Anti-lock hydraulic brake system for automotive vehicles

US4824182A · kind A · utility

Assignee

• Alfred Teves GmbH · DE

Inventors

• Helmut Steffes · Hattersheim, DE
• Norbert Ocvirk · Offenbach, DE
• Gunther Buschmann · Griesheim, DE
• Anton David · Dreieich, DE
• Johannes Graeber · Frankfurt am Main, DE
• Otto Determann · Darmstadt, DE
• Ivica Batistic · Frankfurt am Main, DE

Key dates

• Filing date: Sep 4, 1987
• Grant date: Apr 25, 1989
• Expiry date: Sep 4, 2007

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S303/04
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

An anti-lock hydraulic brake system which includes a brake pressure generator composed of a master cylinder, a brake power booster inserted upstream thereof and a pressure modulator interposed between the master cylinder and the brake power booster. A resetting unit is formed by supplementing the pressure modulator with a valve assembly which connects a resetting chamber of the pressure modulator to either a pressure-compensating reservoir or an auxiliary-pressure source. The braking pressure in the wheel brakes is controlled, according to a time-multiplex method, by wheel valves inserted into the pressure-fluid conduits and by the pressure modulator. In order to check the operability of the brake and of the anti-lock control system, a pressure switch is connected to the pressure modulator and a test circuit is provided which, at predetermined points of time, initiates a test cycle, actuates the valves and compares the valves' operation with the reaction of the pressure switch.