GB2053389A - Disc brake for two-wheeled vehicle - Google Patents

Abstract

The brake has a stationary member 2 adapted to be coupled to a fork (1) and has a groove 28 into which a caliper bridge 19 is slidably inserted. Torque arising on the caliper 11 during braking is transmitted via a surface c of the caliper bridge 19 to an abutting surface within the groove 28 of the stationary member 2 and the arrangement is such that braking torque is reacted by the stationary member 2 for both forward and reverse travel of the vehicle. Backing plates 12b, 13b of pad assemblies 12, 13 are respectively formed with a protruding portion 18 and a pair of shoulder portions 23, 24 which are arranged in relation to side portions 25 of caliper bridge 19 as seen in Figure 3 - torque is transmitted from the pad assemblies 12, 13 to the caliper 11 through surfaces a, b. Protruding portions 18 have oblong slots 21 receiving a pad pin 20. Side portions 25 of caliper bridge 19 are formed with supporting pieces 26 - a pin 27 inserted through pieces 26 and stationary member 2 slidably supports caliper 11 in addition to the groove 28 - bridge 19 sliding interconnection. <IMAGE>

Description

SPECIFICATION Disc brake for two-wheeled.vehicle The present invention relates to disc brakes and more particularly to a floating type disc brake for use with a two-wheeled vehicle, such as a bicycle or motorcycle.

Figure 1 illustrates a conventional disc brake for a two-wheeied vehicle. In this disc brake, protrusions 4 are provided in the front and rear regions on the side of a caliper 3 to either side of a stationary member 2 which is integral with a fork 1 of the vehicle or which is mounted on the fork 1.

The caliper 3 is mounted on the fork 1 by inserting a pin 5 into a through-hole provided in the stationary member 2 and the protrusions 4. The side 6 of the caliper 3 is abutted against the flat surface 7 of the stationary member 2. When the vehicle moves forward, the brake torque is reacted by abutment of the side 6 of the caliper against the fiat surface 7 of the stationary member 2 as a disc A turns in the direction of the arrow in Figure 1. When the vehicle moves backward, the brake torque is reacted by the pin 5 running through the stationary member 2.

In this case, there is no particular problem in reacting the brake torque resulting from forward movement. However, when the vehicle moves backward, the brake torque must be reacted by the pin running through the stationary member, as a result of which, the pin is subjected to high compression and accordingly to large load. Thus, the conventional disc brake is disadvantageous in that it is not desirable to apply a large braking torque during backward movement of the vehicle.

An object of the present invention is to provide a floating type disc brake for a two-wheeled vehicle in which a large braking torque can be reacted without untoward effect during either forward or backward movement of the vehicle.

According to the invention, a disc brake for a two-wheeled vehicle comprises a stationary member adapted to be coupled to the fork of a vehicle, said stationary member having a groove provided in an end surface thereof, first and second pad assemblies disposed, in use, on either side of a brake disc fast for rotation with a wheel to be braked, a caliper adapted to straddle a portion of said disc and for operative engagement with said first and second pad assemblies, said caliper having a caliper bridge slidably disposed in said groove of said stationary member, and a pin slidably interconnecting said caliper and said stationary member to slidably couple said caliper to said stationary member, the arrangement being such that braking torque arising on the caliper during both forward and backward movement of the vehicle is transmitted to the stationary member via interengaging surfaces of the caliper and stationary member within said stationary member groove.

The present invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a front view of a conventional disc brake; Figure 2 is a sectional view of one example of a disc brake according to the present invention, and Figure 3 is a cross-sectional view taken along line X-X of Figure 2.

An example of one form of the disc brake of the present invention is shown in Figures 2 and 3 and comprises a caliper 11 having a caliper cylinder 14, which is secured to a vehicle body not shown in such a manner as to be slidable axially of a disc A, pad assemblies 12 and 13 disposed on opposite sides of the disc A, the former being disposed on the cylinder side of the caliper and the latter being disposed on the wheel (not shown) side. A piston 1 5 is incorporated in the caliper cylinder 14. The caliper 11 includes a caliper bridge 1 9 straddling the periphery of the pad assemblies 12 and 13, and a caliper groove 16. A recess 1 7 is formed in the disc groove 1 6 of the caliper 11 extending parallel to the axis of the disc A thereby forming side portions 25, as particularly shown in Figure 3.The pad assemblies 12 and 13 include backing plates 1 2b and 1 3b, respectively, each of which has a protruding portion 18 extending from the central periphery of the backing plate radially outwardly of the disc A. The protruding portions 1 8 of the backing plates are adapted to be inserted into the recess 1 7 of the caliper bridge 1 9. Each of the protruding portions 1 8 has an oblong slot 21, the longitudinal axis of which is perpendicular to the axis of the disc A, a pad pin 20 being loosely inserted through said slots. At the tip end of the pad pin 20, a slit pin 23 is inserted so as to prevent the unwanted removal of the pad pin 20. Thus, the pad assemblies 12 and 13 are supported by inserting the pad pin 20 through the bridge portion 18 and the oblong slot 21.

