Golf ball
A golf ball for amateur golfers exhibits excellent flight characteristics when hit by the average golfer and also has a good feel at impact that is both soft and solid. The golf ball includes a core, an intermediate layer and a cover, and has coefficient of restitution and compressive deformation relationships that satisfy specific conditions.
1. A golf ball comprising a core, an intermediate layer and a cover wherein, letting LBS, MBS and HBS be the respective coefficients of restitution for the ball at incident velocities of 35 m/s, 45 m/s and 55 m/s, LMS, MMS and HMS be the respective coefficients of restitution for the sphere obtained by encasing the core with the intermediate layer (intermediate layer-encased sphere) at incident velocities of 35 m/s, 45 m/s and 55 m/s and BC be the compressive deformation (mm) of the ball when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf), the ball satisfies formulas (1) and (2) below:
5.10≤( LBS+MBS )× BC≤ 5.50 (1)
5.10≤( LMS+MMS )× BC≤ 5.50 (2),
with the proviso that LBS≥0.820 and LMS≥0.820.
2. The golf ball of claim 1 wherein, letting LCS be the coefficient of restitution for the core at an incident velocity of 35 m/s, LCS≤0.815.
3. The golf ball of claim 1 wherein, letting MCS be the coefficient of restitution for the core at an incident velocity of 45 m/s, MCS≤0.756.
4. The golf ball of claim 1 , wherein the coefficient of restitution for the ball satisfies formula (3) below:
5.90≤( MBS+HBS )/ LBS×BC≤ 6.50 (3).
5. The golf ball of claim 1 , wherein the coefficient of restitution for the intermediate layer-encased sphere satisfies formula (4) below:
5.85≤( MMS+HMS )/ LMS×BC≤ 6.50 (4).
6. The golf ball of claim 1 , wherein the core center and surface have a hardness difference therebetween on the Shore C hardness scale of at least 20.
7. The golf ball of claim 1 which satisfies the surface hardness relationship below:
Shore D hardness at cover surface>Shore D hardness at intermediate layer surface>Shore D hardness at core center.
8. The golf ball of claim 1 which has a construction of at least four layers that includes an envelope layer between the core and the intermediate layer.
9. The golf ball of claim 8 which satisfies the following relationship among surface hardness values:
Shore D hardness at cover surface>Shore D hardness at intermediate layer surface>Shore D hardness at envelope layer surface>Shore D hardness at core center.
10. The golf ball of claim 1 , wherein MBS≥0.780 and MMS≥0.775.
11. The golf ball of claim 3 which satisfies formula (5) below:
5.00≤( MCS+LCS )× BC≤ 5.35 (5).
12. The golf ball of claim 3 which satisfies formula (6) below:
5.70≤( MCS+HCS )/ LCS×BC≤ 6.10 (6).