| 摘要 |
PURPOSE: To expand an actual grounded area and improve a brake force and an edge force by forming so that a block height can also be getting bigger at the same time when a groove depth is getting bigger gradually toward the central part of a tread width section and making through-holes for penetrating to both side parts of the tread from a groove bottom surface in staggered arrangement. CONSTITUTION: Vertical groove 5, lateral grooves or slant groove are formed by a proper assembly on the block 4 having a cut in groove 6 on the surface of a tread part 3. An imaginary line 8 connecting the base part of the block 4 with its groove bottom for a tyre section is constituted so as to be gnawed into the bottom part of the tread 3 in nearly arc shape. The surface of the block 4 is formed so as to be convex at the section of the tread 3. Through holes 9, 9' are mode to one side surface of the tread part 3 from the bottom surface of the groove part and formed in staggered arrangement in a periphery direction for the groove part bottom surface between the convex blocks positioning on the central part. Thereby, an actual grounded area is expanded and a brake force and an edge force are improved. |
