Patent ID: 9283941
Filing Date: 2016-03-15
CPC Classification: B60T

Claim Text:
1. A vacuum booster for a vehicular brake, the booster comprising: a booster shell comprising a front shell half and a rear shell half, the front shell half being shaped like a bowl opened on a rear side and having a flat front attachment portion screwed to a rear flange of a cylinder body of a master cylinder, the rear shell half being shaped like a bowl opened on a front side and having a flat rear attachment portion screwed to a vehicle body, the front shell half and the rear shell half being connected to each other; a fitting cylindrical portion which is fitted with a rear end portion of the cylinder body, is integral with the front shell half, and extends rearward from a central portion of the flat front attachment portion; a booster piston housed in the booster shell so as to be able to reciprocate in a front-rear direction; a diaphragm laid on and joined to a rear surface of the booster piston; a valve cylinder connected to central portions of the booster piston and the diaphragm; and a support cylindrical portion which is disposed concentrically with the fitting cylindrical portion so as to slidably support the valve cylinder, is integral with the rear shell half and extends rearward from a central portion of the flat rear attachment portion, a reinforcement wall for increasing a rigidity of the front attachment portion being formed between an end wall and the front attachment portion so as to form certain angles with the end wall and the front attachment portion, respectively, wherein at least one of the flat front attachment portion and the flat rear attachment portion has a central disc portion which is concentric with the fitting cylindrical portion and plural side disc portions which are disposed around the central disc portion so as to be continuous with the central disc portion and to be spaced from each other; and wherein bolts are inserted through at least a pair of side disc portions of the plural side disc portions, and further comprising: plural link portions which connect the plural side disc portions to the central disc portion of the flat front attachment portion, the plural link portions being narrower at its outer edges than the plural side disc portions and the central disk portion of the flat front attachment portion at its outer edges.