Bicycle rim brake

Patent metadata

Field	Value
Publication number	US-10710672-B2
Application number	US-201816127992-A
Country	US
Kind code	B2
Filing date	Sep 11, 2018
Priority date	Sep 10, 2015
Publication date	Jul 14, 2020
Grant date	Jul 14, 2020

Abstract

Responsive to a hydraulic piston advancing out of a piston housing in a second brake arm and contacting a piston cam surface of a first brake arm, the second brake arm pivots around a second pivot. As this is happening, a cam surface in the second brake arm lifts a contact surface of a first force transfer member of the first brake arm, imparting torque to the first brake arm which then pivots around a first pivot. The cam surface is shaped to impart synchronous motion to the first and second pad holders. Splitting one of the brake arms with a centering member permits a centering adjust feature.

First claim

We claim:

1. A rim brake for a bicycle, the rim brake comprising:
a first brake arm, a first pivot of the first brake arm adapted to be pivotally mounted to a first mounting location on the bicycle, a first pad holder downwardly extending from the first pivot and pivoting around the first pivot in a first angular direction responsive to actuation of the brake;
a second brake arm, a second pivot of the second brake arm adapted to be pivotally mounted to a second mounting location on the bicycle, the second pivot horizontally spaced from the first pivot, a second pad holder downwardly extending from the second pivot and pivoting around the second pivot in a second angular direction opposite the first angular direction responsive to actuation of the brake;
a biasing member of the second brake arm upwardly extending from the second pivot and pivoting around the second pivot with the second pad holder as a unit;
a force transfer member of the second brake arm upwardly extending from the second pivot and operable to transmit torque to the second pad holder in the second angular direction upon actuation of the brake;
a hydraulic piston having a piston actuation axis, wherein the piston actuation axis pivots around the second pivot upon actuation of the rim brake; and
a centering member adjoining the transfer member and the biasing member, the centering member defining an angular position of the force transfer member relative to the biasing member, the centering member adjustable to move the second pad holder without moving the first pad holder.

2. The rim brake of claim 1 , wherein the force transfer member is a second force transfer member, the brake further comprising: a first force transfer member of the first brake arm extending upwardly from the first pivot, the first force transfer member imparting torque in the first angular direction to the first pad holder upon actuation of the brake.

3. The rim brake of claim 2 , further comprising a spring connected to the first force transfer member and the biasing member to urge the first force transfer member toward the biasing member of the second brake arm.

4. The rim brake of claim 3 , wherein the centering member comprises a set screw threadedly received into a bore of the biasing member, an end of the set screw abutting a surface of the second force transfer member.

5. The rim brake of claim 1 , further comprising a hydraulic piston assembly.

6. The rim brake of claim 5 , wherein the hydraulic piston assembly includes the hydraulic piston slidably mounted in a piston housing of the second brake arm.

7. The rim brake of claim 6 , wherein the hydraulic piston assembly is configured such that the hydraulic piston advances along the piston actuation axis responsive to hydraulic fluid pressure to cause a non-horizontal force to be exerted on the first brake arm to move a second brake pad holder in an arcuate direction around the second pivot.

8. The rim brake of claim 1 , further comprising a first force transfer member of the first brake arm, the first force transfer member upwardly extending from the first pivot, and a first contact surface on the first force transfer member in contact with a second contact surface on the force transfer member of the second brake arm to impart torque to the force transfer member of the second brake arm in an arcuate direction around the second pivot.

9. The rim brake of claim 8 , wherein the second contact surface on the second force transfer member of the second brake arm is a transfer cam surface and the first contact surface on the first force transfer member of the first brake arm is a roller, which rolls against the transfer cam surface.

10. The rim brake of claim 9 , wherein the transfer cam surface is so shaped that a first brake pad holder and a second brake pad holder move at the same speed around the first and second pivots.

11. The rim brake of claim 9 , wherein the transfer cam surface is located closer to the second pivot than the hydraulic piston.

12. The rim brake of claim 9 , wherein the transfer cam surface is located in an upper and inboard direction from the second pivot.

13. The rim brake of claim 9 , wherein the first brake arm includes a piston cam surface, an end of the hydraulic piston abuts the piston cam surface, the piston cam surface is located in an upper and inboard direction from the first pivot.

14. The rim brake of claim 13 , wherein the piston cam surface and the transfer cam surface are so shaped that a transfer cam force acting on the transfer cam surface by the first force transfer member will always be parallel to the piston actuation axis.

15. The rim brake of claim 1 , wherein actuation of the hydraulic piston causes the first and second pad holders to move in opposed inboard directions at the same speed.

16. The rim brake of claim 1 , further comprising a spring which urges the first and second pad holders in opposed outboard directions.

17. The rim brake of claim 1 , wherein the hydraulic piston is located in an upper direction from the second pivot.

Assignees

• Sram Llc

Inventors

• Dunlap Iii Charles
• Jordan Brian

Classifications

• B62L1/16 Primary

  the axes being located intermediate the ends of the levers · CPC title

• B62L3/023

  acting on fluid pressure systems · CPC title