US3874481A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic adjuster for a shoe-drum brake
Assignee: Girling Ltd
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Filing: 1973-10-05
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Granted: 1975-04-01
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Expires: 1993-10-05
Abstract
Abstract In an automatic adjuster for a shoe-drum brake in which a twopart strut of adjustable length extends between the shoes adjacent to their actuated ends one part of the strut is formed by a bell-crank lever pivoted on a pin having limited movement relative to the other part which carries a non-rotatable peripherally toothed stud, and one arm of the lever is engaged in a clearance opening in a web of a shoe while the other arm has an arcuate toothed edge resiliently urged into engagement with the stud.
Inventors
- 👤 Hugh Grenville Margetts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:24
CPC Classifications
F; F16; F16D; F16D51/00; F16D51/16; F16D51/18; F16D51/20; F16D65/00; F16D65/38; F16D65/40; F16D65/52
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
193 words
An automatic adjuster for a shoe-drum brake in which arcuate shoes mounted in a stationary back-plate are adapted to be separated at one end to bring them into engagement with a rotatable drum, and as the shoe linings wear the effective length of a two-part strut extending between the shoes adjacent to their actuated ends is automatically increased to compensate for wear, whereIn one part of said strut comprises a bell-crank lever mounted to pivot on a pin passing through a clearance opening in the other part of the strut, a first arm of said lever being received in a slot of limited length in said shoe web and a portion of said arm being formed as a cam which, in the off position of the brake, engages with the radially outer end of said slot to define the off position of the shoe, and a second arm of said lever terminating in an arcuate toothed edge, a peripherally toothed stud is non-rotatably mounted on said other part of the strut, and resilient means are provided for urging said arcuate edge of the second arm of the lever into engagement with said stud.
Claim 2
Dependent Claim
193 words
An automatic adjuster for a shoe-drum brake in which arcuate shoes mounted in a stationary back-plate are adapted to be separated at one end to bring them into engagement with a rotatable drum, and as the shoe linings wear the effective length of a two-part strut extending between the shoes adjacent to their actuated ends is automatically increased to compensate for wear, whereIn one part of said strut comprises a bell-crank lever mounted to pivot on a pin passing through a clearance opening in the other part of the strut, a first arm of said lever being received in a slot of limited length in said shoe web and a portion of said arm being formed as a cam which, in the off position of the brake, engages with the radially outer end of said slot to define the off position of the shoe, and a second arm of said lever terminating in an arcuate toothed edge, a peripherally toothed stud is non-rotatably mounted on said other part of the strut, and resilient means are provided for urging said arcuate edge of the second arm of the lever into engagement with said stud.
Claim 3
Dependent Claim
59 words
An automatic adjuster for a shoe-drum brake as in claim 1 wherein the strut incorporates a manually operable lever adapted to engage one shoe and by reaction on this strut to apply the other shoe, the load being applied to said other shoe through and in alignment with the toothed engagement between said bell-crank lever and said toothed stud.
Claim 4
Dependent Claim
45 words
An automatic adjuster for a shoe-drum brake as in claim 1 wherein the strut incorporates a manually operable lever for applying the brake from a hand-lever and the two-part strut and said lever form an independent sub-assembly for fitting into and removal from the brake.
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) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |