US3633712A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vehicle brake systems
Assignee: Girling Ltd
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Filing: 1970-06-08
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Granted: 1972-01-11
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Expires: 1990-06-08
Abstract
Abstract The invention relates to an automatic slack adjuster for vehicle brakes including first and second screw elements having a reversible screw thread connection therebetween. The reversible screw thread effects automatic adjustment responsively to excess travel of the brake actuator piston whereby to automatically reduce the slack. To prevent over adjustment taking place due to brake deflection when applying the brakes heavily, the brake thrust is transmitted through friction surfaces which act as a clutch to prevent unwanted rotation at the screw thread connection.
Inventors
- 👤 Glyn Phillip Reginald Farr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:38
CPC Classifications
F; F16; F16D; F16D65/00; F16D65/38; F16D65/40; F16D65/52; F16D65/56; F16D65/567; F16D2125/00; F16D2125/18; F16D2125/20; F16D2125/22; F16D2125/26
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
167 words
In a vehicle brake system having first and second members movable relative to one another upon brake application: an automatic slack adjuster disposed between said members and comprising first and second elements associated respectively with said first and second members; a reversible screw thread connection between said screw elements; means for urging said screw elements in an axial direction relatively to one another responsively to excess travel between said members to cause one of said screw elements to advance along the other of Said screw elements and thereby reduce the brake slack; means for inhibiting reverse rotation of said first screw element; and means for preventing rotation of said second screw element, said first member being normally nonrotating, said reverse rotation inhibiting means comprising friction surfaces associated with said first screw element and said first member and urged into abutment with one another by the brake applying thrust upon brake application whereby said relative advance of said screw elements can only take place during takeup of slack.
Claim 2
Dependent Claim
167 words
In a vehicle brake system having first and second members movable relative to one another upon brake application: an automatic slack adjuster disposed between said members and comprising first and second elements associated respectively with said first and second members; a reversible screw thread connection between said screw elements; means for urging said screw elements in an axial direction relatively to one another responsively to excess travel between said members to cause one of said screw elements to advance along the other of Said screw elements and thereby reduce the brake slack; means for inhibiting reverse rotation of said first screw element; and means for preventing rotation of said second screw element, said first member being normally nonrotating, said reverse rotation inhibiting means comprising friction surfaces associated with said first screw element and said first member and urged into abutment with one another by the brake applying thrust upon brake application whereby said relative advance of said screw elements can only take place during takeup of slack.
Claim 3
Dependent Claim
50 words
An adjuster according to claim 1 further including a hydraulic actuator comprising opposed first and second relatively movable components of which the first component is associated with said first screw element, and an auxiliary mechanical actuator fitted to said second component, said mechanical actuator acting on said second screw element.
Claim 4
Dependent Claim
36 words
An adjuster according to claim 2 in which said second actuator component has a bore therein and a plunger slidably received in said bore, said mechanical actuator acting upon said second screw element through said plunger.
Claim 5
Dependent Claim
32 words
An adjuster according to claim 3 further comprising a spring acting between said second screw element and said second actuator component and urging said second screw element relatively towards said mechanical actuator.
Claim 6
Dependent Claim
61 words
An adjuster according to claim 4 further comprising a bush screwed into said second actuator component and a ring fixed to said second screw element, said spring being disposed between said brush and said ring, said second actuator component having an axially offset bore therein and said ring having an axially directed tab thereon engaging axially displaceably in said offset bore.
Claim 7
Dependent Claim
30 words
An adjuster according to claim 3 in which said mechanical actuator comprises a cam journaled in said second actuator component about an axis transverse to the axis of said component.
Claim 8
Dependent Claim
65 words
An adjuster according to claim 1 further comprising a hydraulic actuator having first and second relatively movable actuator components, said first screw element forming a part of said first actuator component and said second screw element being associated with said second actuator component, said friction surfaces being disposed relatively on said first actuator component and on said normally nonrotating member and normally abutting one another.
Claim 9
Dependent Claim
68 words
An adjuster according to claim 1 further comprising a hydraulic actuator having first and second actuator components of which the first component constitutes said normally nonrotating member and the second component is associated with said second screw element, and in which said first screw element comprises a nut, said friction surfaces being disposed respectively on said first actuator component and on said nut and normally abutting one another.
Claim 10
Dependent Claim
13 words
An adjuster according to claim 8 in which said friction surfaces are frustoconical.
Claim 11
Dependent Claim
36 words
An adjuster according to claim 8 wherein said first actuator component has a concentric bore therein and said nut is axially displaceable in said concentric bore, means being provided sealing said nut to said axial bore.
Claim 12
Dependent Claim
33 words
An adjuster according to claim 2 in which said hydraulic actuator includes a fixed body member having a through bore and in which said actuator components comprise opposed pistons slidable in said bore.
Claim 13
Dependent Claim
53 words
An adjuster according to claim 11 for a spot-type disc brake which includes a yoke slidably supported on said body member and directly and indirectly operated friction pads, said first piston acting on said directly operated pad, said second piston acting on said yoke and said yoke acting on said indirectly operated pad.
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) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |