Fixed disc brake caliper with pad wear compensator

#The present invention is directed toward disc brakes, and more particularly toward a pad wear compensator for a disc brake caliper.

#Disc brakes are being included on more and more bicycles as consumers are ever increasingly demonstrating a preference for disc brakes over conventional rim brakes such as caliper brakes, cantilever brakes and side pull cantilever brakes. While both mechanical and hydraulic disc brakes have been available for bicycles for many years, only recently have there been advances in disc brake caliper design that have made disc brakes sufficiently lightweight, reliable and inexpensive to satisfy consumer preferences. While more efficient and powerful caliper drive mechanisms are evolving, to date manufacturers of disc brakes have not adequately addressed consumer need for ease of adjustment and maintenance of these caliper brakes. One area of particular concern is structures for compensating for pad wear.

#One known pad wear compensator provides a set screw that can be advanced within a caliper housing to advance an operatively associated brake pad as the pad wears. The set screw resides within a threaded bore in the housing and requires a turning tool such as a hex wrench to advance the pad. In addition, to lock the pad in a select position, a second locking screw is threadably engaged in the bore to lock the adjustment screw in place. This structure, while allowing for advancement of the pad to compensate for pad wear, is extremely cumbersome to use, requiring the removal of one screw and the turning of two screws as well as the use of a separate tool to make an adjustment. In addition, because the adjustment screw resides within the threaded bore, there is no reliable way to gauge how far the pad has been extended so as to assess remaining pad life. Furthermore, the structure fails to provide any indexing to insure select axial advancement of the brake pad as the adjustment screw is rotated.

#FIG. 1 is a perspective view showing the mechanical disc brake caliper of the present invention mounted to a fork of a bicycle in operative engagement with a brake disc;

#FIG. 2 is the mechanical disc brake caliper of FIG. 1 including an adaptor for mounting to a frame with different mounts;

#FIG. 3A is a front elevation view of the mechanical disc brake caliper of FIG. 1 including a floating cable stop;

#A mechanical disc brake caliper 10 in accordance with the present invention is shown in FIG. 1 mounted to a frame or, more particularly, a front fork 12 of a bicycle in operative engagement with a disc 14. As shown in FIGS. 1-3, the caliper 10 is mounted to a front fork 12 for use with a front wheel. For use with the rear wheel, the caliper is typically mounted to the seat stay, chain stay, drop out plate, after market adapter or the like. The disc 14 in turn is rigidly mounted to the hub of a wheel assembly by the bolts 16. For the sake of clarity, the bicycle wheel and hub are not shown.

#The mechanical disc brake caliper consists of a caliper housing 18 having a pair of mounting feet 20, 22 extending therefrom for attachment to a corresponding pair of internally threaded attachment bosses 24, 26 which extend from the front fork 12. A pair of mounting bolts 28 secure the mounting feet 20, 22 to the attachment bosses 24, 26. The mounting feet preferably include elongate slots 27 (see FIG. 5) receiving the mounting bolts 28 and complimentary pairs of concave/convex washers 30 to provide for adjustable attachment of the mechanical disc brake caliper to a bicycle frame. Such an attachment structure is described in detail in applicant Wayne Lumpkin's, co-pending Patent application Ser. No. 09/383,121, the disclosure of which is hereby incorporated in its entirety herein.

#As seen in FIG. 1, a lever arm 32 is pivotally attached at a first end 34 to the caliper housing 18. A second end of the lever arm 36 has a cable clamp 38 which secures an end of the cable 40. The cable 40 is directed through a cable feed 42 attached to the caliper housing 18 with a cable housing 44 abutting the cable feed 42. While the operation of the mechanical disc brake will be described in considerably greater detail below, it is useful at the outset to understand that the mechanical disc brake caliper is actuated by tension being applied to an opposite end of the cable 40 by a cable actuator such as a conventional cable brake lever (not shown) and this tension causes the lever arm 32 to pivot about pivot axis 46 in the direction of arrow 48 so that the second end of the lever arm 36 is drawn toward the cable guide 42 to advance a brake pad into contact with the disc 14 by a rotary to linear linkage between the first end 34 of the lever arm 32 and the brake pad.