Title:
STEEL CORD, COMPOSITE OF RUBBER AND STEEL CORD, AND TIRE
Document Type and Number:
WIPO Patent Application WO/2008/032538
Kind Code:
A1
Abstract:
Provided are a steel cord particularly useful for reinforcement of a tire crown
section, having no problem of production as seen in conventional products, and
capable of being efficiently produced with stable quality, and a rubber/steel
cord composite and tire using the steel cord. The steel cord has a double-twisted
structure in which N number (N = 2 to 8) of strands (2) each formed by twisting multiple
element wires and having a substantially elliptic cross-section. The steel
cord satisfies the expression of d1/d2 > 1.08, with d1 the length of the major
axis of a strand (2), d2 the length of the minor axis. The steel cord also satisfies
ξc > 0.005, where ξc is expressed by the
expression of ξc = √(-b/2 + √(b2/4
- c)) - 1, where b is -1 + π2(-4R2 + d2)/P2,
c is π2d2k(4π2R2 + P2)/P4,
R is (D-d)/2, k is tan2(π/2 - π/N), and d is (d1 + d2)/2,
with D the diameter in mm of the circumcircle of the cord, P the twisting pitch in
mm of the cord.
Inventors:
IKEHARA, Kiyoshi (3-1-1 Ogawahigashi-cho, Kodaira-sh, Tokyo 31, 1870031, JP)
Application Number:
JP2007/066345
Publication Date:
March 20, 2008
Filing Date:
August 23, 2007
Export Citation:
Assignee:
BRIDGESTONE CORPORATION (10-1, Kyobashi 1-chome Chuo-k, Tokyo 31, 1040031, JP)
株式会社ブリヂストン (〒31 東京都中央区京橋１丁目１０番１号 Tokyo, 1040031, JP)
株式会社ブリヂストン (〒31 東京都中央区京橋１丁目１０番１号 Tokyo, 1040031, JP)
International Classes:
D07B1/06; B60C9/00; B60C9/22
Attorney, Agent or Firm:
HONDA, Ichiro (6th Floor, Ikeden Building12-5, Shimbashi 2-chom, Minato-ku Tokyo 04, 1050004, JP)
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