Master cylinder e.g. for motor vehicle hydraulics, forms pressure-equalizing connection between primary and secondary pressure chambers when pressure in primary chamber is less than that in secondary chamber

摘要

A piston (2) is provided with one or more recesses at an end facing a primary pressure chamber (6), and on which a seal (3) sits. A protrusion (11) of a seal stop is provided between two sealing lips (3.1,3.2), and has an opening (11.1). A through-flow opening extends from the side of the sealing stop (12) in the direction of the seal, to the primary pressure chamber. The dynamic sealing lip is lifted from the outside diameter (2.1) of the piston when the piston is in a neutral position, and the pressure in the primary pressure chamber is less than in a secondary chamber (7), forming a pressure-equalizing connection between primary and secondary pressure chambers.