| 摘要 |
<p>PURPOSE:To improve the durability of a bead portion in a radial tire for heavy load like bus by disposing two hard and soft layers constituted beadeipexes, a short fiber mixing rubber protective layer and an additional reinforcing layer having specified constitution to constitute the bead portion. CONSTITUTION:A carcass 4 has steel cords 2 arranged radially and having both ends thereof folded-back from the inside to the outside about a bead core 3. In a region surrounded by said carcass 4 and a cord reinforcing layer 5 disposed adjacent the outside of the bead portion of the carcass 4 are provided a beadeipex 6 extending from a bead core 3 to a side wall, an additional reinforcing layer 7 covering said folded-back portion 4a or the upper end of a cord reinforcing layer 5 and a protective layer 8 consisting of short fiber mixing rubber covering the upper outside end of bead portion of said layer 5 while being inserted between the outside of bead portion of said beadeipex 6 and the upper end of the additional reinforcing layer 7. And said beadeipex 6 consists of two layers of a converging high elasticity rubber layer disposed inside a tire and low elasticity rubber layer disposed adjacent the outside of the high elasticity rubber layer.</p> |
