GB460660A - Improvements in gear shifting mechanism - Google Patents

Abstract

460,660. Controlling change-speed gearing. HILL ENGINEERING CORPORATION. June 28, 1935, No. 18549. Convention date, June 29; 1934. [Class 80 (ii)] Mechanism for changing speed in a vehicle gear-box 19, Fig. 1, comprises a selector gear shift lever 20 movable in parallel planes or slots 1-R and 2-3, Fig. 3, in a gate g towards one of which, the slot 2-3, it is biassed, a power actuator 37 for moving the lever 20 in these slots, a motor 57 rigid with the actuator for displacing the actuator so that the lever 20 moves in a transverse slot t, and means comprising a single lever or knob 99, Fig. 8, for controlling the actuator 37 and the motor 57 one after the other. In the arrangement shown, the power source is suction in the engine manifold 11, Fig. 1. This suction is turned on by a valve 32 as described, for example, in Specification 449,545, when a stem 34 is depressed by a cam 36 on the accelerator, not shown, being released to close the throttle 14. This suction admitted to a pipe 31 first acts in a servomotor 27 to pull a lever 25 left of Fig. 1 and so open the engine clutch 21. A suction differential then builds up in a chamber 66 behind a check valve 67 leading by pipes 72, 71 to control valves 74, 84 of the actuator 37 and motor 57. The gear lever 20 cannot therefore be moved until after the clutch 21 is open. The actuator 37 is supported on a joint 48, Fig. 3, so that a spring 62 biases the gear lever 20 into the slot 2-3 between middle and high speeds. Suction must be admitted to the motor 57 to pull the lever 20 through the slot t to the slot R-1. The actuator 37 is double acting and has two pipe lines 82, 83 from its ends leading to ends of the barrel 73 of the valve 74, Fig. 4. A slide valve 74 connects the suction pipe 72 to either of the pipes 82, 83 to exhaust the two ends of the actuator 37, and this valve 74 has cut-away air ports 152 so that when the valve is in mid position, the lever 20 can be moved by hand without obstruction. The valve 74 is connected at 106 to a lever arm 103 rigid with a tube 94, Fig. 7, which passes up through the steering column 93 to a lever arm 96, Fig. 8, which supports the knob lever 99. Thus rotating the knob 99 around the column 93 works the valve 74 to operate the actuator 37. A ball 124, Fig. 7, locks the knob 99 in two gear positions with the gear lever 20 at the four ends of the gate slots. The motor 57 is singleacting with a single pipe line 87 which is normally vented at 91<1>, Fig. 5. To energize the motor 57, Fig. 3, to overcome the bias spring 62, a valve plug 88 must be turned to the position shown dotted in Fig. 5. This is done by robating a lever 92 upwards of Fig. 7 by pulling upwards a rod 108 sliding centrally of the column 93, and this is done by depressing the knob 99 to the position shown dotted in Fig. 8, a lock ball 117, Fig. 7, holding it there. Therefore to-and-fro sideway displacements of the knob 99 shift the gear lever 20 between middle and high speeds unless the knob is in the depressed position, when the shifts are between low and reverse. The knob 99 can be moved at any time to preselect, the change taking place on releasing the accelerator which admits suction first to the clutch servomotor 27 and afterwards to the actuator 37 and motor 57. Release of the accelerator at any time by opening the engine clutch effects free running or freewheeling. An auxiliary electrical device controlling this free running is shown in Fig. 10. A valve plunger 128 obstructs the passage from the manifold 11 so as to render the servo mechanism inoperative unless a coil 127 is energized from the car battery 129, 132 being the ignition switch. A wire 135 is earthed at 139 through the arm 136 of a speedometer or like device 137 except at high speeds, when the arm 136 leaves a contact 138. Therefore, at high speeds, the valve 128 is closed and the engine clutch held engaged so that the engine can be used for braking. The coil wire 135 is also at low speeds earthed at 144 through wires 140, 143 and a switch 146 which is opened when struck by a selector rod 145 when high speed is put in. In order to run free on high speed, a branch switch 148 is simply closed, which keeps the circuit of the coil 127 completed. Specifications 457,108 and 457,179 also are referred to.