| 摘要 |
<p>PROBLEM TO BE SOLVED: To increase carry by dint of enhancing a dimple effect which disturbs flow of air and improving an aerodynamic characteristic by arranging dimples closely so as not to generate specific numbers of land parts whose areas are relatively large among the land parts, i.e., parts except for the dimples on a surface of a golf ball. SOLUTION: A spherical surface of a golf ball whose total of dimples 1 are set to, for example, 432 and diameters of the dimples 1 are set from 4.30 mm to 2.70 mm and areas of the dimples 1 are set from 14.5 mm2 to 5.7 mm2 is divided into, for example, 20 pieces of units. A rectangle 10 whose short side's size is more than 0.4 mm and area is more than 0.8 mm2 which is indicated by painting in black is provided in one of the units. Excellent dimple effect can be obtained by setting the land parts which can from rectangles to no more than 40 portions on the whole surface of sphere of the golf ball when the above processes are done on the golf ball without a large circle passage which does not cross with the dimples completely on a parting line which is formed when the golf ball is formed.</p> |
