US4628977A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High-durable pneumatic radial tires
Assignee: Bridgestone Corp
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Filing: 1984-10-31
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Granted: 1986-12-16
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Expires: 2004-10-31
Abstract
Abstract A high-durable pneumatic radial tire is disclosed using steel cords in at least one of the carcass and the belt. This steel cord is produced by twisting plural steel filaments each having a tensile strength of not less than 220 kgf/mm 2 , whose metallic structure being a fine pearlite structure having an average value of interlamellar distance between cementites of 300-500 Å and an average sectional area of single pearlite crystal grain in filament section of not more than 20 μm 2 .
Inventors
- 👤 Takao Ogino
- 👤 Yoichi Watanabe
- 👤 Shigehisa Sano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:28
CPC Classifications
D; D07; D07B; D07B1/00; D07B1/06; D07B1/0606; D07B1/066; B; B60; B60C; B60C9/00; B60C9/0007; B60C9/18; B60C9/20; B60C9/2003; B60C9/2006; C; C21; C21D; C21D8/00; C21D8/06; D07B2205/00; D07B2205/30; D07B2205/3021; D07B2205/3025; D07B2205/3035
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
124 words
A high-durable pneumatic radial tire comprising a tread portion, a pair of side portions extending from the tread portion, a pair of bead portions extending from the side portions, and a carcass reinforced with a belt embedded in the tread portion, in which steel cords are used in at least one of the carcass and the belt, characterized in that said steel cord is produced by twisting plural steel filaments each having a tensile strength of not less than 220 kgf/mm 2 , whose metallic structure being a fine pearlite structure having an average value of interlamellar distance between cementites of 300-500 Å and an average sectional area of single pearlite crystal grain in filament section of not more than 20 μm 2 .
Claim 2
Dependent Claim
124 words
A high-durable pneumatic radial tire comprising a tread portion, a pair of side portions extending from the tread portion, a pair of bead portions extending from the side portions, and a carcass reinforced with a belt embedded in the tread portion, in which steel cords are used in at least one of the carcass and the belt, characterized in that said steel cord is produced by twisting plural steel filaments each having a tensile strength of not less than 220 kgf/mm 2 , whose metallic structure being a fine pearlite structure having an average value of interlamellar distance between cementites of 300-500 Å and an average sectional area of single pearlite crystal grain in filament section of not more than 20 μm 2 .
Claim 3
Dependent Claim
41 words
A high-durable pneumatic radial tire according to claim 1, wherein said steel cords used in at least one of the carcass and the belt is covered with a coating rubber having a modulus at 50% elongation of 10-40 kgf/cm 2 .
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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) | 1989-12-15 | 1990-06-16 | 1990-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-15 | 1994-06-16 | 1994-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-15 | 1998-06-16 | 1998-12-16 | $7700.00 | Window Closed / Lapsed |