfaces 28 A, 28 B. The cutting edge central portion 34 A can be wider than an adjacent portion 40 of the peripheral upper surface 30 A (shown in FIG. 2C ). The cutting edge central portion 34 A can be wider than an adjacent portion 42 of the peripheral front sub-surface 30 B (shown in FIG. 2E ). In this example, the cutting edge 34 can also comprise first and second edge-portions 34 B, 34 C ( FIG. 2A ) extending along each insert side surface 28 A, 28 B.
[0091] For the insert 12 to be configured for parting-off, it is beneficial for the cutting edge to be wider than the remainder of the insert 12 in a direction perpendicular to the insert center axis A I , as understood from FIG. 2E .
[0092] The third corner region R 3 can comprise an insert first lower abutment surface 32 C and an insert second lower abutment surface 32 D.
[0093] For similar reasons to those mentioned above in connection with the insert rear abutment surface 32 B, the insert first lower abutment surface 32 C comprises projection portions 32 C 1 , 32 C 2 separated by a recess 32 C 3 ( FIG. 2B ).
[0094] An insert overall height H 1 (also called the “insert height”) is shown extending from an uppermost point 44 of the peripheral upper sub-surface 30 A to a lowermost point 46 of the peripheral lower sub-surface 30 C. In this example, H 1 =12 mm.
[0095] An insert front height H 2 is shown along the peripheral front sub-surface 30 B, i.e. from the uppermost point 44 of the peripheral upper sub-surface 30 A to a lowermost point 48 of the insert first lower abutment surface 32 C. In this example, H 2 =10 mm.
[0096] It will be noted that optional but preferred manufacturing relief recesses (e.g. 50 A, 50 B, 50 C), are not considered for these measurements. It will also be understood that even if considered, their values are small relative to the dimensions under discussion.
[0097] An insert front-lower height H 3 is shown from the lowermost point 48 of the insert first lower abutment surface 32 C and parallel with the insert overall height H 1 , to the lowermost point 46 of the peripheral lower sub-surface 30 C. In this example, H 3 =2 mm.
[0098] An insert second lower abutment length H 4 is shown measurable along a line parallel with the insert second lower abutment surface 32 D and starting from an upper end 52 A of a linear portion adjacent a radius and extending to a lower end 52 B of the linear portion. In this example, H 4 =1 mm.
[0099] An insert lower rear height H 5 is shown from a lowermost point 46 of the insert peripheral lower sub-surface 30 C to a lowermost point 54 of the peripheral rear sub-surface 30 D. In this example, H 5 =2.3 mm.
[0100] An insert mid-rear height H 6 is shown from the lowermost point 54 of the peripheral rear sub-surface 30 D to an uppermost point 56 thereof. In this example, H 6 =6.4 mm.
[0101] An insert upper rear height H 7 is shown from the uppermost point 56 of the peripheral rear sub-surface 30 D to the uppermost point 44 of the peripheral upper sub-surface. In this example, H 7 =3.3 mm.
[0102] An insert overall depth H 8 (also called the “insert depth”) is shown extending from a rearmost point 60 of the peripheral rear sub-surface 30 D to a front point 62 of the peripheral front sub-surface 30 B. In this example, H 8 =12 mm.
[0103] Even though specific measurements are given above, it will be understood that the proportions shown are optimal values that should be considered as preferred ranges relative to each other (at least when differed by less than 25%, and preferably less than 15%). For example, the present values are H 1 =12 mm and H 3 =2.3 mm. Accordingly for a value of H 3 =2.3 mm, H 1 should preferably be designed within 25% of 12 mm (i.e. ±3 mm) or stated differently: 9 mm≦H 1 ≦15 mm, and more preferably 10.2 mm≦H 1 ≦13.8 mm. It will be understood that for the smaller abutment lengths, e.g. the insert second lower abutment surface 32 D, a minimum size is need for functionality and it may not be practical to reduce the size much or at all from the value given.
[0104] In this example the fourth corner region R 4 is formed with a chamfered shape. Above the chamfer, the fourth corner region R 4 can comprise a rearwardly facing insert rear non-abutment surface 32 BN, which is located adjacent to and below the insert rear abutment surface 32 B. As seen in the side view of FIG. 2D , the insert rear abutment surface 32 B and insert rear non-abutment surface 32 BN can be collinear.
[0105] FIGS. 2B, and 2E to 2G , show an insert lateral securing arrangement 64 is shown.
[0106] The insert lateral securing arrangement 64 can comprises insert first and second inward slanted surfaces 64 A, 64 B. A relief recess 64 C is shown between the slanted surfaces 64 A, 64 B.
[0107] FIG. 2F shows the insert first and second inward slanted surfaces 64 A, 64 B forming a concave shape. An obtuse external angle θ 1 of between 110° and 130° is preferred, with values closer to 120° being considered more preferred.
[0108] Since the slanted surfaces in this example extend inwards, only a section taken from an inner perspective view, in this case section 2 G- 2 G, i.e. FIG. 2G , shows how the slanted surfaces can also, preferably, be forwardly inclined relative to the peripheral rear sub-surface. Most preferably at an internal angle θ 2 of between 10° and 30°, with values closer to 20° being considered more preferred.
[0109] Ideally, the slanted surfaces 64 A, 64 B contact the tool 14 via the centrally located insert securing portions designated 64 D 1 , 64 D 2 .
[0110] Drawing attention to FIGS. 1C, and 3A to 3C , the clamp 16 , and the clamp mechanism 20 is shown in detail.
[0111] Clamp forward, rearward, upward and downward directions D CF , D CR , D CU , D CD are shown for the purposes of explanation. These directions are not meant in absolute terms but only as reference to relative positions of other portions of the clamp 16 . Also shown are clamp first and second width directions D CW1 , D CW2 which are orthogonal to a clamp plane P C .
[0112] The clamp 16 can comprise a clamp head 66 extending from a shank 68 .
[0113] The clamp head 66 can comprise a clamp upper surface 70 A, a clamp lower surface 70 B and a clamp peripheral surface 70 C connecting the clamp upper and lower surfaces 70 A, 70 B.
[0114] The clamp head 66 can comprise a clamp front head portion 72 A, a clamp rear head portion 72 B and a clamp intermediary head portion 72 C.
[0115] A clamp front head portion 72 A can comprise a downwardly directed clamp-insert abutment surface 74 A. The clamp-insert abutment surface 74 A can preferably be planar shaped.
[0116] The clamp intermediary head portion 72 C can have the same depth (along the clamp forward and rearward directions D CF, D CR ) as the shank 68 , and can be, optionally integrally, connected thereto via the clamp lower surface 70 B.
[0117] The clamp rear head portion 72 B can comprise a clamp-tool abutment surface 76 located at the clamp peripheral surface 70 C. The clamp-tool abutment surface 76 can be planar shaped.
[0118] A central longitudinal clamp plane P C of the clamp head 66 can coincide with line 3 B and is oriented perpendicular to the sheet showing FIG. 3A .
[0119] Referring to FIG. 3C , the clamp upper surface 70 A at, at least, the clamp rear head portion 72 B of the clamp can be ridge shaped 78 . In this example there are two clamp inwardly slanted surfaces 78 A, 78 B meeting at a clamp apex 78 C.
[0120] The shank 68 can be cylindrical and extend from the clamp head 66 to a shank end 80 .
[0121] The shank 68 can comprise first and second recesses 82 , 84 .
[0122] The first recess 82 faces forward and is configured to receive the locking screw 22 therein, for holding the clamp 16 against the insert 12 in a clamped position. The first recess 82 and locking screw 22 may be structurally and functionally similar to the “first recess 18 E” and “biasing screw 20 ” disclosed in U.S. Pat. No. 9,033,621, the description of which is incorporated herein by reference, and hence will not be described in more detail.
[0123] The second recess 84 faces rearward and is configured to prevent undesired ejection of the clamp 16 from a clamp hole 102 . This function may be best appreciated from the view in FIG. 5B , which is before the locking screw 22 is released. While the clamp-spring 26 is considered beneficial in quick release of an insert 12 , it also increases the tendency for the clamp 16 to fall from the tool when unclamping the insert 12 , hence the benefit of the second recess and anti-fallout member 24 . It will be understood that such construction may be less beneficial in circumstances when the spring, instead, is configured to pull the clamp 16 into the clamp hole or there is no spring in a design.
[0124] The tool 14 will be described in more detail as well as a corner portion 90 A ( FIG. 1C ), thereof which is shown in more detail in FIGS. 4A to 4D .
[0125] The corner portion 90 A, and in this example the entire tool 14 , can comprise opposite tool first and second side surfaces 86 A, 86 B and a tool peripheral surface 88 ( FIG. 1A ) connecting the tool side surfaces 86 A, 86 B.
[0126] Tool forward, rearward, upward and downward directions (D TF , D TR , D TU , D TD ) are shown for the purposes of explanation. These directions are not meant in absolute terms but only as reference to relative positions of other portions of the tool 14 . Also shown are tool first and second width directions D TW1 , D TW2 which are parallel, but not necessarily coaxial with a tool plane P T extending perpendicular to the tool side surfaces 86 A, 86 B.
[0127] A tool axis A T is schematically shown in the center of the tool 14 in FIG. 1A .
[0128] The tool 14 , in this example, is a parting-off blade. For the tool 14 to be configured for parting-off, it is beneficial for the cutting edge of the insert 12 to have a width W E ( FIG. 1B ) wider than the at least a corner 90 A of the tool 14 which comprises the insert seat 92 A, and even more beneficially wider than a width W B of the remainder of the entire tool 14 .
[0129] The tool 14 can, for example as shown, have an additional insert seat 92 B at another corner 90 B.
[0130] The tool 14 can be 180° rotationally symmetric about the tool axis A T .
[0131] Referring to FIG. 1A , the tool peripheral surface 88 can comprise a tool upper sub-surface 88 A, a tool front sub-surface 88 B, a tool lower sub-surface 88 C, and a tool rear sub-surfaces 88 D.
[0132] The tool upper sub-surface 88 A can be ridge shaped with a longitudinally extending upper ridge 94 . In this example there are two tool inwardly slanted surfaces 94 A, 94 B meeting at a tool upper apex 94 C.
[0133] The tool lower sub-surface 88 C can also be ridge shaped with a longitudinally extending lower ridge 96 as shown in FIG. 1B . In this example there are two tool inwardly slanted surfaces 96 A, 96 B meeting at a tool lower apex 96 C.
[0134] FIGS. 4A to 4D do not show the upper ridge 94 and is limited upwardly to the dashed line Y in FIG. 1C , and similarly the corner only extends downwardly to the dashed line X in FIG. 1C . This is because the corner portion views have been taken only to relate to elements of the exemplary design connected with mounting the insert 12 and can be applied to different tools, e.g. those that do not have ridge shaped elements.
[0135] The insert seat 92 A can comprise an upwardly facing tool first lower abutment surface 98 C, a rearwardly facing tool second lower abutment surface 98 D, a forwardly facing tool rear abutment surface 98 B and a tool relief sub-surface 98 E between the second lower abutment surface 98 D and the tool rear abutment surface 98 B. The tool relief sub-surface 98 E can comprise a forwardly facing tool rear non-abutment surface 98 BN. The rear non-abutment surface 98 BN located adjacent to and below the tool rear abutment surface 98 B.
[0136] When a cutting insert 12 occupies the insert seat 92 A, a tool relief recess 93 is formed between the cutting insert's peripheral lower sub-surface 30 C and the tool relief sub-surface 98 E. Also, a rear relief gap 100 can separate the insert rear non-abutment surface 32 BN and the tool rear non-abutment surface 98 BN. The rear relief gap 100 can be contiguous with the tool relief recess 93 , in a side view of the tool. As best seen in FIGS. 5A and 5B at least a portion of the rear relief gap 100 can extend rearward of the tool rear abutment surface 98 B.
[0137] The tool peripheral surface 88 adjacent the insert seat 92 A can comprise the clamp hole 102 . It will be noted that a clamp axis A C is slanted in a downward-rearward direction. The slanted orientation of the clamp hole 102 provides additional thickness and hence structural strength to the wall of the insert seat 92 A, most notably beneficial adjacent to the rear relief gap 100 . Such structural strength is provided while keeping the clamp head 66 proximate to an insert 12 in a mounted-clamped position to reduce bending forces on the clamp 16 .
[0138] The tool peripheral surface 88 can comprise a forwardly facing tool-clamp abutment surface 104 . The tool-clamp abutment surface 104 can face the insert seat, and extend upwardly from behind clamp hole 102 towards the tool upper sub-surface 88 A. The tool-clamp abutment surface 104 can be oriented parallel with the clamp axis A C (in this example it also extends in a downward-rearward direction) for mounting of the clamp 16 to the corner 90 A.
[0139] The tool peripheral surface 88 can comprise a locking screw hole 106 . The locking screw hole 106 can comprise internal threading 108 . It will be noted that a screw axis A S is similarly not orthogonal with the tool front sub-surface 88 B but slanted in an upward-rearward direction.
[0140] The insert seat 92 B can have a seat height L 1 extending from an imaginary first extension line E 1 of the tool upper sub-surface 88 A (at a height of the dashed line Y in FIG. 1C , i.e. excluding the optional upper ridge 94 ) to a lowermost point 110 of the tool relief sub-surface 98 E. In this example L 1 =12.4 mm.
[0141] A tool front height L 2 extends from the tool first lower abutment surface 98 C to the imaginary first extension line E 1 . In this example, L 2 =10 mm.
[0142] A tool front-lower height L 3 extends from the lowermost point 110 of the tool relief sub-surface 98 E and parallel with the tool height L 1 , to the tool first lower abutment surface 98 C. In this example, L 3 =2.4 mm.
[0143] A tool second lower abutment length L 4 extends along a line parallel with the tool second lower abutment surface 98 D and starting from an upper end 112 A of a linear portion 114 adjacent a radius and extending to a lower end 112 B of the linear portion. In this example, L 4 =1 mm.
[0144] A tool lower rear height L 5 extends from the tool first lower abutment surface 98 C to an imaginary second extension line E 2 parallel with the first extension line E 1 and extending from a lowermost point 116 of the tool rear abutment surface 98 B. In this example, L 5 =3.8 mm.
[0145] A tool mid-rear height L 6 is shown from the lowermost point 116 of the tool rear abutment surface 98 B to an uppermost point 118 thereof. In this example, L 6 =2.6 mm.
[0146] A tool upper rear height L 7 is shown from an uppermost point 118 of the tool rear abutment surface 98 B (or an extension line E 3 extending therefrom and parallel with the first extension line E 1 ) to the first extension line E 1 . In this example, L 7 =3.6 mm.
[0147] A tool overall depth L 8 (also called the “tool depth”) is shown extending from the tool rear abutment surface 98 B to an imaginary fourth extension line E 4 , parallel with and extending from the tool front sub-surface 88 B. In this example, L 8 =11 mm.
[0148] Even though specific measurements are given above, it will be understood that the proportions shown are optimal values that should be considered as preferred ranges relative to each other (at least when differed by less than 25%, and preferably less than 15%).
[0149] Referring to FIGS. 4A and 4B , a tool lateral securing arrangement 120 is shown formed at the tool second lower abutment surface 98 D. The tool lateral securing arrangement 120 complements the insert securing arrangement 64 , mutatis mutandis. For example the tool lateral securing arrangement 120 can comprise tool first and second inward slanted surfaces 120 A, 120 B. A securing arrangement nose 120 C is shown between the slanted surfaces. FIG. 4A shows the tool first and second inward slanted surfaces 120 A, 120 B forming a convex shape. An obtuse internal angle θ 3 of between 110° and 130° is preferred, with values closer to 120° being considered more preferred.
[0150] The tool's slanted surfaces can also, preferably, be forwardly inclined to correspond to the insert's inclination. Preferably they are forwardly inclined at an external angle of between 10° and 30°, with values closer to 20° being considered more preferred.
[0151] In FIGS. 4A, 4B , schematically shown are intended abutment regions.
[0152] Ideally, the slanted surfaces 64 A, 64 B of the insert 12 contact centrally located tool securing portions designated 120 D 1 , 120 D 2 .
[0153] Referring to FIG. 4B , it will be noted that although the tool first lower abutment surface 98 C is planar, contact with the insert first lower abutment surface's projection portions 32 C 1 , 32 C 2 results in spaced apart abutment regions designated 98 C 1 , 98 C 2 .
[0154] Similarly, although the tool rear abutment surface 98 B is planar, contact with the insert rear abutment surface's projection portions 32 B 1 , 32 B 2 results in spaced apart abutment regions designated 98 B 1 , 98 B 2 .
[0155] It will be apparent from the description of the insert 12 and the tool 14 why the abutment surfaces advantageously, but not essentially, are configured to contact at pairs of spaced apart abutment regions. It will also be noted that it is preferred that the abutment surfaces of the insert have concave shapes (i.e. comprising the projections and recess).
[0156] Referring also to FIGS. 5A and 5B , mounting and removal of the insert 12 to the tool assembly 10 , which in this example comprises a clamp mechanism 20 , will be explained.
[0157] Initially, when the insert 12 is spaced apart from the tool 14 , i.e. before the insert 12 is mounted to the tool 14 , the locking screw 22 is in a retracted position (not shown) such that the conical abutment surface 22 B does not apply an upward or downward force on the clamp 16 .
[0158] The clamp 16 , according to this example, is biased by the clamp-spring 26 in an upward direction and is retained in the tool 14 by abutment of the anti-fallout member 24 and a lower surface 84 A of the second recess 84 of the clamp 16 .
[0159] The insert 12 is then mounted to the insert seat 92 A in a mounted-unclamped first position, i.e. the insert 12 can be freely removed, e.g. without a tool. This is because the insert seat 92 A is a rigid insert seat which is not configured to flex elastically when the insert is mounted thereto and grip the insert 12 .
[0160] In the mounted-unclamped first position, the tool first lower abutment surface 98 C abuts the insert first lower abutment surface 32 C ( FIG. 5A ); the tool second lower abutment surface 98 D abuts the insert second lower abutment surface 32 D ( FIG. 5A ); and the tool rear abutment surface 98 B abuts the insert rear abutment surface 32 B ( FIGS. 5A and 5B ). However, the rear relief gap 100 is present between the insert rear non-abutment surface 32 BN and the tool rear non-abutment surface 98 BN.
[0161] The locking screw 22 is then moved towards the clamp 16 , and the conical abutment surface 22 B contacts the first recess 82 thereby moving the clamp 16 downwardly, compressing the clamp-spring 26 and, in addition to the insert and tool abutting via the surfaces mentioned above, also causing the clamp-insert abutment surface 74 A to abut the insert upper abutment surface 32 A ( FIGS. 5A and 5B ), to secure the insert 12 in a mounted-clamped second position as shown in FIGS. 1A, 1B etc. Notably, the second recess 84 is designed to not contact the anti-fallout member 24 in this position ( FIG. 5B ) and thus a gap 84 C remains between an upper surface 84 B of the second recess 84 and the anti-fallout member 24 . In this second position, the rear relief gap 100 remains between the insert rear non-abutment surface 32 BN and the tool rear non-abutment surface 98 BN.
[0162] According to this example, the clamp 16 remains in a correct rotational alignment by the planar shaped clamp-tool abutment 76 and planar shaped tool-clamp abutment surfaces 104 abutting each other. This abutment also provides a counter moment M 1 to the moment M 2 caused by abutment of the clamp-insert abutment surface 74 A with the insert upper abutment surface 32 A ( FIG. 5B ).
[0163] Notably, a resultant first clamping force F 1 ( FIG. 5B ) caused by the clamp-insert abutment surface 74 A abutting the insert upper abutment surface 32 A can be directed downwardly in a direction which is rearward of the insert's peripheral front sub-surface 30 B, and preferably can even be rearward of the insert's first and second lower abutment surfaces 32 C, 32 D. Since the clamp-insert abutment surface 74 A and the insert upper abutment surface 32 A are both planar, the first clamping force F 1 is in an orthogonal direction to these surfaces.
[0164] To elaborate, if the first clamping force F 1 would be replaced with a hypothetical clamping force designated as F 2 , which is shown as directed at an intersection 30 N of the insert's peripheral front and lower sub-surfaces 30 B, 30 C (and thus not be directed “rearward” of the insert's peripheral front sub-surface 30 B) such force direction could cause the insert 12 to tend to pivot during machining. Such pivoting being even more likely if the resultant force would be directed even more towards the insert's peripheral front sub-surface 30 B.
[0165] A resultant additional clamping force F 3 caused by the tool second lower abutment surface 98 D abutting the insert second lower abutment surface 32 D is directed in a rearward direction towards a region below where the tool rear abutment surface 98 B abuts the insert rear abutment surface 32 B. Stated differently, the additional clamping force F 3 is directed towards the rear relief gap 100 . This can assist in avoiding causing the insert pocket 92 A from having a resilient clamping effect.
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A tool assembly for heavy duty machining includes an insert, tool and clamp for securing the insert to a rigid insert seat of the tool. The insert is a solid cutting insert including a single cutting edge located at a corner region thereof. At a diagonally opposed corner region the insert is not subjected to clamping forces.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of the filing date of U.S. Provisional Application Ser. No. 60/913,118, entitled “Pocket With Secure Dividers” filed on Apr. 20, 2007, the entirety of which is incorporated herein by reference.
BACKGROUND
[0002] The present invention is directed to a pocket, and more particularly, to a pocket having dividers securely received therein.
[0003] Pockets may be used to store various items such as loose papers, writing utensils, or the like. Such pockets may include a divider or dividers positioned therein so that the contents of the pocket can be easily compartmentalized and organized. In addition, it may be desired to provide a secure attachment means such that the dividers are securely attached to the pocket and are not easily removed or torn.
SUMMARY
[0004] The present disclosure in one aspect provides a pocket assembly that includes a major panel and a pocket panel coupled together to define a pocket therebetween. A divider is placed in the pocket to partition the pocket into two or more compartments. The divider comprises a securing element secured to at least one of the major and pocket panels.
[0005] In one embodiment, the securing element may be a tab extending from the divider and attached to the at least one of the major and pocket panels. The pocket may be provided at its bottom with an opening while the tab may extend through the opening and may be attached to the outside surface of the at least one of the major and pocket panels. The tab may be folded flat against the outside surface of the at least one of the major and pocket panels to be attached thereto. The opening may be a slit formed along the bottom edge of the at least one of the major and pocket panels. The major and pocket panels may be pivotally secured together about the bottom edge.
[0006] In another embodiment, the divider may include at least one divider panel, and the tab may be coupled to the at least one divider panel along its lower edge. The divider may include two or more divider panels. First and second ones of the two or more divider panels may be foldably connected together along their common lower edge, and the tab may be formed from the first divider panel and joined to the second divider panel along the lower edge. The first and second divider panels may be folded about the common lower edge into a face-to-face relationship such that the tab protrudes downwardly from the second divider panel. Alternatively, the two or more divider panels may be separate panels, and each of them may have the tab so that the each divider may be individually coupled to the at least one of major and pocket panels by the tab of the each divider panel.
[0007] In a further embodiment, the major panel may include a set of openings formed therethrough. The openings may be positioned and aligned to allow the pocket assembly to be coupled to a binding mechanism.
[0008] In a still further embodiment, the pocket panel may be generally rectangular in shape. The pocket panel may be securely coupled to the major panel along at least two secured outer edges while leaving at least one free outer edge unattached to the major panel. The assembly may further comprise a side flap coupling one of the at least two secured outer edges of the pocket panel to the major panel to allow the pocket to expand.
[0009] The present disclosure in a second aspect provides a portfolio which includes a major panel and a pocket panel coupled together to define a pocket between the respective inside surfaces of the major and pocket panels. A divider is received in the pocket. The pocket panel is coupled to the major panel along its lower edge to define the bottom of the pocket. The pocket is provided at its bottom with an opening. The divider comprises a tab extending outwardly of the pocket through the opening and is attached to the outside surface of one of the major and pocket panels.
[0010] In one embodiment of this aspect, the pocket panel may be foldably coupled to the major panel along the lower edge. The opening may be formed along the lower edge, and the tab may be folded about the lower edge onto the outside surface of the one of the major and pocket panels to be attached to the outside surface.
[0011] In another embodiment, the portfolio may further include a second major panel foldably coupled to the first major panel. A spine may be positioned between the first and second major panels. Further, a binding mechanism may be mounted to one of the spine and either one of the first and second major panels. A second pocket panel may be coupled to the second major panel to define a second pocket between the second major panel and the second pocket panel. In such an embodiment, a second divider may be received in the second pocket. The second pocket panel may be provided at the bottom thereof with an opening. The second divider may comprise a tab extending outwardly of the second pocket through the opening of the second pocket. The tab of the second divider may be attached to the outside surface of one of the second major and second pocket panels.
[0012] In a further embodiment, the portfolio may further comprise a closure flap pivotally coupled to the upper edge of the first major panel. The closure flap may include a locking tongue while the pocket panel may have a tongue socket engageable with the locking tongue.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a front perspective view of a portfolio in a closed position incorporating a pocket/divider design;
[0014] FIG. 2 is a front perspective view of the portfolio of FIG. 1 shown in its open position;
[0015] FIG. 3 is a side cross-section taken along line 3 - 3 of FIG. 2 ;
[0016] FIG. 4 is a side cross-section taken along line 4 - 4 of FIG. 2 ;
[0017] FIG. 5 is a top view of a blank which can be used to form the portfolio of FIGS. 1 and 2 ;
[0018] FIG. 6 is a top view of a blank which can be used to form the dividers shown in FIGS. 2-4 ;
[0019] FIG. 7 is a front perspective view of the dividers of FIG. 6 , shown in a partially folded state;
[0020] FIG. 8 is a front perspective view of the folded dividers of FIG. 7 positioned above the assembled portfolio of FIG. 5 ;
[0021] FIG. 9 is a front perspective view of the dividers and the portfolio of FIG. 8 in an assembled condition;
[0022] FIG. 10 is a front perspective view of a portfolio and a single-ply divider exploded away from the portfolio;
[0023] FIG. 11 is a front perspective view of another portfolio utilizing a pocket and divider design; and
[0024] FIG. 12 is a front perspective view of the portfolio of FIG. 11 shown in an opened position with the dividers exploded away from the pocket.
DETAILED DESCRIPTION
[0025] FIGS. 1-4 illustrate a portfolio, generally designated 10 , including a pair of opposed major panels 12 , 14 . The major panels 12 , 14 are pivotally attached to each other along a central fold line 16 . In this manner, each major panel 12 , 14 is independently pivotable about the fold line 16 such that the portfolio 10 is moveable between a closed position ( FIG. 1 ) wherein the major panels 12 , 14 are generally parallel, aligned and face each other, and an open position ( FIG. 2 ) wherein the major panels 12 , 14 lay generally flat and coplanar and do not face each other.
[0026] If desired, a spine (not shown) may be positioned between the major panels 12 , 14 . Further, if desired, a binding mechanism (not shown) may be mounted to the spine or to either of the major panels 12 , 14 . In the illustrated embodiment, each of the major panels 12 , 14 includes a set of openings 18 formed therethrough, wherein the openings 18 are positioned and aligned to allow the portfolio 10 to be coupled to a three-ring binding mechanism or the like.
[0027] A generally rectangular pocket panel 20 , 22 is attached to the inner surface of each associated major panel 12 , 14 to define a pocket 24 therebetween. More particularly, each pocket panel 20 , 22 may be securely coupled to the underlying major panel 12 , 14 along two secured edges (i.e. a bottom edge 26 and an outer edge 28 ), leaving two free edges (top edge 30 and inner edge 32 ) along which the associated pocket 24 can be accessed. In the illustrated embodiment, an expandable gusset or side flap (such as an accordion-style gusset) 34 is coupled to the outer edge 28 of the pocket panel 20 to allow the associated pocket 24 to expand as desired.
[0028] A set of dividers 40 , 42 may be positioned in the pocket 24 . In the illustrated embodiment, each of the dividers 40 , 42 is generally rectangular, having an angled corner 44 and a protruding tab 46 . In the illustrated embodiment, each divider 40 , 42 is made of a generally transparent material although, if desired, the dividers 40 , 42 can be made of opaque or various other materials.
[0029] Each divider 40 , 42 may have a width (i.e. in the left-to-right direction of FIGS. 2 and 5 ) about equal to the width of the associated pocket panel 20 /major panel 12 to allow the contents of the pocket 24 to be completely divided/segregated. More particularly, in one embodiment, each divider 40 , 42 may have a width within at least about 10% or at least about 20%, or at least about 30% of the width of the associated pocket panel 20 and/or major panel 12 . Furthermore, each divider 40 , 42 may have a height (i.e. extending in the top-to-bottom direction of FIGS. 2 and 5 ) close to the height of the portfolio 10 /major panels 12 , 14 such that the dividers 40 , 42 can extend through a stack of loose leaf papers of various heights stored in the associated pocket 24 . Thus, in one embodiment, each divider 40 , 42 may have a height within at least about 10%, or at least about 20%, or at least about 30%, of the height of the portfolio 10 and/or associated major panel 12 .
[0030] The pocket 24 defined by pocket panel 20 has a narrow opening or slit 48 formed along its bottom edge 26 , as best shown in FIGS. 5 and 8 . At least one of the dividers 40 , 42 includes a tab portion 50 which protrudes through the opening 48 and is folded flat against the outer surface of the pocket panel 20 . The tab 50 may then be attached to the underlying pocket panel 20 to securely couple the tab 50 /divider(s) 40 , 42 to the portfolio 10 /pocket panel 20 . The tab 50 can be attached to portfolio 10 /pocket panel 20 by any of a wide variety of methods, such as heat welding, sonic welding, stitching, adhesives, staples, rivets or other mechanical fasteners, etc.
[0031] The tab 50 may have a relatively long length (i.e. extending along the left-to-right direction of FIG. 2 ) to ensure adequate coupling strength. More particularly, the tab 50 may extend along at least about 10%, or at least about 20% or at least about 30%, or at least about 40% of the width (i.e. extending in the left-to-right direction of FIG. 2 ) of the associated major panel 12 , pocket panel 20 and/or divider 40 , 42 . The opening 48 may have a length that is about equal to the length of the associated tab 50 (i.e. within about 10% of the length of the tab 50 ) such that the opening 48 closely receives the tab 50 therethrough.
[0032] In this manner, the tab 50 securely retains the divider(s) 40 , 42 to the portfolio 10 /pocket panel 20 . More particularly, the tab 50 provides an attachment structure that can be easily accessed and formed during manufacturing/assembly. Furthermore, because the tab 50 is folded about a bottom edge 26 of the pocket panel 20 , the fold 52 provides further secure attachment. For example, the fold 52 of the tab 50 may accommodate stresses if the divider(s) 40 , 42 are attempted to be pulled upwardly out of the associated pocket 24 .
[0033] In order to assemble the portfolio of FIGS. 1-4 , in one embodiment the blank 54 of FIG. 5 may be provided. Each pocket panel 20 , 22 may be pivoted about the lower edge 26 of the associated major panel 12 , 14 such that the pocket panels 20 , 22 lay generally flat against the associated major panel 12 , 14 . The gusseted side flap 34 and opposite side flap 58 are then pivoted inwardly until each side flap 34 , 58 lays on top of the associated pocket panel 20 , 22 . The side flaps 34 , 58 are then attached to the associated pocket panel to complete the pockets 24 and provide the portfolio 10 shown in, for example, FIG. 8 .
[0034] Next, as shown in FIG. 6 , in one embodiment a blank 60 for forming the dividers 40 , 42 may be provided. In the illustrated embodiment, the dividers 40 , 42 are formed from a single, unitary piece of sheet-like material 62 . A generally “U”-shaped cut 64 is formed in the blank 60 to define the tab 50 which is positioned adjacent to a central fold line 52 of the blank 60 . Next, as shown in FIG. 7 , the blank 60 is folded about the central fold line 52 such that the tab 50 protrudes downwardly from the dividers 40 , 42 . Thus, in the illustrated embodiment, the tab 50 is formed as a single piece that is unitary with at least one divider 40 , 42 , or with both dividers 40 , 42 .
[0035] Next, as shown in FIG. 8 , the assembled dividers 40 , 42 are positioned above the assembled portfolio 10 and the dividers 40 , 42 are inserted into the associated pocket 24 such that the tab 50 protrudes through the opening 48 ( FIG. 9 ). The tab 50 is then folded upwardly and coupled to the outer surface of the pocket panel 20 , resulting in the assembly shown in FIG. 2 . However, the tab 50 could alternately be folded in the opposite direction such that the tab 50 wraps around the outer surface of the major panel 12 .
[0036] The portfolio 10 (i.e. including major panels 12 , 14 , pocket panels 20 , 22 , side flaps 34 , 58 , spine, etc.), along with the dividers 40 , 42 can be made of any of a wide variety of materials, including but not limited to plastic (such as polypropylene or vinyl), cardboard, paperboard, plastic encased cardboard, etc. In addition, the components of the portfolio 10 and dividers 40 , 42 can be attached/assembled by any of a wide variety of methods, such as heat welding, sonic welding, stitching, adhesive, staples, rivets or other mechanical fasteners, etc. Further, while the illustrated embodiment shows only pocket panel 20 receiving the dividers 40 , 42 therein, if desired, both pocket panels 20 , 22 or only pocket panel 22 may receive the dividers 40 , 42 .
[0037] FIG. 10 illustrates another embodiment of the invention, wherein only a single divider 40 having a tab 50 is configured to be coupled to the portfolio. If desired, multiple of the single-ply dividers 40 of FIG. 10 can be coupled to the portfolio 40 , wherein each divider 40 includes its own associated tab 50 . This arrangement may provide greater strength in that each divider 40 is individually coupled by its own tab 50 . However, the embodiment shown in FIGS. 6 and 7 (wherein two dividers 40 , 42 share a tab 50 ) may be advantageous that only a single blank 60 and relatively few steps are required to produce a dual divider assembly.
[0038] FIGS. 11 and 12 illustrate another embodiment of the invention wherein the portfolio 70 includes a major panel 12 , a pocket panel 20 defining a pocket 24 therebetween, and a pair of dividers 40 , 42 received in the pocket 24 . In this embodiment, the pocket panel 20 is relatively large, having a surface area of about equal to the surface area of the major panel 12 . The pocket panel 20 is secured to the underlying major panel 12 about bottom edge 26 and side edge 32 thereby leaving top edge 30 and inner edge 28 as free edges. A closure flap 72 is pivotally coupled to an upper edge of the major panel 12 .
[0039] The closure flap 72 may include a tooth or locking element 74 that can be inserted into and through an opening or socket 76 of the pocket panel 20 to thereby secure the portfolio 70 in a closed position. However, any of a variety of closure mechanisms, such as hook-and-loop fasteners (such as VELCRO®), clasps, hooks, loops, elastic components, brackets, magnets, interengaging geometries or the like may be used to retain the closure flap 72 in a closed position. The dividers 40 , 42 , having a configuration and assembly similar to the dividers 40 , 42 shown in FIGS. 6 and 7 and described above, may be received in the pocket 24 and coupled to the pocket 24 by the tab 50 extending through the opening 48 of the pocket 24 . In the embodiment shown in FIGS. 11 and 12 , the tab 50 is folded rearwardly about the major panel 12 and attached thereto, such that the tab is generally not visible in FIG. 11 .
[0040] The pocket/divider designs of the above embodiments can be used in nearly any pocket used alone, or used in pockets in conjunction with, or integrated into, other school and office items, such as binders, notebooks, portfolios, planners, date books, insert pockets and the like. The pocket/divider design provides an assembly that can be quickly and easily manufactured, yet provides a secure attachment mechanism due to the folded and attached nature of the tab.
[0041] Having described the invention in detail and by reference to the various embodiments, it should be understood that modifications and variations thereof are possible without departing from the scope of the claims of the present application.
[0042] One embodiment of the present invention provides a pocket assembly including first and second generally flat, parallel panels. The first panel is coupled to the second panel at least partially along at least one edge, and is not coupled to the second panel at least partially along another edge, to define a pocket therebetween. The pocket includes an opening formed therethrough. A divider including a tab is received in the pocket such that the tab extends through the opening and is attached to the pocket to thereby attach the divider to the pocket.
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A pocket assembly includes a major panel and a pocket panel coupled together to define a pocket between the panels. A divider is placed in the pocket to partition the pocket into two or more compartments. The divider comprises a securing element secured to at least one of the major and pocket panels.
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FIELD OF THE INVENTION
[0001] The present invention relates to new methods of selecting and breeding organisms, in particular organisms which exhibit symbiotic behaviour with symbionts such as fungal endophytes or epiphytes or bacterial microbiome in plants, and to new organisms and symbiota developed thereby.
BACKGROUND OF THE INVENTION
[0002] The phenotype of many species of livestock, crops and pastures depends on the interaction between the genotype of the individual and the genotype of a symbiont. Important plants, including forage grasses, legumes, trees, shrubs, and vines are commonly found in association with endophytes including fungi, bacteria, viruses and microbes. Similarly, important animals, including cattle, sheep, pigs, goats, etc. have such endophytes present in their gut and rumen.
[0003] Both beneficial and detrimental horticultural, agronomic and veterinary properties result from such associations, including improved tolerance to water and nutrient stress and resistance to insect pests.
[0004] For example, ryegrass plants can show improved drought tolerance and persistency if a fungal endophyte of the correct genotype colonises the plant. Similarly, in grasses, insect resistance may be provided by specific metabolites produced by the endophyte, in particular loline alkaloids and peramine. Other metabolites produced by the fungal endophyte, for example lolitrems and ergot alkaloids, may be toxic to grazing animals and reduce herbivore feeding.
[0005] Considerable variation is known to exist in the metabolite profile of symbionts such as endophytes. For example, fungal endophyte strains that lack either or both of the animal toxins have been introduced into commercial ryegrass varieties.
[0006] In animals, the microorganisms present in the gut are responsible for digestion of an animal's feed. Rumen microbes-bovine symbiota may example, in improving feed conversion efficiency and reducing methane production. In ruminants, successful digestion of poor quality feed may depend on having a particular rumen microbiome profile.
[0007] Molecular genetic markers such as simple sequence repeat (SSR) markers have been developed as diagnostic tests to distinguish between symbiont taxa and detect genetic variation within taxa. The markers may be used to discriminate symbiont strains with different toxin profiles.
[0008] However, there remains a need for methods of identifying, isolating and/or characterising organisms which exhibit symbiotic behaviour with symbionts such as endophytes. Difficulties in artificially breeding of these symbiota limit their usefulness. For example, many of the novel endophytes known to be beneficial to pasture-based agriculture exhibit low inoculation frequencies and are less stable in elite germplasm.
[0009] Moreover, in traditional breeding techniques, for example in forage grasses such as perennial ryegrass and tall fescue, grass varieties are bred using classic cross-breeding techniques and grass genotypes are selected for their superior characteristics, after monitoring their performance over a period of multiple years. The selected grass genotypes that form the experimental variety are then inoculated with a single endophyte and the resulting grass-endophyte associations are evaluated for any favourable characteristics such as insect resistance. The individual experimental synthetic varieties deploying a single endophyte in them are then evaluated for agronomic performance and resulting animal performance by grazing animals over a period of years. This evaluation process may reveal that the single endophyte being deployed in the different experimental synthetic varieties may not show vegetative and/or intergenerational stability in some of these varieties or the desired alkaloid profile conferred by the single endophyte may vary between different synthetic varieties failing to confer appropriate levels of insect resistance or causing animal toxicoses. It would be a significant development in the art if this time-consuming process could be accelerated or otherwise improved.
[0010] It is accordingly an object of the present invention to overcome, or at least alleviate, one or more of the difficulties or deficiencies associated with the prior art.
SUMMARY OF THE INVENTION
[0011] United States patent applications filed 1 Jun. 2012 and 7 Sep. 2012, entitled ‘Novel Organisms’, the entire disclosures of which are incorporated herein by reference, describe methods of deploying multiple symbionts in multiple organisms and to select for improved symbiotic compatibility and performance early in the breeding process. That is symbiont-organism genotype combinations are bred and screened for desired characteristics including improved symbiota compatibility and performance ab initio. To facilitate this, applicants have developed methods for large-scale establishment of symbiota through artificial seed production and inoculation methods.
[0012] Accordingly, in a first aspect of the present invention, there is provided a method for preparing artificial seeds which method includes:
providing a source of plant seeds; subjecting the seed(s) to a surface-sterilisation step; isolating seed embryo(s) from the surface-sterilised seed(s); and coating the embryo(s) with a coating to form artificial seed(s).
[0017] The seeds may be from any suitable plant. The plant may be a grass, preferably a perennial grass, legume, vine, shrub, tree, herb, flower, shrub or bush. The method according to this aspect of the present invention is particularly applicable to grasses and legumes.
[0018] The seeds may be surface-sterilised by any suitable technique. Preferably the seeds are sterilised by treating them with an acid such as hydrochloric acid and bleach, such as sodium hypochlorite. Preferably the acid and bleach treatments are performed sequentially. The acid treatment may be for a period of from 1 hour to 24 hours, preferably overnight. The bleach treatment may be for a period of 5 minutes to 1 hour, preferably approximately 20 minutes. The bleach treatment may be performed twice on successive days, with the seeds being treatment, for example using sterile distilled water, and stored at approximately 4 to 30° C., preferably approximately 24° C.
[0019] Embryos may be isolated from the treated seeds by techniques known to those skilled in the art.
[0020] In a preferred embodiment, the embryos may be treated to create one or more points of entry for the symbiont, e.g. endophyte. For example, the embryo may be punctured or its surface otherwise damaged, for example by scratching or etching, to facilitate entry of the symbiont. In a particularly preferred embodiment, a hypodermic needle or similar may be used to create single or multiple puncture holes in the surface of the embryo.
[0021] The coating may be of any suitable type to encapsulate the embryo, including alginate, agar, polyco 2133, carboxy methyl cellulose, carrageenan, gelrite, guargum, sodium pectate, tragacanth gum and the like. In a preferred embodiment the coating is alginate, more particularly calcium alginate.
[0022] In a preferred embodiment, the embryos may be mixed with the coating and drops of coating containing individual embryos placed in a polymerising solution such as calcium chloride solution, preferably while stirring, to form artificial seeds. Artificial seeds may be collected following approximately 1-60 minutes stirring, preferably after approximately 15 minutes stirring.
[0023] In a preferred embodiment the embryos may be inoculated with a symbiont such as a fungal endophyte prior to coating. In a preferred form, the embryos may be directly inoculated with endophyte mycelium.
[0024] Alternatively, in a particularly preferred embodiment, isolated embryos may be coated with a symbiont-containing coating layer, such as a fungal endophyte-containing coating layer.
[0025] In this embodiment, the inoculation step may include:
providing a source of seed embryos; inoculating the embryos with one or more symbionts such as fungal endophytes; and coating the inoculated embryo(s) with a coating to form artificial seed(s).
[0029] Alternatively, the inoculation step may include:
providing a source of seed embryos; and coating the embryos with a coating containing symbionts such as fungal endophytes to form artificial seed(s).
[0032] In a preferred embodiment the seeds may be double coated with a second coating layer. Preferably the second coating layer is alginate, more preferably calcium alginate, even more preferably coloured calcium alginate. In a preferred embodiment, the artificial seeds with the first coating layer may be air dried prior to coating with the second layer.
[0033] In a preferred embodiment, the method may further include coating the artificial seeds with a second coating layer, said second coating layer preferably containing added nutrients suitable for sustaining the embryo and/or symbiont.
[0034] Alternatively, the second coating layer may not contain added nutrients, this nutrient deprived layer being designed to, for example, reduce endophyte out-growth during germination and restrict endophyte growth in close proximity to the embryo.
[0035] In another aspect of the present invention, there is provided an artificial seed selected from the group consisting of:
(a) a plant embryo inoculated with one or more symbionts and coated with a coating to encapsulate the embryo; and (b) a plant embryo coated with a symbiont-containing coating layer.
[0038] Preferably, the artificial seed is double coated with a second second coating layer may include added nutrients or may be a nutrient deprived layer, as described herein.
[0039] Preferably, the embryo is from a plant selected from the group consisting of grasses and legumes. Preferably it is isolated by techniques as hereinbefore described.
[0040] Preferably, the embryo is treated to create one or more points of entry for the symbiont.
[0041] In a particularly preferred embodiment symbiont may be a fungal endophyte.
[0042] In another particularly preferred embodiment, the artificial seed may be produced by a method as hereinbefore described.
[0043] In a preferred embodiment, the method of the present invention may further include
growing the artificial seeds to form plantlets or seedlings; and screening the plantlets or seedlings for symbiont presence such as fungal endophyte presence.
[0046] The step of growing the artificial seeds may be undertaken using any suitable growth medium. A germination medium such as MS (Murashige and Skoog), modified MS or MS+BAP (6-benzylamino purine) is particularly preferred.
[0047] The seedlings may for example be screened for symbiont-specific, e.g. fungal endophyte-specific simple sequence repeats (SSRs).
[0048] A large scale endophyte discovery program has been undertaken to establish the ‘library’ of fungal endophyte strains. A collection of perennial ryegrass and tall fescue accessions has been established.
[0049] The endophytes selected to inoculate the embryo may be selected utilising the techniques described in an Australian patent application filed 1 Jun. 2012 entitled “Novel Endophytes”, to the present applicant, the entire disclosure of which is incorporated herein by reference. The novel endophytes described therein are particularly preferred.
[0050] Genetic analysis of endophytes in these accessions has led to the identification of a number of novel endophyte strains. These novel endophyte strains are genetically distinct from known endophyte strains. Metabolic profiling may be undertaken to determine the toxin profile of these strains.
[0051] Specific detection of endophytes in planta with SSR markers may be used to confirm the presence and identity of endophyte strains artificially inoculated into, for example, plants, plant lines, plant varieties and plant cultivars.
[0052] The inoculated germplasm may be screened by genetic analysis and/or metabolic profiling. For example, techniques of genetic analysis described in the Australian provisional patent application entitled “Novel Endophytes” may be used.
[0053] Alternatively, or in addition, the inoculated germplasm may be subjected to genetic analysis (genetically characterised) to demonstrate genetic distinction from known symbiont-genotype symbiota and to confirm the identity of symbiont, e.g. fungal endophyte, strains artificially inoculated into, for example, plants, plant lines, plant varieties and plant cultivars.
[0054] By ‘genetic analysis’ is meant analysing the nuclear and/or mitochondrial DNA of the symbiont such as the fungal endophyte.
[0055] This analysis may involve detecting the presence or absence of polymorphic markers, such as simple sequence repeats (SSRs) or mating-type markers. SSRs, also called microsatellites, are based on a 1-7 nucleotide core element, more typically a 1-4 nucleotide core element, that is tandemly repeated. The SSR array is embedded in complex flanking DNA sequences. Microsatellites are thought to arise due to the property of replication slippage, in which the DNA polymerase enzyme pauses and briefly slips in terms of its template, so that short adjacent sequences are repeated. Some sequence motifs are more slip-prone than others, giving rise to variations in the relative numbers of SSR loci based on different motif types. Once duplicated, the SSR array may further expand (or contract) due to further slippage and/or unequal sister chromatid exchange. The total number such that in principle such loci are capable of providing tags for any linked gene.
[0056] SSRs are highly polymorphic due to variation in repeat number and are co-dominantly inherited. Their detection is based on the polymerase chain reaction (PCR), requiring only small amounts of DNA and suitable for automation. They are ubiquitous in eukaryotic genomes, including fungal and plant genomes, and have been found to occur every 21 to 65 kb in plant genomes. Consequently, SSRs are ideal markers for a broad range of applications such as genetic diversity analysis, genotypic identification, genome mapping, trait mapping and marker-assisted selection.
[0057] Known SSR markers which may be used to investigate endophyte diversity in perennial ryegrass are described in van Zijll de Jong et al (2003) Genome 46 (2): 277-290.
[0058] Alternatively, or in addition, the genetic analysis may involve sequencing genomic and/or mitochondrial DNA and performing sequence comparisons to assess genetic variation between symbionts such as fungal endophytes.
[0059] The symbiotum derived from the artificial seed established from the symbiont-inoculated embryo may be subjected to metabolic analysis to identify the presence of desired metabolic traits.
[0060] By ‘metabolic analysis’ is meant analysing metabolites, in particular toxins, produced by the symbionts, such as fungal endophytes. Preferably, this is done by generation of inoculated plants for each of the symbionts and measurement of e.g. toxin levels, resistance to pests and/or diseases, or tolerance to water and/or nutrient stress in planta. More preferably, this is done by generation of isogenically inoculated plants for each of the symbionts and measurement of toxin levels in planta.
[0061] By a ‘desired genetic and metabolic profile’ is meant that the symbiont such as a fungal endophyte possesses genetic and/or metabolic characteristic beneficial phenotype in an organism harbouring, or otherwise associated with, the symbiont.
[0062] Such beneficial properties include improved tolerance to water and/or nutrient stress, improved resistance to pests and/or diseases, enhanced biotic stress tolerance, enhanced drought tolerance, enhanced water use efficiency, enhanced tolerance to extremes of temperature, reduced toxicity, enhanced nutrient availability and enhanced vigour in, for example, a plant with which the symbiont is associated, relative to a control plant lacking the symbiont or containing a control symbiont such as standard toxic (ST) endophyte.
[0063] Such beneficial properties also include reduced toxicity of the associated plant to grazing animals.
[0064] For example, tolerance to water and/or nutrient stress may be increased by at least approximately 5%, more preferably at least approximately 10%, more preferably at least approximately 25%, more preferably at least approximately 50%, more preferably at least approximately 100%, relative to a control symbiont such as ST endophyte or to a no symbiont control plant. Preferably, tolerance to water and/or nutrient stress may be increased by between approximately 5% and approximately 50%, more preferably between approximately 10% and approximately 25%, relative to a control symbiont such as ST endophyte or to a no symbiont control plant.
[0065] For example, plant resistance to pests and/or diseases may be increased by at least approximately 5%, more preferably at least approximately 10%, more preferably at least approximately 25%, more preferably at least approximately 50%, more preferably at least approximately 100%, relative to a control plant. Preferably, plant resistance to diseases and/or pests may be increased by between approximately 5% and approximately 50%, more preferably between approximately 10% and approximately 25%, relative to a control plant.
[0066] For example, water use efficiency and/or plant vigour may be increased by at least approximately 5%, more preferably at least approximately 10%, least approximately 25%, more preferably at least approximately 50%, more preferably at least approximately 100%, relative to a control symbiont such as ST endophyte or to a no symbiont control plant. Preferably, tolerance to water and/or nutrient stress may be increased by between approximately 5% and approximately 50%, more preferably between approximately 10% and approximately 25%, relative to a control symbiont such as ST endophyte or to a no symbiont control plant.
[0067] For example, toxicity may be reduced by at least approximately 5%, more preferably at least approximately 10%, more preferably at least approximately 25%, more preferably at least approximately 50%, more preferably at least approximately 100%, relative to a control symbiont such as ST endophyte or to a no symbiont control plant. Preferably, toxicity may be reduced by between approximately 5% and approximately 100%, more preferably between approximately 50% and approximately 100% relative to a control symbiont such as ST endophyte or to a no symbiont control plant.
[0068] In a preferred embodiment toxicity may be reduced to a negligible amount or substantially zero toxicity.
[0069] In a preferred embodiment, the symbiont such as a fungal endophyte may exhibit a desired toxin profile.
[0070] Preferably the endophyte is isolated from a fescue species, preferably tall fescue.
[0071] Preferably, the endophyte is of the genus Neotyphodium , more preferably it is from a species selected from the group consisting of N. uncinatum, N. coenophialum and N. lolii , most preferably N. coenophialum . The endophyte may also be from the genus Epichloe , including E. typhina, E. baconii and E. festucae . The endophyte may also be of the non- Epichloe out-group. The endophyte may also be from a species selected from the group consisting of FaTG-3 and FaTG-3 like, and FaTG-2 and FaTG-2 like.
[0072] The endophyte may also be from the genus Acremonium , include and endophytes from Brachiaria - Urochloa grasses as described in Australian patent application No. 2011902393 entitled “Fungi and associated methods”, to the present applicant, the entire disclosure of which is incorporated herein by reference.
[0073] By a ‘desired toxin profile’ is meant that the symbiont such as an endophyte produces significantly less toxic alkaloids, such as ergovaline or Lolitrem B, compared with a plant inoculated with a control symbiont such as standard toxic (ST) endophyte; and/or significantly more alkaloids conferring beneficial properties such as improved tolerance to water and/or nutrient stress and improved resistance to pests and/or diseases in the plant with which the symbiont is associated, such as peramine, N-formylloline, N-acetylloline and norloline, again when compared with a plant inoculated with a control symbiont such as ST or with a no symbiont control plant.
[0074] In a particularly preferred embodiment, the endophyte may be selected from the group consisting of E1, NEA10, NEA11 and NEA12, which were deposited at The National Measurement Institute on 5 Jan. 2010 with accession numbers V10/000001, V10/000002, V10/000003 and V10/000004, respectively, and are described in International patent application PCT/AU2011/000020, the entire disclosure of which is incorporated herein by reference.
[0075] In a particularly preferred embodiment, the endophyte may be selected from the group consisting of NEA16, NEA17, NEA18, NEA19, NEA20, NEA21 and NEA23, which were deposited at The National Measurement Institute on 3 Apr. 2012 with accession numbers V12/001413, V12/001414, V12/001415, V12/001416, V12/001417, V12/001418 and V12/001419, respectively, and are described in an Australian patent application filed 1 Jun. 2012 entitled ‘Novel endophytes’, to the present applicant, the entire disclosure of which is incorporated herein by reference.
[0076] In a particularly preferred embodiment, the endophyte may be selected from the group consisting of Acremonium 1.1.A (1.1A), 3.3.A (3.3A), 5.1.B (5.1B), 9.2.A (9.2A) and 12.1.A (12.1A), which were deposited at The National Measurement Institute on 15 Jun. 2011 with accession numbers V11/011 V11/011372, V11/011373, and V11/011374, respectively, which are described in Australian patent application No. 2011902393 entitled “Fungi and associated methods”, to the present applicant, the entire disclosure of which is incorporated herein by reference.
[0077] Such endophytes may have a desired toxin profile as hereinbefore described.
[0078] In a preferred embodiment of the present invention, the symbiont(s) such as endophyte(s) may include a genetic variation, for example, to enhance endophyte trait introgression in plants such as grasses to enhance vegetative stability of the symbiotum, intergenerational stability of the symbiotum, abiotic stress tolerance (e.g. water stress) of the symbiotum, biotic stress tolerance (e.g. disease resistance) of the symbiotum, nutrient use efficiency (e.g. phosphorus use efficiency, nitrogen use efficiency) of the symbiotum.
[0079] The genetic variation may be introduced utilizing any standard techniques, e.g. via one or more of random mutagenesis, di/poly-ploidisation, targeted mutagenesis; cisgenesis; transgenesis; intragenesis.
[0080] In a preferred embodiment, the endophyte(s) may be endophyte variants as described in an Australian patent application filed 1 Jun. 2012 entitled “Designer Endophytes”, to the present applicant, the entire disclosure of which is incorporated herein by reference.
[0081] In a particularly preferred embodiment, the endophyte may be selected from the group consisting of an endophyte variant selected from the group consisting of NEA12dh5, NEA12dh6, NEA12dh13, NEA12dh14, and NEA12dh17, which were deposited at The National Measurement Institute on 3 Apr. 2012 with accession numbers V12/001408, V12/001409, V12/001410, V12/001411 and V12/001412, respectively.
[0082] Such endophytes may have a desired toxin profile as hereinbefore described.
[0083] Preferably, the organism is inoculated with the symbiont such as an endophyte by a method selected from the group consisting of infection, breeding, crossing, hybridization and combinations thereof.
[0084] In one embodiment, the plant may be inoculated by isogenic inoculation. This has the advantage that phenotypic effects of symbionts such as endophytes may be assessed in the absence of host-specific genetic effects. More particularly, multiple inoculations of endophytes may be made in plant germplasm, and regenerated plantlets transferred to soil or other growth medium.
[0085] In another embodiment, a ‘library’ of plant germplasm may be inoculated with multiple symbionts such as endophytes. This has the advantage of enabling favourable host-endophyte associations to be established, identified and selected ab initio.
[0086] The identification of an endophyte of the opposite mating-type that is highly compatible and stable in planta provides a means for molecular breeding of endophytes for perennial ryegrass. Preferably the plant may be infected by hyper-inoculation.
[0087] Hyphal fusion between endophyte strains of the opposite mating-type provides a means for delivery of favourable traits into the host plant, preferably via hyper-inoculation. Such strains are preferably selected from the group including an endophyte strain that exhibits the favourable characteristics of high inoculation frequency and high compatibility with a wide range of germplasm, preferably elite perennial ryegrass and/or tall fescue host germplasm and an endophyte that exhibits a low inoculation frequency and low compatibility, but has a highly favourable alkaloid toxin profile.
[0088] The symbiont-infected, e.g. endophyte-infected plants may be cultured by known techniques. The person skilled in the art can readily determine appropriate culture conditions depending on the plant to be cultured.
[0089] The screening step may include analysing plant metabolites. The metabolites may be analysed by known techniques such as chromatographic techniques or mass spectrometry, for example LCMS or HPLC. In a particularly preferred embodiment, symbiont-infected, e.g. endophyte-infected plants may be analysed by reverse phase liquid chromatography mass spectrometry (LCMS). This reverse phase method may allow analysis of specific metabolites (including lolines, peramine, ergovaline, lolitrem, and janthitrems, such as janthitrem I, janthitrem G and janthitem F) in one LCMS chromatographic run from a single symbiont-infected plant extract.
[0090] In a particularly preferred embodiment, the endophytes may be selected from the group consisting of NEA2, NEA3, NEA6, NEA10, NEA11, NEA12, E1, NEA17, NEA21, NEA23, NEA18, NEA19, NEA16, NEA20, NEA12dh5, NEA12dh6, NEA12dh13, NEA12dh14, NEA12dh17, NEA12-DsRed and IRM1-35.
[0091] In another particularly preferred embodiment, LCMS including EIC (extracted ion chromatogram) analysis may allow detection of the alkaloid metabolites from small quantities of symbiont infected, e.g. endophyte-infected, plant material. Metabolite identity may be confirmed by comparison of retention time with that of pure toxins or extracts of endophyte-infected plants with a known toxin profile analysed under substantially the same conditions and/or by comparison of mass fragmentation patterns, for example generated.
[0092] The genetic analysis may be conducted as described above. The seedlings may for example be screened for symbiont-specific, e.g. endophyte-specific simple sequence repeats (SSRs).
[0093] Alternatively, or in addition, the seedlings may be screened for the presence of favourable symbiota via molecular phenotyping. The molecular phenotyping may be performed utilising the methods described in an Australian provisional patent application filed 1 Jun. 2012 entitled “Molecular phenotyping method”, to the present applicant, the entire disclosure of which is incorporated herein by reference.
[0094] In this method seedlings may be screened for the presence of favourable symbiota via molecular phenotyping. The seedlings may, for example, be assessed for improved alkaloid production and/or improved water soluble carbohydrate:protein ratio. Such techniques may utilise an enzymatic assay, colorimetric assay, SSR markers and/or other metabolomic analysis techniques. Such analyses may be semi- or substantially automated.
[0095] Thus, the method may include screening symbiota for the presence of desirable characteristics, said method including molecular phenotyping a population of symbiota.
[0096] In a preferred embodiment, the method may include assessing the population of symbiota for alkaloid production and/or water soluble carbohydrate (WSC):protein ratio. Preferably this assessment is done using one or more methods selected from the group consisting of enzymatic assays, colorimetric assays, SSR markers and metabolomic analysis.
[0097] In a preferred embodiment, assessment of alkaloid production includes measurement of alkaloid profile and/or content in the population. Preferred alkaloids include peramine, lolitrem B and ergovaline. In a preferred embodiment, alkaloids may be inferred by SSR markers and detected by metabolomic analysis, more preferably a combination of SSR marker and metabolomic analysis are used.
[0098] In another preferred embodiment, WSC:protein ratio may be assessed. WSC may be quantified using an enzymatic assay. In a preferred embodiment, individual concentrations for sucrose, glucose, fructose and fructans may be determined. Protein may be quantified using a colorimetric assay.
[0099] In a particularly preferred embodiment, protein may be quantified by a method including:
extracting proteins from the symbiota using an alkali, such as NaOH, preferably a weak NaOH solution; quantification of proteins using a colorimetric assay, s assay.
[0102] Detection may be carried out, for example, using a plate reader.
[0103] The symbiota may be of any suitable form, including inoculated embryos, plant seeds, germinating seeds, seedlings, plantlets, plants, etc.
[0104] Preferably the seeds are derived from symbiont-infected e.g. endophyte-infected plants e.g. plant/endophyte symbiota.
[0105] In the method according to this aspect of the present invention, the screening step may include screening artificial seeds by accelerated ageing, which is described in an Australian patent application filed 1 Jun. 2012 entitled ‘Method for selection of stable symbiota’, to the present applicant, the entire disclosure of which is incorporated herein by reference.
[0106] That patent application describes a method of assessing the compatibility and/or stability of plant symbiont symbiota, such as plant/endophyte symbiota, said method including:
providing a source of seeds including symbiont such as fungal endophyte inoculated plant embryos; and screening the seeds and/or their offspring for compatibility and/or stability of the plant/symbiont association (i.e. symbiota) such as plant-fungal endophyte symbiota by applying accelerated ageing thereto.
[0109] In the accelerated ageing procedure, the artificial seeds, or their offspring, may be subjected to deteriorative conditions, preferably by means of high temperature and/or increased moisture content. In a particularly preferred embodiment the seeds may be exposed to an environment of high relative humidity. For example, the seeds may be exposed to temperatures of approximately −20 to 50° C., preferably 10 to 45° C., more preferably 15 to 40° C., even more preferably 25 to 40° C. and/or to humidity levels of approximately 60% to 100%, preferably 80% to 100% for periods of e.g. approximately 1 to 30 days, preferably preferably 4 to 7 days.
[0110] Accelerated ageing reduces symbiont e.g. endophyte viability i.e. it allows counter-selection of unstable associations and permits the ranking of symbiota based on their stability.
[0111] Preferably the method includes the further step of subjecting the selected symbiota populations to a rapid symbiont such as fungal endophyte viability assay.
[0112] Accordingly, the method of the present invention may further include assessing the compatibility and/or stability of a plant symbiont association (i.e. symbiotum) such as plant-fungal endophyte symbiota including:
providing a source of seeds including symbiont e.g. fungal endophyte inoculated plant embryos; screening the seeds and/or their offspring for compatibility and/or stability of the plant/symbiont association (i.e. symbiotum) such as plant-fungal endophyte symbiota by applying accelerated ageing thereto; and subjecting the selected symbiota populations to a rapid symbiont such as fungal endophyte viability assay.
[0116] The viability assay step according to this aspect of the present invention may include:
culturing the seeds to generate plantlets, seedlings or germinating seeds; extracting DNA and/or RNA from the plantlets, seedlings or germinating seeds; and subjecting the extracted DNA and/or RNA to an assay for in planta expressed symbiont-specific gene(s), such as fungal endophyte-specific gene(s).
[0120] Preferably the seeds are derived from symbiont-inoculated plants, such as fungal endophyte-inoculated plants.
[0121] Preferably the seeds are artificial seeds, as hereinbefore described.
[0122] The seeds may be from any suitable plant. The plant may be a grass, preferably a perennial grass, legume, vine, shrub, tree, herb, flower, shrub or bush. The method according to this aspect of the present invention is particularly applicable to grasses and legumes.
[0123] The rapid endophyte viability assay is described in an Australian patent application filed 1 Jun. 2012 entitled ‘Method for rapid endophyte viability assessment’, to the present applicant, the entire disclosure of which is incorporated herein by reference.
[0124] Preferably the seeds are cultured for a relatively short period of time, so that a rapid assessment of symbiont viability such as fungal endophyte viability may be obtained. Preferably the seeds are cultured for approximately 1 to 10 days, more preferably 3 to 10 days, more preferably 3 to 7 days, more preferably 3 to 5 days.
[0125] Applicants have found that symbiont specific, e.g. endophyte specific, genes are expressed in this time frame, enabling early in planta symbiont viability assessment.
[0126] In a preferred form the DNA/RNA may be extracted from the leaves of seedlings, more preferably from the epicotyl, hypocotyl or similar embryonic shoot of the seedlings. In grasses, the DNA/RNA may be extracted from tillers. In another preferred form the DNA/RNA may be extracted from whole germinating seeds.
[0127] Preferably the RNA and DNA may be co-extracted, preferably in a single step. Preferably, the DNA/RNA may be extracted from 1 to 10 day-old, preferably 3 to 10 day old, more preferably 3 to 7 day old, more preferably 3 to 5 day-old epicotyls, hypocotyls or similar embryonic shoots of seedlings, in order to accelerate the process.
[0128] The assay may be an assay used to amplify and simultaneously quantify a targeted DNA/RNA molecule in the extracted DNA/RNA. Preferably the assay is a quantitative real-time polymerase chain reaction (Q-PCR/qRT-PCR) assay, or kinetic polymerase chain reaction (KPCR) assay. In a particular the assay may be a TaqMan or similar assay.
[0129] The symbiont specific genes such as endophyte specific genes may be of any suitable type. Preferably it is only, highly or mainly expressed in planta. Fungal endophyte genes encoding the proteins 7490, 8263, 0005 and 2232 are particularly preferred.
[0130] Primers are designed for amplification of the targeted gene(s) by methods known to those skilled in the art.
[0131] The seeds may be from any suitable plant. The plant may be a grass, preferably a perennial grass, legume, vine, shrub, tree, herb, flower, shrub or bush. The method according to this aspect of the present invention is particularly applicable to grasses and legumes.
[0132] Preferably the seeds are derived from symbiont-infected plants such as fungal endophyte-infected plants e.g. plant/endophyte symbiota.
[0133] The method according to this aspect of the present invention may further include subjecting the selected symbiota populations to phenotyping for assessment of symbiota performance and/or maintenance of desired characteristics; and selecting symbiota for poly-crossing to generate a synthetic symbiota variety, for example by polycrossing.
[0134] For example, the selected symbiota variety may be subjected to a symbiont identification assay, such as an endophyte identification assay, followed by polycrossing to generate a next generation seed. Optionally, the above steps may be repeated to confirm symbiota stability, desired characteristics, symbiont e.g. fungal endophyte identity and/or symbiont e.g. fungal endophyte incidence in the next seed generation.
[0135] Accordingly, in a further aspect of the present invention, there is symbiota including one or more plants containing one or more symbionts such as fungal endophytes produced utilising the method described above.
[0136] The plant may be a grass, tree, flower, herb, shrub or bush, vine or legume, or a product thereof.
[0137] The method steps described above may be repeated to develop later generations of symbiota seeds or plants.
[0138] In a further aspect, the present invention provides a plant, plant seed or other plant part derived from an artificial seed or symbiont-containing plant of the present invention and stably infected with a symbiont such as a fungal endophyte.
[0139] Preferably, the plant cell, plant, plant seed or other plant part is a grass, more preferably a forage, turf or bioenergy grass, such as those of the genera Lolium and Festuca , including L. perenne and L. arundinaceum and of the genera Brachiaria and Urochloa , including B. brizantha, B. decumbens, B. humidicola and U. mosambicensis.
[0140] By ‘plant cell’ is meant any self-propagating cell bounded by a semi-permeable membrane and containing plastid. Such a cell also required a cell wall if further propagation is desired. Plant cell, as used herein includes, without limitation, seeds suspension cultures, embryos, meristematic regions, callus tissue, leaves, roots, shoots, gametophytes, sporophytes, pollen and microspores.
[0141] As used herein, except where the context requires otherwise, the term “comprise” and variations of the term, such as “comprising”, “comprises” and “comprised”, are not intended to exclude further additives, components, integers or steps.
[0142] Reference to any prior art in the specification is not, and should not be taken as, an acknowledgment or any form of suggestion that this prior art forms part of the common general knowledge in Australia or any other jurisdiction or that this prior art could reasonably be expected to be ascertained, understood relevant by a person skilled in the art.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0143] In the figures:
[0144] FIG. 1 shows artificial seeds generated through Ca-alginate coating of perennial ryegrass embryos using a coating with Ca-alginate matrix without added nutrients.
[0145] FIG. 2 shows Ca-alginate coating of perennial ryegrass embryos into artificial seeds using coating with coloured Ca-alginate matrix. Artificial seeds of perennial ryegrass coloured with Queen Green (90610); a) air-dried artificial seeds; b) artificial seeds plated on germination medium. Artificial seeds of perennial ryegrass coloured with Queen Pink (92330); c) air-dried artificial seeds; d) artificial seeds plated on germination medium.
[0146] FIG. 3 shows Ca-alginate coating of perennial ryegrass embryos into artificial seeds using coating with multiple Ca-alginate matrix layers. a) Artificial seeds of perennial ryegrass coated with first coating (non-coloured) Ca-alginate layer (layer A) with added nutrients. b) Artificial seeds of perennial ryegrass coated with two (first layer A; non-coloured plus second layer B; Queen Green-coloured) Ca-alginate layers with added nutrients; c) double-coated artificial seeds placed on germination medium.
[0147] FIG. 4 shows Ca-alginate coating of perennial ryegrass embryos into artificial seeds using coating with multiple Ca-alginate matrix layers. a)-c) Cross-sections of artificial seeds of perennial ryegrass coated with first coating (non-coloured) Ca-alginate layer (layer A) and second coating with Queen-Pink or Queen-Green coloured Ca-alginate layer (layer B). d)-e) Cross-sections of artificial seeds of perennial ryegrass coated with first coating (non-coloured) Ca-alginate layer (layer A) and second coating with Queen-Green coloured Ca-alginate layer (layer B).
[0148] FIG. 5 shows germination of seeds, embryos and artificial seeds of perennial ryegrass cv. Bronsyn E− (endophyte free, 2668 seed batch). a) Original seeds: 1° A germination frequency on filter paper; b) Surface-sterilized seeds: 10% germination frequency on filter paper; c) Isolated embryos: 48% germination frequency on germination medium; d) Artificial seeds (with germination medium): 40% germination frequency on MS medium.
[0149] FIG. 6 shows germination of seeds, embryos and artificial seeds of perennial ryegrass cv. Bronsyn E+ (endophyte plus, 2667 seed batch). a) Original seeds: 10% germination frequency on filter paper; b) Surface-sterilized seeds: 30% germination frequency on filter paper; c) Isolated embryos: 90% germination frequency on germination medium; d) Artificial seeds (with germination medium): 81% germination frequency on MS medium.
[0150] FIG. 7 shows germination of artificial seeds and development of artificial-seed derived seedlings in perennial ryegrass.
[0151] FIG. 8 shows freshly isolated seed-derived embryos of perennial ryegrass individually placed in wells of a) 96-well and b) endophyte mycelium suspension added to individual wells and allowed to partly air-dry under laminar flow prior to c) production of artificial seeds coated with Ca-alginate layer.
[0152] FIG. 9 shows artificial seeds produced by method 1.
[0153] FIG. 10 shows germinating artificial seeds produced by method 1.
[0154] FIG. 11 shows artificial seeds produced by method 2.
[0155] FIG. 12 shows artificial seeds produced by method 2 with endophyte outgrowth.
[0156] FIG. 13 shows artificial seeds produced by method 3.
[0157] FIG. 14 shows artificial seeds produced by method 3 with endc
[0158] FIG. 15 shows germinating artificial seeds produced by method 3.
[0159] FIG. 16 shows endophyte suspensions at different dilution rates.
EXAMPLE 1
Method for Large-Scale Generation of Grass-Endophyte Symbiota (Artificial Seeds)
[0160] The objective of the work was to develop an efficient, robust and low-cost method for large-scale production of grass endophyte symbiota. The method should be:
a) applicable to inoculation of 10 s-100 s of endophyte in 100 s-1000 s of grass genotypes; b) applicable to perennial ryegrass, tall fescue and Brachiaria ; and c) applicable to inoculation of novel and designer endophytes with de novo generated genetic variation [i.e. induced mutagenesis (ionizing radiation, colchicine), targeted mutagenesis, transgenesis, cisgenesis, intragenesis, etc.].
[0164] The method should further enable next-generation ab initio molecular breeding, selection and evaluation of grass-endophyte symbiota [rather than breeding and selection of grass host followed by endophyte inoculation and symbiota evaluation only].
[0165] The experimental strategies—and corresponding experimental steps—implemented include:
1. Large-Scale Perennial Ryegrass Seed-Derived Embryo Isolation and Artificial Seed Production
[0166] A. Develop an efficient, low-cost, large-scale seed surface-sterilization method;
B. Develop an efficient, low-cost, large-scale seed-derived embryo isolation method;
C. Develop an efficient, low-cost, large-scale artificial seed production method;
D. Test germination frequency and germination stages of artificial seeds;
E. Assess endophyte presence in seedlings derived from artificial seeds generated with embryos isolated from endophyte-plus seeds;
2. Large-Scale Endophyte Inoculation into Perennial Ryegrass Artificial Seeds
F. Develop an efficient, low-cost, large-scale endophyte inoculation method for artificial seeds [based on seed-derived embryo inoculation with endophyte mycelium followed by artificial seed production including double/multiple coating (inner layer plus endophyte, outer layer as ‘pseudo-aleurone/endosperm’) of artificial seeds]; and
G. Assess endophyte presence in seedlings derived from artificial seeds generated with embryos isolated from endophyte-minus seeds inoculated with novel endophytes.
Large-Scale Perennial Ryegrass Seed-Derived Embryo Isolation and Artificial Seed Production
A) Seed Surface Sterilization Method
[0167] The seed surface sterilization method implemented includes the following steps:
[0168] Day 1: seeds were soaked in 10% sulphuric acid overnight.
[0169] Day 2: treated with 10% Domestos for 20 min and stored at 24 C after wash with distilled sterile water.
[0170] Day 3: treated with 10% Domestos for 20 min and stored at 2 distilled sterile water, followed by embryo isolation [see B) below].
[0171] Four independent experiments were conducted with 200 seeds each.
[0172] No bacterial or fungal contamination was observed.
B) Embryo Isolation Method
[0173] Based on the successful surface-seed sterilization method [see A) above], 1,000 ryegrass seed-derived embryos can be isolated by one person within 4 hours.
Artificial Seed Production Method
[0174] Ca-Alginate Coating of Perennial Ryegrass Embryos into Artificial Seeds
i) Coating with Ca-Alginate Matrix without Added Nutrients
[0175] For the Ca-alginate coating of perennial ryegrass embryos into artificial seeds using a coating with Ca-alginate matrix without added nutrients, the following steps were undertaken:
Embryos were freshly isolated and mixed with 3% sodium alginate solution. Alginate drops were placed into 50 mM calcium chloride solution while stirring at 60 rpm. Each drop contains one embryo. Artificial seeds were collected after 15 min stirring and washed with sufficient distilled sterile water.
[0179] Artificial seeds were placed on germination medium MS or MS+1 mg/L BAP.
[0180] FIG. 1 shows artificial seeds generated through Ca-alginate coating of perennial ryegrass embryos using a coating with Ca-alginate matrix without added nutrients.
[0000] ii) Coating with Ca-Alginate Matrix with Added Nutrients
[0181] For the Ca-alginate coating of perennial ryegrass embryos into artificial seeds using a coating with Ca-alginate matrix with added nutrients, the following steps were undertaken:
Embryos were freshly isolated and mixed with 3% sodium alginate in modified MS medium consisting of MS (without CaCl2)+750 mg/L glutamine+5 μM CuSO 4 +1.95 g/L MES. Alginate drops (containing individual embryos) were placed in 50 mM calcium chloride solution while stirring at 60 rpm. Each drop contains a single seed-derived isolated embryo. Artificial seeds were collected after 15 min stirring and thoroughly washed with distilled sterile water. Artificial seeds were placed on MS medium plates for germination.
iii) Coating with Coloured Ca-Alginate Matrix
[0187] For the Ca-alginate coating of perennial ryegrass embryos into artificial seeds using a coating with coloured Ca-alginate matrix with added nutrients, the following steps were undertaken:
[0188] Embryos were freshly isolated and mixed with 3% sodium alginate in modified MS medium consisting of MS (without CaCl2)+750 mg/L glutamine+5 μM CuSO 4 +1.95 g/L MES.
[0189] Different food dyes [i.e. 10 μL/ml Queen Green (90610) or Queen Pink (92330)] were added to the sodium alginate coating solution to colour coating matrix thus establishing basis to demonstrate potential for multi-layer coating.
[0190] Alginate drops (containing individual embryos) were placed in 50 mM calcium chloride solution while stirring at 60 rpm.
[0191] Each drop contains a single seed-derived isolated embryo.
[0192] Artificial seeds were collected after 15 min stirring and thoroughly washed with distilled sterile water.
[0193] Artificial seeds were placed on MS medium plates for germination.
[0194] FIG. 2 shows Ca-alginate coating of perennial ryegrass embryos into artificial seeds using coating with coloured Ca-alginate matrix.
[0000] iv) Coating with Multiple Ca-Alginate Matrix Layers
[0195] For the Ca-alginate coating of perennial ryegrass embryos into artificial seeds using a coating with multiple Ca-alginate matrix layers, the following steps were undertaken:
Embryos were freshly isolated and mixed with 3% sodium alginate in modified MS medium [consisting of MS (without CaCl 2 )+750 mg/L glutamine+5 μM CuSO 4 +1.95 g/L MES] as the first coating layer (layer A) to make artificial seeds. Alginate drops (containing individual embryos) were placed in 50 mM calcium chloride solution while stirring at 60 rpm. Each drop contains a single seed-derived isolated embryo. Artificial seeds coated with layer A were collected after 15 min stirring and thoroughly washed with distilled sterile water. The average diameter of the artificial seed freshly coated with layer A is 4 mm. Artificial seeds coated with layer A were placed in Petri dish and allowed to air-dry for 1-2 hours in a laminar flow cabinet. The diameter of the air-dried artificial seed coated with layer A is 2 mm. Air-dried artificial seeds coated with layer A were mixed with 3% sodium alginate in modified MS medium [consisting of MS (without CaCl2)+750 mg/L glutamine+5 μM CuSO 4 +1.95 g/L MES] coloured with food dye [i.e. 10 μL/ml Queen Green (90610)] as the second coating layer (layer B) to make double-coated artificial seeds; following the same procedure.
[0200] FIG. 3 shows Ca-alginate coating of perennial ryegrass em seeds using coating with multiple Ca-alginate matrix layers.
[0201] FIG. 4 shows Ca-alginate coating of perennial ryegrass embryos into artificial seeds using coating with multiple Ca-alginate matrix layers.
[0202] Freshly isolated seed-derived embryos of perennial ryegrass are individually placed in wells of a) 96-well or b) 384-well plates. With the aid of a disposable syringe sodium alginate solution is added to the individual wells and single embryos in alginate solutions are loaded in the syringe. With the aid of the syringe individual embryos coated with alginate solution are dropped into polymerising CaCl2 solution under agitation for production of artificial seeds. The use of 96-well plate is preferred over the 384 well plate for production of artificial seeds of perennial ryegrass.
Assessing Germination Frequency of Artificial Seeds
[0203] In order to assess germination frequency of artificial seeds, the following steps were undertaken:
[0000] Germination of Seeds, Embryos and Artificial Seeds of Perennial Ryegrass Cv. Bronsyn E. (Endophyte Free, 2668 Seed Batch)
[0204] Seed germination frequency was comparatively assessed for ( FIG. 5 ):
[0000] a) Original seeds: 1% germination frequency on filter paper;
b) Surface-sterilized seeds: 10% germination frequency on filter paper;
c) Isolated embryos: 48% germination frequency on germination medium;
d) Artificial seeds (with germination medium): 40% germination frequency on MS medium.
Germination of Seeds, Embryos and Artificial Seeds of Perennial Ryegrass Cv. Bronsyn E+ (Endophyte Plus, 2667 Seed Batch)
[0205] Seed germination frequency was comparatively assessed for ( FIG. 6 ):
[0000] a) Original seeds: 10% germination frequency on filter paper;
b) Surface-sterilized seeds: 30% germination frequency on filter paper;
c) Isolated embryos: 90% germination frequency on germination medium;
d) Artificial seeds (with germination medium): 81% germination frequency on MS medium.
[0206] FIG. 7 shows germination of artificial seeds and development of artificial-seed derived seedlings in perennial ryegrass.
[0000] Assessing Endophyte Presence in Seedlings Derived from Artificial Seeds
[0207] In order to assess endophyte presence in seedlings derived from artificial seeds, the following experiments were undertaken:
[0000] Endophyte Presence in Seedlings Derived from Seeds and Artificial Seeds of Perennial Ryegrass Seed Cv. Bronsyn E+ (Endophyte Plus, 2667 Seed Batch)
[0208] Twenty seedlings of Bronsyn E + (2667) seeds germinated on filter paper were transferred to soil.
[0209] Twenty five seedlings from germinated artificial seeds generated with Bronsyn E plus (2667) seed-derived embryos were transferred to soil. The embryos in artificial seeds were sterilized using 10% H 2 SO 4 overnight treatment.
[0210] Following 6 week grow-out of seedlings derived from seeds a endophyte presence was assessed based on endophyte-specific SSR test.
[0211] Twenty seedlings of Bronsyn E. plus (2667; containing ST endophyte) seeds germinated on filter paper were transferred to soil, leading to 13 of 19 seedlings (68%) testing positive for ST endophyte presence in the endophyte-specific SSR test.
[0212] Twenty five seedlings from germinated artificial seeds generated with Bronsyn E plus (2667) seed-derived embryos were transferred to soil. The embryos in artificial seeds were sterilized using 10% H 2 SO 4 overnight treatment, leading to 19 of 23 seedlings (83%) testing positive for ST endophyte in the endophyte-specific SSR test, clearly indicating that the methods for seed surface sterilization, large-scale embryo isolation, and artificial seed production with Ca-alginate coating do not negatively affect viability of a resident endophyte.
Large-Scale Inoculation of Endophytes in Perennial Ryegrass Artificial Seeds
[0213] Different methods for the large-scale inoculation of endophytes in perennial ryegrass artificial seeds were developed, with examples of methods 1 to 3 described below:
[0000] Inoculation of Isolated Seed-Derived Embryos with Endophyte Mycelium and Production of Endophyte-Infected Artificial Seeds in Perennial Ryegrass
[0214] Freshly isolated seed-derived embryos of perennial ryegrass are individually placed in wells of a) 96-well and b) endophyte mycelium suspension added to individual wells and allowed to partly air-dry under laminar flow prior to c) production of artificial seeds coated with Ca-alginate layer ( FIG. 8 ).
[0000] Method 1: Direct Inoculation of Isolated Embryos with Endophyte Suspension Prior to Ca-Alginate Coating
[0215] Method 1, inoculation of isolated seed-derived embryos with er and production of endophyte-infected artificial seeds in perennial ryegrass, is based on direct inoculation of isolated embryos with endophyte suspension prior to Ca-alginate coating as follows:
[0216] Freshly isolated embryos of perennial ryegrass are incubated with endophyte suspension ( 1/16 dilution) for 30 mins at RT in individual wells of 96-well plates.
[0217] Inoculation suspension is removed from well and inoculated embryos are allowed to partly air-dry on filter paper disks.
[0218] Artificial seeds are produced ( FIG. 9 ) with endophyte-inoculated embryos with 3% sodium alginate-containing modified MS growth medium [MS (without CaCl 2 )+750 mg/L glutamine+5 μM CuSO 4 +1.95 g MES+1 mg/l BAP].
[0219] Artificial seeds are allowed to germinate on MS medium for germination.
[0220] Freshly isolated embryos of perennial ryegrass are directly inoculated with endophyte suspension (⅛ dilution), partly air-dried and then coated with Ca-alginate in individual wells of 96-well plates.
[0221] Artificial seeds from perennial ryegrass directly inoculated with endophyte and then coated with Ca-alginate layer are able to germinate on MS germination medium ( FIG. 10 ).
[0000] Method 2: Direct Coating of Isolated Embryos with Endophyte-Containing Ca-Alginate Layer
[0222] Method 2, inoculation of isolated seed-derived embryos with endophyte mycelium and production of endophyte-infected artificial seeds in perennial ryegrass, is based on direct coating of isolated embryos with endophyte-containing Ca-alginate layer as follows:
[0223] Embryos of perennial ryegrass are freshly isolated in endophyte dilution) in individual wells of 96-well plates.
[0224] Two-fold concentration sodium alginate (6%) modified MS medium [MS (without CaCl 2 )+750 mg/L glutamine+5 μM CuSO 4 +1.95 g MES+1 mg/l BAP] is added to the individual wells to coat embryos with an endophyte-containing alginate layer.
[0225] Artificial seeds are produced with endophyte-layer coated embryos ( FIG. 11 ).
[0226] Artificial seeds are allowed to germinate on MS medium for germination.
[0227] Embryos of perennial ryegrass are freshly isolated and coated with endophyte suspension (⅛ or 1/16 dilutions) with Ca-alginate then added to generate an endophyte-containing alginate layer coating the embryos in individual wells of 96-well plates.
[0228] Following culture, endophyte out-growth is observed from the endophyte-containing alginate layer used to coat the isolated embryos of perennial ryegrass (irrespectively of endophyte suspension dilution rate used; FIG. 12 ) demonstrating viability of the endophyte included in the Ca-alginate coating layer.
[0000] Method 3: Double-Coating of Artificial Seeds Generated from Endophyte Inoculated Isolated Embryos
[0229] Method 3, inoculation of isolated seed-derived embryos with endophyte mycelium and production of endophyte-infected artificial seeds in perennial ryegrass, is based on double-coating of artificial seeds generated from endophyte-inoculated isolated embryos as follows:
[0230] Freshly isolated embryos of perennial ryegrass are coated with an endophyte suspension ( 1/16 dilution), mixed with alginate [6% Ca-alginate in modified MS medium (without CaCl 2 )+750 mg/L glutamine+5 μM CuSO 4 +1.95 g MES+1 mg/l BAP] to generate a first coating layer containing endophytes in 96-well plates.
[0231] Artificial seeds with a first endophyte-containing alginate layer coating freshly isolated embryos of perennial ryegrass are blot-dried on filter paper in laminar air flow for 30 mins and then coated with a second alginate layer of 3% Ca-alginate without any nutrients.
[0232] Double-coated artificial seeds with endophyte-containing layer coated embryos of perennial ryegrass are then germinated on MS medium.
[0233] Second coating with nutrient deprived medium of endophyte-inoculated artificial seeds aims to reduce endophyte out-growth during germination and restrict endophyte growth in close proximity to isolated perennial ryegrass embryo ( FIG. 13 ).
[0234] Artificial seeds with a first endophyte-containing alginate layer coating freshly isolated embryos of perennial ryegrass are blot-dried on filter paper in laminar air flow for 30 mins and then coated with a second alginate layer of 3% Ca-alginate without any nutrients.
[0235] Endophyte growth is mainly restricted to inner alginate coating layer for a period of up to 3 weeks ( FIG. 14 ).
[0236] Embryos of perennial ryegrass are freshly isolated directly in endophyte suspension (⅛ dilution), then partly air-died and coated with a first alginate layer [3% Ca-alginate in modified MS medium (without CaCl 2 )+750 mg/L glutamine+5 μM CuSO 4 +1.95 g MES+1 mg/l BAP] in individual wells of 96-well plates.
[0237] Artificial seeds with directly endophyte-inoculated embryos of perennial ryegrass are stored at 4 C overnight and then coated with a second alginate layer of 3% Ca-alginate without any nutrients.
[0238] Double-coated artificial seeds with directly endophyte-inoculated perennial ryegrass are then germinated on MS medium.
[0239] Double-coated artificial seeds with directly endophyte-inoculated embryos of perennial ryegrass germinated on MS medium show germination rates comparable to the original seed batch used for embryo isolation ( FIG. 15 ).
[0000] Assessing Endophyte Presence in Seedlings Derived from Artificial Seeds with Seed-Derived Embryos Inoculated with Novel Endophytes
[0240] In order to assess endophyte presence in seedlings derived from artificial seeds with seed-derived embryos inoculated with novel endophytes (e.g. NEA11) using Method 1, the following experiment was undertaken:
[0000] Endophyte Presence in Seedlings Derived from Artificial Seeds Produced with Embryos from Perennial Ryegrass Seed Cv. Bronsyn E− (Endophyte Minus, 2668 Seed Batch) Inoculated with Novel Endophyte NEA11
[0241] Following 6 week grow-out of seedlings derived from artificial seeds, endophyte presence was assessed based on endophyte-specific SSR test.
[0242] Twenty-three seedlings from germinated artificial seeds generated with Bronsyn E minus (2668) seed-derived embryos inoculated with NEA11 using Method 1 were transferred to soil. 6 of 23 seedlings (i.e. 26%) tested positive for NEA11 endophyte presence in the endophyte-specific SSR test demonstrating the establishment of symbiota (Table 1). Endophyte presence in symbiota established from germinated artificial seeds generated with perennial ryegrass seed-derived embryos inoculated with novel endophyte NEA11 using Method 1 was confirmed following 3 months after transfer to soil.
[0000]
TABLE 1
Assessing Endophyte Presence in Seedlings Derived from Artificial
Seeds with Seed-Derived Embryos Inoculated with Novel Endophytes
SSR Marker
NLESTA1QA09
NLESTA1NG03
NLESTA1CC05
Endophyte
Seedling
Allele 1
Allele 2
Allele 1
Allele 2
Allele 1
Allele 2
detected
2668_4
153
184
226
167
NEA11
2668_15
153
184
226
167
NEA11
2668_1
153
184
226
167
NEA11
2_2
153
184
226
167
NEA11
2668 Bb1
153
184
226
167
NEA11
2668_13
153
184
226
167
NEA11
Large-Scale Inoculation of Designer Endophytes in Perennial Ryegrass Artificial Seeds
[0243] Large-scale inoculation of designer endophytes derived from induced mutagenesis through colchicine-treatment (e.g. NEA12dh17) or derived from X-ray mutagenesis (e.g. IRM1-35) in perennial ryegrass artificial seeds is carried out using methods 1 to 3 described above.
[0244] Freshly isolated embryos of perennial ryegrass are incubated with designer endophyte (e.g. NEA12dh17, IRM1-35) suspension ( 1/16 dilution) for 30 mins at RT in individual wells of 96-well plates.
[0245] Inoculation suspension is removed from well and inoculated embryos are allowed to partly air-dry on filter paper disks.
[0246] Artificial seeds are produced with designer endophyte-inoculated embryos with 3% sodium alginate-containing modified MS growth medium [MS (without CaCl 2 )+750 mg/L glutamine+5 μM CuSO 4 +1.95 g MES+1 mg/l BAP].
[0247] Artificial seeds are allowed to germinate on MS medium for germination.
[0248] Freshly isolated embryos of perennial ryegrass are directly inoculated endophyte (e.g. NEA12dh17, IRM1-35) suspension (⅛ dilution), partly air-dried and then coated with Ca-alginate in individual wells of 96-well plates.
[0249] Artificial seeds from perennial ryegrass directly inoculated with designer endophytes (e.g. NEA12dh17, IRM1-35) and then coated with Ca-alginate layer are able to germinate on MS germination medium leading to the establishment of symbiota. Designer endophyte presence and identity in the symbiota generated following large-scale inoculation of designer endophytes derived from induced mutagenesis through colchicine-treatment (e.g. NEA12dh17) or derived from X-ray mutagenesis (e.g. IRM1-35) in perennial ryegrass artificial seeds is demonstrated using an endophyte-specific SSR test.
Large-Scale Inoculation of Transgenic Endophytes in Perennial Ryegrass Artificial Seeds
[0250] Large-scale inoculation of transgenic endophytes derived from genetic transformation of NEA12 endophyte with plasmid containing a chimeric gene for expression of the DsRed fluorescent marker gene (e.g. NEA12-DsRed) in perennial ryegrass artificial seeds is carried out using method 1 described above.
[0251] Freshly isolated embryos of perennial ryegrass are incubated with transgenic endophyte (e.g. NEA12-DsRed) suspension ( 1/16 dilution) for 30 mins at RT in individual wells of 96-well plates.
[0252] Inoculation suspension is removed from well and inoculated embryos are allowed to partly air-dry on filter paper disks.
[0253] Artificial seeds are produced with transgenic endophyte-inoculated embryos with 3% sodium alginate-containing modified MS growth medium [MS (without CaCl 2 )+750 mg/L glutamine+5 μM CuSO 4 +1.95 g MES+1 mg/l BAP].
[0254] Artificial seeds are allowed to germinate on MS medium for germination.
[0255] Freshly isolated embryos of perennial ryegrass are directly inoculated with transgenic endophyte (e.g. NEA12-DsRed) suspension (⅛ dilution), partly air-dried and then coated with Ca-alginate in individual wells of 96-well plates.
[0256] Artificial seeds from perennial ryegrass directly inoculated with transgenic endophyte (e.g. NEA12-DsRed) and then coated with Ca-alginate layer are able to germinate on MS germination medium leading to the establishment of symbiota with transgenic endophytes. Transgenic endophyte presence and identity in the symbiota generated following large-scale inoculation of transgenic endophyte (e.g. NEA12-DsRed) in perennial ryegrass artificial seeds is demonstrated using an endophyte-specific SSR and transgene-specific PCR test.
Large-Scale Inoculation of Novel Endophytes in Tall Fescue Artificial Seeds
[0257] Large-scale inoculation of novel endophytes from tall fescue (e.g. NEA17, NEA19, NEA20) in tall fescue artificial seeds is carried out using method 1 described above.
[0258] Freshly isolated embryos of tall fescue are incubated with novel fescue endophytes (e.g. NEA17, NEA19, NEA20) suspension ( 1/16 dilution) for 30 mins at RT in individual wells of 96-well plates.
[0259] Inoculation suspension is removed from well and inoculated embryos are allowed to partly air-dry on filter paper disks.
[0260] Artificial seeds are produced with novel endophyte-inoculated embryos with 3% sodium alginate-containing modified MS growth medium [MS (without CaCl 2 )+750 mg/L glutamine+5 μM CuSO 4 +1.95 g MES+1 mg/l BAP].
[0261] Artificial seeds are allowed to germinate on MS medium for germination.
[0262] Freshly isolated embryos of tall fescue are directly inoculated endophytes (e.g. NEA17, NEA19, NEA20) suspension (⅛ dilution), partly air-dried and then coated with Ca-alginate in individual wells of 96-well plates.
[0263] Artificial seeds from tall fescue directly inoculated with novel fescue endophytes (e.g. NEA17, NEA19, NEA20) and then coated with Ca-alginate layer are able to germinate on MS germination medium leading to the establishment of symbiota. Novel endophyte presence and identity in the symbiota generated following large-scale inoculation of novel fescue endophytes (e.g. NEA17, NEA19, NEA20) in tall fescue artificial seeds are demonstrated using an endophyte-specific SSR test.
EXAMPLE 2
Endophyte Inoculation Method in Perennial Ryegrass
[0264] This example describes enhancement of endophyte inoculation frequency following puncturing isolated embryos of perennial ryegrass with an hypodermic needle prior to inoculation using method 1 (direct inoculation) or method 2 (coating with endophyte containing Ca-alginate layer).
[0265] Embryos isolated from perennial ryegrass seeds were inoculated with endophyte NEA11 using either methods 1 or 2, with endophyte suspensions at different dilution rates (¼, ⅛, 1/16; see FIG. 16 ) subjected, with and without wounding of embryos with a hypodermic needle. Puncturing of embryos prior to inoculation greatly enhanced inoculation efficiency, demonstrated by SSR-based endophyte detection in 6 week old symbiota recovered from artificial seeds derived from inoculated embryos (see Table 2).
[0000]
TABLE 2
Number and frequency of endophyte-inoculated perennial
ryegrass plants recovered following different endophyte
inoculation treatment methods
PDB
Endophyte Detected
Treatment
Method
conc
Wounding
NEA11
E-
Inoculation %
A
1
1/16
No
0
42
0
B
1
1/8
No
0
42
0
C
1
1/8
Puncture
11
29
27.5
D
2
1/16
No
0
42
0
E
2
1/8
No
0
42
0
F
2
1/8
Puncture
9
9
50
Method 1: Direct Inoculation of Isolated Embryos with Endophyte Suspension Prior to Ca-Alginate Coating
Method 2: Direct Coating of Isolated Embryos with Endophyte-Containing Ca-Alginate Layer
EXAMPLE 3
Endophyte Inoculation Method in Perennial Ryegrass and Tall Fescue
[0266] This example describes enhancement of endophyte inoculation frequency following puncturing isolated embryos of perennial ryegrass ( L. perenne ) and tall fescue ( F. arundinacea ) with an hypodermic needle prior to inoculation using method 1 (direct inoculation) or method 2 (coating with endophyte containing Ca-alginate layer).
[0000] Method 1: Direct Inoculation of Isolated Embryos with Endophyte Suspension Prior to Ca-Alginate Coating
Method 2: Direct Coating of Isolated Embryos with Endophyte-Containing Ca-Alginate Layer
[0267] Embryos isolated from seeds from different varieties were inoculated with different endophytes (NEA11 and NEA17) using either methods 1 or 2, with and without wounding of embryos with hypodermic needle. Puncturing of embryos prior to inoculation greatly enhanced inoculation efficiency, demonstrated by SSR-based endophyte detection in 6 week-old symbiota recovered from artificial seeds derived from inoculated embryos (see Table 3).
[0000]
TABLE 3
Number and frequency of endophyte-inoculated perennial ryegrass and tall fescue
plants recovered following different endophyte inoculation treatment methods
No. of artificial seeds
No. of artificial seeds
Method 1
Method 1 plus wounding
Species
Variety
Experiment
Endophyte
Total
Negative
Positive
Total
Negative
Positive
L. perenne
Alto
1
NEA11 (LpTG-2)
42
42
0
20
16
4
2
NEA11 (LpTG-2)
21
21
0
21
20
1
3
NEA11 (LpTG-2)
84
84
0
40
29
11
F. arundinacea
Dovey
1
NEA11 (LpTG-2)
42
42
0
40
39
1
L. perenne
Alto
1
NEA17 (FaTG-2)
42
42
0
42
42
0
F. arundinacea
Dovey
1
NEA17 (FaTG-2)
70
70
0
35
35
0
Finesse
2
NEA17 (FaTG-2)
42
42
0
70
70
0
No. of artificial seeds
No. of artificial seeds
Method 2
Method 2 plus wounding
Species
Variety
Experiment
Endophyte
Total
Negative
Positive
Total
Negative
Positive
L. perenne
Alto
1
NEA11 (LpTG-2)
84
84
0
18
9
9
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The present invention relates to new methods of selecting and breeding organisms, in particular organisms which exhibit symbiotic behaviour with symbionts such as fungal endophytes or epiphytes or bacterial microbiome in plants, and to new organisms and symbiota developed thereby. More particularly, the present invention provides artificial seeds comprising symbiota, and methods for preparing and using such artificial seeds, as well as plants, plant seeds and other plant parts derived from artificial seeds or symbiont-containing plants of the present invention.
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BACKGROUND OF THE INVENTION
Prior art heat exchangers and evaporative processes as employed for refrigeration and the like have recognized drawbacks which thus far have defied correction. Evaporators for refrigeration systems, air conditioning and other uses commonly employ an interior liquid running in a conduit whose walls transfer heat to the running liquid from an exterior fluid which may be gas or liquid requiring cooling. The interior liquid within the conduit undergoes evaporation and continually is converted into a gas. Until this conversion is complete, the interior running fluid is a gas and liquid mixture. The percentage of gas in the mixture increases until the interior fluid is all gas and no liquid and the evaporative process is completed.
In this gradual evaporative process, a gas bubble film tends to develop on the interior surface of the conduit for the running liquid and this film greatly hinders the transfer of heat through the wall of the conduit or tube to the liquid internally of the gas bubble film. In order to minimize this hinderance to efficient heat transfer, the interior running mixture must be propelled with a turbulent velocity to break up the gas bubble film in order to increase heat transfer efficiency. This, in turn, requires a greater consumption of energy.
Additionally, as the percentage of gas in the interior running fluid increases, the heat transfer hinderance factor correspondingly increases. For example, when the mixture becomes 60% gas and 40% liquid, the heat transfer rate in that part of the conduit drops to 40%, and in the area where the mixture is 90% gas and 10% liquid, the heat transfer rate drops to only 10%. Since a constant size tube or conduit is ordinarily employed in an evaporator, the average heat transfer rate all along the conduit is only about 50% of the true capacity of the heat exchanger or evaporator.
To increase the velocity and turbulence of the interior running fluid mixture not only consumes energy but increases internal friction which heats up the inside liquid. This obviously further decreases the ability of the system to transfer heat from the exterior fluid to the interior fluid. To cope with these two disadvantages, the heat transfer area (tube size) must be increased to increase the volume of internal liquid. It is also necessary to increase the energy of devices necessary for the removal of the interior liquid. In practice, a virtual dilemna is created. Because the exterior fluid such as air also has zones of unequal temperatures, the heat exchanger must simultaneously cope with unequal heat loads in different areas. This makes it impossible to choose a single efficient internal running fluid gas-liquid ratio. It follows from this that if a heavily heat loaded area of the exchanger would be cooled by a weakened liquid mixture, say 80% gas and 20% liquid, then, according to the above-explained process, the weakened liquid mixture and the lowest heat transfer capacity area will be asked to satisfy the heaviest heat transfer requirement which will be an impossibility. This phenomena compels the use of oversized heat exchanger components (a waste of material) and the maintenance of increased internal and external turbulent fluid flow (a waste of energy).
In addition to all of this, there is another inherent disadvantage in conventional heat exchangers concerning the interior working pressure determining temperature of evaporation of the liquid which is critical to system design. If the interior heat load rises, the inside liquid evaporating temperature also rises. As a consequence, the temperature differential between the interior and exterior fluids is diminished and this also requires additional enlargement of the heat transfer wall sides to meet requirements. The resulting over-dimensioning of the heat exchanger structure is wasteful of metal and labor.
SUMMARY OF THE INVENTION
To overcome the above-discussed inherent drawbacks of the prior art and to provide a heat exchanger structure and an evaporative process of increased efficiency and economy, the present invention offers the following, briefly stated. The finned or baffled heat exchanger body is constructed to provide therein multiple rather closely spaced through passages constructed from interfitting contiguous deformed areas of the fins. Each such through passage contains multiple tiered liquid traps and coaxial gas orifices surrounded by the liquid traps. The gas and liquid within each passage flow in opposite directions through the heat exchanger body. The liquid is admitted into each passage independently by a control valve or other device located at the entrance of the passage. Before entry, the liquid will have substantially zero gas content to prevent the discussed hinderance to heat transfer caused by gas bubbles at the start of the process. To prevent internal fluid friction and consequent harmful heating of the internal liquid, the latter enters each through passage of the exchanger at very low velocity. The arrangement permits continuous evacuation of gas in one direction and continuous liquid supply to empty liquid traps of each through passage in the opposite direction, as where certain traps have had their liquid converted into gas through evaporation. At the entrance of each through passage, a pressure-responsive device will control the flow of gas and will open when a certain gas pressure is reached. The liquid in counter-flow relationship to the gas will be admitted to each passage only when the gas pressure responsive control device is open. This control device is commonly some sort-of valve, or a gas flow restrictor.
The invention possesses the following advantages among others:
1. It allows opposite coaxial flow directions in each passage of the heat exchanger between gas and liquid.
2. It allows quick and efficient gas evacuation from the liquid because liquid evaporation takes place in a large number of shallow traps or troughs along each through passage.
3. The invention makes it feasible to maintain independently in each through passage the most desirable evaporative temperature; and this is obtained by the gas pressure valve in the entrance of each passage which releases gas immediately at a pressure corresponding to the ideal evaporative temperature.
4. It allows precision liquid supply only into required areas of the heat exchanger, and the liquid is supplied to the entrance of particular passages when the valve opens to let the gas out of the particular passage. It permits the delivery of liquid only into particular zones of particular passages where liquid has evaporated from a trap or traps. The empty traps will be efficiently refilled in the controlled evaporation procedure.
5. The invention permits when required the desired reduction in pressure of outgoing gas in each passage. This can be accomplished by valving and/or by regulation of gas flow orifice size at each terrace or level of each passage. Gas bubble removal from each passage can be enhanced by the action of a brush or hammering means in each passage.
6. The invention enables the control of evaporation and of heat exchange capability to respond to hot spots in a three dimensional pattern which has never been possible previously.
Other features and advantages of the invention will become apparent during the course of the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary cross sectional view taken through the wall of a prior art heat exchanger conduit showing the heat transfer hinderance caused by the gas bubble film.
FIG. 2 is a schematic view showing the traditional evaporative process in a heat exchange conduit such as a refrigerant evaporator according to the prior art.
FIG. 3 is a fragmentary perspective view of a controlled performance heat exchanger according to the invention.
FIG. 4 is an enlarged fragmentary vertical section showing a portion of one through passage in the heat exchanger shown in FIG. 3.
FIGS. 5 through 8 are similar views showing modifications of the passage structures and gas discharge control means.
FIGS. 9 through 15 are fragmentary views showing modified heat exchanger structures according to the invention adaptable to particular applications or uses.
DETAILED DESCRIPTION
Referring to the drawings in detail wherein like numerals designate like parts, FIGS. 1 and 2 depict schematically the deficiencies of the prior art discussed previously in some detail, which deficiencies the present invention seeks to eliminate substantially. FIG. 1, on a very enlarged scale, shows a wall fragment 20 of a heat exchanger tube having a fluid medium running therethrough such as any well known refrigerant. The tube 20, for example, may be a portion of a refrigeration evaporator structure. As explained previously, a film 21 of gas bubbles tends to develop over the interior surface of the metal wall 20 hindering the transfer of heat from the exterior fluid, such as ambient air, to the interior fluid in the tube 20.
FIG. 2 depicts schematically the gradual phase change occurring in a refrigerant running through an evaporator coil or in another type of heat exchanger having an internal fluid to receive heat from an external fluid through the metal wall of the coil 22 which has a constant cross section throughout its length. At the start of the heat exchange cycle or refrigeration cycle, the internal fluid is completely liquid; near the middle of the cycle and the middle of the coil 22 the internal fluid has picked up heat and is half liquid and half gas. Near the end of the heat exchanger coil and cycle, the internal fluid is predominantly gas and at the end of the coil and cycle, it is completely gas. If the numerals 23 and 24 represent areas of the heaviest heat loading, it will be appreciated that the system is being required to transfer the greatest amounts of heat from one fluid medium to another in the area where the weakened internal liquid mixture has the lowest heat transfer capacity. This is the situation which exists in the prior art as was fully described previously and this is the situation which is corrected by the present apparatus and method.
Referring to FIG. 3 showing one possible embodiment of the invention, a heat exchanger such as a refrigeration evaporator unit, radiator structure or a similar device, comprises a plurality of equidistantly spaced parallel flat metal plates or fins 25 of any required size and shape to satisfy particular needs. The metal plates 25, as best shown in FIG. 4, are individually deformed at spaced intervals to produce thereon a multiplicity of depressed somewhat conically tapered cup-like extensions 26 adapted to nest or telescope coaxially and to be anchored together by bonding, soldering or mechanically. the arrangement of the interfitting extensions 26 forms multiple parallel closely spaced columns through the heat exchanger perpendicular to the plates 25 thereof to produce a strong integral structure.
Each extension 25 includes a shallow annular liquid trap 27 at its bottom surrounding a central axial gas flow aperture means or nozzle 28, 28a, 28b, 28c, etc. These nozzles are graduated in diameter and decrease progressively in size between the opposite sides of the heat exchanger defined by the plates 25. In appropriate cases, the nozzles may increase in size rather than decrease in the same direction illustrated in FIG. 4. The nozzles 28, 28a, 28b, 28c, etc. can be seen to form a gas through passage completely through the heat exchanger at the axial center of each column formed by the attached interfitting cup-like extensions 26. Within each such column, a plurality of the liquid traps 28 in tiered relationship surround the gas nozzles and the axial through passages produced thereby.
As shown in FIGS. 3 and 4, at the top of each column formed by the extensions 26 is a liquid admission unit 29 through which an internal liquid, such as a refrigerant, completely free of gas, is introduced into the entrance of each column of the heat exchanger. In the bottom of each admission unit 29 is a gas pressure responsive spring-urged ball check valve 30 or equivalent means releasably closing the outlet orifice of the unit 29. This valve 30 is also a pressure-responsive outlet valve for gas flowing upwardly in the column through nozzles 28, 28a, 28b, etc. During operation, liquid metered into each column by one device 29 at each opening of the valve 30 flows downwardly in small amounts and enters the traps 27 to be held thereby. Gas is simultaneously flowing upwardly or counter to the liquid flow in each gas passage defined by coaxial nozzles 28, 28a, 28b, etc. The gas outlet valves 30 open in response to a predetermined gas pressure to release the gas from each column and the counter-flowing liquid can enter that particular column only when the valve 30 is open, as will be further discussed.
Over the entire heat exchanger containing a multitude of the described columns, the operation of each column is independent from every other column of the system to enable the system to operate most efficiently for transferring heat in response to local hot spots or comparatively cooler spots which may exist over the area of the heat exchanger. It will of course be understood that an exterior fluid, such as ambient air in an air conditioner or the like, is flowing between the spaced plates 25 externally of the columns made up of the extensions 26. Heat contained in this external fluid is continuously transferred through the plates 25 and the walls of the extensions 26 to the internal fluid in liquid form contained at all times in small amounts in the tiered traps 27. This arrangement produces a closely controlled evaporation of liquid in the multiple columns of the heat exchanger in terms of local thermal conditions existing across the entire heat exchanger, ranging from very hot spots to comparative cool spots. Even within the individual columns of the heat exchanger, the system can operate with maximum efficiency and respond to localized thermal conditions within that particular column. For example, if a hot spot exists near the axial center of one column, the liquid in one or two of the traps 27 may be entirely evaporated at those points only and not in the traps 27 above and below. The conversion of this localized liquid in the gas running through the nozzles 28, 28a, 28b, etc. can elevate the gas pressure sufficiently to open the valve 30 and admit enough liquid from the adjacent device 29 to refill the one or two empty traps 27 of that particular column with vaporizable liquid. Simultaneously, this same independent mode of operation can take place in every column throughout the entire heat exchanger to produce a truly regulated evaporative process and a truly controlled performance heat exchanger in a three dimensional sense. That is, controlled liquid vaporization and controlled transfer of heat between an exterior and an interior fluid can take place differentially over the area of the heat exchanger spanned by the plates 25 and over the thickness thereof defined by the columns consisting of the engaged extensions 26. It can be seen that the described construction and mode of operation brought about by the invention completely eliminates the inherent drawbacks of the prior art discussed previously and illustrated in FIGS. 1 and 2. Because the system throughout contains only separated and isolated small volumes of liquid in the traps 27 instead of one continuous flowing mass of liquid, the tendency for films of gas bubbles hindering heat transfer to develop is greatly minimized or eliminated, and any bubbles which do develop are quickly carried off in the gas stream running through the nozzles 28, 28a, 28b, etc.
FIGS. 5 through 8 show variations in the construction of the liquid trapping and counter-flow gas discharging columns in the heat exchanger which can be substituted for the satisfactory arrangement shown in FIGS. 3 and 4.
For example, in FIG. 6, heat exchanger plates 25a have formed integral tapered telescoping cups 26a extending oppositely to the cups 26 and including central gas flow apertures 31, 31a, 31b, etc. which are graduated in size oppositely in comparison to nozzles 28, 28a, 28b, etc. Liquid traps 27a similar to the traps 27 are formed by the side walls of cups 26a and the nozzles forming the graduated apertures 31, 31a, 31b, etc. which they surround. A pressure responsive gas discharge control valve 39a similar to the valve 30 is provided for the endmost gas flow aperture 31b. In FIG. 6, as in FIG. 4, the gas flow is upward against the valve 30a and liquid flow is downward into the traps 27a only when the valve 30a is unseated. The overall mode of operation is unchanged from that described relative to FIGS. 3 and 4.
FIG. 5 shows another construction for each column of the heat exchanger wherein the ball check valve at the entrance to the column may be eliminated without any significant change in beneficial mode of operation. In FIG. 5, plates 25b have formed thereon interfitting cup-like extensions 26b which are secured in assembled relationship. Small liquid traps 27b are formed as shown, and all but the uppermost elements 26b have central gas discharge nozzles 32. The uppermost one or two extensions 26b in lieu of a ball check valve have domes 33 and 34 having multiple restricted gas slots 35 through which the flowing gas in each column can be discharged gradually under pressure. The counter-flow liquid component flows down the inner wall surfaces of the elements 26b into the respective liquid traps 27b and from each such trap flows through small ports 36 and into the next lowermost trap by continuing to run down the side walls of the elements 26b. It can be seen that the three dimensional control of performance of a heat exchanger and the three dimensional control of evaporation of an internal liquid can be achieved through the invention in a highly refined way by varying the gas flow passages locally within each column of the system in a manner similar to what is shownn in FIG. 5. That is to say, other elements 26b below the top two can have differently designed flow restrictors in any sequence desired to cope with localized conditions in the exterior or ambient fluid.
FIG. 7 shows a further variation in heat exchanger column design, wherein plates 25c having interfitting tapered cup-like extensions 26c, liquid traps 27c and gas flow nozzles 37 make up a heat exchanger. A spring-urged plug type gas flow control valve 38 carriers a depending attached stem 39 having brush sections 40 radiating therefrom in the chambers formed by the interfitting elements 26c. These brush sections continually clean the internal surfaces of the elements 26c and they also retard the formation of gas bubble films on the heat transfer walls of the columns of the heat exchanger.
FIG. 8 shows yet another variation in the heat exchanger column structure where metallic sponge 41 or the like may be placed inside of one column extension element 42 and a metallic screen element 43 inside of the heat lowermost element 42, followed by a woven sponge 44 in the next lowermost element 42 of the column. The arrangement of these elements in individual columns and in adjacent columns of the heat exchanger can be varied to achieve the desired controlled performance in a particular situation.
In addition to the heat exchanger structures illustrated in FIGS. 3 through 8, the shaping of the heat exchanger fins or plates can be widely varied to suit particular needs and applications within the capability of the invention which are many and varied.
For example, when used for collecting solar heat, FIG. 9, the exchanger plates 45 may be constructed as parallel inclined downwardly flanged channels capable of trapping heated air beneath them in the several still air pockets 45' formed by the channels 45 surrounding the interfitting tapered cup-like extensions 46 forming columns throughout the heat exchanger in the same manner shown in FIGS. 3 through 8 and for the same general purpose.
Similarly, in FIG. 10, for utilizing solar heat in a horizontal collector, stacked plates 47 have depressed corrugations 48 forming multiple still air heat traps 47' surrounding the several columns formed through the structure by interfitting tapered elements 49. In all cases, the columns conduct an internal fluid to which heat is transferred through the metal walls from an external fluid, as described in connection with FIGS. 3 through 8.
FIG. 11 shows another important embodiment of the heat exchanger in the form of a solar collector having an insulating base 50 and a transparent or translucent cover panel 51 suitably anchored thereto. Between the base 50 and cover panel 51 are placed plural equidistantly spaced parallel fins 52 also serving as support ribs for the cover panel 51 and allowing evacuation of the air trapping spaces beneath the cover panel for much greater thermal efficiency. The several fins or ribs 52 prevent the cover panel 51 from collapsing under the effect of the applied vacuum. The ribs 52 are joined at multiple points along their lengths by columns of sleeve elements 53 forming continuous fluid passages through the heat exchanger as described previously in the application, in FIGS. 3 through 8 for example.
Another variant of the structure is shown in FIGS. 12 and 13. A cylindrical tubular heat exchanger is constructed from a helically coiled channel member 54, the individual convolutions of which are stacked as shown in FIG. 13 and joined by interfitting tapered cup extensions 55 forming fluid passage means of any of the types shown in FIGS. 3 through 8. A liquid running through the helical trough of the coiled structure can be the exterior fluid in heat exchange relationship with the internal fluid running inside of connected elements 55. Three fluids, such as an external liquid and internal liquid and gas components, can be employed in the arrangement of FIGS. 12 and 13.
FIGS. 14 and 15 show a modification of the device in FIGS. 12 and 13, where, instead of a helically coiled trough 54, a straight trough 56 or pan is employed having a raised central tunnel element 57 mounted thereon forming a tunnel passage 58 for one fluid. A second fluid, namely a liquid, runs in the troughs or channels 59. A third fluid, such as a liquid-gas mix, runs in the passages of columns 60 formed by interfitting elements 61 exactly as described for the arrangements in FIGS. 3 through 8. FIG. 15 shows how the straight pans 56 may be stacked and joined in a multi-tier heat exchanger.
Throughout this application, the heat exchanger structure has been discussed primarily with relation to the evaporative process. It should be recognized that the same structure is equally suited for the condensing process which is the reciprocal of evaporation. When employed in the condensing process, care must be exercised to promptly evacuate the condensing liquid as by means of the several drain openings 36 in the embodiment shown in FIG. 5 where gas is rising upwardly through nozzle 32 and restricting slots 35 in the condensing process. The restricting slots 35, like the nozzles 28 through 28c in FIG. 4, or 40 through 44 in FIGS. 7 and 8, have the task of diminishing mechanically the gas energy content. In this way, the condensing capacity of the heat exchanger structure is perfected. Similarly, in the evaporating process, the compressor's work and energy demands are facilitated.
It is to be understood that the forms of the invention herewith shown and described are to be taken as preferred examples of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention or scope of the subjoined claims.
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An essentially tubeless heat exchange structure and an attendant controlled evaporative or condensing process is disclosed. A finned heat exchanger body has multiple spaced through passages constructed by locally deforming the fin metal. Each through passage includes multiple terraced liquid traps and coaxial orifices for counter-flowing gas. A liquid supply device and gas pressure relief device is provided for each through passage. The physical construction of the finned heat exchanger body can vary widely depending upon application.
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SCOPE OF INVENTION
The invention consists of an infrared clinical thermometer which, during measurement of the body temperature of the patient, is put at a preset distance from the patient.
PRIOR ART
Traditional mercury thermometers are well known and still widely used for both medicine and veterinary purposes, even though they require excessively long times (4-5 minutes) to yield a response, and they are not always easy to read or very precise.
Fast-reading mercury thermometers have been developed, Which, however, have not been very successful on the market because they are costly and brittle. Digital thermometers, albeit representing an undoubted technical advance on clinical mercury thermometers, are not without certain drawbacks and limitations deriving basically from their response time, not less than 30-60 seconds, which is (or may be) too long when it is necessary to obtain the body temperature of particularly restless new-born, babies, or else of animals.
Infrared clinical thermometers have recently come on the market, which comprise basically a sensor that detects in a very short time (2-3 seconds) the intensity of the infrared radiation emitted by a preset point of the body of the patient and a logic that processes the signal emitted by the sensor to determine the body temperature of the patient and to show it on a display, normally of a digital type, forming part of the thermometer itself.
As temperature measuring point, the ear drum membrane is normally used, which is located immediately near the hypothalamus (i.e., the gland which regulates body temperature) and which is normally reached by inserting a probe connected to the sensor into the auditory canal. This probe forms a single piece with the sensor and may protected by a cap which is preferably interchangeable.
These infrared thermometers present, however, certain drawbacks. In the first place, measuring the temperature at the ear drum cannot certainly be considered “non-invasive”, since the probe anyway causes a certain discomfort to the patient. In addition, for obvious hygienic reasons it is necessary (or at least very advisable) to apply an interchangeable protective cap to the probe, or else clean the probe after each measuring. These are all things that are uncomfortable and inconvenient, especially in hospitals.
Finally, the precision of the thermometer reading may be impaired by a set of factors that are not always exactly foreseeable or assessable, such as, for example, an imperfect positioning of the end of the probe and/or the presence of wax in the auditory canal, etc. On the other hand, the infrared sensors currently available an the market are of such a size that they cannot be introduced into the auditory canal of the patient, and hence it is essential to use a probe (containing a wave-guide having suitable characteristics) which “conveys” to the sensor the infrared radiation emitted by the ear drum membrane, at the same time preventing the sensor from being affected by the infrared radiation emitted by the surrounding areas, for example, the auricular region.
Remote infrared measuring devices are already known.
WO-A-92/02792 shows a remote temperature difference measuring device comprising a casing including at least a sensor for sensing the infrared radiation emitted by a surface, a measuring circuit comparing the value currently measured by the sensor with a value stored into a memory circuit and display means to display the algebraic difference between said two values; the measuring device further comprising means for positioning said sensor, including a pair of sources of conical light rays positioned outside said casing. and inclined with respect to the axis thereof: when the conical light rays are superimposed, the sensor is at a preset distance from the surface and is perpendicular thereto.
The predominant aim and use of WO-A-92/02792 is for measuring a difference of temperature: only if the stored value of temperature is known and/or it is constant, can WO-A-92/02792 be used for measuring a temperature by algebraically adding the known value to the difference of temperature read on the display means.
GB-A-2,291,498 shows a remote temperature detector, including a lens for focusing radiation from the heat source on a sensor belonging to the detector and a laser aiming system including a laser beam splitter assembly and a mirror: the two components of the split laser beam converge on the focal point of the sensor lens.
The laser beam splitter assembly acts as a laser beam splitter and as a deflecting means; the laser source, the laser beam splitter assembly and the mirror are positioned outside the casing of the detector shown by GB-A-2,291,498. Subject of the present invention is an infrared clinical thermometer that is exempt the limits and disadvantages presented by infrared thermometers of a known type.
SUMMARY OF INVENTION
The subject of the present invention is an infrared thermometer comprising at least a sensor which detects infrared radiation and a logical unit which processes the signal emitted by the sensor and drives display means for displaying the body temperature of the patient.
During measurement of patient's temperature, the sensor is put at a preset distance from the body of the patient, determined preferably by means of an optical aiming system belonging to the thermometer and comprising means for generating a pair of light rays and optical means that cause the aforesaid light rays to converge in a preset point, whose distance from the sensor is equal to the preset distance, the optical means being different from the generating means.
The sensor, the logical unit, the display means, the means for generating the pair of light rays and the optical means are positioned inside the casing of the thermometer.
LIST OF FIGURES
The invention will now be described in greater detail with reference to an embodiment thereof, which is presented purely for illustrative reasons and in no way exhausts the possibilities. The invention in shown in the attached figures, where:
FIG. 1 shows a block diagram of a thermometer according to the invention, including a first embodiment of the optical aiming system;
FIG. 2 shows a schematic presentation of a second embodiment of the optical aiming system of FIG. 1;
FIG. 3 presents a schematic flow chart illustrating the operation of the logical unit of FIG. 1 . In the attached figures, the corresponding elements are identified by means of the same numerical references.
DETAILED DESCRIPTION
FIG. 1 shows a block diagram of a thermometer according to the invention. In the figure are visible the outer casing of the thermometer ( 1 ), the sensor ( 2 ) for detecting the infrared radiation emitted by the body (p) of the patient, the logical unit ( 3 ) which receives and processes the signal emitted by the sensor ( 2 ) to determine the body temperature of the patient, which is displayed on a display ( 4 ) preferably, but not necessarily of a digital type—and an optical aiming system which reveals visually a preset distance (d) generating a pair of light rays which converge in a preset point (P), the distance of which from the sensor ( 2 ) corresponds to the aforesaid preset distance (d).
An infrared thermometer is not described herein since it is already known (for example, from the published international patent application No. WO 94/20023). It will suffice to recall that, given the same body temperature of the patient, the amount of infrared radiation detected by the sensor ( 2 )—and, consequently the amplitude of the signal emitted by the sensor ( 2 )—is a function, among other things, of the distance between the sensor ( 2 ) and the body (p) of the patient, and that the body temperature detected by the thermometer ( 1 ) is in turn a function of the signal emitted by the sensor ( 2 ).
The thermometer ( 1 ) is (or may be) calibrated in a way that is in itself known to measure with the desired precision the body temperature of a patient when the sensor ( 2 ) is put at the preset distance (d) from the body (p) of the patient.
Consequently, the thermometer ( 1 ) is able to detect the body temperature of the patient with a precision that depends also on the precision with which the condition of placing the sensor ( 2 ) at the distance (d) from the body (p) of the patient is respected.
The optical aiming system belonging to the thermometer object of the present invention, which generates a pair of light rays ( 5 ) converging in the point (P) at a distance (d) from the sensor ( 2 ), is a simple, but effective, solution to the problem of determining rapidly and with acceptable precision whether the sensor ( 2 ) of the thermometer ( 1 ) is correctly positioned at the distance (d) from the body (p) of the patient.
An optical aiming system according to the invention comprises means for generating the pair of light rays ( 5 ) that converge in the preset point (P) and optical means ( 9 ) that cause the aforesaid light rays ( 5 ) to converge in the preset point (P).
In the embodiment shown in FIG. 1, the means for generating the pair of light rays ( 5 ) include a light source ( 6 ), means ( 7 ) which split the light ray emitted by the source ( 6 ), and means ( 8 ) that deflect the light rays coming out of the splitting means ( 7 ) to make them converge in the preset point (P).
In FIG. 1 the means for splitting the light rays ( 7 ) and the means for deflecting the light rays ( 8 ) consist of optical prisms, but, without departing from the scope of the invention, the splitting means ( 7 ) may consist of an optical prism, and the deflecting means ( 8 ) may consist of mirrors.
In the example of embodiment here illustrated each one of the optical means ( 9 ) that cause the aforesaid light rays ( 5 ) to converge in the preset point (P) consists of a pair of plane-convex lenses, but without departing from the scope of the invention it is possible to use biconvex lenses or other equivalent optical means. In order to measure the body temperature of the patient, the operator pushes a first push-button ( 10 ) belonging to the thermometer ( 1 ), which activates the optical aiming system—in FIG. 1, the first push-button ( 10 ) activates, via the logical unit ( 3 ), the light source ( 6 )—,displaces the thermometer ( 1 ) until the point (P) where the light rays ( 5 ) converge is positioned on the patient's skin, and pushes a second push-button ( 11 ) belonging to the thermometer ( 1 ), which activates the thermometer 1 —in FIG. 1, the second push-button ( 11 ) drives the logical unit ( 3 ). The optical means ( 9 ) illustrated in FIGS. 1 and 2 cause each of the two light rays ( 5 ) to be convergent so that they become point like only in the preset point (P). In this case, if the sensor ( 2 ) of the thermometer ( 1 ) is at the preset distance (d) from the patient's body (p), the two rays ( 5 ) coincide in point (P); otherwise, the operator sees on the body of the patient two distinct luminous areas, one for each of the light rays ( 5 ), which are reduced in width and get closer to one another as the distance between the sensor ( 2 ) and the body (p) of the patient gets closer to the preset value (d).
In fact, the light rays ( 5 ) reach the patient's skin before they met if the thermometer ( 1 ) is too close to the body (p) of the patient; they reach the patient's skin after crossing one another and then diverging again if the thermometer ( 1 ) is too far from the body (p) of the patient.
In In the embodiment described here the push-buttons ( 10 ) and ( 11 ) have a different mechanical response (i.e., they require a different pressure to be activated) and are operated by the operator through a single button ( 12 ); however, without departing from the scope of the invention, the push-buttons ( 10 ) and ( 11 ) may be operated directly by the operator, or a “double-action” push-button combining the functions of the push-buttons ( 10 ) and ( 11 ) may be used.
FIG. 2 is a schematic representation of a second embodiment of the optical aiming system, where the means for generating said pair of converging light rays ( 5 ) include a pair of light sources ( 13 ), equal to one another, located at the sides of the sensor ( 2 ) and inclined with respect to the axis of longitudinal symmetry of the thermometer ( 1 ), so as to cause the light rays emitted by the light sources ( 13 ) to converge in the preset point (P).
According to one of its possible embodiments, the thermometer ( 1 ) may be used also to detect the body temperature of the patient by contact, i.e., by resting on the body (p) of the patient the end of the thermometer ( 1 ) corresponding to the window made of material that is transparent to infrared radiation (not explicitly indicated in the figures) behind which the sensor ( 2 ) is located. The distance (which is known) between the window positioned at the end of the thermometer ( 1 ) and the sensor ( 2 ) is indicated in FIGS. 1 and 2 by (d′).
The said thermometer ( 1 ) is hence calibrated, in a known way, to measure, with the desired precision, the body temperature of a patient when the distance between the sensor ( 2 ) and the body (p) of the patient has the aforesaid value (d) or (d′). The mode of operation of the thermometer ( 1 ) (at a distance or by contact) can be selected by the operator using a switch (or other functionally equivalent means) schematically indicated by ( 14 ) in FIGS. 1 and 2.
A measurement by contact may be advantageous if compared to a measurement at a distance when the environmental conditions (e.g., very ventilated and/or very hot or very cold conditions) could affect the precision and/or reliability of a measurement at a distance. In a clinical/hospital field, it may be considered useful and/or advantageous to be able to confirm, through a measurement by contact, the result of a measurement at a distance (or vice versa) when the body temperature of a patient measured through the former measurement is unexpectedly high or low, or else when it is higher than a preset value T 0 .
FIG. 3 is a schematic representation of a flow chart illustrating the operation of a logical unit ( 3 ) belonging to a thermometer ( 1 ). First of all the operation will be illustrated of a logical unit ( 3 ) belonging to a thermometer ( 1 ) able to carry out only measurements at a distance; subsequently, this description will be integrated with that of the further functional steps carried out by the logical unit ( 3 ) of a thermometer ( 1 ) suitable for making also measurements by contact.
When the thermometer ( 1 ) is activated, the logical unit ( 3 ) performs (phase 1 ) possible self-diagnostics procedures, and checks (phase 2 ) whether the first push-button ( 10 ), which activates the optical aiming system, has been pushed. If the first push-button ( 10 ) has not been pushed, the logical unit ( 3 ) checks (phase 3 ) whether a preset deactivation time t 1 has elapsed (e.g., 30 seconds) before switching off (phase 4 ) the display ( 4 ), if this was on, and checks again (phase 2 ) whether the first push-button ( 10 ) has been pushed.
This condition (return to phase 2 ) will be hereinafter referred to as “return to wait state”.
If the first push-button ( 10 ) has been pushed (phase 2 ), the logical unit ( 3 ) activates (phase 5 ; in FIG. 3 this passage is schematically indicated by a dashed line) the optical aiming system, enables (phase 16 ) operation of the second push-button ( 11 ) and, after verifying (phase 6 ) that the second push-button ( 11 ) has been pushed, activates (phase 7 ) the procedure (not described herein because it is in itself known) for temperature measuring at a distance, and switches on (phase 8 ) the display ( 4 ) to display for a preset period of time the temperature measured before returning to the wait state.
If the second push-button ( 11 ) has not been pushed, the logical unit ( 3 ) checks (phase 9 ) that the first push-button ( 10 ) has been released before switching off (phase 10 ) the optical aiming system and returning to the wait state; otherwise, it checks again (phase 6 ) whether the second push-button ( 11 ) has been pushed. If the thermometer ( 1 ) is able to carry out also measurements by contact, it includes also the switch ( 14 ), and the logical unit ( 3 ) is able to perform at least the following further functional steps:
if the first push-button ( 10 ) has been pushed (phase 2 ), the logical unit ( 3 ) acquires (phase 11 ) the position of the switch ( 14 ): if the switch ( 14 ) is positioned on “measurement at a distance” (phase 12 ), the logical unit ( 3 ) activates (phase 5 ) the optical aiming system and enables (phase 16 ) operation of the second push-button ( 11 ); otherwise, it checks (phase 13 ) whether the switch ( 14 ) is positioned on “measurement by contact”;
if the switch ( 14 ) is positioned on “measurement by contact” (phase 13 ), the logical unit ( 3 ) disables (phase 14 ) the optical aiming system; otherwise, it checks again whether the switch ( 14 ) is positioned on “measurement at a distance” (phase 12 );
once the optical aiming system has been disabled (phase 14 ), the logical unit ( 3 ) first verifies (phase 15 ) that a preset time interval t 2 (e.g., 8 seconds), necessary for stabilizing the internal temperature of the sensor (which might have changed on account of the previous measurement by contact), has elapsed since the previous measurement by contact, and then enables (phase 16 ) operation of the second push-button ( 11 ). If the preset time t 2 has not elapsed, the logical unit ( 3 ) checks again whether the switch ( 14 ) is positioned on “measurement at a distance” (phase 12 );
if the second push-button ( 11 ) has been pushed (phase 6 ), the logical unit ( 3 ) checks (phase 17 ) whether the switch ( 14 ) is positioned on “measurement at a distance” before activating (phase 7 ) the aforesaid procedure for measuring temperature at a distance; otherwise, it activates (phase 18 ) a procedure (not described herein because it is in itself known and anyway similar to that for temperature measuring at a distance) for measuring the temperature by contact and switches on (phase 8 ) the display ( 4 ) to display for a preset period of time the temperature measured, before returning to the wait state.
In the embodiment illustrated in the flow chart of FIG. 3, after switching on (phase 8 ) the display ( 4 ) to display for a preset period of time the temperature measured, the logical unit ( 3 ) first verifies (phase 19 ) that the switch ( 14 ) is positioned on “measurement at a distance” and that the temperature measured is higher than the aforesaid preset value T 0 , and then shows on the display ( 4 ) (phase 20 ) for a preset time a prompt to carry out a control measurement by contact before returning to the wait state; otherwise, it returns directly to the wait state.
Without departing from the scope of the invention, it is possible for a technician to make an optical aiming system, subject of the present description, all the modifications and improvements suggested by normal experience and by the natural evolution of techniques to the infrared thermometer comprising.
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A clinical thermometer is described, based on the measurement of the infrared radiation emitted by the patient, in which the body temperature of the patient in obtained in a non-invasive way and (normally) without any contact between the thermometer and the patient. During measurement of the temperature, the thermometer ( 1 ) is put at a preset distance (d) from the body of the patient, a distance which is normally determined by an optical aiming system consisting of two converging rays of light ( 5 ). A thermometer according to the invention may be used to obtain the temperature of the patient also by contact.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from Korean Patent Application No. 10-2011-0112376 filed on Oct. 31, 2011 and 10-2012-0106615 filed on Sep. 25, 2012, which applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a headlamp of a vehicle, and more particularly, to an automotive headlamp which is structured in a simple manner to secure a sufficient amount of light, emit light in different/various beam patterns, and improve heat dissipation efficiency.
[0004] 2. Description of the Related Art
[0005] Vehicles are typically equipped with various automotive lamps having a lighting function and a signaling function, among others. That is, automotive lamps enable the driver of the vehicle to easily detect objects around and ahead of the vehicle while driving at night or in a dark area. They also inform other vehicles and road users of the vehicle's driving state. For example, a headlamp and a fog lamp are designed for providing light, and a direction indicator, a taillight, a brake light, and a side marker are designed for signaling.
[0006] Recently, many automotive lamp manufactures have begun to use halogen lamps or high-intensity discharge (HID) lamps as light sources. Additionally, light-emitting diodes (LEDs) have been used as light sources as well. LEDs have a color temperature of approximately 5500 K which is close to that of sunlight. Thus, LEDs cause the least eye fatigue. In addition, LEDs increase the freedom of lamp design due to their small size and are economical due to their semi-permanent lifespan.
[0007] LEDs, in particular, are being introduced to reduce lamp configuration complications and decrease the number of manufacturing processes required to produce a headlamp. In particular, attempts are being made to extend lamp life using characteristics of LEDs. Furthermore, since limited space is not an issue due to the small size of the LEDs, they may be utilized in a plethora of applications.
[0008] Of the various types of automotive lamps, a headlamps use more than one beam pattern unlike other types of lamps which typically use only one. For example, the headlamp may emit light in a beam pattern optimum for driving conditions of the vehicle such as travelling speed, travelling direction, road surface conditions, and ambient brightness. In so doing, the headlamp may ensure driver visibility without blinding other vehicle drivers on the road. Generally, one or more LEDs are used to emit light in each beam pattern while securing a sufficient amount of light. However, to emit light in different beam patterns, elements corresponding to each beam pattern are required. Accordingly, this increases the number of parts, costs and space required. In addition, when LEDs are used as light sources of automotive lamps, the light emission efficiency of the LEDs rapidly deteriorate as the temperature rises.
[0009] Therefore, a solution that can emit light in various beam patterns, secure a sufficient amount of light, and prevent a temperature rise due to heat emitted from LEDs while reducing the number of parts, costs and space required to emit light in different beam patterns is required.
SUMMARY OF THE INVENTION
[0010] Aspects of the present invention provide an automotive headlamp in which a plurality of lamp modules, which use light-emitting diodes (LEDs) for emitting light in different beam patterns as light sources, are placed in different directions from an optical axis of the automotive headlamp to minimize the space required and emit light in various beam patterns and in which a lamp module for emitting light in a predetermined beam pattern consists of a plurality of lamp modules to secure a sufficient amount of light.
[0011] Aspects of the present invention also provide an automotive headlamp in which heat sinks are installed to efficiently prevent a temperature rise due to heat emitted from LEDs.
[0012] However, aspects of the present invention are not restricted to the one set forth herein. The above and other aspects of the present invention will become more apparent to one of ordinary skill in the art to which the present invention pertains by referencing the detailed description of the present invention given below.
[0013] According to an aspect of the present invention, there is provided an automotive headlamp including: a plurality of lamp modules disposed in different directions from an optical axis of the automotive headlamp; and a projection lens projecting light emitted from one or more of the lamp modules, wherein each of the lamp modules includes: a light source unit emitting light downward; and a reflector disposed under the light source unit and reflecting light emitted from the light source unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The above and other aspects and features of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings, in which:
[0015] FIG. 1 is a perspective view of an automotive headlamp according to a first exemplary embodiment of the present invention;
[0016] FIG. 2 is a schematic front view of a first lamp module and a second lamp module according to the first exemplary embodiment of the present invention;
[0017] FIG. 3 is a perspective view of an automotive headlamp according to a second exemplary embodiment of the present invention;
[0018] FIG. 4 is a schematic front view of a first lamp module and a second lamp module according to the second exemplary embodiment of the present invention;
[0019] FIG. 5 is a schematic diagram illustrating the direction in which light travels in the automotive headlamp of FIGS. 1 and 2 ;
[0020] FIGS. 6 and 7 are schematic views of heat sinks according to the first exemplary embodiment of the present invention;
[0021] FIG. 8 is a schematic view of heat pads according to an exemplary embodiment of the present invention;
[0022] FIG. 9 is a schematic view of heat sinks according to the second exemplary embodiment of the present invention;
[0023] FIGS. 10 and 11 are perspective views of an assembled automotive headlamp according to an exemplary embodiment of the present invention;
[0024] FIG. 12 is a plan view of the assembled automotive headlamp shown in FIGS. 10 and 11 ; and
[0025] FIG. 13 is a base view of the assembled automotive headlamp shown in FIGS. 10 and 11 .
DETAILED DESCRIPTION OF THE INVENTION
[0026] Advantages and features of the present invention and methods of accomplishing the same may be understood more readily by reference to the following detailed description of exemplary embodiments and the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art, and the present invention will only be defined by the appended claims. Like reference numerals refer to like elements throughout the specification.
[0027] In some embodiments, well-known manufacturing processes, well-known structures and well-known technologies will not be specifically described in order to avoid ambiguous interpretation of the present invention.
[0028] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting 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 elements, steps, and/or operations, but do not preclude the presence or addition of one or more other elements, steps, operations, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
[0029] Embodiments of the invention are described herein with reference to perspective, cross-sectional, side, and/or schematic illustrations that are illustrations of idealized embodiments of the 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 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. In the drawings, each element may be exaggerated or reduced for clarity.
[0030] Automotive headlamps according to embodiments of the present invention will now be described with reference to the attached drawings.
[0031] FIG. 1 is a perspective view of an automotive headlamp 1 according to a first exemplary embodiment of the present invention. FIG. 2 is a schematic front view of a first lamp module 100 and a second lamp module 200 according to the first exemplary embodiment of the present invention.
[0032] Referring to FIGS. 1 and 2 , the automotive headlamp 1 according to the first exemplary embodiment may include the first lamp module 100 , the second lamp module 200 , a shield 300 , and a projection lens 400 . In the first embodiment of the present invention, the first lamp module 100 and the second lamp module 200 are disposed in different directions from an optical axis C of the projection lens 400 and used/configured to emit light in different beam patterns. In the first embodiment of the present invention, the first lamp module 100 may be disposed above the optical axis C and used to emit light in a low-beam pattern, and the second lamp module 200 may be disposed below the optical axis C and used to emit light in a high-beam pattern.
[0033] In addition, the first lamp module 100 and the second lamp module 200 are used in the first embodiment of the present invention. However, the present invention is not limited thereto, and a lamp module can be added or removed according to beam patterns used.
[0034] The first lamp module 100 may include a first light source unit 110 which emits light downward and a first reflector 120 which reflects light emitted from the first light source unit 110 so that the light is directed toward a lower part of the projection lens 400 . The first light source unit 110 may include a light source 111 and a substrate 112 on which the light source 111 is installed. The light source 111 may be installed on a bottom surface of the substrate 112 to emit light downward. The first reflector 120 may be disposed under the first light source unit 110 to reflect light emitted from the first light source unit 110 and may be shaped in the form of an oval or free curved surface having an open surface.
[0035] The second lamp module 200 may include a second light source 201 which emits light downward and a second reflector 202 which reflects light emitted from the second light source 201 such that the light travels toward an upper part of the projection lens 400 . Like the first light source unit 110 , the second light source unit 201 may include a light source 201 a and a substrate 201 b on which the light source 201 a is installed. The light source 201 a may be installed on a bottom surface of the substrate 201 b to emit light downward. Also like the first reflector 120 , the second reflector 202 may be disposed under the second light source unit 201 to reflect light emitted from the second light source unit 201 and may be shaped like an oval or free curved surface having an open surface.
[0036] In the first embodiment of the present invention, the light source 111 of the first light source unit 110 and the light source 201 a of the second light source unit 201 may be, but are not limited to, light-emitting diodes (LEDs). In addition, the first reflector 120 and the second reflector 202 may be physically connected to each other or separated from each other. When the first reflector 120 and the second reflector 202 are disposed under the first light source unit 110 and the second light source unit 201 , respectively, the entire first reflector 120 and the entire second reflector 202 may be disposed under the first light source unit 110 and the second light source unit 201 , respectively, or part of the first reflector 120 and part of the second reflector 202 may be disposed under the first light source unit 110 and the second light source unit 201 , respectively.
[0037] In the first embodiment of the present invention, light emitted from the first lamp module 100 may travel toward the lower part of the projection lens 400 , and light emitted from the second lamp module 200 may travel toward the upper part of the projection lens 400 . To this end, the first reflector 120 may reflect the light emitted from the first lamp module 100 toward the lower part of the projection lens 400 , and the second reflector 202 may reflect the light emitted from the second lamp module 200 toward the upper part of the projection lens 400 . In addition, each of the first lamp module 100 and the second lamp module 200 may be placed at a predetermined angle to the optical axis C.
[0038] The shield 300 may be disposed in front of the first lamp module 100 and the second lamp module 200 . The shield 300 may form a predetermined cut-off line by blocking part of light emitted from one or more of the first lamp module 100 and the second lamp module 200 . The shield 300 may be shaped like a plate having a semicircular groove 310 at a side thereof. The shape of the groove 310 can vary, however, and is not limited to the illustrative embodiment of the present invention.
[0039] In the first exemplary embodiment of the present invention, the shield 300 may block or reflect part of light emitted from the first lamp module 100 in order to project the light in the low-beam pattern. To reflect part of light, a surface of the shield 300 may be coated with a reflective layer.
[0040] In FIGS. 1 and 2 described above, one lamp module is disposed above and below the optical axis C. However, this is merely an example used to help understand the present invention, and the present invention is not limited to this example. One or more of the first lamp module 100 and the second lamp module 200 may also consist of a plurality of lamp modules arranged in a particular direction.
[0041] FIG. 3 is a perspective view of an automotive headlamp 1 according to a second exemplary embodiment of the present invention. FIG. 4 is a schematic front view of a first lamp module 100 and a second lamp module 200 according to the second embodiment of the present invention. In FIGS. 3 and 4 , the second lamp module 200 consists of a plurality of lamp modules. Referring to FIGS. 3 and 4 , unlike the above-described automotive headlamp 1 of FIGS. 1 and 2 , the automotive headlamp 1 according to the second embodiment of the present invention may include the second lamp module 200 which consists of a lamp module 210 and a lamp module 220 respectively disposed on both sides of an optical axis C. In the second embodiment of the present invention, the second lamp module 200 consists of two lamp modules. However, the number of lamp modules that constitute the second lamp module 200 can vary, and thus should not be limited hereto.
[0042] The first lamp module 100 , a shield 300 , and a projection lens 400 of FIGS. 3 and 4 are identical to those described above with reference to FIGS. 1 and 2 , and thus a detailed description thereof will be omitted.
[0043] In the second embodiment of the present invention, the lamp module 210 and the lamp module 220 are respectively disposed on both sides of the optical axis C in an orientation which is horizontal to each other. However, the present invention is not limited thereto.
[0044] The lamp module 210 may include a light source unit 211 and a reflector 212 , and the lamp module 220 may include a light source unit 221 and a reflector 222 . The light source unit 211 and the light source unit 221 may include light sources 211 a and 221 a and substrates 211 b and 221 b on which the light sources 211 a and 221 a are installed, respectively. The light sources 211 a and 221 a may be disposed on bottom surfaces of the substrates 211 b and 221 b to emit light downward.
[0045] As in FIGS. 1 and 2 , in FIGS. 3 and 4 , the light source 211 a of the light source unit 211 and the light source 221 a of the light source unit 221 may be LEDs. The reflector 212 may be disposed under the light source unit 211 to reflect light emitted from the light source unit 211 , and the reflector 222 may be disposed under the light source unit 221 to reflect light emitted from the light source unit 221 . If the reflector 212 and the reflector 222 are disposed under the light source unit 211 and the light source unit 221 , respectively, the whole of the reflector 212 and the whole of the reflector 222 may be disposed under the light source unit 211 and the light source unit 221 , respectively, or part of the reflector 212 and part of the reflector 222 may be disposed under the light source unit 211 and the light source unit 221 , respectively.
[0046] The reflector 212 and the reflector 222 may be physically connected to each other or independently attached. The light source unit 211 and the light source unit 221 may be situated at first focal points of the reflector 212 and the reflector 222 , respectively. The reflector 212 and the reflector 222 may have identical or different second focal points behind the projection lens 400 . If the second lamp module 200 consists of a plurality of lamp modules arranged in a particular direction as described above, a sufficient amount of light can be secured with relatively low power consumption.
[0047] FIG. 5 is a schematic diagram illustrating the direction in which light travels in the automotive headlamp 1 of FIGS. 1 and 2 . The principle illustrated in FIG. 5 can also apply to the automotive headlamp 1 of FIGS. 3 and 4 . Referring to FIG. 5 , the first lamp module 100 may be disposed above the optical axis C, and the second lamp module 200 may be disposed below the optical axis C. The shield 300 may be disposed in front of the first lamp module 100 and the second lamp module 200 .
[0048] The first light source unit 110 of the first lamp module 100 and the second light source unit 201 of the second lamp module 200 emit light downward. The light emitted from the first light source unit 110 and the light emitted from the second light source unit 201 may be reflected respectively by the first reflector 120 and the second reflector 202 to reach the projection lens 400 via the shield 300 , as indicated by arrows in FIG. 5 .
[0049] In FIG. 5 , light is passing through the groove 310 of the shield 300 to reach the projection lens 400 is illustrated as an example. However, the present invention is not limited to this case. Part of the light can also be blocked or reflected by a surface of the shield 300 which does not have the groove 310 .
[0050] In the above-described embodiments of the present invention, LEDs are used as light sources. However, since LEDs are vulnerable to heat, their performance may deteriorate when the LEDs are exposed to heat. Therefore, heat sinks may be used to prevent a temperature increase due to heat emitted from the LEDs.
[0051] FIGS. 6 and 7 are schematic views of heat sinks 500 installed on lamp modules according to the first exemplary embodiment of the present invention. In FIGS. 6 and 7 , an example heat sink 500 installed on each lamp module of the automotive headlamp 1 of FIGS. 1 and 2 is illustrated. Referring to FIGS. 6 and 7 , the first lamp module 100 and the second lamp module 200 may be disposed above and below the optical axis C of the projection lens 400 . In this case, the heat sinks 500 may be installed on the first lamp module 100 and the second lamp module 200 , respectively.
[0052] Specifically, in the first embodiment of the present invention, the first reflector 120 is disposed under the first light source unit 110 in the first lamp module 100 , and the second reflector 202 is disposed under the second light source unit 201 in the second lamp module 200 . Therefore, the heat sinks 500 may be installed on the first light source unit 110 and the second light source unit 201 , respectively. That is, the heat sinks 500 may be installed on a top surface of the substrate 112 of the first light source unit 110 and a top surface of the substrate 201 b of the second light source unit 201 , respectively.
[0053] Each substrate 112 of the first light source unit 110 and substrate 201 b of the second light source unit 201 may extend in one direction along the length of a corresponding heat sink 500 . For this reason, a relatively large-sized heat sink 500 can be installed. In addition, the shape of the substrate 112 of the first light source unit 110 and the shape of the substrate 201 b of the second light source unit 201 can vary according to the shape of a corresponding heat sink 500 .
[0054] In FIGS. 6 and 7 , the heat sinks 500 are installed on the first light source unit 110 and the second light source unit 201 in order to efficiently dissipate heat. That is, since heat is concentrated in upper parts of the first lamp module 100 and the second lamp module 200 due to natural convection, the heat sinks 500 may be installed on the first light source unit 110 and the second light source unit 201 , respectively. Heat pads 510 may also be formed between the substrates 112 and 201 b and the heat sinks 500 as shown in FIG. 8 to make contact surfaces between the substrates 112 and 201 b and the heat sinks 500 level and increase heat transfer efficiency accordingly.
[0055] In the first exemplary embodiment of the present invention, each of the heat sinks 500 includes a plurality of heat dissipating pins which extend upward from above a corresponding light source unit 110 or 201 . However, this is merely an example used to help understand the present invention, and the present invention is not limited to this example. Each of the heat sinks 500 may also be a heat pipe or a heat spreader. For example, a side of the heat spreader may be bent in order to increase heat transfer area.
[0056] FIG. 9 is a schematic view of heat sinks 500 installed on lamp modules according to the second embodiment of the present invention. In FIG. 9 , an example heat sink 500 installed on each lamp module of the automotive headlamp 1 of FIGS. 3 and 4 is illustrated. Referring to FIG. 9 , the first lamp module 100 may be installed above the optical axis C of the projection lens 400 , and the lamp module 210 and the lamp module 220 that constitute the second lamp module 200 may be disposed below the optical axis C to be horizontal to each other. In this case, the heat sinks 500 may be disposed on the lamp modules 100 , 210 , and 220 , respectively.
[0057] Specifically, in the second embodiment of the present invention, the first reflector 120 is disposed under the first light source unit 110 in the first lamp module 100 , and the reflector 212 and the reflector 222 are disposed under the light source unit 211 and the light source unit 221 in the lamp module 210 and the lamp module 220 , respectively. Therefore, the heat sinks 500 may be disposed on the first light source unit 110 , the light source unit 211 and the light source unit 221 , respectively. That is, the heat sinks 500 may be installed on a top surface of the substrate 112 of the first light source unit 110 and top surfaces of the substrates 211 b and 221 b of the light source unit 211 and the light source unit 221 , respectively.
[0058] In the second exemplary embodiment of the present invention, a single heat sink 500 may extend over the top surfaces of the light source unit 211 and the light source unit 221 . However, the present invention is not limited thereto. Separate heat sinks 500 can also be installed on the top surfaces of the substrates 211 b and 221 b of the light source unit 211 and the light source unit 221 , respectively.
[0059] The substrate 112 of the first light source unit 110 and the substrates 211 b and 221 b of the light source unit 211 and the light source unit 221 may extend in one direction along the length of a corresponding heat sink 500 . For this reason, a relatively large-sized heat sink 500 can be installed. In addition, the shape of the substrate 112 of the first light source unit 110 and the shapes of the substrates 211 b and 221 b of the light source unit 211 and the light source unit 221 can vary according to the shape of a corresponding heat sink 500 .
[0060] In FIG. 9 , the heat sink 500 is installed on each light source unit 110 , 211 or 221 to provide efficient heat dissipation. That is, since heat is concentrated in an upper part of each lamp module 100 , 210 or 220 due to natural convection, the heat sink 500 may be installed on each light source unit 110 , 211 or 221 accordingly to dissipate this heat. Although not shown in FIG. 9 , heat pads may also be formed between the substrates 112 , 211 b and 221 b and the heat sinks 500 as shown in FIG. 8 to make contact surfaces between the substrates 112 , 211 b and 221 b and the heat sinks 500 level and increase heat transfer efficiency.
[0061] FIGS. 10 and 11 are perspective views of an assembled automotive headlamp 1 according to an embodiment of the present invention. FIG. 12 is a plan view of the assembled automotive headlamp 1 shown in FIGS. 10 and 11 . FIG. 13 is a base view of the assembled automotive headlamp 1 shown in FIGS. 10 and 11 . In FIGS. 10 through 13 , the assembled structure of the automotive headlamp 1 of FIGS. 3 , 4 and 9 is illustrated as an example. The same structure may also apply to the automotive headlamp 1 of FIGS. 1 and 2 . For simplicity, reference numerals for some elements are omitted. However, elements substantially identical to those of FIGS. 3 , 4 and 9 are indicated by like reference numerals.
[0062] Referring to FIGS. 10 through 13 , in the automotive headlamp 1 according to the current embodiment, a first lamp module 100 may be installed above an optical axis C of a projection lens 400 , and a second lamp module 200 may be installed below the optical axis C. In addition, a lamp module 210 and a lamp module 220 of a second lamp module 200 may be disposed in a horizontal orientation to each other.
[0063] In the first lamp module 100 , a first light source unit 110 may be formed on a bottom surface of a heat sink 500 , and a first reflector 120 may be coupled to the heat sink 500 by first coupling members 710 (e.g., first set of screws). In addition, in the lamp module 210 and the lamp module 220 , a light source unit 211 and a light source unit 221 may be formed on a bottom surface of a heat sink 500 , and a reflector 212 and a reflector 222 may be coupled to the heat sink 500 by second coupling members 720 (e.g., a second set of screws).
[0064] In addition, at least one of the heat sinks 500 installed on the first lamp module 100 , the lamp module 210 and the lamp module 220 may be integrally connected to a lens holder 410 which supports the projection lens 400 by connecting portions 600 . In the current embodiment of the present invention, the heat sink 500 installed on the lamp module 210 and the lamp module 220 may be connected to the lens holder 410 by the connecting portions 600 . In the current embodiment of the present invention, the lens holder 410 is connected to at least one of the heat sinks 500 installed on the first lamp module 100 , the lamp module 210 and the lamp module 220 . However, the present invention is not limited thereto. The lens holder 410 can also be connected to any one of the elements included in each lamp module 100 , 210 or 220 .
[0065] A shield 300 may include an extension portion 320 formed by extending a front end of the shield 300 located near a focus behind the projection lens 400 backward. In the exemplary embodiment of the present invention, the extension portion 320 may be mounted on the connecting portions 600 . In addition, the front end of the shield 300 may be curved so that it is gradually displaced toward both sides of the projection lens 400 along a focal plane behind the projection lens 400 .
[0066] Coupling portions 130 may be formed on one side of the heat sink 500 installed on the first lamp module 100 and may be coupled to a surface of the extension portion 320 which extends backward from the shield 300 . Coupling members 131 (e.g., a third set of screws) may be inserted into the coupling portions 130 , thereby coupling the coupling portions 130 , the extension portion 320 and the connecting portions 600 to each other. In the embodiment of the present invention, the extension portion 320 and the coupling portions 130 are flat plate-shaped portions, and a surface of the extension portion 320 is coupled to respective surfaces of the coupling portions 130 by the coupling members 131 . However, the present invention is not limited thereto, and the extension portion 320 and the coupling portions 130 can also be coupled to each other using various coupling methods such as hook coupling and sliding coupling.
[0067] In the current embodiment of the present invention, the heat sink 500 installed on the first lamp module 100 is coupled to a surface of the extension portion 320 . However, this is merely an example used to help understand the present invention, and the present invention is not limited to this example. At least one of the heat sinks 500 formed on the first lamp module 100 and the lamp module 210 and the lamp module 220 may be coupled to a surface of the extension portion 320 of the shield 300 according to the position or direction of the extension portion 320 which extends from the shield 300 .
[0068] Advantageously, the above described lamp modules which use LEDs as light sources are placed in different directions from an optical axis of the headlamp, and the other elements are placed so that they can be shared by the lamp modules. Therefore, the space required can be minimized while light can be emitted in various beam patterns. In addition, since a plurality of lamp modules are installed in a predetermined direction from the optical axis of the headlamp, a sufficient amount of light can be secured. Furthermore, heat sinks may be installed on light source units to efficiently prevent a temperature increases due to heat emitted from the LEDs.
[0069] However, the effects of the present invention are not restricted to the one set forth herein. The above and other effects of the present invention will become more apparent to one of daily skill in the art to which the present invention pertains by referencing the claims.
[0070] While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. The exemplary embodiments should be considered in a descriptive sense only and not for purposes of limitation. The scope of the present invention is defined by the following claims, rather than by the above-described detailed description. The meanings and scope of the claims, and all modifications or modified shapes, which are derived from equivalent concepts thereof, should be understood as being included in the scope of the present invention.
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Provided is a headlamp of a vehicle, and more particularly, an automotive headlamp which is structured in a simple manner to secure a sufficient amount of light, emit light in different beam patterns, and improve heat dissipation efficiency thereof. The automotive headlamp includes: a plurality of lamp modules disposed in different directions from an optical axis of the automotive headlamp; and a projection lens projecting light emitted from one or more of the lamp modules. Each of the lamp modules includes a light source unit emitting light downward, and a reflector disposed under the light source unit and reflecting light emitted from the light source unit.
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BACKGROUND
1. Field of the Invention
The invention relates to detecting and correcting errors in arrays after successful ABIST testing, where diagnostic testing is performed upon the array after ABIST testing, and the detected error or fault is isolated.
2. Background Art
The problem of past s390-processors was, that whenever a PU (processor unit) has an array with errors found by abist-tests, there was no possibility to disable part or all of this array. In this cases the PU couldn't be used at all since the abist-tests didn't pass IML.
Especially the sensitive PCAMs used in Bluefire did often fail and decrease the yield heavily, and therefore we looked for a solution to get also PUs with defect array sets running.
Because the yield-problem will most likely get bigger with new technologies and having more cores on a chip, it might be useful to have also partial good chips with failing arrays for spare PUs or at least for chip and system bring-up.
Actually array fails occurring during normal operation mode (after abist-tests did run successfully) leads in deletion of the failing array set. This ensures, that the PU can be used also after an upcoming fail, but with less array sets (results in slightly decreased performance, but w/o showing functional problems). The problem is, that PUs with defective arrays found on the tester cannot be used in a system.
Because of the given performance delta it also implies that such a processor can not be shipped the same as a processor without any array sets disabled for the performance delta between the two is readily measurable.
SUMMARY OF THE INVENTION
The DANU-Processor has a TLB2 which is a 4 set, associative, hierarchical lookaside buffer (2 levels of hierarchy). Each of the sets has a RAM part (random access memory) and a CAM part (content access memory). Especially the CAM-part is very sensitive to fails with the new technology, and therefore a solution was necessary which enables a processor to disable one or more defect sets of the TLB2. This makes it possible (especially during the bring-up process) to use also the processors with defective TLB2 arrays which increases the yield during bring-up dramatically. Since now processors with one or more failing TLB2 array sets must be configured out and cannot be used.
The functional logic could delete sets already in the Freeway-system, but this works only for fails occurring after the IML sequence, because during IML the ABIST do check the arrays, and fails being present already at that point didn't pass the ABIST-test (MISR signature fails) and therefore this processor having a defect TLB2-set couldn't be used, even though the processor would work properly with one or even all TLB2-sets being defect.
The solution is to use e-fuses (one fuse for each of the sets) and to have separate misr latch busses for each set of the array. This new array misr latch structure enable the abist engine to handle the disabled sets from the array. The abist engine can analyze each set unique from each other.
If a set is failing in the fab, the fuse for this set will be blown and the chip can used.
PU's having defective array sets can be used in the system, either for bring-up or shipping. The yield is dramatically increased with the new array delete mechanisms.
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 are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a simplified schematic diagram showing a processor unit with three arrays, e.g., translation look aside buffers, one of which is shown as defective. The processor includes associated ABIST test units. The output is “anded.”
FIG. 2 is a simplified schematic diagram showing a processor unit with three arrays, e.g., translation look aside buffers, one of which is shown as defective. The processor includes associated ABIST test units, and fused inputs to take defective arrays out of service. The output is “anded.”
FIG. 3 illustrates several associated arrays with an E-fuse isolating a defective array. An E-fuse indicates a bad PCAM set that will disable the clocking and force a constant value to the MISR latches for the master and slave PCAMS.
FIG. 4 illustrates an overall processor with an input latch bank, dynamic PCAM array, deselect quad control line, and array and data logic.
DETAILED DESCRIPTION
The steps of the method are as follows:
The first step is checking for failing array sets during fabrication, that is ABIST testing. As part of or after testing, appropriate fuses are blown to deactivate failing array set. For example, during bring-up only performance degradation will be noticed but no functional degradation and no ABIST-fail will occur.
As to ABIST-fails found during bring-up:
a) Analyze reported ABIST-fail; b) Blow appropriate e-fuse to deactivate failing array set; c) Rerun ABIST with standard setup, d) The fail will not occur, because the MISR signature will be good due to the masking by the described built-in hardware, i.e., blowing the fuse.
In system run:
a) The system starts and runs the ABIST tests b) The activated fuses will force “good” MISR-signatures in order to pass the ABIST test during IML c) SE reads out the fuse values and sets the delete-latches (via scan-chain) for each fused array set. This is necessary to tell the translator logic not to use the defective array set. d) The system runs with less performance, but functionally correct
For future designs this logic delete latches can be set directly by the fuses instead of doing this SE controlled.
This is illustrated in the Figures, Starting with FIG. 1 , FIG. 1 is a simplified schematic diagram showing a processor unit 101 with three arrays, e.g., translation look aside buffers 103 , one of which is shown as defective 105 . The processor includes associated ABIST test units 107 . The output is “anded” 109 .
FIG. 2 is tracks FIG. 1 , but in addition it shows how the e-fuse values are read-out by the SE (Service Element) in order to set the “ignore Data latches” with the appropriate values.
FIG. 3 illustrates several associated arrays with an E-fuse isolating a defective array. An E-fuse 111 indicates a bad PCAM set that will disable the clocking and force a constant value to the MISR latches for the master and slave PCAMS. It is to be noted that read data from a deselected set or quad must not get into the MISR or array data out latches for both master and slave PCAMs.
FIG. 4 illustrates the implementation of the deselection inside a PCAM-set. 201 is the input latch bank of a PCAM, 205 the dynamic PCAM array, 209 the deselect quad control line switch and 213 the MISR logic.
BHT
The branch prediction takes the deletion logic a step further where as the performance impact is around 1/1000 th of 1% of PU performance. The branch prediction logic consist of a BTB, branch target buffer, which has 8 k entries. The array is 4-way set associative and is 2 k deep. Each entry in this table is 64 bits. This places the array at over ½ million array bits which were priority required to be perfectly designed in the manufacturing process.
As per the TLB2, the BTB contains a mechanism at run time to detect an array failure, which could have developed over time, and to delete the appropriate set such that the processor unit could continue running without encountering further failure encounters from the given set of the BTB array. Such a deletion process required entries to 1) no longer be written to this set of the array and 2) ignore any future errors detected from this set of the given array as data from this set is no longer in use.
When the ABIST engine checks for the validity of an array, it is checking cell by cell for functional compliance. It is therefore possible to not only detect which set of the given array is bad, but also which precise entry of the array is bad for the exact bad cell is known. Fuses are not only contained for the given set but also the given index for the entry of the bad cell. For a given bad array cell, this now allows disable actions to take place on 1/8192 nd of the array entries over ¼ th of the array entries.
When a write is to take place to the index value which contains a bad cell in one of the sets, logic which determines the set to write a given entry into makes it appear that the set with the bad cell is disabled. This prevents the given set with the bad cell from being written to. Upon moving array from the index with a bad entry, in respect to a write, the given set no longer looks as though it is deleted.
The invention may be implemented, for example, by having the system for testing the array and enabling the abist engine to handle disabled sets from the array. The abist engine can analyze each set unique from each other so that if a set is failing under test, the fuse for this set will be blown, and the processing unit used PU's having defective array sets can be used in the system, and executing the method as a software application, in a dedicated processor or set of processors, or in a dedicated processor or dedicated processors with dedicated code. The code executes a sequence of machine-readable instructions, which can also be referred to as code. These instructions may reside in various types of signal-bearing media. In this respect, one aspect of the present invention concerns a program product, comprising a signal-bearing medium or signal-bearing media tangibly embodying a program of machine-readable instructions executable by a digital processing apparatus to perform a method for isolating defective cells in a processing unit.
This signal-bearing medium may comprise, for example, memory in a server. The memory in the server may be non-volatile storage, a data disc, or even memory on a vendor server for downloading to a processor for installation. Alternatively, the instructions may be embodied in a signal-bearing medium such as the optical data storage disc. Alternatively, the instructions may be stored on any of a variety of machine-readable data storage mediums or media, which may include, for example, a “hard drive”, a RAID array, a RAMAC, a magnetic data storage diskette (such as a floppy disk), magnetic tape, digital optical tape, RAM, ROM, EPROM, EEPROM, flash memory or magneto-optical storage. As an example, the machine-readable instructions may comprise software object code, compiled from a language such as “C++”, Java, Pascal, ADA, assembler, and the like.
Additionally, the program code may, for example, be compressed, encrypted, or both, and may include executable code, script code and wizards for installation, as in Zip code and cab code. As used herein the term machine-readable instructions or code residing in or on signal-bearing media include all of the above means of delivery.
While the foregoing disclosure shows a number of illustrative embodiments of the invention, it will be apparent to those skilled in the art that various changes and modifications can be made herein without departing from the scope of the invention as defined by the appended claims. Furthermore, although elements of the invention may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated.
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Detecting and correcting errors in arrays after ABIST testing, after ABIST testing, detected errors are faults are isolated by blowing a fuse.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims priority from Japanese Patent Application No. JP 2005-056648 , filed Mar. 1, 2005, the entire disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to how to control a write current in a magnetic disk drive.
[0003] In recent years, magnetic disk drives including hard disk drives are used not only in computers, but also in hard disk recorders, portable music players, car navigation systems, and the like. Thus, the use of magnetic disk drives is expanding. Following this tendency, content handled by the magnetic disk drives is not limited to textual information. In recent years, the content covers music, images, video, and the like.
[0004] As shown in FIG. 6 , for example, a magnetic disk drive comprises: a plurality of magnetic disks 400 , each of which has a non-magnetic disk such as glass on which a magnetic layer is laminated; and a plurality of magnetic heads 401 . Each of the magnetic heads 401 includes a write head for writing data to each magnetic disk 400 , and a read head for reading data from said each magnetic disk 400 . The plurality of magnetic disks 400 are mounted to one spindle 402 . The plurality of magnetic heads 401 , the number of which is the same as the number of surfaces of the magnetic disks 400 , are mounted to arms 403 . The arms 403 are pivotally moved by a voice coil motor (hereinafter referred to as “VCM”) 404 . When write processing of writing data to the magnetic disk 400 or read processing of reading data from the magnetic disk 400 is performed, the magnetic head 401 is moved to a position that faces a surface of the magnetic disk 400 . When both of the write processing and the read processing are not performed, the magnetic head 401 is unloaded from the surface of the magnetic disk 400 .
[0005] In such a magnetic disk drive, data is written to an area that is concentrically located on the magnetic disk 400 ; or data is read out from the area. This area is called a track.
[0006] FIG. 7 is a diagram illustrating an example of tracks 501 located on a magnetic disk 500 . As shown in FIG. 7 , a plurality of tracks 501 are concentrically located at constant intervals (track pitch T). Each of the tracks 501 includes servo areas S and data areas D. The servo areas S are used to write information that is used when a magnetic head (not illustrated) is positioned at the time of read/write processing. The data areas D are used to write user data such as music data. It is to be noted that this data area D can be divided into the smallest units that can be accessed by the magnetic head. These units are called sectors.
[0007] It is demanded to increase the capacity of the magnetic disk 500 without sacrificing the miniaturization of the magnetic disk drive as a whole. In order to meet the demand, the recording density is improved, for example, by increasing the density (linear recording density) of data that is written in the circumferential direction of the tracks 501 located on the magnetic disk 500 , or by reducing the width of each of the tracks 501 to narrow the track pitch T so that the track density is increased.
[0008] FIG. 8 is a diagram partially illustrating a structure of a write head. In this write head, by applying an electric current to a coil 600 , a magnetic field is generated between a surface of an upper magnetic pole piece 601 that faces a magnetic disk surface (hereinafter referred to as “air bearing surface 602 ”) and a lower magnetic pole piece 603 . The magnetic field causes the magnetic disk surface to be magnetized, with the result that data is written there. In order to narrow the track width so that the recording density is improved as described above, for example, it is necessary to narrow the tip of the write head. However, if the tip of the write head becomes narrower and narrower, the tip is saturated with magnetic flux. Accordingly, a phenomenon will occur in which a magnetic field leaks out not only from the air bearing surface 602 of the upper magnetic pole piece 601 but also from the side 604 of the upper magnetic pole piece 601 . For this reason, if the track pitch is narrow, a leakage field from this side 604 extends over adjacent tracks that are located on both sides of a target track to which data is written. This leakage field from the side 604 is feeble in comparison with a write magnetic field that is generated between the air bearing surface 602 and the lower magnetic pole piece 603 so as to write data to a target track. The leakage field in question, therefore, does not immediately exert an influence upon data in the adjacent tracks. However, the data in the adjacent tracks is gradually erased if the leakage field repeatedly extends over the adjacent tracks multiple times. As a result, a phenomenon occurs eventually in which the data cannot be read out. This phenomenon is called ATI (Adjacent Track Interference).
[0009] With the object of solving the problem of ATI, for example, taking into consideration a change in temperature of a magnetic disk drive, a write-current value was heretofore determined (for example, see patent document 1 (Japanese Patent Laid-open No. 10-312504 )).
[0010] However, as described above, fields and applications in which magnetic disk drives are made use of are expanded. For example, even if the same magnetic disk drive is used, a possibility of the occurrence of ATI may change to a large extent depending on how the magnetic disk drive is used by end users.
[0011] To be more specific, for example, if an end user uses a magnetic disk drive as a large-capacity storage medium for a music player, once music data is written to the magnetic disk drive, what is performed is mainly reading of the music data. Since the number of times data is written is small, therefore, the problem of ATI hardly occurs.
[0012] On the other hand, for example, if the end user uses the magnetic disk drive as a storage medium to which image data as a photograph taken by a digital camera is temporarily written, image data is frequently written or erased. Accordingly, the problem of ATI is liable to occur.
[0013] The conventional magnetic disk drives described above could not sufficiently prevent such ATI encountered depending on how the magnetic disk drive was used by the end user, in some cases.
BRIEF SUMMARY OF THE INVENTION
[0014] The present invention has been devised in view of the above-mentioned problems. It is therefore a feature of the present invention to provide a write-current control chip capable of effectively preventing ATI encountered depending on how a magnetic disk drive is used, and a magnetic disk drive using the write-current control chip.
[0015] In order to solve the above-mentioned problems, according to one aspect of the present invention, there is provided a magnetic disk drive in which a magnetic head writes data to a magnetic disk. The magnetic disk drive includes: an acquisition module for acquiring the number of times of write processing in which data is written to the magnetic disk; a determination module, on the basis of the acquired number of times of write processing, for determining a write-current value used when the magnetic head writes data to the magnetic disk; and an instruction mechanism for instructing the magnetic head to write the data to the magnetic disk by use of the determined write-current value.
[0016] According to another aspect of the present invention, there is provided a magnetic disk drive in which a magnetic head writes data to a magnetic disk. The magnetic disk drive includes: an acquisition module for acquiring an amount of data written to the magnetic disk; a determination module, on the basis of the acquired amount of data, for determining a write-current value used when the magnetic head writes data to the magnetic disk; and an instruction mechanism for instructing the magnetic head to write the data to the magnetic disk by use of the determined write-current value.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a block diagram illustrating a main configuration of a magnetic disk drive according to one embodiment of the present invention.
[0018] FIG. 2 is a functional block diagram illustrating, as an example, main processing of a write-current control chip according to one embodiment of the present invention.
[0019] FIG. 3 is a graph illustrating write-current candidate values according to one embodiment of the present invention.
[0020] FIG. 4 is a flowchart illustrating main steps executed by a write-current control chip according to one embodiment of the present invention.
[0021] FIG. 5 is a functional block diagram illustrating, as another example, main processing of a write-current control chip according to one embodiment of the present invention.
[0022] FIG. 6 is an explanatory diagram illustrating an example of a magnetic disk drive.
[0023] FIG. 7 is an explanatory diagram illustrating tracks located on a magnetic disk.
[0024] FIG. 8 is an explanatory diagram illustrating an example of a write head.
DETAILED DESCRIPTION OF THE INVENTION
[0025] A write-current control chip (hereinafter referred to as “control chip”) and a magnetic disk drive using the control chip in question according to one embodiment of the present invention will be below described with reference to the drawings. In this embodiment, the control chip operates as part of the magnetic disk drive.
[0026] FIG. 1 is a block diagram illustrating a main configuration of the magnetic disk drive that uses this control chip. As shown in FIG. 1 , this magnetic disk drive includes: a micro processing unit (hereinafter referred to as “MPU”) 100 ; a nonvolatile memory 101 ; a random access memory (hereinafter referred to as “RAM”) 102 ; a hard disk controller (hereinafter referred to as “HDC”) 103 ; a data buffer 104 ; a servo controller 105 ; a R(read)/W(write) channel 106 ; a R/W amplifier 107 ; a write head 108 ; a read head 109 ; a magnetic disk 110 ; a VCM driver 111 ; a VCM 112 ; an arm 113 ; and a magnetic head 114 .
[0027] The MPU 100 includes a CPU (central processing unit), and operates according to a program stored in the nonvolatile memory 101 . In this embodiment, part of this MPU 100 performs main processing of write current control including the determination of a write-current value used in write processing. Specific contents of this write-current control processing will be described in detail later. This MPU 100 has an instruction part that generates instruction data including a command for specifying a write-current value, and then outputs the instruction data to the HDC 103 . The nonvolatile memory 101 can be realized by use of a flash ROM (read only memory) or an EEPROM (electronically erasable and programmable read only memory). The nonvolatile memory 101 stores a program (software) to be executed by the MPU 100 , and stores data that is generated as a result of the processing performed by the MPU 100 . The RAM 102 is made use of as a working memory for keeping various kinds of data that is used in the processing performed by this MPU 100 .
[0028] The HDC 103 receives, from a host computer, write data to be written to the magnetic disk 110 , and stores the write data in question in the data buffer 104 formed of a SRAM (static RAM) or a DRAM (dynamic RAM). Next, this HDC 103 determines an address on the magnetic disk 110 at which the write data is written. More specifically, the HDC 103 determines: an identification number for identifying a surface of the magnetic disk 110 to which write data should be written; a track number, and a sector number, on the magnetic disk 110 ; and a number of the write head 108 that performs write processing on the surface of the magnetic disk 110 . Then, the HDC 103 outputs to the servo controller 105 a command that moves the write head 108 to the determined address on the magnetic disk 110 . After that, the servo controller 105 acquires, through the R/W amplifier 107 and the R/W channel 106 , servo information that is written to the magnetic disk 110 . The servo information is read out by the read head 109 . On the basis of the acquired servo information, the servo controller 105 outputs a command to the VCM driver 111 so that the write head 108 is moved to a position of a track that includes a sector on the magnetic disk 110 specified by the HDC 103 . According to the command received from the servo controller 105 , this VCM driver 111 drives the VCM 112 so that the arm 113 pivotally moves. As a result, the write head 108 of the magnetic head 114 , which is mounted at the tip of the arm 113 , is moved to a target track position. Thus, as soon as it is ready for write processing, the HDC 103 reads out the write data stored in the data buffer 104 , and then outputs the write data to the R/W channel 106 . Incidentally, allowing for the rotation of the magnetic disk 110 , this HDC 103 outputs the write data in question to the R/W channel 106 in the timing in which the write head 108 can write the write data to a target sector on the magnetic disk 110 , the target sector being identified by an identification number.
[0029] The R/W channel 106 encodes the write data received from the HDC 103 , and then outputs the encoded write data to the R/W amplifier 107 . Using the write-current value specified by the instruction data received from the HDC 103 , the R/W amplifier 107 instructs the write head 108 to write to the magnetic disk 110 the encoded write data received from the R/W channel 106 . According to the instruction received from the RIW amplifier 107 , the write head 108 writes the encoded write data to the magnetic disk 110 .
[0030] In addition, also at the time of read processing, as is the case with the write processing, the read head 109 is first positioned at a track position on the magnetic disk 110 . Here, at the track position a sector exists to which data to be read out is written. Next, on completion of the positioning, the read head 109 reads out the data from the target sector in the timing when the specified sector on the rotating magnetic disk 110 arrives at a position of the read head 109 . Then, the R/W amplifier 107 amplifies a waveform of the data that has been read out. Further, the R/W channel 106 decodes the amplified data into an original state of data before outputting the decoded data to the HDC 103 . The HDC 103 outputs the data to the host computer.
[0031] Next, control processing of a write current will be described. The control processing is performed by a control chip used in the magnetic disk drive. In this embodiment, this control chip is a chip comprising the MPU 100 and the HDC 103 . FIG. 2 is a functional block diagram illustrating main processing performed by the control chip. As shown in FIG. 2 , this control chip functionally includes the number-of-times-of-write-processing acquisition part 200 , a write-processing frequency calculation part 201 , and a write-current-value determination part 202 .
[0032] The number-of-times-of-write-processing acquisition part 200 acquires the number of times of write processing in which the write head 108 writes data to the magnetic disk 110 in the magnetic disk drive. More specifically, for example, this number-of-times-of-write-processing acquisition part 200 counts, for each surface of the magnetic disk 110 , the number of times the HDC 103 (refer to FIG. 1 ) has received write data from the host computer, or the number of times the write head 108 has written the write data to the magnetic disk 110 . After that, this acquisition part 200 generates a data table for storing the number of times of write processing. In the data table, a total value of the number of times of write processing counted for each magnetic disk surface is stored with the total value being associated with an identification number for identifying said each magnetic disk surface. The acquisition part 200 then stores the data table in the nonvolatile memory 101 . It is to be noted that this acquisition part 200 may also write, to the magnetic disk surface, the data table for storing the number of times of write processing.
[0033] Moreover, for example, during the operation of the magnetic disk drive (for example, while the power of the magnetic disk drive stays in an On state), this number-of-times-of-write-processing acquisition part 200 may also keep the number of times of write processing in a memory, such as the RAM 102 , to which read/write accesses can be made at high speed. To be more specific, in this case, for example, when the magnetic disk drive is started up (for example, when a program stored in the ROM is started up), this acquisition part 200 reads out the number of times of write processing stored in the nonvolatile memory 101 , and keeps the number of times of write processing in the RAM 102 . Then, when write processing is newly performed on a certain surface of a magnetic disk, the acquisition part 200 performs update processing of the data table for storing the number of times of write processing kept in the RAM 102 . This update processing is performed by adding the new write processing in question to a total value of the number of times of write processing that is associated with the identification information for identifying the surface of the magnetic disk on which the new write processing has been performed.
[0034] Additionally, in this case, before the power of the magnetic disk drive is turned off (for example, when an instruction to turn the power of the magnetic disk drive off is inputted from the host computer), this number-of-times-of-write-processing acquisition part 200 stores the number of times of write processing, which is kept in the RAM 102 , in the nonvolatile memory 101 or the magnetic disk 110 . Incidentally, not only at the instant when the power of the magnetic disk drive is interrupted, but also during the operation, this acquisition part 200 may store the number of times of write processing, which is kept in the RAM 102 , in the nonvolatile memory 101 , for example, at predetermined time intervals. Together with the identification information of the magnetic disk surface, which is associated with the number of times of write processing after the update, this acquisition part 200 outputs the number of times of write processing after the update to the write-processing frequency calculation part 201 or the write-current-value determination part 202 .
[0035] On the basis of the number of times of write processing that has been received from the number-of-times-of-write-processing acquisition part 200 , the write-processing frequency calculation part 201 calculates, as a frequency of write processing, the number of times of write processing per unit time on a magnetic disk surface that is identified by the identification information received from the acquisition part 200 . More specifically, the calculation part 201 calculates, for example, a period of time during which the power of the magnetic disk drive is in the On state (this period of time is Power On Hour (hereinafter referred to as “POH”)), and then calculates a frequency value of write processing by dividing the number of times of write processing by the POH.
[0036] To be more specific, this write-processing frequency calculation part 201 acquires the elapsed time after the power of the magnetic disk drive is turned on (for example, the elapsed time after the supply of an electric current to the magnetic disk drive is started), and then keeps the elapsed time in the RAM 102 . After that, the calculation part 201 calculates, as the latest POH, the elapsed time after the power in question is turned on until the number of times of write processing is received from the number-of-times-of-write-processing acquisition part 200 . Then the calculation part 201 calculates the latest write-processing frequency value by dividing the number of times of write processing by the latest POH. It is to be noted that this elapsed time is counted by use of, for example, a timer included in the magnetic disk drive, and that this calculation part 201 acquires the elapsed time that is monitored by the timer.
[0037] Alternatively, for example, if the power of the magnetic disk drive is turned ON and is then turned OFF, the write-processing frequency calculation part 201 also may keep, in the nonvolatile memory 101 , the elapsed time after the power of the magnetic disk drive is turned ON until the power is turned OFF. After that, when a write-processing frequency is calculated, the POH may be calculated which includes the elapsed time after the power is turned ON until the power is turned OFF. In this case, for example, when the calculation part 201 receives the number of times of write processing from the number-of-times-of-write-processing acquisition part 200 , the calculation part 201 calculates an accumulated POH by adding the latest POH to the past POH after the power is turned ON in the past until the power is turned OFF. Then the calculation part 200 calculates an accumulated write-processing frequency value by dividing the number of times of write processing by the accumulated POH. Then, the calculation part 201 outputs, to the write-current-value determination part 202 , the calculated write-processing frequency value together with the identification information of the magnetic disk surface corresponding to the write-processing frequency in question (more specifically, the identification information received from the acquisition part 200 ).
[0038] On the basis of the write-processing frequency value received from the write-processing frequency calculation part 201 , the write-current-value determination part 202 determines a write-current value that is used when the write head 108 writes write data to a magnetic disk surface (i.e., a magnetic disk surface identified by the identification number received from the calculation part 201 ) corresponding to the write-processing frequency.
[0039] To be more specific, for example, if the nonvolatile memory 101 or the RAM 102 keeps a plurality of predetermined write-current candidate values, this write-current-value determination part 202 selects one write-current candidate value from among the plurality of write-current candidate values on the basis of the write-processing frequency value received from the write-processing frequency calculation part 201 . Then the determination part 202 adopts the selected write-current candidate value as a write-current value used for actual write processing. Incidentally, the embodiment will be described, as an example, in a case where the nonvolatile memory 101 or the RAM 102 keeps three write-current candidate values (hereinafter referred to as a “first candidate value A”, a “second candidate value B”, and a “third candidate value C”).
[0040] As shown in FIG. 3 , these write-current candidate values, which are kept beforehand, are determined on the basis of the relationship between a write-current value used in the magnetic disk drive (a horizontal axis in FIG. 3 ) and a bit error rate (hereinafter referred to as “BER”) obtained when the write-current value in question is used (a vertical 5 axis in FIG. 3 ).
