Pneumatic brake booster and method of manufacturing it

Pneumatic brake booster, in particular for motor vehicles, having a booster housing, the interior of which is subdivided by at least one movable wall into a vacuum chamber and a working chamber, and having a control valve for controlling a pneumatic pressure difference acting upon the movable wall, which control valve projects along an axis into the booster housing and comprises a substantially cylindrical control valve housing, to the outside of which the movable wall is workingly connected in that a collar of a plate associated with the movable wall is deformed along its periphery at least in sections radially into the control valve housing, wherein

• in a portion of the control valve housing overlapped by the collar of the plate a plurality of recesses are provided, which are spaced apart from one another in peripheral direction and into which the collar of the plate is radially deformed, and that
• the recesses are accessible from the end of the control valve housing disposed in the booster housing, and that
• the recesses at the end of the control valve housing disposed in the booster housing form radial undercuts for spring arms of a retaining element, which is used to position a force output tappet of the brake booster, and that said undercuts are accessible from the direction of the end of the control valve housing disposed outside of the booster housing.