Rotary valve actuator and linkage

Abstract

A rotary valve actuator and linkage include an actuator having a tubular housing with end caps and a piston that is moved by fluid pressure against a compression spring. A rolling diaphragm is used to bias the piston. A pair of ports are provided on opposite sides of the housing, and a linkage having two arms is interconnected with the piston through the ports. The linkage is coupled to a rotary valve shaft and linear movement of the piston causes rotational movement of the shaft. The linkage includes two separate arms and a centerpiece. In one embodiment, the arms and the centerpiece interengage each other at angled surfaces that force the centerpiece and the arms into radial engagement with the shaft when axial compression is provided to the arms and centerpiece to force them toward each other. In another embodiment, each of the linkage arms is provided with a collet having radially movable portions. The collet is forced into a recess in the centerpiece, causing the radially movable portions to be locked in engagement with the shaft.

Dependencies are inferred from the claim text.