| 摘要 |
An improvement of an axial portion of a power piston and a retainer engaging therewith for a booster. An axial portion of the power piston is formed with a first tubular portion, which is provided with a second tubular portion located outward of the first tubular portion. The first tubular portion is fitted over a flange of a valve body from the rear side, and an annular retainer engages the second tubular portion from the front side, thereby securing the axial portion of the power piston, which is formed with the both tubular portions, on the flange of the valve body. The retainer includes a plurality of engaging pawls, which engage the outer peripheral surface of the second tubular portion of the power piston by point contact. This reduces the axial size of the valve body, and hence the axial size of the booster. |
