GB1050590A - - Google Patents

Abstract

1,050,590. Valves. INTERNATIONAL BUSINESS MACHINES CORPORATION. Oct. 22, 1965 [Dec. 23, 1964], No. 44752/65. Heading F2V. With a hollow spool-valve 30 and a lift valve 36 in the positions shown, a " sense " port 16 is connected to a supply port 14 via a spool groove 32, which "sense" port is also connected to a device that indicates when flow is transmitted to a working port 26 and can be used for timing the apparatus connected to the latter; a chamber 23 in series with the working port 26 is also connected to the supply port 14 by spool ports 35 and a passage 20 with which co-operates an adjustable restrictor 21. A chamber 22 at the opposite end of the spool valve is open to supply pressure via a leak around the end of the spool; the spool and lift valve are urged to the position shown by supply pressure acting on a piston 25 joined to the lift valve 36; the lift valve seats upon the spool valve. When fluid is drawn from chamber 23 through the working port 26 the chamber pressure falls due to the restrictor 21 and the supply pressure in chamber 22 moves both valves to the right until the spool is stopped by the ring 34 abutting a casing part 11; the lift valve 36 continues to move to open a direct path from the supply port 14 through the hollow spool 30 to the chamber 23 so by-passing the restriction. The port 16 is then connected to a return port 15.