| 摘要 |
A heavy duty pneumatic tire having an improved durability is disclosed. This tire comprises a carcass of a bias structure composed of at least 12 rubberized laminated ply layers each containing organic fiber cords embedded therein, and divided into three inner, middle and outer ply groups by three bead cores, the cords of which are crossed with each other, as a reinforcement for a toroidal casing inclusive of a tread. In a region extending from an upper area of a bead portion of the casing within a range of 0.15 to 0.45 times a tire height as measured from a bead base of the tire, at least an average cord distance between adjacent ply layers at the middle and outer ply groups is made substantially wider than at the inner ply group and a cord distance between adjacent ply layers at the outer ply group is made substantially not more than at the middle ply group. |
