EP0157045A1
Expired / Lapsed
EP
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Radial pneumatic tyres
Assignee: Bridgestone Corp
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Filing: 1984-10-31
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Granted: —
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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 is a fine pearlite structure having an average value of interlamellar distance between cementites of 300-500 A 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
EP
Data Source
google_patents
Last Synchronized
2026-11-08 01:32
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
122 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 the carcass and/or the belt, characterized in that each said steel cord is produced by twisting plural steel filaments, each having a tensile strength of not less than 220 kgf/mm 2 (2160 MPa), whose metallic structure is a fine pearlite structure having an average value of the interlamellar distance between cementites of 300-500 and an average sectional area of single pearlite crystal grain in filament section of not more than 20 µm 2 .
Claim 2
Dependent Claim
122 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 the carcass and/or the belt, characterized in that each said steel cord is produced by twisting plural steel filaments, each having a tensile strength of not less than 220 kgf/mm 2 (2160 MPa), whose metallic structure is a fine pearlite structure having an average value of the interlamellar distance between cementites of 300-500 and an average sectional area of single pearlite crystal grain in filament section of not more than 20 µm 2 .
Claim 3
Dependent Claim
34 words
A high-durable pneumatic radial tire according to claim 1, wherein the said steel cords are covered with a coating rubber having a modulus at 50% elongation of 10-40 kgf/cm 2 (0.98 - 3.9 MPa).
References Cited (Backward Citations)
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