Anti-slice golf ball construction
A golf ball has a cover and a core which is made as a single piece or of two or more parts (for example an inner core covered by an outer core or mantle layer). The ball has non-spherical aspects in at least some parts and may also have different specific gravities in different parts of the ball. The different shaped ball parts combined with the different specific gravities of the materials for different ball parts results in a differential between the moments of inertia of the different spin axes. The golf ball is spherical, but the inner layers are not necessarily completely spherical or symmetrical layers or parts.
1. A multi-piece golf ball, comprising:
an outer surface having a plurality of dimples configured to provide selected aerodynamic properties to the ball, and wherein the outer surface of the golf ball is divided into plural dimple areas comprising at least two bands which extend at an angle to one another around the periphery of the ball and cross over at two diametrically opposed locations and additional dimple areas defined between the two bands, the bands containing first dimples and the additional dimple areas containing second dimples, the first and second dimples having different dimple parameters;
a core comprising at least one piece;
a cover layer surrounding the core and comprising at least one piece;
at least one piece of the ball having an at least partially non-spherical first surface which faces outwards;
a second piece of the ball directly surrounding said first surface having an inwardly facing, second surface of complementary, at least partially non-spherical shape opposing said first surface;
said at least one piece of the ball having a higher specific gravity than at least one other piece;
the ball having first, second and third orthogonal axes; and
the core and cover layer are configured such that the ball has a first moment of inertia (MOI) with respect to the first orthogonal axis which is higher than the MOI with respect to the second and third orthogonal axis.
2. The golf ball of claim 1 , wherein the core comprises an inner core and an outer core layer surrounding the inner core, the outer core layer comprising said at least one piece having said at least partially non-spherical first surface.
3. The golf ball of claim 1 , wherein the core comprises a one piece core with an outer surface comprising said at least partially non-spherical first surface.
4. The golf ball of claim 1 , wherein said cover layer comprises an inner cover layer and an outer cover layer of uniform thickness which surrounds said inner cover layer.
5. The golf ball of claim 1 , wherein the difference between said first MOI and the MOI relative to second and third orthogonal axes is less than 3 gm/cm 2 .
6. The golf ball of claim 1 , wherein the core and cover layer are configured such that the MOI of each orthogonal axis is different from the MOI of the other two orthogonal axes.
7. The golf ball of claim 1 , wherein the features on the outer surface are configured such that the golf ball exhibits a first coefficient of drag (CD) and a first coefficient of lift (CL) when spinning about one of said orthogonal axes and the golf ball exhibits a second CD and a second CL different from the first CD and first CL, respectively, when spinning about at least one of the other two orthogonal axes.
8. The golf ball of claim 7 , wherein the CD and CL are lower when the ball spins about said one orthogonal axis.
9. The golf ball of claim 1 , wherein the at least partially non-spherical first surface is a completely non-spherical surface and the opposing surface is of matching non-spherical shape.
10. The golf ball of claim 1 , wherein the non-spherical surface is elliptical.
11. The golf ball of claim 10 , wherein the difference between a maximum and minimum radius of the elliptical surface is approximately 0.05 inches.
12. The golf ball of claim 1 , wherein the at least partially non-spherical first surface has diametrically opposite flattened areas.
13. The golf ball of claim 12 , wherein the second surface has inner flattened areas facing the flattened areas of the first surface, the second surface comprising an inner surface of the cover layer facing the core and the cover layer has a first thickness at the flattened areas and a second thickness spaced from flattened areas, the first thickness being greater than the second thickness.
14. The golf ball of claim 1 , wherein the at least partially non-spherical first surface has a first flattened band extending around the perimeter of the surface, and the opposing second surface has a matching second flattened band in face to face engagement with the first flattened band.
15. The golf ball of claim 14 , wherein the first and second flattened bands define an equatorial plane of the ball and a polar axis perpendicular to the equatorial plane, and polar regions of the at least partially non-spherical first surface comprise flattened areas.
16. The golf ball of claim 14 , wherein the core comprises an inner core and a mantle layer surrounding the inner core, and said first surface is the outer surface of said mantle layer.
17. The golf ball of claim 16 , wherein said mantle layer has a first thickness in the spherical part and a second thickness less than the first thickness in said flattened band.
18. The golf ball of claim 15 , wherein the cover layer is of greater thickness at the polar and equatorial regions than the remainder of the cover layer.
19. The golf ball of claim 1 , wherein at least one core or cover layer of the ball has regions of varying thickness.
20. The golf ball of claim 1 , wherein the ball has a one piece inner core, an outer cover layer, and an intermediate layer between the core and cover layer, the first surface comprising an outer surface of said intermediate layer and the intermediate layer has at least first and second different thicknesses in at least first and second different regions of the layer.
21. The golf ball of claim 20 , wherein the intermediate layer comprises an outer core layer.
22. The golf ball of claim 20 , wherein the intermediate layer comprises an inner cover layer.
23. The golf ball of claim 20 , wherein the difference in thickness between the two regions is in the range from about 0.03 to 0.06 inches.
24. The golf ball of claim 20 , wherein the cover layer has first and second different thicknesses in first and second different regions corresponding to and overlying the first and second regions of the intermediate layer.
25. The golf ball of claim 24 , wherein the first thickness is less than the second thickness in the intermediate layer and the first thickness is greater than the second thickness in the surrounding cover layer.
