Output push rod and spring retainer

Abstract

A brake booster (,) having a housing (,) with a control valve (,) located in an axial bore (,) of a hub (,) carried by a movable wall (,). The movable wall (,) separates the interior of the housing into a first chamber (,′) and a second chamber (,′). The control valve (,) in a first mode communicates the first chamber (,′) with the second chamber (,′) to provide for equal pressures therein and in a second mode communicates the second chamber (,′) with a surrounding environment to create a pressure differential across the movable wall (,). A reaction member (,) carried by the movable wall (,) communicates an operational force created by the pressure differential into an output push rod (,). After the operational force overcomes a return spring (,′), the output push rod (,) moves pistons (,) in a master cylinder (,) to correspondingly pressurize fluid therein which is supplied to wheel brakes to effect a brake application. The brake booster (,) is characterized by a retainer (,) having a base (,) with an axial opening (,) and a plurality of axial legs (,) which extend from the base (,). With the base (,) located in the axial bore (,) a shaft (,) of the output push rod (,) passes through the axial opening (,) while the plurality of axial legs (,) are located in corresponding a plurality of arcuate and axial slots (,) in the hub (,) located on the peripheral surface of the axial bore (,). The plurality of axial legs (,′) frictionally engage the hub (,) to position the base (,) in the axial bore (,) such that the head (,) of the output push rod (,) is positioned adjacent the reaction member (,) and the shaft (,) is located along the axis of the axial bore (,).