GB838387A - A fluid-operated valve mechanism with momentarily actuated control - Google Patents

Abstract

838,387. Valves. ROSS OPERATING VALVE CO. Aug. 25, 1958 [Oct. 23, 1957], No. 27240/58. Class 135. A three-way double spool valve assembly 11, Fig. 1, is interposed between a solenoid-operated three-way valve 12 and a fluid motor 13. The pilot valve 12 when actuated connects the inlet 15 to the working conduit 17. The valve assembly 11, Fig. 2, comprises a control spool 35 and an actuating spool 36. The conduit 17 leads to a chamber 41 of the spool 35 the closure member 44 of which controls the port between two chambers 43, 38..A spring 45 urges the spool 35 to the right to interconnect the chambers 43, 38. A ball detent 49 controlled by a cam surface 48 of the spool 35 normally engages a groove 52 of the spool 36 which is thereby locked in the position shown, so that a closure member 72 thereon is positioned to allow flow between chambers 68, 69 the latter of which is connected through an exhaust port 71 to the conduit 21, Fig. 1, and a closure member 65, Fig. 2, closes the port between the chambers 63, 68. Fluid under pressure is continuously supplied to the chamber 63 of the spool 36. When the pilot valve 12 is momentarily actuated, fluid under pressure is supplied to the chamber 41 so forcing the spool 35 to the left closing the interconnecting port between the chambers 43, 48. The ball detent 49 drops from groove 52 so that the fluid pressure in the chamber 63 causes the spool 36 to move to the left so that closure members 65, 72 open and close their respective ports. Fluid now flows from supply chamber 63 to chamber 68 which is connected to the motor 13, Fig. 1, by line 18. When chamber 41, Fig. 2, exhausts on de-energization of pilot valve 12, the spring 45 returns the spool 35 to the right and the ball-detent 49 is forced into the groove 53 of the pool 36 which is thereby locked in its actuated position. The chamber 68 is then connected to an accumulator chamber 57 and to a return chamber 55 of the spool 36 via passage 73, chambers 43, 38 and passage 56. The pressure in chamber 55 urges the spool 36 to the right but the spool is locked by the detent 49 until the spool 35 is moved to the left as before by pressurization of chamber 41 on actuation of pilot valve 12. When the spool 36 is returned to the right by the fluid pressure in chamber 55, the working chamber 68 is connected to exhaust via the chamber 69 so that the piston of the motor 13, Fig. 1, is returned by the spring 23. The spool 35 returns to the right as before and the ball detent again engages the groove 52. The piston 22, Fig. 1, has thus one reciprocation for every two actuations of the pilot valve 12. Where it is desired, say, that a piston actuated main simple lift valve in a supply conduit is given one actuation for every four or six, or eight, or ten, &c., actuations of a solenoid-operated valve, two or three or four or five &c. of the above described valve assemblies 11 are arranged in series in a stack which also contains the pilot valve and the said main simple lift valve. Two modifications in which compressible or incompressible fluid may be used are described. In the first, Fig. 10, the accumulator chamber 57 of Fig. 2 is omitted and the working chamber 108 of the actuating spool is connected to chamber 109 of the control spool the chamber 112 of which is connected by a conduit 116 to a chamber 126 of a threeway piston valve 118 which controls the supply of fluid to the return chamber 122 of the actuating spool. In the second example, Fig. 11 (not shown), the accumulator chamber 57 is connected to another accumulator chamber one wall of which comprises a spring-loaded piston.