Golf balls having volumetric equivalence on opposing hemispheres and symmetric flight performance and methods of making same
Golf balls according to the present invention achieve flight symmetry and overall satisfactory flight performance due to a dimple surface volume ratio that is equivalent between opposing hemispheres despite the use of different dimple geometries, different dimple arrangements, and/or different dimple counts on the opposing hemispheres.
1. A golf ball consisting of a first hemisphere and a second hemisphere separated by an equator, the first hemisphere consisting of a plurality of first hemisphere dimples disposed on the surface thereof and the second hemisphere consisting of a plurality of second hemisphere dimples disposed on the surface thereof, wherein each dimple is considered to be located in the hemisphere in which its center is positioned and no dimple has a center positioned on the equator, and wherein:
the first hemisphere dimples consist of a plurality of non-polar dimples, and, optionally, a polar dimple;
the second hemisphere dimples consist of a plurality of non-polar dimples, and, optionally, a polar dimple;
the first hemisphere dimples and the second hemisphere dimples have the same non-circular plan shape, the non-circular plan shape having reference points A, B, C and D located thereon;
the first hemisphere dimples have substantially the same directional orientation, such that, for each non-polar dimple of the first hemisphere, the axis that intersects the perimeter of the dimple at reference points A and B on the plan shape is parallel to the equatorial plane of the golf ball;
the second hemisphere dimples have substantially the same directional orientation, such that, for each non-polar dimple of the second hemisphere, the axis that intersects the perimeter of the dimple at reference points C and D on the plan shape is parallel to the equatorial plane of the golf ball;
the first hemisphere dimples have a different directional orientation than the second hemisphere dimples, such that a first reference line connecting reference points A and B on the plan shape and a second reference line connecting reference points C and D on the plan shape have an angular difference of from 30° to 150°; and
the absolute difference between the average dimple surface volume of the first hemisphere and the average dimple surface volume of the second hemisphere is less than 3.5×10 −6 in 3 .
2. The golf ball of claim 1 , wherein the golf ball includes dimples having at least two different diameters.
3. The golf ball of claim 1 , wherein the outer surface of the golf ball does not contain a great circle which is free of dimples.
4. A golf ball consisting of a first hemisphere and a second hemisphere separated by an equator, the first hemisphere having a plurality of first hemisphere dimples disposed on the surface thereof and the second hemisphere having a plurality of second hemisphere dimples disposed on the surface thereof, wherein each dimple is considered to be located in the hemisphere in which its center is positioned and no dimple has a center positioned on the equator, and wherein:
the first hemisphere dimples consist of a plurality of non-polar dimples, and, optionally, a polar dimple;
the second hemisphere dimples consist of a plurality of non-polar dimples, and, optionally, a polar dimple;
the first hemisphere dimples and the second hemisphere dimples have the same non-circular plan shape, the non-circular plan shape having reference points A, B, C and D located thereon;
the first hemisphere dimples have substantially the same directional orientation, such that, for each non-polar dimple of the first hemisphere, the axis that intersects the perimeter of the dimple at reference points A and B on the plan shape is parallel to the equatorial plane of the golf ball;
the second hemisphere dimples have substantially the same directional orientation, such that, for each non-polar dimple of the second hemisphere, the axis that intersects the perimeter of the dimple at reference points C and D on the plan shape is parallel to the equatorial plane of the golf ball;
the first hemisphere dimples have a different directional orientation than the second hemisphere dimples, such that a first reference line connecting reference points A and B on the plan shape and a second reference line connecting reference points C and D on the plan shape have an angular difference of from 30° to 150°,
the absolute difference between the average dimple surface volume of the first hemisphere and the average dimple surface volume of the second hemisphere is less than 3.5×10 −6 in 3 ; and
wherein the first hemisphere dimples and the second hemisphere dimples have a plan shape selected from ovals, squares, triangles, and rectangles.
