Servobrake comprising a reduced-reaction master cylinder

摘要

A servobrake ( 10 ) including a pneumatic brake booster ( 12 ) and a master cylinder ( 22 ) with a main piston ( 20 ) that slides in a front pressure chamber ( 24 ). The main piston ( 20 ) has a fixed first rear end ( 46 ) acted on by a pneumatic piston ( 16 ) of the booster ( 12 ) and a moving second rear end ( 48 ) acted on by a feeler ( 18 ) of the booster ( 12 ) that is a coaxial with the piston ( 16 ) and acts upon a reaction ram ( 52 ) to communicate pressure forces in a front pressure chamber ( 24 ) of the master cylinder to the second end ( 48 ). A hydraulic isolation valve shutter ( 58 ), independent of the internal piston ( 50 ) of the ram ( 52 ), is activated when the input force of the booster ( 12 ) exceeds a given rate threshold so that the braking force is not reduced.