[0041] Here, when data is read out from the magnetic disk 110 by the read head 109 and the R/W channel 106 decodes the data, the BER is calculated as a ratio of the number of error bits of the decoded data to the number of bits of the decoded data that have been read out. In other words, the BER is calculated as a probability that an error occurs when a certain number of bits of data are read out. For example, if one-bit error occurs when 10 n − bit data is read out, a calculation is made as follows: log BER = 1/10 n =− n. Accordingly, in FIG. 3 , it is understood that with a decrease in value of logBER in the vertical axis, a probability of the occurrence of an error decreases (more specifically, BER is small). Moreover, three curves X, Y, Z shown in FIG. 3 indicate respective logBER values corresponding to data read out from a specific track to which the data is written. These curves X, Y, Z are obtained when, by use of each write-current value shown in the horizontal axis, write processing is performed on the adjacent tracks, on both sides, of the specific track the predetermined number of times, i.e., x times, y times, and once respectively (x, y are integers that are two or more; and x is larger than y).
[0042] As shown in FIG. 3 , if write processing is performed x times in the magnetic disk drive, the first candidate value A is set as the maximum write-current value at which logBER is smaller than a predetermined upper limit L. In other words, the first candidate value A is set as an upper limit of the write-current value.
[0043] In addition, if write processing is performed y times, which is smaller than x times, 25 in the magnetic disk drive, the second candidate value B is set as a write-current value at which logBER becomes minimum. Incidentally, this number of times y is set as the number of times of write processing that is assumed to be performed in the average operation of the magnetic disk drive by end users.
[0044] Moreover, if write processing is performed x times in the magnetic disk drive, the 30 third candidate value C is set as a write-current value at which logBER becomes minimum. In other words, the third candidate value C is set as a lower limit of the write-current value.
[0045] Incidentally, as shown in FIG. 3 , the second candidate value B is set as a write-current value that is smaller than the first candidate value A, and that is large than the third candidate value C.
[0046] In this embodiment, by setting beforehand the write-current candidate values in this manner, if write processing is performed x times in the magnetic disk drive, the write-current-value determination part 202 can set a write-current value within a range within which, as shown in FIG. 3 , a value of logBER does not exceed the predetermined upper limit L of logBER.
[0047] To be more specific, for example, if the nonvolatile memory 101 or the RAM 102 keeps a plurality of predetermined write-processing frequency threshold values, this write-current-value determination part 202 compares the write-processing frequency value received from the write-processing frequency calculation part 201 with the plurality of write-processing frequency threshold values. Then, on the basis of the result of the comparison, the determination part 202 selects from among three write-current candidate values one write-current candidate value that satisfies predetermined selection conditions, and then adopts the selected write-current candidate value as a write-current value.
[0048] To be more specific, in this case, for example, it is assumed that the nonvolatile memory 101 keeps two frequency threshold values in advance (hereinafter referred to as a “first frequency threshold value p” and a “second frequency threshold value q”; and the first frequency threshold value p is smaller than the second frequency threshold value q). If it is judged that the write-processing frequency received from the write-processing frequency calculation part 201 is smaller than the first frequency threshold value p that is one of the two frequency threshold values, this write-current-value determination part 202 selects the first candidate value A, and then adopts the first candidate value A as a write-current value. Next, if it is judged that the write-processing frequency is equivalent to the first frequency threshold value p or more, and that the write-processing frequency is smaller than the second frequency threshold value q, the determination part 202 adopts the second candidate value B as a write-current value. If it is judged that the write-processing frequency in question is equivalent to the frequency threshold value q or more, the determination part 202 adopts the third candidate value C as a write-current value.
[0049] In addition, the write-current-value determination part 202 may also determine a write-current value on the basis of the number of times of write processing received from the number-of-times-of-write-processing acquisition part 200 . To be more specific, in this case, the determination part 202 compares, for example, the number of times of write processing received from the acquisition part 200 with a plurality of predetermined threshold values of the number of times of write processing, which are kept in the nonvolatile memory 101 or the RAM 102 . After that, on the basis of the result of the comparison, the write-current-value determination part 202 selects, from among three write-current candidate values, one write-current candidate value that satisfies predetermined selection conditions, and then adopts the selected write-current candidate value as a write-current value.
[0050] To be more specific, in this case, it is assumed that two number-of-times threshold values are kept beforehand in the nonvolatile memory 101 (hereinafter referred to as a “first number-of-times threshold value v” and a “second number-of-times threshold value w”; and the first number-of-times threshold value v is smaller than the second number-of-times threshold value w). For example, if the number of times of write processing received from the number-of-times-of-write-processing acquisition part 200 is judged to be smaller than the first number-of-times threshold value v, this write-current-value determination part 202 adopts the first candidate value A as a write-current value. Next, if it is judged that the number of times of write processing is equivalent to the first number-of-times threshold value v or more, and that the number of times of write processing is smaller than the second number-of-times threshold value w, the determination part 202 adopts the second candidate value B as the write-current value. If it is judged that the number of times of write processing in question is larger than the second number-of-times threshold value w, the determination part 202 adopts the third candidate value C as the write-current value.
[0051] The write-current-value determination part 202 outputs to the HDC 103 a command that instructs the HDC 103 to perform, by use of the write-current value that has been determined in such a manner, write processing on a magnetic disk surface corresponding to the write-current value in question. As a result, by using the write-current value that has been determined by the write-current-value determination part 202 , the write head 108 performs the write processing of writing to the magnetic disk surface that is specified by the determination part 202 .
[0052] Furthermore, in this embodiment, the control chip may acquire the amount of data that is written to the magnetic disk 110 by the write head 108 so that a write-current value used when the write head 108 writes data to the magnetic disk in question is determined on the basis of the acquired amount of data.
[0053] FIG. 5 is a functional block diagram illustrating main processing performed by the control chip in the above case. To be more specific, as shown in FIG. 5 , this control chip functionally includes an amount-of-write-data acquisition part 203 , the write-processing frequency calculation part 201 , and the write-current-value determination part 202 . Incidentally, the calculation part 201 and the determination part 202 determine a write-current value on the basis of the amount of write data by performing processing similar to the processing of determining a write-current value on the basis of the number of times of write processing or the write-processing frequency, which has been described above.
[0054] To be more specific, this amount-of-write-data acquisition part 203 acquires, for example, the number of bytes of write data that is received from the host computer by the HDC 103 , and also acquires, as the amount of write data: a total value of the number of bytes of write data that has been written to the magnetic disk 110 within a period of time from the shipment of the magnetic disk drive until the time at which the HDC 103 receives the write data from the host computer; a total value of the number of bytes of data that has been most recently written to the magnetic disk 110 within a fixed period of time; and the like. The acquisition part 203 then keeps the values in the nonvolatile memory 101 or the RAM 102 .
[0055] In this case, the write-current-value determination part 202 determines a write-current value, for example, on the basis of the amount of write data that has been acquired by the amount-of-write-data acquisition part 203 in the past. To be more specific, in this case, for example, as with the case where a write-current value is determined on the basis of the number of times of write processing, the determination part 202 compares the amount of write data received from the amount-of-write-data acquisition part 203 with a plurality of threshold values of the amount of write data, which are kept in the nonvolatile memory 101 or the RAM 102 . On the basis of the result of the comparison, the determination part 202 selects, from among the plurality of write-current candidate values, one write-current candidate value that satisfies predetermined selection conditions, and then adopts the selected write-current candidate value as a write-current value. In this case, for example, as is the case with the example shown in FIG. 3 , the plurality of write-current candidate values include: a first candidate value (an upper limit of the write-current value) that is set as the maximum write-current value at which logBER is smaller than a predetermined upper limit when a first predetermined amount of data is written in the magnetic disk drive; a second candidate value that is set as a write-current value at which logBER becomes minimum when a second amount of data, which is smaller than the first amount of data, is written; and a third candidate value (a lower limit of the write-current value) that is set as a write-current value at which logBER becomes minimum when the first amount of data is written. Incidentally, the write-current-value determination part 202 may also determine the write-current value within a range within which a value of logBER does not exceed a predetermined upper limit of logBER when the first amount of data is written in the magnetic disk drive.
[0056] In this case, as is the case with the above-mentioned calculation of a write-processing frequency from the number of times of write processing, the write-processing frequency calculation part 201 calculates, as a write-processing frequency, the amount of write data that has been written per unit time by dividing the amount of write data received from the amount-of-write-data acquisition part 203 by POH. For example, as is the case with the determination of the write-current value on the basis of the number of times of write processing and the write-processing frequency described above, the write-current-value determination part 202 determines a write-current value on the basis of the write-processing frequency received from the calculation part 201 .
[0057] Next, a flow of processing in which the control chip determines a write-current value will be described. Here, a description will be made, as an example, of a case where the magnetic disk drive is configured beforehand (for example, at the time of shipment of the magnetic disk drive) to use the second candidate value B as a write-current value, and then the control chip changes the write-current value used in the magnetic disk drive according to the frequency of write processing performed in the magnetic disk drive. It is to be noted that the nonvolatile memory 101 keeps two write-processing frequency threshold values (hereinafter referred to as a “first frequency threshold value p” and a “second frequency threshold value q”) that are predetermined on the basis of, for example, the performance and reliability of the magnetic disk drive.
[0058] FIG. 4 is a flowchart illustrating, as an example, main steps of processing performed by the control chip. The HDC 103 may receive new write data from the host computer, or write processing may be performed so that the write data in question is written to a certain magnetic disk surface (hereinafter referred to as a “target disk surface”). In this case, as shown in FIG. 4 , the number-of-times-of-write-processing acquisition part 200 updates a total value of the number of times of write processing by adding the number of times of new write processing in question to the total value of the number of times of past write processing, which is kept in the RAM 102 with this total value in question being associated with an identification number of the target disk surface (S 300 ). Then, the acquisition part 200 outputs, to the write-processing frequency calculation part 201 , the identification number of the target disk and the number of times of write processing after the update.
[0059] On receipt of the number of times of write processing from the number-of-times-of-write-processing acquisition part 200 , the write-processing frequency calculation part 201 calculates, as an accumulated POH, the elapsed time until the receipt of the number of times of write processing. After that, the calculation part 201 calculates a write-processing frequency value f corresponding to the target disk surface by dividing the write-processing frequency by the accumulated POH (S 301 ). Then, the calculation part 201 outputs the write-processing frequency value f and the identification number of the target disk to the write-current-value determination part 202 .
[0060] First of all, the determination part 202 judges whether or not the write-processing frequency value f received from the calculation part 201 is smaller than the first frequency threshold value p (S 302 ).
[0061] In this case, if it is judged that the write-processing frequency value f is smaller than the first frequency threshold value p (Yes in the step S 302 ), the determination part 202 adopts the first candidate value A as a write-current value to be used for write processing on the target disk (S 303 ), and then the processing ends.
[0062] On the other hand, if it is judged that the write-processing frequency f is equivalent to the first frequency threshold value p or more in a step S 302 (No in the step S 302 ), the determination part 202 further judges whether or not the write-processing frequency f is smaller than the second frequency threshold value q (S 304 ).
[0063] Here, if it is judged that the write-processing frequency value f is smaller than the second frequency threshold value q (Yes in the step S 304 ), the determination part 202 adopts the second candidate value B as a write-current value to be used for write processing on the target disk (S 305 ), and then the processing ends.
[0064] On the other hand, if it is judged that the write-processing frequency f is equivalent to the second frequency threshold value q or more in the step S 304 (No in the step S 304 ), the write-current-value determination part adopts the third candidate value C as a write-current value to be used for the write processing on the target disk (S 306 ), and then ends the processing.
[0065] It is to be noted that the write-current control chip and the magnetic disk drive according to the present invention are not limited to the examples described above. For example, the number-of-times-of-write-processing acquisition part 200 may also be configured to acquire not only the number of times of write processing but also the number of times of read processing. In this case, as a write-processing frequency, the write-processing frequency calculation part 201 calculates, for example, a ratio of the number of times of write processing to the total number of times of processing that is the sum of the number of times of write processing and the number of times of read processing, a ratio of the number of times of write processing to the number of times of read processing, or the like.
[0066] In addition, the write-processing frequency calculation part 201 may acquire the elapsed time in various kinds of timing when the control chip or the magnetic disk drive performs processing so as to calculate POH by use of the elapsed time. Examples of the various kinds of timing include, for example, timing when the HDC 103 receives write data from the host computer, and timing when the number-of-times-of-write-processing acquisition part 200 updates the number of times of write processing. To be more specific, in this case, the calculation part 201 calculates a write-processing frequency value by dividing a total value of the number of times of write processing by POH, for example. The total value of the number of times of write processing is within the past fixed period of time, i.e., within a predetermined fixed period of time before the acquisition part 200 updates the number of times of write processing. The POH indicates the past fixed period of time. Additionally, in this case, the determination part 202 determines the write-current value on the basis of the write-processing frequency within the latest fixed period of time that has been calculated by the calculation part 201 , and the magnetic disk drive then performs the write processing by use of the determined write-current value.
[0067] Moreover, for example, even if the calculation part 201 cannot receive the number of times of write processing from the acquisition part 200 , the calculation part 201 may also calculate the write-processing frequency value at predetermined time intervals. To be more specific, in this case, according to a predetermined schedule, i.e., in periodical timing, the calculation part 201 calculates a write-processing frequency value by dividing a total value of the number of times of write processing by a total value of POH. This total value of the number of times of write processing is one held by the RAM 102 or the nonvolatile memory 101 at that time. This write processing is all the ones that have been performed after the shipment of a magnetic disk drive. Alternatively, the calculation part 201 calculates a write processing frequency value by dividing a total value of the number of times of write processing within the latest fixed period of time, i.e., a past fixed period of time from that point of time, among the total value of the number of times of write processing, by POH corresponding to the past fixed period of time. In this case, the write-current-value determination part 202 periodically determines a write-current value on the basis of the write-processing frequency received from the calculation part 201 , and the magnetic disk drive performs the write processing by use of the periodically determined write-current value.
[0068] Further, for example, the HDC 103 may receive a plurality of write data from the host computer, and the HDC 103 may keep part of the plurality of write data in the data buffer 104 . In this case, the number-of-times-of-write-processing acquisition part 200 also acquires the number of write data kept in the data buffer 104 (hereinafter referred to as “the number of waiting write processing”). In addition, the write-current-value determination part 202 also determines a write-current value on the basis of the number of waiting write processing.
[0069] More specifically, in this case, the acquisition part 200 acquires the number of waiting write processing, for example, while the write head 108 performs write processing relating to one piece of write data. Then, the acquisition part 200 outputs, to the calculation part 201 , an updated total value of the number of times of write processing to which the number of waiting write processing in question is added. The calculation part 201 calculates a write-processing frequency value on the basis of the number of times of write processing including the number of waiting write processing, and then outputs the write-processing frequency value to the determination part 202 . After that, the determination part 202 determines a write-current value on the basis of the write-processing frequency value, and then outputs a command to the HDC 103 to perform write processing by use of the write-current value.
[0070] In this case, for example, the magnetic disk drive may also perform write processing for write data corresponding to the number of waiting write processing (i.e., write data kept in the data buffer 104 ) by use of the write-current value determined on the basis of the number of waiting write processing. To be more specific, for example, the data buffer 104 keeps each write data by associating it with an identification number for identifying the write data. The control chip associates the write-current value determined on the basis of the number of waiting write processing, with an identification number for identifying write data corresponding to the number of waiting write processing for outputting them to the HDC 103 . Thus, the control chip instructs the HDC to perform the processing of the write data by use of the write-current value.
[0071] In this case, the control chip may determine the write-current value on the basis of the amount of write data that is kept in the data buffer 104 (i.e., the amount of data to be written to the magnetic disk 110 by executing write processing of the write data). More specifically, in this case, for example, the amount-of-write-data acquisition part 203 acquires the number of bytes of write data kept in the data buffer 104 ; and the write-current-value determination part 202 determines a write-current value used for write processing of the write data on the basis of the number of bytes of the write data, or on the basis of a write-processing frequency calculated by the write-processing frequency calculation part 201 by use of the number of bytes of the write data.
[0072] It is to be understood that the above description is intended to be illustrative and not restrictive. Many embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents.
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Embodiments of the present invention provide a write-current control chip capable of effectively preventing adjacent track interference (ATI) that occurs depending on how a magnetic disk drive is used, and to provide a magnetic disk drive using the write-current control chip. In one embodiment, a write-current control chip and a magnetic disk drive using the same are provided. The write-current control chip includes: an acquisition module for acquiring the number of times of write processing in which a magnetic head writes data to a magnetic disk in the magnetic disk drive; a determination module, on the basis of the acquired number of times of write processing, for determining a write-current value used when the magnetic head writes data to the magnetic disk; and an instruction mechanism for instructing the magnetic head to write the data to the magnetic disk by use of the determined write-current value.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a national stage application under 35 U.S.C. §371 of PCT/EP05/04525, filed Apr. 27, 2005.
RELATED U.S. APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
REFERENCE TO MICROFICHE APPENDIX
Not applicable.
FIELD OF THE INVENTION
The invention relates to an electrosurgical Instrument.
BACKGROUND OF THE INVENTION
Electrosurgical instruments have been used for many years in high-frequency surgery, in order to coagulate and/or cut biological tissue. In this process a high-frequency current is conducted through the tissue to be treated, so that the latter becomes altered owing to protein coagulation and dehydration. The tissue thus contracts in such a way that the vessels are closed and bleeding is stanched. A subsequent increase in current density causes an explosion-like evaporation of the tissue fluid and tearing apart of the cell membranes, so that the tissue is completely transected. Procedures of this kind present the advantage, as opposed to a purely mechanical cutting process, that hemostasis is produced at the cut edges.
The employment of bipolar instruments is becoming increasingly significant, because the current intensities are less than in the case of monopolar instruments. It is especially advantageous that the current route between the electrode parts of bipolar instruments can be calculated and does not pass for large distances through the patient's body.
Bipolar instruments comprise substantially two clamp parts having an articulated connection to one another, with gripping devices provided at their proximal ends for manipulation of the clamp parts. At distal ends of the clamp parts there are electrode parts for grasping tissue and for conducting a coagulation current through the tissue. The HF current generated by a HF generator is conducted to the electrode parts of the bipolar instrument by way of current-supply devices.
When the bipolar instruments described above are being used, after a coagulation procedure cutting instruments must be employed for the final transection of the coagulated tissue. The cut is carried out with either a surgical scissors or a HF cutting instrument. However, this use of different instruments requires interruption of the surgical operation, which is thus unnecessarily prolonged.
To counteract this disadvantage, multifunctional instruments have meanwhile come into use, designed at least for both coagulation and cutting. Such an instrument is known, for example, from the document DE 199 15 060 A1, with which diverse working devices such as forceps, hooks or even ultrasonic devices and electrodes for cutting or coagulation can be put into operation by actuators. A control unit enables the planned working steps to be carried out consecutively.
The embodiment of a multifunctional instrument described there, however, has the disadvantage that coagulating and cutting are still two different treatments, to be performed successively in time, even though the steps can be carried out by single instrument. A first procedure must therefore be intentionally ended, after which a second procedure is, again intentionally, begun. Between these procedures at least one manipulation must be done, namely to activate the multifunctional instrument for the next task. This, too, unnecessarily delays the course of the operation. In addition, during the activation of a procedure errors can occur regarding the setting of appropriate operating parameters, such as a suitable HF current.
Known multifunctional instruments of the kind described above furthermore comprise poles that are electrically insulated from one another, being provided for coagulation and for cutting respectively, so that the instrument must have relatively large dimensions. This distinctly limits the surgeon's freedom of movement in the operation region and hence limits the range of functions for which the known instruments can be used.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed towards the provision of an electrosurgical instrument whereby an operation, in particular one requiring several procedural components, can be performed in the simplest manner and with an optimized sequence of steps.
In particular, according to the present inventions an electrosurgical instrument is provided that comprises two branches connected in an articulated manner, which can be actuated to open or close as is appropriate for a clamping, spreading or cutting tool. The instrument further comprises electrode parts at distal ends of the branches, which are electrically insulated from one another and are used for grasping tissue and conducting a coagulation current through the tissue to coagulate it, as well as current-supply devices to deliver the coagulation current to the electrode parts. On at least one electrode part of the instrument there is additionally formed a cutting section designed as cutting electrode, so that the electrode part comprises the cutting section and a coagulation section. Furthermore, a control unit to control the HF current is provided, such that when a threshold value characterizing properties of the monitored tissue has been reached, a cutting current different from the coagulation current is supplied to at least the cutting section.
It will be appreciated that on the electrode part designed for coagulation a cutting section is disposed in such a way that at a suitable point in time, i.e. when a certain stage of the operation has been reached, it acts as cutting electrode. Therefore the surgeon is not burdened with making decisions at the transition from a coagulation phase into a subsequent cutting phase. At the same time optimal operating parameters, such as the correct current intensity, can be generated with no need for the operator to set these independently by way of the voltage at the HF generator. Thus the temporal sequence of events between the individual operation phases and the momentarily required HF current are optimally matched to one another. The operation can thus be carried out while sources of error are eliminated as far as possible.
In a first preferred embodiment switching devices associated with the control unit detect the threshold value as a specified distance between the branches, so that the cutting current is supplied in dependence on this distance. As soon as the distance between the branches, i.e. between the electrode parts, has fallen below a specified value, the cutting current is supplied at least to the cutting section. In this process the switching devices, when actuated, send to the control unit a signal that causes the latter to supply an appropriate cutting current to the cutting section, by way of a high-frequency generator. The distance serves to identify the situation in which a cutting process can be carried out, i.e. the fact that that the electrode parts are at a distance from one another such that cutting has just become possible for the first time. The distance between the electrode parts in this case can be defined by the level of the adjusted HF voltage.
The switching devices are advantageously provided on at least one of the branches and/or on a spacer disposed on at least one of the branches. This is advantageous because the distance is then detected directly by the switching devices, which can simultaneously initiate the cutting process.
In one preferred embodiment the switching devices are constructed as a push-button switch. This is then preferably attached to the spacer on the one branch, so that when the switch is touched by the opposite branch and thus when the threshold value is reached—in this case the specified distance between the electrode parts—the cutting current is supplied to the cutting section. This is a particularly simple design with which to trigger the cutting process in an economical manner, when the distance between the electrode parts becomes less than the specified value.
In another preferred embodiment the switching devices are constructed as a non-contact switch. These have the advantage that it is not necessary for the branches to touch one another, and therefore the mechanism is less vulnerable to wear and tear while operating precisely.
It is advantageous for the non-contact switches then to be designed, for example, as proximity switches or also as reed contacts. For instance, if a reed contact is attached to the one branch and a magnet to the opposite branch, then the reed contact switches as soon as the magnet is at a certain distance from the reed contact. A proximity switch operates similarly, e.g. an inductive proximity switch. The proximity switch attached to the one branch switches as soon as a metal object disposed on the opposite branch generates eddy currents in an electromagnetic alternating field of the proximity switch. In the case of a switch such as is described here, the switching distance can preferably be defined occasionally by the metal object inserted into the alternating field.
The control unit is advantageously associated with a device for resistance measurement that detects the threshold value in terms of the ohmic resistance of the tissue, so that the cutting current is supplied in dependence on this ohmic resistance. The measurement of tissue resistance enables determination of a precise point in time at or after which a cutting process can be started. As soon as the progress of the operation has caused a specific resistance to be reached within the tissue, the control unit causes the appropriate cutting current to be supplied to the cutting section. This procedure is extremely reliable because the tissue resistance, when altered by coagulation, provides a precise reference value for when a cutting process can be begun.
In another preferred embodiment the control unit is associated with an electric-arc monitor and/or current monitor that detect the threshold value in the form of an optimal time for ending coagulation, so that the cutting current is supplied in dependence on the coagulation end-point time. That is, the cutting current is supplied at least to the cutting section as soon as coagulation has been terminated on the basis of the signal provided by the corresponding monitor. Thus the supply of the cutting current advantageously occurs at a time that is ideal for the course of the operation. The ways in which the current monitor and arc monitor function are described extensively, for example, in the document EP 0 253 012 B1.
Preferably the cutting section at the at least one electrode part is constructed as a tapering region, with respect to the coagulation section of the at least one electrode part. In this case coagulation section and cutting section can constitute an integrally constructed electrode, or else the two regions are disposed independently of one another. The tapered configuration of the cutting section enables the current density from the cutting section to be increased as is required for cutting tissue. The electrode part in which the coagulation section and the cutting section are integral can act as coagulation electrode over its entire surface area, i.e. over both the surface of the coagulation section and the surface of the cutting section, whereas the tapered cutting section alone is available for a later cutting process. In the case of coagulation and cutting regions that are separate from one another, these can be employed both in combination and also separately from one another. To the smaller surface region, designed as cutting section, an adequate cutting current corresponding to the above considerations is supplied by way of the current-supply devices. Thus one and the same instrument can be used both for coagulation and also for cutting.
In one preferred embodiment the cutting section is formed on the at least one electrode part as an edge structure with a substantially triangular cross section. A triangular cross section enables the successive transition from a large surface region of the electrode part to its tapered edge section. The gradual transition is especially well suited for inserting the whole electrode part as coagulation electrode, given a tissue with adequate thickness, and at an advanced stage of the operation using the cutting section alone for cutting.
It is advantageous for the cutting section to be formed on the at least one electrode part as an edge structure with a substantially circular cross section. In this embodiment a relatively large electrode surface is available for the coagulation process, given a tissue with adequate thickness, whereas the shaped edge of the cutting section is of hardly any importance. In contrast, at an advanced stage of the operation and if the opposed electrode parts of the electrosurgical instrument are sufficiently close, because of the edge configuration of the cutting section the current density can be increased sufficiently to make possible a cutting process.
Another solution provides that the cutting section on the at least one electrode part is substantially spherical in shape. This allows the cutting surface to be kept larger and a correspondingly broad cut to be made.
The solution in accordance with the invention provides for the cutting section to have a pointed, needle or loop-type shape. This corresponds to other customary forms of cutting electrodes, so that cutting can be carried out with the instruments ordinarily used for the particular application.
In one preferred embodiment the cutting section is formed on each of the opposed electrode parts. Because here two sections are designed for cutting, an especially precise cutting action can be achieved, because the current density can be increased at both electrode parts.
The cutting section can also, however, be disposed outside the coagulation section, i.e. be constructed separately therefrom, as already mentioned above. In this case it is advantageous for the cutting section to be constructed as a component that can be moved relative to the coagulation section, by means of positioning devices. The cutting section can then be removed from the coagulation region during a coagulation process, so that no undesired cutting actions occur at this time. When the threshold value is reached, the cutting section or sections can be brought into the appropriate position, i.e. the position required for cutting.
Preferably the positioning devices comprise a two-armed lever that is rotatably mounted in one of the branches; this lever comprises a first and a second end, the first end being provided to accommodate the cutting section and the second end, to make contact with the opposite branch or a spacer situated on the opposite branch. When the second end contacts the opposite branch, the cutting section can be moved in the direction of the opposite electrode part. The positioning devices additionally comprise a readjustment means, so that the cutting section can be moved back into the starting position when contact has ended. This makes it especially simple to retract the cutting section into the coagulation section during the coagulation phase, so as to avoid impairment of the coagulation process by the cutting section. In this case, as soon as the threshold value has been reached and a contact has been made, the cutting section rotates out of its resting position. The cutting current can be supplied to the now exposed cutting section, for example by way of the switching devices, which in accordance with the above description are disposed on the spacer or at the second end of the lever and which deliver an appropriate signal to the control unit. Because of the simple mechanical construction, such a multifunctional electrosurgical instrument is economical and simple to manufacture. The positioning of the cutting section is furthermore independent of any force exerted by the surgeon's hand, because the control unit is activated exclusively on the basis of making contact. It is also possible for a positioning device such as just described to be provided on both branches.
One preferred embodiment provides for a device serving as a receptacle for the cutting section to be attached to the first end of the two-armed lever. In this case it is advantageous that the cutting section can be temporarily removed. The advantage here is obtained when the cutting section is to be cleaned after an operation phase, or when no cutting process is intended. This arrangement allows the cutting section to be inactivated in the simplest manner.
One possible implementation of the device consists in constructing the cutting section as an integral component of the first end of the two-armed lever. Thus the positioning device can be manufactured in a particularly simple way.
One preferred embodiment provides that the readjustment means for the lever arm has the form of a spring element disposed in the branch that comprises the positioning devices. A spring element is a component that is simple to install and economical, and that always fulfills the required function with hardly any wear and tear.
One solution in accordance with the invention provides that the cutting section is made of an anti-adhesion coating and/or of an erosion-resistant material. The heat developed when HF current is introduced into the tissue to be treated does not only cause the desired coagulation or cutting effects. In addition, for instance, tissue remnants and blood can become burned onto the electrode parts of the clamps, in particular, so strongly as to impair the current flow. An anti-adhesion coating reduces such contamination and should be provided in particular at each cutting section. A layer of erosion-resistant material can additionally protect the cutting section from wear and tear caused by the high HF current.
Exemplary embodiments of the invention will now be described in greater detail with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic end view of an electrode arrangement in a first embodiment of electrosurgical instrument according to the invention.
FIG. 2 is a view similar to that of FIG. 1 but of a second embodiment of instrument.
FIG. 3 is a view similar to that of FIG. 1 but of a third embodiment of instrument.
FIG. 4 is a view similar to that of FIG. 1 but of a fourth embodiment of instrument.
FIG. 5 is a functional block diagram of an embodiment of electrosurgical instrument according to the invention.
FIG. 6 is a sectional view, along the line VI-VI in FIG. 7 , of an electrode arrangement in a fifth embodiment of instrument.
FIG. 7 is a side view of the electrode arrangement shown in to FIG. 6 .
FIG. 8 a is a current/time diagram in which the time course of the current intensity is represented for different operational modes of an electrosurgical instrument according to the invention.
FIG. 8 b is a voltage/time diagram in which the time course of the voltage is represented for the various operational modes represented in FIG. 8 a .
DETAILED DESCRIPTION OF THE INVENTION
In the following description, the same reference numerals are used for identical parts or parts with identical actions.
FIGS. 1 to 3 show various embodiments of an arrangement of electrode parts 18 , 19 situated opposite one another. In each case, an explicit cutting section 18 a is formed on only one electrode part 18 . It should be pointed out that these are schematic drawings, which show a front view of only the electrode parts 18 , 19 . The electrosurgical instrument 10 that incorporates the electrode parts 18 , 19 is not shown here.
Formation of the cutting section 18 a can ideally be achieved by tapering the associated electrode part 18 , so that the electrode part 18 ultimately comprises a coagulation section 18 b and a cutting region, i.e. the cutting section 18 a . The reduction of the electrode surface allows the current density to be increased at the cutting section 18 a, as is required for cutting tissue. The electrode part 18 comprising the integral coagulation section 18 b and cutting section 18 a can act as the coagulation electrode over the entire surface area during a coagulation process, i.e. over both the surface area of the coagulation section 18 b and that of the cutting section 18 a, whereas the tapered cutting section 18 a alone is available for a later cutting process. For the cutting process it is provided that a cutting current different from the coagulation current is supplied to the cutting section 18 a.
If the cutting section 18 a is an edge structure with a triangular cross section, as shown in FIG. 1 , the gradual transition from a large surface area to the tapered edge region makes it possible to a particularly great degree for the entire electrode part 18 to be employed as coagulation electrode, given sufficient tissue thickness, and in an advanced stage of the operation to use only the cutting section 18 a for cutting.
If the cutting section 18 a is formed on the at least one electrode part 18 as an edge structure with a circular cross section, as shown in FIG. 2 , a relatively large electrode surface is available for the coagulation process, whereas the edge structure in the cutting section 18 a is of hardly any importance, given sufficient tissue thickness. During the subsequent course of the operation, if the opposed electrode parts 18 , 19 of the electrosurgical instrument 10 are sufficiently close to one another, because of the edge structure of the cutting section 18 a the current density can be increased to such an extent as to make a cutting process possible.
In the case of a substantially spherical cutting section 18 a at the at least one electrode part 18 , as is shown in FIG. 3 , the cutting surface can be made larger so that a correspondingly broad cut can be carried out.
The cutting section 18 a, 19 a can also be constructed in a pointed, needle-like or loop-like shape.
FIG. 4 shows an electrode arrangement in which the cutting section 18 a, 19 a is in each case formed on the opposed electrode parts 18 , 19 . Here, again, explicit coagulation sections 18 b, 19 b are provided at the two electrode parts 18 , 19 . This drawing should also be understood as merely schematic. Since there are two sections 18 a, 19 a designed for cutting, an especially precise cutting action can be achieved, because the current density at the two electrode parts 18 , 19 can be increased.
FIG. 5 shows a functional block diagram in which the electrosurgical instrument 10 is connected to a high-frequency surgical appliance 60 . The components of the HF-surgery appliance 60 illustrated here are exclusively, and hence schematically, those required to explain the invention.
The HF-surgery appliance 60 comprises an input connector 63 by way of which, for instance, actuating devices such as finger and/or foot switches (not shown) can be connected in order to activate and/or inactivate the HF current. The actuating devices here can preferably be implemented by a computer arrangement, and in practical application are connected by way of a control unit (not shown) to a HF generator 61 . For the sake of simplicity the input connector 63 in this drawing is connected directly to the HF generator 61 , as shown by a dashed line. On the output side of the HF-surgery appliance 60 there are provided a first output connector 64 and a second output connector 65 , by way of which the electrosurgical instrument 10 can be connected.
The central component of the HF-surgery appliance 60 is the controllable HF generator 61 for producing a HF current, or stated more precisely to produce a voltage U HF . By adjusting the voltage U HF , the current intensities I HF needed for the various operational modes, such as coagulation or cutting, can be set as desired. The HF generator 61 is connected to a control unit 62 . The control unit 62 is designed to receive signals from switching devices 50 disposed on the electrosurgical instrument 10 .
The switching devices 50 are disposed between branches 11 , 12 of the electrosurgical instrument and detect a threshold value, e.g. as a specific distance between the branches 11 , 12 , i.e. between the electrode parts 18 , 19 . The distance between the electrode parts 18 , 19 serves here to characterize the fact that a cutting procedure can be carried out, and is therefore matched to the level to which the HF voltage has been set. As soon as the branches 11 , 12 have been brought together to the specified distance, the switching devices 50 are actuated and conduct a signal to the control unit 62 . This then initiates delivery of the appropriate cutting current from the HF generator 61 to the cutting sections 18 a, 19 a, by of the associated proximal ends 15 , 16 of the electrosurgical instrument. It should be pointed out that here, again, the cutting section may be formed at only one or at both electrode parts 18 , 19 . For the following explanations it is assumed that each of the electrode parts 18 , 19 comprises a cutting section 18 a, 19 a.
As a means of detecting the distance and activating the control unit 62 that controls the cutting current it is possible to use push-button switches but also non-contact switches, such as reed-contact or proximity switches. With contact-type switches the electrosurgical instrument can have an especially economical construction, whereas non-contact switches operate extremely precisely and are substantially free of abrasion.
Regarding the exact arrangement of the switching devices, reference is made to the description of FIGS. 6 and 7 .
The threshold value can also be detected, for example, by way of a device for resistance measurement (not shown) associated with the control unit 62 . As soon as the operation has proceeded to the point at which a specific resistance in the tissue has been reached, the control unit 62 causes an appropriate cutting current to be supplied to the relevant cutting section 18 a, 19 a . Accordingly, the threshold value is specified in terms of an ohmic resistance.
It is also possible for the control unit 62 to be equipped with an electric-arc monitor and/or a current monitor (not shown), so that the threshold value can be detected as the optimal time to terminate coagulation. The cutting current is then supplied to at least the relevant cutting section 18 a, 19 a as soon as coagulation has been stopped because of the signal provided by the corresponding monitor. Hence delivery of the cutting current advantageously occurs at a time that is optimal for the experimental procedure. The ways in which the current monitor and arc monitor function are described in detail, for example, in the document EP 0 253 012 B1.
FIG. 6 shows an electrode arrangement in a fifth embodiment, as sectional view along the line VI-VI in FIG. 7 . FIG. 7 shows a side view of the electrosurgical instrument 10 according to FIG. 6 . The electrosurgical instrument 10 is designed here as a tweezers-shaped instrument.
In these figures distal ends 13 , 14 of the branches 11 , 12 of the electrosurgical instrument 10 are illustrated, as well as the associated electrode parts 18 , 19 . As can be seen in particular in FIG. 7 , within one branch 12 a two-armed lever 30 with a first end 31 and a second end 32 is seated so as to be rotatable about an axle 34 ; the first end 31 is provided as a holder for the cutting section 19 a, and the second end 32 is provided to make contact with the opposite branch 11 or a spacer 20 disposed on the opposite branch 11 . Here the lever 30 assists positioning of the cutting section 19 a, so that the latter can be moved relative to the section 19 b provided for the purpose of coagulation. That is, in this embodiment the electrode part 19 consists of two independent sections, the coagulation section 19 b and the cutting section 19 a.
So that the lever 30 can be seated in the branch 12 , the latter comprises a recess 21 into which the first end 31 of the lever 30 can be embedded, preferably so as to be completely enclosed. The recess is formed both in the coagulation section 19 b of the branch 12 and in the branch 12 itself. Because this arrangement enables the cutting section 19 a to be embedded in a recess, the possibility that the cutting section 19 a will interfere with the coagulation electrode 19 b during the coagulation process is avoided.
As the branches 11 , 12 are being moved towards one another by the operator, the spacer 20 continuously approaches the second end 32 of the lever 30 . The second end 32 in this embodiment comprises a bearing surface 33 . As soon as the spacer 20 on the opposite branch 11 comes into contact with the bearing surface 33 , the first end 31 of the lever 30 is lifted out of a resting position, emerging from the branch 12 , so that the cutting section 19 a projects out of the coagulation electrode 19 b . The cutting section 19 a and the opposite electrode part 18 can now cooperate with one another in a cutting phase. For this purpose the spacer 20 or the bearing surface 33 comprise the switching devices 50 described in detail above. When the spacer 20 or the bearing surface 33 makes contact with the switching devices 50 , actuation of the latter causes the corresponding cutting current to be supplied to the cutting section 19 a by way of current-supply devices 17 , as likewise described above.
In the branch 12 containing the lever 30 a spring element 40 is provided. This is connected at a first end 41 to the branch 12 and at a second end 42 to the second lever end 32 . Because the bearing surface 33 of the second lever end 32 is in contact with the spacer 20 of the opposite branch 11 , and/or with the switching devices 50 disposed on the spacer 20 or the bearing surface 33 , the spring 40 attached to the second lever end 32 , e.g. a spiral spring, is compressed. As soon as the contact is broken, the spring 40 moves the lever 30 back into its resting position, so that the lever end 31 bearing the cutting section 19 a sinks back into the branch 12 . The coagulation electrode 19 b is thus again made available to coagulate tissue. The spring element 40 is an economical component that is simple to install and always performs the required function with hardly any wear and tear.
The switching devices 50 can furthermore also be positioned at other places on the branches 11 , 12 . In this case non-contact switches would be especially worth consideration, as they communicate a signal to the control unit when a specified distance between the electrode parts 18 , 19 has been reached, even without any direct contact.
The first end of the two-armed lever 31 can comprise a receptacle for the cutting section 19 a, so that the latter can be readily removed from the electrosurgical instrument, e.g. for the purpose of cleaning. Alternatively, it is possible to make the first lever end 31 integral with the cutting section 19 a, which results in a device that is extremely economical to manufacture.
Because of the simple mechanics of the positioning device 30 just described for the cutting section 19 a, a multifunctional electrosurgical instrument 10 can be manufactured in a simple and economical manner.
The cutting section 18 a, 19 a can preferably be constructed with an anti-adhesive coating and/or with a layer of abrasion-resistant material. This avoids the possibility that tissue will be burnt onto the cutting section, or that the material will wear out.
FIG. 8 a is a diagram illustrating the typical variation in intensity of the HF current in dependence on different modes of operation. On the ordinate is shown the current intensity I HF and on the abscissa, the time t. FIG. 8 b is the voltage/time diagram corresponding to FIG. 8 a . Here the ordinate shows the voltage U HF and the abscissa, again, the time t. Because both figures are schematic illustrations, the units are not shown.
According to FIG. 8 a, at a time t 1 a coagulation mode is switched on and the current begins to flow through the tissue to be coagulated. As the tissue becomes warmer, the current intensity I HF increases, until a time t 2 . From the time t 2 on, the tissue begins to coagulate, and hence a vaporization phase is initiated. Because of the heat development associated with the HF current, a specified region of tissue can be altered or destroyed by protein coagulation and dehydration. In this process, the colloidal components of the tissue that had been present in solution first enter the gel state, and then as gel components they lose fluid and so become still more compact; the tissue is “cooked”. The resistance of the tissue rises accordingly, so that because of the falling conductivity of the tissue the current intensity I HF decreases until a time t 3 . When the drying of the tissue has reached a certain stage, coagulation comes to a halt. Between the times t 3 and t 4 , a cutting mode is activated. During this period, the graph shows a relatively constant level of current intensity I HF , because the tissue resistance remains substantially the same throughout the cutting process.
As shown in FIG. 8 b , the HF generator is set to a particular voltage U HF for the time interval t 1 to t 3 . The cutting mode that follows the coagulation mode requires an increase in this voltage U HF between the times t 3 and t 4 . The current intensity I HF is ultimately dependent on the level to which the voltage U HF has been set and on the resistance of the already coagulated tissue. At the time t 4 the cutting mode can be terminated, for example by an automatic switching-off device.
LIST OF REFERENCE NUMERALS
10 Electrosurgical instrument
11 Clamp part, branch
12 Clamp part, branch
13 Distal end
14 Distal end
15 Proximal end
16 Proximal end
17 Current-supply devices
18 Electrode part
18 a Cutting section, cutting electrode
18 b Coagulation section, coagulation electrode
19 Electrode part
19 a Cutting section, cutting electrode
19 b Coagulation section, coagulation electrode
20 Spacer
21 Recess
30 Two-armed lever, positioning device
31 First end of lever
32 Second end of lever
33 Bearing surface
34 Axis of rotation
40 Spring element
41 First end of spring element
42 Second end of spring element
50 Switching devices
60 HF-surgery appliance
61 HF generator
62 Control unit
63 Input connector
64 First output connector
65 Second output connector
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The invention relates to an electrosurgical instrument that comprises two branches joined to one another in an articulated manner, which can be actuated to open or close in a manner corresponding to a clamping, spreading or cutting tool. The instrument further comprises electrode parts at distal ends of the branches, which are used for grasping tissue and passing a coagulation current through the tissue for the purpose of coagulating it and which are electrically insulated from one another, as well as current-supply devices to supply the coagulation current to the electrode parts. In addition, on at least at one electrode part, a cutting section designed as a cutting electrode is provided whereby the electrode part comprises the cutting section and a coagulation section. In addition a control unit is provided to control the HF current in such a way that when a threshold value characterizing a particular property of the grasped tissue has been reached, a cutting current different from the coagulation current is supplied to at least the cutting section.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 11/068,424, entitled “Method and Apparatus for Creation and Maintenance of Database Structure,” filed on Feb. 28, 2005, which is a continuation of U.S. Pat. No. 6,917,941 (application Ser. No. 10/035,635) entitled “Method and Apparatus for Creation and Maintenance of Database Structure,” filed on Dec. 28, 2001, the entire disclosures of which are incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the field of relational databases. More particularly, the present invention relates to a relational database that facilitates electronic commerce or “e-commerce” as conducted on an electronic communications network through the creation, maintenance and update of electronic lists, made up of items in the database, from any point on the electronic communication network.
BACKGROUND OF THE INVENTION
[0003] The growth of electronic communications networks, such as the Internet, as well as various intranets, extranets, and other local area networks (LANs) and wide area networks (WANs) has presented a fertile ground in which to transact commerce. The amount of commerce transacted on-line over these networks has grown such that online or electronic commerce (also known as “e-commerce”) has become a major channel through which goods and services are bought and sold. In parallel with the growth in electronic commerce has come a growth in the information available regarding the goods and services available for sale online. As this growth has occurred, online providers of goods and services have sought to develop ever more efficient means of linking potential customers with the goods and services sought by those potential customers.
[0004] Despite these efforts, inefficiencies continue to pervade the mechanisms used to transact e-commerce. At present, potential customers have numerous locations from which to obtain information regarding goods and services for sale online. Many of these locations provide the potential customers with the ability to capture and evaluate information regarding the goods and services for sale at that particular location. However, the potential customers are not provided with a satisfactory tool for capturing, cataloging and evaluating the information gathered at all of these locations against each other, nor are they provided with a tool for updating the information that they have captured and cataloged. Likewise, potential customers are left with no tool for capturing information regarding products and services for sale online and products and services for sale offline in a single location. Instead, the potential customer is left to individually visit multiple locations to manually catalog the information captured at one location against information captured at other locations. The potential customer must manually evaluate the information captured online against other information captured online and against information captured offline. Potential customers are further required to individually re-visit each location (both online or offline) to update previously captured information. Without an adequate tool that enables the potential customer to efficiently and effectively capture, aggregate, catalog, evaluate, and update information from all sources in a single place, potential customers find themselves ill equipped to evaluate the myriad collection of often varying prices, inventories, and terms under which the goods and services that they are seeking to purchase are being offered for sale both online and offline. As a result, the online purchasing process often proves far less efficient and effective than other sales channels. Untold online business opportunity is lost when potential customers become overwhelmed with the information available to them in the online purchasing process and never reach the point of consummating their sale. Likewise, untold future sales are lost as post-sale frustration ensues when the customers realize that their purchase did not take place at the price and on the terms that were the most favorable available to them at the time of sale because they failed to fully and effectively evaluate all of the information and options available to them both online and offline.
[0005] Thus, while e-commerce is a viable channel of selling goods and services, from the viewpoint of the consumer, it is often not an efficient and effective channel of buying goods and services. It would be highly desirable to have a method and apparatus that enabled consumers to more fully utilize the possibilities of e-commerce.
BRIEF SUMMARY OF THE INVENTION
[0006] The invention solves the problems described by providing a single tool that allows the potential customer to capture and aggregate the volume of information regarding the products and services that are available to them online in a single database. Preferably, the single tool also allows the customer to capture and aggregate offline purchasing information in the same database. This tool preferably permits the analysis of all information, captured both online and offline, in a single location. Preferably, the location can be any computer connected to the Internet that is available to the potential customer. The tool preferably provides potential customers with automated updates of the information regarding the goods and services that the potential customer is considering purchasing throughout the period of time during which the potential customer is making a purchasing decision. Likewise, once a decision to purchase a good or service is made, the tool preferably provides a direct path online to the dealers of that good or service. The tool is preferably independent of any given online or offline provider of goods or services, and “sits above” the network through which providers offer their goods and services for sale. The tool allows the potential customer to efficiently and effectively locate and evaluate information regarding goods and services offered by many providers, preferably both on and offline, without tying the potential customer to any one provider.
[0007] The invention further solves the problems described by providing a single tool that allows a manufacturer to establish and maintain a display on its web site. The display of information preferably contains information regarding the vendors at which the products produced by the manufacturer are offered for sale, either online or offline. The present invention allows a manufacturer to establish a direct link from the display of information to the web sites of the vendors offering the manufacturer's products for sale online. Preferably, the display of information includes information regarding the price, availability, and features of the manufacturer's products. The information displayed is automatically updated with changes in existing information or new information. Preferably, the manufacturer may customize the display of information to include only the information regarding its products, and only the vendors offering its products, that the manufacturer desires to include in the display.
[0008] The invention preferably provides a data structure for facilitating the efficient storage and retrieval of information regarding the products and services in the form of a database. The information regarding each product or service is stored in the form of an object in the database. Each object contains a number of fields. Each field in each object in the database corresponds to a defined attribute of the products and services to be stored in the database. Preferably, each object contains a field corresponding to an attribute of the product or service stored in that object for which there is information available. The attribute to which each field corresponds is preferably also one of the defined attributes of the products and services to be stored in the database. Preferably, each field has an associated identifier corresponding to the attribute to which the field corresponds. Preferably each object has an associated identifier corresponding to the product or service stored in the object. Preferably, objects and fields are able to be referenced and retrieved from the database by way of their identifiers.
[0009] The invention provides a method for configuring a database system to store information regarding a plurality of items, the method comprising: establishing a database on a computer system; establishing within the database a first object corresponding to a first item of the plurality of items; generating within the first object at least one field; associating a field identifier with each the field; and storing at least a portion of the information within each the field. Preferably, for the plurality of items, the method further provides: defining at least one attribute of the plurality of items; creating a field identifier corresponding to each defined attribute of the plurality of items, the field identifiers comprising a set of field identifiers; and wherein the step of generating comprises: obtaining item information regarding the first item; dividing the item information into at least one category, wherein each category corresponds to a field identifier; and generating within the first object a field corresponding to each the category. Preferably, the step of associating comprises, for each field: selecting from the set of field identifiers the field identifier that corresponds to the same defined attribute of the plurality of items that the field corresponds to; and associating the selected field identifier with the field. Preferably, each field identifier is unique. Preferably, each field identifier includes a numeric code. Preferably, each defined attribute of the plurality of items describes a trait of the plurality of items and each defined attribute of the item describes a trait of the item. Preferably, the step of defining at least one attribute of the plurality of items comprises: obtaining information regarding the plurality of items; dividing the information regarding the plurality of items into at least one category; and defining an attribute of the plurality of items that describes the information in each category. Preferably, the information regarding the plurality of items is obtained from an analysis of the plurality of items. Preferably, the item information is obtained from an analysis of the plurality of items. Preferably, the step of storing comprises, for each the field, storing in the field the item information in the category corresponding to the field.
[0010] Preferably, each field is identifiable and retrievable from the database by way the field identifier. Preferably, each field identifier is unique. Preferably, the information regarding the first item is a first product or a first service. Preferably, the information within each field is information regarding the first product or the first service, respectively. Preferably, the database is a relational database. Preferably, an object identifier is associated with each object identifier. Preferably, each object identifier is unique. Preferably, each object identifier is a user name and password. Preferably, each object is identifiable and retrievable from the database by way of the object identifier.
[0011] In another aspect, the invention provides a method for configuring a database system to store information regarding a plurality of items, the method comprising, for each item in the plurality of items, defining at least one attribute of the plurality of items, creating a field identifier corresponding to each defined attribute of the plurality of items, the field identifiers together comprising a set of field identifiers, establishing a database on a computer system; establishing within the database a first object corresponding to a first item of the plurality of items, obtaining item information regarding the first item, dividing the item information into at least one category, wherein each category corresponds to a field identifier, generating within the first object a field corresponding to each category, selecting from the set of field identifiers the field identifier that corresponds to the same defined attribute of the plurality of items that the field corresponds to, associating the selected field identifier with the field, and, for each field, storing in the field the item information in the category corresponding to the field.
[0012] In another aspect, the invention provides a database system configured to store information regarding a plurality of items, each item in the plurality of items having at least one item attribute, the database system comprising: a computer having memory, a database stored in the memory, a first object in the database corresponding to one item of the plurality of items, the first object corresponding to the first item, at least one field in the first object, a field identifier associated with each field; and information regarding the first item stored in the first object. Preferably, the plurality of items have a predetermined set of attributes, and the computer system includes a predetermined list of field identifiers, each field identifier in the predetermined list corresponding to one of the predetermined set of attributes, and the at least one field comprises one field corresponding to each attribute in the predetermined set of attributes for which information is known regarding the first item. Preferably, the at least one field comprises one field corresponding to each attribute in the predetermined set of attributes that is also an item attribute of the first item. Each field identifier associated with each field preferably comprises the field identifier corresponding to the attribute in the predetermined set of attributes to which the field corresponds. Preferably, the field identifier associated with each the field comprises an identifier unique to the attribute in the predetermined set of attributes to which the field identifier corresponds. Preferably, each field identifier associated with each field comprises a unique field identifier. Preferably, each field identifier associated with each field comprises a numeric code. Each attribute of the predetermined set of attributes preferably comprises a trait of the plurality of items and each attribute of each item in the plurality of items comprises a trait of that item. Preferably, the information regarding the first item stored in the first object comprises information regarding the first item stored in each field of the first object. Preferably, the information stored in each field of the first object corresponds to the same attribute of the first item to which the field corresponds. The database is preferably adapted to categorize the information regarding each item into categories wherein the information in each category describes an attribute of the item, and defines the attribute described by the information in each category. Preferably, each field in the first object is identifiable and retrievable from the database by way of the field identifier associated with that field. Preferably, the information regarding the plurality of items comprises information regarding a plurality of products, services, or product and services. The database preferably comprises a relational database. Preferably, an object identifier is associated with the first object. Preferably, each object identifier comprises a unique identifier. Preferably, each object identifier comprises a user name and password. Preferably, the first object is identifiable and retrievable from the database by way of the object identifier.
[0013] In another aspect, the invention provides a method for configuring a database system to store a plurality of lists containing information regarding a plurality of items, the method comprising: establishing a list database on a server computer system, the list database including a first list associated with a first list identifier, establishing a management tool on a client computer system, remote from the server computer system, the management tool including the list identifier, establishing a communications link between the client computer system and the server computer system, retrieving the first list from the list database to the management tool responsive to the first list identifier, revising the retrieved first list, and updating the first list in the list database to reflect the revision to the retrieved first list. Preferably, the step of establishing a list database comprises: establishing within the list database a first list object corresponding to the first list, generating within the first list object a first list field, associating a first list identifier with the first list object. Preferably, the step of retrieving comprises retrieving the first list object from the list database. Preferably, the step of revising comprises storing in the first list field of the retrieved first list object information regarding one of the plurality of items, the one of the plurality of items being the first item. Preferably, the step of updating comprises updating the first list object in the list database to reflect the revision to the retrieved first list object. The step of generating preferably comprises associating a first list field identifier with the first list field, the first list field identifier corresponding to the information stored in the first list field. Preferably, the step of revising comprises storing in the first list field information corresponding to the first list field identifier. The step of associating preferably comprises: generating the first list identifier, and associating the first list identifier with the first list object. Preferably, the first list identifier is unique. Preferably, the first list identifier includes a user name and password generated by a user of the list database.
[0014] Preferably, the step of revising comprises: establishing an item database on the server computer system, the item database including stored information relating to the first item; and creating a pointer in the first list field referencing the information relating to the first item stored in the item database. The step of revising preferably comprises: establishing an item database on the server computer system, the item database including stored information relating to the first item, and creating a copy in the first list field of the information relating to the first item stored in the item database. The step of revising further preferably comprises, responsive to a command issued to the management tool, identifying the first list field and revising the first list field to remove the stored information regarding the first item from the first list field. The step of revising further preferably comprises: establishing an item database on the server computer system, the item database including first item information relating to a first item, and responsive to a command issued by the management tool, revising the first list field to include a pointer referencing the first item. Preferably, the method comprises retrieving the first item information from the item database to the management tool; and displaying a graphical representation of the first item information on a user interface of the management tool.
[0015] Preferably, the step of revising comprises: capturing information relating to a first provided item, and the step of revising comprises revising the first list field to include a pointer referencing the first provided item. The step of capturing preferably comprises: establishing a communications link between the client computer system and an item provider computer system, the item provider computer system remote from the client computer system and including information relating to a first provided item, responsive to a command issued to the management tool, locating the first provided item on the item provider computer system, and capturing the information relating to the first provided item. Preferably, the step of capturing comprises: providing a template database on a template database server computer system remote from the client computer system, the template database including one or more templates, each corresponding to an information structure, determining a structure for the information relating to the first provided item, retrieving a template corresponding to the structure from the template database to the management tool, applying the template to the provided item information to parse the information relating to the first provided item, and capturing the parsed information with the management tool. Preferably, the step of revising comprises: establishing an item database on the server computer system, the item database storing information relating to a plurality of items, comparing the captured information relating to the first provided item with the information stored in the item database relating to the plurality of items, responsive to a pre-established rule, revising the information stored in the item database relating to the plurality of items to include the information relating to the first provided item. Preferably, the step of revising comprises revising the first list field to include a pointer referencing the information relating to first provided item in the item database. Preferably, the step of responsive to a preestablished rule, revising the information stored in the item database relating to the plurality of items comprises: determining if the information stored in the item database relating to the plurality of items includes the captured information relating to the first provided item, and revising the information stored in the item database relating to the plurality of items to include the captured information relating to the first provided item if the information stored in the item database relating to the plurality of items does not include the captured information relating to the first provided item.
[0016] Preferably, the step of revising comprises: providing information relating to a first provided item to the management tool, establishing an item database on the server computer system, the item database storing information relating to a plurality of items, revising the information stored in the item database relating to the plurality of items to include the information relating to the first provided item. Preferably, the step of revising comprises revising the first list field to include a pointer referencing the information relating to the first provided item in the item database.
[0017] Preferably, the first list field stores information regarding a first item. Preferably, responsive to a command issued by the management tool, the method includes the steps of establishing a communications link between the client computer system and an item provider computer system, the item provider computer system remote from the client computer system and offering the first item for sale, and facilitating the purchase of the first item from the item provider computer system. Preferably, the step of revising comprises the step of capturing purchase information relating to the purchase of the first item and updating the first list in the list database to reflect the inclusion of the purchase information in the retrieved first list. The purchase information preferably comprises information relating to one or more of: price, quantity, shipping method, and delivery date. The step of establishing a communications link between the client computer system and the server computer system preferably comprises establishing a communications link using one or more of the Internet, a wide area network, and a local area network. The step of establishing a communications link between the client computer system and the list database server computer system preferably comprises: providing a browser tool on the client computer system, instructing the browser tool to locate the item provider computer system; and instructing the browser tool to search the item provider computer system for the provided item information.
[0018] Preferably, the method comprises: establishing an item database on the server computer system, establishing within the item database a first item object corresponding to the first item, generating within the first item object at least one item field, associating an item field identifier with each item field, and storing at least a portion of the information regarding the first item within each item field. The step of revising preferably comprises storing in the first list field of the retrieved first list object a pointer referencing the first item object.
[0019] Preferably, the method comprises: establishing an item database on the server computer system, the item database storing information relating to the plurality of items, capturing information regarding a first provided item and information regarding a provider of the first provided item, comparing the captured information with the information stored in the item database relating to the plurality of items to determine if the captured information is included in the information stored in the item database, and revising the item database to any captured information not included in the information stored in the item database. Preferably, the step of revising comprises: establishing within the item database a first item object corresponding the first provided item, generating within the first item object at least one item field, associating an item field identifier with each item field, and storing a portion of the information regarding the first provided item within each item field. Preferably, the step of revising comprises establishing within the item database a first provider object corresponding to the item provider, generating within the first provider object at least one item field, associating a provider field identifier with each the provider field, and storing a portion of the information regarding the item provider within each provider field. Preferably, the item database includes a first item object, comprising associating the provider object with the first item object. Preferably, the step of revising comprises storing in the first list field of the retrieved first list object a pointer referencing the first item object. Preferably, the first list includes a first item and wherein the step of revising comprises the step of, responsive to a command issued to the management tool, identifying the first item and revising the retrieved first list to remove the first item from the retrieved list.
[0020] The step of revising preferably comprises: establishing an item database on an item database server computer system remote from the client computer system, the item database including item information relating to a first item, responsive to a command issued by the management tool, retrieving the item information from the item database to the management tool, and responsive to a command issued by the management tool, capturing the item information relating to the first item, and revising the retrieved first list to include the item information relating to the first item.
[0021] The step of revising comprises: establishing a communications link between the client computer system and an item provider computer system, the item provider computer system remote from the client computer system and including information relating to a first provided item, responsive to a command issued to the client computer system, locating the first provided item on the item provider computer system, capturing the information relating to the first provided item with the management tool, and responsive to a command issued by the management tool, revising the retrieved first list to include the information relating to the first provided item. Preferably, the step of capturing comprises: providing a template database on a template database server computer system remote from the client computer system, the template database including one or more templates, each corresponding to an information structure, determining a structure for the information relating to the first provided item, retrieving a template corresponding to the structure from the template database to the management tool, applying the template to the provided item information to parse the information relating to the first provided item; and capturing the parsed information with the management tool. Preferably, the step of revising the retrieved first list comprises establishing an item database on an item database server computer system remote from the client computer system, the item database including stored information relating to a first item, comparing the information relating to the first provided item with the stored information relating to the first item, responsive to a pre-established rule, revising the stored information relating to the first item to include the information relating to the first provided item, and responsive to a command issued to the management tool, revising the retrieved first list to include the information relating to the first provided item. Preferably, the step of responsive to a pre-established rule, revising the information relating to the first item comprises: determining if the information relating to the first provided item and the information relating to the first item relate to the same item, and revising the information relating to the first item to include the information relating to the first provided item if the information relating to the first item relates to the same item as the information relating to the first provided item. Preferably, the step of revising comprises providing information relating to a first provided item to the management tool, and, responsive to a command issued to the management tool, revising the retrieved first list to include the information relating to the first provided item.
[0022] Preferably, the retrieved first list includes a first item and the method comprises, responsive to a command issued by the management tool, establishing a communications link between the client computer system and an item provider computer system, the item provider computer system remote from the client computer system and offering the first item for sale, and purchasing the first item from the item provider computer system. Preferably, the step of revising comprises: capturing purchase information relating to the purchase of the first item, and updating the first list in the database to reflect the inclusion of the purchase information in the retrieved first list. Preferably, the purchase information comprises information relating to one or more of: price, quantity, shipping method, and delivery date. Preferably, the step of establishing a communications link between the client computer system and the list database server computer system comprises establishing a communications link using one or more of the Internet, a wide area network, and a local area network. Preferably, the step of establishing a communications link between the client computer system and the list database server computer system comprises, providing a browser tool on the client computer system, instructing the browser tool to locate the item provider computer system, and instructing the browser tool to search the item provider computer system for the provided item information.
[0023] In another aspect, the invention provides a method for creating an electronic list of items, the method comprising: establishing a list database on a server computer system, establishing a management tool on a client computer system remote from the server computer system, the management tool including a list identifier, establishing a communications link between the server computer system and the client computer system, responsive to a signal issued by the client computer, establishing a communications link to an item provider computer system remote from both the server computer system and the client computer system, locating an item on the item provider computer system, responsive to a command issued to the management tool, adding a pointer referencing the item to a list associated with the list identifier in the list database on the server computer system.
[0024] In another aspect, the invention provides a method for maintaining an electronic list, the method comprising: establishing a management tool on a client computer system, the management tool including a list identifier, establishing on a server computer system remote from the client computer system an item database including item information relating to a first item, and a list database including a list associated with the list identifier, the list including the first item, establishing a communications link to an item provider computer system remote from both the server computer system and the client computer system, responsive to a command from the server computer system, updating the item information in the item database; and responsive to a command issued to the client computer system and the list identifier, retrieving to the client computer system the updated information corresponding to an item on the list associated with the list identifier.
[0025] In another aspect, the invention provides a method for maintaining an electronic shopping list on a computer system linked to a network, the shopping list including at least one record, each record containing information relating to a product, the method comprising: establishing a shopping list management toolbar on an Internet browser on a client computer system, the client computer system in communication with the Internet, establishing on a server computer system in communication with the Internet, a shopping list database, the shopping list database including a first shopping list having a shopping list identifier, providing the shopping list identifier to the shopping list management toolbar, communicating the shopping list identifier to the shopping list database, retrieving a copy of the first shopping list from the shopping list database to the shopping list management toolbar responsive to the shopping list identifier, establishing communications via the Internet with a product provider computer system, the product database including product information relating to a first product, revising the retrieved copy of the first shopping list on the shopping list management toolbar to include a pointer referencing the product information relating to the first product, and updating the first shopping list in the shopping list database to reflect the revisions to the retrieved shopping list.
[0026] Numerous other features, objects and advantages of the invention will become apparent from the following description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a block diagram of a preferred embodiment of a network on which the present invention is intended to operate;
[0028] FIG. 2 is an exemplary view of a computer screen depicting the operation of the user interface of the management tool in an embodiment of present invention;
[0029] FIG. 3 is another view of the computer screen of FIG. 2 showing the display of items from the item database of FIG. 1 ;
[0030] FIG. 4 is yet another view of the computer screen of FIG. 2 after the connection to a provider web site;
[0031] FIG. 5 is a further view of the computer screen of FIG. 2 illustrating the capture of information from the provider web site; and
[0032] FIGS. 6 and 7 are views of a computer screen depicting the operation of the user interface of the management tool in another embodiment of present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0033] As will be described in greater detail below, the present invention relates to a data structure for use in creating and maintaining electronic databases of information. Referring to FIG. 1 , the embodiments of the present invention are implemented as logical operations in a computer system, such as 10 and 30 . The logical operations of the embodiments of the present invention are implemented as a sequence of computer-implemented operations, steps or modules running in the form of computer software on the computing system. One of ordinary skill in the art will appreciate that the particular implementation of the operations, steps or modules comprising the present invention will depend on the decisions of the individual practicing the invention, the capabilities of the computer system or systems on which the present invention is to be implemented, and the demands to be placed on the present invention during operation. Accordingly, it is to be understood that the present invention need not be restricted to a single embodiment, and it is to be further understood that any embodiment implementing the operations, steps and modules described herein and shown in the attached drawings, and their equivalents, is intended to come within the scope of the present invention.
[0034] As will be described in greater detail below, databases and systems 12 , 13 , of databases embodying the data structure of the invention are particularly well-suited to the creation and maintenance of user-defined electronic lists of goods, services and other items. In one such embodiment, the invention allows online customers to create and maintain electronic lists 52 ( FIG. 2 ) made up of products and services being offered for sale both on and off the Internet. An electronic list created by such an embodiment of the invention may be accessed from any computer 30 linked to the Internet, regardless of where the list was first created or last accessed. Once accessed, a list created by such an embodiment of the invention may be updated by capturing information from an online database of information, from a Web page on which a product or service is displayed, or manually from any source available to the user of the list. Each list created by such an embodiment of the invention is universal and is independent from any given single provider of goods or services. The list of such an embodiment of the invention facilitates automatic updating of the electronic list whenever new information, such as a lower price, relating to a good or service on the list becomes available. The invention may thus be used by an online customer to maintain a single electronic list having products and services that are offered for sale by various vendors or providers of goods or services. In another embodiment, the invention allows for manufacturers of goods and providers of services to establish lists of their own goods and services on their own web sites and to maintain direct links from those lists to web sites where those products and services are offered for sale. In this embodiment of the invention, online customers visiting the web site of a manufacturer or provider maintaining such a list are thus able to link directly to a web site on which they can purchase the product or service without leaving the web site of the manufacturer or provider. The list of this embodiment of the invention further facilitates automatic updating of the manufacturer's list as new information about the goods or services on the list, such as inventory and dealer stock, become available.
[0035] As noted above, the invention relates to a data structure for creating and maintaining a database. A database embodying the data structure of the present invention is implemented as a sequence of computer software operations, steps or modules on a computer system. In particular, a database embodying the data structure of the present invention takes the form of a relational database, such as 12 and 13 , of the type accommodating the storage and retrieval of information in the form of records populating the database. Each record populating a database embodying the present invention takes the form of an object. Each object corresponds to a particular product, service, or other item and stores information relating to that product, service, or item. The information stored in each object includes information regarding one of the products, services, or other items about which information is stored the database. Each object may be provided with an object identifier used to identify that object within the database. The information is organized according to a data structure defined by fields. Each field is assigned a field identifier and stores information. The type of information stored in each field is determined by the field identifier given to the field. Each field identifier corresponds to a particular attribute, trait, or category of information describing the product, service or other item to which the object corresponds.
[0036] Table 1 contains a listing of field identifiers for a database storing objects that correspond to products, the names of the attributes corresponding to each field identifier, and the descriptions of the attributes corresponding to each field identifier. As shown in Table 1 below, a single field identifier is defined for each unique attribute. Fields bearing a particular field identifier store information regarding only the unique attribute of the product, service or item to which that particular field identifier corresponds. For example, a field that holds information about the name of a product is given the field identifier corresponding to product name. Accordingly, all fields having a particular identifier store information and values regarding the same particular attribute of the product, service or item to which the object corresponds. It will thus be appreciated by one of ordinary skill in the art that a database embodying the data structure of the present invention may be adapted to store information relating to various products, services or other items by changing the field identifiers of the database to reflect general attributes of the product, service or item to be stored in the database.
[0000]
TABLE 1
Field
Identifier
Field Name
Field Description
817
Operating System
The required operating system for software to be compatible
with your computer or PDA. Most computers and peripherals
are sold with an operating system already installed.
1150
Hard Drive Capacity
The capacity is the amount of storage space available
measured in gigabytes.
1156
Modem Type
This refers to the type of modem the product is equipped with
upon purchase. Internal means it is inside of your product.
External means the modem is connected to the outside of your
product. PCMCIA modems are used in laptop computers.
Cable modems require a cable connection rather than a
telephone connection, and cellular modems allow you to
connect to the Internet using a cellular phone.
1178
Processor
The processor is the chip used to drive the computer. The
number in the processor's name is how fast the processor has
been clocked to perform. A higher number indicates a
faster processor.
1217
Case Style
A cabinet that houses the hard drive, floppy drive, and other
inner components of a computer.
1383
Olympus
NULL
1384
Athena
1619
Speakers Included
These are the type of speakers that come with the product
when you purchase it.
1641
Desktops
Looking to outfit your home or business with a complete
computing system, or do you just need to upgrade? Here you
will find both stand alone units and complete computing
systems - including keyboard and mouse.
2481
Name
The manufacturer, name and model number of the product.
2488
Description
Description of the product.
2489
Image URL
URL for an image of the product.
2492
Manufacturer ID
The name of the manufacturer that makes the product.
2493
Model Number
The manufacturer's model number assigned to the product.
2495
Price
This represents the lowest price available from the vendors
selling the product. An “N/A” in this column indicates
that youknowbest currently does not have any vendors that
sell this product.
2594
Notes
The notes section is reserved for in-house, youknowbest use
only. Anything someone might need to know about the
product that you pick up on can be written here.
2595
Datasheet URL
Click on the manufacturer's datasheet URL and it will take
you directly to the manufacturer's web page with information
about the product.
3023
Desktop Computers
3221
Computing
Everything computer-related you need to organize your
home, business, and personal life - including computers,
laptops, printers, scanners, and more.
3228
Computer Systems
Here you will find desktops, laptops, and servers to fit all
your computing needs, whether you are a first time buyer or
a information technology professional.
3423
Modem (yes/no)
A modem is needed to be able to connect to the internet.
Some computing devices are equipped with a modem at
purchase and some require an additional purchase in order to
connect.
3424
NIC
A NIC or Network Interface Card is a circuit board/card
that is installed and provides capability to connect to a
network.
[0037] The types of field identifiers that are available in a database having a data structure of the invention are defined during configuration of the database. The particular field identifiers defined during configuration are based on the general attributes of the products, services, or other items being stored in the database. For each attribute for which information is to be stored in the database, a field identifier is defined. As described above, each field identifier thus defines the type of information that will be stored in a field that is assigned that field identifier. Accordingly, the field identifiers comprise a form of meta information, or “information about information”. In the case of the data structure of the invention, each field identifier comprises information about the type of information held in any field that has been given that field identifier, namely the attribute about which that field holds information. Fields comprise information, namely information describing the attribute of the product, service, or other item to which the field identifier corresponds.
[0038] It is not necessary that each object in the database include a field corresponding to each of the field identifiers that have been defined for that database. In particular, an object will not have a field corresponding to an attribute of the product, service or other item to which that object relates unless information is known about that attribute. For example, while the weight of certain products may be known, the weight of others may not. The objects corresponding to the products for which there is no weight information will have no field corresponding to the field identifier for product weight. Likewise, an object will not include fields that are not relevant to the product, service or other item to which the object corresponds. For example, a product to which an object corresponds may have no processor. Thus, that object will have no field corresponding to the field identifier for processor speed. Accordingly, the fields in the data structure of each object will depend on the individual attributes of the product, service or item to which the object corresponds and the information known about those attributes. One of ordinary skill in the art will appreciate that the data structure of an object may also include different fields depending on whether the item to which the object corresponds to a product, service, or other item.
[0039] A database having the data structure of the present invention supports the retrieval of information from the objects in the database through traditional query methods. For example, all of the fields in each object in the database may be queried to determine if any of the fields in any of the objects in the database contain a particular value. The data structure described by the invention also enables databases embodying the invention to support additional types of query methods based on the fact that each object in the database need not include fields corresponding to each of the field identifiers that have been defined for that database. In particular, it is possible to define various subsets and lists of the objects populating a database of the present invention, wherein each object in the subset or list shares one or more fields that bears a particular field identifier. In such a case, only those objects in the database having the attribute to which the particular field identifier corresponds will be retrieved. For example, only certain objects may have a screen and thus possess the attribute of screen resolution. By querying the database to retrieve those objects that have a field that bears the field identifier for screen resolution, it is possible to return all objects that have a screen resolution, regardless of the other attributes of those objects. One of ordinary skill in the art will appreciate that the objects returned by the query described in the previous sentence may be further queried to return those objects having a screen resolution within a particular range. Likewise, it will be readily appreciated that the subsets of objects sharing one common field identifier need not have all of the same field identifiers and that an object may thus be a member of multiple groups wherein each group is defined by those objects sharing a different field identifier.
[0040] In the following description of the present invention, objects stored in a database of the present invention are referred to in terms of the type of product, service or other item to which the object corresponds. In particular, an object corresponding to a product is referred to as “product object”; an object corresponding to a vendor or provider is referred to as a “vendor object”; and an object corresponding to a list is referred to as a “list object”. Likewise, the fields used to store information in each object and the field identifiers used to identify the various types of fields that comprise the data structure of each object are referred to in terms of the attribute to which the field identifier of each field corresponds. For example, a field identifier corresponding to the attribute of product name is referred to as a “product name field identifier” and a field bearing the product name field identifier is referred to as a “product name field”. The information regarding a particular attribute of the particular product, service or other item to which an object relates is stored in a field is referred to interchangeably as “information” or a “value”.
[0041] As noted above, the present invention lends itself to the creation and maintenance of user-defined electronic lists. One of ordinary skill in the art will appreciate that the data structure of the present invention may be adapted to accommodate the storage of information relating to goods, services or other items by defining field identifiers in the database that correspond to the attributes of those goods, services or other items. By way of example, the present invention may be implemented to create a system of databases adapted to create and maintain electronic lists of products, the vendors at which those products are sold, and other information regarding the attributes of those products. A system of databases of the type described in the current example include a product database 12 and a list database. Both the product database and the list database are built using the data structure of the present invention. The product database stores information relating to the products that make up the lists. The information in the product database is stored in the form of product objects and vendor objects. Each product object stores information corresponding to a particular product. The information stored in each product object is specific to the particular product to which the product object corresponds and that will not vary depending on the vendor offering that product for sale. For example, a product object may contain information regarding the name, model number, and manufacturer of the product, or information regarding other attributes of the product such as the weight, speed, and resolution of the product. Table 2 shows an example of the information stored in a product object of the type described in the present example. As shown in Table 2, the information stored by the product object is organized into fields. Each field bears a field identifier corresponding to the attribute to which the information stored in that field relates. The product object contains fields corresponding only to those attributes relevant to the product to which the product object corresponds.
[0000]
TABLE 2
Product
Field
Object
Identifier
Attribute
Information/Value
21987
2414
Manufacturer
Compaq
2481
Name
Compaq iPaq
2488
Description
This uniquely designed product is ideal for
corporate network environments and for employees
who primarily use their PC for mainstream office
productivity applications and corporate
Internet/Intranet access.
2489
Image URL
http://www.warehouse.com/MecaImages/www/
prodimage_standard/I77822.jpg
2492
Manufacturer ID
14
2493
Model Number
470018-160
2495
Price
459.97
3365
Q/A Status
Accepted
3423
Modem (yes/no)
No
3424
NIC
No
2594
Notes
kh 12/7 cleanup
2595
Datasheet URL
http://www5.compaq.com/products/Internetdevices/
Models/iPAQ_175756_003.html
2493
Model Number
175756-003
817
Operating System
Windows 2000
474
Display Size Inches
None
542
Base Memory
128
1150
Hard Drive Capacity
8.4
1156
Modem Type
None
1178
Processor
P3-500 MHz
1217
Case Style
Mini Tower
1619
Speakers Included
Integrated Speakers
2334
RateItAll.com Ratings
1.0
2344
ConsumerReview.com
5.0
Ratings
[0042] Each vendor object stores information corresponding to a particular version of a particular product being offered by a particular vendor. The information stored in each vendor object is specific to the particular version of the particular product being offered by the particular vendor to which the vendor object corresponds. For example, the vendor object contains a pointer referencing the product object corresponding to the product to which the vendor object corresponds. As noted, this information may be in the form of a pointer which references the relevant product object. Alternatively, the information may be in the form of a copy of the relevant product object itself. The vendor object further includes information relating to the particular vendor that is offering the particular version of the product for sale. This information may take the form of a pointer or reference to a separate file, either in the product database as the vendor item or in a separate database, containing information regarding the vendor. Such information may include, for example, the name and location of the particular vendor. Alternatively, the information regarding the particular vendor may be contained in the vendor object itself. The vendor object also includes other information relating to the other attributes of the particular version of the product to which the vendor object relates. For example, the vendor object may store information relating to the price, color, and quantity of the particular version of the product offered by the vendor to which the vendor object corresponds. Table 3 shows an example of the information stored in vendor objects of the type described in the present example. As shown in Table 3, the information stored by the vendor objects is organized into fields. Each field bears a field identifier corresponding to the attribute to which the information stored in that field relates. The vendor objects contain fields corresponding only to those attributes relevant to the version of the product and the vendor to which the vendor object corresponds.
[0000]
TABLE 3
Field
Vendor Item
Identifier
Attribute
Value
9325871
2482
Product Object
21987
2481
Name
Compaq iPAQ C/800 20 GB 64 MB NIC Win98
2483
Availability
−1
2484
Buy URL
http://www2.warehouse.com/product.asp?pf%5Fid=CP18060&blind=no&cat=pc
2485
Category Hint
pc
2489
Image URL
http://www2.warehouse.com/MecaImages/www/prodimage_standard/I77822.jpg
2491
Manufacturer
Compaq Commercial
2492
Manufacturer ID
14
2493
Model Number
470018-160
2495
Price
579
2498
Vendor SKU
CP18060
2499
Last Feed Date
1008186673
3313
Resolved Buy URL
http://www2.warehouse.com/product.asp?pf_id=CP18060&blind=no&cat=pc
6359
Additional
Audio Output: Sound card-PCI-16-Bit 48 KHz stereo Dimensions (W × D × H):
Information
5.4 in × 10.3 in × 13.6 in Form Factor: 168-PIN - non-parity -
Storage Hard Drive: 1 × 20 GB internal
. . .
. . .
. . .
. . .
9336738
2480
Product Object
21987
2481
Name
Compaq iPaq
2483
Availability
−1
2484
Buy URL
http://www.cdw.com/shop/products/default.asp?EDC=316787
2488
Description
This uniquely designed product is ideal for corporate network environments
2489
Image URL
http://webobjects.cdw.com/staticimg/full/3/1/6787.jpg
2491
Manufacturer
Compaq Computer
2492
Manufacturer ID
14
2493
Model Number
470018-160
2495
Price
599.86
2498
Vendor SKU
316787
2499
Last Feed Date
1008186670
3313
Resolved Buy URL
http://www.cdw.com/shop/products/default.asp?EDC=316787
6359
Additional
Connectivity Serial port: 1 Parallel port: 1 Video
Information
port: 1 Mouse port: 1 USB port: 2 10/100 Mbps
Ethernet port: 1 Keyboard port: 1 NIC
information: 10/100 Ethernet Additional
information:
. . .
. . .
. . .
. . .
9424808
2482
Product Object
21987
2481
Name
Compaq Ipaq Legacy Cel 800 MHz
2483
Availability
232
2484
Buy URL
http://www.insight.com/web/apps/productpresentation/index.php?product_id=470018-160
2488
Description
The Compaq iPAQ desktop is ideal for corporate network environments and employees who
primarily use their PC for mainstream office productivity applications and corporate
Internet/intranet access.
2489
Image URL
http://www.insight.com/graphics/us/products/mn/470018-160_mn.jpg
2493
Model Number
470018-160
2495
Price
579.99
2498
Vendor SKU
470018-160
2499
Last Feed Date
1008186670
3313
Resolved Buy URL
http://www.insight.com/web/apps/productpresentation/index.php?product_id=470018-160
6359
Additional
>> Intel Celeron 800 Mhz Processor >> 64 MB
Information
SDRAM; 20 GB Hard Drive >> Integrated Audio and NIC >> Microsoft Windows 98
[0043] Based on the foregoing description, it will be appreciated by one of ordinary skill in the art that the product database of the present example contains one product object corresponding to each product for which information is stored in the product database. However, the database may contain multiple vendor objects corresponding to each product. In particular, for any given product object in the database there may be multiple vendors offering for sale the product to which that product object corresponds. Likewise, each vendor offering that product for sale may offer multiple versions of the product at different prices. Accordingly, to capture this information, the database will contain a vendor object corresponding to each version of the product being offered by each vendor offering that product for sale.
[0044] The list database 13 of the present example stores information relating to lists of products for which there are product objects in the product database. The lists are stored in the list database in the form of list objects. Each list object stores information corresponding to a particular list of product objects in the product database. For example, a list object may contain information regarding the user who created the list, a unique name for the list, and a password used to access the list. Each list object further stores information relating to the product objects in the product database that corresponds to the products on the list. The information relating to each product object that corresponds to a product on the list takes the form of a pointer referencing a product object in the product database that correspond to products on the list. However, it will be appreciated that the information relating to each product object that corresponds to a product on the list may also take the form of a copy of the product object itself. Table 4 shows two tables exemplifying the storage of information on the list database. As shown in Table 4, information regarding the lists stored in the list database may be organized into a table of fields in which each list is identified by a user identifier indicating the user who generated the list, a list identifier indicating the list itself, and a list name identifier indicating the name given to the list by the user. In addition, Table 4 shows a depiction of the information stored in a list object of the type described in the present example. The information stored by the list objects is organized into fields. Each field bears field identifiers. As shown in Table 4, a list object includes a user identifier field containing the user identifier given to the user who generated the list, a list identifier field containing a list identifier identifying the particular list itself, and a product identifier field holding pointers of references to the product identifiers of the product in the product database that are on the list. The list object may also contain fields corresponding to other attributes of the products on the list, such as the position on the list held by a particular product and the source from which the information regarding the product stored in the product database was obtained.
[0000]
TABLE 4
List Name
User Identifier
List Identifier
Identifier
54841
845
Products
946
Christmas Gifts
1023
Wish List
. . .
. . .
. . .
55871
342
Services
563
Gifts
673
Birthday
List
Product
List Position
Source
User Identifier
Identifier
Identifier
Identifier
Identifier
54841
845
12346
1
845
12345
2
845
12342
3
845
23423
10
[0045] Each list created by the present invention thus defines a subset of product objects in the product database that are pointed to by the list object corresponding to that list. Likewise, other lists generated by the present invention define other subsets of the product objects in the product database that are pointed to by the list objects corresponding to those lists. Thus, in practice, a list is generated by creating a new list object in the list database and providing that list object with information in the form of pointers that refer or point to those product objects in the product database that correspond to the products that are to be added to the list. Likewise, a desired list is retrieved from the list database by querying the list database to retrieve those lists that have a given value in the field that bears the field identifier corresponding to the list name. It will be appreciated by one of ordinary skill in the art that the present invention teaches that each product object may be a member of multiple lists, and that, regardless of the number of lists that contain a given product object, the database need only contain a single copy of that given product object. Accordingly, it will be further appreciated that by updating the information in a single product object in the product database, each of the electronic lists that point to that product are likewise updated.
[0046] As noted above, the present invention is well-suited to the creation and maintenance of user-defined lists of products. Referring to FIG. 1 , what follows below is a description of an embodiment of the present invention in which the item database described in the example above comprises a product database 12 and the list database described in the example above comprises a list database 13 (see Table 4). The product database 12 is a database having a data structure of the type described above, populated by product objects and vendor objects. Each product object contains information corresponding to a unique product. Each vendor object contains information corresponding to a particular version of a product offered by a particular vendor or provider. List database 13 is a database having a data structure of the type described above, populated by list objects. While the following description is based on an embodiment of the present invention comprising a product database populated by product objects and vendor objects, it will be appreciated by one of ordinary skill in the art that the present invention may also embody a service database populated by service objects, or a mixed database populated by both product objects and service objects. Thus, in the most general description of the invention we refer to the database 12 and an item database. In any of these cases, the present invention is equally effective in creating and maintaining lists including products, services, or both products and services, respectively. Likewise, it will further be appreciated that while the functions of the product database and list database are described as being carried out on two separate databases, each embodying the data structure of the present invention, in alternative embodiments, the functions of the product database and list database may be carried out on the same database, or on multiple product databases and multiple list databases.
[0047] The embodiment of the present invention described below is configured to operate under a client/server computing model and, in particular, to operate on the system shown in FIG. 1 . The system shown in FIG. 1 includes a server computer system 10 , located at a node on a communications network 20 . The system further includes any number of client computer systems 30 , each located at a node on communications network 20 , and product provider computer systems 80 , also located at nodes on communications network 20 . Communication is supported between and amongst the nodes on communications network 20 , and thus between server computer systems 10 , client computer systems 30 , and provider computer systems 80 , through a series of communications links 22 . Communications links 22 of the present invention may be accomplished by either terrestrial, wireless, or satellite means, provided that communications link 22 is capable of sustaining electronic communications between the nodes connected by communications link 22 . FIG. 1 also shows product database 12 residing on server computer system 10 . Accordingly, it will be understood that product database 12 is in electronic communication with client computer systems 30 and provider computer systems 80 via communications network 20 .
[0048] As shown in FIG. 1 , communications network 20 of the system on which the present invention may operate includes the world wide web portion of the Internet (referred to herein interchangeably as the “Internet” or the “Web”). However, it will alternatively be appreciated that communications network 20 may include any other local area network, wide area network, or communications network capable of supporting electronic communications between two or more nodes. In the interest of simplifying the description of the present invention, FIG. 1 depicts a system including several client computer systems 30 and several product provider computer systems 80 . However, it will be understood that the present invention may be implemented to operate on a communications network 20 having additional client computer systems 30 and additional product provider computer systems 80 , each operating under the principles described herein with respect to client computer systems 30 and product provider computer systems 80 shown in FIG. 1 . Likewise, while server computer system 10 is shown in FIG. 1 as being located at a single node on communications network 20 , it will be understood that the present invention also lends itself to the use of a server computer system 10 distributed over two or more nodes on communications network 20 .
[0049] Server computer system 10 of the system shown in FIG. 1 includes a computer server capable of serving information to one or more nodes on communications network 20 defined by the Internet. Client computer system 30 of the system on which the present invention is intended to operate includes a personal computer, network terminal, personal digital assistant, telephone, or other electronic device capable of being operably attached to and communicating over the communications network 20 . Each product provider computer system 80 is a node on communications network 20 through which vendors and manufacturers of products offer various products for sale, or through which information regarding products is made available. As such, in the case that communications network 20 is the Internet, each product provider computer system 80 embodies a Web page displaying products offered for sale and providing various information regarding those products. In each case, it will be readily understood by one of ordinary skill in the art that the exact specifications of communications network 20 , server computer system 10 , and each client computer system 30 and product provider computer system 80 of the system on which the present invention is intended to operate will depend on factors such as the number of nodes on communications network 20 , the amount of information being communicated across communications network 20 , and the desired speed of operation of the present invention.
[0050] The embodiment of the present invention implemented to operate on the system shown in FIG. 1 includes a management tool with which user-defined lists of products may be created and maintained. The management tool is implemented as a sequence of operations, steps or modules implemented in the form of client-side computer software on client computer system 30 . Accordingly, the management tool is capable of sustaining communications with server computer system 10 and, in particular, sending commands and instructions to server computer system 10 and receiving the results of those commands and instructions from server computer system 10 . Referring to FIG. 2 , the management tool includes a user interface 40 used to display information regarding the operation of the management tool on display 32 of client computer system 30 . As shown in FIG. 2 , user interface 40 preferably takes the form of a tool bar on an Internet browser computer software program and includes a series of computer software-implemented buttons for use in providing instructions and commands to the management tool. It will be appreciated that user interface 40 may also take the form of a computer software program that is separate and independent from any Internet browser computer software program. As used herein, the term “Internet browser” is intended to mean one of the generally available computer software programs that is used to navigate, access and view the web sites on the Internet. It is well understood that an Internet browser will take different embodiments depending on the specifications of client computer system 30 and display 32 on which the Internet browser has been implemented. Likewise, user interface 40 of the management tool will take different embodiments depending on client computer system 30 and display 32 on which user interface 40 is implemented.
[0051] As noted above, the management tool includes a series of computer software-implemented buttons used to issue commands to the management tool to perform certain operations on the list database and product database. In particular, the embodiment of user interface 40 depicted in FIG. 2 includes a new list button 41 , open button 42 , find button 44 , and add button 46 . It will be appreciated by one of ordinary skill in the art that while the embodiment shown in FIG. 1 includes the aforementioned buttons, alternative embodiments of the management tool may include additional buttons providing for other operations to be performed on the list database and the product database, and the list objects, product objects, and vendor objects contained therein. New list button 41 is used to issue a command to the management tool to create a new list in list database 13 . Open button 42 is used to issue a command to the management tool to retrieve a list of product objects from list database 13 and to display that list on user interface 40 . Find button 44 is used to issue a command to the management tool to search product database 12 for a product object corresponding to a product having certain characteristics and to display the results of that search on user interface 40 . A user utilizes add button 46 , preferably by clicking on it, to issue a command to the management tool to add a product object corresponding to the product information displayed in product information field 48 to a list that has already been retrieved to user interface 40 . A further description of the operation of user interface, and the buttons and fields displayed thereon, follows below.
[0052] The embodiment of the present invention described herein teaches that a list may be created by providing the management tool with the information necessary to create a new list and instructing the management tool to establish a new list by selecting new list button 41 . The information necessary to establish a new list includes a list name or code by which the list will be identified. The list name or code may include, for example, a user name and password. In the present embodiment of the invention, the list name or code is provided to the management tool and new list button 41 is selected. Responsive to such command, the management tool instructs list database 13 to create a new list object and to create a field in the new list object to store the list name or code provided to the management tool. It will be understood from the foregoing description that the field identifier given to the field storing the list name or code is the same field identifier that is given to the field in all other list objects that stores the name or code for those list objects. Once created, the list may be updated and managed, as is described in greater detail below. A previously created list may be accessed from any client computer system 30 on communications network 40 by entering the unique list identifier associated with the list into the management tool. In practice, a list identifier is entered into a data field on user interface 40 . The management tool transmits a query to list database 41 to identify and retrieve to the management tool those list objects having a list identifier corresponding to the list identifier entered into user interface 40 . As shown in FIG. 2 , upon retrieval of the list objects corresponding to the entered list identifier, the product database is queried to obtain information regarding each of the product objects pointed to by the list object and the management tool generates a graphical representation of list 50 including graphical representations of each of product objects 52 pointed to by the list object. The information stored in the vendor objects that refer to each of the product objects pointed to by the list object may then be accessed by selecting any of the graphical representations of product objects 52 displayed in the graphical representation of list 50 . In an alternative embodiment of the invention, the graphical representation of list 50 may itself include a graphical representation of the vendor objects that refer to each of the product objects pointed to by the list object. As will be described below, the list that is currently being displayed on user interface 40 may be managed. Management of the list may include, for example, making additions to or subtractions from the list. The list that is currently being displayed on user interface 40 will be referred to herein as the “current list.” As the foregoing description indicates, the present embodiment of the invention teaches that the product objects and vendor objects comprising a list are retrieved from product database 12 on server computer system 10 to the management tool on client computer system 30 . As a result, it will be appreciated that each list created by the present invention is a universal list insofar as the product objects and vendor objects comprising the list may be retrieved from server computer system 10 to a management tool resident on any client computer system 30 on communications network 20 , regardless of where the list was originally created or accessed in the past.
[0053] A product may be added to the current list by locating a product object corresponding to that product in product database 12 and adding a pointer referring to that product object to the list object corresponding to the current list. As shown in FIG. 3 , user interface 40 of the management tool includes a search field 54 . In practice, a description of a product is entered into search field 54 and find button 44 is selected. A query command is issued by the management tool to product database 12 . Responsive to the query command, product database 12 retrieves to the management tool all product objects having fields that contain information corresponding to the description entered into search field 54 . A graphical representation of the retrieved product objects is generated and displayed in the form of a list 56 on user interface 40 . A desired product 58 from list 56 may be added to the current list by identifying a desired product 58 to be added to the current list and selecting add button 46 . Responsive to such command, the management tool instructs the list database to add to the list object corresponding to current list a pointer referring to the product object that corresponds to desired product 58 and, as shown in FIG. 3 , add a graphical representation 60 of the product object corresponding to desired product 58 to the graphical representation of current list 50 .
[0054] The present invention also teaches that a product may be added to a current list by detecting and capturing information regarding that product from a provider computer system 80 . As shown in FIG. 4 , upon locating a product provider computer system 80 that includes a display of information 62 regarding a particular product, the management tool detects and captures the display of information 62 regarding the product on provider computer system 80 . Based on the detected and captured information, the management tool queries product database 12 to determine if product database 12 includes a product object corresponding to the product for which information 62 has been detected and captured, and a vendor object corresponding to the vendor and version of the product for which information 62 has been detected and captured. If product database 12 does not include a product object or a vendor object corresponding to the product for which information 62 has been detected and captured, a new product object corresponding to the product for which information 62 has been detected and captured, and a new vendor object corresponding to the vendor of the product and the version of the product for which information 62 has been detected and captured, are created using information 62 . If product database 12 includes a product object corresponding to the product for which information 62 has been detected and captured, but does not include a vendor object corresponding to the version of the product and the vendor offering the product, a new vendor object corresponding to the vendor of the product and the version of the product is created. As will be appreciated from this description, information 62 that has been detected and captured is categorized and associated with an attribute for which a field has been created in the product database and stored in the field corresponding to that attribute in either the product object or vendor object. As will be described in greater detail below, the present embodiment of the invention accommodates the verification of information 62 prior to the creation of the product object and vendor object.
[0055] If product database 12 contains an existing product object and vendor object corresponding to the product for which information 62 has been detected and captured, information 62 contained in the existing product object and vendor object is compared against the detected and captured information 62 . If the detected and captured information 62 is not present in the product object and vendor object, the detected and captured information 62 is verified and, pending verification, the product object and vendor object is updated to include the detected and captured information 62 . If the detected and captured information 62 is present in the product object and the vendor object, the product object and vendor object are not modified. In either case, the management tool then displays the information from the new, updated, or existing product object, as applicable, in product information field 48 . The product for which information 62 has been detected and captured may be added to the current list by selecting add button 46 . Responsive to such command, the management tool adds a pointer to the product object or vendor object corresponding to the information displayed in product information field 48 to the list object corresponding to the current list and, as shown in FIG. 5 , adds a graphical representation 64 of the product object corresponding to the information displayed in product information field 48 to the graphical representation of list 50 on user interface 12 .
[0056] As noted above, the present embodiment of the invention teaches that information 62 regarding a product that is detected and captured from a provider computer system 80 may be verified prior to being incorporated into either a new or existing product object or vendor object. The step of verification may include a comparison of the detected and captured information 62 against existing records to determine if the detected and captured information 62 corresponds in form and range to existing information for similar products. The step of verification may also include comparison against records provided by a manufacturer or vendor of a product to determine if the detected and captured information 62 corresponds with the existing records. Verification may include a manual verification by a system operator. By way of example, the model numbers and serial numbers used by a particular manufacturer generally will follow a format unique to that manufacturer. Thus, a form of verification may include checking the model and serial number found in the detected and captured information 62 against the format of the model and serial number used by the manufacturer of the product corresponding to the detected and captured information 62 . By way of further example, verification may include checking the model number found in the detected and captured information 62 against the product objects in product database 12 that have the same model number to determine if other information found in the detected and captured information 62 (such as the product name and manufacturer) matches the equivalent information found in the product objects having the same model number. Still another example of verification may include checking the price found in the detected and captured information 62 to determine if it falls within a reasonable range of the prices for the product to which the detected and captured information 62 corresponds.
[0057] It is noted above that the present embodiment of the invention teaches that, in performing the step of comparing the product objects and vendor objects in product database 12 against the detected and captured information 62 , the management tool updates the product object corresponding to the product, and the vendor object corresponding to the vendor and version of the product, to include the captured and detected information 62 . The process of updating the product and vendor objects generally includes adding information to the product and vendor objects that is not yet included in the product and vendor objects or adding information to the product and vendor objects that is more current or more desirable than the existing information in the existing product and vendor object. By way of example, if information 62 detected and captured from provider computer system 80 includes a price for the product that is lower (and thus more desirable) than the price then included in the vendor object, pending verification (as discussed above), the vendor object will be updated to reflect the lower price and the vendor offering that lower price. Likewise, if information 62 detected and captured from provider computer system 80 includes a price for the product that is higher (and thus less desirable) than the price then included in the vendor object, pending verification, the vendor object will not be updated to reflect the higher price. In either case, the information regarding the product displayed in product information field 48 will reflect the lower of the captured and detected price and the price included in the vendor object. Accordingly, by way of further example, and as shown in FIG. 5 , while information 62 detected and captured from product provider computer system 80 reflects a price of $194.88 for the product, the information displayed in product information field 48 reflects a lower price of $174.94 that had been included in the vendor object for that product.
[0058] The present invention further teaches that a product may be added to a list by manually entering information regarding that product into the management tool. In the case of manual entry, information regarding a product is entered into product information field 48 , and add button 46 is selected. Responsive to this command, the management tool captures the manually entered information from product information field 48 , creates a new product object and a new vendor object corresponding to the product corresponding to the manually entered product information, and revises product database 12 to include that new product object and vendor object.
[0059] Products may also be deleted from a list by selecting the graphical representation of the product object to be deleted from the graphical representation of list 50 and selecting delete button 65 . Responsive to this command, the management tool removes the pointer to the selected product object from the list object corresponding to the current list, thus removing the product from the current list. It will be appreciated that by deleting a product from a list, the product object corresponding to that product is not also deleted from product database 12 , and that the product object will remain listed on any other user-defined lists that contain a pointer referencing that product object.
[0060] One of ordinary skill in the art will understand that references made herein to “identifying”, “selecting”, or “activating” a button on a computer screen are intended to refer to the act of issuing a command to the computer to choose and enact the computer-implemented set of commands associated with that button. Such acts are commonly accomplished by positioning a pointer above the button and depressing one or more of the buttons on a mouse device, by tapping on the button with a stylus device, or by any other conventionally known process or operation generally known in the art.
[0061] As is noted above, each user-defined list generated by the present invention is a list of pointers or references to product objects in product database 12 wherein each product object corresponds to a particular product and includes fields containing information regarding that product. Likewise, each product object is referenced by one or more vendor objects in product database 12 wherein each vendor object corresponds to a particular version of the product being offered by a particular vendor. Given that the information included in the product objects pointed to in each list, and the vendor objects referencing those product objects, are subject to periodic updates as described above, it should be understood that each time that a list is accessed, the information retrieved from the product objects pointed to by that list, and the vendor objects referenced by those product objects, will reflect any updates that have been made to that information in the interim since that list was last accessed. Put another way, by updating a single product object to include new information, all lists that contain pointers to that product object are thereby updated to include the new information. By way of example, if a product object pointed to by a particular list is updated after the pointer to that product object is added to the list (or after that list has been last accessed), the next time the list is accessed, the list will reflect the updated product object, rather than the product object in the form that it existed when it was added to the list (or when the list was last accessed). Accordingly, the present embodiment of the invention provides the benefit of being self-updating through use. In particular, as users create and maintain lists of products, new and updated information is stored in the product database in the form of new product objects and updates to existing product objects, as is described in detail above. As new product objects and updates to existing product objects are stored in the product database, the lists referencing those product objects are automatically updated to include such new information. Accordingly, the present invention provides the benefit of supporting the generation and maintenance of lists that are automatically updated as the product objects and vendor objects in the product database are updated.
[0062] In addition to new and updated information being provided to product database 12 through users of the database, product database 12 may also be populated with new and updated product objects received directly from vendors and manufacturers of products. In such an embodiment, a file containing product information may be received from a vendor or manufacturer and the product information directly input into product database 12 . Alternatively, a communications link may be established between computer systems operated by the vendors and manufacturers of products and product database 12 . Such communications link may take the form of communications network 20 , or any other generally accepted form of electronic communication. Once such a link is established, updated product information from those vendors and manufacturers may be sent directly to product database 12 . In either case, it will be appreciated that the vendors and manufacturers of products may be able to provide information relating to the products that is not generally available for detection and capture from provider sites 80 . For example, while a provider site 80 may not include information pertaining to the existing inventory and availability of a product offered for sale on provider site 80 , the vendor or manufacturer may, in addition to the attributes noted above, provide real-time, up-to-date information relating to existing inventory and availability of their products.
[0063] While the embodiment of the present invention shown in the figures and described above includes product database 12 and list database 13 as resident on server computer system 10 , in an alternate embodiment, the management tool of the present invention includes a database on client computer system 30 for storing copies of the lists accessed through that client computer system 30 . It will be appreciated that, by maintaining a database of the lists accessed through a client computer system 30 on that client computer system 30 , such lists may be accessed from the copy on client computer system 30 rather than from product database 12 . Accordingly, it will be appreciated that such an embodiment allows for the list to be accessed when client computer system 30 is not in communication with server computer system 10 via communications network 20 . In such an embodiment, upon accessing list database 13 to retrieve a list, the management tool will execute the additional step of checking for differences between the copy of the list maintained on client computer system 10 and the list retrieved from list database 13 . In the event that differences are detected, the management tool will synchronize the record of the list on the client computer system with the list retrieved from list database 13 .
[0064] In addition to providing a tool with which consumers may create and maintain lists of products and services, as described above, the present invention also lends itself to the generation of manufacturer-defined lists of vendors who offer that manufacturer's products for sale. In particular, a product manufacturer may maintain a web site on which the manufacturer displays information regarding its products. As shown in FIG. 6 , such a web site may include a display of information 66 regarding a product produced by that manufacturer and a hyperlink button 68 to further information regarding the product. However, unless the manufacturer has established a relationship with a vendor of its products, or unless the manufacturer has established a means to offer its own products for sale on its web site, a potential customer visiting the web site will be required to leave the manufacturer's web site and locate the web site of a vendor of that manufacturer's products before being able to purchase the products displayed on the manufacturer's web site. The present invention may be used to provide such a manufacturer with the ability to offer a list of updated information on its web site regarding the vendors that offer its products for sale, and with the ability to facilitate a direct link from the manufacturer's web site to web sites maintained by such vendors where the manufacturer's products may be purchased online.
[0065] As shown in FIG. 6 , under this aspect of the present invention, the manufacturer's web site has been equipped with a button 70 linking the display of information 66 to a separate Web page including information regarding the pricing and availability of product described in information 66 . By selecting the pricing and availability button 70 , the manufacturer's web site queries product database 12 to retrieve the product object in product database 12 that corresponds to the product for which information 66 is displayed on the manufacturer's web site, and the vendor objects referencing that product object. Referring to FIG. 7 , product database 12 generates a graphical representation 72 of the product object for the product to which information 66 corresponds, and the vendor objects referencing that product object. Graphical representation 72 may include any of the information that is stored in the fields of the product object and the vendor object. In the embodiment shown in FIG. 7 , graphical representation 72 includes information regarding the pricing and availability of the product and hyperlinks to the web sites maintained by the vendors at which the product is offered for sale. By selecting one or more of the hyperlinks, a user of the manufacturer's web site may link directly to a web site maintained by a vendor of the products produced by that manufacturer without leaving the web site of the manufacturer.
[0066] As noted above, the list generated on the manufacturer's web site by the present invention is a manufacturer-defined list. Accordingly, the present invention teaches that the manufacturer may select what portion of the information stored in the fields of the product object and vendor object is to be displayed in graphical representation 72 . For example, the manufacturer operating the web site shown in FIG. 7 has chosen that graphical representation 72 include information on price and availability of the product for Vendors A-C. However, it should be appreciated that the information actually stored in the product object may include additional information regarding the product, and the information stored in the vendor objects referencing that product object may include information regarding additional vendors of that product, and that the manufacturer may have chosen to selectively suppress such additional information from graphical representation 72 . By way of example, the manufacturer may have instead elected to suppress the display of certain vendor identifiers that correspond to vendors that are not preferred vendors of the manufacturer. Likewise, the manufacturer may have elected to display only certain information regarding the product, while suppressing other information from graphical representation 72 .
[0067] Accordingly, there has been described herein a new and novel database and method of operation to facilitate the generation and maintenance of lists of information contained in the database. It should be understood that the particular embodiments shown in the drawings and described within this specification are for purposes of example and should not be construed to limit the invention which will be described in the claims below. Further, it is evident that those skilled in the art may now make numerous uses and modifications of the specific embodiments described, without departing from the inventive concepts. It is also evident that the steps recited may in some instances be performed in a different order; or equivalent structures and processes may be substituted for the various structures and processes described.
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The invention provides a method for configuring a database system to store information regarding a plurality of items, the method comprising: establishing a database on a computer system; establishing within the database a first object corresponding to a first item of the plurality of items; generating within the first object at least one field; associating a field identifier with each the field; and storing at least a portion of the information within each the field; the database system configured to store information regarding a plurality of items, each item in the plurality of items having at least one item attribute, the database system comprising a computer having memory, a database stored in said memory, a first object in said database corresponding to one item of the plurality of items, said first object corresponding to the first item, at least one field in said first object, a field identifier associated with each said field, and information regarding said first item stored in said first object.
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FIELD OF THE INVENTION
[0001] The present invention relates to color ink compositions for ink-jet printing, and more particularly, to color ink compositions that enhance pen performance while minimizing color bleed.
BACKGROUND OF THE INVENTION
[0002] The combination of low cost and high quality output have recently made ink-jet printers a popular alternative to other types of non-impact printers such as laser printers.
[0003] The ink-jet printing process involves the ejection of fine droplets of ink onto a print medium such as paper in response to electrical signals generated by a microprocessor. Typically, an ink-jet printer utilizes a pen set mounted on a carriage that is moved relative to the surface of a print medium. In commercially available ink-jet color printers, such as the DESKJET™ printer available from Hewlett-Packard Company, a four-pen set including cyan, yellow, magenta and black inks is generally employed to achieve the necessary color combinations.
[0004] A typical pen includes print heads with orifice plates that have very small nozzles (typically 10-50 μm diameter) through which the ink droplets are ejected. Adjacent to these nozzles are ink chambers where ink is stored prior to ejection. Ink drop ejection is currently achieved either thermally or piezoelectrically. In thermal ink-jet printing, each nozzle is associated with a resistor element. Each resistor element is in turn connected to a microprocessor, whose signals direct one or more resistor elements to heat up rapidly. This causes a rapid expansion of ink vapor that forces a drop of ink through the associated nozzle onto the print medium. In piezoelectric ink-jet printing, ink droplets are ejected due to the vibrations of piezoelectric crystals stimulated by electrical signals generated by the microprocessor.
[0005] Interactions between the ink and pen architecture (e.g. the resistor element, nozzle, etc.) strongly influence the reliability of pen performance. In addition, interactions between the ink and both the surface and bulk of the print medium play a key role in determining print quality. A significant amount of research has recently been conducted to produce improved ink compositions for ink-jet printers that exhibit favorable interactions with both the pen architecture and the print medium.
[0006] A variety of complex interactions between the ink and pen architecture can affect both the short and long term reliability of pen performance. For example, kogation, defined as the build up of residue on the surface of resistor elements as a result of repeated firings, can cause individual thermal heaters to fail, leading to a gradual degradation in pen performance.
[0007] Puddling and crusting relate respectively to the formation of ink puddles and insoluble crusts on the orifice plates of the printhead. Such obstructions lead to poor drop ejection characteristics (e.g. drop volume, velocity and direction), and hence to a degradation in print quality. Again, ink composition plays an important role in determining the extent of these two phenomena; the low surface tension of surfactant containing inks may cause puddling, while the evaporation of a volatile ink composition could lead to crusting.
[0008] In addition to the aforementioned properties affecting the reliability of the pens of a given pen set, a particular concern for color ink-jet printing, has been the mixing or “bleeding” that occurs both on the surface and within the print medium when inks of two different colors are printed side by side. Bleeding may cause undesired color formation at the interface (e.g. when cyan and yellow mix to give green) and a concurrent loss of color separation, resolution, and edge acuity. The more contrasting the two adjacent liquids are in color (e.g. black and yellow), the more visual the bleed. Several methods, including reducing dry times and increasing penetration rates, have been proposed to reduce bleed of adjacent printing liquids. In addition, pH-sensitive dyes may also be employed to control bleed.
[0009] U.S. Pat. No. 5,181,045 (incorporated by reference herein) discloses a method of ink-jet printing wherein one ink (a pH sensitive ink, usually a black ink) contains a colorant that becomes insoluble under defined pH conditions, and a second ink (the target ink, usually a color ink) has a pH that renders the colorant contained in the first ink insoluble. To completely control bleed, this method typically requires a pH differential of 4-5 units between the two inks. Accordingly, an ink with a pH not exceeding 4 would be preferred to effectively eliminate bleed from a pH-sensitive ink having a pH of 8.
[0010] U.S. Pat. No. 5,785,743 (incorporated by reference herein) discloses that the addition of an organic acid component to the so-called target ink composition reduces the pH differential required to control bleed to as little as 1-3 units. As a result, the pH of the target ink could be as high as 7 and still eliminate bleed from an encroaching pH-sensitive ink having a pH of 8, thereby reducing some of the corrosion risks associated with low pH inks.
SUMMARY OF THE INVENTION
[0011] The invention is an ink-jet ink composition. The composition comprises at least one colorant and a vehicle. The vehicle includes a mixture of succinic acid and at least one second organic acid. The second organic acid may be a monofunctional, difunctional or polyfunctional organic acid. The second organic acid may be glutaric acid, oxalic acid, maleic acid, methylsuccinic acid, malonic acid, adipic acid, fumaric acid, dihydroxyfumaric acid, malic acid, mesaconic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, aspartic acid, glutamic acid, 1,2-, 1,3- and 1,4-cyclohexane dicarboxylic acids, 1,2,3-cyclohexane tricarboxylic acid, 1,2,4-cyclohexane tricarboxylic acid, 1,3,5-cyclohexane tricarboxylic acid, 1,2- and 1,3-cyclopentane dicarboxylic acids, citric acid, tartaric acid, dihydroxyterephthalic acid, 1,2,3-, 1,2,4- and 1,2,5-benzene tricarboxylic acids, tricarballylic acid, 1,2,4,5-benzene tetracarboxylic acid, norbomene tetracarboxylic acid, 3,3′, 4,4′-benzophenone tetracarboxylic acid, 1,2,3,4,5,6-benzene hexacarboxylic acid, acetic acid, polyacrylic acid, glycolic acid, and derivatives thereof. Preferably the second organic acid is glutaric acid.
[0012] The concentration of succinic acid may be from about 2 to about 8 wt %, for example from about 3 to about 6 wt %. The concentration of glutaric acid may be from about 0.1 to about 4 wt %, for example from about 0.5 to about 1.5 wt %.
[0013] The vehicle may further include from about 0.1 to about 7 wt % surfactants and from about 5 to about 25 wt % organic cosolvents.
BRIEF DESCRIPTION OF THE DRAWING
[0014] The invention is described with reference to the sole figure of the drawing, in which FIG. 1 is a series of photographs of cross-hatchings in which a pigment black ink was printed adjacently to a series of magenta color inks.
DETAILED DESCRIPTION
[0015] The invention will now be described in detail with particular reference to aqueous ink-jet ink compositions and the materials therein.
[0016] A. Ink Compositions
[0017] Exemplary embodiments of the ink compositions comprise, by weight (all percents are by weight unless otherwise indicated) from 0.01 to 50%, preferably from 5 to 25% organic cosolvents; from 0 to 40%, preferably from 0.1 to 7% surfactants; from 3 to 12% mixed organic acids; and from 0.5 to 10% dye. The remainder of the ink compositions are mostly water; however, other components such as biocides that inhibit growth of microorganisms; chelating agents such as EDTA that eliminate deleterious effects of heavy metal impurities; buffers; and viscosity modifiers or other acrylic and non-acrylic polymers, may be added to improve various properties of the ink composition.
[0018] In a preferred embodiment of the invention, the ink compositions comprise, by weight, about 18% organic cosolvents, about 6% surfactants, about 6% mixed organic acid, and about 4% dye.
[0019] B. Ink Composition Materials
[0020] 1. Organic Cosolvents
[0021] One or more organic cosolvents may be used to prepare the ink compositions of the present invention. In a preferred embodiment, the organic cosolvents are water-soluble. Exemplary water-soluble organic cosolvents suitable for this purpose include, but are not limited to, aliphatic alcohols, aromatic alcohols, diols, triols, amides, ketones, polyketones or ketoalcohols, nitrogen-containing heterocyclic ketones, ethers, glycol ethers, poly(glycol) ethers, alkylene glycols, polyalkylene glycols, thioglycols containing alkylene groups, lower alkyl ethers of polyhydric alcohols and lactams. The concentration of the organic cosolvents may range from 0.01 to 50 wt %, preferably from 5 to 25 wt %.
[0022] 2. Surfactants
[0023] One or more water soluble surfactants may be employed in the formulation of a vehicle for the ink. For convenience, examples of surfactants are divided into two categories: (1) non-ionic and amphoteric and (2) ionic. The former class includes the alkyl polyethylene oxides (POEs); alkyl phenyl POEs; ethylene oxide/propylene oxide block copolymers; acetylenic POEs; POE esters; POE diesters; POE amines; POE amides; and dimethicone copolyols. U.S. Pat. No. 5,106,416 (incorporated by reference herein) discusses many of the surfactants listed above in greater detail. Amphoteric surfactants such as substituted amine oxides or members of the Octyl dimethyl glycine family of octylamine choloroacetic adducts are also useful in the practice of this invention. Cationic surfactants such as protonated POE amines, and anionic surfactants such as diphenyl sulfonate derivatives like, but not limited to, sodium hexadecyl diphenyloxide disulfonate, and ethoxylated oleoalcohol phosphate esters may also be used.
[0024] Non-ionic/amphoteric surfactants are preferred over the ionic surfactants. Specific examples of surfactants that are preferably employed in the practice of this invention include Secondary alcohol ethoxylate, SURFYNOL™ CT-11, Octyl dimethyl glycine, Sodium hexadecyl diphenyloxide disulfonate, Oleyl triethoxy mono diphosphate, iso-hexadecyl ethylene oxide 20 (available from the ICI Group as ARLASOLVE™ 200), and amine oxides such as N,N-dimethyl-N-dodecyl amine oxide, N,N-dimethyl-N-tetradecyl amine oxide, N,N-dimethyl-N-hexadecyl amine oxide, N,N-dimethyl-N-octadecyl amine oxide, N,N-dimethyl-N-(Z-9-octadecenyl)-N-amine oxide. The ink composition of the present invention comprises by weight from 0 to 40%, preferably from 0.1 to 7%, surfactants.
[0025] 3. Organic Acids
[0026] Two or more organic acids may be included in the ink compositions of the present invention. As mentioned earlier, the organic acids effectively reduce the pH differential between adjacent inks that is preferentially required to control color bleed. Preferably succinic acid is one of the organic acids. Exemplary organic acids suitable for use as additional organic acids include monofunctional organic acids, difunctional organic acids, and polyfunctional organic acids. These include, but are not limited to, glutaric acid, oxalic acid, maleic acid, methylsuccinic acid, malonic acid, adipic acid, fumaric acid, dihydroxyfumaric acid, malic acid, mesaconic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, aspartic acid, glutamic acid, 1,2-, 1,3- and 1,4-cyclohexane dicarboxylic acids, 1,2,3-cyclohexane tricarboxylic acid, 1,2,4-cyclohexane tricarboxylic acid, 1,3,5-cyclohexane tricarboxylic acid, 1,2- and 1,3-cyclopentane dicarboxylic acids, citric acid, tartaric acid, dihydroxyterephthalic acid, 1,2,3-, 1,2,4- and 1,2,5-benzene tricarboxylic acids, tricarballylic acid, 1,2,4,5-benzene tetracarboxylic acid, norbomene tetracarboxylic acid, 3,3′,4,4′-benzophenone tetracarboxylic acid, 1,2,3,4,5,6-benzene hexacarboxylic acid, acetic acid, polyacrylic acid, glycolic acid, and derivatives thereof. Preferably glutaric acid is a second organic acid of the invention. The ink composition of the present invention preferably comprises by weight from 3 to 12% mixed organic acid.
[0027] 4. Dyes
[0028] Suitable dyes for the present invention include but are not limited to aqueous dyes such as Direct Blue 86, Direct Blue 199, Direct Yellow 132, Acid Yellow 132, Direct Red 9, Direct Red 32, Acid Yellow 23, Acid Blue 185, Acid Blue 9, Acid Red 17, Acid Red 52, Acid Red 249, and Reactive Red 180. The ink composition of the present invention preferably comprises by weight from 0.5 to 10% aqueous dye.
EXAMPLES
[0029] In order to further illustrate the invention, some exemplary compositions are set forth below.
Example 1
Bleed
[0030] Ink-jet ink compositions were prepared as shown in Table 1 (all values are weight percentages unless otherwise indicated):
TABLE 1 Ink Inks Ink comprising comprising comprising Glutaric acid Glutaric and Succinic acid Component only Succinic acids only Alkyl diol 15.0 15.0 15.0 Polyethylene glycol 3.3 3.3 3.3 Octyl dimethyl glycine 4.4 4.4 4.4 Secondary alcohol 0.7 0.7 0.7 ethyloxylate Sodium hexadecyl 0.5 0.5 0.5 diphenyloxide disulfonate Oleyl triethoxy mono 0.4 0.4 0.4 diphosphate Succinic acid 1 0.0 0.9-4.5 5.4 Glutaric acid 1 6.0 5.0-1.0 0.0 Chelating agent 0.1 0.1 0.1 Magenta dye 4.2 4.2 4.2 Water balance balance balance pH 2 4.0 4.0 4.0
[0031] A black to magenta color bleed test was performed on Union Camp JAMESTOWN™ paper using the ink-jet ink compositions of Table 1. The color bleed results obtained are depicted in FIG. 1. The color bleed test involved printing a pigment black ink (used in the HP DESKJET 970 PROFESSIONAL SERIES™ printer) adjacently to a series of magenta color inks. As can be seen from Table 1, the magenta color inks comprised organic cosolvents, surfactants and a magenta dye. In addition the magenta color inks each included 450 mmol organic acid per kg wherein, the molar fraction of glutaric acid was (a) 1.000, (b) 0.833, (c) 0.667, (d) 0.500, (e) 0.333, (f) 0.167 and (g) 0.000 and the remaining fraction consisted of succinic acid.
[0032] The results shown in FIG. 1, indicate that color bleed is acceptable for all of the inks, and hence that inks containing a mixture of succinic and glutaric acid perform as well as inks that contain succinic or glutaric acid only. Similar results were obtained when the color bleed test was performed on Hewlett-Packard BRIGHT WHITE INKJET™ paper or Champion DATACOPY™ paper.
Example 2
Reliability
[0033] The short term and long term decap performance of the ink formulation shown in Table 2 were measured.
TABLE 2 Ink comprising Component Glutaric and Succinic acids Alkyl diol 15.0 polyethylene glycol 3.5 Octyl dimethyl glycine 3.8 Secondary alcohol ethoxylate 0.6 Sodium hexadecyl diphenyloxide 0.5 disulfonate Oleyl triethoxy mono diphosphate 0.4 succinic acid 4.6 glutaric acid 0.9 chelating agent 0.1 magenta dye 4.2 water balance pH 1 4.0
[0034] Short term decap performance describes the period in between successive firings a nozzle can tolerate without a defect. The ink-filled pens were placed in the printer and used to print a so-called “print file” with a predetermined print pattern.
[0035] The print file was set to cause the nozzles to pause between successive ink drop ejections for predetermined periods of time. The printed nozzle pattern was examined for defects such as weak (i.e. producing low drop volume and/or velocity), misdirected, or non-functional nozzles. The longest inoperative time that a nozzle could withstand between resistor firings without a defect is reported as short term decap. It is desirable that the nozzles tolerate long periods of inactivity between resistor firings, typically short term decap times are required to be longer than 3 seconds. Here, a score of “marginal” was given for decap times in the range 1-3 seconds, of “good” in the range 3-5 seconds, and of “very good” for any decap time longer than 5 seconds. The ink composition of Table 2 exhibited good short term decap performance.
[0036] Long term decap performance describes the level of nozzle recovery after the nozzles have been idle for an extended period of time. To test this, the nozzles were left untaped (i.e. exposed to air) at ambient temperature for a period of three days. Following this storage period, the ink-filled pens were placed in the printer and used to print a predetermined “print file.” Pen performance was evaluated by measuring the percentage of nozzles that recovered after printing the print file four times without interruption. A nozzle was considered to have recovered if it fired drops of the proper volume and velocity and in the proper location. It is preferred that 100% of the nozzles recover; however, acceptable recovery levels for such a storage period are in the range of 93-100%. Here, a score of “marginal” was given for recovery levels lower than 93%, of “good” in the range 93-97%, and of “very good” in the range 97-100%. The ink composition of Table 2 exhibited very good long term decap performance.
[0037] Conclusion
[0038] The benefits of the present invention are highlighted when the color bleed data and pen reliability data are combined. In Example 1 it was shown that succinic and glutaric acids can be used interchangeably and as a mixed acid system in an ink composition without any loss of bleed control. In Example 2 it was shown that the mixed acid system exhibits good short term decap times and very good long term decap recovery.
[0039] In addition, the use of mixtures of organic acids instead of individual organic acids is even more beneficial when the combined organic acids complement each other in some way. For example, while succinic acid is an irritant at high concentrations, glutaric acid is not. On the other hand, glutaric acid is about an order of magnitude more expensive than succinic acid. A suitable mixture of the two not only exhibits improved pen performance but minimizes toxicity and cost in comparison to an ink composition that comprises only succinic acid or only glutaric acid.
[0040] Other embodiments of the invention will be apparent to those skilled in the art from a consideration of the specification or practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope of the invention being indicated by the following claims.
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Ink-jet ink compositions are described comprising a mixture of succinic acid and at least one second organic acid. The ink-jet ink compositions alleviate color bleed, and lead to reliable pen performance when incorporated in a pen architecture.
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RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S. Provisional Application No. 60/885,127, entitled SASH LIFTER FOR CASEMENT WINDOWS, filed Jan. 16, 2007, which is hereby fully incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to an improved casement window, and more specifically to a casement window sash lifter having structure to counteract sash sag.
BACKGROUND OF THE INVENTION
[0003] Casement window assemblies are well known in the art and described in, for example, U.S. Pat. No. 3,845,585 to Cecil, entitled “Casement Window,” and U.S. Pat. No. 4,254,583 to Smits, et al., entitled “Window Unit,” which are both hereby incorporated by reference herein. In general, a casement window includes a window sash comprised of a sheet of glass surrounded by wood, vinyl, or metal structure. The window sash of a casement window is generally operably disposed in the window frame with an upper hinge assembly and a lower hinge assembly. Typically, a crank mechanism is coupled to the sash for selectively opening and closing the window. To ensure proper performance of the casement window, the window sash should be squarely aligned within the window frame.
[0004] A common drawback of casement windows is sash sag, which occurs when the sash portion of the window becomes out-of-square with the window frame. Sash sag can result from a number of factors, including movement during installation, improper hinge positioning by the window manufacturer, settling of the building, warpage of the window, the effect of gravity upon the sash in the open position, or fatigue or contact with the window frame as the window is opened and closed.
[0005] A window with sash sag will not properly seal and puts undue strain on the sealing elements surrounding the sealed glass assembly, leading to failure. As a result the window may be less effective in inhibiting infiltration of air and moisture into the structure, thereby increasing energy costs for heating and cooling of the building. Moreover, the improper seal may allow moisture into the window frame itself and surrounding structure, which can lead to deterioration of the window frame and the structure.
[0006] In some circumstances, sash sag may be severe enough such that the frame interferes with the ability of the window sash to be completely closed. This interference increases force and torque throughout the entire casement window assembly and may make it more difficult for a user to open and close the window. In some cases, the sash sag may result in premature failure or even prevent the window from closing altogether.
[0007] To inhibit sash sag, it is important that the window sash remain square within the window frame, including during transport of the window assembly. To that end, shipping blocks are commonly used to stabilize the window sash within the window frame during shipment of the window assembly. These shipping blocks are typically designed to be removed from the window assembly upon installation. The shipping blocks are often stapled to the window assembly in locations where they are not readily seen. As a result, they are sometimes left in place after installation and as the window is operated and sash sag occurs over time, they interfere with opening and closing of the window and can cause damage to the window frame and sash. Eventually, permanent damage to the window assembly can result due to scraping of the block against the window frame and twisting of the window sash about its hinges.
[0008] One solution to correct sash sag is by realigning the hinge so that the window sash sits properly within the window frame. However, on some windows this requires disassembly of the hinge, which is labor intensive and costly. Alternatively, sash sag may be corrected with an adjustable hinge mechanism. An example of an adjustable mechanism designed to alleviate sash sag is disclosed in U.S. Pat. No. Re. 34,657 ('657 reissue) to LaSee, entitled “Cam Adjustment Device For Casement Window Unit,” which is hereby incorporated by reference herein. More specifically, the '657 reissue discloses an index cam comprising a series of serrations that can engage a plurality of serrations on the track of the hinge assembly, which permits the cam to move relative to the track and facilitates adjustment of a link connected to a casement window sash. A drawback to this mechanism, however, is that the engagement of the serrations on the cam with corresponding serrations on the track only permits predetermined, or defined, movements of the cam within the track. Additionally, the detailed structure of the cam and the track can increase manufacturing costs and make it more difficult to adjust the window sash once the hinge assembly has been installed.
[0009] Another drawback of casement windows is that they are prone to forced entry. Typically a locking mechanism is provided on the vertical frame member opposite the hinge side of the window. These locking mechanisms generally are selectively engagable with the window sash to latch the window sash in place at one or more points when the sash is closed. Typically, however, a gap is provided between the window sash and the window frame at the top and bottom of the window to allow for some misalignment of the sash. This gap can sometimes be sufficiently large so to allow the sash to be pried vertically within the frame a sufficient distance so that the locking mechanism is disengaged. In this way, an intruder can defeat the locking mechanism to gain entry to the structure through the window.
[0010] Therefore, there is a need in the window industry for an apparatus and method for inhibiting sash sag that is passive in operation and does not require the disassembly of the casement window, or manual adjustment by the user to counteract and/or eliminate sash sag, and that can be manufactured at a lower cost relative to existing hinge assemblies used to reduce sash sag. Moreover, apparatuses and methods of inhibiting forced entry and damage during shipping are also needed to address the drawbacks identified above.
SUMMARY OF THE INVENTION
[0011] The sash lifter of the present disclosure addresses the above-mentioned needs by providing an apparatus that is a single passive piece without any moving parts. The sash lifter assembly of the present invention can be mounted on a track structure of a hinge assembly, buttressing the sash to counteract and/or eliminate sash sag without the disassembly of the casement window assembly or manual adjustment by the user. Sash lifters according to an embodiment of the invention may also be positioned at other locations on the frame in addition to or as an alternative to a sash lifter on the hinge track.
[0012] In a first embodiment, the sash lifter may include a base and an arcuate top portion, or positioning surface. The sash lifter further includes an aperture therethrough and a notch in the arcuate positioning. In operation, the sash rides up on the arcuate positioning surface as the sash is rotated into a closed position, thereby smoothly lifting the sash into position in the frame as the sash is closed.
[0013] In another embodiment, a protrusion may extend from the bottom of the sash lifter transverse to a fastener aperture. When mounted on a track structure of a hinge assembly, the protrusion fits into a correspondingly sized aperture in the hinge track to enable precise positioning of the sash lifter on the track. The protrusion may be made sufficiently thin or made from a crushable or frangible material so as to be crushed or fractured from the sash lifter when the sash lifter is fastened to a surface without an aperture, thereby enabling level and secure attachment of the sash lift to nearly any surface.
[0014] In another embodiment, the sash lifters have a barrier structure extending outward that may be placed on the top and bottom members of the window frame proximate the side opposite the hinge. The barrier structure of the sash lifter fits into the gap between the sash and frame to inhibit vertical shifting of the sash within the frame, thereby reducing the ability of an intruder to disengage the lock mechanism of the window to gain unauthorized entry to the structure.
[0015] In yet another embodiment, the sash lifter may be used as a shipping block and be left in place after window installation to serve as an FER block and/or sash lifter.
[0016] Accordingly, in some embodiments, a casement window system according to the present invention comprises a window frame, a window sash, a hinge assembly coupling the window sash to the window frame, and a sash lifter. The hinge assembly includes a track portion on the window frame. The track portion defines at least one aperture. The sash lifter comprises a body with a first side presenting a sash positioning surface and a generally opposing second side presenting a frame mounting surface. The body defines an opening for receiving a fastening member. The sash lifter also comprises a protrusion extending outwardly from the second side. The protrusion mates with the aperture on the track portion of the hinge assembly to locate the sash lifter on the track portion.
[0017] In a further embodiment, a window system according to the present invention comprises a window frame, a window sash in the window frame defining a gap therebetween, a hinge assembly coupling the window sash to the window frame, and a sash lifter on the window frame. The sash lifter comprises a body and a tail portion. The body presents a sash positioning surface and defines an opening for receiving a fastening member to fasten the sash lifter to the frame. The tail portion extends into the gap defined between the window frame and the window sash.
[0018] In other embodiments, the body may present a distal end and a proximal end, the sash positioning surface sloping generally upward from the distal end to the proximal end. The sash positioning surface may define a substantially arcuate region between the distal and proximal sash ends. Alternatively, the sash positioning surface may define a substantially planar region between the distal and proximal ends. The sash positioning surface may also define both a substantially arcuate region and substantially planar region between the distal and proximal ends, the substantially arcuate region being located generally distally and the substantially planar region being located generally proximally. The sash lifter may substantially prevent lateral movement of the window sash within the window frame. The body of the sash lifter may further define a notch at the distal end. The protrusion may be snap-fit into the aperture. The aperture may be elongate and the protrusion may be slidable in the aperture. The tail portion may inhibit vertical shifting of the window sash within the window frame.
[0019] In a further embodiment, a casement window system according to the present invention comprises a window frame, a window sash, a hinge assembly coupling the window sash to the window frame, and a sash lifter. The hinge assembly includes a track portion on the window frame. The sash lifter comprises a body and a means for locating the sash lifter on the window frame. The body has a first side presenting a sash positioning surface and a generally opposing second side presenting a frame mounting surface. The body defines an opening for receiving a fastening member.
[0020] In other embodiments, the means for locating the sash lifter on the window may comprise a protrusion extending outwardly from the frame mounting surface. The window frame may be made from wood, the protrusion being adapted to facilitate penetration of the wood. The window frame may define a groove and may be made from a non-wood material, the protrusion being adapted to collapse into the groove. The track portion of the hinge assembly may define an aperture and the protrusion may mate with the aperture to located the sash lifter on the track portion.
BRIEF DESCRIPTION OF THE FIGURES
[0021] The embodiments of the present invention may be more completely understood in consideration of the following detailed description of various embodiments in connection with the accompanying drawings, in which:
[0022] FIG. 1 is a perspective view of a casement window assembly according to an embodiment of the present invention in an open position;
[0023] FIG. 2 is an outside elevation view of a casement window assembly according to an embodiment of the present invention in a closed position;
[0024] FIG. 3 is a top plan view of a track structure of a hinge assembly according to an embodiment of the present invention;
[0025] FIG. 4 is a top plan view of a track structure of a hinge assembly according to an embodiment of the present invention;
[0026] FIG. 5 is a top plan view of a track structure of a hinge assembly according to an embodiment of the present invention;
[0027] FIG. 6 is a top view of an embodiment of a sash lifter according to an embodiment of the present invention;
[0028] FIG. 7 is a side perspective view of an embodiment of a sash lifter according to an embodiment the present invention;
[0029] FIG. 8 is a side plan view of a sash lifter according to an embodiment of the present invention mounted on a track;
[0030] FIG. 9 is a side plan view of a sash lifter according to an embodiment of the present invention mounted on a track;
[0031] FIG. 10 is a top view of a sash lifter according to an embodiment of the present invention;
[0032] FIG. 11 is a fragmentary side view of a window frame and a window sash with a sash lifter according to an embodiment of the present invention the sash being lifted into position with the sash lifter; and
[0033] FIG. 12 is a fragmentary side view of a window frame and a window sash with a sash lifter according to an embodiment of the present invention with the sash lifter positioned as a forced entry resistance block; and
[0034] While the present invention is amendable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the present invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0035] Referring to FIG. 1 , a window assembly is depicted generally with reference numeral 101 . Although window assembly 100 and the components of window assembly 100 depicted in FIGS. 1-12 are adapted for use as casement window, one skilled in the art will readily recognize that window assembly 100 may include any number of other configurations. As such, the embodiments of the present invention depicted in FIGS. 1-12 are merely illustrative of one such window assembly 100 . Other window assemblies 100 may also incorporate alternative embodiments of the present invention.
[0036] Window assembly 100 generally includes window frame 102 , window sash 104 , hinge assembly 106 , and sash lifter 108 . Although sash lifter 108 can be used for a variety of purposes and in a number of different ways, sash lifter 108 is generally mounted to window frame 102 or hinge assembly 106 to facilitate transportation of window assembly 100 , alleviate sash sag, and/or provide enhance forced-entry resistance (FER).
[0037] Referring to FIGS. 1-2 , a conventional residential casement window assembly 100 generally includes a window frame 102 having two vertical frame members 110 , 112 , an upper horizontal frame member 114 and a lower horizontal frame member 116 . Window assembly 100 also comprises a window sash 104 . Window sash 104 generally includes upper horizontal member 118 , lower horizontal member 120 , vertical frame members 122 , 124 , and glass assembly 126 , which may include one or more panes 128 , 130 . In general, window sash 104 is sized to closely fit within window frame 102 in order to seal out moisture and maintain the environment within the structure.
[0038] Window assembly 100 further generally includes hinge assembly 20 . In an example embodiment, window assembly 106 includes upper hinge assembly 106 a lower hinge assembly 106 b . Hinge assemblies 106 generally which facilitate hingably mounting window sash 104 in window frame 102 . Each hinge assembly 106 generally include track 132 mounted to the window frame 102 , sash arm 134 coupled to the window sash 104 , support arm 136 mounted on a first end to track 132 and to the sash arm 134 at the opposing end, and crank mechanism 138 . Sash 104 is operated by rotating crank mechanism 138 so that window sash 104 pivots about the vertical axis. Further general details of casement window hinge assemblies are included in U.S. patent application Ser. No. 11/268,759, owned by the owners of the present invention, and hereby fully incorporated herein by reference.
[0039] Various embodiments of track 132 of hinge assembly 106 are depicted in FIGS. 3-5 . Referring to FIG. 3 , track 132 defines substantially circular apertures 140 in an example embodiment. Apertures 140 may, for example, be anchoring holes adapted to receive fastening members such as screws or nails for mounting sash lifter 108 to window frame 102 . Apertures 140 may also be adapted to directly receive sash lifter 108 . Referring to FIG. 4 , track 132 defines elongated slots 142 in another embodiment. Like apertures 140 , slots 142 may be adapted to receive fastening members such as screws or nails for mounting sash lifter 108 to window frame 102 . Referring to FIG. 5 , track 132 defines mating structure 144 adapted to directly receive sash lifter 108 . Structure 144 may, for example, be a groove or a raised surface. Generally, mating structure 144 is adapted to mate with a complementary structure of sash lifter 108 .
[0040] Referring to FIGS. 6-10 , sash lifter 108 includes body 146 . Body 146 generally has an arcuate top surface 148 . Sash lifter 108 may further define channel 150 . Channel 150 generally extends through body 146 and is adapted for receiving fastening member 152 . Referring to FIGS. 7-8 , body 146 may also include track-engaging protrusion 154 extending from bottom surface 156 in an example embodiment. Track-engaging protrusion 154 generally provides positive engagement with track 132 at anchoring hole 26 . Referring to FIG. 9 , body may include track-engaging recess 158 in an alternative embodiment. Track-engaging recess 158 generally provides positive engagement with mating structure 144 of track 132 .
[0041] Referring to FIG. 11 , sash lifter 108 may be mounted directly onto track 132 for ease of use and assembly. A conventional track screw or other fastening member may be placed through channel 150 into aperture 140 or slot 142 to secure sash lifter 108 to track 132 . Mounting sash lifter 108 through aperture 140 or slot 142 on track 132 enables level and secure positioning of sash lifter 108 on track 132 . In embodiments of track 132 in which mating structure 144 is a groove, sash lifter 108 can be secured to track 132 by positioning track-engaging structure 154 into groove. In embodiments of track in which mating structure 144 is a raised surface, sash lifter 108 can be secured to track 132 by positioning the raised surface of mating structure 144 into track-engaging recess 158 of sash 108 .
[0042] Sash lifter 108 is generally a single piece without any moving parts that may be mounted directly on track 132 such that sash lifter 108 buttresses window sash 104 to prevent sash sag. Thus, once mounted on track 132 , sash lifter 108 remains in place keeping the window assembly 100 square and need not be adjusted like conventional hinge assemblies. Sash lifter 108 may also include notch 160 in arcuate top surface 148 .
[0043] Referring to FIG. 10 , an alternate embodiment of sash lifter 108 is depicted. In this embodiment, sash lifter 108 may function as a forced-entry resistance block in an FER system. As depicted in FIG. 10 , sash lifter 108 may include tail portion 162 . Sash lifters 30 may be mounted on upper horizontal frame member 114 and lower horizontal frame member 116 opposite hinges 106 a , 106 b , as depicted in FIG. 2 . Tail portion 162 fits into gap 164 between window frame 102 and window sash 104 . In this position, sash lifters 108 inhibit vertical motion of window sash 104 within window frame 102 . As a consequence, sash lifters 108 can impede an intruder from defeating the locking mechanism of the window, which is typically provided on the side of the window opposite the hinges, by moving window sash 104 vertically within window frame 102 .
[0044] In operation, as depicted in FIG. 11 , as sash 104 is closed, sash 104 rides up on arcuate top surface 148 and is smoothly lifted into position in the window frame 102 . It will be appreciated that the position of sash lifter 108 on track 132 promotes engagement of the sash lifter 108 with the window sash 104 over a relatively greater range of motion of window sash 104 .
[0045] Sash lifter 108 may be used as an FER block in wood, aluminum or plastic extrusion windows. In the FER block embodiment, track-engaging structure 154 may collapse into a groove in the frame to allow flat mounting on the surface of vinyl or aluminum frames. In wood frames, track engaging structure 154 may penetrate the wood allowing a flat mount. Alternatively, the lip may be made sufficiently dimensionally thin or of crushable or frangible material so as to be crushed or fractured from sash lifter 108 when sash lifter 108 is fastened to a surface without an aperture, thereby enabling level and secure attachment of the fastener to nearly any planar surface.
[0046] In yet another embodiment, sash lifter 108 may be used as a shipping block. However, unlike conventional shipping blocks which are designed to be removed prior to installation, sash lifter 108 may remain in place after the window assembly is installed to function as sash lifter 108 .
[0047] The embodiments above are intended to be illustrative and not limiting. Additional embodiments are within the claims. Although the present invention has been described with reference to particular embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
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A sash lifter for positioning a window sash within a window frame of a casement window includes a body portion presenting a sash positioning surface. As the window sash is rotated within the window frame about an axis of rotation defined by at least one hinge assembly, the window sash encounters the sash lifter and rides along the sash positioning surface until it is properly situated within the window frame. The sash lifter may include a barrier structure extending transverse to the axis of rotation to facilitate positioning of the sash lifter within a track of the hinge assembly. The sash lifter may also include a tail structure extending outward from the body portion for increased forced-entry resistance.
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BACKGROUND OF THE INVENTION
Catalytic cracking of heavy petroleum fractions is one of the major refining operations employed in the conversion of crude petroleum oils to desirable fuel products such as high-octane gasoline fuels used in spark-ignited internal combustion engines. Illustrative of "fluid" catalytic conversion processes is the fluid catalytic cracking process wherein suitably preheated high molecular weight hydrocarbon liquids and vapors are contacted with hot, finely-divided, solid catalyst particles, either in a fluidized bed reactor or in an elongated riser reactor, and maintained at an elevated temperature in a fluidized or dispersed state for a period of time sufficient to effect the desired degree of cracking to lower molecular weight hydrocarbons typically present in motor gasolines and distillate fuels. Suitable hydrocarbon feeds boil generally within the range from about 400° to about 1200° F. and are usually cracked at temperatures ranging from 850° to 1100° F.
In a catalytic process some non-volatile carbonaceous material, or "coke", is deposited on the catalyst particles. Coke comprises highly condensed aromatic hydrocarbons which generally contain 4-10 wt. % hydrogen. As coke builds up on the catalyst, the activity of the catalyst for cracking and the selectivity of the catalyst for producing gasoline blending stock diminish. The catalyst particles may recover a major proportion of their original capabilities by removal of most of the coke therefrom by a suitable regeneration process.
Catalyst regeneration is accomplished by burning the coke deposits from the catalyst surface with an oxygen-containing gas, such as air. Many regeneration techniques are practiced commercially whereby a significant restoration of catalyst activity is achieved in response to the degree of coke removal.
The regenerated catalyst is recycled to contact fresh hydrocarbon feedstock and to convert hydrocarbon to more valuable products.
SUMMARY OF THE INVENTION
This invention relates to an improved fluid catalytic cracking process for the introduction of circulating catalyst into the hydrocarbon feedstock. It has been found that in fluid catalytic cracking processes there are advantages to having the regenerated, recycle catalyst returned to the riser at more than one locus. Furthermore, it is even more preferred if the first stream of regenerated, recycled catalyst which is first contacted with the feedstock is introduced in a quantity sufficient to raise the feed temperature into the reactive range, that is above 850° F. and preferably above 950° F., and thereby vaporize most of the distillable portion of the feed.
DETAILED DESCRIPTION
In the processing of hydrocarbons in a fluid catalytic cracking process, the increasing cost and shortage of supply of crude oil is causing the necessity to process unconventional sources of hydrocarbons such as, for example, reduced crude, coal derived oil, oil shale, and tar sand derived oil. This dilemma requires that the conventional fluid catalytic cracking processes be modified to satisfactorily utilize these feedstocks. One method which may be a desirable modification of the conventional fluid catalytic cracking process is to have multiple regenerated catalyst inlets to the reactor riser. We have discovered that a superior fluid catalytic cracking process is obtained if the first stream of regenerated catalyst to the riser has a flow rate sufficient to raise the temperature into the reactive range, that is above the 850° F. and preferably above 950° F., and thereby vaporize most of the vaporizable portion of the feedstock.
The preferred embodiment of the invention is illustrated in the example hereinafter described. The following initial description of the invention will be set only in terms of the preferred embodiment. Other embodiments of the invention, which include feedstocks, catalyst flow systems, and catalysts will then be described. Although the general description will only refer to two regenerated, recycle catalyst lines to the reactor riser, the invention may be applied to a process having three or more catalyst supply lines.
Accordingly, a broad embodiment of the present invention may be characterized as a method for contacting a hydrocarbon containing feedstock in a fluid catalytic process with at least two streams of regenerated, recycled catalyst wherein a first portion of the recycled catalyst vaporizes the majority of the fresh feedstock. In a more particular embodiment of the invention is a process for catalytically cracking hydrocarbonaceous feedstocks having a Conradson Carbon Number greater than about 1 wherein fluidizable cracking catalyst, contaminated with metals to a level of vanadium and nickel of greater than about 1000 ppm, and which catalyst has been deactivated with coke deposits is withdrawn from the cracking reaction zone, stripped of volatile material, passed to a regeneration zone, and recycled after regeneration to the reaction zone, the method comprising: (a) contacting said feedstock with at least a portion of said recycled, regenerated catalyst which catalyst has a flow rate sufficient to raise the temperature into the reactive range, that is above 850° F. and preferably above 950° F., and thereby vaporize most of the vaporizable portion of said feedstock; and (b) contacting said feedstock combined with said first portion of recycled, regenerated catalyst with a second portion of recycled, regenerated catalyst.
Although the type of catalyst is not an essential portion of this invention, catalyst is required and a suitable catalyst can be any commercially available cracking catalyst. Preferably, catalysts are zeolitic. Zeolitic or molecular sieve catalysts for converting hydrocarbons to gasoline fractions are well known in the art and are commercially available. Non-zeolite catalysts may also be used.
The catalysts generally have a particle size of about 5 to about 150 microns and preferably predominantly about 40 to about 80 microns. A process designed to utilize a reduced crude or similar hydrocarbon can benefit most significantly from the present invention.
Such hydrocarbon containing feedstocks contain heavy metals including nickel and vanadium in quantities usually greater than about 2-3 ppm. and heptane-insolubles in quantities usually greater than about 0.1 weight percent. Another characteristic of reduced crude which is also often referred to as black oil is the Conradson Carbon level which is expressed as a weight percent of the reduced crude fraction. Typical reduced crude oils and the like generally have a Conradson Carbon level of about one weight percent or greater. The procedure for determining the Conradson Carbon level provides a weight percent number which reflects the total residue including carbon resulting from the high temperature pyrolysis of the hydrocarbon sample. These contaminants have heretofore precluded the facile utilization of contaminated feedstocks in fluid catalytic cracking processes by depositing excessive amounts of coke and metals upon the catalyst. The excess coke must be removed from the catalyst during regeneration in order to yield an active recycle catalyst for introduction into the reactor riser. The metals are essentially permanently deposited on the catalyst and are not removed by conventional catalyst regeneration or oxidation. Gradual build-up of the metals on the catalyst permits the promotion of undesirable side reactions which lower the yield and quality of the desired product.
The method of the present invention obviates or at least tends to minimize the undesirable side reactions hereabove described. Under normal circumstances, the coke on the catalyst will occupy active sites and the catalyst activity will be reduced. But with the case of two or more regenerated catalyst introduction locations and with a majority of the feedstock vaporized before reaching the location of additional catalyst introduction locations, freshly regenerated and active catalyst is allowed to contact an essentially vaporized hydrocarbon feedstock and to selectively produce the desired quality products.
The preferred feedstocks utilized with the present invention more than likely contain non-distillable hydrocarbons which are generally thought to be coke precursors under relatively high temperature conditions such as those encountered in catalytic cracking. Since these non-distillables by their very nature will not vaporize and will probably immediately agglomerate on the first hot, regenerated catalyst particles which they encounter, somewhat less than 100 volume percent of the feedstock will vaporize and require the transmittal of the necessary heat of vaporization provided by hot, regenerated catalyst. If the temperature is raised into the reactive region, the light hydrocarbons produced will also assist in volatizing the heavier components. It is also foreseen that diluent streams, such as steam or light hydrocarbon gases, could also be introduced with the bottom of the riser in order to maximize the degree of vaporization of the feed. Therefore, according to the present invention, the flow of hot, regenerated catalyst to the first catalyst inlet is determined by the selected temperature, preferably above 950° F., and by the amount of vaporizable hydrocarbons present in any one given feedstock. Once that essentially all of the vaporizable hydrocarbons have been vaporized, the feedstock is then contacted with a second stream of hot, regenerated catalyst.
Suitable hydrocarbon feedstocks include light gas oils, heavy gas oils, vacuum gas oils, kerosenes, deasphalted oils and residual fractions, as well as suitable fractions derived from shale oil, tar sands, synthetic oils and the like. Such fractions may be employed singly or in any desired combination.
The following example is presented in illustration of the preferred embodiment and is not intended as an undue limitation on the generally broad scope of the invention as set out in the appended claims.
EXAMPLE
Simulated tests were made to illustrate the advantage of this invention. The tests were based upon cracking a light Arabian reduced crude having an initial boiling point of 680° F., a gravity of 17.9° API, 2.9 weight percent sulfur, 6.4 ppm nickel, 21.3 ppm vanadium and a Conradson Carbon of 7 weight percent. The tests were conducted in an upflow riser with a zeolite fluid cracking catalyst. The operating conditions of all tests include a raw-oil temperature of 500° F., a catalyst regenerator temperature of 1355° F., a reactor pressure of 20 psig., a total catalyst to oil ratio of 8.95 pound/pound and a reactor outlet temperature of 1030° F.
The tests differ only in the manner of admission of catalyst to the riser. In the base test, the total amount of catalyst is admitted to the bottom of the riser together with the total hydrocarbon feed stream. In the simulated comparative test which is illustrative of the present invention, 61.7 percent of the total catalyst charge is introduced to the bottom of the riser together with the total hydrocarbon feed stream while the remaining 38.3 percent is charged to the riser at a subsequent catalyst inlet in order to be admixed with the stream which comprises the feed stream which has been previously admixed with the hereinabove mentioned 61.7 percent of the total catalyst. In the comparative test, it is estimated that 61.7 percent of the total catalyst is required, in order to reach the desired temperature of about 1000° F. in the lower vaporizing zone of the riser.
In the base case, the conversion was 76.8 volume percent as compared to 79.0 volume percent in the comparative case. Further details of the results from both of these tests are presented in Table I. From a comparison of the product distribution and conversion for each of the tests, the enhanced product yields of the comparative test are apparent.
TABLE I______________________________________TEST SUMMARY Conventional 2-Inlet______________________________________ConditionsConfigurationRaw oil temperature, ° F. 500 500Reactor outlet temperature, ° F. 1030 1030Regenerator temperature, ° F. 1355 1355Catalyst oil ratio, lb/lb 8.95 8.95% of catalyst to first inlet 100 61.7% of catalyst to second inlet -- 38.3Conversion, volume % 76.8 79.0Product DistributionH.sub.2 S, plus C.sub.2.sup.-, wt. % 6.57 6.50C.sub.3 's, wt. % 7.28 7.30C.sub.4 's, wt. % 9.00 9.60C.sub.5 -380 @ 90% gasoline, vol. % 50.60 52.70Light cycle oil, vol. % 11.80 10.50Clarified oil, vol. % 11.40 10.50Coke, wt. % 10.40 10.40FeedstockLight Arabian 680° F. reduced crudeGravity, °API 17.9Sulfur, wt. % 2.92Conradson carbon, wt. % 7.0Nickel, ppm 6.4Vanadium, ppm 21.3______________________________________
The foregoing description and example demonstrate the method by which the present invention is effected and the benefits afforded through the utilization thereof.
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An improved fluid catalytic cracking process providing improved product yield and selectivity and reduced catalyst deactivation which employs a split flow of catalyst to the reactor riser.
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TECHNICAL FIELD
This invention relates to an apparatus for forming a stack of sheet-like objects, in particular but not exclusively a stack of banknotes formed in a cashbox.
BACKGROUND ART
Various devices are known for forming stacks of banknotes. One such device is described in published European patent application No. 0684929. This discloses an apparatus which incorporates a pusher plate with which a banknote may be pushed from the plane along which the banknote is transported to the stacking mechanism (transport plane), into a cashbox situated adjacent to the banknote plane. The pusher plate is connected by a pivoted lever arrangement via a cam, to a drive motor. The pivoted lever arrangement operates with a “scissors action” to cause the pusher plate to push the banknote into the cashbox against the action of a spring mounted stack surface. The banknotes are retained in a stack in the cashbox, when the pusher plate is withdrawn, by flanges which abut the ends of the uppermost surface of the banknote stack.
Although this type of arrangement provides an efficient method of stacking banknotes, the required depth of stroke of the pusher plate is linked to the size of the aperture through which the banknote is pushed. Thus, a short depth of stroke is only possible if the aperture is relatively large. However, cashboxes with relatively large apertures suffer from the disadvantage of being difficult to make secure (i.e. self closing) on detachment from the stacking device. The cashbox aperture may be made smaller by increasing the depth of stroke of the pusher plate. However, an increased depth of stroke results in an increased cashbox depth for any given size of banknote stack. As space is often at a premium in such circumstances, for example in combined banknote validator and stacker devices, this too is an undesirable consequence.
Furthermore, if banknotes of differing lengths are to be stacked in a cashbox incorporating stack retaining flanges, the aperture must be significantly shorter than the length of the shortest banknote to be stacked. This is in order that the flanges at the ends of the aperture may retain even the shortest banknotes. This results in a minimum length of pusher plate stroke being further increased in order to successfully stack the longest banknotes through the same aperture size and hence a corresponding increase in the depth of the cashbox.
In order that the flanges should retain the stack of banknotes, it may be important that the banknotes are presented for stacking in a predetermined orientation. For example, if a banknote of maximum length is skewed on being stacked, its greater diagonal length may prevent it from being successfully stacked. Additionally, it may also be important that the banknotes are accurately positioned lengthwise with respect to the cashbox aperture, in order to be reliably stacked. A sufficient lengthwise offset will result either in an end of the banknote not being stacked, or alternatively an end of the banknote not being retained by a flange, or both.
As cashboxes used with such devices often incorporate a spring mounted stacking surface against which a pusher plate or piston must work, a further problem may arise in such devices. Namely, despite successfully pushing the banknote into the cashbox, the banknote may not completely flatten against the stack. As the stack surface is again biased against the retaining flanges by the spring mounted stacking surface banknotes may become crumpled, causing an irregular banknote stack.
U.S. Pat. No. 4,809,967 and U.S. Pat. No. 5,014,857 disclose a stacking device of the piston type which aims to address the problem of ensuring that banknotes flatten correctly on the stack surface during the stacking process. These disclosures teach to incorporate pivotally mounted “unfolding” plates in the piston assembly. These are arranged to displace horizontally as the piston stroke increases in the vertical direction; thus assisting in flattening a banknote against the stack.
However despite assisting with flattening banknotes in the stacking procedure the device of U.S. Pat. No. 4,809,967 and U.S. Pat. No. 5,014,857 suffers from the same drawback as that of EP 0684929A, in that a short depth if stroke is only possible of the cashbox aperture is relatively large; or, conversely a small aperture is only achievable if the stroke length is relatively long.
A further stacking device is disclosed in U.S. Pat. No. 4,834,230 and U.S. Pat. No. 4,807,736 which employs a pair of rotors in place of a piston in order to stack banknotes in a cashbox. However, like the device of U.S. Pat. No. 4,809,967 and U.S. Pat. No. 5,014,857, this device suffers from the disadvantage that a short depth of stroke is only possible if the cashbox aperture is relatively large. Additionally, such a device may suffer from the disadvantage of a banknote being incorrectly stacked (for example, one end of the banknote not being retained in the cashbox by a retaining flange) if the banknote is erroneously presented for stacking in a non-central manner.
A further such device is described in granted European patent 0470329. This discloses an apparatus which transports banknotes between opposing belts entrained around rollers of a carriage, which is arranged to traverse an open surface of a cashbox. As the carriage moves over the stack of banknotes, the entrained banknote is deposited on the stack. The stack of banknotes is retained in the cashbox by one of the transporting belts which lie across the uppermost surface of the banknote stack.
Such a device does not require vertical movement of the piston or pusher, and hence the cashbox depth can be smaller for a given capacity. However, this arrangement also requires the cashbox construction to be substantially open and consequently difficult to make secure on detachment from the stacking device. Indeed in such a design the aperture of the cashbox must be at least as large as the banknotes which are to pass through it.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided a device for stacking banknotes, comprising a cashbox and a stacker arranged to stack banknotes of predetermined dimensions in said cashbox, said cashbox having a surface including an aperture therein, said aperture having a dimension in a first direction of W, said device being arranged to receive a banknote at a position overlying said aperture, said banknote having a dimension in said first direction of L, said stacking means being arranged to push said banknote through said aperture and into a stacked position in said cashbox, wherein said banknote is pushed to a predetermined maximum depth D in said cashbox relative to said aperture such that D<(L−W)/2.
It will be appreciated that where a standard reciprocating piston action is used to push a banknote through an aperture of a cashbox which is narrower than the width of the banknote, a relationship between the minimum required depth of stroke to push a given banknote completely through the aperture and the width of the aperture may be derived.
This minimum stroke depth occurs when the banknote is pushed through the aperture symmetrically across its width. In this case the banknote will be pushed entirely within the cashbox when the piston stroke, relative to the aperture, is equal to half the difference between the banknote width and the aperture width.
However in mechanisms according to the present invention the relationship between the aperture width and the stroke depth is not fixed in this manner for a given banknote size. Thus a reduced cashbox aperture size may be achieved without necessitating a long stroke length. Therefore improved cashbox security and a reduced cashbox size may advantageously be achieved.
In a further aspect of the invention there is provided a device for stacking documents comprising a stacker and a stack surface, the stacker being arranged to push a document partially through an aperture defined by at least one surface such that the document at least partially contacts the stack, the stacker being further arranged to move along the stack and under the surface, entraining the document through said aperture into a stacked position, wherein the stacker comprises an extensible membrane positioned between the stacker and the document, arranged to contact the document during the stacking procedure.
By incorporating a flexible membrane in the stacking device, between the stacker and the document (for example a banknote), the degree of control over the document may be increased. Thus the possibility of the document being incorrectly stacked, due to slippage between the stacker and the document or the document being damaged in the stacking process, is significantly reduced.
Other aspects and embodiments of the invention, with corresponding objects and advantages, will be apparent from the following description and claims. The invention will now be illustrated, by way of example only, with reference to the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a 0.62:1 scale diagram illustrating the structure and function of the banknote stacking mechanism according to a first embodiment of the invention;
FIG. 2 a is a perspective view of a rotor which may be used in first, second and fourth embodiments of the invention;
FIG. 2 b is a perspective view of an alternative rotor design which may be used in first, second and fourth embodiments of the invention;
FIGS. 3 a-d are a series of diagrams shown in 1:1 scale illustrating the structure and function of the banknote stacking mechanism according to a second embodiment of the invention;
FIG. 4 a illustrates a rotor according to the third embodiment of the invention;
FIG. 4 b is a 1:1 scale drawing illustrating the structure and arrangement of the rotors according to the third embodiment of the invention, shown from above in the resting state;
FIG. 4 c is a 1:1 scale drawing illustrating a side view of the arrangement of the rotors according to the third embodiment of the invention, in operation;
FIG. 5 is a plan view of the membrane used in the fourth embodiment of the invention;
FIGS. 6 a-d are a series of diagrams shown in 1:1 scale illustrating the working of the fourth embodiment of the invention with the cashbox partially removed;
FIGS. 7 a-d are a series of diagrams shown in 1:1 scale illustrating the working of fourth embodiment of the invention with the cashbox in place;
FIG. 8 is a perspective view of a banknote stacking mechanism according to the firth embodiment of the invention;
FIG. 9 is a cross sectional view of the banknote stacker of FIG. 8 illustrating its mode of operation;
FIGS. 10 a and 10 b illustrate a banknote handling machine including a cashbox with which a stacking mechanism according to the present invention may be used.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
Referring to FIG. 1, a banknote stacking system according to the first embodiment of the invention is shown. The system comprises a banknote transport system, a stacking mechanism and a cashbox 5 . The stacking mechanism and the transportation mechanism are housed in a banknote handling apparatus, such as a validator (shown in FIG. 10 ), to which a cashbox 5 is removably attached.
Banknote Transport System
A banknote 1 is transported to the stacking mechanism in a direction perpendicular to the plane of the diagram by the transportation mechanism, which comprises opposing pairs of rollers 2 a , 2 b and 3 a , 3 b . The banknote 1 is engaged by transportation rollers 2 a , 2 b , 3 a , 3 b parallel to its lengthwise edges. That is to say it is transported in the direction of its longitudinal axis. The spacing between the pairs of rollers 2 a , 2 b and 3 a , 3 b is arranged such that even the minimum size of banknote for which the mechanism is designed may be securely held and transported.
The rollers 2 a , 2 b , 3 a , 3 b position the banknote 1 above an aperture 4 of the cashbox 5 . In this embodiment, the aperture 4 is approximately half of the width of the banknote; i.e. approximately 31 mm across. The position of the leading edge of the banknote 1 is sensed using photosensors (not shown), or other suitable position sensing devices, which are occluded by the banknote 1 when it is in the correct position. The output from the photosensors is then used to inhibit further transport of the banknote 1 .
The rollers 2 a , 2 b , 3 a , 3 b are located on either side of the aperture 4 , such that the banknote 1 is gripped with a positive force and held flat and parallel to the aperture 4 prior to being stacked. This is achieved by mounting the lower rollers 2 a , 3 a on fixed axles 6 and mounting the opposing rollers 2 b , 3 b on shafts 7 , which are free to move to a limited extent in the vertical direction. The shafts 7 are biased downwards towards the lower rollers 2 a , 3 a by compression springs 8 contained within the shafts 7 .
Although rollers are used in the present embodiment for the transportation of the banknotes, a belt driven transportation system could alternatively be used.
Stacking Mechanism
The stacking mechanism comprises a pusher plate 9 , a rotor 10 and a stack support surface 13 located inside the cashbox 5 .
Pusher Plate
The pusher plate 9 comprises a flat plate made from a plastics material or metal. It is connected by the centre of its upper surface to a solenoid (not shown) using any suitable fastening. The solenoid is arranged to cause the pusher plate 9 to reciprocate in a vertical direction. The solenoid may however be replaced by other suitable means. For example, a pivoted lever arrangement driven by an electric motor via a cam, as discussed with reference to published European patent application No. 0684929.
Rotor
A detailed view of the rotor 10 is shown in FIG. 2 a . The rotor 10 comprises two rotor arms 20 mounted on an axle 11 . In this embodiment the rotor arms 20 have a straight sided profile. However, various other profiles may be used, for example a circular profile extending through 93°. as shown in FIG. 2 b . At one end of the axle 11 is situated a crank arm 21 through which rotational movement is applied to the rotor 10 by an electric motor and gear train (not shown). A support bar 22 connects the two rotor arms 20 and provides added rigidity to the rotor assembly. Adjacent the support bar 22 , situated between the extremities of the rotor arms 20 , is a rotating axle 23 , which forms a banknote engaging surface. Since it is free to rotate relative to the banknote 1 during the stacking process the levels of friction acting on the banknote 1 are reduced. This may be beneficial as the banknote 1 may otherwise be prone to tearing during the stacking process, especially if the mechanism is operating at high speed. The rotating axle 23 may alternatively be replaced by a non-rotating banknote contacting surface made from a low friction material such as PTFE.
The separation between the two rotor arms 20 in the direction of the axle 11 , is chosen such that the overall width of rotor 10 is slightly less than the corresponding dimension of the aperture 4 , through which it must pass. This ensures that a high degree of control over the banknote 1 is achievable during the stacking process.
The entire rotor assembly may be manufactured by any suitable means such as a one piece plastics injection moulding, with the exception of rotating axle 23 which may be joined to the main rotor assembly by means of a snap fit. Alternatively, it may be manufactured through individually machined or moulded plastics or metal components, or a combination thereof.
Stacking Process
Prior to the actuation of the stacking mechanism, the positive gripping force exerted by the roller 3 b is removed from the banknote 1 . This achieved by raising the associated shaft 7 using a solenoid (not shown), against the spring force of the spring 8 to give a clearance between the rollers 3 a and 3 b . Alternatively, this may equally be achieved by lowering the roller 3 a relative to roller 3 b.
The benefit of giving a clearance between the opposing rollers 3 a and 3 b is to ensure that banknote 1 will not be subject to undue stress which might cause it to tear on being stacked. It should be noted that at this stage the rollers 2 a , 2 b continue to engage the right-hand end of the banknote 1 as shown in FIG. 1 .
The pusher plate 9 is initially situated in its resting position parallel to and slightly above the transport plane of the banknote 1 , as shown in FIG. 1 . On actuation, the pusher plate 9 descends through the transportation plane of the banknote 1 , through the aperture 4 of the cashbox 5 to the required depth. The required depth must be sufficient for the left-hand end of the banknote 1 to be entrained through the aperture 4 and fall beneath the left-hand abutment surface 15 as shown in FIG. 1 . The pusher plate 9 descends no further than the minimum distance required in order to ensure reliable stacking of the banknote 1 , in order to allow the depth of the cashbox 5 to be minimised for a given capacity.
This action causes the free left-hand end of the banknote 1 to be pushed through the aperture 4 of the cashbox 5 and on to a stack surface, which may be either a support plate 13 , or the surface of a stack of banknotes 12 already stacked on support plate 13 .
Since the right-hand end of the banknote 1 is held between the rollers 2 a , 2 b , the surface of the banknote 1 will move laterally in relation to the pusher plate 9 as it descends into the cashbox 5 . This situation is illustrated by the dashed representations of the pusher plate and the banknote referenced 9 ′ and 1 ′ respectively.
The support plate 13 is supported upon a compression spring 14 . The compression spring 14 compresses to take up any excess travel in the length of stroke of the pusher plate 9 , beyond that required to bring the left hand end of banknote 9 into contact with stack surface 12 ; 13 , as shown in FIG. 1 . The position of the support plate 13 and the compression spring 14 when the pusher plate is fully lowered are shown by dashed representations of the support plate 13 ′ and the compression spring 14 ′. The degree to which the compression spring 14 is compressed depends upon the height of any existing banknote stack on the support plate 13 .
At this stage, the right-hand roller pair 2 a , 2 b is disengaged, thus freeing the right-hand end of the banknote 1 , as shown in FIG. 1 . However, as the left-hand end of the banknote 1 is securely maintained on the stack surface 12 ; 13 by the pusher plate 9 , the position of the banknote 1 is positively controlled throughout.
The rotor mechanism 10 is then actuated, driven by a reversible DC motor and drive train (not shown). The rotor 10 is rotated approximately 90° anti-clockwise, with reference to FIG. 1, from its resting position (shown in solid line) where the rotating axle 23 of the rotor 10 is positioned above the resting position of the pusher plate 9 , to its extended position (shown in dotted line referenced by numeral 10 ′). This causes the right-hand end of banknote 1 to be withdrawn from the clearance between rollers 2 a and 2 b , entrained downwards through the aperture 4 and unrolled sideways along the stack surface 12 ; 13 , such that it falls beneath the right-hand hand abutment surface 16 , as shown in FIG. 1 .
It will be noted from FIG. 1 that the maximum depth of penetration of the rotor 10 into the cashbox 5 is no more than that of the pusher plate 9 . This ensures that the movement of the rotor 10 is not obstructed by the stack surface 12 ; 13 .
It will also be noted that the maximum dimensions of the pusher plate 9 are limited by the corresponding dimensions of the aperture 4 . Within this constraint it is desirable that the banknote contacting area of the pusher plate 9 is large to increase the control over the positioning of the banknote 1 . Unlike known stacking systems, the size of the pusher plate 9 of the present embodiment is not directly related to the depth of stroke of pusher plate.
When the banknote 1 is fully contacting stack surface 12 ; 13 , the rotor 10 rotates clockwise, as shown in FIG. 1, back to its resting position and subsequently the pusher plate 9 is also returned to its resting position above the banknote transport plane. As the pusher plate 9 is returned to this position, the compression spring 14 returns the stack surface 12 ; 13 to its uppermost limit, against the movement of the pusher plate 9 . This movement of the stack surface is limited by the abutment surfaces 15 , 16 located on the interior surface of the cashbox 5 .
Thus, stack surface 12 ; 13 is continually under a compressive load between compression spring 14 and pusher plate 9 or abutment surfaces 15 , 16 . Because the banknote is flattened on the stack surface by the stacking mechanism, the scope for a banknote to become incorrectly positioned prior to being forced against the abutment surfaces 15 , 16 is greatly reduced.
Subsequently, rollers 2 a , 2 b , 3 a , 3 b are re-engaged in order to receive a further banknote 1 to be stacked, at which time the stacking cycle is ready to restart.
In this embodiment, despite the fact that the pusher plate 9 and the initial position of banknote 1 are centrally located with respect to the rollers 2 a , 2 b , 3 a , 3 b , the final stacked position of the banknote 1 is offset with respect to this position. This offset is a function of the distance between the banknote transport plane and the length of stroke of pusher plate 9 .
It will be apparent to the skilled reader that the present embodiment of the invention is tolerant of misalignment of the banknote 1 as it is presented for stacking at the stacking mechanism, since no datum edge is relied upon in order to effect the stacking operation. Furthermore, because each banknote 1 is effectively stacked by positioning part of the banknote 1 on the stack 12 and subsequently flattening the remainder against the stack 12 , this embodiment is also able to cope with a wide range of banknote sizes.
Second Embodiment
Referring to FIG. 3, a stacking mechanism according to the second embodiment of the invention is shown. Features in the second embodiment which are similar to features already discussed with reference to the first embodiment, are referenced using the same numerals and are not discussed further in detail. Unlike the first embodiment, the second embodiment does not utilise a pusher plate or piston in the stacking process but incorporates two rotors with the circular profile shown in FIG. 2 b and as described with reference to the first embodiment.
Banknote Transport System
In this embodiment, the banknote 1 is transported to the stacking mechanism by a banknote transport system similar to that described with reference to the first embodiment.
However, in this embodiment the banknote 1 is transported in the region of the stacking mechanism by drive rollers 30 situated above the banknote transport plane and at either side of the cashbox aperture 4 . Each drive roller 30 is opposed by a trapped bearing 32 situated beneath the banknote transportation plane.
The drive rollers 30 are supported rigidly on axles 31 and the trapped bearings 32 are mounted along opposing edges 26 of the cashbox aperture 4 , such that they have two rotational degrees of freedom.
The trapped bearings 32 may be manufactured from metal or plastics material and are mounted proud of the profile of the upper surface of the cashbox 5 . The drive rollers 30 are manufactured from plastics or any other suitable material and have a rubberised tyre or circumferential surface to positively grip the banknote 1 .
The spacing between the drive rollers 30 and the trapped bearings 32 on either side of the aperture 4 is such that even the minimum width of banknote for which the mechanism is designed may be securely held and transported.
In this embodiment (illustrated in FIGS. 3 a-d in 1:1 scale) the maximum banknote width is approximately 95 mm. The minimum banknote width is approximately 70 mm. In this instance this is limited by the spacing of abutment surfaces 15 and 16 . In practice this spacing could be reduced to a slightly greater width than the aperture width if required. In this embodiment the aperture width is approximately 24 mm.
As in the first embodiment, transportation belts may be used in the place of rollers.
Stacking Mechanism
The stacking mechanism in this embodiment comprises two rotors 10 , each as described with reference to the first embodiment. Each rotor 10 is mounted and driven in a similar manner to that described with reference to the first embodiment. Referring to FIG. 3 a , the rotors 10 are shown to be mounted opposing each other, with sufficient clearance between them in order that they do not interfere with each other when they are rotated about their axes 11 .
Stacking Process
Referring to FIG. 3 a , a banknote 1 is shown having been transported between the drive rollers 30 and the trapped bearings 32 to a position above the cashbox aperture 4 . The banknote 1 is shown as being transported to the stacking mechanism in a direction perpendicular to the plane of the diagram by the transportation mechanism.
As with the first embodiment, prior to the actuation of the stacking mechanism, the positive gripping force exerted by the rollers 30 is removed from the banknote 1 . This is achieved by raising the associated mounting axles 31 to give a clearance between the rollers 30 and the trapped bearings 32 . However, unlike the first embodiment in which the rollers on one side of the banknote only are released, this occurs on both sides of the banknote 1 in the present embodiment.
FIG. 3 a illustrates the start of the stacking process. The rotors 10 are caused to rotate in synchronism about their respective axles 11 in the directions indicated by the arrows in the Figure. As was described with reference to the first embodiment, the movement of the rotors 10 is entrained using an electric motor and a gear train (not shown). As the angle of rotation of each of the rotors 10 increases, the rotating axles 23 of the rotors 10 are brought into contact with the upper surface of the banknote 1 , in a roughly central position with respect to the banknote 1 . The synchronous operation of the rotors 10 ensures that the force exerted on banknote 1 is even. The possibility of the banknote 1 being skewed upon being stacked is therefore diminished.
Continued rotation of rotors 10 causes the banknote 1 to be entrained around the rotating axle 23 of each rotor 10 and onto stack surface 12 ; 13 , as is shown in FIG. 3 b.
As the trapped bearings 32 are free to rotate both in the direction of transportation of the banknote 1 and in the perpendicular direction, the banknote 1 is freely moveable both in the transportation stage, and subsequently downwards in the direction of the cashbox 5 during the stacking process.
Alternatively, this objective may be achieved by arranging the trapped bearings 32 to be moveable with respect to the fixed drive rollers 30 . Prior to the stacking process they may be lowered in order to allow the banknote 1 to be stacked freely.
As the rotors 10 continue to rotate, their rotating axles 23 , diverge from one another along the upper surface of the banknote 1 . As previously described, the rotation of the rotating axles 23 ensures that no undue frictional forces are exerted on banknote 1 , thus reducing the chance of banknote 1 being damaged during the stacking process.
As the rotors 10 rotate further, their depth in the cashbox 5 increases. This is allowed for by the compression spring 14 which allows the support surface 13 to be depressed. As is shown in FIGS. 3 c and 3 d , the further rotation of the rotors 10 causes the rotating axles 23 of the respective rotors 10 to diverge. This has the effect of causing the banknote 1 to be further entrained about the trapped bearings 32 as the banknote 1 progressively enters the cashbox 5 , until it has entirely entered the cashbox 5 and is flattened against stack surface 12 ; 13 , as is shown in FIG. 3 d . This occurs at the maximum degree of rotation of the rotors 10 ; approximately 90°. It is desirable that the actual degree of rotation of the rotors 10 is sufficient to make the banknote contacting portions 23 of the rotors 10 reach or just pass the point of maximum depth of penetration into the cashbox 5 . This facilitates the unrolling of the banknote and reduces the risk of the banknote being incorrectly stacked.
At this point, as the rotors 10 are circular in profile the ends of each rotor are positioned directly beneath the axis about which they rotate.
As the rotors 10 rotate in the reverse direction, out of the cashbox 5 , the banknote stack is biased under the influence of the spring 14 towards the aperture 4 , against the retreating rotors 10 . As the rotors 10 withdraw from cashbox 5 entirely, the stack surface 12 ; 13 is urged by the compression spring 14 against the abutment surfaces 15 , 16 situated on the inside of the upper surface of the cashbox 5 . The abutment surfaces 15 , 16 ensure that positive control over the stack surface 12 ; 13 is always maintained.
This embodiment of the invention yields the same advantages as the first embodiment. In addition, however, the aperture 4 of the cashbox 5 may be smaller in this embodiment due to the absence of the pusher plate, which may increase the degree of security which may be imparted to a cashbox for use with this embodiment. In this embodiment of the invention the minimum width of the aperture 4 must be at least twice the thickness of rotor arm 20 , approximately 14 mm. Therefore a minimum aperture width of approximately 15 mm may be achieved in this embodiment.
Furthermore the speed with which a banknote may be stacked may be increased as in this embodiment both rotors 10 act simultaneously, as opposed to the arrangement in the first embodiment where the rotor and the pusher plate are actuated at different times.
Third Embodiment
The third embodiment of the invention operates in a similar manner to that described with reference to the second embodiment and similar features will not be described further in detail.
In this embodiment, the rotors 40 are of a slightly different design compared to those previously described.
Referring to FIG. 4 a , a rotor according to the present embodiment is illustrated. Unlike the rotor 10 previously described, rotor 40 has no to support bar 22 or rotating axle 23 . Rotor 40 has three rotor arms 41 (although this number could be higher or lower). At the end of each rotor arm 41 is a wheel 42 . Each wheel 42 forms a banknote engaging surface, which fulfils the same function as the rotating axle 23 of rotor 10 . Alternatively, the rotating wheels 42 may be replaced by non-rotating banknote contacting surface made from a low friction such as PTFE.
The arms 41 of opposing rotors 40 are thus arranged to interdigitate. This is illustrated in FIGS. 4 b and 4 c which respectively show the rotor structure and arrangement from above in the resting state and from the side in operation.
This provides the added advantage that aperture 4 of cashbox 5 may be made narrower, yet still allow the entry of the rotors in order to stack the banknotes; thus, cashbox 5 may be more easily made secure when it is removed from the validator. Specifically, the minimum width of the cashbox aperture 4 (approximately 10 mm in this embodiment) is limited by the thickness of one rotor arm 41 , which in this case is 7 mm.
Fourth Embodiment
In the fourth embodiment the stacking mechanism operates in a similar manner to that described with reference to the second and third embodiments and similar features will not be described further. However, in the fourth embodiment the positional control exerted over the banknote 1 during the stacking process is improved through the use of a banknote contacting membrane 50 interposed between the rotors 10 ; 40 and the banknote 1 .
Membrane
A membrane 50 according to the present embodiment is illustrated in plan view in FIG. 5 . The membrane 50 may be made of various wear resistant materials which may be produced in thin flexible sheets and suitable for rolling on rollers; such as polyester, mylar (TM), kevlar (TM) and Gore-tex (TM).
The membrane 50 is symmetrical about the dotted centre line and has a single connection point 51 situated at each end. The connection points 51 provide a means of attaching the membrane 50 to rollers 53 , 54 upon which the membrane 50 is wound. It is advantageous to have a single point of attachment to each roller as this reduces the possibility of the membrane 50 becoming skewed when it is wound on or off the rollers 53 , 54 .
The membrane 50 also comprises a central friction strip 52 , situated on its banknote contacting side. This is beneficial in terms of increasing control over the banknote 1 during the stacking process by increasing the level of friction between the membrane 50 and the banknote 1 . In the present embodiment the friction strip 52 is made from vulcanised rubber which is bonded to the membrane 50 . However, it may be made from any other suitable high friction material and attached to the membrane by any other suitable method, such as by stitching.
The membrane 50 is mounted upon rollers 53 , 54 , as shown in FIG. 6, which are spring loaded and mounted in the chassis of the stacker mechanism. This is achieved using springs (not shown) internal to the rollers 53 , 54 . The effect of the springs is to bias the rollers 53 , 54 in the directions indicated by the arrows in FIG. 6 a . Therefore, in its resting state the membrane 50 is held taught between the rollers 53 , 54 , entrained over two guide rollers 55 , 56 , which are also mounted in the chassis of the stacker mechanism, as shown in FIG. 6 .
Stacking Operation
Referring to FIG. 7, a stacking mechanism according to the fourth embodiment of the invention is shown.
FIG. 7 a illustrates the start of the stacking cycle, which is as described with reference to the second and third embodiments, with the exception of the addition of membrane 50 , and so common features will not be discussed further in detail.
As the rotors 10 ; 40 are caused to rotate about their respective axes 11 they contact the membrane 50 , which is positioned between the banknote 1 and the rotors 10 ; 40 . Further rotation of the rotors 10 causes the membrane 21 to be pushed downwards and entrained first around the guide rollers 55 , 56 , as shown in FIG. 7 a and then around trapped bearings 32 , which are located at either side of the aperture 4 . The purpose of the guide rollers 55 , 56 is to prevent the membrane 50 from snagging on the rollers 30 .
The rollers 53 , 54 are caused to rotate in the directions indicated by the arrows in FIG. 7 a , against their respective spring force bias, as the membrane 50 unrolls from them under the action of the rotors 10 ; 40 . As the rotors 10 ; 40 move the membrane 50 downwards through the banknote transportation plane, as shown in FIG. 7 b , the banknote 1 is contacted by the friction strip 52 . As the friction strip 52 displaces only in a vertical sense, and hence remains centred in the mechanism throughout the stacking process, it serves to reduce any skewing of the banknote which might otherwise occur.
As the rotors 10 ; 40 rotate further, as shown in the sequence illustrated in FIGS. 7 b to 7 d , the banknote 1 is pushed through the cashbox aperture 4 and brought into contact with the stack surface 12 ; 13 as shown in FIG. 7 b . The banknote 1 is then unrolled in a sideways direction with respect to the stack surface 12 ; 13 as shown in FIGS. 7 c and 7 d.
Subsequently, as the rotors 10 ; 40 rotate in reversed directions on exiting the cashbox 5 , membrane 50 is tensioned by the springs in axles 53 , 54 , which ensure that there is no slack in the membrane 50 during the removal of rotors 10 ; 40 , from cashbox 5 . Since there is no relative movement between the membrane 50 and the stacked banknote 1 in the plane of the surface of the stack 12 ; 13 , the banknote 1 is not disturbed by the withdrawal of the rotors 10 ; 40 and the membrane 50 .
Fifth Embodiment
Referring to FIGS. 8 and 9, a stacking mechanism according to the fifth embodiment of the invention is shown. In general terms, the mechanism of this embodiment fulfils the same functions as those described in the first embodiment. Features in this embodiment which are similar to features already discussed are referenced using the same reference numerals and will not be discussed further in detail.
Whereas the mechanism of the first embodiment incorporates a stacking mechanism and a transportation mechanism which are housed in a banknote handling apparatus, to which a cashbox is removably attached, the mechanism of the current embodiment incorporates part of the transportation mechanism and the entire stacking mechanism in the cashbox itself. This feature greatly enhances the level of security which may be provided for a detachable cashbox. As a result of this feature, the aperture 4 through which banknotes are stacked is internal to the outer casing of the cashbox. Therefore, on being detached from the banknote handling device, for example a validator, there is no external aperture large enough to allow a person to tamper with the contents of the cashbox.
Transportation Mechanism
Referring to FIG. 8, it will be noted that the cashbox according to the present embodiment consists of an inner and an outer envelope, referenced by numerals 60 and 61 respectively. A banknote 1 is introduced into the cashbox 5 in the direction of arrow “A”, by the transportation mechanism of a banknote handling apparatus to which the cashbox 5 is attached. The aperture (not shown) through which a banknote 1 may be introduced into the cashbox need only be slightly larger than the width-wise cross sectional dimensions of the largest banknote 1 with which the apparatus is designed to work, further increasing the level of security of the cashbox 5 . On entering the cashbox 5 , the banknote 1 is engaged by opposing pairs of belts 62 , 62 a and 63 , 63 a which are arranged to grip the banknote 1 along each of its longitudinal edges. The belts 62 , 62 a and 63 , 63 a are driven by rollers 64 , which in turn are driven by a connection (not shown) from the banknote handling apparatus drive mechanism through an aperture (not shown) in the wall of cashbox 5 . The upper belts 62 , 63 of the drive arrangement are biased using springs 65 in order to keep the banknote 1 firmly in contact with opposing belts 62 a , 63 a.
Stacking Mechanism
Referring to FIG. 9, it can be seen that as with previous embodiments, in this embodiment banknotes are stacked onto a plate 13 which is supported by a spring 14 . This allows the banknote stack 12 to be displaced by the stacking mechanism as a new banknote 1 is stacked and to return as the stacking mechanism retreats in order that the uppermost banknote 1 in the stack 12 abuts the abutment surfaces 15 , 16 of the upper wall 66 of the inner envelope 60 of the cashbox 5 . Thus, the banknote stack 12 is always maintained under positive control as discussed in previous embodiments.
Referring again to FIG. 8, the stacking mechanism comprises an actuation lever 70 which is moveable in the direction of the arrow shown in FIG. 8 by an external drive mechanism (not shown). This may take the form of a simple gear, for example, connected via an aperture in the cashbox wall to an electric motor housed in the banknote handling apparatus. The rotation of actuation lever 70 causes the rigidly connected assembly of rod 71 , connecting arm 72 and roller axle 73 to rotate about the longitudinal axis of rod 71 , such that the roller axle 73 enters the cashbox aperture 4 (best seen in FIG. 9) in a radial channel 90 in the end wall of the inner cashbox envelope 60 .
The actuation lever 70 , rod 71 , connecting arm 72 and roller axle 73 may be manufactured from any suitable rigid material such as steel and interconnected using standard manufacturing techniques.
The roller axle 73 has mounted at either end a roller 74 , 75 . Each roller 74 , 75 is provided with a rubber tyre for engaging a piston 80 , 81 , 84 which will be described in more detail below. The roller axle 73 is secured at the end of roller 74 only, to connecting arm 72 ; thus avoiding the need for providing further channels in the internal envelope 60 , which would be required for securing the second end of roller axle 73 . The roller axle 73 is free to rotate against the spring bias of an internally mounted spring (not shown) housed in connecting arm 72 , the biasing of which acts in the direction of the arrow shown in FIG. 9 . The rollers 74 and 75 are mounted on the roller axle 73 such that they are free to rotate independently of the roller axle 73 .
