GB573713A - Improvements in or relating to hydraulic rams - Google Patents

Abstract

573,713. Hydraulic machines. COLLEY, R. H. Dec. 31, 1943, No. 21938. [Classes 69 (ii) and 135] The supply of liquid to alternative ends of the cylinder of a ram 10, which may operate the change-speed gear of the supercharger of an internal-combustion engine, is controlled by a valve 19 yieldingly displaced, e.g. by liquid supplied to its ends through valves 33, 34 solenoidally operated, from its neutral position, a lost-motion coupling between ram and valve returning the valve to its neutral position at the end of a stroke, while a centralizing spring 50 returns the valve to its neutral position when not constrained by the ram or the yielding means. The lost-motion coupling comprises a lever 45 freely mounted on a shaft which also freely carries a double arm 51, 52 and a single arm 48 connected to the arm 51 by the spring 50 and having an abutment 49 ; the arms coact with pins respectively on the lever and on a cam 12 actuated by the ram to operate the control. Liquid flows to the valve through a pipe having a lightly-loaded valve 16, and in the neutral position flows away through pipe 23 ; when the valve is moved to an end position, the liquid passes by a pipe 28 or 29 to the ram cylinder and escapes through the other pipe and pipe 23. Pipes 30, 38 also convey liquid from opposite sides of the valve 16 to the solenoidal valves, operation of which determines whether the lower or higher pressure liquid is conveyed to either end of the valve 19. The solenoids may be actuated by hand or automatically, e.g. by aneroid devices, a manual over-riding switch being provided. Specification 572,936 is referred to.