GB1059919A - Improvements in or relating to pump controls - Google Patents

Abstract

1, 059, 919. Reciprocating pumps. HARRY KRUGER G.m.b.H. Nov. 14, 1963, No. 45063/63. Heading F1A. In a control arrangement for controlling the reciprocating movement of a fluid-operated doubleacting, single cylinder pump, control valves 82 operated by a power piston 17 are connected by fluid passages STU, Fig. 2 (not shown), to a control housing so that a control piston 61, carrying a slide valve 67 may be displaced between two end positions by the operating fluid. As the power cylinder piston 17 moves upwardly from the position shown in Fig. 1 compressed air flowing into control housing 51 passes through duct HU to the lower cylinder space through an enlarged bore similar to HO. The air in the upper cylinder space flows out through passage HO and passes through slide valve 67 to leave by exit LA. During the upward movement of the power piston the inner space of the control valve is under pressure so that pressure is communicated to the interior of the upper control valve 82 through an upper control passage STU (not shown). When power piston 17 moves the upper valve member 82 against the loading of spring 83, the upper passage STU (not shown) is vented to atmosphere and ball valve member 66 is pressed against the upper valve rest by pressure below the ball and the control piston 61, carrying valve plate 67, is moved upwardly. Braking pins 73 unseat ball 66 to reduce the impact of control piston 61 on the control housing cover. Slide valve 67 connects passage HU with outlet LA and on completion of the reversal operation compressed air flows through the lower ring 64 and the lower control passage STU to the lower control valve 82. During the upward stroke ball valve 41 is closed and suction valve 40 is open, the pumped fluid being delivered at FA and drawn in at FE. During downward movement, suction valve 40 closes and ball valve 41 opens and an amount of fluid corresponding to the difference in diameter between the working piston and the piston rod is again delivered. In another embodiment, compressed air enters distributor (91), Fig. 3 (not shown) and passes through valve (92) into a lower control piston bushing (58) through a reducing valve (93) and then into the interior of the control housing (51) through groove (E) and integral passages. Air above power piston (17) passes through upper main passage (HO) through slide valve (67) into the vent opening (LA). Just prior to the previous reversal of the power piston, the opening of valve (82) vented the underside of control piston (61) to atmosphere via the axial bores in bushing (58), the lower control passage (STU), the lower main passage and openings (HU) and (LA). Air then flows through opening (HU) through a lower main passage (not shown) into the lower piston space to drive piston (17) upwardly, the control piston (61) having just been moved into the opened position by the compressed air above it, ball valve (66) being closed. During the upward stroke, ball valve (41) is closed and ball valves (40), (42) are open, fluid being delivered at (FA). At the downward stroke ball valve (40) closes and ball valve (41) opens, fluid again being delivered at (FA). A filling connection in the pump may be used for admitting cleaning solvents and the power system has a vent valve.