| 摘要 |
<p>HYDRAULIC BRAKE BOOSTER RESERVE SYSTEM A hydraulic brake booster provides a housing within which a spool valve is slidably mounted. The housing forms a pressure chamber and the spool valve is movable from a first position venting the pressure chamber to a second position, communicating the pressure chamber to a fluid pressure source as the spool valve moves toward the second position. A piston or cylindrical accumulator is also slidably mounted in the housing and moves in response to pressurized fluid in the pressure chamber to actuate braking. In order to hydraulically actuate braking when the pressure source is disabled, the piston includes a storage chamber within which pressurized fluid from the pressure chamber is stored. With the source disabled an operator actuating means moves the spool valve to the second position to close the pressure chamber to the pressure source. Further movement of the operator actuating means actuates a check valve to open the storage chamber to the pressure chamber so that pressurized fluid is communicated to the pressure chamber to move the piston for actuating braking.</p> |
