GB1208003A - Pump with piston and diaphragm - Google Patents

Abstract

1,208,003. Diaphragm pumps. P.W. SCHLOSSER. Oct.4, 1967 [Oct.28, 1966], No.45100/67. Heading F1A. A hydraulically actuated diaphragm pump comprises a diaphragm 19, Fig.1, clamped between a housing member 12 and a member 70 by bolts clamping a housing member 11 to member 12, member 70 being free to move axially to increase the clamping action on the diaphragm periphery when actuating piston 15 is on its pressure stroke, the right-hand surface of member 70 exposed to driving pressure being greater than the left-hand surface. The central portion of diaphragm 19 is clamped between a rigid plate 80, a soft plate 79 and a rigid plate 78, a bolt 74 clamping the assembly to a spacer 73 and another rigid plate 76, which limits the delivery stroke of the diaphragm to planar position 85 by abutting the righthand face of member 70. On abutting member 70, plate 76 engages a sealing ring 83 to close-off actuating chamber 17 from the diaphragm. Movement of an inlet valve ball 35 in the pumping chamber 18 is controlled by a resilient retainer member 36, and movement of delivery valve ball 46 is controlled by a spring-loaded cage 47. An air release valve 58 in the delivery passage is opened by depressing a knob 60, Fig.3. The actuating piston 15 requires a cup washer 115, Fig.4, mounted on a member 100 between rigid discs 103, 108, with an intermediate seal 107 of elastically extrudable material. Clearance is provided between seal 107 and member 100 into which material of the cup washer can extrude during the return stroke of the actuating piston. A sealing boot 110 clamped between the cylinder and the piston rod prevents entry of air behind the piston, leakage past the piston on the driving stroke returning to the actuating chamber on the return stroke. Additional actuating liquid is supplied to the actuating chamber from a reservoir 120, Fig.1 driving the return stroke via a pipe 121, ball valve 123, Fig.3, and port 124, the clearance between ball 123 and passage 176 being sufficiently small for a very small flow, to ensure the maximum suction stroke of the diaphragm. Excess liquid in the actuating chamber is released through a pressure-relief valve 139 during the delivery stroke, the valve spring loading being adjustable by a screw 142. Air in the actuating chamber is bled off through a ball valve 163 controlled by a knob 165, air bubbles being visible in a transparent tube 167. Actuating piston 15 may be driven by an electric motor through crank 96.