Steel cords for the reinforcement of rubber articles and method of producing the same

摘要

A steel cord for the reinforcement of rubber articles has a three-layer twisting structure comprising a core of 2 steel filaments, a middle sheath layer of 6 steel filaments and an outer sheath layer of 11 steel filaments, in which a ratio of filament diameter ds in the middle and outer sheath layers to filament diameter dc in the core (ds/dc) is within a range of 1.15-1.5 and a twisting pitch of the core is not less than 20 mm, and is used as a reinforcing member in a heavy duty pneumatic radial tire, conveyor belt and the like.