| 摘要 |
PCT No. PCT/FR98/01551 Sec. 371 Date Jul. 24, 1998 Sec. 102(e) Date Jul. 24, 1998 PCT Filed Jul. 16, 1998 PCT Pub. No. WO99/06257 PCT Pub. Date Feb. 11, 1999A pneumatic brake booster having a right casing (10) divided in a leaktight fashion by a first moving partition (12) into a front chamber (14) and a rear chamber (16). The front chamber (14) being permanently connected to a source of low pressure (V) with the rear chamber (16) being selectively connected to the front chamber (12) and as source of high pressure by a three-way valve (40) operated by an operating rod (34). A three-way and two position solenoid valve (68) has a first inlet connected to the source of low pressure (V), a second inlet connected to a source of high pressure (A) and outlet connected to the rear chamber (14). A second moving partition (54,54') divides the rear chamber (14) into a working chamber (16) and a control chamber (50,50') with the outlet of the solenoid valve (68) being connected to the control chamber (50,50'). A pneumatic piston (20) which passes in leaktight sliding through the second moving partition (54,54') has a stop (72) which engages and moves the second moving partition (54,54') when the pneumatic piston (20) moves in a forward direction. The second moving partition (54,54') independently moving into engagement with the first moving partition (12) in response to output from the solenoid valve (68) to develop an output force and effect a brake application.
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