US4290470A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Porous tire tread and method of bonding discrete particles to form same
Assignee: BTR Industries Ltd
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Filing: 1980-03-06
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Granted: 1981-09-22
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Expires: 2000-03-06
Abstract
Abstract An unpatterned (grooveless) porous tire tread and a pneumatic tire incorporating the porous tread, together with methods of manufacturing the tire tread as a separate item and as an integral part of the tire are described. The tire tread has numerous randomly orientated and randomly distributed interconnected passages extending from the surface substantially throughout the tread. These passages provide water drainage paths preventing build-up of water between the tire tread and a wet road. The tire tread is preferably manufactured by bonding particulated elastomeric material with a binder mixture that forms a polymer upon curing. Whether formed separately or integrally with a tire, the tread mould is unpatterned.
Inventors
- 👤 Arthur R. Williams
- 👤 Gareth T. Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:53
CPC Classifications
B; B60; B60C; B60C11/00; B60C11/03; B60C11/032; B60C11/14; Y; Y10; Y10S; Y10S152/00; Y10S152/902; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
132 words
An unpatterned grooveless tire tread for a motor vehicle tire, wherein the tread comprises an assembly of numerous discrete particles of elastomeric material bonded together to form a cohesive nonsolid mass with adjacent particles bonded together only at separated portions thereof, and intermediate said bonded portions, the particles being spaced-apart to provide passages which are randomly distributed and randomly oriented, said passages extending substantially throughout the tread, including from a highway-contacting surface of the tread, said passages constituting voids in the tread, the total void content of the tread being in the range from 10% to 60% of the overall volume of the tread, such that in use of a tire incorporating said tread, said passages provide for drainage of water away from the portion of tread surface contacting a wet highway.
Claim 2
Dependent Claim
132 words
An unpatterned grooveless tire tread for a motor vehicle tire, wherein the tread comprises an assembly of numerous discrete particles of elastomeric material bonded together to form a cohesive nonsolid mass with adjacent particles bonded together only at separated portions thereof, and intermediate said bonded portions, the particles being spaced-apart to provide passages which are randomly distributed and randomly oriented, said passages extending substantially throughout the tread, including from a highway-contacting surface of the tread, said passages constituting voids in the tread, the total void content of the tread being in the range from 10% to 60% of the overall volume of the tread, such that in use of a tire incorporating said tread, said passages provide for drainage of water away from the portion of tread surface contacting a wet highway.
Claim 3
Dependent Claim
31 words
A tire tread according to claim 1 wherein the average cross-sectional area of the passages is large relative to the cross-sectional area of adjacent tread material between and defining the passages.
Claim 4
Dependent Claim
31 words
A tire tread according to claim 1 wherein the average cross-sectional area of the passages is small relative to the cross-sectional area of adjacent tread material between and defining the passages.
Claim 5
Dependent Claim
21 words
A tire tread according to claim 1 wherein the void content is substantially uniformly distributed throughout the volume of the tread.
Claim 6
Dependent Claim
26 words
A tire tread according to claim 1 wherein the void content varies between different regions of the tread substantially according to a predetermined void distribution pattern.
Claim 7
Dependent Claim
41 words
A tire tread according to claim 5 wherein the void distribution pattern is such that the void content decreases with increasing distance radially inwardly from the tread surface which will contact a road when the tread is part of a tire.
Claim 8
Dependent Claim
41 words
A tire tread according to claim 5 wherein the void distribution pattern is such that the void content increases with increasing distance radially inwardly from the tread surface which will contact a road when the tread is part of a tire.
Claim 9
Dependent Claim
31 words
A tire tread according to claim 5 wherein the void distribution pattern is such that the void content decreases with increasing distance laterally inwardly from the lateral edges of the tread.
Claim 10
Dependent Claim
31 words
A tire tread according to claim 5 wherein the void distribution pattern is such that the void content increases with increasing distance laterally inwardly from the lateral edges of the tread.
Claim 11
Dependent Claim
15 words
A tire tread according to claim 1 wherein the numerous discrete particles are irregularly shaped.
Claim 12
Dependent Claim
16 words
A tire tread according to claim 10 wherein said particles have at least two different sizes.
Claim 13
Dependent Claim
26 words
A tire tread according to claim 10 wherein said particles have a volumetric size or sizes in the range from 6.5×10 -5 cc to 15 cc.
Claim 14
Dependent Claim
26 words
A tire tread according to claim 10 wherein said particles have a hardness or a range of hardnesses in the range 30 to 85 Shore A.
Claim 15
Dependent Claim
15 words
A tire tread according to claim 1 wherein the numerous discrete particles are regularly shaped.
Claim 16
Dependent Claim
15 words
A tire tread according to claim 1 wherein said particles are bonded by interparticle fusion.
Claim 17
Dependent Claim
33 words
A tire tread according to claim 15 wherein said particles are of uncured rubber and said interparticle fusion comprises the cross-linking of the material of adjacent particles at their points of mutual contact.
Claim 18
Dependent Claim
21 words
A tire tread according to claim 1 wherein said particles are mutually bonded into a cohesive mass by a binder matrix.
Claim 19
Dependent Claim
46 words
A tire tread according to claim 17 wherein the binder matrix is composed of a binder material which solidifies upon curing to form the binder matrix with the particles thereby bound together, said binder material being a reaction mixture which forms a polymer upon being cured.
Claim 20
Dependent Claim
19 words
A tire tread according to claim 18 wherein said reaction mixture comprises hydroxyl-tipped liquid polybutadiene, and liquid methylene-bis-aniline di-isocyanate.
Claim 21
Dependent Claim
20 words
A tire tread according to claim 18 wherein said reaction mixture comprises an isocyanate-functional polyurethane prepolymer, and a diamine curative.
Claim 22
Dependent Claim
25 words
A tire tread according to claim 18 wherein said reaction mixture comprises ethylene oxide tipped polypropylene glycol, ethylene glycol, triemthylol propane, and liquified diphenylmethane 4,4'-di-isocyanate.
Claim 23
Dependent Claim
14 words
A pneumatic tire comprising a carcass, and a tire tread according to claim 1.
Claim 24
Dependent Claim
27 words
A pneumatic tire according to claim 22, in the form of a radial tire, and incorporatng a tread-reinforcing breaker disposed between said carcass and said tire tread.
Claim 25
Dependent Claim
20 words
A tire tread according to claim 1, wherein said particles have a volumetric size of at least 5×10 -4 cc.
Claim 26
Dependent Claim
26 words
A tire according to claim 25, wherein said particles have a volumetric size or sizes in the range from 5×10 -4 cc to 4×10 -2 cc.
Claim 27
Dependent Claim
31 words
A tire tread according to claim 1, wherein said particles are of granulated rubber of hardness in the range 60-70 Shore A, of irregular shapes and sizes up to 0.5 cc.
Claim 28
Dependent Claim
36 words
A tire tread according to claim 1, wherein said particles are of granulated rubber of hardnesses in the range 60-70 Shore A, of irregular shapes and with an average particle size graded to 10 B.S. mesh.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-09-21 | 1985-03-23 | 1985-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-21 | 1989-03-23 | 1989-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-21 | 1993-03-23 | 1993-09-22 | $7700.00 | Window Closed / Lapsed |