US3811538A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brake adjusters
Assignee: Girling Ltd
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Filing: 1973-03-19
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Granted: 1974-05-21
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Expires: 1993-03-19
Abstract
Abstract A slack adjuster for a drum or disc brake has a housing, preferably in the form of a cylinder body; a first member, preferably a hydraulic piston, slidable in the housing and a second or strut member normally resting against a stop in the housing. A non-reversible screw-threaded connection between the first and second members comprises an internal thread on the former and an external thread on the latter. The adjuster includes a screw member fixed relative to the housing and a drive ring member. A reversible screw-thread connection is formed by an external thread on the screw member and an internal thread on the drive ring member. Mating clutch surfaces are provided on the second member and the drive ring and are normally urged towards one another. The normal brake slack is accommodated by axial clearance, preferably at the reversible screw-thread connection. When lining wear has taken place the axial clearance is taken up and slight rotation occurs at the reversible screw-thread. Upon brake release, slight rotation occurs in the opposite direction and this is transmitted to the non-reversible screw-thread connection via the clutch surfaces.
Inventors
- 👤 G Farr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:20
CPC Classifications
F; F16; F16D; F16D59/00; F16D59/02; F16D65/00; F16D65/14; F16D65/16; F16D65/22; F16D65/28; F16D65/38; F16D65/40; F16D65/52; F16D65/56; F16D65/561; F16D2121/00; F16D2121/02; F16D2121/12; F16D2125/00; F16D2125/18; F16D2125/58; F16D2125/66
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
169 words
A slack adjuster for a brake system comprising in combination: a housing; a first member slidable in said housing and having an internal screw-thread thereon; a second member having thereon an external screw-thread mating with said internal thread to form a non-reversible screw-thread connection; a stop in said housing, said second member having a normally resting position in which it lies against said stop in said housing, said second member being rotatable relatively to said first member to adjust the axial resting position of said first member relative to said housing; a screw member axially and rotatably fixed relative to said housing and having an external screw-thread thereon; a drive ring member having thereon an internal screwthread mating with the last-mentioned external thread to form a reversible screw-thread connection; and mating clutch surfaces on said second member and said drive ring member, said mating clutch surfaces being urged towards one another, the normal brake slack being accommodated by axial clearance provided at at least one of said screw-thread connections.
Claim 2
Dependent Claim
169 words
A slack adjuster for a brake system comprising in combination: a housing; a first member slidable in said housing and having an internal screw-thread thereon; a second member having thereon an external screw-thread mating with said internal thread to form a non-reversible screw-thread connection; a stop in said housing, said second member having a normally resting position in which it lies against said stop in said housing, said second member being rotatable relatively to said first member to adjust the axial resting position of said first member relative to said housing; a screw member axially and rotatably fixed relative to said housing and having an external screw-thread thereon; a drive ring member having thereon an internal screwthread mating with the last-mentioned external thread to form a reversible screw-thread connection; and mating clutch surfaces on said second member and said drive ring member, said mating clutch surfaces being urged towards one another, the normal brake slack being accommodated by axial clearance provided at at least one of said screw-thread connections.
Claim 3
Dependent Claim
24 words
A slack adjuster according to claim 1 further comprising means resiliently biassing said drive ring member against said clutch surface on said second member.
Claim 4
Dependent Claim
25 words
A slack adjuster according to claim 2 in which said resilient bias means comprises a compression spring disposal between said screw and drive ring members.
Claim 5
Dependent Claim
16 words
A slack adjuster according to claim 1, in which said clutch surfaces comprise conical friction surfaces.
Claim 6
Dependent Claim
25 words
A slack adjuster according to claim 1 in which said reversible screw-thread connection has axial clearance at which the normal brake slack is accommodated exclusively.
Claim 7
Dependent Claim
26 words
A slack adjuster according to claim 5 further comprising resilient means biassing said second member to take up any axial clearance at said non-reversible screw-thread connection.
Claim 8
Dependent Claim
35 words
A slack adjuster according to claim 6 in which said resilient means is operative between said second and screw members and serves to hold said screw member in a fixed position relative to said housing.
Claim 9
Dependent Claim
28 words
A slack adjuster according to claim 1 further comprising resilient means biassing said screw member to hold said screw member in a fixed position relative to said housing.
Claim 10
Dependent Claim
36 words
A slack adjuster according to claim 8 in which said screw member is biassed by said resilient means against said housing stop to prevent rotation and axial displacement of said screw member relative to said housing.
Claim 11
Dependent Claim
34 words
A slack adjuster according to claim 1 in which said housing comprises a hydraulic actuator cylinder body having a cylinder bore and said first member comprises an actuator piston slidable in said cylinder bore.
Claim 12
Dependent Claim
18 words
A slack adjuster according to claim 10 in which said stop comprises an internal collar in said housing.
Claim 13
Dependent Claim
31 words
A slack adjuster according to claim 10 in which said cylinder body is double-ended and houses two said opposed hydraulic pistons and two said slack adjusters associated respectively with said pistons.
Claim 14
Dependent Claim
44 words
In a drum brake having a pair of brake shoes; a slack adjuster according to claim 12 in which said double-ended cylinder body is disposed between adjacent ends of said pair of brake shoes, each said piston acting on a respective brake shoe end.
Claim 15
Dependent Claim
17 words
A slack adjuster according to claim 13 which comprises fixed abutments for the other brake shoe ends.
Claim 16
Dependent Claim
17 words
A slack adjuster according to claim 13 which comprises a strap interconnecting the other brake shoe ends.
Claim 17
Dependent Claim
19 words
A slack adjuster according to claim 13 which comprises a further actuator acting between the other brake shOe ends.
Claim 18
Dependent Claim
27 words
A slack adjuster according to claim 16 in which said further actuator comprises a hydraulic actuator having opposed pistons operative respectively on said other brake shoe ends.
Claim 19
Dependent Claim
15 words
A slack adjuster according to claim 16 in which said further actuator comprises a ''''roller-expander.''''
Claim 20
Dependent Claim
19 words
A slack adjuster according to claim 18 which further comprises hydraulic cylinder and piston means for operating said ''''roller-expander.''''
Claim 21
Dependent Claim
30 words
A slack adjuster according to claim 18 which further comprises a brake spring for operating said ''''roller-expander'''' and a fluid-operated piston for compressing said brake spring to release said ''''roller-expander.''''
Claim 22
Dependent Claim
90 words
In a drum brake having a pair of brake shoes: a slack adjuster according to claim 10 in which said cylinder body is disposed between adjacent ends of said pair of brake shoes and said actuator piston acts on said end of one brake shoe while the cylinder body acts as a fixed abutment for said end of the other brake shoe, and another hydraulic cylinder body containing an actuator piston and another said slack adjuster associated therewith disposed in like manner between the other ends of said brake 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) | 1977-05-20 | 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 |