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:
Jun. 12, 1990
Filed:
Apr. 12, 1989
Wilfried Wagner, Huettenberg-Weidenhausen, DE;
Lothar Schiel, Hofheim, DE;
Alfred Teves GmbH, Frankfurt am Main, DE;
Abstract
In an anti-lock automotive vehicle brake system comprising a vacuum brake power booster, a considerable reduction of manufacturing and assembling costs is obtained while the system's reliability in operation is simultaneously augmented by the incorporation into this brake system of a second movable wall arranged within the vacuum brake power booster to which a controllable pressure differential may be applied. The wall isolates two pneumatic working chambers and, in the case of slip control, is movable in a direction opposite to the actuating direction of the master brake cylinder by two compensating cylinders which are connected with the master brake cylinder pressure chambers. A hydraulic chamber which is normally in communication with an unpressurized pressure-fluid supply reservoir is sealed from the reservoir by a retention valve during slip control to hydraulically prevent brake petal induced pressure from being applied to the master cylinder.