| 摘要 |
<p>PURPOSE: To provide a durable tire without bead wire by arranging an aggregate of reinforcing webs in which cords arranged in a bead upward end part and are intersected each other at an acute angle, on an annular element surrounded by carcasses, and providing the bead having the same breaking strength in vertical tension, as that of conventional tires. CONSTITUTION: A bead 4 has an annular element 7. Reinforcing webs 8i, 9i made up of two rubber layers 80, 90 respectively abut on it, and extend upward from the annular element, and reinforcing cords 81, 91 are arranged in the rubber. The angle formed at any point of the cord by the cord direction and a tangent to a circle passing on the point on the cord is acute: 0<α<=10 deg.. A resistance to rupture in traction of the annular element 7, measured in its longitudinal direction is remarkably smaller than that necessary for a bead wire in a known tire, but a resistance to rupture in traction of areinfircing web aggregate 40A, measured in its longitudinal direction, is at least equal to that necessary of the bead wire in a known tire. The mechanical breaking strength is mainly maintained by the annular element 7 and the reinforcing webs 8, 8, 9.</p> |
