AIR DRIVE PUMPS AND COMPONENTS THEREFOR

摘要

An air driven double diaphragm pump has two opposed pumping cavities with diaphragms extending thereacross. A shaft extends between the diaphragms and through an actuator housing. The housing includes a control valve assembly having a control valve to direct pressurized air to one or the other of the dual pumping cavities and two relief valves which cooperate with the pump shaft position to release air from one end or the other of the control valve for the shifting thereof. Shuttle valve elements are positioned between the control valve and the pumping chambers. The shuttle valve elements are slidably positioned within the valve cavities to move between extreme positions under the pressures within the input and the pumping cavity. In one extreme position, the pumping cavity is in communication with an exhaust having a tapered passage. In the other, the exhaust is cut off and pressurized air is able to pass through a one-way valve in a passageway through the shuttle valve element to charge the pumping chamber.