Pneumatic timer for differential piston pump - has larger face in chamber with inlet and larger outlet throttles

摘要

The pneumatic timer moves an actuator at regular intervals between the initial and working positions by supplying it with compressed air. Air pressure is directed onto the first and smaller face(A1) of a differential piston(4, 5) forming the actuator, bringing it into the initial position, and simultaneously part of the compressed air charges a chamber(8) via a throttle(9), the chamber being closed by a second and larger face(A2) of the piston. As pressure builds up in the chamber, this piston face if lifted off its seat towards the working position. This frees a third and larger face(A3) of the piston to exposure to the air pressure in the chamber, and moving the piston briskly into the working position.