PNEUMATIC SERVOMOTOR WITH FLOATING REACTION PLATE AND REACTION CAPABLE OF DYNAMIC CANCELLATION

摘要

The invention concerns a motor vehicle power brake pneumatic servomotor comprising in standard manner: a rigid case (1); a mobile baffle plate (2); a pneumatic piston (3); a control rod (4) receiving an input force and acting on a plunger (5) for actuating a three-way valve (6) and cause a booster force acting on the piston; and a thrusting rod (7) ending in a cup (9) wherein is housed a reaction plate (9) which receives the input force and the booster force. The invention is characterised in that it comprises an intermediate force transmitting member (10) which slides relative to the piston (3) and to the plunger (5), and members (33, 103, 81, 16) for selectively subjecting the cup (8) to the piston and ensuring, after the brakes have been suddenly applied, that a braking force is maintained even if the driver eases his effort.