| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the durability of bead portions of a pneumatic tire. SOLUTION: The pneumatic tire is so designed that at least one carcass ply made of a steel cord is extended toroidally from a tread portion to bead portions via sidewall portions and is turned back in an inner-to-outer direction along the tire radius around a bead core embedded in each bead portion and an adjacent rubber stiffener as well, and that each turnup portion of the carcass ply has a wrap portion that winds around the bead core along the periphery thereof. The rubber stiffener comprises soft rubber and hard rubber overlapped from a direction along the tread width. The hard rubber is inwardly of the soft rubber in the tire, and the overlap surface creates an S-shaped or inverted- S-shaped wave.</p> |
