Fluid-pressure and analogous brake systems – Speed-controlled – Having a valve system responsive to a wheel lock signal
Reexamination Certificate
1998-12-17
2001-05-15
Oberleitner, Robert J. (Department: 3613)
Fluid-pressure and analogous brake systems
Speed-controlled
Having a valve system responsive to a wheel lock signal
C303S113200
Reexamination Certificate
active
06231131
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a hydraulic brake systems and more particularly relates to traction control systems.
BACKGROUND OF THE INVENTION
A brake system of this type is disclosed in Japanese patent application No. 94-171487. The brake system concerned is an anti-lock brake system which, in contrast to conventional brake systems operating according to the recirculation principle, includes neither a low-pressure accumulator nor outlet valves in the return lines from the wheel brakes to the suction side of the return pump. To produce a dynamic pressure in the wheel brakes, the return lines have only restrictors which produce a pressure gradient between the wheel brakes and the suction side of the return pump. The pressure in the wheel brakes is reduced by closing the inlet valves in the brake branch lines to the wheel brakes so that the pump pressure will not reach the wheel brakes. The braking pressure is decreased because the pressure fluid is permanently discharged from the wheel brakes.
An object of the present invention is to retrofit a brake system of this type for traction slip control by minimum possible additional effort, i.e., the least number of electric lines the minimal additional logic structure for valves.
Thus, the present invention permits a brake system in vehicles with one driven axle to perform traction slip control operations by at most four additional solenoid valves. Only the driven wheels require an outlet valve which permits a sufficient braking pressure increase by the return pump alone. There is no need for a low-pressure accumulator in traction slip control. When three individual two-way/two-position directional control valves are chosen, alternatively, either the change-over valve in the suction line to the return pump or the separating valve in the brake line, or both these valves can be operated hydraulically. Solenoid valves are preferably used as outlet valves in order that an amount of braking pressure can be increased or decreased in the wheel brakes in conformity with requirements. When the change-over valve and the separating valve are united in a combination valve, the combination valve can either be actuated electromagnetically and, thus, necessitate the second actuation logic beside the outlet valve, or it can be configured as a hydraulically operated combination valve, thus obviating the need for further actuation and electric lines.
REFERENCES:
patent: 5215359 (1993-06-01), Burgdorf et al.
patent: 5290098 (1994-03-01), Burgdorf et al.
patent: 5401085 (1995-03-01), Burgdorf et al.
patent: 5441336 (1995-08-01), Takeuchi
patent: 5486040 (1996-01-01), Beck et al.
patent: 5540487 (1996-07-01), Beck et al.
patent: 5547266 (1996-08-01), Beck et al.
patent: 3505451 (1986-07-01), None
patent: 3630052 (1988-03-01), None
patent: 4224007 (1994-01-01), None
patent: 4403445 (1995-08-01), None
Dinkel Dieter
Otto Albrecht
ITT Manufacturing Enterprises Inc.
Oberleitner Robert J.
Rader, Fishman & Grauer PL
Rodriguez Pamela J.
LandOfFree
Hydraulic brake system with anti-skid control does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hydraulic brake system with anti-skid control, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hydraulic brake system with anti-skid control will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2520245