| 摘要 |
PURPOSE:To restrict any uneven abrasion of an outer rib by constructing a sectional outer ring portion of a tire extending from the width directional central portion of an inner rib adjacent to an outer rib, on the width directional inside of the outer rib, toward the width directional outside, in a circular arc of relatively small radius of curvature. CONSTITUTION:A tire 1 is composed of a toroidal laminate body 2 made up of three carcass layers 3. Four main grooves 8 are formed on the outer surface of a tread 7 arranged outside in the radial direction of the laminate body 2. Three ribs 10 are provided between respective main grooves 8. Sectional outer contours of the tire of an outer rib 10a, an inner rib 10b and a central rib 10c are composed of a circular arc of a single radius of curvature R. In this case, the sectional outer contour of the tire from the width directional central portion to the outside the width direction of the inner rib 10b is composed of a circular arc of a radius of curvature S which is smaller than the radius of curvature R. In this manner, a small radius of curvature region 11 composed of the circular arc of the small radius of curvature S is formed on width directional outer portions of respective inner ribs 10b. |
