US3811537A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shoe drum brakes
Assignee: Girling Ltd
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Filing: 1972-09-22
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Granted: 1974-05-21
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Expires: 1992-09-22
Abstract
Abstract One part of a two-part strut of adjustable length extending between arcuate shoes of a shoe-drum brake adjacent to their actuated ends is formed by a bell-crank lever which is pivotally mounted in the other part, and one arm of the lever is engaged in a slot of limited length in a shoe web while the second arm cooperates with a toothed element rigid with said other part.
Inventors
- 👤 H Margetts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:42
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: 7
Claim 1
Independent Claim
194 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; said adjuster comprising an extensible strut having a first part having operative engagement with one of the shoes, a toothed element rigid with said first part, said strut having a second part comprising a bell-crank lever having a pivot mounted on the first part, said pivot being axially moveable relative to said first part, one arm of said bell crank having an operative connection with said second shoe, resilient means urging the other arm of said bell-crank lever into releasable engagement with said toothed element, said strut being constructed and arranged that when the separation of the shoes during brake application exceeds a predetermined value due to lining wear, the parts of the strut are moved apart until said toothed element and said other arm are disengaged and said bellcrank lever may pivot to a position wherein said other arm reengages the toothed element in the new position when the brake is released to increase the effective length of the strut.
Claim 2
Dependent Claim
194 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; said adjuster comprising an extensible strut having a first part having operative engagement with one of the shoes, a toothed element rigid with said first part, said strut having a second part comprising a bell-crank lever having a pivot mounted on the first part, said pivot being axially moveable relative to said first part, one arm of said bell crank having an operative connection with said second shoe, resilient means urging the other arm of said bell-crank lever into releasable engagement with said toothed element, said strut being constructed and arranged that when the separation of the shoes during brake application exceeds a predetermined value due to lining wear, the parts of the strut are moved apart until said toothed element and said other arm are disengaged and said bellcrank lever may pivot to a position wherein said other arm reengages the toothed element in the new position when the brake is released to increase the effective length of the strut.
Claim 3
Dependent Claim
25 words
An automatic adjuster for a shoe-drum brake as in claim 1 wherein the bell-crank lever pivot is mounted in a slot in said other part.
Claim 4
Dependent Claim
79 words
An automatic adjuster for a shoe-drum brake as in claim 1 wherein the operative connection of the first arm of the bell-crank lever with the second shoe comprises a slot of limited length in a web of the shoe with which it co-operates, and a portion of the arm is formed as a cam which, in the release position of the brake, engages with the radially outer end of the slot to define the adjusted position of the shoe.
Claim 5
Dependent Claim
52 words
An automatic adjuster for a shoe-drum brake as in claim 1 wherein the free end of the second arm of the bell-crank lever is of arcuate form and is provided with teeth complementary to those on the toothed element on the other part of the strut which is of complementary arcuate form.
Claim 6
Dependent Claim
26 words
An automatic adjuster for a shoe-drum brake as in claim 1 wherein the strut incorporates means for applying the brake mechanically for parking or emergency braking.
Claim 7
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 alighnment with the toothed engagement between said bell-crank lever and said toothed element.
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) | 1977-05-20 | 1977-11-19 | 1978-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-20 | 1981-11-19 | 1982-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-20 | 1985-11-19 | 1986-05-21 | $7700.00 | Window Closed / Lapsed |