GB2049078A

GB2049078A - Brake assembly

Info

Publication number: GB2049078A
Application number: GB8010433A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-04-05
Filing date: 1980-03-28
Publication date: 1980-12-17
Also published as: GB2049078B

Abstract

A brake assembly includes a main brake shoe 11 carrying a main brake pad 12 and an auxiliary cleaning means 22 is mounted on and upstream of the main pad 12 with respect to the intended direction of motion of the surface e.g. of a cycle wheel rim 15 to be braked. The cleaning means may comprise a squeegee blade, but is shown as a subsidiary pad 22 mounted on a shoe 21, mounted on shoe 11. A biassing leaf spring 24 is arranged so that on operation of the brake the pad 22 engages the rim 15 first to wipe water and dirt from the surface and further movement of a calliper brake arm 16 moves the pad 12 to engage the rim 15 to perform braking action on the cleaner and drier rim 15, the spring 24 allowing the pad 12 to advance relative to the pad 22. The pad 22 has ridges 23 inclined at an acute angle to the direction of motion of the rim 15. In the embodiment of Figure 2 (not shown) mounting of the subsidiary pad involves a rigid support (31) bolted to shoe 11 and guide pins (32) and coil springs (34, 35). <IMAGE>

Description

SPECIFICATION Brake shoes This invention relates to brake shoes. One application of the invention is to calliper brakes for bicycles.

A brake shoe carries a replaceable brake pad and the brake is applied against a relatively moving surface by pressing the brake shoe towards the surface so that the pad engages the surface. The efficiency of the brake is reduced when the surface is dirty or wet, and the present invention provides means attached to the brake shoe for cleaning the surface upstream of the point of application of the brake pad. Preferably the cleaning means includes biassing means for biassing the remainder of the cleaning means towards the surface. Preferably the cleaning means includes a wiping edge which is inclined at an acute angle to the intended direction of relative movement of said surface. A squeegee blade or a brake pad with inclined ridges form suitable wiping edges.

The biassing means may form the sole support for the cleaning means relative to the brake shoe, and could be in the form of a leaf spring. In an alternative arrangement, a rigid support is provided for the cleaning means from the brake shoe, and the biassing means acts between the rigid support and the cleaning means, for example in form of a coil spring.

Examples of the invention will now be described with reference to the accompanying drawings in which: Fig. 1 is a plan view of one embodiment of the invention, and Fig. 2 is a plan view of an alternative embodiment.

In each embodiment, the brake includes a brake shoe assembly on each side of the rim, but only one assembly has been shown in each embodiment for convenience. The other brake assembly is mounted symmetrically on the other side of the rim. In both embodiments, the brake shoe 11 and pad 12 of the conventional brake are retained, the shoe being fixed to the arm 1 6 of the calliper brake assembly by a nut 13 and bolt 14 in the conventional way. When the cycle rim 1 5 is wet, the brake pad soon becomes saturated with water and its braking efficiency is reduced. In both embodiments, a subsidiary pad 22 is provided, mounted in a subsidiary shoe 21 and located upstream in the normal direction of movement of the wheel rim relative to the main shoe 11.The pad 22 is formed with ridges 23 on its operative surface facing the rim 15, the ridges 23 being inclined at an acute angle to the direction of motion of the rim 15.

In the embodiment of Fig. 1, the auxiliary shoe 21 is mounted on the main shoe 11 by means of a flat leaf spring 24 secured at one end by nut 13 and bolt 14, and by a similar nut 25 and bolt 26 at the subsidiary shoe 21.

In the embodiment of Fig. 2, a rigid support 31 is secured to the brake shoe 11 by the bolt 14 and nut 13 extending upstream of the shoe 11. The subsidiary shoe 21 is provided with a pair of guide pins 32 at its ends, in addition to the bolt 26. The guide pins 32 extend through apertures 33 in the support 31 and coil springs 34 encircle the pins 32 to bias the shoe 25 towards the wheel rim 15 relative to the support 31. A further coil spring 35 is placed between the rear of the support 31 and the nut 25 in order to allow limited relative movement of the shoe 21 relative to the support 31.