The backing plates 1 2b and 1 3b of the pad assemblies 1 2 and 13 have respective pairs of shoulder portions 23 and 24 which extend from both end portions of the periphery of the backing plate radially outwardly of the disc A, as shown in Figure 3. The respective side portions 25 of the caliper bridge 1 9 are interposed between the protruding portion 1 8 and the shoulder portions 23 and 24 of one of the pad assemblies in abutment with the inner surfaces of the shoulder portions 23 and 24 and also in abutment with the upper surface of backing plate 1 2b and 1 3b.

A pair of supporting pieces 26 are integrally formed on the side portions 25 of the caliper bridge 1 9. The stationary member 2 integrally mounted on the aforementioned fork 1 is interposed between the supporting pieces 26. A pin 27 is inserted through the supporting pieces 26 and the stationary member 2. Thus, the caliper 11 is slidably supported in the axial direction of the disc A with respect to the stationary member 2 by way of the pin 27 passing through the supporting pieces 26 and the stationary member 2. In addition, on the lower end of the stationary member 2 as shown in Figure 3, a groove 28 which is wide axially of the disc A is formed in such a manner that the caliper 11 is slidably inserted into the groove 28.

In the disc brake constructed as described above, the brake torque applied to the pad assemblies 12 and 13 is transmitted to the caliper 11 through the abutting surface a of both side portions 25 of the caliper bridge from the inner surfaces of the shoulders 23 and 24 of the backing plates 1 2b and 1 3b and also through the abutting surface b of the side portions 25 of the caliper bridge from the upper surface of the backing plates 1 2b and 1 3b. Then, the brake torque is reacted by abutment of the surface c of the caliper bridge 1 9 and the groove 28 of the stationary member 2.

As is apparent from the above description, in the disc brake of the present invention, the brake torque applied to each brake pad can be reacted by the inner surface of the groove formed on the lower end of the stationary member when the vehicle moves either forward or backward.

Therefore, the disc brake of the invention is advantageous in that it is possible to satisfactorily react a large braking torque resulting from backward movement when compared with a conventional disc brake.

Claims (3)

1. A disc brake for a two-wheeled vehicle comprising, a stationary member adapted to be coupled to the fork of a vehicle, said stationary member having a groove provided in an end surface thereof, first and second pad assemblies disposed, in use, on either side of a brake disc fast for rotation with a wheel to be braked, a caliper adapted to straddle a portion of said disc and for operative engagement with said first and second pad assemblies, said caliper having a caliper bridge slidably disposed in said groove of said stationary member, and a pin slidably interconnecting said caliper and said stationary member to slidably couple said caliper to said stationary member, the arrangement being such that braking torque arising on the caliper during both forward and backward movement of the vehicle is transmitted to the stationary member via interengaging surfaces of the caliper and stationary member within said stationary member groove.

2. A disc brake according to Claim 1 wherein each backing plate has a protruding portion extending from an inner peripheral portion thereof and a pair of shoulder portions extending from respective end peripheral portions, all of said portions extending radially outwardly in relation to the disc when in use, the brake further comprising a support pin extending through the caliper bridge and arranged to pass through the protruding portions of the pad backing plates to support the latter with clearance transverse to the pin direction, and side portions formed on the caliper bridge and adapted to be interposed, in use, between the protruding portion and shoulder portions of each pad assembly, whereby the side portions of the caliper bridge are brought into abutment with the inner surfaces of said shoulder portions and the upper surfaces of the backing plates in order to react braking torque arising on the pads during braking of the disc.

3. A brake disc for a two-wheeled vehicle substantially as hereinbefore described with reference to Figures 2 and 3 of the accompanying drawings.