Patent ID: 6685443
Filing Date: 2004-02-03
Classification: F04B

Abstract:
A pneumatically shifted reciprocating fluid pump comprising:a body defining two pumped fluid pumping chambers; driving means defining a pneumatically driven driving chamber associated with each respective pumped fluid pumping chamber; connecting means connecting the respective driving means; and a pneumatically actuated control valve for supplying a first drive fluid sequentially to each pneumatically actuated driving chamber for effecting reciprocal pumping of the respective driving means, wherein the pump is convertible between two modes of operation wherein in a first mode the pump includes first pneumatically actuated switching means associated with each respective driving means for permitting drive fluid to selectively exhaust from respective pneumatically actuated driving chambers to shift the control valve for sequentially supplying the drive fluid to respective pneumatically actuated driving chambers for reciprocally actuating respective pumping chambers;and a second mode wherein the pump includes second pneumatically actuated switching means associated with the connecting means for permitting an external supply of drive fluid to selectively shift the control valve for sequentially supplying the external supply of drive fluid to respective pneumatically actuated driving chambers for reciprocally actuating respective pumping chambers.