| 摘要 |
PURPOSE:To improve durability of a belt and uneven wearing resistance of a tire, by properly providing the rigidity in the peripheral direction and the sectional direction of a belt layer in the radial tire of lag pattern used for a truck and/or bus. CONSTITUTION:A belt layer 5 consists of plural belts 51-54, and angles alpha1-alpha4 formed by each metallic cord with the equatorial surface of a tire is arranged to 0 deg.<alpha<90 deg.. The proportion of the rigidity Ftheta in the peripheral direction to the rigidity Fphi in the sectional direction by these belts is shown by an equivalent angle alphaeq as defined by Ftheta/Fphi=tan<2>alphaeq. This angle alphaeq is arranged to 18-27 deg. to improve durability of the belt and uneven wearing resistance of the tire. |
