Golf ball with multi-layered core

• US 20040209706A1
• Filed: 05/12/2004
• Published: 10/21/2004
• Est. Priority Date: 11/28/2001
• Status: Active Grant

• Current Assignee: Acushnet Company (FILA Holdings Corp.)
• Original Assignee: Acushnet Company (FILA Holdings Corp.)
• Inventors: Sullivan, Michael J., DeSimas, Antonio U., Ladd, Derek A.
• Granted Patent: US 7,014,575 B2
• Time in Patent Office: Days
• US Class Current: 473/371
• CPC Class Codes: A63B 37/0003 Golf balls
• CPC Class Codes: A63B 37/0045 Thickness
• CPC Class Codes: A63B 37/00621 Centre hardness
• CPC Class Codes: A63B 37/00622 Surface hardness
• CPC Class Codes: A63B 37/0076 Multi-piece balls, i.e. having two or more intermediate layers
• CPC Class Codes: A63B 37/0093 Moisture vapour transmission rate [MVTR]
• CPC Class Codes: A63B 37/04 Rigid cores

Abstract

A golf ball having a multi-layered core comprising at least three core layers and a dimpled cover is disclosed. The core may have three layers, A, B and C, four layers, A, B, C and D, five layers, A, B, C, D and E or up to six layers, A, B, C, D, E and F. In accordance to the present invention, the radius or thickness of each core layer is at least twice as much as the adjacent outer core layer. One outer core layer can be a water vapor barrier layer to protect the ball from water vapor encroachment, which reduces the performance of the ball. Another outer core layer can be a thin dense layer with high specific gravity to increase the rotational moment of inertia to reduce the spin of the ball during flight. Another outer core layer can be a perforated spherical shell to increase the resilience and/or coefficient of restitution of the ball. Another outer core layer could be a cushioning layer to act as a shock absorber. The core layers may also have increasing or decreasing hardness.

Claims

1. A golf ball comprising a core and a cover, wherein the core comprises at least three layers having a thickness and a radius, at least one of the core layers being comprised of a highly neutralized ethylene copolymer, and wherein the radius and the thickness of the core layers follow the equation T_A≧

2T_B≧

4T_C, wherein T_A is the radius of the inner most core, T_B is the thickness of the adjacent outer core layer and T_C is the thickness of the next adjacent outer core layer.

2. The golf ball of claim 1 further comprising a fourth core layer and wherein the radius and the thickness (T) of the core layers follow the equation T_A≧

2T_B≧

4T_C≧

8T_D, wherein T_D is the thickness of the next adjacent outer core layer.

3. The golf ball of claim 2 further comprising a fifth core layer and wherein the radius and the thickness (T) of the core layers follow the equation T_A≧

2T_B≧

4T_C≧

8T_D≧

16T_E, wherein T_E is the thickness of the next adjacent outer core layer.

4. The golf ball of claim 3 further comprising a sixth core layer and wherein the radius and the thickness (T) of the core layers follow the equation T_A≧

2T_B≧

4T_C≧

8T_D≧

16T_E≧

32T_F, wherein T_F is the thickness of the next adjacent outer core layer.

5. The golf ball of claim 1, wherein one of the core layers is a water vapor barrier layer comprised of a compressed exfoliated graphite layer.

6. The golf ball of claim 1, wherein one of the core layers is a thin dense layer.

7. The golf ball of claim 1, wherein one of the core layers comprises substantially no fillers.

8. The golf ball of claim 1, wherein one of the core layers is foamed.

9. The golf ball of claim 1, wherein the core layers have progressively decreasing hardness from the innermost core layer toward the outermost layer, and wherein the hardness of the innermost core layer is at least 15 points on the Shore D scale higher than the hardness of one of the outer core layers.

10. The golf ball of claim 1, wherein the core layers have progressively increasing hardness from the innermost core layer toward the outermost layer and wherein the hardness of the innermost core layer is at least 15 points on the Shore D scale lower than the hardness of one of the outer core layers.

11. The golf ball of claim 1, wherein at least one core layer comprises polybutadiene, a crosslinking agent, a co-crosslinking agent, and a cis-to-trans catalyst.

12. The golf ball of claim 14, wherein the cis-to-trans catalyst is a halogenated organo-sulfur compound.

13. A golf ball comprising a core and a cover, wherein the core comprises at least four layers having a thickness and wherein the thickness (T) of the core layers follow the equation T_A≧

2T_B≧

4T_C≧

8T_D, wherein T_A is the radius of the inner most core, T_B is the thickness of the adjacent outer core layer, T_C is the thickness of the next adjacent outer core layer, and T_D is the thickness of the next adjacent outer core layer wherein the outer core layers are formed as a laminate and at least one is a water vapor barrier and another is a highly neutralized ethylene copolymer.