| 摘要 |
PROBLEM TO BE SOLVED: To suppress the generation of a sawteeth effect by providing to set soft pattern element areas and hard pattern element areas in order, starting from a pattern element area to advance to the grounding surface at first. SOLUTION: A sholder block 1 furnishes two slender branch grooves 3a and 3b respectively, and a sholder block 4 furnishes two slender branch grooves 4a and 4b respectively. By the slender branch grooves 3a, 3b, 4a, and 4b, the block 1 and the block 4 are divided into at least two blocks 1' and two blocks 4' with the same size essentially. The pattern elements 1 and 4 having pattern elements 1' and pattern elements 4' having different rigidities have soft pattern element areas and hard pattern element areas 1' and 4' alternatively, starting from a pattern element area to advance to a grounding surface at first. Consequently, the generation of a sawteeth effect can be suppressed.
|
