EP0251145A2
Expired / Lapsed
EP
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Heavy-duty pneumatic radial tire
Assignee: Yokohama Rubber Co Ltd
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Filing: 1987-06-23
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Granted: —
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Expires: 2007-06-23
Abstract
Abstract A heavy-duty pneumatic radial tire with a radial structure having at least two reinforcing layers provided on the outside of a turnup portion formed by turning up the end of a carcass ply about a bead core from the inside of the tire towards the outside of the tire, wherein a rubber stock is provided in the inside of the outer reinforcing layer so as to cover the end of said turnup portion and the end of the innermost reinforcing layer and wherein the rubber stock contains a cobalt salt in an amount of 0.l to 0.4 parts by weight per l00 parts by weight of rubber in terms of cobalt element and having the dynamic modulus M₂ higher than the dynamic modulus M₁ of coat rubber of the carcass ply and in the range of from l0 to l5 MPa and a thickness d, defined as a distance from the inside surface of the outer reinforcing layer to the end of the turnup portion, l.0 to 4.0 times larger than the diameter r₂ of the reinforcing cord constituting the innermost reinforcing layer.
Inventors
- 👤 Tatsuo Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 19:51
CPC Classifications
B; B60; B60C; B60C9/00; B60C9/02; B60C15/00; B60C15/06; B60C15/0603; B60C15/0607; B60C2015/0617; B60C2015/0625
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
265 words
A heavy-duty pneumatic radial tire having a radial structure comprised of a carcass ply made of a metallic cord, a bead rubber filler interposed between a turnup portion, formed by turning up the end of said carcass ply about a bead core from the inside of the tire towards the outside of the tire, and a main body portion of said carcass ply, and at least two reinforcing layers provided on the outside of said turnup portion, the end of the innermost reinforcing layer being located lower than the end of said turnup portion, the end of the outer reinforcing layer being located higher than the end of said turnup portion, said innermost reinforcing layer being comprised of a reinforcing cord having the modulus larger than a reinforcing cord constituting said outer reinforcing cord, wherein a rubber stock is provided in the inside of said outer reinforcing layer so as to cover the end of said turnup portion and the end of said innermost reinforcing layer, said rubber stock containing a cobalt salt in an amount of 0.l to 0.4 parts by weight per l00 parts by weight of rubber in terms of cobalt element and having the dynamic modulus M₂ higher than the dynamic modulus M₁ of coat rubber of said carcass ply and in the range from l0 to l5 MPa and a thickness d, defined as a distance from the inside surface of said outer reinforcing layer to the end of said turnup portion, l.0 to 4.0 times larger than the diameter r₂ of the reinforcing cord constituting said innermost reinforcing layer.
Claim 2
Dependent Claim
265 words
A heavy-duty pneumatic radial tire having a radial structure comprised of a carcass ply made of a metallic cord, a bead rubber filler interposed between a turnup portion, formed by turning up the end of said carcass ply about a bead core from the inside of the tire towards the outside of the tire, and a main body portion of said carcass ply, and at least two reinforcing layers provided on the outside of said turnup portion, the end of the innermost reinforcing layer being located lower than the end of said turnup portion, the end of the outer reinforcing layer being located higher than the end of said turnup portion, said innermost reinforcing layer being comprised of a reinforcing cord having the modulus larger than a reinforcing cord constituting said outer reinforcing cord, wherein a rubber stock is provided in the inside of said outer reinforcing layer so as to cover the end of said turnup portion and the end of said innermost reinforcing layer, said rubber stock containing a cobalt salt in an amount of 0.l to 0.4 parts by weight per l00 parts by weight of rubber in terms of cobalt element and having the dynamic modulus M₂ higher than the dynamic modulus M₁ of coat rubber of said carcass ply and in the range from l0 to l5 MPa and a thickness d, defined as a distance from the inside surface of said outer reinforcing layer to the end of said turnup portion, l.0 to 4.0 times larger than the diameter r₂ of the reinforcing cord constituting said innermost reinforcing layer.
Claim 3
Dependent Claim
26 words
A heavy-duty pneumatic radial tire according to claim l, wherein the reinforcing cord constituting said reinforcing layer is a metallic cord or an organic fiber cord.
Claim 4
Dependent Claim
52 words
A heavy-duty pneumatic radial tire according to claim 2, wherein the moduli of the reinforcing cord constituting said innermost reinforcing layer, the reinforcing cord constituting said outer reinforcing layer, and the metallic cord constituting said carcass ply are 40,000 to 200,000 MPa, l,000 to 20,000 MPa, and more than l30,000 MPa, respectively.
Claim 5
Dependent Claim
56 words
A heavy-duty pneumatic radial tire according to claim l, wherein the thickness Db of said bead rubber filler defined as a distance from the main body portion of said carcass ply to the end of said turnup portion is 4.5 to l2.0 times larger than the diameter r₁ of the metallic cord constituting said carcass ply.
Claim 6
Dependent Claim
26 words
A heavy-duty pneumatic radial tire according to claim l, wherein the dynamic M₁ of the coat rubber of said carcass ply is 4 to l0 MPa.
References Cited (Backward Citations)
No citation records indexed.
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