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:
Dec. 12, 1989
Filed:
Dec. 13, 1988
Thomas M Atkins, Ann Arbor, MI (US);
Kelsey Hayes Company, Romulus, MI (US);
Abstract
The present invention concerns a vehicle anti-lock brake control system which does not require the use of an auxiliary hydraulic pump and, in the preferred embodiment, is adapted to control only the rear brakes of a four-wheel vehicle. The control system includes a normally open solenoid actuated isolation valve connected between the master cylinder and the rear wheel brakes, and a normally closed solenoid actuated dump valve connected between the rear wheel brakes and a fluid accumulator. A computer control is connected to monitor the rear wheel speed and deceleration and, during braking of the vehicle, functions to control the application of hydraulic pressure to the rear brakes via the isolation and dump valves in order to correct wheel speed departures and prevent lock-up of the brakes. The computer control is adapted to detect a low to high mu road surface change which occurs during a wheel speed departure, and thereafter applies additional pressure to the rear brakes by selectively opening the isolation valve. Further, the control is adapted to detect when one of the rear wheels remains locked after anti-lock measures have been taken. In these instances, the standard operating parameters which control the reapplication of additional pressure are modified.