Linear fluid power actuator assembly

Abstract

An improved fluid power actuator assembly comprising a power piston reciprocatingly mounted in a cylinder bore which is formed in a compact fluid power manifold providing the necessary circuit connections between control valves mounted on the housing and the cylinder bore. The cylinder bore preferably includes two circumferentially spaced signal ports disposed in the wall of the cylinder bore along the path of travel of the piston in addition to the primary power ports located at each end of the cylinder bore to drive the piston. The piston includes at least one circumferential groove and functions as a spool valve for opening and closing communication between the signal ports as the piston travels in the cylinder. Appropriate control valves and signal pressure communicating with the signal ports is disclosed to enable a fluid power signal to be generated which is related to the position of the piston during its travel in the cylinder bore. In turn, this signal is used to actuate a control valve spool element to provide control logic between two operative positions to reverse or otherwise modify the operation of the piston. Included in the control logic circuitry is a toggle type control valve which is actuated by a fluid pressure pulse to cause the main power flow control valve to switch power flow to reverse the direction of the piston stroke.