Brakes – Elements – Brake wheels
Reexamination Certificate
2001-11-28
2004-03-30
Graham, Matthew C. (Department: 3683)
Brakes
Elements
Brake wheels
C188S073200, C188S073380
Reexamination Certificate
active
06712184
ABSTRACT:
This invention relates to a method and apparatus for mounting a brake disc in a disc brake. A particular application of the invention is to a spot-type automotive disc brake in which at least one, and preferably two brake discs are mounted for axial movement in use with respect to a central drive hub which drives the discs and on which they exert a braking effect during use. Typically, the central drive hub is a wheel mounting of an automobile. Certain aspects of the invention may find application outside the confines of spot-type automotive disc brakes. We have established that spot-type single or multi-disc disc brakes of the kind comprising axially moveable discs can provide significant advantages over conventional spot-type automotive disc brakes. These advantages are set out in a series of patent applications which we have filed covering various aspects of the constructional differences between such brakes and conventional automotive disc brakes.
One aspect of these constructional differences relates to the use of resilient means acting between the one or more brake discs and the rotatable mounting therefor. Such resilient means are provided to control certain aspects of the dynamics or movement of the brake discs during use. Reference is made to the disclosure in WO 98/26192 (docket 2558) for a representative prior disclosure in this regard, and likewise to WO 98/25804 (docket 2561). This latter disclosure concerns a disc brake system in which a plurality of leaf springs mounted on a hub and engaging the brake disc apply radially-directed forces between the disc and the hub.
However, we have discovered that the mode of mounting the resilient means with respect to the drive hub is of significance in relation to the effective operation of the resilient means for the brake as a whole, not to mention the resilient function itself.
As a matter of simple design principles, it is to be expected that the optimum arrangement would be as disclosed in our above-identified prior applications, in which the resilient means is mounted on the hub and exerts its resilient or biasing effect on the disc by virtue of limited contact with the disc at certain well defined locations depending on the exact resilient means (or spring) design and the spring location.
Such an approach is consistent with the design principles emerging from the basic structure of the disc brake in which the relatively massive central hub provides a convenient reference base not only structurally for the mounting of the biasing springs, but also a relatively massive heat sink whereby a substantial thermal gradient exists in use between the brake disc with its locally-generated thermal energy and relatively low thermal capacity, whereby thermal factors favour minimising the numbers of components to be subjected to frequent substantial thermal gradients, particularly components such as springs which are reliant upon thermally sensitive physical properties such as resilience.
However, we have discovered that despite the fact that the obviously apparent factors favour the adoption of the disc-mounting principles (with respect to resilient bias) disclosed in the prior art, there are significant and unexpected compensatory advantages in adopting the reverse approach wherein it is the disc itself which provides a mounting base for the resilient means (for example a series of circumferentially-spaced springs), whereby these can be considered as exerting a resilient bias which is directed from their mounting base on the disc to the rotatable disc-mounting hub, contrary to the teachings of the prior art.
Our prior co-pending UK Patent application number GB0010810.0 describes an arrangement in which resilient means are mounted upon the brake discs. The various arrangements and mounting of the resilient means to the disc described in this prior patent offer a considerable improvement over other prior arrangements in which the resilient means are mounted on the hub or (as in DE 20 39 003) lodged between the hub and the disc. However the arrangements disclosed can be further improved, in particular in terms of security of mounting the resilient means to the disc, cost, simplicity of the arrangement and ease of assembly and fitting to the disc, as well as allowing easier assembly of the complete brake unit and fitting of the disc to the hub.
According to the invention there is provided a method and apparatus as defined in the accompanying claims.
In embodiments of the invention there are provided resilient means adapted to be mounted on the axially-slidable brake disc in various ways and in various formats providing individual variations in ease of construction and mounting.
In an embodiment the individual resilient means straddle a series of projecting drive keys of the brake disc which are constructed to slidably cooperate with a series of complementary keyways formed in the rotatable mounting hub for the brake disc. The resilient means are arranged to clip over the drive keys of the disc such that the resilient means are securely attached to the disc. In particular the distal end of the protecting drive keys comprises an enlarged foot portion which is wider than the main disc thickness. The resilient means include an aperture portion which is adapted to allow the resilient means to be fitted over the drive key whilst the resilient means is then, once fitted retained radially on the drive key.
Specifically the aperture is generally dimension to be slightly smaller than the width of the wider end portion of the drive key. The resilient means is installed one side at a time with the resilient means being angled such that the resilient means can be fitted over the wider end portion of the drive key. Once fitted, radial movement inwards of the resilient means is then restricted by the difference in size between the aperture and the wider end portion of the drive key. In other words the resilient means is held in place by abutment against the wider end portion of the drive key.
Preferably the resilient means comprises a leaf spring type format which is originally formed from sheet material. In particular the leaf spring comprises a central generally planar main body portion within which the aperture is defined. A pair of depending arcuate arms extend and curve away from the central portion, such that when fitted the tips of the arms are disposed radially inwards of the main body portion mounted on the drive key with the tips abutting and running on the outer peripheral surface of the hub. The curvature of the arms and their resilience arranged to provide a resilient bias force between the disc and hub in use. Such a leaf spring is relatively simple and cheap to produce, especially when compared to wire spring format resilient means. Furthermore the arcuate nature of the arms permits an increased clearance between the resilient means/disc and hub to be used with reduces problems that can occur in practical use with debris becoming entrained within a smaller clearance.
The mounting of the resilient means on the drive keys, and the symmetrical nature of the resilient means comprising arms which extend from a central main body portion, also means that the line of action of the resilient bias force is directed through the centre of the drive keys. This is particular advantageous since it is the drive keys that locate the disc on the hub and by directing the resilient bias force through the disc to the hub mounting potential problems with binding of the drive keys within the hub keyways and so jamming of the required axial sliding of the disc on the hub are reduced. In other words the resilient means, by virtue of being located on the drive keys mounting the disc to the hub, more directly maintain the drive keys in the correct position within the keyways allowing the disc to freely axially slide as required.
The resilient means also preferably includes locating and load tab features located around the periphery of the aperture. These tabs are arranged and adapted such that when the resilient means is fitted to the disc key the tabs abut an
Challenor Adam
Thorpe William Anthony
Delphi Technologies Inc.
Graham Matthew C.
Howard & Howard
Pezzlo Benjamin A
LandOfFree
Method and apparatus for mounting a brake disc does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for mounting a brake disc, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for mounting a brake disc will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3196976