The banknote stacking mechanism further comprises a piston assembly, as mentioned above. The piston assembly comprises a banknote engaging plate 80 . The plate 80 is dimensioned such that it just fits through the aperture 4 of the upper surface of the inner envelope 60 of cashbox 5 , as viewed in FIGS. 8 and 9. The aperture 4 is in turn dimensioned such that its length (in the direction of banknote transportation) exceeds the length of the longest banknote with which the apparatus is designed to function.
The piston assembly is mounted in a slot 86 in the end wall of the inner envelope 60 which receives a reduced width portion of a guide piece 81 of the piston body, such that the guide piece 81 is free to move linearly in the slot 86 . The guide piece 81 is held in a planar relationship with the end wall of the inner envelope 60 by the end wall of the outer envelope, with which it is a sliding fit. The guide piece 81 is acted on by a spring 83 which biases the piston body towards the upper surface 66 of the inner envelope 60 of cashbox 5 as viewed in FIGS. 8 and 9, such that in its resting condition, as is shown in FIG. 9, the plate 80 of the piston body is situated above the plane of a banknote 1 which is held between each side of the transport mechanism.
The piston body also comprises an arm 84 which extends perpendicularly to the guide piece 81 and which is co-planar with the plate 80 . The entire piston body assembly may be made from any suitable rigid material, such as steel or a plastics material and may be made as a one piece moulding or may be assembled, using standard manufacturing techniques from components parts.
Entrained about the roller axle 73 is a membrane 91 , similar to that described in the fourth embodiment. One edge of the membrane 91 is secured to the roller axle 73 . The membrane 91 extends from near the roller 75 , along approximately the entire length of the plate 80 .
The other edge of the membrane 91 is secured to a longitudinal edge of plate 80 , for example by adhesion, as is shown in FIGS. 8 and 9.
Mode of Operation
As has been described with reference to the previous embodiments, the banknote 1 is transported by the transportation mechanism and held stationary above the aperture 4 prior to the initiation of the stacking procedure. Subsequently, the belt transport system 62 is raised relative to its opposing belt 62 a in order to create a clearance between the belts 62 and 62 a such that an edge of the banknote 1 may be withdrawn during the stacking operation. This is initiated by the rotation of actuation lever 70 in the direction indicated by the arrow on FIG. 9 and as previously described this results in the rotation of roller axle 73 into the inner envelope 60 of cashbox 5 along the radial slot 90 in the end wall of the inner cashbox 60 . In so doing, roller 74 acts on the arm 84 of the piston body, forcing the piston body to slide vertically down into the inner envelope 60 of cashbox 5 , along slot 86 . This in turn causes the underside of the plate 80 to come into contact with the upper surface of the banknote 1 , which is entrained by the plate 80 through the aperture 4 and onto the upper surface of the stack of banknotes 12 in the cashbox, or, onto the support plate 13 if the cashbox is empty.
Once the piston plate 80 has secured one edge of the banknote 1 against the banknote stake 12 , the second banknote edge is release by the raising of the belt transport system 63 relative to its opposing belt transport system 63 a.
As the actuation lever 70 continues to rotate in the direction of the arrow shown in FIG. 8, the action of roller 74 continues to force the piston body downwards against the action of spring 14 shown in FIG. 9 . Thus, as the roller axle 73 moves across the upper surface of the plate 80 , the membrane 91 is wound onto the roller axle 73 by virtue of the biasing spring (not shown) in connecting arm 72 which acts upon the roller axle 73 . This continues until the point at which the roller axle 73 passes off the right hand edge of plate 80 , as viewed in FIG. 9 .
Continued rotation of the actuation lever 70 causes the membrane 91 to unwind, against the action of the spring (not shown) acting upon the roller axle 73 until the roller axle 73 reaches its maximum depth of penetration into the inner envelope 60 of the cashbox 5 . This state is shown in FIG. 9 by the dashed representation of connecting arm 72 ′, roller axle 73 ′, roller 75 ′, plate 80 ′, membrane 91 ′, banknote stack 12 ′ and support plate 13 ′. Thus, the action of roller axle 73 , together with that of the membrane 91 has at this point flattened the remainder of the banknote 1 against the stack 12 .
It should be noted that in this embodiment, as with the mechanism of the first embodiment, the final stacked position of the banknote is laterally offset with regard to the position of the banknotes during transportation.
It should also be noted that at this point, roller 74 continues to exert a downward force on the piston body, via the extreme end of arm 84 . This is despite the fact that the roller axle 73 is no longer situated above plate 80 .
The actuation mechanism then proceeds to drive actuation lever 73 in the reverse direction to rotate the roller axle 73 back out of the inner envelope 60 of cashbox 5 along the radial path defined by slot 90 . The biasing force of spring 83 causes the piston body to return to its normal position, shown in full line in FIG. 9 .
Similarly the biasing force of the spring (not shown) which acts on roller axle 73 causes the membrane 91 to be once again wound onto the roller axle 73 up until the point at which the roller axle 73 again reaches the upper surface of the plate 80 , leaving the banknote in its stacked position. And thereafter to unwind again as the position shown in FIG. 9 is approached.
The skilled reader will appreciate that the present embodiment has the advantages described earlier with respect to the first embodiment of being tolerant of misalignment of the banknote 1 as it is presented for stacking, since no datum edge is relied upon in order to effect the stacking operation.
Similarly, because each banknote 1 is effectively stacked by positioning part of the banknote 1 on the stack 12 and subsequently flattening the remainder against the stack 12 , this embodiment is also able to cope with a wide range of banknote sizes. However, in addition, the presence of the membrane 91 further increases the control which may be exerted upon the banknote 1 during the stacking operation.
Furthermore, the tensile stresses imparted to the banknote 1 are reduced by the presence of the membrane 50 . Therefore, the chances of the banknote 1 being torn by the stacking process are further reduced. Accordingly, the speed of the stacking cycle may be further increased.
The skilled reader will understand that a banknote stacking apparatus according to the present invention may be used in various applications, particularly where banknotes are automatically accepted and validated such as in automated vending machines and banknote changing machines. Referring to FIG. 10 a a banknote validating machine 100 is shown in conjunction with a cashbox 5 . Referring now to FIG. 10 b , an idealised sectional view through the machine 100 is shown. This shows a banknote 1 on the point of being inserted into an aperture 101 from where it is transported along a banknote transportation system 102 by a drive unit 103 and validated by a validation apparatus 104 . The transportation system 102 then transports the banknote 1 to a stacking arrangement 105 so that the banknote 1 may be stacked in the cashbox 5 as has been described in previous embodiments, the stacking arrangement 105 may be located in the validator 100 as it is shown in FIG. 10 b or alternatively in the cashbox 5 itself.
Furthermore, it will be appreciated by the skilled reader that the stacking arrangement 105 employed in a banknote accepting machine may conform to any one of the previously described embodiments.
It will be apparent from the forgoing that various modifications and variations may be employed in relation to the above-described embodiments without departing the spirit or scope of the present invention. In particular, features of the embodiments described may be employed individually or in individual combinations without departing from the scope of the invention.
For example the skilled reader will appreciate that the present invention as described in the second, third and fourth embodiments, could be used to insert documents such as banknotes, loosely through an aperture; thus obviating the need to any stack forming means.
Furthermore, the skilled reader will appreciate that by adjusting the clearance between the upper and the lower halves of the banknote transport mechanism, the present invention could be used to stack bundles of banknotes, which have been held, for example, in a temporary storage device such as an escrow.
The skilled reader will also appreciate that various modifications may be made to the mechanism with which the rotors and the pusher plate are driven. For example, both the rotors and the pusher plate may be driven by a single, non-reversible electric motor, their actuation timing being controlled through the use of cams, for example. Furthermore, the banknote transport mechanism may be arranged to deliver banknotes for stacking at predetermined intervals, allowing the continuous operation of the stacking mechanism.
The skilled reader will also realise that the inventive concept of the present invention may be realised using stacking members which would not normally be termed rotors. For example, the opposing rotors of the second embodiment may be replaced with parallel rods, each supported at either end in an “L” shaped channel. By moving the rods in the “L” shaped channels the required downward and sideways movement for stacking a sheet according to the present invention may be accomplished.
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A device for stacking banknotes, comprising a cashbox and a stacker arranged to stack banknotes of predetermined dimensions in said cashbox, said cashbox having a surface including an aperture therein, said aperture having a dimension in a first direction of W, said device being arranged to receive a banknote at a position overlying said aperture, said banknote having a dimension in said first direction of L, said stacking means being arranged to push said banknote through said aperture and into a stacked position in said cashbox, wherein said banknote is pushed to a predetermined maximum depth D in said cashbox relative to said aperture such that D<(L−W)/2.
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This application is a continuation of application Ser. No. 257,128, filed Oct. 7, 1988, now abandoned, which is a continuation of application Ser. No. 799,911, filed Nov. 20, 1985, now abandoned.
This invention relates to apparatus for dispensing beverages in general, and more particularly to an improved in-home drink dispenser, particularly useful in dispensing carbonated drinks made of a mixture of a concentrate (e.g., a syrup) and a diluent (e.g., carbonated water).
BACKGROUND OF THE INVENTION
In prior U.S. Pat. Nos. 4,408,701; 4,328,909, 4,555,371, 4,363,424, 4,523,697, 4,520,950, 4,570,830, 4,564,483 and 4,664,292 various aspects of an in-home drink dispenser are described. The dispensers disclosed therein have been found to work quite well, particularly the embodiments utilizing gravity feed of the concentrate, for example, the system disclosed in U.S. Pat. No. 4,570,830. There are, however, certain problems with these previous systems. One problem is in maintaining the desired degree of carbonation in the drink. Another problem encountered is the spitting or sputtering which occurs upon the initial opening of the dispense valve due to a build up of pressure.
The previously disclosed system included passages for the diluent in a manifold. There was an area between the connection to a carbonator tank and the dispensing valve where diluent was maintained when the carbonator was disconnected from the system. If the diluent, e.g., carbonated water, was left in these passages for a long period of time, it would, of course, warm up and lose its pressurization and its carbonation when dispensed. Although this is not a major problem, it was felt desirable to avoid this.
In an in-home drink dispenser, it is, of course, important to know how much carbonated water is left and also how much carbon dioxide is left. Knowing when one is about to run out of carbon dioxide is of great importance, particularly where a cylinder is not immediately on hand. The carbonator can be refilled with water and ice, however, if one runs out of carbon dioxide, at a time when the supplier is not open for business, it may be necessary to wait, possibly over a weekend, to get a new cylinder. Thus, the need for an indication of this level is particularly important. Furthermore, in regard to the carbon dioxide cylinders, since the cylinders are being handled by people not used to such, there is a need to take measures to protect the cylinders and to provide for ease of use and insertion and removal from the drink dispenser.
SUMMARY OF THE INVENTION
The present invention provides a particularly attractive in-home drink dispenser which is easy for the consumer to use and which provides a drink which has a proper and repeatable strength and carbonation.
A number of features are incorporated into the drink dispenser of the present invention which give it these qualities. In the first instance, to avoid loss of carbonation when dispensing, a novel expansion chamber is provided. This expansion chamber, which is kept cold, is a gradually enlarging chamber which permits a gradual expansion and lowering of pressure from the pressure inside the carbonator tank of approximately 50 psi to atmospheric pressure at the point where the diluent is discharged from the machine. This, in combination with an arrangement in which it is insured that the glass being filled is positioned so that discharge takes place tangentially to the inside surface of the glass, leads to maintaining the high level of carbonation which is achieved within the carbonator.
Spitting and sputtering is avoided on initial startup of the system by providing in the system, preceding the expansion chamber, an anti-surge valve. This anti-surge valve acts to reduce the pressure in the expansion chamber to a level which will allow dispensing, upon the initial opening of the dispensing valve without spitting or sputtering. In the illustrated embodiment, the expansion chamber and anti-surge valve are installed within the carbonator tank.
Furthermore, the dispensing valve, itself, i.e., the valve that opens to permit flow of the carbonated water out into the glass, is formed as part of the carbonator rather than part of the dispense head. This means that carbonated water no longer exists outside the carbonator. The carbonator includes a connector block by means of which it is coupled to a source of carbon dioxide for carbonating, and within this connecting block there is disposed a shuttle valve which acts as a dispensing valve. The shuttle valve has a radial inlet adapted to be coupled to the outlet from the carbonator tank and an axial outlet.
A dispensing spout is held within a cradle within the dispense head and is in an abutting relationship with the shuttle valve with a seal therebetween, the shuttle valve normally being biased to a closed position. As in the previous dispenser, the concentrate, e.g., syrup is dispensed directly from the syrup package by rotating the cap of the package to open a valve formed therein. This rotation is accomplished by means of a pneumatic actuator which rotates an annular disk, which engages the cap. In accordance with the present invention, this actuator is also coupled to the cradle holding the spout. When the pneumatic actuator is operated, it moves the cradle, causing the shuttle valve to move inwardly to an open position to permit dispensing of the carbonated water through the spout. Guide means are provided for guiding the connecting block of the carbonator and insuring proper alignment of both the gas connection, and the water outlet connection which operates the shuttle valve. Included is a locking apparatus to lock the carbonator in place when in proper alignment. As with previous embodiments, the carbonator simply slides in and out of position to allow ease of removal and insertion when the carbonator needs to be refilled.
As with previous systems, it is necessary to connect a carbon dioxide cylinder to the system. Again, this is done with a connection which, when the connection is made, opens a valve to allow a flow of carbon dioxide out of the gas cylinder. In the connections disclosed in the aforementioned applications, a connecting means which provided a relatively high mechanical advantage was provided. This was thought necessary at the time because of the high pressure acting on the probe entering the cylinder, this pressure being too high for the average person to operate against when inserting the cylinder. This, of course, made insertion of the cylinder more difficult. However, in accordance with the present invention, a very thin probe is utilized. Because the probe is so thin, the area on which the high pressure acts is materially reduced and the force generated is not beyond that which the average person can act against. Thus, a simple connection with a fitting containing the probe which also has pins which fit into appropriate slots on a member secured to the top of the cylinder is utilized. In the illustrated embodiment, the gas tank is suspended from the fitting containing the probe, the fitting also containing a pressure regulator. By so suspending the gas cylinder, it is possible to measure its weight by providing an upward bias to the probe fitting, using suitable springs.
In accordance with the present invention, the fitting to which the gas cylinder is attached is supported rotatably within a hood, the hood forming a lever which is biased upwardly. The hood rotates on a shaft supported in a bracket which is attached to a wall of the dispenser. Springs act between the bracket and the hood to bias it upwardly. A mechanism, including a planar member, which is guided in a curved slot, maintains the probe vertical so that in any position the user can easily insert a gas cylinder onto the probe without difficulty. The planar member which is guided and which maintains the pin vertical is also provided with indicators visible through a window to indicate the degree of the fullness of the cylinder. A full cylinder will act against the spring and pull the hood all the way down. As the cylinder is used up, the hood will begin to move upwardly until, when the cylinder is completely empty, the hood will be fully up. In accordance with the present invention, the spring is adapted to begin moving the gas cylinder upward only over the last part of the supply, e.g., the last ten percent. Thus, as soon as movement starts the user knows that he is getting near the end of his supply.
The cylindrical member which engages the probe fitting is formed with a pair of arms. The arms are aligned with axial slots which are used for engaging pins positioned on the probe fitting when locking the two fittings together. By aligning the arms with the axial slots, the user is given a guide and knows exactly how to line up the gas cylinder to insert it onto the probe fitting. Preferably, on the hood, there are alignment markings and an arrow, indicating to the user the direction in which to rotate the handles or arms so as to lock the gas cylinder in place. In the illustrated embodiment, there are holes at the ends of the arms through which a finger can be inserted to hold the gas cylinder.
Also, in the preferred embodiment, a cover is placed over this fitting for decorative and protective purposes. The cover has a tear-away tab on the top to allow access to the cylindrical member and fitting when attaching to the probe fitting. The tab cover, however, provides protection during shipping and remains in place until the cylinder is to be used.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the in-home drink dispenser of the present invention.
FIG. 2 is a similar view showing the door to the carbonator compartment and CO 2 compartment opened.
FIGS. 3 and 4 are drawings illustrating the mating mounting assemblies for the drink dispenser carbonator.
FIG. 5 is an exploded view of the carbonator and mounting assembly.
FIG. 6 is an exploded of the mounting assembly in larger scale.
FIG. 7 is a cross section through a portion of the mounting assembly containing a bore for the shuttle.
FIG. 8 is an exploded view of the portion of the mounting assembly containing the cross-section of FIG. 7.
FIG. 9 is an exploded view of the dispensing assembly and dispensing head of the drink dispenser of the present invention.
FIG. 10 is a partially cutaway plan view of the dispenser assembly.
FIG. 11 is a cross section through the dispensing head.
FIG. 12 is an exploded view of the actuating arrangement of the dispense head.
FIG. 13 is a bottom view of a portion of the dispense head showing the manner in which the cradle is guided.
FIGS. 14 and 15 are views showing additional details of the actuator mechanism.
FIG. 16 is a perspective view of the syrup package of the present invention.
FIG. 17 is an exploded view of the parts of the package of FIG. 16.
FIG. 18 is a cross-sectional view through the package of FIG. 16.
FIG. 19 is an exploded view of the assembly inserted inside the carbonator.
FIG. 19A is an elevation view of this assembly partially in cross section.
FIG. 19B is a plan view of this assembly.
FIG. 20 is a plan view partially in cross section of the expansion chamber of FIG. 19.
FIG. 21 is a first cross section through the expansion chamber of FIG. 20 taken along the lines 21--21.
FIG. 22 is a cross section along the lines 22--22 of FIG. 20.
FIG. 23 is a cross section along the lines 23--23 of FIG. 20.
FIG. 24 is an elevation view of the expansion chamber.
FIG. 25 is a partial cross section through the feed line and diffuser assembly within the carbonator.
FIGS. 26 and 27 are cross-sectional views of portions of the diffuser assembly and resin bed.
FIG. 28 is a cross section through the resin bed showing its connection to the chamber containing the anti-surge valve.
FIG. 29 is a cross section of the anti-surge valve of the present invention.
FIG. 30 is an exploded view of the elements attached to the top of the CO 2 cylinder.
FIG. 31 is an elevation view partially in cross section showing the manner in which the CO 2 assembly is attached to a probe fitting in which is incorporated a regulator and also shows part of the weighing mechanism.
FIG. 31A is an enlarged sectional view of the thin probe fitting illustrated schematically in FIG. 31.
FIG. 32 is a perspective view showing the cylindrical member which permits attachment to the probe fitting of FIG. 31.
FIG. 33 is an exploded view of the weighing mechanism of the present invention.
FIGS. 34 and 35 are elevation views, partially in cross section and partially in phantom showing the operation of the weighing mechanism, FIG. 34 showing the weight mechanism with an empty cylinder and FIG. 35 showing the weighing mechanism with a full cylinder.
FIG. 36 is a perspective view showing one manner of maintaining a tangential relationship between the dispensing spout and a glass or cup irrespect of the diameter of the cup.
FIGS. 37a-c show how this device maintains this relationship for different sizes of cups.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 and 2 are perspective views of the improved in-home drink dispenser of the present invention. FIG. 1 shows the drink dispenser 11 with its doors closed. FIG. 2 shows the dispenser 11 with its carbonator door 13 and CO 2 compartment door 15 opened, and the CO 2 cartridge 17 and carbonator tank 18 removed. Also visible in FIG. 2 is the syrup cartridge 19. The syrup cartridge 19 is enclosed by a clear or smokey plastic enclosure 21 to finish off the outward appearance of the dispenser. The CO 2 cylinder 17 has a cover 23 for ease in handling and also for mounting into the dispenser in a manner to be described below. The carbonator 18 has an LCD liquid level gauge 31 and a carbonator connecting assembly 33. The connecting assembly 33 is adapted to mate with an alignment pin 35 within the compartment behind door 13. Below the pin 35 is a locking mechanism 37 for locking the carbonator in place once it is inserted.
FIGS. 3 and 4 show in more detail the carbonator connecting assembly 33 and pin 35 along with the locking assembly 37. The pin 35 and locking mechanism 37 are contained within a molded base member 39 which is mounted between upper wall 43 which abutts the top of member 39 and lower wall 44 which extends below member 39. Walls 43 and 44 may be separate members or may be joined along one end in which case the wall structure will fit around base member 39 of the carbonator compartment. Member 39 has a rear wall 45 perpendicular thereto from which pin 35 extends. Member 39 also has a bottom wall 47 and a side wall 51. The side wall 51 is actually the face of the actuator compartment depicted in FIG. 9. As can be seen in FIG. 9, wall 51 may split into two sections 51a and 51b. The locking mechanism 37 is installed in a recess formed by an L-shaped part 53 extending down from the bottom wall 47. Also extending out from the rear wall 45 is a tubular fitting 55 containing an O-ring seal 57. Seen extending from the end of the fitting 55 is a pin 59 which comprises the tip of a Schrader type valve mechanism which in the position shown is closed but which when then tip 59 is pushed in will be opened. This tubular fitting is coupled to the carbon dioxide supply cylinder through an appropriate pressure reducing valve to supply carbon dioxide to the carbonator 18 for carbonating the water contained therein. The valve 55 mates with a cylindrical fitting 61 on the carbonator connecting assembly 33 seen in FIG. 4. The pin 35 fits into an appropriately tappered bore 63 formed in carbonator connecting assembly 33. Also seen on the carbonator connecting assembly 33 is the outlet 65 for the carbon dioxide leading into the carbonator 18 in a manner which will be seen in more detail below. The water which is carbonated leaves the carbonator and enters an inlet 67 in the carbonator connecting assembly 33 from which it is conducted to an outlet spout which engages the carbonator connecting assembly 33 in a manner to be described in detail below.
Returning to FIG. 3, the locking mechanism comprises a handle 69 mounted to a cylindrical member 71 having a shaft 73 extending through the base of the L-shaped member 53. In this manner, the handle 69 and cylindrical member 71 are mounted for rotation about the axis of the shaft 73. Formed in the surface of the cylindrical member 71 is a cam 75. Cam 75 engages a slot 77 in the rear wall of the L-shaped portion 53. Extending upwardly from the cylindrical member is a stop member 79. The stop extends through an appropriate opening 81 in the bottom wall 47 of the member 39. The cam 75 is formed such that rotation of the handle 69 in a clockwise direction will result in the stop member 79 being moved in the direction of arrow 83 to the position shown in dotted lines. In that position, it engages the rear surface of the carbonator connecting assembly 33 to lock the carbonator in place and prevent the pressure present at the fitting 55 from blowing the carbonator outwardly.
FIG. 5 is an exploded view of the carbonator 18 and the carbonator connecting assembly 33. The outer body 25 of the carbonator is made of molded plastic. Inserted into the top of body 25 is a molded plastic ring 101. Into the plastic ring 101 a stainless steel carbonator tank 103 is inserted. The tank 103 contains holes 105 and 107. When in place, these holes receive fitting 109 and 111. The fittings 109 and 111 are, respectively, the carbon dioxide inlet and the carbonated water outlet. They, respectively, are inserted into the openings 65 and 67 of the carbonator connecting assembly 33 seen in FIG. 4.
The carbonator 18 is provided with a handle made up of a portion 29b molded into the body 25 and another portion 29a inserted thereover. A liquid crystal strip 31 containing an adhesive backing is attached to the tank 103 through an opening 113 provided in the outer case 25 behind handle portion 29b.
The liquid crystal strip 31 responds to temperatures close to 0° C., having one color for temperatures above and another for temperatures below. The handle portions 29a and 29b are provided with opening so the strip 31 may be viewed therethrough. The carbonater is normally filled with water and ice. Thus, strip 31 gives an indication of water level in the tank.
The ring 101 contains threads to engage the lid 27. Thus, the lip 115 of the tank is trapped between the mounting ring 101 and the lid 27 to obtain a good seal. The carbonated water outlet opening bore 117 can be seen on the front of the carbonator connecting assembly 33. Into bore 117 is inserted a shuttle valve assembly. At the base of the bore 117, which is in communication with the inlet 67 seen in FIG. 4, is inserted a biasing spring 119. Next inserted is an O-ring seal 120 and a shuttle member 121. The shuttle member 121 has an inlet port 123 and an outlet port 125. From the bottom of the carbonator connecting assembly 33 a guide and stop member 127 for the shuttle member 121, a biasing spring 129 and a retaining disk 131 are inserted.
This assembly can be seen in more detail in FIGS. 6, 7 and 8. FIG. 6 is an exploded view of the carbonator connecting assembly 33 in larger scale, showing in more detail the shuttle member 121 and O-ring seal 120. FIG. 7 is a cross section through the portion of the carbonator connecting assembly 33 containing the bore 117. As can be seen, the inlet 67 from the carbonator couples to a passage 135 terminating in an outlet opening 137. The outlet opening 137 is surrounded by the O-ring 120. The flat top portion 139 of the shuttle member 121 slides against this O-ring. In the position shown in FIG. 7, a seal is formed. There is no connection to the inlet 123 in the shuttle member 121 and the O-ring seal 120 prevents escape of any carbonated water. The spring 119, in this position, is biasing the shuttle member 121 in an outward direction up against the stop formed by the stop member 127.
As illustrated, stop member 127 is biased upwardly by spring 129, held in place by the disk 131. These parts are shown in exploded view in FIG. 8. As illustrated in the cross section of FIG. 7, the shuttle member 121 has a cylindrical recess 141 in its rear portion into which the spring 119 is inserted. The spring acts between this point and the rear wall of the bore 117. To provide the necessary stops, the bottom of the shuttle member 121 has formed therein a slot 143. When the shuttle member 121 is pushed inwardly against the biasing force of spring 119, in a manner to be described more fully below, the opening 123 is moved to a position where it is aligned with the outlet 137. The outlet 137 and inlet 123 are sealed by the O-ring seal 120. Carbonated water can then flow out of the outlet 125 to the dispensing apparatus which will be described in detail below.
FIG. 9 is an exploded view of the dispensing assembly of the drink dispenser of the present invention. It includes a base portion 201 of molded plastic. The base portion between walls 43 and 44 of FIG. 3 and forms the bottom wall 47, rear wall 45 and a portion of side wall 51 previously described. In addition, the L-shaped portion 53 is integrally molded in this base. Thus, the locking mechanism 37 is again illustrated as are the pin 35 and tubular fitting 55.
Formed in the base 201 is an annular wall 203 having an annular base 205 with an opening 207 therein. A rotatable annular disk 209 is inserted into the opening so formed. This disk 209 is adapted to engage a valving mechanism built into the syrup package in a manner to be described more fully below.
The base 201 also receives a pneumatic actuator 211 which includes a cylinder assembly 213 having an inlet 215 for receiving carbon dioxide to actuate it, a piston 217 which is inserted into the cylinder 213, a slide member 315 for operating the rotatable disk 209 and a biasing return spring 221. In a preferred embodiment a second inlet 216 in cylinder 213 via tube 310 may be used in addition to or in place of spring 221 to return the piston to the unoperated position. Also forming part of this actuating mechanism is an actuator for opening the carbonator valving mechanism described in connection with FIGS. 6-8. This includes a cradle 223 of molded plastic and an insert 225 which forms the carbonated water outlet (i.e., a spout). The cradle and insert engage with the shuttle member 121 of FIGS. 6-8 in a manner to be described more fully below. The cradle 223 is coupled to the slide member 315 by a pin 317 which is inserted into slot 319 formed in cradle 223 such that the carbonator water valve is operated at the same time as the disk 209 is operated to open the valve in the syrup package so that carbonated water and syrup are simultaneously dispensed.
Also illustrated is a spool valve 231 and an actuating mechanism 233 for the spool valve. Actuating mechanism 233 comprises a hinged arm which acts against the stem 235 on the spool valve to cause carbon dioxide supplied over a line 309 to the valve to be coupled over a line 311 to the inlet 215 of the cylinder 213 to operate the actuating mechanism. The pneumatic actuator 211, rotatable disk 209, and cradle 223 are retained in position by a cover 247 which is placed over the base 201. The base 201 is formed with clips 243 molded into it so that the cover 247 will snap into place retaining the various parts in their proper places. Alternately, the base 201 and cover 247 may be fastened together with screw fasteners. An additional bottom cover 245 may also provided for decorative and sanitary purposes.
FIG. 10 is a partially cut-away plan view of the dispenser assembly. At the left of the Figure, the alignment pin 35 is visible as is the fitting 55 with O-ring 57. As illustrated, this fitting 55 is threaded into a portion 301 formed in the base. Coupled to the end of fitting 55 is a supply line 303 which extends to a T-fitting 305. Gas from the cylinder 17 is supplied to the T-fitting over line 307. The second branch 309 of the T-fitting goes to the spool valve 231, the outlet of which, via line 311, is coupled to the inlet of the cylinder 213. A piston rod 313 which forms a portion of piston 217 is visible in this figure.
Referring to FIG. 12, which is an exploded view of the actuator arrangement. The actuator 233 which acts against the stem 235 of the spool valve 231 is shown as are the tubes 309, 310 and 311; tubes 310 and 311 connecting to the cylinder 213. As illustrated, the piston rod 313 is coupled to a slide member 315. The slide member 315 has a downwardly extending pin 317 which engages a slot 319 in cradle 223. Cradle 223 also contains a slot 321 in its bottom, better seen in the bottom view of FIG. 13. The slot 321 is also visible in FIG. 11, which is a cross section through the dispensing unit including cradle 223. As illustrated, slot 321 is placed over a rail 325 and rides thereon. At each end of slot 321 are opposed half cylindrical parts 323 which engage rail 325 to guide cradle 223 and reduce friction.
At the end of the slide member 315 is a cross-shaped projection 327 over which spring 221 fits. As can be seen from FIG. 10, spring 221 abuts against a wall 331. It biases the slide member 315 to the right thereby biasing the piston within cylinder 213 in the same direction. It also biases the cradle 223 by means of pin 317 and slot 319 to the closed position shown in FIG. 10. In addition to or in place of spring 221, a second inlet 216 in cylinder 213 may be provided. The inlet 216 is supplied with gas from cylinder 17 via tube 310 when spool valve 231 is not being actuated. The gas is supplied to the side of piston 217 opposite to the side supplied by inlet 215 and tube 311 so that member 315 and cradle 223 will be moved into the unoperated position.
As illustrated by FIG. 12, insert 225 is inserted into a recess formed for that purpose in cradle 223. The recess includes a horizontally extending portion 333 and a portion 355 angled downwardly. This forms the dispensing spout for the carbonated water and directs the carbonated water stream into a cup which is placed directly below the annular base 205 seen in FIG. 9. Positioning of the spout, i.e., its downward angle and relationship to the side of the cup are important for good mixing and CO 2 retention. The edge of portion 355 is visible in FIG. 10 within the annular ring 209.
In the cross-sectional view of FIG. 11, the manner in which the tubular member 225 rests within the cradle 223 is illustrated. In this cross section, the pin 317 within slot 319 is also visible.
The rotatable disk 209 contains a slot 351 which is adapted to engage a tab on the cap of the syrup package. The body of the syrup package contains another tab which engages with the cover portion 247. (This is described in more detail below). When a glass to be filled is lifted up against the actuator 233 of FIG. 12 and also seen in FIG. 14, it presses against the stem 235 operating valve 231 to admit gas to the cylinder 213. The gas in cylinder 213 moves the piston 217 which cooperates with piston rod 313 to move the slide member 315 to the left, causing a rotation of the annular ring 209 thereby starting to open the valve in the syrup package. Once the pin 317 reaches the other end of the slot 319, it also begins to move the cradle 223. The end of the tubular insert 225 prior to movement is sealingly abutting against the shuttle member 121. Thus, when the cradle 223 begins to move, the tubular insert 225 forces shuttle member 121 to moved inwardly to bring the inlet 123 of shuttle member 121 beneath the outlet 137 to cause a flow of carbonated water through the tubular rubber insert 225. Tubular insert 225 creates a seal with the shuttle outlet 125 to prevent leakage (see FIGS. 6, 7, 8). When the pressure on the actuator 233 is released, the force of the biasing spring 221 moves the slide member 315 to the right, the gas in the cylinder 213 now being vented. As noted above this return can also be done pneumatically or with air pressure instead of or in addition to the spring. This begins immediately to close the valve in the package by rotating the annular ring 209 and as the pin 317 reaches the right hand side of the slot 319, returns the cradle 223 to the position shown in FIG. 10. The end of the rubber insert 225 and its location with respect to the point where the carbonator is inserted is visible in FIG. 3.
FIGS. 14 and 15 show some additional details of the actuator mechanism and the carbonator locking assembly. The arm 69 and cylindrical member 71 are visible as is the cam 75 and the cam slot 77. As illustrated, a central shaft 73 is supported in a bearing formed within a downwardly extending cylindrical member 361 having an appropriate bore therethrough to permit rotation therein. Mounted to the top of the shaft 73 is the stop member 79. Member 79 moves up through the opening 81 so as to lock against the carbonator when the handle 69 is rotated to lock the carbonator in place. Also shown is the alignment pin 35 and the fitting 55 with its O-ring 57. As illustrated, the alignment pin can have a head 363 and be inserted through wall 365 and held in place with a spring clip retainer 367. Also visible in the view of FIG. 15 is the end of the tubular insert 225 which abuts against and seals to the end of shuttle member 121 in the carbonator connecting assembly 33 and acts to open shuttle member 121 therein in the manner described above.
FIGS. 16-18 illustrate the syrup package of the present invention. In the illustrated embodiment the syrup package comprises three molded parts. The first of these is a body or container having a bottom, side walls and a top with a neck 403. At the base of a neck is a tab 405. The second part is an insert 407. The insert comprises a compensating chamber 409, at the top of which there is formed a cylindrical portion 410 which, as can be seen from the cross section of FIG. 18, forms a recess 411. Inside the recess is a conical plug 412 having an arrowhead cross section. Extending from this cylindrical portion is a downwardly conically extending portion 413 and then a another conical portion 415 extending slightly outwardly. Following this is another conical portion 417, but now extending inwardly and forming a baffle. This rests on a plurality of legs 419, which extend down to a portion of annular shape 421 having a U-shaped cross section. Within this portion 421 there is, thus, formed an annular recess 423. As illustrated by the cross section of FIG. 18, the annular cavity 423 receives the neck 403 of the container 401. On the outside wall of portion 421 are formed three projections 425. There is also provided an axially upwardly projecting part 427 on the end of which there is a tab 424 projecting radially outwardly. During assembly, the tab 424 of portion 421 is brought into abutment with the tab 405 at the base of the neck 403 and the two parts fastened together by gluing, welding, mechanical locking, etc.
The final part of the syrup package is a cap-like member 431, having an air inlet tube 433 extending upwardly therefrom. The air inlet tube terminates in a conical portion 435 at the top 437 of the cap 431. In the closed position shown, the top of the tube 433 seals externally against the recess 411 and internally against the arrowshaped conical plug 412 at the top of the compensating chamber 409. Formed in the cap 431 are three cam slots 439. These engage with the projections 425 on portion 421. Also formed in the cap 431 is a tab 441.
As previously discussed, the tab 441 will engage in the slot 351 in the annular ring 209 shown in FIGS. 10 and 12 for example. The tabs 405 and 429 will engage in an appropriate slot 352 in the cover 247 shown in FIG. 9 so that the container is held fixed while the cap 431 can rotate. As the cap 431 rotates, the tube 433 is moved away from the recess 411 and the arrowshaped conical plug 412 to permit a flow of air into the container. At the same time, the cap 431 is moved away from the insert 407 and a seal formed at point 451 between these two members is broken permitting the flow of syrup through an opening 453 in the cap 431. The operation of this type of package is described in detail in my previous application Ser. No. 310,488; and more specifically in Ser. No. 508,559.
Referring to FIGS. 4 and 5, it was noted that there were fittings 111 and 109 which couple, respectively, with a gas outlet 65 of FIG. 4 and a water inlet 67 of FIG. 4. As described in connection with FIG. 5, these two fittings pass through openings 107 and 105 in the stainless steel carbonator tank 103. FIG. 19 is an exploded view of the assembly within the carbonator with which these two fittings 111 and 109 mate. FIGS. 19A and 19B are plan and elevation views of this assembly. The gas inlet 109 is coupled to a fitting 501 which is in the nature of an elbow fitting. The carbon dioxide is coupled through an outlet 503 therefrom into a tubular member 505 mounted to a cylindrical flange 507 on a base member 509. Contained within the base portion of the tubular member 505 is a slow-feed valve of the type described in U.S. application Ser. No. 550,455. A cover 511 is placed over and sealed to the base 509. Gas flows between the base and cover and out through two diffusers 513 and 515. The diffusers are held in place by gasketed bolts 517 which thread into threaded bosses 519 formed in the base 509 with gaskets 521 interposed between the diffusers 513 and 515 and the cover 511 which has provided therein openings 523 for that purpose. The bolts 517 are provided with gaskets 518 to ensure that no gas leaks around the bolts. The diffusers are disclosed in more detail in application Ser. No. 393,299.
The carbonated water within the tank flows out through a resin bed assembly 525, the outlet 527 of which is coupled into an anti-surge valve assembly which is inserted into a chamber 647 formed within member 529. Resin bed assembly 525 is shown as having a sealed lid 539 to permit inserting new charges of resin as the old resin is used up. The outlet 639 of the anti-surge valve is positioned adjacent to the inlet 551 (see FIG. 21) of an expansion chamber 533 made up of a top half 535 and a bottom half 537 onto which is also molded the gas inlet fitting 501. Preferably all of these parts are of molded plastic and sealingly assembled to each other in the manner indicated. The expansion chamber 535 terminates in an outlet 541 which couples with the fitting 111 of FIG. 5.
The nature of the parts 535 and 537 can be better seen with reference to FIGS. 20-26. Referring to FIGS. 20 and 24, the general nature of the expansion chamber is seen. It has a generally spiral shape beginning at an inlet 551. The chamber gradually expands in size as it spirals around, finally reaching the outlet 541. In the cross section of FIG. 21, the inlet 551 is seen which then expands to the size 553 after 180 degrees, to size 555 after another 180 degrees, and to size 557 after another 180 degrees, which is the size being closest to the size at the outlet 541.
The cross section of FIG. 22 shows the outlet fitting 541 and outlet bore 559 and also portions 561 and 563 of the expanding chamber. Each of FIGS. 21 and 22 also shows the member 529 which forms the chamber 647 into which the anti-surge valve, to be described below in connection with FIG. 29, is inserted. FIGS. 20, 23 and 24 also show the construction of the inlet 501 for gas. Gas flowing into the inlet 501, i.e., into its bore 567 which is closed off on the opposite side by a disk 569, seen in FIG. 20, then flows through a hole 571 into the outlet fitting 503 and then into the tubular member 505 described above. Incoming gas flows through the passage 601 in tubular member 505 seen in FIG. 25. At the base of member 505 the slow-feed or two-speed feed valve assembly 603 is installed. Gas flows out of the bottom of this assembly through openings 605 and 607 into the space between base 509 and lid 511. It flows out of the diffusers 513 and 515 held in place by gasketed screws 517 with gaskets 521 interposed between the cover 511 and the diffusers 513 and 515 seen in FIG. 19. In the cross section of FIG. 27, the inlet 611 in the resin bed can be seen along with a further view of the diffuser assembly. Another view showing the diffuser assembly and the resin bed container 525 is shown in FIG. 26. Referring to FIG. 28, the resin bed assembly 525 can be seen in more detail. Inserted sealingly within the resin bed assembly is a cartridge 613 containing beads of resin for filtering and deionizing the water. Water flows through the resin bed 613 to the top thereof and then out of an outlet passage 615. This passage extends radially to an axial passage 616 in a base portion 617 of the member 529 which contains the anti-surge valve sealingly inserted therein. Member 529 in turn is attached to part 537 in the manner described above.
The anti-surge valve itself is illustrated in FIG. 29. It includes a main body member 621. Retained within the body 621 is a valve member 623, which is biased downwardly by a spring 625. An insert 627 inserted into the open end 629 of the body 621 acts as a stop limiting the axial motion of the valve member 623. Extending axially inwardly from this cover 627 are a plurality of legs 631 on the ends of which is formed an annular valve seat 633. Valve seat 633 mates with a sealing ring 635 of triangular cross section formed on the valve member 623. The base of valve member 623 in the center of the sealing ring 635 contains a bore 637. The axial inner end of the body 621 contains a bore 639. An O-ring seal 641 is provided between the valve member 623 and the body 621. A further O-ring seal 643 is provided at the axial inner end of the body 621 and, referring to FIG. 21, seals the body to the wall of the chamber 647 formed by the member 529.
When the anti-surge valve of FIG. 29 is inserted into the chamber 647, the bore 639 is aligned with the inlet of opening 551, these two elements being of essentially the same diameter so that there is a smooth flow therebetween to avoid loss of carbonation. The purpose of the anti-surge valve is to prevent surging and spitting when the carbonated water valve (i.e., the shuttle valve assembly) is first opened. The pressure within the carbonator is, for example, 50 psi. This pressure is reduced to atmosphere by the time the carbonated water is discharged from the outlet spout. It is the purpose of the spiral expansion chamber to gradually expand the water flow to gradually reduce this pressure so that a gradual reduction takes place without the loss of carbonation. In addition, a smooth flow is assured since sharp edges will break loose the carbon dioxide bubbles, as will any turbulence. However, when the shuttle valve assembly is closed, in the absence of an anti-surge valve, pressure builds up within the expansion chamber. The anti-surge valve prevents excessive pressure build up by closing when the sum of the pressure in the expansion chamber and the pressure of the biasing spring, typically 30 psi, equals the pressure inside the carbonator. In this manner, a reduced pressure, e.g., 20 psi, is maintained in the expansion chamber and surge problems are reduced. Once sufficient pressure builds up in the expansion chamber, that pressure plus the spring pressure pushes the valve member 623 downward such that the ring seal 635 seats against the valve seal 633, preventing further pressure build up. Once the shuttle valve assembly is opened, the pressure within the expansion chamber and hence above valve member 623 reduces allowing the pressure in the carbonator to move valve 623 off its seat and flow begins to occur through outlets 637 and 639. Water then flows through the inlet 551, through the spiral expansion chamber of FIG. 22 to the outlet 541.
FIGS. 30-32 illustrate the cover assembly for the carbon dioxide cylinder 17 and its connection to a regulator which also acts as a weighing mechanism. Referring to FIG. 30, over the end of the gas cylinder 17 there is placed first an O-ring seal 701, then a member 703 which has an inner washer-like portion shown as 802 in FIG. 31 overlying the neck section 704 of cylinder 17, and is held in place by a flange 705A on threaded fitting 705, threaded into the threads 707 within the neck section of the cylinder 17. The fitting 705 contains a check valve, shown schematically a 800 in FIG. 31, which is operated when an appropriately sized pin or probe, shown schematically as 801, is inserted into its opening 709. Member 703 contains a central cylindrical portion 711 with two arms 713 at the ends of which rings 715 are formed as finger grips. As best seen from FIG. 32, on the inside of the cylindrical portion 711 are formed two diametrically opposed axially extending slots 719 which lead from edge 711A to horizontal circumferentially extending locking slots 720. These are also shown in FIG. 31. A cover 23 is snapped over the member 703 to give the cylinder the finished appearance illustrated in FIG. 1. The cover is shaped so as to enclose the top of the cylinder and the member 703 and includes side parts 721 with openings 723 which align with the openings 715. These openings permit a finger grip for ease in handling of the cylinder. The cover 23 contains a tear-away top portion 725 with a tab 727 provided to tear off the cover to permit ease of access to the fitting 705.
The handles 713 and 721 also act as an alignment means. As can be seen from FIG. 32, the axial slots 719 are aligned with the handle 721. Thus, when inserting these on a regulator assembly 729 which has a mating fitting 731 with projections 733 thereon, for engaging in the slots 719 and 720, the handles can be used for alignment purposes. The user simply lines up the handles with the pins 733 and then rotates the handles 721 until they are in a predetermined position in which the cylinder is locked in place against the fitting 731. The fitting 731 includes the hollow probe 801 schematically shown in FIG. 31 which fits into and seals within the opening 709 and opens the valve 200 therein to permit the flow of carbon dioxide through the regulator and into the rest of the system. However, the probe is much thinner than previously employed to permit manual connection of the cylinder 17 to the fitting 731.
The regulator 729 is also shown in FIG. 33 which is an exploded view of the regulator and weighing assembly. The fitting 731 of the regulator 729 with its pins 733 is visible at the bottom of the Figure. A shaft 735 extends out from both ends of the regulator. Shaft 735 on the left hand side contains a flat 737. A member 739 to be described in more detail below is placed over this end of the shaft 735. The whole assembly, generally indicated as 740 is inserted into a hood 741 containing holes 743 on each side thereof for accepting the shaft 735. The shaft 735 is held in place in a cylindrical recess of a collar 745 attached to the regulator 729 by means of a cotter pin 747. Thus, after the regulator 729 is inserted in the hood 741, the cylindrical recess of collar 745 is aligned with holes 743 and shaft 735 is inserted through holes 743 and the recess of collar 745. The shaft is then secured in place to collar 745 with cotter pin 747. Thereafter the member 739 can be placed over the end of the shaft 735. The hood 741 has a brim 749 containing thereon indicia 751 and 753 along with arrows 755. The indicia indicate to the user the proper alignment for the handles 721 in the position where the bottle is inserted and the position where it is locked in place. The hood 741 is held by an assembly 757. This includes a U-shaped bracket 759 having holes 761 in its base for mounting to the machine. Extending through the two legs of this U-shaped bracket 759 is a shaft 763. At each end of the shaft is a spring 765. This is a coil spring containing arms 767 and 769 each of which are bent at their ends so as to have a portion parallel to the axis of the spring. The arm 767 contains an axially extending portion 771. Portion 771 engages in one of a plurality of holes 775 in the arm of the bracket 759. The bracket 759 encloses the rear portion of the hood 741 with the shaft 763 extending through the opening 777. The inwardly extending portion 773 of spring arm 769 engages in holes 779. Thus, hood 741 rotates on shaft 763 and is biased upwardly by spring 765.
FIGS. 34 and 35 illustrate manner in which the weighing mechanism operates. The previously mentioned member 739 comprises a planar member containing an arcuate slot 781 therein. The slot 781 slidably engages a pin 782 provided on the inside of one of the walls of the cylinder compartment adjacent to the planar member. Its purpose is to maintain the axis of the fitting 731 vertical irrespective of the rotation of the hood 741. FIG. 34 shows the hood 741 rotated upwardly, corresponding to an empty bottle or no bottle in place. FIG. 35 illustrates the hood 741 rotated downwardly with a full bottle in place. It will be recognized, that the locus of shaft 735 moving between the positions of FIGS. 34 and 35 will exhibit curved motion and, were it not for the slot 781 and pin 782 and the rigid connection of the member 739 to the shaft 735, which in turn is rigidly connected to the regulator 729 and thus to the fitting 731, rotation of the regulator 729 and fitting 731 would take place. It is important that the axis of the fitting 731 be maintained vertical so that CO 2 bottles can be easily removed and inserted. The springs 765, thus, tend to bias the cover 741 upwardly into the position shown in FIG. 34. The weight of a full CO 2 cylinder acts against this biasing action to bring the cover downward to the position shown in FIG. 35.
The member 739 performs a second function, the function of an indicator. At the bottom of the member 739 are painted two areas 783 and 785. Area 783 is painted green, for example, and area 785 is painted red. A viewing window 787 is provided in the drink dispenser housing through which the painted areas 783 and 785 can be observed. With a full bottle, one looks through the viewing window 787 and sees the green area 783. As the bottle begins to empty, the red area 785 begins to appear until, when all red, the bottle is essentially empty. Preferably, the biasing force of the springs 765 is such that they operate only over the last ten percent of carbon dioxide in the bottle. That is to say, only when the bottle is, for example, 10 percent full will the bottle become light enough so that the spring begins to move the cover 741 upwardly. This gives a better indication at the end of supply than would a linear system which would be difficult to calibrate. The biasing force of the spring 765 may be changed as needed based on the users selection of the various holes 775 in bracket 759.
FIGS. 36 and 37a-c illustrate one means of maintaining a tangential relationship between the inside of the glass and the dispensing spout. Such a tangential relationship is desirable so that the carbonated water swirls around the glass in such a way as to mix the water and syrup but in such a way as to not lose its carbonation. Without such control, if, for example, the stream of water impinges directly on an opposing wall of the cup, this will cause a breakup of the bubbles of carbon dioxide and a loss of carbon dioxide and the drink will not taste as it should. Thus, there is provided a surface 801 with a compound curve. This is above the drip tray 803 in the area below the dispense head. The glass is lifted up and guided along the compound curve until it touches the actuator 233 causing actuation in the manner described above and a flow of water from the spout 225. As illustrated in FIG. 37, because of the compound curve, irrespective of the cup size, a flow of water that is more or less tangential to the inside surface of the cup will occur.
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A post mix in-home carbonated drink dispenser has a novel expansion chamber and an anti-surge valve. The expansion chamber is a gradually expanding chamber which reduces carbonation loss as the carbonated liquid passes from the carbonator to the point where the liquid is discharged. The anti-surge valve, which is provided between the carbonator and the expansion chamber is designed to reduce the spitting and sputtering often experienced on start-up of a drink dispenser. The dispensing valve for carbonated water is part of the carbonator and not the dispensing head. This means that no carbonated water exists outside the carbonator. In addition, the dispenser is provided with a thin gas cylinder connecting probe which provides for a simple and easy to use CO 2 cylinder connection.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to and the benefit of Korean Patent Application Nos. 2005-119530, filed Dec. 8, 2005, and 2006-74089, filed Aug. 7, 2006, the disclosures of which are incorporated herein by reference in their entirety.
BACKGROUND
1. Field of the Invention
The present invention relates to a multimode frequency synthesizer using a phase-locked loop (PLL) that can be installed in 802.11 b/g HYPERLAN (HIgh PErformance Radio LAN), Dedicated Short Range Communications (DSRC), 802.11 a, and Ultra Wide Band (UWB) systems having applications in a 2˜9 GHz frequency band.
2. Discussion of Related Art
Recently, as mobile communication services are becoming increasingly widespread, available frequency bands are becoming saturated, and several terminals are required to enjoy various mobile communication services. As a result, developers all over the world are working on a reconfigurable mobile communication system capable of reconfiguring mobile communication services in software and enabling access to various mobile communication services using one terminal regardless of encoding and decoding method. To access necessary services using one terminal regardless of time and place, a wide-band Radio Frequency (RF) transceiver of a mobile communication system is required.
To manufacture the multiband multimode RF transceiver, a wide-band Local Oscillator (LO) are required. FIG. 8 illustrates a conventional wide-band frequency synthesizer including a phase frequency detector 20 , a charge pump 30 , a low pass filter 40 , a voltage-controlled oscillator 50 , and a variable frequency divider 70 .
To satisfy requirements that vary depending on field of application when the frequency synthesizer for multiband multimode is manufactured, there should be a certain amount of flexibility in selecting components of the frequency synthesizer. However, use of a voltage-controlled oscillator, a high speed prescaler, a charge pump, and a loop filter diminishes flexibility in the construction of the frequency synthesizer. Therefore, a plurality of voltage-controlled oscillators and phase-locked loop (PLL) loops are used to manufacture the multiband frequency synthesizer. However, using a plurality of voltage-controlled oscillators and PLL loops results in increased chip size and power consumption.
SUMMARY OF THE INVENTION
The present invention is directed to a multiband multimode frequency synthesizer generating a wide-band (e.g., from 2 GHz to 9 GHz) frequency.
The present invention is also directed to a multiband wide-band frequency synthesizer capable of reducing an occupied area and electric power consumption by using a multimode prescaler.
The present invention is also directed to a wide-band frequency synthesizer with low noise using an inductor-switching voltage-controlled oscillator.
One aspect of the present invention provides a variable frequency divider for dividing an externally applied oscillation signal by a designated integer value and outputting the divided signal as a feedback signal, the variable frequency divider comprising: a prescaler for selecting one of a plurality of dual divisor value sets according to an external frequency selection signal; a main counter for counting the number of output pulses of the prescaler; and a swallow counter for designating an interval divided by a specific divisor value of the dual divisor value sets.
Another aspect of the present invention provides a frequency synthesizer including: a frequency/phase detector for comparing a frequency and phase of a reference high-frequency signal with a frequency and phase of a feedback high-frequency signal; a charge pump for producing an output current corresponding to the result of the comparison performed by the frequency/phase detector; a loop filter for producing an output voltage corresponding to an accumulated value of the output current of the charge pump; a voltage-controlled oscillator for generating an oscillation signal having a frequency corresponding to the output voltage of the loop filter; and a variable frequency divider for dividing an output signal of the voltage-controlled oscillator by a designated integer value, and outputting the result as a feedback signal, wherein at lease two of an amount of unit pumping charges of the charge pump, an RLC value of the loop filter, an RLC value of the voltage-controlled oscillator, and a divisor value of the variable frequency divider are controlled according to a band.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features and advantages of the present invention will become more apparent to those of ordinary skill in the art by describing in detail preferred embodiments thereof with reference to the attached drawings in which:
FIG. 1 illustrates frequency band allocation for 802.11b/g, HYPERLAN (HIgh PErformance Radio LAN), Dedicated Short Range Communications (DSRC), 802.11a, and Ultra Wide Band (UWB);
FIG. 2 is a block diagram of a wide-band multimode frequency synthesizer according to an exemplary embodiment of the present invention;
FIG. 3 is a circuit diagram of a multimode prescaler illustrated in FIG. 2 according to an exemplary embodiment of the present invention;
FIG. 4 is a circuit diagram of a mode controller illustrated in FIG. 3 according to an exemplary embodiment of the present invention;
FIG. 5 is a circuit diagram of a charge pump illustrated in FIG. 1 according to an exemplary embodiment of the present invention;
FIG. 6 is a circuit diagram of an adaptive loop filter illustrated in FIG. 1 according to an exemplary embodiment of the present invention;
FIG. 7 is a circuit diagram of a wide-band LC tuning voltage-controlled oscillator having a switching function illustrated in FIG. 1 according to an exemplary embodiment of the present invention; and
FIG. 8 is a block diagram of a conventional frequency synthesizer.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
Hereinafter, exemplary embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various forms. Therefore, the following embodiments are described in order for this disclosure to be complete and fully enabling of practice of the present invention by those of ordinary skill in the art.
A frequency synthesizer illustrated in FIG. 2 includes a frequency/phase detector for comparing the frequency and phase of a reference high-frequency signal with the frequency and phase of a feedback high-frequency signal; a charge pump 400 for producing a current corresponding to the result of the comparison by the frequency/phase detector; a loop filter 500 for producing a voltage corresponding to an accumulated value of the output current of the charge pump; a voltage-controlled oscillator 200 for generating an oscillation signal having a frequency corresponding to the output voltage of the loop filter 500 ; and a variable frequency divider 300 for dividing the output signal of the voltage-controlled oscillator 200 by a designated integer value to output the divided signal as a feedback signal.
Here, the variable frequency divider 300 includes a prescaler 301 for selecting one of a plurality of dual divisor value sets, a main counter 307 for counting the number of output pulses of the prescaler 301 , and a swallow counter 308 for designating an interval divided by a specific divisor value of the dual divisor value sets.
Meanwhile, when a system including the frequency synthesizer requires a divide-by-2 tuning clock in addition to a main tuning clock corresponding to a channel to be tuned, a 2-frequency divider 204 may be further included as illustrated.
As illustrated in FIG. 1 , a 802.11b/g system uses a frequency range of 2.7 GHz to 2.8 GHz, a HYPERLAN system uses a frequency range of 5.1 GHz to 5.3 GHz, a DSRC system uses a frequency range of 5.4 GHz to 5.5 GHz, a 802.11a system uses a frequency range of 5.5 GHz to 5.7 GHz, and a UWB system uses a frequency range of 3.2 GHz to 8.9 GHz.
A wide-band multimode frequency synthesizer on which a multimode prescaler is mounted as illustrated in FIG. 2 may be used for 802.11 b/g, HYPERLAN, DSRC, 802.11 a, and UWB systems according to a mode selection bit. A terminal having the wide-band frequency synthesizer of the present embodiment may select a desired frequency band for reception and transmission by adjusting the mode selection bit. Generally, the selection of the frequency band corresponds to selection of a communication method type, for example, selecting one of wireless LAN or Digital Multimedia Broadcasting (DMB).
The wide-band frequency synthesizer of FIG. 2 includes a phase frequency detector/switching charge pump 400 , an adaptive loop filter 500 , a wide-band LC tuning voltage-controlled oscillator 200 that can be switched, and a multimode variable frequency divider 300 in which a multimode prescaler is included. Also, it may further include an input buffer 202 for buffering a reference clock having a different frequency for each frequency band and/or an output buffer for buffering a clock output from the voltage-controlled oscillator 200 .
The multimode variable frequency divider 300 that divides an externally applied oscillation signal by the designated integer value to output the result as a feedback signal includes a prescaler 301 for selecting one of a plurality of dual divisor value sets corresponding to a band selected according to an external frequency band selection signal, a main counter for counting the number of output pulses of the prescaler 307 , and a swallow counter 308 for designating an interval divided by a specific divisor value of the dual divisor value sets.
The multimode prescaler 301 divides an output signal of the voltage-controlled oscillator 200 into a frequency corresponding to f pre of FIG. 2 . The multimode prescaler 301 divides the output signal of the voltage-controlled oscillator 200 by ⅔, ⅘, 8/9 and 16/17 according to the mode selection bit, which is an externally applied control signal. According to the mode selection bit, the oscillation frequency of the voltage-controlled oscillator 200 , a value of the loop filter 500 of FIG. 2 , the amount of current of the charge pump 400 may be appropriately selected based on an application frequency band (802.11b/g, HYPERLAN, DSRC, 802.11a, and UWB) of FIG. 1 .
The swallow counter 308 and the main counter 307 control the count according to setting bits C 1 to C 5 . The oscillation frequency may be roughly or finely controlled according to the setting bits C 1 to C 5 and the mode selection bit.
That is, one of the illustrated four dual divisor value sets is selected by the mode selection bit, for example, when a second dual divisor value set (Prsc 2 ) is selected. The main counter 307 counts the output signal f pre of the prescaler 301 tip to the number set by the setting bits C 1 to C 5 , and the swallow counter 308 is set to count to a smaller number than the main counter 307 by the setting bits C 1 to C 5 .
In the beginning, a signal output from the voltage-controlled oscillator 200 and divided-by-5 according to the second dual divisor value set Prsc 2 is output from the prescaler 301 . When the swallow counter finishes counting while the swallow counter and the main counter count the signal divided-by-5, a signal MC is input to the prescaler 301 . The prescaler that receives the signal MC changes the divisor value into 4 and the main counter continues counting the remaining signals divided-by-4. Accordingly, the output signals f div of the main counter 307 may be result values divided by various divisor values according to a fixed output of the voltage-controlled oscillator.
FIG. 3 illustrates a high-speed multimode prescaler 301 used for the wide-band frequency synthesizer of FIG. 2 according to the exemplary embodiment of the present invention. The illustrated multimode prescaler 301 includes two current-mode mode logic (CML) D flip-flops 320 and 330 , three D flip-flops 340 , 350 and 360 , a mode controller 310 , a selector 380 , and a differential-to-single ended signal converter 370 .
A multi-stage cascade-connected flip-flop comprises the three D flip-flops 340 , 350 and 360 and a CML D flip-flop 330 among the components so that an initial stage receives the oscillation signal and counts to a multiple of 2. In addition, an additional flip-flop comprises another CML D flip-flop 320 so that the additional flip-flop receives the oscillation signal and supports a dual counting mode. The selector 380 selects one of output signals of the flip-flop output stages of the multi-stage cascade-connected flip-flop and outputs the selected signal, and the mode controller 310 controls operation of the additional flip-flop according to the output signal of the swallow counter.
The CML D flip-flops 320 and 330 , which are high-speed frequency dividers for diving high output signals of the voltage-controlled oscillator 200 , include AND logic or OR logic. The three D flip-flops 340 , 350 and 360 , which are frequency dividers for dividing a frequency divided by the CML D flip-flops 320 and 330 into a lower frequency, may be implemented as static logic or CML. The signal converter 370 is a circuit for converting a differential signal into a single signal. The selector 380 is implemented as a four-to-one multiplexer that selects one of signals f d1 , f d2 , f d3 and f d4 divided according to the mode selection bits S 1 and S 2 and outputs the selected signal as f pre . The mode controller 310 of FIG. 3 receives an output signal f d2 of the D flip-flop 1 340 , an output signal f d3 of the D flip-flop 2 350 and an output signal f d4 of the D flip-flop 3 360 , and generates an output signal MO according to a mode control input signal MC and mode control bits S 1 and S 0 of FIG. 3 . According to the output signal MO, one of the operation modes of the multimode prescaler 301 —divide-by-⅔, ⅘, 8/9 and 16/17—is selected.
The mode control input signal MC is a setting signal generated by the swallow counter 308 of FIG. 2 , and the output signal MO of the mode controller 310 is input to the CML D flip-flop 320 of FIG. 3 . When the mode control bits are S 1 /S 2 =0/0, the prescaler 301 of FIG. 3 performs a divide-by-⅔ operation, when the mode control bits are S 1 /S 2 =0/1, the prescaler performs a divide-by-⅘ operation, when the mode control bits are S 1 /S 2 =1/0, the prescaler performs a divide-by- 8/9 operation, and when the mode control bits are S 1 /S 2 =1/1, the prescaler performs a divide-by- 16/17 operation.
FIG. 4 illustrates the mode controller 310 of FIG. 3 according to an exemplary embodiment of the present invention. Referring to FIG. 4 , the mode controller 310 includes three two-to-one multiplexers 312 , 314 and 316 , and four OR gates 311 , 313 , 315 and 317 . The mode controller 310 applies a result value obtained by performing OR and MUX operations on a plurality of signals generated by the multi-stage cascade-connected flip-flop 330 , 340 , 350 and 360 and the output signal MC of the swallow counter 308 , to the flip-flop 320 as a control signal.
In FIG. 4 , an output signal of the D flip-flop 1 340 of FIG. 3 is input to an input port C 0 of FIG. 4 , an output signal of the D flip-flop 2 350 of FIG. 3 is input to an input port C 1 , and an output signal of the D flip-flop 3 360 of FIG. 3 is input to an input port C 2 . The mode control signals S 1 and S 0 are input to selection terminals s 1 of illustrated multiplexers 312 , 314 and 316 .
In the multiplexers 312 , 314 and 316 , when the selection terminals s 1 are high, input terminals I 1 of the multiplexers 312 , 314 and 316 are selected, and when the selection terminals s 1 are low, input terminals I 0 of the multiplexers 312 , 314 and 316 are selected. Describing operations of the mode controller 310 in more detail, when the mode control signal is S 1 /S 0 =0/0, the multiplexer 1 312 selects the input terminal I 0 . Therefore, after the setting signal of the swallow counter 308 of FIG. 2 is output at the output terminal MO through the input terminal MC, the setting signal is input to an input terminal B of the CML D flip-flop 1 320 of FIG. 3 . As a result, the prescaler 301 finally performs the divide-by-⅔ operation.
Based on the above description, when the mode control signals are S 1 /S 0 =0/1, the multiplexer 312 selects the input terminal I 1 and the multiplexer 2 314 selects the input terminal I 0 . Therefore, a signal formed by combining the setting signal of the swallow counter 308 of FIG. 2 and the signal f d2 input through the input terminal C 0 of FIG. 4 at OR 1 313 of FIG. 4 is output at the output terminal MO and input to the input terminal B of the CML_D flip-flop 1 320 of FIG. 3 so that the prescaler 301 performs a divide-by-⅘ operation.
In addition, when the mode control signal is S 1 /S 0 =1/0, the multiplexer 1 312 of FIG. 4 selects the input terminal I 1 , the multiplexer 2 314 selects the input terminal I 1 , and the multiplexer 3 316 selects the input terminal I 0 . Therefore, after a signal formed by combining, at OR 2 315 of FIG. 4 through OR 1 313 of FIG. 4 , the setting signal of the swallow counter 308 of FIG. 2 , the signal f d2 input through the input terminal C 0 of FIG. 4 , and the signal f d3 input through the input terminal C 1 of FIG. 4 , is output at the output terminal MO of FIG. 4 and input to the input terminal B of the CML_D flip-flop 1 320 of FIG. 3 so that the prescaler 301 performs a divide-by- 8/9 operation.
Further, when the mode control signal is S 1 /S 0 =1/1, the multiplexer 1 312 of FIG. 4 selects the input terminal I 1 , the multiplexer 2 314 selects the input terminal I 1 , and the multiplexer 3 316 selects the input terminal I 1 . Therefore, after a signal formed by combining, at OR 1 313 of FIG. 4 through OR 2 315 of FIG. 4 , the setting signal of the swallow counter 308 of FIG. 2 , the signal f d2 input through the input terminal C 0 of FIG. 4 , the signal f d3 input through the input terminal C 1 of FIG. 4 , and the signal f d4 input through the input terminal C 2 of FIG. 4 , is output at the output terminal MO of FIG. 4 and input to the input terminal B of the CML_D flip-flop 1 320 of FIG. 3 so that the prescaler 301 performs a divide-by- 16/17 operation. According to the present invention, the division ratio of the multimode prescaler 301 of FIG. 3 may be extended to 32/33, 64/65, 128/129, etc.
The phase frequency detector/switching charge pump 400 of FIG. 2 consist of a phase frequency detector and a charge pump, and FIG. 5 illustrates an embodiment of the charge pump. The illustrated charge pump 420 has a structure that can switch current according to a corresponding mode in FIG. 2 . In the charge pump 420 of FIG. 5 , V 0 , V 1 , V 2 and V 3 are switches that are turned on or off according to the mode control signals S 1 and S 0 and control current of the charge pump 420 . In the charge pump 420 , four current sources I 0 , I 1 , I 2 and I 3 that constitute a plus current source block 423 have different sizes from four current sources I 0 , I 1 , I 2 and I 3 that constitute a minus current source block 424 , and current from both sets of current sources is output or intercepted according to the on/off status of the switches V 0 to V 3 . Up and Dn signals of FIG. 5 are generated at the phase frequency detector (not shown).
FIG. 6 illustrates a loop filter 500 of FIG. 2 . The loop filter 500 is a second order low-pass filter having a loop filter value set appropriately for a desired application band based on the on/off status of the switches V 0 to V 3 of FIG. 2 according to the mode control signals S 1 and S 0 . In FIG. 2 , capacitors C 0 to C 3 for storing electricity, resistors R 0 to R 3 for filtering, and capacitors C 02 , C 12 , C 22 and C 32 for filtering have different values from one another, their values being determined according to the application band of FIG. 1 . The above method is applied to a third or fourth order loop filter.
FIG. 7 illustrates the wide-band LC tuning voltage-controlled oscillator 200 of FIG. 2 according to an exemplary embodiment of the present invention. The voltage-controlled oscillator 200 of FIG. 7 includes an LC tuner comprising two inductors L and four switching inductors, two MOS varactors VR, and eight switching capacitors. The voltage-controlled oscillator 200 turns switches V 0 to V 3 on/off according to a combination of the mode control signals S 1 /S 0 and the setting bits C 1 to C 5 of the program counter 307 of FIG. 2 to thereby generate a desired oscillation frequency and amplitude.
As described above, according to the mode control bit, which is an externally applied control signal, the divisor value of a variable divisor 300 is determined, a pumping charge of the charge pump 40 is determined, an RC integer value among circuit integer values of the loop filter 500 is determined, and an integer value of the oscillation circuit of the voltage-controlled oscillator and/or a current value of a tail current source are determined. Accordingly, even when a width of frequency fluctuation according to change in a frequency band is large, the frequency synthesizer can operate smoothly.
A multiband multimode frequency synthesizer of the present invention generates a multiband frequency that has a bandwidth range from several to several tens of GHz. Also, since a multimode prescaler is embedded in the frequency synthesizer of the present invention, occupied area and power consumption can be reduced.
In addition, the frequency synthesizer of the present invention uses an inductor-switching voltage-controlled oscillator to generate a wide-band oscillation frequency having a low noise characteristic.
Further, the frequency synthesizer of the present invention in which the multimode prescaler is embedded can generate a radio frequency within a band appropriate for a desired application according to a mode control signal.
While the invention has been shown and described with reference to certain exemplary 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.
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A wide-band multimode frequency synthesizer using a Phase Locked Loop (PLL) is provided. The multiband frequency synthesizer includes a multimode prescaler, a phase detector/a charge pump, a swallow type frequency divider, and a switching bank LC tuning voltage-controlled oscillator having wide-band and low phase noise characteristics. The multimode prescaler operates in five modes and divides a signal up to 12 GHz. The wide-band frequency synthesizer can be used in various fields such as WLAN/HYPERLAN/DSRC/UWB systems that operate in the frequency range from 2 GHz to 9 GHz. The wide-band multimode frequency synthesizer includes a frequency/phase detector for comparing a frequency and phase of a reference high-frequency signal with a frequency and phase of a feedback high-frequency signal; a charge pump for producing an output current corresponding to the result of the comparison performed by the frequency/phase detector; a loop filter for producing an output voltage corresponding to an accumulated value of the output current of the charge pump; a voltage-controlled oscillator for generating an oscillation signal having a frequency corresponding to the output voltage of the loop filter; and a variable frequency divider for dividing an output signal of the voltage-controlled oscillator by a designated integer value, and outputting the result as a feedback signal, wherein at lease two of an amount of unit pumping charges of the charge pump, an RLC value of the loop filter, an RLC value of the voltage-controlled oscillator, and a divisor value of the variable frequency divider are controlled according to a band.
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BACKGROUND OF THE INVENTION
The invention relates to a steam iron comprising: a soleplate; a heating element for heating the soleplate; a control circuit for controlling the temperature of the soleplate by activation of the heating element; a steam generator for generating steam, comprising a steam chamber which is thermally coupled to the soleplate, a water reservoir for holding the water to be evaporated, and a supply device for the controlled supply of water to be evaporated to the steam chamber; and means for activating the steam generator.
Such a steam iron is known from the International Publication (PCT) WO 96/23099. In steam irons of this type steam is generated by admitting an amount of water from the water reservoir to the steam chamber, where the water evaporates. The desired amount of steam can be adjusted by the user with the aid of the means for controlling the steam generator. The evaporation of the water in the steam chamber requires energy which is extracted from the soleplate to which the steam chamber is thermally coupled. The temperature decrease of the soleplate as a result of the steam production is compensated by the control circuit for controlling the temperature of the soleplate. However, such a control always lags behind the temperature decrease, which can sometimes be comparatively large and unexpected, for example when the user changes over from dry-ironing to steam-ironing or when the user gives a steam blast. As a result of this, the temperature of the soleplate, particularly in the case of a thin soleplate with a low thermal inertia, is subject to substantial temperature fluctuations.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a steam iron which exhibits reduced temperature fluctuations. To this end, the steam iron of the type defined in the opening paragraph is characterized in that the control circuit further comprises means for adaptation of the activation of the heating element in response to the activation of the steam generator in anticipation of the expected cooling-down of the soleplate as a result of the supply of the water to be evaporated to the steam chamber.
In the steam iron in accordance with the invention the temperature decrease of the soleplate is anticipated by raising the average power at which the heating element operates as soon as the user demands steam production or increases the steam production. The means for adapting the activation of the heating element "know" how much extra power is needed to compensate for the temperature decrease of the soleplate on the basis of the construction of the steam iron, the instantaneous power of the heating element, the soleplate temperature and the requested amount of steam.
The requested amount of steam can be measured with the aid of the supply device. In an embodiment of the steam iron in accordance with the invention the supply device comprises an electrical pump. By measuring the operating time of the pump or by counting the number of energizing pulses of the electrical pump the amount of water which is evaporated can be measured fairly accurately.
The temperature decrease of the soleplate is anticipated by increasing the heat production of the heating element. In an embodiment the heating element is activated on the basis of a duty cycle control, the desired temperature of the soleplate being controlled by changing the duty cycle. During steam generation the duty cycle is given an extra offset which depends on the amount of steam to be generated.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects of the invention will be described and elucidated with reference to the accompanying drawings, in which
FIG. 1 is a sectional view of an embodiment of a steam iron in accordance with the invention;
FIG. 2A, FIG. 2B and FIG. 2C show signal waveforms in explanation of a control system for power control of a heating element in a steam iron in accordance with the invention; and
FIG. 3 is a flow chart of a control system for a steam iron in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows an embodiment of a steam iron in accordance with the invention. The steam iron comprises a conventional (thick) soleplate 2 which is heated by an electric heating element 4. The instantaneous temperature of the soleplate 2 is measured by means of a temperature sensor 6, for example a PTC resistor, an NTC resistor or a thermocouple element, which is thermally coupled to the soleplate 2. The desired soleplate temperature can be set by the user by means of a temperature selector or temperature control dial 8, but alternatively any other known control means such as push-buttons or touch controls can be used. A control circuit 10 compares the instantaneous temperature of the soleplate 10 with the desired temperature and controls the heat production of the heating element 4, for example by means of a triac in series with the heating element 4, in such a manner that the instantaneous temperature becomes equal to the desired temperature. Instead of the shown control using a temperature sensor 6 and a triac it is possible to use a more conventional control by means of a thermostat to control the temperature of the soleplate 2.
The steam iron further comprises a steam generator 12 having a water reservoir 14, a water pump 16 and a steam chamber 18 which is heated by the soleplate 2. The water pump 16 pumps water from the water reservoir 14 to the steam chamber 18 via a tube 20. The water evaporates in the steam chamber 18 and escapes via steam ports 22 formed in the soleplate 2. The supply of steam is controlled by means of an activation signal AS supplied by the control circuit 10 in response to a control signal from a control knob or control dial 26 by means of which the amount of steam to be produced can be set.
The steam iron further comprises an optional hand sensor 24 arranged in the handle of the steam iron. The hand sensor can be of any known type, for example a capacitive sensor. The hand sensor 24 informs the control circuit 10 whether or not the steam iron is in use.
As soon as the user switches from dry ironing to steam ironing by means of the control dial 26, or wishes to increase the steam production, or wishes to give a steam blast, the (increased) amount of water admitted to the steam chamber will cause the temperature of the soleplate 2 to decrease. This is because the evaporation of the water requires energy which is extracted from the soleplate 2 to which the steam chamber 18 is thermally coupled. As a result of this, the temperature of the soleplate 2 decreases. The decrease is measured by the temperature sensor 6 and is reported to the control circuit 10, which responds thereto by increasing the power output of the heating element 4. A similar situation occurs in the case of a thermostat control. However, the control circuit 10 can only respond when the temperature decrease of the soleplate 2 has already occurred, restoring the desired temperature of the soleplate 2 always being effected after the temperature decrease. As a consequence, the temperature of the soleplate 2 is subject to substantial temperature fluctuations, particularly upon a change-over from dry ironing to steam ironing and when steam blasts are given.
In accordance with the invention the temperature decrease which is due to occur is anticipated. For this purpose, the control circuit 10 comprises means which adapt the power output of the heating element 4 to the amount of steam to be produced. An amount of steam requested by means of the control dial 26 results in a given activation of the water pump 16. It is known how much water this water pump 16 (or any other supply device) conveys from the water reservoir 14 to the steam chamber 18. On the basis of the instantaneous power of the heating element 4, the instantaneous temperature of the soleplate 2 and the requested amount of steam it is possible to calculate how much extra heat the soleplate 2 should produce to compensate for the anticipated temperature decrease of the soleplate 2. This also depends on the construction of the steam iron. Factors which play a part are, for example, the thermal mass of the soleplate and the dimensions and the thermal coupling between the steam container 18 and the soleplate 2.
On the basis of this information, which is partly dynamic and partly depends on the construction of the steam iron, the control circuit 10 sets the power output of the heating element 4 to another value in the case of a changed demand for steam production. More steam requires more power from the heating element. This change in power output of heating element 4 in response to a change in the desired steam production is effected directly, i.e. without intervention of the temperature control. For example, in the case of a change from dry ironing to steam ironing the power the power of the heating element 4 is increased immediately by a value adequate to compensate for the expected temperature decrease.
The variation of the power of the heating element 4 can be effected in various ways. It is possible to connect one or more additional heating elements in order to meet the temporary higher demand for heat. A fine control is then possible by controlling the heat delivered by one of the additional heating elements by means of an electronic switch, for example on the basis of duty cycle control. Another possibility is to adapt the maximum power of the heating element 4 to the highest heat demand in the case of maximum steam production and at the highest ironing temperature and to control this power as required.
FIGS. 2A, 2B and 2C show control signals for power control of the heating element 4 on the basis of duty cycle control, an electronic switch (not shown) connecting the heating element 4 to the mains voltage if the control signal has the value "1" and disconnects it from the mains voltage if the control signal has the value "0". The period of the control signal is T p . T a is the on time and T b is the off time. The sum of the on time T a and the off time T b is equal to the period T p . In the case of a duty cycle of 0 the heating element 4 is switched off completely; in the case of a duty cycle of 1 the heating element 4 is constantly switched on. FIG. 2A represents the situation during dry ironing. The duty cycle T a /T p then varies between two values indicated in broken lines. The variation is dependent on the temperature setting and/or the degree of cooling of the soleplate 2. It is to be noted that the values shown for the switching times have been given merely by way of example and may be different in actual practice. FIG. 2B represents the situation in the case of steam ironing with little steam. In this case, the instant at which the control signal changes over from 0 to 1 has shifted to the left, which results in an increase of the duty cycle and, consequently, of the average power delivered by the heating element 4. The shift to the left, i.e. the offset, and the consequent power increase depends on the amount of steam set by means of the control dial 26. FIG. 2C represents the situation in the case of steam ironing with much steam. In this case, the change-over point has shifted even more to the left (more offset) in order to meet the even greater heat demand. The shift of change-over point, and hence the offset, depends on the steam production set by means of the control disc 26. The variation of the change-over point, which is indicated in broken lines in FIGS. 2A, 2B and 2C and which is superposed on said shift, is caused by the temperature control, which is independent thereof.
FIG. 3 is a flow chart of a control system for controlling the power of the heating element 4. The inscriptions for FIG. 3 are listed in the following Table I:
TABLE I______________________________________Block Inscription______________________________________300 Start302 Read T.sub.set304 -20° C. < T.sub.err < +20° C. ?306 T.sub.soleplate > T.sub.set ?308 Output duty cycle = 1310 Calculate amount of steam312 Output steam314 Output duty cycle = 0316 Hand sensed ?318 Steam required ?320 Get Dc2322 Get Dc3324 Controller326 Output duty cycle328 No steam330 Output Dc1______________________________________
In the flow chart the following parameters are used: T set is the desired temperature set by means of the temperature control dial 8; T soleplate is the temperature of the soleplate 2 measured by means of the temperature sensor 6; T err =T soleplate -T set ; Dc1 is the offset in the duty cycle when the steam iron is in a rest position and is not used; Dc2 is the offset in the duty cycle during steam ironing; and Dc3 is the offset in the duty cycle during ironing without steam.
In a block 302 temperature setting T set of the soleplate 2 is determined. If it deviates too much from the desired temperature (block 304) it is examined whether the soleplate is too cold (block 306). If it is too cold, the full power is applied to heat the soleplate to the desired temperature (block 308), after which the block 302 is carried out again. If it is not too cold, the soleplate is too hot and should be allowed to cool down. This cooling down is expedited by evaporating water (fast cooling). The required amount of steam is calculated (block 310) and is generated by pumping water from the water reservoir 14 to the steam chamber 18. After this, the heating is turned off (block 314) and the program returns to the block 302.
If the temperature of the soleplate has come sufficiently close to the desired temperature (block 304) it is checked whether the hand sensor indicates that the steam iron is in use or not in use (block 316). If it is not in use, the steam production is turned off (block 328) and the power of the heating element 4 is set to a stand-by value of, for example, 100 W by selection of a suitable offset (block 330) and the program returns to the block 302. If the steam iron is in use it is checked whether steam is required (block 318). In this is not the case, the offset corresponding to dry ironing is selected (block 322); if steam is required, the offset corresponding to ironing with the selected amount of steam is chosen. The control circuit 10 (block 324) calculates the duty cycle (block 326), after which the program returns to the block 302. If desired, the control circuit 10 can operate on a fuzzy logic basis, in which case for example T err and the temperature variation of the soleplate as a function of time are divided into classes.
It will be evident that certain control operations and actions in the flow chart are optional and may therefore be omitted without detriment to the anticipating power control. Cooling down with water (blocks 310 and 312) may be omitted. The hand sensor and the stand-by feature may also be dispensed with (blocks 316, 328 and 330).
The sensor 24 in the handle serves to signal whether or not the iron is in use. Instead of or in addition to such sensor 24, a motion sensor or a position sensor can be used. If the steam iron is equipped with a stand, the presence of the iron on the stand can also be signalled by means of a switch which cooperates with projection on or a recess in the stand.
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A steam iron comprises control device(s) for adjusting temperature and steam generation. The soleplate is heated with a heating element controlled by a control circuit which compares the desired temperature with the temperature of the soleplate measured with a temperature sensor. Steam is generated by transporting water from a water tank to a steam chamber which is thermally coupled to the soleplate. The control circuit adapts the power of the heating element upon activation of the steam generator in anticipation of the expected cooling down of the soleplate as a result of the transport of the water to be evaporated to the steam chamber.
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DESCRIPTION
1. Technical Field
This invention relates to a check or relief valve and, more particularly, to a floating high flow shroud and O-ring construction for a check or relief valve.
2. Background Art
Check or relief valves for fluid flow have been known and used for a long time. At one period of time, a movable poppet in the valve was spring-urged against a mating seat to cut off fluid flow. The poppet and seat had to mate precisely and be properly aligned at the point of sealing in order to be effective. Distortion, pitting of the mating elements, nonconcentricity of the mating elements, foreign bodies on one or the other of the mating elements, and the like, caused leaks or other failures of the valves.
With the discovery of the use of seal rings for valves to assist in effecting a complete seal, many of the problems mentioned above were resolved, but new ones resulted. The seal rings were positioned between the mating elements of the valve and cooperated with the mating elements to create the seal. The seal ring, being free to float in the area between the mating surfaces when the valve was opened, sometimes dilates preventing a good seal. At other times, the seal ring was washed out during opening of the valve thereby losing the sealing effect of the seal ring. Occasionally, the seal ring had a tendency to flutter between the mating elements partially covering and uncovering the flow holes in the poppet in an erratic and unpredictable manner. Occasionally, the seal ring will settle against an angular sealing surface of the inlet fitting end, thus tending to cover the largest flow area of the circular holes in the poppet.
One prior art patent, U.S. Pat. No. 3,626,977 to Riley et al, issued Dec. 14, 1971, and assigned to the common assignee of the present invention, provides a retainer ring for the seal ring to prevent dilation of the seal ring to limit freedom of movement of the seal ring to the immediate vicinity of the poppet valve seat to firmly and accurately align the seal ring along its full seating surface. Although the solution set out in U.S. Pat. No. 3,626,977 solved the problems for one style check or relief valve, the retaining ring concept was not usable on many styles of valve.
Another prior art patent, U.S. Pat. No. 2,918,083 to Clark et al, issued Dec. 22, 1959, provides a multi-faceted cage trapped to the fixed valve member and forming a backing for a poppet spring so as to urge the poppet against a seal ring and valve seat. The cage trapped the seal ring against a shoulder on the poppet in a generally concentric manner so that movement of the poppet moved the seal ring against a part of the fixed valve seat. It was found that fluid could flow (particularly high pressure fluid) between the seal ring and shoulder on the poppet and unseat the seal ring. The seal ring could then vibrate, cant, or otherwise misbehave with the same problems recited hereinabove.
The present invention is directed to overcoming one or more of the problems as set forth above.
DISCLOSURE OF INVENTION
In one aspect of the present invention, a check or relief valve is provided with a poppet valve element slidable relative to a male body member. The poppet and male body member have mating valve seats which are adapted to abut each other for sealing purposes with a secondary valve seat on an external annular flange on the poppet aligned with, but out of contact with, a secondary valve seat on the body member. a resilient seal ring is positioned between said secondary valve seats, such that when the mating valve seats are in sealing contact, the resilient seal ring will be compressed into sealing relationship between the secondary valve seats.
A floating shroud encircles the external annular flange, the secondary valve seat on the poppet, and the resilient seal ring with an apertured lip on the shroud radially overlapping the external annular flange on the poppet. An annular flange axially spaced from the lip on the shroud radially overlaps the seal ring. The shroud enslaves the seal ring to move the ring forward with the poppet and to hold the ring out of the mainstream of flow through the flow holes in the poppet. The shroud maximizes the usefulness of the flow holes in the poppet, eliminates seal ring flutter, prevents seal ring expansion due to differential pressure across the ring thereby eliminating washing the seal ring off the poppet.
During high flow, the flow around the poppet will create a reduction in pressure behind the apertures in the annular lip in the shroud, thus moving the seal ring against the secondary valve seat on the poppet to firmly retain the seal ring against distortion and flutter. As the differential pressure across the poppet decays with diminishing flow demand of the system, the poppet will be moved toward the sealed position under pressure from the spring and, since the shroud is free to float within the limitations of the poppet flange outside diameter, it will self-center for perfect sealing between the secondary valve seats.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a vertical sectional view through the mid portion of a check or relief valve showing the improved shroud structure with the valve closed;
FIG. 2 is an enlarged broken away view of the poppet and shroud of FIG. 1 only showing the valve in the open position.
BEST MODE FOR CARRYING OUT THE INVENTION
Referring to the drawings, a check or relief valve 10 embodying the invention is illustrated and includes a housing 12 having an outlet port 14 and a valve chamber 16. The outlet port 14 is formed in a polygonal head portion 18 and has internal threads 20 for connection to a conduit, not shown. The valve chamber 16 is formed in a cylindrical portion 22 of the housing 12 and communicates at one end with the outlet port 14 and has the other end partially defined by a shoulder 24 on a radially inwardly directed flange 25. The cylindrical portion 22 of the housing has an opening 26 at the end opposite the outlet port 14, in which opening 26 is formed internal threads 28.
An inlet fitting 30 has external threads 32 threaded in the threads 28 in the housing and includes a polygonal head portion 34 provided with internal threads 36 to define an inlet port 38 for connection to a fluid conduit conveying fluid to the valve 10. The inlet fitting 30 has an elongate hollow cylindrical extension 40 extending forward of the head portion 34 with said threads 32 formed thereon. The extension 40 has one axial portion 42 having a diameter fitting in the inside of the flange 25. A reduced diameter annular recess 44 is provided in said extension 40 forward of the axial portion 42 for receiving and retaining an O-ring seal 46 and a spacer seal 48 therein. The O-ring seal 46 and spacer seal 48 bear against the inside of the flange 25 and against the base of the recess 44 to effect a seal between the inlet fitting 30 and the housing 12. A packing gland or gasket 50 is seated between the head portion 34, the inner surface of the opening 26 in the housing and the cylindrical extension 40 of the fitting 30 rearward of the threads 32. The gland or gasket 50 further seals the fitting to the housing. A collar 52 defines one wall of the recess 44 and provides a forwardly-facing flat surface 54 which merges into an axially outwardly tapered annular valve seat 56 and an axially rearwardly tapered annular valve seat 58, the two valve seats 56,58 meeting at a ring-shaped apex 59. Both valve seats 56,58 are of substantially equal importance in the flow shut off function, but for definition purposes and since seat 58 is the first seat in the flow path, seat 58 will occasionally be referred to hereinafter as a primary sealing surface and seat 56 will be referred to as a secondary sealing surface.
A poppet valve or member 60 is slidably carried by the extension 40 of the inlet fitting 30 and includes a cylindrical body portion 62 having an outwardly extending sleeve 64 with a plurality of flow ports 66 extending through the sleeve to permit flow between the inside and the outside of the sleeve. The body portion 62 defines a closed wall 68 in axial alignment with the sleeve 64 and has a radially outwardly extending flange 70 around the outer periphery thereof. The flange 70 has a flat surface 72 facing away from the sleeve 64 and has an axially rearwardly tapered annular valve seat 74 facing in the direction of the sleeve 64. Another axially rearwardly tapered annular valve seat 76 is formed on said flange 70 and is axially spaced by an axial land 78 from said valve seat 74. The valve seat 76 joins the sleeve portion 64 of the poppet valve 60 in axially spaced relationship from the flow ports 66 for a purpose that will become apparent hereinafter. As discussed above with seat 58, the valve seat 76 will be referred to as a primary sealing surface and is in alignment with and is intended to seat against the primary sealing surface on the seat 58.
An annular, resilient, flexible seal ring or O-ring 80 encircles the land 78 of the poppet 60 and is of a size that when the poppet 60 is in position with the seat 76 substantially in contact with the seat 58, the seal ring will be compressed between the rearwardly tapered valve seat 74 on the poppet 60 and the outwardly tapered valve seat 56 on the inlet fitting 30.
A spring 82 is located in the valve chamber 16 and extends between the flat surface 72 of the poppet valve 60 and an apertured flow director 84 seated in an annular recess 86 in the tapered wall of the housing 12. The spring urges the sleeve 64 of the poppet valve 60 into the inlet fitting 30 and seats the seat 76 on the poppet against the seat 58 on the fitting and compresses and seals the seal ring 80 between the seat 74 on the poppet and the seat 56 on the fitting. The flow ports 66 are within the sleeve 64 so that flow of fluid through the poppet and past the seated valve seats is prevented.
In one preferred embodiment of the invention, a shroud 90 encircles both the flange 70 of the poppet and the seal ring 80. The shroud 90 includes a cylindrical portion 92 having a radially inwardly directed lip 94 at one end and a radially inwardly directed flange 96 at the other end. The lip 94 extends radially inward in radially overlapping relationship with the outer portion of the flange 70 and forward of said flange 70. A plurality of apertures 98, for instance four in number, extend in an axial direction through said lip and out of alignment with said flange 70 when said shroud is concentric with said poppet 60. The flange 96 on the shroud projects radially inward in overlapping relationship to the seal ring 80 and confines the seal ring 80 to the space between the inner wall 99 of the flange 96 and the rearwardly tapered valve seat 74 on the flange 70. The shroud is dimensioned so that the flange 96 and seal ring 80 are substantially radially out of alignment with the flow ports 66 during flow through the valve.
INDUSTRIAL APPLICABILITY
With the valve 10 in a flow line, the spring 82 will close the valve by seating the seats 76 on poppet 60 against seat 58 on the fitting 30 and by seating the seal ring 80 between the seat 74 on the poppet and the seat 56 on the fitting. When the pressure force of fluid in fitting 30 exceeds the calibrated loading of the spring 82, the poppet 60 will move to the left opening the flow path through the flow ports 66. The opening of the valve and operation of the poppet is according to conventional practice.
As the poppet 60 moves to the left in the drawings, the flange 70 engages with the lip 94 and moves the shroud 90 and seal ring 80 with it, clearing the flow path. The shroud 90 and flange 96 restrain the seal ring 80 preventing flutter of the seal ring, dilation of the seal ring and displacement of the seal ring from its proper location on the poppet. During high flow through the valve, the fluid flowing past the shroud 90 and apertures 98 in the lip 94 creates a reduced pressure in the shroud on the inside of the lip which pulls the seal ring 80 against the valve seat 74 further enhancing the stability of the valve. With the seal ring held out of the flow path, either by the flange 96 or by the reduction in pressure during high flow, the possibility of flutter of the seal ring or the possibility of expanding the seal ring due to differential pressure with the subsequent possibility of being washed off the poppet, are eliminated. The shroud and flange hold the seal ring in a concentric configuration and guide the seal ring into close proximity with the mating seats 74,56 so that the seal ring can selfcenter and seat properly on the seats 74,56 for a complete seal of flow through the poppet.
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A check valve or relief valve is provided with a floating shroud having a retaining lip engaging with a downstream edge of a moving poppet to maintain the shroud and a captured seal ring in proximate relationship with the poppet to maximize the usefulness of the flow ports in the poppet and to eliminate seal ring flutter. The retaining lip of the shroud may have axially directed holes to create a reduction in pressure between the seal ring and the poppet seat to move the seal ring against the poppet seat during high flow conditions.
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SUMMARY OF THE INVENTION
[0001] The present invention describes a subsurface refuse collection system. Comprises an underground bunker, a refuse container, a deposit bin and a cover with automatic opening and closing which can be powered electrically using a solar system. The container is collected by means of an automated crane with automatic hitching to facilitate collection. The system is equipped with multiple devices to measure volume and weight of the refuse deposited in the deposit bin, for the purpose of system monitoring or improvements to the management of truck routes. It also includes a safety device to prevent accidental falls into the underground bunker during collection.
PRIOR ART
[0002] Current subsurface refuse collection systems employ containers which are placed within an underground bunker located under a cover to which the deposit bin is coupled. The cover may be opened manually or automatically. Containers are collected using the crane on the collection truck. When the container is positioned above or next to the collection vehicle, it is opened from below or turned in order to unload the refuse into the vehicle. Hitching of the hook on the truck's crane to the bar on the container is performed manually.
[0003] Portuguese patents 101968, 102148, 102748 and Spanish patents 2036916, 2138480, 2153733, 2228225, 2228226, all issued to MBE SOTKON S.A., exemplify the features of prior art.
[0004] Portuguese patent 101968 and Spanish patent 2138480 refer to urban refuse deposits incorporating a number of independent compartments suitable for depositing refuse of the same or different types, for each of which there is at least one input bin or chute located on the corresponding hinged cover, positioned at a suitable height for refuse to be deposited inside it. Each of the compartments comprises, in its hinged cover, at least one unloading trapdoor into which an emptying chute can be inserted which, by means of vacuum or any other similar effect, empties the refuse into the collection vehicle.
[0005] Portuguese patent 102148 and Spanish patent 2153733 refer to a subsurface refuse system comprising one or more independent compartments for depositing of refuse of the same or different types, for each of which there is at least one input bin or chute located on a hinged cover, each compartment comprising at least one refuse container resting on a platform fitted with suitable means for lifting/lowering the unit between two positions, one underground, concealed by the hinged cover and the other for collection, in which refuse is transferred to the collection vehicles using the vehicle's emptying method, with or without tipping. Said container is equipped with a tray at the bottom fitted with its own means of opening and closing for resulting emptying of refuse without tipping. A different execution model includes a container with a fixed base fitted with its own means of manipulation by a collection vehicle and resulting emptying of refuse by tipping.
[0006] Portuguese patent 102748 and Spanish patents 2228225 and 2228226 refer to a system for opening the cover of underground deposits for solid urban refuse with a hinged cover. The cover comprises one or more hinges which allow it to swing open to an angle of around 90°; one or more locks locking the cover into the closed position; one or more fluid-operated, gas-operated or electric cylinders connecting the cover to the deposit to facilitate opening. The container, consisting of a single body, open on the upper side for use in systems for emptying by turning, equipped with a pair of diametrically opposed latches on the sides, or a double body for use in systems for emptying from below, said container also possessing a double cover with a perforated or multi-perforated tray at the top for drainage or liquids from the refuse towards a closed base.
[0007] There are in all such systems problems to be resolved: Performing automatic hitching of the truck's crane to the bar on the container, performing collection with a single operator, employing alternative energy sources to open the cover, monitoring the entire deposit/collection system and increasing safety during collection.
BRIEF DESCRIPTION OF THE FIGURES
[0008] The following description provided to better describe the present invention is based on the attached drawings that without limiting nature represent:
[0009] FIG. 1 : Schematic side view of the subsurface system in the open position;
[0010] FIG. 2 : Detail of the central lock;
[0011] FIG. 3 : Diagram of a solar system to power the cylinders;
[0012] FIG. 4 : Front view of the outside of the system;
[0013] FIG. 5 : Detail of a channel attached to the bottom of the cover of the system;
[0014] FIG. 6 : Schematic section of the subsurface system in the open position with the container being lifted by the automatic crane of the collection truck;
[0015] FIG. 7 : Automatic hitching system between the automatic crane of the collection truck and the container emptied from below;
[0016] FIG. 8 : Automatic hitching system between the automatic crane of the collection truck and the container with a closed base for emptying by turning;
[0017] FIG. 9 : Safety system in the outer vertical position;
[0018] FIG. 10 : Safety system in the horizontal position to cover the opening of the underground bunker when the container is collected.
[0019] FIG. 11 : System for detection of the weight of refuse deposited;
[0020] FIG. 12 : Detail of the decompression chamber attached to the gas cylinder connected to a button located on the surface.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Is one object of the invention a system equipped with a cover ( 2 ), which has two hinges ( 5 ) on one side and a central lock ( 6 ) on the other with a safety bolt ( 7 ) placed vertically that prevents the rotation of the central lock ( 6 ) tab and consequently keeps the cover ( 2 ) closed. This cover ( 2 ) may be opened or closed automatically by means of gas cylinders ( 8 ) with a decompression chamber ( 41 ) that connected to a button ( 40 ) on a box on the surface enables the automatic closure of the cover by means of decompression of the gas from the cylinders into the chamber ( 41 ); or by electro-hydraulic cylinders ( 8 ); or a mixed system comprising one electro-hydraulic cylinder and one gas cylinder. The gas cylinders ( 8 ) attached to the underground bunker ( 4 ) and to the lid ( 2 ) have a driving action system electrically feed and once the safety bolt ( 7 ) is withdrawn and the lock is turned around ( 6 ) they allow the automated opening of the lid up to 90 degrees and also the automated closing by means of the mentioned button ( 40 ) that should be pressed in a continuous way (as it is represented in FIG. 12 ). The cylinders ( 8 ) may be powered by a solar system comprising one or more photovoltaic panels ( 10 )(As it is represented in picture 3 , where the Panel is located on a post next to the cover ( 2 ) and the deposit bin ( 1 )), or by mains electricity, or electricity provided by the truck or an external generator.
[0022] In FIG. 1 it is represented the subsurface system in the open position, comprising a deposit bin ( 1 ) located at a height of approximately 90 cm, a cover ( 2 ) which opens up to 90 degrees supporting the paving, a container ( 3 ) for collection of refuse and an underground bunker ( 4 ). The cover is fitted with two hinges ( 5 ) on one side and a central lock ( 6 ) on the other. The cover is opened by means of cylinders ( 8 ) fastened to the cover and the underground bunker. The deposit bin ( 1 ), which has an upper cover, may include a central lock ( 11 ) which keeps it closed. For weighing of the refuse deposited in the container ( 3 ) or refuse deposited in the deposit bin ( 1 ) there may be load cells ( 14 ) in the underground bunker or load cells ( 15 ) at the bottom of the deposit bin, as described ahead.
[0023] At FIG. 2 is possible to see the detail of the central lock ( 6 ) with safety bolt ( 7 ) keeping the cover ( 2 ) closed.
[0024] The movements of the cover ( 2 ) are controlled remotely by a mobile device or by a system of buttons as mentioned previously accessible only to the operator located on the street next to the cover ( 2 ), or by the positioning of a mobile device near a radio frequency identification post ( 9 ), located on the street next to the cover.
[0025] After opening the cover ( 2 ), the container ( 3 ) is emptied by means of an automatic hitching system between the container ( 3 ) and the automatic crane ( 18 ) of the collection truck ( 17 ).
[0026] The container for collection by opening from below is completely open on the upper side, and each side is equipped with a set of arms ( 22 ), the upper extremity of which connects to the system located at the top of the crane, and at the lower end are joined to the base ( 19 ), which is articulated by means of hinges ( 20 ). The above set of arms ( 22 ) comprises a movable arm ( 25 ) located within a fixed arm ( 26 ) coupled to the body of the container ( 3 ). Both arms have at the upper end a number of grooves ( 27 and 27 ′) to enable coupling.
[0027] The FIG. 6 shows the subsurface system in the open position with the container ( 3 ) being lifted by the automatic crane ( 18 ) of the collection truck ( 17 ). As it is possible to observe, the top of the automatic crane ( 18 ) is equipped with a coupling system ( 21 ) which hitches to a set of arms ( 22 ) on each side of the container ( 3 ). The set of arms ( 22 ) is connected to the base ( 19 ), articulated with hinges ( 20 ). This coupling system ( 21 ) connected to the arms of the crane is equipped with 1 horizontal arm ( 23 ) and two vertical arms ( 24 ).
[0028] The container with a closed base, for unloading by turning, possesses on the inside of each side a fixed arm ( 31 ) coupled to the body of the container ( 3 ), which at its extremity is equipped with a number of grooves ( 32 ) enabling coupling to the outer element ( 28 ) of the coupling system ( 21 ) located at the top of the crane.
[0029] The top of the truck's collection crane is equipped with a coupling system ( 21 ) with 1 horizontal arm ( 23 ) which can rotate 360 degrees and two other vertical arms ( 24 ) which move vertically by means of fluid-operated cylinders. Each of the vertical arms ( 24 ) of the coupling system ( 21 ) comprises an outer element ( 28 ) and an inner element ( 29 ) which in turn both have at each extremity a grip ( 30 and 30 ′) for coupling, as it is represented in FIG. 7 .
[0030] For containers with a lid in the base, collection can be carried out as follows:
[0031] Automatic opening of the cover ( 2 ) of the subsurface system.
[0032] Movement of the crane ( 18 ) until the top is located above the underground container, controlled automatically by the operator.
[0033] By means of a system using proximity sensors located on the crane ( 18 ) and the container ( 3 ), the inner element ( 29 ) is automatically hitched to the grooves ( 27 ) on the movable arms ( 25 ) of the container, and the outer element ( 28 ) to the grooves on the fixed arm ( 26 ) of the container.
[0034] Based on memorisation of the above movements, the container ( 3 ) is automatically lifted using the crane ( 18 ) of the collection vehicle to the unloading point.
[0035] The base of the container is opened by the operator by means of vertical movement of the inner element ( 29 ) of the vertical arms ( 24 ) of the coupling system ( 21 ), pushing the movable arm ( 25 ) on the container which supports the base.
[0036] The base of the container is closed by the operator following emptying of the refuse by means of opposite vertical movement of the inner element ( 29 ) of the vertical arms ( 24 ) of the coupling system ( 21 ).
[0037] Automatic movement of the container ( 3 ) from the unloading point into the underground bunker ( 4 ).
[0038] Automatic disengagement of the inner element ( 29 ) from the grooves ( 27 ) on the movable arms ( 25 ) of the container, and of the outer element ( 28 ) from the grooves on the fixed arm ( 26 ) of the container.
[0039] Movement of the crane ( 18 ) to the collection point, controlled automatically by the operator.
[0040] Automatic closure of the cover ( 2 ) of the subsurface system.
[0000] Containers with a Closed Base can be Emptied as Follows:
[0041] Automatic opening of the cover ( 2 ) of the subsurface system.
[0042] Movement of the crane ( 18 ) until the top is located above the underground container, controlled automatically by the operator.
[0043] By means of a system using proximity sensors located on the crane ( 18 ) and the container ( 3 ), the outer elements ( 28 ) of the coupling system ( 21 ) located at the top of the crane, are automatically hitched to the fixed arms ( 31 ) coupled to each side of the container
[0044] Based on memorisation of the above movements, the container is automatically moved to the rear of the collection vehicle.
[0045] Positioning of the container onto the rear lifting mechanism for emptying, controlled by the operator
[0046] Automatic movement of the container ( 3 ) from the unloading point into the underground bunker ( 4 ).
[0047] Automatic disengagement of the elements connecting the container ( 3 ) to the crane ( 18 )
[0048] Movement of the crane ( 18 ) to the collection point, controlled automatically by the operator.
[0049] Automatic closure of the cover ( 2 ) of the subsurface system.
[0050] The described automatic hitching system between the automatic crane ( 18 ) of the collection truck ( 17 ) and the container with a closed base for emptying by turning is represented in FIG. 8 . The container is equipped on each side with a fixed arm ( 31 ) which at the upper extremity has a groove ( 32 ) enabling hitching to the outer element ( 28 ) of the coupling system ( 21 ).
[0051] When the container ( 3 ) is removed from inside the underground bunker ( 4 ), a safety device covers the entirety of the opening of the underground bunker ( 4 ) in order to avoid accidental falls during collection. The safety device remains concealed against one of the walls of the underground bunker ( 4 ) whenever the container ( 3 ) is located inside the underground bunker ( 4 ). When the container ( 3 ) is lifted for collection, the device swings into the horizontal position, covering the opening of the bunker( 4 ).
[0052] This safety device, connected to one wall of the underground bunker ( 4 ), is equipped with the following elements to allow automatic positioning and shock absorption: a rotating arm ( 35 ), a gas shock absorber ( 36 ) and a shock-absorbing spring ( 34 ). When the safety device is in the horizontal position during collection of the container ( 3 ), there are two locks ( 37 ) located on the front wall of the bunker ( 4 ) which keep the device secure and stable. When the container ( 3 ) is replaced inside the underground bunker ( 4 ), the locks ( 37 ) are released mechanically by means of two pedals ( 38 ) which are simultaneously depressed by the container ( 3 ), forcing the device to swing back into its initial position. As it is possible to observe in FIG. 9 , the safety system in the outer vertical position comprises a movable element ( 33 ) connected to the rear wall of the underground bunker by means of a unit comprising a rotating arm ( 35 ), a gas shock absorber ( 36 ) and a shock absorbing spring ( 34 ). In FIG. 10 it is represented the safety system in the horizontal position to cover the opening of the underground bunker ( 4 ) when the container ( 3 ) is collected. The movable element ( 33 ) is connected to the front wall of the underground bunker ( 4 ) with two locks ( 37 ) which are released mechanically when two pedals ( 38 ) are depressed simultaneously.
[0053] It is also possible to move the device manually from the inner horizontal position to the outer vertical position for access to the underground bunker ( 4 ) for cleaning or maintenance.
[0054] The upper part of the deposit bin ( 1 ) can be kept closed by means of a lock ( 11 ). This enables it to be opened only by specified users. The lock is operated by positioning a mobile device close to a radio frequency identification system ( 16 ) located in the deposit bin ( 1 ) post, allowing opening of the upper hatch of the deposit bin. Such situation is visible in FIG. 4 where the deposit bin ( 1 ) is equipped with a radio frequency identification system ( 16 ) that enables the lock ( 11 ) opening of the deposit bin ( 1 ) by the positioning of a mobile device close to it. Outside the perimeter of the cover ( 2 ) of the system there is also a radio frequency identification post ( 9 ) which can control the movements of the cover by positioning a mobile device close to it.
[0055] The level of refuse in the container can be monitored by means of a mobile probe ( 12 ) or probes located in the cover ( 2 ) which supply the data to a microprocessor which calculates the level of refuse as a percentage and sends this information to a central module controlling the management of refuse collection, via a communication device. When the percentage of refuse reaches a preset value, the microprocessor can also send a message resulting in activation of a locking device ( 11 ) in the deposit bin ( 1 ) of the subsurface system.
[0056] Is possible to observe in FIG. 5 a channel ( 13 ) attached to the bottom of the cover ( 2 ) of the system which enables the movement of a probe ( 12 ) to read various levels of volume in different parts of the subsurface container ( 3 ).
[0057] The weight of refuse held in the container can also be monitored by means of a load cell ( 14 ) fastened to the underground bunker ( 4 ) and placed under the container ( 3 ) allowing continuous weighing of the container ( 3 ) and refuse placed inside it. A microprocessor receives the information from multiple weighings of the container ( 3 ) according to a preset schedule, calculates the weight of refuse as a percentage, and sends it to a central module controlling the management of refuse collection, via a communication device.
[0058] The weighing of refuse placed in a subsurface refuse collection system, accessible only to specified users, can be carried out in one of two ways:
[0059] A cell ( 15 ) located in the lower part of the bin ( 1 ) allowing continuous weighing of the opening and refuse placed within it.
[0060] A load cell ( 39 ) enabling weighing of the user and the refuse to be deposited, placed on the cover ( 2 ) of the subsurface system next to the deposit bin ( 1 ), configured in such a way that the user must place both feet on it in order for the lock ( 11 ) at the top of the deposit bin to be opened, enabling refuse to be deposited.
[0061] Information received from the weighings of each deposit is processed by a microprocessor which calculates the weight of the refuse as a percentage, and sends it to a central module controlling the management of refuse collection via a communication device.
[0062] In picture 11 it is represented the system for detection of the weight of refuse deposited comprising a load cell ( 39 ) enabling weighing of the user and of the refuse to be deposited, located on the cover ( 2 ) of the subsurface system next to the deposit bin ( 1 ) which is fitted with a lock ( 11 ) on the upper hatch.
[0063] Measurement of the volume of refuse deposited in the bin, accessible only to specified users, can also be carried out by means of a set of probes located on the inner walls of the deposit bin which detect the approximate volume of the bag deposited.
[0064] As it is evident to experts in the area several changes are possible without going against the ambit of the following claims.
[0000] Lisbon, 8 th Oct. 2008
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The present invention relates to a subsurface refuse collection system comprising an underground bunker ( 4 ), a refuse container ( 3 ), a deposit bin ( 1 ) and a cover ( 2 ) with automatic opening and closing which can be powered electrically using a solar system. The container ( 3 ) is collected by means of an automated crane ( 18 ) with automatic hitching to facilitate collection. The system is equipped with multiple devices to measure volume and weight of the refuse deposited in the deposit bin ( 1 ), for the purpose of system monitoring or improvements to the management of truck routes. It also includes a safety device to prevent accidental fails into the underground bunker during collection.
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OTHER RELATED APPLICATIONS
The present application is a continuation-in-part of pending U.S. patent application Ser. No. 11/873,614, filed on Mar. 4, 2008, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a wheeled shopping bag device, and more particularly, to a collapsible, lightweight, yet strong, low cost, recyclable and disposable-wheeled shopping bag device that is environmentally compatible with characteristics that readily allow for its compact stacking, easy deployment, quick opening, stability, and structural strength.
2. Description of the Related Art
Several designs for wheeled shopping bags have been designed in the past. None of them, however, includes the conveniences claimed herein. The present invention utilizes eco-friendly materials with greater resistance and capacity than conventional bags, achieving low cost and weight characteristics, while maintaining sufficient strength and being collapsible for compact stacking and storage as well as being easily deployed by a user.
Applicant believes that the closest related reference corresponds to U.S. Pat. No. 3,197,225 issued to Powell for a Collapsible Shopping Bag hereinafter “Powell Bag”. However, it differs from the present invention because, it relies on the use of hinges and supports made of sheet metal, fabric, or a combination thereof with the intent of being reused and does not rest on its roller system assembly when at rest due to the obtuse angle of attachment of the wheels. The present invention, on the other hand, is made of a disposable, lightweight material, yet with some rigidity, that sits on its roller system when at rest, aided by folds causing it to stand in a substantially upright position. Furthermore, the patented bag does not claim or demonstrate any stacking characteristics if collapsed. Nor does it disclose crossed-members for its base assembly to reduce weight and costs as claimed herein.
One of the disadvantages of the current designs for wheeled bags is that they rely on a multiplicity of parts, such as hinges, fasteners, and reinforcing members, to achieve stability and collapsibility. These parts result in high material and manufacturing cost. These designs must accommodate long term personal reuse, and thus focus on collapsing to the smallest possible dimensions to permit a person to carry them. Still another shortcoming of the current designs is that they are unsuitable for stacking due, among other factors, to lateral instability, protrusions of rigid supports, bulk, and lack of flat surfaces.
The present invention provides a low weight and volumetrically efficient solution for collapsible bags that permit its rapid folding and deployment by using a combination of folds and slots to permit the air to vent in and out of the bag. Trapped air prevents the rapid collapse of bags, especially if the bag's opening is closed. In folding a bag, the opening at the distal end of the bag is typically closed and then folded along a predetermined first folding line, then a second one, until different layers of the flattened bag are stacked over each other. In doing this, air is trapped inside the bag providing some resistance to the folding operation. By providing slots along the vertical walls of the bag, preferably along its diagonal folds, the air inside is allowed to exit. This facilitates the folding of the bag. The reverse operation is also helped. As a user unfolds the bag, air enters through the bag's opening as well as through the slots.
The base or bottom assembly in the present invention includes a pair of coaxially disposed wheels mounted to its underside, opposite to each other at the end of a shaft. The other end includes a spacer leg assembly, opposite to the shaft supporting the coaxially disposed wheels. The dimensions of the spacer leg assembly cooperate with those of the wheels to permit the bag assembly to be at an upright position when at rest. In one of the embodiments, the bottom assembly is implemented using moldable material technology. Minimization of the material used is achieved with two crossed, elongated, and rigid members using molding technology. In one of the embodiments, the crossed members include through openings for permitting the glue to go through and achieve better engagement of the base assembly with the bottom of the bag member. Reinforcement angular members further strengthen the attachment to bushing members that journal the shaft supporting the wheels. Another way of attaching the bottom of the bag members to the base is through the use of ultrasound welding. For this, the paper used for the bag member is covered with a thin film of plastic material that is welded with the plastic material used for the cross members. None of these features are disclosed in the prior art.
The present invention also solves the prior art problems by using a bottom or base assembly with simple parts and paper bags that can be glued and do not require hinges or similar hardware. Strength of the wheeled base is enhanced through the use of reinforced cross-members with a substantially flat upperside. As a result of the design, multiple units may be stacked stably in their collapsed states. The folding characteristics of paper bags achieve collapsibility when integral hinges or folds are created along cooperative locations. The folds are positioned so that the folded portions of the bag member leave a clearance for the spacer leg members to fit in the collapsed disposition.
Other documents describing the closest subject matter provide for a number of more or less complicated features that fail to solve the problem in an efficient and economical way. None of these patents suggest the novel features of the present invention.
SUMMARY OF THE INVENTION
It is one of the main objects of the present invention to provide a collapsible wheeled bag device of sufficient strength and rigidity to carry goods normally carried by the shopper in a non-wheeled bag.
It is another object of this invention to provide a bag with a wheeled mechanism that allows a shopper to pull it when tilted at an angle that varies in accordance with the height of the user's body.
It is also an objective of the present invention to provide a wheeled bag device that is easily and readily deployed and opened by a user as well as collapsed when ready for storage with minimum resistance from the air inside the bag member.
It is still another object of the present invention to provide a device that stacks compactly so that a single device can be removed from the top of the stack without disruption to the rest.
It is also an object of the present invention that the device rests in a substantially upright position when not being pulled by the shopper.
It is yet another object of this invention to provide such a bag device that is inexpensive to manufacture and maintain while retaining its effectiveness.
An objective of the present invention is that the bag has characteristics similar to that of other paper shopping bags, such as its low weight and low cost with enhanced strength.
Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.
BRIEF DESCRIPTION OF THE DRAWINGS
With the above and other related objects in view, the invention consists in the details of construction and combination of parts as will be more fully understood from the following description, when read in conjunction with the accompanying drawings in which:
FIG. 1 represents an isometric view of one the embodiments of the present invention with the wheeled assembly mounted on the longer end of the bottom assembly having a rectangular shape. The folds of the bag assembly and the venting slots 65 along the diagonal folds are shown, as well as venting holes 65 ′.
FIG. 2A shows an isometric view of bag assembly 60 in a partly collapsed condition.
FIG. 2B is another isometric view of bag assembly 60 in a substantially collapsed condition, similar to FIG. 2A .
FIG. 2C shows an isometric view of bag assembly 60 in its fully collapsed state.
FIG. 3A shows a partial isometric enlarged view of the shaft 144 , stopper 50 , and wheel 42 .
FIG. 3B shows an elevational cross-sectional view of shaft 144 inside bushing 28 ′.
FIG. 4 illustrates a top plan view of collapsed bag assembly 60 and handle 62 slid inside.
FIG. 5 illustrates the stackable characteristics of one embodiment of the present invention shown in the previous figures.
FIG. 5A is a partial side elevational representation of the bag folds (without the handles) showing how a clearance space for the contiguously positioned spacer leg member is provided by shortening the length of the folds.
FIG. 5B is similar to the previous figure except that two folds are shortened.
FIG. 6 is a top view of the base or bottom assembly 20 showing two crossed elongated members and the two wheels.
FIG. 7 is a bottom view of what is shown in the previous figure with bushing assembly 28 supporting shaft 44 .
FIG. 7A is an isometric view of bushing assembly 28 used in the previous figure.
FIG. 7B is an alternate embodiment for a bushing assembly referenced with numeral 28 ′.
FIG. 8 is an isometric view of the alternate embodiment shown in the previous four figures using the alternate bushing assembly 28 ′.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, where the present invention is generally referred to with numeral 10 , it can be observed that it basically includes base or bottom assembly 20 , wheel assembly 40 and bag assembly 60 . A user typically tilts wheeled bag device 10 about the end having the wheels and pulls from handles 62 . FIG. 1 shows the end with wheel assembly 40 as the wider side of a bag assembly 60 with a rectangular projection. The shopping bag device 10 stands in a substantially upright position.
Bottom or base assembly 20 is shown in FIGS. 6 through 8 where a molded plastic material is used with sufficient degree of rigidity. This option is compatible with mass production molding techniques and permits the minimization of material usage, as well as its weight, yet maintaining its functionality. This embodiment includes integrally built crossed members 21 and 23 that are angularly disposed with respect to each other. The angle varies depending on the dimensions intended for the bag's footprint. If members 21 and 23 are perpendicular to each other, the footprint will be a square. It is preferred to have a rectangular bag footprint that resembles those of commercially available bags. It has been found that with the angle between members 21 and 23 of approximately 120 degrees, the resulting bag assembly 60 works well. This angle, however, can vary from 60 degrees to 150 degrees and still result in a practical projection for device 10 .
In FIG. 6 , upperside 22 can be observed with the front wheel ends 21 ′ and 23′ connected by wheel assembly 40 . Assembly 40 includes shaft 44 and wheel members 42 and 42 ′ mounted to the ends. Cross members 21 and 23 are connected by shaft 44 . Shaft 44 includes wheel members 42 and 42 ′ rigidly mounted to the ends of shaft 44 . Shaft 44 is rotatably mounted to the underside 24 of base assembly 20 , as explained below. In FIGS. 3A and 3B , the shaft has a star cross-section with four legs (stars with three legs or five or more can also be used) to minimize its weight.
FIG. 7 shows underside 24 where members 21 and 23 include a perpendicularly mounted reinforcement rib member 29 with sub-ends 29 ′ reinforcing spacer leg member 25 . Adjacent to front ends 21 ′ and 23 ′, bushing assemblies 28 (or equivalent structure such as bushing assembly 28 ′ showing in FIG. 7B ) are mounted. The through openings 27 are aligned to permit shaft 44 to go through and be rotatably journaled. The same applies for alternate bushing assemblies 28 ′ where through openings 27 ′ are also aligned. With assembly 28 ′, shaft 44 is pressed in through cut 26 ′ with a predetermined force magnitude and that cammingly enlarges cut 26 ′ as shaft 44 passes through. Assembly 28 ′ has the advantage of not requiring the disassembly of wheels 42 for its removal. FIG. 8 shows bottom assembly 20 using bushing assemblies 28 ′.
In FIG. 8 , it can also be observed that spacer leg members 25 extend perpendicularly from the ends 21 ″ and 23 ″ of members 21 and 23 , respectively. The dimensions of spacer leg members 25 are selected to cooperate with the dimensions of wheels 42 to approximate a plane that is parallel to a supporting surface, typically horizontal. Reinforcement end 29 ′ keeps member 25 in a perpendicular disposition with respect to members 21 and 23 .
Bag assembly 60 has a bottom wall 64 that is mounted to upperside 22 directly. Bag assembly 60 is thus mounted over upperside 22 directly. Bag assembly 60 extends upright defining a compartment and has an opening at its distal upper end.
Bag assembly 60 has overall dimensions that cooperate with the dimensions of bottom assembly 20 on which it is mounted. The height of bag assembly 60 is ergonomically compatible with the height of most users to permit the user to comfortably pull bag device 10 when tilted. Bag assembly 60 is made out of a paper base material, in one of the embodiments, with a thickness range between 100 and 800 grams per square meter. It has been found that paper material with this thickness provides sufficient rigidity to keep bag assembly 20 open, aided with cooperatively positioned transversal folds along integral hinges. At the same time, several cooperatively designed integral hinges or folds permit the ready deployment and collapse of bag assembly 20 . To permit the entry and exit of air inside bag assembly 20 , slots 65 are inconspicuously perforated through diagonal bag folds 63 . Optionally, through holes 65 ′ can also be used outside of folds 63 . If holes 65 ′ are used instead of slots 65 , then the resistance of diagonal bag fold 63 is increased. Through openings 26 are designed to receive an adhesive therethrough to improve the engagement with upperside 22 .
Bag assembly 60 includes four longitudinal corner bag folds 67 defining longitudinal walls 71 ; 71 ′; 72 ; and 72 ′. Walls 71 and 71 ′ each include one longitudinal bag fold 61 .
To facilitate the collapse or folding of bag assembly 60 , diagonal bag folds 63 and longitudinal bag folds 61 cooperate with longitudinal walls 71 and 71 ′, as best seen in FIGS. 1 and 2A . When bag opening 69 is being closed, air exits also through slots 65 (and, optionally, holes 65 ′). The first fold of the lowermost section of bag assembly 60 results in walls 71 and 71 ′ defining triangular portions 171 , and the lowermost portions of walls 72 and 72 ′ defining rectangular portions 172 and 172 ′. Portions 171 ; 172 ; and 172 ′ are brought towards upperside 22 of bottom assembly 20 . Then, portions 272 and 272 ′ of walls 72 and 72 ′, respectively, are folded, as best seen in FIG. 2B . Portion 272 ′ is longer than potion 272 . This is followed by portions 372 and 372 ′. Portions 472 and 472 ′ are the last ones, in this embodiment, resulting in a footprint confined within the dimensions of upperside 22 of bottom assembly 20 .
In one of the embodiments, portions 372 ; 372 ′; 472 ; and 472 ′ have smaller dimensions than what they would otherwise have to fit the entire footprint or plan projection of upperside 22 , as seen in FIGS. 5A and 5B . This is desirable in order to provide clearance for spacer leg members 25 of adjacent bag device 10 stacked up above, when storing it. This option will minimize the spaces between stacked bag devices, shown in FIG. 5 , reducing somewhat the overall height of the stack.
Wheel assembly 40 includes shaft 44 that is slidably passed through through opening 27 (or 27 ′) allowing shaft 44 to rotate. Wheel members 42 and 42 ′ are rigidly mounted to the ends of shaft 44 . An adhesive can be used to secure wheel members 42 and 42 ′ to the ends of shaft 44 . The ends of shaft 44 protrude a sufficient distance to permit the mounting of wheels 42 and 42 ′ to the former. As shown in FIG. 3A , an equivalent embodiment for shaft 44 is represented as shaft 144 with a star cross-section. This provides additional savings in cost and weight. Stopper 50 is positioned a predetermined distance from wheel 42 to prevent shaft 144 (or 44 ) to limit its transversal movement. In FIG. 3B , shaft 144 is shown in cross-section inside of bushing 28 ′.
For storage, device 10 is volumetrically efficient requiring minimum footprint, as shown in FIG. 4 . FIG. 5 shows one of the preferred manners for stacking up devices 10 , which results in a stable stacked structure. In FIGS. 5A and 5B , the elevational representation of two versions of folded bag 60 is shown to accommodate spacer leg members 25 of different dimensions to permit the adjacent device 10 (shown in broken lines) to fit and this resting in a substantially horizontal position. Optionally, a flat reinforcement member 70 (a sheet of plastic or cardboard) is added either inside of bag assembly 60 ( FIG. 5A ) or outside adjacent to bottom wall 64 ( FIG. 5B ). Member 70 in FIG. 5B can be glued to bottom wall 64 and upperside 22 . This will prevent the rupture of bottom wall 64 .
The foregoing description conveys the best understanding of the objectives and advantages of the present invention. Different embodiments may be made of the inventive concept of this invention. It is to be understood that all matter disclosed herein is to be interpreted merely as illustrative, and not in a limiting sense.
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A low weight wheeled bag device having a bottom assembly having two crossed members with an upperside and an underside. The wheel members are coaxially mounted to a shaft journaled by two bushing members at the ends. Spacer leg members have cooperative dimensions to permit the bottom assembly to be at rest at a substantially parallel and spaced apart relationship with respect to a supporting surface. A bag member with flat bottom wall is mounted over the upperside and extends upwardly defining an internal compartment and an upper end opening. A reinforcement member can be optionally added to the bottom wall to enhance its structural integrity. A user tilts the bag assembly and pulls it from handles mounted adjacent to the opening causing the wheels to roll and the assembly to easily move with its contents.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is related to U.S. patent application having Ser. No. 12/325,221 titled “Dryer With Reverse Tumble Action” filed Nov. 30, 2008 and U.S. patent application having Ser. No. 12/325,219titled “Dryer With Stationary Drying Cycle” filed Nov. 30, 2008.
FIELD OF INVENTION
Embodiments of the present invention relate to bypass switches. More specifically, embodiments of the present invention relate to systems and methods for bypassing centrifugal switches found in dryers.
BACKGROUND OF THE INVENTION
Centrifugal switches are a safety feature that prevents the heating element from operating when the drum is not rotating. Currently, dryers use centrifugal switches to ensure that the heating element does not operate when the drying compartment (i.e. drum) is not rotating. Generally, centrifugal switches used in dryers are normally open and as the drum reaches a minimum rotation speed, the switches are “thrown” to the closed position, thereby completing the circuit and allowed the heating element to receive power. Should the drum stop rotating or the rotation speed fall below the minimum rotation speed, the centrifugal switch returns to the normally open position, thereby breaking the circuit and cutting power to the heating element.
There is a long restart time for gas heating elements. In other words, after power has been cut from the heating elements, there is a long delay in returning the heating element to the same heat output as before the power was cut. For reversible dryers the long restart time presents a significant problem for dryers in which the drum shall change directions multiple times throughout a drying cycle. The restart time can add significant time to the drying cycle. For electric dryers the centrifugal switch typically carries higher current and reversible dryers would cause unnecessary activation and deactivation (i.e. “short cycling”) of the heating element. This would in return reduce the useful life (i.e. reliability) of the centrifugal switch. Simple removing or totally bypassing the centrifugal switch is not an option because removing or totally bypassing the centrifugal switch would remove an important safety feature that prevents runaway heating element conditions. That is, removing the centrifugal switch may lead to the heating element being energized when the drum is stationary for extended periods of time.
Having the above identified problems in mind, there exists a need for a dryer having a configuration that would allow the heating element to remain energized when the drum slows and reverses rotational direction while still preventing the heating elements from remaining energized while the drum is stationary for extended periods of time.
BRIEF DESCRIPTION OF THE INVENTION
Consistent with embodiments of the present invention, dryer centrifugal switch bypass circuits for a dryer having a reverse tumbling action are disclosed. The dryer comprises a drum, a motor, a centrifugal switch, and a heating element. The centrifugal switch bypass circuit comprises a bypass relay operatively connected to the heating element and configured to bypass the centrifugal switch prior to the drum reversing rotational direction, and allow the heating element to remain energized during rotational direction reversal. The centrifugal switch bypass circuit further includes a relay hold circuit operatively connected to the bypass relay and configured to cause the bypass relay to continue bypassing the centrifugal switch during rotational direction reversal.
Still consistent with embodiments of the present invention, methods for bypassing a centrifugal switch are disclosed. The method may include receiving an indication that a drum is reversing rotational direction. The method may further include, once the drum begins reversing the rotational direction, utilizing a bypass relay to bypass the centrifugal switch. Finally, the method may include utilizing a relay hold circuit to cause the bypass relay to continue bypassing the centrifugal switch during reversal of the rotational direction.
Various aspects of the invention may include a relay hold circuit. The relay hold circuit may comprise an optocoupler configured to output a first signal and a NPN transistor configured to be activated by the first signal. The relay hold circuit may further include a field effect transistor configured to output a second signal to a first side of a bypass relay coil. Finally, the relay hold circuit may include a controller configured to determine when the bypass relay coil should be closed and provide a ground signal to a second side of the bypass relay coil to close the bypass relay coil when the controller determines that the bypass relay coil should be closed.
BRIEF DESCRIPTION OF THE FIGURES
Non-limiting and non-exhaustive embodiments are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.
FIG. 1 depicts a control diagram for an electric dryer consistent with embodiments of the invention;
FIG. 2 depicts a control diagram for a gas dryer consistent with embodiments of the invention;
FIG. 3 depicts a wire diagram for a centrifugal switch bypass circuit consistent with embodiments of the invention; and
FIG. 4 depicts a simulation for the wiring diagram of FIG. 3 consistent with embodiments of the invention.
GENERAL DESCRIPTION
Reference may be made throughout this specification to “one embodiment,” “an embodiment,” “embodiments,” “an aspect,” or “aspects” meaning that a particular described feature, structure, or characteristic may be included in at least one embodiment of the present invention. Thus, usage of such phrases may refer to more than just one embodiment or aspect. In addition, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments or aspects. Furthermore, reference to a single item may mean a single item or a plurality of items, just as reference to a plurality of items may mean a single item. Moreover, use of the term “and” when incorporated into a list is intended to imply that all the elements of the list, a single item of the list, or any combination of items in the list has been contemplated. Throughout this specification, electricity, power, and current may be used interchangeably.
Throughout this specification the centrifugal switch will be assumed to be a “normally open” switch and a rotating drum will be said to “throw” or “close” the centrifugal switch. However, it is contemplated that the centrifugal switch may be a “normally closed” switch and a rotating drum may be said to “open” the centrifugal switch. Whether a normally open or normally closed centrifugal switch is implemented, the desired result is that during drum rotation, the centrifugal switch allows the heating element to be activated. In addition, stating a drum is “not rotating” or any equivalent term implies that the drum is either stationary or rotating at a speed too slow to cause a centrifugal switch to be in the closed position.
During a drying cycle the drum may reverse rotational direction multiple times throughout the drying cycle. As a safety measure, centrifugal switches are utilized to deactivate a dryer's heating element when the drum is not rotating. Embodiments of the present invention utilize circuitry, as opposed to a purely software solution, for bypassing a centrifugal switch when reversing the rotational direction of the drum. The circuitry includes components that may create a time constant within the circuit that may limit the amount of time the bypass circuit may be allowed to bypass the centrifugal switch. Furthermore, the circuitry may monitor the rotation of the drum and override the time limit created by the time constant. Most importantly, the circuitry removes the dependence on software for providing the only failsafe to prevent the heating elements from activating when the drum fails to rotate or rotates slower than the required rotation speed.
DETAILED DESCRIPTION
Various embodiments are described more fully below with reference to the accompanying drawings, which form a part hereof, and which show specific embodiments of the invention. However, embodiments may be implemented 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. Accordingly, the following detailed description is, therefore, not to be taken in a limiting sense.
Referring now to the figures, FIG. 1 depicts a control diagram for an electric dryer depicting a control side and a dryer side consistent with embodiments of the invention. Typically an electric dryer operates at 240 VAC with two hot wires (120 VAC each) as indicated by reference numerals 102 and 104 and one neutral wire, as indicated by reference numeral 106 , powering the dryer. Upon entering the dryer electricity flows through an outlet safety backup 108 and an inlet safety 110 . Outlet safety backup 108 and inlet safety 110 are thermostats used to cut power to the dryer should temperatures within the dryer exceed predetermined limits. After the electricity travels through outlet safety backup 108 and inlet safety 110 , it travels to a triac driver 112 and an inner coil relay 114 . After exiting inner coil relay 114 , electricity may flow to an inner heater coil 116 and after exiting triac driver 112 , electricity may flow to a heater triac 118 and to an outer heater coil 120 .
In order to achieve the required 240 VAC, electricity from hot wire 104 must travel through a centrifugal switch 122 . Centrifugal switch 122 may be a single pole double throw switch. In other aspects of the invention centrifugal switch 122 may be a single pole single throw switch. When the drum is not rotating centrifugal switch 122 is open and inner heating coil 116 and outer heating coil 120 do not receive the required 240 VAC needed for operation. Plus, neutral 106 is open preventing current from flowing between hot wire 102 and ground. Once the drum is rotating, centrifugal switch 122 is “thrown” thereby completing the circuit and allowing the dryer to operate as normal.
Hot wire 102 also provides power to an optocoupler 124 . Because optocoupler 124 is also connected to centrifugal switch 122 , optocoupler 124 does not receive power until the drum rotates and centrifugal switch 122 is thrown. During operation of the dryer optocoupler 124 , a bypass relay 126 , microcontroller 130 , and a relay hold up circuit 128 operate to keep inner heating coil 116 and outer heating coil 120 activated while the drum reverses its rotational direction. Note that bypass relay 126 may comprise any switching device.
To reverse the rotational direction of the drum, a controller may shut down the dryer motor. Once the drum has stopped, the polarity on the motor is reversed to cause the motor (i.e. the drum) to reverse rotation direction. During drum rotation, optocoupler 124 is used to power relay hold up circuit 128 , keeping capacitor 314 discharged. Before the drum begins to slow down in order to change rotational direction, bypass relay 126 bypasses centrifugal switch 122 thereby keeping inner heating coil 116 and outer heating coil 120 activated while the drum reverses its rotational direction.
Once the drum has returned to the desired rotation speed, bypass relay 126 opens and power flows through centrifugal switch 122 . If the drum does not reach the desired rotation speed, relay hold up circuit 128 may time out and cause bypass relay 126 to open and prevent or shut down inner heater coil 116 and outer heater coil 120 . The interactions of optocoupler 124 , bypass relay 126 , and relay hold up circuit 128 will be discussed further below with respect to FIG. 3 .
Micropede 130 provides a ground path to a relay coil. Micropede 130 also monitors the state of the centrifugal switch (i.e. open or closed and controls drum rotation/direction and the heating elements via supplementary relays, triacs, etc.
FIG. 2 depicts a control diagram for a gas dryer depicting a control side and a dryer side consistent with embodiments of the invention. Typically a gas dryer operates at 120 VAC with one hot wire (120 VAC) as indicated by reference numerals 202 and one neutral wire, as indicated by reference numeral 206 , powering the dryer. Upon entering the dryer electricity flows through an igniter/shutoff valve relay 232 . Once igniter/shutoff valve relay 232 is powered, power flows through an outlet safety backup 208 and an inlet safety 210 . As described above, outlet safety backup 208 and inlet safety 210 are thermostats used to cut power to the dryer should temperatures within the dryer exceed predetermined limits. After the electricity travels through outlet safety backup 208 and inlet safety 210 , it travels to an igniter/shutoff valve module 234 . Note that igniter/shutoff valve module 234 may be a two-stage gas valve.
In order to complete the circuit and allow igniter/shutoff valve module 234 to activate, electricity from neutral wire 206 must travel through a centrifugal switch 222 . Centrifugal switch 222 may be a single pole double throw switch. In other aspects of the invention centrifugal switch 122 may be a single pole single throw switch. When the drum is not rotating centrifugal switch 222 is open and igniter/shutoff valve module 234 does not activate because the circuit is broken. Once the drum is rotating, centrifugal switch 222 is “thrown” thereby completing the circuit and allowing the dryer to operate as normal.
Hot wire 202 also provides power to an optocoupler 224 . Because optocoupler 224 is also connected to a centrifugal switch 222 , optocoupler 224 does not receive power until the drum rotates and centrifugal switch 222 is thrown. During operation of the dryer optocoupler 224 , a bypass relay 226 , microcontroller 130 , and a relay hold up circuit 228 operate to keep igniter/shutoff valve module 234 activated while the drum reverses its rotational direction.
To reverse the rotational direction of the drum, a controller may shut down the dryer motor. Once the drum has stopped, the polarity on the motor is reversed to cause the motor (i.e. the drum) to reverse rotation direction. During drum rotation, optocoupler 224 is used to power relay hold up circuit 228 keeping capacitor 314 discharged. Before the drum begins to slow down in order to change rotational direction, bypass relay 226 bypasses centrifugal switch 222 thereby keeping igniter/shutoff valve module 234 activated while the drum reverses its rotational direction. The interactions of optocoupler 224 , bypass relay 226 , and relay hold up circuit 228 will be discussed further below with respect to FIG. 3 .
Referring now to FIG. 3 , FIG. 3 will be described with respect to an electric dryer as described in FIG. 1 . FIG. 3 depicts a wire diagram for a centrifugal switch bypass circuit 300 consistent with embodiments of the invention. Centrifugal switch bypass circuit 300 provides a time period in which bypass relay 126 may bypass centrifugal switch 122 to allow the drum to reverse its rotational direction. For discussion purposes, the time period with which FIG. 3 will be described is six seconds. However, it should be understood that the time period may be longer or shorter than six seconds. In addition, the time period need not be fixed. As will be discussed below, the time period may be controlled by a controller 340 .
Centrifugal switch bypass circuit 300 receives 120 VAC from hot wire 104 . During drum rotation, centrifugal switch 122 closes and electricity flows through resistors. While three resistors are shown in FIG. 3 , in other aspects of the invention a single resistor or multiple resistors of various resistance may be used to achieve a desired resistance. A diode controls the current flow.
After flowing through the resistors, current flows to optocoupler 124 which isolates the 120 VAC circuit from the DC low voltage circuits. When centrifugal switch 122 is closed, optocoupler 124 allows a signal 316 (e.g. 5 VDC), which acts as feed back to controller 340 , to indicate that centrifugal switch 122 is closed. In addition, when centrifugal switch 122 is closed, optocoupler 124 allows signal 316 to reach a NPN transistor 310 . Signal 316 activates NPN transistor 310 which allows bypass relay 126 to be activated, thereby bypassing centrifugal switch 122 . When the NPN transistor is on, capacitor 314 is discharged, thereby allowing a field effect transistor (MOSFET) to be in the “on” state and power one side of the by-pass relay.
When centrifugal switch 122 is open, signal 316 is not allowed to activate NPN transistor 310 . When NPN transistor 310 is not active a capacitor 314 begins to charge with a signal 318 (e.g. 12 VDC). Once the charge on capacitor 314 reaches a predetermined level, MOSFET 312 is deactivated by signal 318 . In general, once capacitor 314 is charged it deactivates MOSFET 312 which in turn disables bypass relay 126 so that controller 340 cannot control bypass relay 126 .
When centrifugal switch 122 is closed, controller 340 has the ability to control bypass relay 126 via a backside connection to bypass relay 126 as indicated by reference numeral 330 . For instance, when the drum is about to reverse its rotational direction, controller 340 closes bypass relay 126 so that inner heating coil 116 and outer heating coil 120 may continue to receive power while the drum reverses and centrifugal switch 122 is open. When centrifugal switch 122 opens capacitor 314 begins charging and once it charges, it deactivates MOSFET 312 . If the drum has not begun to rotate by the time MOSFET 312 is deactivated, centrifugal switch 122 is open and bypass relay 126 opens thereby cutting power to inner heating coil 116 and outer heating coil 120 .
In the current example capacitor 314 is a 100 μF capacitor and time delay generated by the RC circuit is six seconds. The time delay may be adjusted by replacing the resistor in the RC circuit with a rheostat and having controller 340 adjusting the rheostat resistance.
Turning now to FIG. 4 , FIG. 4 depicts a simulation for the wiring diagram of FIG. 3 consistent with embodiments of the invention. From 0-1 second centrifugal switch 122 is closed and signal 316 is being allowed to reach NPN transistor 310 . At 1 second, centrifugal switch 122 opens and capacitor 314 begins charging as indicated by reference numeral 406 . After approximately 6 seconds capacitor 314 reaches a predetermined voltage and MOSFET 312 deactivates. When MOSFET 312 deactivates, signal 318 stops and bypass relay 126 opens. At approximately 10 seconds, centrifugal switch 122 closes and capacitor 314 discharges as indicated by reference numeral 406 . Once capacitor 314 drops below a predetermined voltage and MOSFET 312 activates. When MOSFET 312 activates, signal 318 supplies voltage to one side of the bypass relay 126 . The bypass relay 126 is allowed to be activated via the micropede 340 .
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
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Systems and methods for bypassing a centrifugal switch are disclosed. The systems may include a bypass relay operatively connected to the heating element and configured to bypass the centrifugal switch prior to the drum reversing rotational direction, and allow the heating element to remain energized during the drum reversing rotational direction. The centrifugal switch bypass circuit further includes a relay hold circuit operatively connected to the bypass relay and configured to cause the bypass relay to continue bypassing the centrifugal switch during the drum reversing rotational direction. The method may include, once the drum begins reversing the rotational direction, utilizing a bypass relay to bypassing the centrifugal switch. Finally, the method may include utilizing a relay hold circuit to cause the bypass relay to continue bypassing the centrifugal switch during reversal of the rotational direction.
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BACKGROUND OF THE INVENTION
It is often necessary or desirable to deliver particulate material in accurate, measured amounts into containers. For example, a high degree of accuracy in the delivery of particulate material is required when the particulate material is a medication. The term "particulate material" as used herein is intended to include powders or granular material, regardless of the particle size. However, this invention is particularly adapted for use with finely divided particulate material, such as powders.
One way to deliver particulate material is to utilize an apparatus which includes a rotatable turret having a series of openings which can be filled with the particulate material. The turret is rotated to bring the openings to a filling station where the powder is removed from the openings. Rotating turret devices are shown, for example, in Leong U.S. Pat. No. 4,177,941, Colburn U.S. Pat. No. 2,314,031, Hafner U.S. Pat. No. 4,528,848 and Anderson et al U.S. Pat. No. 1,416,156. Unfortunately, none of these devices provides the accuracy and speed desired especially for the delivery of relatively large volumes of various particulate materials, such as medications in powder form.
One desirable technique for transferring the particulate material from the openings to the container at the filling station is with a blast of gas, such as air, under pressure. This is troublesome, however, when the container to be filled is in the form of a bag which can be inflated by the air. The prior art does not deal with this container inflation problem. In addition, equipment that handles particulate materials, particularly powders, is difficult to keep clean because of the tendency of the finely divided material to get between the movable parts of the equipment.
SUMMARY OF THE INVENTION
This invention provides a method and apparatus for the accurate and rapid delivery of relatively large volumes of particulate materials, including powders, into containers. Accordingly, this invention is particularly suited for use with particulate material which must be very accurately measured, such as medications in powdered form. In addition, this invention solves the container inflation problem referred to above and provides other novel and advantageous features.
The features of this invention are applicable to an apparatus which includes a hopper for containing a supply of the particulate material and a movable plate having a plurality of openings therethrough. The plate is positioned below the hopper so that the particulate material from the hopper can fill the openings under the influence of gravity. The plate is moved to move the filled openings to a filling station to thereby transport the particulate material in the openings to the filling station. At the filling station, the particulate material from the openings is transferred to the container. Although the plate could move linearly, preferably it is in the form of a rotatable turret.
With this invention, accuracy of the quantity of particulate material delivered is improved in several ways. For example, the volume of each of the openings in the plate is selected so as to be smaller than the volume of particulate material which is to be loaded into the container. With this construction, a plurality of the openings must have the particulate material therein discharged into the container in order to provide the correct dosage of the particulate material in the container. Consequently, any differences in the quantity of particulate material loaded into the openings tends to be averaged out. To obtain the averaging desired, it is preferred to transfer the particulate material from at least five of the openings to the container. For even better results, a greater number of the openings, such as fifteen, should have the particulate material transferred from them to a single container.
The weight of the particulate material in an opening depends, not only on the volume of the opening, but also on the density of the material in the opening. This invention provides for increased accuracy by using the static head of the particulate material in the hopper to control the density of the material in the openings and by controlling the height or static head of the particulate material in the hopper.
To help assure that a constant volume of the material will be loaded into each of the openings through the complete filling of each of the openings, it is preferred to employ openings which have an axial dimension which is no greater than about the diameter of the opening. In addition, an agitator is used to break up any clumps of the particulate material in the hopper and to further assist in completely filling each of the openings.
To help solve the container-inflation problem when an inflatable container is employed, this invention communicates the interior of the container with a source of reduced pressure to remove at least some of the air or other gas from the container. This may be accomplished following each transfer of material from an opening into the container or following each transfer of material from multiple openings into the container.
To further reduce the container-inflation problem, this invention reduces the volume of air employed in the transfer of material from the openings into the container. This can be accomplished, for example, by directing gas in a generally tubular pattern toward the opening at the filling station. The tubular pattern, which preferably is in general registry with the periphery of the opening at the filling station, provides for thorough removal of the material with a minimum volume of air. If desired, the gas may be directed into the opening in a direction which has components extending both axially and circumferentially of the opening so that at least some of the particulate material is swirled as it is transferred from the opening to the container.
In a preferred construction, the apparatus includes a member below the movable plate for closing the lower ends of the openings in the plate. This member has a discharge port at the filling station, and transfer of the particulate material from the openings to the container is carried out as each opening is brought into registry with the discharge port. Preferably, the plate is indexed to sequentially bring the openings over the discharge port, respectively.
Particulate material tends to get between this member and the movable plate. According to this invention, at least one groove is provided in the confronting surface of the member for collecting material that gets between the plate and the member. This material can be removed in various ways, including the use of vacuum pressure. In addition, the plate and member have confronting surfaces which are coated with a hard low-friction coating.
Although the height of the material in the hopper can be controlled in different ways, in a preferred construction, such controlling means includes a secondary hopper above the first-mentioned or primary hopper, valve means for controlling flow of the material from the secondary hopper to the primary hopper and means responsive to the level of the particulate material in the primary hopper dropping below a predetermined level for opening the valve means. To prevent the valve means from becoming jammed open by the particulate material, it preferably includes a valve seat having at least one aperture, a valve element having at least one aperture and means for mounting the valve element for movement radially of the aperture in the valve seat between an open position in which the apertures are partially in registry and a closed position in which the apertures are not in registry. The maximum extent to which the apertures may be placed in registry in the open position is also adjustable.
The invention, together with additional features and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying illustrative drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view, with the upper or secondary hopper portions broken away, of one form of apparatus constructed in accordance with the teachings of this invention.
FIGS. 2 and 3 are sectional views taken generally along lines 2--2 and 3--3, respectively, of FIG. 1.
FIG. 4 is a fragmentary, isometric view partially in section illustrating the structure adjacent the two filling stations.
FIGS. 5 and 6 are enlarged, fragmentary sectional views illustrating the transfer of particulate material to a container at one of the filling stations.
FIG. 7 is a fragmentary, sectional view similar to a portion of FIG. 5 showing one optional modification to the air supply nozzle.
FIG. 8 is a sectional view similar to FIG. 7 showing a second modification to the air supply nozzle.
FIG. 9 is a view taken generally along line 9--9 of FIG. 8.
FIG. 10 is a fragmentary sectional view illustrating one of the inclined passages through the deflector.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1-3 show an apparatus 11 which generally comprises a housing 13, a primary hopper 15, a secondary hopper 17, valve means 19 for controlling the flow of particulate material from the secondary hopper to the primary hopper and valve operating means 21. Although various different constructions are possible, the housing 13 comprises a peripheral wall 23, a base 25 suitably affixed to the lower end of the peripheral wall and a cover 27 suitably affixed to the upper end of the peripheral wall (FIG. 3).
An annular member 29 is suitably attached to the base 25 as by a plurality of fasteners 31 (only one being shown in FIG. 3) within the housing 13. A movable plate in the form of a rotatable disc or turret 33 is coupled to an indexing drive 35 through a suitable drive mechanism 37 which includes a shaft 39 (FIG. 3), a bearing 41, drive elements 43 and suitable fasteners 45. The drive mechanism 37 is appropriately supported by a supporting structure 47 and projects through an opening in the base 25 whereby it supports the turret 33 for rotational movement on, or very slightly above, the annular member 29.
To minimize the likelihood of particulate material getting between the turret 33 and the annular member 29 and to reduce friction, the confronting surfaces are lapped, coated with a hard lubricating surface and lapped again. For example, the coating may be of the type known as Magnaplate which is available from General Magnaplate Company.
Although various different constructions are possible, in this embodiment, the primary hopper 15 includes a peripheral wall 49 which is attached to the turret 33 for rotation therewith. Thus, the turret 33 may be considered as the floor of the hopper 15 or as simply a separate member that rotates with the hopper.
The turret 33 has openings 51 (FIG. 1) arranged in an outer ring and openings 53 arranged in an inner ring, with the adjacent holes of the two rings being circumferentially offset with respect to each other. Each of the openings 51 is of the same volume, and each of the openings 53 is of the same volume. In this embodiment, all of the openings 51 and 53 are identical. Each of the openings 51 and 53 is in the form of a thin cylinder, and the axial dimension of the cylinder is no greater than about the diameter of the opening, and preferably, the diameter of each of the openings is greater than the axial dimension of the opening.
The annular member 29 has discharge ports 55 and 57 (FIG. 1) arranged at filling stations, respectively, at the correct radial locations so that the rings of holes 51 and 53 can be brought into registry with them, respectively as the turret 33 rotates. As shown in FIGS. 5 and 6, a discharge tube 59 is fixed to the annular member 29 and defines the discharge port 55. The discharge tube leads through the supporting structure 47 to a container 61 which is to receive particulate material. In this embodiment, the container 61 is in the form of an inflatable plastic bag having a non-distensible wall. A vacuum conduit 63 leads from the tube 59 to an appropriate vacuum source 64 (FIG. 3). The discharge port 57 is defined by an identical discharge tube 59 and has an identical vacuum conduit 63. Another of the containers 61 is in direct communication with the discharge tube 59 which defines the discharge port 57.
Stationary air supply tubes or nozzles 65 are mounted, for example, on the cover 27 coaxial with the discharge ports 55 and 57, respectively. Each of the nozzles 65 is coupled to a supply 67 of air under pressure and terminates in very slightly spaced relationship to the upper surface of the turret 33 as shown in FIGS. 5 and 6.
As shown in FIGS. 2-4, the upper surface of the annular member 29 confronts, and is closely adjacent to, the under or lower surface of the turret 33. An inner annular groove 69 and an outer concentric annular groove 71 are formed in the upper surface of the annular member 29. Both of the grooves 69 and 71 are coupled via a conduit 73 to a vacuum source 75 (FIG. 3).
Particulate material 77 is supplied from the secondary hopper 17 (FIG. 2) to the primary hopper 15 under the control of the valve means 19. A rotary agitator 79 (FIG. 3) is rotated by a suitable drive 81 to break up any clumps of the material 77 and to help assure even and complete filling of the openings 51 and 53. The agitator 79 may be of various different designs and, for example, may comprise a plurality of radially extending vanes.
A level or height sensor 83 (FIGS. 3 and 4) senses the upper level of the material 77 in the primary hopper 15. Although various different level sensors can be utilized, in the illustrated embodiment, it comprises a paddle 85 pivotally mounted by an arm 87, which is pivoted about the cover 27, and a proximity switch 89. As the level of the material 77 rises, the paddle 85 pivots to move the arm 87 away from the proximity switch to provide a stop signal when the level of the material reaches a predetermined height. As the level drops, the paddle 85 and arm 87 counterrotate toward the switch 89 to provide a start signal when the level of the material drops to a predetermined level, and the arm 87 is positioned a predetermined distance from the switch 89.
The stop and start signals operate the valve operating means 21 to close and open the valve means 19, respectively. Although the valve means 19 can take different forms, in this embodiment, it includes a valve seat 91 (FIG. 2) having a plurality of apertures 93 extending therethrough and a valve element 95 also having a plurality of apertures 97 extending therethrough. The valve element 95 and the valve seat 91 form, in effect, a floor for the secondary hopper 17. The valve element 95 can be rotated to bring the apertures 97 into registry with the apertures 93 to permit gravity flow of the material 77 from the secondary hopper 17 into the primary hopper 15. The portions of the valve seat 91 and the valve element 95 which contain the apertures 93 and 97 are in closely adjacent, confronting relationship, and the rotation of the valve element 95 provides a shearing or cutting action which acts like scissors to shear the particulate material, including any clumps of material, that may be in the apertures 93 and 97 when the valve means 19 closes.
Although the valve element 95 can be rotated in different ways, in this embodiment, the valve operating means 21 includes a pneumatic actuator 99, a link 101, a rotatable shaft 103, an arm 105 fixed to the shaft 103, a pin 107 carried by the outer end of the arm 105, and an arm 109 coupled to the valve element 95 at its inner end by a coupling 111 and having a slot 113 for receiving the pin 107. In the full line position of FIG. 1, the valve means 19 is closed in that the apertures 93 and 97 are completely out of registry. However, by retracting the actuator 99 in response to a start signal, the arm 109 is pivoted clockwise to the position shown in dashed lines in FIG. 1 to bring the apertures 97 into registry with the apertures 93 so that the material 77 can flow by gravity through the registering apertures into the primary hopper 15. In response to the stop signal, the actuator 99 is extended to the full line position of FIG. 1 to close the valve means 19. The stop and start signals from the level sensor 83 can be processed by fill controls 115 in various ways known in the art to control the actuator 99.
The maximum extent to which the apertures 93 and 97 may be placed in registry can be controlled by varying the position of an adjustable stop 117 (FIG. 1). In the illustrated embodiment, the stop 117 is mounted for movement along parallel guide rods 119 which are suitably retained on a mounting block 121 which is mounted on supporting structure 122. The position of the stop 117 along the rods 119 can be adjusted by rotating a knob 123 which turns a screw 125 which extends through the stop 117. The stop 117 limits the pivoting travel of an arm 126 fixed to the shaft 103. Specifically, a pin 128 carried by the arm 126 engages the stop 117 as shown, for example, in dashed lines in FIG. 1. Using this adjustment, the maximum opening of the valve means 19 can be adjusted.
To provide for more even feeding of the particulate material 77 from the secondary hopper 17 to the primary hopper 15, the secondary hopper can be vibrated when the valve means 19 is open. This can be accomplished, for example, by a fixedly mounted pneumatic actuator 127 (FIG. 2) via a plate 129, fastener 130 and a suitable coupling 131 for attaching the plate 129 to the valve seat 91 and the valve element 95 so that they, along with the secondary hopper 17 can be vibrated vertically relative to the primary hopper 15. A collar and slot connection 133 permit the primary hopper 15 to remain stationary during vibration of the secondary hopper 17.
In operation of the apparatus 11, containers 61 are positioned beneath the discharge tubes 59, and the agitator 79 and the turret are rotated to evenly fill the openings 51 and 53 with the particulate material 77 under the influence of gravity. The indexing drive 35 indexes the rotational movement of the turret 33 so that it sequentially brings each of the openings 51 and 53 into precise registry with the discharge ports 55 and 57, respectively, and dwells there momentarily so that blasts of air under pressure from the nozzles 65 can simultaneously transfer the particulate material at the two discharge ports into the associated container 61. This indexing motion of the turret 33 followed by blasts of air from the air supply 67 is repeated a sufficient number of times to provide the correct quantity of material 77 into each of the containers 61. Vacuum is applied through the vacuum conduit 63 following transfer of the material 77 from the openings 51 and 53 to withdraw air from the containers that has been blown into the containers from the air supply 67. The vacuum may be applied following each indexing motion of the turret 33 or following any predetermined number of indexing motions of the turret. Periodically, such as after each container 61 is filled, vacuum is applied to the conduit 73 to evacuate any of the material 77 that may have gotten between the turret 33 and the annular member 29 and migrated to the grooves 69 and 71.
To maintain substantially constant density of the particulate material 77 in the openings 51 and 53, the height of the material 77 in the primary hopper 15 is closely controlled by the level sensor 83, the valve means 19 and the valve operating means 21. In fact, close control over the weight of material 77 deposited into the container 61 can be obtained from the volume of openings 51 and 53. Fine control over the weight of materal 77 deposited into the container 61 can be obtained by varying the height of the material 77 in the primary hopper 15 to thereby vary the density of the material in the openings 51 and 53. Accuracy is enhanced by utilizing at least five, and preferably about fifteen, of each of the openings 51 and 53 to provide the desired dosage of material to the associated container 61.
Although two rings of the openings 51 and 53 have been shown, obviously any desired number of the rings of openings can be provided. The controls for the sequencing of operations for the apparatus 11 can be conventional.
FIG. 7 shows an alternate air nozzle 65a which includes a tube 151 having a central cylindrical passage 153 extending therethrough and a cone 155 coaxial with the passage 153 and suitably attached to the tube 151 as by a rod 157 and other suitable structure not shown in FIG. 7. The cone 155 preferably terminates flush with the lower end of the tube 151 to define therewith an annular orifice 159, the outer periphery of which is in registry with, and slightly within, the periphery of the opening 51a which is at the filling station.
In use of the nozzle 65a, air under pressure is transmitted from the air supply 67 (FIG. 2) through the passage 153 and the orifice 159 such that the air is ejected from the orifice 159 in a generally tubular column or pattern toward the opening 51a at the filling station. The tubular column of air just fits within the periphery of the opening 51a to, in effect, tend to sever the particulate material 77a from the opening 51a and transfer it to the container 61 (FIG. 6). The tubular column of air represents a lower volume of air than a full cylindrical column of air that would be discharged from the tube 151 if the cone 155 were not employed. Accordingly, less air is transmitted to the container 61 (FIG. 6).
FIGS. 8-10 show a nozzle 65b which includes a tube 151b having an axial passage 153b therethrough and a deflector 161 mounted in the lower, or discharge, end of the tube 151b. In this embodiment, the deflector 161 terminates flush with the lower end of the tube 151b and has a plurality of inclined passages 163 extending therethrough. Each of the passages 163 lies closely adjacent the periphery of the deflector 161 and extends axially and circumferentially through the deflector. As shown in FIG. 10, the angle "X" at which the passage 163 extends circumferentially should be sufficient so that air discharged from the passage 163 can impart a swirling motion to the particulate material 77b in the opening 51b.
In use, air under pressure from the passage 153b enters the inclined passages 163 and is discharged therefrom in the form of a swirling, tubular column or pattern, with the periphery of the tubular column being in registry with, or slightly within, the periphery of the opening 51b. This imparts a swirling motion to the material 77b and results in transfer of the material from the opening 51b to the container therebelow (FIG. 6) with a minimum of air. Thus, the embodiment of FIGS. 8-10 accomplishes a whirlwind-type of ejection of the material 77b from the opening 51b.
Although an exemplary embodiment of the invention has been shown and described, many changes, modifications and substitutions may be made by one having ordinary skill in the art without necessarily departing from the spirit and scope of this invention.
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A method for loading a predetermined amount of particulate material into a container comprising providing a hopper containing a supply of the particulate material and a movable plate at least partly below the hopper, with the plate having a series of openings extending therethrough. The particulate material in the hopper is allowed to flow into and fill at least some of the openings in the plate, and the density of the particulate material in the openings is controlled. The plate is moved to move the filled openings to a filling station, and the particulate material from the openings is transferred to a container at the filling station. A plurality of the filled openings is used to deliver particulate material to each container so that any differences in the quantity of particulate material in the filled openings tends to be averaged.
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BACKGROUND OF THE INVENTION
This invention relates to presses used to form can ends, and particularly easy-open ends. The ends are used to close food and beverage containers or cans.
Ends are formed in a press equipped with a progressive die. The die has upper and lower tooling defining a plurality of stations. Each station has appropriate punches and/or dies for forming the end. The ends are carried or indexed from station to station by a conveyor belt. The ends are held on the belt by a vacuum box. A ram carries the upper tooling in a reciprocating motion into and out of cooperative engagement with the lower tooling. Details of the press structure are shown and described in U.S. Pat. No. 4,904,140, the disclosure of which is incorporated herein by reference.
The food and beverage containers on which the ends are used come in a wide variety of diameters. Naturally the ends must also be formed to match these multiple diameters. In the past, end tooling has been designed to produce only a single diameter end. If a different size end was needed, all of the tooling had to be changed to accommodate the new size. This was a time consuming operation during which, of course, no ends are produced. The down time is such that small runs of limited production sometimes could not be justified. The owner of a press would sometimes forego a small order than accept the down time needed to run a small job.
The present invention is directed to end tooling which accommodates several or multiple diameters without the need for changing all of the tooling.
SUMMARY OF THE INVENTION
This invention relates to tooling for converting easy-open can ends. A primary object of the invention is tooling for converting ends which makes ends of multiple diameters.
Another object of the invention is end tooling of the type described which increases versatility of existing press equipment by enabling production of multiple end diameters without changing all of the tooling. These and other objects which may appear from time to time in the following specification, drawings and claims are achieved by end tooling having cooperatively-engageable upper and lower tooling mounted on a ram and bolster of a press. The press has a conveyor which transports or indexes shells from one station of the tooling to the next. Shells are unfinished ends having a central panel and a turned edge on the periphery of the panel.
The tooling at each station includes a common locating means engageable with a first portion of an edge of any diameter end. The common locating means aligns the end relative to that station's tools. There is also a first custom locating means for a particular diameter end and a second custom locating means for a second or different diameter end. The first and second custom locating means are circumferentially spaced from the common locating means and are engageable with a second portion of an edge of its particular diameter end for further aligning the end.
In particular, the tooling has punch and die caps which form cylindrical end faces. One outside edge of the cap determines the common locating means. Another outside edge surface of the cap determines one of the custom locating means. An arcuate groove in the end face of the cap determines the other custom locating means. The groove also accommodates the turned edge of ends having a smaller diameter than the cap.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view with parts in section of the tooling at one station, showing variable end diameters between the upper and lower tooling.
FIG. 2 is a bottom plan view of the upper tooling, looking in the direction of line 2--2 of FIG. 1.
FIG. 3 is a top plan view of the lower tooling, looking in the direction of line 3--3 of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates the tooling at a station, looking longitudinally of one lane. It will be understood that the complete tooling comprises a plurality of stations, the precise number depending upon the type of end being formed. As an example, one type of end is converted by four rivet form stations, a score station, a panel station, an assembly station for putting a pull tab on, and embossing and checking stations. The station shown in FIG. 1 is the first draw rivet blister station. It will be understood that this is just illustrative of the inventive features, which may be found at each of the stations. Furthermore, more than one lane could be used.
The upper tooling of the station includes a punch holder 10 mounted on a ram 12. The punch cap holder has a threaded opening and counterbore for receiving a bolt 14 and a locating bushing 16 which together attach a punch cap 18 to the punch holder. A locating pin 20 fixes the orientation of the punch cap.
The punch cap comprises a cylindrical body portion 22 having side wall 23 and an end face 24. The end face is undercut at 26 along chord line 28. The punch cap has a bore along one edge which receives a spacer bushing 30 and a punch bushing 32. Both of these bushings have O-ring seals 34. The punch bushing 32 has an opening 36 in the end of it appropriately shaped for drawing a rivet blister.
The end face of the punch cap 18 has two arcuate grooves cut therein, as best seen in FIG. 2. The grooves are interrupted by the cutout 26 and are shown as groove segments 38A, 38B and 40A, 40B. The grooves are centered such that the inside diameters of the grooves are tangent with an edge of the end cap, the point of tangency being indicated at 42 in FIG. 2. The tangent point 42 defines a common locating means as further described below. The arcuate grooves 38, 40 define a set of lands including a full circular land 44, a pair of crescent-shaped lands 46A, 46B, a second pair of crescent-shaped lands 48A, 48B. The outer diameters of the lands 44, 46, and 48 define custom locating means as further described below.
Returning now to FIG. 1, the lower tooling includes a die holder 50 resting on a die shoe 52. The holder 50 supports a die spacer 54. The die spacer 54 has openings through which a guide pin 56 extends. Another opening in the die spacer receives a draw pin 58. The draw pin cooperates with the opening 36 in the punch bushing to form the rivet blister. A locating plug 60 extends through the die spacer and is fixed to the die holder 50 by a bolt 62.
The locating plug 60 limits the upward movement of a spring-loaded die cap 64. The die cap has a cylindrical body having an end face 66 and a side wall 68. The end face and side wall intersect at a corner. The die cap 64 is mounted on spring pins (not shown}which extend through the die spacer 54 and into cavities in the die holder 50. These cavities contain springs which urge the spring pins and die cap 64 upwardly against the locating plug 60. The die cap also has openings which receive the guide pin 56 and the draw pin 58.
The end face 66 of the die cap 64 is somewhat similar to that of the punch cap 18 except that there is no cutout. Looking at FIG. 3, the end face 66 has arcuate grooves 70 and 72 whose internal diameters are tangent at a point 74. Arcuate grooves 70 and 72 define a set of lands on the die cap. There is a circular land 76, a first crescent-shaped land 78 and a second crescent-shaped land 80.
Returning again to FIG. 1, three shells 82, 84, and 86 are shown between the upper and lower tooling. Of course, only one size end is made at a time. The drawing merely illustrates how the same tooling can accommodate different diameters. Each shell has a central panel portion 88 and a turned edge 90 which includes a chuck wall or countersink wall 92 and a radius portion 94.
The underside of the edge 90 is supported by a conveyor (not shown) which has generally circular openings about the size of the panel portions 88, allowing the shells to sit down in the openings with the edge 90 supported on the top of the belt. The upper side of the edges 90 are restrained by the vacuum box rails which are shown at 96 and 98. It will be noted that the rail 96 is the same for each size of shell but that the position of the rail 98 must be adjusted for the various shell sizes. Also, note that the cutout 26 in the punch cap accommodates the vacuum box rail 98. It will also be apparent that the conveyor must have openings sized for a particular diameter shell.
The use, operation, and function of the invention are as follows. The tooling operates more or less in the conventional manner for the largest diameter shell 86. When the conveyor has indexed a shell 86 to a station and the downstroke of the ram begins the punch cap 18 moves into contact with the upper side of the shell. Alignment of the shell with the opening 36 is achieved by the common locating means and custom locating means of the punch cap contacting the turned edge of the shell. By common locating means it is meant a portion of the cap which is operative regardless of the diameter of the shell being converted. A custom locating means is one which operates only with a particular diameter of shell.
In the case of the punch cap 18, the common locating means is the tangent point 42 and the portion of the end face 24 and side wall 23 a few degrees on either side of the tangent point. Actually the corner between the side wall and end face engages the upper inside edge of the countersink wall 92 as the punch cap is lowered. The end is further aligned by custom locating means which in the case of the shell 86 are the outside edges of the lands 48A and 48B. These edges also engage the countersink wall so that the shell is supported in three places on the punch cap.
Further downward movement of the ram brings the shell into engagement with the die cap 64. The die cap also has common locating means and custom locating means. In the case of the shell 86, the common locating means on the die cap is the tangent point 74 and a few degrees of the land 76 on either side of point 74. A slight portion of the side wall 68 and the corner between the side wall and end face 66 engages the underside of the depending radius 94 to locate the shell with respect to the draw pin 58. The custom locating means for shell 86 is the outer edge surface of land 80. This arcuate surface also engages the underside of the depending radius 94 to assure proper location of the shell prior to the die cap bottoming on the die spacer, at which point the drawing operation occurs. Once the return stroke of the ram has pulled the punch cap off of the shell, the conveyor indexes the shells to the next station.
When it is desired to make a different diameter end, the machine is set up as follows. One vacuum box rail 98 is relocated or changed to match the diameter of the new shells. The conveyor belt is also changed. Downstackers, cutoff knives and guides are changed to handle the new diameter. The panel station and score station tooling is changed but that is all that has to be done. This is compared with prior art tooling that required everything to be changed when the diameter changed.
Consider now how the alignment of the new diameter shells will take place. Say for example the end size now being made is that of shells 84. As the punch cap is lowered the common locating means 42 will again engage the countersink wall 92 of shell 84. But the custom locating means will change to the outer surfaces of the lands 46A, 46B. The arcuate grooves 40A and 40B will accommodate the upwardly extending countersink wall. When the shell 84 contacts the die cap 64 it will be aligned by the common locating means 74 and the custom locating means, which, in this case, would comprise the outside edge of the land 78. The groove 72 accommodates the depending radius portion 94 of the shell.
The situation is similar with respect to the smallest diameter end. Again, the common locating points 42 and 74 are involved in aligning the shell 82. The custom locating means in both the upper and lower tooling for the smallest end diameter comprise a complete circle of the lands 44 and 76. Thus, the smallest end is supported all the way around rather than in segments as is the case with the larger diameters. In any event, it can be seen that ends of variable diameters are aligned and supported for conversion, without changing the tooling at every station.
While a preferred form of the invention has been shown and described, it will be realized that alterations could be made thereto without departing from the scope of the following claims. For example, the tooling could be arranged to handle more or less than the three different diameters shown. Or the custom locating means could be a set of locating pins or the like, instead of the crescent-shaped lands shown.
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End tooling for forming easy open can ends has cooperatively-engageable upper and lower tooling defining a plurality of stations. Each station has appropriate punches and dies for progressively converting shells indexed by conveyor into easy open can ends. The tooling is adapted to convert ends of multiple diameters. The punch caps and die caps at each station have cylindrical bodies sized to engage and align a turned edge of a shell. The caps also have one or more arcuate grooves in the end face thereof for receiving the turned edge of ends having a diameter smaller than that of the cap.
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CROSS REFERENCE TO RELATED APPLICATIONS
The present invention is filed under 35 U.S.C. § 371 as the U.S. national phase of International Application No. PCT/NZ2014/000213, filed Oct. 3, 2014, which designated the U.S. and claims the benefit of priority to New Zealand Patent Application No. 616313, filed Oct. 4, 2013, each of which is hereby incorporated in its entirety including all tables, figures and claims.
FIELD OF THE INVENTION
The present invention relates to optical measurement devices and more particularly but not exclusively it relates to a system and apparatus adapted to measure optical properties in-situ.
BACKGROUND TO THE INVENTION
Optical measurement devices are used in a variety of different applications. Optical measurement devices include devices that are used to measure or otherwise determine one or more properties of light such as intensity, colour, wavelength, or other characteristics. One type of optical measurement device is an optical density sensor. One type of optical density sensor is a cell density sensor which operates by shining light through a solution to a receiver. The optical density of the solution changes the amount of absorption or scattering of the passing light. The light receiver outputs a signal dependent on the intensity of the light received, which is in turn dependent on how much scattering or absorption the solution has caused.
Cell density sensors are used in biotechnology, chemical, brewing, wine making, fermentation, pharmaceutical, and other sectors of industry or research. For biotech applications, cell density sensors are ordinarily used to monitor growth of living cells in a cell culture.
A disadvantage with such optical measurement systems is that they typically require an onerous process in order to be used. The process includes repeated removal of a sample of the solution at consecutive time points under sterile conditions, applying that sample to a measurement device, recording the measurement and disposing of the sample. This process increases the risk of contamination, and the loss of sample volume from the solution.
It is an object of the present invention to provide an improved measurement system which overcomes or at least ameliorates some of the abovementioned disadvantage or which at least provides the public with a useful choice. Other objects of the invention may become apparent from the following description which is given by way of example only.
SUMMARY OF THE INVENTION
In one aspect the invention consists in a measurement device adapted for in situ light intensity sensing from within an environment comprising a housing adapted to enclose a control system and fluidly seal the control system from the environment, the housing having an outer wall and a channel fluidly connected to the environment at one or more locations, the control system comprising a controller, a light receiver component and a wireless data transmitter component, the light receiver disposed within the housing to receive light from the channel and output one or more signals indicative of light intensity, and wherein the control system is configured to receive the one or more signals indicative of light intensity from the light receiver, and output a signal indicative of light intensity to the wireless data transmitter.
In one embodiment, the control system further comprises a light source disposed within the housing to define a light path that extends from the light source, through the channel to the light receiver.
In one embodiment, a plurality of optical elements are disposed within the light path and are arranged to prevent light travelling substantially non parallel to the optical path.
In one embodiment, a plurality of optical elements are disposed within the channel and are arranged to prevent light incident to the channel.
In one embodiment, the channel extends between at least two locations on the outer wall of the housing to define a fluid flow path between the at least two locations.
In one embodiment, the channel defines a substantially straight path. In another embodiment, the channel defines a curved path, including for example, a channel having an ‘S’ shape.
In one embodiment, the channel meets the outer wall of the housing at an acute angle in at least one location.
In one embodiment, the channel is adapted to receive a spigot containing wireless power transfer electronics.
In one embodiment, the outer wall of the housing is substantially spherical or at least has a substantially circular profile. For example, the outer wall of the housing has a substantially spheroid profile, including oblate or prolate profiles.
In one embodiment, the outer wall of the housing is shaped to promote mobility when immersed in an environment where optical density is to be measured.
In one embodiment, the measurement device is not tethered, fixed or fastened to any one particular location within the environment.
In one embodiment, the control system further comprises a temperature sensor. In various embodiments, a temperature sensor is located so as to be in contact with the environment within which the device is present, for example, a liquid suspension. In one example, a temperature sensor is located proximate the outer wall of the housing and configured to provide temperature information to the controller. In one example, a temperature sensor is located proximate the light receiver and configured to provide temperature information to the controller. In a further example, a temperature sensor is located proximate the channel.
In one embodiment, the measurement device further comprises a propulsion mechanism operable to propel the device when in-situ, the controller further configured to output a signal to cause operation of the propulsion mechanism.
In one embodiment, the measurement device further comprises a buoyancy mechanism operable to cause floating or sinking of the device when in-situ, the controller further configured to output a signal to cause operation of the buoyancy mechanism.
In one embodiment, the controller is configured to output a signal to cause energisation of the light source.
In one embodiment, the wireless data transmitter is configured to transmit data to a wireless data receiving device.
In one embodiment, the control system further comprises a wireless power receiver, the receiver disposed within the housing proximate the channel so as to receive wireless power signals emitted from within the channel.
In one embodiment, the channel is adapted to receive a spigot containing one or more wireless power transfer components.
In one embodiment, the control system further comprises a plurality of gain setting resistors and the controller is configured to change the configuration of the resistors to affect one or more of the dynamic voltage range output from the light receiver and/or the intensity of the light source.
In one embodiment, the control system further comprises a wireless power receiver, the receiver disposed within the housing proximate the exterior surface so as to receive wireless power signals emitted proximate the exterior surface.
In one embodiment, the wireless power receiver is configured to provide a source of received charging power to a power source.
In one embodiment, the power source is configured to provide power to the control system including one or more components of the control system.
In one embodiment, the housing comprises a first and a second shell section, the first shell section having an engageable sealing surface adapted to couple with an engagable sealing surface of the second shell section, and form, when engaged, a substantially hermetic shell that encloses the control system.
In one example, the housing is a substantially hermetic homogeneous shell.
In one embodiment, the housing further comprises at a first aperture fluidly connected to the environment.
In one embodiment, a tube is disposed with the first aperture and the inside of the tube is arranged to fluidly connect with the environment and the outside of the tube is adapted to seal to housing from the environment.
In one embodiment, the housing further comprises two apertures and the tube is adapted to extend from the first aperture to the second aperture to define a fluid path through the housing.
In one embodiment, the tube is disposed within the light path.
In one embodiment, the tube is an optically transparent material.
In one embodiment, the tube is substantially cylindrical.
In one embodiment, the sealing surface of each of the first and second shell sections is threaded.
In one embodiment, the sealing surface of the first and second shell sections are adapted to engage by interference fit.
In one embodiment, the sealing surface of the first and second shell sections are adapted to compress about an o-ring or sealing device.
In one embodiment, the first and second shell sections are adapted to be chemically or thermally bonded together.
In another aspect the invention broadly consists in a measurement device adapted for in situ light intensity sensing from within an environment comprising a housing adapted to enclose a control system and fluidly seal the control system from the environment, the housing comprising:
a first and a second shell section, the first shell section having an engageable sealing surface adapted to couple with an engagable sealing surface of the second shell section, and form, when engaged, a substantially hermetic shell that encloses the control system.
In one embodiment, the housing further comprises at a first aperture fluidly connected to the environment.
In one embodiment, a tube is disposed with the first aperture, the tube adapted to fluidly connect the environment to the inside of the housing.
In one embodiment, the tube is an optically transparent material.
In one embodiment, the tube is substantially cylindrical.
In one embodiment, the housing has two apertures and the tube is adapted to extend from the first aperture to the second aperture to define a fluid path through the housing.
In one embodiment, the sealing surface of the first and second shell sections is threaded.
In one embodiment, the sealing surface of the first and second shell sections are adapted to engage by interference fit.
In one embodiment, the sealing surface of the first and second shell sections are adapted to compress about an o-ring.
In one embodiment, the shell is substantially spherical or at least has a substantially circular profile.
In one embodiment, the shell is shaped to promote mobility when immersed in the environment.
In one embodiment, the shell is not tethered, fixed or fastened to any one particular location within the environment.
In one embodiment, the first and second shell sections are adapted to be chemically or thermally bonded together.
In another aspect the invention broadly consists in a system comprising a sensor adapted to measure optical density from within an environment and a data processing device, the sensor comprising a housing adapted to enclose a control system and fluidly seal a control system from the environment, the housing having an outer wall and a channel fluidly connected to the environment at one or more locations, the control system comprising a controller, a light receiver component and a wireless data transmitter component, the light receiver disposed within the housing to receive light from the channel and output one or more signals indicative of light intensity, and wherein the control system is configured to receive the one or more signals indicative of light intensity from the light receiver, and output a signal indicative of light intensity to the wireless data transmitter, wherein the data processing device comprises a wireless data receiver configured to receive data transmitted by the wireless data transmitter.
In another aspect the invention broadly consists in a system comprising a sensor device adapted to measure optical density from within an environment and a data processing device, the sensor device comprising a wireless data transmitter configured to wirelessly transmit a signal indicative of an optical density measurement to the data processing device, and the data processing device comprising a receiver adapted to receive a signal indicative of optical density measurements.
In one embodiment, the data processing device is configured to store data received by the wireless data receiver on a storage device.
In one embodiment, the sensor device has an onboard data storage unit. For example, the sensor device has an on-board data storage unit to complement or substitute for the data processing device, for example as a support system in case of network malfunction and other power outages so as to retrieve data.
In one embodiment, the data processing device is configured to compute one or more statistical calculations on the stored data.
In one embodiment, the data processing device is configured to determine a measure of the optical density within the channel.
In one embodiment, the data processing device is configured to display a value indicative of the measure of the optical density within the channel to a display.
In one embodiment, the data processing device is configured to store data indicative of the time data is received from by the wireless data receiver.
In one embodiment, the data processing device is configured to interface with one or more other data processing devices.
In one embodiment, the data processing device comprises a wireless data transmitter adapted to transmit a signal indicative of a measurement to be taken, and the sensor further comprises a wireless data receiver adapted to receive the signal indicative of an optical density measurement to be taken.
In another aspect the invention broadly consists in a measurement system comprising an in situ light intensity sensor operable to measure optical density from within an environment and a data processing device, wherein the data processing device comprises a wireless data transmitter adapted to transmit a signal indicative of a measurement to be taken, and the sensor comprises a wireless data receiver adapted to receive the signal indicative of an optical density measurement to be taken and operate to take a measurement.
In one embodiment, the device is configured to perform one or more of the following steps: store data received by wireless data receiver on a storage device, compute one or more statistical calculations on the stored data, and determine a measure of the optical intensity within the channel, output a value indicative of the measure of the optical intensity within the channel to a display, store data indicative of the time data is received from by the wireless data receiver, transmit the stored data to one or more portable computation devices, or display received data.
In another aspect the invention broadly consists in a control system comprising a controller adapted for use in the measurement device and configured to output a signal to energise a light source in the measurement device, receive information indicative of an optical intensity measurement from a light receiving device, output information indicative of an optical intensity measurement to a wireless data transfer device.
In one embodiment, the controller is further configured to store information indicative of an optical intensity measurement received from a light receiving device.
In one embodiment, the measurement device comprises a power source and the control system is configured to measure the power from the power source.
In one embodiment, the control system further comprises a plurality of gain setting resistors and the controller is configured to change the configuration of the resistors to affect one or more of the dynamic voltage range output from the light receiving device and/or the light intensity of the light source.
In one embodiment, the controller is a microprocessor.
In one embodiment, the control system is further configured to output a signal operable to control or at least initiate operation of one or more of a propulsion mechanism or buoyancy mechanism.
In another aspect the invention broadly consists in a charging station comprising a base and a spigot and adapted to support a measurement device adapted for in-situ optical density sensing from within a fluid environment, wherein the base and/or the spigot are adapted to enclose one or more wireless power transfer components, and wherein the measurement device comprises a housing adapted to enclose one or more wireless power receiver components and the housing has a channel fluidly connected to the environment at one or more locations, and wherein the spigot is adapted to engage the channel to support the measurement device on the charging station.
In another aspect the invention broadly consists in a method of measuring optical density using a device, system, or housing according to any previous statement wherein the method comprises providing the device, system, or housing, operating the controller to receiving a signal from the light receiver and outputting a signal to the wireless data transmitter.
In another aspect the invention broadly consists in a method of charging the power source in the device according to any previous statement, wherein the method comprises providing the charging station, providing the measurement device, engaging the measurement device with the base and/or spigot of the charging device, and energising the one or more wireless power transfer components.
In other aspects, the invention relates to a device, system, housing or station as herein described or shown in any one or more of the accompanying figures.
Other aspects of the invention may become apparent from the following description which is given by way of example only and with reference to the accompanying drawings.
As used herein the term “and/or” means “and” or “or”, or both.
As used herein “(s)” following a noun means the plural and/or singular forms of the noun.
The term “comprising” as used in this specification and claims means “consisting at least in part of”. When interpreting statements in this specification and claims which include that term, the features, prefaced by that term in each statement, all need to be present, but other features can also be present. Related terms such as “comprise” and “comprised” are to be interpreted in the same manner.
As used herein, when the context allows the term “proximate” includes “at”.
It is intended that reference to a range of numbers disclosed herein (for example, 1 to 10) also incorporates reference to all rational numbers within that range (for example, 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9 and 10) and also any range of rational numbers within that range (for example, 2 to 8, 1.5 to 5.5 and 3.1 to 4.7).
The entire disclosures of all applications, patents and publications, cited above and below, if any, are hereby incorporated by reference.
This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described by way of example only and with reference to the drawings in which:
FIG. 1 shows an embodiment of the sensor in schematic form.
FIG. 2 shows a cross section of the sensor of FIG. 1 .
FIG. 3 shows an overview of the sensor in situ and proximate an external control system.
FIG. 4 shows a side elevation of a spherical ( FIG. 4A ) and a spheroid ( FIG. 4B ) sensor, and respective charging platforms.
FIG. 5 shows a cross sectional view a spherical ( FIG. 5A ) and a spheroid ( FIG. 5B ) sensor and the charging platform of FIG. 4 .
FIG. 6 shows a schematic of the components of FIG. 2 in further detail ( FIG. 6A ), and a schematic of the components of FIG. 2 with a temperature sensor ( FIG. 6B ).
FIG. 7 shows a graph comparing the results obtained with a sensor and a bench top spectrophotometer as described in Example 1.
FIGS. 8 to 10 show light and fluid channels arranged within the sensor.
FIG. 11 shows an example of a sensor having an ‘S’ shaped fluid channel.
FIG. 12 shows a spherical ( FIG. 12A-12C ) and a spheroid ( FIG. 12D-12F ) sensor and a layout of the components within the sensor.
FIG. 13 shows the representative spherical ( FIG. 13A-13C ) and the spheroid ( FIG. 13D-13F ) sensors of FIG. 12 with dimensions provided.
FIG. 14 shows a schematic of the components of the control system, network, and user interfaces.
DETAILED DESCRIPTION OF THE INVENTION
Growth in a living cell is an orderly increase in the amount of cellular components. In most living organisms, growth involves the increase in cell mass, duplication of the genetic material (DNA) followed by cell division. The division of cells increases cell number and hence the concentration of cells in a growth medium. A method of estimating cell concentration is by measuring turbidity of a suspension of cells in a liquid medium using photometry. Particle size objects, such as bacteria, suspended in a liquid scatter light that passes through the suspension. This scattering reduces the intensity of the light that is directly transmitted through the suspension. To a human eye, the suspension appears to be turbid or “cloudy”. As more light is scattered with increasing cell concentration, the reduction in light intensity can be used to measure the concentration of cells.
Expressing cell growth mathematically, the intensity I of the light after it has passed through a solution or particle suspension is equal to the intensity I 0 of the incident light, multiplied by 10 −N/N10 , where N is the concentration of particles in suspension and N 10 is the concentration of particles which gives a tenfold decrease in the light intensity.
I=I 0 ·10 −N/N 10 (Beer-Lambert Law)
On rearranging the equation and taking the logarithm to the base 10;
log I/I 0 =log 10 −N/NN 10 or −log I/I 0 =N/N 10
The term −log I/I 0 is known as absorbance or optical density (OD) of a solution or suspension. Optical density is a function of the wavelength of the light and the optical path length through the suspension. Optical density or turbidity of a suspension of cells can—after calibration—be directly converted into cell concentration.
