GB767823A - Improvements in or relating to electromagnetically-operated fluid control valves - Google Patents

Abstract

767,823. Valves. BRITISH MESSIER, Ltd., Aug. 3, 1954 [Aug. 4, 1953], No. 21502/53 Class 135. In a three-way selector valve for controlling the supply and discharge of pressure liquid to and from an actuator, e.g. a jack operating an aircraft undercarriage or flap, the pilot valves operating the main supply and discharge valves of the selector valve comprise electricallyactuated valves 31, 32, urged towards seats 29, 30 by springs 37, 38, and connected by tension wires 33, 34 which pass sealingly through glands 35, 36 to opposite ends of a polarized armature 45 pivoted about its centre and under the control of a reversing switch 50. The valve 31 controls communication between the rear of the piston 18 of a piston actuated supply valve 19 and a passage 41 connected to the actuator connection 14 and the valve 32 between the rear of the piston 26 of a piston-actuated discharge valve 25 and a passage 42 connected to the discharge connection 13. The rear of the pistons 18, 26 are connected to supply pressure and actuator pressure respectively through restricted openings 51, 52. On operation of the switch 50 to rotate the armature 45 anticlockwise the valve 31 is unseated to relieve pressure from behind the piston 18 to connect the actuator to pressure liquid supply, valves 32 and 25 remaining closed. On operation of the switch 50 to rotate the armature clockwise the valve 31 is seated by its spring the valve 32 unseated, to relieve pressure from behind the piston 26. The actuator is then connected to discharge and pressure builds up behind the piston 18 to close the supply valve 19.