Multi-layer golf ball having velocity gradient from faster center to slower cover
View Patent ↗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.
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%.