Noise-damping disc brake shim system

Abstract

The present invention is a noise-damping shim system for use with disc brakes to dampen vibrational noise, or brake squeal. The system includes an inner shim, or noise damper, for placement between the piston and inner brake pad backing plate, where the outer surface of the inner shim adjacent to the piston has a relatively low coefficient of friction, and an outer shim, for placement between the caliper housing and outer brake pad backing plate, where the outer surface of the outer shim has a relatively high coefficient of friction. The outer surface of the inner shim may have a coefficient of friction of between 0.05 and 0.4. The outer surface of the outer shim may have a coefficient of friction of between 0.5 and 1.0. The shims may be single layer or multi-layer and composed of metal and elastomeric material or fabric, optionally with coatings such as polytetrafluoroethylene.

Dependencies are inferred from the claim text.