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:
Oct. 29, 1991
Filed:
Dec. 05, 1990
Lothar Kirstein, Ditzingen, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
An hydraulic dual-circuit brake system with an anti-skid system (ABS) and traction control (ASR) for motor vehicles has a four-channel hydraulic unit with electromagnetic control valves and a return pump with two separate pumping elements for each brake circuit. To supply brake pressure in traction control operation, an additional hydraulic unit is provided, which portions of connect the fluid tank to the return pump and switch the alternating connection of the outlet of the return pump to the master brake cylinder or to the brake fluid tank. For a rapid reduction of brake pressure in the wheel brake cylinders of the driven wheels at the onset of braking during traction control operation, the switch portion has at least one 3/3-way magnetic valve with a pressure limiting valve disposed in a valve bypass. This 3/3-way magnetic valve connects the outlet of the pumping element associated to one driven wheel to the master cylinder in a first position, and in a third position it connects it directly to the brake fluid tank. In a second position, all the working connections are blocked, so that a brake supply pressure can be built up.