BRAKE STRENGTHENING PREPARATION WITH IMPROVED OPERATING CONDITIONS FOR POWER VEHICLES

摘要

Braking device comprising a master cylinder (2), a primary piston (3), a manual control member (4), a booster (6) coupled to the manual control member (4) and an emergency assist valve (VA) comprising a reaction piston (17) through which there passes a ratio control (T) having a head (26a) situated in a chamber (35) lying between the reaction piston (17) and a bushing (36) located further forward in a bore (18) in the primary piston, this bushing (36) having a bore (37) in which there can slide a rapid piston (38), the rear end (45) of which forms, with the head (26a) of the ratio control, a valve (C) capable of closing the inlet to a passage (39) in the rapid piston against the action of a spring (41). The device comprises a means (26, 27, 30) for preventing a sharp retreat of the reaction piston (17) when the manual control member (4) is released after slow braking.