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US5024261A Expired / Lapsed US ⏱️ 0.0 years remaining

Heavy duty pneumatic radial tire with improved steel cord belt

Assignee: Yokohama Rubber Co Ltd
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Filing: 1989-11-01
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Granted: 1991-06-18
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Expires: 2009-11-01
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Abstract

Abstract A heavy duty pneumatic radial tire including between a tread and at least one carcass layer, at least two belt layers, wherein an outermost belt layer disposed most closely to the tread out of all belt layers comprises a steel cord which has a cord structure of 2+7 made of an element wire having a carbon content of 0.77 to 0.92% by weight and a diameter d of 0.28 to 0.40 mm and which has a tenacity at break of (1700˜2050)d 1 .872 (kgf/cord) and a ratio of an elongation at break ε to P.L.E., ε/P.L.E., of at least 30, and a coat rubber having a 50% modulus of 10 to 40 kg/cm 2 , and wherein the outermost belt layer has a thickness of at least 1.67 times the minor diameter but at greatest 1.79 times the major diameter, of the steel cord.

Inventors

  • 👤 Eiji Igarashi
  • 👤 Susumu Imamiya
  • 👤 Yasuo Suzuki

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 01:39
CPC Classifications
D; D07; D07B; D07B1/00; D07B1/06; D07B1/0606; D07B1/062; B; B60; B60C; B60C9/00; B60C9/0007; B60C9/18; B60C9/20; B60C9/2003; B60C9/2006; D07B2201/00; D07B2201/20; D07B2201/2015; D07B2201/2023; Y; Y10; Y10S; Y10S57/00; Y10S57/902

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 192 words
A heavy duty pneumatic radial tire including between a tread and at least one carcass layer comprising carcass cords arranged substantially perpendicular to the circumferential direction of the tire, at least two belt layers comprising steel cords including a least a pair of belt layers disposed adjacent to each other with steel cords in one layer crossing those in the other layer, wherein an outermost belt layer disposed most closely to the tread out of all belt layers comprises a steel cord which has a cord structure of 2+7 made of an element wire having a carbon content of 0.77 to 0.92% by weight and a diameter d of 0.28 to 0.40 mm and which has a tenacity at break of (1700˜2050)d 1 .872 (kgf/cord) and an elongation characteristic having a ratio of an elongation at break ε to an initial stage elongated, ε/P.L.E., of at least 30, and a coat rubber having a 50% modulus of 10 to 40 kg/cm 2 , and wherein said outermost belt layer has a thickness of at least 1.67 times the minor diameter but at greatest 1.79 times the major diameter, of said steel cord.
Claim 2
Dependent Claim 192 words
A heavy duty pneumatic radial tire including between a tread and at least one carcass layer comprising carcass cords arranged substantially perpendicular to the circumferential direction of the tire, at least two belt layers comprising steel cords including a least a pair of belt layers disposed adjacent to each other with steel cords in one layer crossing those in the other layer, wherein an outermost belt layer disposed most closely to the tread out of all belt layers comprises a steel cord which has a cord structure of 2+7 made of an element wire having a carbon content of 0.77 to 0.92% by weight and a diameter d of 0.28 to 0.40 mm and which has a tenacity at break of (1700˜2050)d 1 .872 (kgf/cord) and an elongation characteristic having a ratio of an elongation at break ε to an initial stage elongated, ε/P.L.E., of at least 30, and a coat rubber having a 50% modulus of 10 to 40 kg/cm 2 , and wherein said outermost belt layer has a thickness of at least 1.67 times the minor diameter but at greatest 1.79 times the major diameter, of said steel cord.
Claim 3
Dependent Claim 39 words
A tire as claimed in claim 1, wherein an inner element wire of said steel cord has a twist pitch of 5 to 10 mm and an outer element wire has a twist pitch of 10 to 20 mm.
Claim 4
Dependent Claim 29 words
A tire as claimed in claim 2, wherein said steel cord has a ratio of its major diameter to its minor diameter within a range of 1.1 to 1.4.
Claim 5
Dependent Claim 45 words
A tire as claimed in claim 1, wherein said steel cord comprises an element wire plated with at least one member selected from the group consisting of Cu, Sn and Zn and alloys of two or more thereof, with or without containing Ni or Co.

References Cited (Backward Citations)

US4020887A Cited
US3996733A Cited
GB2039580A Cited
US4349063A Cited
US4520857A Cited
US4518024A Cited
DE3442799A1 Cited
US4715419A Cited
US4609024A Cited
US4690191A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-06-17 1994-12-17 1995-06-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-06-17 1998-12-17 1999-06-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-06-17 2002-12-17 2003-06-18 $7700.00 Window Closed / Lapsed

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