| 摘要 |
<p>A pneumatic booster includes a housing (4), a power piston (4) partitioning the interior of the housing into a front chamber (A) and a rear chamber (B), with the front chamber being connected permanently to a source of a first reference pressure, the rear chamber being selectively communicated with the front chamber and a source of second reference pressure which is higher than the first reference pressure through a valve mechanism, an output shaft (15) receiving the output force from the power piston, and an input shaft (10) receiving an input force for actuating said valve mechanism and receiving a reaction force of the output force. There is provided a device (16,18; 28, 29) between the output shaft (15) and the power piston (4) for changing the reaction force with respect to the output force on the output shaft, a mechanism (23) for rotating the output shaft (15) around the axis thereof, and a device (8) for preventing the rotation of the power piston relative to the housing at least at the non-actuated condition of the pneumatic booster.</p> |
