IP Library Granted Patent US 8,740,729
Granted Patent B2
US 8,740,729 · App. 13/290,158 · Granted Jun 3, 2014

Golf ball

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Quick Facts
Patent No.
US 8,740,729
App. No.
13/290,158
Granted
Jun 3, 2014
Kind
B2
Abstract

A golf ball 2 has, on a surface thereof, a plurality of types of dimples 10 having different diameters from each other. The standard deviation of the curvature radii of cross sections of all the dimples 10 is 0.90 mm or less. The average of the curvature radii of the cross sections of all the dimples 10 is 20% or greater but 40% or less of the diameter of the golf ball. The sum of the volumes of all the dimples is 300 mm 3 or greater but 370 mm 3 or less. The average of the diameters of all the dimples is 3.5 mm or greater but 4.5 mm or less. The ratio of the sum of the areas of all the dimples to the surface area of a phantom sphere of the golf ball is 75% or greater but 95% or less.

Claims (20)

1. A golf ball having, on a surface thereof, a plurality of types of dimples having different diameters from each other, wherein

a standard deviation of curvature radii of cross sections of all the dimples is equal to or less than 0.90 mm, and

an average of the curvature radii of the cross sections of all the dimples is equal to or greater than 20% of a diameter of the golf ball but equal to or less than 40% of the diameter of the golf ball.

2. The golf ball according to claim 1 , wherein the average of the curvature radii of the cross sections of all the dimples is equal to or greater than 20% of the diameter of the golf ball but equal to or less than 35% of the diameter of the golf ball.

3. The golf ball according to claim 1 , wherein a sum of volumes of all the dimples is equal to or greater than 300 mm 3 but equal to or less than 370 mm 3 .

4. The golf ball according to claim 3 , wherein the sum is equal to or greater than 310 mm 3 but equal to or less than 360 mm 3 .

5. The golf ball according to claim 1 , wherein an average of the diameters of all the dimples is equal to or greater than 3.5 mm but equal to or less than 4.5 mm.

6. The golf ball according to claim 1 , wherein the diameter of each dimple is equal to or greater than 3.0 mm but equal to or less than 4.7 mm.

7. The golf ball according to claim 1 , wherein a ratio of a sum of areas of all the dimples to a surface area of a phantom sphere of the golf ball is equal to or greater than 75% but equal to or less than 95%.

8. The golf ball according to claim 1 , wherein a depth of each dimple is equal to or greater than 0.05 mm but equal to or less than 0.24 mm.

9. The golf ball according to claim 1 , wherein a total number of the dimples is equal to or greater than 310 but equal to or less than 440.

10. The golf ball according to claim 1 , wherein

the golf ball comprises a core and a cover,

the cover is formed from a resin composition, and

a base resin of the resin composition is a polyurethane.

11. The golf ball according to claim 10 , wherein

the polyurethane is a thermoplastic polyurethane elastomer that includes a polyurethane component as a hard segment and a soft segment, and

a curing agent for the polyurethane component is an alicyclic diisocyanate.

12. The golf ball according to claim 10 , wherein a Shore D hardness of the cover is equal to or greater than 30 but equal to or less than 60.

13. The golf ball according to claim 10 , wherein a thickness of the cover is equal to or greater than 0.1 mm but equal to or less than 0.8 mm.

Assignments (3)
MERGER Recorded Apr 17, 2018
From: DUNLOP SPORTS CO. LTD.
To: SUMITOMO RUBBER INDUSTRIES, LTD.
Reel/Frame 045959/0204 →
CHANGE OF NAME Recorded Apr 12, 2018
From: SRI SPORTS LIMITED
To: DUNLOP SPORTS CO. LTD.
Reel/Frame 045932/0024 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 7, 2011
From: NAKAMURA, HIROTAKA
To: SRI SPORTS LIMITED
Reel/Frame 027184/0948 →