A disc brake for heavy vehicles. The disc brake may include first and second brake pads, a caliper, and at least one support. The caliper may have a radial opening and a pad strap. The support may support a rear face of at least one of the brake pads and may have a guide formation that may be configured to engage the pad strap and restrict rotation of the brake pad about a radial axis.
1. A disc brake for heavy vehicles, the disc brake comprising:
first and second brake pads arranged to face a brake rotor;
a caliper for applying a clamp load to the first and second brake pads to retard rotation of the brake rotor, the caliper further comprising:
a radial opening dimensioned for fitting and removal of the first and second brake pads therethrough; and
a pad strap arranged to extend over the radial opening and releasably restrain the first and second brake pads at least radially outwardly with respect to the caliper;
wherein the disc brake further comprises at least one support for supporting a rear face of at least one of the first and second brake pads, the support being provided with a guide formation configured to engage with the pad strap and thereby restrict rotation of at least one of the first and second brake pads about a radial axis.
2. The disc brake of claim 1 wherein the guide formation further permits sliding of at least one of the first and second brake pads with respect to the pad strap.
3. The disc brake of claim 2 wherein the guide formation comprises at least one guide surface arranged to slide with respect to the pad strap and restrain rotation.
4. The disc brake of claim 3 wherein the guide formation comprises two opposing guide surfaces arranged to restrain rotation.
5. The disc brake of claim 4 wherein the guide formation comprises circumferentially inward facing surfaces arranged to be guided on circumferentially outward facing surfaces of the pad strap.
6. The disc brake of claim 4 wherein the two opposing guide surfaces are located on first and second guide bars extending from the support over at least one of the first and second brake pads, the first and second guide bars being radially adjacent to the pad strap.
7. The disc brake of claim 6 wherein there is a close running fit between the first and second guide bars and the pad strap.
8. The disc brake of claim 6 wherein the first and second guide bars are located in a radially outward position to the support.
9. The disc brake of claim 3 wherein the at least one guide surface extends outboard of the at least one support.
10. The disc brake of claim 3 wherein the at least one guide surface extends inboard of the at least one support.
11. The disc brake of claim 3 wherein the at least one guide surface is at least twice as deep in an inboard-outboard direction as the at least one support.
12. The disc brake of claim 11 wherein the at least one guide surface is at least three times as deep in the inboard-outboard direction as the at least one support.
13. The disc brake of claim 1 wherein the at least one support is a spreader plate positioned in a face-contacting relationship with at least one of the first and second brake pads and arranged to distribute force from an actuation mechanism of the disc brake to at least one of the first and second brake pads.
14. The disc brake of claim 1 wherein at least one of the first and second brake pads includes a backplate non-removably connected to friction material, the at least one support being the backplate.
15. The disc brake of claim 1 further comprising a pad spring to resiliently bias the at least one support radially inwardly away from the pad strap.
16. The disc brake of claim 15 wherein the pad spring comprises an offset portion extending outboard of the at least one support.
17. The disc brake of claim 15 wherein the pad spring further comprises a formation to hold at least one of the first and second brake pads to the at least one support.