The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 23, 2000
Filed:
Sep. 18, 1998
Hartmut Unterberg, Koblenz, DE;
Lucas Industries plc, , GB;
Abstract
A master cylinder (10) for a hydraulic vehicle braking system comprises a housing (12) which has a bore (14) extending along a longitudinal axis (A), whose one end is closed by an end wall associated with the housing (12) of the master cylinder (10) and whose other opposite end is sealingly closed by a closure element (16). In the bore (14) adjacent to the closure element (16) a piston (18) is accommodated sealingly and axially movable which can be actuated through same, which has a central valve (20) which enables a fluid connection between a fluid reservoir and a pressure chamber (28) which is defined in the bore (14) by the end wall and the piston (18). When the piston (18) is not actuated, the central valve (20) is held in the open position by means of an abutment member (transverse pin 34) acting on the closure element (16). In order to ensure a defined opening point with respect to the piston (18) even then when the central valve (20) is to open against an overpressure, the closure element (16) consists of an annular elastomeric part (42) which faces towards the pressure chamber (28) and of a detachably connected and axially succeeding part (44) made form rigid material which is also designed annularly. For the generation of a quasi-rigid stop the part (44) made from rigid material comprises an annular circumferential projection (46), which is integrally formed with same whose maximum cross-sectional dimension amounts to not more than approximately half of the cross-sectional dimension of the elastomeric part (42), and which penetrates the elastomeric part (42) completely or nearly completely in an axial direction.