SERVOMOTOR FOR EMERGENCY BRAKING

摘要

A pneumatic servomotor for providing an assisted braking of a motor vehicle. The servomotor includes a plunger arrangement with a unidirectional clutch device (56). The clutch device (56) has a coaxial sleeve (58) that slides on a plunger (46) and a substantially ring-shaped key (60) with a given clearance around the sleeve (58). The key (60) is driven by a moving piston (22) in response to a predetermined rate of speed being applied to a control rod (38) by an input force. The predetermined rate of speed causes the key (60) to rock and lock the sleeve (58) with respect to the piston (22) independently of the control rod (38). The unidirectional clutch device (56) comprises at least one locking transverse face (76) for engagement with the sleeve (58). The face (76) is axially directed rearwards from a front end of the sleeve (58) to form a stop for a peg (78) located on the key (60) that extends radially towards the sleeve (58) for axial indexing an end locking position for the sleeve (58).