Boosted braking device with passive safety

摘要

A boosted braking device for a motor vehicle having a master cylinder (M) and a pneumatic booster (S). The booster (S) has a rigid casting (10) divided by a mobile partition (12) into at least a front chamber (14) and a rear chamber (16). A three-way valve (18) carried by the mobile partition (12) is actuated by a control rod (20) to control the pressure in the rear chamber (16) for operating the master cylinder (M). The casing (10) includes a front shell (24) and a rear shell (26) each of which comprises a radial shoulder (28,30) and being secured together by hooping (40) interconnecting with the shoulders (28,30) of the front shell (24) and rear shell (26). The hooping (40) comprises first (40A) and second (40B) part hoops. The first (40A) and second (40B) part hoops are joined together by at least one locking element (50) which is rendered non-functional when the master cylinder (M) is subjected to substantial stress as a result of a frontal or oblique impact of the vehicle.