| 摘要 |
PURPOSE:To improve the durability of a bead portion by providing a plurality of turning points between a particular point relative to a rim and the maximum width position, and specifying the position of a turn-up end, in a carcass line wherein a tire is fitted to a regular rim and is filled with a predetermined inner pressure to be in a standing posture with no load. CONSTITUTION:A plurality of turning points indicated by X are provided between a point A where the carcass 5 of a tire crosses a vertical line stood on a rim diameter line RL, and the maximum width position B of the carcass, wherein the tire is fitted to a regular rim, and is filled with inner pressure of 5% of standard inner pressure to be in a standing posture under no load. When a straight line L connecting two turning points near the point A is drawn to obtain a point P placed most apart from the straight line L between both turning points on the carcass 5 and lines Q1, Q2 vertical to the straight line L are drawn with a vertical distance (d) of within 10mm respectively at both the sides thereof, the turn-up end E of the carcass is positioned between both lines Q1, Q2. In accordance with this construction, the durability of a bead portion can be improved. |
