Patent ID: 8631735

Claim:
A pneumatic booster, comprising: a front shell being mostly configured to have a single piece of material; a rear shell being mostly configured to have a single piece of material; a housing formed of the single piece material of the front shell and the single piece material of the rear shell integrally united to each other at respective openings, and a power piston arranged in the housing so as to divide an interior of the housing into a constant-pressure chamber on the single piece material of the front shell side and a working-pressure chamber on the single piece material of the rear shell side, wherein thrust force of the power piston generated by pressure difference between the constant-pressure chamber and the working-pressure chamber is added to inputted force transmitted from a brake pedal to an input rod so as to obtain combined force, the combined force being outputted with a given boost ratio to an output rod, and wherein a thickness of the single piece material of the front shell is made to be thinner than a thickness of the single piece material of the rear shell, and a tie rod is arranged by penetration of the power piston so as to unite the single piece material of the front shell with the single piece material of the rear shell, the tie rod being provided with a mounting screw portion to a vehicle body on one end side thereof.