| 摘要 |
To prevent negative pressure in the pressure chamber 9 of a booster on failure in the booster pressure supply a non-return valve 28 is connected, directly or indirectly, between the sides of the servo piston 8. The servo piston 8 divides a servo- cylinder 4 into a pressure medium supply chamber 9 and a spring chamber 10 in which a compression spring 11 is guided by a thrust rod 12 of the piston 8 which actuates a piston 13 of a master brake cylinder 14. Slidably connected to the servo piston 8 is a pedal actuated control piston 7 with control edges 23. A pin 18 of the servo piston 8 engages a compression spring 20 accommodated in a bore 19 of the piston 7. The chamber 9 of the servo- cylinder 4 is supplied with pressure oil by means of line 21, duct 22 and control edges 23 from a pump 1 either directly or via a hydraulic accumulator 3. The non-return valve 28 either is disposed in an equalising line 27 between the supply line 21 and a return line 26 extending to a reservoir 2 or alternatively is constituted by a through bore 27% in the servo piston 8 cooperating with a resilient plate 28% secured to the piston 8. <IMAGE> |
