GB548175A - Improvements in and relating to valves adapted for use in hydraulic power transmission systems - Google Patents

Abstract

548,175. Valves. NASH, A. G. FRAZER-. Oct. 30, 1940, No. 15873. [Class 135] A hydraulic control valve particularly adapted for use in a gun turret for controlling the power cylinders for imparting motion of elevation and depression to the guns and for securing azimuthal motion thereof has the several valve members slidably mounted in a common housing which is provided with supply and exhaust connections leading to the power cylinders and to a power supply. In the form shown in the Figure the housing accommodates three separately actuated piston valves, 43, 47, 49, slidably mounted in ported liners 23, 24, 25 secured by screwed plugs 26 and distance pieces 29 in three parallel cylindrical bores 2, 3, 4 in the common casing. The valves 43, 47 control the power cylinders while the valve 49 is adapted either to connect the supply conduit 20 directly to the return main 21a by way of ports 42, 42a or to connect conduit 20 to a series of annular grooves 12, 12a, 12b, surrounding the lines and connected by passages 13 and the exhaust conduit 21a to two similar series of annular chambers 5, 5a and 11, 11a, 11b connected by passages 6, 8 and 10. The valves 43, 47 are normally held in a central neutral position by springs 46, 46a acting on abutments 45, 45a adapted to co-operate with shoulders in the liners. The valve 49 is normally held in the short circuiting position by a spring 51. Annular grooves 14, 14a and 16, 16a surrounding the liners are connected to the power cylinders. Movement downward of the valve 43 connects the supply passage 13 to the annular groove 14a by way of ports 33, 34a and at the same time the annular groove 14 is connected to the return main by way of ports 31, 34 and passages 5, 8, 10 and 11. An upward movement reverses these connections. The valve 47 operates in a similar manner.