GB577922A - Improvements in hydraulic valve mechanism - Google Patents

Abstract

577,922. Hydraulic control valves. ROSE, A. G., and NICHOLLS, K. H. May 18, 1944, No. 9545. [Class 135] A control valve for hydraulically operated apparatus such as a gun turret of an aircraft as described in Specification 577,904, [Group XXI], comprises a valve body 1 with pressure and exhaust passages 8, 11 and outlet ports 13, 14 in communication with pipes 16, 17 leading to the hydraulic motor. The main servo valve comprises a sleeve member 21 adapted to control the supply and exhaust of pressure fluid to the motor through ports 3, 4, 5, 6 and 7 and actuated itself by pressure fluid supplied to piston chambers 37, 38 at its ends under control of a further piston valve 48 actuated by an arm 56 and rod 52 from a lever arm 57 which is connected to, for example, the sighting apparatus of a gun turret. The valve 48 controls ports 41,43 in a sleeve 39 fixed in the servo or relay valve 21 to supply pressure fluid from another port 42 to one or other of the piston chambers 37, 38 so that the relay valve 21 repeats the movement of the valve 48. A follow-up action from the gun turret is obtained by a direct connection on to the casing 1. A continuous " dither " motion is imposed upon the piston valve 48 by an eccentric 61 and follower 53 operated from a rotary oil motor 63, 64 to keep the system "live".