Golf ball dimple profile
The present invention concerns a golf ball having dimples with a cross-sectional profile comprising a conical top portion and a non-conical bottom portion. More particularly, the profiles of the present invention are defined by three independent parameters: dimple diameter (D D ), edge angle (Φ EDGE ), and saucer ratio (S r ). These parameters fully define the dimple shape and allow for greater flexibility in constructing a dimple profile versus conventional spherical dimples. Further, conical dimples provide a unique dimple cross-section which is visually distinct.
1. A golf ball having a generally spherical surface and comprising a plurality of dimples separated by a land area formed on the ball surface, wherein at least a portion of the dimples:
consist of a top conical sidewall, a bottom portion, and a transition surface that connects the top conical sidewall to the land area, wherein the bottom portion is defined by a function rotated about a central axis, the function being selected from the group consisting of polynomial, trigonometric, hyperbolic, exponential functions, and the superposition of two or more thereof, excluding linear functions and functions that result in a cone or sphere;
have a saucer ratio (S r ), defined as the ratio of the bottom portion diameter (D S ) to the dimple diameter (D D ), of from about 0.05 to about 0.75; and
have a transition ratio (T r ) of from 0.02 to 0.50, where the transition ratio (T r ) is defined by the equation T r =1−(D T /D D ), where D D is the dimple diameter and D T is the diameter at the point of intersection between the transition surface and the top conical sidewall.
2. The golf ball of claim 1 , wherein the transition surface is defined by a circular arc rotated about a central axis.
3. The golf ball of claim 1 , wherein T r <S r .
4. The golf ball of claim 1 , wherein T r >S r .
5. The golf ball of claim 1 , wherein T r =S r .
6. The golf ball of claim 1 , wherein there is a defined point of intersection between the transition surface and the top conical sidewall, wherein the difference between the slope of the transition surface and the slope of the top conical sidewall at the point of intersection is 2° or less.
7. The golf ball of claim 1 , wherein there is a defined point of intersection between the top conical sidewall and the bottom portion, wherein a difference between the slope of the top conical sidewall and the slope of the bottom portion at the point of intersection is 2° or less.
8. The golf ball of claim 1 , wherein the dimples have an edge angle (Φ EDGE ) defined by
1.33( S r ) 2 −0.39( S r )+10.40≤Φ EDGE ≤2.85( S r ) 2 −1.12( S r )+13.49.
9. The golf ball of claim 1 , wherein the dimples have a chord depth (d CHORD ) defined by
0.0009( S r ) 2 −0.0035( S r )+0.0062≤ d CHORD ≤0.0030( S r ) 2 −0.0069( S r )+0.0113.
10. A golf ball having a generally spherical surface and comprising a plurality of dimples separated by a land area formed on the ball surface, wherein at least a portion of the dimples:
consist of a top conical sidewall, a bottom spherical cap, and a transitional surface that connects the top conical sidewall to the land area;
have a saucer ratio (S r ), defined as the ratio of the spherical cap diameter (D S ) to the dimple diameter (D D ), of from about 0.05 to about 0.75; and
have a transition ratio (T r ) of from 0.02 to 0.50, where the transition ratio (T r ) is defined by the equation T r =1−(D T /D D ), where D D is the dimple diameter and D T is the diameter at the point of intersection between the transition surface and the top conical sidewall.
11. The golf ball of claim 10 , wherein the transition surface is defined by a circular arc rotated about a central axis.
12. The golf ball of claim 10 , wherein T r <S r .
13. The golf ball of claim 10 , wherein T r >S r .
14. The golf ball of claim 10 , wherein T r =S r .
15. The golf ball of claim 10 , wherein there is a defined point of intersection between the transition surface and the top conical sidewall, wherein the difference between the slope of the transition surface and the slope of the top conical sidewall at the point of intersection is 2° or less.
16. The golf ball of claim 10 , wherein there is a defined point of intersection between the top conical sidewall and the bottom portion, wherein a difference between the slope of the top conical sidewall and the slope of the bottom portion at the point of intersection is 2° or less.
17. The golf ball of claim 10 , wherein the dimples have an edge angle (Φ EDGE ) defined by
1.33( S r ) 2 −0.39( S r )+10.40≤Φ EDGE ≤2.85( S r ) 2 −1.12( S r )+13.49.
18. The golf ball of claim 10 , wherein the dimples have a chord depth (d CHORD )) defined by
0.0009( S r ) 2 −0.0035( S r )+0.0062≤ d CHORD ≤0.0030( S r ) 2 −0.0069( S r )+0.0113.