Brakes – Wheel – Axially movable brake element or housing therefor
Reexamination Certificate
1999-10-26
2001-10-09
Oberleitner, Robert J. (Department: 3613)
Brakes
Wheel
Axially movable brake element or housing therefor
C277S561000
Reexamination Certificate
active
06298955
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to an improved seal for use on the eccentric shafts which actuate air disc brakes, wherein the seal accommodates shaft movement.
Many heavy vehicles utilize air-driven disc brakes. In a standard air-driven disc brake, an air brake actuator selectively extends a push rod to turn an actuation lever. The actuation lever drives an eccentric shaft to rotate. The shaft is mounted eccentrically within an actuation block. When the eccentric shaft turns, it forces the block towards a surface which is to be braked.
As known, the area where the actuation lever attaches to the eccentric shaft is typically outward of a braking assembly. It is desirable to seal this outer area from the inner reaction surfaces between the shaft and the block. Typically, known seals have been a relatively rigid part with resilient sealing portions for engaging against the shaft. A housing, known as a caliper, encloses the block. The seal is typically fixed to the caliper.
The use of the relatively rigid seal body has presented some problems due to practical realities in this type of brake system. In one major problem, the eccentric shaft may sometimes become skewed within the block. When this happens, the seal utilized in the prior art is not as effective, since the seal is designed based upon the assumption that the shaft will be perpendicular to an opening within the block. Thus, the prior art seal does not function as effectively if the shaft is skew, which does happen in braking applications.
When the eccentric shaft has become skew within the prior art seal, there has sometimes been deformation of the sealing area. This is, of course, undesirable.
Also from time-to-time the shaft may move axially which also makes it difficult for the seal to perform properly.
SUMMARY OF THE INVENTION
In a disclosed embodiment of this invention, a seal between the eccentric shaft and the caliper in a disc brake system has a flexible portion between a portion which contacts the shaft and a portion connected to the caliper. The flexible portion is preferably made to be somewhat thinner than the portions contacting the shaft or the caliper. In this way, the portion is able to flex relative to either areas to accommodate shaft skewing, and axial shaft movement.
In a preferred embodiment, the portion which contacts the shaft also has structure for positioning it axially relative to the shaft. In one embodiment, the structure includes a bead on the seal extending into a retention groove on the shaft. In another embodiment, the seal may have a seal stop which contacts a ledge end surface on the shaft. In an alternative embodiment, a finger may extend from the seal and contact a tapered portion on the shaft.
The present invention improves upon the shaft seals utilized in this application by providing a seal which can accommodate shaft skewing, and axial shaft movement. Thus, the inventive seal is better able to withstand and accommodate the real world problem that an eccentric shaft may sometime be skewed and may move axially. These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.
REFERENCES:
patent: Re. 24940 (1961-02-01), Stephens
patent: 3783981 (1974-01-01), Burgdorft
patent: 4274641 (1981-06-01), Cather, Jr.
patent: 4304416 (1981-12-01), Oshima
patent: 4324318 (1982-04-01), Karasudani
patent: 4531748 (1985-07-01), Jackowski
patent: 4588195 (1986-05-01), Antonini
patent: 4598800 (1986-07-01), Marianu
patent: 4635760 (1987-01-01), Le Marchand et al.
patent: 4660684 (1987-04-01), Carre et al.
patent: 4691809 (1987-09-01), Le Marchand et al.
patent: 5244215 (1993-09-01), Cather, Jr. et al.
patent: 5738189 (1998-04-01), Bennett et al.
patent: 5794738 (1998-08-01), Forni et al.
patent: 3236076-A1 (1984-03-01), None
patent: 36 10 569-A1 (1987-10-01), None
patent: 3812495-A1 (1989-10-01), None
Carlson & Gaskey & Olds
Meritor Heavy Vehicle Systems LLC
Oberleitner Robert J.
Williams Thomas J.
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