Patent GB-851023-A (GB)
Title: Improvements in or relating to valve systems for pressure fluid circuits
IPC: F15B13/08
Filed: 1957-09-04
Abstract: 851,023. Valves. LANSING BAGNALL Ltd., and ARNOT, A. E. R. Sept. 4, 1958 [Sept. 4, 1957], No. 27974/57. Class 135. A rectangular valve body 11 has an inlet 12 in one of the narrower faces whilst each of the two larger faces incorporates a circular recess 13 interconnected by parallel passages 16, 21. The inlet 12 opens into an annular port 24 in a valve bore 17, which port communicates with the passage 16; a sliding closure member 22 in the bore 17 embodies a land 23 that is normally positioned to open the bore 17 below the port 24 so that pressure fluid reaches a second annular port 121 intersected by the passage 21. Below the land 23 is a tapered regulating section 123. When the member 22 is moved to close port 24, the inlet 12 opens into the bore 17 above the land 23 which communicates with an outlet 27 via a passage 25 and a chamber 26; the member 22 is urged to the position shown by a spring 30 acting on a sleeve 28 locked to the member. Crossing the chamber 26 is a second bore 31, parallel with bore 17, and housing an hydraulically-balanced sliding-closure member 32 provided with a tapered valve part 34 and an adjacent tapered land 38; the member 32 is biased to the position shown by a spring 35. In the chamber 26, which is of circular crosssection, is a non-return valve 39 of square crosssection so as to permit flow around it to the outlet 27, the valve member being sealed by a spring in a cup 41 bearing against the member 32; the upper end of the member 32 enters a cap 42 with a stem 43, the cap being urged upwardly by a spring 44. A rocker 49, which is pivoted across the top of the body 11, has an actuating lever 50 and adjustable tappets 51, 52 to engage the stem 43, and a cap 53 on the member 22, respectively, so that rocking lever 50 rightwardly lowers member 22 and connects the inlet 12 and port 24 to passage 25 and outlet 27, whilst rocking the lever 50 leftwardly lowers member 32 and connects the outlet 27 to exhaust 37. Above passage 25 is a port 55 leading to a drain passage 56, the port 55 being closed by a land 57 on member 22 when the latter is lowered; a passage 59 connects'the port 55 to an oil seal 58 around member 32 to provide a drain for any leakage from the latter; leakage from member 22 flows direct to passage 56 or, at the bottom, to exhaust 37. An electric switch 60, which is operated by the rocker 49, controls the actuation of an hydraulic pump and hence the movement of a jack, e.g. fed from the outlet 27. The body 11 is provided with holes 65 to enable a number of valves to be bolted together as a gang, the recesses 13, 14 and ports 37, 57 of which come into alignment so that, the valves are in series whereby actuation of any one lever diverts the whole supply to the jack &c. controlled thereby. In a modification, the valves are bolted together, one being reversed relative to the other in order to control a double-acting jack, the rocker of each valve being coupled to a singleacting lever. In this arrangement the drain passage 56 of one of these valves is connected by a pipe to the bottom of a reservoir from which the pump draws its supply so that when the jack causes suction in one of its supply pipes the non-return valve 39 associated therewith opens and enables fluid to be drawn from the reservoir to keep the pipe primed. The valve units may be so arranged that single- and double-acting jacks may be controlled from one valve gang.