US4690191A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radial tire with reinforcing steel cord
Assignee: Bridgestone Corp
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Filing: 1985-12-18
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Granted: 1987-09-01
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Expires: 2005-12-18
Abstract
Abstract A radial tire has a combined reinforcement consisting of a belt composed of at least three piled cord layers with steel cords buried in parallel in rubber in which the cords in each of the layers are set at a relatively small angle with respect to a tire equatorial plane and the cords in at least one pair of the adjacent cord layers are intersectingly arranged at an angle from 15° to 30° and a carcass having cords arranged substantially at right angles with respect to the tire equatorial plane. The steel cords buried in the at least one pair of the cord-intersecting cord layers other than the outermost cord layer have Young's modulus of 6,000 to 16,000 kg/mm 2 and a flexural rigidity of 150 to 250 g, and the initial stage elongation (P.L.E.) of the rubberized cords taken out from the tire is not more than 0.2%. A tire reinforcing steel cord of a two layer twisted construction is also disclosed, which cord is composed of a core consisting of from two to four steel filaments and a single sheath consisting of a plurality of the steel filaments surrounding the core in which the steel filaments have a tensile strength of not lower than 260 kg/mm 2 and a filament diameter of from 0.32 to 0.42 mm; the twisting direction of the core is reversed to that of the sheath; the twisting angle of the sheath, P2, is 72°≦P2≦80° and the core twisting angle (P1) and the sheath twisting angle P2 meet the relation of 1.0≦P1/P2≦1.1.
Inventors
- 👤 Kiyohito Kawasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 02:01
CPC Classifications
D; D07; D07B; D07B1/00; D07B1/06; D07B1/0606; D07B1/062; B; B60; B60C; B60C9/00; B60C9/18; B60C9/20; B60C9/2003; B60C9/2006; D07B1/0626; D07B2201/00; D07B2201/20; D07B2201/2015; D07B2201/2023; Y; Y10; Y10S; Y10S57/00; Y10S57/902
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
255 words
A radial tire having a combined reinforcement consisting of a belt composed of at least three piled cord layers with steel cords buried in parallel in rubber in which the cords in each of the layers are set at a relatively small angle with respect to a tire equatorial plane and the cords in at least one pair of the adjacent cord layers are intersectingly arranged at an angle from 15° to 30° and a carcass having cords arranged substantially at right angles with respect to the tire equatorial plane, wherein the steel cords buried in the at least one pair of the cord-intersecting cord layers other than the outermost cord layer have Young's modulus of 6,000 to 16,000 kg/mm 2 and a flexural rigidity of 150 to 250 g, and the initial stage elongation (P.L.E.) of the rubberized cords taken out from the tire is not more than 0.2% and said cord being a tire reinforcing steel cord of a two layer twisted construction composed of a core consisting of from two to four steel filaments and a single sheath consisting of a plurality of the steel filaments surrounding the core wherein the steel filaments have a tensile strength of not lower than 260 kg/mm 2 and a filament diameter from 0.32 to 0.42 mm; the twisting direction of the core is reversed to that of the sheath; the twisting angle of the sheath, P2, is 72°≦P2≦80° and the core twisting angle P1 and the sheath twisting angle P2 meet the relation of 1.0≦P1/P2≦1.1.
Claim 2
Dependent Claim
255 words
A radial tire having a combined reinforcement consisting of a belt composed of at least three piled cord layers with steel cords buried in parallel in rubber in which the cords in each of the layers are set at a relatively small angle with respect to a tire equatorial plane and the cords in at least one pair of the adjacent cord layers are intersectingly arranged at an angle from 15° to 30° and a carcass having cords arranged substantially at right angles with respect to the tire equatorial plane, wherein the steel cords buried in the at least one pair of the cord-intersecting cord layers other than the outermost cord layer have Young's modulus of 6,000 to 16,000 kg/mm 2 and a flexural rigidity of 150 to 250 g, and the initial stage elongation (P.L.E.) of the rubberized cords taken out from the tire is not more than 0.2% and said cord being a tire reinforcing steel cord of a two layer twisted construction composed of a core consisting of from two to four steel filaments and a single sheath consisting of a plurality of the steel filaments surrounding the core wherein the steel filaments have a tensile strength of not lower than 260 kg/mm 2 and a filament diameter from 0.32 to 0.42 mm; the twisting direction of the core is reversed to that of the sheath; the twisting angle of the sheath, P2, is 72°≦P2≦80° and the core twisting angle P1 and the sheath twisting angle P2 meet the relation of 1.0≦P1/P2≦1.1.
Claim 3
Dependent Claim
29 words
A radial tire according to claim 1, wherein the Young's modulus of the steel cords used in the cord-intersecting cord layers is from 6,000 to 13,500 kg/mm 2 .
Claim 4
Dependent Claim
42 words
A radial tire according to claim 1, which has the cord-intersecting cord layers in which the cords are buried in rubber at a buried cord internal of from 0.9 to 1.5 mm with the rubber occupying area percentage of 40 to 50%.
Claim 5
Dependent Claim
54 words
A tire according to claim 1, wherein said reinforcing cord has a two layer twisted construction of 3+9, and the filament diameter (d) is in a range from 0.34 to 0.385 mm, and the lower limit P2 and upper limit P2 of the sheath twisting angle P2 meets the following formulae, respectively: P2=10.70d+68.40 P2=17.86d+72.40
Claim 6
Dependent Claim
54 words
A tire according to claim 1, wherein said reinforcing cord has the two layer twisted construction of 2+7, and the filament diameter (d) is in a range from 0.36 to 0.42 mm and the lower limit P2 and upper limit P2 of the sheath twisting angle P2 meet the following formulae, respectively: P2=10.70d+68.15 P2=17.86d+72.40
Claim 7
Dependent Claim
54 words
A tire according to claim 1, wherein said reinforcing cord has a two layer twisted construction of 2+6, and the filament diameter (d) is in a range from 0.38 to 0.42 mm and the lower limit P2 and upper limit P2 of the sheath twisted angle (P2) meet the following formulae, respectively; P2=17.86d+71.90 P2=10.70d+67.90
Claim 8
Dependent Claim
55 words
A tire in according to claim 1, wherein said reinforcing cord has a two layer twisted construction of 4+9, and the filament diameter (d) is in a range from 0.335 to 0.38 mm and the lower limit P2 and upper limit P2 of the sheath twisting angle P2 meet the following formulae, respectively: P2=10.70d+68.40 P2=17.86d+72.40
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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) | 1990-08-31 | 1991-03-02 | 1991-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-31 | 1995-03-02 | 1995-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-31 | 1999-03-02 | 1999-09-01 | $7700.00 | Window Closed / Lapsed |