Golf ball
Golf ball 1 has numerous dimples 4 on its surface. The dimple 4 comprises an inclined face 6 , a circular flat face 7 , an annular groove 8 and a round flat face 9 . Surface area s 1 is calculated by summing up the surface area of the inclined face 6 , the surface area of the circular flat face 7 , the surface area of the annular groove 8 and the surface area of the round flat face 9 . The ratio (S 1 /S 2 ) between a summation S 1 of surface areas s 1 of all the dimples, and a summation S 2 of the areas s 2 of the regions cut away by the dimples on the phantom spherical face is equal to or greater than 1.02. Total value (Cb+Cc) of the amount of compressive deformation Cb of the golf ball 1 and the amount of compressive deformation Cc of the core is equal to or greater than 7.0 mm.
1. A golf ball which comprises a core, a cover and numerous dimples formed on the surface of the cover, wherein
the ratio (S 1 /S 2 ) between a summation S 1 of surface areas s 1 of the dimples, and a summation S 2 of the areas s 2 of the regions cut away by the dimples on the phantom spherical face is equal to or greater than 1.02, the total value (Cb+Cc) of the amount of compressive deformation Cb of the golf ball and the amount of compressive deformation Cc of the core is equal to or greater than 7.0 mm, and
the dimples include a dimple having an annular groove.
2. The golf ball according to claim 1 , wherein said amount of compressive deformation Cb is equal to or greater than 3.4 mm, and said amount of compressive deformation Cc is equal to or greater than 4.0 mm.
3. The golf ball according to claim 1 , wherein total volume V of said dimples is 400mm 3 or greater and 800 mm 3 or less.
4. The golf ball according to claim 1 , wherein said dimple having the annular groove has a recessed portion at the center of the dimple.
5. The golf ball according to claim 1 , wherein the cross-sectional shape of the annular groove is u-shaped.
6. The golf ball according to claim 1 , wherein the annular groove has a cross-sectional shape selected from the group consisting of v-shaped, and circular arc.
7. The golf ball according to claim 1 , wherein the annular groove has a cross-sectional shape which is semi-circular.
8. The golf ball according to claim 1 , wherein the ratio (S 1 /S 2 ) is equal to or greater than 1.05 and the total value (Cb+Cc) is equal to or greater than 7.5 mm.
9. The golf ball according to claim 1 , wherein the ratio (S 1 /S 2 ) is equal to or greater than 1.08 and equal to or less than 1.50 and the total value (Cb+Cc) is equal to or greater than 8.0 mm and equal to or less than 13.0 mm.