Piston with central valve for hydraulic brake systems

摘要

PCT No. PCT/EP93/00924 Sec. 371 Date Jan. 7, 1994 Sec. 102(e) Date Jan. 7, 1994 PCT Filed Apr. 16, 1993 PCT Pub. No. WO93/22170 PCT Pub. Date Nov. 11, 1993.The present invention relates to a piston with a central valve, in particular for hydraulic boosters, the valve case (6) which is composed of a supporting insert (8) radially embraced by a valve seat (7). It is disadvantageous in some valve cases that sometimes the positive coupling between the two elements in axial direction is not sufficient. The present invention provides a remedy to this problem by using undercuts behind which the valve seat engages the supporting insert in both directions. In an advantageous improvement, the valve insert is of symmetrical design, and a sealing projection is shaped at the valve seat. The guidance of the valve tappet (19) is performed within the piston (1).