US3776329A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brake wear and adjustment device
Assignee: Self Energising Disc Brakes Ltd
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Filing: 1972-02-15
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Granted: 1973-12-04
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Expires: 1992-02-15
Abstract
Abstract A device for indicating the condition of the brakes of a vehicle is provided which enables the driver to determine whether the brakes are properly adjusted and brake linings are badly worn. The device includes an electrical switch located remotely from the brake lining and which is arranged to be automatically operated to energize an indicator when the lining has worn to a predetermined extent and a second electrical switch which is arranged to be automatically operated when brake adjustment is required. Each of the switches is activatable by variation of a magnetic field.
Inventors
- 👤 F Hope
- 👤 J Pigney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:34
CPC Classifications
F; F16; F16D; F16D65/00; F16D65/14; F16D65/16; F16D65/22; F16D66/00; F16D66/02; F16D66/021; F16D66/022; F16D66/025; F16D2125/00; F16D2125/18; F16D2125/20; F16D2125/22; F16D2125/28; F16D2125/30; F16D2125/44; F16D2125/56
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
192 words
A device for indicating the operating condition of a vehicle brake assembly mounted on an axle housing and having a brake lining and a cam shaft operated by a piston rod, said device comprising: a. a first electrical switch located remotely from and without physical contact with the brake lining, b. said first switch being automatically operated to energize an indicator when the brake lining has worn to a predetermined extent, c. a second electrical switch which is automatically operated to energize an indicator when brake adjustment is required, d. at least one of said switches is associated with a magnetic element, e. said switch and magnetic element being non-movable with respect to each other, f. a shielding element attached to said cam shaft so that it is movably mounted with respect to said switch and magnetic element to an extent dependent upon the brake lining wear or the condition of brake adjustment to control the magnetic field produced by the magnetic element and acting on the switch, and g. a bi-furcated support member attached to said axle housing, h. said associated switch and magnetic element being carried by said bi-furcated support.
Claim 2
Independent Claim
192 words
A device for indicating the operating condition of a vehicle brake assembly mounted on an axle housing and having a brake lining and a cam shaft operated by a piston rod, said device comprising: a. a first electrical switch located remotely from and without physical contact with the brake lining, b. said first switch being automatically operated to energize an indicator when the brake lining has worn to a predetermined extent, c. a second electrical switch which is automatically operated to energize an indicator when brake adjustment is required, d. at least one of said switches is associated with a magnetic element, e. said switch and magnetic element being non-movable with respect to each other, f. a shielding element attached to said cam shaft so that it is movably mounted with respect to said switch and magnetic element to an extent dependent upon the brake lining wear or the condition of brake adjustment to control the magnetic field produced by the magnetic element and acting on the switch, and g. a bi-furcated support member attached to said axle housing, h. said associated switch and magnetic element being carried by said bi-furcated support.
Claim 3
Dependent Claim
40 words
A device as defined in claim 1 wherein a further shielding element is attached to the operating piston rod, a bracket is attached to said axle housing, and a further associated switch and magnetic element are carried by said bracket.
Claim 4
Dependent Claim
155 words
An indicatiNg device for use in a vehicle brake drum assembly having a brake mounted on an axle housing and operated by movement of an actuating rod and rotation of a cam shaft, said indicating device comprising: a. a first electrical indicator means, b. a first electrical switch electrically connected to to said first indicator means and being activatable by variation of a magnetic field, c. said first electrical switch being arranged to be activated by excessive movement of said brake actuating rod whereby said first indicator means is energized automatically when brake adjustment is required, d. a second electrical indicator means, and e. a second electrical switch activatable by variation of a magnetic field, f. said second electrical switch being located outside the brake drum and being arranged to be activated by excessive angular movement of said cam shaft whereby said second indicator means is energized automatically when the brake lining is unduly worn.
Claim 5
Dependent Claim
155 words
An indicatiNg device for use in a vehicle brake drum assembly having a brake mounted on an axle housing and operated by movement of an actuating rod and rotation of a cam shaft, said indicating device comprising: a. a first electrical indicator means, b. a first electrical switch electrically connected to to said first indicator means and being activatable by variation of a magnetic field, c. said first electrical switch being arranged to be activated by excessive movement of said brake actuating rod whereby said first indicator means is energized automatically when brake adjustment is required, d. a second electrical indicator means, and e. a second electrical switch activatable by variation of a magnetic field, f. said second electrical switch being located outside the brake drum and being arranged to be activated by excessive angular movement of said cam shaft whereby said second indicator means is energized automatically when the brake lining is unduly worn.
Claim 6
Dependent Claim
54 words
An indicating device as defined in claim 3 wherein at least one of said first and second electrical switches is associated with a magnetic element, said switch and said magnetic element being movable with respect to each other by an extent dependent upon either the brake lining wear or the condition of brake adjustment.
Claim 7
Dependent Claim
40 words
An indicating device as defined in claim 4 wherein the magnetic element is attached to the cam shaft of the brake drum assembly so as to be adjustable relative thereto and said switch being fixedly attached to said axle housing.
Claim 8
Dependent Claim
83 words
An indicating device as defined in claim 3 wherein at least one of said first and second electrical switches is associated with a magnetic element, said switch and said magnetic element being non-movable with respect to each other, a shielding element being movably mounted with respect to said switch and said magnetic element to an extent dependent upon the brake lining wear or the condition of brake adjustment to control the magnetic field produced by the magnetic element and acting on the switch.
Claim 9
Dependent Claim
41 words
An indicating device as defined in claim 6 wherein said shielding element is attached to said cam shaft of the brake drum assembly, the associated switch and magnetic element being carried by a bi-furcated support member attached to said axle housing.
Claim 10
Dependent Claim
41 words
An indicating device as defined in claim 7 wherein a further shielding element is attached to said actuating rod of the brake drum assembly, an associated switch and magnetic element are each carried by a bracket attached to said axle housing.
Claim 11
Dependent Claim
47 words
An indicating device as defined in claim 3 wherein at least one of said first or second switches includes relatively movable contacts which only engage one another to energize the associated indicator means when the brake lining or brake adjustment of said brake drum assembly require attention.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-03 | 1977-06-04 | 1977-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-03 | 1981-06-04 | 1981-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-03 | 1985-06-04 | 1985-12-04 | $7700.00 | Window Closed / Lapsed |