GB1314533A - Pressure reducing valves - Google Patents

Abstract

1314533 Pressure reducing valves; load responsive braking AUTOMOTIVE PRODUCTS CO Ltd 10 Sept 1971 [16 Sept 1970] 44225/70 Heading F2F A pressure reducing valve adapted for mounting on a vehicle and specifically but not exclusively to control the pressure in the rear wheel braking cylinders has first and second chambers connected respectively to wheel cylinders and a brake master cylinder 61 the valve comprising a stepped piston 14 slidable in a stepped bore the piston 14 including a cavity 28 in which a valve closure member 36 is movable, the closure member 36 having a head 37 engageable with a valve seat 35 to cut off communication between the chambers to effect a pressure reduction in the wheel cylinders when the braking pressure reaches a value to move the piston 14 leftwards: the head 37 is normally held away from the seat 35 by co-operation of a pin 43 with a closure plug 13, and the closure member 36 also includes a stem 38 having a washer 39 slidable thereon the washer 39 being retained on the stem 39 by an enlargement 41 and a coiled compression spring 42 acting between the washer 39 and the head 37. The stem 38 extends into a bore 29 in the piston 14 and the washer 39 abuts against a shoulder 31 in the bore 29. The valve is mounted on the vehicle by means of a bracket 59 and a lever 53 carrying an adjustable tappet 54 to engage a projecting end of the piston 14 is acted on by a tension spring 71 which is connected to the suspension system of the rear axle 67 whereby the action of the valve will be altered corresponding with changes in the axle loading, e.g. during deceleration of the vehicle; the application of full pressure from the master cylinder 61 will be maintained up to a higher pressure value when the wheel loading is higher.