Golf ball

Patent metadata

Field	Value
Publication number	US-9750982-B2
Application number	US-201514933192-A
Country	US
Kind code	B2
Filing date	Nov 5, 2015
Priority date	Dec 26, 2014
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

A golf ball has a large number of dimples 10 on a surface thereof. The dimples 10 include a plurality of small dimples 10 S each having an area of less than 8.0 mm 2 , and a plurality of large dimples 10 L each having an area of equal to or greater than 8.0 mm 2 . A ratio PS of a sum of areas of all the small dimples 10 S to a surface area of a phantom sphere of the golf ball is less than 2.0%. A ratio PL of a sum of areas of all the large dimples 10 L to the surface area of the phantom sphere is equal to or greater than 79.0%. A degree G of uniformity of areas of the large dimples 10 L is equal to or less than 1.15.

First claim

What is claimed is:

1. A golf ball having a large number of dimples on a surface thereof, wherein
the dimples include a plurality of small dimples each having an area of less than 8.0 mm 2 , and a plurality of large dimples each having an area of equal to or greater than 8.0 mm 2 ,
a ratio PS of a sum of areas of all the small dimples to a surface area of a phantom sphere of the golf ball is less than 2.0%,
a ratio PL of a sum of areas of all the large dimples to the surface area of the phantom sphere of the golf ball is equal to or greater than 79.0%, and
a degree G of uniformity of areas (mm 2 ) of the large dimples is equal to or less than 1.15.

2. The golf ball according to claim 1 , wherein the ratio PS is equal to or greater than 0.7%.

3. The golf ball according to claim 1 , wherein the number NS of the small dimples is equal to or greater than 6 but equal to or less than 20.

4. The golf ball according to claim 1 , wherein a ratio (NS/N) of the number NS of the small dimples to a total number N of the dimples is equal to or greater than 0.01 but equal to or less than 0.07.

5. The golf ball according to claim 1 , wherein each dimple has a depth of a deepest portion from a surface of the phantom sphere of equal to or greater than 0.10 mm but equal to or less than 0.65 mm.

6. The golf ball according to claim 1 , wherein a total volume of the dimples is equal to or greater than 450 mm 3 but equal to or less than 750 mm 3 .

7. The golf ball according to claim 1 , wherein
the ratio PL is equal to or greater than 79.5%, and
the degree G of uniformity is equal to or less than 1.10.

8. The golf ball according to claim 7 , wherein
the ratio PL is equal to or greater than 80.0%, and
the degree G of uniformity is equal to or less than 1.05.

9. The golf ball according to claim 1 comprising a core, one or more mid layers positioned outside the core, and a cover positioned outside the mid layers, wherein
the cover has a Shore D hardness greater than a Shore D hardness of each of the mid layers, and
an average THm of products obtained by multiplying a thickness (mm) by a hardness (Shore D) for each of the mid layers, and a product THc obtained by multiplying a thickness (mm) by a hardness (Shore D) for the cover satisfy the following mathematical formula:
THc−THm≦ 50.

10. The golf ball according to claim 9 , wherein the product THm and the product THc satisfy the following mathematical formula:
−50≦THc−THm.

11. The golf ball according to claim 1 comprising a core, one or more mid layers positioned outside the core, and a cover positioned outside the mid layers, wherein
the cover has a Shore D hardness smaller than a Shore D hardness of each of the mid layers, and
an average THm of products obtained by multiplying a thickness (mm) by a hardness (Shore D) for each of the mid layers, and a product THc obtained by multiplying a thickness (mm) by a hardness (Shore D) for the cover satisfy the following mathematical formula:
−60≦THc−THm.

12. The golf ball according to claim 11 , wherein the product THm and the product THc satisfy the following mathematical formula:
THc−THm≦ 40.

Assignees

• Dunlop Sports Co Ltd

Inventors

• Mimura Kohei
• Sajima Takahiro
• Takihara Hironori

Classifications

• A63B37/0017

  Specified total dimple volume · CPC title

• A63B37/002

  Specified dimple diameter · CPC title

• A63B37/0043

  Hardness · CPC title

• A63B37/0012

  Dimple profile, i.e. cross-sectional view · CPC title

• A63B37/0047

  Density; Specific gravity · CPC title