Patent Application
20090014262
The invention relates to a disc brake, in particular for a commercial vehicle, and also to a brake pad for a disc brake.
A disc brake of the generic type is disclosed in DE 199 07 958 A1, for example. What is shown and described in this document is that, in order to protect the inner compartment of the brake caliper, which accommodates actuating spindles of a brake application device, a mounting and functional opening of the caliper is closed off by way of a closure cover, such as plate-type cover. The closure cover is fastened to the caliper by use of screws.
In principle, it is possible when mounting the brake pads for improper mounting to occur, both through the use of an incorrect brake pad not intended and approved for the respective disc brake, and through mixing up the right and left brake pads when fitting them, in which case the brake pads can be mounted in a position in which they are effectively rotated by 180° without this being noticed. The result is that the lining carrier plate is then facing the brake disc. Since the brake disc is no longer operationally reliable, this improper mounting can result in serious and dangerous vehicle operating problems.
Apart from the afore-mentioned improper mounting, the known disc brakes also enable the brake pads to be replaced with external makes (for example, brake pads not from the original manufacturer), which are not approved for the particular vehicle or the particular disc brake.
This can also result in limiting the operational reliability of the disc brake, a situation which is fundamentally unacceptable, especially since disc brakes are among the components of a vehicle which are of particular importance from a safety point of view.
Although attempts have been made to code brake pads, the known codings can be removed by a simple mechanical operation, for example using a hammer and chisel, which means that uncoded brake pads of unauthorized manufacturers can be used without problems.
It is, therefore, an object of the invention to develop a disc brake that achieves an improvement in the operational reliability in combination with a low structural and manufacturing outlay.
According to the invention, a disc brake, particularly for a commercial vehicle, includes a caliper, which straddles a brake disc that is brought into operative contact with brake pads, each brake pad including a lining carrier plate and, fastened thereon, a friction lining. At least one closure cover closes off the caliper and is fastened thereon. The closure cover and the lining carrier plate have a respective elevation and recess which correspond to one another in a coded manner.
This structural design means that only a brake pad designated for this intended use can be mounted in the disc brake. It is ensured at the same time that the brake pad can only be used in such a way that its friction lining material side is oriented to face the brake disc.
Moreover, no external make or product can be used since the elevations and recesses of the closure cover on the one hand and of the lining carrier plate on the other hand that correspond to one another in the coded manner are compatible with one another only in a defined configuration.
This configuration, i.e., the shape and arrangement of the corresponding parts, is determined at the factory, which means that, as a replacement part, use can only be made of the brake pad which has the elevations and cutouts predetermined by the manufacturer of the disc brake.
In addition, the coding allows the prior determination of the brake pads for a specific point of installation. It is thus possible to exactly allocate brake pads with different coefficients of friction of the friction lining materials, as are required for an inner lining and an outer lining, in order, for example, to take account of the different cracking behavior of a brake disc. Any interchange between the two brake pads can thus be ruled out if the coding of the two brake pads or of the associated closure cover is different.
According to an advantageous configuration of the invention, provision is made for at least some of the screws, which are used to fasten the closure cover to the caliper, to serve as elevations, within the meaning of the invention, the screws, in particular the screw heads, being correspondingly modified to engage with recesses or cutouts adapted thereto in the lining carrier plate.
In a manner known per se, the screws are mounted in the peripheral region of the closure cover. Depending on the variation of their position within the periphery, a coding can be achieved, whereby brake pads intended exclusively for a predetermined type can be used which then have corresponding recesses, the screw heads of the screws projecting into the recesses.
A variation of the code can also be obtained by designing the screw heads differently, for example in terms of shape, diameter and length. Here, these differences, to which the recesses or cutouts of the lining carrier plate are adapted, can result in a large number of codes which, inter alia, can be used to rule out any interchange between the right and left brake pads.
A further advantage of the invention is that disc brakes in operation can be retrofitted, in which case the associated screws of the closure cover are then also replaced during a replacement of the brake pads. It is expedient in this case only to provide the coding facility by changing the shape, the length and/or the diameter of the screws.
A particular importance also attaches to the fact that the new disc brake can be produced with low manufacturing outlay. Since such disc brakes, and also in particular the replacement brake pads, are produced in large quantities, the invention offers the advantage of a significantly improved operational reliability with low outlay.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.
For this purpose, actuating spindles 12 are arranged in a mounting compartment 13 of the caliper. These spindles 12 (only one of which is shown) are connected on the one hand to a brake application device (not fully shown) and on the other hand bear against the lining carrier plate 4.
In the direction of the brake disc 3, the mounting compartment 13 is closed off by a closure cover or plate 6, specifically by use of screws 7 which are screwed peripherally into threaded holes in the caliper 1. The screws 7 are guided through holes 11 (
At least some of the screws 7 (in the present exemplary embodiment, two screws 7) are designed in such a way that they include a screw shank 8, which is screwed into the brake caliper 1, and a cylindrical screw head 9, which is produced as a separate part and connected to the respectively associated screw shank 8.
The screw head 9 forms an elevation which projects into a recess 10 in the lining carrier plate 4. The screw head 9 and the recess 10 correspond to one another in the manner of a coding facility. In other words, the screw heads 9 and the recesses or cutouts 10 are tailored to one another in their arrangement, configuration and dimensioning such that, when the closure cover 6 has been firmly screwed into place, only a correspondingly modified brake pad 2 can be used whose lining carrier plate 4 accommodates the screw heads 9 in the desired manner.
As shown very clearly, particularly in
Both the shape of the screw heads 9 and the dimensioning thereof can be freely selected such that a large variety of different codings can be achieved.
In order to facilitate simple mounting, in particular simple insertion of the brake pad 2 from above into the brake caliper 1, the screws 7 forming the elevations are expediently provided in the lower region (as viewed in the direction of insertion) of the closure cover 6.
The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2006 003 748.0 | Jan 2006 | DE | national |
This application is a continuation of PCT International Application No. PCT/EP2007/000618, filed on Jan. 25, 2007, which claims priority under 35 U.S.C. § 119 to German Application No. 10 2006 003 748.0, filed Jan. 26, 2006, the entire disclosures of which are expressly incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2007/000618 | Jan 2007 | US |
| Child | 12181134 | US |
