Brake booster and master cylinder with mounting

Abstract

A brake booster includes a body having a central wall portion on which a, doughnut-shaped reinforcement plate is securely mounted, and bolts mounted on the reinforcement plate for fastening a master cylinder to the central wall portion. The reinforcement plate has an annular ridge extending along an inner peripheral edge thereof and projecting against the reinforcement plate. The master cylinder includes a flange mounted on the body and having an inner peripheral portion held against the central wall portion of the body in axial alignment with the annular ridge, and an outer peripheral portion spaced from the central wall portion by a distance such that the outer peripheral portion of the flange will not be forced into contact with the central wall portion when the master cylinder is actuated for braking action. Therefore, no localized forces are applied by the outer peripheral portion of the flange to the central wall portion of the body. The reinforcement plate held in intimate contact with the central wall portion serves to distribute forces fully over the central wall portion, which is less subjected to concentrated stresses and hence can be of a reduced thickness.