Patent US4437547A successfully refreshed from Google Patents.
US4437547A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Friction lining wear indicators for shoe-drum brakes
Assignee: ZF International UK Ltd
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Filing: 1982-04-29
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Granted: 1984-03-20
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Expires: 2002-04-29
Abstract
Abstract A friction lining wear indicator for shoe-drum brakes comprising a sensor mounted on a brake shoe, which actuates an indicator when the thickness of a friction lining carried by a platform of the shoe for engagement with a drum is less than a predetermined value. In order to locate the sensor at the most effective position without machining the lining or fastening the sensor permanently to the shoe, the sensor is located by a mounting device located in a depression in an edge of the platform, and co-operates with the shoe to retain the sensor adjacent the lining. The mounting device comprises a plastics plug, or a resilient clip, and the retaining device is releasable. The sensor comprises a wire loop or a pressed insulation-coated metal strip, and may be integral with the mounting device. The sensor and the drum are connected in a circuit with the indicator which is actuated when the sensor touches the drum.
Inventors
- 👤 George A. Harmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:22
CPC Classifications
F; F16; F16D; F16D65/00; F16D65/02; F16D65/04; F16D65/08; F16D66/00; F16D66/02; F16D66/021; F16D66/022; F16D66/023; F16D66/024
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
184 words
A friction lining wear indicator for a brake shoe of a shoe-drum brake, said brake shoe including a platform and a friction lining carried by said platform for engagement with a rotatable drum, said platform having axial edges and a depression formed in one of said axial edges by displacement of a portion of said one edge in a radial direction away from said friction lining, said friction lining having a first face for engagement with said platform and a second face for engagement with said drum, a portion of said first face of said friction lining in the region of said displaced portion of said edge being unmodified, said friction lining wear indicator comprising a sensor mounted on said brake shoe, an indicating means adapted to be actuated when the thickness of said friction lining is less than a predetermined value, mounting means for mounting said sensor on said shoe, said mounting means being located in said depression, and retaining means associated with said mounting means for co-operating with said shoe to retain said sensor in a position of use adjacent said lining.
Claim 2
Dependent Claim
184 words
A friction lining wear indicator for a brake shoe of a shoe-drum brake, said brake shoe including a platform and a friction lining carried by said platform for engagement with a rotatable drum, said platform having axial edges and a depression formed in one of said axial edges by displacement of a portion of said one edge in a radial direction away from said friction lining, said friction lining having a first face for engagement with said platform and a second face for engagement with said drum, a portion of said first face of said friction lining in the region of said displaced portion of said edge being unmodified, said friction lining wear indicator comprising a sensor mounted on said brake shoe, an indicating means adapted to be actuated when the thickness of said friction lining is less than a predetermined value, mounting means for mounting said sensor on said shoe, said mounting means being located in said depression, and retaining means associated with said mounting means for co-operating with said shoe to retain said sensor in a position of use adjacent said lining.
Claim 3
Dependent Claim
16 words
A friction lining wear indicator as claimed in claim 1, wherein said retaining means is releasable.
Claim 4
Dependent Claim
45 words
A friction lining wear indicator as claimed in claim 1 or claim 2, wherein said mounting means comprises a plug of plastics material, and said retaining means comprises at least one lip, said lip engaging with said shoe to retain said plug in said depression.
Claim 5
Dependent Claim
19 words
A friction lining wear indicator as claimed in claim 1, wherein said sensor is integral with said mounting means.
Claim 6
Dependent Claim
23 words
A friction lining wear indicator as claimed in claim 1, wherein said sensor comprises a loop of wire separate from said mounting means.
Claim 7
Dependent Claim
19 words
A friction lining wear indicator as claimed in claim 1, wherein said sensor comprises a pressed insulation-coated metal strip.
Claim 8
Dependent Claim
42 words
A friction lining wear indicator as claimed in claim 1, wherein said mounting means is a one-piece plastics plug, said plug being located in a sheared depression in said platform, and said sensor comprises a loop of wire separate from said plug.
Claim 9
Dependent Claim
43 words
A friction lining wear indicator as claimed in claim 1, wherein said mounting means comprises a two-piece plastics plug, said plug being located in a sheared depression in said platform, and said sensor comprises a pressed insulation-coated metal strip separate from said plug.
Claim 10
Dependent Claim
38 words
A friction lining wear indicator as claimed in claim 1, wherein said mounting means comprises a one-piece plastics plug, said plug being located in a sheared depression in said platform, and said sensor is integral with said plug.
Claim 11
Dependent Claim
43 words
A friction lining wear indicator as claimed in claim 1, wherein said mounting means comprises a plug of plastics material, said plug being located in a non-sheared depression in the platform, and said plug coats a pressed metal strip which comprises said sensor.
Claim 12
Dependent Claim
48 words
A friction lining wear indicator as claimed in claim 1, wherein said sensor and said drum with which said lining is adapted to engage are connected in series in a circuit containing said indicating means, such that when said sensor touches said drum said indicating means is actuated.
Claim 13
Dependent Claim
180 words
A shoe-drum brake comprising a rotatable drum, and at least one brake shoe comprising an arcuate web and a platform and a friction lining carried by said platform for engagement with said drum, said platform having axial edges and a depression formed in one of said axial edges by displacement of a portion of said one edge in a radial direction away from said friction lining, said friction lining having a first face for engagement with said platform and a second face for engagement with said drum, a portion of said first face of said friction lining in the region of said displaced portion of said edge being unmodified, said brake also incorporating a friction lining wear indicator, said indicator comprising a sensor mounted on said shoe, an indicating means adapted to be actuated when the thickness of said lining is less than a predetermined value, mounting means for mounting said sensor in said depression, and retaining means associated with said mounting means for co-operating with said shoe to retain said sensor in a position of use adjacent said lining.
Claim 14
Dependent Claim
180 words
A shoe-drum brake comprising a rotatable drum, and at least one brake shoe comprising an arcuate web and a platform and a friction lining carried by said platform for engagement with said drum, said platform having axial edges and a depression formed in one of said axial edges by displacement of a portion of said one edge in a radial direction away from said friction lining, said friction lining having a first face for engagement with said platform and a second face for engagement with said drum, a portion of said first face of said friction lining in the region of said displaced portion of said edge being unmodified, said brake also incorporating a friction lining wear indicator, said indicator comprising a sensor mounted on said shoe, an indicating means adapted to be actuated when the thickness of said lining is less than a predetermined value, mounting means for mounting said sensor in said depression, and retaining means associated with said mounting means for co-operating with said shoe to retain said sensor in a position of use adjacent said lining.
References Cited (Backward Citations)
US3783979A
Cited
FR2260724B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-03-20 | 1987-09-19 | 1988-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-20 | 1991-09-19 | 1992-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-20 | 1995-09-19 | 1996-03-20 | $7700.00 | Window Closed / Lapsed |