Steel cord for reinforcing rubber article and pneumatic tire

Abstract

A steel cord for reinforcing a rubber article which can improve the cut resistant property in the case of treading on an obtusely or sharply pointed projection without decreasing the strength in the axial direction of the cord and without increasing the tire weight, as well as a tire utilizing the same as a reinforcing material, are provided. The steel cord for reinforcing a rubber article has a multi-twisted structure formed by twisting a plurality of sheath strands (2) formed by twisting a plurality of wires around a core strand (2) formed by twisting a plurality of wires, and the core strand (1) and the sheath strands (2) are constituted of an at least 2-layer-twisted structure formed by twisting core wires and sheath wires respectively. In this case the relationship represented by the following formula 1.8≦[(S·cos2α)/{r·(φ1+φ2)}]×100≦4.2 is satisfied, wherein φ1: the diameter of an outermost wire of the strand (1), φ2: the diameter of an outermost wire of the strand (2), r: the center distance between the strand (1) and the strand (2), S: the cross section of the strand (2), and α: the twist angle of the strand (2).

Dependencies are inferred from the claim text.