Multi-layer core golf ball

• US 8,834,298 B2
• Filed: 08/30/2011
• Issued: 09/16/2014
• Est. Priority Date: 01/10/2008
• Status: Active Grant

• Current Assignee: Acushnet Company (FILA Holdings Corp.)
• Original Assignee: Acushnet Company (FILA Holdings Corp.)
• Inventors: Sullivan, Michael J., Ladd, Derek A.
• Primary Examiner(s): Gorden, Raeann
• Application Number:
  US13/221,874
• Publication Number:
  US 20110312443A1
• Time in Patent Office: 1,113 Days
• Field of Search: 473/376
• US Class Current: 473/376
• CPC Class Codes: A63B 37/0023 Covers
• CPC Class Codes: A63B 37/0039 characterised by the material
• CPC Class Codes: A63B 37/0043 Hardness
• CPC Class Codes: A63B 37/0045 Thickness
• CPC Class Codes: A63B 37/0047 Density; Specific gravity
• CPC Class Codes: A63B 37/0051 Materials other than polybutadienes; Constructional details
• CPC Class Codes: A63B 37/00621 Centre hardness
• CPC Class Codes: A63B 37/00622 Surface hardness
• CPC Class Codes: A63B 37/0063 Hardness gradient
• CPC Class Codes: A63B 37/0064 Diameter
• CPC Class Codes: A63B 37/0066 Density; Specific gravity
• CPC Class Codes: A63B 37/0076 Multi-piece balls, i.e. having two or more intermediate layers
• CPC Class Codes: A63B 37/00922 whereby hardness of the cover is lower than hardness of the intermediate layers

Abstract

Golf balls comprising a multi-layer core and a cover are disclosed. The multi-layer core comprises a center and an outer core layer that are both soft relative to a hard intermediate core layer. The Shore C hardness of the outer surface of the center is preferably greater than the Shore C hardness of the geometric center of the center.

Claims

1. A golf ball comprising a core and a cover, wherein the core has an overall diameter of from 1.40 inches to 1.60 inches and comprises:

a center having a diameter of from 0.50 inches to 1.50 inches, a center Shore C hardness (H_center) of 75 or less, an outer surface Shore C hardness (H_{center surface}) of 70 or greater, wherein H_{center surface}>

H_center;

an intermediate core layer having an outer surface Shore C hardness (H_intermediate) of 75 or greater; and

an outer core layer having an outer surface Shore C hardness (H_{outer core}) of 60 or greater;

wherein H_{center surface}<

H_intermediate, H_{outer core}<

H_intermediate, and H_{outer core}−

H_center≦

10.

2. The golf ball of claim 1, wherein the center has a diameter of from 0.75 inches to 1.50 inches, and the outer core layer has a thickness of from 0.03 inches to 0.07 inches.

3. The golf ball of claim 1, wherein H_center is from 50 to 70.

4. The golf ball of claim 1, wherein H_center is from 55 to 70.

5. The golf ball of claim 4, wherein H_{outer core}−

H_center≦

5.

6. The golf ball of claim 1, wherein H_intermediate is from 80 to 95.

7. The golf ball of claim 1, wherein H_center is from 55 to 68, and H_intermediate is from 85 to 95.

8. The golf ball of claim 1, wherein the center is formed from a first rubber composition, the intermediate core layer is formed from a second rubber composition, and the outer core layer is formed from a third rubber composition.

9. The golf ball of claim 1, wherein the center, the intermediate core layer, and the outer core layer each have a specific gravity of from 1.05 g/cc to 1.25 g/cc.

10. The golf ball of claim 1, wherein the center, the intermediate core layer, and the outer core layer each have a specific gravity of from 1.10 g/cc to 1.19 g/cc.

11. The golf ball of claim 1, wherein the cover comprises an inner cover layer formed from an ionomer composition having a Shore D material hardness of 60 or greater, and an outer cover layer formed from a polyurethane or polyurea composition having a Shore D material hardness of 65 or less, and wherein the outer surface hardness of the outer cover layer is less than the outer surface hardness of the inner cover layer.

12. A golf ball comprising a core and a cover, wherein the core has an overall diameter of from 1.40 inches to 1.60 inches and comprises:

a center having a diameter of from 0.50 inches to 1.50 inches, a center Shore C hardness (H_center) of from 50 to 75, an outer surface Shore C hardness (H_{center surface}) of from 65 to 85, wherein H_{center surface}−

H_center≧

10;

an intermediate core layer having an outer surface Shore C hardness (H_intermediate) of 80 or greater; and

an outer core layer having an outer surface Shore C hardness (H_{outer core}) of 60 or greater;

wherein H_{center surface}<

H_intermediate, H_{outer core}<

H_intermediate, and H_{outer core}−

H_center≦

10.

13. The golf ball of claim 12, wherein H_{outer core}>

H_center.

14. The golf ball of claim 12, wherein the center has a diameter of from 0.75 inches to 1.50 inches, and the outer core layer has a thickness of from 0.03 inches to 0.07 inches.

15. The golf ball of claim 12, wherein H_center is from 50 to 72, H_{center surface} is from 70 to 85, H_intermediate is from 80 to 95, and H_{outer core} is from 60 to 82.

16. The golf ball of claim 12, wherein H_center is from 55 to 70, H_{center surface} is from 70 to 85, H_intermediate is from 85 to 93, and H_{outer core} is from 65 to 80.

17. The golf ball of claim 12, wherein the center is formed from a first rubber composition, the intermediate core layer is formed from a second rubber composition, and the outer core layer is formed from a third rubber composition.

18. The golf ball of claim 12, wherein the center, the intermediate core layer, and the outer core layer each have a specific gravity of from 1.05 g/cc to 1.25 g/cc.

19. The golf ball of claim 12, wherein the center, the intermediate core layer, and the outer core layer each have a specific gravity of from 1.10 g/cc to 1.19 g/cc.

20. The golf ball of claim 12, wherein the cover comprises an inner cover layer formed from an ionomer composition having a Shore D material hardness of 60 or greater, and an outer cover layer formed from a polyurethane or polyurea composition having a Shore D material hardness of 65 or less, and wherein the outer surface hardness of the outer cover layer is less than the outer surface hardness of the inner cover layer.