摘要 |
A three-position actuator comprising a casing having a diaphragm dividing the casing into separate pressure chambers, an actuating rod connected to said diaphragm and resilient means urging said diaphragm in one direction. One of the resilient means comprise a movable spring seat with a compression spring interposed between the seat and a plate connected to the diaphragm. The seat and plate are in turn interconnected by a single flat connector strap limiting separation between the plate and diaphragm to an amount approximately one-half the total travel of the diaphragm. In one embodiment of the invention the spring seat is connected to a separate diaphragm. In the preferred embodiment of the invention, only a single diaphragm is employed and the spring seat floats in the casing, with its separation from the diaphragm limited by the connector strap.
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