Magnetic brake pad wear sensor

Abstract

A brake pad wear measuring system is for use on a vehicle equipped with a tire pressure monitoring (TPM) system including a wheel mounted TPM sensor, and a floating caliper disc brake system including a piston supporting an inner brake pad and a floating caliper supporting an outer brake pad, wherein the piston and floating caliper move toward each other along a braking axis in response to application of the brake system so that the brake pads engage and apply a braking force to a brake rotor. The brake pad wear system includes a permanent magnet attached to the floating caliper. The permanent magnet generates a magnetic field and being positioned on the floating caliper so that the TPM sensor of the wheel passes through the magnetic field as the wheel rotates during vehicle operation. The system also includes a field sensor implemented in the TPM sensor. The field sensor detects the magnetic field as the TPM sensor passes through the magnetic field. The system further includes a ferromagnetic target mounted to the piston. The target has a portion positioned to move between the magnet and the TPM sensor in response to brake pad wear to attenuate the strength of the magnetic field acting on the TPM sensor.

Dependencies are inferred from the claim text.