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:
Apr. 07, 1992
Filed:
Dec. 14, 1991
Alwin Stegmaier, North Charleston, SC (US);
Robert Bosch GmbH, Stuttgart, DE;
Abstract
A hydraulic dual-circuit brake system with anti-skid braking (ABS) and traction control (ASR) for motor vehicles having control valve assemblies, each control valve assigned to one wheel brake cylinder of a vehicle wheel for feeding a wheel-slip-dependent brake pressure, and includes one return pump with two separate pump elements for each brake circuit. For supplying brake pressure in traction control, a precharge pump and a valve unit are provided. In the traction control mode the precharge pump feeds brake fluid from a brake fluid tank into the pump element associated with the brake circuit of the driven wheels while the valve unit disconnects the pump element from the master brake cylinder and connects it to the brake fluid tank via a pressure limiting valve. A check valve prevents brake fluid from flowing into the ABS brake circuit during this process via the pressure limiting valve. The air bubbles created upon expansion of the brake fluid at the pressure limiting valve reach the brake fluid tank along with any excess brake fluid and thus are kept away from the master brake cylinder.