Patent GB-1188545-A (GB)
Title: Control Apparatus for a Pressure Medium Operated Change-Speed, Reversing and Steering Gear for Crawler-Tracked Vehicles
IPC: F15B13/02
Filed: 1967-06-09
Abstract: 1,188,545. Controlling vehicles. KLÍCKNER-HUMBOLDT-DEUTZ A.G. 9 June, 1967 [29 June, 1966; 12 April, 1967], No. 26696/67. Heading B7H. [Also in Division F2] In control means for fluid-pressure actuated change-speed, reversing and steering gear in an endless-track vehicle, ratio changing and reversing are controlled by moving a control member longitudinally of the vehicle, differential control of the steering clutches and brakes is effected by moving the control member transversely of the vehicle, the control signals are transmitted from the control member to associated fluid-pressure control means either mechanically, electrically or hydraulically, and a braking pedal is provided for effecting simultaneous disengagement of both clutches and subsequent application of both brakes. As shown in Fig. 5, a handlebar 111 and supporting shaft 133 are moved along the shaft axis to control change-speed gear 4 and reversing gear 3, and the handlebar 111 and shaft 133 are pivoted about the shaft axis to control steering clutches 9, 11 and brakes 24, 25. A pedal 76 controls the vehicle engine 1, and twist-grips 131, 132 on the handlebar 111 control raising and tilting of a loading bucket 89 carried by the vehicle. The shaft 133 is mounted in a housing 134 (Fig. 6) and serves as a sliding valve spool for controlling ratio selection and reversing. A spring-loaded detent 155 locates the shaft 133 in axial positions corresponding to neutral N and gear ratios I, II and III in both forward and reverse. A groove 144 in the shaft connects a passage 141 fed by a fluid-pressure main 39 to either of grooves 63a, 64a communicating with the reversing gear 3 through control lines 63, 64 to determine the direction of travel. A groove 150 connects one of passages 137a, 138a, 139a or 137b, 138b, 139b with a corresponding passage 65a, 66a, 67a or 65b, 66b, 67b communicating with the change-speed gear 4 through control lines 65, 66, 67 to select the respective ratio. Grooves 145, 148, radial passages 147, 149, 151, 152 and an axial bore 146 connect the control lines 63, 64, 65, 66, 67 to a return main 47 as appropriate. A hollow shaft 158 slidably splined to the shaft 133 is formed with cams 162, 163 for actuating clutch and brake valves 164, 165 and 183, 184 spring- biased into neutral positions wherein control lines 34, 35, 37, 38 connected to the steering clutches 9, 11 and brakes 24, 25 communicate with the return main 47 through passages 34b, 37b. When the shaft 133 is rotated in either direction the cam 162 first displaces one of the clutch valves 164 or 165 to connect the respective control line 34, 37 to the pressure main 39 for disengaging the appropriate clutch 9, 11, and the cam 163 then displaces the corresponding brake valve 183, 184 to connect the respective control line 35, 38 to the pressure main for applying the appropriate brake 24, 25. Disengagement of both clutches 9, 11 and application of both brakes 24, 25 when the pedal 71 is depressed is effected by displacing all the valves 164, 165, 183, 184 by means of fluid pressure applied to pistons integral with the valves through lines 181, 182 connected to a braking valve 68 actuated by the pedal. Control valves 84, 85 linked to the twist-grips 131, 132 by cables 129, 130 communicate through lines 95, 96 and 97, 98 with lifting and tilting jacks 90, 91 and 92, 93 for the bucket 89. Levers 101, 102 provide for preselection of the initial or final positions of the bucket 89. The pedal 76 is connected to control means 77 for the engine 1 through a cable 78 and lever 88. The pressure main 39 and return main 47 are associated with an hydraulic supply system including an enginedriven pump 40, a reservoir 42, and pressure holding and limiting valves 45, 46. In a modification, Fig. 4 (not shown) the handlebar is carried by a shaft which actuates a changespeed and reversing control valve through a lever and the clutch and brake control valves through a lever and links. In another embodiment, Fig. 1 (not shown), the handlebar is pivotally mounted on a vertical column which is pivoted about an axis extending transversely of the vehicle to actuate a change-speed and reversing control valve through a push-rod. Pivoting of the handlebar on the column controls clutch and brake valves through a flexible cable. The twist-grips for controlling operation of the bucket may be replaced by handles rotatably mounted at each end of the handlebar.