Patent ID: 7856918
Filing Date: 2010-12-28
Classification: B60T

Abstract:
1. Pneumatic brake booster ( 1 ) comprising: a sealed structure ( 3 ) comprising a rigid casing ( 11 ) forming a funnel ( 19 ) furnished with an opening and a movable wall ( 13 ) dividing the sealed structure ( 3 ) into a low-pressure chamber ( 25 ) and a working chamber ( 27 ), a pneumatic piston ( 5 ) comprising a boss ( 31 ) fixedly attached to the movable wall ( 13 ) and mounted so as to slide in the funnel opening, a valve element ( 33 ) housed in the boss ( 31 ) and a seal ( 35 ) positioned between the boss ( 31 ) and the funnel ( 19 ), an input rod ( 7 ) and an output rod ( 9 ) coupled on either side of the pneumatic piston ( 5 ), and a return spring ( 37 ) to return the pneumatic piston ( 5 ) to a rest position, the return spring ( 37 ) being placed in the low-pressure chamber ( 25 ) between an internal surface ( 45 ) of the rigid casing and the pneumatic piston ( 5 ), characterized in that the pneumatic brake booster ( 1 ) also comprises a force sensor ( 39 ) placed in the low-pressure chamber ( 25 ) and subjected to the pressure variations of the return spring ( 37 ).