SERVOMOTOR COMPRISING A JAMMING KEY

摘要

The invention concerns a pneumatic servomotor for a motor vehicle comprising a mobile piston (22) driven by a plunger actuated by a control rod (38). The invention is characterised in that it comprises a substantially annular jamming key (60), which encloses a sleeve (58) passing through the piston and enclosing the plunger, which is mounted axially relative to the piston with a specific clearance (J), and which is capable, when an input force is applied on the rod (38), of being driven by the piston (22) to leave its support on the servomotor housing and tilt over the periphery of the sleeve (58), so that when the rod (38) and the plunger (46) return rapidly, the jamming key (60) transmits the reaction of the braking master cylinder to the piston (22) after the specific clearance (J) is absorbed.