Bicycle rim brake
AssigneeSram, LLC
InventorsCharles Dunlap, III, Brian Jordan
Life of this patent
Estimating the term…
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.
Claims13
A rim brake for a bicycle, the rim brake comprising:
- a first brake arm having a first pivot adapted for pivotal attachment to the bicycle, a first brake pad holder of the first brake arm downwardly depending from the first pivot, the first brake pad holder configured to move in a first arcuate direction around the first pivot;
- a second brake arm having a second pivot adapted for pivotal attachment to the bicycle, a second brake pad holder of the second brake arm downwardly depending from the second pivot, the second brake pad holder configured to move in a second arcuate direction around the second pivot opposite the first arcuate direction, the second pivot horizontally spaced from the first pivot;
- and
- only one hydraulic piston assembly, the hydraulic piston assembly including a piston slidably mounted in a piston housing of the second brake arm, the piston advancing along a piston axis responsive to hydraulic fluid pressure to cause a non-horizontal force to be exerted on the first brake arm to move the second brake pad holder in the second arcuate direction around the second pivot, the piston axis extending between the first and second pivots;
- and
- a force transfer mechanism between the first brake arm and the second brake arm that causes a force transfer from the first brake arm to the second brake arm, the force transfer mechanism configured to move the first pad holder in the first arcuate direction about the first pivot as the piston advances,
- wherein the force transfer mechanism includes a first force transfer member of the first brake arm, the first force transfer member upwardly extending from the first pivot and a second force transfer member of the second brake arm, the second force transfer member upwardly extending from the second pivot, a first contact surface on the first force transfer member in contact with a second contact surface on the second force transfer member to impart torque to the second force transfer member in the second arcuate direction around the second pivot.
Dependencies are inferred from the claim text.