GB979418A - Differential pressure motor suitable for brakes - Google Patents

Abstract

979,418. Fluid-pressure brakes. MIDLAND-ROSS CORPORATION. May 24, 1961, No. 18697/61. Heading F2F. [Also in Division G3] A differential pressure motor for operating the master cylinder piston 30 of an hydraulic brake system and comprising an annular diaphragm 49 clamped between plates 47, 48 is connected to the piston 30 through a rod 18 and a plurality of radially disposed levers 82 which react on the manual input member 36 to provide " feel " after an initial movement of the motor. With the parts in the positions shown, vacuum from the intake manifold of an internal combustion engine connected at 24 is effective both in a chamber 23 and, through passages 66b, 66, 63, in a chamber 22 so that the motor diaphragm 47, 48, 49 is held by a spring 116 in the rightward position and the levers 82, which are embedded at their outer ends in a rubber ring 86 and bear against a ring 84 secured to the boss of the diaphragm and against a member 91 mounted on the rod 18, are urged by a rubber &c. reaction ring 90 away from engagement with a member 88 on the member 36. When the member 36 is moved inwardly a valve seat 68 carried thereby is brought into engagement with an annular, rubber &c. valve member 76 to interrupt communication between the chambers 22, 23. Further movement of the member 36 lifts the valve member 76 away from a seat 72 to connect the chamber 22 to atmosphere through openings 64, the interior of a bellows 56, and a filter 59, so that the diaphragm is moved to the left. The resistance to movement of the master cylinder causes the levers 82 to be deflected, compressing the rubber reaction ring 90, until their inner ends engage the member 88 to provide " feel " for the operator. The seat 72 moves with the diaphragm so that the movement of the latter corresponds to the movement of the member 36. Specification 979,419 is referred to.