Patent ID: 6068764
Filing Date: 2000-05-30
Classification: B01D,F04B

Abstract:
A pump and shut off valve comprising:a pumping compartment and a feed supply compartment;a drive including a drive shaft which is driven by said drive and which extends into said pumping compartment;a piston in said pumping compartment and dividing said pumping compartment into first and second chambers, and a drive transmitting connector between said drive shaft and said piston to reciprocally move said piston toward and away from said first and second chambers, respectively, to alternately increase and decrease the volume in the respective chambers;first and second fluid inlets for introducing a fluid to said first and second chambers, respectively, and first and second fluid discharges for discharging the fluid from said first and second chambers, respectively;a check valve in each of said first and second fluid inlets permitting the flow of fluid to each of said chambers but preventing the flow from each of said chambers, a check valve in each of said first and second fluid discharges permitting the flow of fluid from each of said chambers but preventing the flow to each of said chambers, and said first and second discharges communicate with said feed supply compartment;a fluid inlet communicating with said feed supply compartment for introducing a fluid to said feed supply compartment, and a fluid discharge from said feed supply compartment for discharging the fluid from said feed supply compartment; anda valve in said feed supply compartment movable in response to a decreased fluid pressure in said first and second discharges from said first and second chambers to permit the flow of fluid between said fluid inlet and said discharge of said feed supply compartment, and in response to an increased fluid pressure in said first and second discharges from said first and second chambers to block the flow of fluid between said fluid inlet and said discharge of said feed supply compartment.