GB515958A - Improvements in or relating to brakes for vehicles - Google Patents

Abstract

515,958. Vehicle brakes. MARTINDALE, A. F. June 16, 1938, No. 17907. [Class 103 (i)] A braking system for a vehicle having front and rear wheels comprises front wheel brakes hydraulically operated and rear wheel brakes . mechanically operated, and a servo device through which one or both sets of brakes are operated. In one form, the front brakes A<1> are operated hydraulically through pipes' B from a master piston B<1>, and the rear brakes C<1> are operated by expanders C<2> from a T-shaped balancer C<4>. The middle arm of the T is connected by a cable D to a lever D<1>, to which the hand brake lever E is connected by a slotted link E Two levers G, G<1>, Figs. 1 and 2, are mounted on a shaft G<2> and have cam surfaces G<3> between them, so that relative movement will cause the lever G<1> to be displaced axially to bear on a boss G<5>on a plate G<4> . freely mounted on the shaft G<2>, which is driven from one of the vehicle shafts and carries a flange' G <7>;thus the flange G is adapted to drive the plate G<4> through a friction surface G<8> and thus operate a cam H, against which bears a roller H<3> on a lever H<1>, connected by a cable j<1> to the lever D<1>. The brake pedal F is connected by a cable J to the lever G, and the lever G<1>is connected by a push-rod J<2> to the piston B<1>. The cam H may be so shaped as to apply the brakes with a different force according to whether the vehicle is moving forward or backward, and may be controlled by a tension spring tending to return it to neutral position. In another form, the rear brakes are operated directly by the brake pedal, and the front brakes hydraulically through the servo device, while in a third form, both sets of brakes are operated through the servo device.