Existing probes have been designed and previously reported for large-scale fermentors or bioreactors. At the laboratory level, bacteria, yeast, fungi or mammalian cells are cultured in glass flasks and incubated at set temperatures in a shaker-incubator. Briefly, live or cryopreserved cells are inoculated into a growth medium, containing required growth supplements, inside a glass flask. This forms a broth of culture media and suspended particulates. The flasks are kept inside a temperature controlled shaking incubator to induce the cells to multiply. To monitor cell growth, aliquots of culture broth are taken manually from the flasks at regular time intervals, and measured using a spectrophotometer. The accurate monitoring of cell growth is—essential for many downstream applications and this offline measurement technique is cumbersome, time consuming, and prone to contamination and human error.
Embodiments of the invention relate to a sensor that is immersible in a solution the optical density of which is desired to be measured. Embodiments of the invention also relate to a system adapted for use with the sensor. The sensor is adapted to wirelessly communicate information to an information processing system and does not require manual removal of a sample or manual use of a spectrophotometer.
FIG. 1 shows a particular embodiment of the sensor 15 in schematic form. The sensor has a housing 4 which substantially encapsulates a plurality of components including a light source 2 and a light receiver 5 configured to receive light from the light source 2 . The receiver 5 can directly face the light source, or the receiver 5 can be arranged such that emitted light is adequately guided by the optical properties of nearby or incident components. In some embodiments where luminance of the solution is desired to be measured, the light source is omitted.
The light source is configured to emit light when provided with an appropriate electrical stimulus. In one example, the light source is a light emitting diode (LED) or similar device which emits light when a voltage is applied. In certain embodiments the light receiver is a photodiode, phototransistor or similar device. The light receiver 5 is configured to output a signal indicative of the light intensity received. The light source 2 and receiver 5 are at least closely matched in terms of the wavelengths upon which they can efficiently transmit or receive. Further, the particular operation wavelength may be selected depending on the absorption properties of a solution desired to be tested. For example, the operation wavelength is aligned with or proximate to a peak absorption wavelength of a solution to be tested to optimise absorption efficiency and dynamic range of the measurements.
The light source 2 and light receiver 5 are located a specific distance apart such that an optical path is located therebetween. A channel 3 is located within the optical path such that light emitted from the light source 2 passes through the channel and to the receiver 5 . The channel 3 has at least one opening fluidly connected with the exterior of the housing 4 such that the solution or suspension fills the channel when the sensor is immersed. The intensity of the light received by the light receiver 5 is indicative of the optical density of the substance within the optical path.
In some configurations the sensor has a number of collimating devices arranged within the channel 3 and optionally also the light path between the light source 2 and light receiver 5 to lower the acceptance angle of the light reaching the receiver and to reduce the amount of light scattered, or reflected off the sides of the channels into the light receiver. Preventing or mitigating the amount of ambient or scattered light from reaching the receiver improves measurement performance. The collimating devices comprise reflective, absorptive, or dispersive optical components having a geometry that provides scattering of the light incident upon it. FIGS. 8 to 11 illustrate configurations of the sensor with ridge like collimating devices 23 arranged within the channel 3 that have the effect of enabling a lower acceptance angle of light to the light receiver, and reducing the reflectance of the channel.
FIGS. 8 and 9 illustrate collimating devices 23 arranged within the light path 26 and transparent members 27 fluidly sealing the light source and light receiver portions of the light path from the channel 3 . The collimating devices 23 are optimally arranged when only light travelling substantially parallel to the channel or light path enters the light receiver. Arrangement of the light path and channel in a substantially perpendicular geometry further improves measurement performance.
In some embodiments the housing has two openings such that the channel 3 extends from one side of the housing 4 to another to create a fluid flow path. This allows fluid to flow through the channel 3 as it is circulated by the natural stirring motion induced by a shaking incubator.
In some embodiments the channel is a cylinder which has a curved inner surface shape that advantageously reduces the chance of bubbles forming in the cavity and affecting the light path. In other embodiments, such as those where bubbles are not a concern, the channel is circular or square or polygonal in cross section. The use of glass or other hydrophilic material to form the channel decreases the tendency of bubbles to stick to the surface. In certain embodiments the channel is sealed to the sensor shell by mechanical seals such as o-rings, or it is chemically bonded by materials such as viscous sealant.
In some embodiments the channel 3 has entry ports 25 angled with respect to the sensor surface or a channel that is at least a serpentine shape. FIG. 11 shows an example of a sensor having an ‘S’ shaped channel 25 and angled entry ports. The ‘S’ shaped channel also helps to prevent ambient light from reaching the light receiver by blocking the line of sight trajectory of light entering the tunnel.
In some configurations a plurality of fins 24 are arranged on the sensor surface such that when immersed within a stirred solution the fins cause the sensor to spin. The fins in combination with the ‘S’ shaped channel promote pumping of the fluid through the channel. A shorter light path through the fluid enables use in higher OD solutions and/or the use of a lower power light source.
In one embodiment the sensor housing could be constructed using 3D printing techniques. A minimum wall thickness is used to ensure structural integrity is maintained during the sensor lifetime. Selective Laser Sintering 3D printing limitations for acrylic based photopolymer or nylon plastic: Objects must be manifold, minimum detail of 0.2 mm, minimum wall thickness of 0.7 mm, maximum temperature of 80° C.
In various embodiments the sensor housing is formed from multiple shell components, such as two hemispheres. The shell components are, for example, chemically or mechanically fastened together to encapsulate the internal components. Mechanical fastenings to secure each shell component include threaded or interference type connections. In some embodiments the shell components comprise two substantially hemispherical shell sections.
Each shell section has a mating surface where the shell sections are to oppose and engage. For example, the mating surface has a threaded connection complimentary to the opposing shell sections such that the shell sections can be screwed together. Alternatively, the mating surface of each shell section is sized to engage with an interference fit and therefore allow the use of non circular engaging surfaces. The housing is then completed by applying pressure to join the two shell sections and force the engagement of the mating surfaces. One or more sealing devices such as o-rings or semi viscous sealant may be employed to ensure leak proof engagement of the shell sections. In another embodiment, sealing is by friction, welding, or other engagement to ensure leak proof engagement, for example so as to form a homogeneous surface.
An optimum form of the sensor 15 for facilitating movement when immersed in a solution is that of a spherical form such as shown in the figures. However, in certain embodiments other forms that facilitate movement of the sensor, or at least do not substantially prevent movement, within a moving solution are utilised. For example, a substantially cylindrical or elliptically shaped housing form, a spheroidal form, or any other curved surface shaped housing form is utilised.
The outer surface of the sensor can include dimples or spikes. Impressions can help reduce fluid drag or provide traction to resist or reduce movement in fast moving fluids. Spikes can be provided where it is desired that the sensor embed itself in material on the bottom of the solution. For example, the sensor can be used in a stream of fluid where measurements are desired to be taken, such as a riverbed. The spikes help to fix the sensor in one location with respect to the stream.
To further facilitate movement of the sensor within an agitated solution, the outer surface of the sensor may include one or more fluid dynamic surfaces operable to impart kinetic energy to the sensor from the solution, or by an induced rotation of the shell with respect to the solution. The surfaces may comprise fins, contours, impressions or depressions joined to or formed in the outer sensor surface.
In some embodiments the sensor is constructed to have an eccentric weight distribution. This can assist in movement of the circulating fluid through the channel, or to preferentially align the channel with a particular direction, such as that of a flow path of a solution.
In some embodiments the light source 2 and receiver 5 are mounted to an electronics substrate 1 that is, in turn, releasably mounted to or within the housing 4 . When mounted to the substrate 1 , the light source and receiver may be readily removed from the sensor 15 and replaced with other combinations. This may allow the selection of particular operation wavelengths and light intensities depending on the solution desired to be tested. In some embodiments the substrate 1 is a circuit board able to flex such that it may easily fit within packaging constraints that sensor housing may impose. However, it is ideal that the light source 2 and receiver 5 are rigidly spaced apart such that alignment is maintained and movement or vibration has no substantial effect on the accuracy of the optical components. One or more guide lugs can be provided within the housing to facilitate repeatable and stable mounting of the substrate 1 .
FIG. 2 shows a cross section of the sensor of FIG. 1 showing the channel 3 disposed in the light path 9 between the light source 2 and the light receiver 5 . The channel 3 is open to receiving solution 8 which causes absorption or scattering of light within the channel and light path.
FIG. 2 also shows a control unit or controller 10 that is configured to connect to the light source 2 , the light receiver 5 , a power source 6 and a wireless communications interface 11 . The control unit is a microprocessor having at least one or more analogue-to-digital converter (ADC) inputs, one or more digital outputs and/or serial data transmission and receiver pins for communication with external protocol capable devices.
FIG. 6 shows a schematic of the components of FIG. 2 in further detail ( FIG. 6A ), and a schematic of the components of FIG. 2 with a temperature sensor 60 ( FIG. 6B ), and in particular shows the controller 10 and connected components. The controller is configured to connect with the wireless communications interface 11 to at least transmit and also receive data from an external system.
In some embodiments the wireless communications interface 11 is a radio transceiver. However, in other embodiments the interface 11 may be a transmitter only. The interface can be, for example, 2.4 GHz transceiver having a common communications protocol such as a Bluetooth transceiver. Other transmission frequencies and protocols may be used. In circumstances where long range communication is required, or communication through matter having substantial radio frequency attenuation, it can be beneficial to use lower frequencies such that wirelessly transmitted power can be kept relatively low to conserve battery power. However, higher transmission frequencies offer benefits such as smaller antennas and may therefore be most appropriately applied in circumstances where limited packaging space is available within the sensor housing 4 . Further, in some embodiments the PCB track or flexible antennas are incorporated. Alternatively, the antenna extends externally to the sensor housing as long as appropriate shield materials suitable for sterilisation are used.
In various embodiments the controller 10 is configured to control energisation of the light source 2 and receive a signal from the receiver 5 indicative of the amount of light received. The controller can facilitate an automated process where, for example, the light source 2 is periodically energised and the receiver 5 output received and stored. Alternatively, the controller can respond to an instruction received via the communications interface 11 to make a measurement.
The controller 10 samples a voltage received from the light receiver 5 via an ADC input pin at periodic intervals. The signal the controller receives from the light receiver 5 is indicative of the light scattered or absorbed by solution within the optical path 3 . The optical density of the solution can be determined from the received signal. As the solution becomes more optically dense, the intensity of the light received by the light receiver is reduced.
In some embodiments the controller has an ADC configured to sample the signal received from the light receiver. The sampled value can optionally be converted a measurement via Beer's Law or stored for later use and/or transmission to an external system. The controller can process the measurement internally, for example using preconfigured software, or the controller can output the raw value to the communications interface and an external processing system may then calculate the measurement value. The controller has a digital output configured to control energisation of output of the light source 2 . The digital output may be configured to provide, for example, a PWM signal representing a desired intensity output. Such a PWM signal may be amplified by appropriate electronics should the controller output not be able to supply enough current on its own.
FIG. 14 presents a schematic depicting one embodiment of the invention, in which one or more sensor devices 15 are controlled by a control system 141 (typically a PC or laptop) in the proximity of the one or more sensor devices. The control system is connected 143 to the one or more sensor devices, for example via Bluetooth 142 , and to a computer network 144 for user interaction. Users 145 can remotely control or monitor the sensor devices by connecting to the control system. In one example, one or more of the sensor devices have an identifier 146 , such as an LED, to differentiate the devices present. The identification process and other sensing aspects of the device can be triggered via software 147 running on the control system. In various embodiments the software is configured to identify one or more of the sensor devices, for example internally by a unique ID, to make it identify itself to the user (for example by LED), to control the measuring functions of the sensor device, to fetch recorded data from the sensor device, and/or to display and/or analyse the data.
To minimise power consumption, in some embodiments the controller is configured to pulse the light source or energise it only for short periods such as when the receiver output is being monitored. Energising the light source for at least 10 ms ensures that light source avoids detecting any transients and that the receiver output is likely to be stable. The light receiver receives enough light in order for it to make correct measurements and that intensity of the light source is constant.
The light receiver output is tuned such that it remains within a linear range and does not saturate. The linearity of response is ensured either by selection of the components during construction or dynamically by a configuration of programmable resistors that are connected to the controller to form voltage divider circuits and/or control the gain of an active signal amplifier. The programmable resistors can be set based on knowledge of the dynamic output range of the light receiver and/or light source to tune either the output sensitivity or intensity respectively. This allows the sensor to be configured to measure a wide range of optical densities and that configuration is changeable using the controller to implement changes in sensitivity and intensity.
In some embodiments, the sensor may incorporate a propulsion mechanism operable to provide motility of the sensor within a vessel. For example, in environments with large fluid volumes, the propulsion mechanism advantageously enables the sensor to operate to sample from several locations within the vessel, and wirelessly transmit the sample to a distal location. Propulsion can be achieved, for example, by having a rotatable fin mounted external to the sensor housing. Rotating the fin by way of a motor propels the sensor within the solution. The propulsion mechanism can also be used to replace a laboratory shaking or stirring platform by actively agitating the solution by the sensor moving in the solution and/or the sensor moving the solution relative to its position. This may be advantageous in circumstances where the optical density of a solution is desired to be known in a non-laboratory environment.
In some embodiments, the sensor incorporates a buoyancy control device. For example, buoyancy control may be desired in environments with vertically large fluid volumes such as beverage fermentation vats. The buoyancy control device advantageously enables the sensor to take measurements from many vertical locations as it rises and sinks. Alternatively, the buoyancy of the sensor could be selected to float or sink in a particular solution to be tested. Buoyancy control can be achieved, for example, by compressing a compressible fluid with a piston to change the internal density of the sensor. Alternatively, a fluid bladder can be used to draw solution into the bladder to change the buoyancy.
In certain embodiments, particularly where the sensor includes a buoyancy and/or a propulsion mechanism, the controller can be configured to actively control propulsion and/or buoyancy of the sensor in-situ. For example, the controller is configured to have the sensor move in the solution while recording measurements. For example, the sensor may be located in a vessel having a large vertical distance such as a fermenter. The sensor can travel the vertical distance by control of buoyancy and/or propulsion while also recording measurements to attain a continuous profile of the vessel. In other embodiments the buoyancy and/or a propulsion mechanism is operated in free form or a predetermined activation pattern. For example, when the buoyancy or propulsion mechanism is configured to cause the sensor to rise and/or sink one or more times.
In some embodiments the sensor includes a second light receiver and optical components configured to reflect a portion of the light transmitted by the light source to that second light receiver. The light received by the second light receiver is indicative of the output power from the light source and can be used as a calibration measure.
In some embodiments the sensor includes one or more temperature sensors arranged within the housing and configured to provide temperature information to the controller. For example, temperature sensors located proximate to the light receiver can be used to compensate for temperature related drift of the light receiver. A temperature sensor located near the power source can be used to indicate excessive temperature generation. A temperature sensor located in contact with or proximate a surface in contact with the environment, for example near the housing surface, or proximate the channel, can be used to indicate environment temperature information, for example solution temperature information.
The power source 6 is configured to provide power to the controller 10 and other components located within the housing 4 . The most useful power source is a rechargeable battery. In this configuration, a charging system 7 is connected to the battery to provide a source of power from which the battery can be recharged. In this configuration the charging system has a wireless power transfer receiver. In other configurations, the charging system and battery may be replaced with a wireless power receiving device that continuously receives power to operate the sensor, or receives power at least when measurements are desired to be taken. Inductive power transfer technology may be used to apply power to the sensor or battery charging system from a remote location without the use of a wired connection.
The power system 7 incorporates appropriate electronics configured to convert a received wireless power signal into a voltage useful for charging the battery or powering electronics within the housing. The particular electronics and configuration required are dependent upon incoming wireless power transfer signals and the particular devices to be powered. Those skilled in the art will recognise the need for the electronic circuits to be tailored to the requirements. However, it is noted that rectification and/or DC to DC conversion circuits are most applicable. The controller 10 may further facilitate power management by, for example, monitoring the voltage of the battery 6 and communicating readings either facilitating transmission of a signal indicative of the need for recharging or automatically activate a recharging process.
In some embodiments the wireless charging system has a coil operating with a voltage of around 5V and frequency between 112-205 kHz on a 100 kHz tuned coil circuit with 5 W max power output. For optimum charging operation, the charging components can include Qi compliant inductive charging with device detection, power transmission management and foreign object detection.
To optimise sensor operation, the power management electronics and the communication electronics are physically separated by a practical distance to mitigate or eliminate electromagnetic or radio frequency interference creating undue noise. Further, separate ground planes between power management electronics and the communication electronics is beneficial to further isolate noise.
To provide power to the sensor a battery can be a single cell 3.7 V lithium ion polymer 110 mA/hr battery having 200 mA discharge and 100 mA charge rates. However any high energy density rechargeable battery could be employed. Alternatively, where the size of the sensor housing is not limited, lower density energy sources could also be used.
In some embodiments, one or more electromechanical kinetic energy harvesting mechanisms may be used in place of, or alongside, a wireless power transfer device to facilitate a source of power to recharge the battery 6 . In this way, movement of the sensor while in use can generate electrical energy used to power onboard electronics or charge a battery. The time required to charge the battery in the sensor may be therefore reduced or not required.
The controller 10 may further be configured to use the light source 2 as a status indicator in configurations where the light source can be seen from outside the vessel containing the sensor. For example, the light source can be flashed to show a code indicative of parameters to a user in visual range. The code can be indicative of information such as, full memory or low battery, or for identification of a particular sensor in an environment where many sensing devices are simultaneously deployed.
FIG. 4 shows a side elevation of a side elevation of a spherical ( FIG. 4A ) and a spheroid ( FIG. 4B ) sensor 15 residing on a spigot 21 that forms part of a charging platform 22 . FIG. 5 shows a cross sectional view the sensor 15 and charging platform 22 of FIG. 4 , and a perspective view of a charging platform 22 without a sensor attached. While the channel 3 of the sensor 15 performs the task of providing an opening that allows the solution to flow into the optical path between the light transmitter 5 and light receiver 4 , it also provides a mounting receptacle that allows the sensor to be mounted securely to the platform. The spigot 21 of the platform 22 incorporates a wireless power transmission, or inductive charging device. The sensor 15 has the wireless power receiving device positioned proximate to the spigot 21 when mounted on the spigot to optimise wireless power transfer efficiency.
When the sensor 15 is not in use, it can be placed upon the platform 22 which then provides wireless power to charge the built in battery 6 . The sensor 15 does not therefore require a wired interface for power transmission or recharging and the sensor has a charged battery when it is required to be used.
FIG. 3 shows an overview of the sensor 15 in-situ and proximate an external control system. The external control system is configured to work harmoniously with one or more sensors by being configured to respond to communication signals transmitted from one or more sensors, store data received from the one or more sensors and optionally display data.
The external control system comprises one or more computational devices and may comprise one or more of a stand-alone computer, laptop 20 , smart phone 19 or tablet type device. A base station 18 may optionally be provided to interface one or more computational devices to one or more sensor devices 15 . The base station 18 may comprise, for example, a wireless communications interface complementary to the wireless communications interface incorporated in the sensor.
The base station 18 may also comprise a wireless power transfer device adapted to provide a wireless power transfer signal to the sensor. The base station 18 may further comprise computational ability and provide a replacement for other computational devices. The base station 18 may further comprise one or more display devices adapted to display data such as a real time optical density measurement or sensor battery capacity status.
The sensor 15 is shown in use whereby it is immersed within a vessel 13 also containing a solution from which an optical parameter, such as the optical density, is desired to be measured. The vessel could be a beaker, flask or similar container. The vessel 13 is optionally located within an incubation cubicle 12 for control of the environmental temperature. The vessel optionally resides atop a plate that provides mechanical movement to the vessel to simulate stirring or agitation of the solution within.
Cell growth rate and/or density in a solution containing live cells can be determined by periodic measurement of optical density of the solution within the sensor channel 3 . The sensor 15 determines a measure indicative of the optical density of the solution 8 and wirelessly transmits a signal indicative of the optical density to the base station 17 for further interpretation. The wirelessly transmitted data may optionally include identification information in the event several sensors are used in close proximity. In this way, the base station may determine the particular sensor from which a signal was received.
The base station may also be configured to transmit a signal to the sensor and the sensor configured to receive that signal and respond appropriately. For example, the base station may be configured to transmit a signal indicative of a sample value to be taken by the sensor. The sensor is configured to receive that signal, determine a measurement from the solution in the channel 3 and transmit data back to the base station 17 . Alternatively, the sensor may transmit blocks of data at periodic intervals which allows the sensor to sample over a longer time period than continuously transmitting data. This minimises the energy consumption associated with data transmission, or for extending operation time should the battery energy be depleted. The base station may further be configured to control activation of any propulsion or buoyancy control within the sensor.
FIG. 12 shows a spherical embodiment ( FIG. 12A-12C ) and a spheroid embodiment ( FIG. 12D-12F ) of the sensor 15 optimised for use in a laboratory vessel and with an optimised layout of the internal components. In particular, FIG. 12A shows a front view and cross sectional view AA, FIG. 12B shows a side view and cross sectional view BB, and FIG. 12C shows a top view and cross sectional view CC.
The sensor 15 has two joinable hemispherical shell sections, an upper shell section 31 and a lower shell section 32 . The shell sections can be joined by a releasable mechanism such as an interference fit or threaded connection.
The channel 3 is formed from a borosilicate (for example, Pyrex™) tube that extends from one extent of the shell to the other. The channel 3 is sealed to the shell sections by o-rings 30 . A light source 2 and light receiver 5 are disposed about the channel.
A collimator 23 is provided proximate the light source and receiver to guide light through the channel, minimise light scattering and minimise ambient light from entering the light receiver.
A battery 6 is located in one portion of the housing and one that is distant from the location of the wireless communication device 11 to minimise shadowing of radio signals. The wireless communication device 11 is a Bluetooth transceiver module. A controller 10 is connected to the wireless communication device 11 , the light source 2 and the light receiver 5 .
FIG. 12D shows a front view and cross sectional view AA, FIG. 12B shows a side view and cross sectional view BB, and FIG. 12C shows a top view and cross sectional view CC, of the spheroid sensor 15 .
The sensor 15 has two joinable hemispherical shell sections, an upper shell section 31 and a lower shell section 32 . The shell sections can be joined by a releasable mechanism such as an interference fit or threaded connection.
The channel 3 is formed from a borosilicate (for example, Pyrex™) tube that extends from one extent of the shell to the other. The channel 3 is sealed to the shell sections by o-rings 30 . A light source 2 and light receiver 5 are disposed about the channel.
A collimator 23 is provided proximate the light source and receiver to guide light through the channel, minimise light scattering and minimise ambient light from entering the light receiver.
A battery 6 is located in one portion of the housing and one that is distant from the location of the wireless communication device 11 to minimise shadowing of radio signals. The battery is connected to a charging coil or coils 121 in the sensor 15 , in which current is induced when the sensor 15 is placed on the charging platform 22 by a charging coil or coils 121 , optionally forming part of a charging PCB 122 , present in the charging platform 22 and the charging platform is powered, for example via a DC jack 123 . The wireless communication device 11 is a Bluetooth transceiver module. A controller 10 is connected to the wireless communication device 11 , the light source 2 and the light receiver 5 .
FIG. 13 shows the representative spherical ( FIG. 13A-13C ) and the spheroid ( FIG. 13D-13F ) sensors of FIG. 12 with dimensions provided. In particular, FIG. 13A shows a cross sectional view AA as depicted in FIG. 13B , FIG. 13C shows a cross sectional view BB as depicted in FIG. 13B , FIG. 13D shows a cross sectional view GG as depicted in FIG. 13E , and FIG. 13F shows a cross sectional view EE as depicted in FIG. 13E .
Key dimensions in the representative spherical sensor of FIG. 13A-13C include the outer sensor dimension of 40 mm and the channel 3 inner dimension of 7 mm. The width of the beam of light is 1 mm and the distance between the light source and detector is 22 mm. Key dimensions in the representative spheroid sensor of FIG. 13D-13CF include the outer sensor diameter of 33 mm and length of 39 mm, and the channel 3 inner dimension of 4 mm. The width of the beam of light is 1 mm and the distance between the light source and detector is 13 mm.
Use of the sensor 15 may further include one or more of the following steps, in any order:
The sensor is placed on the charging base such that the spigot 21 is inserted within the channel 3 that extends through or partly through the sensor housing. The sensor is charged using the wirelessly coupled base station 22 or similarly capable device. The transmitter in the sensor is connected with a receiver to facilitate wireless communication therebetween. The sensor is placed inside a vessel containing a solution to be measured. The vessel containing the sensor is placed upon a mechanical stirring or shaking device such as a shaker incubator to agitate the solution in the vessel. The base station transmits a signal to the sensor when a measurement is desired. The controller receives a signal that a measurement is desired, causes energisation of the light source, measures the signal from the light receiver and outputs information to be transmitted to the base station. The controller is configured to cause energisation of the light source, measure the signal from the light receiver and output information to be transmitted to the base station. The controller is configured to cause energisation of the light source, measure the signal from the light receiver and store measured signals to later be transmitted to the base station. The controller measures the remaining battery capacity. If the capacity is determined to be low, an additional energy harvesting mechanism such as an electro-mechanical generator may operate to convert kinetic energy of the sensor into electricity to charge or supplement the battery. Cleaning the sensor using, for example, a 70% ethanol solution, for re-use.
The sensor may operate to achieve a measurement by using one or more of the following steps, in any order:
Energise the light source 2 for a predetermined period of time. For example, the light source is energised for approximately ten milliseconds. Measure one or more samples indicative of the light received by the light receiver 5 . For example, approximately five samples are recorded by the controller. Perform a statistical calculation of the measured samples. The most useful statistical calculation is where the average of several samples is calculated. Those skilled in the art will appreciate that other statistical or filtering calculations could be performed, or several performed and combined where circumstances dictate that this would provide a more meaningful measure.
The sensor has numerous advantages, including:
A housing that entirely seals internal components from the environment whilst being able to be submerged within a solution to be tested. The sensor can be constructed from a material that is easily chemically sterilised for repeated use in a variety of applications. The sensor is sealed and self contained which helps to prevent contamination. The sensor is stored and used remotely from the base station without requiring a wired interface. The sensor can be transported with a vessel containing a solution, for example, between a storage area and a shaking table where a solution is to develop. The sensor is able to be mobile while immersed in a solution thereby improving the ability of the sensor to provide measurements from a variety of locations within the vessel.
EXAMPLE 1
Assaying Optical Density of Microorganism Culture
Preliminary testing of a sensor 15 was conducted alongside measurements gathered using an Eppendorf BioPhotometer Plus bench top spectrophotometer simulating a typical yeast growth assay.
A widely used laboratory strain Saccharomyces cerevisiae: W303 was cultured overnight to exponential phase in YPD complete media and the cells were collected by centrifuge.
The sensor 15 was sterilized in 70% ethanol and added to fresh media in a sterile culture flask before being placed inside an incubator containing an orbital shaker.
A baseline measurement was taken following a period of approximately ten minutes to allow for temperature equilibration. The base line data output was stable regardless of shaker motion, internal lighting, or shielding of external ambient light. Cells were added to the media at an initial inoculation to OD 600nm 0.1 as measured by the Eppendorf spectrophotometer.
Cells were then added to the culture media at a volume equivalent to 0.1 OD 600nm units and at each point measurements were made in parallel using both the commercial spectrophotometer and sensor 15 up to a final density of 0.8 OD 600nm .
As measurements using the commercial spectrophotometer involved removal of a small sample from the culture, dilution and pipetting into a cuvette, there is some error resulting from the numerous small volume liquid handling steps which is apparent in the data supplied and typical for this type of measurement.
FIG. 7 shows a comparison of the sensor 15 and the bench top spectrophotometer. In-situ photometric device measurements were obtained by averaging 14 samples each consisting of an averaged value of 5 intensity measurements. Manual triggering (in rapid succession) of the measurements were used to obtain the intensity data after addition of each aliquot of cells.
As can be seen, the data provided by the in-situ device of the present invention provides a response to the change in optical density during the course of the experiment. In the case of non-linear response due to saturation, the non-linearity can be corrected by precalibration of the device over the expected optical density range, before deployment. In the case of remaining in the linear regime, no such calibration is required and the results may be directly interpreted and in this case accuracy at least comparable to standard measurement equipment is obtained.
In this specification, where reference has been made to external sources of information, including patent specifications and other documents, this is generally for the purpose of providing a context for discussing the features of the present invention. Unless stated otherwise, reference to such sources of information is not to be construed, in any jurisdiction, as an admission that such sources of information are prior art or form part of the common general knowledge in the art.
Where in the foregoing description reference has been made to elements or integers having known equivalents, then such equivalents are included as if they were individually set forth.
Although the invention has been described by way of example and with reference to particular embodiments, it is to be understood that modifications and/or improvements may be made without departing from the scope or spirit of the invention.
INDUSTRIAL APPLICABILITY
The devices and systems of the invention, and the methods of using them have application in a wide range of industries and environments, including medical, biotechnological and pharmaceutical research and production, food and beverage technologies, industrial processing, the horticultural and agricultural sectors, and others.
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The present invention relates to optical measurement devices and systems, and methods of using these systems and devices, and more particularly but not exclusively it relates to a system and apparatus adapted to measure optical properties in-situ.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a continuing application, under 35 U.S.C. §§120 and 363, of copending international application No. PCT/GB2009/050266, filed Mar. 23, 2009, which designated the United States and was published in English; this application also claims the priority, under 35 U.S.C. §119, of GB patent application No. 0806116.0, filed Apr. 4, 2008; the prior applications are herewith incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] The invention relates to an engine valve system that uses two cams to act on a valve by way of a summation mechanism.
BACKGROUND OF THE INVENTION
[0003] FIG. 1 shows a cam summation engine valve system as disclosed in U.S. Pat. No. 6,941,910. The valve system includes two cams 10 and 12 and a cam summation rocker 14 , herein also termed an “upper rocker,” having cam followers 16 and 18 in contact with both cams. A lower actuating rocker 20 is pivotably connected to the summation rocker 14 and acts, at one end, on a valve 22 , with its other end resting on a hydraulic lash adjuster 24 . An adjustable stop plate 26 is used to limit the expansion of the hydraulic lash adjuster 24 by setting the height of the pivot shaft 30 that connects the lower rocker 20 to the upper rocker 14 . The position of the lower rocker 20 is therefore defined by its contact with the tip of the valve 22 , and the expansion of the hydraulic lash adjuster 24 holding the pivot shaft 30 against the adjustable stop plate 26 .
[0004] Cam summation valve systems using hydraulic lash adjusters have required an adjustable stop, or a graded shim in order for the system clearance (and hence the valve lift) to be adjusted. The functions of this clearance adjustment are twofold. First, the expansion of the hydraulic lash adjusters is limited so that the correct amount of clearance is maintained in the system while the valves are closed. Second, the valve actuating rocker is held in contact with the tip of the valve by the expansion of the hydraulic lash adjusters and the clearance adjustment system so that any clearance must occur between one of the cam profiles and its respective follower(s).
[0005] G.B. Patent Application No. 0708967.5 (WO2008/139221), by the instant Applicants, describes a cam summation engine valve system as shown in FIG. 2 . This figure shows a similar valve system to that shown in FIG. 1 . In both drawings, like parts have been allocated the same reference numerals to avoid repetition. In FIG. 2 , the valve actuating lower rocker 20 is mounted on a manually-adjustable pivot 32 . The valve lift is adjustable through a screw mechanism 34 and contact is maintained between the tip of the valve 22 and the lower rocker 20 at all times through a control spring 36 .
[0006] This configuration replaces the hydraulic-lash-adjusting elements with a mechanical clearance adjustment and maintains the correct amount of clearance in the system while the valves are closed. However, an adjustable pivot 32 is required to allow the amount of clearance in the system to be adjusted. In the absence of such adjustability, there would be no way to compensate for manufacturing tolerances, which may lead to significant variations in valve lift between cylinders, and potentially damaging impact forces between the components of the system. While it provides for clearance adjustment, the system of G.B. Patent Application No. 0708967.5 requires a significant amount of packaging space that may not be available in all engines.
[0007] Therefore, a need exists to overcome the problems with the prior art as discussed above.
SUMMARY OF THE INVENTION
[0008] The invention provides an engine valve system with variable lift & duration that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices and methods of this general type and that provides a more compact adjustment system, which, nevertheless, retains all of the benefits of manual adjustment.
[0009] With the foregoing and other objects in view, there is provided, in accordance with the invention, an engine valve system that includes a first cam, a second cam mounted coaxially with the first cam, a summation rocker adjacent to the first cam and the second cam, a first cam follower coupled to the summation rocker, in mechanical communication with the first cam, and movable in proportion to an instantaneous sum of a lift of the first cam, and a second cam follower coupled to the summation rocker, in mechanical communication with the second cam, and movable in proportion to an instantaneous sum of a lift of the second cam. The engine valve system further includes a valve-actuating rocker pivotably coupled to the summation rocker and operable to open an engine valve in dependence upon a movement of the summation rocker and an eccentric coupling the summation rocker to at least one of the first cam follower, the second cam follower, and the valve-actuating rocker, wherein the eccentric is adjustably rotatably operable to adjust a clearance between at least two components within the engine valve system.
[0010] In accordance with a further feature of the present invention, the eccentric forms at least a portion of the coupling between the summation rocker and the valve-actuating rocker.
[0011] In accordance with another feature, an embodiment of the present invention includes an adjusting mechanism mechanically coupled to and operable to select an angular position of the eccentric with respect to the valve-actuating rocker.
[0012] In accordance with an additional feature, an embodiment of the present invention includes an adjusting mechanism mechanically coupled to and operable to select an angular position of the eccentric with respect to the summation rocker.
[0013] In accordance with a further feature of the present invention, the eccentric forms at least a portion of the coupling between the summation rocker and at least one of the first cam follower and the second cam follower.
[0014] In accordance with another feature, an embodiment of the present invention also includes an adjustably lockable screw mechanism operable to maintain an angular position of the eccentric.
[0015] In accordance with a further feature of the present invention, the adjustably lockable screw mechanism is lockable only in predetermined discrete positions.
[0016] In accordance with yet another feature, an embodiment of the present invention includes a compliant member operable to prevent rotation of the screw mechanism while the engine valve system is in operation.
[0017] In accordance with a further feature of the present invention, the eccentric has a series of discrete adjustment positions.
[0018] In accordance with a yet one more feature of the present invention, the eccentric is maintained in a discrete position by the action of a compliant member.
[0019] In accordance still with an embodiment of the present invention, an engine valve system includes two cams mounted coaxially, a summation rocker coupled to cam followers in contact with both cams and movable in proportion to the instantaneous sum of the lifts of the respective cams, and a valve actuating rocker pivotably coupled to the summation rocker and operative to open an engine valve in dependence upon the movement of the summation rocker, wherein at least one of the couplings of the summation rocker with the cam followers and with the valve actuating rocker incorporates an adjustable eccentric which is rotatable to enable the clearance within the valve system to be set.
[0020] The present invention advantageously utilizes manual clearance adjustments for a cam summation system to provide clearance in the rocker system at a point in its motion cycle. By comparison, if hydraulic elements are used, their expansion needs to be limited. Many of the advantages that hydraulic elements offer in a conventional valve train are not relevant to cam summation systems, where the expansion of the elements is limited by a manual adjustment or a shim. As a manual adjustment method is already required, it is advantageous to apply the adjustment directly to the valve train system, instead of controlling the position of the valve train components indirectly by limiting the expansion of a hydraulic element.
[0021] Embodiments of the invention provide a manual adjustment system that is incorporated into the rocker mechanism and may be adjusted while the valve system is assembled into the engine. As with the invention described in G.B. Patent Application No. 0708967.5, the system uses a control spring to maintain contact between the lower rocker and valve tip throughout the operating cycle.
[0022] An eccentric, i.e. a shaft with two cylindrical surfaces having their axes offset from one another, engaged in the summation lever provides the adjustment of the valve system. This approach offers a lightweight and compact solution for adjusting the system which requires very little additional space compared to the known conventional summation valve systems.
[0023] Clearance adjustments may be made without the need to disassemble the camshaft and rocker system. The absence of hydraulic elements in the system means that consistent valve lift measurements can easily be taken and this allows the valve lifts of each cylinder to be adjusted and re-measured directly.
[0024] Additional advantages and other features characteristic of the present invention will be set forth in the detailed description that follows and may be apparent from the detailed description or may be learned by practice of exemplary embodiments of the invention. Still other advantages of the invention may be realized by any of the instrumentalities, methods, or combinations particularly pointed out in the claims.
[0025] Although the invention is illustrated and described herein as embodied in an engine valve system with variable lift & duration, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. Additionally, well-known elements of exemplary embodiments of the invention will not be described in detail or will be omitted so as not to obscure the relevant details of the invention.
[0026] Other features that are considered as characteristic for the invention are set forth in the appended claims. As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one of ordinary skill in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting; but rather, to provide an understandable description of the invention.
[0027] Before the present invention is disclosed and described, it is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. The terms “a” or “an,” as used herein, are defined as one or more than one. The term “plurality,” as used herein, is defined as two or more than two. The term “another,” as used herein, is defined as at least a second or more. The terms “including” and/or “having,” as used herein, are defined as comprising (i.e., open language). The term “coupled,” as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically.
[0028] As used herein, the terms “about” or “approximately” apply to all numeric values, whether or not explicitly indicated. These terms generally refer to a range of numbers that one of skill in the art would consider equivalent to the recited values (i.e., having the same function or result). In many instances these terms may include numbers that are rounded to the nearest significant figure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and explain various principles and advantages all in accordance with the present invention. The figures of the drawings are not drawn to scale.
[0030] FIG. 1 is an elevational side view of the prior-art valve system of U.S. Pat. No. 6,941,910.
[0031] FIG. 2 is an elevational side view of the valve system described in G.B. Patent Application No. 0708967.5 (WO2008/139221).
[0032] FIG. 3A is a perspective view of a valve system of a first embodiment of the invention shown in its assembled state.
[0033] FIG. 3B is a partially exploded perspective view of the valve system of FIG. 3A .
[0034] FIG. 3C is an elevational end view of the valve system of FIGS. 3A and 3B .
[0035] FIG. 3D is an elevational view of a section on the line I-I in FIG. 3C .
[0036] FIG. 3E is a partial view of the section of FIG. 3D drawn to an enlarged scale.
[0037] FIG. 4A is a perspective view of a valve system of a second embodiment of the invention shown in its assembled state.
[0038] FIG. 4B is a partially exploded perspective view of the valve system of FIG. 4A .
[0039] FIG. 4C is an elevational end view of the valve system of FIGS. 4A and 4B .
[0040] FIG. 4D is a section taken along the line II-II in FIG. 4C .
[0041] FIG. 4E is a section taken along the line III-III in FIG. 4D .
[0042] FIG. 5A is a perspective view of a valve system of a third embodiment of the invention shown in its assembled state.
[0043] FIG. 5B is a partially exploded perspective view of the valve system of FIG. 5A .
[0044] FIG. 5C is an elevational side view of the valve system of FIGS. 5A and 5B .
[0045] FIG. 5D is a section taken along the line IV-IV in FIG. 5C .
[0046] FIG. 5E shows part of the section of FIG. 5D drawn to an enlarged scale.
DETAILED DESCRIPTION OF THE INVENTION
[0047] While the specification concludes with claims defining the features of the invention that are regarded as novel, it is believed that the invention will be better understood from a consideration of the following description in conjunction with the drawing figures, in which like reference numerals are carried forward. It is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms.
[0048] Referring now to FIGS. 3A through 3E , one embodiment of the present invention is several views. FIGS. 3A through 3E show several advantageous features of the present invention, but, as will be described below, the invention can be provided in several shapes, sizes, combinations of features and components, and varying numbers and functions of the components.
[0049] The first embodiment of the invention, shown in FIGS. 3A to 3E , has many elements in common with the Applicants' G.B. Patent Application No. 0708967.5 (WO2008/139221), shown in FIG. 2 . Once again, like reference numerals have been used to designate like components. In particular, an upper rocker 14 with cam followers 16 and 18 is used to operate two valves 22 and is coupled by a shaft 30 to two lower rockers 20 which actuate the respective valves 22 . The lower rockers are, in this case, supported at their ends remote from the valves 22 on fixed pivot posts 132 . A control spring 36 urges the upper rocker 14 downwards so that the lower rockers 20 are kept in contact with the valves 22 at all times. The control spring 36 also biases the upper rocker 14 clockwise as viewed so that the cam follower 16 is maintained in contact with its associated cam lobe at all times and the clearance in the system when the valves are closed and the cam followers are both on the base circles of their cams is developed between the cam follower 18 and its associated cam lobe.
[0050] The pivot shaft 30 that connects the lower rockers 20 to the summation rocker 14 is formed as an eccentric. The axis of the part of the pivot shaft 30 in contact with summation rocker 14 is offset from the axis of the part engaged in the two lower rockers 20 . This allows the position of the summation rocker 14 to be adjusted with respect to the valve actuating rockers 20 by rotation of the pivot shaft.
[0051] In order to set the position of the pivot shaft 30 , one of the valve actuating rockers 20 is fitted with an adjusting screw 40 that engages in a recess in the pivot shaft 30 as shown best in the detail view of FIG. 3E . The pivot shaft 30 is subjected to a unidirectional torque while the valves are being actuated and so it is only necessary for the adjusting screw to react against this torque which will hold the face of the recess in the pivot shaft 30 in contact with the tip of the adjusting screw 40 . The eccentricity of the pivot shaft 30 used to give an acceptable adjustment range will be less than about 1 mm, and hence, the force on the screw need only be very modest to resist the resulting torque.
[0052] The detail view of FIG. 3E provides a detailed view of the adjusting mechanism. The adjusting screw 40 engages in the profiled recess in the pivot shaft 30 and is threaded into the valve-actuating rocker 20 . In order to prevent any rotation of the adjusting screw 40 while the system is in operation, the upper section of the screw is formed with a square section. A retaining spring 42 (see FIG. 3B ), which is used to clip the valve-actuating rocker 20 onto its fixed pivot post 132 , engages with a flat side of the adjusting screw 40 such that turning the screw deflects the spring. While this allows the screw to be intentionally adjusted, the spring force will prevent the screw from rotating during operation due to vibration.
[0053] An additional embodiment of the invention, shown in FIGS. 4A through 4E , uses the same adjustment principle as the previously-described embodiment, but, instead of locating an adjustment screw 40 in the valve actuator, an analogous adjustment screw 40 ′ is incorporated into the summation rocker 14 . This configuration could be advantageous in some applications where the cylinder head configuration prevents easy access to an adjusting screw located in the valve-actuating rocker 20 .
[0054] As with the previous embodiment, the pivot shaft 30 has a recess which is engaged by the adjustment screw 40 ′, as shown in FIG. 4D . The adjustment screw 40 ′, once again, has a square section on its upper portion to allow it to be locked in a simple manner and to prevent it from turning when the engine is operating. In this case, the screw 40 ′ is locked by a sliding plunger 50 which mates with the flat faces on the screw 40 ′, and a spring clip 52 that locates around the summation rocker 14 and urges the plunger into its bore so that it remains in contact with the screw 40 ′.
[0055] The screw 40 ′ may be accessed via the clearance between the camshaft and the central portion of the axle 17 for the two cam followers 16 a and 16 b using a small hexagon key. The configuration allows the valve system clearance to be set directly using a feeler gauge to measure the clearance between the single cam follower 18 and its cam lobe.
[0056] A further embodiment of the invention, which is shown in FIGS. 5A through 5E , incorporates an eccentric in a shaft coupling the cam follower 18 to the summation rocker 14 . The clearance between the cam follower 18 and its respective cam lobe may be adjusted by directly rotating an axle pin 60 mounted on the summation rocker 14 . The axle pin 60 has aligned cylindrical surfaces which engage aligned mounting holes 62 in the summation rocker 14 and a non-coaxial cylindrical surface that acts as a race for the cam follower 18 which is constructed as a needle bearing. The aligned cylindrical surfaces on opposite sides of the eccentric surface and the two holes 62 are of different size to permit the axle pin 60 to be slid into position. The axle pin 60 would otherwise either not be able to pass through one of the holes 62 or through the centre of the cam follower 18 .
[0057] The axle pin 60 has an enlarged head 70 which is centrally recessed to receive an implement, such as a hexagon key, to enable it to be turned. Such rotation alters the position of the eccentric cylindrical surface and sets the clearance in the valve system.
[0058] The head 70 is resiliently urged against the side of the summation rocker 14 by a spring disk 72 . As best seen in FIG. 5E , the underside of the head 70 , that is to say, the side facing the summation rocker 14 , is formed with radial corrugations or grooves that engage a ball 74 located in a blind bore in the side of the summation rocker 14 . This ball catch mechanism defines predetermined adjustment positions as resistance will be encountered when rotating the head by the need to compress the spring disk 72 as the ball 74 passes from one groove to the next.
[0059] The spring disc 72 holds the head 70 firmly in contact with the ball 74 at all times in order to prevent any rotation while the valve system is in operation. As with the eccentric pivot shaft, the rotational forces on the adjuster are modest because it only uses a small eccentric distance.
[0060] It will be appreciated that further alternative embodiments may incorporate a pivot shaft having a series of adjustment steps rather than an adjustment screw. A variety of toothed or ratchet-type arrangements could be configured in order to achieve this objective.
[0061] The above described embodiments of the invention offer the following advantages as compared to existing configurations:
No hydraulic elements are required. No graded components such as shims are required as part of the valve system. The measures for adjustment can be contained within the existing package space for the summation rocker. The system can be configured such that no significant disassembly is required to adjust the valve lift. Simple and repeatable measurement methods may be used to check valve lift. Adjustments may be made and checked instantly.
[0068] The foregoing description and accompanying drawings illustrate the principles, exemplary embodiments, and modes of operation of the invention. However, the invention should not be construed as being limited to the particular embodiments discussed above. Additional variations of the embodiments discussed above will be appreciated by those skilled in the art and the above-described embodiments should be regarded as illustrative rather than restrictive. Accordingly, it should be appreciated that variations to those embodiments can be made by those skilled in the art without departing from the scope of the invention as defined by the following claims.
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An improvement is disclosed for an engine valve system with variable lift and duration of the type that includes two cams mounted coaxially, a summation rocker coupled to cam followers in contact with both cams and movable in proportion to the instantaneous sum of the lifts of the respective cams, and a valve actuating rocker pivotably coupled to the summation rocker and serving to open an engine valve in dependence upon the movement of the summation rocker. In the invention, at least one of the couplings of the summation rocker with the cam followers and with the valve actuating rocker incorporates an adjustable eccentric which is rotatable to enable the clearance within the valve system to be set.
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CROSS REFERENCE TO RELATED APPLICATIONS
"A Process of Fabricating a Portion of an Optical Fiber Capable of Reflecting Predetermined Wavelength Bands of Light", by D. C. Schmadel, Jr., U.S. Ser. No. 546,608, filed Oct. 28, 1983; "A Ruggedized Grated Optical Fiber", by J. E. Goodman et al, U.S. Ser. No. 546,609, filed Oct. 28, 1983; "Process of Tuning a Grated Optical Fiber and the Tuned Optical Fiber", by D. C. Schmadel, Jr. et al, U.S. Ser. No. 546,610, filed Oct. 28, 1983; "Process and Apparatus for Measuring an Evanescent Field in an Optical Fiber", by D. C. Schmadel, Jr., U.S. Ser. No. 546,611, filed Oct. 28, 1983; "Etching Fountain", by J. E. Goodman, U.S. Ser. No. 546,618, filed Oct. 28, 1983; and "Optical Fiber Holder", by J. E. Goodman, U.S. Ser. No. 546,619, filed Oct. 28, 1983, all commonly assigned.
This invention relates to optical fibers. More specifically, this invention relates to a process of fabricating a portion of an optical fiber to reflect predetermined wavelength bands of light.
BACKGROUND OF THE INVENTION
In a gaseous medium such as air, gratings and mirrors are used to control the direction and intensity of light. Light can also pass through a solid medium such as an optical fiber. It would be highly desirable to have a process of producing the effects of mirrors and gratings in the optical fiber. One of the methods of producing the grating in the fiber was described by B. S. Kawasaki et al in Optics Letters, Vol. 3, No. 2, pages 66-68 (August 1978). However, the Kawasaki et al paper was only applicable to gratings in fibers which have a photosensitive core material and with a reflectivity, r, of about 0.6, and having a long interaction length of about 50 centimeters. "Reflectivity" is defined as r 2 /i 2 , where r is the peak amplitude of the electric field for light which was reflected within the core and i is the peak amplitude of the electric field which is within the core and incident on the grating. "Interaction length" is defined as that length measured along the fiber axis over which both the grating and the incident light extend. A long interaction length causes the reflectance band to be very narrow spectrally. This limits the useful applications of the grating. Therefore, it would be highly desirable to have a process of forming gratings in an optical fiber which can exhibit long or short interaction lengths with either high, i.e, r>90%, or low reflectivities.
SUMMARY OF THE INVENTION
This invention is directed to an apparatus for coating optical fibers. The apparatus is usefully incorporated into a process of forming gratings in optical fibers. The apparatus permits the fast and uniform application of, for example, a photoresist to the thin inner cladding of an optical fiber. Thereafter, the fiber coated with the photoresist can be exposed to a wavelength of light at which the photoresist reacts and any further processing steps necessary to complete the fabrication of gratings in the fiber which can exhibit predetermined reflectivities and predetermined interaction lengths. The apparatus solves the difficult problem of applying a coating to an article, such as a wire, an optical fiber, and the like, having a diameter on the order of only about 5 to 50 micrometers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a holder for the optical fiber cable during processing.
FIG. 2 illustrates a cut-away view of an etching fountain.
FIGS. 3 and 4 illustrate an optical fiber coating apparatus.
FIGS. 5 and 6 illustrate an aparatus for testing an evanescent field in an optical fiber.
DETAILED DESCRIPTION OF THE INVENTION
An optical fiber contains a central core through which the light travels surrounded by a cladding of a material having a lower index of reflection than the core. Usually, a protective jacket surrounds the cladding material. A suitable example of an optical fiber is a single mode light polarization maintaining fiber of the Andrew Corporation. To gain access to the cladding and core, the protective jacket is removed with a suitable stripping material such as Photoresist Remover 1112A, a product of the Shipley Corporation. The fiber is contacted with the photoresist remover for a sufficient time to remove the protective jacket. Elevated temperatures of about 50° C.-70° C. speed the reaction. At 60° C., the protective jacket is removed in about 5 to 10 minutes.
Removing the protective jacket exposes an optical fiber coated with a layer of indium. The indium material is supposed to hermetically seal the fiber. The exposed indium-coated fiber is fixed to a suitable holder for the additional processing steps of my invention. Preferably, the holder is fabricated from a corrosion-resistant temperature suitable material such as a ferronickel like Invar® [36% nickel and 64% steel (a carbon content of 0.2%)], or other suitable metals or materials. A method of fixing the indium exposed portion of the fiber is with solder, such as indium solder. Of course, if the fiber does not have an indium coating, then an appropriate material capable of attaching the holder to the fiber should be used. Any holder is suitable provided that the tension on the fiber can be adjusted and it also allows complete access to the exposed portion of the fiber. Initially, the tension is adjusted to maintain a positive tension on the optical fiber.
A preferred holder and optical fiber unit is illustrated as 10 in FIG. 1. Although used in this process with optical fibers, the holder is also suitable for use in processes which involve fine wires, rods, and the like, having diameters on the order of from about 5 to 100 micrometers. The holder 12 is fabricated from Invar® or other suitable temperature-stable materials. Preferably, the holder 12 is a unitary piece with the exception of adjusting means 14. The optical fiber 16 is fixed to the holder 12 with indium solder or by other suitable means. The holder 12 allows complete access to the exposed indium-coated portion to the optical fiber 18 for subsequent processing. The holder 12 has sections 12a and 12b which are thinner than the thickness of the holder 12. This design provides a means for the movement of the holder 12 to tension the fiber 18 by the action of adjusting means 14 on the lever arm portion 12c of the holder 12 without twisting, i.e., moving out of a fixed plane. For example, if the holder is about 4.7 mm thick, then 12a and 12b should be about 1.1 mm across. In other words, 12a, 12b, 12c and 14 act as a tensioning means for the fiber 18 while maintaining it in a fixed plane during tensioning. A suitable adjusting means 14 is a screw of Invar® or stainless steel. An adjustment of about 0.5 mm is suitable for tensioning the fixed optical fiber section 18. Optionally, the holder 12 incorporates a means for attaching 12d, the holder 12 to subsequent processing apparatus as disclosed, for example, in FIGS. 3 and 4. More specifically, the notch 12d orients the holder 12 and permits it to be attached to further processing apparatus in a reproducible and accurate fashion. Suitable dimensions for the holder 12 are about 50 mm from edge to edge across the top of the holder where the fiber 16 is connected (i.e., width) and about 43 mm for the length perpendicular to the width.
After the fiber is mounted in the holder, it is then placed into suitable etching apparatus which contains a suitable indium etchant solution such as 1 molar ferric chloride to remove the indium. A suitable etching period is from about 3 to 10 minutes at room temperature. Alternatively, any commercially available copper printed circuit board etchants, available from the Shipley Corporation, are also suitable. Any etching apparatus is suitable provided that it exposes only the fiber and not the holder to the etching material.
A preferred etching apparatus is the etching fountain 20 illustrated in FIG. 2. The fountain 20 is preferred because it can be used with harsh and dangerous chemicals, such as ferric chloride without a hood to vent the fumes. The fountain 20 has an outer jacket 22 connected to a means for creating a downward flow of air such as a pump 23. The pump 23 creates a downward air flow and removes the noxious vapors and gases from the air space over the work piece. Inside the outer jacket 22 is a central inner chamber 24 connected to a means for injecting a fluid into the chamber 24 such as a tube 25. The tube 25 is connected to a means for circulating a fluid such as pump 29. Surrounding the inner chamber 24 is a an outer overflow receptacle 26 which is also connected to a means for removing fluid from the overflow receptacle 26 such as a tube 27. The tube 27 is also connected to the pump 29. The pump 29 circulates an etchant fluid or solution 28. The upper part of the outer jacket 22 has a means for holding a work piece such as a slit. The slit fits the optical fiber holder 12 and situates the optical fiber 18 or other work piece such as a fine wire or rod just above the top of the inner chamber 24. The inner chamber 24 is designed so that the pumping action of pump 29 exposes the indium coated portion of the fiber 18 to the solution 28 but not the outer jacketed portion of the fiber 16. This prevents the solution from being contaminated by the outer jacket 16. For the indium etching, the pump 29 should deliver a uniform flow so that the indium layer is evenly removed. However, in the next step, when the inner cladding is removed with a suitable cladding etchant to a depth wherein evanescent waves are encountered, the pump 29 should create an oscillating head of etchant solution so that the cladding ends taper to the exposed center without sharp light leaking transitions. The taper is illustrated in FIG. 6. Of course, the etchant solution should not oscillate so violently that it is contaminated by the indium coating, i.e., this second etchant solution should only touch the cladding where the previous etching has removed the indium coating. A peristaltic pump 29, as illustrated, is preferred for this application. Of course, 25 must be flexible when 29 is a peristaltic pump. A suitable material is Tygon® tubing. Since the etchants only touch the fiber 18, the holder 12 may be but does not have to be constructed out of materials which are inert to the etchant solutions. The pump 23 keeps any noxious fumes away from the holder 12 and people working in the area. Although the etching fountain 20 is illustrated for one fiber, it can be scaled up to accommodate any number of fibers, wires or rods. With one fiber, 22, 24 and 26 are preferably tubular in shape, while in a more-than-one fiber design, 22, 24 and 26 are preferably rectangular in shape.
When the indium has been removed, the holder and fiber are removed from the fountain and rinsed in water, and then placed into a second etching fountain to etch away the outer cladding of the optical fiber to a depth wherein evanescent waves are encountered. A suitable etchant solution is four parts of an ammonium bifluoride mixture with water and one part hydrofluoric acid with water, such as "BOE etchant (5-1)" available from Allied Chemical Corporation in Morristown, N.J. A suitable etching period is from about 3 to 8 hours. With the Andrew Corporation fiber, the core and cladding will have a diameter of about 66 micrometers before etching and about 6-10 micrometers after etching. The fountain is designed, as discussed above, to expose only that portion of the fiber from which the indium had been removed. The fountain is operated with a pulsating or oscillating flow pattern to produce a fiber with a taper as illustrated in FIG. 6.
When the fiber has been sufficiently etched, which in the case of the Andrew Corporation fiber might be to a total diameter of about 6 micrometers to about 12 micrometers and preferably about 8 to about 10 micrometers, the fiber and holder are removed from the second etching fountain, rinsed and then placed in a primer coating apparatus. An example of a suitable primer is C-55, HMDS primer, a product of the Shipley Corporation. The priming takes from about 10 to 20 seconds. Any priming apparatus is suitable provided that it primes only the etched portions of the fiber. Preferably, the priming is done by vapor deposition. Alternatively, the coating apparatus described hereinafter can be employed. The holder, the indium coating and other extraneous materials should not contaminate the primer material.
A preferred coating apparatus 30 is illustrated in FIG. 3 with a more detailed section of the apparatus illustrated in FIG. 4. The apparatus 30 has a control arm 32 which incorporates a fluid applicator head 34 for photoresist primer or photoresist and the like. A suitable applicator head 34 is a ruling pen nib. The surface tension of the fluid 36 which is to coat the object such as primer and/or photoresist holds it between the two nib halves which define the fluid reservoir until it is applied to the fiber 18. The control arm 32 is connected to a reversibly rotating disc 42a mounted on a base 42. A control switch 44 and power 46 provides the means for reversibly rotating the control arm 32 in a reciprocating fashion. A guide wheel 40, such as a wheel or bearing, is attached to the lower portion of the control arm 32 as it traces a pattern back and forth across a control track 38 having two upper portions and a lower portion therebetween. Generally, the lower portion of the control track 38 is configured so that about 5 to 25 millimeters of the fiber are coated. Of course, it can be configured to coat any length. When the wheel 40 is in the lower portion of the track 38, the nib 34 containing the material 36 to be coated on the fiber 18 straddles the fiber 18 while material 36 is deposited on the fiber 18 as coating 36a. The thickness of the coating 36a is a function of the viscosity of material 36 in the nib 34 and the speed at which control nib 34 travels across the optical fiber the control nib 34 travels. The track 38 is configured so that the material 36a only coats the etched portion of the fiber 18. The fiber is held by holder 12 and positioning means 48 in the coating apparatus 30. The holder 12 is situated such that the object to be coated is within the nib halves as the control wheel is in the lower portion of the control track 38. Preferably, the lower portion of the track is configured so that the nib halves never touch the fiber 18. The attaching and centering means 12d in holder 12 ensures that the fibers 16 and 18 are held in the same position. The positioning means 48 is designed to surround and support the outside of holder 12 but leave the surface holding the fiber 16 open for coating by the nib 32. The control switch 44 can be a manual switch which the operator merely reversed or an automatic switch to reverse the direction of the arm 32 after it makes a pass over the fiber 18 and rises to an upper portion of the control track 38. The drive for disc 42a can be any standard gear or belt drive. The drive mechanism, not illustrated, is incorporated into the control switch unit 44. Alternatively and not illustrated, the control arm can have a drive motor and guide track, as opposed to the rotating disc, that will permit it to run parallel with the fiber 18 and the control track 38. This apparatus is preferred because it overcomes the surface tension problems of applying a fluid such as photoresist to a thin object, such as a wire, rod, optical fiber, and the like, wherein the diameter is on the order of about 5 to 50 micrometers and more usually on the order of about 10 micrometers for an optical fiber.
After priming, the holder and fiber are removed from the priming apparatus and placed in a photoresist coating apparatus. The photoresist coating apparatus applies a positive photoresist such as Microposit 1400-27® or Microposit 1400-33®, products of the Shipley Corporation. Any photoresist coating apparatus is suitable provided that it applies photoresist only to that portion of the fiber which has been primed. A preferred apparatus is illustrated in FIGS. 3 and 4 and was described above. The photoresist is not applied to those portions of the fiber still coated with indium, nor is the photoresist ever in contact with the holder. This eliminates the possibility of contamination of the photoresist coating. The coating operation as well as all following operations may be implemented in an amber light environment to avoid unwanted exposure of the photoresist. The amber light source should preferably allow less than about 3 millijoules/cm 2 of light between 350 nanometers (nm) and 480 nm wavelength to fall on the photoresist surface.
Thereafter, the fiber and holder are removed from the photoresist coating apparatus and the adjustable holder is adjusted so that the fiber is loose. If during the baking procedure the dimensions of the holder or fiber should change slightly, the fiber will not be stressed to the point of breaking.
Optionally, the fiber and holder are then placed into an oven for a soft bake. For example, with Microposit 1400-27® or Microposit 1400-33®, the soft bake consists of heating the fiber and holder in an oven for about 20 to about 40 minutes and preferably 30 minutes at about 90° C. After the soft bake, the fiber and holder are placed in a container to avoid exposure to cooler, ambient air, removed from the oven, and allowed to cool slowly. Thereafter, the fiber and holder are removed from the container and the adjustable holder is readjusted so that the fiber is taut.
The fiber and holder are then placed in an exposure apparatus in which they are exposed to interfering beams from a light source such as a krypton laser, Model 3000-K produced by Coherent, Inc. The particular laser and wavelength of light is selected to match the exposure sensitivity of the photoresist. A wavelength of about 413 nm is ideal for Microposit 1400-27® or Microposit 1400-33®. The exposure of the photoresist to interfering beams of light creates a pattern wherein the photoresist is exposed periodically along the fiber for a spatial separation of exposure peaks or lines of about 0.3 micrometers. Preferably, the exposure peaks each lie in a plane perpendicular to the fiber axis. The light from the laser is spatially filtered by means of a pinhole and then expanded and collimated. The exposure time is from about 1 to about 5 seconds for a 2-inch diameter beam of about 400 milliwatts total power. When varying the grating dimensions, a determination is made as to the desired grating size and then an interference angle and a light source is selected which can create such a pattern. Thereafter, a suitable photoresist is selected which is sensitive to light of that wavelength.
After exposure, the fiber and holder are removed from the exposing apparatus and the holder is readjusted so that the fiber is loose. Thus, if the developer should be at a slightly different temperature thereby cooling portions of the holder, it will not subject the fiber to additional stress which might cause it to break.
Thereafter, the fiber and holder are placed into a developing apparatus. The developing apparatus is a fountain which contains a suitable developer for the photoresist such as Developer No. 351 CD 23, a product of the Shipley Corporation. The fiber is exposed to the developer for from about 15 to 60 seconds, and preferably about 30 seconds, at room temperature. The developing apparatus is designed to expose the developer to only those portions of the fiber which are coated with photoresist. Thus, the developer will not be contaminated by, for example, the indium on the fiber or the holder. The fiber is then rinsed in deionized water or other suitable rinses. The rinsing can take place either in a large bath where the fiber and holder can be submerged or the fiber and holder can be washed in a fountain similar to the fountain used for the developer solution.
After the fiber is washed, it can then undergo an optional flat exposure procedure at the same light intensity as the original exposure and for a period of from about 1 to 10 seconds. The flat exposure procedure consists of exposing the fiber and holder to white light or light which is within the absorbance band or the exposure band of the photoresist to expose those portions of the photoresist which remain on the fiber and have not been exposed by the original laser beam exposure.
The fiber and holder are placed in an ion beam etching apparatus.
The ion beam etching apparatus uses a source of reactive ions such as fluorine ions derived from tetrafluoromethane or other suitable sources, or other suitable ions to etch the fiber and the photoresist. The fluorine ions will etch that portion of the fiber which is not covered with the lines of the photoresist. Thus, the ion beam will etch gratings into the fiber. The etching takes from about 10 to 30 minutes. Generally, the gratings will be etched from about one-third of the way to about one-half of the way around the circumference of the optical fiber.
A preferred option requires that the fiber can be quickly etched in the ion beam apparatus prior to the chemical etch and the priming and photoresist coating to create a fiber with an off-center core where the cladding is thinner on one side. The thinner cladding area exposes more evanescent wave and orients the fiber for the grating formation in this thinner cladding section. The ion beam etcher need only remove about 1 to 2 micrometers from a side of the fiber to create the necessary offset to orient the fiber.
After the etching, the fiber and holder are removed from the ion beam etching apparatus and placed in a photoresist removal apparatus. The photoresist removal apparatus is again a fountain which allows the photoresist remover, such as Remover 1112A, a product of the Shipley Corporation, to remove the remaining photoresist on the etched fiber. The photoresist is exposed to the remover for from about 10 seconds to about 10 minutes. Alternatively, a solution of nine parts H 2 SO 4 and one part 50% hydrogen peroxide at approximately 90° C. can be used as a remover. The fountain is designed so that only the portion of the fiber which contains photoresist is exposed to the photoresist remover. The finished fiber has a substantially uniform grating along its surface. The gratings on the fiber will reflect specific wavelengths of light passing through the fiber.
The amount of light the fiber reflects can be determined by adjusting the previous steps to create a fiber having a predetermined grating configuration. The closer the gratings are to the core, the greater the reflectivity of the gratings. Alternatively, the strength of the reflectance can be adjusted by adjusting the ion beam's etching time. The reflectivity or the amount of light the fiber will reflect is related to the depth of the grooves of the grating. The greater the depth, the greater the amount of the reflected light. Finally, the angle of interference of the exposing light and the exposing light wavelength determine the spacing of the gratings.
For example, a 0.3 micrometer grating peak spacing requires each of two interfering beams to have propagation vectors which have an angle of 96° between them, or lie nearly in the same plane which contains the axis of the fiber, and have a bisector of the angle between them which is or is nearly perpendicular to the fiber axis. Taking into account the refractive index of the fiber, a 0.3 micrometer grating spacing will reflect light having a wavelength of about 8300 Angstroms. The 0.3 micrometer spacing is peak to peak or valley to valley. The width of a peak or valley is about 0.15 micrometer and the depth from a peak to a valley is about 0.15 micrometer. The second of the interfering beams can be derived from the first beam through the use of a beam splitter. Alternatively, the interference pattern can be produced by the use of a mirror capable of producing Lipman fringes. The interference pattern is created by having the original beam interfere with itself.
If one wants to have a grating which will reflect a lower wavelength light, then the angle between the propagation vectors is adjusted to be more than 96°, for example 100° or 110°. A smaller angle causes the exposed pattern in the photoresist to have a lower spatial frequency. In other words, the separation between the exposed photoresist lines will be greater.
More specifically, varying the process parameters permits the fabrication of gratings with interaction lengths that vary from about 100 wavelengths to about 1 centimeter. The reflectivity r can be varied from about 0.05 to about 0.9 or higher. This wide reflectivity enables to fabrication of gratings that can be adjusted to reflect wavelengths of light between about 7000 Angstroms to about 20,000 Angstroms or higher. Changing the laser lights source can extend the range below 7000 Angstroms or above 20,000 Angstroms.
Furthermore, this process also allows one not only to change the spectral location of the light which is reflected by the grating but also change the shape of the wavelength band. For example, the fiber can be ion beam etched through shutters to reduce the exposure at the ends of the grating. This causes the strength of the reflectivity to vary along the gratings, i.e., the center of the grating portion would exhibit a strong reflectivity and the ends would exhibit weak reflectivity. One could use shutters which vary the amount of the ion beam to etch the grating so as to make gratings which might have a gaussian dependency. Such an adjustment in the process permits the fabrication of gratings which have suppressed side lobes.
Optionally, the etching process can be monitored by the following process to determine the amount and effect of cladding etching so as to better control the reflectivity of a grating. This process occurs during the etching chemical procedure and prior to actually forming the grating on the fiber. The monitoring process requires interrupting the etching chemical process, removing any etchant solution from the fiber, injecting light of nearly the wavelength of the desired reflectance band into an end of the fiber, contacting the etched fiber with a wick saturated with a liquid having an index of refraction higher than that of the fiber core material, for example, phenol, methyl salicylate (i.e., oil of wintergreen) and the like, and measuring the decrease in light output from the fiber end opposite the injection end as caused by the placement of the wick. The accuracy of the process is partly dependent upon knowing which size and contacting length on the fiber touched by the wick. This wick loss decrease, in light output, relates to the strength of the exposed evanescent waves. The greater the light loss, the more the evanescent waves are exposed.
FIGS. 5 and 6 illustrate an apparatus 50 for measuring the evanescent field in an etched optical fiber 18. The optical fiber 16 and the etched portion 18 thereof are held in a holder 12. The core of the etched optical fiber 18 is indicated at 18a. A container 52 holds a solution 54 having a higher index of refraction than the etched optical fiber 18 in the holder 12. Suitable materials are phenol, methyl salicylate, and the like. A stable wick 56, fabricated from a material such as a urethane foam polishing cloth, is placed in the solution 54. Preferably, the wick should be at least as thick as the fiber 18, have known width, and not be subject to expansion. Since the etched length of the fiber is usually about 1 to 4 cm, a suitable width is from about 0.02 mm to about 0.1 mm and preferably is about 0.05 mm. Preferably, the wick should wet the same length of the fiber as the width of the wick because the accuracy is partly based upon knowing the length of the fiber exposed to the high index of refraction solution. To test the entire length of the etched fiber 18, either the wick 56 must be movable along the fiber 18 or the fiber 18 and holder 12 must be movable along the wick. This movement can be accomplished by a motor or person physically moving the fiber or the wick.
With the wetted wick 56 touching the fiber 18, one end of the fiber contains a holder system 58 capable of permitting light from a laser 60 to be injected into the fiber 16. Any standard holder and lense focusing system capable of putting the laser light within the angle of acceptance of the fiber is suitable. The laser should be selected to emit light having a wavelength of interest for reflection when the gratings are formed. For example, if the gratings are to be designed to reflect light at about 8300 Angstroms, then the laser can be a GaAs laser that emits light having a wavelength of about 8300 Angstroms. The light passing through the fiber 16 containing the cladding and core unit 18 is monitored on an optical power meter 62. Any suitable optical power meter can be used or a photodiode capable of converting the optical light signal into an electrical signal can be used. The signal obtained from the optical power meter 62 is recorded on a recorder 64 such as a chart recorder.
As illustrated in FIG. 6, given a constant evanescent field, the greater the depth of the etching, the larger will be the wick light loss coupled out of the fiber 18 through the wick 56 containing the high index of refraction material 54 and the lower will be the recording on the chart recorder 64. By moving either the fiber 18 or the wick 56 along the etched portion of the fiber 16, the uniformity and depth of etching can be determined. Since the gratings will be formed within the fiber 18, the field will be at least as strong as the filed exposed during the test. This process gives a representative correlation between the strength of the exposed field after grating formation.
By repeating this monitoring process several times during the etching process, the process also provides a method of monitoring the etch rate of the fiber. By etching many fibers to have different wick losses and then forming gratings and measuring the reflectivity, the relationship between wick loss for a known length of fiber and reflectivity for a finished grating can be determined empirically for a particular manufacturer's fiber. Using this relationship, the reflectivity of a grating or grating portion can be approximately established immediately after the cladding etching and before the grating formation.
The invention has been described with respect to preferred embodiments. However, it should be understood that the invention is not intended to be limited in any way by the preferred embodiments. Modifications which would be obvious to the ordinary skilled artisan are contemplated to be within the scope of the invention.
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The apparatus is capable of coating thin objects, such as wires, optical fibers, and the like, with fluids such as enamels, photoresist primers, photoresists, and the like. The apparatus is configured so that the area over which the object is coated and the thickness of the coating can be adjusted. The coating is applied in a reproducible manner. The coating is applied without damaging the articles, such as thin wires and optical fibers having diameters on the order of about 5 to 50 micrometers.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to novel substituted deazapurine derivatives which selectively bind to CRF receptors. More specifically, it relates to pyrrolo[3,2-d]pyrimidin-4-amines, pyrrolo[3,2-b]pyridin-4-amines, and pyrrolo[3,2-b]pyridin-4-amines, and their use as antagonists of Corticotropin-Releasing Factor in the treatment of various disease states.
[0003] 2. Description of the Related Art
[0004] Corticotropin-releasing factor (CRF) antagonists are mentioned in U.S. Pat. Nos. 4,605,642 and 5,063,245 referring to peptides and pyrazoline derivatives, respectively. The importance of CRF antagonists is described in the literature, for example, as discussed in U.S. Pat. No. 5,063,245, which is incorporated herein by reference in its entirety. CRF antagonists are considered effective in the treatment of a wide range of diseases including stress-related illnesses, such as stress-induced depression, anxiety, and headache. Other diseases considered treatable with CRF antagonists are discussed in U.S. Pat. No. 5,063,245 and Pharm. Rev., 43: 425-473 (1991).
[0005] International application WO 9413676 A1 discloses pyrrolo[2,3-d]pyrimidines as having Corticotropin-Releasing Factor antagonist acitivity. J. Het. Chem. 9, 1077 (1972) describes the synthesis of 9-Phenyl-pyrrolo[3,2-]pyrimidines.
SUMMARY OF THE INVENTION
[0006] This invention provides novel compounds of Formula I which interact with CRF receptors.
[0007] The invention provides pharmaceutical compositions comprising compounds of Formula I. It further relates to the use of such compounds in treating treating stress related disorders such as post trumatic stress disorder (PTSD) as well as depression, headache and anxiety. Accordingly, a broad embodiment of the invention is directed to a compound of Formula I:
[0008] wherein
[0009] Ar is phenyl, where the phenyl group is mono, di-, or trisubstituted with halogen, hydroxy, lower alkyl, or lower alkoxy, with the proviso that at least one of the ortho positions of the phenyl group is substituted; or
[0010] Ar is 2-, 3-, or 4-pyridyl, 2- or 3-thienyl, 4- or 5-pyrimidyl, each of which is optionally mono-, di-, or trisubstituted with halogen, hydroxy, lower alkyl, or lower alkoxy, with the proviso that at least one of the ortho positions of the Ar substituent is substituted;
[0011] X is CH or nitrogen;
[0012] R 1 is lower alkyl;
[0013] R 2 is hydrogen, halogen, lower alkyl, lower alkoxy, or thioalkoxy; or
[0014] R 1 and R 2 taken together represent —(CH 2 ) n -A-(CH 2 ) m —,
[0015] where n is 2, 3 or 4, A is methylene, oxygen, sulfur or NR 6 , where R 6 is lower alkyl, and
[0016] m is 0, 1 or 2;
[0017] R 3 and R 4 are the same or different and represent
[0018] hydrogen or lower alkyl;
[0019] phenyl, 2-, 3-, or 4-pyridyl, 2-, or 3-thienyl, or 2-, 4-, or 5-pyrimidyl, each of which is optionally mono- or disubstituted with halogen, hydroxy, lower alkyl, or lower alkoxy;
[0020] phenyl lower alkyl, 2-, 3-, or 4-pyridyl lower alkyl, 2- or 3-thienyl lower alkyl, or 2-, 4-, or 5-pyrimidyl lower alkyl;
[0021] cycloalkyl having 3-8 carbon atoms or cycloalkyl lower alkyl where the cycloalkyl portion has 3-8 carbon atoms;
[0022] 2-hydroxyethyl or 3-hydroxypropyl optionally mono or disubstituted with lower alkyl with the proviso that not both R 3 and R 4 are hydrogen; or
[0023] R 3 and R 4 taken together represent —(CH 2 ) n -A-(CH 2 ) m —
[0024] where n is 2, or 3,
[0025] A is methylene, 1,2 phenylene, oxygen, sulfur or NR 6 , wherein R 6 is lower alkyl, phenyl, 2-, 3-, or 4-pyridyl, 2-or 3-thienyl or 2-, 4-, or 5-pyrimidyl, phenyl lower alkyl, 2-, 3-, or 4-pyridyl lower alkyl, 2-or 3-thienyl lower alkyl, or 2-, 4-, or 5-pyrimidyl lower alkyl; and
[0026] m is 1, 2 or 3; and
[0027] R 5 is hydrogen, halogen, lower alkyl, lower alkoxy, or thioalkoxy.
[0028] These compounds, i.e., substituted deazapurine derivatives, are highly selective partial agonists or antagonists at CRF receptors and are useful in the diagnosis and treatment of stress related disorders such as post trumatic stress disorder (PTSD) as well as depression and anxiety.
[0029] Thus, the invention provides compounds, including pharmaceutically acceptable salts of the compounds of formula I, and pharmaceutical compositions for use in treating disease states associated with Corticotropin-releasing factor. The invention further provides methods including animal models relevant to the evaluation of the interaction of the compounds of the invention with CRF receptors. This interaction results in the pharmacological activities of these compounds.
DETAILED DESCRIPTION OF THE INVENTION
[0030] In this document, all temperatures will be stated in degrees Celsius. All amounts, ratios, concentrations, proportions and the like will be stated in weight units, unless otherwise stated, except for ratios of solvents, which are in volume units.
[0031] In addition to compounds of general formula I described above, the invention encompasses compounds of general formula IA:
[0032] wherein
[0033] Ar is phenyl, 2-, 3-, or 4-pyridyl, 2- or 3-thienyl, 4- or 5-pyrimidyl, each of which is mono-, di-, or trisubstituted with halogen, hydroxy, lower alkyl, or lower alkoxy, with the proviso that at least one of the ortho positions of the Ar substituent is substituted;
[0034] X is CH or nitrogen;
[0035] R 1 is lower alkyl;
[0036] R 2 is hydrogen, halogen, lower alkyl, lower alkoxy, or thioalkoxy; or
[0037] R 1 and R 2 taken together represent —(CH 2 ) n -A-(CH 2 ) m —,
[0038] where n is 2, 3 or 4, A is methylene, oxygen, sulfur or NR 6 , where R 6 is lower alkyl, and
[0039] m is 0, 1 or 2;
[0040] R 3 and R 4 are the same or different and represent
[0041] hydrogen or lower alkyl;
[0042] phenyl, 2-, 3-, or 4-pyridyl, 2-, or 3-thienyl, or 2-, 4-, or 5-pyrimidyl, each of which is mono- or disubstituted with halogen, hydroxy, lower alkyl, or lower alkoxy;
[0043] phenyl lower alkyl, 2-, 3-, or 4-pyridyl lower alkyl, 2- or 3-thienyl lower alkyl, or 2-, 4-, or 5-pyrimidyl lower alkyl;
[0044] cycloalkyl having 3-8 carbon atoms or cycloalkyl lower alkyl where the cycloalkyl portion has 3-8 carbon atoms;
[0045] 2-hydroxyethyl or 3-hydroxypropyl optionally mono or disubstituted with lower alkyl with the proviso that not both R 3 and R 4 are hydrogen; or
[0046] R 3 and R 4 taken together represent —(CH 2 ) n -A-(CH 2 ) m
[0047] where n is 2, or 3,
[0048] A is methylene, 1,2 phenylene, oxygen, sulfur or NR 6 , wherein R 6 is lower alkyl, phenyl, 2-, 3-, or 4-pyridyl, 2-or 3-thienyl or 2-, 4-, or 5-pyrimidyl, phenyl lower alkyl, 2-, 3-, or 4-pyridyl lower alkyl, 2-or 3-thienyl lower alkyl, or 2-, 4-, or 5-pyrimidyl lower alkyl, and
[0049] m is 1, 2 or 3; and
[0050] R 5 is hydrogen, halogen, lower alkyl, lower alkoxy, or thioalkoxy.
[0051] In the compounds of the invention, preferred NR 3 R 4 groups include the following:
[0052] Preferred compounds of formula I are those where R 1 is methyl, ethyl or propyl or isopropyl; R 2 is lower alkyl, halogen, or thio lower alkyl; R 5 is lower alkyl or halogen; and R 7 , R 8 , and R 9 represent methyl, ethyl, propyl or isopropyl.
[0053] The invention provides compounds of formula II
[0054] wherein
[0055] R 4 represents hydrogen or lower alkyl;
[0056] R 1 , R 7 , R 8 , and R 9 represent lower alkyl, and
[0057] R 3 represents lower alkyl, or cycloalkyl lower alkyl.
[0058] Preferred compounds of formula II are those where R 1 is methyl, ethyl or propyl or isopropyl; and R 7 , R 8 , and R 9 represent methyl, ethyl, propyl or isopropyl. Particularly preferred compounds of formula II are those where R 1 is methyl, and R 7 , R 8 , and R 9 represent methyl.
[0059] The invention provides compounds of formula III
[0060] wherein
[0061] R 4 represents hydrogen or lower alkyl;
[0062] R 1 , R 7 , R 8 , and R 9 represent lower alkyl; and
[0063] R 3 represents lower alkyl, or cycloalkyl lower alkyl; and
[0064] R 5 is lower alkyl, halogen, or thio lower alkyl.
[0065] Preferred compounds of formula III are those where R 1 is methyl, ethyl or propyl or isopropyl; R 5 is halogen or thio lower alkyl; and R 7 , R 8 , and R 9 represent methyl, ethyl, propyl or isopropyl. Particularly preferred compounds of formula III are those where R 1 is methyl; R 5 is halogen, thiomethyl; and R 7 , R 8 , and R 9 represent methyl, ethyl, propyl or isopropyl.
[0066] The invention provides compounds of formula IV
[0067] wherein
[0068] R 4 represents hydrogen or lower alkyl;
[0069] R 1 , R 7 , R 8 , and R 9 represent lower alkyl; and
[0070] R 3 represents lower alkyl, or cycloalkyl lower alkyl; and
[0071] R 5 is lower alkyl, halogen, or thio lower alkyl.
[0072] Preferred compounds of formula IV are those where R 1 is methyl, ethyl or propyl or isopropyl; R 5 is halogen or thio lower alkyl; and R 7 , R 8 , and R 9 represent methyl, ethyl, propyl or isopropyl. Particularly preferred compounds of formula IV are those where R 1 is methyl; R 5 is halogen, thiomethyl; and R 7 , R 8 , and R 9 represent methyl, ethyl, propyl or isopropyl.
[0073] The invention provides compounds of formula V
[0074] wherein
[0075] R 4 represents hydrogen or lower alkyl;
[0076] R 1 , R 7 , R 8 , and R 9 represent lower alkyl; and
[0077] R 3 represents lower alkyl, or cycloalkyl lower alkyl.
[0078] Preferred compounds of formula V are those where R 1 is methyl, ethyl or propyl or isopropyl; and R 7 , R 8 , and R 9 represent methyl, ethyl, propyl or isopropyl. Particularly preferred compounds of formula V are those where R 1 is methyl, and R 7 , R 8 , and R 9 represent methyl.
[0079] The invention provides compounds of formula VI
[0080] wherein
[0081] R 4 represents hydrogen or lower alkyl;
[0082] R 1 , R 7 , R 8 , and R 9 represent lower alkyl; and
[0083] R 3 represents lower alkyl, or cycloalkyl lower alkyl; and
[0084] R 5 is lower alkyl, halogen, or thio lower alkyl.
[0085] Preferred compounds of formula VI are those where R 1 is methyl, ethyl or propyl or isopropyl; R 5 is halogen or thio lower alkyl; and R 7 , R 8 , and R 9 represent methyl, ethyl, propyl or isopropyl. Particularly preferred compounds of formula VI are those where R 1 is methyl; R 5 is halogen, thiomethyl; and R 7 , R 8 , and R 9 represent methyl, ethyl, propyl or isopropyl.
[0086] The invention provides compounds of formula VII:
[0087] wherein
[0088] R 4 represents hydrogen or lower alkyl;
[0089] R 1 , R 7 , R 8 , and R 9 represent lower alkyl; and
[0090] R 3 represents lower alkyl, or cycloalkyl lower alkyl; and
[0091] R 5 is lower alkyl, halogen, or thio lower alkyl.
[0092] Preferred compounds of formula VII are those where R 1 is methyl, ethyl or propyl or isopropyl; R 5 is halogen or thio lower alkyl; and R 7 , R 8 , and R 9 represent methyl, ethyl, propyl or isopropyl. Particularly preferred compounds of formula VII are those where R 1 is methyl; R 5 is halogen, thiomethyl; and R 7 , R 8 , and R 9 represent methyl, ethyl, propyl or isopropyl.
[0093] In each of formulas II to VII, NR3R 4 optionally represents —(CH 2 ) n -A-(CH 2 ) m — where m, n, and A are as defined above for formula I.
[0094] The invention also provides compounds of formula VIII:
[0095] wherein
[0096] Ar is phenyl, 2-, 3-, or 4pyridyl, 2- or 3-thienyl, 4- or 5-pyrimidyl, each of which is mono-, di- , or trisubstituted with halogen, hydroxy, lower alkyl, or lower alkoxy, with the proviso that at least one of the ortho positions of the Ar substituent is substituted;
[0097] X is CH or nitrogen;
[0098] R 1 is lower alkyl;
[0099] R 2 is hydrogen, halogen, lower alkyl, lower alkoxy, or thioalkoxy; or
[0100] R 3 and R 4 are the same or different and represent
[0101] hydrogen or lower alkyl;
[0102] phenyl, 2-, 3-, or 4pyridyl, 2-, or 3-thienyl, or 2-, 4, or 5-pyrimidyl, each of which is mono- or disubstituted with halogen, hydroxy, lower alkyl, or lower alkoxy;
[0103] phenyl lower alkyl, 2-, 3-, or 4pyridyl lower alkyl, 2- or 3-thienyl lower alkyl, or 2-, 4-, or 5-pyrimidyl lower alkyl;
[0104] cycloalkyl having 3-8 carbon atoms or cycloalkyl lower alkyl where the cycloalkyl portion has 3-8 carbon atoms;
[0105] 2-hydroxyethyl or 3-hydroxypropyl optionally mono or disubstituted with lower alkyl with the proviso that not both R 3 and R 4 are hydrogen;
[0106] R 3 and R 4 taken together represent —(CH 2 ) n -A-(CH 2 ) m —
[0107] where n is 2, or 3,
[0108] A is methylene, 1,2 phenylene, oxygen, sulfur or NR 6 , wherein R 6 is lower alkyl; and
[0109] m is 1, 2 or 3; and
[0110] R 5 is hydrogen, halogen, lower alkyl, lower alkoxy, or thioalkoxy.
[0111] In addition, the invention provides compounds of formula IX:
[0112] wherein
[0113] Ar is phenyl mono-, di-, or trisubstituted with halogen, hydroxy, lower alkyl, or lower alkoxy, with the proviso that at least one of the ortho positions of the Ar substituent is substituted;
[0114] X is nitrogen;
[0115] R 1 is lower alkyl;
[0116] R 2 is hydrogen, halogen, lower alkyl, lower alkoxy, or thioalkoxy; or
[0117] R 3 and R 4 are the same or different and represent
[0118] hydrogen or lower alkyl;
[0119] cycloalkyl having 3-8 carbon atoms or cycloalkyl lower alkyl where the cycloalkyl portion has 3-8 carbon atoms;
[0120] 2-hydroxyethyl or 3-hydroxypropyl optionally mono or disubstituted with lower alkyl with the proviso that not both R 3 and R 4 are hydrogen; or
[0121] R 3 and R 4 taken together represent —(CH 2 ) n -A-(CH 2 ) m —
[0122] where n is 2, or 3,
[0123] A is methylene, 1,2 phenylene, oxygen, sulfur or NR 6 , wherein R 6 is lower alkyl; and
[0124] m is 1, 2 or 3;
[0125] R 5 is hydrogen, halogen, lower alkyl, lower alkoxy, or thioalkoxy.
[0126] Further, the invention provides compounds of formula X:
[0127] wherein
[0128] Ar is phenyl mono-, di-, or trisubstituted with halogen, hydroxy, lower alkyl, or lower alkoxy, with the proviso that at least one of the ortho positions of the Ar substituent is substituted;
[0129] R 1 is lower alkyl;
[0130] R 2 is hydrogen, halogen, lower alkyl, lower alkoxy, or thioalkoxy; or
[0131] R 3 and R 4 are the same or different and represent
[0132] hydrogen or lower alkyl;
[0133] cycloalkyl having 3-8 carbon atoms or cycloalkyl lower alkyl where the cycloalkyl portion has 3-8 carbon atoms;
[0134] 2-hydroxyethyl or 3-hydroxypropyl optionally mono or disubstituted with lower alkyl with the proviso that not both R 3 and R 4 are hydrogen; or
[0135] R 3 and R 4 taken together represent —(CH 2 ) n -A-(CH 2 ) m —
[0136] where n is 2, or 3,
[0137] A is methylene, 1,2 phenylene, oxygen, sulfur or NR 6 , wherein R 6 is lower alkyl; and
[0138] m is 1, 2 or 3;
[0139] R 5 is hydrogen, halogen, lower alkyl, lower alkoxy, or thioalkoxy.
[0140] Representative compounds of the present invention, which are encompassed by Formula I, include, but are not limited to the compounds in FIG. 1 and their pharmaceutically acceptable salts. Non-toxic pharmaceutically acceptable salts include salts of acids such as hydrochloric, phosphoric, hydrobromic, sulfuric, sulfinic, formic, toluene sulfonic, hydroiodic, acetic and the like. Those skilled in the art will recognize a wide variety of non-toxic pharmaceutically acceptable addition salts.
[0141] The present invention also encompasses the acylated prodrugs of the compounds of Formula I. Those skilled in the art will recognize various synthetic methodologies which may be employed to prepare non-toxic pharmaceutically acceptable addition salts and acylated prodrugs of the compounds encompassed by Formula I.
[0142] By aryl or “Ar” is meant an aromatic carbocyclic group having a single ring (e.g., phenyl), multiple rings (e.g., biphenyl), or multiple condensed rings in which at least one is aromatic, (e.g., 1,2,3,4-tetrahydronaphthyl, naphthyl, anthryl, or phenanthryl), which is optionally mono-, di-, or trisubstituted with, e.g., halogen, lower alkyl, lower alkoxy, lower alkylthio, trifluoromethyl, lower acyloxy, aryl, heteroaryl, and hydroxy.
[0143] By aryl or “Ar” is also meant heteroaryl groups where heteroaryl is defined as 5, 6, or 7 membered aromatic ring systems having at least one hetero atom selected from the group consisting of nitrogen, oxygen and sulfur. Examples of heteroaryl groups are pyridyl, pyrimidinyl, pyrrolyl, pyrazolyl, pyrazinyl, pyridazinyl, oxazolyl, furanyl, quinolinyl, isoquinolinyl, thiazolyl, and thienyl, which can optionally be substituted with, e.g., halogen, lower alkyl, lower alkoxy, lower alkylthio, trifluoromethyl, lower acyloxy, aryl, heteroaryl, and hydroxy.
[0144] By alkyl and lower alkyl is meant straight and branched chain alkyl groups having from 1-6 carbon atoms. Specific examples of alkyl groups are methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl tert-butyl, sec-butyl neopentyl and n-pentyl.
[0145] By lower alkoxy and alkoxy is meant straight and branched chain alkoxy groups having from 1-6 carbon atoms.
[0146] By thioalkoxy is meant a straight or branched chain alkoxy group having from 1-6 carbon atoms and a terminal sulfhydryl, i.e., —SH, moiety.
[0147] By thio lower alkyl as used herein is meant a lower alkyl group having a terminal sulfhydryl, i.e., —SH, group.
[0148] By halogen is meant fluorine, chlorine, bromine and iodine.
[0149] Representative examples of pyrrolo[3,2-d]pyrimidines according to the invention are shown in Table 1 below.
TABLE 1 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
[0150] The pharmaceutical utility of compounds of this invention is indicated by the following assay for CRF receptor activity.
[0151] Assay for CRF Receptor Binding Activity
[0152] CRF receptor binding was performed using a modified version of the assay described by Grigoriadis and De Souza (Biochemical, Pharmacological, and Autoradiographic Methods to Study Corticotropin-Releasing Factor Receptors. Methods in Neurosciences, Vol. 5, 1991). Membrane pellets containing CRF receptors were resuspended in 50 mM Tris buffer pH 7.7 containing 10 mM MgCl 2 and 2 mM EGTA and centrifuged for 10 minutes at 48000 g. Membranes were washed again and brought to a final concentration of 1500 g/ml in binding buffer (Tris buffer above with 0.1% BSA, 0.15 mM bacitracin and 0.01 mg/ml aprotinin.). For the binding assay, 100 ul of the membrane preparation was added to 96 well microtube plates containing 100 μl of 125 I-CRF (SA 2200 Ci/mmol, final concentration of 100 pM) and 50 μl of drug. Binding was carried out at room temperature for 2 hours. Plates were then harvested on a Brandel 96 well cell harvester and filters were counted for gamma emissions on a Wallac 1205 Betaplate liquid scintillation counter. Non specific binding was defined by 1 μM cold CRF. IC 50 values were calculated with the non-linear curve fitting program RS/1 (BBN Software Products Corp., Cambridge, Mass.). The binding characteristics for examples from this patent are shown in Table 2.
TABLE 2 Compound Number 2 IC 50 (μM) 1 0.110 5 0.500
[0153] The compounds of general formula I may be administered orally, topically, parenterally, by inhalation or spray or rectally in dosage unit formulations containing conventional non-toxic pharmaceutically acceptable carriers, adjuvants and vehicles. The term parenteral as used herein includes subcutaneous injections, intravenous, intramuscular, intrasternal injection or infusion techniques. In addition, there is provided a pharmaceutical formulation comprising a compound of general formula I and a pharmaceutically acceptable carrier. One or more compounds of general formula I may be present in association with one or more non-toxic pharmaceutically acceptable carriers and/or diluents and/or adjuvants and if desired other active ingredients. The pharmaceutical compositions containing compounds of general formula I may be in a form suitable for oral use, for example, as tablets, troches, lozenges, aqueous or oily suspensions, dispersible powders or granules, emulsion, hard or soft capsules, or syrups or elixirs.
[0154] Compositions intended for oral use may be prepared according to any method known to the art for the manufacture of pharmaceutical compositions and such compositions may contain one or more agents selected from the group consisting of sweetening agents, flavoring agents, coloring agents and preserving agents in order to provide pharmaceutically elegant and palatable preparations. Tablets contain the active ingredient in admixture with non-toxic pharmaceutically acceptable excipients which are suitable for the manufacture of tablets. These excipients may be for example, inert diluents, such as calcium carbonate, sodium carbonate, lactose, calcium phosphate or sodium phosphate; granulating and disintegrating agents, for example, corn starch, or alginic acid; binding agents, for example starch, gelatin or acacia, and lubricating agents, for example magnesium stearate, stearic acid or talc. The tablets may be uncoated or they may be coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monosterate or glyceryl distearate may be employed.
[0155] Formulations for oral use may also be presented as hard gelatin capsules wherein the active ingredient is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin, or as soft gelatin capsules wherein the active ingredient is mixed with water or an oil medium, for example peanut oil, liquid paraffin or olive oil.
[0156] Aqueous suspensions contain the active materials in admixture with excipients suitable for the manufacture of aqueous suspensions. Such excipients are suspending agents, for example sodium carboxymethylcellulose, methylcellulose, hydropropylmethylcellulose, sodium alginate, polyvinylpyrrolidone, gum tragacanth and gum acacia; dispersing or wetting agents may be a naturally-occurring phosphatide, for example, lecithin, or condensation products of an alkylene oxide with fatty acids, for example polyoxyethylene stearate, or condensation products of ethylene oxide with-long chain aliphatic alcohols, for example heptadecaethyleneoxycetanol, or condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol such as polyoxyethylene sorbitol monooleate, or condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol anhydrides, for example polyethylene sorbitan monooleate. The aqueous suspensions may also contain one or more preservatives, for example ethyl, or n-propyl p-hydroxybenzoate, one or more coloring agents, one or more flavoring agents, and one or more sweetening agents, such as sucrose or saccharin.
[0157] Oily suspensions may be formulated by suspending the active ingredients in a vegetable oil, for example arachis oil, olive oil, sesame oil or coconut oil, or in a mineral oil such as liquid paraffin. The oily suspensions may contain a thickening agent, for example beeswax, hard paraffin or cetyl alcohol. Sweetening agents such as those set forth above, and flavoring agents may be added to provide palatable oral preparations. These compositions may be preserved by the addition of an anti-oxidant such as ascorbic acid.
[0158] Dispersible powders and granules suitable for preparation of an aqueous suspension by the addition of water provide the active ingredient in admixture with a dispersing or wetting agent, suspending agent and one or more preservatives. Suitable dispersing or wetting agents and suspending agents are exemplified by those already mentioned above. Additional excipients, for example sweetening, flavoring and coloring agents, may also be present.
[0159] Pharmaceutical compositions of the invention may also be in the form of oil-in-water emulsions. The oily phase may be a vegetable oil, for example olive oil or arachis oil, or a mineral oil, for example liquid paraffin or mixtures of these. Suitable emulsifying agents may be naturally-occurring gums, for example gum acacia or gum tragacanth, naturally-occurring phosphatides, for example soy bean, lecithin, and esters or partial esters derived from fatty acids and hexitol, anhydrides, for example sorbitan monoleate, and condensation products of the said partial esters with ethylene oxide, for example polyoxyethylene sorbitan monoleate. The emulsions may also contain sweetening and flavoring agents.
[0160] Syrups and elixirs may be formulated with sweetening agents, for example glycerol, propylene glycol, sorbitol or sucrose. Such formulations may also contain a demulcent, a preservative and flavoring and coloring agents. The pharmaceutical compositions may be in the form of a sterile injectable aqueous or oleaginous suspension. This suspension may be formulated according to the known art using those suitable dispersing or wetting agents and suspending agents which have been mentioned above. The sterile injectable preparation may also be sterile injectable solution or suspension in a non-toxic parentally acceptable diluent or solvent, for example as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono-or diglycerides. In addition, fatty acids such as oleic acid find use in the preparation of injectables.
[0161] The compounds of general formula I may also be administered in the form of suppositories for rectal administration of the drug. These compositions can be prepared by mixing the drug with a suitable non-irritating excipient which is solid at ordinary temperatures but liquid at the rectal temperature and will therefore melt in the rectum to release the drug. Such materials are cocoa butter and polyethylene glycols.
[0162] Compounds of general formula I may be administered parenterally in a sterile medium. The drug, depending on the vehicle and concentration used, can either be suspended or dissolved in the vehicle. Advantageously, adjuvants such as local anaesthetics, preservatives and buffering agents can be dissolved in the vehicle.
[0163] Dosage levels of the order of from about 0.1 mg to about 140 mg per kilogram of body weight per day are useful in the treatment of the above-indicated conditions (about 0.5 mg lo about 7 g per patient per day). The amount of active ingredient that may be combined with the carrier materials to produce a single dosage form will vary depending upon the host treated and the particular mode of administration. Dosage unit forms will generally contain between from about 1 mg to about 500 mg of an active ingredient.
[0164] It will be understood, however, that the specific dose level for any particular patient will depend upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, route of administration, and rate of excretion, drug combination and the severity of the particular disease undergoing therapy.
[0165] A representative illustration of methods suitable for the preparation of compounds of the present invention is shown in Schemes I and II. Those having skill in the art will recognize that the starting materials may be varied and additional steps employed to produce compounds encompassed by the present invention.
[0166] wherein Ar, R 1 , R 2 , R 3 , R 4 , and R 5 are as defined above for formula I.
[0167] where Ar, n, m, and A are as defined above for formula I.
[0168] The disclosures in this application of all articles and references, including patents, are incorporated herein by reference.
[0169] The invention is illustrated further by the following examples which are not to be construed as limiting the invention in scope or spirit to the specific procedures and compounds described in them.
EXAMPLE 1A
[0170] [0170]
[0171] To a stirred mixture of sodium methoxide (2.78 g, 51 mmol) and ethyl formate (4.0 g, 54 mmol) in 100 mL of benzene was added 2,4,6 trimethylphenylacetonitrile (8.0 g, 50 mmol) over 5 min. After stirring for an additional hour it was treated with water (100 mL) and the layers were separated. The aqueous layer was separated and acidified with 10% HCl and extracted with ethyl acetate. After drying the solvent was removed in vacuo to afford a-formyl-2,4,6-trimethylphenylacetonitrile as colorless crystals melting at 120-122° C.
EXAMPLE 1B
[0172] [0172]
[0173] A mixture of a-formyl-2,4,6 trimethylphenylacetonitrile (4.5 g, 24 mmol) and sarcosine ethyl ester hydrochloride (3.7 g, 24 mmol) in 100 mL of benzene was refluxed in a Dean-Stark apparatus for 16 h. The solvent was removed in vacuo to afford N-Methyl-N-[2-(2,4,6-trimethylphenyl)-2-cyanovinyl]-glycine ethyl ester as a pale yellow oil.
EXAMPLE 1C
[0174] [0174]
[0175] A solution of N-Methyl-N-[2-(2,4,6-trimethylphenyl)-2-cyanovinyl]-glycine ethyl ester (6.8 g, 24 mmol) in 0.28M ethanolic sodium ethoxide (100 mL) was heated at 70° C. for 6 h. The reaction was cooled and evaporated in vacuo. The residue was treated with water and neutralized with acetic acid and the product was extracted with ethyl acetate. After drying the solvent was removed in vacuo to afford 3-Amino-2-ethoxycarbonyl-1-methyl-4-(2,4,6trimethylphenyl)-1H-pyrrole as a yellow oil.
EXAMPLE 1D
[0176] [0176]
[0177] A solution of 3-Amino-2-ethoxycarbonyl-1-methyl-4-(2,4,6-trimethylphenyl)-1H-pyrrole (2.0 g, 7 mmol) in 20 mL of formamide was heated at 140° C. for 12 h. After cooling the mixture was poured into water and the resulting solid was collected and washed with more water and dried to afford 5-Methyl-7-(2,4,6-trimethylphenyl)-5H-pyrrolo[3,2-d]pyrimidin-4-ol as a tan solid melting at 230-232° C.
EXAMPLE 1E
[0178] [0178]
[0179] A mixture of 5-Methyl-7-(2,4,6-trimethylphenyl)-5H-pyrrolo[3,2-d]pyrimidin-4-ol (100 mg) and phosphorous oxychloride (0.5 mL) was heated at reflux for 3 hours. Excess reagent was removed in vacuo and the residual 4-chloro compound was treated with N-propylcyclopropylmethylamine (100 mg) and triethylamine (100 mg) in xylene (2 mL) and the mixture was refluxed for 8 hours.
[0180] After diluting the reaction mixture with ethyl acetate and washing with dilute bicarbonate solution, the organic layer was dried and the solvent removed in vacuo. The residue was chromatographed on silica gel to afford N-cyclopropylmethyl-N-propyl-5-methyl-7-(2,4,6-trimethylphenyl)-5H-pyrrolo[3,2-d]pyrimidin-4-amine (Compound 1) as an oil. The HCl salt from ethyl acetate/HCl melted at 205-207° C.
EXAMPLE II
[0181] The following compounds are prepared essentially according to the procedures described in Examples IA-E above.
[0182] a) N,N-Dipropyl-5-methyl-7-(2,4,6trimethylphenyl)-5H-pyrrolo[3,2-d]pyrimidin-4-amine (Compound 2) melting at 116-118° C.
[0183] b) N,N-Diethyl-5-methyl-7-(2,4,6-trimethylphenyl)-5H-pyrrole[3,2-d]pyrimidin-4-amine (Compound 3).
[0184] c) N,N-Dimethyl-5-methyl-7-(2,4,6-trimethylphenyl)-5H-pyrrolo[3,2-d]pyrimidin-4-amine (Compound 4).
[0185] d) N-Butyl-N-Ethyl-5-methyl-7-(2,4,6trimethylphenyl)-5H-pyrrolo[3,2-d]pyrimidin-4-amine (Compound 5) melting at 126-128° C.
[0186] e) N-(2-Hydroxyethyl)-N-Ethyl-5-methyl-7-(2,4,6-trimethylphenyl)-5H-pyrrolo[3,2-d]pyrimidin-4-amine (Compound 6).
[0187] f) 4-(1-Homopiperidinyl)-5-methyl-7-(2,4,6-trimethylphenyl)-5H-pyrrolo[3,2-d]pyrimidine (Compound 7) melting at 140-142 C.
[0188] g) N-(1-Ethylpropyl)-5-methyl-7-(2,4,6-trimethylphenyl)-5H-pyrrolo[3,2d]pyrimidin-4-amine (Compound 8).
[0189] h) N-(1-Hydroxymethylpropyl)-5-methyl-7-(2,4,6-trimethylphenyl)-5H-pyrrolo[3,2d]pyrimidin-4-amine (Compound 9) melting at 118-120° C.
[0190] i) N,N-Dipropyl-5,6-dimethyl-7-(2,4,6-trimethylphenyl)-5H-pyrrolo[3,2-d]pyrimidin-4-amine (Compound 10).
[0191] j) N-(1-Hydroxymethylpropyl)-5,6-dimethyl-7-(2,4,6-trimethylphenyl)-5H-pyrrolo[3,2d]pyrimidin-4-amine (Compound 11).
[0192] k) N-(1-Hydroxymethylpropyl)-2,5-dimethyl-7-(2,4,6trimethylphenyl)-5H-pyrrolo[3,2d]pyrimidin-4-amine (Compound 12).
[0193] l) N,N-Dipropyl-2,5-dimethyl-7-(2,4,6-trimethylphenyl)-5H-pyrrolo[3,2-d]pyrimidin-4-amine (Compound 13).
[0194] m) N-Cyclopropylmethyl-N-propyl-6-chloro-5-methyl-7-(2,4,6-trimethylphenyl)-5H-pyrrolo[3,2-d]pyrimidin-4-amine (Compound 14).
[0195] n) N-Cyclopropylmethyl-N-propyl-2-chloro-5-methyl-7-(2,4,6-trimethylphenyl)-5H-pyrrolo[3,2-d]pyrimidin-4-amine (Compound 15).
[0196] o) N-Cyclopropylmethyl-N-propyl-6-bromo-5-methyl-7-(2,4,6-trimethylphenyl)-5H-pyrrolo[3,2-d]pyrimidin-4-amine (Compound 16).
[0197] p) N-Cyclopropylmethyl-N-propyl-6-thiomethyl-5-methyl-7-(2,4,6-trimethylphenyl)-5H-pyrrolo[3,2-d]pyrimidin-4-amine (Compound 17).
[0198] q) N-Cyclopropylmethyl-N-propyl-2-thiomethyl-5-methyl-7-(2,4,6-trimethylphenyl)-5H-pyrrolo[3,2-d]pyrimidin-4-amine (Compound 18).
[0199] r) N-Cyclopropylmethyl-N-propyl-2-chloro-5-methyl-7-(2,4,6-trimethylphenyl)-5H-pyrrolo[3,2-b]pyridin-4-amine (Compound 19).
[0200] s) N-Cyclopropylmethyl-N-propyl-5-methyl-7-(2,4,6-trimethylphenyl)-5H-pyrrolo[3,2-b]pyridin-4-amine (Compound 20).
[0201] t) N-(1-Hydroxymethylpropyl)-5-methyl-7-(2,4,6-trimethylphenyl)-5H-pyrrolo[3,2b]pyridin-4-amine (Compound 21).
[0202] u) N-Cyclopropylmethyl-N-propyl-5-amino-9-(2,4,6-trimethylphenyl)-1,2-dihydro-3H-pyrimido[5,4-e]pyrrolizine (Compound 22).
[0203] v) N-(1-Hydroxymethylpropyl)-5-amino-9-(2,4,6-trimethylphenyl)-1,2-dihydro-3H-pyrimido[5,4-e]pyrrolizine (Compound 23).
[0204] w) N-Cyclopropylmethyl-N-propyl-5-amino-7-methyl-9-(2,4,6-trimethylphenyl)-1,2-dihydro-3H-pyrimido[5,4-e]pyrrolizine (Compound 24).
[0205] x) N-Cyclopropylmethyl-N-propyl-5-amino-9-(2,4-dichlorophenyl)-1,2-dihydro-3H-pyrimido[5,4-e]pyrrolizine (Compound 25).
[0206] y) N,N-Dipropyl-5-methyl-7-(2,4-dichlorophenyl)-5H-pyrrolo[3,2-d]pyrimidin-4-amine (Compound 26).
[0207] z) N-Cyclopropylmethyl-N-propyl-5-amino-9-(2,4,6-trimethylphenyl)-1,2-dihydro-3H-pyrido[2,3-e]pyrrolizine (Compound 27).
[0208] The invention and the manner and process of making and using it, are now described in such full, clear, concise and exact terms as to enable any person skilled in the art to which it pertains, to make and use the same. It is to be understood that the foregoing describes preferred embodiments of the present invention and that modifications may be made therein without departing from the spirit or scope of the present invention as set forth in the claims. To particularly point out and distinctly claim the subject matter regarded as invention, the following claims conclude this specification.
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Disclosed are compounds of formula (I), wherein Ar represents an aryl or heteroaryl group; and R 1 , R 2 , R 3 , R 4 and R 5 represent organic or inorganic substituents, which compounds are highly selective partial agonists or antagonists at human CRF1 receptors and, thus, are useful in the diagnosis and treatment of treating stress related disorders such as post traumatic stress disorder (PTSD) as well as depression, headache and anxiety.
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The present invention relates to an apparatus for operating a blind, in particular, but not exclusively, a vertical window blind, and also to a method of operating such a blind using the apparatus.
BACKGROUND OF THE INVENTION
It is known to provide a vertical louver blind comprising a plurality of louver carrier trucks constrained to move longitudinally within a headrail. Typically, each truck includes a louver carrier which is rotatable about a vertical axis. In such known vertical louver blinds, translational movement of the carrier trucks is effected by a first drive means and a rotation of the vertical louvers carried by respective louver carriers is effected by a second separate drive means. Each of the two drive means includes a respective operating apparatus whereby a user can control the operation of the drive means. Thus, conventional vertical louver blinds have two separate controls for arranging the blind in the desired configuration, which at best detracts from the aesthetic appeal of the blind, and at worst can be confusing for a user as to which operating apparatus has which effect, thus leading to frustration on the part of the user.
Accordingly, it is desired to provide a vertical louver blind with a simplified operating means.
SUMMARY OF THE INVENTION
Thus, in accordance with a first aspect of the present invention, there is provided a vertical blind assembly including a plurality of louver carrier trucks slidably carried within a headrail, each truck including a louver carrier mounted for rotation about an axis; wherein the blind assembly further includes an operating means selectively engageable with a first drive means for urging the trucks to move lengthwise within the headrail and a second drive means for rotation of the louver carrier of each truck about its respective axis.
Embodiments of the present invention thus only require a single operating means for the control of both the translational movement of the trucks along the headrail and the rotational movement of the louver carriers about their respective axes.
The operating means preferably comprises an operating wand.
Preferably, the operation of the vertical blind is caused by rotation of the relevant drive means, which in turn is effected by rotation of the wand when engaged with that drive means.
In a preferred embodiment, the wand includes an engagement element and each of the first and second drive means includes a receiving portion arranged to be capable of receiving at least a portion of the engagement element, whereby the desired drive may be achieved by interengagement of the engagement element, or a portion thereof, with the first or second drive receiving portion.
The wand desirably includes an upper wand portion which carries the engagement element, the engagement element being disengaged from one of the drive means and engaged with the other of the drive means via axial movement of the upper wand portion.
The first drive means may include a chain wheel capable of driving a chain which is preferably connected either directly or indirectly to at least one of the trucks for causing longitudinal movement of the or each truck within the headrail. The term “chain” is intended to include a cord comprising a plurality of equally spaced balls or spheres attached to the cord, as is conventially used with this type of blind assembly. Each louver carrier truck may be connected to the truck or trucks adjacent to it, and the chain may be connected to one of the trucks (the “lead” truck) such that movement of the lead truck longitudinally within the headrail results in the remainder of the louver carrier trucks either being pulled along behind it or pushed by it in the desired direction. This type of arrangement results in the simple and effective control of the movement of the louver carrier trucks within the headrail.
The second drive means preferably includes a generally cylindrical sleeve carrying an external worm gear. A common drive rod preferably cooperates with the louver carrier of each truck and carries a gear wheel which is meshed with the external worm gear of the sleeve such that rotation of the sleeve causes rotation of the drive rod via the gear wheel. This in turn results in rotation of each of the louver carriers.
The operating wand preferably includes at least one hinge to enable a user more easily to rotate the wand. More preferably, the operating wand includes two hinges and is arrangeable in the form of a crank.
In accordance with a second aspect of the present invention there is provided a method of operating a vertical blind apparatus according to the first aspect of the invention, the method including engaging the operating means with the first or second drive means and energising the engaged drive means to cause the desired movement of the louvers. Thus, if it is desired to effect translational movement of the carrier trucks along the headrail, then the first drive means is engaged and energised. Alternatively, if it is desired to rotate the louvers about their respective axes, then the second drive means is engaged and energised.
An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawing which shows an exploded view of one end of a vertical louver blind headrail assembly.
For the avoidance of doubt, it should be noted that in the following description, references to “up”, “down” and to related terms, refer to the orientation that the relevant component(s) of the blind adopt when installed for normal use, as they are shown in the drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an embodiment of the first aspect of the invention, namely a vertical blind headrail assembly 2 including a headrail 4 , an end cap 6 and an operating wand 8 .
DETAILED DESCRIPTION OF THE INVENTION
The operating wand 8 includes a lower wand portion 10 hingeably coupled at one end 9 to a first end 11 of an intermediate wand portion 12 . The other end 13 of the intermediate wand portion 12 is likewise hingeably coupled to a first end 15 of an upper wand portion 14 . This arrangement of upper wand portion 14 , intermediate wand portion 12 and lower wand portion 10 allows the wand to be arranged in the form of a crank, as shown in the drawing, which permits easier rotation of the wand 8 .
The upper wand portion 14 is connected at its other end to a wand operating element 18 via a universal joint element 16 which is common in wand-operated drive apparatus.
The operating element 18 includes an engagement pin 20 which is friction fitted within an aperture 19 through the operating element 18 such that both ends of the engagement pin 20 project beyond the outermost cylindrical surface of the operating element 18 .
The operating element 18 includes towards its upper end a shoulder 36 and extending axially from the shoulder 36 a cylindrical projection 38 having a diameter smaller than the diameter of the main body of the operating element 18 .
Upon assembly of the headrail apparatus, the operating element 18 is located within a through hole 17 in the base of the end cap 6 whereby a connecting portion 23 of the operating element 18 extends beyond the through hole 17 and is hingeably connected to one end of the universal joint element 16 . The main body of the operating element 18 is sized such that it is axially slidably within the through hole 17 . A cylindrical sleeve 22 having a bore 21 of diameter substantially equal to that of the diameter of the through hole 17 is then arranged such that the bore 21 surrounds a portion of the operating element 18 and is arranged substantially coaxially with the through hole 17 . The length of the bore 21 is less than the length of the main body of the operating element 18 and the operating element can slide axially within the bore 21 . The cylindrical sleeve 22 carries on its outer cylindrical surface an external worm gear 24 . It also includes a pair of channels 26 coaxially arranged on the upwardly facing surface of the sleeve 22 on opposite sides of the bore 21 .
The engagement pin 20 is then friction fitted within the through hole 19 with its opposite end portions extending therefrom. The channels 26 are arranged to be capable of receiving the projecting end portions of the engagement pin 20 .
A top plate 40 covers an upper portion of the end cap 6 and an aperture 42 through the top plate 40 receives an upper end portion of the projection 38 of the operating element 18 such that the projection 38 acts as a journal borne within the aperture 42 .
The top plate 40 also has rotatably coupled thereto a chain wheel 28 , which includes a cylindrical bore 30 . The cylindrical bore 30 is arranged to be substantially coaxial with the aperture 42 and the projection 38 , and is sized to receive therewithin a portion of the projection 38 . The chain wheel 28 also includes on its downwardly facing end surface a pair of channels (not shown) corresponding to channels 26 in the upwardly facing end surface of the cylindrical sleeve 22 .
The louver blind headrail assembly 2 further includes a metal drive rod 52 which extends the length of the headrail 4 passing through each of the louver carriers (not shown). The drive rod 52 carries at one end thereof a gear wheel 50 having on its outwardly facing cylindrical surface a plurality of teeth 51 . The gear wheel 50 is rotatably coupled to the end cap 6 such that the teeth 51 mesh with the external worm gear 24 , whereby rotation of the cylindrical sleeve 22 results in a corresponding rotation of the metal drive rod 52 . This in turn co-operates with a torque transfer apparatus within each louver carrier truck to rotate the louver carrier about a vertical axis, thus rotating a louver suspended from the louver carrier.
In use, to move the carrier trucks longitudinally within the headrail 4 , the upper wand portion 14 of the operating wand 8 is moved axially upwards until the engagement pin 20 engages with the downwardly facing channels (not shown) formed in the chain wheel 28 . The wand is then rotated and a cord carrying a plurality of equally spaced plastic balls (not shown) is driven to rotate by virtue of jaws 32 of the chain wheel 28 engaging with respective plastic balls on the chain. The chain is connected to the lead, louver truck (not shown) which is caused to move longitudinally within the headrail 4 in a direction which is dependent upon the sense (i.e. clockwise or anti-clockwise) in which the chain wheel is rotated by the operating wand 8 . The remaining trucks are either pulled or pushed by the lead truck, depending upon the direction in which the lead truck is moved.
Alternatively, if a user desires to rotate each louver about its vertical axis, then the upper wand portion 14 of the operating wand 8 is moved axially downwards until the projecting ends of the engagement pin 20 engage within the channels 26 of the sleeve 22 and the operating wand is then again rotated in the desired sense. The external worm gear 24 is meshed with the teeth 51 of the gear wheel 50 and rotation of the cylindrical sleeve 22 results in rotation of the drive rod 52 via the external worm gear 24 and the gear wheel 50 . The rotation of the drive rod 52 results in the rotation about a respective vertical axis of the louvers carried by the carrier trucks. Again, the direction or sense of the rotation is determined by the direction or sense in which the operating wand is rotated.
This preferred embodiment has been described by way of an example only and it will be apparent to those skilled in the arts that many alterations can be made that are still within the scope of the invention.
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An apparatus for operating a vertical louver blind having a plurality of louver carrier trucks slidably mounted within a headrail, wherein each of the carrier trucks includes a louver carrier which is mounted for rotation about a vertical axis, and an operating wand which is selectively engageable with first or second transmissions at any given time.
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CROSS-REFERENCE TO RELATED APPLICATION
The present application claims the benefit of priority of International Patent Application No. PCT/EP2006/004360 filed on May 10, 2006, which application claims priority of German Patent Application No. 10 2005 023 535.2 filed May 21, 2005. The entire text of the priority application is incorporated herein by reference in its entirety.
FIELD OF DISCLOSURE
The disclosure pertains to a system and to a method for conveying open, liquid-filled containers.
BACKGROUND OF THE DISCLOSURE
In the process of filling containers with liquid, it is often necessary to transport the containers in the open state after they have already been filled with the liquid. This need exists, for example, in the area between a filling device and a capping device. For reasons of sales psychology, it is desirable for containers to be filled as full as possible, because the buyer will reject a partially filled container in the belief that it does not contain the full amount promised, even if the container is overdimensioned and the content corresponds exactly to the nominal value. In the case of containers which are filled up to the top or close to the top, however, there is the danger that the liquid can slosh out; that is, some of the nominal content can be lost and, the outside surfaces of the containers and the conveyor device can be contaminated. This danger becomes worse as the transport speed increases and is especially severe in the case of containers with a wide neck such as jars or the wide-neck bottles now coming into more widespread use.
SUMMARY OF THE DISCLOSURE
The disclosure is based on the task of creating a system and a method which make it possible to convey open, liquid-filled containers easily and at high speed.
Through the disclosed design, bottles with standard-sized openings as well as wide-neck containers can be conveyed at high speed without the danger that the liquid will slosh out and be lost or that the machinery and the containers will become contaminated.
The anti-slosh device is advisably installed at the transition between two conveying devices, i.e., the place where the danger of sloshing is the greatest.
Because it is almost impossible, especially at high transport speeds, to determine the exact position where sloshing occurs, it is advisable to design the anti-slosh device in such a way that it acts over a certain predetermined distance along the transport route. As a result, the anti-slosh device will also act over a longer period of time on the liquid, which contributes to the reliable prevention of sloshovers.
The anti-slosh device is designed in such a way that it exerts a restraining pressure on the surge which develops inside the container. This is achieved preferably in a simple manner by injecting a gas under pressure through a nozzle, which is aimed at a point inside the container where a surge can be expected to develop. This most-likely surge formation point can be determined empirically, or it can be calculated on the basis of the prevailing accelerations, centrifugal forces, and inertial forces.
Because the surge which forms at the inside surface of the container will always be close to and underneath the opening of the container, the nozzle is preferably directed at this point.
To prevent the liquid from experiencing a new pulse of energy as a result of the abrupt termination of the restraining pressure, that is, of the injection of the gas, since this could lead to additional sloshing, the velocity of the gas flow is preferably decreased from a higher value at the beginning of the injection process to a lower value at the end of the injection process.
To ensure that the anti-slosh device acts over a certain predetermined distance along the transport route, the nozzle can be designed as a slot nozzle with a predetermined length in the transport direction. The nozzle is preferably stationary. It is also possible, however, to provide a nozzle which can be carried along over the predetermined transport distance.
The inventive design is suitable especially for conveyor systems with circular conveyors arranged in series. As experience has shown, sloshing frequently occurs in the area where the containers are transferred from one conveyor to another, because here is where the transport direction changes. By using the nozzle proposed according to the invention to inject gas into the containers, the transfer of the filled containers from a filling machine or a transfer device, for example, to a capping machine can be accomplished smoothly and at high speed without the fear of sloshing.
An especially preferred method for preventing sloshing consists in injecting gas under pressure into the interior of the container.
BRIEF DESCRIPTION OF THE DRAWINGS
An exemplary embodiment of the disclosure is explained in greater detail below on the basis of the drawings:
FIG. 1 shows a schematic diagram of the formation of a surge;
FIG. 2 shows a schematic diagram of the effect of an exemplary embodiment of the disclosed design;
FIG. 3 shows a diagram of the shape of a nozzle, where FIG. 3A shows a view in perspective and FIG. 3B a longitudinal cross section;
FIG. 4 shows a view, in perspective, of a nozzle with a different shape;
FIG. 5 shows a schematic diagram of a first exemplary embodiment of the disclosed system;
FIG. 6 shows a schematic diagram of another exemplary embodiment of the disclosed system; and
FIG. 7 shows a schematic diagram of another exemplary embodiment of an disclosed system.
DETAILED DESCRIPTION
FIG. 1 shows the processes which occur during the formation of a surge in a container 1 , which is filled with a liquid 2 . The container 1 is a so-called wide-necked container; that is, it has a neck 1 a with an opening 1 b of a diameter “d” which is larger than the diameter of standard bottles such as wine or beer bottles. These types of containers 1 are used, for example, to hold juice, milk, milk-based drinks, or yogurt preparations.
Under unfavorable, discontinuous, or abrupt transport movements, such as those which can occur when, for example, the transport direction changes during a transfer from one conveyor to another or during a sudden acceleration or a sudden braking, a surge 2 a forms in the container 1 . That is, as a result of inertia, the liquid 2 rises along the inside surface of the container on one side and falls on the opposite side. Depending on the intensity of the pulse which causes the surge to form, the liquid can slosh out; that is, a portion 2 b of the liquid can splash out or escape from the opening 1 b of the container 1 , whereas the rest of the liquid of the surge 2 a falls back into the container 1 and acquires an essentially flat surface again after the energy of the pulse has dissipated.
To prevent the liquid 2 from sloshing out, an anti-slosh device 3 is used, the action of which is explained in greater detail on the basis of FIG. 2 . With this anti-slosh device 3 , it is possible to exert a restraining force on the liquid 2 , namely, a force effectively and locally limited to the place where a surge 2 a can be expected to form. A most-likely slosh formation point 4 of this type can be determined empirically or calculated, and it will usually be located, for example, where there is a changeover from one conveyor device to another, namely, at the point where the liquid 2 is subjected to the transport forces of the new conveyor device. Because at least the portion 2 b of the surge 2 a which sloshes out is previously located at the inside surface of the container 1 , it can be assumed that a most-likely surge formation point 4 is located with the greatest probability on the inside surface of the container 1 .
To apply a restraining force to the surge 2 a , it is preferable to use a gas under pressure. For this purpose, air or some other suitable gas, possibly a sterile and/or inert gas, can be used. The gas is directed through a nozzle 5 at the most-likely surge formation point 4 on the inside surface of the container 1 and thus restrains the formation of a surge 2 a in this area at least to such an extent that sloshing-out is prevented.
FIG. 3 shows an enlarged view of an exemplary embodiment of a symmetric nozzle 5 a with a nozzle orifice 1 , which is arranged symmetrically to, and in a direct line with, a gas feed inlet 12 . FIG. 3A shows a view from below, and FIG. 3B shows a cross section through the nozzle orifice 11 . It is advisable, although not absolutely necessary, to provide the nozzle slot or nozzle orifice 11 with a certain curvature to adapt it to the curvature of the transport section and/or to the curved inside contour of the container 1 , as can be seen in FIGS. 3A and 3B . It can also be seen that the nozzle orifice 11 is oriented in such a way that the gas is injected under pressure near the inside wall in the neck area 1 a of the container 1 and onto the surface of the liquid in the container 1 in such a way that the flow of gas is essentially parallel to and a certain distance away from the center line of the neck 1 a.
The pressure used to inject the gas can be either calculated or determined empirically and is on the order of approximately 500 Pa.
It has been found advisable to allow the flow of gas to taper off slowly, because an abrupt termination would subject the liquid to an additional pulse of energy, which could lead to the formation of another surge. This can be achieved passively by the use of a suitably designed nozzle 5 . As is the case, for example, with the nozzle 5 b shown in FIG. 4 , most of the gas exits the nozzle orifice 11 in the area near the gas inlet, whereas the exit velocity decreases with increasing distance from the gas feed inlet 12 . The nozzle 5 b differs from the nozzle 5 a by its asymmetric design. In particular, the feed inlet 12 for the compressed gas is located at the beginning of the nozzle orifice 11 , i.e., to one side of it, whereas the volume of the interior space in the nozzle decreases with increasing distance from the inlet 12 . The design of the nozzle orifice 11 is similar to that of nozzle 5 a.
Another possibility is to expand the nozzle orifice 11 in a wedge-like manner in the transport direction of the containers 1 . As a result, the exit velocity decreases progressively even though the pressure remains the same.
It is also possible, however, to control the pressure actively in such a way that it decreases during the passage of a container 1 under the nozzle orifice 11 . This pressure control is especially suitable for anti-slosh devices in which only one container is located under the nozzle 5 at a time.
FIG. 5 shows the application of the disclosed principle to a first exemplary embodiment of an disclosed system 6 . The system 6 comprises a first conveyor 7 , indicated only schematically. It is designed here as a circular conveyor, and it carries a plurality of holders (not shown), each of which holds one container 1 . The containers 1 are carried by the first conveyor 7 in a transport dimension F 1 along a circular path around a center of rotation (not shown) of the conveyor 7 . A second conveyor 8 is also provided, to which the containers 1 arriving in the transport direction F 1 are transferred and then conveyed onward in a transport direction F 2 along a circular path around a center of rotation 9 of the second conveyor 8 . The transfer takes place by means of a transfer device 10 , which is indicated in the schematic diagram of FIG. 5 only by the point at which the transfer occurs. The transfer device 10 is located at the point where the conveyors 7 and 8 are the closest together, and it leads to a change in the transport direction F from a first circular path F 1 to a second circular path F 2 . That is, an S-shaped transport curve is established for the containers 1 , and this is associated with a change in the sign of the centripetal acceleration. The transfer device 10 can be formed, for example, by stationary guide rails for the containers.
As FIG. 5 shows, a surge develops as a result of the transport movement on the first conveyor 7 . This surge rises along the inside surface of the container 1 facing away from the rotational axis of the conveyor 7 . The surge will also form on the conveyor 8 , but on the opposite inside surface of the container 1 . As a result of the movement of the liquid from one inside surface to other inside surface, there exists the danger that some of the liquid will slosh out of the container, but this is prevented by the inventive anti-slosh device 3 . The anti-slosh device 3 comprises the nozzle 5 a , which, in the exemplary embodiment shown here, is stationary and is designed as a slot nozzle. The nozzle orifice is preferably curved around the rotational axis 9 of the second conveyor 8 . The nozzle 5 a is assigned to the transfer device 10 and is installed in particular above the second conveyor 8 immediately downstream from the transfer point. The nozzle orifice 11 of the nozzle 5 a extends over a predetermined distance “A” along the transport route in the transport direction F 2 of the second conveyor 8 downstream from the transfer device 10 , i.e., from the transfer point. The nozzle orifice 11 is directed at the opening 1 b of the containers 1 and at the inside wall facing away from the rotational axis 9 during transport by the second conveyor 8 , that is, at the outward-facing wall. As a result, it is ensured first that gas is injected under pressure for a sufficient length of time onto the surface of the liquid of the developing surge at the most-likely surge formation point 4 , so that sloshing is prevented. Second, it is ensured at the same time that, regardless of circumstances, gas will still be blown onto the surface of the developing surge even if surge formation has been delayed. Such delays can occur, for example, when the container 1 is slightly tilted or when some other type of irregularity occurs during operation. The transport distance A over which it is possible for the gas to be injected extends preferably over an arc of 10-15 degrees and especially over an arc of approximately 13 degrees, but this can be varied in accordance with specific circumstances such as the type and properties of the liquid, the degree to which the container is filled, the transport rate, the manner in which the transfer is accomplished, the size of the container opening, the shape of the container, etc.
FIG. 6 shows another exemplary embodiment of the described designed system 26 , which is the same as the system 6 according to FIG. 5 except for the details to be described below. The same or comparable components are designated by the same reference numbers and will thus not be explained again. The system 26 , however, contains an anti-slosh device 30 of a different design.
In the exemplary embodiment presented here, the system 26 contains an anti-slosh device 30 a , 30 b for each of the two conveyors 7 and 8 ; they are of identical design except for the modifications required to adapt them to the different conveyors 7 and 8 . The anti-slosh device 30 contains a nozzle 5 c for each container 1 being transported on the associated conveyor 7 , 8 . The nozzle 5 c moves together with the assigned container 1 at the same speed and over the same transport distance as the assigned container 1 . The nozzle 5 c also has a curved nozzle orifice 11 ′, which extends over a predetermined distance A in the transport direction, which essentially matches the inside width of the container opening 1 b , so that the compressed gas is blown only into the opening 1 b and not onto the outside surface of the container 1 . The nozzle orifice 11 ′ is directed onto a most-likely surge formation point 4 at and parallel to the inside wall of the container 1 . For each of the two circular conveyors 7 , 8 , this point is located on the side of the inside surface of the container 1 which faces away from the associated rotational axis. Each of the nozzles 5 c is connected by a compressed gas feed line 12 to a gas distributor 13 , which is preferably located on the rotational axis of the associated conveyor 7 , 8 . The gas distributor 13 ensures that each nozzle 5 c is supplied with compressed gas over a predetermined transport distance A.
In the case of the anti-slosh device 30 b on the second conveyor 8 , the predetermined transport distance A extends over essentially the same transport distance down-stream from the transfer device 10 as was described on the basis of the system 6 according to FIG. 5 . The gas distributor 13 on the second conveyor 8 also ensures that the injection pressure, i.e., the pressure which is exerted on the surface of the liquid, decreases from a higher value in the vicinity of the transfer device 10 to a lower value at the end of the transport distance A.
When the anti-slosh device 30 a of the first conveyor 7 of the system 26 is used, it becomes possible to increase the velocity of the conveyor 7 without causing any sloshing of the liquid. For this purpose, the gas distributor 13 ensures that the nozzle 5 c of the anti-slosh device 30 a injects gas during the entire time that the associated container 1 is being transported on the first conveyor 7 . This prevents the liquid from rising along the inside wall of the container 1 while it is on the conveyor 7 , namely, the rise which is caused by the centrifugal forces developing on the conveyor 7 .
The following table shows an example of the active control of the injection pressure over the required transport distance A when a container according to FIG. 2 is being transferred by a star wheel transfer device (pitch circle, 1,080 mm) to a capping machine (pitch circle, 1,080 mm) for a system output of 55,000 bottles/hr with a filling level of 22.8 mm at 1,666 revolutions per hour (166.6°/sec).
Pressure
Start
End
Time (sec)
Angle, °
500 Pa
0.255 sec
0.305 sec
=0.05
8.33°
300 Pa
0.305 sec
0.315 sec
=0.01
1.66°
150 Pa
0.316 sec
0.325 sec
=0.01
1.66°
50 Pa
0.326 sec
0.335 sec
=0.01
1.66°
Total Distance = 13.31°
As can be seen, after 0.05 sec the pressure at the nozzle outlet is reduced in stages to 0 Pa. The rise in the liquid at the end of the injection process can be reduced even more by decreasing the pressure even more slowly.
The system 36 according to FIG. 7 differs from the system 6 according to FIG. 5 essentially in that here an asymmetric nozzle 5 d with a nozzle orifice 11 of constant width is used. The gas feed line 12 is connected laterally to the end of the nozzle 5 d facing in the transport direction F 2 . For this reason and also because the height of the nozzle 5 d decreases in the direction opposite the transport direction F 2 , the flow velocity of the outgoing gas decreases gradually in the area B of the nozzle orifice 11 adjacent to the gas feed line 12 . This leads to a corresponding decrease in the pressure exerted by the incoming gas on the liquid in the container 1 as the container passes by the nozzle 5 d in the transport direction F 2 .
As a modification of the previously described and illustrated exemplary embodiments, the disclosure can also be used in conjunction with linear conveyors or combinations of circular and linear conveyors. The use of the inventive anti-slosh device also makes it possible to increase the startup speed or to reduce the braking time, since the inventive anti-slosh device prevents the liquid from the sloshing out at higher accelerations or faster braking. The nozzle which can be carried along with the container does not necessarily have to be carried along over the entire transport distance; it is sufficient for the nozzle to be carried along only as long as it is necessary to inject gas onto the surface of the liquid.
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A system for conveying open containers filled with liquid, especially wide-necked containers, whereby the containers can be conveyed in the open state safely and without contamination, including an anti-slosh device which prevents the liquid from sloshing out as the containers are being transported.
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This application is a continuation-in-part application of U.S. Ser. No. 08/990,840 filed Dec. 15, 1997.
FIELD OF THE INVENTION
The present invention relates to collating apparatus for collating loose articles and more particularly, the present invention relates to an apparatus for arranging and/or collating articles into a neat orderly array and a method of employing the apparatus.
BACKGROUND OF THE INVENTION
Many different forms of collating arrangements are known in the art and one of the chief drawbacks of those existing arrangements is realized with the degree of labour intensity. Generally speaking, several personnel are involved in handling the articles to eventually be packaged and this often leads to difficulties in terms of damaged goods as well as complications with respect to health standards. Further limitations revolve around the fact that the additional personnel add labour costs to the overall process.
One of the references which is representative of the arrangements in this art is U.S. Pat. No. 5,201,398, issued Apr. 13, 1993 to Clugston for an apparatus designed for unscrambling sealed containers. In the apparatus, the Clugston device incorporates a water tank filled with water and containers to be unscrambled are passed in a scrambled manner into the water container and eventually lowered into the intake of the vessel. It is indicated in the specification that the containers are passed from the conveyor and distribution and movement of the containers occurs on an unscrambler bed. Distribution and movement is facilitated by pressurized fluid supplied by nozzles 44 . The pressurized gas or fluid urges the containers onto slide plates 14 , which are downwardly inclined relative to the discharge point of the unscrambler bed. The articles are then slidably transported to a further stage referred to as a lane transition section. The Clugston reference, although teaching a useful apparatus, incorporates fairly involved procedure for transporting the articles. It is submitted that this arrangement is useful only in situations where the articles are hermetically sealed. This would have little use, if any, to collate foodstuffs which are assembled into an array and packaged at a downstream operation.
A further example of generally related art in this field is set forth in U.S. Pat. No. 3,608,271, issued Sep. 28, 1971, to Pilat. The arrangement taught in this patent is directed to a coin wrapping machine, which incorporates a ramp for transportation of the coins. The Pilat reference, although having the ramp transportation system, would not be an effective arrangement to transport foodstuffs in view of the fact that it has been specifically designed for transportation of small articles, in this case, coins.
Other references of general relevance to the subject matter set forth herein, include U.S. Pat. Nos. 2,186,652, 2,250,427, 4,105,108, and 5,123,516.
It would be desirable if there were a method for collating loose articles into an orderly array which is significantly less labour intensive and which reduces the contact between the product and the personnel packaging the product.
The present invention is directed to solving the difficulties as set forth herein.
SUMMARY OF THE INVENTION
One object of the present invention is to provide an improved method for collating loose articles into an orderly array.
A further object of the present invention is to provide a method of collating loose articles from a relatively disordered state, comprising the steps of:
providing a plurality of channels having a width dimension, the channels for slidably transporting the articles, the channels having a receiving end for receiving the articles and a discharge end for discharging the articles, each channel having a width dimension, diagonal wall, opposed wall and top edge, each channel having a generally sawtooth configuration adjacent the receiving end with the width dimension progressively decreasing from the receiving end to the discharge end, the receiving end being elevated relative to the discharge end;
introducing the articles at the receiving end at any orientation relative to the channels;
sliding the articles down a respective channel to progressively orient the articles; and
discharging the articles in an ordered array.
Any number of channels may be employed in the arrangement and this will depend upon the volume of article to be packaged among other factors. The channel may be formed of any suitable material having a low coefficient of friction in order to ensure quick transportation of the product from the receiving end of the apparatus to a discharge end. To this end, the receiving end will be elevated relative to the discharge end in order to provide a “ramp effect” and thus facilitate sliding of the article down the channel. Suitable materials for construction of the channels include aluminum, Teflon TM suitable plastics or other suitable metals acceptable to the food industry and also providing the necessary degree of friction. As a further feature, the temperature of the channels may be controlled (heated, cooled) depending upon the type of product to be collated.
The channels may include pegs, cams or some additional element on the top edges in order to reposition, for example, a potato patty from a generally horizontal position relative to the channel to a position where the patty is vertically oriented within the channel. This may also be achieved by providing a texture on the top edge of the channels or simply having different material on adjacent top edges to provide a different coefficient of friction. This will ensure that any randomness in the orientation of the product is eliminated by the edging to reposition the article. In this manner, the channels provide a self-aligning feature for the articles contacting them.
A further object of one embodiment of the present invention is to provide a method of collating loose unpackaged food articles from a relatively disordered state, comprising the steps of:
providing a plurality of channels having a width dimension, the channels for slidably transporting the articles, the channels having a receiving end for receiving the articles and a discharge end for discharging the articles, each channel having a width dimension, diagonal wall, opposed wall and top edge, each channel having a generally sawtooth configuration adjacent the receiving end with the width dimension progressively decreasing from the receiving end to the discharge end, the receiving end being elevated relative to the discharge end;
introducing the articles at the receiving end at any orientation relative to the channels;
sliding the articles by gravity along edges of the channels while simultaneously repositioning the articles into the channels;
orienting the articles within a respective channel during the sliding from a non-vertical altitude to a substantially vertical altitude; and
discharging the articles in an ordered array for packaging.
Having thus described the invention, reference will now be made to the accompanying drawings illustrating preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an overall schematic illustration depicting a sorting, collecting and packaging procedure;
FIG. 2 is a top plan view of the apparatus according to one embodiment;
FIG. 3 is a sectional view along line 3 — 3 of FIG. 2; and
FIG. 4 is a section along line 4 — 4 of FIG. 2 .
Similar numerals in the Figures denote similar elements.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, FIG. 1 broadly illustrates a sorting, collecting and packaging system in schematic form.
The articles, in this example, patties, may be ovular or rectangular, are typically discharged into a freeze tunnel conveyor from previous processing operations (not shown). The articles are unpackaged in the example. The freeze tunnel is broadly denoted by numeral 10 . From the freeze tunnel 10 , the articles are passed on to a dispensing conveyor 12 which orients the patties from travelling widthwise to a lengthwise arrangement. Inspectors 14 , in the conveyor line 12 , typically examine the patties for quality assurance purposes and remove any broken or otherwise inferior patties. The patties are then passed on to the collating apparatus, broadly denoted by numeral 16 to be discussed hereinafter in much greater detail. From the collating apparatus 16 , the patties are then conveyed via conveyor 18 to a packaging machine 20 , which receives trays 22 in timed sequence in order to charge a tray 22 with patties. The charged trays 24 are then passed on to, for example, a shrink wrap machine 26 . Having thus generally described the overall process sequence, reference will now be made in greater detail to the collating apparatus 16 shown best in FIGS. 2, 3 and 4 .
FIG. 2 illustrates a top plan view of the collating apparatus 16 with parts removed for clarity. As is illustrated, the collating apparatus includes a receiving end 30 and a discharge end opposed therefrom and denoted by numeral 32 . The collating apparatus 16 includes a plurality of discrete channels 34 regularly spaced from one another and extending from the receiving end 30 to the discharge end 32 . Channels 34 each have a width dimension broadly denoted by numeral 36 in FIG. 2, which width dimension progressively decreases from the receiving end 30 to the discharge end 32 such that the overall apparatus 16 converges from the receiving end to the discharge end. In this convergent pattern, the width dimension within any channel remains constant relative to an adjacent channel.
FIG. 3 illustrates a section along line 3 — 3 of FIG. 2 which depicts the channels 34 in a generally sawtooth formation. As is illustrated, each channel includes a first substantially vertical wall 38 and a diagonally oriented wall 40 , the orientation being relative to the vertical wall 38 . Diagonal wall 40 terminates in a substantially horizontal base wall segment 42 and further includes a second vertical wall 44 , which is at approximately 90° relative to partial wall 42 and in a parallel and spaced relationship with wall 38 . In this manner, at least at the receiving end and somewhat spaced therefrom, the channels start with a straight wall 38 / 44 and an inclined wall 40 . The spacing between the channels 34 is less than the length of the patty P, but greater than the width of the patty P.
Generally proximate end 32 , the inclined wall 40 in each channel 34 is substantially vertical. This is illustrated in FIG. 4 . The transition from an angular wall 40 to its substantially vertical orientation is progressive along the length of channel 16 as is illustrated in FIG. 2 . In this manner, the patty P moves along the collating apparatus 16 , it is moved from a generally inclined form to a vertically oriented disposition. This facilitates arranging the patty P into an orderly array at end 32 for subsequent charging into a tray 22 as broadly illustrated in FIG. 1 .
In order to achieve this, the collating apparatus 16 and more particularly, the end 30 , is elevated somewhat relative to end 32 . The elevation may be from about 20° to about 40° or greater relative to the horizontal. By providing the elevation, this facilitates sliding of the patties P down the channels from end 30 to 32 .
In operation, the patties P generally enter the receiving end of the apparatus 16 at the various orientations relative to one another. This is typically random and is illustrated in FIG. 2 where one patty is between channels 34 whereas the other is disposed in a cross channel form. By providing the arrangement of the channels 34 as illustrated in FIG. 3, this random disposition is solved simply by having the patty P fall into the channel 34 . It is then automatically turned on its side by virtue of the configuration of the channel 34 as it travels down the inclined apparatus 16 by gravity. In order to ensure that the cross channel patties positively are oriented on a side such as that shown in FIG. 3, small pegs 46 may be employed at the crest or the juncture of walls 38 and 40 . By providing pegs 46 , if the article is cross channel or riding the crests, the pegs ensure reorientation or repositioning to the form shown in FIG. 3, i.e. the patty is on an edge within the channel 34 . This occurs simultaneously as the patty is advanced by sliding.
It is clearly envisioned in the absence of pegs 46 , the top edges of channels 34 may be composed of materials having different coefficients in order to induce the proper disposition of the patty P into the channel 34 . Other forms of locating may be employed such as means for vibrating the channels 34 , cammed internal surfaces inter alia.
FIG. 3 shows in chain line, the gradual change in attitude of the patty P as the same travels the course of the channel 34 .
The present invention thus alleviates the need superfluous personnel in the packaging procedure and further avoids excessive handling by personnel of the product to be packaged.
It will be appreciated by those skilled that although potato patties have been indicated to be the article, the apparatus and methodology are amenable to any article that may be packaged.
Although embodiments of the invention have been described above, it is not limited thereto and it will be apparent to those skilled in the art that numerous modifications form part of the present invention insofar as they do not depart from the spirit, nature and scope of the claimed and described invention.
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A foodstuff collating apparatus having a plurality of discrete channels within which foodstuffs are collated. The apparatus is elevated at one end to provide a slide for the foodstuff with the channels converging from one end of the apparatus to the other. As the foodstuff slides down a channel, the former is oriented from a random position to an ordered vertical disposition.
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BACKGROUND OF THE INVENTION
This invention relates to a process for preparing bicyclic, β-lactam antibiotics. Specifically it relates to preparing 6- and 2-substituted-1-carbadethiapen-2-em-3-caboxylic acids and their pharmaceutically acceptable salts and esters (I): ##STR3## wherein, inter alia, R 1 and R 2 are independently selected from hydrogen, substituted and unsubstituted: alkyl, aryl, aralkyl, and R 3 is inter alia, selected from hydrogen, --R, --OR, --SR,; wherein R is substituted and unsubstituted: alkyl, aryl and aralkyl.
In general, the process of this invention provides the substituted carbapenem (I) via a transition metal carbonyl complex induced ring closure and carbonyl insertion of an appropriately substituted aminoalkene. This general reaction has been reported in the literature for the preparation of the unsubstituted, antibiotically inactive bicyclic β-lactams 4 and 7 [Wong, et al., J.A.C.S. 99 2823, (1977)]: ##STR4## wherein: F p =η 5 --C 5 H 5 Fe(CO) 2 . In the Wong, et al., scheme, the complex 2 is obtained from the olefinic amine by exchange reaction with F p (isobutene)tetrafluoroborate. Successive deprotonation with tri-n-butylamine followed by potassium tert-butoxide gives the piperidine complex 3, which is coverted with Ag 2 O (THF, 65° C., 20 h) to the lactam 4.
A similar sequence, employing 1-pentenylammonium tetrafluoroborate gives the pyrrolidine complex 5. An attempt to convert this directly to β-lactam by oxidation led instead to a polyamide (v CO 1590 cm -1 ) due to the high reactivity of this lactam. However, when 5 was heated in THF for 4 h in the presence of 10 molar % of triphenylphosphine it was smoothly converted to the chelate 6 in 80% yield. Treatment of 6 with freshly precipitated Ag 2 O for 5 min. at 25° C. led to the disappearance of chelate carbonyl absorptions and formation of β-lactam 7.
There is a continuing need for new antibiotics. For unfortunately, there is no static effectiveness of any given antibiotic because continued wide scale usage selectively gives rise to resistant strains of pathogens. In addition, the known antibiotics suffer from the disadvantage of being effective only against certain types of microorganisms. Accordingly, the search for new antibiotics and processes for their preparation continues.
Thus, it is an object of the present invention to provide a process for preparing the above-described carbapenems which are useful in animal and human therapy and in inanimate systems. These antibiotics are active against a broad range of pathogens which representatively include both gram positive bacteria such as S. aureus, Strep. pyogenes, and B. subtilis, and gram negative bacteria such as E. coli, Pseudomonas, Proteus morganii, Serratia, and Klebsiella.
DETAILED DESCRIPTION OF THE INVENTION
The process of the present invention can conveniently be summarized by the following diagram: ##STR5## In words relative to the above diagram, 1, wherein A is a non-critical counter ion such as tetrafluoroborate, hexafluorophosphate, or the like, is exchanged with the complex 2 wherein the olefin is selected from the group consisting of isopropylene, ethylene, propylene, isobutylene and the like and F p is dicarbonyl η 5 -cyclopentadienyl iron: η 5 --C 5 H 5 Fe(CO) 2 . The exchange reaction to provide complex 3 is conducted in a solvent such as THF, dioxane, DMF and the like at a temperature of from -20° to 100° C. for from 10 min. to 6 hours. The reaction 3→4 is accomplished by successive deprotonation. Ideally, the first deprotonation is accomplished with a base such as tri-n-butylamine, tri-isopropylamine, triethylamine or the like; the second deprotonation step, to abstract the pyrrolidine proton, is accomplished with one equivalent of a base such as potassium t-butoxide, sodium methoxide, lithium ethoxide or the like. Such deprotonations are conducted in the same solvent used in the initial exchange reaction. The reaction 4→5 is accomplished by treating 4 with a catalytic amount (10 to 20 molar %) of a triorganophosphine such as triphenylphosphine, tri-n-butylphosphine, tri-p-tolylphosphine or the like in a solvent such as THF, DME, ether, dioxane or the like at a temperature of from 40° to 100° C. for from 1 to 10 hours. Intermediate 5 is oxidized with from 1 to 2 equivalents of an oxidizing agent such as silver (I) oxide, copper (II) oxide, lead dioxide, chlorine or the like in a solvent such as THF, nitromethane, ether, DME or the like at a temperature of from -40° to 100° C. for from 0.5 to 6 hours to provide 6. A second oxidation [6→7] is conducted preferably with an oxidizing agent such as m-chloroperbenzoic acid, hydrogen peroxide, perbenzoic acid, peracetic acid or the like in a solvent such as THF, methylene chloride, nitromethane or the like at a temperature for from -10° to 60° C. for from 0.1 to 4 hours. The resulting sulfoxide (7) is treated with a base such as triethylamine, piperidine, pyridine, diisopropylamine or the like in a solvent such as THF, methylene chloride, acetonitrile, nitromethane or the like at a temperature of from 0° to 60° C. for from 0.1 to 4 hours to provide the unsaturated species 8, which species, when R 5 is a readily removable protecting group such as benzyl, p-nitrobenzyl, o-nitrobenzyl, p-methoxylbenzyl or the like, is deblocked by hydrogenolysis in a solvent such as ethylacetate, dioxane, dioxane/buffer or the like in the presence of a metal catalyst such as palladium on carbon, platinum, RhCl(CO) 2 φ or the like under a hydrogen pressure of 1 to 40 atmospheres at 0° to 60° C. for from 0.1 to 6 hours. It should be noted that in the above reaction diagram, R 5 may be hydrogen. Thus, protection, though preferred, is not required, Also, R 5 may be a pharmaceutically effective ester radical such as pivaloyloxymethyl, p-t-butylbenzyl, 3-methyl-3-butenyl, phenyl or the like in which case the final deblocking reaction 8→9 is not necessary.
The compounds made available by the present invention are valuable antibiotics active against various gram-positive and gram-negative bacteria and, accordingly, find utility in human and veterinary medicine. Such sensitive bacteria representatively include: Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae Serratia, Salmonella typhosa, Pseudomonas and Bacterium proteus. The resulting compounds may further be utilized as additives to animal feed, for preserving foodstuffs, and as disinfectants. For example, they may be employed in aqueous compositions in concentrations ranging from 0.1 to 100 parts of antibiotic per million parts of solution in order to destroy and inhibit the growth of harmful bacteria on medical and dental equipment and as bactericides in industrial applications, for example, in waterbased paints and in the white water of paper mills to inhibit the growth of harmful bacteria.
These antibiotics may be used alone or in combination as an active ingredient in any one of a variety of pharmaceutical preparations. These antibiotics and their corresponding salts may be employed in capsule form or as tablets, powders or liquid solutions or as suspensions or elixirs. They may be administered orally, intravenously or intramuscularly.
The compositions are preferably presented in a form suitable for absorption by the gastro-intestinal tract. Tablets and capsules for oral administration may be in unit dose presentation form, and may contain conventional excipients such as binding agents, for example, syrup, acacia, gelatin, sorbitol, tragacanth, or polyvinylpyrrolidone; fillers for example, lactose, sugar, maize-starch, calcium phosphate, sorbitol or glycine; lubricants, for example, magnesium stearate, talc, polyethylene glycol, silica; disintegrants, for example, potato starch or acceptable wetting agents such as sodium lauryl sulphate. The tablets may be coated according to methods well known in the art. Oral liquid preparations may be in the form of aqueous or oily suspension, solution, emulsions, or syrups; or may be presented as a dry product, for reconstitution with water or other suitable vehicles before use. Such liquid preparations may contain conventional additives such as suspending agents, for example, sorbitol, syrup, methyl cellulose, glucose/sugar syrup, gelatin, hydroxyethylcellulose, carboxymethyl cellulose, aluminum stearate gel or hydrogenated edible oils, for example almond oil, fractionated coconut oil, oily esters, propylene glycol, or ethyl alcohol; preservatives, for example methyl or propyl p-hydroxybenzoates or sorbic acid.
Compositions for injection may be presented in unit dose form in ampules, or in multidose container. The 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. Alternatively, the active ingredient may be in powder form for reconstitution with a suitable vehicle, e.g. sterile, pyrogen-free water, before use.
The compositions may also be prepared in suitable forms for absorption through the mucous membranes of the nose and throat or bronchial tissues and may conveniently take the form of powder or liquid sprays or inhalants, lozenges, throat paints, etc. For medication of the eyes or ears, the preparations may be presented as individual capsules, in liquid or semi-solid form, or may be used as drops, etc. Topical applications may be formulated in hydrophobic or hydrophilic bases as ointments, creams, or lotions.
Also, in addition to a carrier, the instant compositions may include other ingredients such as stabilizers, binders, antioxidants, preservatives, lubricators, suspending agents, viscosity agents or flavoring agents and the like. In addition, there may also be included in the compositions other active ingredients to provide a broader spectrum of antibiotic activity.
For veterinary medicine the composition may, for example, be formulated as an intramammary preparation in either long or quick-release bases.
The dosage to be administered depends to a large extent upon the general health and weight of the subject being treated, and the route and frequency of administration--the parenteral route being preferred for generalized infections and the oral route for intestinal infections. In general, a daily oral dosage consists of from about 2 to about 600 mg. of active ingredient per kg. of body weight of the subject in one or more applications per day. A preferred daily dosage for adult humans lies in the range of from about 15 to 150 mg. of active ingredient per kg. of body weight.
The instant compositions may be administered in several unit dosage forms as, for example, in solid or liquid orally ingestible dosage form. The compositions per unit dosage, whether liquid or solid may contain from 0.1% to 99% of active material, the preferred range being from about 10-60%. The composition will generally contain from about 15 mg. to about 1500 mg. of the active ingredient; however, in general, it is preferably to employ a dosage amount in the range of from about 100 mg. to 1000 mg. In parenteral administration the unit dosage is usually the pure compound in a slightly acidified sterile water solution or in the form of a soluble powder intended for solution.
The following Examples further illustrate the process of the present invention. All temperatures are given in °C.
EXAMPLE 1 ##STR6##
The ammonium tetrafluoroborate species (1) (10 mmol) is treated with isobutene iron complex (2) (10 mmol) in 50 ml THF for 1 hr at 25° C. To the mixture is added tri-n-butylamine (10 mmol); the mixture is stirred for 10 min at 25° C. followed by the addition of potassium t-butoxide (10 mmol); stirring is continued for 15 min. at 25° C. The resulting mixture containing the pyrrolidine complex (4) is treated with triphenylphosphine (1 mmol) for 4 hr at reflux. The pyrrolidine chelate (5 ) so obtained is mixed with freshly precipitated Ag 2 O (10 mmol) for 5 min. at 25° C. to yield the bicyclic β-lactam (6) which is oxidized with m-chloroperbenzoic acid (10 mmol) for 10 min at 25° C. to give the sulfoxide (7). Treatment of (7) with triethylamine (10 mmol) for 20 min. at 25° C. gives the desired 2-phenyl-6α-methyl-1-carbapenem benzyl ester (8). To the solution of (8) is added 50 ml water and NaHCO 3 (10mmol) then the mixture is subjected to hydrogenolysis under 40 psi H 2 in the presence of 10% Pd/C (2 mmol) for 3 hr at 25° C. to give the crude sodium salt of 2-phenyl-6α-methyl-1-carbapenem (9). The product 9 is purified by an XAD-2 column (1"×12") which is eluted with water then 10% THF/water to give, after lyophilization, 9.
EXAMPLE 2 ##STR7## Benzyl bromide (10 mmol) in 30 ml DMF is treated with sodium thiophenoxide (10 mmol) for 6 hr at 60° C.; the mixture is then evaporated to dryness in vacuo. The residue is taken up with methylene chloride and washed with water. The organic layer is separated, dried over sodium sulfate and chromatographed by a silica gel column (1'×10"), eluting with 10% ethylacetate/cyclohexane to give the expected phenylthiophenylmethane. Treatment of phenylthiophenylmethane with n-bytyllithium (10 mmol) in 30 ml tetrahydrufuran (THF) at -78° C. for 10 min is followed by addition of allylbromide (10 mmol) and stirred for 1 hr at 25° C. The resulting mixture containing (1a) is again chilled to -78° C. and treated with n-butyllithium (10 mmol) for 10 min then benzyloxalylchloride (10 mmol) for 1 hr at 25° C. to give (2) which is isolated by a silica gel column (4× 20 cm), eluting with 50% EtOAc/50% CH 2 Cl 2 . Treatment of 2 with hydroxyamine (10 mmol) for 1 hr at 25° C. followed by reduction with Raney nickel (1 mmol) in 1 N sodium hypophosphite (20 ml), 1 N NaOH (20 ml) and 30 ml ethanol for 3 hr at 25° C. yields the amine ester, which is purified by a Dowex - 50 column (4 cm×20 cm), eluting with 0.1 N HBF 4 . On lyophilization of the resulting eluate, compound 1 is obtained.
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A process is disclosed for preparing antibiotic 6- and 2-substituted-1-carbadethiapen-2-em-3-carboxylic acids and their pharmaceutically acceptable salts and esters (I) ##STR1## wherein: R 1 and R 2 are selected from hydrogen, alkyl aryl, and aralkyl; and R 3 is hydrogen, --R, --OR, or --SR, wherein R is hydrogen, alkyl, aryl or aralkyl. The process comprises complexing an appropriately substituted δ,ω-unsaturated amino acid with a transition metal carbonyl complex, followed by oxidatively induced ligand transfer and ring closure: ##STR2## wherein: F p =η 5 --C 5 H 5 Fe(CO) 2 and F p (isobutene.sup.⊕ represents a cationic complex between F p and an olefin such as isobutene, which complex cation is employed in the initial ligand exchange reaction; R 4 is lower alkyl or phenyl; R 5 is a readily removable blocking group or pharmaceutically acceptable ester radical; and R 1 , R 2 and R 3 are as defined above.
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RELATED APPLICATION
This is a continuation of application Ser. No. 07/759,961 filed on 16 Sep. 1991, now abandoned, which is a continuation of parent application Ser. No. 07/411,716 filed on 25 Sep. 1989 now abandoned which is a continuation in part of Ser. No. 07/339,682 filed on Apr. 18, 1989 now abandoned.
FIELD OF THE INVENTION
This invention relates in general to the field of biochemistry and medicine, and more particularly to the use of liposomes in the diagnosis and treatment of ischemic tissue.
BACKGROUND OF THE INVENTION
Ischemia is a deficiency of blood in tissue, and is a significant medical problem. For example, heart disease is a leading cause of morbidity and mortality and two related conditions which are of significant concern are myocardial ischemia (tissue anemia in the heart muscle as a result of obstruction of the blood supply such as by vasoconstriction), and myocardial infarct or infarction (an ischemic condition resulting in the localized death of heart muscle and caused by the particulate obstruction of the flow of arterial blood). While progress has been made in the treatment of ischemic tissue, there is much room for improvement.
One problem with potential antiischemic agents is the action of these agents on other than ischemic tissue. For example, many potent coronary vasodilators are ineffective during myocardial ischemia because they dilate nonischemic coronary blood vessels as well as the ischemic vessels, which draws blood flow away from the ischemic zone. Additionally, many antiischemic compounds (e.g., calcium entry blockers) would be more effective if the agent could be targeted directly to the ischemic region.
Thus, it has been a desideratum to provide a drug delivery system to selectively deliver a compound into an ischemic myocardial bed, that is, deliver an active agent preferentially to infarcted heart tissue rather than nonischemic tissue. In this regard, the terms "ischemic" or "ischemia" as used herein refer to tissue in the state of traumatic tissue anemia and include infarcted tissue.
Phospholipid vesicles (liposomes) have been pursued in the hope that they would concentrate in selected tissues and result in additional enhancement in the delivery of active agents from this tissue specificity. Accordingly, workers have attempted to employ liposomes for the delivery of active agents to myocardial tissue. For example, in a publication by Caride and Zaret in Science 198, 735-738 (1977) multilamellar liposomes of approximately 1,000 nm in diameter with either net positive, negative or neutral charge were administered to mammals after the induction of embolic closed-chest interior wall myocardial infarction. The liposomes were labeled with 99m Tc-DTPA (Diethylene triamine pentaacetic acid). While this publication reports an accumulation of positive and neutral MLVs in infarcted myocardial tissue, free 99m Tc-DTPA has been shown to accumulate in ischemic myocardium (ten times that of normal myocardium after a circulation time of one hour) and further data has shown that the accumulation of 99m Tc-DTPA in infarcted myocardium observed in the subject reference was actually due to the release of vesicle contents in circulation and subsequent accumulation of free 99m Tc-DTPA in the damaged myocardium.
The publication by Mueller et al. in Circulation Research 49, 405-415 (1981) reports the use of a protein marker ( 131 I-albumin) retained in 400 to 700 nanometer small, unilamellar liposomes. The results show a slight accumulation of positive liposomes in ischemic myocardium compared to normal myocardium (ischemic/normal equal 1.38:1) and no net accumulation in ischemic myocardium was seen with neutral liposomes (ratio 0.81:1).
An article in Cardiovascular Research 16, 516-523 (1982) Cole et al. describes myocardial liposome uptake in the early stages of myocardial infarction and concluded that 75 to 125 nm liposomes show no evidence of preferential uptake by ischemic myocardium. The authors suggest that liposomes thus have limited potential as a means of drag delivery in myocardial infarction. Antibodies have also been covalently bound to liposomes in an attempt to deliver such vesicles preferentially to certain tissues, but the results have been less than successful in many instances.
SUMMARY OF THE INVENTION
According to the invention, a method is provided for targeting ischemic tissue in a patient, comprising introducing into the patient's bloodstream an amount of liposomes, of a size of less than 200 nm (preferably unilamellar vesicles) and preferably characterized by being comprised of chemically pure synthetic phospholipids, most preferably having aliphatic side chains of a length of at least 16 carbons, and containing a therapeutic or diagnostic agent, sufficient to preferentially deliver (i.e., target) a quantity of the agent to the ischemic tissue in the essential absence of antibodies bound to the liposomes to effect the delivery. The expression "chemically pure phospholipids" is meant to define phospholipids which are essentially free of deleterious detergent moieties and impurities which cause aggregation of small unilamellar vesicles (SUVs) formed therefrom, and which are more than 97% pure.
Preferably, the SUVs have a diameter predominantly of from 50 to 100 nm, are essentially neutral in charge, and incorporate phospholipids having a side chain length of from 16 to 18 carbon atoms. More preferably, the liposomes are prepared from distearoyl phosphatidylcholine and include cholesterol (most preferably in an amount of from 10 to 50% of total lipid) as a vesicle stabilizer.
The targeted ischemic tissue is preferably ischemic myocardial tissue such as reversibly infarcted myocardial tissue, and the method has shown efficacy in targeting active agents thereto. While I do not wish to be bound by any particular theory as to the targeting of the liposomes to acute myocardial ischemic tissue, it appears that the liposomes pass through capillaries with increased permeability (increased pore size) and can preferentially penetrate ischemic tissue, such as ischemic myocardium, relative to a nonischemic region.
A variety of diagnostic agents may be encapsulated within the liposomes and used in the method of the invention. In the examples below, a radioactive isotope of indium ( 111 In) is loaded into the liposomes and could permit gamma imaging of acute myocardial ischemia. In addition, appropriate liposomal NMR contrast agents such as are described in U.S. Pat. No. 4,728,575 may be administered for imaging myocardial ischemia by magnetic resonance techniques.
As to therapeutic agents, enzymes which catalyze the breakdown of superoxide or oxygen radical species (e.g., superoxide dismutase) may be incorporated into appropriate vesicles, as may therapeutic agents such as catalase or glucose oxidase, or dihydro-pyridine compounds such as nicardipine. The particular diagnostic or therapeutic agents which may be used with the invention will be apparent to those of skill in the art following disclosure of this discovery, and do not constitute part of the invention per se.
In the illustrative examples, radiolabelled liposomes are employed to delineate ischemic tissue and thus demonstrate the ability of the method of the invention to selectively deliver therapeutic or diagnostic agents to traumatized ischemic myocardium. With this disclosure, the use of additional diagnostic or therapeutic agents in connection with the treatment of myocardial ischemia or infarct will be apparent to one of skill in the art.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 displays blood clearance data in dogs for 111 In-labelled liposomes with time. Data are expressed as the radioactivity (CPM)/g blood. For each point, N=4. The values are expressed as mean±S.D.
DETAILED DESCRIPTION
Preparation of Liposomes
The liposomes which are used in the invention are small unilamellar liposomes of a size of less than 200 nm, preferably having a diameter of from 50 to 100 nm. As noted above, the vesicles are preferably comprised of chemically pure synthetic phospholipids having saturated aliphatic side chains and most preferably are prepared from phospholipids such as distearoyl phosphatidylcholine. Cholesterol is advantageously incorporated into the liposomes to increase the stability of the vesicles which are used in the disclosed process.
A wide variety of therapeutic or diagnostic agents may be incorporated in the inner aqueous space or the lipid bilayer of the liposomes by methods which will be apparent to one of skill in the art. In the following examples a chelating compound and an ionophore are employed for loading external cations for radiolabelling into the vesicles. The preferred ionophore is A23187, but other useful ionophores are polyethers such as lasalocid A(X-537A) and 5-bromo derivatives of lasalocid; cyclic depsipeptides such as beauvericin; and cyclic peptides such as valinomylin. The chelating agent is preferably nitriloacetic acid (NTA) although other chelators may also be used.
The liposomes are prepared by dissolving the phospholipid and cholesterol in an appropriate organic solvent, such as chloroform, and evaporating the solvent to form a lipid film. If, as in the following examples, an ionophore is employed to load the diagnostic or therapeutic agent into the liposomes, this compound may be added to the lipid solution before evaporation.
The dried lipid film is then hydrated in an appropriate aqueous phase, such as phosphate-buffered saline or other physiologically appropriate solution. Water soluble drugs or therapeutic agents may be contained in the hydrating solution, although if remote loading is desired a loading agent such as a chelating agent described above may be added to the hydrating solution to be encapsulated within the inner aqueous space of the liposome.
Upon the addition of the hydrating solution, liposomes of varying size spontaneously form and encapsulate a portion of the aqueous phase. Thereafter, the liposomes and suspending aqueous solution are subjected to a shear force such as sonication, or processed through a homogenizer according to the method described in U.S. Pat. No. 4,753,788; to produce vesicles within the specified size. The liposomes are then processed to remove undesirable compounds from the suspending solution, for example the chelating agent or unencapsulated drug, which may be accomplished through processes such as gel chromatography or ultrafiltration. If necessary, the product is then concentrated to remove excess buffer solution. Since the liposomes are smaller in size than 0.2 micron, they are then passed through a sterile 0.22 micron filter to remove any microorganisms which may be present in the suspension. Thereafter, the liposomes are filled into sterilized glass containers and stoppered with a sterilized elastomer closure.
EXAMPLE 1
SUVs have been prepared by formulating an organic solution of distearoyl phosphatidylcholine and cholesterol in a 2:1 molar ratio, evaporating the solution to dryness to form a lipid film, and further drying the lipid under vacuum. In order to permit the subsequent loading of the 111 In into the vesicles, a divalent ionophore (A23187) was added to the lipid solution before evaporation. In a typical preparation, 20 μmoles distearoyl phosphatidylcholine, 10 μmoles cholesterol and 0.04 μmoles A23187 were dissolved in chloroform, dried to a thin film at 60° C. under a stream of nitrogen and then dried in vacuo overnight.
The dried lipid film was then hydrated with an appropriate aqueous phase, for example, phosphate-buffered saline solution (0.9% NaCl and 5 mM sodium phosphate, pH 7.4) containing a chelating agent for loading the 111 In 3+ , and a shear force applied to form the SUVs. In a typical preparation, the dried lipids were hydrated with phosphate-buffered saline containing 1 mM nitrilotriacetic acid (NTA) as a chelating agent, and the mixture was sonicated at approximately 65° C. until the suspension cleared (approximately five minutes) and then centrifuged at 400 g. Unencapsulated NTA was removed from the vesicles by filtering the mixture through a Sephadex G-50 column. The liposomes were determined by a Nicomp Model 270 submicron particle size analyzer to have a mean diameter less than 100 nm.
EXAMPLE 2
A 2:1 molar ratio mixture of distearoyl phosphatidylcholine and cholesterol was dissolved in chloroform, along with the ionophore A23187. These components were thoroughly mixed until completely dissolved. This solution was then placed in a rotary evaporator to remove the chloroform and deposit a lipid film on the surface of the evaporator flask. Alternatively, other known drying methods could be used to form the lipid film or powder.
The chelating material (NTA) was then mixed in phosphate buffered saline and the resulting solution was added to the lipid film. The liposomes thus formed were processed through a homogenizer, according to the process taught in U.S. Pat. No. 4,753,788 to Gamble, to produce vesicles having a mean diameter not to exceed 100 nanometers. The liposomes were then passed through a gel chromatography column to remove the chelating agent which remained in the suspending solution outside the liposomes. The product was then concentrated through a hollow fiber concentrator to remove excess buffer and to concentrate the liposome suspension.
Thereafter, the liposomes were filtered through a 0.22 micron sterile filter and transferred to sterilized glass containers in a class 100 hood and stoppered with a sterilized elastomer closure. Throughout this process, appropriate QA/QC procedures were employed to ensure sterile processing conditions.
Vesicle Loading
As noted above, the vesicles may be loaded with amphiphilic agents during lipid film formation, with aqueous-soluble agents during hydration, or by other known loading procedures. Since the targeting of the liposomes to myocardial tissue is best demonstrated by the delivery of radioactive agents, the gamma-imaging agent 111 indium 3+ was loaded into the liposomes immediately prior to use.
EXAMPLE 3
Loading has been accomplished by using incubation mixtures consisting of 500 μl of vesicles, 35 μl of 3.4 μM InCl 3 in 104 mM sodium citrate (pH 7.4), and 1-50 μl of 111 In 3+ , depending on the required activity. The volume of PBS equal to twice that of the 111 indium 3+ addition was included in the incubation mixture. Incubation time and temperature may be selected according to published procedures such as Mauk et al. Analytical Biochemistry 94, 302-307 (1979), which is incorporated herein by reference. Generally, the loading is performed by incubation at 60° to 80° C. for 15 to 60 minutes. The incubation is terminated by cooling the sample followed by the addition of 10 mM EDTA in PBS. Up to 90% of the added 111 indium can be incorporated into the preformed liposomes by this method, and the liposomes produce specific activities of up to 300 μCi/mg lipid.
EXAMPLE 4
Vials produced in the process of Example 2 each contained 4.7 ml of the liposome suspension (25 mg liposomes per ml), and contained small unilamellar liposomes having a diameter predominantly of from 50 to 100 nm. The liposomes in these vials were loaded according to the following process. 0.2 ml of 0.1M sodium citrate for injection was added to each vial and mixed well. Following standard radiopharmaceutical procedures to calculate radiopharmaceutical dosages, an amount of 111 indium chloride solution sufficient to yield the prescribed dose of 111 In 3+ at time of injection was then added. This mixture was then incubated at 80° C. for 30 minutes, followed by cooling to room temperature.
0.1 ml of 0.1M sodium edetate for injection was then added to stop the liposome loading by chelating any excess 111 In. During this process, the radioactive loading efficiency was tested by withdrawing 0.5 ml of the liposome solution prior to terminating the liposome loading procedure, and transferring the solution to a 1.5 ml centrifuge vial containing 0.5 g Chelex 100. The contents of the centrifuge vial were incubated for 5 minutes at room temperature, with occasional mixing, and the total radioactivity of the centrifuged vial was determined using a dose calibrator.
0.5 ml of 0.1 m sodium citrate for injection was then added to the centrifuge vial and then mixed. The vial was then centrifuged for 5 minutes at moderate speed to compact the Chelex 100. 0.5 ml of the supernatant was removed with an appropriate syringe and the radioactivity of the supernatant determined. The calculation for loading efficiency was determined by dividing twice the supernatant radioactivity by the total radioactivity, times 100 to yield percent loading efficiency. In all instances, the loading efficiency was greater than 90%.
Targeting to Ischemic Myocardial Tissue
EXAMPLE 5
An example of the preferential delivery of the small unilamellar liposomes of the invention to ischemic myocardial in the absence of antibody targeting tissue is demonstrated by the use of the labeled liposomes produced in accordance with the procedures in Examples 2 and 4. The liposomes were administered to animals and found to target such tissue.
All animals used were mongrel dogs of either sex (16-20 kg, N=4). The animals were anesthetized before surgery using 30 mg/kg sodium pentobarbital as an i.v. injection. Polyethylene catheters were inserted into a femoral artery and vein for measurement of blood pressure and heart rate, for blood sampling, and for injection of liposomes. The trachea was cannulated and the animal was artificially respired with a Harbard respirator using room air. Eucapnia was maintained and monitored with a Godart-Statham capnograph. A left thoracotomy was performed at the fifth intercostal space, a partial pericardiotomy exposed the heart, and a pericardial cradle was formed. Approximately one cm of the left anterior descending coronary artery (LAD) was isolated just distal to its first major branch and a silk ligature was loosely placed around the vessel. Aortic pressure and heart rate were measured using a Statham P23AA transducer and recorded on a Beckman R-411 recorder. Blood samples obtained from the femoral artery catheter were analyzed electrometrically for blood gases and pH (Radiometer BMS 3 blood gas analyzer).
At this time, 6 mg/kg of 111 In labelled liposomes prepared as in Examples 2 and 4 were injected i.v. After injection of the liposomes into the animals, arterial blood samples were taken 1, 2, 3, 4, 5, 10 minutes and 1, 2, 3, 4, 5, 6 hours post injection and the blood radioactivity was determined later. Ten minutes after liposome injection, the LAD was occluded via the surgical silk snare and the occlusion was continued for 2 hours. At this time, the occlusion was released and the reperfusion was allowed to continue for 4 hours.
At the end of the experiment, blood gas and hemodynamic variables were again s determined and then the heart was removed. The aorta was perfused at a pressure of 100 mm Hg with saline to clear the coronary vessels of blood. The left ventricular free wall was then cut into 6 transmural pieces from the ischemic zone and 6 from the nonischemic zone. These pieces were then divided into subepicardial and subendocardial halves. Samples of the liver and gracilis muscle were also taken. The radioactivity was then determined in both blood and tissue samples using a Hewlett-Packard gamma counter.
All data were analyzed using a paired T-test. The tissue and blood clearance data were expressed as the counts per minute (CPM) of radioactivity per gram of tissue or blood. All data are presented as mean±S.D.
Hemodynamic data are shown in Table 1. All values were within the normal range for dogs. No differences existed for any of these variables during the course of the experiment. No changes in blood gases were seen during the experiment.
The blood clearance data for the liposomes are shown in FIG. 1. As can be seen there is a fast initial clearance followed by a slower clearance phase. The data are expressed as the CPM radioactivity (CPM)/g blood. It is apparent that more than half of the liposomes were cleared from the blood at the end of the experiment.
Data for myocardial tissue clearance of liposomes are shown in Table 2. The data are expressed as the CPM/g tissue. The ischemic region in all animals contained significantly more radioactivity compared to its paired nonischemic region. This difference was 5-10 fold. Within the ischemic zone, the subendocardium contained twice the radioactivity contained in the subepicardium and this difference was significant. The liver was actively clearing liposomes with the CPM/g cleared being 12.34×10 4 ±5.49×10 4 PM/g and skeletal muscle cleared an amount similar to the nonischemic region of the heart 0.11×10 4 ±0.01×10 4 CPM/g.
Summary Biodistribution of Labelled Liposomes in Canine Ischemia
Animals: 16-20 kg dogs--4 studied
Avg. total lipid dose: 6 mg/kg×18 kg=108 mg lipid
Avg. total radioactivity (calculated from avg. blood level at injection): 1300×10 5 cpm
Avg. biodistribution at 6 hrs: cpm/gm (×10 4 )
ischemic subendocardium 2.2±1.1
ischemic subepicardium 1.6±0.9
nonischemic subendocardium 0.26±0.10
nonischemic subepicardium 0.27±0.14
Blood 2.0±0.5
Skeletal muscle 0.11±0.01
Liver 12.3±5.5
Myocardial ischemia and infarction are characterized among other things by an increase in capillary permeability. This increased permeability may allow selective drug delivery to the ischemic region by using appropriately sized liposomes as delivery vehicles. In the present study, the ischemic region localization of radioactivity (and presumably liposomes) was 5-10 times greater compared to the nonischemic myocardium. While I do not wish to be bound by any particular theory, it appears that the liposomes were localized in the ischemic zone due to increased capillary permeability. Interestingly, the ischemic subendocardium tended to localize more liposomes compared to the ischemic subepicardium. This may reflect the fact that the subendocardium is usually more at risk during ischemia. The nonischemic subepicardial-subendocardial difference in localization of liposomes was not significantly different.
The high liver clearance of liposomes is not surprising as this organ is one of the major sites of blood borne particulate removal. This also indicates that the 111 In was bound to liposomes, as 111 In that is free would probably not be cleared by the liver. The estimated labelling efficiency was 70-80%. The nonischemic myocardium and skeletal muscle had relatively low liposome localization.
From the description set forth above, it will be apparent that liposomes having a size of less than about 200 nanometers, preferably 60 to 100 nm will preferentially target active agents such as diagnostic or therapeutic agents to an ischemic myocardial region, and in particular permit the selective localization of the liposomes into the ischemic subendocardium which is typically more at risk, thus facilitating drug delivery to the region of greatest ischemic severity.
From this description the essential characteristics of the invention can be readily ascertained and, without departing from the spirit and scope thereof, the invention can be adapted to various usages. Changes in form and substitution of equivalents are contemplated as circumstances may suggest or render expedient, and although specific terms have been employed herein, they are intended in a descriptive sense and not for purposes of limitation.
TABLE 1______________________________________Hemodynamic data for liposome treated animals beforeand after LAD occlusion and reperfusion. Before After Occlusion Occlusion + Reperfusion______________________________________Systolic Blood 137 ± 22 136 ± 22Pressure (mm Hg)Diastolic Blood 116 ± 27 100 ± 20Pressure (mm Hg)Heart Rate 160 ± 28 182 ± 21(Beats/min)______________________________________ All values are mean ± S.D. (N = 4)
TABLE 2______________________________________Localization of .sup.111 In-labelled liposomes in theischemic and nonischemic myocardium. Ischemic Region Nonischemic Region (×10.sup.4) (×10.sup.4) Subepi- Subendo- Subepi- Subendo- cardium cardium cardium cardium______________________________________Radioactivity 1.55 2.22* 0.27** 0.26**CPM/g ± ± ± ± 0.92 1.14 0.14 0.10______________________________________ All values are mean ± S.D. (N = 4) *Significantly different from its respective subepicardial region value ( 0.05) **Significantly different from its respective ischemic region value (P 0.05)
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Liposomes of a size of less than 200 nanometers target ischemic myocardial tissue and preferentially deliver active agents to infarcted areas in the absence of antibodies bound to the liposomes to effect the delivery.
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RELATED U.S. APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
REFERENCE TO MICROFICHE APPENDIX
Not applicable.
FIELD OF THE INVENTION
The invention relates to the use of dapsone as the first effective treatment against the disabling consequences associated with cerebral infarction in patients.
BACKGROUND OF THE INVENTION
For the pharmacological treatment of the brain stroke, some drugs have been historically used, with little clinical efficiency; among them, Citicoline. In a recent study, published in 2002 (Davalos A, Castillo J., Alvarez-Sabin J., Secades J J., Mercadal J., Lopez S., Cobo E., Warach S., Sherman D., Clark W M., Lozano R., Oral citicoline in acute ischemic stroke: an individual patient data pooling analysis of clinical trials. Stroke 33(12):2850-2857, 2002), it was demonstrated that this drug produced an improvement of 25% in average, three months after its administration to patients with brain stroke, while the patients that received a placebo improved 20% in average. As it can be inferred from these results, this pharmacological treatment is not capable of reducing the brain damage associated with brain stroke, in more than 20-30% in average.
On the other hand, the research and the development of new drugs to prevent the consequences of brain stroke, have produced disappointing results. In 2001, for example, the Food and Drug Administration of the United States of America, approved the use of 5 drugs against cardiac diseases, and no drug against brain stroke. This leads to the fact that there is no selective drug treatment for this serious illness.
The invention herein has as its objective to demonstrate the use of dapsone as the first efficient treatment against the disabling consequences associated with brain stroke in these patients.
Dapsone is a currently used drug, for the chemotherapy treatment of leprocy and in the prophylaxis against pneumonia by pneumocystis carinii. Considering that leprocy is a less frequent disease, the therapeutic use of dapsone has been limited recently.
Acute brain stroke is the third most common cause of death, and the main cause of disability in the world population. In view of the serious consequences that brain stroke means to the society under the terms of rehabilitation and medical care expenses, a new therapeutical agent, more efficient than the current was searched, synthesizing dapsone in as a new neuroprotective compound.
BRIEF SUMMARY OF THE INVENTION
The invention herein has as its objective to develop a product for the therapeutic use in the treatment of acute brain stroke. This disease is amply distributed in the world population, with an incidence of 500,000 to 750,000 people affected a year in the United States of America alone, thus it was decided to look for other therapeutic alternatives that are more efficient than those currently used.
In the search of a new therapeutic agent, more efficient than the current, for the pharmacological treatment of brain stroke, dapsone was synthesized as a compound with the following formula:
The drug dapsone has not been produced in Mexico since the eighties, and neither its raw material is produced.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 shows a graph illustration of neurological scale scores.
FIG. 2 shows a graph illustration of ischemic volume percentage.
FIG. 3 shows a graph illustration of NIH scale scores.
DETAILED DESCRIPTION OF THE INVENTION
For such reasons, the work herein demonstrates, through an experimental model, and by means of a clinical controlled trial in patients with acute brain stroke, that dapsone is efficient to prevent the adverse consequences of the disease, when administered within the first twelve hours after the ischemic event.
The pharmacological tests were performed using the experimental model of acute brain stroke for permanent obstruction of the middle cerebral artery in rats, introducing a suture thread through the internal carotid artery of the animals (Example 1). The drug was also administered to patients with acute brain stroke, that attended the Emergency Services of the National Institute of Neurology and Neurosurgery “Manuel Velasco Suarez”, in Mexico City (Example 2).
The results of the experiments with rats, demonstrate that dapsone (I) at a dose of 9.325 mg/kg, had an efficacy of 93%, while at a dose of 12.5 mg/kg was 91% efficient to reduce the volume of brain damage produced by the stroke in the experimental stroke model, provoked in rats.
The efficiency results in patients, demonstrated that dapsone to a dose of 200 mg was capable of improving the neurological symptoms of patients in 67% in average.
The effective dose for dapsone, is 0.013 mmoles/kg.
No side effects were presented for the dose used.
Particularly, the following techniques are used:
Synthesis of Dapsone
Dapsone may be synthesized by different routes, but the following synthesis is offered as an example. The synthesis was performed in two steps:
1.—60 g of acetanilide were placed in an Erlenmeyer flask, and were slowly heated until all the solid material was melted. The resulted viscous liquid was cooled using an ice bath, leaving a solid material in the bottom of the flask. 165 ml of chlorosulfonic acid was added, without removing the ice. Later, the flask was removed from ice, carefully agitated and reaction was performed during 10 minutes, at the end of which the mixture of the reaction was heated again, until the total solubilization of the remaining acetanilide, letting it react again for 10 minutes more. The product was cooled and carefully poured in a container with ice and water, the precipitate was filtered and washed with cold water. The precipitate was collected, dissolved in chloroform and extracted three times with water, collecting the chloroformic phase, which was placed on an ice bath, precipitating the purified tionile chloride (reported melting point of the intermediary product: 149° C.).
