PNEUMATIC RADIAL TIRE FOR HEAVY LOAD

摘要

PURPOSE:To improve the durability of a carcass layer by using a stranded type steel cord in bundle as a carcass cord in which each strand is stranded with the same pitch in the same standing direction. CONSTITUTION:A carcass layer 5 of one layer in which a cord angle against a circumferential direction EE' of a tire is 90 deg. is provided to wrap a bead wire 3 and to run along a side wall portion 2 and the inside surface of a tread 1. A stranded type steel cord in bundle in which each strand is stranded with the same pitch in the same stranding direction is used as a carcass cord 10 composing the carcass layer 5. A steel wire in which a stranding angle theta in a standing direction opposite to a stranding direction of a cord is set to the angle 35.3 deg. + or -8 obtained by measuring from the acute angle side against the axis of the carcass cord 10 is wound on the cord as a wrapping wire 11.