When the brake is operated, the calliper brake arm 16 will move the main brake shoe 11 towards the rim 1 5. The auxiliary pad 22 is mounted so that it engages the rim 1 5 before the main pad 12, and the inclined ridges 23 on the pad 22 wipe water and dirt particles from the rim 1 5. As the calliper brake arm is moved further towards the rim 15, the main pad 12 will engage it and perform a braking action as in the conventional brake, but now the rim 1 5 will be cleaner and drier, so that the pad 12 will not become saturated and braking efficiency is improved.

The resilience of the flat spring 24 in Fig. 1, and of the coil springs 34 and 35 ensures that the pressure applied to the auxiliary pad 22 is not sufficient for effective braking action, so that the pad 22 will not become worn and the inclined ridges 23 will remain on the surface of the pad 22 for a reasonable period. The resilience of the springs 24, 34 and 35 will ensure that the wiping device operates satisfactorily even though the main pad 1 2 becomes worn during use.

In the embodiment of Fig. 2, the spring 35 acts against the springs 34, but is provided in order to act against the nut 26 so that it does not vibrate loose during use. The position of the nut 26 on the bolt 25 is varied to adjust the rest position of the pad 22 relative to the pad 12. The spring 35 and the nut 26 could be replaced by a lock nut, although this would be less convenient to adjust since spanners would be required.

In the embodiment of Fig. 2, it would be possible for the rigid support 31 to be made integral with the brake shoe 11, or with the calliper arm 16.

It will be seen that the auxiliary shoe and pad provides a useful arrangement for wiping the rim before the main brake is applied, without applying undesired friction to the rim when the brake is not applied, as would be the case with a wiping device permanently applied to the rim.

1. A brake assembly comprising a main brake shoe supporting a replaceable brake pad for engagement with a relatively moving surface, and means attached to the main brake shoe for cleaning the surface upstream of the point of application of the brake pad.

2. An assembly as claimed in Claim 1 wherein the cleaning means comprises biassing means for biassing the cleaning means towards said surface.