2.—123.6 ml. of anhydrous nitrobenzene were placed in a reaction container, 89.2 g of aluminum chloride were added and slowly heated; to the hot mixture 41.3 g of tionile chloride were added, heating the reaction mixture to a temperature of 140-145° C., and slowly added 13 g of acetanilide, keeping the reaction temperature during two hours. At the end of this period, the raw reaction material was poured in 104 ml of acidified water with hydrochloric acid; precipitating a dark colored product, which was re-crystallized with diluted acetic acid. After the re-crystallization and filtration, the solid material was refluxed with hydrochloric acid 5N during 30 minutes, later the reaction mixture was neutralized, precipitating white crystals (raw DDS), that were re-crystallized with ethanol.
Chemical Characterization of the Synthesized Compound
To determine the authenticity of the synthesized compounds, the melting point of them was measured, resulting of 151-153° C. for the reaction intermediate tionile chloride and 172-175° C. for DDS.
The melting points reported for these compounds are 149° C., 175-176° C. for the intermediate and the DDS, respectively.
Preferential Mode to Perform the Invention
EXAMPLE 1
Evaluation of Neuroprotective Effect of Dapsone in the Acute Brain Stroke, Induced by the Occlusion of the Middle Cerebral Artery of the Rat
Dapsone was evaluated as neuroprotector in the brain stroke model produced by occlusion of the middle cerebral artery. The drug was suspended in a suitable vehicle.
3 groups of 5 animals each were treated with: Saline isotonic solution (551, control group), Dapsone (12.5 mg/kg) and Dapsone (9.375 mg/kg) injected by intraperitoneal route, 30 minutes after the occlusion of the middle cerebral artery, as described below.
The permanent selective brain ischemic was produced in the animals through introducing a suture thread intraluminal through the carotid artery. All animals received continuous anesthesia during the surgical procedure with halotane 1.5%, through a face mask. Animals were placed in dorsal decubitus position, fixed and shaved in the anterior cervical region to make an incision in the middle line from the sternum towards the region of the sternohiodeous muscle, to its side rim, identifying in this side the middle rim of the sternocleidomastoideus and the superficial cervical aponeurosis in its deep leaf, same that was cut to leave exposed the common carotid blow and inside the caudal belly of the digastric. A cutting dissection of the common carotid was performed, until the hypoglose loop. The carotid bifurcation was identified, external carotid and its occipital and thyroid branches, the two latter were joined with mono-filament of 8-0 as well as with electrocoagulation for its later cut. The internal carotid was dissected in a length of approximately 5 mm and at that time the pterigo-palatine artery was identified. A microchip was placed or it was joined with mono-filament 6-0. Once the flux was stopped through these artery affluent, the mono-filament nylon 3-0 was introduced towards the internal carotid artery, through the stub of the external carotid artery, for a length of 17 mm as of the bifurcation. The wound was closed, and the animal was left to recover, with water and food ad libitum. In all cases, ischemia was verified by macroscopic observation and for the position of the thread.
Evaluation of the Neuroprotective Effect of Dapsone in Rats.
During the 96 hours after the ischemic procedure, the animals were neurologically evaluated using a functional scale, each 24 hours. This scale establishes rates from 0 to 5, according to the seriousness of the signs that the animal presents: 0=without neurological alteration; 1=difficulty to totally extend the anterior extremity; 2=circular movement towards the right; 3=falls to the right; 4=animal does not walk spontaneously and has a consciousness depressed level; 5=death.
Determination of the Tissue Volume of Damage
At the end of the 96 hours of observation, animals were sacrificed with an overdose of sodium pentobarbital by intraperitoneal route, and their brains were extracted by craniectomy. Once extracted, the brains were fixed with anhydrous alcohol during two weeks. The usual histological process was performed, as well as sections of 10 μm, storing a section each 200 μm. The latter were stained with the hematoxiline-eosine technique. All sections were observed by a pathologist, who was not aware of the treatment group, to determine, macro and microscopically, the ischemic zones.
The area of each tissue section was determined using a digital analysis system and a photographic amplifier. In all cases an amplification 1:10 was performed. Each section was assessed for 3 determinations: A) total area, including ventriculus B) Ventricular area C) Ischemic area, according to the pathologist's review. To determine the lesion volume the following formula was used:
V
=
P
(
0.2
mm
)
10
where P is the sum of areas (in mm 2 ), 0.2 mm is the fixed length between each section and the division between 10 is due to the amplification of each cut for volume measurement. Applying the formula, three different volumes were obtained: Total, ventricular and ischemic. The ventricular volume was subtracted from the total volume, to obtain the brain parenchyma. The latter was used as reference to obtain the lesion percentage using the ischemic volume.
EXAMPLE 2
Evaluation of the Neuroprotective Effect of Dapsone in Patients with Acute Brain Stroke
This study evaluated the neuroprotector effect of dapsone in patients that, having suffered an acute brain stroke for thrombo-embolism, were admitted to the Emergency Services of the National Institute of Neurology and Neurosurgery “Manuel Velasco Suarez”. Dapsone was administered in a single dose of 200 mg in suspension, orally. The suspension is kept stable in refrigeration at 4° C., for up to one month.
Dapsone was administered blinded to 15 patients, while other 15 patients were administered with an anti-acid suspension, as a placebo medication. Patients were randomly allocated into one of the treatment groups, using random numbers, generated by a pocket calculator. Both medications were administered during the first twelve hours after the brain stroke. As result of these procedures, the clinical trial was randomized, double-blind and placebo-controlled.
The evaluation of clinical signs and symptoms was performed in blind by an expert neurologist, with the NIH scale, that quantifies the intensity of disabilities caused by the brain stroke. Said scale was applied at the time the patient entered the study (day zero) and 2, 6 and 30 days after the brain stroke. A stroke is considered as moderately severe or severe, when the NIH rated a value higher than seven.
Statistical Analysis
Dapsone doses were used in the range of 1 to 12.5 mg/kg, orally in case of patients, or intraperitoneal in case of the rats.
For the neurological scale and percentage of the lesion volume in rats, the statistical significance was determined with the Kruskal-Wallis test, followed by the U test of MannWhitney.
The NIH scale results in the two groups of patients were statistically analyzed with analysis of variance analysis (ANOVA) using as co-variables the NIH scale at the admittance day (day zero), as well as the gender, age, blood pressure and other important clinical variables for the patient's performance.
Values of ≦0.01 and 0.05 were taken, to determine the limit of statistical significance.
The results of the neurological evaluation in rats are shown in FIG. 1 , where the scores of the neurological test as a function of time can be observed, after producing the stroke in the rats. The results are expressed as the average of 4 independent experiments. D=Dapsone (9.375 and 12.5 refers to the dose in mg/kg, ip), *p<0.05 (Kruskal-Wallis test followed by Mann-Withney test).
The data of the neurological test in rats showed that the animals treated with dapsone at the two doses employed, recovered better from the ischemic lesion, significantly, compared to the control group.
The results of lesion volume are presented in FIG. 2 , showing the percentage of ischemic lesion, 96 hours after producing the stroke in rats. The results are expressed as the average+/−standard error of 4 independent experiments. D=Dapsone (9.375 and 12.5 refers to the dose in mg/kg, ip), *p<0.05 (Kruskal-Wallis test, followed by Mann-Withney test).
The data obtained show that dapsone protected in 93% at the dose of 9.375 mg/kg and 90% at the dose of 12.5 mg/kg, respectively, in comparison with the control group.
The results in patients with acute thrombo-embolic brain stroke, are shown in FIG. 3 , which presents the scores of the neurological scale (NIH) as a function of time (in days) after administering dapsone or the placebo. The results are expressed as the average of 15 patients per group +/−the standard error. D=Dapsone, *p (<0.05, **p<0.01 (Analysis of Variance test, with co-variables).
The results from patients treated with 200 mg of dapsone orally, show a significant clinical improvement. This improvement was in average 67%.
The evaluation of the neuroprotective effect of dapsone of the invention herein, may be summarized as follows:
A significant reduction in the severity of the neurological symptoms in rats, of 50% was observed, in comparison with the control group. Reductions of 93% and 90% in the lesion volume of these same animals was also observed.
Regarding the study in patients, the clinical improvement was in average 67%.
These results show that dapsone is more efficient than the currently existing drugs in the market for the treatment of acute brain stroke. This, with a preferred dose of dapsone in the range of 1 to 12.5 mg/kg, administered during the first 12 hours of the acute brain stroke, though dapsone may also be administered in repeated doses.
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The use of dapsone is the first effective treatment against the disabling consequences associated with cerebral infarction in patients. Dapsone was evaluated as a neuroprotector in the cerebral infarction model produced by the occlusion of the middle cerebral artery in rats and in patients suffering from acute cerebral infarction caused by thromboembolism. In both studies, dapsone displayed a reduction of between 70 and 90% in the adverse effects which occur as a consequence of the infarction.
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FIELD OF THE INVENTION
The present invention relates to an apparatus for scraping a roll surface to remove surface deposits that cause surface defects in a molten metal coating process.
BACKGROUND OF THE INVENTION
Continuous hot-dip galvanizing lines are known in the art. A cleaned strip of steel is heat-treated and passed from the furnace into a coating bath without being exposed to air. The coating bath contains molten zinc or zinc-aluminum (Zn—Al) alloy. As the strip emerges from the coating bath, an air knife is directed at both sides of the strip to control the weight and thickness of the coating.
After the strip enters the coating bath from the submerged furnace snout, the strip is held under the surface of the liquid metal by a submerged roll called a sink roll. Inter-metallic particles and oxides form in the bath and create undesirable substances known as dross. Dross occurs in several forms, and each form has several causative factors. The primary causes of dross are impurities in the bath (primarily iron) and temperature differentials between the molten bath, the entering substrate steel, and the sink roll equipment. Dross can form on the sink roll, causing degradation in the quality of the coated strip metal in the form of dents, resulting in defective product that fails to meet product specifications. By successfully removing the dross from a sink roll, it is possible to increase the yield and the quality of the coating process.
A sink roll assembly with accumulated dross must be replaced periodically for machining of the surface within acceptable tolerances. In zinc-aluminum continuous coating lines, replacement of a sink roll frequently takes two to four hours, and sometimes longer, during which the continuous production line is idle. When there is no dressing or scraping of the sink roll, a typical sink roll assembly in a high-speed coating line operates for three to five days, (or nine to fifteen operating shifts). The roll assembly must be disassembled, machined and reassembled, at considerable time and expense, before it can be placed back into the coating line.
In some cases, dross is removed manually by a worker manipulating a pole-mounted scraper, requiring the worker to stand directly above the pot containing molten metal 55% Zn—Al at 1100° F. For worker safety and for environmental reasons, it is desirable to avoid handling manual tools directly above liquid metal.
Mechanical scrapers have also been employed to solve the problem of dross buildup. There are two types of mechanical scrapers for cleaning the dross from sink rolls. A full-width blade is a stationary blade contacting the rotating sink roll. The blade extends the entire width of the sink roll. The full width blade wears to the profile of the sink roll over time due to the constant friction. Sink rolls are periodically removed for resurfacing, and may be machined with a crowned profile. Also if dross does appear on a sink roll despite the use of the full width mechanical scraper, the defect creates a wear spot on the scraper blade, thus permanently transferring a defect to the finished steel product.
A second type of mechanical scraper blade employs a short blade, approximately ¼ or less of the roll width. The short-blade scraper device is disposed above the molten metal bath and traverses the entire width of the sink roll by a worm drive, from which the scraper blade depends. The pressure applied by the scraper blade against the sink roll is adjusted by various means, such as by a system of weights and flotation device appended to the scraper arm to counter the weight of the blade; or by the use of a scraper blade drive unit responsive to a torque sensing device to regulate the pressure of the traversing blade. The use of a torque sensor unit in combination with a scraper blade driver is complex and expensive. The floatation device, however, is cumbersome and inflexible, requiring the operator to physically add or remove weights or floats for adjustment. Moreover, the positioning of a worm drive above a molten metal bath introduces corrosion and bending of the worm drive member in the hot environment.
Controlling the force applied to the sink roll by the scraper is critical, since the sink roll rotates by the frictional force between the steel and the sink roll as the strip passes under the sink roll. The application of excessive force may cause the sink roll to slip against the steel strip, creating scratches and other defects. By contrast, application of insufficient force may result in accumulation of dross.
Thus, there is a need for an improved sink roll scraper blade system with automatically controlled scraping pressure, and a traversing means disposed away from exposure to the molten metal bath.
SUMMARY OF THE INVENTION
Essentially, the preferred embodiment of the apparatus comprises a pair of independently controlled, twin-bladed articulated scraper heads mounted on movable arms, with pneumatic pressure control, that permits a methodical wiping of the entire surface of a roll as the submerged roll rotates in a pot, and scraper blades traverse the roll along its axis.
According to one aspect of the invention, there is disclosed an apparatus for scraping a roll surface in a molten metal coating process comprising a support member having a pair of linearly movable arms supported thereon. The support member depends from a bridge structure spanning a continuous metal coating line, and a pair of arms, the arms being disposed on opposite sides of said support member. Each arm has a scraper assembly portion attached thereto. In a preferred embodiment, each scraper assembly portion has two blades affixed thereto, a forward scraper blade and a rear scraper blade, with a connecting portion connecting the two blades. The connecting portion has a first pivot point for attaching the connecting portion to the arm associated with the scraper assembly portion, the first pivot point being disposed between said forward and rear scraper blades for following the radial contours of the roll surface. Connecting portion also includes a second pivot point to allow the blades to pivot along the crowned axis of the roll. There is provided a means for advancing the arms such that at least one scraper blade presses against the roll surface under pressure. There is also control means for controlling the pressure of the scraping force of said blades applied to the roll surface. A traversing means provides for communicating lateral movement of said blades laterally along the axis of the roll while scraping against the roll.
Means for advancing arms comprises a cylinder operatively connected to and responsive to a source of pressurized gas. Scraper assembly connecting portion also has a pair of limit portions to restrict the angle of rotation about the pivot point of said blade assembly in relation to said arm. There may also be included means for pivotally connecting each said scraper assembly to the associated arm to create a second degree of rotation for said scraper assembly relative to said arm, to allow said blades to pivot along the crowned axis of the roll.
In a preferred embodiment the means for advancing arms comprises a cylinder operatively connected to and responsive to a source of pressurized gas, the pressure in said cylinder being is variably controlled by said control means.
A control means comprises a digital controller in electronic communication with an analog device, such as a proportional control valve, such that the pressure may be varied over a predefined range corresponding to zero pressure up to full line pressure. Traversing means comprises a motor, an actuator portion, and a cylinder portion, the cylinder portion being operatively connected to the support member, such that the motor drives said actuator portion, thereby imparting linear motion to the support member through said cylinder portion, causing said blade or blades to traverse the horizontal axis of the roll in contact with the surface of the roll.
A speed control interface in electronic communication with said motor portion and said control means controlling the speed of said motor from a speed reference point communicated from said control means.
In another aspect of the invention, a method is disclosed for scraping a roll surface rotating in a molten metal coating process comprising traversing a support assembly to one side, lifting the arms attached to said the assembly to a fully retracted position to disengage scraper blades from contact with a roll surface; initiating a scraping cycle by means of a trigger signal; lowering the arms and scraper blades in the mid-point of the sink roll; increasing the pressure reference from lifting pressure to approximately zero; energizing one or more directional valves; increasing the pressure value gradually to a preselected pressure; extending the cylinder in a controlled manner to engage the scraper head gently on to the sink roll; moving the engaged scraping head at a controlled, predetermined speed from the sink roll mid point to the fully traversed out position; stopping the traversing means upon reaching the fully traversed out position; and lifting the scraper head from the roll surface by removing pressure from the cylinder; then repeating the sequence until a predetermined number of cycles are completed.
In another aspect of the method, a counter is incremented in the control means after each cycle, comparing said counter after each repetition of a cycle, repeating another cycle until a pre-selected number of cycles is completed, and then traversing the support assembly to one side of the sink roll and lifting the arms away from the surface of the roll. The trigger may be selected from one or more of the following: a timer which activates the sequence on a regular time based interval; a weld signal from the weld tracking logic in the PLC; or an operator initiated “Cycle Now” pushbutton.
It is an object of the invention to provide two or more independently operated arms that allow one or more scrapers to independently scrape against the roll to remove dross and other surface imperfections.
It is further object of the invention to provide twin-blade articulated scraper heads in pressurized contact against the roll and transverse the blades across the roll during rotation.
A further object of the invention is to provide a methodical wiping of the entire roll face during roll rotation through traverse motion of the scraper heads, allowing every point on the roll face to contact the front and back blades at least one time during roll rotation and traversal of the scraper heads.
Yet another object of the invention is to provide optional independent control of the scraper heads.
Another object of the present invention is to provide pivotal motion of each scraper head in two directions to conform to roll radius or curvature, and to the roll axis or crown.
It is still another object of the invention to provide a pressurized cylinder coupled to each scraper head for advancing and retracting the associated scraper head under controlled pressure, which is adjustable by the operator to apply more or less pressure as required.
Another object of the present invention is to provide a digital processor system for controlling the pressure applied by scraper blades against the roll, and for controlling the speed and travel of the scraper heads traversing the roll surface.
Another object of the present invention is to provide a structural support and integrity, with minimal weight, for the scraper heads and movement arms.
A further object of the invention is to provide a transport drive mechanism that is remote from the heat of the molten metal pot, to either side and not directly above the pot.
Further objects of the invention will be made apparent in the following Detailed Description and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of the invention;
FIG. 2 is a sectional view taken along the lines 2 - 2 in FIG. 1 ;
FIG. 3 is an elevational view of the scraper blade assembly;
FIG. 4 is a plan view of the scraper blade assembly taken along the lines 4 - 4 in FIG. 3 ;
FIG. 5 is a schematic diagram of the scraper blade assembly and roll;
FIG. 6 is a schematic diagram of the control system;
FIG. 7 is a human machine interface displaying the invention in manual control mode;
FIG. 8 is a FIG. 7 is a human machine interface displaying the invention in automatic control; and
FIGS. 9A through 9D illustrate a sequence of operation for one cycle of the preferred method and apparatus of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 and 2 , a portion of a continuous metal strip coating line is shown. The continuous steel strip 50 is fed at an oblique angle into a pot 12 containing molten zinc or zinc/aluminum alloy, passing under a sink roll 16 redirecting the strip upward and out of the pot into a pair of rollers. The sink roll is suspended in the pot from a bridge support structure 46 spanning the coating line.
A sink roll scraper assembly is generally designated as 10 . A sink roll 16 is submerged in a molten metal pot 12 . The sink roll scraper assembly 10 includes a support member 14 having a pair of scraper arms 18 , 20 . An arm 18 or 20 is disposed at either side of support member 14 . Each scraper arm 18 , 20 has a scraper head assembly 22 , 24 attached at an end adjacent to the sink roll 16 . Scraper arm 20 at one side of the support member 14 is captured in a lower guide sleeve 26 , 28 and an upper guide sleeve 30 , 32 , to align the scraper arm when advancing and retracting the scraper head assembly 24 . Similarly, on the opposite side of support member 14 , scraper arm 18 is captured at two points on the support member at guide sleeve 26 and guide sleeve 30 . Guide sleeves have an annular opening coaxially aligned with the associated arm to permit lower telescoping movement for advancing and retracting the scraper head assembly 22 . Support member 14 is preferably comprised of a rigid, durable plate material capable of withstanding high temperature. To minimize the weight of the support member, in the preferred embodiment, support member includes horizontal top and bottom arms 14 a , 14 b , connected by a web portion 14 c . The side edges of the web 14 c are cut away, to form an hourglass shaped backing plate. Other structural configurations for the support member may be employed, within the scope of the appended claims.
Cylinder 34 , is operatively connected to scraper arm 18 and cylinder 36 is operatively connected to arm 20 . Each cylinder advances or retracts the arm with which it is associated. Arms 18 , 20 may operate independently of one another. In normal operation, both arms operate so as to cover the entire width of the roll in a single cycle. Preferably, the cylinders are pneumatically pressurized with direction action pressing the scraper head assembly into contact with the roll; and pressurized in the opposite direction so as to retract scraper head assemblies 22 , 24 away from contact with the roll when not scraping.
A traversing cylinder 38 is driven by an electromechanical actuator motor 40 , which acts on transport shaft 42 to impart lateral movement to scraper assembly 10 , such that scraper head assemblies 22 , 24 traverse back and forth to cover the entire surface of sink roll 16 . Traversing cylinder 38 and electromechanical actuator motor 40 are positioned off to one side of pot 12 , removed from the heat radiating directly above the pot. A lower transport rail 44 is provided to both support the scraper assembly and to guide the lateral movement of the lower portion of scraper assembly 10 . Rail 44 preferrably employs a wear coating to reduce friction. Rail 44 prevents the arms 18 , 20 from kicking back, and positions support member 14 in an inclined plane directed at roll 16 .
As can be seen in FIG. 2 , the continuous steel sheet 50 exits oven chute 76 below the surface of molten metal 48 , the chute having a controlled atmosphere to prevent oxidation of the steel surface. Sheet 50 travels under sink roll 16 , upward to first exit roller 52 , then to second exit roller 54 . After the strip passes the second exit roller 54 , the strip exits the molten metal and passes through air knifes (not shown) suspended above the surface of the molten metal.
Referring next to FIG. 3 , there is a side view of one scraper head assembly 24 . Scraper head assemblies 22 , 24 are substantially identical. First connector portion 60 has an aperture 70 into which pin 72 is inserted, for articulating the head assemblies to conform to the circular profile of the sink roll. In the preferred embodiment, two blades are employed on each scraper assembly. However, it is noted a single blade embodiment may also be employed, within the scope of the appended claims. In the dual-blade embodiment, forward blade holder 62 is attached to first connector portion 60 at one end. Rear blade holder 64 is attached to the first connector portion 60 at the end opposite forward blade holder 62 . Forward blade holder 62 has forward blade 66 removably attached to the bottom edge for scraping away surface imperfections. A rear blade 68 is removably attached to rear blade holder 64 . Blades 66 , 68 are replaceable wear elements. Rear blade 68 engages a surface of the sink roller to scrape any imperfections that are missed by the front blade 66 , such as when forward blade 66 becomes damaged, so as to avoid the necessity to replace forward blade 66 for minor imperfections for which rear blade 68 compensates. Hinge pin 72 mates with an eye (not shown) on hinge portion 84 (shown in FIG. 5 ) attached to the end of scraper arm 20 .
Referring to FIG. 4 , a top view of the scraper head assembly 24 is taken along the lines 4 - 4 of FIG. 3 . A second connector portion 58 is shown with forward blade holder 62 attached at a forward end and rear blade holder 64 attached at the opposite end of second connector portion 58 . Stop limits 74 , 78 are provided to limit the rotation of the head assembly about hinge pin 72 . In the preferred embodiment, the allowable articulation angle is approximately six degrees. More or less articulation is not necessary, as the front blade 66 may lift too easily from the roll surface, or alternately, be unduly restricted. Connector portions 58 , 60 may be curved as illustrated in FIG. 5 to accommodate the roll curvature. While the preferred embodiment discloses two connector portions connecting blade holders, a singular connector portion, or a plurality of connector portions may be alternately employed.
Referring next to FIG. 5 , there is a schematic diagram showing the intersection of sink roll 16 and pivot point of hinge pin 72 at a tangent line 80 . Tangent line 80 passes through a point 82 at which scraper blade 62 impinges against sink roll 16 . Tangent line 80 intersects the sink roll at a peripheral point 82 and passes above or through the axis of pin 72 . Maintaining this angular relationship minimizes blade chatter at the point 82 at which forward blade 66 impinges upon the roll. The lifting force caused by the rotation of sink roll 16 causes the forward blades to chatter results It is advantageous to eliminate or reduce chatter to prevent surface flaws due to the lifting of forward blade 66 . The inventors have determined that the defined tangent line 80 must pass through the axis or above the axis of the pivot point of hinge pin 72 in order to achieve a stable relationship that avoids chatter. Further, rear blade 68 and blade holder 62 provide stabilization of forward blade and holder 66 , 62 by resisting blade chatter. Rear blade 68 impinges at an angle that is either perpendicular or intersects with the roll at an acute angle to the roll surface, so as to avoid the tenancy of the sink roll rotation to lift the rear blade.
Control of Scraper Arms
Control of the linear arm movements and the traversing movements may be accomplished in several ways, including direct manual operation. In the preferred embodiment, Referring to FIG. 6 , the sink roll scraper system includes a digital controller 100 for controlling the lateral movement of the transport shaft 38 , and the linear movement of the arms 18 , 20 . Movement of scraper pneumatic cylinders 34 , 36 and electromechanical actuator motor 40 are controlled by an electrical signal from a digital computer device, preferably a programmable logic controller (PLC) 100 . The operator may select from automatic or manual modes of control. Each arm is capable of independent operation, permitting the operator to selectively scrape an area on the roll surface. Under normal operation, arms 18 , 20 are applied alternately to the scraper roll, under pressure from their associated cylinders. The cylinder pressure is adjustable through the PLC. Pressure is varied by the PLC over a full range from zero to maximum operating pressure. The line operating pressure in the preferred embodiment is approximately 50 pounds per square inch The preferred pressurizing gas is nitrogen, although any compressed gas may be used.
The scraper operates cyclically in automatic mode, scraping the roll surface for a portion of every hour. For example, in a Zn—Al coating line, the cycle setting in the preferred embodiment is approximately ten minutes per hour of operation. The portion of time may be varied by the operator according to factors such as coating hardness or line speed. While the blades are scraping the roll, transport shaft 42 oscillates horizontally above the pot 12 , moving the support member 14 and the blades transversely, so that the entire width of the roll 16 is covered by the dual blade configuration. Generally, the lateral stroke of the transport shaft 42 and traversing cylinder 38 does not exceed one-half the width of the roll, and may be less than one half the roll width, depending on the width of the blades. The short stroke reduces cycle time for scraper blade assemblies 22 , 24 to pass back and forth across the roll surface.
The electromechanical actuator motor 40 for the transport shaft 42 is preferably a variable speed motor, controlled through the PLC. Control may be automatic or manual, as indicated above.
Control signals are derived from a combination of Operator requests and System Interfaces, processed through the programmable controller. The pneumatic cylinders are controlled by a combination of an electronic pressure regulator in line with a spring return single solenoid operated directional valve, preferably, although a dual directional valve configuration is also capable of operating the cylinders.
An electronic pressure regulator valve (not shown) is controlled by an analog signal over its operating range of control pressure. The analog signal is generated from the PLC using the Operator Requested pressure setting from the human machine interface (HMI), which is described in greater detail below. Any changes in pressure set point are ramped in the PLC for smooth operation. Directional valves 102 , 104 transfer the controlled pressure from the regulators 106 , 108 to stroke the cylinders up or down. The downstroke engages and upstroke disengages the scraper heads from the sink roll. The signal to energize the directional valves solenoids is derived from an operator request input to the PLC 100 to engage the scraper head assemblies 22 , 24 , when in manual control, or from an HMI when the PLC is set in automatic mode. In the preferred embodiment, the directional valves are proportionally controlled via the PLC. It is noted that control of the directional valves via the PLC is disclosed by way of example and not by limitation. Other, less sophisticated means may be employed within the scope and spirit of the present invention, to control the operation of the cylinders. For example, direct manually operated directional valves, or relay-operated valves may be employed
The PLC 100 transmits a speed control signal to variable frequency drive 110 for the frequency set point. PLC 100 also transmits separate control signals for Run, Forward and Reverse operation. The drive 110 transmits signals to PLC 100 to indicate drive running, speed and motor current controller, for control processing. PLC logic determines when the limit of travel is reached by reference to drive running, speed and current signals. When the limit of travel is detected in one direction, further movement in that direction is inhibited by the PLC.
Human Machine Interface (HMI) Description
There is an interactive human machine interface (HMI) 200 provided with the scraper unit, in electrical communication with the PLC or other digital controller. The HMI 200 comprises a graphical screen as shown in FIGS. 7 & 8 . Any of a number of commercially available touchscreen devices may be used for the interface screen. FIG. 7 shows the scraper unit in manual control mode. FIG. 8 shows the scraper in automatic control mode. The mode of operation may be switched from manual to auto by the manual/auto button 210 . The automatic sequence can be triggered from the “cycle now” button 212 when in automatic mode. By “button”, what is meant is a graphical depiction of a button on the screen, representing a virtual pushbutton. The screen area of the button is touched by the operator to select the option that is represented by the button. The number of complete cycles that the automatic sequence should complete can be adjusted by the “No. of cycles” input button 214 .
The traverse movement of the scraper (referred to as “East” and “West”) is controlled from the traverse motor interface 216 . The traverse motor interface button 216 allows the operator to change the speed of traverse via the speed reference operator input, and to jog the scraper unit East and West via the jog pushbuttons 218 , 220 . Jog East and jog West buttons are visible only in manual mode. Indications of motor running, direction, speed and current are displayed to the operator 222 . Up and down movement of the scraper blade assemblies is controlled from the scraper head interface 224 .
The East and West scraper heads interfaces allow the operator to change the scraping pressure via the pressure reference operator inputs 226 , 228 and to lift and lower the heads to engage and disengage them from the sink roll via the lift/lower buttons 230 - 236 . Lift and lower buttons 230 - 236 are visible only in manual mode. In automatic mode, the arms and scraper blade assemblies are interlocked to operate in unison, and raising and lowering is done through the PLC according to the selected time cycle. Optionally, other indicators on the screen indicate nitrogen pressure; traverse fully east and fully west; and cylinder directional valve commands.
The scraper heads scraping pressure references may be adjusted by the operator input from 0 to line pressure, which in the disclosed embodiment is approximately 70 psi. These signals are interpreted by the PLC and converted to an analog signal for the electronic pressure regulators.
Automatic System Control
In automatic mode the scraper directional movements are controlled entirely by the PLC using operator input speed and pressure reference values.
The automatic sequence is enabled when the scraper is selected for auto mode and the process line is running. The automatic method for scraping the roll while the roll is rotating in the pot of molten metal is as follows:
The support assembly is traversed by the transport shaft to one side and the arms attached to the support assembly are lifted to a fully retracted position, disengaging the scraper blades from contact with the roll surface. A scraper cycle is then initiated by means of a trigger signal. Next, the arm that is positioned above the mid-point of the roll is lowered against the sink roll, the pressure reference is increased from lifting pressure to approximately zero, and directional valves are energized. The pressure value is gradually increased to a preselected pressure suitable for cleaning dross from the roll surface. The cylinder is then extended in a controlled manner to engage the scraper head gently on to the sink roll. The scraper head is then moved laterally by the transport shaft acting on the support member at a controlled, predetermined speed from the sink roll mid point to the fully traversed out position. The opposing arm is now positioned at the mid-point of the sink roll and the arm is lowered to engage the roll surface, while the first arm is retracted from the roll surface. The traversing means stops upon reaching the fully traversed out position. Then the scraper head is lifted from the roll surface by removing pressure from the cylinder, returning the arms to the retracted position. The transport shaft is returned to the starting position and the sequence is then repeated until a predetermined number of cycles are completed. A counter in the control means is incremented after each cycle. The counter value is compared with the number of selected cycles after each repetition of a cycle. The cycle is repeated until the counter value matches the number of cycles selected. The support assembly then traverses to one side of the sink roll and lifts the arms away from the surface of the roll. The trigger may be 1) a timer within the PLC which activates the sequence on a regular time based interval; 2) a weld signal from the weld tracking logic in the PLC; or 3) an operator initiated “Cycle Now” pushbutton.
The automatic sequence is enabled when the scraper is selected for auto mode and the process line is stopped. The sequence executes the following steps:
Return the traverse to the fully west side (unless already at fully east side) and both scraper heads are commanded to lift. Wait for a sequence trigger. The trigger originates from a timer in the PLC which activates the sequence on a regular time based interval, or from an operator initiated “Cycle Now” button. The traverse drive is commanded to run at the operator input speed reference to move from one end of travel to the opposite end of travel. When the PLC detects that the traverse motor has reached end of travel the command to run is released. Both scraper heads are commanded to lower. The PLC commands the pressure references to ramp from lifting pressure to approximately zero psi. When the pressure references have reached approximately zero pressure the directional valves are energized and the pressures are ramped to the scraping pressure reference. This causes the cylinders to extend in a controlled manner to engage the scraper heads gently on to the sink roll.
Scraper heads are then commanded to disengage or lift away from the roll surface. The PLC transmits a signal to the directional valves to de-energize, causing the cylinders to retract and the heads to lift. The PLC checks whether the pre-selected number of cycles have been completed, if not the cycle is repeated, and if so, the scraper assembly returns to the resting position.
Referring next to FIGS. 9A through 9D , a cycle is illustrated, by way of example and not by limitation. In FIG. 9A , the normal resting position is illustrated, in which arms 18 , 20 are both in the raised position above roll 16 . Arm 18 is disposed above the approximate mid-point of the roll. In FIG. 9B , the first step of the sequence is to lower the arm directly above the mid-point against the roll, as indicated by arrow 102 , and traverse to the edge of the roll opposite arm 20 , as indicated by arrow 104 . In FIG. 9C , the next step of the cycle is to raise the arm 18 which is now at or beyond the edge of roll 16 , as indicated by arrow 106 . Arm 20 is now disposed above the approximate mid-point, and is lowered against the roll as indicated by arrow 108 , and traverses the roll in the opposite direction as indicated by arrow 110 . In FIG. 9D , the last step of the cycle is shown, in which arm 20 is raised after reaching the edge of roll 16 , and both arms 18 , 20 are in the raised position in which they began the cycle. This cycle may be repeated manually, or by use of the automated feature by selecting the number of cycles in the automatic mode as described above. It should be noted that the cycle described in FIGS. 9A-9D is only one of many possible sequential combinations that may be employed in the present invention. Other sequences may be used, and the invention may be practiced non-cyclically as well, such as when the operator sets the position of one or both scrapers using manual control mode, to scrape the roll at a specified point where, for example, a dent occurs in the strip.
According to the provisions of the patent statutes, we have explained the principle, preferred construction, and mode of operation of the present invention, and have illustrated and described what we now consider to represent its best embodiments. However, it should be understood that within the scope of the appended claims and the foregoing description, the present invention may be practiced otherwise than as specifically illustrated and described.
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An apparatus for scraping the surface of a sink roll in a molten metal coating process comprises a support member having a pair of linearly movable arms supported thereon. The support member depends from a bridge structure spanning a continuous metal coating line, and a pair or arms, the arms being disposed on opposite sides of said support member. Each arm has a scraper assembly portion attached thereto. Each scraper assembly portion has two blades affixed thereto, a forward scraper blade and a rear scraper blade, with a connecting portion connecting the two blades. The connecting portion also has a first pivot point for attaching the connecting portion to the arm associated with the scraper assembly portion, the first pivot point being disposed between said forward and rear scraper blades for following the radial contours of the roll surface. A second pivot point permits the blades to follow the crown of the roll. Pneumatic cylinders advance the arms such that at least one scraper blade presses against the roll surface under pressure. There is also control means for controlling the pressure of the scraping force of said blades applied to the roll surface. A traversing means provides for communicating lateral movement of said blades laterally along the axis of the roll while scraping against the roll.
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RELATED APPLICATION DATA
[0001] This application, pursuant to 35 U.S.C. §119(e), is a divisional patent application of U.S. Patent Publication 2008/0292035 (U.S. patent application Ser. No. 12/122,541), filed on May 16, 2008.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to techniques for improving the throughput and reliability of wireless links by bonding communication channels together. More particularly, the invention relates to techniques for using multi-beam antennas to communicate with spatially separated wireless access points that are then bonded to increase channel bandwidth.
[0004] 2. Description of Related Art
[0005] It is well known in the art to increase the bandwidth and reliability of a communication interface by combining, or bonding, two or more sets of interface hardware. A network interface card on a host computer, for example, may be limited to a certain maximum data rate. A second network interface card can be added to the host computer, and software running on the host computer can be made to divide up information packets across the two network interface cards such that portions of a message to be transmitted are sent over both network interface cards simultaneously. If each network card operates at its full bandwidth, the combined bandwidth of the entire system is effectively doubled. At the receiving end, the two network data streams are received simultaneously, and the receiving computer reassembles the transmitted data message by properly organizing the packets received from each of the two network interface cards.
[0006] Alternatively, the technique of adding a second network interface card to a host computer can be used to create redundancy for the transmission of important data. In this case, the host computer sends the same data packets over two independent network interface cards. The receiving computer compares the incoming data from the two channels to assure that the data is received without error. If a mismatch between the two channels is discovered, the receiving computer can request a retransmission of the corrupted data.
[0007] The channel bonding methods described above are generally applied to hard-wired connections over copper wire or fiber optics because such hard-wired systems provide good isolation between the two or more independent communication channels. When channel bonding is attempted over wireless networks, interference between the multiple wireless network cards can cause communication failures or excessively high error rates. To minimize interference, the multiple wireless systems can be tuned to different frequency channels. However, of the eleven channels in the 2.4-GHz frequency band of the IEEE 802.11b and g wireless standards, only channels 1 and 11 are spaced sufficiently far apart that they may be used simultaneously without excessive interference, limiting the channel-frequency choices. Furthermore, equipment that uses channel bonding on channels 1 and 11 will effectively use up the entire 802.11 spectrum, locking out any other wireless networks in the broadcast area. As a result of the competition for bandwidth of multiple network users, the overall data throughput may actually decrease.
[0008] A solution to this problem is to spatially separate the wireless data streams that are to be bonded in order to reduce interference from simultaneous transmissions that are at or near the same frequency. Current wireless network cards and laptop computer systems use omni-directional, low-gain antennas to communicate with wireless access points. Such antennas provide little spatial discrimination and are thus not suitable for this purpose. However, providing a dedicated processor to generate spatially separated beams can add significant complexity and cost. Accordingly, it would be useful to provide a wireless system that can communicate simultaneously over multiple, spatially separated beams that can be bonded into a single virtual channel to provide increased data bandwidth and/or improved communication channel reliability. It would further be useful to use existing processor resources to support digital beam forming to create a low-cost smart DBF antenna for consumer electronics.
SUMMARY OF THE INVENTION
[0009] A system is provided that enhances the throughput and reliability of wireless communications by providing multi-beam user terminals that exhibit directional discrimination. Multiple wireless communication channels are matched with multiple beams, and the channels are bonded into a single virtual channel, thereby increasing data bandwidth while reducing interference and multi-path effects that can degrade communications.
[0010] An embodiment of a wireless communication system in accordance with the present invention includes a media center that contains communication data to be sent wirelessly to one or more user terminals. The media center is physically attached to at least two wireless access points, such as those that comply with the IEEE 802.11 wireless networking specification. The media center divides the communication data to be sent into portions that will be broadcast from each of the access points. If the primary objective is to increase the speed of data transfer, the two portions will contain little if any overlapping data. If the primary purpose is to provide robustness, the two portions will contain significant amounts of overlapping data.
[0011] A user terminal is configured to receive the data from the two access points. The user terminal includes an antenna that is composed of at least two radiating elements. When signals from the access points arrive at the radiating elements of the array antenna, signals from each of the array elements are processed by a beam-forming processor. The beam-forming processor adjusts the amplitude and phase of the signals received from the individual antenna array elements in order to create at least two beams pointing in different directions. By properly adjusting the amplitude and phase of the received signals, they can be made to add coherently for certain directions and incoherently for other directions. The beam-forming processor is thus used to create one beam that points in a direction to the first access point and a second beam that points in the direction of the second access point.
[0012] The user terminal then demodulates the first beam and the second beam to recover the first data portion and the second data portion. The two portions are then bonded together to create a single virtual channel. If the two portions contain little data overlap, the effect of the bonding operation is to increase the data throughput by approximately a factor of two. On the other hand, if there is significant data overlap between the first and second portions, the effect is to improve the robustness of the wireless communication system by providing redundant data information without slowing the information transfer rate.
[0013] The beam forming process may be performed in either the analog or digital domain. In an analog system, the analog signals received from each element of the antenna array are routed through phase shifters to adjust their relative phase and through amplifiers to scale their amplitudes. The scaled and phase-shifted signals are then combined to form a composite coherent beam pointing in the selected direction. Simultaneously, a second set of phase shifters and amplifiers is used to adjust the same antenna array signals by different amounts to create a second coherent beam that points in a second direction. The directions of the coherent beams are set to point to the access points that are broadcasting the communication data.
[0014] In a digital beam-forming system, the signals from the antenna array are first digitized using an analog-to-digital (A/D) converter. The digital samples are then multiplied by complex beam weighting factors that include both amplitude and phase components. Different sets of weighting vectors will create beams pointing in different directions. The digital beam-forming processor may create any number of digital beams by multiplying the sampled data from the A/D converter by different sets of weighting vectors and then combining the weighted samples to form composite coherent beams.
[0015] In an embodiment of a beam-forming system in accordance with the present invention, the digital processing and formation of multiple beams is performed in a dedicated beam-forming processor. However, an alternative embodiment of a beam-forming system in accordance with the present invention uses already-existing processing resources to perform the beam-forming algorithms. For example, in a system using a laptop computer as the user terminal, a fraction of the processing power, typically 5% to 10%, of the laptop's general-purpose microprocessor would be reserved for real-time beam-forming processing. The beam-forming algorithms would thus run in the background, behind the other processing tasks of the laptop computer, and would demand processing resources as needed. Thus, the electronics associated with the transmit/receive antenna would simply convert received microwave waveforms to digital bit streams and would convert digital bit streams to transmitted microwave waveforms. The antenna would thus act as a low-cost smart DBF antenna that could be integrated with consumer electronics having inherent processing power that could be utilized. Software running on the main processor of the consumer electronics device would execute the beam-forming processing steps.
[0016] Behind the array antenna is a radio-frequency front end. This may comprise a low-noise amplifier (LNA) associated with each antenna element, followed by a band-pass filter and a frequency down-converter to convert the received radio-frequency signals to a lower intermediate frequency before being digitized by an A/D converter. Alternatively, because fast A/Ds may be capable of handing the 2.4 GHz signals of the IEEE 802.11 standard directly, the down-conversion stage may be eliminated, and digitization may take place directly at radio frequency.
[0017] The transmit side of a user terminal according to the present invention operates similarly. In transmit, a router splits data into two paths. The data in each of the paths is modulated onto a digital baseband waveform which is then sent to a digital beam forming (DBF) processor. Each DBF processor applies appropriate complex beam weighting factors to adjust the amplitudes and phases of the waveforms to be applied to the elements of the patch antenna array. As discussed above, the DBF processors could be dedicated units or the algorithms could execute on the primary processor of the host device to embed the beam-forming vectors into the digital data stream sent to the antenna. Analog waveforms are then synthesized from the digital baseband waveforms by D/A converters. The analog waveforms are then frequency up-converted to radio frequency, filtered, amplified by solid-state power amplifiers or similar devices, and applied to elements of the patch array. Note that with very high-speed D/A converters, direct radio-frequency synthesis may be possible, and the frequency up-conversion stage could then be eliminated.
[0018] In an alternative embodiment of a wireless communication system in accordance with the present invention, signals from the elements of the receiving array antenna may be combined before digitization in order to reduce the number of A/D converters required and to make the radio-frequency front end more conducive to being implemented in a radio-frequency integrated circuit (RFIC). In order to combine the signals in such a way that the individual signals from each antenna element can be recovered for subsequent beam-forming processing, a series of orthogonal modulating codes is used. The signal from each of the array elements is passed through a bi-phase modulator. The modulating input of each bi-phase modulator is driven by a pseudonoise (PN) code. The PN codes are chosen to be mutually orthogonal and are applied synchronously to the signals from each of the array elements. The modulated signals are then summed and digitized by a single A/D converter. In the digital domain, the composite sample stream is then convolved with each of the PN codes, and owing to the orthogonal nature of each of the codes, only the signal component originally modulated with that code will be recovered. Digital sample streams associated with each of the elements of the antenna array are thus presented to the digital beam forming processor, and multiple beams can be synthesized. As discussed previously, the digital beam forming unit could be a dedicated processing unit or could comprise a portion of the general-purpose microprocessor of the host device. In its most integrated form, a smart antenna in accordance with the present invention would comprise patch antenna elements and a radio-frequency integrated circuit. The RFIC would send digital data to the main microprocessor of the host device, which would calculate and apply the beam weight vectors to create multiple digital beams. In transmit, digital data would be multiplied by weighting vectors in the host microprocessor, and a digital data stream with embedded beam-forming vectors would be delivered to the RFIC, which would then transmit the data from the antenna elements.
[0019] From the foregoing discussion, it should be clear to those skilled in the art that certain advantages have been achieved in a communication system employing channel bonding over multiple antenna beams that achieve spatial separation, thereby reducing interference and increasing data bandwidth. Further advantages and applications of the invention will become clear to those skilled in the art by examination of the following detailed description of the preferred embodiment. Reference will be made to the attached sheets of drawing that will first be described briefly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 depicts a media center connected to two spatially-separated wireless access points, and a multi-beam user terminal in accordance with the present invention.
[0021] FIG. 2 illustrates an alternative embodiment of a multiple-beam channel bonding communication system in accordance with the present invention.
[0022] FIG. 3 is a block diagram of an embodiment of the receive portion of a user terminal in accordance with the present invention.
[0023] FIG. 4 is a block diagram depicting an embodiment of the transmit portion of a user terminal in accordance with the present invention.
[0024] FIG. 5 is a block diagram of an alternative embodiment of a user terminal in accordance with the present invention.
[0025] FIGS. 6A and 6B depict perspective views of an embodiment of a user terminal comprising a laptop computer with a four-element patch antenna array.
[0026] FIG. 7 depicts a block diagram of an embodiment of a user terminal constructed from commercial-off-the-shelf networking components.
[0027] FIG. 8 depicts a media center connected to three spatially-separated wireless access points, and a multi-beam user terminal in accordance with the present invention; All APs feature omni directional antenna patterns for both transmitting and receiving functions and one of the APs are connected through IP networks.
[0028] FIG. 9 depicts a media center connected to three spatially-separated wireless access points, and two multi-beam user terminals in accordance with the present invention; All APs feature omni directional antenna patterns for both transmitting and receiving functions and one of the APs are connected to the media center through IP networks.
[0029] FIG. 10 depicts a media center connected to three spatially-separated wireless access points, and two multi-beam user terminals in accordance with the present invention; All APs feature multiple beams for both transmitting and receiving functions and one of the APs are connected to the media center through IP networks.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0030] The invention provides a system for bonding multiple wireless communication channels using multi-beam directional antennas in order to improve communication bandwidth and reliability. In the detailed description that follows, like element numerals are used to indicate like elements appearing in one or more of the figures.
[0031] FIG. 1 depicts a block diagram of an embodiment of a multiple-beam wireless networking system in accordance with the present invention. A media center 108 stores data that it makes available to a wireless network over two spatially separated wireless access points 104 and 106 . A user terminal 102 includes a multi-beam antenna capable of pointing narrow beams 110 and 112 in the directions to the two access points 104 and 106 , respectively. The user terminal 102 includes a digital-beam-forming (DBF) processor described in more detail below with reference to FIG. 3 . The DBF processor allows the construction of two spatially-separated beams that can be independently steered toward the access points 104 and 106 . Of course, more than two access points and more than two beams are also possible and would fall within the scope and spirit of the present invention. Because of the spatial separation achieved by the pointing of the two independent beams, both can operate at the same frequency without causing interference problems. Software well known in the art runs on the media center 108 and on the user terminal 102 to split network packets into portions that will be sent across a first path comprising the first access point 104 and the first user beam 110 , and a second path comprising the second access point 106 and the second user beam 112 . Since both access points operate at their full individual data rates, the amount of data received by the user terminal 102 in a given time is effectively doubled. Alternatively, a second copy of the data sent to the first access point 104 can also be sent to the second access point 106 . The user terminal 102 then receives redundant copies of the same data from two independent sources. This redundancy can be used to improve the reliability and quality of the link while avoiding the reduction in data rate collateral to the use of error-correcting codes.
[0032] Wireless hubs or routers usually feature digital data buffers. One such a wireless hub or a router can play the role of the media center in FIG. 1 , performing the functions of: receiving digital data, buffering the data, and re-transmitting the received or buffered digital data to designated users via IP networks including wireless networks.
[0033] FIG. 2 illustrates an alternative embodiment of a multiple-beam wireless networking system in accordance with the present invention that does not require the access points to be spatially separated. The media center 202 is connected to two wireless access points 204 and 212 that may be located very close to one another. Each access point, however, includes a DBF processor and an appropriate array antenna that allows it to create a narrow, directional beam, i.e., 208 and 210 . For an indoor application, each access point beam 208 and 210 can be directed toward a wall 206 and 214 or other surface that is capable of reflecting a portion of the incident energy. The user terminal 102 , also includes a DBF processor and appropriate antenna elements allowing the creation of at least two beams 110 and 112 that are pointed in a direction to line up with the reflected energy from the access-point beams 208 and 210 .
[0034] Of course, other configurations are possible in which the access-point beams 208 and 210 are pointed directly at the user terminal beams 110 and 112 , as long as the directional selectivity of the beams is high enough to limit interference from the neighboring beam. Furthermore, systems that include more than two access points and more than two user-terminal beams also lie within the scope and spirit of the present invention.
[0035] Of course, an access point, AP 1 204 or AP 2 212 can feature more than one direction beams 208 or 210 to support multiple users concurrently and would fall within the scope and spirit of the present invention.
[0036] FIG. 3 is a block diagram of the receive side of an embodiment of a DBF system used to create multiple user-terminal beams in accordance with the present invention. The system depicted in FIG. 3 comprises a four-element array antenna. Each of the elements includes an antenna element 302 , a radio-frequency front end 304 , and an analog-to-digital converter 306 . The radio-frequency front end 304 includes a low-noise amplifier 312 , followed by a band-pass filter 314 to limit out-of-band noise, a frequency down-converter 316 , and an intermediate-frequency or baseband-frequency amplifier 318 . The analog-to-digital converter 306 samples the frequency-down-converted signals and presents the samples to two digital beam forming (DBF) processors 308 and 310 for processing the received radio-frequency signals. Of course, a single DBF processor may also be used that is capable of performing two independent beam calculations within the sampling rate of the A/D converters 306 . At the 2.4 GHz IEEE 802.11 frequency band, it is also feasible to digitize the incoming signal directly at the RF frequency with a very fast A/D and high-speed digital processing. Such a system that eliminates the down-conversion hardware would also fall under the scope and spirit of the present invention.
[0037] The DBF processors 308 and 310 apply complex weighting factors to the signal samples received from each of the RF channels to adjust the amplitude and phase of the samples. The weighted samples are then combined by the first DBF processor 310 to form a coherent beam pointing in a first direction, and they are combined by the second DBF processor 308 with a different set of weighting factors in order to produce a coherent beam pointing in a second direction. Proper selection of the weighting factors used in the digital beam-forming process thus allows the received RF energy to be analyzed from two independent directions. As the distance between the antenna elements is increased, the width of the synthesized beams decreases, improving the directional selectivity of the antenna array.
[0038] For high-performance systems, the DBF processors 308 and 310 can be implemented in one or more dedicated beam-forming processors. However, for many systems utilizing a smart DBF antenna, there is excess processing power in the main processor of the host device or user terminal that can be used to perform the DBF function. For example, in a personal laptop computer using digital beam forming, a portion of the general-purpose microprocessor capacity, typically 5% to 10%, could be allocated to real-time processing of the digital-beam-forming algorithms. DBF processors 308 and 310 would then physically reside within the main host processor and would take advantage of the processing power already present in the system.
[0039] The summed coherent beam samples from the first DBF processor 310 and the second DBF processor 308 are then independently demodulated at 322 and 320 to recover the baseband data. The two baseband data streams are then passed to the bonding unit 324 that combines the data packets in order to recover the full message sent over the two spatially separated paths.
[0040] FIG. 4 is a block diagram of the transmit side of an embodiment of a DBF system used to create multiple user-terminal beams in accordance with the present invention. Data to be transmitted is sent to a router 374 that splits the data into two separate paths in order to take advantage of the full bandwidth of each path. The data streams are modulated 370 and 372 onto baseband digital waveforms that are then sent to two digital beam forming (DBF) processors 356 and 358 . Note that a single DBF processor that is fast enough to multiplex both beams could also be used. Furthermore, the DBF processors could be implemented within the main microprocessor of the host device, as described previously. Each DBF processor 356 and 358 applies complex beam weighting vectors to each digital baseband waveform in order to create four weighted outputs from each data stream destined for the elements of the patch array antenna 350 . The phase and amplitude profile imparted by the DBF processor to each set of baseband data will direct each data stream in a separate direction as it leaves the antenna 350 . Each of the weighted digital waveforms is then routed through a digital-to-analog (D/A) converter 354 to synthesize an analog baseband waveform. The analog waveform is then amplified 368 and frequency up-converted 364 to radio frequency. Note that very high-speed D/As may enable direct synthesis at radio frequency, in which case, the frequency up-conversion stage may be eliminated. The up-converted RF signals are then band-pass filtered 362 , amplified by solid-state power amplifiers 360 or similar RF amplifiers, and applied to the elements of the patch array 350 .
[0041] FIG. 5 is a block diagram of an alternative embodiment of a user terminal in accordance with the present invention. An antenna aperture is comprised of four antenna elements 404 . Each element is connected to a low-noise amplifier 430 and then to a band-pass filter 402 . In order to reduce the number of analog-to-digital converters required, the signals from the four antenna elements are then mixed with orthogonal codes that enable the four signal streams to be combined, digitized, and then subsequently separated out into constituent streams. A code generator 406 generates four separate mutually orthogonal pseudorandom codes that are synchronous with each other. Each code is applied to a bi-phase modulator 432 in order to modulate the signal stream from the corresponding antenna element. The four modulated signal streams are then combined in a summing unit 414 . The combined data stream is then frequency down-converted to an intermediate frequency at 408 , amplified at 410 , and then digitized by a single analog-to-digital converter. Of course, with a sufficiently high-speed analog-to-digital converter, it is possible to digitize directly at the RF frequency and eliminate the down-conversion stage 408 . The coding, combining, and digitizing steps are well suited to integration into a single radio-frequency integrated circuit (RFIC) as indicated by the dashed border 434 .
[0042] The digitized data stream is then passed to the digital beam forming processors 416 and 418 . Convolving the digitized data stream with the same orthogonal synchronized code sequences used to combine the individual antenna-element data streams allows the individual streams to be extracted. The extracted digitized streams from the four antenna elements are then multiplied by a first set of complex weighting vectors in the first DBF processor 418 to form a coherent beam pointing in a first direction. They are also multiplied by a second set of complex weighting vectors in the second DBF processor 416 to form a coherent beam pointing in a second direction. The two beams are then demodulated at 420 and 422 and the extracted data packets are then combined in the bonding unit 424 to create a virtual channel with twice the bandwidth of each individual beam. It should be appreciated that a system with more or fewer than four antenna elements or with more than two synthesized beams would also fall within the scope and spirit of the present invention.
[0043] Similar orthogonal code processing may be employed on the transmit side in order to reduce the number of D/A converters and frequency up-converters required. This would be particularly advantageous for systems synthesizing directly at radio frequency that would require an expensive and high performance D/A converter.
[0044] FIGS. 6A and 6B are front and rear perspective views of a laptop computer system incorporating a four-element array antenna in accordance with an embodiment of the present invention. The laptop computer includes a keyboard portion 502 and a screen portion 504 . On the back of the screen portion 504 , four antenna patch elements 506 , 508 , 510 , and 512 are located. The radio-frequency integrated circuit 434 and DBF processing hardware 416 and 418 (see FIG. 4 ) may be located within the laptop housing. The DBF processor may also be integrated with the main laptop processor, which would be configured to dedicate a fraction of its computational power to the digital-beam-forming algorithm. It should be appreciated that other configurations of a patch-antenna array, including configurations that use more or fewer than four elements, would fall within the scope and spirit of the present invention.
[0045] FIG. 7 is a block diagram of a system demonstrating a multi-beam channel bonding system in accordance with an embodiment of the present invention. The system depicted in FIG. 7 is built using commercial off-the-shelf (COTS) components and features an analog multi-beam beam former 604 rather than a digital beam forming system.
[0046] An example of an analog multi-beam beam former, or beam forming network (BFN) is a four-by-four Butler Matrix that has four element ports and four beam ports. Such a device is capable of forming four orthogonal beams simultaneously. The four element ports are the inputs in receive mode and the outputs in transmit mode. Similarly, the four beam ports are the outputs in receive mode and the inputs in transmit mode. These four beams point in four fixed directions and cover approximately one quarter of the entire field of view.
[0047] To transmit data, a computer 614 communicates with an Ethernet router 612 that communicates with two wireless access points 610 and 608 implementing the IEEE 802.11 protocol. A bi-directional switch matrix 606 includes two inputs and four outputs and serves as a beam-selection mechanism, connecting two of the four available beams individually to the communication paths. The switch matrix 606 routes the output of each access point 610 and 608 simultaneously to two of the four inputs of the analog beam forming network (BFN) 604 . The analog BFN 604 simultaneously divides each of the two input signals into four paths, applies appropriate phase and amplitude weighting individually to the two signals from the access points 608 and 610 , sums the two weighted signals in each of the four paths, and then routes them to the four elements of the patch array 602 . The phase and amplitude factors applied by the analog BFN 604 cause a transmitted beam to be radiated in one of four directions that can be selected via the switch matrix. The direction of the beam radiated by the patch array 602 can be changed by selecting different switch positions in the switch matrix 606 to apply different signals to the inputs of the BFN 604 .
[0048] In receive mode, the system works similarly. The signals detected by each of the four radiating elements, e.g., 620 , are passed to the analog beam former 604 which then applies the appropriate phase and amplitude correction factors to cause the four signals to add coherently. The switch matrix is set such that the coherent beam from a first direction is switched to the first access point 610 , and the coherent beam from a second direction is switched to the second access point 608 . The Ethernet router 612 combines the packets from each of the two access points and bonds them into a single virtual channel with enhanced bandwidth.
[0049] Thus, a multi-beam system is achieved that uses beam forming to spatially separate simultaneous wireless network connections and then bond them together for enhanced bandwidth and reliability. Those skilled in the art will likely recognize further advantages of the present invention, and it should be appreciated that various modifications, adaptations, and alternative embodiments thereof may be made within the scope and spirit of the present invention. The invention is further defined by the following claims.
[0050] FIG. 8 depicts a block diagram of an embodiment of a multiple-beam wireless networking system in accordance with the present invention. A media center 108 stores data that it makes available to a wireless network over three spatially separated wireless access points AP 1 104 , AP 2 106 and AP 3 806 . AP 3 806 is connected via an IP network 808 . All three APs feature omni-directional radiation patterns. More specifically the pattern 1041 is associated with AP 1 104 , the pattern 1061 with AP 2 106 , and the pattern 8061 with AP 3 806 . A user terminal 102 includes a multi-beam antenna capable of pointing three narrow beams 110 , 112 and 812 in the directions to the three access points 104 , 106 and 806 , respectively. The user terminal 102 includes a DBF processor described in more detail below with reference to FIG. 3 . The DBF processor allows the construction of three spatially-isolated beams that can be independently steered toward the access points AP 1 104 , AP 2 106 and AP 3 806 .
[0051] Because of the spatial separation achieved by the pointing of the three independent beams, all can operate at the same frequency concurrently without causing interference problems. Software well known in the art runs on the media center 108 and on the user terminal 102 to split network packets into portions that will be sent across a first path comprising the first access point AP 1 104 and the first user beam 110 , a second path comprising the second access point AP 2 106 and the second user beam 112 , and a third path comprising the third access point AP 3 806 and the third user beam 812 . Since all three access points operate at their full individual data rates, the amount of data received by the user terminal 102 in a given time is effectively tripled.
[0052] Wireless hubs or routers usually feature digital data buffers. One such a wireless hub or a router can play the roles of the media center 108 in FIG. 8 ; receiving digital data, buffering the data, and re-transmitting the received or buffered digital data to designated users via IP networks including wireless networks.
[0053] FIG. 9 depicts a block diagram of an embodiment of a multiple-beam wireless networking system in accordance with the present invention. A media center 108 stores data that it makes available to a wireless network over three spatially separated wireless access points AP 1 104 , AP 2 106 and AP 3 806 . AP 3 806 is connected via an IP network 808 . All three APs feature omni-directional radiation patterns. More specifically the pattern 1041 is associated with AP 1 104 , the pattern 1061 with AP 2 106 , and the pattern 8061 with AP 3 806 . This network supports two user terminals 102 and 902 . The first user terminal 102 includes a multi-beam antenna capable of pointing three narrow beams 110 , 112 and 812 in the directions to the three access points 104 , 106 and 806 , respectively. The second user terminal 902 includes a multi-beam antenna capable of pointing three narrow beams 910 , 912 and 914 in the directions to the three access points 104 , 106 and 806 , respectively. Both user terminals 102 and 902 include a DBF processor described in more detail below with reference to FIG. 3 . The DBF processor allows the construction of three spatially-isolated beams that can be independently steered toward the access points AP 1 104 , AP 2 106 and AP 3 806 .
[0054] Wireless hubs or routers usually feature digital data buffers. One such a wireless hub or a router can play the roles of the media center 108 in FIG. 9 ; receiving digital data, buffering the data, and re-transmitting the received or buffered digital data to designated users via IP networks including wireless networks.
[0055] Because of the spatial separation achieved by the pointing of the three independent beams from the first user terminal, all can operate at the same frequency concurrently without causing interference problems. Software well known in the art runs on the media center 108 and on the user terminal 102 to split network packets into portions that will be sent across a first path comprising the first access point AP 1 104 and the first user beam 110 , a second path comprising the second access point AP 2 106 and the second user beam 112 , and a third path comprising the third access point AP 3 806 and the third user beam 812 . Since all three access points operate at their full individual data rates, the amount of data received by the user terminal 102 in a given time is effectively tripled.
[0056] However, when the first user terminal operates, the second terminal must operate in a different frequency slot, or different time slots, or via other multiplexing schemes. There are no frequency re-use among the two user terminals because of the omni directional antenna pattern features in the APs.
[0057] FIG. 10 depicts a block diagram of an embodiment of a multiple-beam wireless networking system in accordance with the present invention. A media center 108 stores data that it makes available to a wireless network over three spatially separated wireless access points AP 1 104 , AP 2 106 and AP 3 806 . AP 3 806 is connected via an IP network 808 . All three APs feature multiple concurrent beams. More specifically AP 1 104 generates two independent beam patterns 1004 , AP 2 106 produces two independent beam patterns 1006 , and AP 3 806 the two beam patterns 1008 . This network supports two user terminals 102 and 902 . The first user terminal 102 includes a multi-beam antenna capable of pointing three narrow beams 110 , 112 and 812 in the directions to the three access points 104 , 106 and 806 , respectively. The second user terminal 902 includes a multi-beam antenna capable of pointing three narrow beams 910 , 912 and 914 in the directions to the three access points 104 , 106 and 806 , respectively. Both user terminals 102 and 902 include a DBF processor described in more detail below with reference to FIG. 3 . The DBF processor allows the construction of three spatially-isolated beams that can be independently steered toward the access points AP 1 104 , AP 2 106 and AP 3 806 .
[0058] Wireless hubs or routers usually feature digital data buffers. One such a wireless hub or a router can play the roles of the media center 108 in FIG. 9 ; receiving digital data, buffering the data, and re-transmitting the received or buffered digital data to designated users via IP networks including wireless networks.
[0059] Because of the spatial separation achieved by the pointing of the three independent beams from the first user terminal, all can operate at the same frequency concurrently without causing interference problems. Software well known in the art runs on the media center 108 and on the user terminal 102 to split network packets into portions that will be sent across a first path comprising the first access point AP 1 104 and the first user beam 110 , a second path comprising the second access point AP 2 106 and the second user beam 112 , and a third path comprising the third access point AP 3 806 and the third user beam 812 . Since all three access points operate at their full individual data rates, the amount of data received by the user terminal 102 in a given time is effectively tripled.
[0060] Similarly, when the first user terminal operates, the second terminal may also operate in a same frequency slot due to angular isolation by the directional antenna pattern features in the APs. In fact, it will be even better to use orthogonal beams (OB) in the APs to provide enhanced isolations among different users. There are two pointing directions for each AP as indicated. The two OB beams generated by an AP will exhibit the following features;
[0061] 1. A first beam is formed with
a. a beam peak toward user 1 terminal 102 and b. a deep null toward user 2 terminal 902 .
[0064] 2. A second beam is formed concurrently with
a. a beam peak toward user 2 terminal 902 and b. a deep null toward user 1 terminal 102 .
[0067] When each access point with N independent and concurrent beams (e.g. N=2), the three APs, AP 1 104 , AP 2 106 , and AP 3 806 can support N spatially separated users through the same frequency slot, each user is equipped with an identical terminal 102 . Because of the spatial separation among the N users, and directional isolations achieved by the pointing of the N independent beams from the APs and the three concurrent beams for the N users, the 2N links can operate at the same frequency without causing interference problems.
[0068] As far as one of the N users is concerned; there are three APs available to triple his/her data rate and throughput. Similarly as far as one of the three APs is concerned, there are N concurrent beams available operating at a common frequency slot to service up to N different users simultaneously.
[0069] Of course, more than two users and more than two beams per access point as well as more than two access points are also possible and would fall within the scope and spirit of the present invention.
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A system is provided that enhances the throughput and reliability of wireless communications by providing multi-beam user terminals that exhibit directional discrimination. Multiple wireless communication channels are matched with multiple beams created from an array antenna by a beam-forming processor. The multiple wireless communication channels are bonded into a single virtual channel, thereby increasing data bandwidth while reducing interference and multi-path effects that can degrade communications. The beam-forming function may be performed in a dedicated beam-forming processor or may reside within a general-purpose microprocessor located in the user terminal. In addition, a wireless communications system with access points featuring multiple beams that exhibit directional discrimination that can concurrently support multiple users with multi-beam terminals via a common frequency channel. Both forward and return links feature multiple-folded frequency reuse, enabling multiple users with higher throughput and improved reliability. The spectrum utility of the communications system has been enhanced with multiple folds.
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This is a division of application Ser. No. 756,355, filed Jan. 3, 1977, now U.S. Pat. No. 4,190,418, which is a continuation-in-part of application Ser. No. 649,049, filed Jan. 14, 1976, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to apparatus for applying dyes to webs so as to obtain a smoothly changing gradation in the amount of dye present on the web as a function of the distance from a specified edge.
There are currently commercially available glass lenses which have been dyed with a gradation in shade from a deep hue, generally at the top of a lens, vignetting to a very light hue as the dye area nears the bottom of the lens. The lenses for such sunglasses are usually prepared by dipping each lens slowly into a dye material and removing the lens so dipped. The result of this individual dipping is a differential dyeing as a function of the residence time of each lens in the dye solution, but the process is a slow and expensive one.
The object of this invention is to provide a means for the continuous production of a web material having a predetermined dye density gradient. The web may be cut into sunglass lenses after the dyeing process.
Another object is to provide the means for assuring a requisite differential residence time in the dye bath without introducing striations which mark the limit of dye contact.
A still further object is to provide apparatus useful in the continuous preparation of a web with a dye density gradient.
Other objects of the invention will in part be obvious and will in part appear hereinafter.
The invention accordingly comprises the apparatus possessing the construction, combination of elements and arrangement of parts which are exemplified in the following detailed disclosure.
SUMMARY OF THE INVENTION
This invention is concerned with apparatus for dyeing a web in a continuous manner so as to impart a dye density gradient to the web across the narrow, or transverse dimension of the web. The web so dyed may then be cut into lens blanks.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing wherein
FIG. 1 is a perspective view of an apparatus for providing a dye density gradient to a web in accordance with this invention;
FIG. 2 is a perspective view of another embodiment of the apparatus of this invention; and
FIG. 3 is a side view of a section of the web as it enters the dye bath.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, the apparatus of the instant invention, which generally comprises a dye bath container and associated web-transport equipment is depicted.
Dye bath container 11, which is adapted to retain dye bath 12, is associated with means for conducting a web 14 longitudinally into dye bath container 11, and progressively transversely submerging the web 14 into the dye bath 12, and conducting the web 14 out of dye bath 12. These conducting means generally comprise adjustable pulleys 15, 16 and 17. There is also shown means for producing waves on the surface of the dye bath. Such wave-producing means comprise a frame 18, paddles 19 attached to the frame 18, and means 20 attached to the frame 18 for moving the frame 18 and attached paddles 19 in a reciprocating manner. The dye bath container may be associated with heating means (not shown). The dye bath material itself comprises either a solution or dispersion of a dye which may be, for example, a water-soluble dye in a water solution, an organic solvent-soluble dye in, for example, an alcohol-water mixture, or preferably a water dispersible dye dispersed in water. A preferred dye is one which is absorbed by the web only at a temperature above about 180° F. which obviates the possibility of unintentionally staining the web by random spattering of cool dye onto the web. A preferred dye is the dispersion sold as a "catalytic dye" by Brainpower Inc. of Florida although other dispersions, such as the commercially available Rit dyes may be used.
The web 14 preferably comprises a continuous flexible sheet of material having a transverse, or widthwise dimension small relative to its longitudinal, or lengthwise dimension. The top and bottom edges are substantially parallel. In a preferred embodiment the transverse dimension may be, for example, approximately 5 to 10 cm while the longitudinal dimension, may be several hundred meters. Preferably this flexible web will comprise a transparent synthetic plastic material and will be initially provided on a supply spool 21, threaded through the conducting or transport means and onto the take-up spool 22.
FIG. 2 shows the preferred embodiment of the apparatus of the present invention wherein additional adjustable transport means conduct the web progressively transversely into and out of the dye bath three times before conducting the webs onto the take-up spool 22. Obviously the intensity gradient of the dyeing may be controlled by precisely adjusting the residence times of progressive transverse points of the web in the dye bath.
In operation a spool containing a web of material to be dyed is fixed in a position adjacent the dye bath 12 such that a plane through longitudinal dimension of the web as it enters the dye bath is preferably substantially perpendicular to the surface of the bath and the top and bottom edges of the web are at a small acute angle to the surface of the dye bath. This orientation results in the bottom edge of the web being progressively immersed into the bath as the web proceeds from the spool and then progressively emersed from the bath so that a differential transverse residence time is established for the web in the dye bath. This operation essentially comprises conducting the web progressively, transversely into the dye bath to a point of maximum submersion, then conducting the web out of the dye bath. Dye which adheres to, but is not absorbed by the web can be easily washed from the surface of the web before drying and winding.
Referring to FIG. 3, there is depicted a side view of a section of web 14 entering dye bath 12 in the direction indicated by the arrow marked 32. The bottom edge 30 of the web enters the dye bath at an angle acute to the average surface of the dye bath. Top edge 31 is essentially parallel to bottom edge. It can be seen that those points on the web nearer the bottom edge have a longer residence time in the dye bath than do those points further away from the bottom edge, closer to the top edge. X and Y denote, respectively, the longitudinal and transverse dimensions of the web.
Preferably the dye bath will contain up to about 25 % of a water miscible solvent having a low vapor pressure such as, for example, ethylene glycol, which will keep the dye from crystallizing on the surface of the web so that excess, unabsorbed dye may be washed off. A preferred concentration of ethylene glycol is approximately ten per cent by volume.
The amount of dyeing at any point in the web is directly related to the time of exposure of that point to the dye bath material in the dye bath container, i.e., the residence time of that point in the bath. For a given transverse segment, those points exposed to the dye bath for a longer residence time, that is, those points first submerged into the dye bath and last removed from the dye bath, have a greater exposure to the dyeing material and have more dye absorbed than those points having a shorter residence time. The progression of points on a given transverse segment, starting at one edge of that segment and moving to the other edge with the residence time varying constantly from one point to the next will result in a dye density gradient on that transverse segment.
The web, after the dyeing, will then have excess liquid removed from its surfaces by, for example, a squegee. The dyed web may then be washed, dried and rolled in conventional manner.
As stated above the web may comprise a transparent synthetic plastic material such as oriented polyvinyl alcohol which is commonly used in the manufacture of sunglass lenses, though any suitable synthetic plastic web material may be used. The web of the preferred embodiment comprises a sheet of a plastic laminate comprising the following layers in sequence: a layer of polymerized polyethylene glycol dimethacrylate, a layer of cellulose acetate butyrate, a polarizing layer comprising an iodine-stained, molecularly oriented polyvinyl alcohol, a second layer of cellulose acetate butyrate and a second layer of polymerized polyethylene glycol dimethacrylate.
The washed, dried, dyed web may be cut into lens blanks so that the dye density gradient, which is transverse with respect to the web, runs from what may be designated as the top of a sunglass lens to the bottom of such a lens.
It is important in producing a dye density gradient on the web that a smooth gradient is obtained and therefore it is important that there be introduced no striations indicating an abrupt change in density. Such striations can be avoided by disturbing the surface of the dye bath, for example, by creating waves on the surface. These waves may be formed, for example, by paddles 19 attached to means for moving said paddle back and forth in the dye bath. Such means are shown in the figures as the frame 18 and means 20 for moving the frame in a reciprocating manner. The waves, so set up, introduce a constantly changing but random surface configuration and make possible the avoidance of formation of the striations which might be introduced and destroy the smooth gradient.
Since certain changes may be made in the above apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
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Means orient a web to lie in a vertical plane and feed the web longitudinally through a dye bath in a generally horizontal path and with progressive transverse immersion and emersion. Reciprocating paddle means produce a wave form to the bath surface.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation in-part of co-pending application Ser. No. 09/501,467, filed Feb. 9, 2000, which is a continuation-in-part of Ser. No. 09/350,620, now U.S. Pat. No. 6,177,366, filed on Jul. 9, 1999, which is a continuation-in-part of Ser. No. 09/335,257, now U.S. Pat. No. 6,177,365, filed on Jun. 17, 1999; this application is also a continuation-in-part of co-pending application Ser. No. 09/406,264, now U.S. Pat. No. 6,220,309, filed on Sep. 24, 1999. These parent, grand-parent, and great-grandparent applications are herein entirely incorporated by reference.
FIELD OF THE INVENTION
All U.S. Patents cited herein are entirely incorporated by reference.
This invention relates generally to coated inflatable fabrics and more particularly concerns airbag cushions to which very low add-on amounts of coating have been applied and which exhibit extremely low air permeability. The inventive inflatable fabrics are primarily for use in automotive restraint cushions that require low permeability characteristics (such as side curtain airbags). Traditionally, heavy, and thus expensive, coatings of compounds such as neoprene, silicones and the like, have been utilized to provide such required low permeability. The inventive fabric utilizes an inexpensive, very thin coating to provide such necessarily low permeability levels. Thus, the inventive coated inflatable airbag possesses a coating comprising an elastomeric material (or materials) in contact with the target fabric wherein the elastomeric material possesses a tensile strength of at least 2,000 psi and an elongation at break of at least 180%. The coating is then applied to the airbag surface in an amount of at most 3.0 ounces per square yard (and preferably forms a film). The inventive airbag exhibits a characteristic leak-down time (defined as the ratio of inflated bag volume to bag volumetric leakage rate at 10 psi) of at least 5 seconds after inflation. The resultant airbag cushions, particularly low permeability cushions exhibiting very low rolled packing volumes, are intended to reside within the scope of this invention.
BACKGROUND OF THE PRIOR ART
Airbags for motor vehicles are known and have been used for a substantial period of time. A typical construction material for airbags has been a polyester or nylon fabric, coated with an elastomer such as neoprene, or silicone. The fabric used in such bags is typically a woven fabric formed from synthetic yarn by weaving practices that are well known in the art.
The coated material has found acceptance because it acts as an impermeable barrier to the inflation medium. This inflation medium is generally a nitrogen or helium gas generated from a gas generator or inflator. Such gas is conveyed into the cushion at a relatively warm temperature. The coating obstructs the permeation of the fabric by such gas, thereby permitting the cushion to rapidly inflate without undue decompression during a collision event.
Airbags may also be formed from uncoated fabric which has been woven in a manner that creates a product possessing low permeability or from fabric that has undergone treatment such as calendaring to reduce permeability. Fabrics which reduce air permeability by calendaring or other mechanical treatments after weaving are disclosed in U.S. Pat. No. 4,921,735; U.S Pat. No. 4,977,016; and U.S Pat. No. 5,073,418 (all incorporated herein by reference).
Silicone coatings typically utilize either solvent based or complex two component reaction systems. Dry coating weights for silicone have been in the range of about 3 to 4 ounces per square yard or greater for both the front and back panels of side curtain airbags. As will be appreciated by one of ordinary skill in this art, high add on weights substantially increase the cost of the base fabric for the airbag and make packing within small airbag modules very difficult. Furthermore, silicone exhibits very low tensile strength characteristics that do not withstand high pressure inflation easily without the utilization of very thick coatings.
The use of a particular type of polyurethane as a coating as disclosed in U.S. Pat. No. 5,110,666 to Menzel et al. (herein incorporated by reference) permits low add on weights reported to be in the range of 0.1 to 1 ounces per square yard but the material itself is relatively expensive and is believed to require relatively complex compounding and application procedures due to the nature of the coating materials. Patentees, however, fails to disclose any pertinent elasticity and/or tensile strength characteristics of their particular polyurethane coating materials. Furthermore, there is no discussion pertaining to the importance of the coating ability (and thus correlated low air permeability) at low add-on weights of such polyurethane materials on side curtain airbags either only for fabrics which are utilized within driver or passenger side cushions. All airbags must be inflatable extremely quickly; upon sensing a collision, in fact, airbags usually reach peak pressures within 10 to 20 milliseconds. Regular driver side and passenger side air bags are designed to withstand this enormous inflation pressure; however, they also deflate very quickly in order to effectively absorb the energy from the vehicle occupant hitting the bag. Such driver and passenger side cushions (airbags) are thus made from low permeability fabric, but they also deflate quickly at connecting seams (which are not coated to prevent air leakage) or through vent holes. Furthermore, the low add-on coatings taught within Menzel, and within U.S. Pat. No. 5,945,186 to Li et al., would not provide long-term gas retention; they would actually not withstand the prolonged and continuous pressures supplied by activated inflators for more than about 2 seconds, at the most. The low permeability of these airbag fabrics thus aid in providing a small degree of sustained gas retention within driver and passenger airbag cushions to provide the deflating cushioning effects necessary for sufficient collision protection. Such airbag fabrics would not function well with side curtain airbags, since, at the very least, the connecting seams which create the pillowed, cushioned structures within such airbags, as discussed in greater detail below, would exhibit too high a leakage rate upon inflation at requisite high gas pressures. As these areas provide the greatest degree of leakage during and after inflation, the aforementioned patented low coating low permeability airbag fabrics would not be properly utilized within side curtain airbags, in particular side curtain airbags intended to provide extended rollover protection.
As alluded to above, there are three primary types of different airbags, each for different end uses. For example, driver-side airbags are generally mounted within steering columns and exhibit relatively high air permeabilities in order to act more as a cushion for the driver upon impact. Passenger-side airbags also comprise relatively high air permeability fabrics which permit release of gas either therethrough or through vents integrated therein. Both of these types of airbags are designed to protect persons in sudden collisions and generally burst out of packing modules from either a steering column or dashboard (and thus have multiple “sides”). Side curtain airbags, however, have been designed primarily to protect passengers during side crashes provide rollover protection by retaining their inflation state for a long duration, and generally unroll from packing containers stored within the roofline along the side windows of an automobile (and thus have a back and front side only). Side curtain airbags therefore not only provide cushioning effects but also provide protection from broken glass and other debris. As such, it is imperative that side curtain airbags, as noted above, retain large amounts of gas, as well as high gas pressures, to remain inflated throughout the longer time periods of the entire potential rollover situation. To accomplish this, these side curtains are generally coated with very large amounts of sealing materials on both the front and back sides. Since most side curtain airbag fabrics comprise woven blanks that are either sewn, sealed, or integrally woven together, discrete areas of potentially high leakage of gas are prevalent, particularly at and around the seams. It has been accepted as a requirement that heavy coatings were necessary to provide the low permeability (and thus high leak-down time) necessary for side curtain airbags. Without such heavy coatings, such airbags would most likely deflate too quickly and thus would not function properly during a rollover collision. As will be well understood by one of ordinary skill in this art, such heavy coatings add great cost to the overall manufacture of the target side curtain airbags. There is thus a great need to manufacture low permeability side curtain airbags with less expensive (preferably lower coating add-on weight) coatings without losing the aging, stability, and permeability characteristics necessary for proper functioning upon deployment. To date, there has been little accomplished, if anything at all, alleviating the need for such thick and heavy airbag coatings from side curtain airbags.
Furthermore, there is a current drive to store such low permeability side curtain airbags within very thin, preferably, though not necessarily, cylindrically shaped modules. Since these airbags are generally stored within the rooflines of automobiles, and the area available is quite limited, there is always a great need to restrict the packing volume of such restraint cushions to their absolute minimum. However, the previously practiced low permeability side curtain airbags have proven to be very cumbersome to store in such cylindrically shaped containers at the target automobile's roofline. The actual time and energy required to roll such heavily coated low permeability articles as well as the packing volume itself, has been very difficult to reduce. Furthermore, with such heavy coatings utilized, the problems of blocking (i.e., adhering together of the different coated portions of the cushion) are amplified when such articles are so closely packed together. The chances of delayed unrolling during inflation are raised when the potential for blocking is present. Thus, a very closely packed, low packing volume, low blocking side curtain low permeability airbag is highly desirable. Unfortunately, the prior art has again not accorded such an advancement to the airbag industry.
OBJECTS AND BRIEF DESCRIPTION OF THE INVENTION
In light of the background above, it can be readily seen that there exists a need for a low permeability, side curtain airbag that utilizes lower, and thus less expensive, amounts of coating, and therefore exhibits a substantially reduced packing volume over the standard low permeability type side curtain airbags. Such a coated low permeability airbag must provide a necessarily long leak-down time upon inflation and after long-term storage. Such a novel airbag and a novel coating formulation provides marked improvements over the more expensive, much higher add-on airbag coatings (and resultant airbag articles) utilized in the past.
It is therefore an object of this invention to provide a coated airbag, wherein the coating is present in a very low add-on weight, possessing extremely high leak-down time characteristics after inflation and thus complementary low permeability characteristics. Another object of the invention is to provide an inexpensive side curtain airbag cushion. A further object of this invention is to provide an highly effective airbag coating formulation which may be applied in very low add-on amounts to obtain extremely low permeability airbag structures after inflation. An additional object of this invention is to provide an airbag coating formulation which not only provides beneficial and long-term low permeability, but also exhibits excellent long-term storage stability (through heat aging and humidity aging testing). Yet another object of the invention is to provide a low permeability side curtain airbag possessing a very low rolled packing volume and non-blocking characteristics for effective long-term storage within the roofline of an automobile.
Accordingly, this invention is directed to an airbag cushion comprising a coated fabric, wherein said fabric is coated with an elastomeric composition in an amount of at most 3.0 ounces per square yard of the fabric; and wherein said airbag cushion, after long-term storage, exhibits a characteristic leak-down time of at least 5 seconds. Also, this invention concerns an airbag cushion comprising a coated fabric, wherein said fabric is coated with an elastomeric composition; wherein said elastomeric composition comprises at least one elastomer possessing a tensile strength of at least 2,000 psi and an elongation of at least 180%; and wherein said airbag cushion, after long-term storage, exhibits a characteristics leak-down time of at least 5 seconds. Additionally, this invention encompasses a coated airbag cushion which exhibits a packing volume factor (measured as the rolled diameter of the airbag cushion divided by the measured depth of coverage measured from the attachment point of the target automobile's roofline to lowest point of coverage below the roofline after inflation) of at most 0.05.
The term “characteristic leak-down time” is intended to encompass the measurement of time required for the entire amount of inflation gas introduced within an already-inflated (to a peak initial pressure which “opens” up the areas of weak sealing) and deflated airbag cushion upon subsequent re-inflation at a constant pressure at 10 psi. It is well known and well understood within the airbag art, and particularly concerning side curtain (low permeability) airbag cushions, that retention of inflation gas for long periods of time is of utmost importance during a collision that results in rollover and other subsequent problems. Side curtain airbags are designed to inflate as quickly as driver- and passenger-side bags, but they must deflate very slowly to protect the occupants during roll over and side impact. Thus, it is imperative that the bag exhibit a very low leakage rate after the bag experiences peak pressure during the instantaneous, quick inflation. Hence, the coating on the bag must be strong enough to withstand the shock and stresses when the bag is inflated so quickly. Thus, a high characteristic leak-down time measurement is paramount in order to retain the maximum amount of beneficial cushioning gas within the inflated airbag. Airbag leakage after inflation (and after peak pressure is reached) is therefore closely related to actual pressure retention characteristics. The pressure retention characteristics (hereinafter referred to as “leak-down time”) of already-inflated and deflated side curtain airbags can be described by a characteristic leak-down time t, wherein: t ( second ) = Bag volume ( ft 3 ) Volumetric leakage rate ( SCFH *) at 10 Psi × 3600
*SCFH: standard cubic feet per hour.
It is understood that the 10 psi constant is not a limitation to the invention; but merely the constant pressure at which the leak-down time measurements are made. Thus, even if the pressure is above or below this amount during actual inflation or after initial pressurizing of the airbag, the only limitation is that if one of ordinary skill in the art were to measure the bag volume and divide that by the volumetric leakage rate (at 10 psi), the resultant measurement in time would be at least 5 seconds. Preferably, this time is greater than about 9 seconds; more preferably, greater than about 15 seconds; and most preferably, greater than about 20 seconds.
Likewise, the term, “after long-term storage” encompasses either the actual storage of an inventive airbag cushion within an inflator assembly (module) within an automobile, and/or in a storage facility awaiting installation. Furthermore, this term also encompasses any storage which is intended to simulate such long-term storage (through oven-aging, as one example) as well. Such a measurement is generally accepted, and is well understood and appreciated by the ordinarily skilled artisan, to be made through comparable analysis after representative heat and humidity aging tests. These tests generally involve 107° C. oven aging for 400 hours, followed by 83° C. and 95% relative humidity aging for a subsequent 400 hours and are universally accepted as proper estimations of the conditions of long-term storage for airbag cushions. Thus, this term encompasses such measurement tests. The inventive airbag fabrics must exhibit proper characteristic leak-down times after undergoing such rigorous pseudo-storage testing.
The inventive elastomeric coating composition must comprise at least one elastomer that possesses a tensile strength of at least 2,000 psi and an elongation to break of greater than about 180%. Preferably, the tensile strength is at least 3,000 psi, more preferably, 4,000, and most preferably at least about 6,000 (the high end is basically the highest one can produce which can still adhere to a fabric surface). The preferred elongation to break is more than about 200%, more preferably more than about 300%, and most preferably more than about 600%. These characteristics of the elastomer translate to a coating that is both very strong (and thus will withstand enormous pressures both at inflation and during the time after inflation and will not easily break) and can stretch to compensate for such large inflation, etc., pressures. Thus, when applied at the seams of a side curtain airbag, as well as over the rest of the airbag structure, the coating will most preferably (though not necessarily) form a continuous film. This coating acts to both fill the individual holes between the woven yarns and/or stitches, etc., as well as to “cement” the individual yarns in place. During inflation, then, the coating prevents leakage through the interstitial spaces between the yarns and aids in preventing yarn shifting (which may create larger spaces for possible gas escape).
The utilization of such high tensile strength and high elongation at break components permits the consequent utilization, surprisingly, of extremely low add-on weight amounts of such coating formulations. Normally, the required coatings on side curtain airbags are very high, at least 3.0 ounces per square yard (with the standard actually much higher than that, at about 4.0). The inventive airbag cushions require at most 3.0 (preferably less, such as 2.0, more preferably 1.8, still more preferably, about 1.5, and most preferably, as low as 0.8) ounces per square yard of this inventive coating to effectuate the desired high leak-down (low permeability). Furthermore, the past coatings were required to exhibit excellent heat and humidity aging stability. Unexpectedly, even at such low add-on amounts, and particularly with historically questionable coating materials (polyurethanes, for example), the inventive coatings, and consequently, the inventive coated airbag cushions, exhibit excellent heat aging and humidity aging characteristics. Thus, the coating compositions and coated airbags are clearly improvements within this specific airbag art.
Of particular interest as the elastomer components within the inventive elastomeric compositions are, specifically, polyamides, polyurethanes, acrylic elastomers, hydrogenated nitrile rubbers (i.e., hydrogenated NBR), fluoroelastomers (i.e., fluoropolymers and copolymers containing fluoro-monomers), ethylene-vinylacetate copolymers, and ethylene acrylate copolymers. Also, such elastomers may or may not be cross-linked on the airbag surface. Preferably, the elastomer is a polyurethane and most preferably is a polycarbonate polyurethane elastomer. Such a compound is available from Bayer Corporaiton under the tradename Impranil®, including Impranil® 85 UD, ELH, and EHC-01. Other acceptable polyurethanes include Bayhydrol® 123, also from Bayer; Ru 41-710, EX 51-550, and Ru 400-350, both from Stahl USA. Any polyurethane, or elastomer, for that matter, which exhibits the same tensile strength and elongation at break characteristics as noted above, however, are potentially available within the inventive coating formulation and thus on the inventive coated airbag cushion. In order to provide the desired leak-down times at long-term storage, however, the add-on weights of other available elastomers may be greater than others. However, the upper limit of 3.0 ounces per square yard should not be exceeded to meet this invention. The desired elastomers may be added in multiple layers if desired as long the required thickness for the overall coating is not exceeded. Alternatively, the multiple layer coating system may also be utilized as long as at least one elastomer possessing the desired tensile strength and elongation at break is utilized. In particular, such a coating system may include, as one example, a polyurethane-based bottom layer (for good tensile strength for low air permeability)(with an optional adhesion promoter present between the layer and the fabric) and a second layer of silicone (to provide excellent aging resistance, for example). Other types of such multiple coating systems are disclosed within grand-parent application Ser. No. 09/350,620, above fully incorporated by reference.
Other possible components present within the elastomer coating composition are thickeners, antioxidants, flame retardants, coalescent agents, adhesion promoters, and colorants. In accordance with the potentially preferred practices of the present invention, a dispersion (either solvent- or water-borne, depending on the selected elastomer) of finely divided elastomeric resin is compounded, or present in a resin solution, with a thickener and a flame retardant to yield a compounded mix having a viscosity of about 8000 centipoise or greater. A polyurethane is potentially preferred, with a polycarbonate polyurethane, such as those noted above from Bayer and Stahl, most preferred. Other potential elastomeric resins include other polyurethanes, such as Witcobond™ 253 (35% solids), from Witco, and Sancure, from BFGoodrich, Cleveland, Ohio; hydrogenated NBR, such as Chemisat™ LCH-7335X (40% solids), from Goodyear Chemical, Akron, Ohio; EPDM, such as EP-603A rubber latex, from Lord Corporation, Erie, Pa.; butyl rubber, such as Butyl rubber latex BL-100, from Lord Corporation; and acrylic rubber (elastomers), such as HyCar™, from BFGoodrich. This list should not be understood as being all-inclusive, only exemplary of potential elastomers. Furthermore, the preferred elastomer will not include any silicone, due to the extremely low tensile strength (typically below about 1,500 psi) characteristics exhibited by such materials. However, in order to provide effective aging and non-blocking benefits, such components may be applied to the elastomeric composition as a topcoat as long as the add-on weight of the entire elastomer and topcoat does not exceed 3.0 ounces per square yard and the amount of silicone within the entire elastomer composition does not exceed 20% by weight. Additionally, certain elastomers comprising polyester or polyether segments or other similar components, may not be undesirable, particularly at very low add-on weights (i.e., 0.8-1.2 oz/yd 2 ) due to stability problems in heat and humidity aging (polyesters easily hydrolyze in humidity and polyethers easily oxidize in heat); however, such elastomers may be utilized in higher add-on amounts as long, again, as the 3.0 ounces per square yard is not exceeded.
Among the other additives particularly preferred within this elastomer composition are heat stabilizers, flame retardants, primer adhesives, and materials for protective topcoats. A potentially preferred thickener is marketed under the trade designation NATROSOL™ 250 HHXR by the Aqualon division of Hercules Corporation which is believed to have a place of business at Wilmington, Del. In order to meet Federal Motor Vehicle Safety Standard 302 flame retardant requirements for the automotive industry, a flame retardant is also preferably added to the compounded mix. One potentially preferred flame retardant is AMSPERSE F/R 51 marketed by Amspec Chemical Corporation which is believed to have a place of business at Gloucester City N.J. Primer adhesives may be utilized to facilitate adhesion between the surface of the target fabric and the elastomer itself. Thus, although it is preferable for the elastomer to be the sole component of the entire elastomer composition in contact with the fabric surface, it is possible to utilize adhesion promoters, such as isocyanates, epoxies, functional silanes, and other such resins with adhesive properties, without deleteriously effecting the ability of the elastomer to provide the desired low permeability for the target airbag cushion. A topcoat component, as with potential silicones, as noted above, may also be utilized to effectuate proper non-blocking characteristics to the target airbag cushion. Such a topcoat may perform various functions, including, but not limited to, improving aging of the elastomer (such as with silicone) or providing blocking resistance due to the adhesive nature of the coating materials (most noticeably with the preferred polyurethane polycarbonates).
Airbag fabrics must pass certain tests in order to be utilized within restraint systems. One such test is called a blocking test which indicates the force required to separate two portions of coated fabric from one another after prolonged storage in contact with each other (such as an airbag is stored). Laboratory analysis for blocking entails pressing together coated sides of two 2 inch by 2 inch swatches of airbag fabric at 5 psi at 100° C. for 7 days. If the force required to pull the two swatches apart after this time is greater than 50 grams, or the time required to separate the fabrics utilizing a 50 gram weight suspended from the bottom fabric layer is greater than 10 seconds, the coating fails the blocking test. Clearly, the lower the required separating shear force, the more favorable the coating. For improved blocking resistance (and thus the reduced chance of improper adhesion between the packed fabric portions), topcoat components may be utilized, such as talc, silica, silicate clays, and starch powders, as long as the add-on weight of the entire elastomer composition (including the topcoat) does not exceed 3.0 ounces per square yard (and preferably exists at a much lower level, about 1.5, for instance).
Two other tests which the specific coated airbag cushion must pass are the oven (heat) aging and humidity aging tests. Such tests also simulate the storage of an airbag fabric over a long period of time upon exposure at high temperatures and at relatively high humidities. These tests are actually used to analyze alterations of various different fabric properties after such a prolonged storage in a hot ventilated oven (>100° C.) (with or without humid conditions) for 2 or more weeks. For the purposes of this invention, this test was used basically to analyze the air permeability of the coated side curtain airbag by measuring the characteristic leak-down time (as discussed above, in detail). The initially produced and stored inventive airbag cushion should exhibit a characteristic leak-down time of greater than about 5 seconds (upon re-inflation at 10 psi gas pressure after the bag had previously been inflated to a peak pressure above about 15 psi and allowed to fully deflate) under such harsh storage conditions. Since polyurethanes, the preferred elastomers in this invention, may be deleteriously affected by high heat and humidity (though not as deleteriously as certain polyester and polyether-containing elastomers), it may be prudent to add certain components within a topcoat layer and/or within the elastomer itself. Antioxidants, antidegradants, and metal deactivators may be utilized for this purpose. Examples include, and are not intended to be limited to, Irganox® 1010 and Irganox® 565, both available from CIBA Specialty Chemicals. This topcoat may also provide additional protection against aging and thus may include topcoat aging improvement materials, such as, and not limited to, polyamides, NBR rubbers, EPDM rubbers, and the like, as long as the elastomer composition (including the topcoat) does not exceed the 3.0 ounces per square yard (preferably much less than that, about 1.5 at the most) of the add-on weight to the target fabric.
Other additives may be present within the elastomer composition, including, and not limited to, colorants, UV stabilizers, fillers, pigments, and crosslinking/curing agents, as are well known within this art.
The substrate to which the inventive elastomeric coatings are applied to form the airbag base fabric in accordance with the present invention is preferably a woven fabric formed from yarns comprising synthetic fibers, such as polyamides or polyesters. Such yarn preferably has a linear density of about 105 denier to about 840 denier, more preferably from about 210 to about 630 denier. Such yarns are preferably formed from multiple filaments wherein the filaments have linear densities of about 6 denier per filaments or less and most preferably about 4 denier per filament or less. In the more preferred embodiment such substrate fabric will be formed from fibers of nylon, and most preferred is nylon 6,6. It has been found that such polyamide materials exhibit particularly good adhesion and maintenance of resistance to hydrolysis when used in combination with the coating according to the present invention. Such substrate fabrics are preferably woven using fluid jet weaving machines as disclosed in U.S. Pat. Nos. 5,503,197 and 5,421,378 to Bower et al. (incorporated herein by reference). Such woven fabric will be hereinafter referred to as an airbag base fabric. As noted above, the inventive airbag must exhibit extremely low permeability and thus must be what is termed a “side curtain” airbag. As noted previously and extensively, such side curtain airbags (a.k.a., cushions) must retain a large amount of inflation gas during a collision in order to accord proper long-duration cushioning protection to passengers during rollover accidents. Any standard side curtain airbag may be utilized in combination with the low add-on coating to provide a product which exhibits the desired leak-down times as noted above. Most side curtain airbags are produced through labor-intensive sewing or stitching (or other manner) together two separate woven fabric blanks to form an inflatable structure. Furthermore, as is well understood by the ordinarily skilled artisan, such sewing, etc., is performed in strategic locations to form seams (connection points between fabric layers) which in turn produce discrete open areas into which inflation gasses may flow during inflation. Such open areas thus produce pillowed structures within the final inflated airbag cushion to provide more surface area during a collision, as well as provide strength to the bag itself in order to withstand the very high initial inflation pressures (and thus not explode during such an inflation event). Other side curtain airbag cushions exist which are of the one-piece woven variety. Basically, some inflatable airbags are produced through the simultaneous weaving of two separate layers of fabric which are joined together at certain strategic locations (again, to form the desired pillowed structures). Such cushions thus present seams of connection between the two layers. It is the presence of so many seams (in both multiple-piece and one-piece woven bags) which create the aforementioned problems of gas loss during and after inflation. The possibility of yarn shifting, particularly where the yarns shift in and at many different ways and amounts, thus creates the quick deflation of the bag through quick escaping of inflation gasses. Thus, the base airbag fabrics do not provide much help in reducing permeability (and correlated leak-down times, particularly at relatively high pressures). It is this seam problem which has primarily created the need for the utilization of very thick, and thus expensive, coatings to provide necessarily low permeability in the past.
Recently, a move has been made away from both the multiple-piece side curtain airbags (which require great amounts of labor-intensive sewing to attached woven fabric blanks) and the traditionally produced one-piece woven cushions, to more specific one-piece woven fabrics which exhibit substantially reduced floats between woven yarns to substantially reduce the unbalanced shifting of yarns upon inflation, such as in Ser. Nos. 09/406,264 and 09/668,857, both to Sollars, Jr., the specifications of which are completely incorporated herein and described in greater depth hereafter:
The term “inflatable fabric” hereinafter is intended to encompass any fabric which is constructed of at least two layers of fabric which can be attached and/or sealed to form a bag article. The inventive inflatable fabric thus must include double layers of fabric to permit such inflation, as well as single layers of fabric either to act as a seal at the ends of such fabric panels, or to provide “pillowed” chambers within the target fabric upon inflation. The term “all-woven” as it pertains to the inventive fabric thus requires that the inflatable fabric having double and single layers of fabric be produced solely upon a loom. Any type of loom may be utilized for this purpose, such as water-jet, air-jet, rapier, and the like. Patterning may be performed utilizing Jacquard weaving and/or dobby weaving, particularly on fluid-jet and/or high speed rapier loom types.
The constructed fabric may exhibit balanced or unbalanced pick/end counts; the main requirement in the woven construction is that the single layer areas of the inflatable fabric exhibit solely basket-weave patterns. These patterns are made through the arrangement of at least one warp yarn (or weft yarn) configured around the same side of two adjacent weft yarns (or warp yarns ) within the weave pattern. The resultant pattern appears as a “basket” upon the arrangement of the same warp (or weft) yarn to the opposite side of the next adjacent weft (or warp) yarn. Such basket weave patterns may include the arrangement of a warp (or weft) yarn around the same side of any even number of weft (or warp) yarns, preferably up to about six at any one time, most preferably up to about 4.
The sole utilization of such basket weave patterns in the single layer zones provides a number of heretofore unexplored benefits within inflatable fabric structures. For example, such basket weave patterns permit a constant “seam” width and weave construction over an entire single layer area, even where the area is curved. As noted above, the standard Oxford weaves currently utilized cannot remain as the same weave pattern around curved seams; they become plain weave patterns. Also, such basket weave seam patterns permit the construction of an inflatable fabric having only plain woven double layer fabric areas and single layer “seams” with no “floats” of greater than three picks within the entire fabric structure. Such a fabric would thus not possess discrete locations where the air permeability is substantially greater than the remaining portions of the fabric. Additionally, such a weave structure permits the utilization of as low as two different weave densities (patterns, etc.) in the area of the produced seam. Thus, the seam itself is of one weave pattern and the weave pattern in the area directly adjacent to the seam is another weave pattern. No other patterns are utilized in that specific seam area. By directly adjacent, it is intended that such a described area is within at most 14 yarn-widths, preferably as low as 2 yarn-widths, and most preferably between about 4 and 8 yarn-widths, from the actual seam itself. Such a limitation on different weave densities has never been accomplished in all-woven airbags in the past.
Generally, the prior art (such as Thornton et al., supra) provides seam attachments exhibited at least three different weave densities within the directly adjacent area of the seams themselves. Furthermore, the prior art weaving procedures produce floats of sometimes as much as six or seven picks at a time. Although available software to the weaving industry permits “filling in” of such floats within weave diagrams, such a procedure takes time and still does not continuously provide a fabric exhibiting substantially balanced air permeability characteristics over the entire structure. The basket-weave formations within the single fabric layers thus must be positioned in the fabric so as to prevent irregularities (large numbers of floats, for example) in the weave construction at the interface between the single and double fabric layers (as described in FIG. 2, below). Another benefit such basket weave patterns accord the user is the ability to produce more than one area of single layer fabric (i.e., another “seam” within the fabric) adjacent to the first “seam.” Such a second seam provides a manner of dissipating the pressure from or transferring the load upon each individual yarn within both seams. Such a benefit thus reduces the chances of deleterious yarn shifting during an inflation event through the utilization of strictly a woven fabric construction (i.e., not necessarily relying upon the utilization of a coating as well). The previously disclosed or utilized inflatable fabrics having both double and single fabric layer areas have not explored such a possibility in utilizing two basket-weave pattern seams. Furthermore, such a two-seam construction eliminates the need for weaving a large single fabric layer area within the target inflatable fabric. The prior art fabrics which produce “pillowed” chambers for airbag cushions (such as side curtains), have been formed through the weaving of entire areas of single fabric layers (which are not actually seams themselves). Such a procedure is time-consuming and rather difficult to perform. The inventive inflatable fabric merely requires, within this alternative embodiment, at least two very narrow single fabric layer areas (seams) woven into the fabric structure (another preferred embodiment utilizes merely one seam of single layer fabric); the remainder of the fabric located within these two areas may be double layer if desired. Thus, the inventive fabric permits an improved, cost-effective, method of making a “pillowed” inflatable fabric.
The inflatable fabric itself, as noted above, is preferably produced from all-synthetic fibers, such as polyesters and polyamides, although natural fibers may also be utilized in certain circumstances. Preferably, the fabric is constructed of nylon-6,6, however, polyesters are also highly preferred. Mixtures of such fibers are also possible. The individual yarns utilized within the fabric substrate must generally possess deniers within the range of from about 40 to about 840; preferably from about 100 to about 630. Most preferably, such deniers average over the entire airbag fabric structure at most 525; more preferably average at most 420; and also preferably average 315 and even as low as 210, if desired. In such instances of such low average deniers (420 and below), the thickness of the fabric structure itself is quite low and thus, with the inventive coating applied at low add-on levels, exhibits excellent low packing volumes.
As noted above, coatings should be applied to the surface as a necessary supplement to reduce the air permeability of the inventive fabric. Since one preferred ultimate use of this inventive fabric is as a side curtain airbag which must maintain a very low degree of air permeability throughout a collision event (such as a rollover where the curtain must protect passengers for an appreciable amount of time), a decrease in permitted air permeability is highly desirable. With such a specific weaving pattern within the inventive inflatable fabric, lower amounts of coatings are permissible (as compared to other standard additions of such materials) to provide desired low inflation gas permeability. Any standard coating or laminate film, such as a silicone, polyurethane, polyamide, polyester, rubber (such as neoprene, for example), and the like, as discussed above, may be utilized for this purpose and may be applied in any standard method and in any standard amount on the fabric surface. However, the necessary amount of such a coating (or layers of coatings or laminate film or layer of laminate films) required to provide the desired low permeability is extremely low and is discussed in greater depth above. Again, the particular weave structures of the inventive inflatable fabric permits the utilization of such low coating amounts to provide the desired low permeability characterstics.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice for the invention. It is to be understood that both the foregoing general description and the following detailed description of preferred embodiments are exemplary and explanatory only, and are not to be viewed as in any way restricting the scope of the invention as set forth in the claims.
With such an improvement in one-piece side curtain airbags (and inflatable fabrics), the possibility of high leakage at seams is substantially reduced. These airbags provide balanced weave constructions at and around attachment points between two layers of fabrics such that the ability of the yarns to become displaced upon inflation at high pressures is reduced as compared with the standard one-piece woven airbags. Unfortunately, such inventive one-piece woven bags are still problematic in that the weave intersections may be displaced upon high pressure inflation such that leakage will still most likely occur at too high a rate for proper functioning. As a result, there is still a need to coat such one-piece woven structures with materials which reduce and/or eliminate such an effect. However, such one-piece woven structures permit extremely low add-on amounts of elastomeric coatings for low permeability effects. In fact, these inventive airbags function extremely well with low add-on coatings below 1.5 and as low as about 0.8 ounces per square yard.
Furthermore, although it is not preferred in this invention, it has been found that the inventive coating composition provides similar low permeability benefits to standard one-piece woven airbags, particularly with the inventive low add-on amounts of high tensile strength, high elongation, non-silicone coatings; however, the amount of coating required to permit high leak-down times is much higher than for the aforementioned Sollars, Jr. inventive one-piece woven structure. Thus, add-on amounts of as much as 1.5 and even up to about 2.2 ounces per square yard may be necessary to effectuate the proper low level of air permeability for these other one-piece woven airbags. Even with such higher add-on coatings, the inventive coatings themselves clearly provide a marked improvement over the standard, commercial, prior art silicone, etc., coatings (which must be present in amounts of at least 3.0 ounces per square yard).
Additionally, it has also been found that the inventive coating compositions, at the inventive add-on amounts, etc., provide the same types of benefits with the aforementioned sewn, stitched, etc., side curtain airbags. Although such structures are highly undesirable due to the high potential for leakage at these attachment seams, it has been found that the inventive coating provides a substantial reduction in permeability (to acceptable leak-down time levels, in fact) with correlative lower add-on amounts than with standard siliconeand neoprene rubber coating formulations. Such add-on amounts will approach the 3.0 ounces per square yard, but lower amounts have proven effective (1.5 ounces per square yard, for example) depending on the utilization of a sufficiently high tensile strength and sufficiently stretchable elastomeric component within the coating composition directly in contact with the target fabric surface. Again, with the ability to reduce the amount of coating materials (which are generally always quite expensive), while simultaneously providing a substantial reduction in permeability to the target airbag structure, as well as high resistance to humidity and extremely effective aging stability, the inventive coating composition, and the inventive coated airbag itself is clearly a vast improvement over the prior airbag coating art.
Of particular importance within this invention, is the ability to pack the coated airbag cushions within storage containers at the roof line of a target automobile in as small a volume as possible, such as within cylindrically or polygonally shaped modules. In a rolled, accordion-style, Z-folded (or any other) configuration (in order to best fit within the storage module itself, and thus in order to best inflate upon a collision event downward to accord the passengers sufficient protection), the inventive airbag may be constricted to a stored shape of as low volume as possible. It has been found that the best, though not the only, test of determining the effective low volume exhibited by a non-inflated side curtain airbag is to roll any bag lengthwise until it is substantially cylindrical in shape. In such a shape, it is preferable that the target side curtain airbag have a diameter of at most 23 millimeters. The term “diameter” is intended to encompass any cross-section of the inflatable fabric in its rolled storage configuration such that the length of the stored fabric is the same as the length of the inflated fabric, and measuring the greatest distance between opposite points on such a cross-sectional area. It should and would be well understood by one of ordinary skill in this particular art that the actual side curtain measured does not have to be stored in such a specific rolled manner in practice, only that, in order to assess the rolled packing volume in terms of diameter compared with depth, the target side curtain should be first laid flat and then rolled into a substantially cylindrical shape with the subsequent measurement of diameter then taken.
Thus, in one non-limiting example, a 2 meter long cylindrical roofline storage container, the necessary volume of such a container would equal about 830 cm 3 .(with the volume calculated as 2[Pi]radius 2 ) Standard rolled packing diameters are at least 25 millimeters for commercially available side curtain airbag cushions (due to the thickness of the required coating to provide low permeability characteristics). Thus, the required cylindrical container volume would be at least 980 cm 3 . Preferably, the rolled diameter of the inventive airbag cushion during storage is at most 20 millimeters (giving a packed volume of about 628 cm 3 ) (and up to 23 millimeters and as low as possible, for example, about 16 millimeters) which is clearly well below the standard packing volume. Of course, the ability to provide very low packing volumes in directly related to the thickness of coating applied to the airbag itself, as well as, possibly, the denier fibers utilized to produce the bag itself. The lower the denier, the thinner the bag construction, and thus, the potential for lower packing volumes. In relation, then, to the depth of the airbag cushion upon inflation (i.e., the length the airbag extends from the roofline down to its lowest point along the side of the target automobile, such as at the windows), a packing volume equal to the quotient of the particular bag's packed diameter (again in its rolled state although any other packing configuration, such as “accordion-style,” “Z-fold”, and the like, may be utilized as well as rolling in actual practice) divided by inventive airbag cushion's depth (which is often, though not required to be measured, at approximately 17 inches or 431.8 millimeters) should be at most 0.05. Preferably this factor should be at most 0.486 (21 millimeter diameter), more preferably at most about 0.0463 (20 millimeters) or 0.044 (19 mm), or 0.0417 (18 mm), or 0.0394 (17 millimeters). Most preferably, the denier fibers utilized are about 420 on average and thus with a coating add-on amount of about 0.8 ounces/square yard provides a packing diameter of about 18 millimeters (and thus a packing volume factor of about 0.0417).
The prior art, having extremely thick coatings with relatively high denier fibers (420 and higher) provides, at best, a packing diameter of about 24 millimeters which thus provides (with a coating in excess of 4.0 ounces per square yard, generally) a packing volume factor of about 0.0556, well above the 0.05 limit taught above. As discussed above, with lower average denier fibers utilized within the subject side curtain airbag, the packing volume may be reduced. Such as within the scope of this invention as the primary, though not only, aim of reducing such packing volume is to provide an highly effective (i.e., very low permeability), low add-on coating to the target side curtain airbag. Of course, the aforementioned range of factors does not require the airbag depth to be at a standard of 17 inches, and is primarily a function of coating thickness, and thus add-on weight, as well as yarn denier. As should be evident, however, longer (deeper) bags would require greater diameters in packing within a cylindrical storage capsule.
Surprisingly, it has been discovered that any elastomer with a tensile strength of at least 2,000 psi and an elongation at break of at least 180% coated onto and over both sides of a side curtain airbag fabric surface at a weight of at most 3.0 ounces per square yard, and preferably between 0.8 and 2.0, more preferably from 0.8 to about 1.5, still more preferably from 0.8 to about 1.2, and most preferably about 0.8 ounces per square yard, provides a coated airbag cushion which passes both the long-term blocking test and long-term oven aging test with very low, and extended permeability upon and after inflation. This unexpectedly beneficial type and amount of coating thus provides an airbag cushion which will easily inflate after prolonged storage and will remain inflated for a sufficient amount of time to ensure an optimum level of safety within a restraint system. Furthermore, it goes without saying that the less coating composition required, the less expensive the final product. Additionally, the less coating composition required will translate into a decrease in the packaging volume of the airbag fabric within an airbag device. This benefit thus improves the packability for the airbag fabric.
While the invention will be described and disclosed in connection with certain preferred embodiments and practices, it is in no way intended to limit the invention to those specific embodiments, rather it is intended to cover equivalent structures structural equivalents and all alternative embodiments and modifications as may be defined by the scope of the appended claims and equivalence thereto.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Two potentially preferred elastomer compositions of this invention was preferably produced in accordance with the following Tables:
TABLE 1
Standard Water-Borne Elastomer Composition
Component
Parts (per entire composition)
Resin (30-40% solids content in water)
100
Natrosol ® 250 HHXR (thickener)
10
Irganox ® 1010 (stabilizer)
0.5
DE-83 R (flame retardant)
10
TABLE 2
Standard Solvent-Borne Elastomer Composition
Component
Parts (per entire composition)
Resin (30-40% solids content in solvent)
100
Irganox ® 1010 (stabilizer)
0.5
DE-83 R (flame retardant)
10
TABLE 3
Standard Solvent-Borne Elastomer Composition
Component
Parts (per entire composition)
Resin (25-40% solids content in solvent)
100
Irganox ® 1010 (stabilizer)
0.5
DE-83 R (flame retardant)
10
Desmodur CB-75 (adhesion promoter)
2
(The particular resins are listed below in Table 4 and thus are merely added within this standard composition in the amount listed to form preferred embodiments of the inventive coating formulation).
The compounded compositions exhibited viscosities measured to be about 15,000 centipoise by a Brookfield viscometer. Once compounding was complete, the individual formulations were applied to separate articles being both sides of one-piece Jacquard woven airbags (having 420 denier nylon 6,6 yarns therein) as discussed within the Sollars, Jr. application noted above. Such applications were performed through a fixed gap coating procedure. The bag was then dried at an elevated temperature (about 300° F. for about 3 minutes) and thus form to form the necessarily thin coatings. As noted above, scrape coating may also be followed to provide the desired film coating; however, fixed gap coating provides the desired film thickness uniformity on the bag surface and thus is preferred. Scrape coating, in this sense, includes, and is not limited to, knife coating, in particular knife-over-gap table, floating knife, and knife-over-foam pad methods. The final dry weight of the coating is preferably from about 0.6-3.0 ounces per square yard or less and most preferably 0.8-1.5 ounces per square yard or less. The resultant airbag cushion is substantially impermeable to air when measured according to ASTM Test D737, “Air Permeability of Textile Fabrics,” standards.
In order to further describe the present invention the following non-limiting examples are set forth. These examples are provided for the sole purpose of illustrating some preferred embodiments of the invention and are not to be construed as limiting the scope of the invention in any manner. These examples involve the incorporation of the below-noted preferred elastomers within the coating formulations of TABLES 1-3, above.
Each coated bag was first subjected to quick inflation to a peak pressure of 30 Psi. Air leakage (SCFH) of the inflated bag was then measured at 10 Psi pressure. The characteristic leak-down time t(sec) was calculated based on the leakage rate and bag volume.
TABLE 4
Tensile
Elonga-
T (sec).
T (sec.)
Coating add-
Example Number/
Strength
tion at
Before
Post-
on weight
Elastomer
(Psi)
break (%)
aging
aging*
(oz/yd2)
1. Impranil ® 85
6000
400
18.1
16.3
0.8
UD
2. Ex 51-550
3100
320
110.2
105
0.8
3. Impranil ®
7200
300
120.2
125
0.9
ELH
4. Ru ® 41-710
7000
600
27.3
26.4
0.8
5. Ru ® 40-350
7000
500
34.4
36.2
0.8
6. Bayhydrol ®
6000
300
8.6
5.7
0.8
123
7. Dow Corning
700
90
<2
<2
2.1
3625**
8. Silastic 94-
1400
580
<2
<2
1.8
595-HC**
9. Ru ® 40-415
5000
180
<2
<2
0.8
10. Sancure ®
3000
580
25.2
<2
0.8
861
11. Witcobond ®
6000
600
28.4
<2
0.8
290H
*Aging conditions: 107° C. oven aging for 16 days, followed by 83° C. and 95% relative humidity aging for 16 days.
**The resins are silicone rubbers.
As noted above, Examples 1-6 work extremely well and are thus within the scope of this invention. Examples 10 and 11 show some limitations, polyester based elastomers (Witcobond® 290H) exhibit excellent heat aging (oxidation) stability but tend to hydrolyze easily at high humidity; polyether based elastomers (Sancure® 861) have excellent hydrolysis resistance, but poor oxidation performance. However, these elastomers have proven to be acceptable permeability reducers at higher add-on weights below the maximum of 3.0 ounces per square yard. Furthermore, although silicones show excellent resistance to heat aging and hydrolysis (humidity aging), they, however, possess limited tensile strength and tear resistance resistance. Natural rubber, SBR, chloroprene rubbers and others containing unsaturated carbon double bonds have excellent hydrolysis resistance. But the unsaturated carbon double bond that gives their elasticity oxidizes readily and the properties of the rubber change after heat aging. Elastomers that have good physical properties and excellent resistance to hydrolysis and oxidation are preferred for this application. Polyurethanes based on polycarbonate soft segments are the preferred materials for this application.
The airbag of Example 3 exhibited a sliding coefficient of friction constant of roughly 0.6. A comparative thick silicone-coated side curtain airbag which included a non-woven layer, exhibited a constant of about 0.8.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of an inventive all-woven inflatable fabric showing the preferred double and single layer areas including two separate single layer areas.
FIG. 2 is a weave diagram illustrating a potentially preferred repeating pick pattern formed using repeating plain weave and basket weave four-pick arrangements.
FIG. 3 depicts the side, inside view of a vehicle prior to deployment of the inventive side curtain airbag.
FIG. 4 depicts the side, inside view of a vehicle after deployment of the inventive side curtain airbag.
FIG. 5 depicts a side view of a side curtain airbag.
FIG. 6 provides a side view of a side curtain airbag container.
FIG. 7 provides a cross-sectional perspective of the stored airbag within the container of FIG. 6 .
DETAILED DESCRIPTION OF THE DRAWINGS
Turning now to the drawings, in FIG. 1 there is shown a cross-section of a preferred structure for the double fabric layers 12 , 14 , 18 , 20 , 24 , 26 and single fabric layers 16 , 22 of the inventive inflatable fabric 10 . Weft yarns 28 (exhibiting preferably deniers of about 420 each) are present in each of these fabric layer areas 12 , 14 , 16 , 18 , 20 , 22 , 24 , 26 over and under which individual warp yarns 38 , 40 , 42 , 44 (also exhibiting deniers preferably of about 420) have been woven. The double fabric layers 12 , 14 , 18 , 20 , 24 , 26 are woven in plain weave patterns. The single fabric layers 16 , 22 are woven in basket weave patterns. Four weft yarns each are configured through each repeating basket weave pattern within this preferred structure; however, anywhere from two to twelve weft yarns may be utilized within these single fabric layer areas (seams) 16 , 22 . The intermediate double fabric layer areas 18 , 20 comprise each only four weft yarns 28 within plain weave patterns. The number of such intermediate weft yarns 28 between the single fabric layer areas 16 , 22 must be in multiples of two to provide the maximum pressure bearing benefits within the two seams 16 , 22 and thus the lowest possibility of yarn shifting during inflation at the interfaces of the seams 16 , 22 with the double fabric layer areas 12 , 14 , 24 , 26 .
FIG. 2 shows the weave diagram 30 for an inventive fabric which comprises two irregularly shapes concentric circles as the seams. Such a diagram also provides a general explanation as to the necessary selection criteria of placement of basket-weave patterns within the fabric itself. Three different types of patterns are noted on the diagram by different shades. The first 32 indicates the repeated plain weave pattern throughout the double fabric layers ( 12 , 14 , 18 , 20 , 24 , 26 of FIG. 1, for example) which must always initiate at a location in the warp direction of 4X +1, with X representing the number of pick arrangement within the diagram, and at a location in the fill direction of 4X+1 (thus, the pick arrangement including the specific two-layer plain-weave-signifying-block 32 begins at the block four spaces below it in both directions). The second 34 indicates an “up-down” basket weave pattern wherein an empty block must exist and always initiate the basket-weave pattern at a location in the warp direction of 4X+1, with X representing the number of repeating pick arrangements within the diagram, and at a location in the fill direction of 4X+1, when a seam (such as 16 and 22 in FIG. 1) is desired (thus, the pattern including the pertinent signifying “up-down” block 34 includes an empty block within the basket-weave pick arrangement in both the warp and fill directions four spaces below it). The remaining pattern, which is basically a “down-up” basket weave pattern to a single fabric layer (such as 16 and 22 in FIG. 1) is indicated by a specifically shaded block 36 . Such a pattern must always initiate at a location in the warp direction of 4X+1 and fill of 4X+3, or warp of 4X+3 and fill of 4X+1, when a seam is desired. Such a specific arrangement of differing “up-down” basket weave 34 and “down-up” basket weave 36 pattern is necessary to effectuate the continuous and repeated weave construction wherein no more than three floats (i.e., empty blocks) are present simultaneously within the target fabric structure. Furthermore, again, it is believed that there has been no such disclosure or exploration of such a concept within the inflatable fabric art.
As depicted in FIG. 3, an interior of a vehicle 110 prior to inflation of a side curtain airbag (not illustrated) is shown. The vehicle 110 includes a front seat 112 and a back seat 114 , a front side window 116 and a back-side window 118 , a roofline 120 , within which is stored a cylindrically shaped container 122 comprising the inventive side curtain airbag (not illustrated). Also present within the roofline 120 is an inflator assembly 124 which ignites and forces gas into the side curtain airbag ( 126 of FIG. 4) upon a collision event.
FIG. 4 shows the inflated side curtain airbag 126 . As noted above, the airbag 126 is coated with at most 2.5 ounces per square of a coating formulation (not illustrated), preferably polyurethane polycarbonate. The inventive airbag 126 will remain sufficiently inflated for at least 5 seconds, and preferably more, as high as at least 20 seconds, most preferably.
FIG. 5 shows the side curtain airbag 126 prior to storage in its uninflated state within the roofline cylindrically shaped container 122 . The thickness of the airbag 126 , measured as the packing diameter (as in FIG. 7, below) as compared with the depth of the airbag measured from the roofline cylindrically shaped container 122 to the bottom most point 128 of the airbag 126 either in its uninflated or inflated state at most 0.05. Larger factors are possible with higher add-on coating weights and larger yarns. Smaller yarns may be utilized with lower or larger add-on coating weights as well which meet this limitation as well.
FIGS. 6 and 7 aid in understanding this concept through the viewing of the rolled airbag 126 as stored within the container 122 along line 2 . The diameter measurement of the airbag 126 of Example 3, above, is roughly 20 millimeters. The standard depth of side curtain airbags is roughly 17 inches, or about 431.8 millimeters. Thus, the preferred packing volume factor is about 0.046 (20 mm/431.8 mm). A comparative silicone-based thick coating add-on weight of about 4.0 ounces per square yard provided a diameter of about 25 millimeters for a factor of about 0.0579 (25 mm/431.8 mm).
There are, of course, many alternative embodiments and modifications of the present invention which are intended to be included within the spirit and scope of the following claims. In particular, it is to be understood that any side curtain airbag of any production method and structure which exhibits low permeability measurements with very low coating add-on amounts, and specifically meets the packing volume (be it as a rolled fabric, or packed accordion-style, or other packed configuration) limitations noted above is within the scope of this invention.
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Coated inflatable fabrics, more particularly airbags to which very low add-on amounts of coating have been applied, are provided which exhibit extremely low air permeabilities. The inventive fabrics are primarily for use in automotive restraint cushions which require low permeability characteristics (such as side curtain airbags). Traditionally, heavy, and thus expensive, coatings of compounds such as neoprene, silicones and the like, have been utilized to provide such required low permeability. The inventive fabric utilizes an inexpensive, very thin coating to provide such necessary low permeability levels. Thus, the inventive coated airbag possesses a coating of at most 3.0 ounces per square yard, most preferably about 0.8 ounces per square yard, and exhibits a leak-down time (a measurement of the time required for the entire amount of gas introduced within the airbag at peak pressure during inflation to escape the airbag at 10 psi) of at least 5 seconds as well as very low packing volumes (for more efficient use of storage space within a vehicle). All coatings, in particular elastomeric, preferably, though not necessarily, non-silicon coatings, and coated airbags meeting these criteria are intended to reside within the scope of this invention.
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TECHNICAL FIELD
[0001] This invention relates to a technique for recommending content for viewing at night.
BACKGROUND ART
[0002] Today, users can acquire content from a variety of sources, including on-line content providers such as Technicolor's M-GO content delivery service. In connection with providing users with content, many on-line content providers also provide personalized content recommendations usually by taking into account the user's past viewing history. Often, content providers make recommendations based on what content will engage a user the most. For present purposes, the phrase “engage a user” relates to the level of interest of a user in a particular piece of content. The phrase “excite a user,” as used hereinafter, relates to a degree to which a particular piece of content stimulates or arouses the user (thus increasing the user's physiological response measurable by an increase in blood pressure or galvanic skin response). In some instances, the content that will most engage will most excite the user. However, viewing exciting content prior to bed time can disturb a viewer's sleep cycle because exciting videos often have bright, vivid in colors and/or dynamic audio which can adversely affect the viewer's senses, and thus affect sleep. Moreover, exciting content even without vivid colors and/or dynamic audio can leave the viewer agitated after viewing which can also adversely affect sleep patterns. For this reason, many users avoid watching exciting video content at night.
[0003] There currently exist software programs that filter content to alter visual attributes of the content, such as color, screen brightness and contrast, among others. Reducing the visual impact of the content makes the content more suitable for night-time viewing. For example, research has shown that content rich in the blue part of the visual spectrum tends to keep the human brain active, thus adversely affecting sleep patterns. However, altering the display attributes affects the quality of the video content perceived by the user. Moreover, altering the visual attributes of the content will not necessarily make the content less dramatic in terms of stimulating the user so as to adversely affect sleep patterns,
[0004] Thus, a need exists for a content recommendation technique that takes into account the ease of night time viewing and impact on the user's sleep.
BRIEF SUMMARY OF THE INVENTION
[0005] Briefly, in accordance with an illustrative embodiment of the present principles, a method for recommending content from among a collection of available content commences by determining for each of available content at least one of a first, second and third content ratings related to (1) content characteristics that interfere with sleep patterns; (2) excitement level of the content; and (3) dynamic range of content audio, respectively. Thereafter, which of the available content having a highest content rating value for the at least one of the at least one of a first, second and third content ratings that least interfere with sleep patterns is established. The available content having the highest content rating is recommended.
BRIEF SUMMARY OF THE DRAWINGS
[0006] FIG. 1 depicts a block schematic diagram of a content delivery system for generating content recommendations in accordance with the present principles;
[0007] FIG. 2 depicts an exemplary content receiving device comprising part of the system of FIG. 1 and
[0008] FIG. 3 depicts in flow chart form the steps of a process for generating content recommendations in accordance with the present principles.
DETAILED DESCRIPTION
[0009] FIG. 1 depicts a block diagram of an embodiment of a system 100 for delivering content to a home or end user for practicing the content recommendation method of the present principles. The system 100 includes a content source 102 , such as a movie studio or production house or agent thereof for providing movies, television programs and/or other audio-visual content. The content source 102 can supply content in at least one of two forms. For example, the content source 102 can supply content to a broadcast affiliate manager 104 , typically, a broadcast television network, such as the American Broadcasting Company (ABC), National Broadcasting Company (NBC), Columbia Broadcasting System (CBS), etc. The broadcast affiliate manager 104 may collect and store the content, and can schedule delivery of the content over a delivery network, shown as the delivery network 106 . Delivery network 106 can include a satellite link transmission from a national center to one or more regional or local centers. The delivery network 106 can also include local content delivery using local delivery systems such as over-the-air broadcast, satellite broadcast, or cable television broadcast.
[0010] A content receiving device 108 , typically situated in a user's home, enjoys a connection to the delivery network 106 to enable a user to search and select content. The content receiving device 108 can take many forms and could exist as a set top box/digital video recorder (DVR), a gateway, a modem, etc. Further, the content receiving device 108 could act as entry point, or gateway, for a home network system (not shown) that includes additional devices configured as either client or peer devices in such a network.
[0011] The content source 102 can also supply a second form of content, hereinafter referred to as special content. Special content can include content delivered for premium viewing, pay-per-view content or content otherwise not provided to the broadcast affiliate manager 104 . For example, such special content can include movies, video games or other audio/visual content. In many cases, the special content can comprise content specifically requested by the user, in contrast to content which the broadcast affiliate manager 104 selects and schedules for delivery.
[0012] In practice, the content source 102 supplies special content to a content manager 110 , which can comprise service provider, such as an Internet website, affiliated with a content provider, broadcast service, or delivery network service. Thus, the content manager 110 can incorporate Internet content for delivery to users. In this regard, the content manager 110 typically delivers content to the user's content receiving device 108 over a separate delivery network 112 , which can include one or more high-speed broadband communications networks, including the Internet. Note that the content delivery network 112 could also serve to deliver content from the broadcast affiliate manager 104 , and by the same token, the delivery network 106 could deliver appropriately formatted content from the content manager 110 , although FIG. 1 does not specifically depict such cross links between the networks 106 and 112 . In addition, the user may also obtain content through the content receiving device 108 directly from the Internet via delivery network 112 without necessarily having the content managed by the content manager 110 .
[0013] Delivery of the special content can occur separately from the broadcast content. Thus, the special content can exist as an alternative media for selection by the user. For instance, the special content could comprise a library of movies not yet available as broadcast content. Alternatively, the special content can augment the broadcast content, thus providing alternative information, purchase and merchandising options, enhancement material, etc. In another embodiment, the special content could completely replace all or part of the broadcast content
[0014] As discussed, the content receiving device 108 can receive content from one or both of delivery networks 106 and delivery network 112 . The content receiving device 108 processes the received content based on user preferences and commands. The content receiving device 108 may also include a storage device, such as a hard drive or optical disk drive, for recording and playing back content. Further details of the operation of the content receiving device 108 and features associated with playback of stored content will become apparent in accordance the description of the content receiving device provided hereinafter in relation to FIG. 2 . The content receiving device 108 provides the content processed thereby to a display device 114 , which can comprise a conventional 2-D type display or an advanced 3-D display.
[0015] The content receiving device 108 can interface with a second screen, such as a touch screen control device 116 , which could include a laptop computer, tablet, smart phone or other device with wireless communications and information processing capabilities. Depending on its capabilities, the touch screen device 116 can display content, either the same as, or different from, the content displayed on the display device 114 . For example, the touch screen control device 116 could execute a second screen application that would enable the user to control the content receiving device 108 and/or the display device 114 . Another second screen application executed by the touch screen display device 116 could enable the user to interact with the content. The touch screen control device 116 can interface with receiving device 108 using any well-known wireless transmission protocols, such as infra-red (IR) or radio frequency (RF) communications and could employ such standard protocols such as the infra-red data association (IRDA) standard, Wi-Fi, Bluetooth and the like, or any proprietary protocol.
[0016] Still referring to FIG. 1 , the system 100 also includes a back end server 118 and a usage database 120 . The back end server 118 includes a personalization engine that analyzes content usage information from a user and makes content recommendations based on such information in accordance with the present principles as described in greater detail below. The usage database 120 stores the content usage information. In some cases, the usage database 120 could comprise part of the back end server 118 . In the illustrated embodiment, the back end server 118 enjoys a connection to the delivery network 112 .
[0017] FIG. 2 depicts a block diagram of an exemplary embodiment of the content receiving device 108 of FIG. 1 . The content receiving device of FIG. 2 can comprise part of a gateway device, modem, set-top box, or other similar communications device (not shown). The content receiving device 108 could also comprise part of another system including an audio device or a display device. In either case, the block diagram of FIG. 2 has omitted some elements, such as a power supply, that support the operation of the content receiving device 108 in the interest of conciseness, as such elements well known to those skilled in the art.
[0018] The content receiving device 108 of FIG. 2 includes an input signal receiver 202 that receives content from either of the networks 106 and 112 of FIG. 1 . The input signal receiver 202 can take the form of one of several known receiver circuits for receiving, demodulating and decoding signals having various network protocols. Typically, a user controls the input signal receiver 202 via a remote control (not shown) or other device such as the touch screen control device 116 or FIG. 1 , which interfaces with the content receiving device 108 via a touch panel interface 222 .
[0019] The input signal receiver 202 supplies a demodulated and decoded signal to an input stream processor 204 , which performs the final input signal selection and processing, including separation of video from audio. The input stream processor 204 supplies the audio to an audio processor 206 for conversion from the received format (e.g., a compressed digital signal), to an analog signal. The audio processor 206 transmits the analog audio to an audio interface 208 for subsequent transmission to the display device 114 of FIG. 1 and/or a separate audio reproduction system or other device (not shown). Alternatively, the audio processor 206 could supply digital audio to the audio interface 208 for output to the display device 114 or other system or device using a High-Definition Multimedia Interface (HDMI) cable or alternate audio interface such as via a Sony/Philips Digital Interconnect Format (SPDIF). The audio interface 208 may also include amplifiers for driving one more sets of speakers (not shown). The audio processor 206 will performs any necessary conversion for the storage of the audio.
[0020] The input stream processor supplies the video to a video processor 210 . The video can have one of several well-known several formats and the video processor 210 undertakes the necessary conversion of the video for storage and for output to a display interface 218 that connects to the display device 114 of FIG. 1 . The display interface 218 can comprise an analog signal interface such as red-green-blue (RGB) or a digital interface such as HDMI.
[0021] The content receiving device 108 of FIG. 2 includes a storage device 212 for storing audio and video from the audio processor 206 and the video processor 210 , respectively. The storage device 212 records and plays back under the control of a controller 214 , based on user entered commands, e.g., record, play, fast-forward (FF) and rewind (REW), received from the user via the user interface 216 and/or the touch panel interface 222 . The storage device 212 can comprise a hard disk drive, one or more large capacity integrated electronic memories, such as static RAM (SRAM), or dynamic RAM (DRAM), or an interchangeable optical disk storage system such as a compact disk (CD) drive or digital video disk (DVD) drive. The storage device supplies recorded audio and to the audio interface 204 and the display interface 218 , respectively, for consumption by the user.
[0022] The controller 214 enjoys connections to the various other elements in the content receiving device 108 , including the input stream processor 202 , the audio processor 206 , the video processor 210 , the storage device 212 , and the user interface 216 . The controller 214 manages the conversion process for converting the input stream signal into audio and video signal for storage on the storage device 212 or for display on the display device 114 of FIG. 1 . The controller 214 also manages the retrieval and playback of stored content.
[0023] The controller 214 has a connection to a control memory 220 (e.g., volatile or non-volatile memory, including RAM, SRAM, DRAM, ROM, programmable ROM (PROM), flash memory, electronically programmable ROM (EPROM), electronically erasable programmable ROM (EEPROM), etc.) for storing information and instruction code for controller 214 . The Control memory 220 can also store a set of elements, such as graphic elements, containing content. Alternatively, the control memory 220 can store the graphic elements in identified or grouped memory locations and use an access or location table to identify the memory locations for the various portions of information related to the graphic elements. Further, the implementation of the control memory 220 can include several possible embodiments, such as a single memory device or, alternatively, more than one memory circuit communicatively connected or coupled together to form a shared or common memory. Still further, the memory may be included with other circuitry, such as portions of bus communications circuitry, in a larger circuit.
[0024] FIG. 3 depicts the steps of a method 300 for recommending content suitable for night-time viewing. The content recommendation method 300 of the present principles takes account of at least one or more of the following factors that influence content suitability for night-time viewing:
[0025] 1. Visual characteristics that interfere with sleep patterns, such as color, brightness, and contrast for example;
[0026] 2. The excitement level of the content (e.g., the content includes dramatic visual scenes, for example, car chases, fighting, gun fire, and the like); and
[0027] 3. The dynamic range of the audio (e.g., loudness, pitch and frequency, for example.)
[0028] To enable the content method 300 of the present principles to take into account the above-listed factors, the content provided by the content source 102 typically will have a first, second, and third content rating associated therewith. The first content rating reflects the degree to which characteristics of the content, and especially visual attributes of the content, such as color, brightness, and contrast, interfere with human sleep. Content that has characteristics, and especially visual attributes that interfere with sleep, such as a color palette having in the blue spectrum will have a relatively low content rating. Thus, for example, assume a first content rating on a scale of 1-10, with content having a first content rating of “1” most interfering with human sleep, and “10” for content that least interferes with sleep. Thus, content having a color palette heavy in the blue spectrum typically would have a first content rating of, for example say 1-2, whereas content with little if any blue might have a first content rating of 7-8. Establishing a first content rating for other visual attributes that influence sleep, such as brightness and contrast could occur by determining what percentage of the content had contrast and/or brightness or other such visual factors above a threshold level, for example 75-80% of a total available level. Other techniques could serve to establish a first content rating for the content.
[0029] Typically, the content will also have a second rating based on its excitement level. Determining the excitement level could occur by determining what percentage of the content has scenes that depict action (e.g., car chases, gun fights, physical altercations, and the like). Thus, content having a high level of excitement would have a low second content rating. Conversely, content having a low level of excitement would have a high second content rating. Like the first content rating, in one embodiment of the present principles the second content rating could also employ a 1-10 scale.
[0030] In addition, the content typically will have a third content rating based on the dynamic audio in the content. The dynamic audio in the content can be measured in several different ways. For example, one measure of dynamic audio would be the frequency (how often) the audio changes from a first threshold, for example 50-60 dB to levels in excess of a second threshold, for example 85-90 dB. Another measure would be the percentage of the content that has audio in excess of a set threshold (e.g., 85-90 dB). Other audio attributes of the content such as pitch and frequency would also affect the second content rating.
[0031] Typically, the content producer will assign first, second and third content ratings to the content. The personalization engine 118 of FIG. 1 can then assess the first, second and third content ratings of content in the content source 102 to recommend content, which has the highest of all three ratings. Basing the recommendation on the content with the highest of all three ratings reduces the likelihood of recommending content which may have one or even two high content ratings, but a very low rating for the other category and thus still interfere with the user's sleep.
[0032] In some instances, the content producer might supply content with only two or only one content ratings. Thus, the personalization engine 118 will have to make a recommendation on that content rating alone. Alternatively, the personalization engine 118 could screen the content having such missing content ratings (or even no content ratings at all) to assign the content ratings itself and then make the content recommendation based on such assigned content ratings. In alternate embodiments of the present principles the receiving device can include a personalization engine of the present principles, such as the personalization engine 118 of FIG. 1 , for making content recommendations and even assigning content ratings as described above.
[0033] The foregoing describes a technique for recommending content for viewing at night.
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A method for recommending content from among a collection of available content includes determining for each of available content at least one of a first, second and third content ratings related to (1) content characteristics that interfere with sleep patterns; (2) excitement level of the content; and (3) dynamic range of content audio, respectively. Thereafter, the content having a content rating that least interfere with sleep patterns is established. The available content having the content rating that least interferes with sleep patterns is recommended.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This utility patent application claims benefit of priority to U.S. provisional patent application 60/711,481, filed Aug. 25, 2005, which is hereby incorporated by reference in its entirety.
STATEMENT OF GOVERNMENTAL SUPPORT
[0002] This invention was made during work supported by U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The government has certain rights in this invention.
REFERENCE TO SEQUENCE LISTING OR COMPACT DISK
[0003] None
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The present invention generally relates to the field of nanostructure positioning and orientation on substrates, and more particularly to the field of molecular sized nanoelectromechanical systems (NEMS).
[0006] 2. Related Art
[0007] US PG PUB 20030190278 “Controlled deposition of nanotubes” discloses methods for depositing nanotubes.
[0008] Diehl et al. “Self-assembled, deterministic carbon nanotube wiring networks,” Angew. Chem. Int. Ed. 41:353 (2002) disclose a “minimal lithography” technique for chemically assembling small deterministic crossbars of SWNT ropes. Spatial positioning of the SWNTs is induced by an alternating current field.
[0009] Yamamoto et al. “Orientation and purification of carbon nanotubes using AC electrophoresis,” J. Phys. D. Appl. Phys. 31: L34-L36 (1998) discloses orientation of nanotubes in isopropyl alcohol. The authors report that other methods for orienting nanotubes exist, such as slicing of a polymer resin matrix containing nanotubes and transferring nanotubes trapped in the pores of a ceramic filter onto a polymer surface.
[0010] Rao et al. “Larger-scale assembly of carbon nanotubes,” Nature 425:36 (2003) discloses the assembly of single walled nanotubes (SWNTs) on organic molecular marks applied to a substrate by stamping or lithography. The authors created two distinct surface regions coated either with polar chemical groups or non-polar groups. The SWNTs adhered to the nonolar regions.
[0011] Lay et al. “Simple Route to Large-Scale Ordered Arrays of Liquid-Deposited Carbon Nanotubes” Nano Letters 4(4):603-606 (2004) discloses ordered arrays of carbon nanotubes deposited at room temperature from aqueous suspensions onto silanized SiO 2 surfaces.
[0012] Cumings et al. US 2002/0070426 A1 disclose a method for forming a telescoped multiwall carbon nanotube (“MWCNT”). Such a telescoped multiwall nanotube is shown in this publication to act as a linear bearing in an electromechanical system. That is, the walls of a multiwalled carbon nanotube are concentrically separated and are shown to telescope axially inwardly and outwardly. In Science 289:602-604 (28 Jul. 2000), a scientific publication related to the 2002/0070426 A1 patent publication, Cumings and Zettl describe a low friction nanoscale linear bearing, which operates in a reciprocal (i.e. telescoping) manner.
[0013] Den et al. U.S. Pat. No. 6,628,053 discloses a carbon nanotube device comprising a support having a conductive surface and a carbon nanotube, wherein one terminus of the nanotube binds to the conductive surface so that conduction between the surface and the carbon nanotube is maintained. The device is used as an electron generator.
[0014] Falvo et al. Nature 397:236-238 (Jan. 21, 1997) disclose studies involving the rolling of carbon nanotubes using atomic force microscope (AFM) manipulation of multiwall carbon nanotubes (MWCNT, termed in the paper “CNT”). No bearing properties are disclosed.
[0015] Minett et al. Current Applied Physics 2:61-64 (2002) disclose the use of carbon nanotubes as actuators in which the driving force is obtained from a deformation of the nanotube when a charge is applied. The authors, in their review, also disclose the preparation of a suspended carbon nanotube across two metallic contacts growth of nanotubes across two metal contacts in a process that involved E-beam lithography and selective patterning.
[0016] Cumings et al. Nature 406:586 (Aug. 10, 2000) disclose techniques for peeling and sharpening multiwall nanotubes. These sharpened tubes are disclosed as having utility as biological electrodes, microscopic tips, etc.
[0017] Fraysse at al. Carbon 40:1735-1739 (2002) discloses carbon nanotubes that act like actuators. In concept, a SWNT may be disposed above a substrate and between a pair of metal-on-oxide layers. The nanotubes act as actuators though a cantilever effect achieved through longitudinal deformation of the nanotube.
[0018] Zhao et al. “Nanowire Made of a Long Linear Carbon Chain Inserted Inside a Multiwalled Carbon Nanotube,” Rev. Lett. 90, 187401 (2003), discloses a one-dimensional (1D) carbon structure, carbon nanowires (CNWs), discovered in the cathode deposits prepared by hydrogen arc discharge evaporation of carbon rods.
[0019] Fennimore et al. “Rotational actuators based on carbon nanotubes,” Nature 424, 408-410 (2003), discloses rotational actuators based on carbon nanotubes deposited on a substrate.
[0020] Recent advances in nanoscale synthesis and fabrication techniques have opened the door to the manufacture of true nanoelectromechanical systems (NEMS). For example, multiwall carbon nanotubes (MWCNTs) have been utilized as key enabling elements for nanoscale electrostatically-driven torsional 1 and rotational 2 actuators, orders of magnitude smaller than their microelectromechanical (MEMS) counterparts. Due to their small size, robust design and near-perfect atomic structure, such constructs hold great promise as building blocks for complex nanoelectromechanical systems. The utility of individual actuators can be significantly increased by their incorporation into arrays of devices. Such arrays could serve in a variety of applications, including adaptive optics, high frequency mechanical filters, mass sensors, and microfluidic gates and pumps.
[0021] A fundamental challenge in the development of NEMS arrays (and of nanotube- and nanowire-based devices in general) is the large-scale controlled placement of molecular sized building blocks on a substrate. Methods based on chemical vapor deposition (CVD) avoid this problem by, for example, growing nanotubes directly on the substrate where they ultimately will be located 3 . Unfortunately, such methods are unable to produce very high quality multi-walled carbon nanotubes as are often required for NEMS applications 2, 4 . Furthermore, CVD is commonly a high temperature process, which severely limits compatibility with substrate materials or other system components. Hence, there is much interest in low temperature techniques to aid in the selective placement and alignment of prefabricated nanostructures. There has been some progress in developing fluidic techniques for aligning nanowires 5 and nanotubes 6, 7 , and various functionalization schemes have been explored for placing nanotubes on particular areas of a substrate 8-10 . Unfortunately nearly all of these methods necessitate rather complex substrate topology or involved and limiting chemistry.
BRIEF SUMMARY OF THE INVENTION
[0022] The present invention comprises methods of placing one or more nanostructures in a predetermined position on a substrate, and the arrays thereby produced. The method of placing a nanostructure in a predetermined position on a substrate comprises: a) forming a thin layer of polymer coating on a substrate; b) exposing a selected portion of the thin layer of polymer to alter a selected portion of the thin layer of polymer; c) forming a suspension of nanostructures in a solvent, wherein the solvent suspends the nanostructures and activates the nanostructures in the solvent for deposition; and d) flowing a suspension of nanostructures across the layer of polymer in a flow direction; and thereby: e) depositing a nanostructure in the suspension of nanostructures only to the selected portion of the thin layer of polymer coating on the substrate to form a deposited nanostructure oriented in the flow direction.
[0023] The thin layer of polymer coating is preferably provided by a resist composition that can be chemically altered by incident radiation. This permits lithographic patterning of the layer, which can achieve a precise, yet complex positioning of nanostructures. Further, the orientation of deposited nanostructures may be controlled by controlling the flow of the solvent suspension. The substrate can be any material which can support nanostructures. Preferably the substrate is silicon which can be etched and processed with various layers according to known semiconductor manufacturing techniques.
[0024] A suspension of nanostructures can be achieved by preparation of nanostructures that are placed into a solvent and sonicated. The liquid “solvent” is preferably an aromatic solvent having good leaving groups that can bind with the nanostructures. The binding may include, but it not limited to: van der Waals, ionic, hydrogen, electrostatic, or covalent bonding. The solvent flow operates to cause individual nanostructures to adhere with a predefined orientation (aligned by the solvent flow) to selected portions of a substrate that has a polymer coating defined by radiation. This may be done by spin coating onto the substrate. In the case of roughly symmetric nanostructures, orientation may be unimportant, so flow may not be required for deposition.
[0025] Each nanostructure that is characterized by a high geometrical aspect ratio (including, but not limited to nanowires, nanorods, MWNTs, an others) or other asymmetry such as electric or magnetic dipole moment, is substantially oriented by flow of the nanostructure suspension relative to the coating. For some nanostructures, orientational order is unimportant, however the positional placement is still readily achieved by the methods described here.
[0026] By exposing a selected portion of the polymeric layer, predetermined regions which are adherent to nanostructures are defined. This patterning may be done by a variety of processes. In a preferred process, the polymeric layer is bombarded with an e-beam sufficient to break down the polymer in the selected areas to an elemental or roughened state, referred to as “carbonized.” The layer is then removed with a solvent, leaving only a thin layer of roughened polymer.
[0027] One embodiment of the invention contemplates that the nanostructures are positioned in arrays to create higher order structures on a nanoscale. These higher order structures will involve further processing, while the nanostructures deposited by the present method have been found to remain in place. Further processing may include etching, metal deposition, or the addition of barrier or doping layers. Although not meant to be limiting, an array of nanorotors wired together is demonstrated here and included in the present invention. It is believed that the methods disclosed here may be used for other nanostructures to selectively position pluralities of nanostructures at controlled positions on a suitably coated substrate. For nanostructures having sufficiently high aspect ratios, the nanostructure suspension flow properties will align to the flow due to the shear properties. For low- to no-aspect nanostructures, a flow may not be required, as orientation may not be as important.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1A is an array of MWCNTs placed by fluidic alignment and beam-activated adhesion.
[0029] FIG. 1B shows an increased magnification image of the nanotube device marked with a black box in FIG. 1A , where the MWCNT support shaft can be just seen running vertically through the actuator paddle.
[0030] FIG. 2 . Fluidic alignment of MWCNTs by spinning the substrate. A suspension of nanotubes was pipetted onto this sample while it was spinning at 5000 RPM, with the center of rotation ˜6 mm below and to the right of the area shown. The substrate was in its pristine state before deposition; alignment marks were patterned and deposited afterwards.
[0031] FIG. 3A shows the controlled deposition of nanotubes, where the edge of an unaligned mat of MWCNTs deposited on an area activated by the electron beam. The edge of the beam-activated area runs horizontally through the center of the image.
[0032] FIG. 3B shows the controlled deposition of nanotubes, where SWCNTs are placed by fluidic alignment onto beam activated lines which were oriented parallel to the direction of fluid flow.
[0033] FIG. 3C shows the controlled deposition of nanotubes, where MWCNTs are placed by fluidic alignment perpendicular to beam-activated lines. The arrows indicate the direction of flow.
[0034] FIG. 4A is a graphic representation of arrays of the nanotubes according to the present method.
[0035] FIG. 4B is an electron microscopic view of two pixels of a proposed implementation of the array of FIG. 4A .
[0036] FIG. 5 is a schematic illustration of adhesion of tubes to different polymer lines.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Definitions
[0037] Nanostructure means a nanoelectromechanical device that comprises one or more elements having at least one characteristic minimum dimension of less than or equal to 200 nm, and may be exemplified, without limitation, by components including one or more of: a nanotube; a nanowire; a nanorod; a noncrystalline or amorphous nanostructure; a nanocrystal; a supramolecular structure (i.e., a structure comprised of multiply-conjoined molecular and atomic units); a single walled carbon nanotube; a multiwalled carbon nanotube; a stripped (extendable) multiwalled carbon nanotube; a carbon nanowire; a carbon nanosheet; a carbon nanobelt; a carbon nanotube bundle; a boron-nitride nanotube; a silicon nanotube; a silicon nanobelt; a silicon nanowire; a compositionally modulated silicon nanowire; and a silicon nanosheets. Without limitation, some nanostructures act as nanomotors, nanomechanical resonators, nanobeam deflectors, sensors, actuators, device components, etc. Nanostructures have been proposed as the basic building blocks for a new generation of electronic and mechanical systems, including memory and logic components (e.g., see T. Rueckes, K. Kim, E. Joselevich, G. Y. Tseng, C. L. Cheung, and C. M. Lieber, Science 289, 94 (2000); C. P. Collier, E. W. Wong, M. Belohradsky, F. M. Raymo, J. F. Stoddart, P. J. Kuekes, R. S. Williams, and J. R. Heath, Science 285, 391 (1999); A. Bachtold, P. Hadley, T. Nakanishi, and C. Dekker, Science 294, 1317 (2001); S. J. Tans, A. R. M. Verschueren, and C. Dekker, Nature 393, 49 (1998)); light emitting devices and photodetectors (e.g., see M. H. Huang, S. Mao, H. Feick, H. Q. Yan, Y. Y. Wu, H. Kind, E. Weber, R. Russo, and P. D. Yang, Science 292, 1897 (2001); F. Duan, Y. Huang, Y. Cui, J. F. Wang, and C. M. Lieber, Nature 409, 66 (2001); J. A. Misewich, R. Martel, P. Avouris, J. C. Tsang, S. Heinze, and J. Tersoff, Science 300, 783 (2003); J. F. Wang, M. S. Gudiksen, X. F. Duan, Y. Cui, and C. M. Lieber, Science 293, 1455 (2001)); electromechanical actuators (e.g., see A. M. Fennimore, T. D. Yuzvinsky, W. Q. Han, M. S. Fuhrer, J. Cumings, and A. Zettl, Nature 424, 408 (2003)); biological imaging technologies (e.g., see M. Bruchez, M. Moronne, P. Gin, S. Weiss, and A. P. Alivisatos, Science 281, 2013 (1998)) and drug delivery systems (e.g., see S. R. Sershen, S. L. Westcott, N. J. Halas, and J. L. West, Journal of Biomedical Materials Research 51, 293 (2000)). With their small size and high surface-to-volume ratio, nanostructured devices can be faster, cheaper, more efficient, and more sensitive than their conventional analogues.
[0038] Dimension means the length, width, or height of a three dimensional object, such as a nanostructure. A minimum dimension means the smallest of length, width, or height for a particular nanostructure.
[0039] Solvent means a liquid comprising one or more constituents that is able to dissolve or suspend a nanostructure and allow the nanostructure to be deposited on an exposed polymer coating on a substrate.
Introduction
[0040] Although not meant to be limiting in any way, the controlled position and controlled orientation deposition of carbon nanotubes is described in great detail here below. These techniques have been successfully performed in the laboratory. It is believed that such techniques may be readily applied to other nanostructures for controlled deposition onto a suitably coated and prepared substrate. For nanostructures having sufficient aspect ratios, the orientation of the nanostructures may be controlled. By sequentially depositing and neutralizing the attachment sites on the substrates (whether by covering with a neutral layer, a metal layer, or other means), it is believed that further coating, sensitizing, and flowing may result in sequential sets of deposited nanostructures having controlled locations and orientations. It would appear that successive nanostructure depositions may be made with different nanostructures, allowing the building of large numbers of nanostructures having complex, potentially three-dimensional nature, with a variety of similar or different components.
[0041] Following is described the controlled orientation and controlled location deposition of carbon nanotubes that have mirrors mounted to them. Such devices may act as switches or controlled reflectors.
I. Experimental
[0042] Described below is the fabrication of ordered arrays of nanoscale torsional actuators consisting of metal mirrors bonded to precisely oriented multiwall carbon nanotubes. The fabrication is facilitated by a new nanotube alignment method that employs localized electron beam activation of a silicon-oxide surface. The processes involved a combination of novel room-temperature methods for both aligning and selectively depositing nanotubes onto a topologically benign surface. Using these methods, which can easily be integrated into traditional semiconductor manufacturing processes, arrays of aligned torsional NEMS devices based on MWCNTs have been fabricated.
[0043] FIG. 1A shows one section of a prototype array 100 of torsional actuators that has been produced. In the array 100 are rows of actuators 110 , 120 , and 130 . An individual actuator 140 , as described below in Section II, Generalized Apparatus, and shown in FIG. 1B , consists of five main elements: a bottom anchor 141 , a top anchor 142 , a suspended MWCNT 143 spanning between the bottom anchor 141 and the top anchor 142 , a suspended rectangular metal mirror or paddle 144 , and the conducting back gate 145 buried beneath the surface. The suspended MWCNT serves both as the torsional element and the electrical connection to the gold paddle mounted at its center. The two gold anchors 146 and 147 hold the ends of the MWCNT in place respectively on bottom anchor 146 and top anchor 147 . Asymmetric electrostatic fields applied between the gold paddle and the back gate work to create an attractive force which causes the paddle to undergo an angular displacement and the MWCNT to twist. If the outer MWCNT shell is compromised, free rotational motion of the actuator becomes possible.
[0044] Actuators of the type shown in FIGS. 1A and 1B have been previously individually fabricated and characterized 1, 2, 11 . Effective torsional spring constants range from 10 −15 to 10 −12 N m, depending on the MWCNT geometry. Typical devices have moments of inertia ˜10-30 kg m, yielding resonance frequencies in the tens of MHz range (with smaller paddle sizes and shorter exposed MWCNT lengths the resonance frequencies can be extended to above 1 GHz). A key advance of the present work is the ability to produce such devices, or any desired nanostructure, in an array configuration. The array of FIG. 1A was produced by first growing very high quality MWCNTs using an arc-plasma method, purifying the nanotubes, and then selectively depositing and aligning the nanotubes on an appropriate Si-based substrate for lithographic processing and creation of the NEMS device array.
[0045] One major enabling step in the array fabrication process is MWCNT targeted deposition and alignment. In this embodiment, the alignment method exploits the surface velocity obtained by a fluid as it flows off of a spinning substrate, and is distinct from previous alignment attempts involving either dielectrophoresis 12 or deposition from a solution driven across a surface by gas 6, 7 or microfluidic flow 5 . Arc-grown MWCNTs were suspended in orthodichlorobenzene (ODCB) at a concentration of 100 mg/l by ultrasonication in a VWR Model 75D Aquasonic bath for 60 seconds at level 3. The suspension was then pipetted drop by drop onto the center of a silicon substrate mounted on a spin coater rotating at 3000 RPM. The suspension flowed radially across and off of the substrate. Once the surface is dry, the next drop is deposited. It has been found that if the next drop is deposited while the substrate is still wet, the deposition is less dense and contains a larger percentage of unaligned nanotubes.
[0046] The preferred nanotube concentration is between about 50 to 500 mg/l. Sonication is determined by the particular instrument or method used. The presently employed VWR Model 75D provides adequate dispersions/suspension at 30-120 seconds at level 3. The spin coater should generally be set to 3000 to 5000 RPM.
[0047] FIG. 2 shows the results of a typical deposition/alignment run 200 . MWCNTs are observed to align with the fluid flow direction 210 (from upper left to lower right in the figure), with longer MWCNTs (e.g. 220 ) generally more aligned than shorter segments (e.g. 230 ). Typically, 90% of MWCNTs over 1 μm in length lie within ±1° and 95% lie within ±5° of the direction of fluid flow, a significant improvement over previously reported results 6, 7 .
[0048] Although the MWCNTs of FIG. 2 are aligned, they are still randomly positioned. For many multi-component engineered NEMS structures, including arrays, pre-determined positional order is necessary. The deposition process can be further refined by locally activating the substrate to place MWCNTs in target locations. Previous targeting attempts via surface functionalization have been made using self-assembled monolayers (SAMs) with polar functional groups 8-10 . The success of these techniques is dependent upon the quality of the SAM, however, with degraded performance occurring when more (or less) than a monolayer is deposited 13 . Ideally, localized nanotube deposition should involve a surface layer which is simple to deposit and insensitive to variations in thickness.
[0049] One preferred location targeting method exploits a surface layer that is already present in standard lithographic work and does not require a single monolayer. The layer consists of the residual polymer left behind when resists used in electron beam lithography are removed by an acetone wash. In this method, poly[methylmethacrylate—methacrylic acid] (P[MMA-MAA]) in ethyl lactate (6%) was spun-coat at 3000 RPM for 30 seconds onto a silicon substrate with 1 μm of thermally grown oxide. It was then baked on a hot plate at 185° C. for 3 minutes and stripped in acetone for 5 minutes. When left untreated, the residual coating actually inhibits nanotube deposition out of ODCB, as evidenced by lower deposition rates than those seen on pristine silicon substrates.
[0050] Targeted adhesion of nanotubes by this layer is activated by exposure to the low energy electron beam of a scanning electron microscope (SEM). FIG. 3A shows 300 the edge 310 of a patterned area onto which nanotubes 320 have been randomly deposited with no alignment. The preferential deposition of nanotubes on the selected area (lower half of the figure 330 ) is easily apparent. By controlling the raster of the electron beam, it is possible to create any desired adhesion pattern on the substrate. By combining targeted adhesion and fluidic alignment, deposition of nanotubes in an ordered fashion becomes feasible. FIG. 3B shows single walled carbon nanotubes (SWCNTs) 340 that have been deposited from a solution flowing parallel to patterned lines of activated substrate, while FIG. 3C is an example of MWCNTs deposited from a solution flowing nearly perpendicular to patterned lines of activated substrate; here the trailing edge of the nanotubes adheres to the targeted region. MWCNT 350 is one example of a relatively longer MWCNT that is nearly perfectly aligned with the flow direction. If the activated regions are dots rather than lines, then a targeted array is possible, as is the case for the two-dimensional MWCNT array underlying the structures of FIG. 1A . If non-purified nanotubes are used in the alignment and targeted deposition process, carbon onions and other byproducts of the arc discharge process adhere to the beam activated areas as well.
[0051] To determine the source of selective deposition following electron beam activation, other surface coatings have been tested. Coatings of polymethylmethacrylate (PMMA) in anisole (2% PMMA) and in chlorobenzene (3.5% PMMA) produce similar results. Substrates with no polymer present (pristine wafers, or those which had been plasma cleaned or soaked for 12 hours in acetone) show no evidence of selective adhesion following beam exposure.
[0052] Polymer chains in PMMA experience several structural transitions when exposed to increasing doses of electron irradiation. At the low doses normally used in electron beam lithography, the polymer chains undergo scission, allowing for their selective removal by an appropriate developer. At higher doses, nearby chains become cross-linked. For an acceleration voltage of 15 keV, cross-linking prevails over scission at doses of ˜1500 μC/cm 2 . As the dosage is further increased, a highly cross-linked network is formed (˜10000 μC/cm 2 at 15 keV) 14 . It has been found that the minimum dose for selective nanotube adhesion is 5000 μC/cm 2 , with an optimal dose of ˜50,000 μC/cm 2 .
[0053] These doses, however, are only effective at low acceleration voltages (˜1 keV), and correspond to much higher doses at 15 kV. Due to their higher interaction cross-section, low energy electrons have a higher stopping power than high energy electrons (stopping power is the rate at which electrons transfer energy to the material they are traveling through and has been studied extensively for many materials 15 ). For carbon, the stopping power of 1 keV electrons is roughly seven times greater than that of 15 keV electrons 16 . A minimum dose of 5000 μC/cm 2 at 1 keV is therefore far in excess of the equivalent cross-linking threshold dose discussed above, which suggests modification of the PMMA beyond simple cross-linking PMMA has also been shown to graphitize when subjected to large doses of ion beam irradiation 17 . The lack of adhesion to cross-linked networks and the large effective doses being delivered are highly suggestive that the graphitization threshold has been reached. It is believed that knowledge this is the first time this effect has been demonstrated with electron beam irradiation.
[0054] Targeted deposition is selective to the solvent used in the nanotube suspension. The effect is not observed for a majority of common solvents and solutions (dichloroethane, isopropanol, acetone, ethyl lactate, and 1% sodium dodecyl sulfate in water). Of the solvents tested to date, only ODCB (and to a lesser extent, methoxybenzene) resulted in effective targeted deposition. Ultrasonication of SWCNT in ODCB has been shown to create a sonopolymer which coats the surface of the nanotubes. 18 Although this method requires less ultrasonication than was reported to cause significant coating by the sonopolymer, inspection of similarly dispersed MWCNTs by TEM has shown that while the nanotubes are still mostly pristine, there are isolated sections covered with a thin amorphous coating. It is suggested that polymerized solvent adhering to the nanotubes increases their interaction with the beam activated substrate—in effect, the nanotubes must be activated along with the substrate.
[0055] Once arrays of MWCNTs or similar structures have been deposited, further processing and device fabrication can be relatively straightforward. In the torsional actuator demonstration array, the nanotubes are first placed in an array configuration on a degenerately doped silicon wafer with 1 micron of thermally grown oxide on its top surface. The paddle and anchors are then patterned by electron beam lithography and deposited by electron beam evaporation of gold. To suspend the structures, approximately 500 nm of the silicon oxide is selectively removed with a buffered hydrofluoric acid etch. In the prototype array shown in FIG. 1A , each row of actuators is connected together to simplify the wiring arrangement and still allow for semi-independent actuation. The actuators could be made completely independent through the use of vias or a segmented back gate. Multilayer processing would also allow for higher density packing of devices.
[0056] Torsional actuator arrays operating at radio frequencies might find use in optical switching or in adaptive optics applications. With each actuator serving as a high frequency mechanical filter, such an array could also be used for parallel signal processing in telecommunications. Furthermore, by tracking the frequency shift of each actuator, an array of individually functionalized actuators could be used as mass sensors for simultaneous environmental monitoring of a variety of substances.
[0057] The ability of the invention described here to orient and preferentially place molecular structures paves the way for their integration into mass produced devices. Aside from the torsional actuator array already described, an immediate, simple application is the use of nanotubes as electrical interconnects between units of an integrated circuit (especially desirable due to their ability to carry extremely high electrical and thermal current densities). The unique physical properties of carbon nanotubes could be harnessed in other applications as well, such as high density arrays of field effect transistors, gas sensors or biosensors. Alternate geometrical configurations, including radially aligned nanotubes, crossed nanotubes, etc. could be easily fabricated using the techniques described here.
II. Generalized Method and Apparatus
A. Higher Order Structures
[0058] The present method and structure utilizes a nanotube to which has been affixed a rotor plate that can be rotatably moved about the nanotube axis in a torsional, reciprocating manner (actuator) or, alternatively, can be rotated in a 360° spinning mode (motor). The axial movement is imparted by electrostatic forces between the rotor and at least one stator. These elements are electrically conductive and therefore generate electrical forces and fields that will cause movement of the rotor through attractive or repulsive forces, either electrostatically or magnetically. Alternatively, if the rotor is made magnetic (e.g. if the rotor is made of a ferromagnetic material such as iron), it can be moved by magnetic field-generated forces. A spinning ferromagnetic material throws off a magnetic current and may be used as a generator.
[0059] The actuator/motor is essentially designed like an electric motor which has a plurality of electrically chargeable components in fixed relation to a rotating member on a nanotube axle. The overall size scale of the present actuator/motor is of the order of 300 nm. This will convey a sense of the size of the present device, wherein the diameter of the MWNT is approximately 5 to 100 nanometers and the gap between the anchor pads can be as small as 200 nm.
[0060] FIG. 4A shows that the rotor plate, when covered with metal, could serve as a mirror, with obvious relevance to ultra-high-density optical sweeping and switching devices 400 (the total actuator/motor size is just at the limit of visible light focusing). The light source could be any type of optical signal. A detailed view of two pixels 410 , 420 in such an implementation is shown in FIG. 4B .
[0061] The light source could be above the substrate or in plane. It could be used for on-chip fabrication. In this case, the light/laser beam would come in horizontally, perpendicular to the nanotube, perhaps passing just above the rotor in its relaxed, horizontal state. When the rotor is flat the beam would not be deflected, but upon application of a voltage and rotation of the rotor, the beam would be reflected up above the plane to another device or channel.
[0062] The rotor plate could also serve as a paddle for inducing and/or detecting fluid motion in microfluidics systems, as a gated catalyst in wet chemistry reactions, as a bio-mechanical element in biological systems, or as a general (potentially chemically functionalized) sensor element. In a microfluidics application, the fluid would be channeled between an actuator and an anchor, and such projections would be etched in a way so as to define fluid impermeable channels. It is also possible that the charged oscillating metallic plate could be used as a transmitter of electromagnetic radiation.
[0063] Construction of a nanorotor device is further described in US PG PUB 20050017598 “Rotational actuator or motor based on carbon nanotubes,” and Modi, A., N. Koratkar, et al. 2003, “Miniaturized gas ionization sensors using carbon nanotubes,” Nature 424 (July 10):171-174, Kong et al. “Nanotube molecular wires as chemical sensors,” Science. 2000 Jan. 28;287(5453):622-5, hereby incorporated by reference.
[0064] As shown in FIG. 3B of the '598 PGPUB, the resist was patterned using commercially available electron beam writing software, namely NPGS software (Nanometer Pattern Generating System, which may be obtained from available from Joe Nabity, Ph.D. J C Nabity Lithography Systems P.O. Box 5354 Bozeman, Mont. 59717 USA), loaded on a JEOL 6400 SEM (JEOL USA, Inc.). The JEOL-6400 with NPGS is a high-resolution, electron beam lithography system used for writing complex patterns in resists from the nanometer scale up to 5 mm. The striped regions in FIG. 3B of the PG PUB represent areas of resist where the e beam struck and disrupted the resist so that it could be removed in subsequent steps. The electron beam resist was developed in methyl isobutyl ketone:isopropyl alcohol 1:3 for one minute, causing removal of the resist. Next, chromium (10 nm), then gold (90 nm) was evaporated onto the nanotube and (incidentally) the surrounding area. The Cr layer improves adhesion of the gold that is used for electrodes and stators. Next, the resist that remained after the MIBK step ( FIG. 3C of the PG PUB), and the Au/Cr on top of it, were lifted off in acetone. The Cr/Au was subsequently annealed at 400° C. to ensure better electrical and mechanical contact between the Cr and the MWNT.
[0065] Then, as shown in FIG. 3F of the PG PUB, an HF etch was used to remove roughly 500 nm of the SiO 2 surface to provide clearance sufficient to permit the rotor plate to be rotated by 90° C. (and more). Note that the area under the rotor R is exposed to the HF from the sides through an undercutting process so that the Au/CR attached to the nanotube is free of underlying SiO 2 . That is, the tube and metal are resting on the anchors that are into and above the plane of the drawing, along the axis of the nanotube. The conducting Si substrate (typically used as the “back gate” electrode in three-terminal nanotube field-effect devices) here serves as the gate stator, i.e. below the rotor plate.
[0066] In addition to arrays of rotators, arrays of sensors can be fabricated. SWNT chemical gas sensors are described in Collins et al. “Extreme oxygen sensitivity of electronic properties of carbon nanotubes,” Science 287:1801-1804 (2000), hereby incorporated by reference for purposes of describing nanotubes configurable as gas sensors.
B. Nanotubes
[0067] The preferred nanotube, particularly in connection with the higher order configuration including a rotatable element is a multiwalled carbon nanotube (MWNT). MWNTs were synthesized by the standard arc technique as described in Ebbesen et al. U.S. Pat. No. 5,641,466 issued Jun. 24, 1997, hereby incorporated by reference to describe a method for large-scale synthesis of carbon nanotube. These nanotubes have a near perfect carbon tubule structure that resembles a sheet of sp2 bonded carbon atoms rolled into a seamless tube. They are generally produced by one of three techniques, namely electric arc discharge, laser ablation and chemical vapor deposition. The arc discharge technique involves the generation of an electric arc between two graphite electrodes, one of which is usually filled with a catalyst metal powder (e.g. iron, nickel, cobalt), in a Helium atmosphere. The laser ablation method uses a laser to evaporate a graphite target which is usually filled with a catalyst metal powder too. The arc discharge and laser ablation techniques tend to produce an ensemble of carbonaceous material which contain nanotubes (30-70%), amorphous carbon and carbon particles (usually closed-caged ones). The nanotubes must then be extracted by some form of purification process before being manipulated into place for specific applications. The chemical vapor deposition process utilizes nanoparticles of metal catalyst to react with a hydrocarbon gas at temperatures of 500-900° C. A variant of this is plasma enhanced chemical vapor deposition in which vertically aligned carbon nanotubes can easily be grown. In these chemical vapor deposition processes, the catalyst decomposes the hydrocarbon gas to produce carbon and hydrogen. The carbon dissolves into the particle and precipitates out from its circumference as the carbon nanotube. Thus, the catalyst acts as a ‘template’ from which the carbon nanotube is formed, and by controlling the catalyst size and reaction time, one can easily tailor the nanotube diameter and length respectively to suit. Carbon tubes, in contrast to a solid carbon filament, will tend to form when the catalyst particle is ˜50 nm or less because if a filament of graphitic sheets were to form, it would contain an enormous percentage of ‘edge’ atoms in the structure. Alternatively, nanotubes may be prepared by catalytic pyrolysis of hydrocarbons as described by Endo, et al., in J. Phys. Chem. Solids, 54, 1841 (1993), or as described by Terrones, et al., in Nature, 388, 52 (1997) or by Kyotani, et al., in Chem. Mater., 8, 2190 (1996), the contents of all of which are incorporated by reference for describing nanotube preparation.
[0068] Alternative forms of nanotubes (e.g. boron nitride) can be formulated with boron, nitrogen, or other elements. Suitable materials are described in US PGPUB 20010023021 “BxCyNz nanotubes and nanoparticles,” hereby incorporated by reference as describing the making of suitable boron nitride nanotubes. Single walled nanotubes can also be used to provide a rotor support component for embodiments not involving free rotation, i.e. actuators, which have reciprocating radial movement.
C. Substrate
[0069] The present structure was formed by the deposition of various layers and components onto a crystralline silicon chip. Degenerately doped silicon substrates were covered with SiO 2 . Silicon was chosen because photolithographic, etching, and other techniques for its manipulation are readily available. Other inert materials that can be physically shaped could also be used for the present actuator/motor, such as plastic polymer or glass. Flexible polymer films may also be employed as substrates. Polymreic material such as used in the resist could also be used.
D. Deposition of Nanotubes in Preselected Areas
[0070] As described above, the present method for selective deposition of nanotubes involves the use of standard semiconductor processing technology, for ease of scale up. However, variations on the described are possible. The steps in placing one or more nanotubes in a preselected location include: coating the substrate with a resist; patterning the resist to provide nanotube-adherent regions; and flowing an appropriate nanotube suspension across the patterned substrate so that the nanotubes are aligned in a direction of flow and “stick” at the defined adherent regions. Essentially, a positive resist is used whereby, when the resist is exposed to radiation, the radiation breaks down the resist and allows it to be removed by an appropriate solvent. The resist is not entirely removed, leaving a thin layer behind which “snags” or adheres to carbon-containing nanotubes. The preferred interaction is carbon-carbon (i.e. hydrophobic), but other interactions may be designed. Without being bound to any one theory, it is thought that the high exposure to electron beam radiation breaks down the resist to an amorphous layer containing at least a portion of elemental or graphitic carbon, which adheres to the nanotubes, while the unexposed resist retains its ordered, crystalline, and/or polymeric form, presenting little surface attraction for nanotubes moving across the surface.
Resist
[0071] The term “resist” is used in a general sense as used in microcircuit fabrication. It need only be resistant to nanotube adhesion in one state (i.e. in the unexposed state in the case of a positive resist) and adhesive to nanotubes in the other state (i.e. exposed state in the case of a positive resist). Positive resists are preferred, in that the radiation exposure used is much higher than ordinarily employed, in order to chemically break down the resist. For e-beam resists, it is preferred to use low acceleration voltage (0.1-2, preferably about 1.0 keV). The exposure time is adjusted to provide at least about 5,000 μC/cm 2 , preferably about 50,000 μC/cm 2 . Other forms of radiation may be used, e.g. x-rays or intense light (e.g. extreme ultraviolet).
[0072] Some of the positive e-beam resists are: PMMA (Poly methyl methacrylate), EBR-9 (another acrylate based resist), PBS (Poly butene-1-sulphone), ZEP (a copolymer of a-chloromethacrylate and a-methylstyrene).
[0073] Polymethyl methacrylate (PMMA) was one of the first materials developed for e-beam lithography. It is the standard positive e-beam resist and remains one of the highest resolution resists available. PMMA is usually purchased in two high molecular weight forms (496 K or 950 K) in a casting solvent such as chlorobenzene or anisole. PMMA is spun onto the substrate and baked at 170 C to 200 C for 1 to 2 hours. Electron beam exposure breaks the polymer into fragments that are typically dissolved by a developer such as MIBK. MIBK is usually diluted by mixing in a weaker developer such as IPA. A mixture of 1 part MIBK to 3 parts IPA produces very high contrast but low sensitivity. By making the developer stronger, say, 1:1 MIBK:IPA, the sensitivity is improved significantly with only a small loss of contrast. EBR-9 is an acrylate-based resist, poly(2,2,2-trifluoroethyl-chloroacrylate), sold by Toray Inc. This resist is 10 times faster than PMMA, ˜10 C/cm 2 at 20 kV. Its resolution is, however, more than 10 times worse than that of PMMA, ˜0.2 m. Poly(butene-1-sulfone) is a common high-speed positive resist used widely for mask plate patterning. For high-volume mask plate production, the sensitivity of 1 to 2 C/cm 2 is a significant advantage over other positive resists. However, the processing of PBS is difficult and the only advantage is the speed of exposure. Another possible resist is ZEP-520 from Nippon Zeon Co. ZEP consists of a copolymer of -chloromethacrylate and -methylstyrene. Sensitivity at 25 kV is between 15 and 30 C/cm 2 , an order of magnitude faster than PMMA and comparable to the speed of EBR-9. Unlike EBR-9, the resolution of ZEP is close to that of PMMA. Other UV sensitive resists used for e-beam include EBR900 from Toray, the chemically amplified resist ARCH from OCG, and the deep-UV resists UVIII and UVN from Shipley. The products from Shipley have been optimized for DUV (248 nm) exposure, and have higher resolution than that of AZ5206. The use of DUV resists allows exposure by both photons and electrons in the same film, thereby reducing e-beam exposure time.
[0074] A negative resist could be used, for example, by sputtering it with carbon atoms. The top surface is made rough or chemically active enough to snag nanotubes. One then patterns the resist in the usual way and get snagging areas left in the locations that have been patterned. The developed areas everywhere else would not have the carbon coating and would not snag. PMMA itself can be a negative resist, with high radiation doses as done in the examples (see http://www.jcnabity.com/negwheel.htm). If these samples were to be developed (put in acetone) after the high dosage treatment, the polymer everywhere else would be removed but the burnt-in sections would remain, so, in a sense this is a negative resist.
[0075] Some of the negative tone e-beam resists are: COP (an epoxy copolymer of glycidyl methacrylate and ethyl acrylate) and Shipley SAL (has 3 components, a base polymer, an acid generator, and a crosslinking agent).
[0076] Another suitable resist is disclosed in US PGPUB 20050164123 to Mizutani, published Jul. 28, 2005, entitled “Positive resist composition and pattern formation method using the same.” A suitable acrylate olefin copolymer resist is disclosed in US PGPUB 20050153236 to Lim, et al. published Jul. 14, 2005, entitled “Novel polymer and chemically amplified resist composition containing the same.” US PGPUB 20040256358 to Shimizu, et al., Dec. 23, 2004, also discloses suitable resists and removal solvent. U.S. Pat. No. 5,910,392 to Nozaki, et al., issued Jun. 8, 1999, entitled “Resist composition, a process for forming a resist pattern and a process for manufacturing a semiconductor device” discloses another suitable type of resists for use with an eximer laser. A wide variety of acrylate-based resists are known in the art, which would be adaptable to the present process. A number of suitable acrylate resists are disclosed in U.S. Pat. No. 4,156,745 to Hatzakis, et al. issued May 29, 1979, entitled “Electron sensitive resist and a method preparing the same.” All these published applications and patents are incorporated by reference for purposes of describing the manufacture, application, radiation and removal of suitable resists.
Removing Resist
[0077] In general, any solvent may be used to remove the resist; it is important to match the solvent to the resist and to adjust the solvent exposure to leave a thin layer of resist, rather than just underlying substrate. Various types of organic remover solutions have been proposed including mixtures of organic solvents such as phenol, halogenated hydrocarbon solvents and the like and a surface active agent such as alkylbenzene sulfonic acid and the like, mixtures of an alkylbenzene sulfonic acid, etc. A thin layer is considered to be preferably 1-4 nm, but may be more, depending on the topology desired in the final product. For example, when using PMMA, one may use methylene chloride and acetone, which will strip PMMA, as will NMP (Remover 1165). PMMA is also is removed very well by strong bases (KOH), and by acid normally hostile to organics, such as NanoStrip. Oxygen plasmas also etch PMMA very well.
[0078] The presently preferred process uses pure acetone for 3-10 minutes, most preferably about 5 min.
Nanotube Suspensions
[0079] As described, nanotubes may be suspended in a solvent in a soluble or insoluble form and spin-coated over a surface to generate a composite nanotube/nanowire film. In such an arrangement the film created may be one or more nanotubes, depending on the spin profile and other process parameters. With regard to the solution for suspending the nanotubes, ODCB and methoxybenzene have been exemplified. Other solvents that form a coating on nanotubes which promote adhesion to a carbonized surface may be employed. The term “carbonized” is used in a general sense to refer to layers which are not polymeric chains, but rather forms of elemental carbon, including graphite, etc. These include other halogenated benzene compounds.
[0080] Appropriate solvents include and are not limited to: dimethylformamide, n-methyl pyrollidinone, n-methyl formamide, orthodichlorobenzene, and paradichlorobenzene. Other materials such as 1,2, dichloroethane, alcohols, water with appropriate surfactants such as sodium dodecylsulfate or TRITON X-100 may be used in combination with these solvents. For a discussion of possible solvents, see US PGPUB 20050052894 to Segal et al. published Mar. 10, 2005, “Uses of nanofabric-based electro-mechanical switches,” hereby incorporated by reference relative to coating and depositing nanotubes and nanowires.
[0081] In one aspect of the invention may comprise a sonicated suspension of nanotubes in an organic solvent, comprising an aromatic compound bound to a good leaving group (i.e. that is replaced in a nucleophilic substitution reaction). Anything with a pKa of less than about 25 is a good leaving group if the molecule bears a negative charge and can form a carbonyl group when the leaving group leaves. As is known, “good leaving groups” include halides, tosyl groups, NH3, etc.
Application of Nanotubes to Substrate
[0082] The nanotube suspension, in appropriate solvent, is spin coated onto the substrate having a treated resist layer defining sticking points for the nanotubes. The orientation of the nanotubes is determined by the direction of flow. The nanotubes align longitudinally along the direction of flow. The flow will be radial across the center of rotation in a spin coating step. The center of rotation may be changed to achieve different nanotube orientations, as described below in connection with FIG. 5 . Alternatively, a gas flow cell may be used to slow the nanotube suspension across the substrate, which then may remain stationary. Suitable liquid or gas flow cells are commercially available, e.g. for use with spectrophotometers (e.g. Axsun NIR analyzers). Further description of a gas flow cell implementation is found in Xin et al. “Directional Orientation of carbon nanotubes on surfaces using a gas flow cell,” Nano Letters 4:1481-1484 (2004), hereby incorporated by reference as guidance for implementation of a flow cell device for delivering a nanotube suspension to a substrate.
[0083] As shown in FIG. 5 , it is thought that tubes may be arrayed orthogonally, or at any desired angle, or in contact with each other 500 . When the substrate is rotated so that radial flow follows the {right arrow over (X)} direction in the plane of the paper, tubes 512 will adhere to line 510 at their trailing edge. The substrate (or alternatively the flow chamber) may then be rotated so that radial flow follows the {right arrow over (Y)} direction (also in the plane of the paper), and tubes 516 will adhere to line 514 , oriented in the direction of outward flow from rotational center Y.
CONCLUSION
[0084] While the foregoing structures and their methods of construction and operation has been described in reference to particular embodiments, many variations and embellishments are possible in view of the above teachings. Therefore, it is intended that the present invention not be limited to the specific embodiments described above, but rather to the scope of the appended claims.
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[0097] (13) Valentin, E.; Auvray, S.; Goethals, J.; Lewenstein, J.; Capes, L.; Filoramo, A.; Ribayrol, A.; Tsui, R.; Bourgoin, J. P.; Patillon, J. N. High-density selective placement methods for carbon nanotubes. Microelectronic Engineering 2002, 61-2, 491.
[0098] (14) Koval, Y. Mechanism of etching and surface relief development of PMMA under low-energy ion bombardment. Journal of Vacuum Science \& Technology B 2004, 22, 843.
[0099] (15) See for example the NIST stopping power and range tables available at http://phyiscs.nist.gov/PhysRefData/Star/Text/contents.html and references contained therein.
[0100] (16) Joy, D. C.; Suichu, L.; Gauvin, R.; Hovington, P.; Evans, N. Experimental measurements of electron stopping power at low energies. Scanning Microscopy 1996, 10, 653.
[0101] (17) Davenas, J.; Thevenard, P.; Boiteux, G.; Fallavier, M.; Lu, X. L. Hydrogenated Carbon Layers Produced by Ion-Beam Irradiation of Pmma and Polystyrene Films. Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Atoms 1990, 46, 317.
[0102] (18) Niyogi, S.; Hamon, M. A.; Perea, D. E.; Kang, C. B.; Zhao, B.; Pal, S. K.; Wyant, A. E.; Itkis, M. E.; Haddon, R. C. Ultrasonic dispersions of single-walled carbon nanotubes. Journal of Physical Chemistry B 2003, 107, 8799.
