摘要 |
<p>Servo boosters for vehicle hydraulic braking systems are described which incorporate a novel arrangement for providing an increasing reaction force on the input member in response to an increasing output force. In the novel arrangement a first thrust assembly is interposed between the input member and the output member, and a second thrust assembly is interposed between the movable wall of the booster, which may be a diaphragm or a piston, and the output member. The thrust assemblies each generally consist of rotatable parallel plates having inclined ramp surfaces on opposed faces co-operating with balls or rollers located between the plates. Some of the plates of the two thrust assemblies are keyed together. Axial forces between the members generate torques in the thrust assemblies and since the torques must balance each other as a result of the connections between the plates a fixed relationship is maintained between the input and output forces and the force exerted by the movable wall. In the constructions disclosed a single plate is common to both thrust assemblies.</p> |