| 摘要 |
PURPOSE:To use a tire on a snowy or frozen road, by forming branch grooves which branch from oblique grooves of the tread, on the way of the longitudinal course of them to the both sides, and end at the land parts, as the one side branch grooves are parallel or inclined at a slight angle with or to a plane including the center circumferential line of the tire, and the other side branch grooves are parallel or inclined at a slight angle with or to a plane including axis of rotation. CONSTITUTION:Oblique grooves 4a, 4b of a tire are extendedly formed from the tread ends 2a, 2b of the tread part 1 toward the center of the tread part 1, and many lines of the oblique grooves 4a, 4b are formed as the start points are positioned on the outer circumference of the tire at intervals. A plural number of sipes 7 are formed in the land parts 6 partitioned by the oblique grooves 4a, 4b. Moreover, branch grooves 8a, 8b, 9a, 8b which branch from the oblique grooves 4a, 4b, in the longitudinal course of them to the both sides, and end at the land parts 6, are formed as the one side branch grooves 8a, 8b are parallel or inclined at a slight angle with or to a plane including the center circumferential line of the tire, and the other side branch grooves 9a, 9b are parallel or inclined at a slight angle with or to a plane including axis of rotation of the tire. |