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A method for controlled deposition and orientation of molecular sized nanoelectromechanical systems (NEMS) on substrates is disclosed. The method comprised: forming a thin layer of polymer coating on a substrate; exposing a selected portion of the thin layer of polymer to alter a selected portion of the thin layer of polymer; forming a suspension of nanostructures in a solvent, wherein the solvent suspends the nanostructures and activates the nanostructures in the solvent for deposition; and flowing a suspension of nanostructures across the layer of polymer in a flow direction; thereby: depositing a nanostructure in the suspension of nanostructures only to the selected portion of the thin layer of polymer coating on the substrate to form a deposited nanostructure oriented in the flow direction. By selectively employing portions of the method above, complex NEMS may be built of simpler NEMSs components.
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This is a divisional of application Ser. No. 08/494,971 filed on Jun. 26, 1995, now U.S. Pat. No. 5,674,171.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a roll outer layer material for hot rolling steel which exhibits excellent resistance to surface deterioration and wear resistance and elimination of accidents, such as breakage of the roll during manufacture or rolling, as well as a method of manufacturing a roll for hot rolling.
2. Description of the Related Art
To manufacture hot rolled steel plates or strips, a slab having a thickness ranging from 130 to 300 mm and manufactured by the continuous casting process or by blooming is heated by a heating furnace, and then hot rolled by a rough rolling mill and a finish rolling mill to obtain a strip having a thickness ranging from 1.0 to 25 mm. After the thus-obtained strip is coiled by a coiler, it is cooled. The cooled strip is subjected to various finish operations such as cutting, slitting, marking, bundling etc., in finish lines. In the work roll of a conventional finish rolling mill, a high Cr cast iron, Adamite, or a Ni grain cast iron or the like is used as the outer layer material, and a gray cast iron or a ductile cast iron exhibiting excellent toughness is used as the inner layer material. The work roll of a conventional finish rolling mill is a composite roll manufactured by centrifugally casting these outer and inner layer materials.
In recent years, rolling conditions tend to become severe and an improvement in the productivity of rolling has been required. Hence, there has been a demand for rolling rolls exhibiting higher wear resistance.
To meet such requirements, for example, Japanese Patent Laid-Open Nos. Sho 60-124407 and Sho 61-177355 have proposed the use of a high V cast iron as the outer layer material manufactured by the centrifugal casting process.
However, when used as the outer layer material of a roll manufactured by centrifugal casting, a high V cast iron has a disadvantage in that a V carbide having a small specific gravity is centrifugally separated, thus making the characteristics of the roll outer layer material non-uniform in the direction of thickness thereof. Hence, it has been proposed in, for example, U.S. Pat. No. 5,316,596 and Japanese Patent Laid-Open Nos. Hei 4-365836, Hei 5-1350 and Hei 5-339673 to add Nb to prevent segregation.
More specifically, it has been found that in a composite carbide of Nb and V, segregation of a carbide in primary crystal is reduced because the specific gravity of the composite carbide is higher than that of the V carbide (specific gravity: 5.77) and closer to the specific gravity (7.0) of the molten metal than the V carbide. Accordingly, it has been proposed to make a Nb/V ratio 2.0 or above and basically to not add W in order to prevent segregation of an eutectic carbide.
Although the above-described high V and high V--Nb roll outer layer materials are advantageous in terms of the improvement of the wear resistance, the present inventors found that a hard V or Nb carbide (MC carbide) in the high V or high V--Nb material tend to form projected parts near the surface of the roll during rolling. Such parts act as spikes and increase the coefficient of friction between a rolled material and the surface of the roll. Accordingly, a roll having an outer layer made of such a high V or high V--Nb material has the following disadvantages:
(a) Rolling load is increased excessively.
(b) Secondary scale is generated in the surface of a rolled material due to frictional heat, thus generating surface roughening of the rolled material.
(c) The roll surface is damaged due to excessive frictional heat generated during rolling under a high pressure, thus generating surface roughening of the rolled material.
Furthermore, since wear resistance of the roll is improved and the useful life of a roll before roll changing is thus increased, another problem involving spalling of the roll surface (hereinafter referred to as "banding") is encountered during rolling. This is due to fatigue occurred at the portion of the roll located immediately below the surface thereof.
The above-described problems (a) to (c) are remarkable in a roll used under an environment of large heat load, such as a roll for use in a hot rolling stand in a front stage of finish strip mill.
Furthermore, since wear resistance of the roll is improved, the load applied to the roll is usually increased. Thus, there is the possibility that a very small defect generated in the roll during manufacture thereof leads to an accident, such as breakage of a roll.
SUMMARY OF THE INVENTION
In view of the aforementioned problems of a conventional roll outer layer material, an object of the present invention is to provide a roll outer layer material which exhibits excellent wear resistance and has a low coefficient of friction in order to solve the problems (a) to (c).
Another object of the present invention is to provide a roll outer layer material which eliminates banding which would occur when a roll is used over a long period.
Still another object of the present invention is to provide a method of manufacturing a roll for hot rolling which has no defect therein and thus prevents breakage during the use of the roll.
The present invention provides a roll outer layer material for hot rolling which consists essentially, as analyzed in weight percent, of 2.5-4.0% C, 6.0-20% Cr, 2.0-15% Mo, 3.0-10.0% V, 0.6-5.0% Nb, 3.0% or below Si, 3.0% or below Mn, C, V, Nb and Cr satisfying a formula (1)
10.5(%)≦6.5.C(%)-1.3.V(%)-0.7.Nb(%)≦2.Cr(%)-2(%)(1)
with the balance of Fe and incidental impurities.
The present invention further provides a method of manufacturing a roll for hot rolling, which comprises the steps of:
centrifugally casting an outer layer material consisting essentially, as analyzed in weight percent, of 2.5-4.0% C, 6.0-20% Cr, 3.0-10.0% V, 0.6-5.0% Nb, 2.0-15%, Mo, 3.0% or below Si, 3.0% or below Mn, C, V, Nb and Cr satisfying a following formula (1):
10.5(%)≦6.5.C(%)-1.3.V(%)-0.7.Nb(%)≦2.Cr(%)-2(%)(1)
with the balance of Fe and incidental impurities;
centrifugally casting graphite steel containing 0.5% or above of C as an intermediate layer; and
casting an axis material which is a spheroidal graphite cast iron, a flake graphite cast iron or a graphite steel.
C is present in the intermediate layer in an amount which satisfies a following formula (2):
C (intermediate layer)≧2.0-0.5 (C-0.2 V-0.11 Nb)(outer layer)(2)
Other objects and advantages of the invention will become apparent from the following description taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph illustrating the correlation between the relations between C, V and Nb with the coefficient of friction;
FIG. 2 is a graph illustrating the correlation between C, V, Nb and Cr with the amount of wear;
FIG. 3 illustrates dependency of the generation of a boundary defect on the amount of C in an intermediate layer during casting;
FIG. 4 is a graph illustrating the relation between the number of cracks generated in a carbide due to fatigue and the amounts of Mo and Cr;
FIG. 5 is a graph illustrating dependency of the generation of cracks on a Mo/Cr ratio;
FIG. 6 is a graph illustrating comparison between a roll according to the present invention and a conventional roll in terms of the rolling load; and
FIG. 7 is a graph illustrating comparison between a roll according to the present invention and a conventional roll in terms of the degree of wear resistance.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
(A) Basic concept of the invention
First, the basic technical concept of the present invention will be described.
The structure of a high V or high V--Nb roll outer layer material is made up of proeutectic carbides (including V and Nb carbides), eutectic carbides (including Cr, Mo and Fe carbides) and a base. During rolling, the less hard base selectively wears, resulting in projection of the hard proeutectic and eutectic carbides. An increase in the coefficient of friction occurs because the proeutectic carbides act as projections and because shoulders are generated between the matrix which occupies most of the structure and the proeutectic carbides. Hence, the frictional force is reduced to prevent an excessive increase in the rolling load and generation of secondary scale in the surface of a rolled material and to prevent generation of surface roughening of the rolled material either by changing the amount or shape of the proeutectic carbides or by lessening the shoulders between the proeutectic carbides and the portion other than the proeutectic carbides.
It is possible to generate eutectic carbides having the second highest hardness in the structure of the roll outer layer material in which the proeutectic carbides have the highest hardness. Thus, shoulders between the proeutectic carbides and the portion other than the proeutectic carbides can be lessened to reduce the coefficient of friction of the roll outer layer material by increasing eutectic carbides in the structure of the roll outer layer material.
Furthermore, in order to reduce fatigue of the roll surface layer portion and hence restrict banding, the present inventors consider that strengthening of the proeutectic carbides, eutectic carbides and matrix structure is effective. Thus, it is considered that fatigue resistance (banding resistance) can be improved due to strengthening by solid-solution or precipitation by increasing the amounts of adequate alloy elements to be added to the roll.
The roll according to the present invention is particularly suitable for use in a hot rolling stand in a front stage of finishing strip mill. Where there are n stands in a mill, the front stage is a group of rolling stands from the first stand to n/2th stand (or to if n is an odd number). This stage performs rolling at a rolling reduction of 85 to 90% with the thickness of a slab, which does not yet enter the finishing strip mill,and in such a manner that the temperature of the slab at the outlet side of the each stand is between 850° and 900° C.
(B) Composition of the roller outer layer material according to the present invention
C: 2.5 to 4.0%
The addition of C is essential to form a hard carbide which is required to improve wear resistance of the roll outer layer material. The presence of less than 2.5% C makes formation of a sufficient amount of carbide impossible, thus reducing wear-resistance of the roll outer layer material while increasing the coefficient of friction thereof which can be a cause of surface roughening. The addition of more than 4.0% C has no significance in terms of the effect of reducing the coefficient of friction and it reduces wear resistance.
The preferred proportion of C is between 2.8 and 3.5%.
Si: 3.0% or below
The addition of an adequate amount of Si assures deoxidation and castability. Since the effect of the addition thereof is saturated if the proportion exceeds 3%, the proportion is limited up to 3%. The preferred range is between 0.1 and 1.5%.
Mn: 3.0 or below
The inclusion of Mn is effective to remove S in the form of MnS and to strengthen the structure. The upper limit of the proportion thereof is 3%, because the effect of the addition of Mn is saturated if the proportion exceeds 3%. The preferred proportion is between 1.0 and 1.2%.
Cr: 6.0 to 20%
Cr forms a tough eutectic carbide and thus the presence thereof is advantageous to improve wear resistance. A solid-solution of Cr in the matrix strengthens the matrix structure and improves fatigue characteristics, and improves adhesion of a oxide layer on the roll. Thus, the introduction of Cr is mandatory. The amount of Cr added is 6.0% or above. However, since the effect of improving wear resistance is saturated when the amount of Cr exceeds 20%, the proportion of Cr is limited up to 20% to prevent deterioration in resistance to sticking.
The preferred proportion is between 8.0 and 20%.
Mo: 2.0 to 15%
Mo forms a carbide, like Cr, and thus the inclusion thereof is advantageous to improve wear resistance. Further, Mo concentrates in the carbide and strengthens the carbide. Mo enhances banding resistance. These effects can be obtained at 2,0% or above Mo. However, since the effects are saturated when the proportion exceeds 15%, the proportion of Mo is limited up to 15%.
FIG. 4 illustrates the relation between the number of fatigue cracks generated in the surface of a sample subjected to the double disk slide-contact rolling fatigue test and the amounts of Mo and Cr. When Mo exceeds 2.0%, the number of cracks is halved. Up to about 15%, as the amount of Mo increases, the number of cracks decreases. Regarding Cr, the effect of the addition of Cr increases, as the proportion of Cr increases.
The preferred proportion of Mo according to the present invention is between 3 and 12%.
Mo/Cr ratio: 0.25 or above
There is a preferred range for Mo/Cr ratio from the viewpoint of banding resistance. FIG. 5 shows the rearranged results shown in FIG. 4 with the Mo/Cr ratio as the abscissa.
As can be seen from FIG. 5, when Mo/Cr ratio is 0.25 or above, the number of cracks generated greatly decreases. The number of cracks is minimized when Mo/Cr ratio is between 0.3 and 1.0. Thus, in order to prevent banding, Mo/Cr ratio is set to 0.25 or above with a preferred range being between 0.3 and 1.0.
Ni: 1.0% or below
The addition of Ni improves hardenability and thus expands the operation range for quenching. The addition of Ni is more effective for rolls having a large roll diameter. Thus, Ni is added when necessary. Since the presence of more than 1.0% Ni forms an unstable structure in which, for example, residual γ is present, it is limited up to 1.0%.
W: 1.0% or below
In the present invention, the inclusion of W, which bonds with C to form a hard carbide, has no effect of improving wear resistance and surface roughening inhibiting property of the roll (of reducing the coefficient of friction). Further, the presence of more than 1.0% W promotes segregation of carbides (further promotes segregation during centrifugal casting), and deteriorates wear resistance and surface roughening resistance. Thus, the inclusion of W is not generally necessary in the invention. If W is added, however, depending on the conditions under which the roll is used, the preferred W proportion must be 1.0% or below.
Co: 5% or below
Since the presence of Co stabilizes the structure at high temperatures, Co is added if necessary. However, the effect of Co addition in terms of the improvement of wear resistance and surface roughening inhibiting property of the roll is not apparent. The preferred proportion of Co is limited up to 5% from the economical viewpoint.
V: 3.0 to 10.0%, Nb: 0.6 to 5.0%
V is essential to form a hard MC or M 4 C 3 carbide which is the most effective substance to improve wear resistance. The effect of V addition can be discerned at 3.0% or above. The presence of more than 10.0% has no effect and causes a problem during casting, such as a making micro cavity. Thus, the presence of V is limited up to 10.0%. The preferred proportion is between 4.0 and 7.0%.
Like V, Nb forms an MC carbide which is the effective substance to improve wear resistance. Further, Nb restricts segregation of a V carbide, and thus enables the provision of an outer layer in which the MC carbide is uniformly dispersed even if the centrifugal casting process is used to manufacture a roll. The effect of Nb addition can be discerned at 0.6% or above. The presence of up to 5.0% has no effect and causes a problem during casting, such as a making micro cavity. Thus, the presence of Nb is limited up to 5.0%. Further, the addition of Nb or V alone forms a rough bulk carbide or a dendritic carbide, and thus greatly deteriorates wear resistance. Thus, Nb must be added together with V.
The preferred proportion of Nb is between 1.0 and 3.0%.
Parameter: 10.5(%)≦6.5.C(%)-1.3.V(%)-0.7.Nb(%)≦2.Cr(%)-2(%)
The present invention is characterized in that the composition of a roll exhibiting excellent wear resistance and surface roughening inhibiting property satisfies the above-described formula. In a high V--Nb roll, whereas formation of hard V (Nb) C greatly improves the wear resistance of the roll, it increases the coefficient of friction, thus generating surface roughening of the plates. Hence, the present inventors had the following formula which calculated the amount of C consumed by both V and Nb as follows:
(6.5.C(%)-1.3.V(%)-0.7.Nb(%)),
studied the relation between the amounts of V and Nb and the total amount of C added, and correlated the coefficient of friction with the resultant relation. The results are shown in FIG. 1. That is, the present inventors found that a high V--Nb type composition must satisfy the formula (10.5(%)≦6.5.C(%)-1.3.V(%)0.7.Nb(%)) in order to obtain a coefficient of friction (about 0.28) similar to that of a high Cr cast iron suitable for use as a hot rolling stand in a front-stage of finishing strip mill.
It was observed that in a composition which satisfies the above-described formula, a reduction in the amount of Cr greatly deteriorated wear resistance and fatigue resistance. The present inventors hypothesize that in a composition which satisfies the above formula in which large amounts of eutectic carbides are present, a reduction in the amount of Cr reduces the amount of Cr distributed into the eutectic carbides, thus lowering wear resistance. Thus, the present inventors studied the relation between 6.5.C(%)-1.3.V(%)-0.7.Nb(%)) and the amount of Cr, and correlated the amount of wear and the resultant relation. The results are shown in FIG. 2. That is, it is apparent that the composition, which satisfies 10.5(%)≦6.5.C(%)-1.3.V(%)-0.7.Nb(%) and thus has a low coefficient of friction, must satisfy 6.5.C(%)-1.3.V(%)-0.7.Nb(%)≦2.Cr(%)-2(%) to provide a roll exhibiting excellent wear resistance.
It is thus apparent that in a high V--Nb roll exhibiting excellent wear resistance and surface roughening inhibiting property, a composition must satisfy 10.5(%)≦6.5.C(%)-1.3.V(%)-0.7.Nb(%)≦2.Cr(%)-2(%).
The results shown in FIGS. 1, 2 and 4 are based on the examples.
(C) The reason why the amount of Cr in the intermediate layer is limited in the present invention when the intermediate layer is formed by casting will be described below.
In a composite three-layer roll, the boundary portion between the outer layer and the intermediate layer and the boundary portion between the intermediate layer and the inner layer are metallurgically joined. A defect, such as internal shrinkage, must not be present in any of these boundary portions. The present inventors inspected the presence or absence of a boundary defect, which could be inspected during manufacture from the surface of the roll by ultrasonic flaw detection, of a broken roll and of a unbroken abolished roll by cutting the roll. They found that internal shrinkage was present in the boundary portion of the broken roll between the outer layer and the intermediate layer.
The mechanism of generation of internal shrinkage in the boundary portion is as follows:
In centrifugal casting, a molten metal forming the outer layer is first poured into a cooled metal mold. Solidification starts from the outer side of the molten metal which is contact with the metal mold. After the entire molten metal is solidified, a molten metal forming the intermediate layer is poured. The poured molten metal forming the intermediate layer melts the inner side of the outer layer again. Thereafter, the melted outer layer and the intermediate layer (in which the outer layer component is present as the result of remelting) are solidified by cooling through the metal mold and outer layer. At that time, if the melting point of the outer layer is higher than or equal to the melting point of the intermediate layer, solidification apparently starts from the outer side which is close to the mold and proceeds inwardly. If the melting point of the outer layer is lower than the melting point of the intermediate layer, the intermediate layer first solidifies, and then the boundary portion between the outer layer and the intermediate layer solidifies. At that time, internal shrinkage may be generated depending on the shrinkage rate of the outer layer.
The present inventors centrifugally cast (140 G) an outer layer first and then an intermediate layer, and finally stationarily cast the axis material (the inner layer a spheroidal graphite cast iron), and inspected the presence or absence of a boundary defect between the inner layer and the intermediate layer by conducting ultrasonic flaw detection tests on the outer layer and the intermediate portion from the outer surface of the roll. It can be seen from FIG. 3 that the range which does not substantially generate a boundary detect is determined by
C (intermediate layer)≦2.0-0.5(C-0.2 V-0.11 Nb) (outer layer)(2)
C concentration of the intermediate layer in the formula (2) is the value obtained during casting, and does not include the amount of C contained in the intermediate layer as the result of remelting of the outer layer. C, V and Nb concentrations of the outer layer in the formula (2) are those obtained during casting and are equivalent to those of the manufactured outer layer.
In FIG. 3, the presence or absence of porosity in the boundary portion is determined by obtaining a ultrasonic flaw detection index from the results of the ultrasonic flaw detection test on the boundary portion between the outer layer and the intermediate layer in the manner described below. The ultrasonic flaw detection index is a product of the total defective area obtained by ultrasonic flaw detection and the reflection echo peak rate of a standard defective sample. A reflection echo peak rate 0.2 or above is regarded as "boundary portion porosity is present". This is because when a ultrasonic flaw detection test is conducted on the boundary portion between the outer layer and the intermediate layer of the roll, even if the boundary portion is not defective at all, a reflection echo of about 0.15 is obtained due to a difference in the structure between the outer layer and the intermediate layer.
The standard defective sample from which the reflection echo peak rate was obtained was made of a material having a composition which consisted of 4.2% C, 0.5% Si, 0.5% Mn, 7.2% Cr, 3.1% Mo, 6.0% V and 2.2% Nb. The sample had a thickness of 100 mm. A defect of 2 mm was formed at a position of 50 mm in the direction of the thickness of the sample.
A desirable amount of C in the intermediate layer is 0.5% or above, although it is restricted by the above-described formula. Less than 0.5% C increases the viscosity of the molten metal, making it impossible for the molten metal to be uniformly distributed in the mold during centrifugal casting. Accordingly, variations in the amount of melted outer layer become too great, making the use of a resulting roll impossible.
EXAMPLES
Example 1
Samples equivalent to roll outer layer materials and having chemical compositions shown in Table 1 were each melted, and quenched at temperatures which started from 1000° C. and then were tempered at 550° C. to manufacture sample materials. Wearing test was two-disk sliding friction type which employed a sample material of φ50×10 and the other material of φ190×15. The test was conducted by rotating the sample material at 800 rpm in a state wherein it was pressed against the other material heated to 900° C. under a load of 100 kgf while the sample material was water cooled. In order to increase the surface damage of the sample material and to enable relative evaluation of the coefficient of friction, the wear test was conducted for 120 minutes at a sliding rate of 14.2% to examine the amount of wear and the average coefficient of friction.
The results of the wear test are shown in Table 2.
Samples B-1 to B-8 which do not satisfy the formula
10.5(%)≦6.5.C(%)-1.3.V(%)-0.7.Nb(%)
have coefficients of friction which are about 30% higher than that of a high Cr cast iron. If such a material is used for a hot rolling roll, a rolling load is increased, thus causing surface roughening of the plate.
Samples D-1 to D-5 which do not satisfy the formula
6.5.C(%)-1.3.V(%)-0.7.Nb(% )≦2.Cr(%)-2(%)
exhibit greatly deteriorated wear resistance. In contrast to these comparative examples, the examples according to the present invention have coefficients of friction which are similar to that of a high Cr cast iron, and wear resistances which are 7 times that of a high Cr cast iron.
Samples C-1 and C-2 are comparative examples in which W is not present in the determined amount, and sample C-3 is a comparative example in which Nb is not present in the determined amount. It is apparent from Table 2 that wear resistance of these comparative examples is greatly reduced.
That is, it is possible according to the present invention to provide a roll outer layer material for hot rolling suitable for use in hot rolling finish front stage which exhibits excellent wear resistance and a low coefficient of friction and an hence excellent surface roughening inhibiting property by optimizing the composition of the outer layer material and by mutually restricting the amounts of C, Cr, V and Nb.
TABLE 1-1__________________________________________________________________________(Example of the invention) C Si Mn P S Mo Cr V Nb W Co Ni__________________________________________________________________________A1 2.5 0.9 0.5 0.03 0.01 4.2 8.1 3.5 0.8 -- -- --A2 2.6 0.5 0.4 0.03 0.01 3.8 6.5 4.3 1.1 -- -- --A3 2.9 0.3 0.5 0.01 0.01 5.2 7.0 5.1 1.4 -- -- --A4 3.0 0.4 0.6 0.01 0.01 2.4 8.3 3.6 1.0 -- -- --A5 3.0 0.5 0.5 0.03 0.03 2.5 8.4 3.5 1.1 -- -- 0.8A6 3.0 0.3 1.1 0.03 0.02 6.9 12.4 3.7 1.2 -- -- --A7 3.0 0.6 0.3 0.02 0.01 5.1 9.9 4.9 1.4 -- -- --A8 3.1 0.3 0.3 0.02 0.01 7.4 8.0 4.4 2.2 -- -- --A9 3.2 1.0 0.3 0.03 0.01 3.6 8.4 4.9 0.9 -- -- --A10 3.2 0.9 0.9 0.04 0.01 4.5 9.5 4.2 3.8 -- -- --A11 3.2 1.2 0.9 0.03 0.01 7.8 7.8 6.6 2.4 -- -- --A12 3.4 0.7 0.5 0.03 0.01 6.5 7.2 6.8 2.3 -- -- --A13 2.9 0.3 0.4 0.05 0.03 3.5 8.5 5.0 1.4 -- -- --A14 2.9 0.4 0.4 0.06 0.03 3.6 8.5 5.1 1.5 0.6 -- --A15 3.0 0.3 0.4 0.04 0.03 3.6 8.5 5.0 1.5 -- 3.8 --A16 2.9 0.4 0.4 0.02 0.01 7.4 18.6 4.8 1.4 -- -- --A17 3.0 0.3 0.3 0.05 0.04 7.5 18.5 4.9 1.5 0.5 4.0 --A18 3.1 0.4 0.5 0.02 0.01 4.4 14.8 5.0 1.4 -- -- --A19 3.1 0.3 0.4 0.01 0.01 4.2 12.0 5.0 1.5 -- -- --A20 3.8 1.1 0.6 0.03 0.02 5.3 13.4 9.1 3.2 -- -- --A21 3.6 0.5 0.3 0.02 0.01 11.2 17.3 6.2 1.8 -- -- --A22 3.4 0.3 0.2 0.01 0.01 8.2 14.6 5.8 1.6 -- -- --__________________________________________________________________________
TABLE 1-2__________________________________________________________________________(Comparative example) C Si Mn P S Mo Cr V Nb W Co Ni__________________________________________________________________________B1 2.2 0.6 0.5 0.03 0.01 3.0 5.7 5.1 1.5 -- -- --B2 2.7 0.6 0.5 0.03 0.01 4.6 7.2 7.0 1.8 -- -- --B3 2.7 0.5 0.6 0.03 0.01 2.8 4.1 5.5 2.0 -- -- --B4 2.7 0.6 0.4 0.03 0.02 4.0 7.8 5.6 1.5 -- -- --B5 2.8 1.5 0.3 0.03 0.02 2.6 6.0 5.9 1.6 -- -- --B6 3.2 0.3 0.3 0.04 0.02 7.1 7.8 8.0 2.1 -- -- --B7 3.2 0.3 1.1 0.03 0.02 6.8 6.2 8.1 4.5 -- -- --B8 2.7 0.5 0.6 0.04 0.03 2.4 13.1 6.1 1.8 -- -- --C1 3.1 0.3 0.4 0.01 0.01 4.5 12.5 5.2 1.4 3.6 -- --C2 2.9 0.3 0.4 0.04 0.02 3.6 8.6 5.0 1.4 1.9 -- --C3 3.0 0.3 0.3 0.05 0.03 3.5 8.5 5.2 0.2 -- -- --D1 2.9 1.2 0.6 0.03 0.01 3.1 5.1 4.9 1.5 -- -- --D2 3.0 0.8 0.4 0.03 0.01 2.3 6.6 4.8 1.4 -- -- --D3 2.9 0.4 0.5 0.04 0.03 3.2 4.5 4.8 0.9 -- -- --D4 3.2 1.3 0.4 0.03 0.01 1.9 6.9 5.0 0.8 -- -- --D5 3.8 1.1 1.1 0.04 0.01 3.0 5.7 8.1 4.6 -- -- --E 2.80 0.60 0.80 0.03 0.01 2.60 17.8 -- -- -- -- --(HighCrcastiron)__________________________________________________________________________
TABLE 2-1______________________________________(Example of the invention) Amount of wear Coefficient 6.5 C-1.3 V-0.7 Nb 2 Cr-2 (g) of friction______________________________________A1 11.1 14.2 0.21 0.28A2 10.5 11.0 0.23 0.29A3 11.2 12.0 0.19 0.28A4 14.1 14.6 0.24 0.27A5 14.2 14.8 0.24 0.27A6 13.9 22.8 0.23 0.27A7 12.2 17.8 0.19 0.28A8 12.9 14.0 0.21 0.28A9 13.8 14.8 0.23 0.27A10 12.7 17.0 0.21 0.28A11 10.5 13.6 0.19 0.29A12 11.7 12.4 0.19 0.29A13 11.4 15.0 0.16 0.27A14 11.2 15.0 0.23 0.29A15 12.0 15.0 0.16 0.27A16 11.6 35.2 0.15 0.26A17 12.1 35.0 0.15 0.27A18 12.7 27.6 0.15 0.26A19 12.6 22.0 0.14 0.26A20 10.6 24.8 0.16 0.29A21 14.1 32.6 0.17 0.26A22 13.4 27.2 0.15 0.26______________________________________
TABLE 2-2______________________________________(Comparative example) Amount of wear Coefficient 6.5 C-1.3 V-0.7 Nb 2 Cr-2 (g) of friction______________________________________B1 6.6 9.4 0.19 0.39B2 7.2 12.4 0.18 0.39B3 9.0 6.2 0.52 0.37B4 9.2 13.6 0.24 0.36B5 9.4 10.0 0.39 0.36B6 8.9 13.6 0.22 0.38B7 7.1 10.4 0.19 0.39B8 8.4 24.2 0.48 0.37C1 12.4 23.0 0.62 0.31C2 11.4 15.2 0.50 0.28C3 12.6 15.0 0.54 0.27D1 11.4 8.2 0.63 0.28D2 12.3 11.2 0.52 0.28D3 12.0 7.0 0.67 0.28D4 13.7 11.8 0.58 0.27D5 11.0 9.4 0.55 0.29E 18.2 33.6 1.62 0.28(HighCrcastiron______________________________________
Example 2
Composite rolls, having a diameter of 800 mm and a length of 2400 mm, were each manufactured by centrifugally casting (140 G) first an outer layer material (having a thickness of 100 mm) and then an intermediate layer material (having a thickness of 40 mm), and then by static casting an inner layer material. Table 3 shows the compositions of the outer layers and intermediate layers. The inner layer material of each of the composite rolls was a spheroidal graphite cast iron. Table 4 shows the boundary portion porosity index of each roll. Samples G-1 to G-6 are comparative examples which do not satisfy the formula (2).
C (intermediate layer)≧2.0-0.5(C-0.2 V-0.11 Nb) (outer layer)(2)
In these comparative examples having high ultrasonic flaw detection detect indexes, D2 and D5 rolls were broken during manufacture and G2 to G5 rolls were broken during heat treatment. Thus, the use of G-1 to G-5 rolls was suspended because there was the possibility that an accident would occur during rolling.
The results of the inspection of internal porosity are shown in FIG. 3. It was found that when the amount of C in the intermediate layer was a value determined by
C≧2.0-0.5(C-0.2 V-0.11 Nb)
(components of the outer layer material), a roll for hot rolling having no internal defect could be manufactured.
TABLE 3-1__________________________________________________________________________(Example of the invention) C Si Mn Mo Cr V Nb Co W__________________________________________________________________________F1 Outer Layer 2.6 0.9 0.5 4.0 8.5 3.3 0.7 -- -- Intermediate Layer 1.2 1.5 0.6 -- -- -- -- -- --F2 Outer Layer 2.6 0.6 0.5 4.2 6.8 4.3 0.8 -- -- Intermediate Layer 1.2 1.6 0.6 -- -- -- -- -- --F3 Outer Layer 3.0 0.3 0.3 3.5 8.3 4.8 1.4 -- -- Intermediate Layer 1.5 2.0 0.8 -- -- -- -- -- --F4 Outer Layer 3.0 0.3 1.1 5.1 12.2 5.1 1.6 -- -- Intermediate Layer 1.5 1.5 0.5 -- -- -- -- -- --F5 Outer Layer 3.1 0.6 0.3 5.1 9.9 3.3 0.8 -- -- Intermediate Layer 1.1 1.6 0.6 -- -- -- -- -- --F6 Outer Layer 3.4 0.3 0.3 7.4 10.1 5.5 2.2 -- -- Intermediate Layer 1.0 1.4 0.7 -- -- -- -- -- --F7 Outer Layer 3.5 1.0 0.7 7.6 10.5 3.6 1.1 3.1 0.4 Intermediate Layer 0.8 1.5 0.5 -- -- -- -- -- --__________________________________________________________________________
TABLE 3-2__________________________________________________________________________(Comparative example) C Si Mn Mo Cr V Nb Co W__________________________________________________________________________G1 Outer Layer 2.7 0.6 0.5 4.1 8.5 3.4 0.9 -- -- Intermediate Layer 0.9 1.5 0.6 -- -- -- -- -- --G2 Outer Layer 2.6 0.5 0.6 4.2 6.6 4.5 0.9 -- -- Intermediate Layer 1.1 1.6 0.6 -- -- -- -- -- --G3 Outer Layer 2.8 0.3 0.3 5.1 8.5 4.9 1.4 -- -- Intermediate Layer 0.9 1.4 0.7 -- -- -- -- -- --G4 Outer Layer 3.1 0.8 0.4 5.1 10.0 4.3 0.7 -- -- Intermediate Layer 0.7 1.5 0.5 -- -- -- -- -- --G5 Outer Layer 3.8 1.3 0.4 7.5 10.2 5.3 2.3 -- -- Intermediate Layer 0.7 1.6 0.6 -- -- -- -- -- --G6 Outer Layer 2.2 0.3 0.3 2.5 6.2 5.3 1.6 -- -- Intermediate Layer 1.4 2.0 0.8 -- -- -- -- -- --__________________________________________________________________________
TABLE 4__________________________________________________________________________C % inintermediate Boundary LayerLayer 2-0.5 (C-0.2 V-0.11 Nb) porosity index__________________________________________________________________________F1 1.2 1.07 (outer layer) 0 Example of theF2 1.2 1.17 (outer layer) 0.1 inventionF3 1.5 1.06 (outer layer) 0F4 1.5 1.10 (outer layer) 0F5 1.1 0.82 (outer layer) 0F6 1.0 0.97 (outer layer) 0F7 0.8 0.67 (outer layer) 0G1 0.9 1.04 (outer layer) 64 ComparativeG2 1.1 1.20 (outer layer) 49 ExampleG3 0.9 1.17 (outer layer) 138G4 0.7 0.92 (outer layer) 57G5 0.7 0.76 (outer layer) 18G5 1.4 1.52 (outer layer) 6__________________________________________________________________________
Example 3
Samples equivalent to roll outer layer materials and having chemical compositions shown in Table 5 were made by melting and casting, and quenched at temperatures which started from 1000° C. and were then tempered at 550° C. to manufacture sample materials. A two-disk sliding friction test, which employed a sample material of φ50×10 and the other material of φ190×15, was conducted at a sliding rate of 14.2% for 200 minutes by rotating the sample at 800 rpm in a state wherein it was pressed against the other material heated at 800° C. under a pressure of 130 kg while the sample was water cooled. The surface of each of the samples subjected to the test was SEM observed to examine the number of cracks generated in the carbide.
The relationships between the number of cracks generated and the amounts of Mo and Cr are shown in FIG. 4. The number of cracks generated is reduced by half at 2% or above of Mo. Up to about 15% of Mo, the more the amount of Mo, the less the number of cracks generated. The number of cracks generated in a 9% Cr material is less than that in a 7% Cr material. Thus, the effect of Cr addition is discerned.
Cracks in the carbide are generated by synergism of rolling and heat fatigue and sliding stress during the test. Thus, the results obtained by the experiments are a simulation of the fatigue which will occur in the roll surface in an actual rolling, and thus clarify that the materials according to the present invention exhibit excellent banding resistance.
TABLE 5__________________________________________________________________________C Si Mn Cr Mo V Nb Mo/Cr__________________________________________________________________________7% Cr2.9 0.3 0.3 7.1 1.2 5.9 2.0 0.17 Comparative Examplematerial3.0 0.3 0.3 7.2 2.2 5.8 2.2 0.31 Example of the2.9 0.4 0.3 7.2 4.1 6.1 2.1 0.57 invention9% Cr3.0 0.3 0.4 9.2 2.3 6.0 2.0 0.25material3.1 0.4 0.3 9.1 3.2 6.0 2.0 0.353.1 0.3 0.3 9.1 4.8 6.1 2.1 0.533.2 0.4 0.3 9.0 7.6 6.0 2.1 0.842.9 0.4 0.4 9.1 1.4 6.2 2.0 1.2512% Cr3.2 0.4 0.2 12.1 2.2 5.9 2.0 0.18material3.2 0.4 0.2 12.0 3.1 5.8 2.2 0.263.1 0.3 0.3 12.0 5.0 6.1 2.1 0.423.2 0.4 0.3 12.1 8.9 6.0 2.0 0.743.1 0.4 0.2 12.0 12.3 6.0 2.0 1.0315% Cr3.2 0.3 0.4 15.0 2.5 6.1 2.1 0.17material3.2 0.4 0.3 14.9 3.9 6.0 2.1 0.263.3 0.3 0.3 15.0 14.1 6.2 2.0 0.94__________________________________________________________________________
Example 4
In the composite rolls shown in Table 3, heat treatment consisting of quenching which started from 1050° C. and hardening at 550° C. was conducted on examples F3 and F4 according to the present invention and comparative example G6. Each of the rolls obtained was used in the second stand in an actual hot strip mill.
It was observed in actual rolling that the rolling load of examples F3 and F4 according to the present invention was equivalent to that of a high Cr cast iron of a conventional roll, as shown in FIG. 6, and that wear-resistance of the examples according to the present invention was at least 6 times that of a high Cr cast iron, as shown in FIG. 7.
Comparative example G6 involves a material in which the composition of the outer layer did not satisfy the restricted range, namely 6.5 C(%)-1.3 V(%)-0.7 Nb(%)=6.29The rolling load of comparative example G6 was about 20% higher than that of a high Cr cast iron roll, and thus surface roughening of the rolled material occurred. Wear resistance of comparative example G6 was inferior to that of the examples according to the present invention.
It is therefore possible according to the present invention to provide a roll for hot rolling by centrifugal casting exhibiting excellent productivity and economical properties in which an outer layer thereof exhibits excellent wear resistance, a low coefficient of friction and hence an excellent surface roughening inhibiting property, and excellent banding resistance, and a greatly reduced breakage accident occurrence during manufacture or rolling.
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A roll outer layer material for hot rolling includes, as analyzed in weight percent, of 2.5-4.0% C, 6.0-20% Cr, 3.0-10.0% V, 0.6-5.0% Nb, 2.0-15% Mo, 3.0% or below Si, 3.0% or below Mn, C, V, Nb and Cr satisfying a following formula (1),
10.5(%)≦6.5.C(%)-1.3.V(%)-0.7.Nb(%)≦2.Cr(%)-2(%)(1)
, and the balance being Fe and incidental impurities. A method of manufacturing a roll for hot rolling includes the steps of centrifugally casting an outer layer material having the above composition, centrifugally casting graphite steel containing 0.5% or above of C as an intermediate layer, and casting an axis material which is a spheroidal graphite cast iron, a flake graphite cast iron or a graphite steel. C is present in the intermediate layer in an amount which satisfies a following formula (2),
C (intermediate layer)≧2.0-0.5 (C-0.2 V-0.11 Nb)(outer layer)(2)
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This is a continuation of application Ser. No. 336,236, filed Dec. 31, 1981 now abandoned.
BACKGROUND OF THE INVENTION
The invention relates to a device for the storage of digital information in the form of magnetic bubbles in a magnetizable layer located in a bias magnetic field which extends transverse to the layer. The device comprises a number of drive patterns which are in the form of contiguous disc patterns of mainly a first scale. Each of the drive patterns comprise a generator element for generating magnetic bubbles which represents a first access element, and a detector element for detecting magnetic bubbles which represents a second access element. Each of the access elements comprise an excitation loop which can be selectively controlled by an electric current. A rotary field generator is provided for driving bubbles along the relevant drive patterns by way of a rotary magnetic field.
A device of this kind is known from the article by G. Almasi, et al entitled "Nucleation of 1-μm" "Bubbles via Charged Walls" (IEEE Trans. on Magnetics, Vol. MAG-16, No. 1, Jan. 1980, pages 89-93. A contiguous disc pattern is to be understood to mean herein a pattern of contiguous more or less disc-shaped elements or rhombic elements. It is formed, notably, by local implantation of ions. Small scale deviations from the basic shape may occur due to edge effects. Due to the fact that the disc patterns are contiguous, the drive patterns have the appearance of straight or curved strips whose edges exhibit a given serration. The domains are driven along these edges. The scale can be defined, for example, as the mean period of the serration.
FIG. 4 of the article by Almasi et al shows a number of drive patterns, each of which comprises a generator loop. The generator loops being electrically connected in series.
The advantage of this contiguous disc technology is that the sizes of the magnetic bubbles may be comparatively small with respect to the smallest detail of the geometry of the drive patterns (for example, in comparison with drive structures comprising T-shaped and I-shaped patterns of vapor-deposited permalloy). If the smallest details to be realized have a fixed dimension which is determined by the technology, therefore, comparatively small bubble diameters can be used. As a result, a high information density can be realized. Due to the small diameters of the bubbles used, the scale of the excitation loops will be large in comparison with the dimensions of the magnetic bubbles. Thus, the mutual positioning of drive patterns and excitation loops is subject to severe requirements as regards accuracy.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a device of the kind described above in which for each period of the rotary magnetic field, access operations can be performed on the bubble information in different phases thereof. As a result, series and parallel operations are combined without giving rise to a substantial increase in the number of control wires for the access elements, while, moreover, a large tolerance range exists as regards the values of the various operational parameters.
According to the invention, contiguous disc patterns having a larger scale are provided at selected locations. As a result, no excessive requirements will be imposed as regards the accuracy of the mutual positioning of the larger disc pattern and an associated excitation loop. Relevant streams of information-carrying bubbles are processed at contiguous disc patterns of a second scale which is at least 1.8 times larger than the first scale. These larger contiguous disc patterns are each associated with a corresponding element of a series of access elements, the relevant excitation loops of the series being included in a first series connection for an excitation current. The first series connection is excitable at least twice per period of the rotary magnetic field in relevant, different phases of the rotary magnetic field. The excitation loops are staggered on the larger disc patterns with phase differences of less then 360° for the selective processing, under the control of an excitation current pulse, of a bubble from the series of magnetic bubbles present on these access elements. Each bubble present in a locally formed preferred position.
Thus, for each period of the rotary magnetic field, the series of access elements is addressed a number of times. Bubble information is processed, each time the series is addressed, in only one of these access elements. "Processing" is to be understood to mean herein the generating of bubble information, the detection of bubble information or the annihilation of bubble information. Thus, each time the series is addressed, an interaction occurs between a signal (the absence or presence of a bubble at a bubble position) in the magnetic (contiguous disc) circuit, and a signal outside the magnetic circuit, i.e. on the excitation loop.
It has been found that a scale which is a factor of 1.8 times larger than the basic scale enables one to provide different excitation loops with mutually different phases. This is subject to the choice of the first or basic scale. The second scale may also be, for example, three times larger than the first scale. In that case several excitation loops can be included in the same series or the first scale may be chosen to be smaller. The mutual phase differences between successive elements of the series may be ≦90°. In that case a comparatively large number of excitation loops can be included in the same series.
The access elements of said series may be detection elements, the excitation current pulse being capable of stretching a magnetic bubble present within the excitation loop. Inside the excitation loop there may be provided a magnetoresistance element which is connected to a detection circuit. When a number of information-containing bubbles (or empty bubble locations) in the relevant drive patterns are transported in parallel to the larger disc pattern, they will be detected in different phases of the rotary magnetic field. Because the excitation loops are connected in series, only a limited number of external connections will be required. If the magnetoresistance elements are also connected in series, again only a small number of external connections will be required, and a parallel/series conversion will be realized.
The access elements of the series may be selectively activatable generator elements in that the excitation pulse can selectively annihilate a magnetic bubble present in the excitation loop. The drive patterns are each associated with a second excitation loop which operates in the same phase and which acts as a generator loop. The second excitation loop is included in a second series connection for an excitation current pulse which can be activated at most once per period of the rotary magnetic field. For each drive pattern a bubble path extends from the generator loop to a storage structure for magnetic bubbles via the access element. Thus, a number of bubbles are generated in parallel in the same phase of the rotary magnetic field, are subsequently transported to the further disc pattern of larger scale, and are selectively annihilated or not annihilated in different phases of the magnetic field in order to assign the information "0" or "1" thereto. Subsequently, the information-containing bubbles or void bubble positions are transported to a storage structure.
This embodiment of the invention is based on the following considerations:
(a) In the same generator loop, a bubble is generated only once per period of the rotary magnetic field. As a result, the phase tolerance in the relevant excitation current pulse is comparatively large. Furthermore, the current pulses may have a comparatively long duration without successive current pulses adversely affecting one another.
(b) When use is made of drive patterns formed by means of the ion implantation technique, the dimension of the bubbles will be independent of the local scale of the drive patterns. The tolerance as regards the intensity of the bias magnetic field will not be affected either by a larger scale.
(c) As a result of the larger scale of the larger disc patterns, they offer more room for the second excitation loop, so that the location of the loop need not satisfy very narrow tolerances. It is also easier to annihilate a bubble than to generate a bubble. Therefore, the generating operation is performed only once per rotary field period in parallel. The information is imparted to the bubbles by selective annihilation. The excitation current pulses for annihilation require only a comparatively short duration. Therefore, it is not objectionable that the same series connection must be capable of performing an annihilation, for example, eight times per rotary field period.
(d) The excitation frequency of the annihilation is higher than the rotary field frequency. As a result, a high bit rate can be realized on the information input. A series/parallel conversion is implicitly realized.
It is also to be noted that the above selective annihilation can be used for the selective modification of the information of a stream of information-containing bubbles, for example, selective erasing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically shows a drive pattern for use in a device according to the invention.
FIG. 2 schematically illustrates the generator elements of a number of drive patterns.
FIG. 3 graphically shows a the currents in the excitation loops as a function of time.
FIG. 4 schematically illustrates the detector elements of a number of drive patterns.
FIG. 5 schematically shows a detection circuit.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a drive pattern for use in a device according to the invention. The disc patterns are shown as rhombi. As has already been stated, the technology may cause small scale deviations during the manufacture thereof. The domains travel along the serrated edges of the drive patterns. The normal scale of the drive patterns is defined as the period of the serration, λ, of the edge. For example, in FIG. 1 is the distance between A and B.
The same normal scale occurs below point C. The reference 20 denotes a disc pattern having a scale which is a factor of 4 times larger in this embodiment than that of the disc patterns at the left and bottom of the Figure. Arrows on the disc element 20 indicate nine preferred positions on the edge of disc 20 for a bubble (1 to 9). These edge positions are successively preferred as the rotary magnetic field rotates to the direction corresponding to the direction of the arrow shown at each of these points. When the rotary field rotates clockwise, the bubbles will travel from the edge position "1" to the edge position "9". In reaction to further rotation of the rotary field, the bubbles will first move along the lower side of the disc element 22 and subsequently, via position 24, in the direction of position 26.
There are also three drive patterns 30, 32, and 34, each of which comprises a closed loop for the bubbles. A conductor 28 is arranged on the plate of magnetic material between the drive pattern 24/26 and the drive patterns 30, 32, and 34. This conductor is to be excited by a current pulse generator (not shown), so that three bubbles can be transported in parallel between these drive patterns. A transport of this kind is known per se. FIG. 1 is not true to scale in this respect. Thus, an attractive storage structure with main loops and auxiliary loops is formed for magnetic bubble memories.
An element for generating a stream of information-containing bubbles will be described with reference to FIG. 2. A bubble detector element may be connected to the main loop according to the known technique. Another detection technique will be described hereinafter with reference to the FIGS. 4 and 5. The bubble detector element can be connected to a number of drive patterns together with or without an element according to FIG. 2. Only the right edge of the pattern of the segment 24-26 is shown in FIG. 2. For the formation of the drive pattern for the magnetic bubbles the left edge is not of importance in this respect, so it need not be described either. Patterns of this kind are also covered by the customary interpretation of "contiguous disc pattern". The disc pattern 22 has a scale which is approximately twice as large as the standard scale (lower part of the figure). In some cases the change from the scale of the element 20 to the standard scale can be realized in one step. In other cases more than one intermediate step (such as the element 22) will be necessary.
FIG. 2 illustrates the generator elements of a number of drive patterns. They are provided together on a single layer of magnetic material. Only the part of each of these drive patterns which corresponds to the part above and to the right of the indication 24 in FIG. 1 is shown. FIG. 2 shows five drive patterns 36, 38, 40, 42, and 44. Each of the drive patterns comprises a first excitation loop which forms part of a current conductor 46 provided on the plate of magnetic material. When the rotary field has the direction indicated in FIG. 1 at the element 20, position 2, the bias magnetic field inside the excitation loop can be counteracted by a suitable current pulse in the conductor 46 to such an extent that a new bubble is formed at this area by nucleation. For all of the drive patterns 36, 38, 40, 42, and 44, this condition is currently satisfied, so that five bubbles are generated in parallel.
The rotary magnetic field which biases the magnetic layer rotates clockwise. The bubbles generated at 48 and corresponding areas are driven so that they are retained for approximately one half of a rotary field cycle in a valley of the drive pattern (for example, at the reference 50) and subsequently they travel to the next valley (for example to the reference 52) during a next half cycle of the rotary field in order to remain there for another half period. In the outside of a bend (for example, along the disc pattern 20 in FIG. 1), more time is required to proceed from one valley to the next valley. In the inside of a bend, (for example, at the reference 24 in FIG. 1), less time is required.
The bubbles are generated at the position 48 when the rotary magnetic field is directed according to the arrow "2" (FIG. 1). Approximately 33/8 cycles of the rotary field are then necessary to transport the bubble to the position "1" in FIG. 1. At that instant, but preferably after 37/8 cycles of the rotary field, the excitation loop 54 can be activated by a current pulse in the conductor 56 so that the bias magnetic field is locally intensified and a bubble present at position 1 is annihilated. After another 1/8 cycle of the rotary magnetic field, that is, after four cycles from the generation of bubble, a bubble can be annihilated at the area of the excitation loop 58 on the drive pattern 38. After 41/8 cycles, a bubble can be annihilated at the area of the excitation loop 60 on the drive pattern 40. After 4 2/8 cycles, a bubble can be annihilated at the area of the excitation loop 62 on the drive pattern 42. After 43/8 cycles, a bubble can be annihilated at the area of the excitation loop 64 on the drive pattern 44.
Further drive patterns are not shown. However, it is also possible to provide further drive patterns which comprise excitation loops which are a mirror image of the relevant excitation loops 54, 58, 60, and 62 in FIG. 2. If only a single excitation of the conductor 46 takes place, so that only a single row of bubbles is simultaneously generated, the conductor 56 can be excited in eight different phases of the rotary magnetic field for the selective annihilation each time of one bubble of a row of eight bubbles. It is to be noted, however, that the situation will be different if a continuous row of the bubbles is generated in each cycle of the rotary magnetic field. When the first row of bubbles has reached the positions which correspond to the loop 64, the next row will already have reached the positions of the loop 54 again. This is because this row remains stationary at this area 54 for approximately one half cycle of the rotary magnetic field. If the loop 54 is not used and its mirror image (at position 9 in FIG. 1) is not used either, the conductor 56 in the configuration shown can be excited seven times per cycle of the rotary field in order to annihilate a magnetic bubble. The conductor 46 can then be excited once per cycle of the rotary magnetic field in order to generate these bubbles.
FIG. 3 in this respect shows a time diagram of the currents in the excitation loops. Curve 80 shows the excitation of the conductor 46. This excitation operation takes place once per cycle. The length of the cycle of the rotary magnetic field is indicated by the arrow P. Curve 82 shows the excitation of the conductor 56. Thus, with the orientations each time shifted through 45° according to FIG. 2, this conductor can be excited at most seven times per cycle for the selective introduction of information. Therefore, only at the phase "North-West" (corresponding to arrow "2") does a pulse occur on the curve 80. On the curve 82 only at the phase "West" is a pulse absent. The excitation pulse of curve 80 may be longer than that shown. In other cases a larger or smaller number of loops may be used per period.
FIG. 4 illustrates the detector elements of a number of drive patterns. Four such patterns (100, 102, 104, and 106) having this larger scale are shown. They may be connected to the remainder of the drive patterns in the same way as shown in FIG. 2 for the disc patterns 36, 38, 40, 42, and 44. These connections have been omitted in FIG. 4 for the sake of clarity. On these disc patterns there are arranged the excitation loops 108, 110, 112, and 114 according to relevant orientations which differ by 45° in this embodiment. They are connected in series for an excitation current which is activated in the relevant phases of the rotary magnetic field, exactly like the loops 54, 58, 60, 62 and 64 in FIG. 2. The generator for the excitation current is not shown.
Inside the excitation loops there are provided magnetoresistance elements 116, 118, 120, and 122 which are denoted by shading. These elements consist of permalloy provided on the plate of magnetic material. They are excited by a measuring current, the voltage drop being determined by the resistance which depends on a locally present magnetic bubble. The elements 116 and 118 are electrically connected in series, as are the elements 120 and 122. Each pair serves each time as a reference detector (dummy) for the other pair. As a result, the disturbances by the rotary magnetic field are compensated for.
The following remarks can be made as regards the dimensions. The period of the serration of the drive patterns amounts to, for example, four times the bubble diameter in the normal scale. The diagonal of the elements having the second scale (100, 102 . . . ) is then, for example, four times larger. Thus, for a bubble diameter of 2 microns, the diagonals of the large patterns will then be 32 micrometers. The length of the magnetoresistive elements will then be, for example, approximately 60 microns, regardless of the orientation.
FIG. 5 is a detailed representation of a detection circuit. The terminal 138 receives the measuring current which is divided into two equal parts by the resistors shown. If the resistor 132 represents the measuring resistance, the resistance 134 will form the reference detector and vice versa. The signals are received by the differential amplifier 130 which, therefore, can generate a detection signal four times per period of the rotary field in this embodiment. The waveform of the detector currents is as shown in FIG. 3, curve 82, but reversed, so that now the field inside the exciation loops has to be decreased. The duration of an excitation pulse must be sufficient to enable a magnetic bubble to cover the entire associated magnetoresistance element by expansion. There must also be a sufficient period of time available for the subsequent contraction. In the set-up shown in FIG. 4, the measuring resistance as well as the reference resistance are formed by two of the elements 116, 118, 120, and 122 in series. The roles of measuring resistance and reference resistance are then reversed once each cycle. Thus, a given parallel/series conversion is realized. The information successively appears on the output 136 of the differential amplifier 130.
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A memory device utilizing magnetic bubbles which are driven by a rotary magnetic field on contiguous disc drive patterns. These disc patterns have mainly a first scale. Each drive pattern also comprises a further disc pattern of a substantially larger scale. These further disc patterns each time comprise an excitation loop. These loops are mutually staggered with respect to the phase of the rotary field and are electrically connected in series. The series connection can be excited during relevant phases of the rotary magnetic field in order to selectively process a bubble then present in a locally formed preferred position from among the magnetic bubbles present on the larger disc patterns. The processing operation may be generating, detecting and annihilating bubbles.
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FIELD OF THE INVENTION
[0001] The field of the present invention relates to the enhanced recovery of hydrocarbons in reservoir rocks, by means of medium sweep techniques using aqueous solutions comprising chemical products.
BACKGROUND OF THE INVENTION
[0002] The recovery of oil from oil fields often requires injection of a displacing fluid, most often water, to maintain the pressure in the reservoir so as to allow production, through displacement of the oil in place, from injection wells to production wells arranged according to a previously optimized scheme for the field considered.
[0003] In the case of water injection, this displacing fluid can be injected alone or it can, on the contrary, contain chemical agents intended to improve sweeping of the oil in place.
[0004] Among these chemical agents, on the one hand, surfactants are intended to reduce trapping of the oil in the pores of the rock through reduction of the water-oil interfacial tension and possibly modification of the rock wettability; on the other hand, polymers provide higher viscosity to the water, thus increasing its hydrocarbon phase sweep efficiency.
[0005] However, these two categories of enhancing products undergo losses in the reservoir due to many phenomena, among which retention or adsorption of the products on the rock, which can be high and obviously detrimental to the economic interest of such recovery methods. The presence of divalent cations in place in the reservoir water and on the rock minerals (notably clays) still increases these losses.
[0006] The injection of other agents, generally alkaline products (such as sodium carbonate, soda, etc.) is therefore recommended prior to injecting aqueous sweeping fluids containing enhancing products such as surfactants and polymers. These rock conditioning agents, dissolved in various chemical forms, dissociated or not into ions, involve many chemical equilibria in aqueous phase:
[0007] salt precipitation reactions (divalent cation salts in place notably),
[0008] multiple interactions with the rock (ion exchange and adsorption with modification of the charges of the solid surface),
[0009] possibly also reactions with some constituents of the oil in place (formation of soaps with the surfactant). The injection of a conditioning agent alone can even already improve the recovery of oil in relation to the conventional injection of water without any chemical agent.
[0010] All these physico-chemical phenomena have to be taken into account in order to determine the volumes and concentrations of the products to be injected, and the modes of injection (flow rates, distribution in the field via the injection scheme, etc.), for the phase of conditioning the reservoir rock (injection of alkaline conditioning agents) as well as, subsequently, the enhanced water slugs (through surfactants and/or polymers), intended to improve the recovery and the displacement efficiency.
[0011] This dimensioning of the injected solutions is essential because it determines the feasibility and the profitability of these methods, via:
[0012] (a) the size and the cost of the facilities: surface facilities for preparing the solutions (surfactants, polymers); number, arrangement and well pumping equipments,
[0013] (b) the conditioning product and enhancer masses required (volumes and concentrations), therefore their cost,
[0014] (c) and, of course, the efficiency in terms of oil recovery.
[0015] Dimensioning these conditioning product and enhancer injections involves computations on a reservoir model discretized in form of elementary units of volume (cells), wherein the fluxes of the phases in presence (water and hydrocarbon phases: oil and/or gas), the transport and the evolution of the chemical species (bringing into or keeping in solution, precipitation, adsorption, conversion to other chemical species) have to be calculated so as to determine the amounts of product lost within the reservoir and the oil recovered in the production wells. This dimensioning involves studying the sensitivity to the multiple operating parameters (concentrations, slug size, flow rates, well placement, etc.), which therefore requires a reliable, powerful (fast) and efficient (in terms of usability of the results) simulator.
[0016] Reliability implies taking account of the various physico-chemical mechanisms involved. Power means short simulation times so as to be able to simulate multiple scenarios intended to understand and to select a dimensioning that guarantees the feasibility and maximizes the profitability of the operation.
[0017] Finally, the simulator efficiency means here a prediction tool requiring known information in a number of data as limited as possible by the user, and whose results interpretation and optimization is easy and fast via sensitivity studies with a small number of input parameters.
[0018] Considering the complex mode of action of the aforementioned products, the prediction models are complex because they usually include the multiple chemical species involved in the equilibrium reactions within the aqueous phase, such as: water-oil equilibrium, reactions of precipitation, adsorption on the rock, or others.
[0019] Taking into account all the chemical species and all the phenomena involved in the transport of the enhancing and conditioning products on the reservoir scale considerably increases the size of the numerical systems to be solved and therefore the computation time.
SUMMARY OF THE INVENTION
[0020] The present invention thus relates to a method for enhanced hydrocarbon recovery in an underground reservoir rock comprising injecting an aqueous conditioning solution containing an alkaline agent, wherein the following stages are carried out:
[0021] determining the in-situ effects of said injection by means of a flow simulation on a reservoir model discretized in cells, said simulation taking into account the transport from cell to cell of the alkaline agent as the principal agent and without taking account of the transport from cell to cell of species referred to as intermediate species that result from the injection of the principal agent in aqueous solution, the concentrations of said intermediate species being determined analytically in each cell,
[0022] deducing from said simulation the injection conditions and the physicochemical characteristics of said aqueous conditioning solution.
[0023] The evolution of the pH value in each cell can be deduced from the alkaline solution injection simulation.
[0024] The alkaline agent loss in the reservoir rock can be deduced.
[0025] The alkaline agent can be Na 2 CO 3 .
DETAILED DESCRIPTION
[0026] The object of the invention is to overcome the heavy drawback linked with the complexity of the numerical injection dimensioning models by maintaining the reliability, by improving the ease of implementation through a limited parametrization (i.e. minimum information to be known by the user) and by allowing easier interpretation of results obtained more rapidly. In order to illustrate the present invention, we consider hereafter the injection of sodium carbonate (Na 2 CO 3 ), which is the alkaline agent conventionally used for alkaline solution injection. To simplify the illustration of the advantages of the present invention, we consider the simulation of the injection, into a reservoir, of a solution of this alkaline agent Na 2 CO 3 in the absence of any other salt.
[0027] The implementation of the present invention comprises the stages that consist, at each time step of the simulation of such a displacement, in:
[0028] 1. modelling the transport from cell to cell of the only chemical additive(s) of the injection water, in the present case carbonate Na 2 CO 3 , referred to as the “principal” species, without taking into account the transport of the chemical species referred to as “intermediate” species resulting from the multiple equilibria obtained by bringing this “principal” agent into aqueous solution, i.e., in the present case, HCO 3 − , CO 3 2− , H 2 CO 3 , Na + , H + and OH − ;
[0029] 2. determining locally, in each reservoir cell, and directly through analytical means, the concentrations of the multiple species in aqueous phase resulting from dissociation, adsorption on the rock, and possibly precipitation (in the presence of divalent cations in place notably) and/or reaction equilibria. This determination allows to deduce the effects of the chemical agent, notably the pH modification and the surface condition (wettability) of the rock in the case of an alkaline agent. The analytical solution advantageously guarantees that solutions are obtained rapidly in comparison with the conventional iterative numerical methods such as, for example, Newton's method.
[0030] The concentrations values relative to the chemical species in solution resulting from the transport of the alkaline agent between the cells and the various local equilibria in each cell allow to update:
[0031] the phase properties, notably pH value, interfacial tension, viscosity,
[0032] the displacement parameters, for example by means of relative permeability curves as a function of the capillary number,
[0033] these data being required for precise and reliable solution of the transport fluxes from cell to cell.
[0034] In order to clearly illustrate the advantages of the present invention in relation to the existing know-how, we compare hereafter, by way of non-limitative example, the injection of a Na 2 CO 3 aqueous solution as the “principal” conditioning agent and in the absence of any other salt. We also compare the approach and the solution methods according to the present invention with those implemented in the prior art. It can be noted that the effects of this agent (carbonate) result from the dissociation of the CO 3 2− carbonate ions to HCO 3 − ions and OH − ions, the latter having the effect of modifying the pH of the aqueous solution and the surface condition of the rock due to their adsorption by the rock.
[0035] Approach No.1 defines 2 species, the Na + and OH − ions, to the exclusion of any other principal or secondary species. This approach is predictive of the pH evolution of the solutions produced by the production wells only in the case of soda injection, and not in the case of sodium carbonate injection.
[0036] In fact, it is not possible to consider that the injection of a sodium carbonate concentration in aqueous phase is equivalent to the injection of the OH − ions obtained after bringing this carbonate into solution, because the CO 3 2 − carbonate ions are not totally dissociated into OH − and HCO 3 − ions, they rather dissociate as they progress in the reservoir due to the equilibrium displacement (CO 3 2− +H 2 O->HCO 3 − +OH − ) caused by the adsorption of the OH − ions by the reservoir rock. This behavior is referred to as “buffer” effect.
[0037] Approach No.2 is notably described in the SPE Reservoir Engineering issue of May 1991 by B. Bazin and J. Labrid: “ Ion Exchange and Dissolution/Precipitation Modeling: Application to the Injection of Aqueous Fluids Into a Reservoir Sandstone ”, pages 233-238. This approach takes account of the displacement from cell to cell that involves other chemical species (monovalent and divalent salts other than those coming from sodium carbonate). This approach No.2 is predictive, but complex and cumbersome insofar as the method is iterative.
[0038] Indeed, the two advantages of the present invention in relation to this approach No.2 appear in lines A and B of the table below.
[0000]
Approach No. 1
Approach No. 2
Present invention
Input data relative
Na + and OH
Na + and CO 3 2− concentrations
Na 2 CO 3 concentration
to the solution
concentrations
equal in moles to that of
injected
CO 3 2− carbonate, which is
the active species
A. Principal
Na + , OH −
Na + , total carbon C
Na 2 CO 3
species transported
(C═H 2 CO 3 + HCO 3 − + CO 3 2− )
in aqueous phase
Local equilibria
OH − adsorption
(1) H 2 O <--> H + + OH −
within each cell
equilibrium:
(2) CO 3 2− + H 2 O <--> HCO 3 − + OH −
allowing to
OH − solution <-->OH − rock
(3) HCO 3 − + H 2 O <--> H 2 CO 3 + OH − (equilibrium not
calculate the
considered within the context of the present invention)
secondary species
(4) OH − adsorption equilibrium:
concentrations, the
OH − solution <--> OH − rock
resulting pH, and
the concentrations
of the principal
species transported
in aqueous phase
B. Mode of (local)
Analytical solution of
Iterative solution of the
Direct analytical solution
solution of the
the adsorption
CO 3 2− , HCO 3 − , H 2 CO 3 , OH − rock and OH − solution
of (1), (2) and (4) (H 2 CO 3
(principal and
equilibrium only
concentrations (from which
being negligible in a basic
secondary) species
the pH value is deduced)
medium) giving access to
equilibria of the
the pH and to the
aqueous solution
concentration of the
within each cell
principal species Na 2 CO 3
in aqueous solution
[0039] line A of the table indicates that the number of principal species transported by simulation is limited to the necessary minimum (only one in the example considered) in the model object of the present invention, i.e. only the conditioning additive(s), without taking account of the species generated in aqueous solution. The size of the numerical transport model to be solved is thus reduced. Therefore, in the present example, for each cell of the reservoir model, the concentration balances of the chemical species in aqueous phase should be written only for one principal species instead of 2;
[0040] line B of the table indicates that the equilibria solution within each cell, intended to determine notably the effects of the principal additive, the reduction of the adsorbing power of the rock through adsorption of the secondary chemical species OH − , is carried out using a direct analytical method within the scope of the present invention, instead of an iterative method within the scope of approach No.2, which is an advantage in terms of robustness and a guarantee for obtaining the solutions. Considering these advantages, the use of the analytical method is adopted, including all the cases where its use requires approximations in the equilibria processing, and the absence of significant impact of said approximations on the predictions is controlled separately (according to the state of the art), which is for example the case here for the hypothesis of absence of the chemical species H 2 CO 3 , totally permitted considering the basic character of the solutions in presence, which prevents dissociation of the species HCO 3 − .
[0041] It can be noted that the present invention can be implemented without any significant loss of precision in the quality of the results obtained. Thus, for the example described above, two simulators operating according to the present invention and to approach No.2 of the prior art predict quasi-identical pH value evolutions, i.e. whose order of magnitude of the differences (of the order of 0.1 unit pH maximum) is smaller than the differences (considered acceptable by the person skilled in the art) between the predictions of the models and the real observations from laboratory experiments.
[0042] FIG. 1 illustrates these results. It relates to the pH evolution at the outlet of a (carbonate-free) water-saturated laboratory core sample during the injection of one pore volume (VP) of an aqueous sodium carbonate solution at a concentration of 10 g/l, followed by the injection of a high volume of flush water.
[0043] The pH value of the solution (effluent) at the core outlet was measured at regular intervals throughout the injection (about 8 pore volumes VP). The dots in FIG. 1 represent the measurements. This experiment was simulated according to approach No.2 on the one hand (represented in FIG. 1 by a dot-and-dash line) and according to the method of the present invention on the other hand (represented in FIG. 1 by a full line). The goal of the simulation is to reproduce the pH evolution of the effluent measured after breakthrough of the solution injected, said breakthrough being obtained after injecting about 1 pore volume VP. FIG. 1 shows that the pH response curve simulated by means of the method according to the present invention is quasi-superimposed on the response curve simulated using approach No.2. Furthermore, the difference between the two simulated curves is much smaller than the difference (considered acceptable) between any one of these curves and the measured data.
[0044] Another example is described hereafter in order to show the application of the invention to more complex situations.
[0045] It consists in injecting an alkaline agent into a reservoir whose water in place contains divalent calcium and magnesium cations (in form of chlorides for example) that precipitate in the presence of carbonate. During an alkaline injection, calcium carbonate and magnesium carbonate precipitate in the pores of the rock. By disregarding the effects of cation exchanges between the rock and the solution, the injection of Na 2 CO 3 then involves the following equilibria:
[0000] H 2 O<-->H + +OH − (1)
[0000] CO 3 2− +H 2 O<-->HCO 3 − +OH − (2)
[0000] HCO 3 − +H 2 O<-->H 2 CO 3 +OH − (3)
[0000] OH − adsorption equilibrium: OH − solution<-->OH − rock (4)
[0000] Ca ++ +CO 3 2− <-->CaCO 3 (s) (5)
[0000] Mg ++ +CO 3 2− <-->MgCO 3 (s) (6)
[0046] where CaCO 3 (s) and MgCO 3 (s) represent the precipitated calcium and magnesium carbonates (solids).
[0047] It is reminded that equilibrium (3) is almost entirely displaced to the left in a basic medium, which is the case with an alkaline injection of sodium (or soda) carbonate. 5 equilibria then remain, which involve the nine (9) species H + , OH − solution (OH − in solution), OH − rock (OH − adsorbed), CO 3 2− , HCO 3 2− , Ca++, CaCO 3 (s), Mg ++ and MgCO 3 (s) connected by the following seven (7) relations:
[0048] the equations of the previous 4 equilibria in aqueous solution:
[0000]
k
1
=
[
H
+
]
[
OH
-
]
k
2
=
[
HCO
3
-
]
[
OH
-
]
[
CO
3
2
-
]
ks
3
=
[
Ca
2
+
]
[
CO
3
2
-
]
ks
4
=
[
Mg
2
+
]
[
CO
3
2
-
]
[0049] an adsorption equilibrium for the OH − ions distributed among the aqueous solution and the solid surface of the rock according to an adsorption isotherm of the form as follows:
[0000]
q
ads
=
q
ma
x
b
·
[
OH
-
]
1
+
b
·
[
OH
-
]
,
[0050] where q ad , and q max represent the mass fractions adsorbed and adsorbable on the rock, [OH − ] the concentration of OH − in aqueous solution, b a characteristic constant,
[0051] an electroneutrality equation for the aqueous solution,
[0052] and finally a species conservation equation: all of the carbon in solution coming from the carbonate of the injected solution.
[0053] In a first approach, the problem thus comprises two degrees of freedom (9 minus 7).
[0054] Two strategies are possible to solve this problem:
[0055] 1. According to the prior art, at least 2 species are transported and the concentrations of the other species, notably the OH − ions in solution adsorbed by the solid, are determined locally in each cell using an iterative method.
[0056] 2. According to the present invention, only one principal species is transported, the chemical agent (carbonate) in solution. Locally, in each cell, the concentrations of the OH − ions in solution adsorbed by the solid are determined by direct analytical solution of the previous equations. Such a calculation is possible because the precipitations of the divalent ions in place only subtract the injected agent (carbonate) as it reaches the cells.
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The present invention relates to a method for enhanced hydrocarbon recovery in an underground reservoir rock comprising injecting an aqueous conditioning solution containing an alkaline agent, wherein the in-situ effects of the injection are determined by means of a flow simulation on a reservoir model discretized in cells, by taking into account the transport of the alkaline agent and without taking into account the transport of species referred to as intermediate species that result from the injection of the principal agent in aqueous solution, the intermediate species concentrations being determined analytically in each cell.
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FIELD OF THE INVENTION
[0001] The present invention is a device designed for the treatment of wounds and bums, through the enhancement of circulation while providing an active anti-microbial agent to deter the risk of infection.
BACKGROUND OF THE INVENTION
[0002] When the body sustains a wound or a bum, the trauma to the tissue is susceptible to infection and possible necrosis. Commonly, most wounds, pending on the severity, heal easily with little or no significant treatment. Some wounds, however, pending on the patient, require more treatment in order to assure proper healing.
[0003] For many patients, either due to their failure to seek care altogether or get proper medical treatment or because of the body's own inability to ward off infection results in wound or a burn that becomes severely infected. Contributing many times to the body's slow process of healing is the lack of presence of adequate circulation to the site of injury. Such circumstances require the need for a device that will provide enhanced circulation to the site while providing a zone of inhibition from infection.
[0004] Therefore, the need exists for a treatment device and method for the treatment of wounds and bums, and additional for a treatment device and method to treat wounds and bums in patients suffering from circulatory problems.
BRIEF SUMMARY OF THE INVENTION
[0005] A device for treating wounds on an individual is disclosed. The device includes a flexible foam, a treatment suitable for treating the wound placed within or in relative proximity to the foam, and a flexible fabric with recoverable properties substantially circumferencing the wound and the treated foam. The flexible fabric maintains the treated foam in substantial proximity to the wound to allow the treatment to treat the wound.
[0006] A bandage suitable for treating wounds on an exterior limb is disclosed. The bandage includes a butterfly shaped flexible fabric, at least one Hook and loop material type fastener attachment located on the edge of the butterfly shaped flexible fabric, at least two foam layers located axially in the center of the butterfly shaped flexible fabric, and a medication suitable for treating the wound proximately located with respect to at least a first of the at least two foam layers. The butterfly shaped flexible fabric is suitable to be wrapped around the limb and fastened using the at least one Hook and loop material type fastener attachment, and the wrapped fabric maintains the at least two foam layers in proximate location with the wound such that the medication is located appropriately with the wound to provide treatment.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0007] Understanding of the present invention will be facilitated by consideration of the following detailed description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings, in which like numerals refer to like parts and in which:
[0008] FIG. 1 depicts a plan view of a first bandage according to the present invention;
[0009] FIG. 2 depicts a side elevation of the bandage of FIG. 1 ;
[0010] FIG. 3 depicts a side elevation of a second bandage embodiment having a second, different edge profile;
[0011] FIG. 4 depicts a side elevation of a third bandage embodiment having yet a third, different edge profile;
[0012] FIG. 5 depicts a top plan view of a fourth bandage embodiment different in size from the earlier embodiments;
[0013] FIGS. 6A and 6B illustrate a bandage embodiment of the present invention;
[0014] FIG. 7 illustrates one of the bandages of the previous figures being used on a patient's limb with an auxiliary foam pad;
[0015] FIG. 8 depicts a side elevation of an auxiliary foam boot which may be used with or without a bandage of the present invention;
[0016] FIG. 9 depicts a side elevation of an auxiliary foam low boot, which may be used with or without bandages of the present invention;
[0017] FIG. 10 depicts a top plan view of the boots of FIGS. 8 and 9 ;
[0018] FIG. 11 depicts a leg bandage according to an aspect of the present invention;
[0019] FIG. 12 depicts a bandage according to an aspect of the present invention; and,
[0020] FIG. 13 depicts an embodiment of the present invention including a foam according to an aspect of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] It is to be understood that the figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the present invention, while eliminating, for the purpose of clarity, many other elements found in typical treatment devices, methods and systems. Those of ordinary skill in the art may recognize that other elements and/or steps are desirable and/or required in implementing the present invention. However, because such elements and steps are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements and steps is not provided herein. The disclosure herein is directed to all such variations and modifications to such elements and methods known to those skilled in the art.
[0022] FIGS. 1 and 2 depict an exemplary bandage embodiment according to the present invention. Bandage 10 may include an outer, flexible adhesive member 11 , in the form of a flexible strip 12 , with a layer of adhesive 13 , such as an FDA approved medical grade adhesive, on an inner major planar side. An outer major planar side of strip 12 forms an outer side of bandage 10 . Bandage 10 further includes a flexible foam inner member 14 that may be at least generally planar and that may be generally centered on strip 12 . An adhesive, or other adhering agent, such as Hook and loop material type fastener, for example, on inner major side of the strip may be used to fix one major side, such as a proximal side of inner member 14 facing strip 12 , to strip 12 , and at least some of adhering agent 13 may be exposed or exposable under a release strip (not depicted) on flexible strip 12 extending around the foam inner member 14 , thereby allowing for the securing of bandage 10 . A thin liner 16 formed by a layer of conventional bandage, such as gauze or other similar material, conventionally used to directly contact an open wound may be provided on the remaining, distal major side of foam member 14 facing away from flexible strip 12 , so as to prevent direct contact of the foam with the user's skin or wound. The foam may be flexible, and may be, for example, a polymer-based foam of a density selected to respond to arterial and/or veinal circulatory system pulses, such as by allowing for deformation, by the pulses, and a springing back, by the foam, to its original position after the arterial or veinal blood vessel begins to relax. Thus, the foam may act like an auxiliary, external blood pump. Alternatively, minimal contact of the foam with the body may be employed. In such a configuration, a contra-compression may be used, to thereby provide only slight contact to the wound or burn.
[0023] The foam member may be open celled for air passage therethrough. One such foam may be a polyether foam grade, which may have the following characteristics: an apparent density of between about 0.77 and 0.97 lbs/ft 3 ; an indentation force deflection of about 28-34 lbs to achieve a 25% deflection in a four (4) inch thick piece of foam, fourteen (14) inches square in size; a tensile strength of about 10 PSI (KPA); an ultimate elongation of 100%; a tear strength of about 1 lb per inch; and a compression set of about 10% loss when compressed 90% for about 22 hours at 70° C. Similar foams in a range of densities of at least between 0.5 and 6 lbs/ft 3 may likewise be used successfully with the present invention.
[0024] The foam member, or one or more layers thereof, may be about one-half to about one and one-half inches thick. The thinner material may be suggested for grade 1 dermatological conditions (redness) while a thicker material may be suggested for all dermatological conditions above grade 1 . Foams thicker than about one and one-half inch might also be used. Forms of foam other than sheet, and other porous or otherwise gas filled flexible solid materials, might be used in place of conventional sheet foam described above. Foams may be placed in multiple layers to obtain maximum therapeutic effect, and the characteristics of each layer may differ. For example, the thickness of each layer may be varied, and the medications or treatments at each layer may be varied, such as to allow timed release of different medications or treatments, at different times, by different layers. Further, for example, certain treatments may be undesirable for placement in direct contact with skin, but may nonetheless be therapeutic in nature if placed proximate to the afflicted area. The layers of foam may number two, three, or four, for example.
[0025] Treatments placed in or on the foam may take the form of a liquid, such as a salve or the like, or the form of a crystal, such as a nano crystal, for example. The treatments may be or include therapeutic remedies to speed the curing of the patient's affliction. Such treatments may include analgesics, pain relievers, antiseptics configured to clean contaminated wounds and bums, antibiotics for infections or sepsis, medicated dressings, corticosteroid hormones, tetanus shots, growth factors or other substances that stimulate healing. Treatments may further include characteristics that match, or simplify association with, the characteristics of the foam used in the bandage. For example, foam may contain any anti-microbial agents which will ensure a decrease in patient's bioload to a wound thus preventing the risk of infection. Examples may include silver in various forms, or other anti-biotic therapy. For example, AlphaSan RC2000 powder from Milliken contains 10% silver. This may be a high grade and high concentration of silver in a crystallized form, which may allow for heavier loading of the foam with the crystals than lower grade silver content powders. For example, the silver sodium hydrogen zirconium phosphate may include a silver ion concentration of about 0.5 to about 1.0%. Further, the silver sodium hydrogen zirconium phosphate may include a silver ion concentration of about 0.3 to about 1.5%. Further, for example, this silver may be provided in the form of a nano crystallized silver sodium hydrogen zirconium phosphate, which based on the loading of the foam, may provide a silver ion concentration of 8.5%×0.10 (10%)=0.85%.
[0026] Liner 16 may be any conventional cotton, polymer or cotton/polymer blend bandage gauze from any of a variety of suppliers. Liner 16 may be as thin as practicable. The gauze may be treated with a coating such as Teflon, or may be made from such a material to prevent sticking to the wound. For other materials, a coating 18 may be provided on the gauze member 16 of A+D Ointment or other suitable, dermatological ointment. A layer 20 of medication, e.g., an antibiotic and/or antifungal ointment, may be applied on the exposed upper surface over or in place of the dermatological ointment for direct contact with the afflicted area.
[0027] Liner 16 and underlying foam member 14 may be of a size to fully span and extend beyond the edges of any afflicted area, the wound or burn, and adhering member 12 may extend at least two more inches beyond the outer periphery of foam member 14 (or foam member 14 with gauze 16 ) on all sides. Alternatively, the foam member or members may extend beyond the outer periphery of the adhering member, as discussed further hereinbelow.
[0028] As illustrated in FIG. 2 , any sharply delineated edges or other potential contact sources on bandage 10 may be eliminated. To that end, thinnest liner 16 may be used to minimize any step around the outer perimeter of liner 16 . Also, the foam material, which may be supplied in generally planar sheets, may be provided with side edges 17 which extend transversely to the major sides of foam inner member 14 and flexible strip 11 and which may be other than perpendicular to the generally planar and parallel opposing major sides of foam member 14 .
[0029] More specifically, each foam member 14 has an outer perimeter formed by side edges 17 , which extends around and between its pair of opposing major sides. The foam inner member may diminish in thickness or change in shape in the outer perimeter around the foam inner member sufficiently smoothly to avoid creation of any abrupt contact change along the skin of the individual wearing the bandage. Such an abrupt contact change may hinder blood flow through the skin under the foam inner member. Thus, the perimeter may lack any substantial discontinuity (e.g. transversely extending step or other change in height of the member or the like along the periphery) sufficiently abrupt to create a discontinuous contact change along the skin of the individual receiving the bandage along the periphery of the foam inner member. Generally speaking, a discontinuity may be caused by a sharp edge, that is, a side edge with a surface perpendicular or at least sufficiently near perpendicular to the plane of foam member 14 to cause the skin at the perimeter of the foam inner member to fold around the edge of the perimeter sufficiently severely to reduce or stop the flow of blood through the fold of the skin.
[0030] Bandage 10 may also take the form of a tapered edge surface which may need not be straight. As may be evident to those possessing an ordinary skill in the pertinent arts, undercuts such as those depicted in FIGS. 2 and 3 may provide at least as uniform a contact application as the tapered cut of FIG. 4 , while providing more uniform contact of the foam to the wearer's skin over the entire area of the foam. Unless such edge treatment is provided to the foam, or some other treatment is provided to equivalently eliminate any abrupt transition along the outer periphery of foam member 14 , a discontinuous contact change may be created near the afflicted area, and such a transition may interfere with blood flow through and immediately below the skin to the afflicted area. To the same end, adhering member 11 may be as thin as practicable to eliminate the creation of a relatively sharp edge at the outer periphery of either member, because such edge may also act as a contact source cutting off the blood flow to the skin, such as especially where the bandaged area of the wearer must be placed upon a support surface.
[0031] Bandage 10 may be applied to the afflicted area with or without medication or other such materials on its exposed treatment surface and adhered to the body of the patient for a period of time depending upon a treatment selected. Bandages of the present invention may be applied to the afflicted area with moderate contact, something between what would be regarded as a loose fitting and a tight fitting for a bandage. The bandage may be applied to the afflicted area with enough contact so that circulatory system pulses are transmitted to the foam and the foam may be able to compress and relax in response to the circulatory system pulses but not so tight as to curtail or diminish the occurrence or strength of the circulatory pulses. Obviously, the optimal contact will vary for each case and may depend on the treatment delivery requirements. The bandage may be removed after a period of time, such as three days, for example, and the afflicted area may be cleaned and treated and a new bandage applied, if necessary.
[0032] Bandages of the present invention may be provided in various sizes and shapes. The proportions of adhering member 11 may be varied with respect to flexible foam member 14 and/or liner 16 , as indicated by bandage embodiment 110 shown in FIG. 5 . FIG. 5 illustrates bandage 110 with another form of cut-outs, such as a butterfly. It will be apparent to those possessing an ordinary skill in the pertinent arts that other shapes may be used and needed for the treatment of wounds. The present invention may be adapted to be used with virtually any conventional or special form of adhesive bandage.
[0033] While generally square/rectangular bandages and components have been shown, these are intended to only be illustrative. Showing such shaped bandages is based, in large part, upon the widespread availability of rectangularly shaped bandages and bandage components and requirements of the present invention. Adhesive bandages 10 , 110 as described above, may be used on virtually any exposed surface of the human body which may become wounded or burned.
[0034] FIGS. 6A and 6B illustrate an embodiment of a bandage of the present invention employing smooth outer edges of foam, lacking discontinuity, wherein the foam member may have multiple layers, and wherein the foam member layers may extend beyond the outer periphery of adhesive member 11 . A back view and a breakaway view of a three layered foam member are illustratively shown, and the base layer of the foam member may be adhered to the bandage. Adhered point or points 12 whereat the foam may be adhered by an adhesive such as a glue, a hook and loop material type fastener, or other sanitary and medically safe adhering mechanism. Further, the adhered point may be a removable adhesive wherein the foam may be removably attached to the bandage. There may be one or more adhered points, and foam adhesion 12 that makes up the adhered points may be, for example, one or more points, one or more strips, or any other pattern of adhesive.
[0035] FIG. 7 illustrates schematically the use of one of bandages 110 of the present invention on a limb, for example, a leg 40 , to increase the flow of blood into the afflicted area from beyond bandage 10 itself. A separate strip or patch 50 of the flexible foam material may be applied over bandage 10 or 110 , overlapping the bandage and extending beyond the bandage, such as in a longitudinal orientation with respect to the limb, to improve circulation along the limb through of the afflicted area. Strip or patch 50 may be held in position against limb 40 by one or more strips 52 of material, such as the same adhesive cloth material mentioned above for use as adhering member 11 . Strip 50 may define a corridor along which the flow of blood may be assisted or boosted. A length of fabric tubing with recoverable properties may be applied over the affected limb and over strip 50 to hold substantially, if not all, of patch 50 against limb 40 to thereby provide greater foam/skin contact and more efficient auxiliary pumping action by strip 50 . FIG. 7 illustrates use of foam strip 50 to improve circulation in the calf and below. Strip 50 , for example, may extend, in such an embodiment, from just above the tendon-Achilles insertion of the tendon to the top of the calf muscle just below the knee. While two adhesive strips 52 have been depicted, it would be evident to a person having ordinary skill in the pertinent arts that a greater number of strips may be used. Alternatively, the foam strip 50 may be held in place with a cloth wrap or a length of fabric tubing with recoverable properties, such as a stocking.
[0036] Feet and lower legs are typically the extremities initially or most seriously affected by poor blood circulation. To that end, FIGS. 8-10 depict an exemplary high foam boot 60 and a low foam boot 70 , respectively, which may be used in place of a conventional length of foam-like strip 50 on the foot or foot and lower leg area. Boots 60 , 70 may be formed from the aforesaid foam material, such as one and one-half inch thick foam material, and applied over the user's foot and over any bandage 10 or 110 applied directly to an affected area. Boots 60 , 70 may be held in place in close contact with the skin of the foot or foot and lower leg by suitable means such as an fabric tubing with recoverable properties, such as a bandage or a length of the fabric tubing 80 of the type referred to above. Boots 60 , 70 may be made manually by wrapping a length of flexible foam sheet around the foot or foot and lower leg and cutting away the overlapping portion of the foam to leave a single, foam layer covering. This covering may be held in place by fabric tubing with recoverable properties, such as a bandage or fabric tubing. It may also be apparent to those possessing an ordinary skill in the pertinent arts that such boots may be specially made, such as in various sizes, and may be provided with such amenities as Hook and loop material type fastener closures for long term durability and ease of use. The high boot may be designed to extend upward to the tuberosity of the tibia at the knee joint. It may be also envisioned that such boots may be made with a foam having its own fabric tubing with recoverable properties character or may be formed with an fabric tubing with recoverable propertiesized material so that it may be slipped on and off and worn like a slipper-sock. Boots 60 , 70 may be used without underlying bandages to encourage foot or foot and lower leg blood circulation even before circulatory injuries arise.
[0037] FIG. 11 depicts an exemplary embodiment of a leg bandage, wherein the foam makes up at least a portion of the outer portion of the bandage, and wherein a remaining portion of the bandage may be made up of adhering member 11 . In such an embodiment, the adhering layers may contact the bandage to the afflicted area and may be placed on opposing ends of adhesive member 11 , such that the opposing ends of the adhesive member may be adhered to the foam member. A resizable bandage, such as for placement around a limb, may be provided. In this configuration, a protective layer, or coating, may be provided on the outer periphery of the foam member.
[0038] FIG. 12 depicts an embodiment of a bandage of the present invention wherein a multi-layered foam may be removably provided in a smaller bandage that provides more convenient range of motion and better breathability. As shown in FIG. 12 , the adhering member may be a strip, which may be of a suitable length and width to cover afflicted areas of various sizes, while wrapping around, for example, an afflicted limb. The strip may be provided, for example, in a variety of sizes. The foam illustratively shown may be permanently or removably secured to the strip, and may be a multiple layered foam. The strip may include one or more adhering layers 13 , such as a single adhering layer on one end that seals to the outer face of an opposing end of adhering member 11 strip, or such as an adhering layer on one end that seals to adhering layer 13 at the opposing outer face of adhering member 11 . According to an aspect of the present invention including multiple adhering layers 13 , the adhering layers may provide a permanent or a removable adhesion, such as a medically safe glue, epoxy, Hook and loop material type fastener, or grabbing tab, for example.
[0039] FIG. 13 depicts an embodiment of the present invention including a bi or tri layer foam that may be removably attached to a multi-point adhesive, adjustable fit bandage. The bandage illustratively shown may include two or more “wings”, wherein each wing includes, on the inner part of the adhesive member, an adhesive, such as a Hook and loop material type fastener, and wherein the outer part of each opposing wing likewise includes an adhesive acceptor, such as a Hook and loop material type fastener acceptor. The adhesive on the outer part of the opposing wing may be of a length sufficient to allow the attachment of the inner part of the first wings at various locations along the outer part of the opposing wings, thereby providing a bandage that may be varied in size, and which may be further varied in sizes at different points within the bandage itself dependently upon the number of wings provided. The foam may be removably attached to allow changing of the foam without changing of the bandage, such as to allow for placement of foams of different numbers of layers or different types of medication onto the bandage.
[0040] Those of ordinary skill in the art will recognize that many modifications and variations of the present invention may be implemented without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modification and variations of this invention provided they come within the scope of the appended claims and their equivalents.
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A device for treating wounds on an individual is disclosed. The device includes a flexible foam, a treatment suitable for treating the wound placed in relative proximity to the foam, and a flexible fabric with recoverable properties substantially circumferencing the wound and the treated foam. The flexible fabric maintains the treated foam in substantial proximity to the wound to allow the treatment to treat the wound. A bandage suitable for treating wounds on an exterior limb is disclosed. The bandage includes a butterfly shaped flexible fabric, at least one Hook and loop material type fastener attachment located on the edge of the butterfly shaped flexible fabric, at least two foam layers located axially in the center of the butterfly shaped flexible fabric, and a medication suitable for treating the wound proximately located with respect to at least a first of the at least two foam layers. The butterfly shaped flexible fabric is suitable to be wrapped around the limb and fastened using the at least one Hook and loop material type fastener attachment, and the wrapped fabric maintains the at least two foam layers in proximate location with the wound such that the medication is located appropriately with the wound to provide treatment.
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BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to devices for transferring a cryogenic liquid from a stationary source into a rotating machine such as a dynamoelectric machine having a superconducting winding on its rotor.
Cryogenic liquids such as helium have substantial benefits in cooling electrical conductors such as a superconducting field winding on the rotor of an AC generator but their use presents delicate problems in transferring the liquid from a stationary source into the rotating member and in maintaining thermodynamic and mechanical stability under all conditions, including transient fault conditions, for which the machine is designed to be operable. That is, the need is for transfer devices that are not only effective under some ideal set of conditions but which are also effective for a range of perturbations in the system that can be normally expected to occur sometime in operation.
An approach to a fluid transfer coupling for cryogenically cooled rotors is presented in Laskaris U.S. Pat. No. 3,991,588, Nov. 16, 1976. Here, a stationary supply tube runs axially within the end of a delivery conduit, that rotates with the rotor shaft, in a bayonet type of fit. By the means disclosed in the patent, coolant is delivered from the tube to form an annular liquid region on the surface of the conduit by centrifugal action. Coolant is intended to be prevented from escaping between the tube and the conduit by a seal element affixed to the conduit that extends radially inward a greater distance than the anticipated extent of the annular liquid region. This arrangement is not regarded as desirable or effective where the machine can be normally expected to be subject to transient fault conditions in which a pressure buildup occurs in the rotor causing a large mass of liquid to back up in the supply tube and conduit and to substantially flood the entire volume of those channels.
The foregoing considerations were taken into account and solved by the apparatus disclosed in Eckels et al. U.S. Pat. No. 4,356,700, Nov. 2, 1982, in which the bayonet coupling is designed for operation under flooded conditions with a threaded throwback or wind back seal disposed on the interior surface of the rotating conduit proximate the end of the fixed supply tube so that the rotation of the conduit induces fluid flow continuously in a downstream direction as the fluid is carried by the threads on the surface of the conduit. This is a successful arrangement but requires careful consideration of the design of the threaded member in relation to all the possible coolant supply conditions to insure that the threads are continuously effective to move coolant in the downstream direction without any appreciable amount of coolant escaping upstream which would be adverse to the system. Additionally, another aspect of the transfer system that affects the performance of the coupling is that the normal supply of coolant, through the fixed tube, is a churning mixture of liquid and vapor that induces mechanical pulsations giving rise to a critical mechanical natural frequency, hence subjecting the end of the fixed tube, which cannot be readily supported directly, to vibration that can cause it and its coaxial vacuum seal to be abraded by the rotating conduit, which itself may be subjected to some incidental radial motion.
The foregoing problems are addressed and solved by the present invention which utilizes a transfer device of the same general character as that of the abovementioned Eckels et al. U.S. Pat. No. 4,356,700, which is herein incorporated by reference for the entirety of its disclosure, with the improvement thereto of having an upstream seal and bearing device, such as in the form of an annular washer-shaped element, affixed to the inner wall of the rotatable conduit at the upstream end of the threaded member providing the throwback function. The washer has an inner diameter less than that of the threaded member for preventing movement of liquid upstream therefrom and, in addition, the inner diameter surface of the washer serves as a bearing surface for relative motion of the rotatable conduit and the stationary tube. The arrangement preferably locates the washer element closely proximate the downstream end of the coaxial sleeve that is disposed around the stationary tube and vacuum sealed therewith. The washer element extends radially inward from the rotatable conduit past the outer radial extent of the coaxial sleeve on the stationary tube. This allows the seal and bearing device or washer to safely limit and control mechanical vibration to which the stationary tube and its coaxial sleeve are subjected.
What is achieved is an arrangement in which the dynamoelectric machine winding can be designed for certain permissible transient fault conditions during which pressure rise in the rotor causes liquid to reverse flow in the conduit and in the tube with the upstream seal and bearing device preventing reverse flowing liquid from escaping between the outer surface of the tube and the inner surface of the conduit and also doubling as a bearing element for the relative motion of the fixed and rotating members.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic illustration of a helium transfer system of a superconducting rotor showing the general location of elements of the present invention;
FIG. 2 is a side view, partly broken away and partly in section, of a more specific embodiment of the coupling portion of the present invention; and
FIG. 3 is a plan view of an element of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a superconducting rotor 10 is shown that has a cryogenically cooled winding 12 therein. Cryogenic coolant, such as helium, is supplied from an external source 14 through a stationary tube 16 that extends within a rotating conduit 18 that is joined with the rotor 10 for rotating therewith. In this view, the solid arrows indicate the direction of coolant supplied into the rotor 10 during normal operation while the dashed arrows indicate the reverse direction in which coolant may flow during transient conditions during which a transfer device 20 in accordance with the present invention provides mechanical and thermodynamic stability.
The transfer device 20 is between the stationary tube 16 through which the coolant is supplied and the rotating conduit 18 proximate the end of the stationary tube and extending somewhat upstream therefrom. Its intended function is to permit backflow through the stationary tube 16 under the indicated transients but to prevent backflow between the tube and the rotating conduit 18.
An additional element of the general view of FIG. 1 is a vapor trap and regulator 22 disposed axially inward of the end of the stationary tube 16 that has a cooperative affect with the transfer coupling 20 and may be of a character such as is shown in Eckels U.S. Pat. No. 4,280,071, July 21, 1981, which is herein incorporated by reference for its entire disclosure.
Referring to FIG. 2, a liquid helium transfer coupling 20 is illustrated in accordance with a specific embodiment of the present invention and it is generally consistent with above-mentioned Eckels et al. U.S. Pat. No. 4,356,700. The rotating conduit 18 is disposed coaxially about the stationary supply tube 16. The stationary tube 16 is disposed within another stationary sleeve 24 in order to form a vacuum jacket in conjunction with a seal ring 26. This jacket 24 is used to insulate a major portion of the length of the stationary tube 16. A clearance gap 28 exists around the outer stationary sleeve 24 and a gap 29 around the inner stationary tube 16 where it extends beyond the vacuum jacket.
Device 20 comprises a cylindrical threaded insert 30 disposed on the rotating conduit 18 in the vicinity of the delivery end of the stationary tube 18. Part of the threaded insert 30 extends forward and part to the rear of the delivery end of the tube 18. The insert 30 has threads which run in a direction that, in response to rotation of the rotating elements in the direction R, creates a force on the liquid helium that moves it out of the clearance gap 29 downstream towards the rotor. Therefore, these threads operate to advance coolant toward the rotor no matter in which direction coolant flow is occurring in a particular time in the supply tube 16 itself.
In accordance with the present invention the device 20 is provided with an additional element 32 that is a seal and bearing device at the end of the threaded insert 30 proximate the beginning of the stationary tube's outer sleeve 24. The seal and bearing element 32, shown in plan view in FIG. 3, is essentially an annular washer-shaped element which may be made of brass, for example. The washer 32 is affixed to the wall of the rotating conduit 18 at the end of the threaded insert 30 and extends within the gap 29 between the conduit and the stationary tube 16 to a greater extent than the threads and also completely emcompasses the extent of the gap 28 between the sleeve 24 and the rotating conduit.
There may be a certain amount of vapor allowed to escape between the rotating and stationary elements through the remaining gap 29a between the washer 32 and the tube 16. This is beneficial in order to reduce the temperature gradient in the metal elements 24 and 18, and hence heat leak, while retaining effectiveness against flow of liquid.
In addition to the gap sealing function provided by the washer element 32, it provides a significant bearing function. That is, because of the dynamic instabilities of the stationary tube 16 during operation with coolant supplied therethrough and the rotation of the rotating conduit 18, there may occur incidental contact between the elements 18 and 24 that are closely spaced, such as by a gap 28 of about 0.035 inch (about 0.9 mm). The washer element 32 permits the relative motion between the two to be limited and controlled to avoid damage.
For the sealing and bearing functions as intended herein, it would normally be desirable that the inside diameter of the washer 32 be closely spaced to the outer surface of the stationary tube 16 such as by a distance of about 0.030 inch (about 8 mm.) in gap 29a. In other dimensions applicable hereto, the inner surface of the rotating conduit 18 and the outer surface of the stationary tube 16 would be about 0.030 inch (about 1.8 mm.) apart, for example. The threaded insert would have threads extending about 0.035 inch (about 0.9 mm.) from the surface of the conduit 18, for example, that is, at least somewhat less than the radial dimension of the washer 32 of about 0.040 inch (about 1.0 mm.).
It is therefore seen that the present invention provides a simple and yet effective improvement in rotating helium transfer systems by permitting the supeconducting generator to be more fault worthy by allowing reverse flow of coolant without impairment due to liquid losses as well as permitting control of the mechanical instabilities induced in the system during normal operation.
Fault worthiness of superconducting rotors and stability of their cooling system are also affected by coolant vapor return paths through the conductive leads of the rotor winding; see Eckels copending application (W. E. Ser. No. 51,175), filed of even date herewith and assigned to the present assignee, for a description of that aspect of the system.
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A liquid coolant transfer device that has a stationary tube fit within a rotating conduit and a threaded throwback seal on the surface of the rotating element is further provided with a seal and bearing device in the form of a washer affixed to the conduit at the end of the threaded insert and extending across the gap between the rotating and stationary tubes for preventing liquid coolant flow therethrough even during severe flooding caused by faults within the electrical machine with which it is connected.
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FIELD OF THE INVENTION
[0001] The apparatus described herein is generally directed to the field of valves; and, more directly, to the field of air valves for inflatable devices.
BACKGROUND OF THE INVENTION
[0002] The use of inflatable devices has long been associated with water sports and recreational activities involving water. For the most part, this has been the case because inflatable devices are generally capable of floating on water. With the explosion of the availability of inexpensive plastic products, recreational devices such as beach balls and water wings became increasingly common at pools and beaches during the latter half of the 20 th century.
[0003] Inflatable devices have also been used for more sophisticated recreational purposes. For example, inner tubes have traditionally been used as a simple watercraft. Inner tubes float in water, even with a rider in place, and provide a relatively ergonomic shape to secure the rider comfortably. They are also sufficiently durable for this use. Inner tubes can be used to float in a calm body of water, or they can be used as passive vehicles in a flowing body of water, such as a river. Inner tubes can also be towed behind powered watercraft. These activities are known as “tubing.”
[0004] Inner tubes are well suited for water recreation, especially given that they were not designed for this use. However, they have several drawbacks, which in part result from being used outside of their design specifications. One major drawback is that they are designed to be inflated at a high pressure. This means that a high pressure pump must be used to inflate them. This also means that it takes a relatively long time to inflate and deflate inner tubes. There is also a risk of violent rupture because of the high potential energy of a high pressure reservoir. Such an event could cause human injury or property damage.
[0005] As a result, there has been a move to produce simple watercraft and other water recreation devices from PVC instead of rubber, as in an inner tube. Watercraft and devices in this newer wave tend to be low pressure inflatables. They also incorporate design improvements in ergonomics and maneuverability for recreational use.
[0006] Despite being inflated to a low pressure, these devices often have a substantial volume of inflatable space. This makes fast and easy inflation and deflation an engineering challenge. Most of the design work that goes in to addressing this challenge is focused on the air valves for these devices. The valves must be able to accommodate a large flow volume for both inflation and deflation. They must be air tight when closed, even during hard use or stressful conditions. Furthermore, they must accommodate inflation from sources not capable of producing high inflation pressures. Thus, there remains a need in the art for air valves for inflatable devices that meet these design requirements.
SUMMARY OF THE INVENTION
[0007] A housing has an upper end, a lower end, and an opening extending between the upper and lower ends, the housing being sealingly attachable to an inflatable device. A check valve has a body member with an upper end, a lower end, an outer surface sized and shaped to be selectively matingly received in the opening of the housing, and an inner surface defining a passageway. The check valve is coupled to the housing by a first tether. A cap has an upper end, a lower end, and an outer surface sized and shaped to be selectively matingly received in the passageway of the check valve. The cap is coupled to the housing by a second tether.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is an inflatable device incorporating one embodiment of the air valve.
[0009] FIG. 2 is blown-up view of the air valve shown in FIG. 1 .
[0010] FIG. 3 is a perspective view of the embodiment of the air valve shown in FIG. 2 in a fully opened position.
[0011] FIG. 4 is a cross-section of the embodiment shown in FIG. 2 in a fully opened position.
[0012] FIG. 5 is a perspective view of the embodiment shown in FIG. 2 in a partially opened position.
[0013] FIG. 6 is a cross-section of the embodiment shown in FIG. 2 in a partially opened position.
[0014] FIG. 7 is a perspective view of the embodiment shown in FIG. 2 in a closed position.
[0015] FIG. 8 is a cross-section of the embodiment shown in FIG. 2 in a closed position.
[0016] FIG. 9 a is a perspective view of a second embodiment of the air valve in a fully opened position.
[0017] FIG. 9 b is a perspective view of the embodiment shown in FIG. 9 a in a partially opened position.
[0018] FIG. 9 c is a perspective view of the embodiment shown in FIG. 9 a in a closed position.
[0019] FIG. 10 a is a perspective view of a third embodiment of the air valve in a fully opened position.
[0020] FIG. 10 b is a perspective view of the embodiment shown in FIG. 10 a in a partially opened position.
[0021] FIG. 10 c is a perspective view of the embodiment shown in FIG. 10 a in a closed position.
DETAILED DESCRIPTION OF THE INVENTION
[0022] FIG. 1 is an inflatable device 100 incorporating one embodiment of the air valve 110 . Inflatable device 100 may be a watercraft, floating lounge, air mattress, inflatable pool, or a variety of other devices. Inflatable device 100 comprises an air reservoir 120 , which typically must be filled with air at or above the pressure in the surrounding environment to perform some intended function. Air valve 110 is the device that enables inflation and deflation of inflatable device 100 . Air is transferred to and from air reservoir 120 through air valve 110 . Air valve 110 must provide a passageway for delivery of air, but must also be capable of retaining air within air reservoir 120 at pressure when inflation is complete. One advantage of an inflatable device having an air valve over an inflated device not having an air valve (such as a balloon) is that an inflatable device can be “topped off” or re-inflated to the maximum pressure if the relative pressure subsides due to leakage, distention of the air reservoir, or a decrease in atmospheric pressure (due to weather or altitude changes, for example). Another advantage is that inflatable device 100 is also capable of being deflated for easy transport and storage. The presence of air valve 110 on inflatable device 100 makes inflatable device 100 capable of being re-inflated or “topped off” and deflated. FIG. 2 is blown-up view of air valve 110 shown in FIG. 1 .
[0023] FIG. 3 is a perspective view of the embodiment of air valve 110 shown in FIG. 2 in a fully opened position. Air valve 110 comprises housing 300 . Housing 300 comprises opening 410 . A check valve 340 is coupled to housing 300 via a first tether 310 . A cap 350 is coupled to housing 300 via a second tether 320 . In this embodiment, second tether 320 is coupled to housing 300 at a 90 degree angle with respect to first tether 310 . In other embodiments, second tether 320 is coupled to housing 300 at any angle with respect to first tether 310 .
[0024] First pull tab 330 is on an outward end of first tether 310 , with check valve 340 intermediate first pull tab 330 and housing 300 . First pull tab 330 and first tether 310 are one continuous piece having a first hole 392 . First hole 392 couples check valve 340 to first tether 310 . First tether 310 is coupled to an inward end of check valve 340 and first pull tab 330 is coupled to an outward end of check valve 340 . In one embodiment, check valve 340 has a first annular groove on its upper end. The first annular groove in that embodiment is arranged to couple check valve 340 to first tether 310 . The first annular groove has an inner diameter that is the same as the diameter of first hole 392 . In that embodiment, first hole 392 has a smaller diameter than the outer surface of check valve 340 . This allows a secure coupling of check valve 340 to first tether 310 . Second pull tab 380 is on an outward end of second tether 320 , with cap 350 intermediate second pull tab 380 and housing 300 . Second pull tab 380 , second tether 320 , and cap 350 are made from a single continuous piece.
[0025] FIG. 4 is a cross-section of the embodiment shown in FIG. 2 in a fully opened position. In the illustrated embodiments, check valve 340 is a boston valve. A boston valve comprises a perforated plate 400 with an abutting flexible disc 370 . Flexible disc 370 is on the reservoir side and the perforated plate 400 is on the atmospheric or external side. During inflation, the pressure is greater on the outer side than the reservoir side. The pressure differential induces a flow through perforated plate 400 . This flow is only resisted by the rigidity of flexible disc 370 , which is small. Therefore, the air flow easily deforms flexible disc 370 such that it no longer obstructs the perforations in perforated plate 400 . Air then flows from the high pressure outer side to the low pressure reservoir 120 with relatively little resistance. When an external pressure source is removed, reservoir 120 will be at a higher pressure than the atmosphere or the outside of check valve 340 . In this condition, the flow is reversed and flexible disc 370 is deformed, however it is deformed towards the perforations instead of away from them. Therefore, the high pressure air forces flexible disc 370 to cover the perforations, preventing the flow of air. Thus the boston valve is a one-directional valve comprising flexible disc 370 which is arranged to selective engage perforated plate 400 when pressure within inflatable device 100 exceeds pressure on the outside of inflatable device 100 . Other embodiments may not use a boston valve, and may use some other type of valve.
[0026] Check valve 340 includes annular rim 390 which is adapted to mate with a second annular groove 430 when check valve 340 is inserted into opening 410 . This ensures that the fit between check valve 340 and opening 410 is secure and air-tight. Housing 300 comprises an upper end 440 and a lower end 450 . In one embodiment, lower end 450 is sealingly attached to inflatable device 100 .
[0027] FIG. 5 is a perspective view of the embodiment shown in FIG. 2 in a partially opened position. FIG. 6 is a cross-section of the embodiment shown in FIG. 2 in a partially opened position. FIG. 7 is a perspective view of the embodiment shown in FIG. 2 in a closed position. FIG. 8 is a cross-section of the embodiment shown in FIG. 2 in a closed position. In this embodiment, second tether 320 is coupled to housing 300 at a 90 degree angle with respect to first tether 310 as viewed from above air valve 110 as if looking through air valve 110 into inflatable device 100 .
[0028] To inflate reservoir 120 , a user folds first tether 310 and inserts check valve 340 into opening 410 in housing 300 as shown in FIG. 5 . The user then inflates the reservoir through check valve 340 either using human lung power or a mechanical pump. When a user has inflated inflatable device 100 to desired volume or pressure, the user removes the source of pressurized air. As discussed above, check valve 340 prevents the escape of air from reservoir 120 in this condition. The user then folds second tether 320 and places cap 350 into passageway 420 in check valve 340 to fully close air valve 110 as shown in FIG. 7 . This prevents debris or fluids from entering check valve 340 , or inadvertent opening of check valve 340 , or damage to check valve 340 . Cap 350 also provides an extra barrier to the escape of air from reservoir 120 . In this final position, air valve 110 is in a closed position and inflatable device 100 is ready for use. A user may top off the pressure in inflatable device 100 or access check valve 340 for some other reason by removing cap 350 from passageway 420 and leaving check valve 340 in place (i.e. the partially opened position) as shown in FIG. 5 . It is easy for a user to remove or insert cap 350 without disturbing check valve 340 or inadvertently deflating air reservoir 120 because the two parts are independently tethered to housing 300 .
[0029] In order to deflate air reservoir 120 , a user first removes cap 350 from passageway 420 by pulling second pull tab 380 . Second, the user removes check valve 340 from opening 410 by pulling first pull tab 330 . This allows air to escape through opening 410 in housing 300 , which is a relatively short passageway with a relatively large diameter. Thus, air encounters little resistance as it escapes from the reservoir. As a result, opening 410 facilitates rapid deflation of inflatable device 100 , which is advantageous to a user.
[0030] FIG. 9 a is a perspective view of a second embodiment of the air valve in a fully opened position. FIG. 9 b is a perspective view of the embodiment shown in FIG. 9 a in a partially opened position. FIG. 9 c is a perspective view of the embodiment shown in FIG. 9 a in a closed position. First tether 310 and second tether 320 may be coupled to opposite sides of housing 300 . When air valve 110 is in a closed position, first pull tab 330 is adapted to fit between, on one side, check valve 340 and, on the other side, second tether 320 and second pull tab 380 . First pull tab 330 is sufficiently thin to fit in between these parts in a closed position. First pull tab 330 is also shaped so as to fit into air valve 110 in a streamlined manner when air valve 110 is in a closed position. In this embodiment, first pull tab 330 is a flattened ring and surrounds cap 350 in a closed position of air valve 110 . First pull tab 330 can be any shape that is ergonomic to pull and can fit between cap 350 and check valve 340 in a closed position.
[0031] First pull tab 330 has a second hole 900 which is shaped to allow cap 350 to be inserted through second hole 900 before being inserted into passageway 420 . In order to close this embodiment of air valve 110 , a user must fold over first pull tab 330 , insert cap 350 through second hole 900 , and insert cap 350 into passageway 420 . In one embodiment, second hole 900 is the same shape as the cross-section of cap 350 or sized and shaped to closely receive cap 350 . Once in a closed position, first pull tab 330 is held securely in place by second tether 320 and second pull tab 380 .
[0032] FIG. 10 a is a perspective view of a third embodiment of the air valve in a fully opened position. FIG. 10 b is a perspective view of the embodiment shown in FIG. 10 a in a partially opened position. FIG. 10 c is a perspective view of the embodiment shown in FIG. 10 a in a closed position. In this embodiment, first tether 310 and second tether 320 are coupled to opposite sides of housing 300 . In this embodiment, second tether 320 comprises orifice 1000 adjacent to housing 300 . Orifice 1000 provides clearance for first pull tab 330 , so that in a closed position of air valve 110 , first pull tab 330 protrudes from orifice 1000 . First pull tab 330 can be any shape that is ergonomic to pull and does not interfere with second tether 320 in a closed position.
[0033] Although the invention has been described with reference to embodiments herein, those embodiments do not limit the scope of the invention. Modification to those embodiments or different embodiments may fall within the scope of the invention.
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A housing has an upper end, a lower end, and an opening extending between the upper and lower ends, the housing being sealingly attachable to an inflatable device. A check valve has a body member with an upper end, a lower end, an outer surface sized and shaped to be selectively matingly received in the opening of the housing, and an inner surface defining a passageway. The check valve is coupled to the housing by a first tether. A cap has an upper end, a lower end, and an outer surface sized and shaped to be selectively matingly received in the passageway of the check valve. The cap is coupled to the housing by a second tether.
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FIELD OF THE INVENTION
[0001] This invention relates to a process for the manufacture of institutional towels with the resulting towel having a much longer life expectancy.
BACKGROUND OF THE INVENTION
[0002] It is well known to manufacture towels in a process utilizing yarn spun from 100% cotton fibres. In manufacturing such a towel, the yarn is woven, as is well known, on a loom with the 100% cotton yarn being contained in the ground, fill, and pile yarns. In fact it is the 100% cotton aspect of the towel that makes it more “desirable” by the consumer since it is fixed in the mind of the purchaser that 100% cotton towels are more absorbent than other types of towels. However, when considering an institutional towel there are many drawbacks to providing 100% cotton spun yarns woven into towels since there are other issues which must be considered, which from an institutional standpoint creates disadvantages to the institution, for example a hotel chain.
[0003] In manufacturing a typical towel through a continuous process, the towel is woven from the yarns accumulated on beams with the output from the loom being a continuous web of interconnected toweling product which must be bleached to remove any materials applied during the slashing process including a washing step. The toweling products are subsequently dyed through a cold pad batch or beck dying process, washed and finally dried, then separated and finished into towels, or other terry products.
[0004] The output therefore from the process includes towels of different colours including white, and various other shades. For a towel or a towel product for the retail market, the consumer is quite content to wash the coloured towels without bleaching and to apply a fabric softener either in the wash or in the dryer.
[0005] However, with institutional towels the concerns for the life expectancy of the towel becomes very important. Institutional towels are washed with bleach time after time and as a result it can be expected that the colour will fade after as little as ten washings with the colour being substantially gone after twenty washings. This is quite costly for the industry and therefore as a rule most institutional towels are white. By selecting a white colour, the towels may be washed over and over without the risk of fading. Further coloured institutional towels will fade, even without bleach, and will become unacceptable before they wear out.
[0006] It is known in the patent literature to provide a towel construction wherein it is suggested that yarns for ground fill, ground warp and the pile warp, although preferably being made of cotton, may also be manufactured from yarns made of blends of cotton and polyester. For example, U.S. Pat. No. 4,726,400 describes this alternative. It is also discussed within U.S. Pat. No. 4,726,400 that a checkered patent may be provided in the terry cloth by utilizing different colour yarns. There is no discussion however as to how the yarns might be manufactured and coloured. We are also aware of other constructions for towels, for example U.S. Pat. No. 3,721,273 discusses in the Background of the Invention a preference of cotton and alternatively that synthetic fibres may be blended with the cotton fibres. Rayon yarns are also discussed in relation to their absorbency in that the rayon may be woven into the towel in the form of a 3-pick terry weave. U.S. Pat. No. 3,721,272 discusses that terry yarns have been formed of shrinkable synthetic fibres blended with cellulosic fibres, such as cotton. U.S. Pat. No. 3,721,274 teaches a woven terry towel wherein the ground warp and/or the filling yarns are composed of a blend of polyester and cellulosic fibres, but the terry pile is manufactured from 100% cotton. Within the reference is it stated that polyester has been heretofore considered an undesirable fibre for use in terry towels due to its low moisture absorbency characteristics. In fact, U.S. Pat. No. 6,062,272 issued May 16, 2000 teaches an all cotton pile with polyester being in the ground fabric. The pile yarns although desirably all cotton may include small quantities of other fibres such as polyester or rayon which would result in a corresponding decrease in the absorbency of the finished towel product. Specifically in the examples various compositions are described.
[0007] However, in spite of the general discussions in the above-mentioned patent literature there is no discussion of the present problems facing the institutions which purchase institutional towels. The towels used in for example, the hotel industry are generally white and if not white then they will be rendered unusable in twenty washing cycles. This is highly undesirable since most institutions bleach their laundry including towels for health reasons and would prefer to present the hotel guests with an attractive set of towels which have an unique colour and which colour match one another, other than a white set of towels.
[0008] It is therefore a primary object of this invention to provide an institutional towel and toweling products which are coloured and yet which are colour-fast.
[0009] It is a further object of this invention to provide an institutional towel and toweling product which is the result of a manufacturing process resulting in minimum variation from batch to batch of the final product colour.
[0010] It is a further object of this invention to provide an institutional towel that has a significantly longer life expectancy.
[0011] It is a further object of this invention to provide an institutional towel ensemble which includes a matching set of toweling products having very little colour variation from item to item.
[0012] It is a further object of this invention to provide a process of manufacturing an institutional towel which eliminates the need to dye the towel at the towel mill.
[0013] Further and other objects of the invention may become apparent to those skilled in the art when considering the following summary of the invention and a more detailed description of the preferred embodiments illustrated herein.
SUMMARY OF THE INVENTION
[0014] According to a primary aspect of the invention there is provided a process for manufacturing toweling products comprising the steps of:
[0015] 1) Providing cotton fibres;
[0016] 2) Providing pre-dyed polyester fibres;
[0017] 3) Orienting the fibres of the cotton in substantially a uniform parallel direction by carding;
[0018] 4) Orienting the pre-dyed polyester fibres in substantially parallel direction by a carding process;
[0019] 5) Draw blending the cotton and pre-dyed polyester fibres in a slivering process preferably in a ratio of 8 to 14% of the pre-dyed polyester fibres with the balance being the cotton fibre;
[0020] 6) Following the intimate draw blending of the pre-dyed polyester and cotton fibres spinning the slivered fibres into twisted yarns having a pre-determined colour which will be imparted to the toweling product;
[0021] 7) Accumulating the yarns on a loom beam following warping/slashing the yarns in preparation for the weaving process;
[0022] 8) Weaving said coloured yarn into the ground warp, the fill and the pile warp yarns in the toweling product which preferably is a continuous process;
[0023] 9) Preferably bleaching and subsequently washing and drying said toweling product prior to finishing;
[0024] wherein the colour in the toweling product is obtained by the weaving process only with no subsequent dying process being necessary and wherein the resulting towel products have
[0025] i) a minimum colour variation from batch to batch,
[0026] ii) are colour fast, the colour being imparted to the toweling product by the pre-dyed polyester fibre allowing all institutional towels resulting from this process to be able to be washed and handled together,
[0027] iii) a significantly longer life expectancy of the towel imparted by the polyester fibre, and
[0028] iv) the ability of the toweling product to be manufactured into a matching set of toweling products having minimum colour variation from product to product.
[0029] The resulting institutional towel from this process overcomes many of the deficiencies and problems experienced in the institutional towel industry having a severe limitation in terms of white only in order to minimize the handling problem which would result should colours have to be separated.
[0030] In relation to life expectancy it has been, through experimentation, proven that such a towel manufactured for experimental purposes has undergone 100 washes with bleaching, but it has not lost it's luster and has not faded in spite of having been bleached. The towel was manufactured from the drawn blend yarn of a vanilla colour.
[0031] The colour therefore in the institutional towel has been imparted to it by spinning yarns of a drawn blend of pre-dyed polyester fibres and natural cotton fibres. The resulting towel therefore is colour-fast, as a result, many times over those towels dyed in conventional manners. Typically as discussed in the background towels may be washed twenty times before one might expect the colour to be significantly altered. The experimental towels produced did not fade and retained their luster through 100 wash cycles.
[0032] According to yet another aspect of the invention there is provided an institutional coloured towel (and preferably manufactured from the above-mentioned process) which comprises coloured yarns draw blended of a pre-determined amount of pre-dyed polyester fibre with the remainder being natural cotton fibres resulting in a yarn of predetermined colour, said toweling product having ground warp, fill, and terry loop fibres manufactured from said yarn resulting in said institutional towel having a predetermined colour which is colour fast, has little variance from lot to lot, may be washed and bleached, is conveniently handled by an institution, has an increased life expectancy imparted by the polyester, and which has reproducible colour of the finished towel product from batch to batch.
[0033] It is therefore expected that other colours other than a vanilla colour obtained with the 12.5% brown pre-dyed polyester fibre may also be manufactured. Pastel shades of blue, red, green or the like may be manufactured in the form of an institutional towel which is superior when compared to known institutional towels of all cotton construction in terms of convenience and handling through the washing and bleaching cycles with the resulting increase in life expectancy while maintaining its colour and luster. The colour is reproducible from batch to batch and from product to product so that complete bath ensembles can be provided to the institution with matching colours from the face cloth, the bath towel and the hand towel and the bath mats.
[0034] According to yet another aspect of the invention there is provided a method of colouring a towel, and preferably an institutional towel, comprising weaving said towel from twisted yarn spun from an intimate, drawn blend of a predetermined amount of pre-dyed polyester fibre, preferably in the range of 8-14%, with the balance being cotton fibre, said coloured yarn thereafter being spun from said drawn blend and all of said ground yarns, fill yarns and pile yarns making up said towel being formed from said drawn blended twisted coloured yarn to form said institutional towel which has the properties of: 1) being colourfast; 2) being consistent in colour from batch to batch; 3) being consistent in colour from towel product type to towel product type, for example, for a bath towel, face towel, wash cloth, and bath mat; 4) being capable of being bleached and washed without fading or loosing it's luster; and 5) having an extended life expectancy.
[0035] According to yet another aspect of the invention there is provided a towel and preferably an institutional towel, preferably manufactured from the above method comprising twisted yarn spun from an intimate, drawn blend of a predetermined amount of pre-dyed polyester fibre, preferably in the range of 8-14%, with the balance being cotton fibre, said coloured yarn thereafter being spun from said drawn blend and all of said ground yarns, fill yarns and pile yarns making up said towel being formed from said drawn blended twisted coloured yarn to form said institutional towel which has the properties of: 1) being colourfast; 2) being consistent in colour from batch to batch; 3) being consistent in colour from towel product type to towel product type, for example, for a bath towel, hand towel, wash cloth, and bath mat; 4) being capable of being bleached and washed without fading or loosing it's luster; and 5) having an extended life expectancy.
[0036] The aspect of providing a colour within an institutional towel is a considerable improvement for the hotel industry which no longer will be required to supply bland white towels or run the risk of having considerable expense if coloured towels are selected. By providing a towel by the above-mentioned method any pastel shade of towel can be manufactured including vanilla, pink, light blue, light green, grey and any other pastel type of shade without sacrificing a great deal of absorbency in the towel. It is considered that the advantages of such an institutional towel or for that matter a coloured towel in the retail trade are more than offset by the minimal loss in absorbency.
[0037] According to another aspect of the invention there is provided a coloured institutional towel comprising ground warp, fill, and pile warped yarns, all of said yarns being coloured by intimately draw blending a predetermined amount of pre-dyed polyester fibre with cotton fibre when the yarn is spun and twisted to thereby form a predetermined colour for the institutional towel.
[0038] For a preferred vanilla towel the twisted yarn includes a predetermined amount of predyed polyester fibre having a predetermined denier, and tenacity and fibre length. No limitations however to these variables is contemplated for use in the institutional towel. For the vanilla towel the predyed polyester fibre has a beige colour but as discussed it may have a different colour depending on the shade of towel desired. The colour of the predyed polyester is established by trial and error, and specified by a matching comparison with a coloured swatch. The predyed polyester/cotton draw blended twisted yarn is manufactured with a predetermined twist (turns per inch) in the yarn. The ground and fill yarns may or may not have substantially the same twist as the pile yarns although they are of course of the same colour.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] [0039]FIG. 1 is a flow chart of the Process of Manufacture of the present invention utilized in the manufacture of the Institutional Towel thereof.
[0040] [0040]FIG. 2 is a schematic perspective view of the towel product manufactured from the process steps of FIG. 1.
[0041] [0041]FIG. 3 is a close up perspective view of the yarn elements and how they are woven into the terry product illustrated in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0042] Referring to FIG. 1, a process flow chart is illustrated which describes the manner in which the Institutional Towel is manufactured. The towel product ( 5 ) therefore of FIG. 2 is manufactured so as to overcome many of the deficiencies in prior institutional towels. As discussed in the Background of the Invention, most institutional towels are white because otherwise they would not stand up to the washing and bleaching cycles. It is appreciated that a towel product in a hotel, for example, would be washed on a daily basis. Should these towels and various towel products such as wash cloths, hand towels, bath towels, bath mats, bath robes, etc. be coloured, as is desirable, then they would have to be sorted out from the regular laundry flow and could not be subjected to bleaching. However, if they are not sorted then these toweling products would not stand up and the colour would fade by approximately 20 cycles.
[0043] Therefore, to address this problem, the present invention provides an Institutional Towel that is preferably vanilla in colour but may be other pastel shades such as grey, light blue, light green, yellow or the like. The toweling product formed by carrying out the process of FIG. 1 will have the preferred vanilla colour and will have very little shade variance from batch to batch of towels, and from batch to batch of matching toweling products making up a bath assemble. This minimum variation from batch to batch and from toweling product to toweling product is important especially after many washing cycles. It is desirable that the product stand up to the rigors of such washing and bleaching cycles and yet not fade, yet still matching the colour for the bath mat, bath towel, face towel, and wash clothes. It is also a result of this invention that the product is coloured without the necessity of carrying out a dying process at the towel mill. The resulting towel product stands up to many, many washings because of the extra strength imparted to the yarns by the presence of polyester. The polyester is distributed throughout the towel having been blended with cotton in manufacturing the yarn and therefore this strength and resilience of the product is distributed throughout all of the yarns including the ground, fill and pile yarns.
[0044] Referring to FIG. 1, the polyester is purchased in raw fibre form, with the fibres having been pre-dyed in this example to a brown colour, which when blended with the cotton fibres will result in a yarn having a vanilla colour. The materials are received in bales and the fibres are somewhat compacted as received. The fibres therefore must be separated sufficiently so as to be able to be properly handled. As is known, the cotton is cleaned. Once the fibres have been broken down in the sense that they have been separated and the bulk density thereof has been drastically reduced, they are in the form that they can be passed through a carding machine in order to take the fibres that are randomly distributed in the pre-dyed polyester and the cotton and to orient them in a generally parallel direction. The result of the carding process is that the fibres are laid out in a parallel direction in a long extended, untwisted rope like element. This is the case with both the pre-dyed polyester and the cotton. The continuous filaments therefore, having been carded are then accumulated to be fed through a slivering machine, and is utilized to create an intimate draw blend of the cotton and pre-dyed polyester carded fibres. The products are slivered together, that is to say draw blended, at a ratio of between 8 to 14% polyester, and the remainder being cotton. The resulting slivered element is continuous and is of considerable larger diameter than the prior carded products. The slivered continuous elements are therefore accumulated and fed into a yarn spinning machine, and the yarn product is spun from the intimately draw blended slivered mixture of polyester and cotton. The resulting twisted yarn is then accumulated again and processed through a warping/slashing process and coated with a compound to enable the yarn to stand up and impart to it a certain robust quality required during the weaving process. The yarn is therefore accumulated on a beam and fed to a loom for the toweling product to be manufactured. The ground yarn, the fill yarn and the pile yarns are all manufactured from the same coloured yarn intimately draw blended to provide the preferred vanilla colour. The resulting towel products are therefore finished and prepared for distribution, once the towels have been washed in caustic and bleached to remove the coating compound and dried to enable finishing. The resulting toweling products therefore have all of the desired qualities of the institutional towel product previously discussed with an unexpectedly much longer extended life than what might have been expected from the use of a draw blended yarn product that is pre-coloured. The towel product is therefore coloured without the necessity of including the dye step in the towel manufacturing process and the handling of chemicals required in order to do so. The safety within the mill therefore is enhanced and the product has proven by experimentation to be much superior to previously known institutional towels and towel products.
[0045] The coloured towel product ( 5 ) is illustrated in FIG. 2 with the preferred three pick weaving step shown in close up in FIG. 3 with all of the yarns shown in FIG. 3 therefore including the vanilla colour draw blended twisted yarn previously manufactured at the yarn mill. The towel product therefore includes the pile coloured yarns ( 20 ) the ground coloured yarns ( 30 ) and the fill coloured yarns ( 40 ) which are woven in a manner as is well known on a loom. All of the yarns are those which have a vanilla colour and contain an intimate draw blend of polyester and cotton. The coloured towel product preferably includes 75 threads per inch for the pile yarn, 60 threads per inch for the fill yarn and 45 threads per inch for the ground yarns. Up to three pile picks may be woven between two adjacent weft yarns of ground fabric. The result is a towel without an increase in the amount of polyester therein, but a different significant distribution which imparts the significant advantages identified above.
[0046] For the preferred vanilla towel ( 5 ) the twisted yarn ( 20 , 30 , 40 ) includes a predetermined amount of predyed polyester fibre having a predetermined denier, and tenacity and fibre length. No limitations however to these variables is contemplated for use in the institutional towel. For the vanilla towel ( 5 ) the predyed polyester fibre has a beige colour. The colour of the predyed polyester is established by trial and error, and specified by a matching comparison with a coloured swatch. The predyed polyester/cotton draw blended twisted yarn ( 20 , 30 , 40 ) are manufactured with a predetermined twist (turns per inch) in the yarns. The ground and fill yarns ( 30 , 40 ) may or may not have substantially the same twist as the pile yarns ( 20 ) although they are of course of the same colour.
[0047] As many changes can be made to the preferred embodiment of the invention without departing from the scope thereof; it is intended that all matter contained herein be considered illustrative of the invention and not in a limiting sense.
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A colored institutional towel comprising ground warp, fill, and pile warped yarns, all of said yarns being colored by intimately draw blending a predetermined amount of pre-dyed polyester fiber with cotton fiber when the yarn is spun and twisted to thereby form a predetermined color for the institutional towel.
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BACKGROUND OF THE INVENTION
Conventional case for storing floppy disk for computor use is designed to put all disks together into the case in a way like a card-index system used in a library. However, such a conventional case has the following defects:
1. The disks are crowded or overlapped within the case whereby the insertion or withdrawal of a disk among the piles of disks is inconvenient and will take time. The abrasion caused between the contacting surfaces of the disks will deteriorate the disks and influence the precision of the disks.
2. The discription label adhered on the disk which is vertically standing and put into disk case can be read when stored in disk case. However, when the disk is put into disk drive for computer operation, the words description on disk will become reversed to the reader or operator and thus increase inconvenience for the user.
3. A conventional disk case is made from plastic material. The disk stored in the plastic case will be interfered in a surrounding having magnetic flux to reduce the precision of the disk.
The present inventor has found the defects of conventional disk case and invented the present collapsible storage box for floppy disk.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a collapsible storage box for floppy disk including a casing, a switch means and a plurality of collapsible storage bags retractably formed in the casing, whereby the switch means is actuated to open a cover of the casing and the storage bags will be automatically extended for taking a disk out from the bag in a more convenient way without abrasing the disk.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective drawing of the present invention.
FIG. 2 is a side-view sectional drawing of the present invention.
FIG. 3 is a side-view drawing taken from X--X' direction of FIG. 2.
FIG. 4 is a side-view drawing taken from Y--Y' direction of FIG. 2.
FIG. 5 is side-view drawing taken from Z--Z' direction of FIG. 2.
FIG. 6 is a side-view sectional drawing taken from S--S' direction of FIG. 4.
DETAILED DESCRIPTION
As shown in the figures, the present invention comprises a casing 1 having an upper cover 12 and a bottom case 11, a switch means 2 and a collapsible storing means 3.
The upper cover 12 is pivotedly mounted on the rear wall plate 111 of bottom case 11 by a hinge which comprises several hinge holes 112, 121 and several restored springs 14 jacketed in pin 13 to restore upper cover 12 in an opening tendency. An extension lip 122 is formed on the front edge of upper cover 12.
A lock 21 of switch means 2 is fixed on a hole 151 formed on the front wall plate 15 of case 11. A rectangular locking latch 212 is fixed on the inner portion of lock 21 by a nut 211 to normally face a corresponding rectangular hole 221 which is formed on the lower portion of push-button 22 to allow the normal depressing action of push-button 22. Push-button 22 is lowerly formed with two side pins 222 pivotedly fixed on two holes 162 of two brackets 161 fixed on the portion of bottom plate 16. Two extension plates 163 are formed on brackets 161 to define the backward motion of push-button 22. Push-button 22 is formed with an extension bar 223 which is jacketed with a compression spring 224 resiliently backing against the inside wall of wall plate 15. The upper portion of push-button 22 is formed with a lip hole 225 to engage with the extension lip 122 of cover 12 for closing upper cover 12 on bottom case 11. A partition plate 23 is formed to enclose the lock 21 within a compartment disposed by bottom plate 16, front wall plate 15 and plate 23 within said bottom case 11 but to project push-button 22 outwards as FIG. 2 shown.
A collapsible storing means 3 consists of a plurality of collapsible storage bags 31 each being formed by binding an upper transparent film 312 with a lower base plate 311 to store the floppy disk A for computor use. Each bag 31 is formed with two side wing portions 313, each being formed with a big hole 314 and a small hole 315 and a slit 316 being cut to communicate with hole 314 with hole 315. Two wires 33 tensioned by two tension springs 332 respectively are connected to two lugs 123, 167 formed on upper plate 12 and bottom plate 16. Each wire 33 is formed with a plurality of balls 331 each divided in equal distance. Wire 33 fixed with balls 331 is passing through the big holes 314 formed on the wing portions 313 and then wire 33 is moved from each slit 316 to pass through the small holes 315 to allow each ball 331 slidingly backing each bag 31 to extend all the bags 31, as a sector shape as taken from side view therefrom, when opening the upper cover 12 and pulling the wire 33.
The inner end of each bag 31 is terminated with a rolled portion 317 and a pin 32 which is pivotedly fixed in two pin holes 165 respectively formed on two triangle supporting plates 164 disposed on both sides of bottom plate 16. The pin holes 165 are slopingly formed on the slope side of triangle supporting plate 164 so as to form sector-type collapsible bags when extended. The number of holes 165 is the same as the number of bags 31. Each plate 164 is bent outwards to form a hook 166 to define each pin 32 and prevent its falling from the supporting plate 164.
The bottom case 11 is made from metals having magnetic absorbing property, to absorb magnetic flux so as to prevent from magnetic interference to the floppy disks A stored in the casing 1.
When opening the present invention, the push-button 22 is depressed to open upper cover 12 as restored by springs 14, the wire 33 with balls 331 will be pulled to extend all storage bags 31 to form a sector shape so that each disk A is easily taken out from each bag. When not in use, the cover 12 is closed and the lock 21 is actuated to rotate latch 212 in 90 degrees so as to obstruct the rectangular hole 221 of push button 22 whereby the button 22 can not be depressed. When retracting all bags within the casing 1, each ball 331 formed on wire 33 will separate every two neighbouring bags 31 to prevent the overlapping, abrasion between the bags.
The present invention has the following advantages superior to conventional disk cases:
1. The storage bags 31 can be opened as a sector type and the disks stored therein will be easily taken out or taken in without damaging the disks.
2. When retracting all bags within the casing, each bag is separated from another bag so as to eliminate the abrasion of disks during storage or handling.
3. The description label can be directly adhered on disk as "B" shown in FIG. 1 which will also be easily read when put into a disk drive due to the same reading direction.
4. The present invention has property to prevent from interference by magnetic flux so as to ensure the reliability and precision of the disk.
5. The present invention can be easily and fastly closed after opening the cover so as to have a dust-proof property. In closing state the disks originally stored in the bags will not be exposed to the outside surrounding to have a sound dust-proof effect.
However, the conventional disk case is difficult to open or close and whenever taking out the disk from the open case, the disk will be easily contaminated by air or environmental pollutants.
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A collapsible storage box for floppy disk includes a casing, a switch means and a collapsible storing means consisting of a plurality of storage bags for storing floppy disk for computor use whereby the collapsible bags can be extended to form a sector type for easy and convenient take-out or take-in service for the floppy disks.
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TECHNICAL FIELD OF THE INVENTION
This invention is related in general to the field of semiconductor processing. More particularly, the invention is related to a method of forming contacts and vias in semiconductor.
BACKGROUND OF THE INVENTION
A challenge for semiconductor processing engineers is the formation of submicron contacts and vias with high aspect ratios. Forming the contacts and vias with aluminum is preferred over tungsten because of aluminum's lower resistance, fewer overall process steps, and improved electromigration performance. However, aluminum reflow for contact or via filling has not been widely accepted due to the higher deposition temperature and difficulty in completely filling the high aspect ratio contacts and vias. With the advent of a force-fill™ process developed by Electrotech Ltd. of Bristol, United Kingdom, a metal, typically aluminum, sputtered onto the semiconductor surface can be forcibly extruded into the small via or contact openings by exerting high pressure at an elevated temperature. Although this force-fill™ process enhances the filling of the via and contact recesses and openings, the force-fill process also creates substantial cracks or splits in the metal film surface.
The fill metal surface splitting or cracking is similar in appearance to the cracks in dry parched earth. The cracks may extend substantially into the metal film as to interfere with the conduction of current therethrough. Further, particulate defects and process induced defects on patterned silicon wafers are generally detectable with the use of optical defect detection equipment and laser scatter defect detection equipment. However, the detection equipment is more likely to generate erroneous detection results due to the grain boundary cracks. These cracks trap a large percentage of the incident light or laser, which causes them to appear as dark and ragged-edged lines. These dark lines are detected by the optical and laser scatter equipment as nuisance defects, making detection of true particulate defects difficult without significantly reducing the effective sensitivity of the equipment.
SUMMARY OF THE INVENTION
Accordingly, there is a need for a processing method that would completely fill the contacts and vias but substantially eliminate the fill metal surface cracks and/or splits.
In accordance with the present invention, a semiconductor processing method of forming contacts and vias is provided which eliminates or substantially reduces the disadvantages associated with prior methods.
In an aspect of the invention, a method of filling openings in a semiconductor includes the steps of first forming a fill metal layer over the semiconductor which substantially covers the openings. Thereafter, a surface coating of a predetermined material is formed over the fill metal layer. Then, high pressure is applied on the surface coating to force the fill metal into the openings.
An advantage of the present invention is the elimination or great reduction of cracking and splitting in the contact and via fill metal film surface. As a result, the conductivity of the metal film is enhanced and nuisance defects detected by semiconductor inspection equipment is substantially reduced. The narrowings of the linewidth that may occur due to such surface cracks can also affect electromigration reliability of leads carrying the vias. This invention additionally results in improved reliability.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention, reference may be made to the accompanying drawings, in which:
FIGS. 1A and 1B are cross-sectional views of a semiconductor process to eliminate fill metal surface cracks according to the teachings of the present invention; and
FIGS. 2A and 2B are cross-sectional views of an alternate semiconductor process to eliminate fill metal surface cracks according to the teachings of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiments of the present invention are illustrated in FIGS. 1-2, like reference numerals being used to refer to like and corresponding parts of the various drawings.
Referring to FIG. 1A, a cross-sectional view of an upper surface of a wafer 10 is shown. A metal layer or structure 16, M 1 , is embedded in an inter-level oxide 18. An opening 20 to metal layer 16 may be created in inter-level oxide 18 by conventional processes, such as patterning and etching. Thereafter, one or more barrier/adhesion layers 22 and 24 may be formed on the bottom and sidewalls of recess or opening 20. The use of barrier/adhesion layers 22 and 24 enhances void-free plug formation and facilitates the deformation of the fill metal into opening 20. Barrier/adhesion layers 22 and 24 may be formed by depositing a titanium layer 22 and then a titanium nitride layer 24 thereon, for example. A typical thickness of titanium layer 22 is approximately 400 Å and of titanium nitride layer 24 is approximately 500 Å.
Subsequently, a layer of fill metal 30 is formed on the surface of wafer 10, completely covering and bridging opening 20. Fill metal 30 may be aluminum, aluminum alloy, or any other suitable conductor, and may be deposited by sputtering thereon at approximately 400-450° C. The thickness of fill metal layer 30 may be equal to or greater than the diameter of opening 20, which may be approximately 1 μm. In the conventional force-fill process, pressure ranging from 400 to 700 atmospheres is then applied isostatically to force fill metal 30 to enter and fill opening 20. However, as set forth above, this process results in cracking and splitting over the fill metal surface.
According to the teachings of the present invention, prior to the force-fill step, a thin surface coating layer 32 is formed on top of fill metal layer 30. Surface coating layer 32 may be formed by depositing an anti-reflective coating (ARC) of titanium nitride, titanium tungsten, silicon nitride, or other suitable metal on top of fill metal layer 30. Alternatively, surface coating layer 32 may be formed by exposing fill metal layer 30 to ambient air to form an oxide of the fill metal, for example. A surface coating layer 32 of nitride of the fill metal may also be formed by introducing nitrogen. When the fill metal is aluminum, its exposure to oxygen causes the formation of aluminum oxide, and exposure to nitrogen produces aluminum nitride. Surface coating layer 32 formed by depositing the anti-reflective coating may have a thickness less than 1000 Å and generally in the range of 50-500 Å. On the other hand, the oxide or nitride surface coating layer 32 may have a thickness of approximately 10-50 Å.
After the formation of surface coating layer 32, pressure is exerted isostatically on surface coating layer 32 which overlies fill metal layer 30. The pressure forces the fill metal to descend into opening 20 and substantially fills the void therein, as shown in FIG. 1B.
Referring to FIG. 2A, an alternate embodiment of the present invention is shown. A metal layer or structure 46, M 1 , is embedded in an inter-level oxide 48. An opening 50 to metal layer 46 in inter-level oxide 48 may be created by patterning and etching. One or more barrier/adhesion layers 52 and 54 may be formed on the bottom and sidewalls of opening 50. As described above, barrier/adhesion layers 52 and 54 may be formed by depositing titanium and then titanium nitride, for example. A typical thickness of titanium layer 22 is approximately 400 Å and of titanium nitride layer 24 is approximately 500 Å.
A layer of fill metal 60 is then formed on the surface of wafer 40, completely covering and bridging opening 50. Fill metal 60 may be aluminum, aluminum alloy, or any other suitable conductor, and may be deposited by sputtering at approximately 400-450° C.
According to the teachings of the present invention, prior to the force-fill step, a first surface coating layer 62 is formed on top of fill metal layer 60. First surface coating layer 62 is preferably titanium. On top of first surface coating layer 62 a second surface coating layer 64 is formed. Second surface coating layer 64 may be formed by depositing an anti-reflective coating (ARC) of titanium nitride, titanium tungsten, silicon nitride, or other suitable metal on top of first surface coating layer 62. Alternatively, surface coating layer 64 may be formed by exposing first surface coating layer 62 to ambient air to form an oxide or by exposing to nitrogen to form a nitride, for example. The combined thickness of first and second surface coating layers 62 and 64 may be no more than 1000 Å. This is a typical thickness range but the invention is not so limited.
After the formation of surface coating layers 62 and 64, pressure is exerted isostatically thereon. The high pressure forces the fill metal to descend into opening 50 and substantially fills the void therein, as shown in FIG. 2B.
When contacts and vias are formed in the manner described above according to the teachings of the present invention, the surface coating layer or layers tend to hold the fill metal grains together or minimize the shear forces exerted thereon due to the high force-fill pressure. Accordingly, cracking and splitting in the fill metal surface are greatly reduced or eliminated. When an anti-reflective coating is used as a surface coating layer of the present invention, no process step is added since the application of the anti-reflective coating normally occurs subsequently in wafer processing.
Although several embodiments of the present invention and its advantages have been described in detail, it should be understood that mutations, changes, substitutions, transformations, modifications, variations, and alterations can be made therein without departing from the teachings of the present invention, the spirit and scope of the invention being set forth by the appended claims.
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A method of filling openings (20, 50) in a semiconductor (10, 40) includes the steps of first forming a fill metal layer (30, 60) over the semiconductor which substantially covers the openings (20, 50). Thereafter, a surface coating (32, 62, 64) of a predetermined material is formed over the fill metal layer (30, 60). Then, high pressure is applied on the surface coating (32, 62, 64) to force the fill metal into the openings (20, 50). Metal film surface cracks previously plaguing force-fill processes are thereby eliminated or substantially reduced.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to devices used in the manufacture of nonwoven sheeting and, specifically, to devices known as crosslappers which provide a means for transferring filaments or fleece from a feed means such as a carding machine to a delivery means such as a laydown machine in such a way that the laydown machine receives a web of uniform thickness and density and, if desired, of modified weight basis and width.
2. Description of the Prior Art
U.S. Pat. No. 3,877,628, issued Apr. 15, 1975 on the application of Asselin et al., discloses a crosslapper having a certain guide belt arrangement to minimize disruption of the fleece by air flow during high speed operation of the device. That patent recognizes the difficulty of eddies of air which blow the fleece and disrupt the web in high speed operation, and attempts to improve the situation by carrying the fleece between two closely-positioned guide belts prior to the fleece transfer. There is no mention of the construction of guide belts used therein.
U.S. Pat. No. 3,558,029, issued Jan. 26, 1971 on the application of Manns, discloses a crosslapper in which a carded web is advanced by being positively held between conveyer belts. This arrangement is said to deposit the web evenly and without formation of folds. It is said that the conveyer belts can be formed from continuous fabrics made from synthetic material.
British Patent No. 1,527,230, published Oct. 4, 1978 on the application of Jowett, discloses a modified crosslapper wherein there is provision for the lattices or conveyer belts to operate at variable speeds throughout each cycle. There is no mention of the kind or construction of the conveyer belts.
U.S. Pat. No. 3,851,681, issued Dec. 3, 1974 on the application of Egan, U.S. Pat. No. 4,376,455, issued Mar. 15, 1983 on the application of Hahn, and U.S. Pat. No. 4,408,637, issued Oct. 11, 1983 on the application of Karm, disclose woven fabrics useful as the support belt for papermaking processes.
U.S. Pat. No. 4,379,735, issued Apr. 12, 1983 on the application of MacBean, discloses a particular construction of woven fabric for use on so-called "twin wire" paper making machines.
In the field of airlay crosslappers, it has been customary for fleece transporting belts to be made from impermeable material and, as can be seen from the references discussed above, it has been customary to minimize the effects of air eddies in the lay-down by means of sandwiching the fleece between two belts. In the field of papermaking machines, it has been customary to use foraminous screens to strain water from the so-called "furnish" during wetlay. Crosslappers and papermaking machines are from entirely different fields and references from one field do not suggest any application in the other field. Nevertheless, the present invention relates to crosslappers utilizing fleece transporting belts made from foraminous fabrics with significant void fraction.
SUMMARY OF THE INVENTION
The present invention provides a crosslapper comprising fleece feed means, at least one endless, foraminous, fleece transporting belt for accepting fleece from the fleece feed means; reciprocating belt carriage means for moving the fleece transporting belt continuously through the endless length of the belt means and reciprocatingly in a rectilinear path; and fleece delivery means for accepting fleece from the fleece transporting belt and moving it continuously in a rectilinear path substantially perpendicular to the path of the reciprocating belt carriage means.
The foraminous fleece transporting belt is important to this invention for the purpose of providing an escape for air entrained during acceptance of the fleece from the fleece feed means in high speed operation. The foraminous fleece transporting belt has a significant void fraction to ensure the ready passage of air in both directions during operation of the crosslapper.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified representation of a crosslapper of general nature improved by means of foraminous fleece transporting belts; and FIG. 2 is a representation of how it can be altered and further improved by means of foraminous fleece transporting belts in accordance with this invention.
FIG. 3 is a simplified representation of another crosslapper of general nature improved by means of foraminous fleece transporting belts; and FIG. 4 is a representation of how it can be altered and further improved by means of foraminous fleece transporting belts in accordance with this invention.
DETAILED DESCRIPTION OF THE INVENTION
A crosslapper for use in building webs of fleece must be constructed such that the fleece is carried from a feed means and laid, in a reciprocating manner, onto a further delivery means rapidly and with a minimum of disruption.
There are several forces at work on the crosslapper machinery and on the fleece, itself, which cause the fleece to be dislocated. One of the most important forces is the eddying of air currents around the fleece. The fleece is of extremely low bulk density and the rapid, reciprocating movement of the massive crosslapper creates a considerable movement of air which blows the fleece out of its proper position.
The tendency of recent operation is for crosslappers to be required to operate with wider beds and at faster speeds. The increased sizes and the increased speeds both contribute to the aforementioned eddying effects. As was previously discussed, the eddying effects have, in the past, been reduced by means of sandwiching the fleece between two transporting belts so that the fleece is held in place. There has arisen a problem with the sandwiching, also, however, in that the moving of two transporting belts into close proximity causes a squeezing or compressing of the delivered air and fleece. The air must escape from between the belts before the "fleece sandwich" is completed. Moreover, in high speed operation, the belts which sandwich the fleece are subject to independent movement and to irregular flapping movement toward and away from each other. Such flapping movement causes the sandwiched fleece to be disturbed and moved and displaced. Again, due to wider beds and higher speeds, it is more and more difficult to operate successfully.
It has, also, been found important to provide for passage of air in the other direction, back into the fleece when the fleece is being held between two belts and the belts are quickly separated. On separation of the belts during high speed processing, air must rush in to fill the space created by the separation. In lightweight fleece, this inrush of air causes the edges of the fleece to be forced in and folded, which causes defects in the final fleece blanket. The deleterious effects of inrushing air are greatly reduced when the air can come in through the belts rather than around them.
In the past, crosslapper transporting belts have been continuous, impermeable, sheets of fabric or film. The sandwiching, or two-belt crosslappers, have been designed such that the air can pass only in and out of the sides of the belt systems. The increased width and speeds have made such air escape more difficult and practically nonfeasable. The present invention presents an alternative and solves, the problem of air escape for two-belt. crosslapper systems and for crosslapper systems which pass fleece between a belt and a roll.
The crosslapper represented in FIG. 1 is of a familiar general design and is used herein for purposes of illustrating this invention. In that crosslapper, fleece feed means 11 is a belt running on roll 12 and a mating roll not shown. By means of fleece feed means 11 fleece is introduced to the crosslapper, itself. Fleece feed means can be a belt, as shown, or it can be the delivery end of a carding machine or an interface with any other fleece preparation device. The fleece feed means can be one end of the fleece transporting belt which has merely been positioned to receive fleece from some outside agency for the crosslapping operation. The fleece feed means can, also, be represented by a single, continuous, belt which effectively joins the crosslapper of this invention with a fleece preparing device such as an airlay device. From fleece feed means 11, fleece is moved to or on fleece transporting belt 13. Fleece transporting belt 13 is an endless belt, of foraminous nature, threaded among fixed and movable rollers as will be described. Fixed roller 14 is located in close proximity to roller 12 so that there can be a successful transfer of fleece from the fleece feed means to the fleece transporting belt. Fleece transporting belt 13 is passed around reciprocating belt carriage means 15 and 16; and, between those reciprocating belt carriage means, the fleece transporting belt is passed around a pair of fixed rollers 17 and 18. Reciprocating belt carriage means 15 includes roller 19 which carries the fleece in a reciprocating manner at the upper end of the crosslapper and roller 20 which serves as a loop control for the upper end of fleece transporting belt 13. Reciprocating belt carriage means 16 includes roller 21 which carries the fleece in a reciprocating manner at the lower end of the crosslapper and delivers the fleece through fleece delivery means made up of rollers 22 and 23 to fleece receiving means 29. Roller 24 can serve as an idler roll for the purpose of maintaining a proper tension on the belt system.
The fleece is moved from fleece transporting belt 13 to fleece transporting belt 26 which is continuously run on fixed rollers 27 and 28. Fleece transporting belts 13 and 26 sandwich the fleece to hold it in place until such time that it is moved into the reciprocating carriage means 16 and through the fleece delivery means 22 and 23. The fleece passes through fleece delivery means 22 and 23 and is laid on fleece receiving means 29 continuously in a rectilinear path substantially perpendicular to the path of the reciprocating carriage means.
Fleece receiving means 29 is generally a continuously-moving belt which leads to additional processing of the crosslapped fleece laid thereon. The fleece receiving means 29 can be mounted in a support 30 and driven by a rotating means 31.
The crosslapper represented in FIG. 2 is the same as that shown in FIG. 1 except that, in the case where foraminous transporting belts are used, one of the rollers can be omitted for even more efficient operation In the crosslapper of FIG. 1, when impermeable transporting belts are used, there is a need for having roller 17 to support the transporting belt 13 and a separate roller 28 to support the transporting belt 26. Without separate rollers, when impermeable belts are used at high speed operation, the fleece is blown out the sides of the belts. In the crosslapper of FIG. 2 (elements corresponding to elements in FIG. 1 bear the same numbers) roller 28 has been eliminated and both transporting belts 13 and 26 are run over roller 17. Because the transporting belts are foraminous, the fleece can be conducted as a sandwich continuously from its introduction to transporting belt 26, at the upper end of the crosslapper, to its separation from the transporting belts at the lower end of the crosslapper; and there is no longer any need for the space between rollers 17 and 28 of the device in FIG. 1, under high speed operation, to prevent blowing the fleece away from the rollers.
The crosslapper of FIG. 3 is similar to that described in U.S. Pat. No. 3,877,628. In that crosslapper, feed means 11 is a section of fleece transporting belt 13 onto which fleece is fed. Fleece transporting belt 13 is an endless belt, of foraminous construction. Fixed rollers 12, 12a, and 14 support belt 13 at the fleece feeding end. Belt 13 is passed through reciprocating belt carriage means 15, around fixed roller 17, through reciprocating belt carriage means 16, and back to fixed rollers 28 and 28a. The endless loop is completed by idler roller 24 which maintains tension on belt 13. In the crosslapper of FIG. 3, endless, foraminous, fleece transporting belt 26 passes through reciprocating belt carriage means 15, around fixed roller 17, and through reciprocating belt carriage means 16 along, and in the same path with, fleece transporting belt 13. The fleece transporting belt 26, however, is run around fixed rollers 18 and 18a to maintain proper tension on the belt.
Fleece is moved from fleece feed means 11 and fleece transporting belt 13 to the reciprocating carriage means 15 where the fleece is sandwiched between fleece transporting belt 13 and fleece transporting belt 26. The fleece is sandwiched between the fleece transporting belts until is reaches reciprocating carriage means 16 where it passes through rollers 22 and 23 of the fleece delivery means which are included in, and carried along with, reciprocating carriage means 16. Fleece passed through the fleece delivery means is laid on fleece receiving means 29 continuously in a rectilinear path substantially perpendicular to the path of the reciprocating carriage means.
The crosslapper represented in FIG. 4 is the same as that shown in FIG. 3 except that, in the case where foraminous transporting belts are used, several of the rollers can be omitted for even more efficient operation. In the crosslapper of FIG. 3, when impermeable fleece transporting belts are used, there is a need for having several rollers included in the reciprocating carriage means. Without such rollers, when impermeable belts are used at high speed operation, the fleece is blown out the sides of the belts. In the crosslapper of FIG. 4 (elements corresponding to elements in FIG. 3 bear the same numbers) rollers 20a and 20b have been eliminated from reciprocating carriage means 15 and rollers 22a, 22b, 23a, and 23b have been eliminated from reciprocating carriage means 16. Because the transporting belts are foraminous, the fleece can be conducted as a sandwich continuously from its introduction to transporting belt 26 to its separation from the transporting belts at the fleece delivery means; and there is no longer any need for extra rollers to provide constant tension on the belt.
The fleeces eligible for use with the crosslapper of this invention include all of those used on crosslappers of the prior art. Fleeces are, generally, made from fiber staple of about 0.25 to about 12 inches long and up to as much as about 50 denier, with a basis weight of about 0.2 to 20 ounces/square yard. Of course, the crosslapper of this invention can, also, be used to fold fabrics, to lay up composites, to ply sheets and films, and the like, to the same extent and purpose as the crosslappers of the prior art.
As has been pointed out above, the foraminous material used for the fleece transporting belts of this invention can be made from any material presently used for other foraminous belts such as those used in papermaking arts. They could be made from metallic wire although such is not preferred due to the excessive weight of the metal. They can be made from synthetic fibers or a combination of metallic wire and synthetic fibers. The fibers which are most often used in manufacture of fleece transporting belts of this invention include polyamides, polyesters, glass, or combinations of those materials. The fibers are usually monofilaments and they can be coated or not.
It is important that the fleece transporting belts be electrically conductive in order to eliminate any buildup of static electricity. Generation of static electricity is a common problem in handling fleece and such static electricity must be completely dissipated in order to avoid a disruption of the fleece transport and laydown. Wire belts are, of course, conductive. Belts made from synthetic fibers can have conductive particles or materials incorporated into the fibers, themselves, or a few metal wires or conductive fibers can be woven together with the nonconductive synthetic fibers or the fibers can have a conductive coating.
The weave which is used for the fleece transporting belts is not critical or particularly important so long as the weave is relatively open and is not such as will cause the fleece to become lodged in the belt and become difficult to pull away from the belt. It is believed that any relatively open weave which will release the fleece and will not pass fleece through the belt, is eligible for use in the fleece transporting belts of this invention.
One aspect of the fleece transporting belt which is important to practice of this invention is the degree of openness of the weave. Openness of a weave in foraminous belts such as those used in this invention can be measured by a parameter known as the air permeability. Air Permeability is determined by ASTM Test Method D 737-75 and is reported in units of ft 3 /ft 2 min which can be converted to metric units (cm 3 /cm 2 s) by multiplying by a factor of 0.508. It is believed that belts having an air permeability as low as about 150 ft 3 /ft 2 min would be operable in this invention, although an air permeability of 200-1200 ft 3 /ft 2 min is much preferred.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A fleece was prepared using the airlay device and process described in U.S. Pat. No. 3,906,588. The fleece was made up of polyester staple about 0.75 in (1.9 cm) long with a filament denier of about 1.35.
A crosslapper with a configuration similar to that of the device of FIG. 1, herein was fitted with foraminous fleece transporting belts made from carbon-filled, nylon monofilaments and polyester filaments in a weave pattern as shown in U.S. Pat. No. 3,851,681 and having an air permeability of about 725 ft 3 /ft 2 min.
The fleece was introduced onto the fleece feed means of the crosslapper and the crosslapper was successfully operated at a rate exceeding 60 meters/minute.
As a control, attempts were made to operate the same crosslapper using impermeable fleece transporting belts; and the fleece could not be successfully conducted through the device at any speed.
In a second run, rayon staple about 1.5 inches long and of about 2-2.5 filament denier was carded into a 2-meter feed batt of about 2 ounces/square yard weight basis and was fed to a crosslapper having the same configuration as described above.
When the same foraminous fleece transporting belts described above were used, the crosslapper could be run at a speed in excess of 80 meters/minute. The upper operating limit was controlled by the upper limit of the crosslapper drive motor.
When impermeable belts of the prior art were used, the crosslapper could be operated at about 40-50 meters/minute. The upper operating limit was controlled by disruption and displacement of the fleece due to belt flapping and air movement eddys.
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A crosslapper is disclosed utilizing at least one foraminous transporting belt to permit rapid escape of entrained air during fast operation of wide-bed machinery.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] The application claims the benefit of U.S. Provisional Application Ser. No. 60/482,229, filed Jun. 24, 2003.
FIELD OF THE INVENTION
[0002] This invention relates to a method and apparatus for casting composite metal ingots, as well as novel composite metal ingots thus obtained.
BACKGROUND OF THE INVENTION
[0003] For many years metal ingots, particularly aluminum or aluminum alloy ingots, have been produced by a semi-continuous casting process known as direct chill casting. In this procedure molten metal has been poured into the top of an open ended mould and a coolant, typically water, has been applied directly to the solidifying surface of the metal as it emerges from the mould.
[0004] Such a system is commonly used to produce large rectangular-section ingots for the production of rolled products, e.g. aluminum alloy sheet products. There is a large market for composite ingots consisting of two or more layers of different alloys. Such ingots are used to produce, after rolling, clad sheet for various applications such as brazing sheet, aircraft plate and other applications where it is desired that the properties of the surface be different from that of the core.
[0005] The conventional approach to such clad sheet has been to hot roll slabs of different alloys together to “pin” the two together, then to continue rolling to produce the finished product. This has a disadvantage in that the interface between the slabs is generally not metallurgically clean and bonding of the layers can be a problem.
[0006] There has also been an interest in casting layered ingots to produce a composite ingot ready for rolling. This has typically been carried out using direct chill (DC) casting, either by simultaneous solidification of two alloy streams or sequential solidification where one metal is solidified before being contacted by a second molten metal. A number of such methods are described in the literature that have met with varying degrees of success.
[0007] In Binczewski, U.S. Pat. No. 4,567,936, issued Feb. 4, 1986, a method is described for producing a composite ingot by DC casting where an outer layer of higher solidus temperature is cast about an inner layer with a lower solidus temperature. The disclosure states that the outer layer must be “fully solid and sound” by the time the lower solidus temperature alloy comes in contact with it.
[0008] Keller, German Patent 844 806, published Jul. 24, 1952 describes a single mould for casting a layered structure where an inner core is cast in advance of the outer layer. In this procedure, the outer layer is fully solidified before the inner alloy contacts it.
[0009] In Robinson, U.S. Pat. No. 3,353,934, issued Nov. 21, 1967 a casting system is described where an internal partition is placed within the mould cavity to substantially separate areas of different alloy compositions. The end of the baffle is designed so that it terminates in the “mushy zone” just above the solidified portion of the ingot. Within the “mushy zone” alloy is free to mix under the end of the baffle to form a bond between the layers. However, the method is not controllable in the sense that the baffle used is “passive” and the casting depends on control of the sump location—which is indirectly controlled by the cooling system.
[0010] In Matzner, German patent DE 44 20 697, published Dec. 21, 1995 a casting system is described using a similar internal partition to Robinson, in which the baffle sump position is controlled to allow for liquid phase mixing of the interface zone to create a continuous concentration gradient across the interface.
[0011] In Robertson et al, British patent GB 1,184,764, published 21 Dec. 1965, a moveable baffle is provided to divide up a common casting sump and allow casting of two dissimilar metals. The baffle is moveable to allow in one limit the metals to completely intermix and in the other limit to cast two separate strands.
[0012] In Kilmore et al., WO Publication 2003/035305, published May 1, 2003 a casting system is described using a barrier material in the form of a thin sheet between two different alloy layers. The thin sheet has a sufficiently high melting point that it remains intact during casting, and is incorporated into the final product.
[0013] Takeuchi et al., U.S. Pat. No. 4,828,015, issued May 9, 1989 describes a method of casting two liquid alloys in a single mould by creating a partition in the liquid zone by means of a magnetic field and feeding the two zones with separate alloys. The alloy that is feed to the upper part of the zone thereby forms a shell around the metal fed to the lower portion.
[0014] Veillette, U.S. Pat. No. 3,911,996, describes a mould having an outer flexible wall for adjusting the shape of the ingot during casting.
[0015] Steen et al., U.S. Pat. No. 5,947,194, describes a mould similar to Veillette but permitting more shape control.
[0016] Takeda et al., U.S. Pat. No. 4,498,521 describes a metal level control system using a float on the surface of the metal to measure metal level and feedback to the metal flow control.
[0017] Odegard et al., U.S. Pat. No. 5,526,870, describes a metal level control system using a remote sensing (radar) probe.
[0018] Wagstaff, U.S. Pat. No. 6,260,602, describes a mould having a variably tapered wall to control the external shape of an ingot.
[0019] It is an object of the present invention to produce a composite metal ingot consisting of two or more layers having an improved metallurgical bond between adjoining layers.
[0020] It is further object of the present invention to provide a means for controlling the interface temperature where two or more layers join in a composition ingot to improve the metallurgical bond between adjoining layers.
[0021] It is further object of the present invention to provide a means for controlling the interface shape where two or more alloys are combined in a composite metal ingot.
[0022] It is a further object of the present invention to provide a sensitive method for controlling the metal level in an ingot mould that is particularly useful in confined spaces.
SUMMARY OF THE INVENTION
[0023] One embodiment of the present invention is a method for the casting of a composite metal ingot comprising at least two layers formed of one or more alloys compositions. The method comprises providing an open ended annular mould having a free end and an exit end wherein molten metal is added at the feed end and a solidified ingot is extracted from the exit end. Divider walls are used to divide the feed end into at least two separate feed chambers, the divider walls terminating above the exit end of the mould, and where each feed chamber is adjacent at least one other feed chamber. For each pair of adjacent feed chambers a first stream of a first alloy is fed to one of the pair of feed chambers to form a pool of metal in the first chamber and a second stream of a second alloy is fed through the second of the pair of food chambers to form a pool of metal in the second chamber. The first metal pool contacts the divider wall between the pair of chambers to cool the first pool so as to form a self-supporting surface adjacent the divider wall. The second metal pool is then brought into contact with the first pool so that the second pool first contacts the self-supporting surface of the first pool at a point where the temperature of the self-supporting surface is between the solidus and liquidus temperatures of the first alloy. The two alloy pools are thereby joined as two layers and cooled to form a composite ingot.
[0024] Preferably the second alloy initially contacts the self-supporting surface of the first alloy when the temperature of the second alloy is above the liquidus temperature of the second alloy. The first and second alloys may have the same alloy composition or may have different alloy compositions.
[0025] Preferably the upper surface of the second alloy contacts the self-supporting surface of the first pool at a point where the temperature of the self-supporting surface is between the solidus and liquidus temperatures of the first alloy.
[0026] In this embodiment of the invention the self-supporting surface may be generated by cooling the first alloy pool such that the surface temperature at the point where the second alloy first contacts the self-supporting surface is between the liquidus and solidus temperature.
[0027] Another embodiment of the present invention comprises a method for the casting of a composite metal ingot comprising at least two layers formed of one or more alloys compositions. This method comprises providing an open ended annular mould having a feed end and an exit end wherein molten metal is added at the feed end and a solidified ingot is extracted from the exit end. Divider walls are used to divide the feed end into at least two separate feed chambers, the divider walls terminating above the exit end of the mould, and where each feed chamber is adjacent at least one other feed chamber. For each pair of adjacent feed chambers a first stream of a first alloy is fed to one of the pair of feed chambers to form a pool of metal in the first chamber and a second stream of a second alloy is fed through the second of the pair of feed chambers to form a pool of metal in the second chamber. The first metal pool contacts the divider wall between the pair of chambers to cool the first pool so as to form a self-supporting surface adjacent the divider wall. The second metal pool is then brought into contact with the first pool so that the second pool first contacts the self-supporting surface of the first pool at a point where the temperature of the self-supporting surface is below the solidus temperature of the first alloy to form an interface between the two alloys. The interface is then reheated to a temperature between the solidus and liquidus temperature of the first alloy so that the two alloy pools are thereby joined as two layers and cooled to form a composite ingot.
[0028] In this embodiment the reheating is preferably achieved by allowing the latent heat within the first or second alloy pools to reheat the surface.
[0029] Preferably the second alloy initially contacts the self-supporting surface of the first alloy when the temperature of the second alloy is above the liquidus temperature of the second alloy. The first and second alloys may have the same alloy composition or may have different alloy compositions.
[0030] Preferably the upper surface of the second alloy contacts the self-supporting surface of the first pool at a point where the temperature of the self-supporting surface is between the solidus and liquidus temperatures of the first alloy.
[0031] The self-supporting surface may also have an oxide layer formed on it. It is sufficiently strong to support the splaying forces normally causing the metal to spread out when unconfined. These splaying forces include the forces created by the metallostatic head of the first stream, and expansion of the surface in the case where cooling extends below the solidus followed by re heating the surface. By bringing the liquid second alloy into first contact with the first alloy while the first alloy is still in the semi-solid state or, and in the alternate embodiment, by ensuring that the interface between the alloys is reheated to a semi-solid state, a distinct but joining interface layer is formed between the two alloys. Furthermore, the fact that the interface between the second alloy layer and the first alloy is thereby formed before the first alloy layer has developed a rigid shell means that stresses created by the direct application of coolant to the exterior surface of the ingot are better controlled in the finished product, which is particularly advantageous when casting crank prone alloys.
[0032] The result of the present invention is that the interface between the first and second alloy is maintained, over a short length of emerging ingot, at a temperature between the solidus and liquidus temperature of the first alloy. In one particular embodiment, the second alloy is fed into the mould so that the upper surface of the second alloy in the mould is in contact with the surface of the first alloy where the surface temperature is between the solidus and liquidus temperature and thus an interface having met this requirement is formed. In an alternate embodiment, the interface is reheated to a temperature between the solidus and liquidus temperature shortly after the upper surface of the second alloy contacts the self-supporting surface of the first alloy. Preferably the second alloy is above its liquidus temperature when it first contacts the surface of the first alloy. When this is done, the interface integrity is maintained but at the same time, certain alloy components are sufficiently mobile across the interface that metallurgical bonding is facilitated.
[0033] If the second alloy is contacted where the temperature of the surface of the first alloy is sufficiently below the solidus (for example after a significant solid shell has formed), and there is insufficient latent heat to reheat the interface to a temperature between the solidus and liquidus temperatures of the first alloy, then the mobility of alloy components is very limited and a poor metallurgical bond is formed. This can cause layer separation during subsequent processing.
[0034] If the self-supporting surface is not formed on the first alloy prior to the second alloy contacting the first alloy, then the alloys are free to mix and a diffuse layer or alloy concentration gradient is formed at the interface, making the interface less distinct.
[0035] It is particularly preferred that the upper surface of the second alloy be maintained a position below the bottom edge of the divider wall. If the upper surface of the second alloy in the mould lies above the point of contact with the surface of the first alloy, for example, above the bottom edge of the divider wall, then there is a danger that the second alloy can disrupt the self supporting surface of the first alloy or even completely re-melt the surface because of excess latent heat. If this happens, there may be excessive mixing of alloys at the interface, or in some cases runout and failure of the cast. If the second alloy contacts the divider wall particularly far above the bottom edge, it may even be prematurely cooled to a point where the contact with the self-supporting surface of the first alloy no longer forms a strong metallurgical bond. In certain cases it may however be advantageous to maintain the upper surface of the second alloy close to the bottom edge of the divider wall but slightly above the bottom edge so that the divider wall can act as an oxide skimmer to prevent oxides from the surface of the second layer from being incorporated in the interface between the two layers. This is particularly advantageous where the second alloy is prone to oxidation. In any case the upper surface position must be carefully controlled to avoid the problems noted above, and should not lie more than about 3 mm above the bottom end of the divider.
[0036] In all of the preceding embodiments it is particularly advantageous to contact the second alloy to the first at a temperature between the solidus and coherency temperature of the first alloy or to reheat the interface between the two to a temperature between the solidus and coherency temperature of the first alloy. The coherency point, and the temperature (between the solidus and liquidus temperature) at which it occurs is an intermediate stage in the solidification of the molten metal. As dendrites grow in size in a cooling molten metal and start to impinge upon one another, a continuous solid network builds up throughout the alloy volume. The point at which there is a sudden increase in the torque force needed to shear the solid network is known as the “coherency point”. The description of coherency point and its determination can be found in Solidification Characteristics of Aluminum Alloys Volume 3 Dendrite Coherency Pg 210.
[0037] In another embodiment of the invention, there is provided an apparatus for coating metal comprising an open ended annular mould having a feed end and an exit end and a bottom block that can fit within the exit end and is movable in a direction along the axis of the annular mould. The feed end of the mould is divided into at least two separate feed chambers, where each feed chamber is adjacent at least one other feed chamber and where the adjacent feed chambers are separated by a temperature controlled divider wall that can add or remove heat. The divider wall ends above the exit end of the mould. Each chamber includes a metal level control apparatus such that in adjacent pairs of chambers the metal level in one chamber can be maintained at a position above the lower end of the divider wall between the chambers and in the other chamber can be maintained at a different position from the level in the first chamber.
[0038] Preferably the level in the other chamber is maintained at a position below the lower end of the divider wall.
[0039] The divider wall is designed so that the heat extracted or added is calibrated so as to create a self-supporting surface on metal in the first chamber adjacent the divider wall and to control the temperature of the self-supporting surface of the metal in the first chamber to lie between the solidus and liquidus temperature at a point where the upper surface of the metal in the second chamber can be maintained.
[0040] The temperature of the self-supporting layer can be carefully controlled by removing heat from the divider wall by a temperature control fluid being passed through a portion of the divider wall or being brought into contact with the divider wall at its upper end to control the temperature of the self-supporting layer.
[0041] A further embodiment of the invention is a method for the casting of a composite metal ingot comprising at least two different alloys, which comprises providing an open ended annular mould having a feed end and an exit end and means for dividing the feed end into at least two separate, feed chambers, where each feed chamber is adjacent at least one other feed chamber. For each pair of adjacent feed chambers, a first stream of a first alloy is fed through one of the adjacent feed chambers into said mould, a second stream of a second alloy is fed through another of the adjacent feed chambers. A temperature controlling divider wall is provided between the adjacent feed chambers such that the point on the interface where the first and second alloy initially contact each other is maintained at a temperature between the solidus and liquidus temperature of the first alloy by means of the temperature controlling divider wall whereby the alloy streams are joined as two layers. The joined alloy layers are cooled to form a composite ingot.
[0042] The second alloy is preferably brought into contact with the first alloy immediately below the bottom of the divider wall without first contacting the divider wall. In any event, the second alloy should contact the first alloy no less than about 2 mm below the bottom edge of the divider wall but not greater than 20 mm and preferably about 4 to 6 mm below the bottom edge of the divider wall.
[0043] If the second alloy contacts the divider wall before contacting the first alloy, it may be prematurely cooled to a point where the contact with the self-supporting surface of the first alloy no longer forms a strong metallurgical bond. Even if the liquidus temperature of the second alloy is sufficiently low that this does not happen, the metallostatic head that would exist may cause the second alloy to feed up into the space between the first alloy and the divider wall and cause casting defects or failure. When the upper surface of the second alloy is desired to be above the bottom edge of the divider wall (e.g. to skim oxides) it must in all cases be carefully controlled and positioned as close as practical to the bottom edge of the divider wall to avoid these problems.
[0044] The divider wall between adjacent pairs of feed chambers may be tapered and the taper may vary along the length of the divider wall. The divider wall may further have a curvilinear shape. These features may be used to compensate for the different thermal and solidification properties of the alloys used in the chambers separated by the divider wall and thereby provide for control of the final interface geometry within the emerging ingot. The curvilinear shaped wall may also serve to form ingots with layers having specific geometries that can be rolled with less waste. The divider wall between adjacent pairs of feed chambers may be made flexible and may be adjusted to ensure that the interface between the two alloy layers in the final cast and rolled product is straight regardless of the alloys used and is straight even in the start-up section.
[0045] A further embodiment of the invention is an apparatus for casting of composite metal ingots, comprising an open ended annular mould having a feed end and an exit end and a bottom block that can fit inside the exit end and move along the axis of the mould. The feed end of the mould is divided into at least two separate feed chambers, where each feed chamber is adjacent at least one other feed chamber and where the adjacent feed chambers are separated by a divider wall. The divider wall is flexible, and a positioning device is attached to the divider wall so that the wall curvature in the plane of the mould can be varied by a predetermined amount during operation.
[0046] A further embodiment of the invention is a method for the casting of a composite metal ingot comprising at least two different alloys, which comprises providing an open ended annular mould having a feed end and an exit end and means for dividing the feed end into at least two separate, feed chambers, where each feed chamber is adjacent at least one other feed chamber. For adjacent pairs of the feed chambers, a first stream of a first alloy is fed through one of the adjacent feed chambers into the mould, and a second stream of a second alloy is fed through another of the adjacent feed chambers. A flexible divider wall is provided between adjacent feed chambers and the curvature of the flexible divider wall is adjusted during casting to control the shape of interface where the alloys are joined as two layers. The joined alloy layers are then cooled to form a composite ingot.
[0047] The metal feed requires careful level control and one such method is to provide a slow flow of gas, preferably inert, through a tube with an opening at a fixed point with respect to the body of the annular mould. The opening is immersed in use below the surface of the metal in the mould, the pressure of the gas is measured and the metallostatic head above the tube opening is thereby determined. The measured pressure can therefore be used to directly control the metal flow into the mould so as to maintain the upper surface of the metal at a constant level.
[0048] A further embodiment of the invention is a method of casting a metal ingot which comprises providing an open ended annular mould having a feed end and an exit end, and feeding a stream of molten metal into the feed end of said mould to create a metal pool within said mould having a surface. The end of a gas delivery tube is immersed into the metal pool from the feed end of mould tube at a predetermined position with respect to the mould body and an inert gas is bubbled through the gas delivery tube at a slow rate sufficient to keep the tube unfrozen. The pressure of the gas within the said tube is measured to determine the position of the molten metal surface with respect to the mould body.
[0049] A further embodiment of the invention is an apparatus for casting a metal ingot that comprises an open-ended annular mould having a feed end and an exit end and a bottom block that fits in the exit end and is movable along the axis of the mould. A metal flow control device is provided for controlling the rate at which metal can flow into the mould from an external source, and a metal level sensor is also provided comprising a gas delivery tube attached to a source of gas by means of a gas flow controller and having an open end positioned at a predefined location below the feed end of the mould, such that in use, the open end of the tube would normally lie below the metal level in the mould. A means is also provided for measuring the pressure of the gas in the gas delivery tube between the flow controller and the open end of the gas delivery tube, the measured pressure of the gas being adapted to control the metal flow control device so as to maintain the metal into which the open end of the gas delivery tube is placed at a predetermined level.
[0050] This method and apparatus for measuring metal level is particularly useful in measuring and controlling metal level in a confined space such as in some or all of the feed chambers in a multi-chamber mould design. It may be used in conjunction with other metal level control systems that use floats or similar surface position monitors, where for example, a gas tube is used in smaller feed chambers and a feed control system based on a float or similar device in the larger feed chambers.
[0051] In one preferred embodiment of the present invention there is provided a method for casting a composite ingot having two layer of different alloys, where one alloy forms a layer on the wider or “rolling” face of a rectangular cross-sectional ingot formed from another alloy. For this procedure there is provided an open ended annular mould having a feed end and an exit end and means for dividing the feed end into separate adjacent feed chambers separated by a temperature controlled divider wall. The first stream of a first alloy is fed though one of the feed chambers into the mould and a second stream of a second alloy is fed through another of the feed chambers, this second alloy having a lower liquidus temperature than the first alloy. The first alloy is cooled by the temperature controlled divider wall to form a self-supporting surface that extends below the lower end of the divider wall and the second alloy is contacted with the self-supporting surface of the first alloy at a location where the temperature of the self-supporting surface is maintained between the solidus and liquidus temperature of the first alloy, whereby the two alloy streams are joined as two layers. The joined alloy layers are then cooled to form a composite ingot.
[0052] In another preferred embodiment the two chambers are configured so that an outer chamber completely surrounds the inner chamber whereby an ingot is formed having a layer of one alloy completely surrounding a core of a second alloy.
[0053] A preferred embodiment includes two laterally spaced temperature controlled divider walls forming three feed chambers. Thus, there is a central feed chamber with a divider wall on each side and a pair of outer feed chambers on each side of the central feed chamber. A stream of the first alloy may be fed through the central feed chamber, with streams of the second alloy being fed into the two side chambers. Such an arrangement is typically used for providing two cladding layers on a central core material.
[0054] It is also possible to reverse the procedure such that streams of the first alloy are feed through the side chambers while a stream of the second alloy is fed through the central chamber. With this arrangement, casting is started in the side feed chambers with the second alloy being fed through the central chamber and contacting the pair of first alloys immediately below the divider walls.
[0055] The ingot cross-sectional shape may be any convenient shape (for example circular, square, rectangular or any other rectangular or irregular shape) and the cross-sectional shapes of individual layers may also vary within the ingot.
[0056] Another embodiment of the invention is a cast ingot product consisting of an elongated ingot comprising, in cross-section, two or more separate alloy layers of differing composition, wherein the interface between adjacent alloys layers is in the form of a substantially continuous metallurgical bond. This bond is characterized by the presence of dispersed particles of one or more intermetallic compositions of the first alloy in a region of the second alloy adjacent the interface. Generally in the present invention the first alloy is the one on which a self-supporting surface is first formed and the second alloy is brought into contact with this surface while the surface temperature is between the solidus and liquidus temperature of the first alloy, or the interface is subsequently reheated to a temperature between the solidus and liquidus temperature of the first alloy. The dispersed particles preferably are less than about 20 μm in diameter and are found in a region of up to about 200 μm from the interface.
[0057] The bond may be further characterized by the presence of plumes or exudates of one or more intermetallic compositions of the first alloy extending from the interface into the second alloy in the region adjacent the interface. This feature is particularly formed when the temperature of the self-supporting surface has not been reduced below the solidus temperature prior to contact with the second alloy.
[0058] The plumes or exudates preferably penetrate less than about 100 μm into the second alloy from the interface.
[0059] Where the intermetallic compositions of the first alloy are dispersed or exuded into the second alloy, there remains in the first alloy, adjacent to the interface between the first and second alloys, a layer which contains a reduced quantity of the intermetallic particles and which consequently can form a layer which is more noble than the first alloy and may impart corrosion resistance to the clad material. This layer is typically 4 to 8 mm thick.
[0060] This bond may be further characterized by the presence of a diffuse layer of alloy components of the first alloy in the second alloy layer adjacent the interface. This feature is particularly formed in instances where the surface of the first alloy is cooled below the solidus temperature of the first alloy and then the interface between first and second alloy is reheated to between the solidus and liquidus temperatures.
[0061] Although not wishing to be bound by any theory, it is believed that the presence of these features is caused by formation of segregates of intermetallic compounds of the first alloy at the self supporting surface formed on it with their subsequent dispersal or exudation into the second alloy after it contacts the surface. The exudation of intermetallic compounds is assisted by splaying forces present at the interface.
[0062] A further feature of the interface between layers formed by the methods of this invention is the presence of alloy components from the second alloy between the grain boundaries of the first alloy immediately adjacent the interface between the two alloys. It is believed that these arise when the second alloy (still generally above its liquidus temperature) comes in contact with the self-supporting surface of the first alloy (at a temperature between the solidus and liquidus temperature of the first alloy). Under these specific conditions, alloy component of the second alloy can diffuse a short distance (typically about 50 μm) along the still liquid grain boundaries, but not into the grains already formed at the surface of the first alloy. If the interface temperature in above the liquidus temperature of both alloys, general mixing of the alloys will occur, and the second alloy components will be found within the grains as well as grain boundaries. If the interface temperature is below the solidus temperature of the first alloy, there will be not opportunity for grain boundary diffusion to occur.
[0063] The specific interfacial features described are specific features caused by solid state diffusion, or diffusion or movement of elements along restricted liquid paths and do not affect the generally distinct nature of the overall interface.
[0064] Regardless how the interface is formed, the unique structure of the interface provides for a strong metallurgical bond at the interface and therefore makes the structure suitable for rolling to sheet without problems associated with delamination or interface contamination.
[0065] In yet a further embodiment of the invention, there is a composition metal ingot, comprising at least two layers of metal, wherein pairs of adjacent layers are formed by contacting the second metal layer to the surface of the first metal layer such that the when the second metal layer first contacts the surface of the first metal layer the surface of the first metal layer is at a temperature between its liquidus and solidus temperature and the temperature of the second metal layer is above its liquidus temperature. Preferably the two metal layers are composed of different alloys.
[0066] Similarly in yet a further embodiment of the invention, there is a composite metal ingot, comprising at least two layers of metal, wherein pairs of adjacent layers are formed by contacting the second metal layer to the surface of the first metal layer such that the when the second metal layer first contacts the surface of the first metal layer the surface of the first metal layer is at a temperature below its solidus temperature and the temperature of the second metal layer is above its liquidus temperature, and the interface formed between the two metal layers is subsequently reheated to a temperature between the solidus and liquidus temperature of the first alloy. Preferably the two metal layers are composed of different alloys.
[0067] In one preferred embodiment, the ingot is rectangular in cross section and comprises a core of the first alloy and at least one surface layer of the second layer, the surface layer being applied to the long side of the rectangular cross-section. This composite metal ingot is preferably hot and cold rolled to form a composite metal sheet.
[0068] In one particularly preferred embodiment, the alloy of the core is an aluminum-manganese alloy and the surface alloy is an aluminum-silicon alloy. Such composite ingot when hot and cold rolled to form a composite metal brazing sheet that may be subject to a brazing operation to make a corrosion resistant brazed structure.
[0069] In another particularly preferred embodiment, the alloy core is a scrap aluminum alloy and the surface alloy a pure aluminum alloy. Such composite ingots when hot and cold rolled to form composite metal sheet provide for inexpensive recycled products having improved properties of corrosion resistance, surface finishing capability, etc. In the present context a pure aluminum alloy is an aluminum alloy having a thermal conductivity greater than 190 watts/m/K and a solidification range of less than 50° C.
