| 摘要 |
A hydraulic booster for a brake system comprising a booster piston, a pressure-control device, an annular piston bearing against the booster piston and a central piston which is movable within limits relative to the annular piston by the brake pedal and actuates the pressure-control device. In this arrangement, the central piston and the annular piston are adapted to be coupled together after the force of a spring is overcome whereupon these two pistons are movable as one. The central piston is permanently subjected to the pressure acting on the booster piston when the brake system is actuated. |
