GB848850A - Centrifugal clutch operating system - Google Patents

Abstract

848,850. Gearing for stopping and starting machinery. STANDARD MOTOR CO. Ltd. Jan. 2, 1959 [Jan. 9, 1958], No. 858/58. Class 80 (2). To increase the speed of a motor car engine during emergency ratio downshift while braking the car, thus re-engaging an internally centrifugally-controlled main clutch previously disengaged by the slowing of the engine and thereby restoring engine braking, closing of a gear lever mounted switch 46 is caused to energize a solenoid 48 opening a valve 23 so that the suction in the engine inlet manifold 10, connected through a tank 14 and pipes 15, 19 to the valve, is communicated through a pipe 25 to a servomotor 28 controlling the main clutch and simultaneously through a pipe 35 to a diaphragm servomotor 34 having a rod 36 connected via a lost motion pin-and-slot device 36a and a lever 37 to the engine throttle 11, which is thereby opened. The car engine is accordingly accelerated to re-engage the centrifugal main clutch, which is, however, maintained disengaged by the suction energized servomotor 28 until ratio establishment has been completed, when release of the gear lever and opening of the switch 46 mounted thereon de-energizes the solenoid 48 to restore the valve 23 to the position shown, the servomotor 28 then being vented through the valve and through passages 21a, 31, 20a, 24 to the ambient atmosphere so that it re-engages the clutch. Centrifugal engagement of the clutch on starting the car from rest is overridden by a second valve 22, controlled by a solenoid 47 energized by increasing engine speed so that an engine-driven dynamo 43 actuates a relay switch 44 to complete a circuit therethrough. In the position shown, corresponding to the engine idling with the car at rest, suction from the inlet manifold 10 is fed via the tank and the pipe 14, 15 to pipes 16, 18 and the valve 22, whence suction passes through the pipes 20a, 21a and through the valve 23 to the pipe 25 and the servomotor 28, which is energized to the clutch disengaged position. When the switch 46 is closed during movement of the gear-lever from the neutral to a ratio established position, the two solenoids 47, 48 are momentarily energized and move the valves 22, 23 to the positions shown dotted, the valve 23 maintaining the suction in the servomotor which is accordingly not effected. On opening the engine throttle 11 for the vehicle to move off, increasing speed of the engine-driven dynamo 43 closes the relay switch 44 which energizes the solenoid 47 so that the valve 22 moves to the position shown dotted, thereby shutting off the suction supply through the pipe 18, &c., to the servomotor 28, instead vented through the pipes &c. 25, 23, 21a, 20a, 24 to the atmosphere, whereby the clutch engages and the car moves off. A valve 38 on the rod 36 of the diaphragm motor 34 closes the passage 31 leading to the atmosphere when the servomotor 28 is de-energized. A switch 49 in the circuit to the speed-operated solenoid 47 is opened when the engine choke is actuated, thereby preventing the accordinglyincreased engine and dynamo speed from positioning the valve 22 to cause engagement of the main clutch. A modified arrangement of the electric circuit, including a relay switch energized by single wire in a steering-column mounted gear-lever, Fig. 2 (not shown), may replace the direct switching arrangement 46.