Motors: expansible chamber type – Working member position feedback to motive fluid control – Follower type
Patent
1990-12-17
1992-10-27
Look, Edward K.
Motors: expansible chamber type
Working member position feedback to motive fluid control
Follower type
F15B 910
Patent
active
051580047
DESCRIPTION:
BRIEF SUMMARY
INTRODUCTION
The present invention relates to a brake power booster, in particular for automotive vehicles, comprising a booster housing which is sealingly subdivided by at least one axially movable wall into at least one vacuum chamber and at least one working chamber, having a resetting spring placed in the vacuum chamber on the master-cylinder side and a mechanically actuatable control valve to connect the working chamber to the vacuum chamber and/or to the atmosphere, the control valve housing thereof being rigidly coupled to the movable wall, with a rubber-elastic reaction plate, which abuts on a head flange of a push rod nd which transits the brake force onto an actuating piston of a master cylinder fitted to the booster housing on the vacuum side, being arranged in a bowl-shaped insert member which latter is placed in a recess of the control valve housing whose walls extend beyond the head flange on the master-cylinder side and whose bottom is facing the control valve housing.
BACKGROUND OF THE INVENTION
Brake power boosters of the species with retaining arrangements to prevent drop out of the push rod are known in most various designs, e.g. from the applicant's older application DE-OS 37 09 172. Clamping rings, plastic rings fastened by ultrasonic sealing or gluing, or sheared-in metal rings are used as retaining means. In any case, there is the need to mount at least one additional component part. This is expensive and complicates the assembly.
SUMMARY OF THE INVENTION
It is, therefore, the object of the instant invention to provide a brake power booster wherein the push rod is prevented from dropping out in a simple manner lending itself to low-cost manufacture, there being taken into account in particular the possibility of a partly automated production as well as the special assembly problem in respect of master cylinders integrated into the brake power booster by way of preassembly of individual groups of component parts.
This object is achieved by a blow-shaped insert member which receives the reaction plate and including positively integrally formed, acting retention features acting to prevent the push rod from dropping out of the insert. Engagement of the insert by a resetting spring arranged in the pressure chamber holds the insert itself in a recess in the control valve housing. The integrally forned retention features allow preassembly of the push rod, reaction plate and insert member outside of the booster and hence permits an automated production as well.
Retaining noses, indentations or sheared-in depressions formed in the insert member on the master-cylinder side serve as retention features to secure the push rod flange in the insert. In a favorable manner, several circumferentially spaced tabs may be shaped at the insert member on the side closest to the master cylinder, the tabs serving as an abutment surface for the resetting spring. This simple measure permits mounting the insert member without other complicated attachments. The assembly, too, is very simple.
A particularly inexpensive embodiment of this invention provides that the insert member is formed as a sheet-metal stamped piece.
Possible embodiments of the present invention are described with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1, is an axial cross-section taken through a tandem-type brake power booster with a bowl-shaped insert member;
FIG. 2, shows an axial cross-section through another embodiment of the insert member, as well as the reaction plate and the push rod;
FIG. 3, is a top view of a third variant of the insert member; and
FIG. 4, shows the variant of the insert member shown in FIG. 3 in a cross-section taken along the line marked therein.
DETAILED DESCRIPTION OF THE PREFERRED AND ALTERNATIVE EMBODIMENTS
FIG. 1 illustrates a booster housing 1 which is subdivided by a rigid wall 2 and two movable walls 3 into two vacuum chambers 4 and two working chambers 5. Each movable wall 3 is sealed in relation to the booster housing 1 by means of a rolling diaphragm 6
REFERENCES:
patent: 4583446 (1986-04-01), Morimoto
patent: 4587884 (1986-05-01), Tsubouchi
patent: 4757748 (1988-07-01), Kawasumi et al.
patent: 4813338 (1989-03-01), Mortimer et al.
patent: 4882980 (1989-11-01), Arino et al.
Kalpakjian, S. "Deep Drawing" in Encyclopedia of Materials Science and Engineering (copyright 1986) vol. 2 pp. 1024-1026.
Alfred Teves GmbH
Lewis J. Gordon
Look Edward K.
Lopez F. Daniel
Seitter Robert P.
LandOfFree
Brake power booster, in particular for automotive vehicles does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Brake power booster, in particular for automotive vehicles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Brake power booster, in particular for automotive vehicles will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-899689