GB556549A - Improvements in or relating to liquid pressure remote control systems - Google Patents

Abstract

556,549. Hydraulic remote control systems. AUTOMOTIVE PRODUCTS CO., Ltd., and CARLTON, Q. H. June 17, 1941, No. 7665. [Class 69 (ii)] A two-pipe line liquid pressure remote control system of the kind in which a transmitter A and a receiver B coupled by a pair of pipe lines C.D. each comprise a pair of cylinder-and-piston units 66, 72, 73, 74, 75, the pair of pistons 66 being coupled mechanically in each case to move in opposite senses is constructed to maintain correct phase relation between the transmitter and receiver and for returning them to correct phase if necessary. As shown the pistons 66 of the transmitter are operated by connection of links 67 with a lever arm 68 operated by a handle 105, and the cylinders 72, 73 are surrounded by a reservoir 65 from which liquid can pass to either of the pipe lines of low pressure via passages and a non- return valve 88. Passage of liquid from the cylinders is normally prevented by a spring-closed valve 85 to which is attached a rod 93 fitted with a head 94 capable of engaging a guide 96 at the end of the extreme upward movement of the pistons 66. This engagement takes place if the phase is incorrect, and to permit of movement of the upper pistons relatively to the valve rods 93 the links 67 in their upward movement engage spring-controlled stops 97 which permit a greater movement of the right-hand piston 66 than the normal movement corresponding to exact equality of movement of the transmitting piston with the receiving pistons. The transmitting pressure is applied by a rigid stop. When the apparatus is left unused the arm 105 may be moved clockwise far enough to cause the spring stop 97 to raise the plunger of cylinder 73 far enough to open valve 85 and connect the system to the reservoir 65. The arm 105 is locked in this position and so temperature changes are prevented from altering the phase relations adversely during storage. In a modified form the pairs of pistons in the transmitter and receiver are coaxial and arranged in a single long cylinder of uniform diameter. The pistons are operated by rack-and-pinion mechanism controlled by arms fitted with fixed stops and spring stops respectively, and adapted to open valves which connect the cylinders to a reservoir it the devices are out of phase, but not otherwise.