Electronic stroke sensor for air disc brake
First Claim
1. A method of detecting a fault condition of an air disc brake, comprising the steps of:
- providing a brake actuator having a pushrod being extensible from said brake actuator for actuating a lever arm of an air disc brake;
monitoring, with a pushrod sensor, a changing length of extension of said pushrod from said brake actuator;
monitoring, with a pressure sensor, an air pressure of said brake actuator;
counting, with a dithering counter, a number of dithers of said pushrod between two positions while monitoring said length of extension of said pushrod from said brake actuator;
determining, with a processor, a low lining brake clearance condition of said air disc brake based on a combination of said counting said number of dithers of said pushrod between two positions while monitoring said changing length of extension of said pushrod and said air pressure of said brake actuator.
1 Assignment
0 Petitions
Accused Products
Abstract
A vehicle brake monitor assembly for an air disk brake includes a brake actuator having a pushrod projecting from inside a chamber of said brake actuator. The pushrod releasably actuates a lever arm of a caliper thereby moving the disk brake into a braking position when the pushrod is in an extended position and releasing the disk brake from the braking position when the pushrod is in a retracted position. The pushrod includes a pushrod shaft and a contact member biased in a telescoping relationship relative to the pushrod shaft and the lever arm of the caliper abuts the contact member counteracting the bias of the contact member. A sensor is integrated with the assembly proximate the contact member and detects movement of the pushrod relative to the lever arm and to the pushrod shaft.
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Citations
23 Claims
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1. A method of detecting a fault condition of an air disc brake, comprising the steps of:
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providing a brake actuator having a pushrod being extensible from said brake actuator for actuating a lever arm of an air disc brake; monitoring, with a pushrod sensor, a changing length of extension of said pushrod from said brake actuator; monitoring, with a pressure sensor, an air pressure of said brake actuator; counting, with a dithering counter, a number of dithers of said pushrod between two positions while monitoring said length of extension of said pushrod from said brake actuator; determining, with a processor, a low lining brake clearance condition of said air disc brake based on a combination of said counting said number of dithers of said pushrod between two positions while monitoring said changing length of extension of said pushrod and said air pressure of said brake actuator. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A vehicle brake monitor assembly comprising:
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a brake actuator having a pushrod slidably extending from a chamber of said brake actuator, said pushrod actuating a lever arm thereby moving the vehicle brake into an actuated position when said pushrod is disposed in an extended position and allowing the vehicle brake to move into a retracted position when said pushrod is disposed in a retracted position; a pressure sensor for sensing pressure from actuating a brake pedal; an optical sensor transmitting a light signal toward the pushrod and sensing an amount of reflectivity of a plurality of zones; a controller programmed to determine which of a plurality of fault conditions of said brake actuator is present dependent upon output from said pressure sensor and said optical sensor; and said controller determines a low lining clearance condition by said optical sensor by sensing a number of dithers of said pushrod between adjacent zones when said pressure sensor senses normal air pressure. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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Specification