Golf ball dimples with a catenary curve profile

• US 7,641,572 B2
• Filed: 02/15/2008
• Issued: 01/05/2010
• Est. Priority Date: 09/03/1997
• Status: Expired due to Fees

• Current Assignee: Acushnet Company (FILA Holdings Corp.)
• Original Assignee: Acushnet Company (FILA Holdings Corp.)
• Inventors: Aoyama, Steven, Nardacci, Nicholas M.
• Primary Examiner(s): GORDEN, RAEANN
• Application Number:
  US12/071,087
• Publication Number:
  US 20080220907A1
• Time in Patent Office: 690 Days
• Field of Search: 473383-385
• US Class Current: 473/383
• CPC Class Codes: A63B 37/00065 located around the pole or the equator
• CPC Class Codes: A63B 37/0012 Dimple profile, i.e. cross-sectional view
• CPC Class Codes: A63B 37/0019 Specified dimple depth
• CPC Class Codes: A63B 37/002 Specified dimple diameter
• CPC Class Codes: A63B 37/00215 Volume ratio
• CPC Class Codes: A63B 37/0032 Hardness gradient
• CPC Class Codes: A63B 37/0034 Deflection or compression
• CPC Class Codes: A63B 37/0096 Spin rate

Abstract

A golf ball having an outside surface with a plurality of dimples formed thereon. The dimples on the ball have a cross-sectional profiles formed by a catenary curve. Combinations of varying dimple diameters, shape factors, and chordal depths in the catenary curve are used to vary the ball flight performance according to ball spin characteristics, player swing speed, as well as satisfy specific aerodynamic magnitude and direction criteria.

Claims

1. A golf ball having a plurality of recessed dimples on the surface thereof, wherein at least a portion of the plurality of recessed dimples have a profile defined by the revolution of a catenary curve according to the following function:

$y=\frac{d_c(\cosh <br><br>\left(\mathrm{sf}*x\right)-1}{\cosh <br><br>\left(\mathrm{sf}*\frac{D}{2}\right)-1}$

wherein y is the vertical direction coordinate away from the center of the ball with 0 at the center of the dimple;

x is the horizontal (radial) direction coordinate from the dimple apex to the dimple surface with 0 at the center of the dimple;

sf is a shape factor;

d_c is the chordal depth of the dimple;

D is the diameter of the dimple; and

wherein D is between about 0.115 inches and about 0.185 inches, sf is from about 5 to about 200, and d_c is from about 0.002 inches to about 0.008 inches.

2. The golf ball of claim 1, wherein at least a portion comprises about 50 percent or more of the dimples on the golf ball.

3. The golf ball of claim 1, wherein at least a portion comprises about 80 percent or more of the dimples on the golf ball.

4. The golf ball of claim 1, wherein D is between about 0.125 inches and about 0.185 inches.

5. The golf ball of claim 1, wherein sf is from about 10 to about 100.

6. The golf ball of claim 1, wherein sf is from about 10 to about 75.

7. The golf ball of claim 1, wherein d_c is from about 0.004 inches to about 0.006 inches.

8. The golf ball of claim 1, wherein D is between about 0.115 inches and about 0.185 inches, sf is from about 10 to 100, and d_c is from about 0.004 inches to about 0.006 inches.

9. The golf ball of claim 1, wherein the golf ball comprises a plurality of dimples having an aerodynamic coefficient magnitude defined by C_mag=√

(C_L²+C_D²) and an aerodynamic force angle defined by Angle=tan<sup>−

1</sup>(C_L/C_D), wherein C_L is a lift coefficient and C_D is a drag coefficient, wherein the golf ball comprises;

a first aerodynamic coefficient magnitude between about 0.24 and about 0.29 and a first aerodynamic force angle between about 32 degrees and about 39 degrees at a Reynolds Number of about 230000 and a spin ratio of about 0.080; and

a second aerodynamic coefficient magnitude between about 0.24 and about 0.29 and a second aerodynamic force angle between about 33 degrees and about 41 degrees at a Reynolds Number of about 208000 and a spin ratio of about 0.090.

10. The golf ball of claim 9, further comprising:

a third aerodynamic coefficient magnitude between about 0.25 and about 0.30 and a third aerodynamic force angle between about 34 degrees and about 42 degrees at a Reynolds Number of about 190000 and a spin ratio of about 0.10; and

a fourth aerodynamic coefficient magnitude between about 0.25 and about 0.31 and a fourth aerodynamic force angle between about 35 degrees and about 43 degrees at a Reynolds Number of about 170000 and a spin ratio of about 0.11.

19. The golf ball of claim 1, wherein the volume ratio is at least about 0.60.

11. A golf ball having a plurality of recessed dimples on the surface thereof, wherein at least a portion of the plurality of recessed dimples have a profile defined by the revolution of a catenary curve according to the following function:

$y=\frac{d_c(\cosh <br><br>\left(\mathrm{sf}*x\right)-1}{\cosh <br><br>\left(\mathrm{sf}*\frac{D}{2}\right)-1}$

wherein y is the vertical direction coordinate away from the center of the ball with 0 at the center of the dimple;

x is the horizontal (radial) direction coordinate from the dimple apex to the dimple surface with 0 at the center of the dimple;

sf is a shape factor and from about 10 to about 75;

d_c is the chordal depth of the dimple and from about 0.004 inches to about 0.006 inches; and

D is the diameter of the dimple.

12. The golf ball of claim 11, wherein D is between about 0.115 inches and about 0.185 inches.

13. The golf ball of claim 11, wherein D is between about 0.125 inches and about 0.185 inches.

14. The golf ball of claim 11, wherein at least a portion comprises about 50 percent or more of the dimples on the golf ball.

15. The golf ball of claim 11, wherein at least a portion comprises about 80 percent or more of the dimples on the golf ball.

16. The golf ball of claim 11, wherein the golf ball comprises a plurality of dimples having an aerodynamic coefficient magnitude defined by C_mag=√

(C_L²+C_D²) and an aerodynamic force angle defined by Angle=tan<sup>−

1</sup>(C_L/C_D), wherein C_L is a lift coefficient and C_D is a drag coefficient, wherein the golf ball comprises;

a first aerodynamic coefficient magnitude between about 0.24 and about 0.29 and a first aerodynamic force angle between about 32 degrees and about 39 degrees at a Reynolds Number of about 230000 and a spin ratio of about 0.080; and

a second aerodynamic coefficient magnitude between about 0.24 and about 0.29 and a second aerodynamic force angle between about 33 degrees and about 41 degrees at a Reynolds Number of about 208000 and a spin ratio of about 0.090.

17. The golf ball of claim 16, further comprising:

a third aerodynamic coefficient magnitude between about 0.25 and about 0.30 and a third aerodynamic force angle between about 34 degrees and about 42 degrees at a Reynolds Number of about 190000 and a spin ratio of about 0.10; and

a fourth aerodynamic coefficient magnitude between about 0.25 and about 0.31 and a fourth aerodynamic force angle between about 35 degrees and about 43 degrees at a Reynolds Number of about 170000 and a spin ratio of about 0.11.

18. The golf ball of claim 11, wherein the volume ratio is at least about 0.60.