[0070] In yet another particularly preferred embodiments the alloy core is a high strength non-heat treatable alloy (such as an Al—Mg alloy) and the surface alloy is a brazeable alloy (such as an Al—Si alloy). Such composite ingots when hot and cold rolled to form composite metal sheet may be subject to a forming operation and used for automotive structures which can then be brazed or similarly joined.
[0071] In yet another particularly preferred embodiment the alloy core is a high strength heat treatable alloy (such as an 2xxx alloy) and the surface alloy is a pure aluminum alloy. Such composite ingots when hot and cold rolled form composite metal sheet suitable for aircraft structures. The pure alloy may be selected for corrosion resistance or surface finish and should preferably have a solidus temperature greater than the solidus temperature of the core alloy.
[0072] In yet another particularly preferred embodiment the alloy core is a medium strength heat treatable alloy (such as an Al—Mg—Si alloy) and the surface alloy is a pure aluminum alloy. Such composite ingots when hot and cold rolled form composite metal sheet suitable for automotive closures. The pure alloy may be selected for corrosion resistance or surface finish and should preferably have a solidus temperature greater than the solidus temperature of the core alloy.
[0073] In another preferred embodiment, the ingot is cylindrical in cross-section and comprises a core of the first alloy and a concentric surface layer of the second alloy. In yet another preferred embodiment, the ingot is rectangular or square in cross-section and comprises a core of the second alloy and a annular surface layer of the first alloy.
BRIEF DESCRIPTION OF THE DRAWINGS
[0074] In the drawings which illustrate certain preferred embodiments of this invention:
[0075] FIG. 1 is an elevation view in partial section showing a single divider wall;
[0076] FIG. 2 is a schematic illustration of the contact between the alloys;
[0077] FIG. 3 is an elevation view in partial section similar to FIG. 1 , but showing a pair of divider walls;
[0078] FIG. 4 is an elevation view in partial section similar to FIG. 3 , but with the second alloy having a lower liquidus temperature than the first alloy being fed into the central chamber;
[0079] FIGS. 5 a , 5 b and 5 c are plan views showing some alternative arrangements of feed chamber that may be used with the present invention;
[0080] FIG. 6 is an enlarged view in partial section of a portion of FIG. 1 showing a curvature control system;
[0081] FIG. 7 is a plan view of a mould showing the effects of variable curvature of the divider wall;
[0082] FIG. 8 is an enlarged view of a portion of FIG. 1 illustrating a tapered divider wall between alloys;
[0083] FIG. 9 is a plan view of a mould showing a particularly preferred configuration of a divider wall;
[0084] FIG. 10 is a schematic view showing the metal level control system of the present invention;
[0085] FIG. 11 is a perspective view of a feed system for one of the feed chambers of the present invention;
[0086] FIG. 12 is a plan view of a mould showing another preferred configuration of the divider wall;
[0087] FIG. 13 is a microphotograph of a section through the joining face between a pair of adjacent alloys using the method of the present invention showing the formation of intermetallic particles in the opposite alloy;
[0088] FIG. 14 is a microphotograph of a section through the same joining face as in FIG. 13 showing the formation of intermetallic plumes or exudates;
[0089] FIG. 15 is a microphotograph of a section through the joining face between a pair of adjacent alloys processed under conditions outside the scope of the present invention;
[0090] FIG. 16 is a microphotograph of a section through the joining face between a cladding alloy layer and a cast core alloy using the method of the present invention;
[0091] FIG. 17 is a microphotograph of a section through the joining face between a cladding alloy layer and a case core alloy using the method of the present invention, and illustrating the presence of components of core alloy solely along grain boundaries of the cladding alloy at the joining face;
[0092] FIG. 18 is a microphotograph of a section through the joining face between a cladding alloy layer and a cast core alloy using the method of the present invention, and illustrating the presence of diffused alloy components as in FIG. 17 ; and
[0093] FIG. 19 a microphotograph of a section through the joining face between a cladding alloy layer and a cast core alloy using the method of the present invention, and also illustrating the presence of diffused alloy components as in FIG. 17 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0094] With reference to FIG. 1 , rectangular casting mould assembly 10 has mould walls 11 forming part of a water jacket 12 from which a stream of cooling water 13 is dispensed.
[0095] The feed portion of the mould is divided by a divider wall 14 into two feed chambers. A molten metal delivery trough 30 and delivery nozzle 15 equipped with an adjustable throttle 32 feeds a first alloy into one feed chamber and a second metal delivery trough 24 equipped with a side channel, delivery nozzle 16 and adjustable throttle 31 feeds a second alloy into a second feed chamber. The adjustable throttles 31 , 32 are adjusted either manually or responsive to some control signal to adjust the flow of metal into the respective feed chambers. A vertically movable bottom block unit 17 supports the embryonic composite ingot being formed and fits into the outlet end of the mould prior to starting a cast and thereafter is lowered to allow the ingot to form.
[0096] As more clearly shown with reference to FIG. 2 , in the first feed chamber, the body of molten metal 18 gradually cools so as to form a self-supporting surface 27 adjacent the lower end of the divider wall and then forms a zone 19 that is between liquid and solid and is often referred as a mushy zone. Below this mushy or semi-solid zone is a solid metal alloy 20 . Into the second feed chamber is fed a second alloy liquid flow 21 having a lower liquidus temperature than the first alloy 18 . This metal also forms a mushy zone 22 and eventually a solid portion 23 .
[0097] The self-supporting surface 27 typically undergoes a slight contraction as the metal detaches from the divider wall 14 then a slight expansion as the splaying forces caused, for example, by the metallostatic head of the metal 18 coming to bear. The self-supporting surface has sufficient strength to restrain such forces even though the temperature of the surface may be above the solidus temperature of the metal 18 . An oxide layer on the surface can contribute to this balance of forces.
[0098] The temperature of the divider wall 14 is maintained at a predetermined target temperature by means of a temperature control fluid passing through a closed channel 33 having an inlet 36 and outlet 37 for delivery and removal of temperature control fluid that extracts heat from the divider wall so as to create a chilled interface which serves to control the temperature of the self supporting surface 27 below the lower end of the divider wall 35 . The upper surface 34 of the metal 21 in the second chamber is then maintained at a position below the lower edge 35 of the divider wall 14 and at the same time the temperature of the self supporting surface 27 is maintained such that the surface 34 of the metal 21 contacts this self supporting surface 27 at a point where the temperature of the surface 27 lies between the solidus and liquidus temperature of the metal 18 . Typically the surface 34 is controlled at a point slightly between the lower edge 35 of the divider wall 14 , generally within about 2 to 20 mm from the lower edge. The interface layer thus formed between the two alloy streams at this point forms a very strong metallurgical bond between the two layers without excessive mixing of the alloys.
[0099] The coolant flow (and temperature) required to establish the temperature of the self-supporting surface 27 of metal 18 within the desired range is generally determined empirically by use of small thermocouples that are embedded in the surface 27 of the metal ingot as it forms and once established for a given composition and casting temperature for metal 18 (casting temperature being the temperature at which the metal 18 is delivered to the inlet end of the feed chamber) forms part of the casting practice for such an alloy. It has been found in particular that at a fixed coolant flow through the channel 33 , the temperature of the coolant exiting the divider wall coolant channel measured at the outlet 37 correlates well with the temperature of the self supporting surface of the metal at predetermined locations below the bottom edge of the divider wall, and hence provides for a simple and effective means of controlling this critical temperature by providing a temperature measuring device such as a thermocouple or thermistor 40 in the outlet of the coolant channel.
[0100] FIG. 3 is essentially the same mould as in FIG. 1 , but in this case a pair of divider walls 14 and 14 a are used dividing the mouth of the mould into three feed chambers. There is a central chamber for the first metal alloy and a pair of outer feed chambers for a second metal alloy. The outer feed chambers may be adapted for a second and third metal alloy, in which case the lower ends of the divider walls 14 and 14 a may be positioned differently and the temperature control may differ for the two divider walls depending on the particular requirements for casting and creating strongly bonded interfaces between the first and second alloys and between the first and third alloys.
[0101] As shown in FIG. 4 , it is also possible to reverse the alloys so that the first alloy streams are fed into the outer feed chambers and a second alloy stream is fed into the central feed chamber.
[0102] FIG. 5 shows several more complex chamber arrangements in plan view. In each of these arrangements there is an outer wall 11 shown for the mould and the inner divider walls 14 separating the individual chambers. Each divider wall 14 between adjacent chambers must be positioned and thermally controlled such that the conditions for casting described herein are maintained. This means that the divider walls may extend downwards from the inlet of the mould and terminate at different positions and may be controlled at different temperatures and the metal levels in each chamber may be controlled at different levels in accordance with the requirements of the casting practice.
[0103] It is advantageous to make the divider wall 14 flexible or capable of having a variable curvature in the plane of the mould as shown in FIGS. 6 and 7 . The curvature is normally changed between the start-up position 14 and steady state position 14 ′ so as to maintain a constant interface throughout the cast. This is achieved by means of an arm 25 attached at one end to the top of the divider wall 14 and driven in a horizontal direction by a linear actuator 26 . If necessary the actuator is protected by a heat shield 42 .
[0104] The thermal properties of alloys vary considerably and the amount and degree of variation in the curvature is predetermined based on the alloys selected for the various layers in the ingot. Generally these are determined empirically as part of a casting practice for a particular product.
[0105] As shown in FIG. 8 the divider wall 14 may also be tapered 43 in the vertical direction on the side of the metal 18 . This taper may vary along the length of the divider wall 14 to further control the shape of the interface between adjacent alloy layer. The taper may also be used on the outer wall 11 of the mould. This taper or shape can be established using principals, for example, as described in U.S. Pat. No. 6,260,602 (Wagstaff) and will again depend on the alloys selected for the adjacent layers.
[0106] The divider wall 14 is manufactured from metal (steel or aluminum for example) and may in part be manufactured from graphite, for example by using a graphite insert 46 on the tapered surface. Oil delivery channels 48 and grooves 47 may also be used to provide lubricants or parting substances. Of course inserts and oil delivery configurations may be used on the outer walls in manner known in the art.
[0107] A particular preferred embodiment of divider wall is shown in FIG. 9 . The divider wall 14 extends substantially parallel to the mould sidewall 11 along one or both long (rolling) faces of a rectangular cross section ingot. Near the ends of the long sides of the mould, the divider wall 14 has 90° curves 45 and is terminated at locations 50 on the long side wall 11 , rather than extending fully to the short side walls. The clad ingot cast with such a divider wall can be rolled to better maintain the shape of the cladding over the width of the sheet than occurs in more conventional roll-cladding processes. The taper described in FIG. 8 may also be applied to this design, where for example, a high degree of taper may be used at curved surface 45 and a medium degree of taper on straight section 44 .
[0108] FIG. 10 shows a method of controlling the metal level in a casting mould which can be used in any casting mould, whether or not for casting layered ingots, but is particularly useful for controlling the metal level in confined spaces as may be encountered in some metal chambers in moulds for casting multiple layer ingots. A gas supply 51 (typically a cylinder of inert gas) is attached to a flow controller 52 that delivers a small flow of gas to a gas delivery tube with an open and 53 that is positioned at a reference location 54 within the mould. The inside diameter of the gas delivery tube at its exit is typically between 3 to 5 mm. The reference location is selected so as to be below the top surface of the metal 55 during a casting operation, and this reference location may vary depending on the requirements of the casting practice.
[0109] A pressure transducer 56 is attached to the gas delivery tube at a point between the flow controller and the open end so as to measure the backpressure of gas in the tube. This pressure transducer 56 in turn produces a signal that can be compared to a reference signal to control the flow of metal entering the chamber by means known to those skilled in the art. For example an adjustable refractory stopper 57 in a refractory tube 58 fed in turn from a metal delivery trough 59 may be used. In use, the gas flow is adjusted to a low level just sufficient to maintain the end of the gas delivery tube open. A piece of refractory fibre inserted in the open end of the gas delivery tube is used to dampen the pressure fluctuations caused by bubble formation. The measured pressure then determines the degree of immersion of the open end of the gas delivery tube below the surface of the metal in the chamber and hence the level of the metal surface with respect to the reference location and the flow rate of metal into the chamber is therefore controlled to maintain the metal surface at a predetermined position with respect to the reference location.
[0110] The flow controlled and pressure transducer are devices that are commonly available devices. It is particularly preferred however that the flow controller be capable of reliable flow control in the range of 5 to 10 cc/minute of gas flow. A pressure transducer able to measure pressures to about 0.1 psi (0.689 kPa) provides a good measure of metal level control (to within 1 mm) in the present invention and the combination provides for good control even in view of slight fluctuations in the pressure causes by the slow bubbling through the open end of the gas delivery tube.
[0111] FIG. 11 shows a perspective view of a portion of the top of the mould of the present invention. A feed system for one of the metal chambers is shown, particularly suitable for feeding metal into a narrow feed chamber as may be used to produce a clad surface on an ingot. In this feed system, a channel 60 is provided adjacent the feed chamber having several small down spouts 61 connected to it which end below the surface of the metal. Distribution bags 62 made from refractory fabric by means known in the art are installed around the outlet of each down spout 61 to improve the uniformity of metal distribution and temperature. The channel in turn is fed from a trough 68 in which a single down spout 69 extends into the metal in the channel and in which is inserted a flow control stopper (not shown) of conventional design. The channel is positioned and leveled so that metal flows uniformly to all locations.
[0112] FIG. 12 shows a further preferred arrangement of divider walls 14 for casting a rectangular cross-section ingot clad on two faces. The divider walls have a straight section 44 substantially parallel to the mould sidewall 11 along one or both long (rolling) faces of a rectangular cross section ingot. However, in this case each divider wall has curved end portions 49 which intersect the shorter end wall of the mould at locations 41 . This is again useful in maintaining the shape of the cladding over the width of the sheet than occurs in more conventional roll-cladding processes. Whilst illustrated for cladding on two faces, it can equally well be used for cladding on a single face of the ingot.
[0113] FIG. 33 is a microphotograph at 15× magnification showing the interface 80 between an Al—Mn alloy 81 (X-904 containing 0.74% by weight Mn, 0.55% by weight Mg, 0.3% by weight Cu, 0.17% by weight, 0.07% by weight Si and the balance Al and inevitable impurities) and an Al—Si alloy 82 (AA4147 containing 12% by weight Si, 0.19% by weight Mg and the balance Al and inevitable impurities) cast under the conditions of the present invention. The Al—Mn alloy had a solidus temperature of 1190° F. (643° C.) and a liquidus temperature of 1215° F. (657° C.). The Al—Si alloy had a solidus temperature of 1070° F. (576° C.) and a liquidus temperature of 1080° F. (582° C.). The Al—Si alloy was fed into the casting mould such that the upper surface of the metal was maintained so that it contacted the Al—Mn alloy at a location where a self-supporting surface has been established on the Al—Mn alloy, but its temperature was between the solidus and liquidus temperatures of the Al—Mn alloy.
[0114] A clear interface is present on the sample indicating no general mixing of alloys, but in addition, particles of intermetallic compounds containing Mn 85 are visible in an approximately 200 μm band within the Al—Si alloy 82 adjacent the interface 80 between the Al—Mn and Al—Si alloys. The intermetallic compounds are mainly MnAl, and alpha-AlMn.
[0115] FIG. 14 is a microphotograph at 200× magnification showing the interface 80 of the same alloy combination as in FIG. 13 where the self-surface temperature was not allowed to fall below the solidus temperature of the Al—Mn alloy prior to the Al—Si alloy contacting it. A plume or exudate 88 is observed extending from the interface 80 into the Al—Si alloy 82 from the Al—Mn alloy 81 and the plume or exudate has a intermetallic composition containing Mn that is similar to the particles in FIG. 13 . The plumes or exudates typically extend up to 100 μm into the neighbouring metal. The resulting bond between the alloys is a strong metallurgical bond. Particles of intermetallic compounds containing Mn 85 are also visible in this microphotograph and have a size typically up to 20 μm.
[0116] FIG. 15 is a microphotograph (at 300× magnification) showing the interface between an Al—Mn alloy (AA3003) and an Al—Si alloy (AA4147) but where the Al—Mn self-supporting surface was cooled more than about 5° C. below the solidus temperature of the Al—Mn alloy, at which point the upper surface of the Al—Si alloy contacted the self-supporting surface of the Al—Mn alloy. The bond line 90 between the alloys is clearly visible indicating that a poor metallurgical bond was thereby formed. There is also an absence of exudates or dispersed intermetallic compositions of the first alloy in the second alloy.
[0117] A variety of alloy combinations were cast in accordance with the process of the present invention. The conditions were adjusted so that the first alloy surface temperature was between its solidus and liquidus temperature at the the upper surface of the second alloy. In all cases, the alloys were cast into ingots 690 mm×1590 mm and 3 metres long and then processed by conventional preheating, hot rolling and cold rolling. The alloy combinations cast are given in Table 1 below. Using convention terminology, the “core” is the thicker supporting layer in a two alloy composite and the “cladding” is the surface functional layer. In the table, the First Alloy is the alloy cast first and the second alloy is the alloy brought into contact with the self-supporting surface of the first alloy.
TABLE 1 First Alloy Second Alloy L-S Casting L-S Casting Location and range temperature Location and range temperature Cast alloy (° C.) (° C.) alloy (° C.) (° C.) 051804 Clad 0303 660-659 664-665 Core 3104 654-629 675-678 030826 Clad 1200 657-646 685-690 Core 2124 638-502 688-690 031013 Clad 0505 660-659 692-690 Core 6082 645-563 680-684 030827 Clad 1050 657-646 695-697 Core 6111 650-560 686-684
[0118] In each of these examples, the cladding was the first alloy to solidify and the core alloy was applied to the cladding alloy at a point where a self-supporting surface had formed, but where the surface temperature was still within the L-S range given above. This may be compared to the example above for brazing sheet where the cladding alloy had a lower melting range than the core alloy, in which case the cladding alloy (the “second alloy”) was applied to the self supporting surface of the core alloy (the “first alloy”). Micrographs were taken of the interface between the cladding and the core in the above four casts. The micrographs were taken at 50× magnification. In each image the “cladding” layer appears to the left and the “core” layer to the right.
[0119] FIG. 16 shows the interface of Cast #051804 between cladding alloy 0303 and core alloy 3104. The interface is clear from the change in grain structure in passing from the cladding material to the relatively more alloyed core layer
[0120] FIG. 17 shows the interface of Cast #030826 between cladding alloy 1200 and core alloy 2124. The interface between the layers is shown by the dotted line 94 in the Figure. In this figure, the presence of alloy components of the 2124 alloy are present in the grain boundaries of the 1200 alloy within a short distance of the interface. These appear as spaced “fingers” of material in the Figure, one of which is illustrated by the numeral 95 . It can be seen that the 2124 alloy components extend for a distance of about 50 μm, which typically corresponds to a single grain of the 1200 alloy under these conditions.
[0121] FIG. 18 shows the interface of Cast #031013 between cladding alloy 0505 and core alloy 6082 and FIG. 19 shows the interface of Cast #030827 between cladding alloy 1050 and core alloy 6111. In each of these Figures the presence of alloy components of the core alloy are gain visible in the grain boundaries of the cladding alloy immediately adjacent the interface.
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A method and apparatus are described for the casting of a composite metal ingot comprising at least two separately formed layers of one or more alloys. An open ended annular mould has a feed end and an exit end and divider wall for dividing the feed end into at least two separate feed chambers, where each feed chamber is adjacent at least one other feed chamber. For each pair of adjacent feed chambers a first alloy stream is fed through one of the pair of feed chambers into the mould and a second alloy stream is fed through another of the feed chambers. A self-supporting surface is generated on the surface of the first alloy stream and the second alloy stream is contacted with the first stream such that the upper surface of the second alloy stream is maintained at a position such that it first contacts the self-supporting surface where the self-supporting surface temperature is between the liquidus and solidus temperatures of the first alloy or it first contacts the self-supporting surface where the self-supporting surface temperature is below the solidus temperatures of the first alloy but the interface between the two alloys is then reheated to between the liquidus and solidus temperatures, whereby the two alloy streams are joined as two layers. The joined alloy layers are then cooled to form a composite ingot. This composite ingot has a substantially continuous metallurgical bond between alloy layers with dispersed particles of one or more intermetallic compositions of the first alloy in a region of the second alloy adjacent the interface.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. Ser. No. 220,245 filed Dec. 23, 1980, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to a multi-function revolving door, and more particularly to a revolving door which is capable of regular use as well as use for emergency exit purposes.
In order to allow a steady traffic of persons walking in and out of buildings, such as shopping centeers, hospitals, airports, etc., it is necessary to have door arrangements in order to keep the indoor climate under control. Three systems are available: air curtains, automatic sliding or swing doors, and revolving doors. These solutions are good from a technical point of view, but the known products available all have serious drawbacks.
Air curtains are extremely energy consuming and therefore costly to operate. In a cold climate, it is impossible to suppress a draft in town blocks caused by the tall, relatively warm air in the building, creating what is known as the chimney effect. Furthermore, air curtains cannot control the drifting-in of dust. Also, noise passes unhindered into the building.
Automatic sliding or swing doors are less expensive to operate than air curtains, but they let as much as up to ten times the quantity of cold air into the building (or air conditioned cold air out) as the quantity ventilated by revolving doors. Dust and noise inlet are also unsatisfactorily controlled, especially during peak hours.
The present state of art respecting revolving doors is exemplified by U.S. Pat. Nos. 906,175; 1,030,266; 1,303,988; 2,523,980; 3,782,035; 3,020,038; 3,497,997; and 3,766,686.
Revolving doors constitute the one construction ensuring a permanent seal between the outdoor and indoor air masses. They provide the buildings with excellent noise, dust and draft control, and very low energy loss, thus reducing operation costs, and costs of maintenance.
Revolving doors of known construction do not provide buildings with an emergency exit capacity of sufficient volume independent of the position of the revolving body, and are either (1) dependent on a turning of the revolving body to one of a limited number of positions before folding of the door leaves results in a free passage or (2) are capable of establishing only one passageway. The first arrangement is not practical for a panicky crown and thus not acceptable to the public authorities, and the second arrangement does not provide adequate escape volume.
Revolving doors of known design have the upper bearing for the revolving body supported above said body. They are in this respect dependent on the adjacent structure in the building or otherwise have a supporting structure integrated into the door canopy.
Traffic in and out of public buildings includes persons with shopping carts, baby carriages, and persons in wheel chairs, or otherwise handicapped. The capacity to let such "traffic units" pass can only be provided by revolving doors with large diameters, i.e., diameters exceeding two meters and often more than three meters. These large rotating bodies are relatively heavy constructions. The rotation of the revolving door, therefore, is often motorized to enable handicapped persons, and persons otherwise unable to push the door leaves, to pass.
The motor drive for the rotating body of a revolving door requires either space in the building structure below the door floor, or space and supporting structure in the superjacent building parts. The hard push caused by a relatively fast moving heavy door leaf catching up with a slowly walking person, or the more violent "bumps" executed by a door leaf hitting an immobile person or lost item, are technical problems not satisfactorily resolved until now.
SUMMARY
Accordingly, an object of the present invention is to provide a large motorized revolving door overcoming the aforementioned disadvantages of prior art revolving doors.
As herein described, there is provided an improved motorized revolving door wherein the center member has the cross sectional shape of a cross, a square, a circle or any other shape exhibiting a diagonal dimension (the distance between two opposite door leaves) of at least 30 percent of the door diameter.
According to the invention, there is provided a revolving door comprising first and second side members having arcuate inner walls symmetrically disposed about a door rotation axis; a generally cylindrical door central member mounted for rotation about said axis in a given direction, the transverse diagonal dimension of said member having a value at least equal to 0.3 of the distance between said walls as measured along a line extending through said axis, said member having four longitudinal hinge means; a door panel pivotally secured to each of said hinge means, each door panel having a normal position extending radially of said member and being capable of rotation through a first predetermined angle in said given direction and a second predetermined angle in the opposite direction; biasing means for urging each said door panel toward the normal position thereof from both of said directions and for opposing deflection of each door panel from said normal position with a predetermined threshold force or torque; latching means for retaining said door panels in an emergency position alongside said central member; motor drive means for rotating said central member in said given direction; and a control unit for controlling the operation of said motor drive means.
IN THE DRAWING
FIG. 1 is a partially exploded perspective view of a revolving door according to a preferred embodiment of the invention;
FIGS. 2a through 2d show various positions of the revolving door and its hinged door panels, which provide various operational functions of the door;
FIG. 3 is a functional block diagram showing the manner in which the operation of the door is controlled;
FIG. 4 is a top plan view showing the structure of the central portion of the door; and
FIG. 5 is a cross-sectional front elevation view of said door central portion, taken along the cutting plane 5--5 shown in FIG. 4.
DETAILED DESCRIPTION
According to a preferred embodiment of the invention, each door leaf is hinged in such a way that it can swing clockwise and counter-clockwise relative to the central member of the rotating body, the normal position of the leaf being radially out from the center axis of the rotating body and having a holding power to be overcome, to swing a door leaf away from this normal position. Each door leaf has a switch for breaking the power supply to the motor driving the rotating body when the door leaft is swung in a direction opposite to its normal direction of rotation.
Each door leaf may have a hydraulic door mechanism of the type utilized in swinging doors, for enabling the door leaves to function with (i) a holding position when pointing radially from the center of the rotating body and (ii) other holding positions when swung to one of the extreme positions with the unhinged side of the door leaf as close as possible to the central member of the rotating body. In any other position the hydraulic mechanism will urge the door leaf back to the radially pointing position.
The central member of the rotating body may be a hollow structure providing space for the stationary structure rigid enough to support the upper bearing for the revolving body. This arrangement provides an installation independent of the building structure superjacent to the revolving door. The central member of the rotating body, being a hollow structure, may be shaped to house the motorized drive for turning the rotating body.
The motor drive is controlled by a control unit. The control unit may have provision for manual setting, input from touch-free sensors and outputs for the motor drive and automatic door locks. The space in front of each entrance (the outdoor and the indoor entrances) to the revolving door may be monitored by a touch-free sensor (radar-, radio-, light- or induction sensor) providing an output signal to the control unit when a person is approaching (wanting to pass the door), said signal resulting in an increase in rotation speed for providing comfortable passage.
Each door leaf may be equipped with a touchfree sensor monitoring the space in front of the door leaf (in the direction of the mechanical rotation) over a distance of about 25 centimeters (10 inches) and providing a signal to the control unit in case a part of a person or item is detected within the space covered, said signal resulting in an immediate reduction in rotation speed.
The motorized revolving door shown in FIG. 1 has a generally cylindrical rotatable door central member 13, which contains the electric motor drive to rotate said member; stationary side walls 19; and a canopy 23.
As best seen in FIGS. 4 and 5, the door central member 13 is rotationally supported by a central tower 31, which has a base 32 secured to the building floor 33 by suitable bolts 34. A support/drive shaft 35 is secured to, rotates and supports the upper portion of the door central member 13. The shaft 35 and door central member 13 are rotationally supported on the tower 31 by means of an upper bearing 36.
A door central member motor drive 12 consists of an electric motor 37 supported on a shelf 38 of the tower 31, and meshed drive gears 38, 39 and 40 for allowing the motor 37 to rotate the shaft 35 and door central member 13.
The lower portion of door central member 13 is rotationally guided by an idler bearing ring 41 which surrounds the lower portion of the tower 31.
Thus the support and drive arrangement for the door central member 13 is self-contained by virtue of the tower 31, so that the moving elements of the revolving door may be conveniently tested in the manufacturing plant, and subsequently rapidly and easily installed on the construction site, substantially independent of the building structure superjacent to the revolving door. As shown in FIG. 5, the motor drive mechanism may be entirely contained within the stationary tower 31, which may if desired, be made high enough to help support the canopy structure 23.
As best seen in FIGS. 2a through 2d, four door panels 16 extend radially from each of the "corners" 17 of the door central member 13, each panel being hinged at the corresponding corner, said panels being biased into the "normal" radial positions shown in FIG. 2a by means of conventional hydraulic door closer mechanisms 18 (see FIG. 1).
Each door panel 16 is held in its normal radial position so that a certain minimum torque or force is required in order to swing it clockwise or counter-clockwise relative to said normal position. The required panel deflection torque is preferably in the range of 20 to 100 Newton-meters and is preferably manually adjustable. Any door panel left alone in a position between its normal position and one of its two extreme positions is influenced by a force generated by the corresponding door closer 18 to bring the door panel back to its normal position. We prefer a door closer of hydraulic type functioning within the range of 150° clockwise and 150° counterclockwise relative to the normal position, such as door closer type GEZE 360 W power Z F=150° from Gretsch & Co. GmbH, D-725 Leonberg, West Germany.
Although for clarity of explanation, the door closers 18 are shown in FIG. 1 as being visible to persons using the door, preferably they should be hidden above the level of the canopy 23.
As best seen in FIG. 2a, the diagonal dimension C of the central member 13 is at least 0.3 of the revolving door diameter D, and is preferably on the order of 42% thereof.
The radial dimension R of the central member 13 is preferably at least about 75% of the door panel width d. The width of each of the door panels 16 is no greater than 35% of the width D of the revolving door; and the radial dimension R of the central member 13 is at least 15% of the revolving door width D.
Each of the door panels 16 is capable of swinging through an angle of at least 125° clockwise and counter-clockwise relative to its normal position; said angle preferably being in the range of 125° to 135°.
In large diameter revolving doors providing passage for persons with large dimension items, the radial distance R between the rotation axis and door panel hinge axis may be in the range of 0.15 to 0.35 times the door diameter D, and the door will provide acceptable emergency exit for the building served by the door. Revolving doors with small diameters will not usually provide emergency passageways of sufficient width if made according to the present invention. Doors according to the present invention are for this reason most suitable for doors with diameters exceeding two meters.
At night or when the building is closed, the control switch 11 is set to a "Lock" position, which causes the control unit 10 to rotate the central member 13 (via the motor drive 12) to a locked position as shown in FIG. 2a, wherein all four door panels 16 abut the arcuate stationary walls 19. A door central member position sensor 20 coupled to the motor drive 12 and central member 13 provides a signal to the control unit 10 indicating when the central member 13 has reached the Lock position. Thereupon the control unit 10 engages the automatic door panel locks 30 to prevent rotation of the door panels 16 on their hinges. The door panel locks 30 are preferably disposed substantially in the structure of the canopy 23.
When it is evening, or at other times when building traffic is low, or when the door rotation is to be stopped for any other reason, the control switch 11 is set to a "Stop" position in which the central member 13 remains stationary in the position shown in FIG. 2a but the automatic door panel locks 30 are not activated, so that individuals may traverse the revolving door by pushing two aligned door panels. Where automatic evening operation is desired, the control unit 10 may be set ("Evening" position of switch 11) so that each time a person is detected by one of the ultrasonic or radar Doppler-effect detectors or entry sensors 22, the control unit causes the central member 13 to rotate for a period of 2 minutes, during which operation is as hereafter described for the "Day" modes.
When rapid and/or unobstructed ingress and egress through the revolving door is desired, for example during the summer, the door panels 16 may be manually rotated to the positions shown in either FIG. 2c or 2d, and maintained in said positions by conventional (automatically operating) retainers, which are a part of each of the hydraulic closers 18.
In an emergency, the door panels 16 may be manually rotated to lie flat against the central member 13 as shown in FIG. 2b, and maintained in said positions by the aforementioned retainers. The resulting emergency passageways are available independently of the position in which the revolving door central member has stopped; and regardless of whether the central member 13 is moving or stationary. The utilization of the emergency passageway does not require use of any tools or maneuvering or handles; a simple pressing force applied to a door panel will open up the passageway.
Thus our motorized revolving door provides the advantages of a revolving door and simultaneously a permanently and instantly available emergency exit for a panicky crown, the emergency exit comprising a permanent indoor opening to the revolving door, two passageways around the central member 13, and a permanent opening from the revolving door to the outside area. The total width of the emergency passageways throughout their extension equals or exceeds the width of the permanent openings to the revolving door.
This combination of functions eliminates the need for additional wall area and floor space for placing an emergency exit door next to a revolving door; and improves security by eliminating an opening in the building wall.
The motor control unit 10 (FIG. 3) is operated buy a control switch 11 which has a position "Day" allowing the motor drive 12 to turn the door central member 13 counterclockwise with a speed of one revolution per minute (r.p.m.) except when a person is recognized by one of the entry sensors 14, in which case the control unit 10 increases the speed to be four r.p.m. This speed is maintained during one full revolution, after which the speed is again reduced to one r.p.m. The slow 1 r.p.m. "resting speed" indicates the direction in which to pass through the door and also reduces the time required to reach the desired 4 r.p.m. speed for passage.
If a person entering the revolving door moves too slowly, in relation to the speed of the door, his presence is recognized by the corresponding one of the proximity sensors 15 mounted on the door leaf catching up with him, resulting in an immediate reduction of rotating speed of the member 13 to 1 r.p.m. and thus preventing an overtake.
If a person falls or loses an item, he or it is reached by a door panel 16 moving at slow speed only since the proximity detectors 15 have reduced the speed of the door. The slow moving door panel is then swung back in the clockwise direction by engagement with the person, relative to the central member 13. The deflection of the door panel from its normal position is detected by the corresponding one of the door panel swing-back sensors 21, which sends a corresponding signal to the control unit 10 to cause it to stop the rotation of the central member 13. When the person moves forward (counterclockwise) or backward (clockwise) away from the door panel, the panel returns to its normal position and the central member 13 thereupon resumes its rotation.
In case of an electrical failure, the door functioning is as described under control switch position "Stop". If the blackout period is expected to last a long time, door panels may be swung to the positions 16a as shown in Fig.2c, leaving only one swingdoor 16b to be passed during entering or leaving the building.
The control unit 10 is an electronic control unit on the front panel of which there is a timer switch 24 for recording the number of hours the door has been rotating. If desired, the switch 24 may be programmed to automatically switch the control unit 10 between Day, Evening and Lock modes at predetermined times.
The control unit 10 produces output signals for the motor drive 12 and for the automatic door panel locks 30. Signals for the motor drive are "stop", "slow speed", and "high speed". Signals for the solenoid-operated door panel locks are either "lock" or "release". The door panel swing-back sensors 21 are placed so that each one senses whether one of the four door panels 16 is swung back from its normal, radial position relative to the central member 13. Swinging back is swinging against the direction of the motor drive rotation, i.e., swinging clockwise. If one door panel is swung back, the corresponding sensor emits a signal to the control unit to cause an immediate stop of the motor drive. A normal door panel position or a position swung forward does not produce any signal, thus allowing orders of lower priority to be executed. The door swing-back sensors may be position sensors of magnetic type, i.e., ESBi 100 S obtainable from ELTRONIC, CH-3073 Grumlingen, Switzerland.
The door panel anti-overtaking sensors are mounted one on each of the door leaves registrating and reporting by sending a signal in case a body or an item appears approximately 25 cm (10 inches) in front of the door panel. "In front" means in the direction given by the mechanical rotation (normally counter-clockwise). The signal is a "slow speed" signal and is in priority second to a "stop" signal produced by any door panel swing-back sensor. The anti-overtaking sensors are of the "touch-free" type, preferably a light sensor, i.e., a Dihlogik OIS 20, obtainable from WEEDER-ROOT DENMARK, DK-2670 Greve Strand, Denmark.
The entry sensors 22 are placed to cover each of the two entrances to the revolving door; the outside entrance and the inside entrance. The sensors are of the non-contact type, preferably of the ultrasonic or radar type distance-responsive or Doppler effect, i.e., Doormaster type MW 02, manufactured by H.E. Michelsen Pty. Ltd., Pymble, NSW 073, Australia.
When an approaching person or moving object is detected by any of the entry sensors 14, a signal "passage is wanted" is emitted to the control unit 10. The control unit 10 responds to this input by producing an output signal "high speed" to the motor drive 12; this signal being maintained during approximately the time needed for the central member to rotate one full revolution running at high speed, i.e., 1/4 minute. The order is executed to the extent no orders of higher priority are received from any of the door panel sensors.
The door central member position sensor 20 is mounted on the central member 13 for producing a "stop" signal once during each rotation of the central member. The "stop" signal enables the control unit to stop the motor drive exactly when the central member is turned to a position placing two door panels (each with a lockplate opposite an automatic tie bolt on the wall(s) 19) just inside the outdoor entrance to the door. The door central member position sensor 20 is preferably of the magnetic type, i.e., the very same type used as door panel swing-back sensor type ESBi 100 S, obtainable from ELTRONIC, CH-3073 Grumlingen, Switzerland.The "stop" signal from the door central member position sensor is inhibited in the control unit 10 except when the control switch 11 is set on either "Lock" or "Stop". If the control switch 11 is turned to "Night", the "stop" signal from the door central member position sensor 20 is inhibited in the control unit 10 for approximately two minutes after the last "passage wanted" signal is received from a door entry sensor 14.
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A revolving door in which the center revolving support is generally cylindrical with a diameter at least 0.3 that of the space between the stationary walls of the door. Four door panels are hinged to the central member, and maintained in their normal positions by hydraulic door closers, so that the door panels can be rotated about their hinges to storage positions alongside the central member, and can be deflected when the door panels catch up to persons within the door. Radar type sensors detect the presence of people entering the doors, and speed up the rotation speed of the doors to facilitate movement through them. Proximity sensors on the door panels slow down the rotation of the door when a door panel begins to catch up to a person within the door. Door swing-back sensors detect when a door panel is pushed back (against the direction of door rotation) by contact with a person within the door, and cause the door to stop rotating upon such an occurrence. Means is also provided to store the door in a rotational position in which all four door panels engage stationary side walls, and to lock the door panels against the side walls in the storage position.
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FIELD OF THE INVENTION
The present invention pertains to a burner for the thermal regeneration of a particle filter, which is arranged in the tailpipe of an internal combustion engine, especially a diesel engine.
BACKGROUND OF THE INVENTION
P 44 43 133.3 suggests a burner for the thermal regeneration of a particle filter in an exhaust gas aftertreatment system of an internal combustion engine, wherein the burner is arranged coaxially in front of the particle filter, and the exhaust gas flow to be treated is introduced between the burner and the particle filter. As a result, the particle filter cannot be reached by the exhaust gas flow axially, which means, among other things, a complicated design of the exhaust gas aftertreatment system and leads to a non-optimal temperature distribution in the tailpipe in the area of the burner and of the particle filter.
SUMMARY AND OBJECTS OF THE INVENTION
The primary object of the present invention is to provide a burner for the thermal regeneration of a particle filter of the type described in the introduction, which has a simple design and operates highly efficiently, and whose combustion chamber is especially located completely in the exhaust gas flow of the tailpipe.
According to the invention, a burner for the thermal regeneration of a particle filter is provided which is arranged in a tailpipe of an internal combustion engine, particularly a diesel engine. The tailpipe is provided with a section of increased diameter. In the section of increased diameter, a central, coaxial vaporizing combustion chamber is provided. The combustion chamber has a closed, arched flow inlet in an upstream direction relative to the exhaust gas flow and is provided with an opening in the downstream direction. The exhaust gas flow flows around the vaporizing combustion chamber on a jacket circumference.
The vaporizing combustion chamber preferably has a central combustion chamber section in the form of a coaxial perforated pipe. The vaporizing combustion chamber is preferably held and centered in the expanded section of the tailpipe by a first exhaust gas-swirling means arranged in the jacket annular space. The first exhaust gas-swirling means preferably has guide blades.
The upstream flow inlet of the vaporizing combustion chamber preferably has a lateral air inlet channel. The vaporizing combustion chamber preferably has a first lateral fuel supply with a lateral glow means.
The vaporizing combustion chamber or pilot combustion chamber is preferably followed by a second combustion stage. The second combustion chamber stage preferably has a second lateral fuel supply with a closed circular line, which introduces the second fuel supply into the jacket annular space in an area of the first exhaust gas swirling means, wherein the fuel opening end of the second fuel supply is arranged downstream. The second fuel supply preferably extends at least partially in the interior of the first exhaust gas-swirling means and the second fuel supply especially extends through holes of said guide blades of said first exhaust gas-swirling means. A second fuel supply of the second combustion chamber stage includes a timing valve or a mechanical atomizer which valve or atomizer injects the fuel directly into the flame of the vaporizing combustion chamber or pilot combustion chamber.
The vaporizing combustion chamber is preferably followed by a first flame retention baffle, preferably a radiating plate, which is an ignition aid and evaporating surface for the second combustion chamber stage. The first flame retention baffle is coaxially followed by additional flame retention baffles. The additional flame retention baffles are preferably arranged concentrically in the tailpipe section of increased diameter.
The combustion air of the second combustion chamber stage is preferably the residual air of the exhaust gas of the internal combustion engine. The engine exhaust gas flow is preferably divided into a primary flow and a secondary flow for better mixing of the burner exhaust gas and the engine exhaust gas.
According to a second variant of the invention a burner for thermal regeneration of a particle filter is arranged in a tailpipe of an internal combustion engine, particularly a diesel engine. The tailpipe has a straight section of increased diameter in which a pilot combustion chamber is provided in the form of a torch igniter with a lateral flame glow plug, the igniter being fastened to the jacket of the expanded tailpipe section. The housing of the torch igniter has a downstream tapering open end which extends in parallel to an axis of the tailpipe.
The tapering open end of the torch igniter housing is preferably located centrally in the tailpipe. The torch igniter preferably has a lateral ignition air connection. The torch igniter housing preferably has an engine exhaust gas inlet opening in the upstream direction.
The torch igniter is preferably preceded in the upstream direction by a central air diffuser (air shower element) which has a lateral connection piece for the supply of additional air.
The first fuel supply line is preferably arranged in front of the torch igniter. The torch igniter is preferably followed by the second fuel supply line in the downstream direction. The first and second fuel supply lines preferably have a closed circular line on the jacket and line webs, which extend radially into the expanded tailpipe section and are provided with the discharge openings in the downstream direction. The torch igniter with the second fuel supply line is preferably followed by one or more additional coaxial flame retention baffles, which are located in the tailpipe section of increased diameter.
According to a third variant of the invention, a burner for the thermal regeneration of a particle filter which is arranged in a tailpipe of an internal combustion engine, particularly a diesel engine is provided. The tailpipe has a straight tailpipe section of increased diameter in which a second vaporizing combustion chamber with a flame glow plug is provided. The second vaporizing combustion chamber has a fuel supply and the second combustion chamber is arranged at least partially in the section of increased diameter.
The second vaporizing chamber preferably has a second combustion chamber stage. The second vaporizing combustion chamber preferably has a cylindrical part which is open in the upstream and downstream directions and is fastened, via a second exhaust gas-swirling means, in the jacket annular space, between the cylindrical part and the tailpipe.
The flame glow plug is preferably arranged behind the second exhaust gas swirling means in the downstream direction and is fastened in a tangential connection piece of the expanded tailpipe section and extends into the jacket annular space between the cylindrical part and the extended tailpipe section. The additional exhaust gas-swirling means is preferably followed by a second fuel supply, which extends essentially radially into the jacket annular space.
An exhaust gas-deflecting means is preferably arranged behind the flame glow plug and preferably arranged behind the optionally present second fuel supply and is arranged in the jacket annular space. A third fuel supply is preferably arranged behind the exhaust gas deflecting means and is fastened in the expanded tailpipe section.
The second and/or third fuel supply preferably has a jacket closed circular line section, which has radially inwardly directed fuel opening sections. The third fuel supply is preferably located, viewed in an axial direction, approximately in an area of a downstream open end of a cylindrical part of the second vaporizing combustion chamber. The third fuel supply is followed in a downstream direction by one or more additional flame retention baffles, which extend coaxially to the cylindrical part.
According to an additional variant of the present invention, a burner for the thermal regeneration of a particle filter is provided arranged in a tailpipe of an internal combustion engine, particularly a diesel engine. The tailpipe has a straight tailpipe section of increased diameter in which an air atomization combustion chamber is provided, which is a closed, arched flow inlet end in an upstream direction, is open in the downstream direction and around which the exhaust gas flow flows along a jacket circumference. The air atomization combustion chamber is preferably coaxially arranged.
The air atomization combustion chamber preferably has a central air atomization nozzle which is provided with a radial fuel supply line and with a radial air supply line, wherein the air atomization nozzle is followed by a radial igniting means. The arched flow inlet end of the air atomization combustion chamber preferably has an additional radial air supply line. The fuel supply line and the air supply line are preferably followed by a guide means, which also acts as a holder for the air atomization nozzle in the air atomization combustion chamber.
The air atomization combustion chamber is preferably designed as a flame tube with jacket openings in the downstream direction. The downstream end of the flame tube is preferably tapered and is fastened to an inner circumference of the expanded tailpipe section via the exhaust gas guide means. One or more additional coaxial flame retention baffles are preferably arranged behind the air atomization combustion chamber. These additional flame retention baffles are preferably followed by an expanding coaxial mixing space with the guide means, which is joined by the particle filter in the tailpipe.
The air atomization combustion chamber has a second combustion chamber stage wherein the additional fuel supply line with the individual nozzles is provided.
It is common to all four above-mentioned burner variants that the combustion chambers are located, even if only partially, in a straight section of increased diameter of the tailpipe. The expanded tailpipe section or the combustion chamber diameter is selected here to be such that the pressure drop of the exhaust gas flowing through will be as small as possible.
The first design variant is designed especially as a vaporizing combustion chamber in the expanded, straight section of the tailpipe, which is preferably used as a so-called soot burner (afterburner) in the tailpipe of a diesel engine.
The vaporizing combustion chamber is designed in the form of a pilot combustion chamber and has a lateral glow means (glow plug, sheathed element glow plug), which is supplied with air and at which the fuel supplied to it is primarily ignited. The pilot combustion chamber is preferably operated at constant output, even though output control may be provided as well.
The pilot combustion chamber exhaust gas-swirling means is on the circumference of its jacket and is maintained by the exhaust gas-swirling means centered in the expanded tailpipe. This swirling means consists preferably of guide blades, which are hollow on the inside and through which the fuel for a second main stage is supplied via fuel lines. Air may also be sent through the guide blades when necessary. The energy contained in the exhaust gas is used for atomization in this form of fuel supply. Supplied fresh air may also be used for this purpose.
A first flame retention baffle, which is preferably designed as a radiating plate, whose shape and geometry are determined experimentally, is located at the outlet of the pilot burner. The radiating plate is used as an ignition aid during operation and as an evaporating surface for the second combustion chamber stage.
The residual oxygen of the engine is preferably used for the combustion in the second combustion chamber stage.
The flame retention baffles mentioned below are useful for maintaining the flame at different exhaust gas mass flow rates. The adjustment of one or more flame retention buffers arranged downstream is performed based on experimentation.
To achieve better mixing of the burner exhaust gases with the engine exhaust gases, the engine exhaust gas may be divided into a primary flow and a secondary flow, which contributes to the cooling of the jacket of the combustion chamber, on the one hand, and brings about good mixing and controlled supply of the engine exhaust gas to the combustion chamber, on the other hand.
The fuel may also be supplied to the second combustion chamber stage via the combustion chamber jacket before or after the exhaust gas-swirling means. This would thus be the actual vaporizing combustion chamber in the conventional sense of the term.
However, the fuel may also be supplied to the second stage via a timing valve (mechanical atomizer nozzle), which injects the fuel directly into the flame of the pilot combustion chamber. As a result, rapid ignition of the second stage takes place in operation, and the full operating capacity of the burner is immediately available.
The first design variant of the present invention has especially the following advantages:
Only a small amount of air needs to be supplied for the pilot combustion chamber,
the burner heats the exhaust gas flow directly, as a result of which a homogeneous temperature distribution is obtained in front of the particle filter,
the evaporating surface is preheated by the exhaust gas of the engine, so that good starting properties are obtained; on the other hand, the evaporating surface is cooled by the engine exhaust gas during the burner operation, so that no thermal overload will develop,
the burner is insensitive to contamination, which ensures reliable starting behavior,
the flow can reach the particle filter axially, which means a simplified design and good temperature distribution,
the burner may be installed between the exhaust gas discharge and the particle filter as desired.
The second design variant is characterized especially by a pilot combustion chamber in the form of a torch igniter in a straight section of increased diameter of the tailpipe, wherein the torch igniter has a lateral flame glow plug with fuel supply and an additional air supply in the form of an air shower (diffuses/diffuser with shower type outlets) arranged in front of it.
The torch igniter advantageously has a lateral ignition air connection and is arranged in a housing which tapers at the downstream end and is open and extends especially coaxially to the tailpipe. The housing may have an engine exhaust gas inlet opening in the upstream direction.
A first and/or second fuel supply lines, which laterally open from the jacket side into the expanded, straight tailpipe section, may be provided before and/or after the torch igniter, i.e., the second embodiment of a burner may be designed for one or two burner stages.
It is advantageous that the flame glow plug used may be of the prior-art design and be supplied with air from the secondary user compressed air system of a motor vehicle. A small, independent air supply may optionally be provided. On the whole, a very simple design is obtained.
The third design variant of a burner also provides for the use of a flame glow plug, which is combined with a vaporizing combustion chamber. Just as the above-mentioned design variants, the above-mentioned components are completely in the exhaust gas flow of an engine in a straight section of increased diameter.
The vaporizing combustion chamber may be designed for a two-stage burner operation and it may ensure a primary exhaust gas flow and a secondary exhaust gas flow due to the design of a cylinder part that is open in front and rear in the tailpipe. The simple design with the use of commercially available components and the use of air from a secondary user compressed air system of a motor vehicle are advantageous here as well.
The latter design variant of the present invention is characterized by an air atomization combustion chamber in a straight section of increased diameter of a tailpipe, likewise operated according to the full exhaust gas mass flow principle.
The air atomization combustion chamber is similar to the first design variant as far as the shape of the combustion chamber is concerned, i.e., a closed, arched flow inlet end located in the upstream direction, as well as an end open in the downstream direction, wherein the exhaust gas flow flows around the jacket circumference of the combustion chamber housing.
An air atomization nozzle, which may be especially a so-called two-component nozzle, i.e., which may have a lateral air supply and a lateral fuel supply line, is preferably located centrally in the air atomization combustion chamber.
The above-mentioned so-called "by-pass burner" may be designed as a single-stage burner or as a two-stage burner. It requires that atomization air from the compressed air system or from a turbocharger or from a separate compressor be provided. The ignition takes place via a spark gap.
The necessary burner output is advantageously generated via a nozzle. The engine exhaust gas flow is split into two partial flows (secondary and primary) and is passed through the combustion chamber as well as past the combustion chamber. The primary exhaust gas flow is mixed with the secondary burner exhaust gas at the end of the air atomization combustion chamber designed in the form of a flame tube, where corresponding guiding means may be present to improve the mixing.
The insensitivity to contamination along with reliable ignition is especially advantageous. Moreover, good premixing of the air and fuel is achieved directly at this outlet, and there is consequently no separation. The ignition takes place very rapidly, as in the case of a switch. In particular, the burner output is very good, and it is available in a short time after start-up. This design variant otherwise has the same advantages as the above-mentioned design variants.
It should be mentioned that the burner output can be controlled mechanically via a speed-dependent fuel admission pressure and by means of an expanding element acting as a needle lift transducer. The nozzle needle is coupled with an expanding element here. Like the burner, the expanding element is also located in the full exhaust gas mass flow and it changes the lift of the nozzle needle and consequently also the amount of fuel as a function of the exhaust gas temperature. The fuel admission pressure will build up as a function of the engine speed (as in prior-art distributor injection pumps). Thus, the amount of fuel injected depends on the exhaust gas temperature and the speed. The mass of the exhaust gas is proportional to the engine speed in the case of naturally aspirated engines. Mechanical burner output control is thus possible. The load signal (e.g., charging pressure) must be sent in the case of turbocharged and charge-cooled engines, e.g., the charging pressure-speed pressure controller - fuel pressure information. The expanding element must be adapted to the necessary burner output and the engine.
The above-mentioned mechanical burner output control has a simple design and requires only an igniting device, a triggering signal, and a fuel release signal.
In the above-mentioned design variants, air can be supplied, in general, via an air shower (diffuser element) or it can be added directly in the combustion chamber for combustion for improved mixing in the case of insufficient supply by the residual oxygen of the engine exhaust gas.
To form or improve a homogeneous, ignitable mixture, it may be useful to provide corresponding guiding means, especially guide blades, in front of the fuel supply point.
The entire regeneration time can be reduced by the use of vaporizing burners in the exhaust gas if the burner is also ignited when the engine is started and is operated at a low output. When regeneration is required, the burner output can then be increased immediately, without a long start-up procedure.
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
In the drawings:
FIG. 1 is a schematic axial sectional view of a first design variant of a full-flow burner in the area of a straight tailpipe section of increased diameter;
FIG. 2 is a schematic sectional view similar to FIG. 1 of a second design variant of a full-flow burner;
FIG. 3 is a schematic sectional view similar to FIGS. 1 and 2 of a third design variant of a full-flow burner;
FIG. 4 is a schematic cross sectional view through the burner according to FIG. 3 along line A--A;
FIG. 5 is a schematic axial sectional view of a fourth design variant of a full-flow burner similar to the above design variants; and
FIG. 6 is a schematic axial sectional view of a modified version of the design variant according to FIG. 5 with a second combustion chamber stage.
DESCRIPTION OF THE PREFERRED EMBODIMENT
According to FIG. 1, a burner 1 for the thermal regeneration of a particle filter (not shown) is provided in an exhaust gas aftertreatment system of an internal combustion engine, especially a diesel engine. The burner 1 is located entirely in the exhaust gas flow. According to the drawing, the exhaust gas flow A arrives from the left from the exhaust gas turbocharger and flows after the burner 1 to the particle filter in the tailpipe, which is located to the right according to FIG. 1.
The burner 1 according to the first design variant in FIG. 1 has a central, coaxial vaporizing combustion chamber 5, which has a closed, arched flow inlet end 6 in the upstream direction and is provided with an opening 7 in the downstream direction. The flow bypasses the full-flow burner in the tailpipe of a diesel engine (it can also be used as a burner of a catalytic converter for a spark ignition engine) on the jacket circumference during operation due to the vaporizing combustion chamber being arranged inside the expanding, straight tailpipe section. The combustion chamber diameter is selected to be such that the pressure drop on the combustion chamber is as low as possible.
The vaporizing combustion chamber 5 (or pilot combustion chamber) has a central section in the form of a perforated pipe 8, which extends coaxially to the axis of the tailpipe 3. On the whole, the vaporizing combustion chamber 5 is held and centered in the expanded tailpipe section 4 by a first exhaust gas-swirling means 9, which is located in the jacket annular space 10. The first exhaust gas-swirling means 9 has especially guide blades, which are hollow on the inside, for a purpose to be described below.
The flow inlet end 6 of the vaporizing combustion chamber 5, which is arched in the upstream direction, comprises a first lateral air inlet channel 11, which is led through the jacket of the expanded tailpipe section 4.
The vaporizing combustion chamber 5 also comprises a first lateral fuel supply means 12 with a lateral glow means 13 (sheathed element glow plug, glow plug), by which the fuel supplied is primarily ignited ("pilot combustion chamber").
The vaporizing combustion chamber or the pilot combustion chamber may be followed by a second combustion chamber stage B, as is shown in FIG. 1.
The second combustion chamber stage B comprises a second lateral fuel supply means 14, which introduces the second fuel into the jacket annular space 10 in the area of the first exhaust gas-swirling means 9 via a closed circular line, wherein the fuel opening end 16 of the second fuel supply extends toward the downstream side and is opened there. In the exemplary embodiment according to FIG. 1, the second fuel supply 14 extends in the area of the first exhaust gas-swirling means 9 inside the hollow guide vanes, in corresponding holes.
The opening 7 of the vaporizing combustion chamber 5 is followed in the downstream direction by a first flame retention baffle 17 in the form of a radiating plate, which is an ignition aid and an evaporating surface for the second combustion chamber stage B.
The first flame retention baffle 17 is followed, in an additionally expanded tailpipe section 19, by one or more additional coaxial flame retention baffles 18, which are fastened to the inner circumference of the expanded or enlarged tailpipe section.
The vaporizing combustion chamber is preferably operated at constant output during operation. The so-called pilot combustion chamber, which is supplied with air, is ignited via the glow means 13, by which the primary fuel supply is ensured as well. The exhaust gas flow A, which is additionally mixed with the second fuel supply 14 and is swirled by the exhaust gas-swirling means 9, is then ignited in the so-called main combustion chamber behind the first flame retention baffle 17 in the downstream direction. The flame retention baffles 18 arranged farther behind ensure the stabilization of the flame in different exhaust gas mass flows. The burner can be placed into the exhaust gas flow somewhere between the exhaust gas outlet of the diesel engine and the particle filter.
The second design variant of a burner 1 for the thermal regeneration of a particle filter, which is illustrated in FIG. 2, is also provided as a so-called full-flow burner in a straight tailpipe section 4 of increased diameter similar to that in FIG. 1. The expanded tailpipe section 4 is provided with a pilot combustion chamber in the form of a torch igniter 20 with lateral flame glow plug 21, and the torch igniter 20 is fastened to the jacket of the tailpipe section 4. The housing 22 of the torch igniter 20 has an open end 23, which tapers in the downstream direction and extends coaxially to the tailpipe 3 or the expanded tailpipe section 4. The housing 22 of the torch igniter 20 has an engine exhaust gas inlet opening 25 in the upstream direction. A lateral igniting air connection 24, which extends through the jacket of the expanded tailpipe section 4, is also located in the area of the inlet opening 25.
The torch igniter 20 is preceded in the upstream direction by a central air shower (diffuser) 26, which has a lateral connection piece 27 for supplying additional air.
A first fuel supply line 28 is located behind the air shower 26, and a second fuel supply line 29 is located behind the torch igniter 20, and the two fuel supply lines 28 and 29 are provided with a closed circular line 30 on the jacket and have line webs 31 extending radially into the interior of the tailpipe section 4. The line webs 31 have a series of outlet openings 32 in the downstream direction for the optimal mixing of the fuel with the air and the exhaust gas flow A.
The torch igniter, designed as a two-stage igniter according to FIG. 2, also has one or more additional coaxial flame retention baffles 18, which are arranged after the second fuel supply line 29 in the downstream direction, are located in a second, expanded tailpipe section and ensure the stabilization of the flame in the reaction space of the second tailpipe section located there.
Like the above-described second exemplary embodiment, the exemplary embodiment of a full-flow burner 1 shown in FIGS. 3 and 4 provides for a flame glow plug 21 with a primary fuel supply 34, doing so in a two-stage vaporizing combustion chamber 33 with a coaxial cylinder part 35, which is concentrically fastened circumferentially in the tailpipe 3 or in the expanded tailpipe section 4 via a second exhaust gas-swirling means 36 and an exhaust gas-deflecting means 39.
The second exhaust gas-swirling means 36 has oblique baffle plates in the manner of a screw thread and is located on the upstream side of the cylinder part 35. The exhaust gas-deflecting means 39 comprises individual angular baffle plates and is located at the downstream end of the cylinder part 35.
Due to the cylinder part 35 being open in the front and in the rear, exhaust gas can flow primarily directly through the cylinder part, and the secondary exhaust gas flow is subjected to intense swirling through the means 36 and 39.
A second fuel supply 38 is located between the latter means 36 and 39, and fuel can be mixed with the swirled secondary exhaust gas flow by this second fuel supply 38 radially through the expanded tailpipe section. The second vaporizing combustion chamber 33 has, for a second combustion chamber stage B, a third fuel supply 40 with a closed circular line 41 on the jacket, similarly to the second fuel supply 38. The pre-combusted secondary exhaust gas flow, extremely swirled by the exhaust gas-deflecting means 39, is thus further mixed with a third fuel and subjected to afterburning together with the primary exhaust gas flow in the second combustion chamber stage, where the flame is stabilized by additional flame retention baffles 18 located there before the treated hot exhaust gas flow is fed to the particle filter (not shown).
The exemplary embodiment of a full-flow burner 1 shown in FIG. 5 is characterized especially by a straight tailpipe section 4 of increased diameter, in which an air atomization combustion chamber 43, which has a closed, arched flow inlet end 6 similar to the first design variant in the upstream direction and is open, especially tapered, in the downstream direction, is arranged coaxially. The air atomization combustion chamber, forming a jacket annular space 10, is held concentrically in the expanded tailpipe section 4. The exhaust gas flow A flows through the jacket annular space 10.
The air atomization combustion chamber 43 has a central air atomization nozzle 44 and is designed as a so-called two-component nozzle, i.e., it is provided with a lateral fuel supply line 45 and a lateral air supply line 46. The nozzle 44 is held in a central position inside the air atomization combustion chamber by an air swirling guide means 49. The air atomization nozzle 44 is followed by a lateral ignition means 47.
The arched flow inlet end 6 of the air atomization combustion chamber 43, which is closed in the upstream direction and is a so-called "by-pass combustion chamber," has an additional air supply line 48, which opens radially and additionally supplies the interior of the combustion chamber with air.
The downstream part of the air atomization combustion chamber 43 is designed as a so-called flame tube and has a plurality of jacket openings 50, through which a primary exhaust gas flow A' is guided from the jacket annular space side into the interior of the flame tube and combusted. The primary exhaust gas flow A' unites after the exhaust gas guide means 51 in a so-called mixing section, which is provided with an additional flame retention baffle 18.
After the additional flame retention baffle 18, a splitting is performed in an expanded exhaust gas-mixing space 52, in which a splitting guide means 53 with conically expanded baffle plates is located. After the mixing space 52, the very hot afterburned exhaust gases are sent to the particle filter 2 proper, which is then freed by burning off the particles or of soot for regenerating the filter.
The exemplary embodiment of a full-flow burner 1 shown in FIG. 6 extensively corresponds to the exemplary embodiment according to FIG. 5, but, unlike the latter, it has a second combustion chamber stage B. The second combustion chamber stage B comprises an additional fuel supply line 54 with a closed circular line on the jacket and individual nozzles 55 at a short distance before the exhaust gas guide means 51 in the jacket annular space 10, as well as a downstream tailpipe section 19 of increased diameter with additional flame retention baffles 18 similar to FIGS. 1 and 2.
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.
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Four design variants of a full-flow burner for the thermal regeneration of a particle filter in an exhaust gas aftertreatment system of an internal combustion engine, especially a diesel engine, which is arranged fully in the tailpipe, especially in an expanded, straight coaxial tailpipe section, are suggested according to the present invention. As a result, the flow can enter a particle filter axially, which means simplified design and good temperature distribution. The full-flow burners are preheated by the heat of the exhaust gas of the engine during the start phase. The exhaust gas of the engine cools the burner surface during the phase of burner operation, so that thermal overload is avoided.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a Continuation of U.S. patent application Ser. No. 11/800,723 filed May 7, 2007, which has issued as U.S. Pat. No. 8,151,379. U.S. patent application Ser. No. 11/800,723 is incorporated by reference herein in its entirety.
BACKGROUND
This invention relates generally to toilets that can remove waste from a toilet bowl efficiently with small amounts of water.
Water shortages are serious problems in many regions. This had led to government regulation regarding water use efficiency of certain products. For example, some jurisdictions regulate the maximum amount of water used by a toilet during a flush. While usage of as much as 7 gallons per flush was conventional in the early 1950s, current regulations in some jurisdictions require that no more than 1.6 gallons of water be used per flush. There are proposals to reduce the permitted usage further (e.g., to 1.2 gallons/flush).
Even when there is no governmental requirement restricting water usage, environmentally conscious consumers often prefer low water usage toilets. Moreover, water utilities are significantly increasing the cost of water supply, providing yet another motivation for consumers to prefer low water usage toilets.
As water usage per flush cycle is reduced, it is important that cleaning efficiency remain at acceptable levels. If cleaning efficiency is compromised, the consumer will in some situations be led to flush a second time, frustrating the regulatory, conservation, and cost savings goals.
Complicating matters is that in addition to cleaning the bowl sides, the flush water has other functions. It is typically used to form a gravity siphon which helps move the waste out of the bowl. Also, the water is needed to rinse the bowl once the main waste has been dislodged and evacuated. Further, water is needed to re-establish an odor seal in the trap. Also, water needs to be available to clean the entire circumference of the bowl. These additional requirements complicate the design of low water usage toilets.
One way to improve the efficiency of cleaning is to pressurize the cleaning supply of water. However, this can unacceptably increase the cost of the toilet.
Another approach is to split the rim flow into two unequal branches. See, for example, U.S. Pat. Nos. 4,930,167 and 6,397,405. However, prior systems of this type could have evacuation issues at low water usage rates.
Another approach is to use a tapered passage at the bottom of the bowl near the bowl outlet (which generally is referred to as a “jet”) to more efficiently start the siphon out of the bowl. See, for example, U.S. Pat. Nos. 5,218,726, 5,283,913 and 6,145,138. However, achieving adequate cleaning along the sides of the bowl is difficult with low water usage when a substantial portion of the water has been diverted for jet use.
Yet another approach is to use a multi-loop vortex flow approach. See, for example, U.S. Patent Application Publication No. 2004/0040080. This takes energy out of the water before it reaches the siphon trap, which could be problematic.
In U.S. Patent Application Publication No. 2003/0115664 there was a toilet disclosed with some rim flow along a right branch, some rim flow along a left branch, and some flow down and straight ahead. However, this design had certain inefficiencies which constrained the reduction in water usage. For example, water entered at a right angle to the rim, thereby dissipating cleaning energy. Further, some water was used in an opposing manner.
It is therefore desired to develop further improved toilets to reduce water usage without undesirably compromising cleaning or other water closet performance characteristics.
SUMMARY
An exemplary embodiment relates to a toilet which has a bowl having an upper rim channel and a water distribution structure for delivering water from a water supply to the bowl. The water distribution structure has an entry suitable to link with the water supply (e.g., a toilet tank or Flushometer type supply) and at least three exit channels.
A first of the exit channels communicates with the rim channel so as to provide at least counter clockwise flow around a first side of the rim channel. A second of the exit channels communicates with the rim channel so as to provide at least clockwise flow around an opposed side of the rim channel from the first side of the rim channel. A third of the exit channels communicates with a rearward portion of the rim channel.
The rim channel has a first enlarged opening to the bowl adjacent a rearward portion of the bowl, and a second enlarged opening to the bowl adjacent a forward portion of the bowl. The water distribution structure is configured so that when water is delivered to the rim channel a vortex of water will be developed in the bowl.
In an exemplary embodiment, the third exit channel is configured to feed water to the rim channel at an angle relative to the rim channel. Also, the first exit channel is suitable to carry a greater volume of water than the second exit channel (e.g., its cross sectional area is greater), and the first and second exit channels are each suitable to carry greater volumes of water than the third exit channel.
In another exemplary embodiment, the toilet bowl has a forward-to-back vertical central plane. The first and third exit channels link with the rim channel on one side of the vertical central plane and the second exit channel links with the rim channel on an opposite side of the vertical central plane.
In yet another exemplary embodiment, the first and second enlarged openings each have a central point on the same side of the vertical central plane, the bowl is provided with an integral rearward extension, the water distributor is integrally formed along the rearward extension, and the rim channel is an open rim style rim channel in which a gap between sides of the rim channel is varied to form the enlarged openings.
With this embodiment, entering water from the tank or other supply is thus split into three flows. One flow directly enters the bowl near its rear from the rim channel. Another flow, the primary flow, joins that first flow in part and in addition serves two other functions. One function is to wash one side of the bowl. Another is to pass almost to the front of the bowl and then enter the bowl in a large stream. Yet another flow is primarily to wash the opposite side of the bowl, albeit most preferably it also assists in washing the upper rear of the bowl.
The water enters the rim channels at an angle so as to keep the energy of the water largely intact. Surprisingly, the flow from the essentially forward (e.g., one o'clock or alternatively 11 o'clock) position avoids the need for a jet, thereby permitting all flow to enter from the rim channel in the exemplary embodiments.
Another exemplary embodiment relates to a toilet having a bowl with an upper rim channel, and a water distribution structure for delivering water from a water supply to the bowl. The water distribution structure has an entry suitable to link with the water supply and at least two exit channels.
A first of the exit channels communicates with the rim channel so as to provide both a counter clockwise flow and a clockwise flow around a first side of the rim channel if water is supplied to the toilet. There is also a second of the exit channels which communicates with the rim channel so as to provide a flow pattern selected from the group consisting of clockwise flow and counter clockwise flow around an opposed side of the rim channel from the first side of the rim channel if water is supplied to the toilet.
The rim channel has a first enlarged opening to the bowl adjacent a rearward portion of the bowl, and a second enlarged opening to the bowl adjacent a forward portion of the bowl. The water distribution structure is configured so that if water is delivered to the rim channel a vortex of water will be developed in the bowl.
Regardless of the aspect of the invention applied, as a result, with less water usage, effective cleaning can be achieved. The water is used in a way to also facilitate rinsing, evacuation and re-seal.
Current tests indicate that effective cleaning can be achieved at 1.6 gallons per flush, and further indicate that these toilets may provide effective cleaning with even lower levels of water use per flush. Such toilets can be manufactured using conventional molding techniques, without significant additional costs above those experienced with conventional cast toilets.
These and still other advantages of the present invention will become more apparent, and the invention will be better understood, by reference to the following description of preferred embodiments of the present invention which follows (with reference to the accompanying drawings).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of a toilet according to an exemplary embodiment.
FIG. 2 is a lower, left fragmentary perspective view of a portion of the toilet of FIG. 1 .
FIG. 3 is a lower, right fragmentary perspective view of the toilet of FIG. 1 .
FIG. 4A is a top view of the toilet of FIG. 1 , without the water tank, at the initiation of a flush cycle.
FIG. 4B is a view similar to that of 4 A, but with the flush progressing into a cleaning vortex.
FIG. 5 is a cross-sectional view taken along section line 5 - 5 in FIG. 1 .
FIG. 6 is a cross-sectional view taken along section line 6 - 6 in FIG. 4A .
FIG. 7 is a cross-sectional view taken along section line 7 - 7 in FIG. 4A .
FIG. 8 is a cross-sectional view taken along section line 8 - 8 in FIG. 4A .
FIG. 9 is a cross-sectional view taken along section line 9 - 9 in FIG. 4A .
FIG. 10 is a cross-sectional view of another exemplary embodiment of a toilet, which is similar to FIG. 5 , but instead illustrates a holed rim structure instead of an open rim design.
FIG. 11 is a top view of yet another exemplary embodiment of a toilet.
DETAILED DESCRIPTION
With general reference to the Figures, and more particularly to FIGS. 1 , 4 A, 4 B and 5 , there is shown a toilet 20 which includes a bowl 22 with a rim 24 at an upper extent 26 of bowl 22 . The rim 24 has a rim channel 28 therein. The bowl 22 can be conceptually considered to have a central vertical plane 30 .
There is a water tank 32 , which may have the usual internal flush valve, a flush actuator and other fittings as are required (not shown). Alternatively, toilet 10 can be a tankless design which is directly connected to line water pressure via a Flushometer type valve (also not shown). The bowl 22 discharges into a trap and drain line (also not shown).
A rear extension 34 can extend from rim 24 . It includes a water distributor structure 36 which is in communication with both the water supply and three exit channels 38 , 40 and 42 . The exit channels in turn are in fluid communication with the rim channel 28 . The channels 38 , 40 , 42 extend at corresponding angles 46 , 48 , 50 respectively. Each of the channels 38 , 40 , 42 are nonparallel with the vertical central plane 30 .
The angle 46 is greater than the angle 48 , and the angle 50 is greater than the angle 48 , for optimal vortex formation. The channel 38 and the channel 40 are on the same side of the vertical central plane 30 as each other, and the channel 42 is on an opposite side.
While three exit channels are preferred, it should be appreciated that to address particular concerns with particular style toilets one or more additional exit channels may be also used. Further, where one of the exit channels provides both clockwise and counter clockwise flow due to its angle of entry and positioning, in some cases only two exit channels need be used.
In any event, in our preferred embodiment, the channel 38 has a larger cross-sectional area 52 than the channel 40 with its cross-sectional area 54 , or that of channel 42 and its cross-sectional area 56 . The cross-sectional area 56 is in turn preferably larger than cross-sectional area 54 . These further facilitate vortex formation, as well as help facilitate evacuation of the bowl. For example, the channel 38 could take 33% to 45% of the total flow, the channel 42 could take 27% to 39% of the total flow, and the channel 40 could take 21% to 33% of the total flow.
The rim 24 of the toilet 20 has gaps 58 , 59 , 60 , 61 ( FIGS. 5-9 ) which allow the flush water to exit continuously from the rim channel 28 into the bowl 22 , albeit at different rates at different places depending on the gap's size. Two distinct sections of the larger gaps 60 , 61 in the rim 24 designates a first biasing flow aperture/enlarged opening 62 having a first center 64 and a second biasing flow aperture/enlarged opening 66 having a second center 68 . The center 68 is preferably −30 degrees to +30 degrees from straight forward, and the center 64 is preferably −30 degrees to +30 degrees from rear.
The orientation and design of biasing flow apertures/enlarged openings 62 , 66 , in conjunction with the orientation and design of the channels 38 , 40 , 42 , create first biasing flow 70 and second biasing flow 72 , which merge in the vicinity of the sump area 74 . This merging/collision, along with the other rim wash 76 emanating from secondary flow apertures 77 , develops into a vortex flow 78 which exits toilet 20 through an outlet 80 in the sump area 74 , overcomes the verge of the toilet trap, helps creates a siphon discharging the contents of the bowl 22 into the trap and sewer line, and then recreates the bowl seal.
The center 64 and center 68 are in this embodiment on a same side of the vertical central plane 30 . The bowl 22 has a water inlet side 82 , and a forward side 84 opposite water inlet side 82 , where the first biasing flow aperture/enlarged opening 62 can be on water inlet side 82 , and second biasing flow aperture/enlarged opening 66 can be on the forward side 84 .
The gap 58 can be the same or different than the gap 59 . Similarly, the gap 60 can be the same or different than the gap 61 . The gaps 60 , 61 are larger than the gaps 58 , 59 .
Note that the narrowing of the gaps 58 and 59 relative to the gap 60 serves a number of functions. For one thing, it permits more of the water from the channel 38 to reach the enlarged opening 66 , while still permitting some water to flow down the bowl sides near 77 .
For another, it helps deliver the water to a rim tapering area 90 in sufficient amounts that the water speed is accelerated as it is delivered to the opening 66 . This added boost further assists in evacuation and vortex formation.
It should also be noted that water coming out of the channel 42 primarily flows clockwise as shown by the arrow 91 . However, there is also a secondary flow 92 counter clockwise to help clean the rear portion of the upper bowl. This is important because the channel 40 is angled away from that region of the bowl to preserve the energy of the water.
The toilet 20 can include mounting holes 86 , 87 for respectively mounting the water tank 32 and a toilet seat (not shown), and a tank inlet hole 88 for providing access for the water tank 32 water inlet (not shown).
The embodiment of the toilet 20 illustrated in FIGS. 1-9 has a rim channel 28 that discharges through a continuous gap, an “open rim” type design. However, the present invention can also be applied to other types of rim channels. For example, FIG. 10 illustrates a toilet 90 which has a rim channel 93 wherein the first biasing flow aperture comprises a first water delivery slot 94 along an underside of the rim, and the second biasing flow aperture comprises a second water delivery slot 96 along the underside of the rim. The secondary flow apertures comprise at least one additional water delivery hole 98 in the rim each smaller than first water delivery hole 94 and/or second water delivery hole 96 . Other aspects of the toilet 90 are the same or similar to the toilet 20 .
Although the embodiments of FIGS. 1-10 illustrate a counterclockwise vortex flow, the present invention can be adapted for clockwise flow as illustrated in FIG. 11 . In this regard, the toilet 100 has the channels 38 , 40 , 42 , which have been placed on the respective other side of the vertical central plane 30 when compared to the placement in the toilet 20 . Similarly, although not shown, the first biasing flow aperture and the second biasing flow aperture are placed on the respective other side of the vertical central plane 30 when compared to the corresponding placement in the toilet 20 , to produce first biasing flow 102 and second biasing flow 104 , which results a clockwise vortex flow 106 . This arrangement can be applied to the open rim arrangement of the toilet 20 or the hole arrangement of the toilet 90 , or some combination thereof.
Further, it should be noted that while flow has been described in the rim channel with reference to both clockwise and counter clockwise flow, it is highly desirable that these mixed direction flows quickly result in a one direction vortex. Hence, for flow out of the channel 42 it is desirable for most of the clockwise energy to be out of the water when it starts dropping along the bowl sides. This can be achieved by elongating channel 42 relative to the channel 38 , and also by widening the rim channel from 6 o'clock to 12 o'clock.
We also prefer to have embodiments where when the flush cycle starts the first water enters from the channel 38 as compared to the channel 42 . This further facilitates vortex formation. We achieve this by having the channel 38 longer than the channel 42 .
Therefore, the present invention is not to be limited to just the described most preferred embodiments. Rather, in order to ascertain the full scope of the invention, the claims which follow should be referenced.
INDUSTRIAL APPLICABILITY
The present invention provides a toilet with reduced water usage while retaining effective cleaning and other performance.
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A toilet, comprising a bowl, a rim provided at an upper portion of the bowl, a rim channel disposed in the rim, a rear extension that extends from the rim, and a water distribution structure provided in the rear extension and configured to receive water from a water supply. The rim channel includes a first opening, a second opening, and a third opening located between the first and second openings, the openings being configured to communicate water to the bowl. The water distribution structure having at least two exit channels configured to communicate water to at least two different locations of the rim channel.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a microwave oven widely used in distribution industries including convenience stores. More particularly, this invention is concerned with a cash register system in a store in which such microwave ovens and a cash register operating as a POS terminal are combined.
2. Description of the Related Art
An existing microwave oven that is widely used for heating box lunches, made dishes, or the like in the distribution industries is normally utilized as follows: a shopper presents all required articles to be purchased to an employee in a store.
The employee recognizes an article, which may need to be heated by a microwave oven, among the wanted articles, and asks the shopper if he/she wants the article to be heated by the microwave oven.
When the shopper replies that he/she wants the article to be heated, the employee loads the article in a heating chamber of the microwave oven in the store, sets heating conditions including a heating time by manipulating setting buttons or the like, and then presses a heating start button so as to start the heating.
Thereafter, the total of the prices for the heated article and the other articles is calculated by a cash register. Thus, a payment by the shopper is completed. The cash registers used in the convenience stores usually operate as POS terminals. Therefore, in the descriptions as set below, POS terminals are used as the cash registers.
On the other hand, the heated article has been handed to the shopper by the employee. That is to say, the POS terminal and microwave oven are not coupled with each other but used independently.
In a store carrying diverse heatable articles, heating conditions differ from article to article. An employee checks the information on heating conditions, which is printed on each article or complied in the form of a list by the store, and sets a time and an output level at a keyboard of a microwave oven every time. This procedure is indispensable.
Moreover, when many shoppers are queuing at a cashier, if there are articles that are requested to be heated and articles that are not requested to be heated, the heating time required for the articles requested to be heated becomes a waiting time for the shoppers.
The length of the processing time greatly affects the sales performance of the store.
Furthermore, at stores in the distribution industries, employees familiar with the operation of equipment including a microwave oven are not always available. It is not rare that novices such as part-time workers must operate the equipment.
In such a case, if a system requires a complex operation, a wait time of shoppers extends to affect the running of a store.
There is therefore a demand for a more efficient and simpler operating method.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a microwave oven and a cash register system for a store enabling an employee of a store, who is requested to operate a microwave oven, to run the store efficiently while reducing the wait time for shoppers and suppressing losses deriving from incorrect operation of the microwave oven.
A microwave oven according to the present invention has the ability to heat an article purchased by a shopper. Further, the microwave oven uses an article information reader to read the article information, and sets heating conditions on the basis of the article information.
The article information reader reads the article information of the article under the control of the microwave oven. The article is required by a shopper, and bears the article information on the surface thereof.
The article information is attached to the surface of the article, and recognized by the article information reader. The contents of the article information include ID information of the article and heating conditions.
In the foregoing configuration, when a shopper enters a store, the shopper selects articles and carries them to the cash register. If there is an article which needs to be heated, either an employee or the shopper loads the article in a heating chamber of the microwave oven. The microwave oven recognizes the article information attached to the surface of the article owing to the article information reader controlled by the microwave oven.
In the present invention, not only an employee of a store but also a shopper can set heating conditions inherent to the article in the microwave oven merely by loading the article in the microwave oven.
A cash register system according to the present invention comprises a cash register and a microwave oven. The cash register calculates payments by shoppers in a store and has the ability to communicate with a microwave oven over a line. The microwave oven has the above-mentioned ability. Further, the microwave oven is connected to the cash register through communication over a line and has the ability to transmit or receive information concerning an article.
The cash register uses the article information to calculate payment by the shopper. The microwave oven heats the article according to the heating conditions included in the article information. The shopper unloads the heated article and uses it.
Moreover, the present invention uses an information carrier (tag) that stores conditions for processing an article and information for distinguishing the article, and that when microwaves are irradiated, transmits the respective information according to the microwaves.
Moreover, according to the present invention, the cash register need not read the article information read by the microwave oven.
Further, it becomes unnecessary to train a new employee of a store so that the employee can manage complex setting of the microwave oven. This brings about such effects that losses of articles resulting from incorrect operation of the microwave oven can be eliminated and that smooth running of the store can be attained.
Furthermore, there can be many modifications. For example, the article information may includes only ID information to identify the article, either of the microwave oven or the cash register comprises a data base system from which heating conditions for heating an article can be retrieved, and the heating control means retrieves heating conditions from said data base. The article information reader may be provided at the cash register. Information regarding heating condition is sent from the cash register to the microwave oven.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more clearly understood from the description as set below with reference to the accompanying drawings, wherein:
FIG. 1 is a diagram showing a constitution of a cash register system including a microwave oven of the first embodiment of the present invention;
FIG. 2 is a schematic block diagram of the first embodiment;
FIG. 3 is a flowchart showing control operations of the microwave oven of the first embodiment;
FIG. 4 is a diagram showing a constitution of a second embodiment of the present invention;
FIG. 5 is a diagram showing the constitution of a third embodiment;
FIG. 6 is a schematic block diagram of a microwave oven of the third embodiment;
FIG. 7 is a flowchart showing control operations of the microwave oven of the third embodiment;
FIG. 8 is a diagram showing the constitution of a fourth embodiment;
FIG. 9 is a flowchart showing control operations of the fourth embodiment;
FIG. 10 is a diagram showing the constitution of a fifth embodiment;
FIG. 11 is a flowchart showing control operations of the fifth embodiment;
FIG. 12 is a diagram showing the constitution of a sixth embodiment;
FIG. 13 is a flowchart showing control operations of the sixth embodiment; and
FIG. 14 is a diagram showing the constitution of a seventh embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows the constitution of the first embodiment relating to a cash register system of the present invention. In FIG. 1, reference numeral 1 denotes a cash register; 2 denotes a microwave oven; 3 denotes an article information reader; 4 denotes an article; 5 denotes an article information recording medium; and 9 denotes a communication line connecting the cash register 1 and the microwave oven 2.
In this embodiment, a POS terminal is used as the cash register 1. The POS terminal has the ability to calculate a payment by a shopper in a store, and includes means for communicating with the microwave oven 2 over the line 9.
The microwave oven 2 has the ability to heat the article 4 by irradiating microwaves onto the article 4. A magnetron is used for irradiating the article. The microwave oven 2 is connected to the cash register 1 through communication line 9.
An optical character recognition (OCR) unit is used as the article information reader 3 accompanying the microwave oven 2. The OCR unit 3 can read and recognize printed numerals and characters by scanning them. The article information recording medium 5 is printed matter attached to the surface of the article 4 and the information regarding the article is represented in a form of printed numerals and characters, namely, in the form of OCR characters. Therefore, the OCR unit 3 can read required information concerning the article 4. The information recorded on the article information recording medium 5 includes an identification (ID) code of each article and information regarding heating conditions for the article such as the heating time. The ID code is reported from the microwave oven 2 to the POS terminal 1.
The article 4 is an article to be heated by the microwave oven 2, for example, a lunch or made dish encased in a heat-proof container made of plastic or the like. The article 4 is heated by the microwave oven 2.
The article information recorded on the article information recording medium 5 attached to an article 4 is read by the OCR 3. The ID code and the information regarding the heating condition are extracted from the article information. The extracted ID code of the article to be heated is sent to the POS terminal 1. The POS terminal 1 recognizes a price of the heated article based on the article information, and the total of the prices for the heated articles and the other articles is calculated by a cash register. Therefore, the POS terminal 1 does not need to read the ID codes of the heated articles.
The POS terminal 1 and microwave oven 2 are connected to each other over the line 9, whereby various kinds of information are transferred and desired control is given.
On the other hand, information regarding heating conditions read by the OCR is used in the microwave oven 2. The microwave oven heats the articles inserted according to the corresponding heating conditions.
FIG. 2 is a schematic block diagram showing an example of the typical constitution of the POS terminal 1 and microwave oven 2 of the present embodiment.
In addition to a facility serving as a normal register, the POS terminal 1 includes an interface (I/O) 11 for communicating with a host-computer that is not shown and an interface (I/O) 12 for communicating with a microwave oven 2.
The POS terminal 1 further comprises a CPU 13, ROM 14, RAM 15, a disk unit 16 for storing article codes in a one-to-one relation with article information such as article names and prices, and a display 17 for displaying payments. These elements are connected through a bus 18.
The microwave oven 2 includes an interface (I/O) 22 for communicating with a POS terminal 1, CPU 23, ROM 24, RAM 25, a magnetron interface 26, a magnetron 27, an I/O unit 28 which operates as an interface for other elements 29 such as switches, an OCR interface 30, and an OCR 3. The CPU 23, ROM 24, and RAM 25 constitute a control unit of the microwave oven 2.
FIG. 3 is a flowchart showing a control operation of the microwave oven 2 in the first embodiment.
In this embodiment, a shopper enters a store, selects articles 4 to be purchased, and carries them to the POS terminal 1. When the selected articles include an article to be heated, either an employee of the store or the shopper himself/herself loads the article in the heating chamber of the microwave oven 2.
At step 101, the OCR 3 of the microwave oven 2 reads information recorded on the article information recording medium 5 attached to an article 4 inserted into the microwave oven 2.
At step 102, the control unit of the microwave oven 2 recognizes an ID code and heating conditions of the article from the information read by the OCR 3.
At step 103, the control unit of the microwave oven 2 sends the ID code to the POS terminal 1 via the I/O 22. The POS terminal 103 searches a price of the article to be heated and adds it to a payment of the shopper.
At step 104, the control unit of the microwave oven 2 controls the magnetron 27 to heat the article 4 according to the heating conditions included in the article information 5, for example, a heating time and a heating output level. The shopper unloads the heated article 4 and consumes it.
In the first embodiment, the article information recording medium 5 is printed matter attached to the surface of the article 4, the information regarding the article is represented in a form of printed numerals and characters, and the OCR unit 3 is used as the article information reader. However, the article information recording medium 5 may be a bar-code, and a bar-code reader can be used as the article information reader.
A known tag disclosed in U.S. Pat. No. 5,214,410 has a facility that can transmit or receive data carried by a radio wave owing to a built-in compact receiving circuit, and that when received data is addressed to the tag, transmits associated data. This tag can be used as the article information recording medium. A possible system constitution using these tags is such that: a tag functioning as such a super-compact transponder as the one mentioned above is attached as the article information recording medium relating to the present invention; and required article information is acquired by receiving a radio wave sent from the tag in response to an inquiry carried by an external radio wave.
In this case, the article information reader 3 is an antenna and receiver to communicate with the tag.
FIG. 4 is a diagram showing a constitution of the second embodiment in which the above-mentioned tag is used as the article information recording medium 8. In FIG. 4, component elements identical to those in FIG. 1 are assigned the same reference numerals.
In this modification, the microwave oven 2 includes a radio-wave article recognizing unit 7 serving as a means for implementing the capability of the article information reader 3.
The radio-wave article recognizing unit 7 has the ability to recognize a response signal sent when a beam irradiator in the microwave oven 2 transmits a beam to a radio-wave article information recording medium 8 attached to the article 4.
The radio-wave article information recording medium 8 is a tag having a function serving as a kind of transponder. The radio-wave article information record 8 has the ability to recognize a request signal carried by an output beam irradiated by the microwave oven 2 and transmits a response signal.
In the radio-wave article information recording medium 8, heating conditions such as a heating time are recorded together with an ID of an article.
In the foregoing constitution, after the article 4 is loaded in the heating chamber of the microwave oven 2 and a door is closed, when a start button is pressed, the microwave oven 2 transmits microwaves with a frequency of 2.5 GHz.
The microwaves are used to heat an article. In response to the microwaves with a frequency band of 2.5 GHz, the radio-wave article information record 8 transmits recorded information.
As mentioned above, the frequency band of microwaves used for heating and transmitted by a microwave oven agrees with the one of microwaves used by the radio-wave article information recording medium 8. This modification makes the most of this point.
With transmission of microwaves with a frequency band of 2.5 GHz from the microwave oven, the radio-wave article information 8 transmits an article ID that is article information and heating conditions as a response signal.
The radio-wave article recognizing unit 7 in the microwave oven 2 receives the response signal and reports the article ID to the POS terminal 1. According to the heating conditions set in the microwave oven 2, the microwave oven 2 heats the article 4.
Herein, a high-speed system can be provided.
Incidentally, an output level of an electromagnetic wave during heating is so high that the radio-wave article information recording medium 8 may be broken when the microwaves are used as they are.
Consequently, before information is read, the output level is minimized. After information including a heating time is acquired, the output level may be raised.
FIG. 5 is a diagram showing a system constitution of the third embodiment of the present invention. In FIG. 5, component elements identical to those in FIG. 1 are assigned the same reference numerals.
In this embodiment, a data base system 6 is included. The data base 6 is connected to the microwave oven 2. The hardware of the data base system 6 is, for example, a hard disk.
In the data base 6, article information is stored in a one-to-one relation with ID information of articles.
FIG. 6 is a schematic block diagram showing an example of the typical constitution of the microwave oven 2 of the present embodiment.
In addition to the constitution of the first embodiment, a disk unit 61 is added. The disk unit 61 stores information of the data base system 6. The article information recorded in the article information recording medium 5 does not include a heating condition of an article. The microwave oven 2 can retrieve article information of an article as well as heating information thereof from the data base 6 on the basis of the ID code of the article 4 read from the article information recording medium 5. When the article 4 is loaded in the heating chamber of the microwave oven 2, the article information recorded in the article information recording medium 5 is read by the article information reader 3 and it is recognized by the control unit of the microwave oven 2.
Article information such as an article name and price recognized by the microwave oven 2 is reported to the POS terminal 1. The microwave oven 2 retrieves heating conditions such as a heating time and heating output level concerning the article from the data base 6, and heats the article 4 according to the conditions.
Aside from the hard disk, a medium such as a RAM, ROM, floppy disk, CD-ROM, or the like can be used as the data base 6.
FIG. 7 is a flowchart showing a control operation of the microwave oven 2 in the third embodiment.
At step 201, the OCR 3 of the microwave oven 2 reads an ID code of the article 4 recorded in the article information recording medium 5 attached to an article 4.
At step 202, the control unit of the microwave oven 2 sends the ID code to the POS terminal 1 via the I/O 22. The POS terminal 1 searches for the price of the article to be heated and adds it to the payment by the shopper.
At step 203, the control unit of the microwave oven 2 searches for a heating condition of the article in the data base system 6.
At step 204, the control unit of the microwave oven 2 controls the magnetron 27 to heat the article 4 according to the heating conditions.
According to this embodiment, the microwave oven 2 manages the data base 6 and can therefore retrieve information at a high speed on the basis of the article information.
FIG. 8 is a diagram showing a schematic constitution of the fourth embodiment of the present invention. In FIG. 8, component elements identical to those in FIG. 1 are assigned the same reference numerals.
In this embodiment, the data base 6 is connected to the POS terminal 1. The data base 6 is, similarly to that in the third embodiment, a hard disk.
On an article in this embodiment, ID information of the article is recorded in the form of a code. No other information is recorded. In the data base 6, ID codes are stored in a one-to-one relation with article information such as article names as well as heating times.
The POS terminal 1 can retrieve article information and heating information from the data base 6 on the basis of the information read from the article information recording medium 5. The information is read by the article information reader 3 located in the microwave oven 2.
FIG. 9 is a flowchart showing a control operation of the microwave oven 2 in the fourth embodiment.
The article 4 to be heated is loaded in the microwave oven 2.
At step 301, the article information reader 3 recognizes the ID information of the article 4 to be heated. At step 302, the ID information is reported to the POS terminal 1. At step 351, the POS terminal 1 receives ID information. At step 352, the POS terminal 1 retrieves article information such as an article name as well as heating conditions from the data base 6. At step 353, the POS terminal 1 sends the heating conditions to the microwave oven 2.
At step 352, the POS terminal 1 searches for the price of the article in the data base system 6 as well as ID and heating information. At step 354, the POS terminal 1 adds the price to the payment by the shopper.
At step 303, the microwave oven 2 receives the heating condition sent from the POS terminal 1. At step 304, the control unit of the microwave oven 2 controls the magnetron to operate in the heating condition.
According to this embodiment, the POS terminal 1 manages the data base 6 and can therefore retrieve the article information concerning diverse kinds and large numbers of articles 4.
FIG. 10 is a diagram showing a constitution of the fifth embodiment of the present invention. In the drawing, component elements identical to those in FIG. 1 are assigned the same reference numerals.
In this embodiment, the microwave oven 2 does not have an article information reader. The POS terminal 1 manages and controls, for example, a handy article information reader 3'. The POS terminal 1 recognizes the article information owing to the article information reader 3'.
The article information 5 attached to the article 4 is read by the article information reader 3' managed and controlled by the POS terminal 1, used for calculation of a payment, and reported to the microwave oven 2 over the line 9.
The microwave oven 2 retrieves heating conditions from the data base 6 connected to the microwave oven 2, and can therefore heat the article 4 according to the heating conditions.
According to the heating conditions retrieved on the basis of the article information read by the article information reader 3' connected to the POS terminal 1, the microwave oven 2 is controlled so that the article 4 can be heated according to given conditions retrieved from the data base 6.
FIG. 11 is a flowchart showing a control operation of the microwave oven 2 in the fifth embodiment.
At step 451, the article information reader 3' recognizes ID information of the article 4 to be heated before the article 4 is loaded in the microwave oven 2. At step 452, the ID information is reported to the microwave oven 2. At step 453, the POS terminal 1 searches for the price of the article in the data base system 6. At step 454, the POS terminal 1 adds the price to the payment by the shopper.
At step 401, the microwave oven 2 receives ID information. At step 402, the control unit of the microwave oven 2 retrieves article information such as heating conditions from the data base 6. At step 403, the control unit of the microwave oven 2 controls the magnetron to operate in the heating condition.
According to this embodiment having the foregoing constitution, the POS terminal 1 can calculate payment at a high speed.
FIG. 12 is a diagram showing the constitution of the sixth embodiment of the present invention. In the drawing, component elements identical to those in FIG. 1 are assigned the same reference numerals.
In this embodiment, the article information reader 3 and data base 6 are not connected to the microwave oven 2.
The hand-held article information reader 3' is, similar to the one in the fifth embodiment, managed and controlled by the POS terminal 1. Owing to the article information reader 3', the article information is recognized by the POS terminal 1.
The data base 6 may be, for example, a hard disk. Based on the article information 5 read by the article information reader 3' connected to the POS terminal 1, heating information can be retrieved.
The article information of the article 4 is therefore read by the article information reader 3' managed by the POS terminal 1 and used for calculation of a payment.
The article information is used for calculation of payment and also used to retrieve heating conditions from the data base 6. The heating conditions are reported to the microwave oven 2. The microwave oven 2 can heat the article 4 according to the reported heating conditions.
FIG. 13 is a flowchart showing a control operation of the microwave oven 2 in the sixth embodiment. At step 551, the article information reader 3' recognizes ID information of the article 4 to be heated before the article 4 is loaded in the microwave oven 2. At step 552, the POS terminal 1 retrieves article information such as a price of the article and the heating conditions from the data base 6. At step 553, the heating condition is reported to the microwave oven 2. At step 554, the POS terminal 1 adds the price, which was found at step 552, to the payment by the shopper.
At step 501, the microwave oven 2 receives the heating conditions for the article. At step 502, the control unit of the microwave oven 2 controls the magnetron to operate in the heating condition.
According to this embodiment having the foregoing configuration, the large-capacity data base 6 can be connected. Consequently, a system enabling high-speed retrieval of information concerning any diverse article 4 can be provided.
FIG. 14 is a diagram showing a constitution of the seventh embodiment of the present invention. In the drawing, component elements identical to those in FIG. 1 are assigned the same reference numerals.
Shown herein is the configuration in which the radio-wave article information 8 attached to an article to be loaded in the microwave oven 2 generates a response signal and functions as a heat source for an article.
An element 10 which can convert electromagnetic energy into thermal energy and accumulate the thermal energy or which can accumulate electromagnetic energy in the form of charge and convert the charge into thermal energy is provided on an article 4 as a heat source.
For example, the heat source has the ability to accumulate charge in a capacitor, and has the ability to keep an article warm by continually transmitting a weak response according to a charge corresponding to a beam sent from the microwave oven 2 after heating is completed and irradiation is completed.
After heating is completed, even if it takes time to carry a heated article to a destination in, for example, the coldest season in the winter, the article can be kept warm. Thus, a facility for keeping a warm state can be provided.
As described so far, according to the present invention, not only the procedure according to which an employee of a store operates a microwave oven can be simplified but also management of articles can be accomplished perfectly. Moreover, the selling situation of articles in a store can be recognized. Since the time required to attend a shopper is shortened, services given at a store can be improved.
Moreover, according to the present invention, not only can waste of articles, or a hazard stemming from incorrect setting of heating conditions by an inexperienced employee or user, be eliminated but also finer heating conditions can be set optimally for each article. Thus, a great contribution to the running or management of a store is expected.
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A microwave oven and a cash register system of a store in which an employee of a store, who is requested to operate the microwave oven, can run the store efficiently while reducing the waiting time for shoppers and suppressing losses deriving from incorrect operation of the microwave oven. The microwave oven includes an irradiator for irradiating microwaves to heat articles, an article information reader for reading article information from an article information recording medium arranged on the surface of the article, and a heating control unit for controlling the irradiator to operate at a condition determined based on the article information read by the article information reader.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an engine idle control system for a vehicle.
2. Description of the Prior Art
There has been known an engine idle control system for a vehicle which has a bypass passage provided in an intake passage of the engine to bypass a throttle valve and controls the amount of air flowing through the bypass passage by control of a duty solenoid valve provided in the bypass passage so that the engine speed converges on a predetermined value when the throttle valve is in an idle position. In such an idle control system, the duty solenoid valve is generally feedback-controlled on the basis of the difference between a target engine speed and the actual engine speed during idling so that the actual engine speed converges on the target engine speed. The feedback control is mainly performed on the basis of an integral control and partly performed on the basis of a combination of an integral control and a proportional control.
However when the engine speed is feedback-controlled by the integral control, the engine speed can be continued to be lowered after the actual engine speed falls below the target engine speed in the case where the engine speed lowers and the engine comes to be to idle during deceleration of the vehicle, which can result in excessively low idling speed or stall of the engine.
Though it is proposed to interrupt the feedback control of the idling speed in Japanese Unexamined Patent Publication No. 54(1979)-72319, it is preferred that the feedback control be effected from deceleration before the engine goes into idle in order to quickly stabilize the engine speed.
SUMMARY OF THE INVENTION
In view of the foregoing observations and description, the primary object of the present invention is to provide an engine idle control system for a vehicle which can control the idling speed of the engine without fear that the engine speed falls excessively low or the engine stalls even when the engine decelerates and goes into idle.
In the idle control system in accordance with the present invention, it is detected whether the engine is revolving by itself or is being driven by the vehicle and the engine speed is controlled by a proportional feedback control on the basis of the difference between the actual engine speed and the target idling speed when the engine is being driven by the vehicle, and is controlled by a control at least a part of which is an integral feedback control when the engine is revolving by itself.
Whether the engine is revolving by itself or is being driven by the vehicle can be determined, for instance, on the basis of the difference between the engine speed and the turbine speed.
Since, in the idle control system of the present invention, the engine speed is controlled by a proportional feedback control on the basis of the difference between the actual engine speed and the target engine speed when the engine is being driven by the vehicle, which is the case when the engine decelerates and goes into idle, the engine speed can be quickly converged on the target engine speed without fear that the engine speed falls excessively low or the engine stalls.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view showing an engine provided with an idle control system in accordance with an embodiment of the present invention,
FIG. 2a and 2b are a flow chart showing the idling speed control by the control unit,
FIG. 3 is a map showing target engine speed-engine coolant temperature characteristics,
FIG. 4 is a map showing base flow rate-engine coolant temperature characteristics,
FIG. 5 is a map for determining the integral feedback correction value,
FIG. 6 is a map for determining the proportional feedback correction amount, and
FIG. 7 is a map for determining the duty ratio for controlling the solenoid valve.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1, an engine 1 has an intake passage 2 and an exhaust passage 3. A hot wire airflow meter 4, a throttle valve 5 and a fuel injector 6 are provided in the intake passage 2. The engine 1 is further provided with an ignition system 10 comprising an ignition coil 7, a distributor 8 and a spark plug 9.
The intake passage 2 is provided with a bypass passage 11 which bypasses the throttle valve 5. The bypass passage 11 is provided with an electromagnetic solenoid valve 12 which controls the flow rate of air flowing through the bypass valve 11 and controls the idling speed of the engine 1. The solenoid valve 12 is controlled by a control unit 13 which may comprise a microcomputer.
The control unit 13 receives output signals from the airflow meter 4, an engine speed sensor 14, an engine coolant temperature sensor 15, a transmission type determining means 16 which determines the type of the transmission the vehicle is provided with (whether the vehicle is provided with an automatic transmission AT or a manual transmission MT), a gear position sensor 17, a turbine speed sensor 18 which detects the rotational speed of the turbine of the automatic transmission, and an idle switch 19 which outputs an on-signal when the throttle valve 5 is full closed, and controls the amount of fuel to be injected from the injector 6, the ignition timing and the idling speed of the engine. The control of the amount of fuel to be injected from the injector 6 and the ignition timing is not directly related with this invention, and accordingly will not be described here.
The control of the idling speed by the control unit 13 will be described with reference to FIGS. 2 to 7, hereinbelow.
In FIG. 2, the control unit 13 reads the engine speed ne, the engine coolant temperature thw, and whether the vehicle is provided with an automatic transmission AT or a manual transmission MT. In the case of an automatic transmission vehicle, the control unit 13 further reads whether the transmission is in N-range or D-range, and reads the turbine speed nt. In the case of a manual transmission vehicle, the control unit 13 further reads whether the gear is in. (steps S1 to S5)
In step S6, the control unit 13 sets a target engine speed nO according to the target engine speed-engine coolant temperature (nO-thw) characteristic map shown in FIG. 3. The nO-thw characteristic map has been stored in the control unit 13 and has an MT nO-thw characteristic curve l1 for setting the target engine speed nO in the manual transmission vehicle, an N-range nO-thw characteristic curve l2 for setting the target engine speed nO in the automatic transmission vehicle when the transmission is N-range, and a D-range nO-thw characteristic curve l3 for setting the target engine speed nO in the automatic transmission vehicle when the transmission is D-range. Then in step S7, the control unit 13 sets a basic flow rate Qbase of air flowing through the bypass passage 11 according to the basic flow rate-engine coolant temperature (Qbase-thw) characteristic map shown in FIG. 4. The Qbase-thw characteristic map has been stored in the control unit 13 and has an MT Qbase-thw characteristic curve l4 for setting the basic flow rate Qbase in the manual transmission vehicle, and an AT Qbase-thw characteristic curve l5 for setting the basic flow rate Qbase in the automatic transmission vehicle. Then in step S8, the control unit 13 sets a D-range correction amount Qdr for compensating for load on the torque convertor of the automatic transmission. The D-range correction amount Qdr is obtained by multiplying the target engine speed nO by a constant KQdr which is set to 0 when the vehicle is provided with the manual transmission or when the automatic transmission is in N-range.
In step S9, the control unit 13 determines whether idle flag Xidl is 1. The idle flag Xidl is set to 1 when the throttle valve 5 is full closed. When the answer to the question in step S9 is yes, the control unit 13 further determines in step S10 whether the vehicle is provided with a manual transmission. When the answer to the question in step S10 is yes, the control unit 13 further determines in step S11 whether the transmission is in neutral. When the answer to the question in step Sll is yes or when the answer to the question in step S10 is no, the control unit 13 proceeds to step S12. In step S12, the control unit 13 calculates a "dull engine speed" ned according to the following formula.
ned=α·ne+(1-α)·ned
wherein α being a constant larger than 0 and smaller than 1. The dull engine speed ned is similar to a weighted average of preceding engine speeds.
Thereafter the control unit 13 calculates in step S13 the absolute difference dne between the dull engine speed ned and the actual engine speed ne. The control unit 13 determines whether feedback flag Xifbn is 0, the feedback flag Xifbn being set to 1 when feedback control is going. When the answer to the question in step S14 is yes, the control unit 13 determines in step S15 whether a counter Cidon has been reset to 0. The counter Cidon is set to a predetermined time when the idle flag Xidl is set to 1. For a while after calculation of the dull engine speed is commenced, the difference between the dull engine speed dne and the actual engine speed ne is not so large and if the difference is used, the feedback control cannot be properly effected. The counter Cidon is set for the purpose of waiting until the difference sufficiently enlarges.
When the answer to the question in step S15 is yes, the control unit 13 determines in step S16 whether the difference dne is smaller than a preset value Kdne. When the operating condition of the engine approaches idle after deceleration, the difference dne becomes smaller than the preset value Kdne. When the answer to the question in step S16 is yes, the control unit 13 proceeds to step S18 after setting the feedback determination flag Xifbn to 1 in step S17. Otherwise the control unit 13 directly proceeds to step S18. In step S18, the control unit 13 determines whether the vehicle is provided with an automatic transmission. When the answer to the question in step S18 is yes, the control unit 13 determines step S19 whether the transmission in D-range. When the answer to the question in step S19 is yes, the control unit 13 determines in step S20 whether the feedback determination flag Xibfn is 1, and when the answer to the question in step S20 is yes, the control unit 13 determines in step S21 whether the actual engine speed ne is higher than the turbine speed nt, that is, whether the engine 1 is revolving by itself. When the answer to the question in step S21 is yes, that is, when the engine 1 has been idling, the control unit 13 sets an integral feedback control executing flag Xifb to 1. On the other hand, when the answer to the question in step S21 is no, that is, when the engine 1 is still decelerating, the control unit 13 sets the integral feedback control executing flag Xifb to 0.
After steps S22 and S23, the control unit 13 determines in step S24 whether the integral feedback control executing flag Xifb is 1. When the answer to the question in step S24 is yes, the control unit 13 determines in step S25 whether a proportional feedback control executing flag Xpfb is 1. When the proportional feedback control is abruptly switched to the integral feedback control, the amount of intake air largely fluctuates and the engine speed fluctuates by a large amount. Accordingly, in step S25, the control unit 13 determines whether the proportional feedback control executing flag Xpfb is 1 in order to know whether the proportional feedback control has been executed. When the answer to the question in step S25 is yes, the control unit 13 determines in step S26 whether a proportional feedback amount of intake air Qpfb is 0, and when the answer to the question in step S26 is yes, the control unit 13 resets the proportional feedback control executing flag Xpfb to 0 in step S27 since when the proportional feedback amount of intake air Qpfb is 0, large fluctuation of the engine speed cannot occur even if the proportional feedback control is switched to the integral feedback control.
Thereafter, the control unit 13 calculates in step S28 the difference dneO between the actual engine speed ne and the target engine speed nO, and calculates in step S29 an integral feedback correction value dQi according to a map shown in FIG. 5 on the basis of the difference dneO (stored in the control unit 13). Further the control unit 13 calculates in step S30 the proportional feedback correction amount Qpfb according to a map shown in FIG. 6 on the basis of the difference dneO (stored in the control unit 13). Then the control unit 13 determines again in step S31 whether the proportional feedback control executing flag Xpfb is 1, and when the answer to the question in step S31 is no, the control unit 13 proceeds to step S33 after setting the proportional feedback correction amount Qpfb to 0 in step S32. When the answer to the question in step S31 is yes, the control unit 13 directly proceeds to step S33. In step S33, the control unit 13 determines whether the integral feedback control executing flag Xifb is 1. When the answer to the question in step S33 is yes, the control unit 13 adds the integral feedback correction value dQi to the preceding value of an integral feedback correction amount Qifb, thereby obtaining a present value of the integral feedback correction amount Qifb (step S34), and thereafter proceeds to step S35. When the answer to the question in step S33 is no, the control unit 13 directly proceeds to step S35.
In step S35, the control unit 13 adds up the basic flow rate Qbase set in step S7, the D-range correction amount Qdr set in step S8, the integral feedback correction amount Qifb and the proportional feedback correction amount Qpfb and thereby obtains a total controlled variable Qtotal. The control unit 13 obtains a control duty ratio of the solenoid valve 12 according to a map shown in FIG. 7 (stored in the control unit 13) and drives the solenoid valve 12 on the basis of the duty ratio. (steps S36 and S37) Thereafter, the control unit 13 returns to step S1.
When the answer to the question in step S9 is no, that is, when the throttle valve 5 has not been full closed, or when the answer to the question in step Sll is no, that is, when the transmission gear is in (in the case of a manual transmission vehicle), the control unit 13 resets the counter Cidon to 0, sets the dull engine speed ned to the actual engine speed ne, sets the difference dne to 0 and resets the feedback determination flag Xifbn to 0. (steps S38 to S41) Thereafter the control unit 13 returns to step S1. When the answer to the question in step S14 is no, the control unit 13 directly proceeds to step S18. When the answer to the question in step S15 is no, that is, when the counter Cidon is not 0, the control unit 13 proceeds to step S18 after decrementing the counter Cidon by 1 in step S42. When the answer to the question in step S18 or S19 is no, that is, when the vehicle is provided with a manual transmission MT, or when the vehicle is provided with an automatic transmission and the transmission is in N-range, the control unit 13 equalizes the integral feedback control execution flag Xifb to the feedback determination flag Xifbn in step S43 and then proceeds to step S24. When the answer to the question in step S24 is no, the control unit 13 sets the proportional feedback control executing flag Xpfb to 1 in step S44 and then proceeds to step S28. Further when the answer to the question in step S25 or S26 is no, the control unit 13 directly proceeds to step S28.
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An engine idle control system for a vehicle causes the engine speed to converge on a target idling speed by feedback control when the engine idles. Whether the engine is revolving by itself or is being driven by the vehicle is detected, and the engine speed is controlled by a proportional feedback control on the basis of the difference between the actual engine speed and the target idling speed when the engine is being driven by the vehicle, and is controlled by a control at least a part of which is an integral feedback control when the engine is revolving by itself.
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This application is a continuation-in-part of Ser. No. 08/667,956 filed Jun. 18, 1996, abandoned.
TECHNICAL FIELD OF THE INVENTION
The present invention relates, in general, to the recovery of information from computer data storage devices and/or media and, in particular, to the recovery of information which is inaccessible by the normal operating environment and to a method for allowing remote diagnosis and remote rectification of such data loss.
BACKGROUND OF THE INVENTION
The true value of a computing system to a user is not limited to the actual cost of the hardware and software components which comprise that system, but also includes the value of the data represented within that system. Indeed, it is quite common that the accounting data, intellectual property, design and manufacturing information, and/or other records which are stored on computing systems in personal and business use are ultimately of a value which far exceeds the value of the computing equipment itself.
Loss of the ability to access data on a computer storage device, such as a disk drive, can occur, often as a result of operator error, errant software, transient electrical events, acts of sabotage, or electrical/ mechanical failures. In many cases, although the data is not accessible by the normal operating environment, the data itself still exists on the storage media, and can be rendered accessible by manipulating the on-media data structures which represent the filesystem(s) employed by the operating environment. Such manipulation of on-media data structures is most reliably performed by trained technicians equipped with highly specialized software tools.
It is occasionally the case that the inaccessibility of data can be the cause of significant cost and/or lost business, sometimes to a catastrophic degree. While some forms of data may be candidates for recreation, the cost of this recreation may range from trivial to prohibitive. Additionally, data recreation takes a finite time, during which aspects of business may be necessarily suspended or hampered due to dependence upon the inaccessible data. There also exist categories of data which are generally acquired in real-time which are not able to be recreated, and which can therefore be considered as irreplaceable.
Traditional redundancy mechanisms, such as off-line backup, tend to provide relief for data loss situations. Restoration from off-line backup can, however, be time-consuming and may provide data which is aged with respect to the data which could potentially be available through data recovery procedures. Therefore, even data losses which are theoretically restorable from off-line backup may be considered as potential data recovery candidates.
Commercial data recovery service businesses address these issues with various categories of service. These typically include both on-site and off-site services. Off-site data recovery services, in which the media or device containing the inaccessible data is processed by a data recovery technician at a service facility, requires physical removal of the media or device from the customer premises and transportation to the service facility. This can cause significant down-time due to the delays induced by shipping. There also exist situations where the data is sensitive and corresponding security considerations dictate that removal of data from the site is not advisable. Many situations are sensitive even to the delays induced by the use of overnight carriers. On-site data recovery services, in which the data recovery technician and specialized equipment travel to the customer premises and perform the service locally, can reduce down-time, but at the added expense of transportation of the technician and the necessary equipment to and from the customer site.
There are remote control methods which allow a computer to be attached to a communications line via communications hardware so as to be controlled by an operator at a second computer, also attached to the communications line via communications hardware. Such hardware configurations are typical in personal computers, and such remote control software is readily available for common personal computer operating systems. Examples of such remote control programs include PCanywhere, Remote 2, Carbon Copy, etc. A drawback of this approach is that the computer being recovered must be running an operating system which supports 'he remote control software. Therefore, this approach is useless when the operating system does not support remote control.
A system and method for reliably allowing the remote recovery of data from computer storage media and devices by a remote technician is, therefore, an acute need in the art. The conventional prior art requires the computer storage media or device to be processed by a technician, either at the customer site or the technician's facility. Performance of data recovery services remotely, over a telephone link, has been successfully employed to overcome the shortcomings of on-site and off-site recovery, but requires that the target computer be able to load an operating system which supports the remote control software and allows access to the data which is desired to be recovered. Unfortunately, the circumstances leading to data loss can frequently also cause the normal operating system to be unstable or unusable. Accordingly, there is a particular need in the art for a method of providing remote data recovery capabilities even when the normal operating system is not necessarily loadable or dependable.
The present invention solves these problems and provides a method and apparatus for remote data recovery from computer data storage devices and/or media which is inaccessible by the normal operating environment and to a method for remote diagnosis and remote rectification of data loss.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a means to enable remote data recovery operations, including, but not limited to, those situations where the normal operating system is not operable.
One embodiment of the invention relates to a method of data recovery comprising the steps of:
establishing a communications link via communications hardware from a local computer having a storage device requiring recovery of data to a remote data recovery computer operated by a technician;
enabling the technician to interact with the local computer while having access to all data recovery programs which are resident at the remote data recovery computer; and
enabling the technician to diagnose and rectify the data loss of the storage device of the local computer.
In one embodiment, the principles of the present invention are achieved by implementing a bootable data recovery operating system which has sufficient functionality to allow communications via communications hardware to the remote technician. The remote technician is further equipped with specialized remote control software which allows communications with the computer running the bootable data recovery operating system via communications hardware. Once the computer under recovery and the remote computer are in communication, data recovery operations on the computer under recovery can proceed under complete control of the remote technician.
In the preferred embodiment, the remote data recovery operating system is sufficiently small to operate directly from its own distribution floppy disk, allowing data recovery operations to proceed in the absence of the normal bootable operating system. It is capable of loading data recovery utility software from either that same distribution floppy disk, or from the remote technician's comparatively vast library of such software, via the communications hardware.
In the preferred embodiment, upon loading, the bootable remote data recovery operating system presents a limited number of choices to the local user, allowing the user to input information regarding the nature of the user's data recovery needs and the user's personal data. Once this information has been input, the local user can confirm his intent to have the operating system establish contact with the remote technician via attached communications hardware. This contact can commence the data recovery operation immediately, or, alternatively, may queue the request such that the data recovery operation proceeds at such time as the data recovery technician has had time to review the request and prepare for the data recovery operation. Once the data recovery operation commences, all control of the local computer is released to the remote data recovery technician. The technician is then able to operate the local computer as though the technician were seated directly in front of it, having access to all data recovery utility software which is available at the technician's site, as well as any which might optionally reside on the data recovery operating system diskette.
In use, data recovery using one embodiment of the present invention might proceed by booting or loading the bootable remote data recovery operating program into the memory of the user's local computer. The remote data recovery operating program then determines the specific hardware configuration of the user's local computer. The remote data recovery operating program might then interrogate the user for his/her name, address, telephone number, etc. It might also interrogate the user for an explanation of the data recovery situation. The remote data recovery operating program then establishes an initial telephone link via communications hardware with the remote data recovery computer and downloads the information entered by the user in the above steps. If time allows, the technician at the remote data recovery computer then takes control of the user's computer via the remote link and begins the remote data recovery process. Otherwise, a later time might be agreed upon for the remote data recovery process. Accordingly, the remote link is terminated and then re-established at the agreed upon time, whereupon remote data recovery commences.
These and various other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the accompanying drawings and descriptive matter, which form a further part hereof, and in which there is illustrated and described a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings wherein corresponding reference numerals generally indicate corresponding parts throughout the several views;
FIG. 1 is a block diagram of an embodiment of an apparatus in accordance with the principles of the present invention;
FIG. 2 is a block diagram of another embodiment of an apparatus in accordance with the principles of the present invention;
FIG. 3 is a software hierarchy diagram of the local environment of an embodiment of the present invention;
FIG. 4 is a flow diagram of the local RDR application of an embodiment of the present invention;
FIG. 5 is a flow diagram of a portion of the local RDR application of an embodiment of the present invention which facilitates remotely controlled operation of the local computer;
FIG. 6 is a flow diagram of a portion of the local RDR application of an embodiment of the present invention which handles communications channel events;
FIG. 7 is a flow diagram of a portion of the local RDR application of an embodiment of the present invention which handles miscellaneous incoming data packets;
FIG. 8 is a flow diagram of a portion of the local RDR application of an embodiment of the present invention which sends outgoing communications data packets;
FIG. 9 is a flow diagram of a portion of the local RDR application of an embodiment of the present invention which intercepts and processes the native operating system API for file create/open/close functions;
FIG. 10 is a flow diagram of a portion of the local RDR application of an embodiment of the present invention which intercepts and processes the native operating system API for file read and write functions;
FIG. 11 is a flow diagram of a portion of the local RDR application of an embodiment of the present invention which intercepts and processes the native operating system API for display-screen read and write functions;
FIG. 12 is a flow diagram of the RDR Communications Server application of an embodiment of the present invention;
FIG. 13 is a flow diagram of a portion of the RDR Communications Server application of an embodiment of the present invention which facilitates negotiation of a callback time with the user of the local computer;
FIG. 14 is a flow diagram of a portion of the RDR Communications Server application of an embodiment of the present invention which downloads to, and causes the execution of the Data Recovery Diagnostic Application at the local computer;
FIG. 15 is a flow diagram of a portion of the RDR Communications Server application of an embodiment of the present invention which downloads a legal agreement to, and causes the execution of the Agreement Reader Application at the local computer;
FIG. 16 is a flow diagram of a portion of the RDR Communications Server application of an embodiment of the present invention which establishes a logical connection between the local computer and an appropriate RDR workstation, and maintains said logical connection;
FIG. 17 is a flow diagram of a portion of the RDR Communications Server application of an embodiment of the present invention which handles File Open/Create/Close request packets from the local computer;
FIG. 18 is a flow diagram of a portion of the RDR Communications Server application of an embodiment of the present invention which handles File Write request data packets from the local computer;
FIG. 19 is a flow diagram of a portion of the RDR Communications Server application of an embodiment of the present invention which handles miscellaneous request data packets from the local computer;
FIG. 20 is a flow diagram of the portion of the RDR Communications Server application of an embodiment of the present invention which handles TCP/IP messages from the RDR workstation computer;
FIG. 21 is a flow diagram of the RDR Workstation main application of an embodiment of the present invention;
FIG. 22 illustrates computer screens representing forms the user of the local computer may fill in to provide information regarding the identity of the user and the nature of the present data loss situation and the corresponding service desired;
FIG. 23 illustrates computer screens which provide information to the administrators of the Remote Data Recovery Facility in order to manage the communications server;
FIG. 24 illustrates computer screens which allow the user of the Remote Data Recovery Workstation to control and to monitor output from programs of the Remote Data Recovery local computer, and to control and to monitor the appearance of the actual screen of the Remote Data Recovery local computer;
FIG. 25 contains descriptive drawings of data structures utilized in an embodiment of the local Remote Data Recovery application;
FIG. 26 contains descriptive drawings of further data structures utilized in an embodiment of the local Remote Data Recovery application as well as descriptive drawings of data structures utilized in an embodiment of the Remote Data Recovery Communications Server application;
FIG. 27 is a flow diagram of the IO logic layer within the local RDR application 308 which implements the capability of "undoing" any modifications made to the local data storage device 26; and
FIG. 28 is a flow diagram of the application which manipulates the log-files to facilitate the abandonment of changes, the committing of the new data, and the potential restoration of original data.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, an embodiment of an apparatus and method for remote recovery of data is now described. Illustrated in FIG. 1 is a block diagram of an embodiment of the present invention. A local remote data recovery (RDR) computer 20, for which a data recovery procedure is needed, is illustrated as having a central processing unit (CPU) and memory 21 (typically arranged on a common system board), a local input device 22, a local display 24, a local storage device 26, and a removable media storage device 28. In addition, the local RDR computer 20 is shown as having a local communications hardware unit 30 for communicating with other computers, for example a modem or a network card. The local RDR computer 20 might be any IBM compatible system or other type of computer system commonly sold by various vendors such as GATEWAY 2000, IBM, APPLE, Hewlett Packard, Compaq, etc. In particular, the main system board of the local RDR computer 20 might have an INTEL CPU, such as a 38G, 486, or 586, or any other microprocessor along with suitable amount of random access memory (RAM). The local input device 22 might be any suitable type of user input device such as a keyboard, mouse, pointer, touch sensitive display screen, etc. More than one user input device 22 might be present. The local display 24 might be any suitable display device such as a visual display unit. The local storage device 26 might be internal or external and might take on varying technologies. The storage device might be a conventional hard drive such as of the Winchester technology, a laser disk, a CD-ROM, etc. The removable media storage device 28 might be a conventional floppy drive or any other suitable removable media drive. The local communications hardware unit 30 might be any conventional type of modem device such as a Hayes compatible modem, an ISDN modem, a wireless modem, or may alternatively be conventional local area network, wide area network or Internet (LAN/WAN/InterNet) connectivity hardware, such as a network card, etc.
An embodiment of a remote data recovery (RDR) workstation 40 for remote data recovery is shown in FIG. 1 having a CPU and associated memory 41, a remote input device 42, remote display 44, a remote storage device 46, and a remote removable media storage device 48. The RDR workstation 40 is also shown as having a remote communications hardware unit 50, such as a modem or network card. It will be appreciated that the RDR workstation 40 and its associated components might be the same as described for the local RDR computer 20 above. It will also be appreciated that the main communications channel 35 between the local RDR computer 20 and the RDR workstation 40 may be a telephone line or traditional LAN/WAN/InterNet connectivity communications channels.
Illustrated in FIG. 2 is yet another embodiment of a system in accordance with the principles of the present invention. In this embodiment, a plurality of RDR workstations 40 are interconnected by a local area network. In the embodiment shown, a file server 60 interconnects the RDR workstations 40 by way of a network 62, preferably a TCP/IP network. The file server 60 has data 64 stored on network shared drives 65 such that the data is accessible by the RDR workstations 40 and the Communications Server 68. The RDR workstations 40 are capable of communicating via the TCP/IP network 62 with the Communications Server 68 in such a fashion as to allow the establishment of one or more logical connections between a selected RDR workstation 40 and any arbitrary network communications hardware unit 69. The network communications hardware units 69 may be modems connected to outside telephone lines or may be network hardware connected to the LAN/WAN/InterNet, or the like. The network hardware communications units 69 communicate with local RDR computers 20 via a communications switch 70, such as a PBX. Accordingly, any one of the RDR workstations 40 may be used to recover data from a local RDR computer 20 over the communications channel 35 concurrently with multiple other RDR workstations 40 being used to recover data from different local RDR computers. This embodiment may be used to allow access to any one of a number of technicians to provide remote data recovery upon dialing a single number, or connecting to a single entity on the LAN/WAN/InterNet.
In the preferred embodiment, a remote data recovery operating program is provided to owners/purchasers of the local RDR computer 20 on a removable storage medium such as a floppy diskette. The program may be purchased at the time of purchasing a computer or, alternatively, purchased through retail outlets or mail order at a later date. It may, additionally, be provided through any number of electronic distribution mechanisms, including the BBS-like operational mode ("Guest Model") of the Communications Server 68 and its network communications hardware unit 69.
The programs thus provided by the remote data recovery operating program include sufficient functionality to allow operation of the local RDR computer 20 and communication via the local communications hardware unit 30 with the RDR workstation 40.
FIG. 3 describes the various software components which comprise the remote data recovery operating program. Various Data Recovery Application programs 300 operate to effect the data recovery and/or diagnostic processes. Such programs might include storage device functional diagnostic routines, storage media analysis routines, sector editors which work in hexadecimal, ASCII, or other formats relevant to the file system under recovery, file unerase routines, and filesystem integrity checking/repairing routines relevant to the file system under recovery. These Data Recovery Application programs 300 correlate in general terms to routines found in the NORTON UTILITIES® or Ontrack's ODR-N™ or DOSUTILS® software packages.
The Data Recovery Application DRA programs 300 interface with the local RDR application 308, through a set of application program interfaces (API's) 310 which interface direct with the basic input/output subsystem (BIOS) 360 and/or the Operating System 340. The local RDR application 308 effectively redirects, or "hooks" these API's in order to allow remote control operation of the DRA 300. Additionally, the local RDR application 308 offers private API's which allow "RDR aware" applications to interface directly with the communications subsystem 312 by providing a "pass through" to "hooked" BIOS functions 316 and OS functions 314. This permits "RDR aware" applications to bypass the redirection of functions, thus enabling an interface to the operator of the local RDR computer 20, as well as the control of the communications subsystem. The remainder of the local RDR application 308 contains communications subsystem code 318 and the local RDR application code 320. A flow diagram of the local RDR application code 320 is shown in FIG. 4.
The software components of such a system may include a Data Recovery Operating System (DROS) 306 as the local RDR computer operating system 340. The DROS 306 allows remote data recovery to occur when the local RDR computer's native operating system does not function. The DROS 306 includes routines necessary to support the local RDR application 308 and any desired data recovery application programs 300 used to perform the data recovery process. Examples of such necessary routines include memory management, file system access and management, application program loading and execution, and peripheral device control functions. These routines generally equate to several of the MS-DOS interrupt 21H functions. In order to allow the local RDR application 308 to operate in addition to any Data Recovery Application programs 300, the DROS 306 may directly emulate the native operating system's calling conventions and protocol. Additionally, a user command interpretation functionality which resembles the native command line interpreter may be provided. The local RDR application 308 may also be run using the native operating system as the local RDR computer operating system 340.
In the example of IBM Compatible Personal Computers, interface to the underlying hardware 380 is achieved through a common interface effected by the Basic Input/Output Subsystem, or BIOS, 360.
The flow diagram of FIG. 4 describes the operation of the local RDR application 308. Upon program entry at step 402, the Private API's 312, 314 and 316 are installed and appropriate Operating System and BIOS "hooks" are installed. This causes any subsequently loaded program to operate under remote control. At step 404, a menu is offered to the operator of the local RDR computer 20 which allows him to specify operation as a New User, a Pre-Registered User, or to Exit the local RDR application 308.
If the New User option is chosen, in step 410, routines are invoked which assess the hardware configuration of the local RDR computer. The user is then requested, at step 412, to fill in forms 2210 and 2220 with information regarding the user's identity, phone numbers, etc., as well as a description of the circumstances and nature of the data recovery situation. Upon completion of the forms, an attempt is made, in step 414, to dial and establish communication with the Remote Data Recovery Facility as a New User.
If the Pre-registered User option is chosen, an immediate attempt is made, in step 420, to dial and establish communication with the Remote Data Recovery Facility as a Pre-registered User.
If the attempt at connecting to the Remote Data Recovery Facility is determined to be unsuccessful, at step 430, a dialog indicating the failed connection is presented, in step 440, to the operator of the local computer, and control is returned to the menu.
If the connection to the Remote Data Recovery Facility is determined to be successful, at step 430, remote controlled activity, under the complete direction of the remote site, is handled according to the logic described hereinbelow, in step 450. When complete, the communications session is terminated, in step 460, and the communications hardware is instructed to terminate the communications session.
If the EXIT option is selected, the local RDR application 308 removes the Private API's 312, 314 and 316 and the previously installed Operating System and BIOS "hooks", at step 406.
FIG. 5 is a flow diagram of the portion of the local RDR application 308 which executes during remote control operation. Following the initialization, in step 504, of critical data structures which govern communications packet reception and file redirection control, the local RDR application 308 enters a loop, steps 510-550. This loop continually handles all communications events, in step 510, and dispatches any commands which may have been sent from the Remote Data Recovery Facility. Once it has been determined, in step 520, that a complete remote command has been received from the Remote Data Recovery Facility, and stored in the local keyboard buffer, the remote command is screened, in step 540, to see if it is a command to hang-up. If a hang-up command has been received, then the routine exits, step 560. If the command is not a hang-up command, as determined by step 540, then the command is passed to the operating system's native command line interpreter, in step 550. Note that the local keyboard buffer is filled by a command originating at the remote input device 42, preferably a keyboard. If it has been determined, at step 520, that there is not a complete command in the local keyboard buffer, then an inactivity timeout detects communication failure, at step 530, and causes an appropriate exit at step 560. The corresponding activity directed by the remote site is described in reference to FIG. 12.
The flow diagram shown in FIG. 6 describes the communication event handler within the local RDR application 308. The communication event handler is called from a multitude of points within the local hooks, for instance step 450, and several of the Operating System and BIOS hooks. The intent of the communication event handler is to service the communications driver, and dispatch any incoming packets, steps 602 through 630. After initiation of the communication event handler, at step 600, the routine determines if any new characters have been received, at step 602. If characters have been received, then the characters are placed in the receive buffer, at step 605, and then a check is made to see if there are any complete data packets in the receive buffer, at step 610. If there are any complete packets in the receive buffer, then these completely formed packets are compared to a list of packet receive control structures 2610. The list is maintained as a singly linked list via the pointer link field 2612. The list is searched to find a matching packet receive control structure. If the type field of the packet matches the packet type number field 2614 of the packet receive control structure 2610, then the packet counter field 2616 is incremented and the routine pointed to by the packet handler routine pointer field 2618 is called. A number of packet handling routines are illustrated in FIG. 7, including file create/open or close ACK packet, step 700, file write-request-list packet, step 710, echo acknowledgment, step 720, screen change acknowledgment, step 730, display data packet, step 740, keystroke packet, step 750, file read packet, step 760, and echo requests, step 770. If, however, the packet received does not match, as determined at step 620, then the packet is ignored, at step 630, and the routine returns to searching for complete packets in the receive buffer, at step 610. If no new characters are received at step 602, then a call is made, at step 650, to ensure that any screen updates which may have occurred but were not able to be sent previously are given the opportunity to reach the transmission queue. Additionally, a determination is made, in step 655, to see if there are any outgoing packets in the transmit queue. If there are, and if there is space available in the transmit buffer, as determined at step 660, then the outgoing packet is appended to the communications driver's transmission buffer, at step 670. The transmission queue is implemented by a singly linked list of outgoing packet descriptors as shown at 2510 of FIG. 25. Each packet descriptor contains a link 2511 to the next element of the list, followed by a collection of fragment length 2512 and fragment pointer 2514 pairs. Each pair describes a region of memory which would comprise the packet to be formed and transmitted. The collection of pairs is terminated by an entry with a length field of zero as shown at 2516. The packets themselves are formed using this "gather write" principle, and, incorporating whatever other encoding, framing, and error control methods as may be deemed appropriate by the implementor prior to placing the data in the transmit buffer at step 670.
FIG. 7 contains flow diagrams representing the behavior of the local RDR application 308 as it handles various packet types.
File Create Acknowledgment, File Open Acknowledgment, and File Close Acknowledgment packets are received at step 700 in response to those packets which were sent requesting the File Create/Open/Close action to occur at the Remote Data Recovery Facility. These File Create/Open/Close Acknowledgment packets are handled at step 702 by merely updating the appropriate file control structure 2520 to reflect the fact that the request has been acknowledged, and to post the status of the File Create/Open/Close operation. This allows the File Create/Open/Close operation which is being acknowledged to proceed.
File Write Request List packets are received, at step 710, in response to an initial File Write request. These File Write Request List packets contain a list of those file segments which the Remote Data Recovery Communications Server is prepared to receive. File Write Request list packets are handled by updating, at step 712, the file control structure 2520 to reflect the new request list, and subsequently sending file write data packets, at step 714, per the updated file control structure 2520. Additionally, updating the file control structure 2520 resets the timeout, at step 716. The file read and write hooks are described further with reference to FIG- 10.
Echo Acknowledgment packets are received, at step 720, as a response to an Echo Request. This echo mechanism is provided for communications diagnostic capabilities. Echo Acknowledgment packets are handled by copying the data content to a dedicated echo buffer, in step 722, such that the program can subsequently further analyze the echo data.
Screen Change Acknowledgment packets are received, at step 730, in response to Screen Change Packets. Screen Change Acknowledgment packets are handled by marking the screen change as no longer being in transit, at step 732.
Display Data Packets are received, at step 740, as instructions to place text on the local RDR computer monitor 24. Display Data Packets are handled by copying the packet data to the local display 24, at step 742, and then sending a Display Data Acknowledgment packet, at step 744, to notify the Remote Data Recovery Communications Server that the packet was successfully received and rendered on the local display 24.
Keystroke Packets are received, at step 750, as keystrokes occur at the RDR workstation 40, and are forwarded through the RDR Communications Server 68. Keystroke Packets are handled by copying the packet keystroke information, at step 752, into the local keyboard buffer. This allows the local RDR application 308 to asynchronously retrieve these keystrokes and interpret them as desired. A Keystroke Acknowledgment packet is then returned, at step 754, after the keystrokes are stored in the local keyboard buffer for subsequent interpretation by the operating system or application programs in the local RDR computer 20.
File Read Data packets are received, at step 760, in response to a File Read Request List packet. File Read Data packets contain actual remote file data segments which have been read and forwarded by the RDR Communications Server 68. File Read Data packets are handled by checking, at step 762, to see if the file segment is the expected segment number in sequence. If not, a revised Read Request List packet is sent, at step 766. If the incoming packet contained the expected sequential segment number as detected at step 762, then the file data is copied to the data buffer, at step 764.
Echo Request Packets are received, at step 770, as a communications diagnostic request. Such an Echo Request Packet is responded to by copying packet data, at step 772, from the Echo Request Packet, and sending an Echo Reply packet, at step 774.
FIG. 8 is a flow diagram of the communications packet send routine within the local RDR application 308. The routine starts by placing the packet for transmission into the transmit queue, at step 810. If the local RDR application 308 calling this routine 800 has requested that this routine 800 not wait for an acknowledgment (ACK), as determined at step 830, then the routine makes a call, at step 835, to the communications event handler, at step 600, to ensure that the packet has an opportunity to be transmitted, then exits with successful status, at step 890. If the local RDR application 308 has requested that this routine should wait for an acknowledgment (ACK), as determined at step 830, a loop is entered which handles communications events until either an ACK occurs, at step 850, leading to a successful exit at step 890, or until a timeout condition is determined at step 860. In the case of a timeout condition, the sequence of transmitting the packet and waiting for an acknowledgment is retried a limited number of times, as determined by step 870. A failure after the retry count is exhausted results in a failure status exit, at step 880.
FIG. 9 is a flow diagram of the File Create/Open/ Close interceptor, or "hook" within the local RDR application 308. This procedure is installed to preempt an attempt by the application to create, open, or close any arbitrary file. The behavior of this hook is first to determine if the file is a remote or local file, at step 910. This is performed during file open/create operations by examining the file-name supplied by the caller of this routine, be it the local RDR application 308 or a Data Recovery Application 300, utilizing any arbitrary convention for naming remote files which can easily distinguish them from local files, and is performed during file close operations by examining the file-handle supplied by the local RDR application 308. If the file is determined to be local by the test, at step 910, execution is transferred to the system's native file create/open/close procedure, at step 912. If the file is determined to be remote, at step 910, an appropriate file create request, file open request, or file close request packet is constructed, at step 920. This packet is then sent, and an acknowledge is waited for, at step 930. The acknowledgment received back reflects the status of the request at the remote end, which affects the content of the file control structure 2520, at step 940. The status is then returned to the operator of the local RDR computer 20 as per the native system's file create/open/close conventions. In the case of remote file create and/or open activities, a file handle is be returned to the caller which is easily distinguishable from any file handle which may have legitimately been returned from the system's native file create or open process. This allows future read/write/ close operations to distinguish local files from remote files.
FIG. 10 is a flow diagram of the File Read and Write interceptor, or "hook" within the local RDR application 308. This procedure is installed to preempt any application attempt to read or write any arbitrary file. The behavior of this hook is first to determine if the file is a remote or local file, at step 1010. This is performed by examining the file-handle supplied by the caller of this routine, be it the local RDR application 308 or a Data Recovery Application 300. If the file is determined by the test to be local, at step 1010, execution is transferred to the system's native file read or write procedure, at step 1012. If the file is determined to be remote, then the file control structure 2520 is updated to reflect the nature of the request at step 1020. Based on the content of the file control structure 2520, an appropriate file read-request or write-request packet is constructed and sent at step 1030. A loop is then entered, at step 1040, which continues handling communications events, step 600, and tests whether the read or write request is completely satisfied at step 1050. If the request has been satisfied, then a successful status is returned to its caller, at step 1090, per the native system's file read/write conventions. If the request is not complete, as determined at step 1050, timeout conditions are monitored at step 1060. If no timeout has occurred, then the routine continues to handle communications, at step 1040, and to monitor for completed requests, at step 1050. If a timeout occurs, at step 1060, then the request is resent, at step 1030 for a limited number of retries. If the retry count becomes exhausted, at step 1020, then the request returns failure status, step 1080, per the native system's file read/write conventions.
The flow diagram for the "hooks" of display screen write and read functions of the local RDR application 308 is shown in FIG. 11. The mechanism suggested intends to record and transmit screen changes to the remote site in a timely fashion with minimal impact on program execution. The screen write function is implemented by first copying the desired screen write information into an internal buffer, at step 1110, which entirely describes the state of the display screen. The purpose of this buffer is to facilitate the screen read hook, at step 1170, as well as to provide the source for screen update packets as they are formed and transmitted. The preferred embodiment utilizes a screen line change descriptor data structure for each line of characters in the local RDR computer display 24. These screen line change descriptors, shown in FIG. 25 at 2560 describe, for each associated line of characters, the range of columns for which characters have been modified by application programs and those modified characters have not yet been placed in the queue for transmission. This range of modified but unsent columns are referred to as the "dirty" range for that line, and are described by the screen line change descriptors 2560 by entries which mark the first (left-most) dirty column 2562 and the last (right-most) dirty column 2564 for each screen line. Following the copying of the new screen characters to the internal buffer, at step 1110, the screen line change descriptors for each affected display line will be modified to ensure that the "dirty" range includes these newly written columns. A call is then made at 1130 to place any unsent screen changes in the transmission queue 2510 for subsequent transmission to the RDR workstation 40.
Attempts to send screen change descriptions to the remote site are described in 1170-1178. If screen change descriptions are presently being sent and are unacknowledged, for example because they are in transit, as determined at step 1172, then no attempt is made to send screen change information at this time. If there exist no current screen change descriptions representing unsent screen changes, determined at step 1174, then no action is taken. If the previous conditions are not met, then the next screen line change descriptor describing a non-zero dirty range is utilized to add an entry at 1178 into the transmission queue which will send the associated dirty screen content from the internal screen buffer. The screen change is now "in-transit", and the associated screen line change descriptor can be cleared. When a subsequent acknowledgment of this screen line change packet is received, the screen change is considered no longer to be "in transit", per step 730. Should a timeout occur without acknowledgment, the screen line change description will be re-transmitted.
The display screen read function hook is implemented by copying the desired information to the local RDR computer's buffer directly from the internal screen rendition buffer, at step 1180.
The main application which implements the RDR Communications Server application in an embodiment of the present invention is described in the flow diagram of FIG. 12. Typically, an application thread for each network communications hardware unit 69 is started which executes steps 1210 through 1280. Upon receipt of an incoming phone call, an ASCII prompt is transmitted, requesting the operator of the local RDR computer 20 to supply the desired service type, at step 1210. This allows use of the Remote Data Recovery Communications Server by traditional "dumb" terminal applications as well as by highly automated call transactions from the local RDR application 308.
In a typical situation where the RDR Communications Server application is called by an arbitrary user with a dumb terminal, the user can respond to the prompt, set at step 1210 as a "guest". This causes the RDR Communications Server application to behave as a classic bulletin board service, with functionality limited only by the creativity of the programmer and the abilities of the local operators terminal application. The usefulness of this "guest" category of service is that it may be used to promote the organization's services/products, in the manner of a classic BBS. Further, it may be used as a download facility to allow the distribution of the local RDR application 308 and associated programs.
Once the local RDR application programs are in the possession of the local user, the local user may install and utilize the applications to access the "new user" category of service from the RDR Communications Server application. The local RDR application 308 is knowledgeable of the prompt set at step 1210 and responses which are expected by the RDR Communications Server application, and are described in FIG. 4.
At step 1225, the RDR Communications Server application determines whether the local RDR application 308 requests the "new user" category of service, at step 404. The files which were produced at the local site describing the hardware configuration, the user information, and the problem description, in steps 410, and 412, are copied to the Remote Data Recovery Facility for further analysis and addition to a registered user database, in step 1230. If it is determined that it is not feasible to proceed with Remote Data Recovery at the present time, at step 1234, a menu is presented and a time to proceed with the Remote Data Recovery process is negotiated, at step 1238.
At such a time that a previously negotiated RDR procedure were to commence, the local RDR application 308 requests the "pre-registered user" category of service from the RDR Communications Server application at step 1235. Such calls are then authenticated against the registered user database, at step 1240. Non-authentic calls are terminated. As individual communications connections are established, and progress through the various stages illustrated in FIG. 12, the state of progress may be described on the operator's console of the Communications Server 68 in a Communication Channel Status window 2310, for example as is shown in FIG. 23.
If the "new user" service was permitted to proceed with the RDR procedure immediately, in step 1234, or alternatively, upon successful authentication of a pre-registered user, in step 1240, an RDR diagnostic process is performed in step 1250. The diagnostic process is described in detail in reference to FIG. 14. A custom legal agreement describing the terms of any proposed data recovery service is produced and then offered to the operator of the local RDR computer 20, in step 1260. The transmission and prosecution of the legal agreement is described in detail in FIG. 15. Should the operator of the local RDR computer 20 agree to the terms of the agreement, as determined at step 1270, then the Remote Data Recovery procedure is performed, in step 1280. The Remote Data Recovery procedure is described in detail in reference to FIG. 16.
The flow diagram of FIG. 13 describes the portion of the RDR Communications Server application which is invoked if, for whatever reason, it was determined that the data recovery process should take place after the initial registration phone call, at step 1234. A file which maintains the schedule and resides on the Network Shared Data Storage 64 of the File Server 60 is read at step 1310. This file is then processed at step 1320 with the needs of this particular data recovery situation at hand, to determine a list of appropriate schedule times for processing the RDR process. Such factors as estimated time to perform the recovery, specific technician availability and other prioritization factors may be used to produce this customized list of appropriate times for providing the Remote Data Recovery Service. An application is activated at the local computer, at step 1330, which then enables viewing the customized schedule list, and, optionally selecting a mutually agreeable time for proceeding with the Remote Data Recovery. If such a time is chosen in step 1340, it is added to the schedule file, at step 1350. If no such time was chosen, at step 1340, a description of further options is presented to the operator of the local RDR computer 20, at step 1360. The options presented in step 1360 may include sending the equipment in to the Remote Data Recovery Facility for traditional off-site recovery, or, requesting on-site category data recovery services.
FIG. 14 is a flow diagram of that portion of the Remote Data Recovery Communications Server which facilitates performance of the Data Recovery Diagnostic. A check is first made, in step 1410, to see if a valid copy of the current version of the diagnostic application exists on the distribution media at the local site. If a valid copy of this diagnostic application does not exist or there is no appropriate version of the diagnostic application, an appropriate version of the diagnostic application is downloaded to the local site, at step 1420. Subsequently, or, if the appropriate diagnostic application was determined to exist in step 1410, the diagnostic application is activated at the local computer, in step 1430. The diagnostic application performs diagnosis of the data recovery situation and places results in a file at the Communications Server 68, in step 1440, for further analysis by the remote technician and/or other applications at the Remote Data Recovery Facility.
FIG. 15 is a flow diagram of the portion of the Remote Data Recovery Communications Hardware application which facilitates the presentation, and optional acceptance by the operator of the local RDR computer 20, of a legal agreement. First, a check is made, in step 1510, to see if a valid copy of the current version of the legal agreement exists on the distribution media at the user site. If the legal agreement does not exist or it is not an appropriate version, an appropriate version of the legal agreement is downloaded to the local site, at step 1520. Following downloading 1520, or, a determination that the appropriate legal agreement is in place at step 1510, the current date and time are noted, at step 1530. An Agreement Reader application is then activated at the local RDR computer 20, at step 1540. The Agreement Reader application allows the operator of the local RDR computer 20 to inspect the legal agreement, and optionally accept the terms included therein. The accept/decline response made by the operator, and the current date and time are again noted, at step 1550. Having accurate knowledge of the date and time of agreement presentation and agreement acceptance may be relevant factors in resolving any possible disputes which may arise regarding contested agreements.
FIG. 16 is a flow diagram of the portion of the Remote Data Recovery Communications Server application which performs the Remote Data Recovery. This process is accomplished by enabling the technician, operating an RDR workstation 40, to remotely control the local RDR computer 20. A logical connection is formed, at step 1610, via TCP/IP with an arbitrary RDR workstation 40 which is available to perform a Remote Data Recovery procedure. Additionally, a unique subdirectory for this session of Remote Data Recovery is created, at step 1620, on the Network Shared Data Storage 64 of the File Server 60. This unique subdirectory is the repository for any session-unique files created by the operator of the local RDR computer 20, as well as any log files which the RDR Communications Server application or the RDR workstation 40 may wish to create. A loop, steps 1640-1660, is then entered which processes any communications packets from the local RDR computer 20, at step 1640, as well as any TCP/IP messages from the RDR workstation 40, at step 1650. If no "hang-up" message is determined to have been received from the RDR workstation 40, in step 1660, then the loop persists. Eventually, the RDR workstation operator causes a "hang-up" message to be sent which breaks the loop, at step 1660, and causes a "HANG-UP" command to be forwarded to the local RDR computer 20, at step 1670.
FIG. 17 is a flow diagram of the portion of the RDR Communications Server application which responds to packets arriving from the local RDR computer 20 over the network communications hardware unit 69 which request a remote file to be opened, created, or closed. The packet contains a file index which ranges from 0 to the maximum number of concurrently open files, and a sequence number which is utilized to distinguish this request as a unique use of the file index. It is therefore possible to utilize the combination of file index and sequence number to determine if this is a unique request, or if this is a retry of a request for which the acknowledgment was lost due to an error in the communications channel 35. If it is determined that this is not a repeat of a prior request, at step 1710, the file is opened/created/closed per the remainder of the packet, at step 1720. If the request is indeed a repeat request, as determined at step 1710, then the file actual open/create/close is bypassed. If the open/create/close request is not successful, as determined at step 1730, a Failure Acknowledgment is transmitted, at step 1760. Alternatively, if the determination, at step 1730, is that the open/create/close request was successful, then the File Connection Data Structures are initialized within the Remote Data Recovery Communications Server, at step 1740, per the open/create/close request packet and then a Successful Acknowledgment is sent, at step 1750.
FIG. 18 is a flow diagram of the portion of the RDR Communications Server application which responds to those packets arriving from the local RDR computer 20 over the network communications hardware unit 69 which request File Write activity. The first packet received is a Write File Initialization Packet, which is checked against the sequence number of the last activity on the file to see if it is a retry of a previously received request, at step 1810. If it is determined that this is not a retry, at step 1810, initialization, including allocation of memory for the activity as well as preparation of the initial file control structure 2620 is performed, at step 1850. If it is determined not to be a retry, at step 1810, then initialization has already been performed but the acknowledgment was lost due to communications errors, and so the initialization is skipped. In either case, flow proceeds to point A of FIG. 18, which is the beginning of the algorithm which determines how to respond to a File Write Packet. A test is made, at step 1860, to determine if all write data has been received to satisfy the entire Write File Initialization Packet. If all data has been received, any data which remains in memory buffers is actually written to the file, at step 1865. The memory which was allocated at step 1850 is now de-allocated at step 1870, and a null request list is sent at step 1880 to indicate that the file write is complete. If, during the test at step 1860, it was determined that there was more file data to be received, an appropriate write request list packet is formulated and sent at step 1890. This request-list requests those file data segments for which data has not yet been received and for which there is available buffer space which currently does not contain any unwritten data.
As File Write Data packets arrive in response to File Write Data Request packets, a decision is made, at step 1815, as to whether this is a retry or not, based on the sequence number in the packet. If it is a retry, then processing continues at Point A. If it is determined not to be a retry, then the packet data is copied, at step 1820, to the buffer which was allocated at step 1850. If the segment number is determined not to be in the appropriate sequence, at step 1825, then the request-list is adjusted, at step 1845, to cause a re-request of any segment(s) which was/were not received. If the segment is determined to be in sequence, at step 1825, as is the case in the absence of communications errors, a test is made, at step 1830, to see if file write activity is currently taking place. If there is no file write activity, then a file write is initiated, at step 1835, of any data buffers which contain unwritten file data. The request-list is then adjusted, at step 1840, to take into account those file segments received thus far, as well as any file data buffers which are now free to receive more data. Processing then continues at Point A.
FIG. 19 describes various packet handlers which exist in the embodiment of the RDR Communications Server application. Echo Request packets are handled, in the routine commencing at step 1900, by sending an Echo Acknowledgment packet, at step 1902, which-contains a copy of any optional Echo Data which was in the original Echo Request packet. File Read Request List packets contain a list of segments of the file for which the local user is ready to receive data. These File Read Request List packets are handled by the routine starting at step 1910, by performing the actual read, at step 1920, and then sending the data, at step 1930, in the form of File Read Data packets. Screen Change Packets, handled by the routine starting at step 1939, are tested, at step 1940, to see if they are retries of a packet already processed. This test, as with many other packets, is performed by virtue of the sequence number contained within the packet. If the packet is determined not to be a retry, at step 1940, it is then processed, at step 1950, by forwarding to the Remote Data Recovery Workstation via a TCP/IP connection. Following this action, or, if the packet was determined to be a retry, a Screen Change Acknowledgment packet is sent, at step 1960, to the local RDR computer 20.
FIG. 20 is a flow diagram representing a thread of execution, steps 2002-2008, which operates continuously within the RDR Communications Server Application for monitoring Remote Data Recovery Workstation connections, and a thread of execution which continuously handles messages from RDR workstations 40 while they are actively involved in remote data recovery operations.
The connection monitor thread, steps 2002-2008, monitors a TCP/IP port which is known to all RDR workstations 40 on the system. The RDR Communications Server application waits, at step 2002, for any RDR workstation 40 to establish a TCP/IP connection. Therefore, any RDR workstation 40 which activates its RDR workstation application, discussed later in reference to FIG. 21, establishes a logical connection via this port. Once a TCP/IP connection is established on this port, another thread of execution is spawned, at step 2006, which handles messages from the RDR workstation 40. The RDR workstation 40 thus connected is noted, at step 2008, as being capable of processing remote data recovery service. Those RDR workstation connections so noted at step 2008 may be described on the operator's console of the Communications Server 68 in a Workstation Status window 2320 as shown in FIG. 23.
The thread, steps 2010-2075, which is spawned, at step 2006, as a result of the TCP/IP connection, is responsible for handling all TCP/IP messages sent by the RDR workstation 40. A separate thread of this sort exists within the RDR Communications Server application for all RDR workstations 40 which are currently established as potential providers of remote data recovery service. These threads begin receiving messages as the operator of the RDR workstation 40 performs activity in the performance of remote data recovery.
Specific TCP/IP messages are generally handled by forwarding these messages to the local RDR computer 20 via various packets over the communications hardware. TCP/IP messages which represent keystrokes are detected, at step 2020, and forwarded, at step 2025, to the local RDR computer 20 as Keystroke packets. TCP/IP messages which represent Display Messages are detected, at step 2030, and a forwarded, at step 2035, to the local RDR computer 20 as Display Data packets. Similarly, a "HANG-UP" TCP/IP message is detected, at step 2040, and forwarded, at step 2045, to cause the local RDR computer 20 to hang-up the telephone connection. The remaining TCP/IP message type is the "LOGOUT" message, which occurs as the result of the RDR Workstation operator exiting the RDR Workstation application. When the "LOGOUT" message is detected, at step 2050, it causes the RDR Communications Server application to note, at step 2075, that this RDR workstation 40 is no longer ready to process remote data recovery services. The TCP/IP connection is then closed and this thread of execution terminates, at step 2080.
FIG. 21 is a flow diagram representing the overall operation of the application which controls the RDR workstation 40. Upon invocation of the RDR workstation application, at step 2100, a logical connection is established, at step 2110, with a RDR Communications Server application via a pre-determined, fixed TCP/IP port on the RDR Communications Server 68. A loop, steps 2115-2120, is then entered which waits until either the Workstation Operator requests that the application be exited, at step 2115, or, a TCP/IP message arrives, at step 2120, from the RDR Communications Server application requesting the start of a Remote Data Recovery session. The Communications Server 68 issues a TCP/IP request to start a Remote Data Recovery session at step 1610. This request 1610 is detected by the RDR workstation 40, at step 2120, and a collection of windows 2410, 2420 and controls 2430, 2440 are drawn on the RDR workstation console 44, as illustrated in FIG. 24.
The macro control buttons 2430 are provided to allow a "macro" capability, such that activation of any individual button issues the equivalent of multiple, pre-configured keystrokes. The status control buttons 2440 are provided to allow the capability of specifying status messages for display on the RDR local computer console 24.
At step 2130, any screen update messages which have been sent by the local RDR computer 20 at step 1170, subsequently forwarded by the Communications Server 68 at step 1950 and received via TCP/IP are rendered on window 2410. Thus, window 2410 shows all screen activity performed by those Data Recovery Application Programs 300 operating at the local RDR computer 20.
At step 2135, any keystrokes from the RDR workstation keyboard 42 are sent via TCP/IP to the Communications Server 68 for forwarding 2020, 2025 to the local RDR computer 20 as keystroke packets. These keystroke packets are received by the local RDR computer 20 as shown at steps 750 and 755 in FIG. 7, thus allowing the operator of the RDR workstation 40 to control the Data Recovery Application Programs 300 operating at the local RDR computer 20.
At step 2140 any Display Data messages which were specified via the activation of control buttons 2440 are sent via TCP/IP to the Communications Server 68 for forwarding 2030, 2035 to the local RDR computer 20 as Display Data packets. The local RDR computer 20 handles these packets by copying them to the local-screen at step 742. Additionally at step 2140, these Display Data messages are rendered on the window 2420, such that the window 2420 maintains an accurate representation of the appearance of the local RDR computer console 24.
When, at step 2150, it is determined that the session is complete, a "HANG-UP" message is sent to the communications server 68 and the windows 2410 and 2420 and controls 2430 and 2440 are cleared, at step 2155.
FIG. 22 contains depictions of computer screens representing forms displayed on the local display 24 which the user of the local RDR computer 20 may fill in to provide information regarding the identity of the user, the nature of the present data loss situation and the corresponding service desired. User identification and other relevant information is ascertained by the form 2210. Information relevant to the proper diagnosis of the data loss and relevant to describing the desired service is ascertained by the user filling out form 2220.
FIG. 23 contains depictions of computer screens displayed by the communications server application which provide the administrators of the Remote Data Recovery Facility to manage the communications server 68. A Communication Channel Status Window 2310 is provided to facilitate monitoring of the status of each configured LAN communication channel 66. Each LAN communication channel 66 may be in a waiting mode, a guest mode, a new user mode, an active data recovery mode, or may be off-line. Additional controls may be provided to facilitate maintenance and configuration of individual LAN communication channels 66 or the communications server 68 as a whole. Additionally, a Workstation Status Window 2320 is provided to allow monitoring of those Remote Data Recovery Workstations 40 which have established TCP/IP connections to the Communications Server 68, and an indication as to the current activity being performed at those Remote Data Recovery Workstations 40.
FIG. 24 contains depictions of computer screens which can be displayed on the RDR workstation display 44. These screens allow the user of the RDR workstation 40 to control and to monitor output from programs of the local RDR computer 20, and to control and to monitor the appearance of the actual screen of the local RDR computer display 24. The Local Program Output window 2410 is a display of the output of all RDR applications 300. This output enables the operator of the RDR workstation 40 to monitor the applications running on the local RDR computer 20. The macro control buttons 2430 provide methods for the operator of the RDR workstation 40 to send frequently-used keystroke sequences to the local RDR computer 20. Use of the status control buttons 2440 allows the operator of the RDR workstation 40 to cause pre-configured or custom status messages to be displayed on the local RDR computer display 24. The Actual Local Display window 2420 then is a display which follows the content of the local RDR computer display 24. This allows the operator of the RDR workstation 40 to remain aware of the status messages which have been displayed.
FIG. 25 contains descriptive drawings of data structures utilized in an embodiment of the local RDR application 300. Diagram 2510 describes an Outgoing Packet Descriptor (OPD) data structure. This OPD 2510, and any OPD's which are linked via the link list pointer 2511, comprise the transmission queue within the Communications subsystem code 318 of the local RDR application 308. The remainder of the data structure consists of pairs of Fragment Length fields 2512 and Fragment Pointer fields 2514. Any number of such pairs of Fragment Length fields 2512 and Fragment Pointer fields 2514 may exist, until a pair with a zero Fragment Length field is encountered 2516, which terminates the list of pairs. Each pair describes a region of memory which comprises a portion of the outgoing packet. This is a classical "gather-write" approach which allows the collection of various portions of the outgoing packet to be collected from widely separated regions of memory.
Diagram 2520 illustrates a local File Control Structure (local FCS). One such local FCS 2520 exists for every potentially concurrent instance of an open remote file within the Local Remote Data Recovery application 308. Further insight into the use of this data structure can be gained by referencing the flow diagrams of FIGS. 7, 9, and 10 as well as the detailed descriptions associated with those flow diagrams. The local FCS 2520 contains a Status Field 2522 which represents the current state of the file, as currently open, currently closed, or in some intermediate state as communications occur. The Sequence Number Field 2524 is altered prior to the initial communications for every remote file read, write, open, create, or close attempt. As such, the Remote Data Recovery Communications Server 68 can determine whether such requests are new requests or retries of requests for which the response was lost due to a communications error. Retries are counted on a per-request basis with the Retry Count Field 2526, such that a limited number of retries can be attempted before an operation is aborted. The Current File Pointer field 2528 is utilized to maintain a record of the offset in the file as used for stream operations. In order to protect against requests or acknowledgments which are lost due to communications errors, a Time Out Field 2530 exists to allow determination of whether sufficient real time has elapsed between the request and any response to that request. Whenever sufficient time has elapsed, it is then assumed that either the request or the response to that request has been lost.
During file read operations, a Read Request List packet is sent to request those file segments which are desired but not yet received. Files are transferred on the basis of quantum units called segments, the segment being a fixed size sequential fragment of the file. Any file data transfer packet contains at most one segment. The fixed size of the segment is predetermined by the programmer, and is based on comnputational convenience, file system performance, and in consideration of the resulting packet size. The Request List is created with an initial segment value equal to the Next Segment To Be Received 2532, and requests as many sequential segments as possible without overrunning the Total Segments Left to Receive Field 2534. Any segments which are received out of sequence are discarded and immediately cause a revised Read Request List to be created and placed in the transmission queue at step 766 of FIG. 7. Also, any timeout condition causes a revised Read Request List to be created and placed in the transmission queue at step 1030 of FIG. 10.
During file write operations, a Write Initialization packet is sent, the Write Initialization packet including a starting segment number and a total byte count. This packet allows the Communications Server 68 to request file segments as the Communications Server's buffering and I/O subsystems becomes ready to receive file segments. The Communications Server 68 makes such requests for file segments by sending File Write Request List packets, which are processed at step 712 of FIG. 7. The data structure fields First Segment Requested 2536 and Segment Count Requested 2538 are taken directly from the File Write Request List packet. File Write Data packet(s) are then placed in the transmission queue. The Next Segment To Send field 2540 is utilized to determine which file segment to start placing in the queue. As long as the Next Segment To Send is within the range described by the First Segment Requested and the Segment Count Requested it is assumed that any difference between Next Segment To Send 2540 and First Segment Requested 2536 is due to packets which are in transit. Receipt of a File Write Request List packet with a null request is interpreted as successful completion of the file write operation.
Diagram 2560 describes Screen Line Change Descriptor (SLCD) data structures used to keep track of which portions of the virtual screen written to by RDR applications 300 have not yet been successfully transmitted to the RDR Communications Server 68. There exists within the SLCD a pair of fields, the First Dirty Column 2562 and the Last Dirty Column 2564, for each line of characters on the screen. This pair of fields describes the inclusive range of columns which contain modified but as yet untransmitted data.
FIG. 26 contains descriptive drawings of further data structures utilized in an embodiment of the local RDR application 308 as well as descriptive drawings of data structures utilized in an embodiment of the RDR Communications Server application.
The data structure described in FIG. 26 at 2610 is the Packet Receive Control (PRC) structure. The PRC is utilized by the RDR local application 308 to decode incoming packets, maintain statistics, and transfer control to the routines of FIG. 7, which are responsible for handling each specific type of incoming packet. The Pointer Link to Next Packet Receive Structure field 2612 is utilized to maintain a collection of such structures in a classic singly linked list. The Packet Type Number field 2614 is matched against the type field of incoming packets, and determines whether this packet should be handled in accordance with this PRC or a subsequent PRC. If the Packet Type Number field is equal to the type field of the incoming packet, the Packet Counter field 2616 is incremented to maintain statistics, and the software routine pointed to by the Pointer to Packet Handler Routine field 2618 is called to handle the processing of the incoming packet.
The data structure 2620 is the File Control Structure (FCS) as utilized within the RDR Communications Server 68. One Server FCS 2620 exists for every potentially concurrent instance of an open remote file within the RDR Communications Server application. Further insight into the use of this data structure can be gained by referencing the flow diagrams of FIGS. 18 and 19 as well as the detailed descriptions associated with those flow diagrams. The Server FCS 2620 contains a Status Field 2622 which represents the current state of the file, as currently open, currently closed, or in some intermediate state as communications occur. The Last Sequence Number Field 2624 is checked on every remote file read, write, open, create, or close attempt. As such, the RDR Communications Server application can determine whether such requests are new requests or retries of requests for which the response was lost due to communications error. Retries are counted on a per-request basis with the Retry Count Field 2626, such that a limited number of retries can be attempted before an operation is aborted. In order to protect against requests or acknowledgments which are lost due to communications errors, a Time Out Field 2630 exists to allow determination of whether sufficient real time has elapsed between the request and any response to that request. Whenever sufficient time has elapsed, it is then assumed that either the request or the response to that request has been lost. As files are created, or opened, the Actual File Handle field 2636 is used to hold the actual file handle utilized by the system for referencing this file in future read, write, or close requests.
During file read operations, Read Request List packets are responded to by merely performing the actual file read as specified in the request list and subsequently sending the requested file data as File Read Data packet(s). Should a Read Request List packet arrive while File Read Data packets are being sent, it should be assumed that a packet was lost due to communications error, and the prior sequence of File Read Data should be halted and the new Read Request List should be honored. Relevant fields of the FCS data structure during read operations are the Current File Pointer 2628, First Segment Requested 2632, Segment Count Requested 2634. These fields are filled from the contents of the Read Request List packet, and are adjusted as the associated File Read Data packets are transmitted.
During File Write operations, Write File Initialization packets are received to define the intended write operation. The Write File Initialization packet provides information for the Current File Pointer 2628, First Segment Requested 2632, and Segment Count Requested 2634 fields of the Server FCS 2620. Additionally, memory is allocated per the request and in consideration of system resource utilization. The Number of Free Segment Buffers field 2636, the Total Number of Segments field 2640, and the Pointers to Segment Buffers 2642 are set to reflect the number of segment buffers allocated and their memory location. As Write File Data packets arrive, they are placed into available buffers and scheduled for writing to the file. Arrival of a file segment will decrement the number of Free Segment Buffers 2638, and successful writing of those segments will again increment the number of Free Segment Buffers 2638. File Write Request List packets are formulated by utilizing the First Segment Requested field 2632 as a starting segment number, and the number of requested segments is limited by either the number of Free Segment Buffers 2638 or the Segment Count Requested 2634 fields. First Segment Requested 2632 and Segment Count Requested 2634 fields are incremented and decremented, respectively, as File Data packets arrive, such that they maintain an accurate description of the file data remaining to be received.
It will be appreciated that the present invention may take on many variations of the above described embodiments. The principle of the present invention is to allow diagnosis of data storage devices and/or data recovery by a remote data recovery computer. In some cases, only the diagnosis is carried out remotely, as the user may elect not to proceed with the actual recovery. In some cases, the recovery is performed at the local computer-and the recovered data re-stored on the local user's storage device 26. In many cases, the data may be downloaded to the RDR network shared drives 65, restored, and saved on a new storage media which is then sent to the user and/or picked up by the user. In some cases, damaged data may be downloaded to the RDR network shared drives 65, restored, and then uploaded back to the local RDR computer 20. It will be appreciated that these are but some of the many scenarios that might occur under the principles of the present invention.
It can be appreciated that automated, detailed logging of noteworthy events, including chat conversations, acceptance of legal agreement(s), data recovery applications used, etc. would be of value in analysis of business trends and as reference material for any dispute which might arise from time to time. Therefore, the preferred embodiment of RDR would include a means for logging events such as the following:
1) Connection start: date/time, client job-id and phone number, communications channel type and speed;
2) Data Recovery Diagnostic/Application program start and stop dates/times as well as any reports from said programs;
3) All chat or conversational messages (in both directions);
4) All legal agreements submitted, client response to said agreements, all attachments or supplements;
5) Complete logs of all data sectors modified and their prior state; and
6) Connection termination date/time.
It can be appreciated that the performance of data recovery can involve postulation of hypothesis which may be proven inaccurate as the recovery process continues. Therefore, is desirable to allow the ability to "undo" the modifications performed to the local storage device 26 if such modifications are subsequently determined to have been based on incorrect assumptions or are otherwise inappropriate. In the preferred embodiment, a mechanism is provided to defer all changes to the local storage device until such time as the operator of the RDR workstation makes the decision to continue or, alternatively, abandon said changes. If the decision is made to commit the changes, then all data which is marked for being changed is first transferred to the RDR facility for archival. Only then is the new data actually written to the local storage device 26. The preferred method to implement such a mechanism is with a file which logs all write activity which would be performed on the local storage device 26. The file resides on the network attached storage device 65 at the remote data recovery site. Each entry within the file contains an identifier which identifies the unique sector and local storage device which is represented, as well as the latest data which was written to that sector. It is effectively a "write-cache".
FIG. 27 is a flow diagram of the IO logic layer within the local RDR application 308 which implements the capability of "undoing" any modifications made to the local data storage device 26. All attempts to write to the local storage device 26 enter this IO logic layer at 2710. If the requested sector(s) have not been previously written there will be no existing entry in the log-file. If this condition is detected at 2720, a log-file entry will be added at 2730, and at 2735 the data to be written will be written into the log-file entry. If at 2720, it is detected that the requested sector(s) have been previously written, the existing log-file entry will be updated at 2740 with the new data to be written. There will therefore exist in this log-file an entry and the current data for every sector which has been written during the data recovery session. All attempts to read the local storage device 26 enter this I0 layer at 2750. If at 2760 it is determined that the requested sector(s) do not exist in the log-file, i.e. they have not been written during this session, data is read directly from the device at 2770. If at 2760 it is determined the requested sector(s) do exist in the log-file, i.e. the sectors have been written during this session, at 2780 the data is read from the log-file to satisfy the request. This gives the appearance to data recovery application programs 300 that the sectors are indeed being written, but these writes are indeed effectively cached by the log-file.
FIG. 28 is a flow diagram of the application which manipulates the log-files to facilitate the abandonment of changes, the committing of the new data, and the potential restoration of original data. Sectors which are decided to have been inappropriately modified can be "undone" at 2810 by removing the corresponding log-file entries at 2815. When it becomes desirable to commit all modifications at 2820, the original data, about to be overwritten, is transferred at 2830 to a file on the network attached storage device 65 at the remote data recovery site. This original data log-file is then archived at 2840. Finally, since the original data has now been safely archived, the log-file data is used to modify the local storage device 26 at 2850. If, for whatever reason, it is deemed appropriate to restore the local storage device 26 to the original state, it is possible to undo all committed changes at 2870. In this case, the original data which was transferred and archived at 2830 and 2840, respectively, is transferred back to the local computer memory at 2880, and all sectors so noted in this original data log-file are restored at 2885 to the local storage device 26, leaving the local storage device 26 in its original state.
It is to be understood, that although numerous characteristics and advantages of the invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of the parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
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Disclosed are an apparatus and a method for remote recovery of inaccessible data on computer storage devices. The method comprises the steps of (1) establishing a communications link from the local computer containing the storage device requiring recovery of data to a remote data recovery computer operated by a technician; (2) allowing the remote technician to interact as though seated in front of the local computer yet having access to all software programs which are resident at the technician's computer, and (3) enabling the remote technician to diagnose and rectify the data loss.
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BACKGROUND OF THE INVENTION
1. Field of The Invention
The present invention is directed to a locking carriage mechanism for a lamp, such as an operating or surgical lamp or light. More particularly, the present invention is directed to a lamp or light carriage mechanism that rides on a track that may be mounted on the ceiling.
2. Related Art
It is often necessary to move a light source such as an electric light within a room or other space to provide lighting where it is most needed. One response to this desire for portability is found in track lighting, which as found application in many residential and commercial uses.
Similarly, in operating rooms or theaters, it is frequently desired to move a light source to a specific location dictated by the positioning of the surgical apparatus and the patient. Numerous apparatus for allowing lighting fixtures to be moved about the room have been designed in response to this need. Among them is a longitudinal track running along at least a portion of the ceiling of the operating room and a carriage mechanism for engaging the track an allowing the light assembly to slide along it.
If insufficient friction exists between the track and the carriage mechanism, the position of the light will be difficult to control and may change when the surgeon has not touched it, through vibration in the building for example. To overcome this difficulty, the prior art developed additional frictional engagement means for increasing the friction between the track and the carriage mechanism. Typically, spring-loaded pads bearing against portions of the track were employed. Such frictional engaging means increase the force required to move the lamp assembly along the track. Once the lamp assembly is put in motion it can be moved with some effort, but the excess drag caused by the frictional engagement means does not go away. Surgeons have found the excess force required to move such a light to be a disadvantage and to present difficulty during surgery.
Accordingly, there is a need for a surgery light carriage mechanism and track assembly that can be moved along a track by application of very little force and that can be positively locked in place at the desired location along the track after adjustment of the position.
SUMMARY OF THE INVENTION
Accordingly, it is the primary object of the present invention to provide an overhead surgery lamp or assembly that can be easily moved along a track by application of very little force.
It is a further object of the present invention to provide and overhead surgery lighting assembly that can be positively locked in place at the desired location along the track after adjustment of the position of the lamp or lighting assembly.
These and other objects of the present invention are achieved by providing a locking carriage mechanism for a lamp comprising a lamp mounting unit including means for mounting a lighthead; a carriage attached to the top of the lamp mounting unit and slidably mounted in a track, which is mounted on the ceiling. The locking carriage further comprises means for normally locking the carriage into position in the track by frictional engagement of the track and a means for releasing the locking means through action of an operator or the surgeon, whereby the position of the carriage and lamp mounting unit can be easily adjusted along the track.
The mounting unit further comprises a housing adapted for slidable movement in a track, a stem depending from the housing, and a means for mounting the lighthead attached to the stem at the end opposite of the housing. The stem typically comprises a tubular stem for allowing electrical wires to be routed through it. The carriage resides within the housing and is slidably mounted within the track, which typically includes two opposed longitudinal channels, or recesses. The locking means includes a mechanical means comprising a pair of substantially opposed brakes that are urged outwardly against the opposing longitudinal channels of the track by a compression spring and the releasing means further comprises electro-mechanical releasing means including a solenoid having a movable core connected to the breaks by linkage that acts to release the brakes when the movable core is drawn into the solenoid, and a means for activating the solenoid disposed on the lighthead mounting means. That is, a switch or button mounted near the handle that the surgeon uses to adjust the position of the light is depressed, thereby activating the solenoid and drawing the movable core into the solenoid. This action causes each of the opposing two brakes to be drawn away from the side walls of the channels in the track, thereby releasing them.
The frictional engagement of the brakes against the opposed channels of the track keeps the lighting assembly firmly in the desired position along the track. When the brakes are released, however, the carriage glides smoothly and easily because it rides on a plurality of low-friction wheels that rotate about roller bearings near their axles.
These and other objects of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a surgery lamp assembly and carriage in a track viewed from below.
FIG. 2 is a perspective view of the light assembly and carriage in a track shown in FIG. 1, viewed from above.
FIG. 3 is a top plan view of the locking mechanism of the light carriage.
FIG. 4 is a cross sectional view taken along lines 4--4 of FIG. 3.
FIG. 5 is an end elevation of the track.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As required, a detailed embodiment of the present invention is disclosed herein. It is, however, to be understood that the disclosed embodiment is merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.
Referring to FIG. 1, there is shown a lamp assembly 10 comprising a track 12, typically mounted on the ceiling of a room, a housing 14 for holding various circuit elements and routing electrical wires, a depending tubular stem 16 connected to the housing 14, and a control head 18, which may include a rheostat 20 for controlling the intensity of the light produced by a lighthead (not shown) that is attached to the control head 18. A handle 22 is attached to the depending tubular stem 16 by the collar 24. The position of collar 24 may be adjusted by the user through means of a set screw (not shown). The handle 22 may be used to rotate the tubular stem 16 about its longitudinal axis to position the light during surgery. A button switch 26 turns the locking mechanism on and off.
Referring to FIG. 2, there is shown a perspective view of the lamp assembly 10 from above. In this view, additional detail of the track 12 can be seen. FIG. 5 provides the best view of several features of the track 12. The track 12 includes a central slot 28, which runs longitudinally the entire length of the track 12, which typically would be about 5 feet to 8 feet long. The track 12 further comprises a pair of opposed track channels, or channels 30 formed by two right angle turns 32, 34 on each of the two opposed sides of the track 12 to form opposing U-shaped channels. The track 12 may be formed through conventional extrusion techniques and the like. Also included are means for delivering electricity to the housing 14 and ultimately to the electric lamps through the track 12. These means are not shown.
Still referring to FIG. 2, there is shown the cable 36, which is fastened to the anchor stop 38, which in turn is fixed to the end of the track. The cable 36 is connected at the end 40 to a ratchet spring mechanism that helps control movement of the housing 14 along the track 12.
Referring to FIG. 5, each channel 30 of the track 14 includes a side wall 42, so that the channel 12 has two opposed parallel channel side walls or side walls 42 against which the brakes 76 bear when the lamp assembly 10 is in the braked or locked position. An outward urging means comprising a compression spring 86 is operatively connected to the brakes 76 through an assembly linkage attached to both brakes 76 and to the compression spring 86, to urge the brakes 76 against the opposed longitudinal side walls 42 in the track 12 channels 30 to maintain the lamp assembly 10 in a normally braked or locked position.
Referring now to FIG. 3, there is shown a plan view of the plate or carriage assembly 50, which includes the carriage plate 52 upon which the carriage hardware is mounted. The carriage plate 52 rides in the interior portion 54 of the track 12 (See FIG. 5). A solenoid 56, designed to operate at 120 volts AC is fixed to the carriage plate 52 by attachment hardware 58. The solenoid 56 includes a movable core 60 of laminated iron, or the like, which is drawn into the solenoid in the direction of the arrow 62 when an electric current flows through the solenoid 56. The plunger or movable core 60 has a protruding end 64, which is fastened to the center link 66 by the roll pin 68 fastened through aligned apertures in the center link 66 and the protruding end 64 of the movable core 60. The roll pin 68 allows for pivotal movement of the two members relative to one another, whereby the angle between the two members can change when the movable core 60 is drawn into the solenoid 56. In a normal, or equilibrium position, these two members are at right angles to one another and lie in substantially the same plane. Naturally, one member must be above and the other below relative to one another but the planes are essentially adjacent, close together, and parallel.
The center link 66 is pivotally mounted on the carriage plate 52 by the roll pin 70, which is adjacent to but displaced from the second end 72 of the center link 66, the first end 74 of the center link 66 being adjacent to the roll pin 68. The roll pin 70 forms a fulcrum about which the center link 66 pivots.
Still referring to FIG. 3, when the center link 66 is pivoted about the fulcrum at the roll pin 70, portions of the center link 66 to the left of the roll pin 70 move in one direction, while portions of the center link 66 to the right of the roll pin or fulcrum 70 move in the opposite direction. This phenomenon is utilized to apply the brakes 76 to the opposed side walls 42 of the track 12, as explained in detail below.
To the left, as illustrated in FIG. 3, of the roll pin or fulcrum 70 along the longitudinal axes of the center link 66 is the short link 78, which is pivotally fastened to the center link 66 by the roll pin 80. To the right of the roll pin or fulcrum 70 and adjacent to the second end 72 of the center link 66, the long link 82 and the center link 66 are fastened together by the roll pin 84, which allows for relative pivotal movement between the two joined members. Thus, the pivot point or fulcrum 70 of the center link 66 is located intermediate, or between, the second end 72 of the center link 66 and the roll pin 80 that attaches the short link 78 to the center link 66. In turn, the short link 78 is attached to the center link 66 at a point between the fulcrum 70 and the first end 74 of the center link 66.
A compression spring 86 is mounted on the compression spring retaining tab 88, which comprises an extension of the short link 78 extending beyond the center link 66. Opposing the tab 88 is the opposed spring retaining tab 90, which is integrally formed with or connected to the long link 82 and is off-set from the long link 82 sufficiently to align with the compression spring retaining tab 88.
The brakes 76 comprise polyethylene caps 92 snapped on over metal feet 98 that penetrate an aperture 94 in the side rails 96 of the carriage 50. The feet 98 further comprise a threaded stud 100 that is adjustably threaded through the nut 102 formed in the short link 78 and the long link 82. A jam nut 104 may be used to tighten the feet 98 into a proper position for the width of a particular track.
The carriage 50 includes a number of wheels that revolve upon roller bearing that provide for smooth and easy movement of the carriage 50 along the track 12. The wheels 110 are horizontal when the track 12 is mounted in the ceiling and they travel in the channels 30 of the track 12. The wheels 110 ride on roller bearings 112. The vertically mounted wheels 114 also ride on roller bearings and they bear against the flange 35 portions of the track 12 and against the upper side wall 37 of the track 12. The roller bearings 116 of the vertically mounted wheels 114 are best seen in FIG. 4.
A suitable source of electrical power to the solenoid 56 is switched on and off by the button switch 26 or other convenient means, such as a pressure switch disposed throughout the handle 22. In operation, the surgeon who wants to move the lamp assembly along the track 12 depresses the button switch 26, thereby energizing the solenoid 56. The magnetic field created by the electricity flowing in the solenoid draws the moveable core 60 into the solenoid 56 in the direction of the arrow 62, causing the center link 66 to pivot about the fulcrum 70 clockwise as illustrated in FIG. 3 in an action that draws the short link 78 and the long link 82 both toward the interior portion of the carriage plate 52. That is, as illustrated in FIG. 3, the short link moves in the direction of the arrow 118 and the long link 82 moves in the direction of the arrow 120. The force exerted upon these link members by the solenoid 56 is sufficient to further compress the compression spring 86 and retract the brakes 92 from engagement with the side walls 42 of the track channels 30. Thus, the lamp carriage assembly can be easily moved along the track 12. When the lamp assembly 10 is in the desired location, the surgeon releases the button switch 26, which cuts off the flow of electricity into the solenoid, allowing the compression spring 86 to urge the short link 78 and the long link 82 outward of the interior portion of the plate, that is, to cause the brakes 76 to engage the side walls 42 of the track channels 30, thereby locking the lamp assembly 10 into its then current position on the track 12.
It is to be understood that while certain forms of this invention have been illustrated and described, it is not limited thereto, except and in so far as such limitations are included in the following claims.
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A lamp assembly for surgery and the like includes a ceiling mounted track having opposed internal channels, a carriage assembly that rides in the track and that is connected to a depending tubular stem which terminates in a control head having a lighthead fastened to it. A switch on the control head energizes a solenoid having a movable core that acts through mechanical linkage to retract a pair of opposing brakes from engagement against the side walls of the track, thereby allowing the lamp assembly to be moved along the track easily. When the solenoid is de-energized, a compression spring urges the brakes firmly against the side walls of the track, locking the light assembly in place along the track.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. National Stage application Ser. No. 11/817,208, filed 27 Aug. 2007, US National Stage of PCT/IB2006/000421, filed 28 Feb. 2006, claiming priority to U.S. Provisional Application Ser. No. 60/657,208, filed 28 Feb. 2006, the contents of which are incorporated by reference.
FIELD OF THE INVENTION
[0002] This invention is in the field of epitaxy growth processes and coating apparatuses. More specifically, the present invention relates to apparatuses and processes for epitaxy forming of a single crystal by deposition of material directly from the vapor or gaseous state.
BACKGROUND OF THE INVENTION
[0003] The III-V compound semiconductor Gallium Nitride (GaN) and its Aluminum (Al) and Indium (In) alloys are ideal materials both for high-frequency and high-power electronic applications (see for example Brown et al., Solid-State El. 46, 1535 (2002), the content of which is incorporated herein by reference thereto). These materials are also ideal for short wavelength light emitting diodes and lasers (see for example Nakamura, Annu. Rev. Mater. Sci. 28, 125 (1998); Nakamura, Science 281, 956 (1998); and Smith et al., J. Appl. Phys. 95, 8247 (2004), the contents of which are incorporated herein by reference thereto).
[0004] One of the main drawbacks of the material is, however, the lack of large, single crystals due to extreme conditions of high temperature and pressure required for their growth in bulk form. The only way to synthesize GaN wafers of significant size is by means of heteroepitaxy, whereby thick, self-supporting GaN layers are grown onto a support substrate such as sapphire or Silicon Carbide (SiC), which substrate is subsequently removed. Thinner heteroepitaxial III-V nitride layers can be used for device processing without removal of the substrate.
[0005] One common problem of all techniques used for heteroepitaxial growth of GaN is the high dislocation density initially present in the growing layers. This problem results from the different lattice parameters of GaN and the available substrate materials, such as sapphire, silicon carbide and silicon (see for example Dadgar et al., Phys. Stat. Sol. (c) 0, 1583 (2003), the content of which is incorporated by reference thereto). As a consequence of the high misfit dislocation density, heteroepitaxial GaN layers tend to contain also a high density of threading dislocations (TD), which degrade device performance whenever they penetrate into any active layers. Many ways have been devised to reduce TD densities to values acceptable for device fabrication, such as buffer layer growth of various forms, or lateral overgrowth with and without the use of masks (see for example Davis et al., Proc. IEEE 90, 993 (2002), the content of which is incorporated by reference thereto).
