Actuating device for an internal shoe brake having an automatic adjusting device

Actuating An actuating device for an internal expanding shoe brake, comprising a housing, at least one expansion piston movably mounted in the housing and an automatic adjusting device, the adjusting device comprising:

• an adjusting bolt, which can be moved relative to the expansion piston in the axial direction and comprises a screw shank that extends into the expansion piston, and a head portion that is operatively connected to a brake shoe,
• a rotatably mounted adjusting nut which is arranged at least in part inside the expansion piston and is in threaded engagement with the screw shank,
• an adjusting lever which is pivotally mounted on the expansion piston, can be moved therewith relative to the housing and is in engagement with the adjusting nut in order to rotate said nut relative to the adjusting bolt,
• a guide element fixed to the housing, with which guide element the adjusting lever interacts such that a movement of the adjusting lever relative to the guide element causes a pivoting movement of the adjusting lever,
• characterised in that the adjusting lever comprises a guide link in the form of a guide slot having two opposing link surfaces that interact with opposing sides of the guide element fixed to the housing in order to convert the movement of the adjusting lever relative to the guide element fixed to the housing into pivoting movements of the adjusting lever.