GB707372A - Improvements in and relating to braking systems of road vehicles - Google Patents

Abstract

707,372. Vehicle brakes. GYREACTA TRANSMISSIONS, Ltd. April 12, 1950 [Jan. 12, 1949], No. 894/49. Class 103(1) A road-vehicle braking system in which the front and rear brakes are applied by a common control member comprises a device which so operates that for a predetermined value of deceleration, other than zero, the ratio of the forces applied to the rear and front brakes respectively is unity, below this value is greater than unity, and above this value is less than unity, the ratio decreasing automatically and continuously as the deceleration increases continuously from below to above the predetermined value. As shown a master cylinder connection 21 communicates with the front and rear brake cylinder connections 26, 26<SP>1</SP> by ports 22 controlled by restriction valves 23 and sliding inertia masses 18, 19, forward movement of the former being resisted by a compression spring 25. Upon initial brake application the spring 25 tends to maintain the front valve 23 closed, thus reducing the pressure in the front brake cylinders below that of the master cylinder. As the deceleration increases the pressures in the front and rear cylinders respectively increase and decrease, until they become equal when the deceleration reaches a value of about “g. The mass 18 is arranged to balance the force exerted by the spring 25 at a deceleration of about ¢g, beyond which the spring ceases to reduce the front brake pressure, but that in the rear brakes falls continuously as the deceleration is increased, reaching a value of approximately half the master cylinder pressure when the deceleration is equal to g. In a modified construction the inertia masses are pivotally mounted, Fig. 4 (not shown). The rear inertia mass may also be spring- loaded so that it tends to remain in its rearmost position under decelerations less than about ¢g.