Patent GB-742314-A (GB)
Title: Improvements in vehicle hydraulic transmission systems
IPC: B60K17/10
Filed: 1952-12-19
Abstract: 742,314. Motor-vehicle hydraulic driving gear. KLATTE, T., [trading as KLATTE, T. [Firm of]]. Dec. 19, 1952 [Dec. 28, 1951], No.32299/52. Classes 79 (2), 79 (3) and 79 (5). A driving unit, comprising an engine 1 and a liquid pressure pump 2, is arranged at each end of a vehicle, the pumps 2 being interconnected by pipes 4, 5 to which motors 10 for driving the vehicle are connected, control valves 18, 29 of the pumps being controlled by a common operating member and each unit having a valve 16 adapted to reverse the motors and operable independently of the corresponding valve in the other unit. As shown, the oil pressure motors 10 are disposed in the hub of the vehicle wheels. Each pump 2 is connected by its output pipe 13 to the reversing valve 16, and oil from the pipe 13 passes through bores 14, 15 in the valve through the pipe 4, for example, to the motors. Returned oil from the motors passes through the pipe 5, bores 25, 26 in the valve 16 and pipes 27, 28 to each pump 2. The valves 18, 29 of the pumps are operated through linkage 21, 22, 20 by a pedal 60, the valves 18 each serving to obstruct a return pipe 23 to the pump 2, and the valves 29 each serving to maintain free passage between the pipes 27, 28. Operation of the linkage causes the output of the pumps 2 to be returned directly thereto by the pipes 23 and the return of oil from the motors to be prevented by disconnecting the pipes 27, 28 so that the motors are not driven. When each valve 16 is rotated through 180 degrees, the motors are reversed, oil from the pipe 13 passing through bores 37, 38 to the pipe 5, for example, and oil from the motors passing through the pipe 4, bores 40, 39 and a pipe through the pipe 4, bores 40, 39 and a pipe 41 to the pipe 28. Furthermore, when each valve 16 is rotated through 90 degrees from [the position shown in Fig. 3, the pipes 4, 5 are disconnected from the pump 2. The valve 16 carries a gear 31 which meshes with a rack on a rod 32, the rod carrying a piston 35 within a cylinder 34 to which are connected pipes 33, 36, the other end of the rod 32 having a geared connection with an arm 42. As shown in Fig. 5, a cock 44 controlled by a lever 46 is mounted on the steering column 43 of the vehicle, pressure oil is delivered to the cock 44 by a pipe 45 and a return pipe 47 is provided. By appropriate movement of the lever 46 the pipe 45 can be connected to either pipe 33, 36 to cause the piston 35 to move to either of its end positions corresponding to the forward or reverse positions of the valve 16. Arranged in the pipes 33, 36 is a valve 48 having through passages 49, 50, Fig. 7. When the valve 48 controlled by a handle 51 is axially moved against the action of a spring 52, the upper and lower sections of the pipes 33, 36 are disconnected and the lower sections interconnected by a channel 53 in the valve 48, the channel enabling the pressures in the faces of the piston 35 to be balanced. Fast with the handle 51 is an arm 56 connected by a link 61 to an arm 62 having a recess 63 adapted to be engaged by a spring-urged plunger 64 on the pedal 60 which also carries a recess adapted to be engaged by a spring-urged button 66 which is depressed to start the engines 1 when the pedal has been depressed. A plate carrying the handle 51 and arm 56 has a recess 59 into which projects a member 55 carried by an arm 54 pivoted on the casing of the valve 48. The arm 54 is connected by a link 57 to the arm 42 so that rotation of the valve 48 causes the valve 16 to be moved into its neutral position through the the pump. Specification 697,541 is referred to. rod 32 so that the motors are disconnected from