Patent GB-582069-A (GB)
Title: Improvements in clutch control mechanism
IPC: B60K23/02
Filed: 1944-07-05
Abstract: 582,069. Variable-speed gearing. BENDIX AVIATION CORPORATION. July 5, 1944, No. 13805. Convention date, Nov. 20, 1943. [Class 80 (ii)] The clutch 12 of a vehicle is engaged and disengaged by a pressure fluid motor 10 under control of a solenoid operated valve 76 which is in turn controlled by a switch 96 actuated by the gear-shift lever 98 and another switch 100 actuated by a transmission governor. The motor 10 is in two parts 54, 56, Fig. 2, the first part comprising a diaphragm 66 which is operated by suction from a conduit 132, and an opening 130 in the carburetter intake, when the throttle valve 124 is opened to effect initial engagement of the clutch through rods 26, 28, cranked lever 30 and clutch lever 36. The suction on the diaphragm 66 and the loading of the clutch is proportional to the rate of flow of air past the opening 130 which is substantially proportional to the engine torque. The final stage of engagement and loading of the clutch is effected by the motor part 56 when the speed of the vehicle reaches a predetermined speed. The solenoid valve 76 which is in circuit with the ignition switch 92 is energised below this speed by the switch 100 to open the chamber 106 of the motor 56 to suction from the intake manifold 104 through conduits 108 and 114 which raises the piston 61 against the pressure of a spring 74 which relieves the pressure of a spring 72 acting on the top of clutch actuating rod 26. When the speed of the vehicle rises sufficiently to operate the governor switch 100 the solenoid valve 76 is de-energised and the chamber 106 of motor part 56 is opened to atmosphere thus allowing the spring 74 to move the piston 61 down and compress the spring 72 which increases the loading on the clutch to its full value. Operation of the clutch with each gear change is effected automatically by the gear lever 98 actuating the switch 96 during the first part of a gear-changing movement to energise the solenoid valve 76 to open the motor part 56 to suction and so release the pressure of springs 74 and 72 on the actuating rod 26 to disengage the clutch, the suction on diaphragm 66 being relieved by release of the accelerator pedal and closing of the throttle valve 124. The separation of the clutch plates is effected by springs 52. On completion of the gear changing movement the switch 96 is opened to de-energise the solenoid valve and the accelerator is opened to cause both parts of motor 10 to load the clutch. A check valve 116 with a bleed hole 140 is provided in the conduit 114 so that the rate of loading of the clutch by the motor part 56 is controlled by the hole 140 whilst the valve 116 can open when the chamber 106 is to be evacuated. Should the throttle be opened suddenly by abnormal operation of the accelerator, resulting in a sudden drop in the manifold vacuum, the suction on motor part 54 may be insufficient to load the clutch in which case the motor part 56 effects the loading owing to the reduced vacuum acting therein. The clutch may be disengaged manually by a connection on to the crank lever 30 from a pedal 47.