| 摘要 |
PURPOSE:To make a diaphragm follow up securely to the movement of a booster piston, by a method wherein an oblong form fitting groove surrounding two tie rods is provided in a back face of a booster piston, and an inside peripheral bead of a diaphragm is fitted into the fitting groove. CONSTITUTION:The back face of the booster piston 2 is provided with the oblong form fitting groove 5 surrounding the two tie rods 11. The inside peripheral bead 4a of the diaphragm 4 which is also oblong in shape is fitted into the groove 5. The groove 5 and the bead 4a are provided with two pairs of notch-and-projection engaging parts 34, 34', which are constituted of notches 35 provided in the rear-side wall of the groove 5 and projections 36 provided on the rear face of the bead 4a so as to be fitted into the notches 35. Accordingly, since the reduction of the flexible range of the diaphragm by the inside peripheral baad surrounding the tie rods is minimized, the diaphragm can securely follow up to the movement of the booster piston. |