5. A golf ball consisting of a first hemisphere and a second hemisphere separated by an equator, the first hemisphere having a plurality of first hemisphere dimples disposed on the surface thereof and the second hemisphere having a plurality of second hemisphere dimples disposed on the surface thereof, wherein each dimple is considered to be located in the hemisphere in which its center is positioned and no dimple has a center positioned on the equator, and wherein:
the first hemisphere dimples consist of a plurality of non-polar dimples, and, optionally, a polar dimple;
the second hemisphere dimples consist of a plurality of non-polar dimples, and, optionally, a polar dimple;
the first hemisphere dimples and the second hemisphere dimples have an elliptical plan shape, the elliptical plan shape having reference points A, B, C and D located thereon, wherein reference points A and B correspond to the endpoints of the major axis of the elliptical plan shape and reference points C and D correspond to the endpoints of the minor axis of the elliptical plan shape;
the first hemisphere dimples have substantially the same directional orientation, such that, for each non-polar dimple of the first hemisphere, the axis that intersects the perimeter of the dimple at reference points A and B on the plan shape is parallel to the equatorial plane of the golf ball;
the second hemisphere dimples have substantially the same directional orientation, such that, for each non-polar dimple of the second hemisphere, the axis that intersects the perimeter of the dimple at reference points C and D on the plan shape is parallel to the equatorial plane of the golf ball; and
the absolute difference between the average dimple surface volume of the first hemisphere and the average dimple surface volume of the second hemisphere is less than 3.5×10 −6 in 3 .
6. The golf ball of claim 5 , wherein the golf ball includes dimples having at least two different diameters.
7. The golf ball of claim 5 , wherein the outer surface of the golf ball does not contain a great circle which is free of dimples.
8. A golf ball consisting of a first hemisphere and a second hemisphere separated by an equator, the first hemisphere having a plurality of first hemisphere dimples disposed on the surface thereof and the second hemisphere having a plurality of second hemisphere dimples disposed on the surface thereof, wherein each dimple is considered to be located in the hemisphere in which its center is positioned and no dimple has a center positioned on the equator, and wherein:
the first hemisphere dimples consist of a plurality of non-polar dimples, and, optionally, a polar dimple;
the second hemisphere dimples consist of a plurality of non-polar dimples, and, optionally, a polar dimple;
the first hemisphere dimples and the second hemisphere dimples have a square plan shape, the square plan shape having reference points A, B, C and D located thereon, wherein reference points A and B correspond to the midpoints of non-adjacent sides of the square plan shape and reference points C and D correspond to non-adjacent vertices of the square plan shape;
the first hemisphere dimples have substantially the same directional orientation, such that, for each non-polar dimple of the first hemisphere, the axis that intersects the perimeter of the dimple at reference points A and B on the plan shape is parallel to the equatorial plane of the golf ball;
the second hemisphere dimples have substantially the same directional orientation, such that, for each non-polar dimple of the second hemisphere, the axis that intersects the perimeter of the dimple at reference points C and D on the plan shape is parallel to the equatorial plane of the golf ball; and
the absolute difference between the average dimple surface volume of the first hemisphere and the average dimple surface volume of the second hemisphere is less than 3.5×10 −6 in 3 .
9. The golf ball of claim 8 , wherein the golf ball includes dimples having at least two different diameters.
10. The golf ball of claim 8 , wherein the outer surface of the golf ball does not contain a great circle which is free of dimples.
11. A golf ball consisting of a first hemisphere and a second hemisphere separated by an equator, the first hemisphere having a plurality of first hemisphere dimples disposed on the surface thereof and the second hemisphere having a plurality of second hemisphere dimples disposed on the surface thereof, wherein each dimple is considered to be located in the hemisphere in which its center is positioned and no dimple has a center positioned on the equator, and wherein:
the first hemisphere dimples consist of a plurality of non-polar dimples, and, optionally, a polar dimple;
the second hemisphere dimples consist of a plurality of non-polar dimples, and, optionally, a polar dimple;
the first hemisphere dimples and the second hemisphere dimples have a triangular plan shape, the triangular plan shape having reference points A, B, C and D located thereon, wherein reference points A and C are equivalent points and correspond to the midpoint of a first side of the triangular plan shape, reference point B corresponds to the midpoint of a second side of the triangular plan shape, and reference point D corresponds to the vertex adjoining the second side and a third side of the triangular plan shape;
the first hemisphere dimples have substantially the same directional orientation, such that, for each non-polar dimple of the first hemisphere, the axis that intersects the perimeter of the dimple at reference points A and B on the plan shape is parallel to the equatorial plane of the golf ball;
the second hemisphere dimples have substantially the same directional orientation, such that, for each non-polar dimple of the second hemisphere, the axis that intersects the perimeter of the dimple at reference points C and D on the plan shape is parallel to the equatorial plane of the golf ball; and
the absolute difference between the average dimple surface volume of the first hemisphere and the average dimple surface volume of the second hemisphere is less than 3.5×10 −6 in 3 .
12. The golf ball of claim 11 , wherein the golf ball includes dimples having at least two different diameters.
13. The golf ball of claim 11 , wherein the outer surface of the golf ball does not contain a great circle which is free of dimples.