GB1459419A - Clutch operating mechanisms for motor vehicles - Google Patents

Abstract

1459419 Clutch control; valves AUTOMOTIVE PRODUCTS Ltd 21 Jan 1974 [22 Jan 1973 25 July 1973] 55641/73 and 35414/73 Headings F2L and F2V A friction clutch on a motor vehicle is disengaged by a slave piston and cylinder 48 supplied with liquid under pressure either from a master cylinder 10 operated by a pedal or from an accumulator 23 through a solenoid 34 operated valve 15, the solenoid 34 being activated by closure of a switch 39, which occurs when the vehicle gear lever is operated. The master cylinder 10 is, when the solenoid is deactivated, connected to the slave cylinder 48 through the valve 15. The return flow to the reservoir 18 when the clutch engages passes through the valve 15, the master cylinder 10 and a restrictor 19, which controls the rate of clutch engagement. The restrictor 19 may only be operative during vehicle braking (when lower gears are usually selected), this being sensed electrically by a brake-operated switch to activate a solenoid in the restrictor, or by a pendulum which senses deceleration or by fluid pressure from the braking system (Fig. 2, not shown). In a further embodiment the slave cylinder has tandem pistons (Fig. 3, not shown) each being operated by one of the pressure sources. The accumulator 23 is charged by a pump 21 which may be driven by the starter motor of the engine, which motor has means to prevent it from engaging the engine when so used. The accumulator may be dispensed with and the pump 21 driven by an electric motor which operates on energization of the solenoid 34.