SERVO WITH ADDITIONAL ADAPTIVE AIR INLET

摘要

Pneumatic brake servo comprising two air pressure sources and including a rigid body (3) separated by an impermeable moveable partition (4) into at least two chambers (3a,3b), the moveable partion being urged by the difference between the pressures in the chambers so as to drive an air piston (5) carrying a control valve (7), the interior (50) of the piston being separated from the second source by a purifying filter (14). The brake servo of the invention includes controlled opening sealing means (15,17) located between the second pressure source (A) and the interior (50) of the piston, controlling an air inlet path that bypasses the filter, and elastic means (18) responsive to a pressure difference between the piston interior and the second pressure source, to selectively open said sealing means when the pressure difference exceeds a given threshold.