STEEL CORD FOR REINFORCING RUBBER ARTICLE AND PNEUMATIC RADIAL TIRE

摘要

PURPOSE: To obtain a pneumatic radial tire having improved maneuvering stability by using a belt layer comprising a steel cord made by piling plural filaments preformed in a wavy pattern changing in a sine curve in a plane. CONSTITUTION: Steel filaments are preformed in a wavy pattern changing in a plane shown by Y=Asin(2πx/λ) so as to make the ratio A/λof the amplitude and the wavelengthλ<=5% error between the mutual filaments. At least two or more and n×filaments are piled to form a steel cord in which a phase difference between the adjoining filaments is (20/n)% the average value of the wavelength of the whole filaments. A carcass comprising a ply of a radial arrangement cord extending in a toroidal state on a bead is used as a skeleton. The steel cord is arranged on at least one belt laid on the carcass so that the wavy pattern of the steel cord is changed along the surface of the belt to give the objective pneumatic radial tire.