GB516091A - Improvements in or relating to fluid pressure remote control systems - Google Patents

Abstract

516,091. Hydraulic transmission of power. AUTOMOTIVE PRODUCTS CO., Ltd., and BEESTON, J. P. July 15, 1938, No. 21071. [Class 69 (ii)] In fluid pressure remote control systems in which a reversible flow pump or transmitter unit is connected by a pair of pipe lines with a double acting slave unit therein, fluid under pressure is forced into one of the pipe lines to move the. slave unit, the other pipe line returning the fluid from the slave unit. A valve device checks the return flow so that the rate of movement of the slave unit is restricted by a force other than through the working liquid. The valve device is spring closed but tends to be opened by the return liquid from the slave unit, the opening being assisted by the pressure of liquid in the pipe line. As shown, a valve device is provided with a pair of passages 11, 12 joined by connections 13, 14 respectively to the working spaces of a double-acting slave cylinder 15 and controlled by ball valves 20, 21, against which bear piston-like intermediate members 24, 25. The latter members are provided with channels 37 bringing recesses 38 into communication with passages 39, 40 leading to pipe lines 41, 42. The pipe lines are connected to a transmitter device comprising a pump 43, reservoir 44 and reversible selector valve 45. Non-return ball valves 48, 49 act in theopposite sense to valves 20, 21 so as to serve as by-passes. When pressure liquid is fed through pipe line 42 to move piston rod 53 of slave unit 15 downwardly the liquid opens the valve 49 and passes through passage 11 and connection 13 to upper working space of unit 15. The liquid pressure thus creates enough force to open the valve 20. If the piston rod 53 tends to move upwardly the corresponding liquid pressure in the connection 13 is unable to force either of valves 49, 21 open until reinforced by the pressure from pipe line 41. A modification of valve device operates in one direction only. The valve device may be employed in a flowequalizing system such as is described in Specification 496,550.