Multi-layer golf ball having velocity gradient from faster center to slower cover

• US 7,530,908 B2
• Filed: 10/16/2007
• Issued: 05/12/2009
• Est. Priority Date: 02/06/2004
• Status: Active Grant

• Current Assignee: Acushnet Company (FILA Holdings Corp.)
• Original Assignee: Acushnet Company (FILA Holdings Corp.)
• Inventors: Bulpett, David A., Sullivan, Michael J., Aoyama, Steven, Boehm, Herbert C., Ladd, Derek A.
• Primary Examiner(s): GORDEN, RAEANN
• Application Number:
  US11/872,777
• Publication Number:
  US 20080171617A1
• Time in Patent Office: 574 Days
• Field of Search: 473/376, 473/374, 473/373, 473/368, 473/367
• US Class Current: 473/376
• CPC Class Codes: A63B 37/0003 Golf balls
• CPC Class Codes: A63B 37/0076 Multi-piece balls, i.e. having two or more intermediate layers
• CPC Class Codes: A63B 37/0078 Coefficient of restitution
• CPC Class Codes: A63B 37/02 Special cores balls with finger holes A63B37/0001, golf ball cores A63B37/005

Abstract

The present invention is directed to multi-layer golf balls having a center, a cover layer, and at least one intermediate layer between the core and the cover layer. The core, the at least one intermediate layer and the cover are constructed to have different initial velocities and COR such that the gradient of the initial velocities and COR progress from a faster center to a slower cover.

Claims

1. A multi-layer golf ball comprising a center, a cover layer, and at least two intermediate layers between the center and the cover layer,

wherein each subassembly of the golf ball has a combined coefficient of restitution value of COR_C for the center, COR_C1 for a first subassembly with a first intermediate layer adjacent to the center, COR_C2 for a second subassembly with a second intermediate layer adjacent to the first intermediate layer and COR_C3 for the ball including the cover layer, and

COR_C≧

COR_C1+0.004;

COR_C1≧

COR_C2+0.004;

COR_C2≧

COR_C3+0.004, and

wherein COR_C is at least 0.815.

2. The multi-layer golf ball of claim 1, wherein COR_C is at least 0.825.

3. The multi-layer golf ball of claim 1, wherein COR_C is at least 0.830.

4. The multi-layer golf ball of claim 1, wherein COR_C1 is at least 0.810.

5. The multi-layer golf ball of claim 1, wherein COR_C1 is at least 0.820.

6. The multi-layer golf ball of claim 1, wherein COR_C2 is at least 0.800.

7. The multi-layer golf ball of claim 1, wherein COR_C2 is at least 0.810.

8. A multi-layer golf ball comprising a center, a cover layer, and at least two intermediate layers between the center and the cover layer,

wherein each subassembly of the golf ball has a combined coefficient of restitution value of COR_C for the center, COR_C1 for a first subassembly with a first intermediate layer adjacent to the center, COR_C2 for a second subassembly with a second intermediate layer adjacent to the first intermediate layer and COR_C3 for the ball including the cover layer, and

COR_C≧

COR_C1+0.004;

COR_C1≧

COR_C2+0.004;

COR_C2 ≧

COR_C3+0.004, and

wherein COR_C is at least 0.815, and

wherein the change in coefficient of restitution from one subassembly to the next larger assembly per the thickness of the next larger subassembly is at least 0.00015 per thousandth of an inch.

9. The multi-layer golf ball of claim 8, wherein said change in coefficient of restitution is at least about 0.00025 per thousandth of an inch.

10. The multi-layer golf ball of claim 8, wherein

the center comprises a highly neutralized polymer formed from a reaction between acid groups on a polymer, a suitable source of cation, an organic acid or the corresponding salt, and

the amount of the suitable source of cation is sufficient to neutralize the acid groups by at least about 80%.

11. The multi-layer golf ball of claim 10, wherein the amount of the suitable source of cation is sufficient to neutralize the acid groups by about 90%.