Golf ball dimple profile
The present invention concerns a golf ball with dimples having a cross-sectional profile comprising a conical base shape and a spherical cap with a prescribed point of tangency to the cone sidewall. More particularly, the conical profiles of the present invention are defined by three independent parameters: dimple diameter (D D ), edge angle (Φ EDGE ), and saucer ratio (S r ) which is a measure of the relative curvature of the dimple bottom. 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 dimple consisting of a top conical edge and a bottom spherical cap, and having a defined point of tangency at an intersection between the top conical edge and the bottom spherical cap, wherein a difference between a slope of the conical edge and a slope of the spherical cap at the point of tangency is less than about 2°,
wherein said dimple has a shape defined by at least a saucer ratio (S r ) and edge angle (Φ EDGE ),
wherein S r is defined as a ratio of dimple diameter (D D ) to spherical cap diameter (D S ) and the value of said ratio is between about 0.05 and about 0.75, and
wherein Φ EDGE is defined as an angle between a first line T 1 tangent to the conical edge and a second line T 2 tangent to a phantom spherical surface.
2. The golf ball dimple according to claim 1 , wherein the difference between the slope of the conical edge and the slope of the spherical cap is less than about 1°.
3. The golf ball dimple according to claim 1 , wherein the slope of the conical edge and the slope of the spherical cap is about equal.
4. The golf ball dimple according to claim 1 , wherein Φ EDGE is calculated by the mathematical equation Φ EDGE =Φ CAP +Φ CHORD ,
wherein Φ CAP is defined by the equation sin −1 (D D /D B ), wherein D D represents the dimple diameter and D B represents the ball diameter
wherein Φ CHORD is defined by the equation tan −1 {(d CHORD −d SAUCER )÷(R D −R S )}, wherein d CHORD represents chord depth, R D represents dimple radius, and R S represents saucer radius, and d SAUCER is defined by the equation d SAUCER =r APEX √{square root over ((r APEX 2 −R S 2 ))} and r APEX is defined by the equation r APEX =R S /sin(Φ CHORD ).
5. The golf ball dimple according to claim 1 , wherein said dimple has a volume ratio (V R ) defined by the ratio of dimple volume (V D ) to theoretical cylindrical volume (V C ) and the value of said ratio is in the range of about ⅓≦V R ≦½,
wherein V D is defined by the equation V D =[⅓π D 2 (d CHORD )]−[⅓πR S 2 (d SAUCER )]+[π(d SAUCER )(3R S 2 d SAUCER 2 )÷6], wherein d CHORD represents chord depth, R D represents dimple radius, R S represents saucer radius, and
wherein V C is defined by the equation πR D 2 (d CHARD ).
6. The golf ball dimple according to claim 1 , wherein said dimple has a saucer ratio S r of about 0.10≦S r ≦0.70.
7. The golf ball dimple according to claim 1 , wherein said dimple has a saucer ratio S r of about 0.20≦S r ≦0.60.
8. The golf ball dimple according to claim 1 , wherein said dimple has a saucer ratio S r of about 0.25≦S r ≦0.55.
9. The golf ball dimple according to claim 1 , wherein said dimple has a saucer ratio S r of about 0.30≦S r ≦0.50.
10. The golf ball dimple according to claim 1 , wherein said dimple has a saucer ratio S r of about 0.35≦S r ≦0.45.
11. A golf ball comprising:
a generally spherical surface;
a plurality of dimples separated by a land area formed on the surface, wherein at least one of the dimples consists of a top conical edge and a bottom spherical cap, and having a defined point of tangency at an intersection between the top conical edge and the bottom spherical cap, wherein a difference between a slope of the conical edge and a slope of the spherical cap at the point of tangency is less than about 2°,
wherein said dimple has a shape defined by at least a saucer ratio (S r ) and edge angle (Φ EDGE ),
wherein S r is defined as a ratio of dimple diameter (D D ) to spherical cap diameter (D S ) and the value of said ratio is between about 0.05 and about 0.75, and
wherein Φ EDGE is defined as an angle between a first line T 1 tangent to the conical edge and a second line T 2 tangent to a phantom spherical surface.
12. The golf ball according to claim 11 , wherein the difference between the slope of the conical edge and the slope of the spherical cap is less than about 1°.
13. The golf ball dimple according to claim 11 , wherein the slope of the conical edge and the slope of the spherical cap is about equal.
14. The golf ball according to claim 11 , wherein Φ EDGE is calculated by the mathematical equation Φ EDGE =Φ CAP +Φ CHORD ,
wherein Φ CAP is defined by the equation sin −1 (D D /D B ), wherein D D represents the dimple diameter and D B represents the ball diameter
wherein Φ CHORD is defined by the equation tan −1 {(d CHORD −d SAUCER )÷(R D −R S )}, wherein d CHORD represents chord depth, d SAUCER represents saucer depth, R D represents dimple radius, and R S represents saucer radius, and
wherein d SAUCER is defined by the equation d SAUCER =r APEX −√{square root over ((r APEX 2 −R S 2 ))} and r APEX is defined by the equation r APEX =R S /sin(Φ CHORD ).
15. The golf ball according to claim 11 , wherein said at least one dimple has a volume ratio (V R ) defined by the ratio of dimple volume (V D ) to theoretical cylindrical volume (V C ) and the value of said ratio is in the range of about ⅓≦V R ≦½,
wherein V D is defined by the equation V D =[ 1 / 3 πR D 2 (d CHORD )]−[ 1 / 3 πR S 2 (d SAUCER )]+[π(d SAUCER ) (3R S 2 +d SAUCER 2 )÷6], wherein d CHORD represents chord depth, d SAUCER represents saucer depth, R D represents dimple radius, and R S represents saucer radius, and
wherein V C is defined by the equation πR D 2 (d CHORD ).
16. The golf ball according to claim 11 , wherein said at least one dimple has a saucer ratio S r of about 0.10≦S r ≦0.70.
17. The golf ball according to claim 11 , wherein said at least one dimple has a saucer ratio S r of about 0.20≦S r ≦0.60.
18. The golf ball according to claim 11 , wherein said at least one dimple has a saucer ratio S r of about 0.25≦S r ≦0.55.
19. The golf ball according to claim 11 , wherein said at least one dimple has a saucer ratio S r of about 0.30≦S r ≦0.50.
20. The golf ball according to claim 11 , wherein said at least one dimple has a saucer ratio S r of about 0.35≦S r ≦0.45.