| 摘要 |
A vacuum-operated brake booster which includes a rolling diaphragm partly abutting against the diaphragm plate. The diaphragm has on its lateral surface close to the booster piston a sealing surface which cooperates both with a valve piston and the booster piston to govern the air flow from the atmosphere to the working chamber in front of the rolling diaphragm. The valve piston is moved by the tappet and with the slidable booster piston which controls the passage leading from the chamber behind the rolling diaphragm to the working chamber. The rolling diaphragm contains on its side remote from the booster piston an abutment surface which bears against a stop provided at the booster housing inner wall in the inactive position of the brake. Upon displacement of the valve piston in the actuating direction, the present booster arrangement generates instantaneously and without lost travel an output force which acts upon the master cylinder piston via the push rod. |
