GB1425470A - Fluid pressure operated clutch release mechanism - Google Patents

Abstract

1425470 Clutch/brake combinations; master cylinders AUTOMOTIVE PRODUCTS Ltd 8 June 1973 [8 June 1972] 26791/72 Headings F2L and F2F In a clutch/brake combination for a motor vehicle in which, after release of a fluid-pressure operated clutch 10 a brake 35 can be operated by fluid pressure to brake the driven shaft, the clutch and brake are operated by a tandem master cylinder 18. Initial depression of a clutch pedal acts on a piston 14 of the master cylinder through a rod 13, this piston moving a piston 15 through a spring 19 so that fluid under pressure passes through a port 25 to a slave cylinder 28 which pivots a lever 29 to disengage the clutch 10, which is a friction clutch. When clutch 10 is disengaged the piston 15 comes against an abutment 21 and further depression of the pedal causes the spring 19 to yield and fluid to pass from between pistons 14 and 15 out of port 24 to engage the brake, which may have a drum 36 acted upon by shoes, or it may be a disc brake 49 (Fig. 3). A relatively weak spring 22 is provided between piston 15 and the end of the chamber 16 of the master cylinder. A spring 34 in the slave cylinder 28 ensures that the clutch is self-adjusting. In an alternative construction the stronger spring, spring 19, is between the piston 15 and the end of chamber 16 so that initial clutch pedal movement causes the pistons to come together, the connections to outlets 24 and 25 being reversed. The disc brake shown in Fig. 3 comprises a disc 50 splined to, and axially movable on, the clutch driven shaft 41. The bell housing 43 of the clutch 40 supports a body 52 which includes a brake-operating piston and cylinder 57, 56, the piston having a brake pad 58 and pressing the disc 50 against a further brake pad 55 in the body 52.