Patent GB-495903-A (GB)
Title: Improvements in or relating to fluid pressure remote control systems
IPC: B63H21/22
Filed: 1937-08-28
Abstract: 495,903. Controlling change - speed and reversing gearing. AUTOMOTIVE PRODUCTS CO., Ltd., and CLENCH, E. C. S. Aug. 28, 1937, Nos. 23609 and 27099. [Class 80 (ii)] In liquid-pressure remote controlling-means for change-speed and /or reversing gear, e.g. for watercraft, liquid under pressure in the change-gear slave-unit A acts also in an engine slaveunit C, so as to set the engine speed-regulating member 27 to idling position during a change. The engine slave-unit C is also controlled independently by a transmitter-unit D having a lever 34 for regulating the engine-speed. The gear slave-unit A comprises a double-acting piston 11, pivotally connected to a reversing-lever 10, and controlled by a transmitter-unit B, which is of the kind described in Specifications 443,839 and 468,976, [both in Group XXIX], and is actuated by turning a hand wheel 17 in the appropriate direction. Both transmitter-units B, D are fed from a common reservoir F. The single-acting engine-controlling slave-unit C comprises a cylinder divided into three chambers 65, 66, 67, Fig. 4, by a main piston 58, on a rod 30, connected to the speed-regulating member 27, Fig. 1, and by an auxiliary piston 59. Pipes 35, 36, Fig. 1, leading from the chambers 67, 66, Fig. 4, are branched into the pipes 15, 16 connecting the change-gear transmitter- and slave-units B, A, so that the existence of pressure for effecting a change, in either pipe 15 or 16 will move the piston 58 to the right of Fig. 4 to set the. engine speedregulating member 27, Fig. 1, to the idling position. The piston 58 is moved to the left of Fig. 4 against a spring 31, to adjusted running positions, by pressure supplied to its right face through piping 33, 32 by the simple singleacting transmitter D, the pressure generated by which is less than that of the gear-transmitter B. The arrangement shown in Fig. 1 is for a Diesel engine in which the engineregulating member 27 is subject to reactions from the governor-control. The engine controllever 34 is retained in adjusted positions by friction only, and in order that such friction shall be as light as possible and the lever 34 still not be influenced by the reactions on the regulating member 27, an automatic checkvalve E is interposed between the pipes 32, 33. Such check-valve comprises a spring-loaded ball-valve 74, Fig. 5, which opens under the heavy pressure created by the gear transmitter unit B in the engine slave-unit C, so that, as the latter is moved to idling position by the former, liquid is forced back to the engine transmitter-unit D and moves the lever 34 to the idling position, at the same time as the engine regulating-member 27. The lower pressure created by the reaction on the regulating- member 27 is insufficient to open the ball-valve 74, so that the setting of the control-lever 34 remains unaffected by such reaction. Pressure from the engine transmitter-unit D reaches the slave-unit C through a spring-loaded ball-valve 76, arranged oppositely to the ball-valve 74 and byepassing the latter. The ball-valve 76 is normally held off its seating by a pin 82, projecting from a piston 78, the right face of which is subjected to the pressure in the transmitter-unit D, so that such pressure moves the piston 78 to the left, releasing the ball-valve 76, which nevertheless remains open to the control-pressure passing towards the engine slave-unit C. When the high-pressure flow is instituted in the reverse direction from the gear transmitter-unit B, by opening the ballvalve 74, the piston 78 again moves to the left, allowing the ball-valve 76 to close to such reverse flow. In the case of a petrol engine, in which the regulating member, viz. : the throttle, is not subject to reactions, the engine slave-unit C is directly connected to its transmitter-unit D, but, in order that the frictional hold on the engine control-lever 34 may be replaced by a positive lock, acting on a toothed quadrant, as described in Specification 486,238, [Group XXIX], a hydraulic accumulator is included in the pipe-line connecting these units, to take the pressure from the engine slave-unit when the latter is moved to idling position by the gear-unit. Cessation of such pressure after the change in the gear unit, allows the hydraulic accumulator to deliver its stored pressure back to the engine slave-unit, and thus return the latter to its original position determined by the setting of the engine control-lever. Signal lights 22, 23, 24, controlled by switches 18, 19, 20 actuated by the piston-rod of the gear slaveunit A indicate the forward-neutral-reverse positions of the reversing lever 10. A number of throttles may be controlled by a common master transmitter or by independent transmitters, single- or double-acting, with a common overriding control by the gear-box transmitter. Specification 443,871 also is referred to.