Sughrue, Mion, Zinn, Macpeak and Seas
Radial tires for running on rough ground
 In pneumatic radial tires for running on rough ground, which are useful for applying to construction vehicles and provided with a tread reinforcing layer composed of a plurality of belts embedded in a crown portion of the tires, which surrounds a carcass composed of at least one cord layer arranged in radial plane of the tire, said tread reinforcing layer comprises a pair of main intersecting belts having different belt width in which cords are arranged so as to intersect with each other across an equator of the tire, and supplemental two belts arranged in the inside and outside of said pair of main intersecting belts respectively, in which cords have an elongation at breakage of at least 40% larger than that of the cords of the main intersecting belts, and an angle of the cords in the belt having the smaller width in the main intersecting belts with respect to the above described equator is 2.degree.-9.degree. smaller than the angle of the cords in the belt having the larger width and an angle of the cords of the supplemental belt positioning between the main intersecting belts and the carcass ply is 35.degree.-60.degree.. 
Bridgestone Tire Company Limited
B Y
B60C Y10T
inventional additional
Yasuo Akira
Suzuki Tamura