Fluid-pressure and analogous brake systems – Speed-controlled – Having a valve system responsive to a wheel lock signal
Reexamination Certificate
1998-07-27
2001-07-31
Oberleitner, Robert J. (Department: 3613)
Fluid-pressure and analogous brake systems
Speed-controlled
Having a valve system responsive to a wheel lock signal
C303S087000
Reexamination Certificate
active
06267457
ABSTRACT:
PRIOR ART
The invention is based on a hydraulic unit as set forth hereinafter.
One such unit is already known from International Patent Disclosure WO 94/08830, in which the damper chamber has a length of approximately twice its diameter, and part of it is continued in a recess of a closure element. A damper chamber embodied in this way is simple to make by metal-cutting machining in the housing block. Since a suitably large chamber volume is necessary if the damper chamber is to have a sufficiently calming effect on the pulsatingly fed volumetric flow of the pump, the diameter of the bore must be correspondingly large, at the indicated ratio to the length. However, this requires a correspondingly large installation space in the housing block of the hydraulic unit, which goes counter to the demand for minimizing the structural volume and saving weight. The severe stress on the closure element from the pump pressure, which results from the dimensions of the damper chamber, requires a screw fastening of the closure element, with a suitable thread length. Moreover, a cylindrical portion of the closure screw with a sealing ring placed in it is necessary, so as to seal off the damper chamber from the outside. This makes the unit more expensive to produce and can lead to errors in assembly.
ADVANTAGES OF THE INVENTION
The hydraulic unit according to the invention has the advantage over the prior art that because of the diameter-to-length ratio, the damper chamber can be disposed in a space-saving way in the direction crosswise to its longitudinal axis. In the damper chamber of the invention, which is smaller in diameter compared with the known embodiment, for the same volumes, the stress on the closure element is less despite identical pressure conditions, so that a rational type of fastening can be made use of, and a special seal can be dispensed with.
The device can be shaped from sheet metal at deep-drawn parts, and because of the shape of the bottom can withstand sufficiently severe stress; the closure element set forth herein also contributes to the effective volume of the damper chamber.
This is also the case in which the closure element can be embodied as a heavy-duty part made by impact extrusion.
REFERENCES:
patent: 5096400 (1992-03-01), Budecker et al.
patent: 5577813 (1996-11-01), Zaviska
patent: 5620028 (1997-04-01), Johnston et al.
patent: 5673978 (1997-10-01), Linkner, Jr.
patent: 5967623 (1999-10-01), Agnew
Benzinger Rolan d
Eberspaecher Peter
Guggemos Johann
Hellebrandt Michael
Pabst Carsten
Greigg Edwin E.
Greigg Ronald E.
Oberleitner Robert J.
Robert & Bosch GmbH
Siconolfi Robert A.
LandOfFree
Hydraulic unit for a slip-controlled motor vehicle brake system 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 unit for a slip-controlled motor vehicle brake system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hydraulic unit for a slip-controlled motor vehicle brake system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2529010