| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent a head from shaking up/down and to the right/left in the case of swinging. SOLUTION: A side surface 5 is formed extending nearly from a sole 7 to a toe 8 between the edge part 3a of a crown 3 and the edge part 4a of a sole 4, and a groove part 9 having a cross section shape such as a circular arc, e.g. is formed along its longitudinal direction. In this case, the part 9 is formed maximizing the whole range where the surface 5 is formed. The depth (a) of the part 9 is nearly 1/2 of or not longer than the width (b) of the surface 5.</p> |
