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US 12,631,234 B2Granted
Drum brake
AssigneeMeritor Heavy Vehicle Braking Systems (UK) Limited
InventorsAlex Szafnauer, Sean Cleary
Life of this patent
Estimating the term…
Abstract
A drum brake assembly that includes a brake drum, first and second brake shoes, a cam shaft, a first tappet, a second tappet, and a wear adjuster mechanism. The wear adjuster mechanism has a cross shaft and a sensor. The sensor is configured to detect rotation of the cross shaft about a longitudinal axis to monitor wear of the first and second brake shoes and a braking surface of the brake drum.
Claims13
A drum brake assembly comprising:
- a brake drum;
- first and second brake shoes that are moveable towards a braking surface of the brake drum during a braking operation;
- a cam shaft that transmits braking force from an actuator to apply the brake;
- a first tappet and a second tappet that transmit braking force from the cam shaft to the first and second brake shoes;
- a wear adjuster mechanism that adjusts the first and second tappets to address wear of the first and second brake shoes and the braking surface of the brake drum, the wear adjuster mechanism including a cross shaft that transmits rotational force from the first tappet to the second tappet;
- a sensor that detects rotation of the cross shaft about a longitudinal axis of the cross shaft in order to monitor wear of the first and second brake shoes and the braking surface of the brake drum;
- and
- a rotation indicator that indicates rotation of the cross shaft to the sensor, wherein the rotation indicator includes a first portion that moves with the cross shaft, and a second portion engaged with the first portion such that movement of the first portion causes proportional movement of the second portion, wherein the sensor detects movement of the second portion,
- wherein the first portion comprises a threaded portion of the cross shaft,
- wherein the second portion comprises a collar mounted on the cross shaft, and an arm, wherein the collar comprises an internal thread that engages the threaded portion and a radial projection configured to engage the arm such that rotation of the cross shaft causes axial movement of the collar with respect to the cross shaft and pivoting of the arm about a first end of the arm, and wherein the sensor is configured to detect pivoting of the arm.
7 more elements
A method of monitoring wear of brake shoes and a braking surface of a drum brake assembly, the method comprising the steps of:
- providing the drum brake assembly that includes:
- a brake drum;
- first and second brake shoes to be moved towards a braking surface of the brake drum during a braking operation;
- a cam shaft that transmits braking force from an actuator to apply the brake;
- a first tappet and a second tappet that transmit braking force from the cam shaft to the first and second brake shoes;
- a wear adjuster mechanism that adjusts the first and second tappets to address wear of the first and second brake shoes and the braking surface of the brake drum, the wear adjuster mechanism including a cross shaft that transmits rotational force from the first tappet to the second tappet;
- a sensor that detects rotation of the cross shaft about a longitudinal axis of the cross shaft in order to monitor wear of the first and second brake shoes and the braking surface of the brake drum;
- a rotation indicator that indicates rotation of the cross shaft to the sensor, wherein the rotation indicator includes a first portion that moves with the cross shaft, and a second portion engaged with the first portion such that movement of the first portion causes proportional movement of the second portion, wherein the sensor detects movement of the second portion;
- wherein the first portion comprises a threaded portion of the cross shaft;
- wherein the second portion comprises a collar mounted on the cross shaft, and an arm, wherein the collar comprises an internal thread that engages the threaded portion and a radial projection configured to engage the arm such that rotation of the cross shaft causes axial movement of the collar with respect to the cross shaft, and pivoting of the arm about a first end of the arm, and wherein the sensor is configured to detect pivoting of the arm;
- a control system that monitors wear of the first and second brake shoes and the braking surface;
- wherein the control system calculates wear from cumulative motion of the cross shaft during multiple braking operations;
- detecting motion of the cross shaft via the sensor;
- and
- using the control system to calculate wear from cumulative motion of the cross shaft.
12 more elements
A drum brake assembly comprising:
- a brake drum;
- first and second brake shoes to be moved towards a braking surface of the brake drum during a braking operation;
- a cam shaft that transmits braking force from an actuator to apply the brake;
- a first tappet and a second tappet that transmit braking force from the cam shaft to the first and second brake shoes;
- a wear adjuster mechanism that adjusts the first and second tappets to address wear of the first and second brake shoes and the braking surface of the brake drum, the wear adjustment mechanism including a cross shaft that transmits rotational force from the first tappet to the second tappet;
- a sensor that detects rotation of the cross shaft about a longitudinal axis of the cross shaft in order to monitor wear of the first and second brake shoes and the braking surface of the brake drum;
- and
- a rotation indicator that indicates rotation of the cross shaft to the sensor, wherein the rotation indicator includes a first portion that moves with the cross shaft, and a second portion engaged with the first portion such that movement of the first portion causes proportional movement of the second portion, wherein the sensor detects movement of the second portion,
- wherein the first portion comprises a threaded portion of the cross shaft,
- wherein the second portion comprises a collar mounted on the cross shaft, and an arm, wherein the collar comprises an internal thread that engages the threaded portion and a radial projection configured to engage the arm such that rotation of the cross shaft causes axial movement of the collar with respect to the cross shaft and pivoting of the arm about a first end of the arm, and wherein the sensor is configured to detect pivoting of the arm,
- and further comprising a control system that monitors wear of the first and second brake shoes and the braking surface, wherein the control system calculates wear from cumulative motion of the cross shaft during multiple braking operations.
8 more elements
Dependencies are inferred from the claim text.