Patent ID: 9133861
Filing Date: 2015-09-15
Classification: B60T,F15B

Abstract:
1. A pneumatic brake servo for motor vehicles comprising: a servo housing, the interior of which is divided into at least one working chamber and at least one vacuum chamber by at least one axially movable wall which can be loaded with a pneumatic differential pressure, having a control valve which controls the differential pressure and is arranged in a control housing for connecting the working chamber to the vacuum chamber or to atmosphere, the movable wall comprising a diaphragm plate and a rolling diaphragm, and the working chamber being sealed by a sealing ring which bears against the control housing and which is clamped in the radial direction in relation to a longitudinal axis of the brake servo, further comprising a circumferential lip formed integrally on the rolling diaphragm, such that at the beginning of an actuation of the brake servo, the lip divides the working chamber into a prechamber and a main chamber, and following the actuation of the brake servo, the lip does not divide the working chamber into the prechamber and the main chamber.