Patent GB-468976-A (GB)
Title: Improvements in or relating to liquid pressure remote control systems
IPC: F15B7/08
Filed: 1936-02-05
Abstract: 468,976. Hydraulic transmission of power. CLENCH, E. C. S., and AUTOMOTIVE PRODUCTS CO., Ltd. Feb. 5, 1936, No. 3528. [Class 69 (ii)] [Also in Group XXVIII] A liquid.pressure remote - control system comprises in combination a transmitter pump, a reservoir, a slave cylinder unit which is fed with pressure liquid from the pump through either one of a pair of pipe lines, a valve device for passing the pressure liquid into one or other of the pipe lines according to the direction in which the transmitter pump is actuated, means whereby the pipe lines are automatically placed in communication with the reservoir whenever the system is inoperative irrespective of the prevailing setting of the slave cylinder unit, and an electrical device for indicating said prevailing setting. The system, Fig. 1, comprises a transmitter unit A which delivers pressure liquid to the double acting receiver B through one of the pipes 14, 16 according to the direction in which the actuating handle 10 is rotated, the return liquid passing through the other of said pipes to a reservoir. The piston rod 15 of the receiver B carries a finger 18 co-operating with a contact strip 20 and resistance 19 connected by wires 21, 22 to a moving coil ohm meter supplied from a battery 27 or a stand-by battery 28 according to the position of a switch 29 ; the battery 27 may be the normal lighting or other battery of an aircraft, watercraft or vehicle. The transmitter pump, Fig. 2, comprises plungers 38, 39, 40 each provided with a ball valve 41 and filter 42, the plungers delivering past delivery valves 44 and passage 45 to a transverse passage 46 ; a pressure-relief valve 47 byepasses liquid back to the reservoir which comprises the chamber 33 enclosing the pump-actuating mechanism. The plungers are reciprocated by eccentrics 52, 53, 54 on a sleeve 51, teeth on which engage teeth on a sleeve 55 fixed to the spindle 30 which is rotated by the hand wheel 10, 11 ; the dog clutch 56 has considerable backlash. The distributing valve arrangement comprises valves 59, 60, Fig. 3, normally urged by springs 61 to a position in which the pipe lines communicate with the reservoir through passages 64, 65, 66 in the valves, and are cut off from the pump delivery 46. A member 69 having ears 67, 68 co-operating with the valves is loosely mounted on the operating spindle and is urged into frictional engagement therewith by a spring 71 ; when the hand wheel 10 is rotated in one direction or the other, one of the valves 59, 60 is depressed so that the corresponding pipe line is disconnected from the reservoir and put in connection with the pump delivery, the other pipe line remaining in connection with the reservoir through that valve which is not depressed. When the hand wheel 10 is released, the valve springs 61 return the member 69 to its central position ; the rotation of the sleeve 55 thus caused is not imparted to the eccentric-sleeve which actuates the plungers, owing to the backlash in the dog clutch. A single transmitter may actuate simultaneously a number of receivers, in which case branch pipe lines 14<a>, 16<a>, Fig. 1, are provided ; the receivers may be mechanically coupled together, in which case a single resistance is employed to actuate the indicator. Alternatively, a selector valve 74, e.g. of the kind described in Specification 468,989, may be provided whereby the transmitter is put into communication selectively with the lines 14, 16 or 14b, 16<b>; the indicator 23 is simultaneously connected to the appropriate wires 21, 22 or 21<b>, 22<b>, the battery circuit of the indicator 23 being opened by a switch 75 automatically operated by the valve 74 to prevent fluctuations during the change over. The selector valve may be so arranged so as to put the transmitter into communication selectively with each of a number of receivers or one of a number of sets of receivers. The receivers may be fitted with mechanical selflocking means which are released automatically by the pressure liquid received from the transmitter as described in Specification 443,871.