US4520857A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High-durable pneumatic radial tires
Assignee: Bridgestone Corp
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Filing: 1983-11-08
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Granted: 1985-06-04
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Expires: 2003-11-08
Abstract
Abstract A high-durable pneumatic radial tire is disclosed. In the tire of this type, steel cords each made from particular steel filaments are used in at least one of belt and carcass. This steel filament has a pearlite structure having an average value of interlamellar distance between cementites of 300-500 Å, and a tensile strength of not less than 220 kgf/mm 2 .
Inventors
- 👤 Takao Ogino
- 👤 Yoichi Watanabe
- 👤 Shigehisa Sano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:45
CPC Classifications
D; D07; D07B; D07B1/00; D07B1/06; D07B1/0606; D07B1/066; B; B60; B60C; B60C9/00; B60C9/0007; C; C21; C21D; C21D9/00; C21D9/52; C21D9/525; D07B2205/00; D07B2205/30; D07B2205/3021; D07B2205/3025; D07B2205/3035
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
92 words
In a high-durable pneumatic radial tire comprising a tread portion, a pair of side portions extending from said tread portion, a pair of bead portions extending from said side portions and a carcass reinforced with a belt embedded in said tread portion, the improvement wherein steel cords each obtained by twisting plural steel filaments with a pearlite structure having an average value of interlamellar distance between cementites of 300-500 Å and a tensile strength of not less than 220 kg/mm 2 are used in at least one of said belt and carcass.
Claim 2
Dependent Claim
92 words
In a high-durable pneumatic radial tire comprising a tread portion, a pair of side portions extending from said tread portion, a pair of bead portions extending from said side portions and a carcass reinforced with a belt embedded in said tread portion, the improvement wherein steel cords each obtained by twisting plural steel filaments with a pearlite structure having an average value of interlamellar distance between cementites of 300-500 Å and a tensile strength of not less than 220 kg/mm 2 are used in at least one of said belt and carcass.
Claim 3
Dependent Claim
40 words
A high-durable pneumatic radial tire according to claim 1, wherein said steel cord applied to at least one of said belt and carcass is covered with a coating rubber having a modulus at 50% elongation of 10-40 kgf/cm 2 .
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) | 1988-06-03 | 1988-12-03 | 1989-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-03 | 1992-12-03 | 1993-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-03 | 1996-12-03 | 1997-06-04 | $7700.00 | Window Closed / Lapsed |