Expansible chamber devices – Collapsible chamber wall portion – Wall portion formed of flexible material
Reexamination Certificate
1999-07-26
2001-09-11
Ryznic, John E. (Department: 3745)
Expansible chamber devices
Collapsible chamber wall portion
Wall portion formed of flexible material
C092S097000, C092S09800R
Reexamination Certificate
active
06286413
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a diaphragm actuator, and more specifically to a diaphragm actuator for the high speed exertion of forces of precise and repeatable amounts with no friction and with no fluid leakage. The invention also relates to a multiple diaphragm actuator for applying linear forces in opposite directions at a point positioned entirely to one side of the actuator.
2. Description of the Prior Art
A variety of what are commonly referred to as diaphragm actuators exist in the art for applying a force to a work piece. A common actuator of this type includes a pair of pressure chambers separated by a diaphragm with means for selectively introducing fluid pressure into, and exhausting fluid pressure from, the pressure chambers. Commonly associated with the diaphragm is an elongated actuator rod which is movable with the diaphragm. This rod extends through one of the pressure chambers and through a sealed opening in the pressure chamber to a work piece. With this type of actuator, forces exerted on the diaphragm and thus the actuator rod by the pressure chambers are controlled by selective introduction and exhaustion of fluid pressure into and out of the opposed pressure chambers.
However, several potential problems exist with this design: First, friction and potential for leakage exist between the actuator rod and the seal members which seal the rod as it exits the one chamber. Whenever there is a possibility of friction and/or leakage, extreme accuracy and repeatability are virtually impossible. Second, the seal members sealing the rod as it exits the one chamber will eventually wear-out and thus need replacement. This results in further inaccuracy and non-repeatability. Thirdly, the volumes of the two opposing chambers are not exactly matched because of the existence of the rod in the one chamber and because the amount of the rod within the one chamber varies as the chamber expands and contracts. This again adversely affects the accuracy of the forces generated on the rod and the repeatability of force generation. Fourthly, because the volume of the chambers must be filled before any force is exerted, rapid-high speed exertion of forces is limited. Accordingly, with known diaphragm actuators such as those described above, the application of extremely accurate, high speed and repeatable forces is difficult, if not impossible, to achieve.
Accordingly, there is a need in the art for an improved diaphragm actuator which is capable of providing extremely accurate, high speed and repeatable forces and which virtually eliminates any inaccuracies and any repeatability concerns resulting from friction or leakage of fluid from the pressure chambers.
SUMMARY OF THE INVENTION
In contrast to the prior art, the present invention relates to a diaphragm actuator which is capable of providing an extremely accurate, high speed and repeatable linear force. This is possible by providing a system having one or more pressure chambers with no seals to wear-out or to create friction or leakage. Further, the diaphragm actuator of the present invention eliminates the existence of any actuator rod within a pressure chamber and substantially reduces or eliminates the chamber volume. Accordingly, with the diaphragm actuator of the present invention, a relatively large, two-directional linear force can be generated at a force receiving point at high speed without loss of accuracy, efficiency or repeatability due to fluid leakage or friction. Further, with the actuator of the present invention, such a two-directional linear force can be generated at a point which is positioned entirely to one side of the diaphragm actuator.
More specifically, one embodiment of the diaphragm actuator in accordance with the present invention includes first and second opposed fluid pressure chambers or cells each having a fluid inlet/outlet port and a diaphragm responsive to the fluid pressure in the respective pressure chamber. Preferably, the fluid pressure chambers and the diaphragms are oriented such that their diaphragms are parallel to oppose one another so that the linear forces exerted by the diaphragms are collinear and are in opposite directions.
In this embodiment, the diaphragm actuator of the present invention further includes an actuator arm assembly which preferably includes a pair of piston members engaging the outer surfaces of the respective diaphragms to receive the respective linear forces from the diaphragms. The actuator arm assembly further preferably includes an arm portion connected with the pistons to transfer the linear forces created by the diaphragms to a work piece. In one embodiment, the point on the work piece to which the arm portion is connected is positioned entirely to one side of the diaphragm actuator. Thus the diaphragm actuator of the present invention has particular applicability to situations in which there is accessibility to only one side of the work piece or the force receiving point.
The diaphragm actuator of the present invention is further configured such that a plurality of such actuators can be positioned in side by side relationship relative to one another and/or stacked vertically relative to one another. With such a structure, diaphragm actuation systems can be designed for exerting opposed linear forces at closely adjacent work pieces or force receiving points. Alternatively, a single stack actuator can be provided with a single piston and opposed pressure chambers.
In a further embodiment, a single diaphragm and associated piston is provided. In this further embodiment, the piston is preferably provided with a spring return. In many or all embodiments it is preferable to reduce the volume of the chambers as much as possible to increase the speed or frequency of the forces. In certain embodiments, this volume is eliminated entirely.
Accordingly, it is an object of the present invention to provide a diaphragm actuator capable of providing extremely accurate, high speed and repeatable linear forces to a work piece.
Another object of the present invention is to provide a precision diaphragm actuator which eliminates inaccuracies due to friction and/or leakage.
Another object of the present invention is to provide a multiple diaphragm actuator in which fluid pressure cells can be positioned adjacent to one another and/or stacked vertically relative to one another to increase the density of force receiving points.
A still further object of the present invention is to provide a diaphragm actuator capable of accurate, high speed and repeatable force output in response to differential pressure input.
These and other objects of the present invention will become apparent with reference to the drawings, the description of the preferred embodiment and the appended claims.
REFERENCES:
patent: 1371242 (1921-03-01), Hopwood
patent: 2292896 (1942-08-01), Morgan
patent: 2372813 (1945-04-01), Darling
patent: 2545857 (1951-03-01), Perkins et al.
patent: 2658525 (1953-11-01), Shannon
patent: 2820434 (1958-01-01), Otto
patent: 2871795 (1959-02-01), Smith
patent: 3251305 (1966-05-01), Schlosser
patent: 3497038 (1970-02-01), Schrader et al.
patent: 3502004 (1970-03-01), Schrader
patent: 3563138 (1971-02-01), Symonds et al.
patent: 3626813 (1971-12-01), Kreuter
patent: 3722373 (1973-03-01), Beach et al.
patent: 3817264 (1974-06-01), Kilayko
patent: 3899959 (1975-08-01), Bertrand et al.
patent: 3975989 (1976-08-01), Hirmann
patent: 4038506 (1977-07-01), Filip
patent: 4208031 (1980-06-01), Jonak
patent: 4209000 (1980-06-01), Ivie
patent: 4272999 (1981-06-01), Perry
patent: 4522220 (1985-06-01), Multrus
patent: 4565501 (1986-01-01), Laurendreau et al.
patent: 4615353 (1986-10-01), McKee
patent: 4754776 (1988-07-01), McKee
patent: 5796007 (1998-08-01), Panagotopulos et al.
patent: 513977 (1939-10-01), None
patent: 631186 (1949-10-01), None
patent: 1323108 (1973-07-01), None
patent: 901674 (1982-05-01), None
Dorsey & Whitney LLP
Ryznic John E.
Tol-O-Matic Inc.
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