Patent ID: 7765913

Claim:
Pneumatic brake booster ( 201 ) having an axis (X), comprising an enclosure divided into a front chamber ( 210 ) and a rear chamber ( 208 ) by a skirt ( 209 ) fastened to a piston ( 205 ) mounted so that it can slide in the axial direction (X), the booster comprising a nonreturn valve ( 225 ) to evacuate air from the front chamber when the pressure prevailing exceeds a certain reference value, characterized in that this nonreturn valve ( 225 ) is internal to the booster ( 201 ) and in that, with the rear chamber ( 208 ) being designed to be connected either to the front chamber ( 210 ) via a channel ( 216 ) passing through the piston ( 205 ) or to an internal part of the piston having the reference value as pressure, the nonreturn valve ( 225 ) is mounted in the piston ( 205 ) such that the moving part ( 227 ) of the nonreturn valve ( 225 ) is between air coming from this channel ( 216 ) and air coming from the internal part of the piston having the reference value as pressure.