Dimple patterns for golf balls
A golf ball dimple pattern based on a square dipyramid, i.e., two square pyramids connected base-to-base, is disclosed. The dimples are arranged within four substantially identical triangular sections on each of two substantially identical hemispheres of the ball.
1. A golf ball having a plurality of dimples disposed on the spherical outer surface thereof, wherein:
the plurality of dimples comprises at least three different dimple diameters, including a minimum dimple diameter, a maximum dimple diameter, and at least one additional dimple diameter;
the golf ball consists of two hemispheres separated by an equator, the two hemispheres having substantially identical dimple arrangements;
each hemispherical dimple arrangement consists of four triangular sections that are defined by projecting the four faces of a square pyramid onto the hemisphere such that each of the four triangular sections is defined by a border consisting of a linear equatorial edge which corresponds to a portion of the equator of the ball and two linear side edges connecting each end of the equatorial edge to a pole of the ball;
the four triangular sections of each hemisphere are substantially identical in size and dimple arrangement;
the dimple arrangement within each of the four triangular sections is not rotationally symmetric about the center of the section;
each of the four triangular sections can be divided into a polar region from latitude angle 0° to latitude angle 30°, an intermediate region from latitude angle 30° to latitude angle 60°, and an equatorial region from latitude angle 60° to latitude angle 90°, where latitude angle 0° is the pole and latitude angle 90° is the equator;
from 2% to 10% of the dimples have an elliptical plan shape; and
each dimple having an elliptical plan shape is located in the polar region.
2. The golf ball of claim 1 , wherein the elliptical plan shape has a major axis and a minor axis, the length of the major axis being greater than the length of the minor axis, and wherein, for each dimple having an elliptical plan shape, the difference between the length of the major axis and the length of the minor axis is 0.020 inches or less.
3. The golf ball of claim 1 , wherein the elliptical plan shape has a major axis and a minor axis, the length of the major axis being greater than the length of the minor axis, and wherein, for each dimple having an elliptical plan shape, the difference between the length of the major axis and the length of the minor axis is from 0.003 inches to 0.020 inches.
4. The golf ball of claim 3 , wherein, for a first portion of the dimples having an elliptical plan shape, the difference between the length of the major axis and the length of the minor axis is from 0.003 inches to 0.005 inches, and, for a second portion of the dimples having an elliptical plan shape, the difference between the length of the major axis and the length of the minor axis is from 0.005 inches to 0.020 inches.
5. The golf ball of claim 1 , wherein the elliptical plan shape has a major axis and a minor axis, the length of the major axis being greater than the length of the minor axis, and wherein, for each dimple having an elliptical plan shape, the ratio of the length of the major axis to the length of the minor axis is from 1.02 to 1.10.
6. The golf ball of claim 5 , wherein, for a first portion of the dimples having an elliptical plan shape, the ratio of the length of the major axis to the length of the minor axis is from 1.02 to 1.04, and, for a second portion of the dimples having an elliptical plan shape, the ratio of the length of the major axis to the length of the minor axis is from 1.04 to 1.10.
7. The golf ball of claim 1 , wherein the elliptical plan shape has a major axis and a minor axis, the length of the major axis being greater than the length of the minor axis, and wherein the length of the minor axis is from 0.120 inches to 0.160 inches.
8. The golf ball of claim 1 , wherein the dimple arrangement includes a shared polar dimple, and wherein the shared polar dimple has a circular plan shape.
9. The golf ball of claim 1 , wherein from 4% to 8% of the dimples have an elliptical plan shape.
10. The golf ball of claim 1 , wherein the plurality of dimples consists of dimples having an elliptical plan shape and dimples having a circular plan shape.
11. The golf ball of claim 1 , wherein the plurality of dimples consists of dimples having an elliptical plan shape and dimples having a non-elliptical, non-circular plan shape.
12. The golf ball of claim 1 , wherein the plurality of dimples comprises dimples having an elliptical plan shape, dimples having a circular plan shape, and dimples having a non-elliptical, non-circular plan shape.
13. The golf ball of claim 1 , wherein the plurality of dimples comprises at least five different dimple diameters.
14. The golf ball of claim 1 , wherein the plurality of dimples comprises at least six different dimple diameters.
15. The golf ball of claim 1 , wherein there are no dimple free great circles on the outer surface of the ball.
16. The golf ball of claim 1 , wherein the dimple arrangement within each of the four triangular sections optionally includes a shared polar dimple having a centroid that lies at the vertex of the two side edges of the section, where the diameter of the shared polar dimple, if present, is not the minimum dimple diameter or the maximum dimple diameter.