| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a golf ball having satisfactory controllability, which increases a flying distance by reducing a spin quantity at the time of shooting with a driver and increases the spin quantity at the time of shooting with an iron or a sand wedge. SOLUTION: This golf ball 1 consists of a core 2 and covers 3 and 4 covering the core 2. The covers 3 and 4 consist of an outer layer cover 4 and an inner layer cover 3 of hardness lower than the cover 4 and the cover 4 is cover- formed surrounding the cover 3 in a state where the cover 4 enters a recessed part formed on the outer surface of this cover 3 in a projecting form of a projection type. The total of the root cross-sectional area of the whole projecting-type projection 4a formed in the cover 3 is 2 to 45% of the surface of an inner cover coated virtual ball obtained by imaging that a recessed part is not formed at the cover 3. The height of the normal direction of the projection 4a is at least 30% of the thickness of the recessed part non-forming place of the cover 3.</p> |
