摘要 |
A casing for use in a brake booster or clutch booster is provided. The casing includes a cylindrical portion which defines an outer periphery thereof, a flat central end wall which is disposed substantially perpendicular to the axis of the cylindrical portion, and a frustoconical portion which interconnects the cylindrical portion and the central end wall. According to the invention, a flat peripheral end wall is disposed between the cylindrical portion and the frustoconical portion so as to be substantially perpendicular to the axis of the cylindrical portion, thus increasing the rigidity of the casing. |