26. The golf ball of claim 24 , wherein the first thickness is greater than the second thickness in the intermediate layer and the first thickness is less than the second thickness in the surrounding layer.
27. The golf ball of claim 24 , wherein the difference between the first and second thickness in the intermediate layer and cover layer is the same, whereby the total thickness of the intermediate and cover layer is the same over the entire surface area of the two layers.
28. The golf ball of claim 2 , wherein at least one of the core and cover layers has an outer surface which is non-uniform in radius.
29. The golf ball of claim 1 , wherein the opposing complementary first and second surfaces are in face to face engagement with no material between the opposing surfaces.
30. The golf ball of claim 1 , wherein the opposing complementary first and second surfaces comprise the outer surface of the core and the inner surface of the cover layer.
31. The golf ball of claim 1 , wherein the core comprises an inner core and an outer core layer, the outer core layer has an inner surface comprising a third surface of at least partially non-spherical shape and the opposing outer surface of the inner core comprises a matching fourth surface of partially non-spherical shape.
32. The golf ball of claim 31 , wherein the opposing first and second surface are part spherical and have complementary non-spherical portions and the opposing third and fourth surface are part spherical and have complementary non-spherical portions in alignment with the non-spherical portions of the first and second surfaces.
33. The golf ball of claim 1 , wherein the MOI differential between the maximum and minimum MOI of the axes is no more than 2%.
34. The golf ball of claim 33 , wherein the MOI differential is in the range from around 0.05% to around 2%.
35. The golf ball of claim 1 , wherein two of said orthogonal axes are perpendicular x and y axes in the equatorial plane of the ball and the third axis is a z axis, and the MOI about the z axis is higher than the MOI about the x and y axes.
36. The golf ball of claim 2 , wherein at least the cover and intermediate layers are of different specific gravity.
37. The golf ball of claim 1 , wherein the core is of non-polybutadiene material.
38. The golf ball of claim 2 , wherein the inner core is spherical and has no recessed regions.
39. The golf ball of claim 1 , wherein the ball is formed from no more than three pieces, comprising a core, a mantle, and an outer cover layer.
40. A multi-piece golf ball, comprising:
a core comprising at least one piece;
a cover layer surrounding the core and comprising at least one piece;
at least one piece of the ball having an at least partially non-spherical first surface which faces outwards;
a second piece of the ball directly surrounding said first surface having an inwardly facing, second surface of complementary, at least partially non-spherical shape opposing said first surface;
said at least one piece of the ball having a higher specific gravity than at least one other piece;
the ball having first, second and third orthogonal axes; and
the core and cover layer are configured such that the ball has a first moment of inertia (MOI) with respect to the first orthogonal axis which is higher than the MOI with respect to the second and third orthogonal axis, wherein the cover layer comprises an outer cover layer having an outer surface having a plurality of features configured to provide selected aerodynamic properties to the ball, wherein the features are configured to create an MOI differential in the outer cover layer alone between at least two of any of the three orthogonal axes of the ball.
41. The golf ball of claim 40 , wherein the remainder of the ball apart from the outer cover layer is configured to create an MOI differential in the remainder of the ball between at least two of any of the three orthogonal axes of the ball.
42. The golf ball of claim 40 , wherein outer cover layer is oriented with respect to the remainder of the ball such that the cover layer MOI differential and the MOI differential in the remainder of the ball are each less than the MOI differential of the whole ball between at least two of any of the three orthogonal axes of the ball.
43. The golf ball of claim 40 , wherein outer cover layer is oriented with respect to the remainder of the ball such that the cover layer MOI differential and the MOI differential in the remainder of the ball when added together are less than the MOI differential of the whole ball between at least two of any of the three orthogonal axes of the ball.
44. A multi-piece golf ball, comprising:
a core comprising at least one piece;
a cover layer surrounding the core and comprising at least one piece;
at least one piece of the ball having an at least partially non-spherical first surface which faces outwards;
a second piece of the ball directly surrounding said first surface having an inwardly facing, second surface of complementary, at least partially non-spherical shape opposing said first surface;
said at least one piece of the ball having a higher specific gravity than at least one other piece;
the ball having first, second and third orthogonal axes; and
the core and cover layer are configured such that the ball has a first moment of inertia (MOI) with respect to the first orthogonal axis which is higher than the MOI with respect to the second and third orthogonal axis, wherein the first surface has at least one outwardly projecting annular band extending around the surface, and the opposing second surface has an inwardly extending annular channel which receives said projecting band.
45. The golf ball of claim 44 , wherein the first surface has a first pair of outwardly projecting annular bands extending around the surface and the second surface has a matching pair of annular channels which receive the annular bands.
46. The golf ball of claim 44 , wherein the bands cross over one another at diametrically opposed cross over regions on opposite sides of the first surface.
47. The golf ball of claim 46 , wherein the bands cross over at a first angle in the range from 20 degrees to 90 degrees.
48. The golf ball of claim 45 , wherein the bands have an outer face and opposite sides which taper outwardly from the outer face to adjacent portions of the first surface.
49. The golf ball of claim 45 , wherein the first surface has diametrically aligned first flat spots at locations spaced from the bands, and the second surface has opposing second flat spots engaging the first flat spots.
50. The golf ball of claim 45 , wherein the height of the band is less than 0.05 inches.