3. An assembly as claimed in Claim 1 or Claim 2 wherein the cleaning means includes a wiping

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Brake shoes This invention relates to brake shoes. One application of the invention is to calliper brakes for bicycles. A brake shoe carries a replaceable brake pad and the brake is applied against a relatively moving surface by pressing the brake shoe towards the surface so that the pad engages the surface. The efficiency of the brake is reduced when the surface is dirty or wet, and the present invention provides means attached to the brake shoe for cleaning the surface upstream of the point of application of the brake pad. Preferably the cleaning means includes biassing means for biassing the remainder of the cleaning means towards the surface. Preferably the cleaning means includes a wiping edge which is inclined at an acute angle to the intended direction of relative movement of said surface. A squeegee blade or a brake pad with inclined ridges form suitable wiping edges. The biassing means may form the sole support for the cleaning means relative to the brake shoe, and could be in the form of a leaf spring. In an alternative arrangement, a rigid support is provided for the cleaning means from the brake shoe, and the biassing means acts between the rigid support and the cleaning means, for example in form of a coil spring. Examples of the invention will now be described with reference to the accompanying drawings in which: Fig. 1 is a plan view of one embodiment of the invention, and Fig. 2 is a plan view of an alternative embodiment. In each embodiment, the brake includes a brake shoe assembly on each side of the rim, but only one assembly has been shown in each embodiment for convenience. The other brake assembly is mounted symmetrically on the other side of the rim. In both embodiments, the brake shoe 11 and pad 12 of the conventional brake are retained, the shoe being fixed to the arm 1 6 of the calliper brake assembly by a nut 13 and bolt 14 in the conventional way. When the cycle rim 1 5 is wet, the brake pad soon becomes saturated with water and its braking efficiency is reduced. In both embodiments, a subsidiary pad 22 is provided, mounted in a subsidiary shoe 21 and located upstream in the normal direction of movement of the wheel rim relative to the main shoe 11.The pad 22 is formed with ridges 23 on its operative surface facing the rim 15, the ridges 23 being inclined at an acute angle to the direction of motion of the rim 15. In the embodiment of Fig. 1, the auxiliary shoe 21 is mounted on the main shoe 11 by means of a flat leaf spring 24 secured at one end by nut 13 and bolt 14, and by a similar nut 25 and bolt 26 at the subsidiary shoe 21. In the embodiment of Fig. 2, a rigid support 31 is secured to the brake shoe 11 by the bolt 14 and nut 13 extending upstream of the shoe 11. The subsidiary shoe 21 is provided with a pair of guide pins 32 at its ends, in addition to the bolt 26. The guide pins 32 extend through apertures 33 in the support 31 and coil springs 34 encircle the pins 32 to bias the shoe 25 towards the wheel rim 15 relative to the support 31. A further coil spring 35 is placed between the rear of the support 31 and the nut 25 in order to allow limited relative movement of the shoe 21 relative to the support 31. When the brake is operated, the calliper brake arm 16 will move the main brake shoe 11 towards the rim 1 5. The auxiliary pad 22 is mounted so that it engages the rim 1 5 before the main pad 12, and the inclined ridges 23 on the pad 22 wipe water and dirt particles from the rim 1 5. As the calliper brake arm is moved further towards the rim 15, the main pad 12 will engage it and perform a braking action as in the conventional brake, but now the rim 1 5 will be cleaner and drier, so that the pad 12 will not become saturated and braking efficiency is improved. The resilience of the flat spring 24 in Fig. 1, and of the coil springs 34 and 35 ensures that the pressure applied to the auxiliary pad 22 is not sufficient for effective braking action, so that the pad 22 will not become worn and the inclined ridges 23 will remain on the surface of the pad 22 for a reasonable period. The resilience of the springs 24, 34 and 35 will ensure that the wiping device operates satisfactorily even though the main pad 1 2 becomes worn during use. In the embodiment of Fig. 2, the spring 35 acts against the springs 34, but is provided in order to act against the nut 26 so that it does not vibrate loose during use. The position of the nut 26 on the bolt 25 is varied to adjust the rest position of the pad 22 relative to the pad 12. The spring 35 and the nut 26 could be replaced by a lock nut, although this would be less convenient to adjust since spanners would be required. In the embodiment of Fig. 2, it would be possible for the rigid support 31 to be made integral with the brake shoe 11, or with the calliper arm 16. It will be seen that the auxiliary shoe and pad provides a useful arrangement for wiping the rim before the main brake is applied, without applying undesired friction to the rim when the brake is not applied, as would be the case with a wiping device permanently applied to the rim. CLAIMS

3. An assembly as claimed in Claim 1 or Claim 2 wherein the cleaning means includes a wiping edge which is inclined at an acute angle to the intended direction of relative movement of said surface.

4. An assembly as claimed in Claim 3 wherein the cleaning means comprises a squeegee blade.

5. An assembly as claimed in Claim 3 wherein the cleaning means comprises a subsidiary pad with inclined ridges.

6. An assembly as claimed in Claim 2 or any claim dependent thereon wherein the biassing means provides the sole support for the cleaning means relative to the main brake shoe.

7. An assembly as claimed in Claim 6 wherein the biassing means comprises a leaf spring.

8. An assembly as claimed in Claim 2 or any one of Claims 3 to 5 when dependent on Claim 2, comprising a rigid support fixedly mounted relative to the main brake shoe, the biassing means acting between the rigid support and the remainder of the cleaning means.

9. An assembly as claimed in Claim 8 comprising means to limit the motion of said remainder of cleaning means relative to said rigid support.

10. An assembly as claimed in Claim 9 wherein said limiting means is adjustable.

11. An assembly as claimed in Claim 10 wherein said limiting means comprises a nut threaded on a bolt forming part of said remainder of said cleaning means and a coil spring compressed between said rigid support and said nut.

12. A brake assembly substantially as hereinbefore described with reference to and as illustrated in either figure of the accompanying drawing.