[0006] The main methods used for growing epitaxial HI-V nitride layers are hydride vapor phase epitaxy (HVPE), metal-organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE). In HVPE, pure metals are used as source materials, and transported as gaseous halides to the reaction zone where they react with a nitrogen-containing gas, usually NH 3 to form an epitaxial layer on a substrate typically heated to above 1000° C. HVPE has the advantage of very high growth rates of up to 100 m/h (see for example U.S. Pat. No. 6,472,300 to Nikolaev et al., the content of which is incorporated herein by reference). Because of its high growth rates, HVPE is mostly used for growing layers many tens of microns thick, and in particular for the fabrication of self-supporting layers as substrates for subsequent MOCVD or MBE steps.
[0007] Low rates and control of sharp interfaces are, however, more difficult to achieve by HVPE, and may require mechanical movement of the substrate between different reactor zones (see for example U.S. Pat. No. 6,706,119 to Tsvetkov et ah, the content of which is incorporated herein by reference). Additionally, the presence of hydrogen gas in the reaction zone requires annealing of the substrate in an inert gas atmosphere, particularly when high p-type doping for example by Mg impurities is to be attained (see for example U.S. Pat. No. 6,472,300 to Nikolaev et al., the content of which is incorporated herein by reference).
[0008] MOCVD (or MOVPE, for “metal-organic vapor phase epitaxy”) is a CVD technique in which metal-organic precursors are used along with other reactive gases containing the anions, such as ammonia in the case of nitride growth. The need for expensive precursor gases, along with rather low growth rates of just a few μm/h, is a significant disadvantage of MOCVD. Furthermore, a buffer layer usually has to be grown for GaN heteroepitaxy on sapphire, SiC or Si, at a lower substrate temperature before the active layer stacks are deposited at temperatures above 1000° C. (see for example U.S. Pat. No. 6,818,061 to Peczalski et al. the content of which is incorporated herein by reference). MOCVD is, however, the technique most often used for growing active layer structures suitable for device fabrication (see for example Wang et al., Appl. Phys. Lett. 74, 3531 (1999) and Nakamura, Science 281, 956 (1998) the contents of which are incorporated herein by reference).
[0009] Large differences in thermal expansion coefficients between common substrates and GaN, together with the high substrate temperatures during growth, present a significant obstacle towards achieving crack-free epitaxial layers. Crack avoidance seems to necessitate rather complicated interlayer schemes (see for example Biasing et al., Appl. Phys. Lett. 81, 2722 (2002) the content of which is incorporated herein by reference). HVPE and MOCVD are both deposition techniques working at atmospheric or somewhat reduced pressures. Reactor geometries and gas flows determine layer uniformities to a large extent.
[0010] By contrast, in MBE, pressures are in the high-vacuum to ultrahigh-vacuum range and mean-free paths therefore greatly exceed reactor dimensions. Metals are evaporated in so-called effusion cells from which molecular or atomic beams travel towards the heated substrate without being scattered in the gas phase. For nitride growth, a nitrogen source yielding activated nitrogen must be used. Activation is usually achieved by means of plasma excitation of molecular nitrogen. A system for epitaxially growing Gallium Nitride layers with a remote electron-cyclotron-resonance (ECR) plasma source for nitrogen activation has been described for example in U.S. Pat. No. 5,633,192 to Moustakas et al., the content of which is incorporated herein by reference. Since Gallium (Ga) is usually supplied from an effusion cell, MBE does not require the expensive metal-organic precursors common in MOCVD. MBE offers moreover excellent control over layer composition and interface abruptness (see for example Elsass et al, Jpn. J. Appl. Phys. 39, L1 023 (2000), the content of which is incorporated herein by reference). Due to its low growth rates on the order of 1 μm/h and complex equipment, however, it is not considered to be a technique suitable for large scale production of semiconductor heterostructures.
[0011] A further method potentially suitable for large scale production of nitride semiconductors (see, for example, U.S. Pat. No. 6,454,855 to von Känel et al. the content of which is incorporated herein by reference) is low-energy plasma enhanced chemical vapor deposition (LEPECVD). In contrast to plasma assisted MBE, where nitrogen activation occurs in a remote plasma source, a dense low-energy plasma is in direct contact with the substrate surface in LEPECVD. The low-energy plasma is generated by a DC are discharge by means of which metalorganic precursors and nitrogen are activated (see, for example, U.S. Pat. No. 6,918,352 to von Känel et al. the content of which is incorporated herein by reference). Potentially, LEPECVD can reach growth rates comparable to those of HVPE (several tens of μm/h, while offering optimum control over the dynamic range of growth rates, such that excellent interface quality can be achieved. Moreover, since activation of the reactive precursors is achieved by means of a plasma rather than thermally, the process is expected to work at lower substrate temperatures. The DC plasma source used in LEPECVD has been shown to be scalable to 300 mm substrates (see for example WO 2006/000846 to von Känel et al., the content of which is incorporated herein by reference).
[0012] Although the term “LEPECVD” has been coined in conjunction with a DC arc discharge (see, Rosenblad et al, J. Vac. Sci. Technol. A 16, 2785 (1998), the content of which is incorporated herein by reference), such a DC arc discharge is not the only way to generate a low-energy plasma suitable for epitaxy. According to prior art, sufficiently low-energy ions suitable for epitaxial growth may result also from electron-cyclotron-resonance (ECR) plasma sources (see Heung-Sik Tae et al., Appl. Phys. Lett. 64, 1021 (1994), the content of which is incorporated herein by reference). An ECR plasma source potentially suitable for epitaxial growth by plasma enhanced CVD on large area substrates has been described, for example, in U.S. Pat. No. 5,580,420 to Katsuya Watanabe et al., the content of which is incorporated herein by reference. In industrial semiconductor processing, large ECR sources are, however, used for etching rather than epitaxy. Very high etch rates have been achieved in the case of III-V nitrides (see for example, Vartuli et al., Appl. Phys. Lett. 69, 1426 (1996), the content of which is incorporated herein by reference).
[0013] Yet other sources of high-density, low-energy plasmas are inductively coupled plasma ICP) sources. These sources have a number of advantages over ECR sources, such as easier scaling to large wafer diameters and lower costs. For a review of the different kinds of ICP sources, see Hopwood, Plasma Sources Sci. Technol. 1, 109 (1992), the content of which is incorporated herein by reference. The most common variants used for plasma processing are helical inductive couplers where a coil is wound around the plasma vessel (for example, see Steinberg et al., U.S. Pat. No. 4,368,092, the content of which is incorporated herein by reference), and spiral inductive couplers with flat coils in the form of a spiral (for example, see U.S. Pat. No. 4,948,458 to Ogle, the content of which is incorporated herein by reference). Plasma sources based on spiral couplers have the advantage of higher plasma uniformity, facilitating scaling to large substrate sizes (for example, see Collison et al., J. Vac. Sci. Technol. A 16, 100 (1998), the content of which is incorporated herein by reference).
[0014] While ICP sources normally are operated at a frequency of 13.56 MHz, operating at lower frequency has been shown to decrease capacitive coupling and thus leading to even lower ion energies (see U.S. Pat. No. 5,783,101 to Ma et al., the content of which is incorporated herein by reference).
[0015] Both, ECR sources and ICP sources are usually used for etching. Very high etch rates for GaN have been obtained also with ICP sources (see Shul et al., Appl. Phys. Lett. 69, 1119 (1996), the content of which is incorporated herein by reference). However, use of these sources for epitaxial growth of semiconductor quality materials is very rare. Recently, it has been suggested to apply an electrically-shielded ICP source for ion plating epitaxial deposition of silicon. This method has the obvious drawback of requiring a metallic collimator inside the deposition chamber (see U.S. Pat. No. 6,811,611 to Johnson, the content of which is incorporated herein by reference).
[0016] ICP sources can also be used for efficient cleaning of process chambers, such as chambers used for thermal CVD, where a remote plasma source is usually employed (see U.S. Pat. No. 5,788,799 to Steger, the content of which is incorporated herein by reference). Chamber cleaning is particularly important for semiconductor processing, where particulate contamination has to be kept as low as possible. Processing chambers equipped with a plasma source, such as an ICP source, do not of course require an additional remote source for efficient cleaning (see U.S. Pat. No. 6,992,011 to Nemoto et al., the content of which is incorporated herein by reference).
[0017] Whatever plasma source is used for generating a low-energy plasma for plasma enhanced chemical vapor deposition, when applied to III-V compound semiconductor growth, carbon incorporation into the growing layers is likely to occur to a much greater extent than in MOCVD.
[0018] Carbon incorporation results from the use of organic precursors in MOCVD and as suggested for LEPECVD (see U.S. Pat. No. 6,454,855 to von Känel et al. the content of which is incorporated herein by reference). The intense plasma used for cracking the precursors in LEPECVD is expected to greatly enhance unintentional carbon uptake, possibly to a degree unacceptable for device applications, since carbon acts as a dopant (see, for example, Green et al., J. Appl. Phys. 95, 8456 (2004), the content of which is incorporated herein by reference).
[0019] It is an objective of the present invention to avoid the drawbacks of prior art techniques mentioned above, such as carbon and hydrogen incorporation, high substrate temperatures, and low deposition rates. An additional major limitation of prior art techniques is a relatively small wafer size (two inch in production, up to 6 inch demonstrated for sapphire substrates). Increased scaling of silicon wafers of up to 300 mm (or more) is one of the objects of the present invention.
SUMMARY OF THE INVENTION
[0020] The present invention is a new low-energy, high density plasma apparatus and a process for fast epitaxial deposition of compound semiconductor layers on to a semiconductor support substrate. The invention provides for the deposition of a large variety of compound layers by being able to controllably alter constituent reagents and/or their concentrations during the deposition process. In a first step of the process, one or several metals are vaporized, and the metal vapors are injected into the interior of the deposition chamber of the apparatus. Vaporization can be accomplished using, for example, effusion cells or sputter targets communicating with the interior of the deposition chamber. Concurrently, upon injection of the metal vapor (e.g., Gallium) into the chamber, a non-metallic and normally non-reactive, nontoxic gas (Nitrogen as N 2 ) is also injected into the chamber. In a second substantially concurrent step, a dense, low-energy plasma is generated and maintained in the deposition chamber by any of a plurality of plasma generating mechanisms (such as an electron-cyclotron-resonance (ECR) plasma, an inductively coupled plasma (ICP) or a DC arc discharge plasma). When fully immersed in the plasma, the non-metallic gas becomes highly activated, and reacts with the metal vapor and forms an epitaxial semiconductor layer (e.g., GaN) on a heated semiconductor substrate supported in the plasma. The invention provides a carbon-free process, because of the absence of organic precursor reagents, and is especially well suited for application to producing semiconductor layers on large-area silicon substrate.
[0021] Additionally, in the absence of any toxic carrier or reagent gases, the process is also extraordinarily environment friendly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a schematic side-view drawing of the system for low-energy plasma-enhanced vapor phase epitaxy (LEPEVPE) with an inductively coupled plasma (ICP) source and effusion cells.
[0023] FIG. 2 is a schematic drawing of a growing film on a substrate exposed to a low-energy plasma.
[0024] FIG. 3 is a schematic view of a plasma confined by a magnetic field.
[0025] FIG. 4 is a schematic side-view drawing of a variant of a system for LEPEVPE with an ICP source and effusion cells, and with substrate face down.
[0026] FIG. 5 is a schematic side-view drawing of a system for LEPEVPE with an ICP source and sputter sources.
[0027] FIG. 6 is a schematic drawing representing a system of the present invention for LEPEVPE with a DC plasma source and effusion cells.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The present invention is a system including an apparatus and process for the epitaxial growth of IH-V semiconductors, especially group III-nitrides, such as GaN, GaAlN, and GaInN. The apparatus provides a low-energy, high-density plasma for plasma enhanced vapor phase epitaxy of semiconductor layers on to a semiconductor support. The present system allows for the economical fabrication of heterostructures suitable for high-frequency power amplifiers, violet, blue and white LEDs (lighting), and blue and ultra-violet semiconductor lasers.
[0029] Referring now to FIG. 1 , the apparatus 10 includes a vacuum deposition chamber 20 having a chamber interior 21 communicating with a vacuum pumping system (not shown), such as a turbomolecular pump, attached to exhaust line 24 . The deposition chamber 20 and the pumping system are chosen such as to being compatible with ultra-clean processing of semiconductors. For example a system allowing for ultra-high vacuum in the absence of process gases has been found to be adequate. Inert and normally non-reactive gases, such as argon and nitrogen, and any additional gases suitable for processing, are supplied to the deposition chamber 20 by means of gas inlets 22 . Nitrogen in the form of N 2 is normally a non-reactive gas. However, when exposed to the plasma field of the present apparatus, the N 2 nitrogen is converted to its atomic form N and becomes highly activated and reactive. The deposition chamber 20 is equipped with a dielectric window 28 through which radio frequency waves are coupled into the chamber interior 21 by means of a spiral coil assembly 30 . The spiral coil assembly 30 communicates with an impedance matching network 32 and a radio frequency generator 34 . Radio frequency waves emanating from the spiral coils excite a dense, low-energy plasma within the interior 21 of the chamber 20 . For example, the inductively coupled plasma source ICP-P 200 from JE PlasmaConsult, GmbH in Wuppertal, Germany, has been shown to yield Argon and Nitrogen ion energies below 20 eV when operated in the pressure range between 10″ 4 and 10″ 2 mbar and powers up to 1 kW.
[0030] A deposition assembly 50 is electrically insulated from deposition chamber 20 by means of insulators 26 . One or more substrate supports 54 are heated from the back by a heating means 52 , such as a resistive heater or by lamp heaters. The substrate support 54 is spaced several skin depths (typically 5-20) away from the location of highest plasma density close to the dielectric window 28 . The skin depth is on the order of 1 cm for the typical operating pressures used according to the invention. The deposition assembly 50 can either be grounded or left electrically floating. Alternatively, the assembly 50 can be connected to a DC bias power supply, or it can be coupled through an impedance matching network 56 to RF generator 58 , giving rise to a DC self-bias. These measures are taken in order to control the electrical potential of substrates 54 with respect to that of the plasma. In this way the electric field component perpendicular to the surface of substrates 54 can be controlled independently from the parameters controlling the plasma 36 . The energy of ions impinging on the substrates can thus be adjusted for optimum epitaxial growth conditions.
[0031] In addition, the deposition chamber 20 is equipped with one or more metal vapor emitters 40 (effusion cells in the embodiment illustrated) from which metals, such as Ga, In and Al, can be vaporized and the vapors injected into the chamber interior 21 . For these metals, the temperature of standard effusion cells used in molecular beam epitaxy (MBE) can easily be adjusted such as to allow much higher evaporation rates than those customary in that technique. For example an increase of Gallium cell temperature by 200° C. was found to be adequate for a 100-fold increase of the GaAs growth rate of 1 monolayer/sec typical in MBE. Similar to MBE, fast-action shutters 42 are controllable to interrupted completely the fluxes from the vapor emitters 40 .
[0032] During epitaxial deposition, the radio frequency power applied to the induction coils 30 and the gas pressures in the chamber 20 are chosen such that the heated substrates 54 are fully exposed to a low-energy plasma. Typically, gas pressures in chamber 20 range between 10″ 4 mbar to 1.0 mbar, with pressures in the range of 10′ 2 to 10″ 1 mbar being the most typical. Under such conditions, activated nitrogen and metal vapor from effusion cells 40 both move by diffusive transport in the plasma. Metal atoms reacting with the nitrogen form an epitaxial nitride layer on the hot substrates 54 .
[0033] Referring now to FIG. 2 , a detailed view of a growing film 55 on a substrate 54 exposed to a low-energy plasma 36 can be seen. The ion density in the plasma decreases exponentially from the dielectric window 28 to the substrate 54 . For example for the plasma source “ICP-P 200,” the ion density in a nitrogen plasma may still exceed 10″ cm′ 3 at a substrate located about 10 cm below dielectric window 28 , when a nitrogen pressure of 10″ 1 mbar at a gas flow of 10 seem, and a rf-power of 1000 W are used. In order to keep the ion energy low, it may be advantageous to keep the total gas pressure fixed, for example around 10 1 mbar, by admitting a controlled flow of Ar through gas inlets 22 to enter the vacuum chamber 20 along with nitrogen gas, when nitrogen partial pressures substantially below 10 1 mbar are used.
[0034] As a result of the efficient activation of the reacting species in a dense plasma 36 , and intense bombardment of the substrate surface 54 by low-energy ions the substrate temperature can be significantly lowered with respect to the substrate temperatures of 1000° C. and more typical for MOCVD. The problems of layer cracking due to different thermal expansion coefficients of typical substrates (sapphire, silicon carbide and silicon) are hence expected to be greatly reduced.
[0035] Referring now to FIG. 3 , a detailed view of part of the vacuum chamber 20 is shown, where in order to confine the plasma 36 , and to increase its density and uniformity, the chamber is optionally equipped with coils or permanent magnets 70 . The magnetic field generated by these coils or permanent magnets helps in shaping the plasma. Even weak fields of the order of 10″ 3 to 10″ 2 Tesla are considered to be sufficient to have a beneficial effect.
[0036] In a preferred embodiment of the invention no reactive gases are used for epitaxial nitride semiconductor growth at all. Additional cells 40 a may contain those doping species which are preferably used in elemental form, such as Mg, Zn and similar metals acting as acceptor impurities. Similarly, dopants acting as donors, such as silicon, may be provided by additional cells 40 a . These emitters 40 a (effusion cells) also are equipped with fast-acting shutters 42 permitting rapid and complete interruption of the dopant vapors. The preferred substrate support 54 choice is silicon in order to allow for scaling up to 300 mm wafers, and potentially beyond. However, the use of other substrates employed in state of the art techniques is equally possible in the new technique according to the invention.
[0037] The combination of effusion cells for metal evaporation with a dense low-energy plasma suitable for epitaxial layer deposition has not been proposed before. We call the new process low-energy plasma enhanced vapor deposition (LEPEVPE). LEPEVPE is a process being operated under completely different conditions with respect to all other known processes, including LEPECVD where a DC plasma discharge and reactive gas phase precursors are used.
[0038] In one embodiment of the invention, the region of the vapor emitters 300 is differentially pumped ( 320 in FIG. 6 ) in order to exclude thermal reactions with the hot metals inside and diffusive transport in the connecting tube to the deposition chamber. In a preferred embodiment of the invention more than one vapor emitter 40 & 40 a (effusion cell) is used per evaporated metal. Each cell can be operated at a different temperature, thereby easily allowing rapid changes in growth rates or doping densities by switching from one cell to another.
[0039] In another embodiment of the invention, additional gas lines 23 are used to insert doping gases into the deposition chamber for those doping elements which are preferably applied in gaseous form. The doping gases, such as Silane for n-type doping, are preferably diluted in a non-reactive gas, such as argon. The dynamic range of doping can be increased by using more than one gas line per doping gas. In a preferred embodiment where vapor emitters 40 a of only the solid source type are used for doping, the process is operated hydrogen-free. This embodiment is especially desirable for p-doped GaN layers since a hydrogen-free process does not need any dopant activation by thermal annealing. The process of the invention is carbon-free because it does not require any carbon-containing precursor gases.
[0040] In the preferred embodiment of the invention illustrated in FIG. 1 , the assembly of substrate supports 54 is facing up. This configuration, customarily used in semiconductor processing, facilitates wafer handling and design of the deposition assembly or substrate holder 50 . According to the invention, LEPEVPE is characterized by a high density low-energy plasma in direct contact with the surface of the substrate support 54 . The surface of the substrate support 54 is therefore under intense bombardment of low-energy ions, the energy of which may be adjusted by appropriate choice of the substrate bias. This is in marked contrast to plasma processing methods using remote plasma sources, which typically deliver radicals only, whereas ion densities at the substrate surface are negligibly low. Heavy substrate bombardment by low-energy ions has been shown to be beneficial to epitaxial growth of device quality semiconductor layers at extremely high growth rates of more than 5 nm/s at substrate temperatures as low as 500° C. (see, for example, von Känel et al, Appl. Phys. Lett. 80, 2922 (2002), the content of which is incorporated herein by reference). According to the invention very high throughputs may therefore be expected by combining LEPEVPE with state of the art wafer handling tools (not shown).
[0041] According to the present invention, the apparatus 10 may be used for growing epitaxial III-V semiconductors, especially group III-nitrides onto specially treated single-crystal substrates 54 . Possible surface treatments of substrates 54 may involve state of the art chemical pre-cleans, in situ thermal cleans or plasma cleans, followed by in situ formation of epitaxial templates, such as oxides, carbides or low-temperature nitrides, suitable for subsequent epitaxial nitride semiconductor growth.
[0042] Referring now to FIG. 4 , an apparatus 10 of the present system is shown in which the substrate support 54 on which the growing materials are deposited is mounted on a table of the substrate holder 50 in the interior chamber 21 which is now facing down. This configuration is characterized by fewer problems with particulate contamination, at the cost of a more complex wafer handling system and design of the substrate holder 50 . As noted above, the deposition chamber 20 may be equipped with optional coils or permanent magnets which may help in shaping the plasma, and is similarly equipped with effusion cells 40 , etc.
[0043] Referring now to FIG. 5 , another embodiment of the invention is shown, whereby the substrate supports 54 mounted on deposition assembly 50 inside the chamber 20 are again facing down. The deposition chamber 20 may be equipped with optional coils or permanent magnets which may help in shaping the plasma (see FIG. 3 ).
[0044] In this embodiment, the elemental metal vapors are supplied to the plasma by means of water cooled sputter sources 60 , holding sputter targets 62 . It is advisable to arrange the sputter targets 60 in the form of concentric rings or ring segments around the dielectric window 28 of the ICP source. The sputter targets are connected through an impedance match box 64 to an RF power supply 66 , whereby power supply 66 provides an alternate voltage at a frequency preferably substantially different to that used by generator 34 to power the ICP coils 30 . This reduces undesirable interferences between the two kinds of power sources 34 and 66 . In another embodiment of the invention, the sputter sources 60 are powered by a DC power supply. It has been shown that for typical pressures-distance products on the order of 0.2×10′ 2 mbar m the thermalization of sputtered particles reaching the substrate is nearly complete, such that electronic-grade semiconductor material can be grown by using sputter sources (see, for example, Sutter et al, Appl. Phys. Lett. 67, 3954 (1995), the content of which is incorporated herein by reference).
[0045] In order to allow cleaning of sputter sources 60 prior to epitaxial layer deposition, chamber 20 may be optionally equipped with a movable shutter assembly 82 allowing the shutter blade 80 to be positioned close to and below the substrates 54 and hence avoiding any sputtered particles to reach the substrate during pre-sputtering.
[0046] In a preferred embodiment of the invention no reactive gases are used for epitaxial nitride semiconductor growth at all. Additional sputter targets 60 a may contain those doping species which are preferably used in elemental form, such as Mg, Zn and similar metals acting as acceptor impurities. Similarly, dopants acting as donors, such as silicon, may be provided by additional sputter targets 60 a . In another embodiment of the invention each sputter gun 62 may be equipped with optional shutters (not shown) in order to avoid cross-contamination between the individual targets 60 .
[0047] During epitaxial deposition, the radio frequency power applied to the induction coils 30 and the gas pressures in the chamber 20 are chosen such that the heated substrates 54 are fully exposed to a low-energy plasma. Typically, gas pressures in chamber 20 range between 10′ 3 mbar to 10″ 1 mbar, with pressures in the range of 10″ 2 to 10′ 1 mbar being the most typical. Under such conditions, activated nitrogen and metal vapor from sputter guns 62 both move by diffusive transport in the plasma and the process proceeds as noted above.
[0048] In another embodiment of the invention sputter guns 62 may be combined with effusion cells 40 , whereby both sources are preferably arranged symmetrically around the dielectric window 28 . The combination of effusion cells and sputter guns for evaporating reactants and dopants in elemental form with a dense low-energy plasma suitable for epitaxial layer deposition has not been proposed before. In a preferred embodiment of the invention more than a single sputter gun 62 and effusion cell 40 are used per evaporated metal. Each source can be operated in such a way as to deliver a different flux of metal vapors, thereby easily allowing rapid changes in growth rates or doping densities by switching from one source to another. In still another embodiment, the effusion cells 40 and sputter guns 62 may be replaced or complemented by electron beam evaporators. Electron beam evaporators are especially suitable for evaporating elements with low vapor pressures, where significant fluxes are difficult to achieve with effusion cells 40 .
[0049] Referring now to FIG. 6 , another embodiment of the invention is shown, in which the apparatus 10 includes a broad area plasma source 100 with an assembly of thermionic cathodes 130 , an inert gas inlet 120 , and an integrated or separate anode 110 . Preferably, the voltage difference between the cathodes 130 and the anode 110 is less than 30 V, to provide that ions striking the substrate have energy less than about 20 V. The plasma source 100 in which an arc plasma 140 can be ignited is attached to a deposition chamber 200 . The deposition chamber, equipped with a load-lock 220 , is pumped for example by a turbomolecular pump 210 communicating with chamber 200 by means of valve 205 , and contains a substrate heater assembly 230 . Gas lines 240 for injecting an inert gas such as nitrogen, and additional gases, such as hydrogen, are connected to the deposition chamber. The plasma density may be changed rapidly by changing the confining magnetic field produced by coils 250 .
[0050] In addition, this chamber is equipped with effusion cells 300 from which metals can be vaporized, such as Ga, In and Al. Additional cells 300 may contain those doping species which are preferably used in elemental form, such as Mg, Zn and similar metals acting as acceptor impurities. The effusion cells are equipped with shutters 310 permitting complete interruption of the metal vapor.
[0051] The heated assembly of substrates 400 is fully exposed to the low-energy plasma generated by the arc discharge in the plasma source and expanding into the deposition chamber through the permeable anode 110 . The arc discharge is sustained by thermionic cathodes 130 in the plasma chamber 200 , and can be operated in a wide pressure range in the deposition chamber from 10″ 4 mbar to at least 10″ 1 mbar, with pressures in the range of 10″ 2 mbar being the most typical. Plasma activated nitrogen flowing through the deposition chamber reacts with the metal vapor, forming an epitaxial nitride film on the substrate 400 .
[0052] Effusion cells are normally used for evaporating metals in ultra-high vacuum for example in a molecular beam epitaxy system. Here, they serve to introduce a metal vapor into a high-density low-energy plasma generated at typical pressures of about 10′ 2 mbar at which transport is diffusive. LEPEVPE is hence a process being operated under completely different conditions with respect to other processes. In one embodiment of the invention, the region of the effusion cells 300 is differentially pumped 320 in order to exclude thermal reactions with the hot metals inside and diffusive transport in the connecting tube to the deposition chamber.
[0053] In a preferred embodiment of the invention more than a single effusion cell 300 is used per evaporated metal. Each cell can be operated at a different temperature, thereby easily allowing rapid changes in growth rates or doping densities by switching from one cell to another. In addition, changes of the plasma density, brought about by changing the magnetic field produced by the coils 250 , can further enhance the dynamic range of growth rates.
[0054] In another embodiment of the invention, additional gas lines 240 a are used to insert doping gases into the deposition chamber for those doping elements which are preferably applied in gaseous form. The doping gases, such as Silane for n-type doping, are preferably diluted in a non-reactive gas, such as argon. The dynamic range of doping can be increased by using more than one gas line per doping gas.
[0055] The process of the invention is carbon-free because it does not require any carbon-containing precursor gases. In a preferred embodiment, it is also operated hydrogen-free. This embodiment is especially desirable for p-doped GaN layers since a hydrogen-free process does not need any dopant activation by thermal annealing.
[0056] Since LEPEVPE is a plasma-activated process it can be operated at lower substrate temperatures than competing techniques where tensile stress induced by different thermal expansion coefficients of epilayer and substrate often lead to undesirable crack formation during cooling from the growth temperature.
[0057] ANNEX A—the below documents are incorporated herein by reference thereto and relied upon.
US PATENT DOCUMENTS
[0000]
U.S. Pat. No. 6,472,300 October 2002 Nikolaev et al.
U.S. Pat. No. 6,706,119 March 2004 Tsvetkov et al.
U.S. Pat. No. 6,818,061 November 2004 Peczalski et al.
U.S. Pat. No. 5,633,192 May 1997 Moustakas et al
U.S. Pat. No. 6,454,855 September 2002 von Känel et al.
U.S. Pat. No. 6,918,352 July 2005 von Känel et al.
U.S. Pat. No. 5,580,420 December 1996 Watanabe et al.
U.S. Pat. No. 4,368,092 January 1983 Steinberg et al.
U.S. Pat. No. 4,948,458 August 1990 Ogle
U.S. Pat. No. 6,811,611 November 2004 Johnson
U.S. Pat. No. 5,788,799 August 1998 Steger et al.
OTHER PATENT DOCUMENTS
[0000]
WO 2006/000846 January 2006 von Känel et al.
ADDITIONAL PUBLICATIONS
[0000]
J. D. Brown et al., “AlGaN/GaN HFETs fabricated on 100-mm GaN on silicon(111) substrates”, Solid-State Electronics, Vol. 46, No. 10 (October 2002) pp. 1535-1539.
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S. Nakamura, “The roles of structural imperfections in InGaN-based blue light-emitting diodes and laser diodes”, Science, Vol. 281 (14 Aug. 1998) pp. 956-961.
G. A. Smith et al., “341 nm emission from hydride vapor-phase epitaxy ultraviolet light-emitting diodes”, Journal of Applied Physics, Vol. 95, No. 12 (15 Jun. 2004) pp. 8247-8251.
R. F. Davis et al., “Gallium nitride materials—progress, status, and potential roadblocks’ Proceedings of the IEEE, Vol. 90, No. 6 (June 2002) pp. 993-1004.
A. Dadgar et al., “Metalorganic chemical vapor phase epitaxy of gallium-nitride on silicon”, physica status solidi (c), Vol. 0, No. 6 (September 2003) pp. 1583-1606.
T. Wang et al., “Electron mobility exceeding 10 4 cmVVs in an AlGaN—GaN heterostructure grown on a sapphire substrate”, Applied Physics Letters, Volume 74, No. 23 (7 Jun. 1999) pp. 3531-3533.
J. Biasing et al., “The origin of stress reduction by low-temperature AlN interlayers”, Applied Physics Letters, Vol. 81, No. 15 (7 Oct. 2002) pp. 2722-2724.
CR. Elsass, “Electron transport in AlGaN/GaN heterostructures grown by plasma-assisted molecular beam epitaxy”, Japanese Journal of Applied Physics, Vol. 39, Part 2, No. 10B (15 Oct. 2000) pp. L1023-L1025.
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Heung-Sik Tae et al., “Low-temperature silicon homoepitaxy by ultrahigh vacuum electron cyclotron resonance chemical vapor deposition”, Applied Physics Letters, Vol. 64, No. 8 (21 Feb. 1994) pp. 1021-1023.
CB. Vartuli et al., “ICI/Ar electron cyclotron resonance plasma etching of III-V nitrides”, Applied Physics Letters, Vol. 69, No. 10 (2 Sep. 1996), pp. 1426-1428.
W. Z. Collison et al., “Studies of the low-pressure inductively-coupled plasma etching for a larger wafer using plasma modeling and Langmuir probe”, Jornal of Vacuum Science and Technology A, Vol. 16, No. 1 (January/February 1998), pp. 100-107.
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A process for epitaxial deposition of compound semiconductor layers includes several steps. In a first step, a substrate is removably attached to a substrate holder that may be heated. In a second step, the substrate is heated to a temperature suitable for epitaxial deposition. In a third step, substances are vaporized into vapor particles, such substances including at least one of a list of substances, comprising elemental metals, metal alloys and dopants. In a fourth step, the vapor particles are discharged to the deposition chamber. In a fifth step, a pressure is maintained in the range of 10̂-3 to 1 mbar in the deposition chamber by supplying a mixture of gases comprising at least one gas, wherein vapor particles and gas particles propagate diffusively. In a sixth optional step, a magnetic field may be applied to the deposition chamber. In a seventh step, the vapor particles and gas particles are activated by a plasma in direct contact with the sample holder. In an eighth step, vapor particles and gas particles are allowed to react, so as to form a uniform epitaxial layer on the heated substrate by low-energy plasma-enhanced vapor phase epitaxy.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of and priority to European patent application No. 15382190.5 filed on Apr. 20, 2015, the entire disclosure of which is incorporated by reference herein.
TECHNICAL FIELD
[0002] The present disclosure relates to a heat exchange device of the so-called floating core type, having a special configuration which allows increasing its durability as it increases its thermal fatigue resistance.
[0003] This disclosure herein is characterized by a configuration having high thermal fatigue resistance due to the special configuration of the end where the floating side of the core is located since stagnation regions that are usually produced in the baffle of the floating end are eliminated by the combination of the shape of the shell and of a deflector. This configuration furthermore results in a low-cost exchanger.
[0004] The device can be applied in EGR (Exhaust Gas Recirculation) systems the use of which in internal combustion engines reduces the emission of contaminant gases, thus protecting the environment.
BACKGROUND
[0005] One of the technical fields undergoing the most intensive development is the field of EGR system heat exchangers since the space and packaging requirements call for increasingly smaller and more efficient devices to allow discharging the same amount of heat in a smaller space.
[0006] When devices are smaller, the same temperature differences are found between areas located closer to one another and therefore result in higher temperature gradients.
[0007] Additionally, heat exchangers formed by a shell housing a bundle of exchange tubes where this bundle of tubes extends between two baffles have the drawback of differential expansion occurring between the shell, directly in contact with the coolant liquid, and in the bundle of tubes, also in direct contact with the hot gas to be cooled. Differential expansion between one component and another is particularly pronounced in the longitudinal direction established by the main direction along which the bundle of tubes extends.
[0008] Among the technical solutions known for preventing differential expansion between the shell and bundle of tubes from giving rise to stresses causing breaks are those based on floating core configurations. The core is the bundle of heat exchange tubes where the tubes are attached at least between two end baffles. One baffle is conjoint with the shell and the other baffle, i.e., the baffle corresponding to the floating end, allows relative movement with respect to the shell. The baffle that allows movement is usually connected, according to the particular configuration of the exchanger, by an elastically deformable element establishing the fluid continuity of the hot gas conduit and it is the one which allows thermal expansion.
[0009] Both fixed and movable baffles are walls located transverse to the bundle of tubes. If the hot gas inlet is at the floating end, the movable baffle is the one that is subjected to higher temperature. Given that the baffle is movable, the coolant liquid flow tends to flow around the perimetral area of the baffle. This condition leads to a stagnation point or region causing the coolant liquid to remain in the hot area without discharging heat until reaching the boiling temperature. This is one of the causes generating thermal fatigue and failure of the device.
[0010] The present disclosure proposes a particular configuration of a floating core device in which the existence of stagnation regions in the baffle on the floating side is prevented, preventing thermal fatigue and therefore prolonging the service life of the device.
SUMMARY
[0011] The present disclosure relates to a heat exchange device adapted for cooling a hot gas by a coolant liquid, particularly configured for preventing thermal fatigue, solving the drawbacks identified above.
[0012] The device comprises:
a bundle of heat exchange tubes extending according to a longitudinal direction X-X′ between a first fixed baffle and a second floating baffle for passage of the hot gas to be cooled, a shell housing the bundle of tubes wherein the space between the shell and the bundle of tubes allows passage of the coolant liquid, wherein:
the shell is closed at one end by the first fixed baffle and comprises at the opposite end a chamber configured by an extension by a shell segment having a larger cross-section closed with a third baffle, a first coolant liquid inlet/outlet is located at a point of the shell on the side of the first baffle and a second coolant liquid inlet/outlet is established in a position of the shell segment having a larger cross-section.
[0017] The heat exchanger has a floating core configuration. The core is formed by a bundle of exchange tubes extending between two baffles, a first baffle which is conjoint with the shell, hence it is referred to as a fixed baffle, and a second floating or movable baffle due to the effect of differential expansion with respect to the shell. The expansion compensated for by the floating core configuration is the expansion in the direction of the exchange tubes. This is the direction identified as longitudinal direction X-X′. The baffles are usually arranged transverse to the longitudinal direction.
[0018] The exchange tubes are tubes through which the hot gas to be cooled passes, and they are externally surrounded by the coolant liquid. The coolant liquid circulates through the space located between the outer surface of the tubes of the bundle of tubes and the shell.
[0019] The shell also extends according to longitudinal direction X-X′. It is closed at one end by the fixed baffle. The shell comprises at the opposite end an extension configured by a segment located at the end opposite the end containing the fixed baffle and the section of which is larger. The larger section of this end segment forms a chamber. The final end of the shell on the side of the chamber formed by the segment having a larger section is closed by a third baffle. One particular way of providing the extension is by two tubular bodies having different sections, i.e., a first tubular body having a smaller section, housing primarily the bundle of tubes, and a second tubular body having larger dimensions located right after the end of the first tubular body. The transition between the first tubular body and the second tubular body can be configured by a transition body formed by a transition surface between the section of the first tubular body and the section of the second tubular body. This transition surface establishes continuity between the first body and the second body assuring leaktightness between them. If the tubular bodies have a circular section, the transition surface can be ring-shaped or even funnel-shaped.
[0020] The heat exchanger can operate under co-current or counter-current flow. Therefore, accesses to the inner space of the shell intended for the coolant liquid are identified as inlet/outlet. There are at least two accesses for the entry and exit of the coolant liquid, a first access located at a point of the shell on the side of the first baffle, i.e., close to the first baffle, and the other access is located on the opposite side located in a position of the shell segment having a larger section. If one of the accesses serves as an inlet then the other one is the outlet.
[0021] Additionally, the device provides that:
the second floating baffle has a manifold in fluid connection with the inlet of the heat exchange tubes, and the manifold is in turn in fluid connection with an inlet for the hot gas arranged in the third baffle, where this fluid connection is by an elastically deformable conduit at least according to longitudinal direction X-X, the second floating baffle together with the manifold are housed in the extension formed by the shell segment having a larger section and spaced by a separation from the shell segment along the perimeter of the assembly to allow passage of the coolant liquid; and the position of the shell segment having a larger section where the second coolant liquid inlet/outlet is located, according to the longitudinal direction, between the second floating baffle-manifold assembly and the third baffle.
[0024] The second baffle or floating baffle of the bundle of tubes is therefore located between the first baffle and the third baffle in a position such that it is housed in the chamber formed by the extension of the shell. Enlargement in longitudinal direction X-X′ is mainly due to the longitudinal expansion of the bundle of tubes so the assembly formed by the second baffle and the manifold distributing hot gas at the inlet of the exchange tubes of the bundle of tubes will move inside this chamber. The longitudinal expansion of the entire core establishes a degree of approaching the third baffle and is compensated for by the deformation capability of the elastically deformable conduit connecting the hot gas inlet of the heat exchanger and the manifold.
[0025] Hot gas therefore enters through an opening of the third baffle and gains access to the manifold through the elastically deformable conduit. The inside of the manifold is in fluid communication with the inside of the exchange tubes such that the hot gas is distributed for passing inside the exchange tubes of the bundle of tubes. In the passage through the exchange tubes, the hot gas transfers its heat to the coolant liquid and reaches the opposite end of the tubes, i.e., the end located in the first baffle. The cooled gas is collected, for example, by another outer manifold, and used for final use thereof as an EGR gas, for example.
[0026] With respect to the inner configuration of the exchanger, it is additionally verified that:
in the perimetral separation between the second floating baffle-manifold assembly and the shell segment having a larger section there is a deflector closing the separation space between the assembly and the shell segment having a larger section at least along a segment of the perimetral separation.
[0028] This configuration primarily affects coolant flow. As indicated above, the heat exchanger can operate under co-current or counter-current flow.
[0029] For example, when the heat exchanger operates under counter-current flow and gas enters on the side of the floating core, the coolant liquid enters the shell on the fixed side of the core and flows towards the second baffle. In this segment, the flow is guided by the shell segment that does not correspond to the extension and is therefore arranged against the exchange tubes since reducing the space between the exchange tubes and the shell reduces the presence of paths having lower resistance which favor preventing flow passage between the exchange tubes, reducing the effectiveness thereof.
[0030] This flow reaches the second baffle which is located, together with the manifold, in the chamber formed by the extension of the shell. Given that this assembly formed by the second floating baffle-manifold is spaced by a separation space with the inner wall of the shell segment having a larger section surrounding them, the flow following a longitudinal direction tends to flow around the baffle in order to pass through the perimetral space.
[0031] If there were no additional element, the streamlines corresponding to this flow would extend longitudinally and, upon reaching the baffle, they would get around it through any of the points in the periphery thereof. If, for example, the baffle has a rectangular configuration and four sides, there is a stagnation point with this configuration corresponding to the lines that do not lead to any of the four sides. If, for example, the baffle is circular, then the stagnation point would be the central area of the baffle since the flow lines would not have a preferred position in the periphery for getting around the second baffle.
[0032] The disclosure herein prevents this stagnation region by including a deflector closing the separation space between the assembly formed by the floating baffle together with the manifold and the extended segment of the shell. This deflector closes the space at least along a perimetral segment. In the counter-current example that is being described, the deflector is located downstream with respect to the second baffle.
[0033] The purpose of this deflector is to prevent the passage of most of the flow lines therethrough allowing only the passage through a perimetral portion of the deflector. Additionally, with this deflector it has been observed that the trajectory of the streamlines located on the side of the second baffle in contact with the coolant liquid is modified because a velocity field parallel to the second baffle is created, minimizing and even eliminating stagnation points. Stagnation points are eliminated by a sweeping effect due to a flow parallel to the baffle identified with the streamlines essentially parallel to the baffle in the proximity thereof. This has the effect of increasing coolant velocity with respect to the hot baffle, i.e., the second baffle, significantly increasing the level of cooling thereof and therefore reducing thermal stresses therein.
[0034] In this same counter-current configuration, the effect of generating a velocity field parallel to the second baffle is upstream of the position of the deflector, whereas under co-current flow, the effect is the same and occurs downstream of the deflector. By numerical flow simulation experiments in both cases, the same technical effect is observed, though somewhat greater when the device operates under counter-current flow.
[0035] Likewise, tests have been conducted with prototypes which, without the deflector, failed due to thermal fatigue with a reduced number of cycles, and where the service life of the same device with this deflector has increased such that the fatigue experiment had to be stopped due to its duration without any failure occurring.
[0036] Several additional technical solutions have been developed for the disclosure herein and are described in the embodiment described below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] The foregoing and other features and advantages of the disclosure herein will be more clearly understood based on the following detailed description of a preferred embodiment provided only by way of illustrative and non-limiting example in reference to the attached drawings.
[0038] FIG. 1 shows one embodiment of the disclosure herein formed by a heat exchanger having a rectangular section configuration. The drawing shows a perspective quarter-section view of the heat exchanger along the entire length to allow observing the inner structure.
[0039] FIG. 2 shows the same embodiment where now only the end corresponding to the floating side is shown and the selected view is a perspective quarter-section view of the segment having a length corresponding to the chamber where the segment having a larger section of the shell is located.
[0040] FIG. 3 shows the same end of the embodiment of the preceding figure where the section is according to a longitudinal plane passing through the center of the device.
[0041] FIG. 4 shows a perspective view of an intake deflector protecting the elastically deformable conduit, among others.
[0042] FIG. 5 shows a perspective view of the deflector.
[0043] FIGS. 6 and 7 show two perspective views of another embodiment wherein a comb-shaped deflector is located near the second baffle in combination with the deflector, and the selected views are a perspective quarter-section view of the segment having a length corresponding to the chamber where the segment having a larger section of the shell is located.
[0044] FIGS. 8 and 9 are the front and the back views of the comb-shaped deflector used in the previous embodiment.
DETAILED DESCRIPTION
[0045] According to the first inventive aspect, the present disclosure relates to a heat exchange device adapted for cooling a hot gas by a coolant liquid. One of the uses of this exchanger is to cool part of the combustion gases produced by an internal combustion engine in order to reintroduce them in the intake forming part of an EGR system.
[0046] FIG. 1 shows one embodiment of the disclosure herein, a heat exchanger with a floating core configuration formed by a shell ( 1 ) in which, in this embodiment, the section of the shell ( 1 ) is essentially rectangular. The fixed side of the exchanger is shown on the left side of FIG. 1 , fixed being understood as the core of the exchanger being conjoint with the shell, and the side where the core is floating and allows thermal expansion in longitudinal direction X-X′ is shown on the right side.
[0047] The exchanger of the embodiment has on the fixed side a fixing flange ( 6 ) which allows screwing the exchanger, for example, to a manifold not depicted in the drawing for the sake of clarity, which manifold receives the outlet gases from the exchanger once they have been cooled.
[0048] In this embodiment, the heat exchanger has a bundle of tubes ( 4 ) extending from a first baffle ( 2 ) conjoint with the shell ( 1 ) to a second floating baffle ( 3 ), i.e., not conjoint with the shell ( 1 ).
[0049] In this embodiment, the first baffle has dimensions greater than the section of the shell ( 1 ) such that the flange ( 6 ) presses this first baffle ( 2 ), for example, against a second flange of the manifold that is not shown.
[0050] The bundle of tubes ( 4 ) has a plurality of support baffles ( 5 ) distributed along the length thereof that are either conjoint with the shell ( 1 ) and without restricting longitudinal movement of the bundle of tubes ( 4 ) passing therethrough or conjoint with the bundle of tubes ( 4 ) passing therethrough and without restricting longitudinal movement with respect to the shell ( 1 ). In any of the embodiments of the support baffles ( 5 ), the generation of stresses due to differential expansion of the exchange tubes ( 4 ) with respect to the shell ( 1 ) is prevented. The support action of these support baffles ( 5 ) is with respect to the transverse direction, for example, preventing inertial effects due to mechanical vibrations, and it also establishes a flow with transverse components increasing heat exchange between the bundle of tubes ( 4 ) and the coolant liquid circulating inside the shell ( 1 ).
[0051] In the embodiment shown in this example, the exchange tubes are hybrid tubes, i.e., having an essentially planar configuration and containing therein a bent plate forming fins increasing the effective exchange surface to facilitate heat transfer from the hot gas to the coolant liquid covering the outside of the exchange tubes ( 4 ). Nevertheless, it is possible to use another tube configuration without modifying the essential features of the disclosure herein.
[0052] The floating end of the heat exchanger shows an extension of the shell ( 1 ). In this embodiment, the extension is achieved using two tubular bodies, a first tubular body ( 1 ) arranged against the bundle of tubes ( 4 ) where one of the ends is the side conjoint with the first baffle ( 2 ), and a second tubular body, a shell segment ( 7 ) having a larger section, making up the end segment located at the opposite end of the exchanger according to longitudinal direction X-X′.
[0053] In this embodiment, the first tubular body of the shell ( 1 ) and the second tubular body, the shell segment ( 7 ) having a larger section, are attached by a transition part ( 13 ) configured by a deep-drawn and die-cut plate. This transition part ( 13 ) receives the first tubular body of the shell ( 1 ) on one side and receives the shell segment ( 7 ) having a larger section on the opposite side, such that this transition part defines the extension region of the first tubular body of the shell ( 1 ).
[0054] The second baffle ( 3 ) is located at the floating end of the bundle of tubes ( 4 ). The exchange tubes of the bundle of tubes ( 4 ) are attached to this second baffle ( 3 ) and this second baffle ( 3 ) is in turn attached to a manifold ( 9 ) which is in communication with the hot gas inlet.
[0055] The manifold ( 9 ) receives incoming hot gases and distributes the gas through the inlets of the exchange tubes ( 4 ) such that the hot gas is forced to enter the exchange tubes ( 4 ).
[0056] In this embodiment, the second baffle ( 3 ) is configured by a die-cut and stamped plate surrounding the manifold ( 9 ) where the contact area between both parts ( 3 , 9 ) is an attachment by brazing.
[0057] The manifold ( 9 ) is connected with the end of the exchanger on the floating side by an elastically deformable conduit ( 10 ). In this embodiment, the elastically deformable element ( 10 ) is a bellow-shaped metal conduit. The closure of the shell at the floating end where the shell segment ( 7 ) formed by a tubular body having a larger section is located, is established by a third baffle ( 11 ) having the hot gas inlet.
[0058] The assembly formed by the second baffle ( 3 ) and the manifold ( 9 ) are housed in the shell segment ( 7 ) having a larger section.
[0059] A coolant liquid inlet/outlet is located at the end of the shell corresponding to the fixed side and the other inlet/outlet is located at the opposite end. In this embodiment, the coolant inlet/outlet of the floating side is configured by a groove ( 7 . 1 ) arranged between the end of the shell segment ( 7 ) having a larger section and the third baffle ( 11 ). This configuration has several technical effects, the first being that of placing this groove ( 7 . 1 ) in the area adjacent to the wall formed by the third baffle ( 11 ), preventing stagnation areas between the inlet/outlet and the third baffle ( 11 ), and the second being that of placing same in an area close to the elastically deformable conduit ( 10 ), favoring cooling thereof.
[0060] The elastically deformable conduit ( 10 ) is what receives the hot gas in a more direct manner when the heat exchanger is operating such that this part ( 10 ) is the part having a higher temperature. The end position of the coolant inlet/outlet favors the entire length of this elastically deformable conduit ( 10 ) being suitably cooled, preventing device failure in this location.
[0061] In this embodiment, the second baffle ( 3 ) and the manifold ( 9 ) also have a rectangular configuration. There is arranged between both components ( 3 , 9 ) and the shell segment ( 7 ) having a larger section a space allowing passage of the coolant liquid since the inlet/outlet is located adjacent to the third baffle ( 3 ).
[0062] Streamlines extend primarily from the space between the tubes of the bundle of tubes ( 4 ) to the chamber (C), formed by the extension of the shell segment ( 7 ) having a larger section, surrounding the assembly formed by the second baffle ( 3 ) and the manifold ( 9 ). These streamlines would contain one or more streamlines that would end in the second baffle, giving rise to a stagnation region were it not for the presence of a deflector ( 8 ) located between the assembly formed by the second baffle ( 3 ) and the manifold ( 9 ), and the shell segment ( 7 ) having a larger section. This deflector ( 8 ) modifies the configuration of streamlines, preventing the symmetry that makes the streamlines tend to surround the entire second baffle ( 3 ).
[0063] In particular, in this embodiment the deflector ( 8 ) extends perimetrally around the assembly formed by the second baffle ( 3 ) and the manifold ( 9 ) in a segment equivalent to three of the four sides of the rectangular configuration of the second baffle ( 3 ) or with respect to the respective four sides of the rectangular configuration of the shell segment ( 7 ) having a larger section with which it establishes the closure.
[0064] The flow is therefore forced to only pass through one of the sides, making this preferred direction cause streamlines to run parallel to the second baffle ( 3 ), preventing stagnation regions.
[0065] In this embodiment, closure on three of the four sides by a deflector ( 8 ) is established around the group formed by the second baffle ( 3 )-manifold ( 9 ) assembly in a perimetral band spaced from the plane defined by the second baffle ( 3 ) in longitudinal direction X-X′ towards the side opposite the fixed end of the heat exchanger.
[0066] It is observed in FIG. 2 , with greater detail on the floating side, that in the section of the drawing corresponding to the horizontal plane of section, the deflector ( 8 ) sits on the second baffle ( 3 ) and presses against the inner wall of the shell segment ( 7 ) having a larger section. Nevertheless, in the section of the drawing corresponding to the vertical plane of section, it is observed that the deflector ( 8 ) sits on the second baffle ( 3 ) but does not extend to the inner wall of the shell segment ( 7 ) having a larger section to allow passage of the coolant liquid. Passage of the coolant liquid according to this FIG. 2 is in the upper part of the drawing in order to observe the difference between the side closure and this opening.
[0067] Nevertheless, in the section of FIG. 3 , the open side is located in the lower part, rotating the device 180° with respect to the X-X′ axis.
[0068] FIG. 5 shows a perspective view of the deflector ( 8 ) used in this embodiment in an essentially rectangular shape, configured for surrounding the second baffle ( 3 ) and the latter in turn surrounding the manifold ( 9 ).
[0069] The deflector ( 8 ) is manufactured from die-cut and bent plate. It internally has a perimetral band giving rise to the seat ( 8 . 1 ) which is supported on the surface of the second baffle ( 3 ). Perimetrally, the perimetral surface is formed by consecutively arranged sheets to prevent passage and to give rise to flexible elements that are arranged against the inner wall of the shell segment ( 7 ) having a larger section. These sheets are distributed perimetrally except on one side, in this case a smaller side, giving rise to a window ( 8 . 3 ) for passage of the coolant liquid.
[0070] There are also small separations ( 8 . 2 ) between sheets which allow a small amount of coolant flow. Passage of this small amount of flow through the separations prevents new stagnation regions from being generated around the deflector ( 8 ).
[0071] It has been found through experiments that this arrangement and configuration of the deflector ( 8 ) located in the chamber (C) prevents stagnation regions in the second baffle ( 3 ) which is in contact with the hottest gas since these same experiments demonstrate that the described configuration generates a flow parallel to the second baffle ( 3 ) entraining any stagnation region, increasing coolant velocity in the area closest to the wall of the metal and therefore preventing thermal fatigue.
[0072] Blocking of the flow by the deflector ( 8 ), like any other surface placed in the way of a flow, generates stagnation regions, precisely the effect to be prevented. Nevertheless, the configuration by sheets distributed with separations ( 8 . 2 ) prevents the formation of these stagnation or recirculation regions without preventing the sweeping effect of the stagnation regions from occurring in the second baffle ( 3 ).
[0073] This change in configuration of streamlines in the coolant flow has been verified by numerical CFD simulations both under co-current and counter-current flow.
[0074] Thermal fatigue test results have also demonstrated that failures which occur without using the deflector ( 8 ) disappear.
[0075] Another technical solution adopted in this embodiment is the existence of a prolongation of the first tubular body of the shell ( 1 ) entering part of the chamber (C) formed by the shell segment ( 7 ) having a larger section. In this case, the velocity of the velocity field in the chamber (C) and particularly the transverse flow running parallel to the second baffle ( 3 ) is increased. The technical effect is better cooling of the second baffle ( 3 ), i.e., the baffle exposed to hot gas the most. The increase in velocity is also observed inside the chamber (C) and therefore reduces new stagnation points generated by the deflector ( 8 ).
[0076] The embodiment of the disclosure herein also incorporates another way to additionally protect the elastically deformable conduit ( 10 ) from the high temperatures to which it is subjected given that the conduit directly receives the incoming hot gas. The way to protect the inlet is by an intake deflector ( 12 ) configured by a tubular segment intended for being housed inside the elastically deformable conduit ( 10 ) but spaced from it. The separation between the elastically deformable conduit ( 10 ) and the intake deflector ( 12 ) establishes a chamber insulating the elastically deformable conduit ( 10 ), reducing direct heat transfer from the hot gas flow. Not only does it establish a separation chamber but it also establishes guidance of the hot gas flow towards the central axis so that it does not hit the walls directly.
[0077] The tubular segment of the intake deflector ( 12 ) expands outwardly in order to be supported on the outer surface of the third baffle ( 11 ). This configuration allows the third baffle ( 11 ), once it is attached to an outer flange, to leave this outer extension of the intake deflector ( 12 ) retained, achieving the fixing thereof. This fixing does not require welding which, with abrupt temperature changes, would be damaged by the expansion stresses that would be produced.
[0078] Additionally, this intake deflector ( 12 ) shows a perimetral rib ( 12 . 1 ) in the extension, which is achieved in this embodiment by deep-drawing, increasing the pressure with which the third baffle ( 11 ) and the outer flange are fixed. Particularly, the perimetral rib ( 12 . 1 ) is located on the outer face of the third baffle ( 11 ) for establishing a pressure type seat after establishing the attachment of the flange.
[0079] The section of FIGS. 1 and 2 shows the groove ( 7 . 1 ) of the coolant liquid inlet/outlet obtained by the spacing of the end edge of the shell segment ( 7 ) having a larger section with the third baffle ( 3 ). A coolant liquid manifold ( 14 ) for receiving/supplying coolant liquid since the coolant liquid manifold ( 14 ) is in fluid communication with the groove ( 7 . 1 ) is formed in this embodiment by a die-cut outer plate.
[0080] The die-cut outer plate giving rise to the coolant liquid manifold ( 14 ) runs parallel to the outer edge of the third baffle ( 11 ), such that together with a flange ( 15 ) having greater resistance, the means of fixing with the outer flange which is not graphically depicted are defined.
[0081] The outer face of the third baffle ( 3 ) together with the perimetral rib ( 12 . 1 ) of the intake deflector ( 12 ) is the seat with which the heat exchanger is attached on the hot side to the outer flange connecting the heat exchanger with the hot gas uptake.
[0082] FIGS. 6 and 7 show another embodiment of the disclosure herein. The shell segment ( 7 ) having a larger section has been obtained by deep-drawing the same plate of the main longitudinal segment of the shell ( 1 ) housing the bundle of tubes ( 4 ), thus generating a step between both segments ( 1 , 7 ). In this particular embodiment, the shell ( 1 ) housing the bundle of tubes ( 4 ) comprises two pieces with a “U” section according to a cross section being joined together along two longitudinal welded lines.
[0083] As it has been disclosed before, according to the disclosure herein the flow is forced to only pass through one of the sides of the deflector ( 8 ), making this preferred direction cause streamlines to run parallel to the second baffle ( 3 ), preventing stagnation regions.
[0084] Even if this change in the velocity field of the coolant flow has been verified by numerical CFD simulations both under co-current and counter-current flow, the effect is more relevant in counter-current flow as the flow of the coolant, when flowing within the bundle of tubes ( 4 ), tends to keep the longitudinal direction X-X′ due to inertial forces. The streamlines are not deviated from the longitudinal direction until the flow is very close to the second baffle ( 3 ) and then is redirected, flowing parallel to the second baffle ( 3 ).
[0085] On the contrary, the co-current flow shows a flow coming from the chamber (C) trying to flow according to the pressure gradient within the bundle of tubes ( 4 ); therefore, as soon as the flow enters into the space located within the bundle of tubes ( 4 ) it is oriented towards the fixed part of the heat exchanger preventing it to flow parallel to the second baffle ( 3 ) and then reducing the effect of the deflector ( 8 ).
[0086] According to the embodiment shown in FIGS. 6 and 7 , a comb-shaped deflector ( 16 ) is located, according to the longitudinal direction X-X′, in the chamber (C).
[0087] As FIGS. 8 and 9 show, the comb-shaped deflector ( 16 ) comprises a transversal body ( 16 . 1 ) and a plurality of parallel projections ( 16 . 3 ) departing from the transversal body ( 16 . 1 ). The parallel projections ( 16 . 3 ) are extended between two lateral plates ( 16 . 2 ). The lateral plates ( 16 . 2 ) and the transversal body ( 16 . 1 ) shows one or more supports ( 16 . 5 ) configured by bending the plate in a perpendicular direction.
[0088] The comb-shaped deflector ( 16 ) is partially housed among the tubes of the bundle of tubes ( 4 ). The transversal body ( 16 . 1 ) is housed between the bundle of tubes ( 4 ) and the shell segment ( 7 ) having a larger section, oriented transversal to the longitudinal direction X-X′.
[0089] The parallel projections ( 16 . 3 ) are inserted into the space between tubes of the bundle of tubes ( 4 ) and parallel to the second floating baffle ( 3 ), being the parallel projections ( 16 . 3 ) separated from the second floating baffle ( 3 ).
[0090] The comb-shaped deflector ( 16 ) comprises at least one support ( 16 . 5 ) in the transversal body ( 16 . 1 ), in the lateral plates ( 16 . 2 ) or in both. The comb-shaped deflector ( 16 ) is fixed, for instance by brazing, or by fixing the supports ( 16 . 5 ) to the internal wall of the chamber (C), or by fixing the parallel projections ( 16 . 3 ) to the bundle of tubes ( 4 ). In the embodiments shown in FIGS. 6 and 7 the supports ( 16 . 5 ) are fixed to the internal wall of the chamber (C) while the parallel projections ( 16 . 3 ) are not; these parallel projections ( 16 . 3 ) are just abutting the tubes of the bundle of tubes ( 4 ) allowing the bundle of tubes ( 4 ) to expand when heated by the hot gas.
[0091] The comb-shaped deflector ( 16 ) shows a further seat surface ( 16 . 3 . 1 ) in the parallel projections ( 16 . 3 ), in this embodiment by bending the plate, allowing the comb-shaped deflector ( 16 ) to rest on the surface of the bundle of tubes ( 4 ), at least in a portion of the seat surface ( 16 . 3 . 1 ).
[0092] The seat surface ( 16 . 3 . 1 ) has at least a first straight portion (a) abutting one flat face of a heat exchanger tube, a second arched portion (b) abutting the curved side of the heat exchanger tube; and, a third straight portion (c) parallel to the opposite flat face of the heat exchanger tube.
[0093] In this embodiment, between the second arched portion (b) and the third straight portion (c) there is a transition straight portion reaching a step (s), this step (s) defining the separation between the parallel projection ( 16 . 3 ) and the flat face of the heat exchanger tube. The separation between the opposite flat side of the heat exchanger tube and the third straight portion (c) allows the flow sweeping any stagnation region of the flow located adjacent to the parallel projections ( 16 . 3 ) of the comb-shaped deflector ( 16 ). In this embodiment, the step (s) is a curved step.
[0094] In one embodiment, not shown in the figures, the seat surface ( 16 . 3 . 1 ) is obtained by using a thicker plate provided with an edge wide enough for allowing a seat surface ( 16 . 3 . 1 ) with a resting surface rather than using a bended portion of the plate.
[0095] In one embodiment, not shown in figures, the third straight portion (c) is also abutting the opposite flat face of the heat exchanger tube allowing to deflect the whole flow of the surrounding region.
[0096] The comb-shaped deflector ( 16 ) further comprises a plurality of windows ( 16 . 4 ) adjacent to the seat surfaces ( 16 . 3 . 1 ) allowing the flow to pass through, preventing stagnation regions generated by the main surface of the transversal body ( 16 . 1 ). As FIGS. 6-9 show, in this embodiment the plurality of windows ( 16 . 4 ) are located out of the bundle of tubes ( 4 ), next to the space between heat exchanger tubes; that is, each window ( 16 . 4 ) is located in correspondence with each space between two flat heat exchanger tubes.
[0097] By running CFD simulations of the heat exchange device with co-current flow, the comb-shaped deflector ( 16 ) has been observed to force the coolant to flow parallel to the second floating baffle ( 3 ) almost on the entire surface of the second floating baffle ( 3 ) preventing the generation of stagnation regions even under co-current flow conditions.
[0098] It is important to insert the transversal body of the comb-shaped deflector ( 16 ) in the side of the rectangular section of the bundle of tubes ( 4 ) corresponding to the side where the window ( 8 . 3 ) of the deflector ( 8 ) is located in order to modify the flow coming from the window ( 8 . 3 ).
[0099] The embodiment shown in FIGS. 6 and 7 avoids the use of the intake deflector ( 12 ). Alternatively, the inlet has a connecting piece ( 17 ) as an interface between a connecting tube (not shown) and the third baffle ( 11 ). This connecting piece ( 17 ) has two different sections in the hole allowing the flow to pass through, a small section in the outer part of the hole and a large section in the inner part of the hole, both different sections separated by a step ( 17 . 1 ).
[0100] The shape of the connecting piece ( 17 ) located at the inlet causes a hot gas jet with a diameter smaller that the large section; therefore, the hot gas at the inlet does not impinge directly over the inner wall of the internal conduit protecting it against high temperatures.
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A heat exchange device of a floating core type, having a special configuration which allows increasing its durability as it increases its thermal fatigue resistance. The device is characterized by a configuration having high thermal fatigue resistance due to the special configuration of the end where the floating side of the core is located since stagnation regions that are usually produced in the baffle of the floating end are eliminated by the combination of the shape of the shell and of a deflector. This configuration furthermore results in a low-cost exchanger.
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BACKGROUND OF THE INVENTION
This invention relates to a novel method for the production of perfluoro-(N-vinylamine) compounds. More particularly, this invention relates to a method for producing, economically in high yields from readily available raw materials, perfluoro-(N-vinylamine) compounds which are useful as intermediates or macromolecular monomers for synthesis of fluorine-containing products such as surfactants, agricultural pesticides, and medicines.
In the perfluoro-(N-vinylamine) compounds represented by the following general formula: ##STR2## [wherein R 1 and R 2 independently stand for a perfluoroalkyl group, providing that the two groups may be coupled either directly or through the medium of an oxygen atom or a nitrogen atom and the two groups may form a five-member or six-member ring in combination with the nitrogen atom to which they are coupled] and a perfluoro-alkyl amino group is joined to either of the carbon atoms of a double bond. By using these perfluoro-(N-vinylamine) compounds as intermediates, therefore, various useful compounds containing the perfluoro-alkyl amino group can be produced.
By copolymerizing these compounds with other fluoro-olefins, it is possible to lower the degree of crystallinity of producing copolymers due to the incorporation of the bulky perfluoro-alkylamino group and allow them to acquire improved mechanical properties. These perfluoro-(N-vinylamine) compounds are highly useful as intermediates for synthesis and as sources for production of fluorine-containing polymers.
These perfluoro-(N-vinylamine) compounds have already been known to the art and have heretofore been produced by the following two methods.
The first method comprises subjecting a perfluoroalkyl amino radical and a suitable fluorine-containing olefin to addition reaction and subsequently subjecting the resultant adduct to a reaction for removal of hydrogen halogenide or a reaction for thermal decomposition thereby re-forming an unsaturated bond.
It is known that perfluoro-(N,N-dimethylvinylamine) (specification of U.S. Pat. No. 3,311,599), perfluoro(N-vinylmorpholine) ["Journal of Chemical Society, Perkin I., page 5 (1973)], and perfluoro-(N-vinylpiperidine) ["Journal of Chemical Society", (C), page 2608 (1968)] can be produced by this first method.
Since this method uses special compounds as starting materials, however, it entails difficulty in procuring the raw materials, complexity of procedure of the production, and deficiency of yield as problems yet to be solved.
The second method comprises converting recently developed perfluoro-carboxylic acid derivatives into perfluoro-(N-vinylamine) compounds by thermal decomposition. Specifically, methods for producing perfluoro-(N-vinylamine) compounds represented by the formulas (Ia) and (Ib) by respectively using as raw materials perfluoro-carboxylic acid derivatives represented by the general formulas (II) and (III) have been known (Japanese Patent Application SHO 60(1985)-162631 and SHO 60(1985)-162632 and U.S. Ser. No. 06/886608, for example. ##STR3## [wherein A stands for a chemical bond, CF 2 , O<, or R--N (wherein R is a perfluoro-alkyl amino group), X has the same meaning as defined above, and X 1 stands for F, perfluoro-alkoxy group, or OM (wherein M has the same meaning as defined above)].
This second method, however, exclusively uses the perfluoro-carboxylic acid derivatives represented by the general formulas (II) and (III) as raw materials. No other perfluoro-carboxylic acid derivative has been known to be usable in the reaction which is effected by the second method.
SUMMARY OF THE INVENTION
An object of this invention is to provide a method for producing perfluoro-(N-vinylamine) compounds useful as intermediates for synthesis and as monomers for the manufacture of fluorine-containing polymers easily from readily available raw materials by the reaction of thermal decomposition.
This invention has been perfected as a result of a study continued for the accomplishment of the object described above.
To be specific, this invention is directed to a method for the production of a perfluoro-(N-vinylamine) compound containing a >NCF═CF 2 group from a perfluoro-compound containing a group of the following general formula: ##STR4## [wherein X stands for one member selected from the group consisting of (a) a fluorine atom and (b) a --OM group (wherein M is one member selected from the group consisting of alkali metal ions and alkaline earth metal ions of a valency of one] and having connected to the aforementioned group a perfluoro-alkyl group having a total of 2 to 6 carbon atoms contained in the main carbon chain thereof by heating the perfluoro-compound to a temperature in the range of 100° C. to 500° C. thereby effecting conversion of the group of the general formula into the >NCF═CF 2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The method of this invention is not anticipated by prior art.
As indicated by the following reaction formulas, when perfluoro-(2-alkoxypropionyl fluorides) and alkali metal salts of acids thereof are thermally decomposed, they undergo a reaction of decarboxylation and give rise to perfluoro-vinyl ethers in high yields. On the other hand, it has been known that in the case of perfluoro-(3-alkoxypropionyl fluorides) and alkali metal salts of acids thereof, they only give tetrafluoro-ethylene and lower perfluorocarboxylic acid fluorides as products of thermal decomposition (Japanese Patent Publication SHO 39(1964)-26709). ##STR5## (wherein R f stands for a perfluoro-alkyl group of 1 to 8 carbon atoms, R' f for F or a perfluoro-alkyl group of 1 to 7 carbon atoms, and X has the same meaning as defined above).
In the case of perfluoro-(3-alkylamino group-substituted propionic acids) which are isoelectronic compounds relative to the perfluoro-(3-alkoxypropionic acids), therefore, it has been held that the acid fluorides and metal salts thereof will similarly undergo decomposition as shown by the following reaction formula. ##STR6## [wherein R' 1 and R' 2 independently stand for a perfluoroalkyl group of 1 to 5 carbon atoms, R 3 for a perfluoroalkyl group having one carbon atom less than R' 2 , and X has the same meaning as defined above).
Thus, these perfluoro-(3-alkylamino group-substituted propionic acids) have never been contemplated as possible raw materials for the production of perfluoro(N-vinylamine) compounds.
The inventor took notice of the ready availability of perfluoro-(3-alkylamino group-substituted propionic acids) and continued a study in search of a method for the production of perfluoro-(N-vinylamine) compounds by using such propionic acids as raw materials. They consequently found unexpectedly that when these perfluoro-(3-alkylamino group-substituted propionic acids) are thermally decomposed, perfluoro-(N-vinylamine) compounds represented by the aforementioned general formula (I) are obtained as products of the thermal decomposition. This invention has been perfected as a result.
Concrete examples of the ##STR7## group in the aforementioned general formula are as follows. ##STR8## (where n and m independently stand for an integer in the range of 1 to 5).
In the method of this invention, perfluoro-compounds represented by the general formula (IV) described below are used as raw materials. Specifically, perfluoro-(3-alkylamino or 3-cyclicaminopropionyl fluorides) or alkali metal salts or alkaline earth metal salts of perfluoro-(3-alkylamino or 3-cyclicaminopropionic acids) are used. ##STR9## (wherein R 1 , R 2 and X have the same meanings as defined above.)
The perfluoro-(3-alkylamino or 3-cyclic aminopropionyl fluorides) are easily obtained, for example, by electrolytically fluorinating a reactive derivatives of 3-alkylamino or 3-cyclicaminopropionic acids in liquid hydrogen fluoride (U.S. Pat. No. 3,471,484). The metal salts of perfluoro-(3-alkylamino or 3-cyclicaminopropionic acids are easily obtained by causing a hydroxide of an alkali metal or alkaline earth metal to react on the perfluoro-(3-alkylamino or 3-cyclic aminopropionyl fluorides) obtained as described above.
The perfluoro-(N-vinylamine) compounds of the general formula: ##STR10## (wherein R 1 and R 2 have the same meanings as defined above) which is aimed at by the present invention is easily obtained by simply subjecting the perfluoro-compounds of the aforementioned general formula (IV) to thermal decomposition. In terms of the smoothness with which the reaction of thermal decomposition proceeds, preferred examples of the perfluoro-compounds to be used advantageously as the raw material include perfluoro-(3-alkylamino or 3-cyclic aminopropionyl fluorides), sodium salts of perfluoro-(3-alkylamino or 3-cyclicaminopropionic acids), and potassium salts of perfluoro-(3-alkylamino or 3-cyclicaminopropionic acids).
The temperature of the thermal decomposition is selected in the range of 100° C. to 500° C., preferably in the range of 100° C. to 300° C. If this temperature is unduly high, there tend to ensue secondary reactions such as unwanted decomposition. If it is unduly low, the conversion is obtained only in a low ratio. Though the time of reaction is variable with the reaction temperature, it is generally in the range of 10 seconds to two hours. The reaction time is short where a high reaction temperature is selected and is long where a low reaction temperature is selected.
The reaction pressure is not an important factor in this reaction of thermal decomposition. The reaction can be carried out effectively under a vacuum, normal atmospheric pressure, or an increased pressure. Preferably, the reaction is carried out under normal atmospheric pressure or under a vacuum because the product of the reaction can be recovered rather easily. The reaction of thermal decomposition, depending on the form of reaction, can be carried out using as a diluent for the reaction mixture either an inert gas such as nitrogen, helium, argon, or carbon dioxide or a non-protonic liquid compound such as a polyether, tetrachloroethylene, or n-heptane. In this case, the ratio of dilution is desired to be not more than 100 times the amount of the reaction mixture.
Further, for the sake of the reaction of thermal decomposition, it is essential that all the substances used in the reaction should contain no water.
Where perfluoro-(3-alkylamino or 3-cyclic-aminopropionyl fluorides) are used as the raw material in the method of this invention, the reaction of thermal decomposition is desired to be carried out in the presence of a metal salt or a metal oxide. In this case, the desired perfluoro-(N-vinylamine) compounds are obtained easily by continuously passing the raw material through a packed bed of the metal salt or metal oxide kept at a prescribed temperature thereby effecting the reaction of thermal decomposition. Though the method of the present invention is not very particular about the material for the reactor used for the thermal decomposition, the reactor is generally made of stainless steel or a Hastelloy metal. The packed bed mentioned above is not limited specifically by shape. It can be used effectively in any shape. Examples of the bed usable advantageously for the reaction include a fixed bed, a moving bed and a fluidized bed.
Concrete examples of the metal salt mentioned above include sodium carbonate, potassium carbonate, lithium carbonate, sodium phosphate, potassium phosphate, barium carbonate, calcium carbonate, magnesium carbonate, potassium sulfate, and sodium sulfate. As examples of the metal oxide, there can be cited zinc oxide and cadmium oxide. Among other metal compounds enumerated above, such solid salts as sodium carbonate and potassium carbonate prove to be particularly desirable because they are capable of decomposing the noxious COF 2 which occurs in the course of the thermal decomposition.
The method of this invention enables the perfluoro(N-vinylamine) compounds to be produced in a high yield through a very simple process from readily available raw materials. Thus, it constitutes an advantageous process for the production of the perfluoro-(N-vinylamine) compounds on a commercial scale.
Further, the perfluoro-(N-vinylamine) compounds produced by the method are used advantageously as an intermediate for the synthesis of fluorine-containing products such as surfactants, agricultural pesticides, and medicines and as a monomer for the production of fluorine-containing polymers.
Now, the present invention will be described more specifically below with reference to working examples. It should be noted that this invention is not limited in any way by these working examples.
EXAMPLE 1
As a raw material, a crude product obtained by electrolytically fluorinating methyl 3-dimethylaminopropionate and distilling the resultant product of fluorination to expel the greater part of low-boiling compounds was used. The perfluoro-(3-dimethylaminopropionyl fluoride) content of this crude product was 48.0% by weight.
In a three-neck flask having an inner volume of 200 ml and provided with a reflux condenser and a dropping funnel, 12.00 g of the crude product mentioned above [containing 5.75 g of perfluoro-(3-dimethylaminopropionyl fluoride)] and 30 ml of water were placed and phenolphthalein was added as an indicator thereto. The contents of the flask were kept agitated with a magnetic stirrer and ice cooled and a concentrated aqueous potassium hydroxide solution was added thereto dropwise until the resultant mixture showed alkalinity.
Then, the contents of the flask were transferred into a beaker having an inner volume of 300 ml and heated over a hot plate for evaporation of water. The residue was transferred into a flask having an inner volume of 200 ml and held therein under a vacuum at 70° C. for about eight hours for desiccation.
The white solid substance thus obtained in the flask was comminuted and, with a gas inlet tube connected to the upper end of the flask, helium gas was continuously supplied at a rate of 80 ml/min into the flask. The flask held in this state was heated in an oil bath to raise the temperature thereof gradually from 150° C. to 200° C. over a period of 60 minutes and the flask was then kept at the elevated temperature further for one hour to effect thermal decomposition of the reaction mixture held therein. The product of the thermal decomposition was condensed and collected in a trap kept cooled to -78° C. Thus, 4.53 g of fluorocarbon was collected.
This fluorocarbon was analyzed by gas chromatography [liquid phase: 1,6-bis(1,1,12-trihydroperfluorododecyloxy)-hexane, carrier: Chromosorb PAW 60 to 80 mesh, carrier gas: helium], IR, 19 FNMR, and Mass. The data consequently obtained were found to agree with the spectroscopic data of known perfluoro-(N,N-dimethylvinyl amine).
The amount of perfluoro-(N,N-dimethylvinyl amine) thus obtained was 38.5 g and the yield thereof 86.0%.
EXAMPLE 2
The procedure of Example 1 was repeated, except that the cell drain product obtained by electrolytically fluorinating methyl 3-diethylaminopropionate was used in its unaltered form as a raw material. The cell drain product contained 83.4% by weight of perfluoro-(3-diethylaminopropionyl fluoride).
First, in a three-neck flask having an inner volume of 200 ml and provided with a reflux condenser and a dropping funnel, 50 ml of water was placed and kept cooled with ice and 32.61 g of the aforementioned cell drain product [containing 27.20 g of perfluoro-(3-diethylaminopropionyl fluoride)] was added dropwise. After completion of this dropwise addition, the resultant mixture was stirred for 50 minutes. Then, the solution consequently formed was neutralized with a concentrated aqueous solution of potassium hydroxide until the solution showed slight alkalinity. Then, the contents of the flask were transferred into a beaker having an inner volume of 300 ml and evaporated to dryness on a hot plate. Consequently, there was obtained 32.0 g of a white solid substance.
Then, in a mortar, this white solid substance and about 20 g of dry finely comminuted calcium fluoride added thereto were mixed and finely comminuted. The resultant fine powdered mixture was transferred into a round-bottomed flask having an inner volume of 200 ml, warmed to 80° C. over an oil bath and dried under a vacuum for one hour. The dry powder was thermally decomposed by being heated under a vacuum (110 mmHg) from 200° C. to 270° C. over a period of about 50 minutes and then kept at the elevated temperature further for 23 minutes. The fluorocarbon emanating from the thermally decomposed mixture was collected in a trap kept cooled at -78° C. As a result, 17.48 g of fluorocarbon was collected.
When the fluorocarbon was analyzed in the same manner as in Example 1, the amount of perfluoro-(N,N-diethylvinyl amine) thus produced was found to be 15.67 g and the yield thereof 69.0%.
The boiling point of this product was 56.0 to 57.0° C., d 4 20 thereof 1.6664, and n D 20 thereof was <1.28. The spectroscopic data of this product were as follows. ##STR11##
EXAMPLE 3
A tube of stainless steel 48.0 cm in length and 2.5 cm in inside diameter provided on the inlet side thereof with an instantaneous evaporator for gasification of raw material and a diluent gas flow regulator and on the outlet side thereof with a low-temperature trap was laid horizontally to serve as a reactor. In this reactor, 86.2 g of powdered sodium carbonate was placed so that the upper surface thereof would fall halfway of the height (diameter) of the tube, with either end of the cylinder sealed with metal wool.
First, the reactor was kept at 220° C. and helium gas was kept supplied thereto at a flow rate of 100 ml/min. Then, 7.17 g of a fluorocarbon mixture [having a perfluoro-(3-morpholinopropionyl fluoride) content of 71.5%] was supplied by the use of a fine metering pump to the instantaneous evaporator over a period of 55 minutes, there to be gasified and mixed with helium gas being introduced at a fixed flow rate. The resultant mixed gas was introduced into the reactor. The product of the reaction was condensed and collected in a trap kept cooled to -78° C.
As a result, there was obtained 4.47 g of fluorocarbon. When this fluorocarbon was analyzed in the same manner as in Example 1, it was found to contain 3.24 g of perfluoro-(N-vinylmorpholine). The conversion was 100% and the yield 76.7%.
EXAMPLE 4
The procedure of Example 2 was repeated, except that a fluorocarbon mixture constituting the cell drain product and having a perfluoro-(3-morpholinopropionyl fluoride) content of 70.3% by weight was used as a raw material.
By neutralizing 22.37 g of the fluorocarbon mixture [containing 15.7 g of perfluoro-(3-morpholinopropionyl fluoride)] with an aqueous potassium hydroxide solution and evaporating the neutralized fluorocarbon mixture to dryness, there was obtained 20.9 g of a white solid substance. By comminuting this solid substance and subjecting the comminuted substance to thermal decomposition under a vacuum, there was obtained 10.80 g of fluorocarbon. When this fluorocarbon was analyzed in the same manner as in Example 1, it was found to contain 1.00 g of perfluoro-(5,6-dihydro-2H-1,4-oxazine), and 9.80 g of perfluoro-(N-vinylmorpholine) (Yield 84.4%).
EXAMPLE 5
In the same reactor as used in Example 2, the procedure of Example 2 was repeated, except that 84.4 g of powdered sodium carbonate was packed in the reactor and a fluorocarbon mixture (cell drain product) having a perfluoro-(3-pyrollidinopropionyl fluoride) content of 71.7% was used as a raw material.
When 5.15 g of this fluorocarbon mixture was supplied to the reactor and thermally decomposed therein over a period of 27 minutes, 3.56 g of fluorocarbon was obtained in the cooled trap. When this fluorocarbon was analyzed in the same manner as in Example 1, it was found to contain 2.31 g of perfluoro-(N-vinylpyrrolidine). The conversion was 100% and the yield 76.5%.
EXAMPLE 6
In the same reactor as used in Example 2, the procedure of Example 2 was repeated, except that 84.4 g of powdered potassium carbonate was packed in the reactor and a fluorocarbon mixture (cell drain product) having a perfluoro-(3-piperizinopropionyl fluoride) content of 61.0% was used as a raw material and the reaction temperature was changed to 200° C.
When 13.49 g of the fluorocarbon mixture was supplied to the reactor and thermally decomposed therein over a period of 60 minutes, there was obtained 8.53 g of fluorocarbon was obtained in the cooled trap.
When this fluorocarbon was analyzed in the same manner as in Example 1, it was found to contain 4.85 g of perfluoro-(N-vinylpiperidine).
The conversion was 100% and the yield 70.2%.
EXAMPLE 7
In the same reactor as used in Example 3, the procedure of Example 5 was repeated, except that 87.5 g of powdered sodium carbonate was packed in the reactor and the product (cell drain product) obtained by electrolytically fluorinating methyl 3-hexamethyleneiminopropionate was used as a raw material, and the reaction temperature was changed to 220° C. The product mentioned above was found to contain 17.7% by weight of perfluoro-(3-hexamethyleneiminopropionyl fluoride) and 18.5% by weight of perfluoro-[3-(methylpiperazino)-propionyl fluoride), an isomer.
When 12.49 g of the flurocarbon mixture was supplied to the reaction and thermally decomposed therein over a period of 45 minutes, there was obtained 7.69 g of fluorocarbon as condensed in the cooled trap.
When this fluorocarbon was analyzed in the same manner as in Example 1, it was found to contain 1.68 g of perfluoro-(N-vinylhexamethyleneimine) and 1.69 g of perfluoro-[N-vinyl(methylpiperazine)] (boiling point 102°-103° C.).
The conversion was 100% and the yield of perfluoro-N-vinylhexamethyleneimine) was 88.5% based on the perfluoro-(3-hexamethyleneiminopropionyl fluoride) supplied initially.
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A perfluoro-(N-vinylamine) compound containing a >NCF═CF 2 group is produced from a perfluoro-compound containing a group of the general formula: ##STR1## (wherein X stands for a fluorine atom or a --OM group having an alkali or alkaline earth metal ion for M) and having connected to the group of the general formula a perfluoro-alkyl group having a total of 2 to 6 carbon atoms contained in the main carbon chain thereof by heating the perfluoro-compound at a temperature in the range of 100° C. to 500° C. thereby effecting conversion of the group of the foregoing general formula into the aforementioned >NCF═CF 2 group.
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FIELD OF THE INVENTION
[0001] The present invention relates to a direct methanol fuel cell (DMFC) and a fuel cell system therewith, and, more particularly, to a DMFC operating on concentrated methanol at an anode thereof and a fuel cell system therewith.
BACKGROUND OF THE INVENTION
[0002] In general, a fuel cell is provided with a membrane electrode assembly (“MEA” hereinafter) having an anode, a cathode and an electrolyte membrane having proton conductivity put therebetween. In a case of a direct methanol fuel cell (“DMFC” hereinafter), methanol/water solution is supplied to the anode as a fuel and air is supplied to the cathode as an oxidant. The DMFC need not be provided with a reformer for extracting hydrogen from the fuel; thereby it is advantageous in view of downsizing thereof.
[0003] The electrolyte membrane has a function of exchanging ions between the cathode and the anode and is necessary to be humidified with water. In general, the water for humidifying is either supplied on the anode side or produced from an oxygen reduction reaction on the cathode side.
[0004] It is known that the methanol partly permeates the electrolyte membrane from the anode to the cathode and such methanol is called “crossover methanol”. The crossover methanol reacts with oxygen at the cathode and causes reduction in fuel utilization efficiency and a counter electromotive force so that the power generation of the fuel cell is suppressed.
[0005] It is important to properly regulate the concentration of methanol inside the anode. An Excessively high concentration leads to a generation of a large amount of the crossover methanol and hence reduction of the power generation. Moreover, in an extreme case, the excessively concentrated methanol may deteriorate the MEA. On the contrary, excessively low concentration leads to shortage of fuel for the power generation.
[0006] The water-methanol mixture regulated in a proper concentration in advance may be stored in a fuel tank. However, in this case, a relatively large fuel tank is necessary. Water may be recovered from the water generated at the cathode and admixed with the methanol so as to be a proper concentration. In this case, concentrated methanol may be stored in the fuel tank so that a relatively small capacity of the fuel tank gives a large energy density. However, additional devices for recovering water are necessary. These conventional practices destroy the advantage of DMFC, namely feasibility of downsizing.
SUMMARY OF THE INVENTION
[0007] The present invention is intended to overcome the above problems and achieves a DMFC system operated directly on concentrated methanol solution by proper control of water flow and distribution inside the fuel cell, without external recovery of cathode water. A key feature of the present invention is to confine abundant water inside a region between the anode flow path and cathode catalyst layer, even with circulating air through a cathode flow channel. This is realized, on one side, by using a cathode microporous layer (MPL) which is made highly hydrophobic so that the product water can be pushed back into the anode through a thin membrane. On the other side of the region, namely on the outside of the anode flow path, a water barrier is inserted, which contains a number of elongated holes or pores in a plate of metals, polymers, or ceramics. This barrier has a unique property that it allows liquid flux only in the direction from the fuel flow path into the anode flow path. Back-diffusion of water in the reverse direction is essentially eliminated. The barrier is thus termed “upwind” water barrier. When the cell is under current, the consumption in the anode catalyst layer and crossover through the membrane of methanol and water will cause a strong liquid flow through these holes/pores toward the anode flow path, thereby creating an effect that the downstream does not influence the upstream. This upwind effect virtually eliminates any escape of water from the downstream (inside the water-rich zone) to the upstream (in the fuel flow path). Therefore, the upwind water barrier and the cathode MPL effectively protect water from escaping and hence maintain a constantly water-rich zone in the vicinity of the anode catalyst layer and membrane. The presence of this water-rich zone inside the fuel cell enables the use of concentrated fuel directly with good fuel efficiency and cell performance.
[0008] According to an aspect of the present invention, a fuel cell is provided with an anode, a cathode, an electrolyte membrane put between the anode and the cathode, an anode flow path capable of channeling gas generated at the anode and being layered on the anode, an upwind water barrier having resistance against back-diffusion of water into the fuel flow path, and a cathode MPL to promote water back flow into the anode.
[0009] Additional advantages and aspects of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein embodiments of the present invention are shown and described, simply by way of illustration of the best mode contemplated for practicing the present invention. As will be described, the present invention is capable of other and different embodiments, and its several details are susceptible of modification in various obvious respects, all without departing from the spirit of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not limitative.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The following detailed description of the embodiments of the present invention can best be understood when read in conjunction with the following drawings, in which the various features are not necessarily drawn to scale but rather are drawn as to best illustrate the pertinent features.
[0011] FIG. 1 is a schematic illustration of a fuel cell system according to a first embodiment of the present invention;
[0012] FIG. 2 is a graph showing a relation between a saturation of liquid and a hydrostatic pressure;
[0013] FIG. 3 is a schematic illustration of liquid water distribution and water-rich zone with respect to a structure of the fuel cell;
[0014] FIG. 4 is a graph showing a concentration distribution of water inside the water barrier;
[0015] FIG. 5 is a schematic illustration of a fuel cell system according to a second embodiment of the present invention; and
[0016] FIG. 6 is a schematic illustration of a fuel cell system according to a third embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Referring to FIG. 1 , a fuel cell system 1 according to a first embodiment of the present invention is provided with a MEA having an anode catalyst layer 3 , a cathode catalyst layer 5 and an electrolyte membrane 7 having proton conductivity put therebetween.
[0018] The anode catalyst layer 3 is for oxidizing a fuel (a methanol aqueous solution) and hence extracting electrons and protons therefrom. The anode catalyst layer 3 is provided with an anode gas diffusion layer 11 disposed adjacent thereto, made of carbon paper for example.
[0019] The cathode catalyst layer 5 is for oxygen reduction where electrons provided with a cathode gas diffusion layer 9 disposed adjacent thereto react with the protons generated at the anode catalyst layer 3 to form water at the cathode catalyst layer 5 .
[0020] The electrolyte membrane 7 is made of any ion-exchange materials having proton conductivity. A preferable example thereof is a copolymer of tetrafluoroethylene and perfluorovinyl ether sulfonate and more preferably “Nafion” as a tradename (DuPont Corp.) can be exemplified.
[0021] A conventional configuration can be applied to the MEA and, therefore, further detailed description will be omitted.
[0022] The cathode gas diffusion layer 9 made of porous carbon cloth or carbon paper is layered on an outer surface of the cathode catalyst layer 5 , opposite to the electrolyte membrane 7 , and exposed to outside air. The cathode gas diffusion layer 9 is processed with a hydrophobicity treatment so as to be hydrophobic for increasing a hydrostatic pressure by a capillary force.
[0023] The anode gas diffusion layer 11 made of porous carbon cloth or carbon paper is layered on a surface of the anode catalyst layer 3 , opposite to the electrolyte membrane 7 . The anode gas diffusion layer 11 is processed with a hydrophilicity treatment so as to be hydrophilic.
[0024] At the anode catalyst layer 3 and the cathode catalyst layer 5 , following reactions respectively progress.
[0025] (Anodic Reaction)
CH 3 OH+H 2 O->CO 2 +6H + +6 e − (1)
[0026] (Cathodic Reaction)
3/2O 2 +6H + +6 e − ->3H 2 O (2)
[0027] Provided that liquid having a volume V 1 occupies a space having a volume V in a porous body, a saturation s of liquid is defined as:
s=V 1 /V (3)
[0028] Provided that a porous body is hydrophilic, a capillary force P c in the porous body is represented by an equation:
p c = σ cos θ c ( ɛ K ) 1 / 2 [ 1.417 ( 1 - s ) - 2.120 ( 1 - s ) 2 + 1.263 ( 1 - s ) 3 ] ( 4 )
If hydrophobic, the capillary force P c is:
p c = σ cos θ c ( ɛ K ) 1 / 2 [ 1.417 s - 2.120 s 2 + 1.263 s 3 ] ( 5 )
where σ is a surface tension of the liquid, θ c is a contact angle of the liquid, ε is a voidage of the porous body and K is a permeability to the porous body. In a case where σ, θ c , ε and K are given, the hydrostatic pressure by the capillary force can be represented as a function of the saturation s of liquid as shown in FIG. 2 . As being understood from FIG. 2 , the hydrostatic pressure is kept equal to or lower than the atmospheric pressure in a hydrophilic porous body and kept equal to or higher than the atmospheric pressure in a hydrophobic porous body.
[0029] In the aforementioned constitution, when CO 2 is generated at the anode catalyst layer 3 by the anodic reaction (1), the saturation s of liquid at the anode catalyst layer 3 goes below 1. When water is generated at the cathode catalyst layer 5 by the cathodic reaction (2), the saturation s of liquid at the cathode catalyst layer 5 goes beyond 0. Furthermore, as mentioned above, the anode gas diffusion layer 11 is hydrophilic and the cathode gas diffusion layer 9 is hydrophobic, thereby the capillary force in the cathode gas diffusion layer 9 is made higher than the capillary force in the anode gas diffusion layer 11 .
[0030] Differential water pressure ΔP induced by the capillary force difference between the cathode gas diffusion layer 9 and the anode gas diffusion layer 11 provides driving force of transporting the water generated at the cathode catalyst layer 5 in part to the anode catalyst layer 3 . The transported water can be utilized to result in the water-rich zone at the anode catalyst layer 3 .
[0031] The net transport of water across the electrolyte membrane 7 includes transfer accompanying with protons transfer from the anode catalyst layer 3 to the cathode catalyst layer 5 (“water drag” hereinafter), diffusion and hydraulic permeation driven by the differential water pressure. The diffusion is driven by a difference in water content through the ion-exchanging membrane 7 . As described above, the differential hydrostatic pressure is induced by the capillary force differentiated by the hydrophilic anode gas diffusion layer 11 and the hydrophobic cathode gas diffusion layer 9 and hence transports the water from the cathode catalyst layer 5 to the anode catalyst layer 3 as mentioned above. Namely, the hydraulic permeation driven by the differential water pressure transfers the water from the cathode catalyst layer 5 to the anode catalyst layer 3 , though saturation of water is lower at the cathode catalyst layer 5 than at the anode catalyst layer 3 .
[0032] Flux of the water drag is represented by an equation:
J drag = n d 1 F ( 6 )
where n d is a number of water molecules per a proton accompanying with the proton, I is a current and F is a Faraday's constant. n d is about 2.5 in a case of a Nafion membrane.
[0033] Flux of the water diffusion driven by the concentration gradient is represented by an equation:
J w , mem = ρ mem D mem H 2 O ( λ c - λ a ) EW δ mem ( 7 )
where λ is a water content [H 2 O]/[SO 3 − ] accompanying with the sulfonate group, which is the ion-exchanging group of Nafion, EW is a molar equivalent, δ is a thickness of the Nafion membrane, D is a diffusion constant of water in Nafion and p is a density of Nafion. λ is about 22 when Nafion comes in contact with liquid water, and about 14 when Nafion comes in contact with saturated water vapor.
[0034] Flux of the water transport is represented by an equation:
J l = ρ mem K mem μ mem δ mem [ σ a cos θ a ( ɛ a K a ) 1 / 2 J ( s m / a ) + σ c cos θ c ( ɛ c K c ) 1 / 2 J ( 1 - s m / c ) ] ( 8 )
where J(s)=1.417(1−s)−2.120(1−s)+1.263(1−s) 3 and μ is a viscocity. The subscript “mem” represents electrolyte membrane. The subscripts “a” and “c” respectively represent anode and cathode. The subscript “m/a” represent a boundary between the electrolyte membrane and the anode and the subscript “m/c” represent a boundary between the electrolyte membrane and the cathode.
[0035] Reducing pore sizes of the porous body so as to reduce permeability of water and increasing water-repellency of the porous-body are preferable to increase the hydrostatic pressure at the cathode. On the other hand, the air or oxygen is necessary to be supplied to the cathode catalyst layer 5 . Consequently, a cathode micro-porous layer 14 made of water-repellency treated carbon having sub-micron pore sizes and a thickness of several tens μm is interposed between the cathode catalyst layer 5 and the cathode gas diffusion layer 9 . Thereby, an increase in the hydrostatic pressure can be consistent with sufficient air supply to the cathode catalyst layer 5 .
[0036] To suppress methanol crossover, the Nafion membrane having a thickness of about 150 μm is applied to conventional DMFCs. However, as being understood from the equation (8), the Nafion membrane is preferably made thinner to facilitate water transport driven by the capillary force difference. Test results have shown that the net water coefficient through the membrane according to the present invention can be reduced to zero or even negative by using Nafion 1135 or thinner membranes, even with circulating air through a cathode flow channel. The membrane thickness should be equal to or thinner than 3.5 mil or 90 μm.
[0037] To maintain a water-rich zone in the anode so as to mitigate methanol crossover through the membrane and fuel loss, an anode flow path 19 is further layered on an outer side of the anode gas diffusion layer 11 with the upwind water barrier 15 . The water barrier 15 has much resistance against back-diffusion of water. Provided that water diffuses from the anode flow path 19 to the fuel flow path 21 , a problem of increase in methanol concentration in the anode flow path 19 , may emerge. The water barrier 15 prevents the diffusion of the water from the anode flow path 19 to the fuel flow path 21 and hence makes it possible to maintain a constantly low methanol concentration in the anode flow path 19 . The water barrier 15 is preferably made of a series of holes regularly or randomly patterned in a plate of chemically stable and corrosion-resistant materials. Consequently, the liquid velocity through the holes, induced by methanol and water supply into the anode catalyst layer when the cell is under current, becomes sufficiently fast. This will lead to a dimensionless number (i.e. Peclet number), defined as u 1 L WB /D H2O , on the order of 10 and higher. Here u 1 is the liquid velocity through the holes in the water barrier, L WB the thickness of the water barrier, and D H2O the water diffusion coefficient in liquid. Once Peclet number reaches 10, a situation called “upwind” results, in which the downstream of the barrier, i.e. inside the anode flow path, does no longer influence the upstream which is located in the anode fuel flow path. FIG. 4 plots the water concentration profile inside the water barrier for various Peclet numbers. As can be seen, at the Peclet number of 10, the gradient in water concentration at the mid-point of the barrier vanishes, thereby indicative of zero back-diffusion of water into the fuel flow path. Such a water barrier effectively protects water from being escaped into the fuel supply with high methanol concentration. The water barrier 15 makes it possible to keep a state where a water concentration in the fuel flow path is kept between, for example, 0 and 30 M when a water concentration in the anode flow path 19 is 50 M.
[0038] Specifically, the liquid velocity through the water barrier is calculated from materials balance at the anode catalyst layer, namely
u l = 1 S I ρ l 6 F [ M MeOH ( 1 + β ) + M H2O ( 1 + α ) ] ( 9 )
where S is the open area ratio of the water barrier 15 , I the operating current density, ρ 1 the methanol/water solution density, F Faraday's constant (96,487 C/mol), M MeOH the molecular weight of methanol (i.e. 32 g/mol), and M H2O the molecular weight of water (i.e. 18 g/mol). β is the ratio of crossover methanol to methanol consumed at the anode for power generation. α is the number of water molecules per proton migrating through the polymer membrane. Evidently, the first and second terms on the right hand side of Equation (9) represent the methanol and water losses from the anode catalyst layer, respectively, once the cell is under current. This means that the liquid flow through the water barrier is activated by electrochemical reactions and current flow through the membrane.
[0039] The anode flow path 19 is configured to channel CO 2 generated by the anodic reaction. The anode flow path 19 uses a buoyant force by gravity or internal pressurization to exhausting CO 2 outward. The anode flow path 19 carries off CO 2 from the anode catalyst layer 3 so that the anodic reaction at the anode catalyst layer 3 is promoted. Water and methanol concentrations in the anode flow path 19 are kept substantially constant by means of an agitation effect caused by transfer of the CO 2 gas.
[0040] In the case that the water barrier is made of electrically conducting materials, there are contacts between the water barrier 15 and the anode gas diffusion layer 11 to enable current collection from the cell. In the case that the water barrier 15 is made of electrically insulating materials, the water barrier will be housed inside an electrically conducting metal grid, mesh or frame to collect electric current from the anode gas diffusion layer. A metal current collector (not shown in FIG. 1 ) is placed on the outside of the cathode gas diffusion layer 9 in order to collect electric current from the cathode side as known to those skilled in the art. The electricity can be obtained between the anode and cathode current collectors.
[0041] In the above constitution, the fuel flow path 21 , the water barrier 15 , the anode flow path 19 , the anode gas diffusion layer 11 , the anode micro-porous layer 13 and such form a fuel supply path for supplying the fuel to the anode catalyst layer 3 of the fuel cell 1 . A fuel pump 27 is disposed on a link flow path 25 interconnecting between the fuel tank 23 , which stores a highly concentrated fuel (50 through 100% methanol, for example), and the fuel flow path 21 . The fuel flow path 21 and the fuel tank 23 are further connected via a recovery flow path 29 so as to recover unreacted methanol from the fuel flow path 21 . A radiator 30 may be disposed on the recovery flow path 29 .
[0042] According to the above constitution, CO 2 generated at the anode catalyst layer 3 by the anodic reaction is exhausted from the anode flow path 19 outward by gravity and/or internal pressurization and the water generated at the cathode catalyst layer 5 by the cathodic reaction is partly transferred to the anode catalyst layer 3 by the capillary force and utilized to dilute the methanol supplied to the anode catalyst layer 3 . A distribution of water concentration in the fuel cell 1 is schematically shown in FIG. 3 .
[0043] On the other hand, the highly concentrated fuel (50 through 100% methanol, for example) supplied from the fuel tank 23 to the fuel flow path 21 penetrates through the water barrier 15 into the anode flow path 19 and the anode gas diffusion layer 11 . The water barrier 15 suppresses back-diffusion of the water from the anode flow path 19 to the fuel flow path 21 . Namely, the water barrier 15 keeps concentration of the fuel in the fuel flow path 21 high.
[0044] The anode micro-porous layer 13 modestly restricts the fuel to penetrating from the anode gas diffusion layer 11 into the anode catalyst layer 3 . Thereby the fuel reaching the anode catalyst layer 3 is further diluted with the water transferred from the cathode gas diffusion layer 9 to the anode catalyst layer 3 by the capillary force. Namely, the fuel is regulated to be in a proper concentration. Meanwhile, excessive fuel at the fuel flow path 21 is recovered via the recovery flow path 29 to the fuel tank 29 .
[0045] As being understood from the above description, according to the present embodiment, the fuel supplied from the fuel tank 23 to the fuel flow path 21 is kept in a constant concentration because the interposed water barrier 15 suppresses the back-diffusion of the water from the anode flow path 19 thereto. The methanol in the anode catalyst layer 3 is mixed with the water transferring from the cathode micro-porous layer 14 and then regulated in an appropriately low concentration. Based on the aforementioned function, the present embodiment allows the highly concentrated fuel to be housed in the fuel tank 23 .
[0046] Therefore the fuel tank 23 can be miniaturized as compared with a case where beforehand diluted methanol aqueous solution having a concentration of about 3 M is stored therein, or larger power generation capacity can be obtained provided that the fuel tank is not miniaturized. Moreover, the water generated at the cathode catalyst layer 5 is moved by means of a capillary force difference and utilized to dilute the fuel so as to be a proper concentration without any additional device therefor so that the whole constitution can be simplified and hence miniaturized.
[0047] A gas-liquid separation membrane 37 may be provided at ends, through which CO 2 is exhausted, of the anode flow path 19 . The anode flow path 19 can exhaust CO 2 in a case where the fuel cell system 1 is oriented to an arbitrary direction.
[0048] This cell design can self start or shut-down. During start-up when a load is applied, the concentrated methanol solution is delivered to the anode fuel path 21 by opening the inlet valve 33 and the outlet valve 35 and by operating the liquid pump 27 , and subsequently to the anode flow path 19 by the liquid flow through the water barrier 15 under action of electrochemical consumption. The cell will then gradually reach a steady state under a constant load. Upon shut-down, the liquid pump 27 is reversely operated and liquid in the fuel path 21 is pumped back into the fuel tank. Then the inlet valve 33 and outlet valve 35 are closed and the liquid pump is stopped.
[0049] In the aforementioned constitution, flux of the methanol supplied to the anode catalyst layer 3 is represented by an equation:
J CH3OH = ( 1 + β ) 1 6 F ( 10 )
where β is a ratio of crossover methanol crossing to methanol contributing to the power generation. Because 1 mole of methanol generates 6 moles of protons and 6 moles of electrons by the anodic reaction (1), flux of methanol necessary to generate a current I is equal to a value of the current I divided by 6F. Flux of methanol crossing over is β times the flux contributing to the power generation. Total flux is the sum of the both fluxes, therefore the equation (10) is obtained. Moreover, flux of the water supplied to the anode catalyst layer 3 is represented by an equation:
J H2O = ( 1 + 6 α ) I 6 F ( 11 )
where α is a number of water molecules per a proton penetrating the electrolyte membrane 7 . “1” described in the bracket corresponds to an amount of water consumed in the anodic reaction (1). Molar ratio of water to methanol supplied to the anode catalyst layer 3 is:
J H2O :J CH3OH =(1+6α):(1+β) (12)
Namely, it is equal to a ratio of (1+a proportion of water penetrating to the cathode):(1+a proportion of methanol crossing over). Provided that a ratio of water to methanol of the methanol aqueous solution stored in the fuel tank is regulated to be equal thereto in advance, the concentration of the methanol aqueous solution is steadily kept constant from the fuel tank 23 through the fuel flow path 21 . Thereby one-pass fuel supply can be enabled. In a case where the fuel circulates from the fuel flow path 21 to the fuel tank 23 , the concentration of the methanol aqueous solution in the fuel tank 23 is kept constant. For example, for β=0.2 (20% fuel crossover) and α=0.4, Equation (12) yields the molarity of 11 M in the fuel supply.
[0050] A second embodiment of the present invention will be described hereinafter with reference to FIG. 5 . In the following description, substantially the same elements as the aforementioned first embodiment are referenced with the same numerals and the detailed descriptions are omitted. In FIG. 5 , the anode catalyst layer 3 , cathode catalyst layer 5 and the electrolyte membrane 7 are represented as a membrane electrolyte assembly (MEA). Furthermore, the anode gas diffusion layer 11 , the anode micro-porous layer 13 , the water barrier 15 , and the anode flow path 19 are represented as a unitary body of an assembly body 33 .
[0051] According to the second embodiment, a porous body 35 is disposed between the fuel tank 23 and the assembly body 33 and the link flow path 25 and the fuel pump 27 are omitted.
[0052] Therefore the present embodiment takes substantially the same effects as the aforementioned first embodiment which allow the highly concentrated fuel to be housed in the fuel tank and the link flow path 25 and the fuel pump 27 can be omitted so that the whole constitution can be simplified.
[0053] A third embodiment of the present invention will be described hereinafter with reference to FIG. 6 . In the following description, substantially the same elements as any of the aforementioned embodiments are referenced with the same numerals and the detailed descriptions are omitted.
[0054] According to the present embodiment, a tank 41 stores a highly concentrated methanol and the concentrated methanol is supplied to the tank 23 by means of a pump P 1 . Furthermore, air is supplied to a cathode flow path 43 layered on an outer side of the cathode diffusion layer 9 and exhaust gas in the cathode flow path 43 is cooled at a condenser 45 so as to condense water vapor contained in the exhaust gas. The condensed water by means of the condenser 45 is recovered to the fuel tank 23 by means of a pump P 3 .
[0055] According to the present embodiment, provided that the concentration of the methanol aqueous solution stored in the fuel tank 23 varies in some degree, a variation of the concentration at the anode catalyst layer 3 can be suppressed because the water barrier from the fuel tank 23 through the anode catalyst layer 3 is relatively much.
[0056] In the previous description, numerous specific details are set forth, such as specific materials, structures, processes, etc., in order to provide a better understanding of the present invention. However, the present invention can be practiced without resorting to the details specifically set forth herein. In other instances, well-known processing techniques and structures have not been described in order not to unnecessarily obscure the present invention.
[0057] Only the preferred embodiments of the present invention and but a few examples of its versatility are shown and described in the present disclosure. It is to be understood that the present invention is capable of use in various other combinations and environments and is susceptible of changes and/or modifications within the scope of the inventive concept as expressed herein.
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A direct methanol fuel cell unit is provided with a fuel cell including an anode, a cathode with a hydrophobic microporous layer, an electrolyte membrane put in-between, and a fuel supply path supplying fuel to the anode. The fuel supply path is provided with an upwind water barrier preventing back-diffusion of water and a gas flow path channeling gas generated at the anode and disposed between the barrier and the anode. A water-rich zone is formed between the water barrier and the cathode microporous layer. Water loss from either side of this zone is eliminated or minimized, thereby permitting direct use of highly concentrated methanol in the fuel flow path with good fuel efficiency and power performance. The cell unit can be applied equally well to both an active circulating air cathode and an air-breathing cathode.
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REFERENCE TO PRIOR APPLICATIONS
[0001] This application is a continuation of: (i) U.S. Design patent application Ser. No. 07/745,995 filed Aug. 9, 1991, which is a continuation of Design Pat. application Ser. No. 07/292,742 filed Jan. 3, 1989; and (ii) U.S. patent application Ser. No. 07/763,870 filed Sep. 19, 1991, which is a continuation of application Ser. No. 07/507,002 filed Apr. 10, 1990, which is a continuation of application Ser. No. 07/319,852 filed Mar. 3, 1989, which is a continuation of application Ser. No. 07/101,832 filed Sep. 28, 1987, which is a continuation-in-part of application Ser. No. 07/926,291, filed Nov. 3, 1986, and now issued as U.S. Pat. No. 4,724,642. The disclosure of U.S. Pat. No. 4,724,624 is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates to outdoor residential constructions, and is particularly concerned with support devices for use in deck construction.
[0003] Various types of devices have heretofore been used for supporting and/or connecting building elements, such as horizontal beams, joists, stringers, posts and pillars, to a base slab, footing, foundation or block member. For example, such devices include anchor studs, metal brackets, or other supports or devices which are permanently embedded in the concrete in the manufacturing process of the blocks and which are required to make them functional. Such devices or additional components are used to provide vertical and lateral mechanical connection of building elements to a base or as components to other elements but do not have an individual identity or non-mechanical application which facilitates the inexpensive and convenient construction of a simple deck, such as a deck that may be built by the average home owner on unprepared and unleveled ground typical to a residential backyard.
SUMMARY OF THE INVENTION
[0004] According to the present invention and forming a primary objective thereof, a deck construction is provided including a novel construction support device, which amounts to an improvement over prior structures.
[0005] A more particular object of the invention is to provide a construction support device of the type described having a novel arrangement of recesses, walls, and sockets for receiving horizontal beams and the like, and also capable of receiving vertical pillars or posts, all in a variety of selected support connections not heretofore available.
[0006] Another object of the invention is to provide an embodiment of the invention comprising a plurality of integrated wall portions disposed in a zig zag pattern and forming one or more full width slots for receiving horizontal beams and the like and also forming a rectangular central socket for receiving a vertical pillar or post.
[0007] Another object of the invention is to provide a pier block of the type described having a novel arrangement of recesses and central socket for receiving horizontal two-inch thick (1½-inch nominal) surface supports, and also capable of receiving vertical wood posts without mechanical connections or additional components, all in a variety of selected support configurations not heretofore available.
[0008] In carrying out these objectives, a construction support device is provided for anchoring a beam or other element to the ground or other building site. The device includes a body having upper and lower portions. The lower portion rests on the building site, and the upper portion includes an open slot for holding a beam edgewise. The slot is formed by spaced-apart side walls. The side walls themselves include connected wall portions, which are integrally joined at right angles.
[0009] The slot includes a center socket portion that is adapted for securely holding the bottom end of a vertically oriented post. The center socket portion is formed by the side walls extending at right angles away from each other to form corner sections. The corner sections are spaced apart substantially further than the width of the open slot to provide substantial corner support to the post.
[0010] In some cases, the side walls which define the slot are part of spaced-apart projections which extend from the upper portion of the body. These projections can be integrally molded with the body to form a single-cast, one-piece block or pier.
[0011] Alternatively, they may be formed of plastic or metal and suitably attached to a base.
[0012] The invention may be practiced with a pair of recesses emanating from the central socket portion to form a single slot which extends unobstructed across the entire breadth of the body. Alternatively, a second pair of recesses may be employed to form a total of two mutually perpendicular slots.
[0013] Support devices in accordance with the invention are particularly suited to the construction of residential decks. Horizontal, coplanar deck support members may be carried by a plurality of the foregoing support devices arranged in rows and columns. The horizontal deck support members are securely seated in the slots defined by the spaced apart side walls.
[0014] Where the deck is to be built on uneven ground, the horizontal members can be supported in a level attitude by a plurality of vertical support pillars. The bottom ends of the vertical support pillars are securely seated in one of the center socket portion, while their respective top ends bear the horizontal members in supporting engagement. The height of the vertical support pillars can vary to span the vertical distance between the uneven ground and the desired plane in which the horizontal support members reside.
[0015] In one embodiment, the construction support device of the invention comprises a body member having a lower surface which serves as a support on a base such as a slab, footing, or pier block. The body member has one or more recess means arranged to receive horizontal beams and the like. The body member also has a central socket for receiving a vertical pillar or post. The recess means are disposed on each of four sides of the body member at 90 degrees apart and communicate with the central socket and the exterior, the pairs of recesses opposite from each other being aligned whereby construction beams or the like can be laid therein in edge and/or end relation. Also, in such embodiment, the construction device has fastener-receiving means therein for attaching a beam or beams and a pillar together, and also for attaching the assembly to the base. In another embodiment, side edges of the body member at the recess openings have downturned projections shaped on a rear portion thereof to frictionally fit on top of pier blocks for anchoring the body member against lateral shifting.
[0016] In another embodiment, the construction support device of the invention is a single cast, one-piece pier block which comprises a body member serving as a capable support on unprepared and unleveled building sites, having localized dips, slopes and random level areas therein. The body member has a single recess means molded into the top surface capable receiving horizontal deck surface support members and also capable of receiving the bottom end of a vertical wood post or pillar. The recess means can have particular dimensions for using conventional, existing lumber sizes and also such dimensions are such that the required integral strength of the block is maintained due to the manufacturing process and application without the necessity of using reinforcing bar steel or additional integral components. All of these features combine in a structural arrangement which automates and standardizes the manufacture and facilitates marketing, at a lower unit and resale cost, a deck that can be preplanned and pre-cut. Such a deck is simplified and inexpensive, and capable of construction by the average do-it-yourself homeowner who desires a deck on the unprepared and unleveled ground of a typical backyard.
[0017] The invention will be better understood and additional objects and advantages will become apparent from the following description taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] [0018]FIG. 1 is a top perspective view of a support device in accordance with a first embodiment of the invention;
[0019] [0019]FIG. 2 is a bottom perspective view of the device shown in FIG. 1;
[0020] [0020]FIG. 3 is a bottom perspective view of a construction support device in accordance with another embodiment of the invention.
[0021] [0021]FIG. 4 is a bottom perspective view of a construction support device in accordance with yet another embodiment of the invention.
[0022] [0022]FIGS. 5, 6, 7 and 8 are perspective views showing various applications of the device of FIG. 1 in association with structural building elements;
[0023] [0023]FIG. 9 is a perspective view of a construction support device which includes lateral stabilizing elements in accordance with a another embodiment of the invention.
[0024] [0024]FIG. 10 is a bottom perspective view of the construction support device of FIG. 9;
[0025] [0025]FIGS. 11 and 12 are perspective views showing various applications of the device of FIG. 9 in association with-structural building elements;
[0026] [0026]FIG. 13 is a perspective view of a construction support device in accordance with another embodiment of the invention;
[0027] [0027]FIG. 14 is bottom perspective view of the construction support device shown in FIG. 13;
[0028] [0028]FIG. 15 is a top perspective view of the construction support device shown in FIG. 13;
[0029] [0029]FIG. 16 is a top plan view of the construction support device shown in FIG. 13;
[0030] FIGS. 17 is a perspective view a construction support device in accordance with another embodiment of the invention;
[0031] [0031]FIG. 18 is a top perspective view of the construction support device shown in FIG. 17;
[0032] [0032]FIG. 19 is a top plan view of the construction support device shown in FIG. 17;
[0033] [0033]FIGS. 20 and 21 are perspective views showing various applications of the device of FIG. 17 in association with structural building elements;
[0034] [0034]FIG. 22 is a perspective view of a deck construction in accordance with the invention employing the construction support device shown in FIG. 17; and
[0035] [0035]FIG. 23 is a perspective view of another deck construction in accordance with the invention employing the construction support device shown in FIG. 17.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0036] According to the present invention, a construction support device is provided which conveniently provides anchoring of a building element to a building site. As illustrated herein, the invention may be practiced in accordance with a first embodiment of FIG. 1, wherein the construction support device is securely attached to a concrete base or pier. The device of FIG. 1 can be inexpensively molded from plastic or stamped from metal and is simplified in its use and constructions.
[0037] Alternatively, the invention may be practiced in accordance with other embodiments, such as shown in FIGS. 13 and 17. There, the device is inexpensively poured from concrete together with a pier block to form a single cast, one-piece body. In either type of embodiment, the invention provides a new and advantageous support for securely seating-construction members in either a horizontal or vertical orientation.
[0038] With reference first to FIGS. 5 through 8, the numeral 10 represents a base or pier block of conventional structure which is commonly used to support decks, carports, etc. This block is generally constructed of concrete and assumes different shapes. In most cases, the block is tapered to a lesser dimension toward the top. The top and bottom surfaces 12 and 13 , respectively, are flat.
[0039] FIGS. 1 - 8 illustrate a construction support device 14 in accordance with a first embodiment of the invention. Construction support device 14 which may be molded, stamped, or otherwise formed from a tough plastic or metal. The body member of the device 14 includes a flat bottom wall 16 and four identically shaped or symmetrical upright quarter sections 18 . Each of the sections 18 comprises four zig zag panels 18 a joined integrally at right angles. These symmetrical quarter sections are shaped to form a recess or opening 20 on each side, with oppositely located recesses being laterally aligned. Also, with this quarter section construction, a square central socket 22 is formed. Laterally aligned recesses 20 provide a pair of full width slots open at the sides.
[0040] Each of the panel sections 18 a has one or more apertures 24 therein provided to receive fasteners, to be seen hereinafter, for securement of building elements to the device 14 . As seen in FIG. 2, cutouts 26 are provided in the bottom wall 16 for reducing the weight of the member as well as for conserving material. Also, apertures 28 are provided in the wall 16 for secured attachment of the member 14 to a base, such as to a block 10 , a concrete slab, or other support means.
[0041] [0041]FIGS. 5, 6, 7 and 8 show various applications of the construction device 14 with building elements such as support members and pillars. FIG. 5 for example shows a horizontal decking surface support member 30 seated edgewise on the bottom wall 16 and extending fully through the device and out both side recesses 20 . FIG. 6 shows a support member 30 similarly supported as in FIG. 5 but also showing a right angle support member 32 extending through. a 90 degree side recess 20 and abutted against the support member 30 . FIG. 7 shows a vertical pillar 34 supported on the device 14 and fitted in the central socket 22 . FIG. 8 shows a pillar 34 similarly fitted in the socket 22 as in FIG. 7 but also showing side beams 32 extending in from all four of the side recesses. These members may simply be fitted in the respective recesses 20 or socket 22 . Preferably, however, secured attachment to the member 14 is accomplished by fasteners 36 extending through the apertures 24 . Also, device 14 can first be secured to the base member 10 by fasteners extending through the apertures 28 .
[0042] [0042]FIG. 3 is a bottom perspective view of a construction device 14 ′ having a bottom wall 16 and side walls 18 in an arrangement similar to that shown in FIGS. 1 and 2. This structure, however, is formed (such as by integral molding) with a plurality of depending foot members 38 . Four of such foot members are shown, as well as a central foot member, but any number of such foot members may be provided. In the FIG. 3 embodiment, the foot members 38 are hollow whereby long fasteners can be inserted down from the top through the wall 16 and into a base for secured attachment of the construction device 14 ′ to the base. FIG. 4 shows a structure similar to FIG. 3 except that the outer foot members 38 ′ are solid and not hollow. This embodiment may be employed in circumstances where it is not necessary to use vertical fasteners around an outer portion of the member.
[0043] FIGS. 9 - 12 illustrate an embodiment of the invention employing means for anchoring the body member against lateral shifting. In this embodiment, the body member 14 ″ is the same as that shown in FIG. 1 with respect to quarter panel sections 18 a and their formation of aligned recesses 20 and central socket 22 . To accomplish the lateral anchoring feature, the outermost panel section 18 a of each quarter section has a depending projection or lip 40 defined by a bottom wall portion 42 integral with side extensions 44 and a rear wall portion 46 . Rear wall portion 46 preferably angles outwardly toward the bottom to coincide with the angle of the side surfaces of pier block 10 . Reel wall portion 46 can extend at a desired angle, so as to have flush engagement with pier block sides of varying shape.
[0044] [0044]FIGS. 11 and 12 show application of the device 14 ″ of FIG. 9 to a pier block. In such arrangement, the device 14 ″ and the building elements therein are anchored or locked against lateral shifting. Fasteners extending through the bottom wall of the device are not necessary, although such fasteners can be used if desired. The cross dimension of the device between rear wall portions 46 can be preselected according to the size of the pier block so that a snug or frictional fit is provided.
[0045] Referring to FIGS. 13 - 21 , it will be seen that the device 14 may be made of concrete and integrally molded into the upper surface 12 ′ of a pier block such as pier block 50 . As shown in FIGS. 13 - 16 , the four upright quarter sections 18 ′ include zig-zag walls 18 a ′ which project from flat bottom wall 16 ′. Recesses 20 ′ define two perpendicular slot portions extending across the full width of upper surface 12 ′. Zig-zag walls 18 a ′ also define the four corners of a square central socket 22 ′.
[0046] With reference to FIGS. 17 - 21 , the concept of the invention can also utilize a pier block 50 ′ having a central socket portion 22 ′ and only two equal narrower recesses 20 ′ which extend inward from outer edges of two opposite sides of the top surface of the block 50 ′ and lead into the central socket portion, as best shown in FIG. 18. The two narrower recesses 20 ′ form but a single slot for receiving a horizontal decking surface support member 30 which also passes through the central socket portion 22 ′, as shown in FIG. 20. The central socket portion 22 ′ is for receiving vertical pillar supports 34 , independent of the two equal narrower recesses 20 ′, as shown by FIG. 21. The horizontal decking surface support members 30 and vertical pillar support members 34 being mutually exclusive to each other in the recess of block 50 ′ and also mutually interchangeable with each other in the same recess of the same block 50 ′.
[0047] The combination of slots and sockets allows a support in accordance with the invention to accommodate both vertical and horizontal beams, and is particularly well-suited for constructing decks on unprepared and unleveled building sites, two examples of those being shown in FIGS. 22 and 23. Such decks, by using the present block, are extremely simplified in their construction and can be supplied in pre-planned, pre-cut units. Other advantages also exist in the structure, as will be apparent hereinafter.
[0048] The deck shown in FIG. 22, designed by the numeral 52 , comprises the pier blocks 50 ′ as the base or ground support for the deck and can have such lumber as two-inch thick (1½ inch thick nominal) horizontal decking surface support member 30 received by the two equal narrower portions 20 ′, also passing through the central socket portion 22 ′ when the vertical pillar support 34 is not in the block 50 ′, those members 30 then supporting the deck surface structure 54 which is nailed in place and those blocks 50 ′ directly receiving member 30 being on localized high or level ground within an unprepared and unleveled building site.
[0049] The deck shown in FIG. 23, designated by the numeral 56 , similarly uses some pier blocks 50 ′ as described above and also illustrates the use of some blocks 50 ′ as the base or ground support for vertical pillar supports 34 set in the central socket 22 ′ when the member 30 is not in block 50 , member 34 then providing support to member 30 when member 30 is not directly received by block 50 due to localized variations of the ground within an unprepared and unleveled building site. A deck support member 30 35 can also be fastened to a building 60 , as shown in FIG. 23.
[0050] The particular structure of the manufactured pier blocks 50 and 50 ′ makes it possible to construct an extremely simplified deck and one which can be pre-planned and pre-cut if desired. That is, such lumber as 2-inch thick deck support members 30 and vertical wood pillars 34 which can be used therewith comprise conventional existing material, namely, the two-inch thick deck support members 30 can comprise 2×6's or 2×4's and pillars 34 can comprise 4×4's.
[0051] The two equal narrower recesses 20 ′ can be 2 inches deep and have a width of 1¾ inches. This latter dimension would receive conventional finished 2×6's (1½ inches thick) and 2×4's (also 1½ inches thick). 2×6's and 2×4's have finished height dimensions of 5½ and 3½ inches, respectively, whereby the deck support members, whether 2×6's or 2×4's, project to a minimum necessary height above the top surface of the blocks 50 when seated in the recess for supporting the decking thereon.
[0052] The central socket portion 22 ′ can be 2 inches deep, similar to the recess portion 20 ′. Such socket is square, and can have dimensions of 3¾ inches for receiving a conventional finished 4×4 (3½ inches square) lumber support pillar. The vertical pillar becomes sufficiently fixed in socket portion 22 ′ in the block for deck construction purposes, as does the deck horizontal support member in the two narrower portions 20 ′, also being within the central socket portion 22 ′ when the member 34 is not in the block 50 , for lateral stability.
[0053] Pier blocks 50 and 50 ′ are designed to provide support to a deck on unleveled or unprepared building sites with no additional components required. For this purpose, the blocks 50 and 50 ′ are tapered to a larger dimension toward the bottom. The top and bottom surfaces are flat and square. The enlarged bottom surface allows the block to serve as its own footing. When two of such recesses 20 ′ are provided, they are standardly aligned across the block. Furthermore, the width of these recesses is less than one-third the width of the block at the top, thus maintaining lateral integral strength of the block. This arrangement maintains a strong concrete block without the necessity of re-bar reinforcement and thus contributes to manufacture of a pier block and deck structure in a pre-planned -and pre-cut unit which is also sufficiently simplified in its use, standardized in its manufacture, and sufficiently inexpensive for deck construction by the average do-it-yourself homeowner.
[0054] Since the recess can be two inches deep, the recesses of the pier blocks 50 and 50 ′ of FIGS. 13 and 17 automatically and non-mechanically center the horizontal decking surface support member 30 and vertical pillars 34 in the pier block (FIGS. 20 and 21) and automates connection and securement of these support members to the pier block for deck constructions 52 and 54 shown in FIGS. 22 and 23. Mounted engagement of the horizontal surface support members and vertical pillars with the block is accomplished without metal-brackets or embedded connectors thus allowing individual blocks of a deck construction on unleveled and unprepared building sites to be adjusted without the need of any disassembly of the deck (i.e. removing bolts, nails or screws). Also, the recess of the pier blocks 50 and 50 ′ maintains horizontal and vertical members in parallel which is critical in construction of the deck.
[0055] It is to be understood that the forms of our invention herein shown and described are to be taken as preferred examples of the same and that other changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of our invention or the scope of the following claims.
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A deck construction including a plurality of supports for anchoring deck construction elements to a building site. The supports include a body (which may be an integrally molded concrete pier) having upper and lower portions. The upper portion includes at least one slot for seating a horizontally oriented construction member. The slot includes a center socket portion having four extended corners for seating the bottom end of a vertically oriented construction member. The slot and center socket are defined by connecting wall portions which may be integral to the body or may be of plastic or metal and suitable secured to the body. In some cases, two mutually perpendicular slots are provided.
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This application is the U.S. National Phase of PCT Application Serial No. PCT/EP2010/063222, filed Sep. 9, 2010, which claims the priority of German Application Serial No. 102009041095.3, filed Sep. 14, 2009 and U.S. Provisional Application No. 61/242,887, filed Sep. 16, 2009, all of which are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
The invention relates to a support material for printing electronic circuits by means of the inkjet printing process with electrically conductive inks.
TECHNICAL BACKGROUND OF THE INVENTION
An essential step in the production of electronic devices and circuits is the manufacture of conductive connections between the components. These connections must follow a predetermined structure in order that the componentry or the device can carry out its intended function. Such structures can be manufactured from conductive materials in a variety of manners, usually from metals or carbon (graphite). Printing processes are particularly suitable for cheap mass production, whereby the circuits are produced by depositing printing inks which contain the conductive materials onto flat electrically insulating, preferably flexible support materials in a single operational step.
When manufacturing electronic circuits, inkjet printing technology can be employed. This means that electrically conductive structures can be deposited on insulating support materials, or components which have already been deposited can be conductively connected, whereby in contrast to other printing techniques such as screen printing, a previously prepared printing mask does not have to be produced; thus, it is possible to carry out manufacturing on a small mass-production scale, or even to manufacture single parts, simply and cheaply. Such applications have been described, for example, in the article by John B Blum, “Printed Circuit Design and Manufacture”, 1 Oct. 2007.
Metal-containing or carbon-containing preparations are usually employed as printing inks; the electrically conductive material is present therein in the form of particles. For inkjet printing, such particles must have very small dimensions, usually less than 1 μm, in order to prevent the printing nozzles from becoming blocked and to prevent the conductive particles from sedimentation in the low-viscosity ink. In order to stabilize the particles against agglomeration and sedimentation, such inks also have to be supplemented with additives such as surfactants or protective colloids, for example. Inks which contain finely divided metallic silver are frequently preferred. Inks of that type are, for example, available from ANP (Advanced Nano Products) in Korea under reference DGP and DGH, from Harima Chemicals Inc, Japan under reference NPS and from Cabot Corporation, USA, under reference CCI-300. The particle size of the silver particles in those inks is in the range from 5 nm to a few hundred nm.
In addition to using rigid support materials such as glass or ceramic as the support materials to be printed, flexible films formed from polymers, in particular polyesters, are preferably employed. Following inkjet printing on such support materials, the solvent contained in the ink evaporates and the non-volatile additives as well as the silver particles remain in the printed layer. Since the additives are electrical insulators, the conductivity of such printed structures is low. For this reason, as described in the data sheets from the ink manufacturers and in the article by John B Blum, “Printed Circuit Design and Manufacture”, 1 Oct. 2007, a thermal post-treatment is necessary at temperatures of at least 100° C. to over 400° C. in order to produce a metallic conductivity in the printed structures. Particularly at low temperatures, the time required for this necessary thermal post-treatment is long, normally more than 1 hour. If higher temperatures are employed in order to reduce the treatment time, however, it is not possible to use the cheap and easily manipulatable flexible films produced from thermoplastic polymers as a support material since the stability of such foils at the high temperatures required is insufficient and they deform.
In the article “Low Temperature Chemical Post-treatment of Inkjet-Printed Nano-Particle Silver Inks” (NIP 24 and Digital Fabrication 2008 Final Program and Proceedings, page 907), Werner Zapka et al describe a process wherein the printed structures are treated with a salt solution following drying. Following use, however, that salt solution has to be removed by washing again, thereby constituting a multi-step process with subsequent repeated drying.
U.S. Pat. No. 3,652,332 A describes the use of porous support materials, in particular coated offset printing paper, to print conductive structures. The printing process used in that case is the letterpress process. The printing inks described for producing the conductive structures are carbon black or flake silver printing inks with particle sizes of distinctly more than 1 μm, which are unsuitable for the inkjet printing process. That patent teaches that the printing medium must have a certain absorbency in order to be able to produce homogeneous printing surfaces with reproducible electrical conductivity. The support materials described in the patent, preferably standard graphical papers coated with clay pigment, do not, however, satisfy the special requirements of inkjet printing with low-viscosity inks containing conductive particles, since they have a coarse and irregular pore structure and low porosity.
US 2009/0087548 A1 describes a process whereby a metallic ink is applied to a support material having a porous layer. The porous layer prevents the printed structures from spreading, so that very fine structures are obtained. In that process, the metal particles enter the porous layer; the porous layer is then removed in the subsequent heat treatment. Even though very high resolution structures can be printed using that process, a subsequent additional process step for removing the porous layer is required. In addition, that process step involves the use of high temperatures of 300° C., which means that the invention cannot be applied to the preferred flexible support materials.
SUMMARY OF THE INVENTION
The object of the invention is to provide a support material for printing electronic circuits using printing inks, which contain electrically conductive particles having a mean particle size of less than 1 μm. It endows the printed structures with high electric conductivity even without thermal post-treatment of the printed material. This support material is especially suitable for inkjet printing with metal or carbon (graphite)-containing inks and means that high resolution printing of fine structures can be carried out.
It has now surprisingly been discovered that the thermal post-treatment of inkjet-printed structures of conductive particles can be dispensed with when the support material contains an outer microporous layer which has a mean pore size of less than 100 nm.
The invention also pertains to a process for producing an electrically conductive structure on the support material described above.
Finally, the invention pertains to a printed circuit, manufactured by printing the support material defined above using a printing ink containing electrically conductive particles using the inkjet printing process.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In a preferred embodiment of the invention, the microporous layer has a mean pore size in the range 5 nm to 50 nm.
Particularly preferably, moreover, the surface of the microporous layer has a mean roughness of less than 1 μm, measured as the Rz parameter in accordance with DIN 4768.
In a particular embodiment of the invention, the outer microporous layer may be a polymer foam manufactured, for example, using a sol-gel process. Examples of such microporous layers have been described in WO 2007/065841 A1.
In a further preferred embodiment of the invention, the outer microporous layer contains fine inorganic and/or organic pigment particles and a hydrophilic binding agent. Examples of pigments which in the context of the invention are suitable for the microporous layer are aluminium oxide, aluminium hydroxide, aluminium oxide hydroxide, aluminium oxide hydrate, silicon dioxide, magnesium hydroxide, kaolin, titanium dioxide, zinc oxide, zinc hydroxide, calcium silicate, magnesium silicate, calcium carbonate, magnesium carbonate and barium sulphate. The quantity of pigments in the microporous layer may be 40% to 95% by weight, preferably 60% to 90% by weight, with respect to the weight of the dried layer.
The particle size of the pigment in the microporous layer is preferably less than 1000 nm, but in particular 50 to 500 nm. The mean particle size of the primary particles is preferably less than 100 nm, in particular less than 50 nm.
The microporous layer contains a water-soluble and/or water-dispersible binding agent. Examples of suitable binding agents are polyvinyl alcohol, completely or partially saponified, cationically modified polyvinyl alcohol, polyvinyl alcohol containing silyl groups, polyvinyl alcohol containing acetal groups, gelatine, polyvinyl pyrrolidone, starch, carboxymethylcellulose, polyethylene glycol, styrene/butadiene latex and styrene/acrylate latex. Particularly preferably, completely or partially saponified polyvinyl alcohols are used. The quantity of binding agent may be 60% to 5% by weight, preferably 50% to 10% by weight, in particular however 35% to 8% by weight, with respect to the weight of the dried layer.
The microporous layer can contain the usual additives and auxiliary substances such as cross-linking agents, ionic and/or non-ionic surfactants, particle-binding substances such as polyammonium compounds, UV absorbers, antioxidants and other light stabilizing and gas resistance improving substances as well as other auxiliary substances.
The coat weight for the microporous layer may be 1 to 60 g/m 2 , preferably 5 to 40 g/m 2 , particularly preferably 10 to 30 g/m 2 .
The microporous layer can be formed as a single layer or in multiple layers.
The base material used as the support material over which the microporous layer is arranged can be a rigid flat material such as glass or a plastic. Preferably, however, a flexible base material is used, such as a plastic film, non-woven material or paper.
In a particularly preferred embodiment, the base material is a base paper. The term “base paper” as used in the context of the invention means an uncoated or surface-sized paper. As well as containing fibres of cellular material, a base paper can contain sizing agents such as alkyl ketene dimers, fatty acids and/or fatty acid salts, epoxided fatty acid amides, alkenyl or alkylsuccinic acid anhydride, wet-strength agents such as polyamine-polyamide-epichlorhydrin, dry strength agents such as anionic, cationic or amphoteric polyamides, optical brighteners, pigments, colorants, defoaming agents and other auxiliary substances which are known in the paper industry. The base paper may be surface-sized. Examples of sizing agents which are suitable for this purpose are polyvinyl alcohol or oxidized starch. The base paper may be produced on a Fourdrinier or Yankee paper machine (roll paper machine). The grammage of the base paper may be from 50 to 250 g/m 2 , in particular 50 to 150 g/m 2 . The base paper may be used in the uncalendered or calendered (smoothed) form.
Particularly suitable base papers are those with a density of 0.8 to 1.05 g/cm 3 , in particular 0.95 to 1.02 g/cm 3 .
Examples of fillers which may be used in base paper are kaolins, calcium carbonate in its natural form such as lime, marble or dolomite, precipitated calcium carbonate, calcium sulphate, barium sulphate, titanium dioxide, talc, silica, aluminium oxide and mixtures thereof.
In a further embodiment of the invention, at least one further layer may be arranged between the base paper and the microporous layer, which further layer contains a hydrophilic binding agent. Particularly suitable examples for this purpose are film-forming starches such as heat-modified starches, in particular corn starches or hydroxypropylated starches. In a preferred form of the invention, low-viscosity starch solutions are used which have Brookfield viscosities in the range 50 to 600 mPas (25% solution, 50° C./100 Upm), in particular 100 to 400 mPas, preferably 200 to 300 mPas. The Brookfield viscosity is measured in accordance with International standard ISO 2555. Preferably, the binding agent does not contain any synthetic latex. The absence of a synthetic binding agent means that waste can be re-utilized without having to be worked up.
In a further embodiment of the invention, at least one pigment is contained in the further layer containing a hydrophilic binding agent. The pigment may be selected from the group formed by metal oxides, silicates, carbonates, sulphides and sulphates. Pigments such as kaolin, talc, calcium carbonate and/or barium sulphate are particularly suitable.
A pigment with a narrow grain size distribution, wherein the dimension of at least 70% of the pigment particles is of less than 1 μm, is particularly preferred. In order to achieve the effect of the invention, the proportion of pigment with the narrow grain size distribution should be at least 5% by weight, in particular 10% to 90% by weight of the total quantity of pigment. Particularly good results are obtained with a proportion of 30% to 80% by weight of the total pigment weight.
A pigment with a narrow grain size distribution in accordance with the invention also comprises pigments with a grain size distribution whereby the dimension of at least approximately 70% by weight of the pigment particles is less than approximately 1 μm, and for 40% to 80% of these pigment particles, the difference between the pigment with the largest grain size (diameter) and the pigment with the smallest grain size is less than approximately 0.4 μm. Particularly preferably, this is a calcium carbonate with a d 50% of approximately 0.7 μm.
In a particular embodiment of the invention, a pigment mixture can be used which consists of the calcium carbonate defined above and kaolin. The calcium carbonate/kaolin proportion is preferably 30:70 to 70:30.
The binding agent/pigment proportion in the layer may be from 0.1 to 2.5, preferably 0.2 to 1.5, but in particular it is approximately 0.9 to 1.3.
The layer containing a hydrophilic binding agent may preferably contain further polymers such as polyamide copolymers and/or polyvinylamine copolymers. The polymer may be used in a proportion of 0.4% to 5% by weight with respect to the mass of the pigment. In a preferred embodiment, the proportion of polymer is 0.5% to 1.5% by weight.
The layer containing the hydrophilic binding agent may be arranged directly on the front face of the base paper or on the back face of the base paper. It may be deposited on the base paper in a single layer or in multiple layers. The coating mass may be applied using any in-line or off-line coating units, the quantity being selected so that after drying, the coat weight per layer is a maximum of 20 g/m 2 , in particular 8 to 17 g/m 2 , or in a particularly preferred embodiment 2 to 6 g/m 2 .
This further layer can be further smoothed using mechanical processes such as calendering or ferrotyping; however, it can also be deposited using cast coating.
In a particularly preferred embodiment of the invention, the base material is a base paper provided with at least one polymer layer on the front face or back face. The term “front face” as used here means that side of the base paper on which the conductive structure is printed.
In accordance with one embodiment of the invention, the polymer layers of the front and back face may contain the same polymer. In a further embodiment of the invention, the polymers employed in the polymer layers of the front and back face are different.
Preferably, the polymer layer arranged on at least one side of the base paper contains a polymer with a water vapour permeability of at most 150 g/m 2 . 24 h for a layer thickness of 30 μm, measured at 40° C. and 90% relative humidity.
The polymer is preferably a thermoplastic polymer. Examples of suitable thermoplastic polymers are polyolefins, in particular low density polyethylene (LDPE), high density polyethylene (HDPE), ethylene/α-olefin copolymers (LLDPE), polypropylene, polyisobutylene, polymethylpentene and blends thereof. However, other thermoplastic polymers such as (meth)acrylic acid ester homopolymers, (meth)acrylic acid ester copolymers, vinyl polymers such as polyvinyl butyral, polyamides, polyesters, polyacetals and/or polycarbonates may be employed.
In a preferred embodiment of the invention, the front face of the base paper is coated with a polymer layer which contains at least 50% by weight, in particular 80% by weight of a low density polyethylene with a density of 0.910 to 0.930 g/cm 3 and a melt-flow index of 1 to 20 g/10 min, with respect to the polymer layer.
In a further preferred embodiment of the invention, the back face of the base paper is coated with a polyolefin, in particular polyethylene. Particularly preferably, a polyethylene blend of LDPE and HDPE is used, wherein the LD/HD proportion is 9:1 to 1:9, in particular 3:7 to 7:3.
Furthermore, the polymer layers may contain white pigments such as titanium dioxide as well as other auxiliary substances such as optical brighteners, colorants and dispersing additives.
The coat weight of the polymer layers on the front face and back face may each be 5 to 50 g/m 2 , preferably 20 to 50 g/m 2 or particularly preferably 30 to 50 g/m 2 .
In a further embodiment of the invention, further layers such as protective layers or gloss-improving layers may be deposited on the outer microporous layer provided for printing with conductive particles using the inkjet printing process. The coat weight of such layers is preferably less than 1 g/m 2 .
The following examples are intended to further illustrate the invention.
EXAMPLES
Fabrication of Base Paper
Eucalyptus cellular material was used to manufacture the base paper. For beating, the cellular material was beaten as an approximately 5% aqueous suspension (thick matter) using a refiner to a degree of beating of 36° SR. The mean fibre length was 0.64 mm. The concentration of cellular material fibres in the thin matter was 1% by weight, with respect to the mass of the cellular material suspension. The thin matter was supplemented with additional substances such as a neutral sizing agent, alkyl ketene dimer (AKD), in an amount of 0.48% by weight, a wet-strength agent, polyamine-polyamide epichlorhydrin resin (Kymene®), in a quantity of 0.36% by weight, and a natural CaCO 3 in a quantity of 10% by weight. The quantities given are with respect to the mass of cellular material. The thin matter, the pH of which was adjusted to approximately 7.5, was transferred from the headbox onto the screen of the paper machine, whereupon sheets were formed by dewatering the web in the screen portion of the paper machine. In the press section, the paper web was further dewatered to a water content of 60% by weight with respect to the web weight. Further drying was carried out in the dryer section of the paper machine using heated drying rollers. A base paper was obtained with a gsm substance of 160 g/m 2 and a moisture content of approximately 7%.
Support Example A (Comparison)
The base paper was coated on the front face and back face with a coating mass consisting of a styrene acrylate binding agent and a pigment mixture formed from calcium carbonate and kaolin with a coat weight of 30 g/m 2 (front face) and 20 g/m 2 (back face), then dried and subsequently smoothed using a calender.
Support Example B (Comparison)
The front face of the base paper was coated with a resin blend formed by 100% by weight of a low density polyethylene (LDPE, 0.923 g/cm 3 ) with a coat weight of approximately 20 g/m 2 in a laminator at a speed of approximately 250 m/min.
The back face of the base paper was coated with a resin blend formed by 100% by weight of a low density polyethylene (LDPE, d=0.923 g/m 2 ) at a coat weight of 20 g/m 2 . Coating was carried out in a laminator at an extrusion speed of 250 m/min.
The front face of the support material was also treated by corona discharge and subsequently coated with a primer layer formed from a solution of polyvinyl alcohol (Mowiol® 04-98 from Kurarai) in water with a dry coat weight of 100 mg/m 2 then dried.
Support Example A1 (Invention)
Support Example A was coated with a coating mass having a solids content of 23% consisting of 80 parts boehmite pigment (Dispersal® HP14 from Sasol), 10 parts pyrogenic aluminium oxide pigment (Aeroxide® Alu C from Evonik Degussa), 8 parts polyvinyl alcohol (Mowiol® 40-88 from Kurarai) and 2 parts boric acid, then dried. The dry coat weight was 20 g/m 2 ; the mean pore size of the layer, measured using mercury porosimetry, was 30 nm.
Support Example B1 (Invention)
In the same manner as for support material Example A1, support Example B was provided with a microporous layer then dried. The dry coat weight was 30 g/m 2 ; the mean pore size of the layer, measured using mercury porosimetry, was 30 nm.
Support Example C1(Invention)
In the same manner as for support material Example A1, a commercially available polyester film (Mylar®) of 125 μm thickness was corona treated and subsequently coated with a microporous layer and then dried. The dry coat weight was 30 g/m 2 ; the mean pore size of the layer, measured using mercury porosimetry, was 30 nm.
Test of Printing Properties
The support materials A, B, A1, B1, C1 and an uncoated commercially available polyester film (Mylar®) were printed with “NPS” type silver ink from Harima Chemicals, Inc, Japan, using a DMP-2800 inkjet printer from Fujifilm DIMATIX®. To this end, 25 mm long and 2 mm wide silver conductive strips were produced 25 mm apart and dried at room temperature for 1 hour.
The electrical resistance of the printed silver conductive strips was measured using a GDM-8251A electrical multimeter manufactured by GWINSTEK, Taiwan, at 23° C. and 50% relative humidity, as well as the electrical resistance between two adjacent printed conductive strips. In addition, the print quality, in particular the uniformity and contour definition of the print, was visually assessed with the aid of a DPM-100 microscope from Fibro Systems AB, Sweden.
The results are summarized in the table below.
Conductive
Resistance
Support
strip
between adjacent
Print
material
resistance
conductive strips
quality*)
Film
600
ohm
>100
Mohm
∘
(comparison)
A
480
ohm
2
Mohm
−
(comparison)
B
580
ohm
>100
Mohm
∘
(comparison)
A1
7
ohm
50
Mohm
+
(invention)
B1
9
ohm
>100
Mohm
+
(invention)
C1
7
ohm
>100
Mohm
+
(invention)
*)Print quality: −: unsatisfactory; ∘: satisfactory; +: good.
It can be seen that the materials of the invention exhibit a low electrical resistance for the printed conductive strips, a high insulative resistance between the conductive strips and a good print quality.
The preferred embodiments of the invention as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention as defined herein and in the following claims.
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Support materials for printing electrically conductive structures by means of inkjet printing with inks which contain conductive particles lead to low resistances for the printed structures without thermal post-treatment when they contain a microporous layer with a mean pore size of less than 100 nm as an outer layer.
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RELATED INVENTION
This invention is related to inventions disclosed in U.S. application Ser. No. 08/553,443 filed Nov. 11, 1995, and U.S. application Ser. No. 08/537,789 filed Oct. 23, 1995.
RELATED INVENTION
This invention is related to inventions disclosed in U.S. application Ser. No. 08/553,443 filed Nov. 11, 1995, and U.S. application Ser. No. 08/537,789 filed Oct. 23, 1995.
BACKGROUND OF THE INVENTION
This invention relates to a refrigerator having a cool air passage capable of circulating cool air into a refrigerating compartment.
As shown in FIG. 1, a conventional refrigerator is constituted by mounting a freezing compartment door 6 and a refrigerating compartment door 7 on a refrigerator body 4 of a thermally insulated structure forming a freezing compartment 2 and a refrigerating compartment 3 which are partitioned from each other by an intermediate partition wall 1 therebetween.
A compressor 11 is installed in a motor compartment 11M that is positioned under the refrigerating compartment 3, a condenser and capillary tube (not shown) are mounted in the interior of the body 4 or placed in the machine compartment 11M, and an evaporator 12 is mounted on the rear wall of the freezing compartment 2. The components are connected to each other by refrigerant tubes (not shown) to perform a refrigeration cycle.
A fan 13 for forcing cool air from the evaporator 12 into the freezing compartment 2 and the refrigerating compartment 3, is disposed above the evaporator 12. In order to guide the flow of the cool air, a grill 14 is placed before the fan 13 and a cool air duct 15a is disposed at the rear wall of the refrigerating compartment 3. Here, numeral 19 indicates a control damper for controlling the quantity of cool air which is introduced into the refrigerating compartment 3, and numeral 8 indicates shelves for receiving food items.
As a method for supplying cool air to the refrigerating compartment, a conventional refrigerator generally adopts a shelf-by-shelf cool air discharged method. As shown in FIG. 2, in this method a plurality of vertically spaced cool air discharge openings 16a, which are provided for several areas partitioned by the shelves 8, is arranged on the cool air duct 15a, so cool air is discharge towards the front into each area formed by the plurality of shelves 8.
In the above shelf-by-shelf cool air discharge method, uniform distribution of the cooled air is not achieved since areas in the direct path of the flowing air receive more cooled air than the remote areas. Arrangement of the food items further contributes to this problem. As an example, a bulky food item near a cool air discharge opening blocks the flow of air, thus such an area receives less cooled air. Still a further problem exists in that since the cool air discharge openings 16a are perpendicular to the flow direction of cool air going through the cool air duct 15a, only a small portion of the cool air from the evaporator 12 passes through the upper cool air discharge openings, but most of the cool air flows down through the cool air duct 15a and discharges into the refrigerating compartment 3 through the lowest cool air discharge openings 16a. Accordingly, food items on the upper shelves of the refrigerating compartment 3 can not keep a proper refrigerating temperature, whereas the food items on the lower shelves are overcooled. Another problem exists in that some newly stored food items may be at an initial temperature significantly higher than the temperature in the cooling compartment. In this case, a need arises for concentrating the cooled air flow to the warm/hot food item to effect rapid cooling as well as to avoid warming of the immediately surrounding food items. Conventional systems do not offer such a compensating means. Accordingly, the above described situations contribute to an undesired condition in which there may exist a significant variation of temperatures throughout the cooling compartment.
In an attempt to distribute the cool air more evenly, a three-wall cool air discharging method has recently been developed. As shown in FIG. 3, a refrigerator according to this method has a plurality of cool air discharge openings 16s on the side walls of the refrigerating compartment 3 as well as the cool air discharge openings 16a on the rear wall of the refrigerating compartment 3, in order to discharge cool air from the side walls as well as the rear wall.
However, such a refrigerator fails to provide a uniform air flow throughout the cooling compartment. That is, there still exist areas such as corners, which are not directly exposed to the cooled air flow. Furthermore, such a refrigerator does not offer means to concentrate the cooled air flow to a specified area depending upon the detected condition of the cooling compartment.
The above-explained inadequacies of conventional refrigerators are especially clear in the case that food items of a higher temperature are stored at remote areas such as the upper or lower corners of the refrigerating compartment.
Since larger-capacity refrigerators suffer from the above problems more noticeably and since consumer demand for such refrigerators has been increasing, the need for solving the above problems has become increasingly important.
SUMMARY OF THE INVENTION
It is, accordingly, an object of this invention to provide a refrigerator capable of maintaining an uniform temperature over the whole volume of a cooling compartment by evenly dispersing the evaporated cool air in multi-directions.
It is a further object to provide a refrigerator capable of achieving concentrated refrigeration of a specified area of the compartment depending upon detected temperatures.
In accordance with advantageous features of the present invention, a refrigerator is provided with an air distribution apparatus disposed on one wall of a refrigerating compartment, an air guiding means disposed in the air distribution apparatus in a vertical manner and for dividing the volume of the cool air introduced from the upper portion of the air distribution apparatus, and an air distribution means disposed at the front of the air guiding means and for horizontally discharging the divided air through a plurality of openings formed at the front area of the air distribution apparatus.
Alternatively, a refrigerator is provided with an air distribution apparatus disposed on one wall of a refrigerating compartment, and an air distribution means disposed in the air distribution apparatus for horizontally discharging an air divided volume of the cool air introduced from the upper portion of the air distribution apparatus through a plurality of openings formed at the front area of the air distribution apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side cross-sectional view of a refrigerator according to a prior art;
FIG. 2 is a front view of a refrigerator adopting a shelf by shelf cool air discharging method according to a prior art;
FIG. 3 is a front view of a refrigerator adopting three wall cool air discharging method according to a prior art;
FIG. 4 is a side cross-sectional view of a refrigerator according to the present invention;
FIG. 5 is a front view of a refrigerator of FIG. 4 with a door opened;
FIG. 6 is an exploded perspective view of a cool air distribution apparatus according to the present invention;
FIG. 7 is a side cross-sectional view of the cool air distribution apparatus taken along line 7--7 in FIG. 6;
FIG. 8 is a rear perspective view of the cool air distribution apparatus;
FIG. 9 is a perspective view of a first embodiment example of an air distributing means.
FIG. 10A is a plan view of FIG. 9 showing the swing-wing system when in a left side localized cooling position;
FIG. 10B is a plan view of FIG. 9 showing the swing-wing system when in a central area localized cooling position;
FIG. 10C is a plan view of FIG. 9 showing the swing-wing system when in a right side localized cooling position;
FIGS. 11A, 11B, 11C are operating views of a position sensing switch adopted to a cool air distribution apparatus;
FIG. 12 is a perspective view of a modified example of the air distributing means of FIG. 9;
FIG. 13 is a perspective view of a second example of an air distributing means;
FIG. 14 is a perspective view showing a modified example of the air distributing means of FIG. 13;
FIGS. 15A, 15B, 15C are perspective views of a third example of an air distributing means and modification embodiments thereof;
FIG. 16 is a rear perspective view of the cool air distribution apparatus without an air guiding means;
FIG. 17 is a perspective view of a fourth embodiment example of an air distributing means;
FIG. 18 is a perspective view showing a modified example of the air distributing means of FIG. 17;
FIG. 19 is a perspective view of a fifth example of an air distributing means;
FIG. 20 is a perspective view showing a modified example of the air distributing means of FIG. 19; and
FIG. 21 is a perspective view of a sixth example of an air distributing means.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 4 to 15 illustrate various embodiments of a cool air distribution apparatus having an air guiding means. In FIG. 4, the refrigerator is comprised of a body 4 shielded by an insulating material which includes a freezing compartment 2 and a refrigerating compartment 3, partitioned by an intermediate wall 1. Further, respective compartments 2,3 are equipped with doors 6,7 on the front side of the compartments 2,3. In the refrigerating compartment 3 are installed a plurality of shelves 8 for placing foodstuffs. At the upper portion of the refrigerating compartment 3 is formed the third compartment 9 for allowing the foodstuffs to be stored within a temperature range relative to the individual characteristics of the specific foodstuffs. A vegetable compartment 10 is formed at the lowest portion of the refrigerating compartment 3. A compressor 11 is installed in a motor compartment 11M, and a condenser and a pressure reducing device, which are not shown are installed in the wall of the body 4 or in the motor compartment 11M. Further, the evaporator 12 is mounted in the rear wall of the freezing compartment 2. All of the components are interconnected by a refrigerant tube (not shown) for accomplishing the refrigerating cycle.
Above the evaporator 12 is installed a fan 13 for forcefully blowing the cool air generated from the evaporator 12 into the freezing compartment 2 and the refrigerating compartment 3. To guide the cool air, a grill 14 is mounted in front of the fan 13. At the rear wall of the refrigerating compartment 3 is mounted a cool air distribution apparatus 17 having a cool air passage and discharge openings which will be explained later. Thus, the cool air generated by the evaporator 12 is divided between the freezing compartment 2 and the refrigerating compartment 3. Numeral 5 is a recess for housing the cool air distribution apparatus 17.
As shown in FIG. 5, the cool air distribution apparatus 17 is installed at the horizontally central portion of the rear wall 3W of the refrigerating compartment 3. An upper portion of the air distribution apparatus 17 is positioned behind the third compartment 9, while a middle and a lower portion of the air distribution apparatus 17 are positioned behind the area of the refrigerating compartment 3 excluding the third compartment 9 and the vegetable compartment 10. That is, the upper end of the air distribution apparatus 17 is placed adjacent to the intermediate wall 1, and the lower end thereof is placed adjacent to the vegetable compartment 10. The entire height of the air distribution apparatus 17 approximately equals the height of the refrigerating compartment 3 plus the third compartment 9.
The cool air distribution apparatus 17, as shown in FIG. 6, comprises a front plate 24 made from a synthetic resin, a rear plate 25 which is made from insulated material and assembled with the front plate 24, and a seal plate 34 covering the back face of the rear plate 25. A set of a cool air distributing or directing means of the present invention, which will be described later in various ways, or a swing-wing 26 is detachably provided at the front surface of the front plate 24. At the upper end of the swing-wing 26 is provided a motor 28 for operating the swing wing 26. The motor 28 is seated on a motor case 29 in the upper portion of the front plate 24. At each side end of the motor 28 is mounted an indoor lamp 30. Numeral 31 is a lamp cover for shielding the lamp 30.
In the embodiment, since the motor 28 is seal-mounted at the upper portion of the swing-wing 26, moisture from the compartment can not penetrate into the motor 28. Because the moisture or the condensed water flows down due to the force of gravity even when the formation of moisture or the condensed water occurs, there is no worry about its penetration into the motor 28. Further, there is less possibility of moisture penetration due to the motor being housed by the case 29. The excess cooling caused by the decrease of the motor speed can not occur due to the indirect contact of moist air. Even if the water penetrates, the water is immediately evaporated by the heat from the lamp 30 mounted nearby, thereby preventing the problem of inoperability of the motor 28 due to the penetration of the water and further, the non-function of the swing-wing 26. Thus, this has the advantage that a decrease of the motor speed, with respect to poor electrical contact, an insulation failure due to the penetration of the moisture, and an excess cooling due to the frost of the penetrating water, never occurs. In the embodiment, a geared motor of which the rotation speed is fixed is employed as the operating motor. However, a stepping motor can be employed to control the rotation speed of the swing-wing in the forward and the reverse directions.
Numeral 32 references a position sensing switch for controlling the rotation position of the swing-wing 26, the switch being operated by a protuberance 33 provided at the upper end of the swing-wing 26. The quantity of the position sensing switch 32 corresponds to the number of respective swing-wings which will be installed in accordance with respective embodiments. Numeral 27 is a grill detachably assembled with the front plate 24 for the protection of the swing-wing 26. The grill 27 prevents foodstuffs housed in the compartment from prohibiting the rotation of the swing-wing 26.
In FIG. 7, the upper portion of the air distribution apparatus 17 comprises an air passage 18 for guiding the flow of the cool air generated from the evaporator 12, a baffle plate 19 for regulating the cool air volume fed into the refrigerating compartment 3 according to the opening/shutting of the baffle plate 19, and a motor 20 for operating the baffle plate 19. The temperature control effected by these components is achieved by the conventional method. Numeral 21 is a baffle cover and is integrally formed with the front plate 24 in the embodiment. Numeral 22 is a spacer which is made from an insulated material. The thickened spacer 22 prevents the cool air passing through the air passage 18, from generating frost on the outside wall of the baffle cover 21. Numeral 23 is an air discharge opening which is provided at the upper portion of the front plate 24, by which the cool air through the air passage 18 is discharged into the third compartment 9. In the embodiment, a couple of the discharging openings 23 are formed at the upper portion of the front plate 24. Therefore, the third compartment 9 is at a lower temperature than the refrigerating compartment 3, since the travelling distance of the air from the air passage 18 to the air discharging opening 23 is shorter than that from the air passage 18 to the middle and lower portions of the air distribution apparatus 17, so less heating of the air occurs. The swing-wing 26 is disposed at the front of the middle and lower portions of the front plate 24. The configuration of the swing-wing 26 of the present invention will be explained in detail later.
The distribution apparatus 17 is detachably installed on the rear wall 3W, and it is more desirable that the front plate 24 is placed against an even surface with respect to the rear wall 3W of the refrigerating compartment 3. That is, as shown in FIG. 6, the seal plate 34 adheres to the rear side of the rear plate 25 which is assembled to the front plate 24, and the swing-wing 26 and the grill 27 are attached to the front plate 24, and then the motor 28 and the indoor lamp 30 are assembled. Finally, the assembly is inserted in the rear wall 3W (FIG. 5). Therefore, in comparison to a prior art apparatus in which many individual components are installed in the refrigerating compartment, respectively, the installation work using the components of the present invention is more simple.
In FIG. 8, the air distribution apparatus 17 comprises an air passage 15 and openings 16A, 16B, 16C which discharge the air from the air passage 15 into the refrigerating compartment 3. The air passage 15 is formed in a longitudinal direction at the rear surface of the air distribution apparatus 17. The openings 16A,16B,16C interconnect the air passage 15 and the refrigerating compartment 3. The openings 16A,16B,16C are vertically spaced along the vertical center line of the apparatus 17. The air passage 15 includes a first duct 35 and a second duct 36, each of which is arranged adjacent to one of the vertical edges of the apparatus 17 such that the ducts 35,36 straddle the openings 16A, 16B,16C. The position of respective openings 16A,16B,16C corresponds with the partitioned space between the shelves 8 of the refrigerating compartment 3. The uppermost opening 16A is disposed at 3/4 H, the middle opening 16B at 1/2 H, and the lower opening 16C at 1/3 H, assuming that the height of the refrigerating compartment 3 is "H". The air passage 15 has first and second ducts 35,36 at each vertical side, and the wing member 26a is placed ahead of the openings 16, where the thickness of the air distribution apparatus 17 is thinnest. Thus, the extent to which the distribution apparatus 17 protrudes into the refrigerating compartment 3 is minimized, to maximize the available volume of the refrigerating compartment 3.
The upper portion of the first and second ducts 35,36 is expanded toward each side of the air passage 18, respectively, while the lower portion of the ducts 35,36 is expanded toward the vegetable compartment 10. The air passing through the air passage 18 flows into the first and second ducts 35,36. Most of the air flows down along the ducts 35,36 to be discharged into the refrigerating and vegetable compartments 3, 10. The remaining volume of the air is discharged toward the third compartment 9 through the discharging opening 23 (FIG. 8).
For guiding the down-flowing air into the refrigerating compartment 3, the air passage 15 comprises first branch ducts 37A-37C which interconnect the first duct 35 and respective openings 16A-C, and second branch ducts 38A-C which interconnect the second duct 36 and respective openings 16A-C. Thus, the air flowing along the first and second ducts 35,36 is guided to the first and second branch ducts 37A,37B,37C,38A,38B,38C, thereby discharging into the refrigerating compartment 3 through respective openings 16A,168,16C. A wide inlet of each of the branch ducts has the configuration that the upper portion thereof is rounded and the lower portion is shaped as a shoulder 371,372,373 in which the middle shoulder 372 is extended farther horizontally outwardly (the right and the left hand of FIG. 8) than the uppermost shoulder 371, and the lower shoulder 373 is extended farther outwardly than the middle shoulder 372. Therefore, since the air traveling along the first duct 35 and the second duct 36 becomes progressively warmer, a greater amount of air is needed to be discharged through the lower openings 16 in order to achieve a uniform temperature within the refrigerating compartment. The configuration of the branch ducts 37,38 as described above is very helpful to ensure that result.
Furthermore, to feed the cool air to the right or left portions of the refrigerating compartment 3, the opening 16A comprises an upper portion 16U and a lower portion 16L, the upper portion 16U being offset toward the first branch duct 37A with respect to the second branch duct 38A, while the lower portion 16L is offset toward the second branch duct 38A with respect to the first branch duct 37A. The air through the portions 16U,16L of the opening 16A is discharged in different directions, thereby causing the smooth discharge flow without a head-to-head collision of the air flows in the refrigerating compartment 3. Next, in the opening 168 adjacent to the opening 16A, the position of the upper, lower portions 16U',16L" are reversed with respect to that of upper, lower portions 16U,16L. That is, the upper portion 16U' is offset toward the first branch duct 378, while the lower portion 16L' is offset toward the second branch duct 38B. Further, at the lowest opening 16C, the position of the upper, lower portions 16U",16L" are reversed with respect to that of the upper, lower portions 16U',16L'. That is, the position of the upper, lower portions 16U',16L' are the same as that of the upper, lower portions 16U,16L of the upper opening 16A. As noted above, the temperature of the air reaching the second branch duct 38A is higher than that of the air reaching the first branch duct 37A. Alternatively, at the opening 16B, the relation of the temperature is reversed. Also, at the opening 16C, the relation of the temperature is the same as at the uppermost opening 16A. That tends to make the temperature at the right and the left sides of the refrigerating compartment more uniform.
FIG. 9 shows a first embodiment of the swing-wing or air distributing means 126. The swing-wing 126 comprises a wing member 126a and a columnar member 126b. The wing member 126a is formed as a plate extending vertically, and is integrally assembled to the columnar member 126b. The columnar member 126b is extended along the longitudinal center of the wing member 126a which is used as the rotating shaft of the wing member 126a. The upper end of the swing-wing 126 is connected to an output shaft of the driving motor (FIG. 6) to operate the swing-wing 126. Further, a protuberance 133 is provided at the upper end of the swing-wing 126 for controlling the rotation position of the swing-wing 126 when a localized air flow to the refrigerating compartment 3 is required. It is more desirable that a couple of swing-wings 126 are installed in the front of the openings 16A,16B,16C to evenly discharge the air coming into the refrigerating compartment 3 through respective openings. One of the swing-wings is rotatably disposed in the front of the openings while being offset toward the right portion of the openings. That is, the longitudinal center line of the columnar member 126b is disposed in front of the right-hand portions of the openings 16. The other swing-wing is rotatably disposed in front of left-hand portions of the openings.
First, the compressor 11 and the evaporator 12, in FIG. 4, are operated and the cool air is generated by the heat-exchange taking place with the circumference of the evaporator 12. The cool air is moved into the freezing 2 and the refrigerating compartment 3 by the fan 13 along the direction of the arrows in FIG. 4. Depending on the temperature of the refrigerating compartment 3 the shutting/opening operation of the baffle plate 19 (FIG. 7) is controlled. As the baffle plate 19 is opened, the cool air from the evaporator 12 is fed into the air passage 18 as shown in FIG. 8, and the air is divided between the right and the left side of the upper portion of the air distributing apparatus 17. A part of the cool air is discharged into the third compartment 9 through the air discharge opening 23 (FIG. 5), while most of the cool air is discharged into the refrigerating 3 and the vegetable compartment 10 after flowing along the first duct 35 and the second duct 36.
In FIG. 8, the air along the ducts 35,36 is guided by the respective branch ducts 37A-C,38A-C so as to be discharged through the openings 16. Further, the air through the openings is distributed to the right or the left side by the rotation of the swing-wing 126 for generating even cooling of the refrigerating compartment.
However, in the specified area, if too many foodstuffs are provided or a relatively hot food is disposed, the temperature becomes unbalanced. To solve the problem, a concentrated cooling in the warmer area needs to be employed.
FIGS. 10A, 10B and 10C show states of left-side cooling, central cooling and right-side cooling, respectively. The concentrated cooling can be achieved by aiming the air flow toward a predetermined direction under the command of the control system. To determine the direction of the concentrated cooling, i.e., the discharge direction of the cool air, a right space or first temperature sensor 52 is installed at the upper central portion of the right wall of the refrigerating compartment 3 and a left space or second temperature sensor 53 is installed at the lower central portion of the left wall of the refrigerating compartment 3 as shown in FIG. 5. The temperature sensors 52,53 as well as the position sensing switch 32 (FIG. 6) are connected to a control member (not shown) by a conventional method. Further, the motor 28 for rotating the swing-wing 126 is connected to the control member. These components can detect a temperature variance in the refrigerating compartment and achieve the effective concentrated cooling.
FIG. 11 illustrates the position sensing switch 32 which determines the datum position of the swing-wing 126, and the protuberance 133 which is rotated against the position sensing switch 32. The protuberance 133 rotates in the direction of the arrow together with swing-wing 26 so as to be operated as shown in FIGS. 11A, 11B, 11C. FIG. 11C shows the moment that the electrical point of the position sensing switch 32 is released. The protuberance has a contacting portion shaped in a smooth rounded manner for preventing any noise generated by the sudden release of the switch.
The amount rotation of the swing-wing 126 is controlled by a control member and the position sensing switch 32 is turned on and off by the protuberance 133 of the swing-wing 126. In the embodiment, the moment when the protuberance 133 is released from the position sensing switch 32 is set as the datum (reference) time (FIG. 11C). The time period of rotation of the swing-wing is checked by a control member, thereby producing the degree of the rotation. For example, assuming that the rotation speed of the swing-wing 126 is 6 rpm, the swing-wing 126 rotates during 10 seconds from the datum point, thereby rotating one turn.
Next, when the concentrated cooling is required for the left side, the swing-wing 126 is temporarily aimed toward the left direction so that the major part of the cool air flow is headed toward the left side as shown in FIG. 10A. Further, when the concentrated cooling is required to the center area, the swing-wing 126 is temporarily aimed in the central direction so that the major part of the cool air flow is headed toward the central area as shown in FIG. 10B. Furthermore, when the concentrated cooling is required for the right side, the swing-wing 126 is temporarily aimed toward the right direction so that the major part of the cool air flow is headed toward the right side as shown in FIG. 10C.
In the following descriptions of various embodiments of the swing-wing, the same numerals and letters are used for elements which function the same as those of the first embodiment, and a further description for the elements is omitted.
FIG. 12 shows a modified example of the first embodiment. The swing-wing 126' comprises a vertical columnar member 126b, and a distributing wing or vane 147' which is disposed on the columnar member 126b in an eccentric manner and is formed like an oval in a cross-section. It is more desirable that a couple of swing-wings 126' are installed at the front of the openings 16A,16B,16C as described in the first embodiment.
FIG. 13 shows a second embodiment of the swing-wings 226R,226L. Each swing-wing 226R,226L comprises a plurality of wing members 241A, 241B and 241C and a columnar member 126b, respectively. In this example, since the right portion 16U of the opening 16A of the air distributing apparatus 17 (FIG. 8) is offset with respect to the left portion 16L thereof, a couple of swing-wings may be employed to achieve the effective air discharge. That is, one of the swing-wings 226R is rotatably disposed in the front of the right portion 16U,16L' and 16U" of the opening's 16A,16B and 16C, while the other of the swing wings 226L is rotatably disposed in the front of the left portion 16L,16U' and 16L" of the openings 16A,16B and 16C. The wing member 241A comprises a dividing member 244A in the form of a rounded plate, and a distributing wing or vane 247 provided perpendicularly on the dividing member 244A. Each dividing member 244A,244B,244C is disposed at a lower boarder of the respective opening, i.e. this dividing member 244A of the right swing-wing 226R is at the lower boarder of the right portion 16U of the opening 16A, while the dividing member 244A of the left swing-wing 226L is at the lower boarder of the left portion 16L of the opening 16A. The diameter of respective dividing members 244A,244B and 244C approximately equals the width of the right or left portion of respective openings 16A,16B and 16C.
In the right swing-wing 226R, the distributing wing 247 is provided with a concave portion 250 and a convex portion 251 which are rounded in series, respectively. That is, the concave portion 250 is smoothly connected to the convex portion in a "S" shape. The height of the distributing wing 247 is the same as the height of respective right or left portions of respective openings. Utilizing that configuration of the distributing member on the dividing member, the direction of most of the cool air is controlled.
The distributing wing 247 of the left swing-wing 226L has a different orientation with respect to the right swing-wing 226R. In the right swing-wing 226R, the concave portion 250 extends in the same direction as the protuberance 133 of the columnar member 126b, while the convex portion 251 extends in the opposite direction. In the left swing-wing 226L, the convex portion 251 extends in the same direction as the protuberance 133 of the columnar member 126b, while the concave 250 extends in the opposite direction. The disposition of the distributing wing 247 is for reducing the flow resistance, corresponding to the disposition of the right, left portions 16U,16L of the opening 16A. The air guided by the distributing wing 247 impinges on the convex portion 251 largely, and flows over the convex portion 251, thereby remarkably reducing the flow resistance.
The cool air generated from the evaporator 12, as shown in FIG. 8, is mostly discharged into the refrigerating compartment 3 and the vegetable compartment 10 after flowing along the first duct 35 and the second duct 36. Thus, the air guided through the first branch duct 37A at the right side flows onto the convex portion 251 of the right distributing wing 226R, while the air guided through the second branch duct 38A at the left side flows onto the convex portion 251 of the left distributing wing 226L, which develops a main flow. Further, the horizontal plate-like dividing member keeps the weak air discharged in approximately a horizontal direction into the refrigerating compartment even when the swing-wing is in the slow rotation mode.
When a concentrated cooling is required for a specified area of the refrigerating compartment, the concentrated cooling as shown in FIGS. 10A, 10B, 10C is achieved by using the protuberance 133 provided at the upper end of the columnar member 126b.
FIG. 14 shows a modified example of the second embodiment. The swing-wing has the same components as the second embodiment in FIG. 13. Additionally, the swing-wing comprises a plurality of grooves 245 formed on the circumference of respective dividing members 241A,241B,241C along the extended direction of the columnar member 126b. The grooves 245 are for the cool air which is not discharged through the grill 27 yet (FIG. 7). The remaining air above the dividing member 241A actively flows down through the grooves 245 as well as the gap G between the rear surface of the grill 27 and the circumference of the swing-wings 226R', 226L'.
FIGS. 15A, 15B illustrate a third embodiment of the swing-wing 326. The swing-wing 326 comprises a plurality of wing members 326a and a columnar member 326b. The wing member 326a comprises a dividing plate 344 having an upper plate 341, a middle plate 342 and a lower plate 343 which are spaced apart from each other in a horizontal manner. The wing member 326a further comprises a distributing wing 347 which provides a first inducing wing 345 formed perpendicularly between the upper plate 341 and the middle plate 342 and a second inducing wing 346 formed perpendicularly between the middle plate 342 and the lower plate 343. In the embodiment, three sets 361,362,363 of the wing members 326a formed with the dividing plate 344 and the distributing wing 347 are integrally assembled with the columnar member 326b (the remaining one 349 will be explained later). That is, the swing-wing 326 is formed so that the three wing members 326a each having a dividing plate 344 and a distributing wing 347 are integrally attached to the columnar member 326b. The upper end of the swing-wing 326 is connected to an output shaft (FIG. 6) of the driving motor 28 to operate the swing-wing 326. It is more desirable that the columnar member 326b is shaped with a crisscross in cross-section.
Numeral 349, in FIGS. 15A and 15B, is a phantom (dummy) wing set which is irrelevant to the discharge of the cool air. Since no opening is provided at the corresponding position to the phantom (dummy) wing 349, it is directly unrelated to the discharging flow of the air. However, through the gap G (FIG. 7) between the rear surface of the grill 27 and the circumference of the swing-wing 26, the cool air is fed into the space housing of the phantom (dummy) wing 349. The air in the space is stirred by the phantom (dummy) wing 349 to increase the distribution effect with respect to the air flowing down to the lower wing member 363. Further, the balancing arrangement of the wing member provides external harmony.
The swing-wing 326 is detachably formed as shown in FIG. 15B to solve the problem rising from the manufacturing process. The upper portion of the swing-wing 326 consists of the upper wing member 361 and the middle wing member 362, and the lower portions of the swing-wing 326 consists of the lower wing member 363. In the case that the respective distributing wings 347 are molded in a different direction from each other (as will be explained in more detail later), there occurs the difficulty that a single cavity molding form can not be used. Therefore, the swing-wing 326 is divided into two portions. In the upper portions 361,362 of the swing-wing 326 the edges 347E,347E' of the distributing wings 345,346 are rotationally offset by 90° to each other. In the lower portion 349,363 of the swing-wing 326 the edges 347E",347E"' of the distributing wing 345,346 are form a zero degree angle with each other. Thus, if the assembling degree between the upper portions 361,362 and the lower portions 349,363 can be changed, the layout of the whole distributing wings 345,346 can be varied. In the embodiment, the edges 347E",347E"' offset by 45° relative to the edge 347E and the edge 347E'. FIG. 15C shows a modified example of the third embodiment, which illustrates the swing-wing 326 without the phantom (dummy) wing set 349.
Similar to the above-described embodiments, the upper, the middle and the lower distributing wings 361,362,363 are rotationally offset. Therefore, the impinging point of air against the wing 347 and the discharging direction from the distributing wing 347 differs from wing to wing, thereby causing the load applied to the distributing wing 347 to diminish. If, instead, the edges 347E,347E', 347E",347E"' of the inducing wings 345,346 were aligned, the cool air would be deflected off the vanes in the same direction, to produce excessive load on the swing-wing. In the embodiment, the rotationally offset relationship of the distributing wing sets results in a more balanced loading.
The edges 347E, 347E', 347E"' are all disposed within a range of 90°.
By using the offset angular disposition of the edges, the cooled air discharged through the openings flows within a range of about 90° toward the specified area of the refrigerating compartment as shown in FIGS. 10A, 10B, 10C, respectively. The direction of the concentrated cooled air flow is controlled by the protuberance 133 provided at the upper end of the columnar member 126b as in the operation of FIGS. 11A, 11B, 11C.
In this embodiment, a single swing-wing 326 is employed, since the configuration of the swing-wing 326 is matched to the nature of the air flow through the openings of the air distribution apparatus 17.
FIGS. 16 to 21 illustrate various embodiments of a cool air distribution apparatus, without an air guiding means, adapted to the previous embodiments. FIG. 16 shows the rear perspective view of another air distribution apparatus without the air passage 15, the openings 16 and the related components. Except for that every component of FIG. 16 is identical to that of FIG. 8. The same component parts as those in 16 are designated by the same reference numerals as in FIG. 8, but the detailed description of the parts will be omitted.
FIG. 17 shows a fourth embodiment of the swing-wing 426R,426L. Each swing-wing 426R,426L comprises a wing member 427 and a columnar member 126b. The wing member 427 is formed as a plate extending in a vertical direction, and has a plurality of horizontal dividing members or wings 444A, 444B and 444C which are equally vertically spaced from each other and are formed perpendicularly on one vertical side surface of the wing member 427. In this example, although dividing members are provided on only one vertical side surface of the wing member 427, both vertical side surfaces could carry dividing members. The position of respective dividing members 444A,444B,444C correspond to the respective lower edges of a plurality of meshed openings (not shown) of the grill 27. Further, respective openings of the grill 27 match up with the partitioned space between the shelves 8 of the refrigerating compartment 3. Therefore, the air flow down through the ducts 35A,36A is guided into respective partitioned spaces of the refrigerating compartment 3.
With reference to FIG. 16, the cool air generated from the evaporator 12 is mostly discharged into the refrigerating compartment 3 and the vegetable compartment 10 after flowing along the first duct 35A and the second duct 36A. Thus, the air guided through the first duct 35A at the right side is directed by impinging on respective dividing members 444A,444B,444C, while the air guided through the second duct 36A at the left side is directed by impinging on respective dividing members 444A,444B,444C. Further, the horizontal plate-like dividing members 444A,444B,444C shown in FIG. 17 keep the impinged air turning in approximately a 90 degree direction into the refrigerating compartment.
When concentrated cooling is required for a specified area of the refrigerating compartment, the concentrated cooling as shown in FIGS. 10A, 10B, 10C is achieved by using the protuberance 133 provided at the upper end of the columnar member 126b.
FIG. 18 shows a modified example of the fourth embodiment. The swing-wing has the same components as the fourth embodiment in FIG. 17. The swing-wing 426' comprises a columnar member 126b extended vertically, and a wing member 4471 which is disposed on the columnar member 126b. It is more desirable that a couple of swing-wings 426' are installed at the first duct 35A and second duct 36A respectively. A plurality of distributing wings 444D,444E,444F are provided which slant downwardly and outward.
FIG. 19 illustrate a fifth embodiment of the swing-wing 526. The swing-wing 526 comprises a wing member 547 and a columnar member 126b. The wing member 547 is formed as a helix shaped plate extending in a vertical manner. Further, the wing member 547 is integrally assembled with the columnar member 126b. Furthermore, the protuberance 133 is provided at the upper end of the swing-wing 526 for controlling the rotation position of the swing-wing 526 when the localized flow in the refrigerating compartment 3 is required. It is more desirable that a couple of swing-wings 526 are installed at the first duct 35A and second duct 36A, respectively. The helix angle of the wing member 547 is more slanted at the inlet or upper portion than at the outlet or lower portion, because the volume of air impinging against the lower portion of the wing member 547 is larger than that on the upper portion thereof. This satisfies the phenomenon that the lower the air goes, the higher the air temperature becomes.
The cool air generated from the evaporator 12, as shown in FIG. 16, is mostly discharged into the refrigerating 3 and the vegetable compartment 10 after flowing along the first duct 35A and the second duct 36A. Thus, the air guided through the first and second ducts 35A,36A at the right or the left side impinges against the upper portion of the wing member 547. A first volume of the impinged air is discharged into the partitioned space between the shelves 8 of the refrigerating compartment 3 through the corresponding upper opening of the grill 27. Through the middle opening of the grill a greater volume of the air flows into the corresponding space. In the lowest opening of grill, a greatest volume of the air is discharged into the space of the refrigerator 3.
When concentrated cooling is required for a specified area of the refrigerating compartment, the concentrated cooling as shown in FIGS. 10A, 10B, 10C is achieved by using the protuberance 133 provided at the upper end of the columnar member 126b.
FIG. 20 shows a modified example of the fifth embodiment. The swing-wing has the same components as the fifth embodiment in FIG. 19. The swing-wing 526' comprises a columnar member 126b extended vertically, and a wing member 547' which is disposed at the columnar member 126b and is formed by successive planar segments arranged in a generally helix shape.
FIG. 21 illustrates a sixth embodiment of the swing-wing 626. The swing-wing 626 comprises a hollow cylindrical member 626b and a columnar member 126b protruded upward or downward from both upper and lower ends of the cylindrical member 626b, and around which the cylindrical member 626b is rotated. The protuberance 133 is provided at the upper end of the upper columnar member 126b for controlling the rotation position of the swing-wing 626 when the localized flow in the refrigerating compartment 3 is required. It is more desirable that a couple of swing-wings 626 are installed at the first duct 35A and second duct 36A, respectively. Further, a helix wing member 647 is formed on the interior wall of the cylindrical member 626b. One side edge 647a of the helix member 647 extends along the interior wall of the cylindrical member 626b. Another side edge 647b of the helix member 647 slants is offset radially inwardly from the wall toward the center of the cylindrical member 626b. On the wall of the cylindrical member 626b, there are a plurality of vertically spaced openings 66A,66B,66C. The position of respective openings 66A,66B,66C corresponds to the partitioned space between the shelves 8 of the refrigerating compartment 3. At the same traverse point of the slant of the helix member 647, the one side end edge 647a of the helix member 647 is horizontally formed, while the other side end edge 647b thereof is slanted upwardly. The slant upward angle of the inner edge 647b relative to the outer edge 647a is lowest at the upper opening 66A, while highest at the lower opening 66C. Thus, the slant upward angle is in the middle at the middle opening 66B. Due to the configuration of the slant, less air is discharged through the upper opening 66A, and more air is discharged through the lower opening 66C.
The cool air generated from the evaporator 12 is mostly discharged into the refrigerating compartment 3 and the vegetable compartment 10 after flowing along the first duct 35A and the second duct 36A. Thus, the air guided through the first and second ducts 35A,36A at the right or the left side flows into the top of the cylindrical member 626b and contacts the helix member 647 adjacent to the upper opening 66A. Part of the impinged air is discharged into the partitioned space between the shelves 8 of the refrigerating compartment 3 through the corresponding upper opening 66A of the grill 27. Through the middle opening 66B a greater volume of the air than that of the upper one flows into the corresponding space. In the lowest opening 66C, a greater volume of the air than that of the middle opening 66B is discharged into the space of the refrigerator 3.
When concentrated cooling is required for a specified area of the refrigerating compartment, the concentrated cooling as shown in FIGS. 10A, 10B, 10C is achieved by using the protuberance 133 provided at the upper end of the columnar member 126b.
As described in detail above, the uniform refrigeration can be accomplished more effectively by means of various embodiments of the swing-wings which disperse the discharged cool air.
In the case that there is any temperature deviation in the compartment, the area with a relatively high temperature can receive concentrating cooling for some period until the uniform temperature is reached. Accordingly, this invention possesses the advantage of achieving the concentrating cooling in any case.
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A refrigerator includes a refrigerating compartment and a cool air distributing system on the back wall thereof. The distributing system includes vertical passages which divide a flow of incoming cool air and conduct the air to vertically spaced discharge openings communicating with the refrigerating compartment. Disposed in the path of air flow is an air directing structure having adjustable vanes for controlling the horizontal direction in which the air flows enter the refrigerating compartment. Each vane is motor driven and can comprise vertical plates or helical elements rotated about a vertical axis. Alternatively, each vane can be a helical vane disposed on the inside surface of a hollow cylinder for guiding an air flow from within the cylinder outwardly through openings formed in a wall of the cylinder.
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