PNEUMATIC CONTROL DEVICE HAVING A REDUCED LOAD

摘要

Pneumatic control device for a vacuum brake servo using, within a piston (5), a tubular sealing member (21) co-operating with a stationary seat (18) and with a moveable seat (19). The tubular sealing member (21) defines, within the piston (5), a chamber (22) with an opening (23) communicating with a passage (20) located between the two seats. As a result, a substantial elastic force acting on the sealing member (21) is not required.