| 摘要 |
PURPOSE:To eliminate any accidental damage of a block while securing drive and brake performance by making the wall surface angle and a groove depth of a block for forming a tread pattern, different on step-in side from those on kick-out side, respectively depending upon specific relation of dimensions. CONSTITUTION:In a pneumatic tyre, plural blocks 3 are partitioningly formed on the tread surface thereof with plural main grooves extending in the circumferential direction and plural sub-grooves 2 crossing respective main grooves. On each block 3 at least one thin slit 4 is formed in parallel to the rotary shaft of the tyre. In this case, the wall surface angle theta2 on the kick-out side of the blocks 3 is set larger than that theta1 on its step-in side. Also, the groove depth d1 on the step-in side of the block 3 is set shallower than that on the kick-out side. The rotational direction R of the tyre is set so that the side of the larger wall surface angle of the block 3 is the circumferential direction section of the tyre can be defined to the kick-out side. |
