| 摘要 |
<p>PURPOSE:To sufficiently suppress the range of a golf ball by providing a project ing part in an optimum shape protruding upward in the shape of a circuling arc in the bottom part of a circular dinple. CONSTITUTION:In the bottom part of a dinple 10 for the golf ball, a projecting part 11 is formed protruding upward in the shape of the circular arc. When a diameter in the maximum diameter of the projecting part is defined as D1 and a diameter in the outer edge of the dinple is defined as D2, in the condition of L=D1/D2, the size of the projecting part 11 is set so that the condition of 0.1<=L<=0.9 can be established. When the height of the projecting part is defined as H1 and the virtual maximum depth of the dinple recessed in the shape of the circular arc, in the condition of K=H1/H2, the size is set so that the condi tion of 0.6<=K<=1.0 can be established. The total number of the dinples is set in the range of about 250-600. As a result, the range of the golf ball can be enough suppressed. Since mold working to use an end mill system can be easily executed, the shape of the dinple can be made uniform.</p> |
