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.

A brake pad wear measuring system for measuring brake pad wear for a vehicle disc brake system includes an inductive sensor operable to create a magnetic field and a target. At least one of the sensor and the target are mounted for movement along a braking axis with a component of the disc brake system. The positions of the sensor and target relative to each other changes in response to application of the disc brake system. The distance that the sensor and target move relative to each other in response to application of the disc brake system increases an amount that is equal to the total wear of the inner and outer brake pads. The sensor is responsive to the change in inductance caused by movement of the target in the magnetic field to provide a signal indicative of brake pad wear.

The present disclosure relates to a brake-wear monitoring system comprising a housing, a brake piston movable relative to the housing along a piston axis, and a sensor assembly configured to produce a sensor signal indicative of an axial position of the brake piston relative to the housing.

A brake pad wear measuring system for measuring brake pad wear for a vehicle disc brake system includes a first and second coil excitable to create a first and second magnetic field and first and second targets associated with the first and second coils. The coils and targets are configured for movement relative to each other along an axis in response to application of the disc brake system. The relative movement along the axis causes the targets to move within the magnetic fields and affect the inductance of the coils. The first coil and the first target are configured so that the inductance of the first coil is indicative of the amount of brake pad wear. The inductance of the second coil is indicative of component shifting transverse to the axis.

A system for monitoring engagement and wear in a brake include: a pin, a first marker positioned on the pin at a first location; a second marker spaced from the first marker long the pin; and a first fixed sensing arrangement. The pin extends in an axial direction parallel to the axis of rotation, and is in contact with and moves with the moveable brake pad in use. The first fixed sensing arrangement is adapted to provide a first signal when adjacent the first or second marker, and a second signal otherwise. The first and second markers and the first fixed sensing arrangement are positioned such that the second signal indicates that the brake is in the engaged position, and a change from the second signal to the first signal indicates that the moveable brake pad and the second brake pad have been worn down by a predetermined amount.

A multiple function brake caliper guide pin for use with a wireless transmitter to transmit brake wear data is disclosed. The pin is part of a brake assembly that includes a brake caliper, a caliper yoke for supporting the caliper in relation to the rotor, opposed brake pads, a wear sensor, and a brake wear sensing assembly comprising a brake caliper guide pin and a wireless transmitter system. The guide pin may be either of a two-piece or a one-piece design and includes a transmitter system attachment end and a yoke attachment end. The transmitter system includes a sensor for sensing brake pad wear and a wireless transmitter for transmitting the sensed wear to a receiver in the vehicle. The sensor may include a tether attached to a brake pad or may include a transmitter and magnet assembly fitted to one or the other of the caliper or the yoke.

A brake (1) with a device for ascertaining a wear limit, the brake (1) comprising: a pressure piece unit (10) comprising a pressure piece (12) designed to press at least one first brake body (3) and at least one second brake body (4) against each other for applying the brake; and a sensor (20) designed to detect a positional relationship between itself and a detection surface (11) of the pressure piece unit (10), wherein if the brake (1) has not reached its wear limit, the positional relationship between the sensor (20) and the detection surface (11) does not change during a movement of the pressure piece (12) in a first direction, and if the brake (1) has reached its wear limit, the positional relationship between the sensor (20) and the detection surface (11) changes during the movement of the pressure piece (12) in the first direction.

Brake wear sensors for the brake disc stacks commonly used in aircraft brake systems are disclosed. An ultrasonic transducer is employed to transmit signals to a reflective surface and to receive the reflected signals in return. The time that elapses between the transmission of the ultrasonic signal and the reception of its reflection correlates with the separation between the transducer and the reflective surface. The reflective surface is operatively connected to a pressure plate of the associated brake disc stack such that, as the stack wears, the reflective surface is displaced along with the pressure plate. That displacement correlates with brake wear. In one embodiment, the ultrasonic brake wear detector is an independent unit mounted to the brake housing, while another embodiment includes the detector as an integral portion of a brake actuator connected to such housing. A third embodiment for use with brake disc stacks exhibiting substantial wear before requiring service employs either twin cylinders, one with a piston and the other a wear pin, or a single cylinder housing a wear pin operatively fixed to the brake disc stack.

A position sensing system for a braking system has a rotor and a caliper assembly disposed at least partially around the rotor. The caliper assembly has a fixed mount bracket and a floating portion. At least two brake pads are attached to the floating portion, operable to exert a force against the rotor in response to a force through the floating portion. A first portion is coupled to the fixed mount bracket. A second portion is coupled to the floating portion such that the second portion moves in response to movement of the floating portion. A sensor assembly measures a distance between the first portion and the second portion. A wireless transmitter sends a signal from the sensor assembly to detached electronics, the signal representing the distance measured.

A method (200) for detecting the clearance of a brake (100) of a motor vehicle, in particular a utility motor vehicle, includes the following steps: reading measurement signals of a wear sensor (115) disposed on the brake (100), determining an output signal value that is representative of the non-actuated state of the brake from the measurement signals, determining an event signal value that is representative of the braking state of the brake from the measurement signals, and determining the clearance from the difference between the event signal value and the output signal value, wherein the measurement signals of the wear sensor are examined for the presence of a characteristic signal oscillation that arises as a result of bringing into contact the brake lining with the counterpart thereof that is to be braked. A controller (10) carries out the method on a brake (100).