US3799295A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vehicle drum brakes
Assignee: Girling Ltd
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Filing: 1971-09-30
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Granted: 1974-03-26
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Expires: 1991-09-30
Abstract
Abstract A brake shoe reaction strut for supporting a brake shoe against braking reaction forces, is constructed as a telescopic strut provided with pre-stressed resilient means for resisting contraction thereof. The resilient means yields under a predetermined thrust loading to permit partial retraction movement of the brake shoes to allow, for example, for thermal contraction of the drum. The strut is advantageously combined with auto-adjuster means for compensating shoe lining wear by increasing the overall length of the strut.
Inventors
- 👤 A Hill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:29
CPC Classifications
F; F16; F16D; F16D65/00; F16D65/38; F16D65/40; F16D65/52; F16D65/56; F16D65/561; F16D65/565; F16D51/00; F16D51/46; F16D51/48; F16D65/02; F16D65/04; F16D65/08; F16D65/09; F16D2125/00; F16D2125/18; F16D2125/58; F16D2125/582
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
161 words
In or for an internal shoe drum brake, a brake shoe reaction strut comprising telescopic strut means and resilient means prestressed to resist contraction of the strut means but adapted to yield to permit some contraction of said strut means under the action of a predetermined thrust applied thereto, said strut means having opposite ends adapted for connection to respective adjacent ends of opposed brake shoes, for transmitting braking reaction forces between the shoes, and adjuster means for increasing the overall length of said strut to compensate for friction lining wear, said adjuster means comprising a pair of telescopically arranged screw threaded members, one of which is adapted at its outer end for connection to one brake shoe, and the other of which forms a part of the telescopic strut means and carries at its outer end a second part of the strut means adapted for connection to the other brake shoe, said parts being urged apart by said resilient means.
Claim 2
Dependent Claim
161 words
In or for an internal shoe drum brake, a brake shoe reaction strut comprising telescopic strut means and resilient means prestressed to resist contraction of the strut means but adapted to yield to permit some contraction of said strut means under the action of a predetermined thrust applied thereto, said strut means having opposite ends adapted for connection to respective adjacent ends of opposed brake shoes, for transmitting braking reaction forces between the shoes, and adjuster means for increasing the overall length of said strut to compensate for friction lining wear, said adjuster means comprising a pair of telescopically arranged screw threaded members, one of which is adapted at its outer end for connection to one brake shoe, and the other of which forms a part of the telescopic strut means and carries at its outer end a second part of the strut means adapted for connection to the other brake shoe, said parts being urged apart by said resilient means.
Claim 3
Dependent Claim
42 words
A strut as claimed in claim 1, wherein the resilient means comprises a stack of frustro-conical spring washers arranged alternatingly as to their conicity, so that some adjacent washers abut each other at their inner peripheries and others at their outer peripheries.
Claim 4
Dependent Claim
49 words
A strut as claimed in claim 2, wherein the first mentioned screw threaded member is a threaded spindle and the other is an internally threaded tubular housing the spindle projecting from one end of the housing and the second strut part extending from the other end of the housing.
Claim 5
Dependent Claim
65 words
A strut as claimed in claim 3, wherein the resilient means is mounted concentrically over the housing and acts between a fixed abutment at the said one end of the housing and an axially movable abutment at the other end of the housing, the said movable abutment engaging the second strut part and serving to transmit thrust forces from that part to the resilient means.
Claim 6
Dependent Claim
50 words
A strut as claimed in claim 4, including means locking said movable abutment against rotation relative to said second strut part, said resilient means urging said movable abutment into frictional engagement with a portion of said housing to restrain relative rotation of said housing relative to said second strut part.
Claim 7
Dependent Claim
101 words
A brake shoe reaction strut comprising telescopic strut means and resilient means pre-stressed to resist contraction of the strut means but adapted to yield to permit some contraction of said strut means under the action of a predetermined thrust applied thereto, in combination with an internal shoe drum brake having a brake shoe supported against braking reaction forces by said strut, brake applying means for applying said brake shoe and lock actuator means for holding said shoe applied for parking purposes, said resilient means being adapted to yield to permit partial shoe retraction to accommodate thermal contraction of the brake drum.
Claim 8
Dependent Claim
101 words
A brake shoe reaction strut comprising telescopic strut means and resilient means pre-stressed to resist contraction of the strut means but adapted to yield to permit some contraction of said strut means under the action of a predetermined thrust applied thereto, in combination with an internal shoe drum brake having a brake shoe supported against braking reaction forces by said strut, brake applying means for applying said brake shoe and lock actuator means for holding said shoe applied for parking purposes, said resilient means being adapted to yield to permit partial shoe retraction to accommodate thermal contraction of the brake drum.
Claim 9
Dependent Claim
99 words
A brake shoe reaction strut comprising telescopic strut means and resilient means pre-stressed to resist contraction of the strut means but adapted to yield to permit some contraction of said strut means under the action of a predetermined thrust applied thereto, in combination with a drum brake comprising a pair of opposed brake shoes, brake applying means acting between said shoes at adjacent ends thereof and lock actuator means for holding said shoes applied after release of said applying means, said strut acting directly between said shoes at adjacent ends thereof to transmit braking reaction forces between said shoes.
Claim 10
Dependent Claim
99 words
A brake shoe reaction strut comprising telescopic strut means and resilient means pre-stressed to resist contraction of the strut means but adapted to yield to permit some contraction of said strut means under the action of a predetermined thrust applied thereto, in combination with a drum brake comprising a pair of opposed brake shoes, brake applying means acting between said shoes at adjacent ends thereof and lock actuator means for holding said shoes applied after release of said applying means, said strut acting directly between said shoes at adjacent ends thereof to transmit braking reaction forces between said shoes.
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) | 1977-03-25 | 1977-09-24 | 1978-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-25 | 1981-09-24 | 1982-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-25 | 1985-09-24 | 1986-03-26 | $7700.00 | Window Closed / Lapsed |