| 摘要 |
PURPOSE:To provide a pneumatic tire which reduces noise more during running than heretofore. CONSTITUTION:The angles of lug grooves 3a, 3b, 3c to a tire peripheral direction in rib rows 2a, 2b, 2c are ranged within the maximum-minimum ratio of 1.1-1.4 as the repetition units of geometric series. The lug groove at the center, the lug groove 3b at the middle and the lug groove 3c at the shoulder have the respective angles of 45-60 deg., 50-70 deg. and 65-85 deg. to the tire peripheral direction, and gradually increased. |
