| 摘要 |
PURPOSE:To increase the wear-durability of blocks and provide high degree of on-ice performance and track pass-over performance. CONSTITUTION:Multiple grooves 2 in circumferential direction which are extended in zigzag form in circumferential direction are provided on the road surface 1 of a tread, and multiple lateral grooves 3 which are extended in lateral direction of the tread and opened from one tread end to the other tread end are formed in the circumferential grooves 2 crossing the lateral grooves 3 to form multiple block rows 4 to 6. Sipes 8 to 11 and 13 are provided on blocks 4a to 6a in each block row. Also the extension component of the sipes in the blocks in circumferential direction of the tread is increased more at a side district 12 than at a center district 7. Then the block shoulder forms at the tread end sections are made in square and round shapes alternately in circumferential direction of the tread, and tread contact ends 6c and 6e is offset from a square shoulder section 6b to lateral outer side at a round shoulder section 6d. |
