Actuator for reciprocating air driven devices

摘要

An actuator valve for an air driven reciprocating device including a housing with a cylinder having a sliding valve piston located therein. The valve piston includes circumferential grooves near the ends of the piston to receive floating piston rings. The piston rings exhibit a positive clearance with the cylinder which allows axial airflow thereby. The housing provides an inlet extending into one side of the cylinder and passageways diametrically opposed extending from the cylinder. Controlled passageways at the ends of the cylinder alternately vent. Between venting, the cylinder accumulates pressure at both ends of the piston. With venting, the pressurized air at the unvented end of the piston shifts the piston toward the vented end. Bleed passageways extend from adjacent the inlet to the ends of the piston to assist shifting once the piston proceeds over center.