Patent ID: 7712501
Filing Date: 2010-05-11
Classification: B60C,Y10T

Abstract:
1. A heavy duty tire comprising: a carcass composed of a single ply of steel cords extending between a pair of bead portions through a tread portion and a pair of sidewall portions and turned up around a bead core in each said bead portion from the inside to the outside of the tire to form a pair of carcass ply turnup portions and a carcass ply main portion therebetween, wherein the bead portions are each provided with a bead reinforcing layer composed of a single ply of steel cords arranged at an angle of from 10 to 40 degrees with respect to the tire circumferential direction, the bead reinforcing layer comprises a belt disposed radially outside the carcass in the tread portion, and consisting of three plies of cords, namely, a radially inner first ply, an intermediate second ply and a radially outer third ply, wherein the cords of the radially outer third ply are inclined toward one direction at an angle of from 13 to 23 degrees with respect the tire equator, the cords of the intermediate second ply are inclined at an angle of from 13 to 23 degrees with respect the tire equator toward one direction which is opposite to that of the radially outer third ply, the cords of the radially inner first ply are arranged at an angle of from 30 to 70 degrees with respect the tire equator toward one direction which is opposite to that of the radially outer third belt ply; and the total of strengths S the strengths S the strength S