GB1376692A - Control valve - Google Patents

Abstract

1376692 Valves KOEHRING CO 30 Nov 1972 [8 Dec 1971] 55382/72 Heading F2V In a control valve having service passages 18, 19 for a double-acting cylinder 20, an inlet passage 23 and an outlet passage 27, a first spool 11 is movable to connect the inlet passage 23 to the service passage 18 and simultaneously to connect an actuating cylinder 45 at the end of spool 12 to fluid pressure in the service passage 18 via passages 50, 49, 51 or 52 and 55 so that the spool 12 is moved to connect the service passage 19 to the outlet 27. Movement of the spool 12 to connect the service passage 19 to the inlet passage will also simultaneously connect the actuating cylinder 46 to the service passage 19 so that the spool 11 will move to connect the service passage 18 to the outlet passage. A spool 13, which has opposite end chambers 60, 61 respectively connected to an inlet feeder passage 22 by passage 63 and the service passage 18, 19 at the higher pressure by passages 65, 66, 69, shuttle valve 71, passage 55 or 56 and passages 51 or 52, 49 and 50, moves to regulate the flow between the inlet passage 23, feeder passage 22 and a passage 24 feeding an adjacent control valve according to the load on the motor. The passages 55, 56 and 69 are formed in part by grooves in the sides of the valve body which are covered by plates. A plurality of such valve bodies containing the spools may be stacked. In modifications the regulating spool 13 is dispensed with and the outlet passages communicate directly with the inlet passage of an adjacent valve.