ROTARY VALVE ACTUATOR WITH ZERO LOST MOTION UNIVERSAL CONNECTION

摘要

A rotary valve actuator (10) with movable actuator linkage maintained in a constant "pull-pull" tension, includes a sliding canister (46), rotatable lever (16), and a return spring (56) substantially aligned in-line with each other. The linear motion of the canister in response to an expanding and contracting pressurized bladder (60) is converted through chain linkage (42) into rotary lever motion. The return spring is connected through respective chain linkage to the lever so the pulling tension of the spring/lever linkage rotates the lever and maintains tension on both chain linkages. Adjustable travel stops are provided. In an alternate embodiment the return spring chain linkage is configured at right angles to the linear movement of the canister. A zero lost motion universal connection includes a splined sleeve (88) matching the splined valve shaft (86) and inserted into a lever bore. A set screw (98) with a flat front end is threaded into the lever and tightened against a flat surface (94) on the splined sleeve exterior.