GOLF BALLS HAVING REDUCED DISTANCE
Golf balls having core formulations including polybutadiene, butyl rubber, or a blend thereof, and low surface coverage dimple patterns are disclosed. The combination of low surface coverage with particular rubber formulations helps to reduce the flight of the ball while also providing improved aerodynamic consistency and maintaining the appearance of a high-performance trajectory.
1 . A golf ball, comprising:
a core layer comprising a rubber formulation of polybutadiene rubber, butyl rubber, or a blend thereof, and
a cover layer comprising a plurality of dimples disposed thereon, wherein the dimples are arranged in a tetrahedral pattern consisting of four substantially identical dimple sections, wherein each dimple section is defined by a spherical triangle,
wherein the dimples in each of the four substantially identical dimple sections have a corresponding dimple diameter and a corresponding edge angle and the dimples in each of the four substantially identical dimple sections comprise:
(i) at least three different dimple diameters including a minimum dimple diameter, a maximum dimple diameter, and at least one additional dimple diameter, wherein each of the at least three different dimple diameters range from about 0.030 inches to about 0.200 inches, and
(ii) substantially identical edge angles, and
wherein the pattern has a surface coverage of about 65 percent or less and the pattern results in at least three dimple-free great circles on the golf ball, and
wherein the surface coverage is related to the amount of polybutadiene rubber present in the rubber formulation according to the following equation:
BR
1
−
SC
≤
2.0
where SC is the surface coverage in the decimal form of percentage and 0 < SC < 1, and BR is the weight percent of polybutadiene rubber, in decimal form, based on the total weight of rubber in the rubber formulation and 0 ≤ BR ≤ 1.
2 . The golf ball of claim 1 , wherein the rubber formulation comprises a blend of polybutadiene rubber and butyl rubber.
3 . The golf ball of claim 1 , wherein the golf ball has a coefficient of restitution (COR) of about 0.780 or less.
4 . The golf ball of claim 1 , wherein the golf ball has a coefficient of restitution (COR) of about 0.740 or less.
5 . The golf ball of claim 1 , wherein the average of all the edge angles (θ µ ) is related to the surface coverage according to the following equation:
88.8
S
C
2
−
116.9
S
C
+
47.7
≤
θ
μ
≤
170.0
S
C
2
−
242.5
S
C
+
106.6
where SC is the surface coverage in the decimal form of percentage and 0 < SC < 1.
6 - 23 . (canceled)
24 . A golf ball, comprising:
a core layer comprising a rubber formulation of polybutadiene rubber, butyl rubber, or a blend thereof, and
a cover layer comprising a plurality of dimples disposed thereon, wherein the dimples are arranged in a tetrahedral pattern consisting of four substantially identical dimple sections, wherein each dimple section is defined by a spherical triangle,
wherein the dimples in each of the four substantially identical dimple sections have a corresponding dimple diameter and a corresponding edge angle and the dimples in each of the four substantially identical dimple sections comprise:
(i) at least three different dimple diameters including a minimum dimple diameter, a maximum dimple diameter, and at least one additional dimple diameter, wherein each of the at least three different dimple diameters range from about 0.030 inches to about 0.200 inches, and
(ii) substantially identical edge angles, and
wherein the pattern has a surface coverage of about 60 percent or less and the pattern results in at least three dimple-free great circles on the golf ball, and
wherein the surface coverage is related to the amount of polybutadiene rubber present in the rubber formulation according to the following equation:
BR
1
−
SC
≤
1.75
where SC is the surface coverage in the decimal form of percentage and 0 < SC < 1, and BR is the weight percent of polybutadiene rubber, in decimal form, based on the total weight of rubber in the rubber formulation and 0 ≤ BR ≤ 1.
25 . The golf ball of claim 24 , wherein the rubber formulation comprises a blend of polybutadiene rubber and butyl rubber.
26 . The golf ball of claim 24 , wherein the golf ball has a coefficient of restitution (COR) and the COR is related to the surface coverage according to the following equation:
C
O
R
1
−
S
C
≤
2.0
where COR is the coefficient of restitution and 0 < COR < 1 and SC is the surface coverage in the decimal form of percentage and 0 < SC < 1.
27 . The golf ball of claim 24 , wherein the golf ball comprises an initial velocity and the initial velocity is related to the surface coverage according to the following equation:
I
V
1
−
S
C
≤
700
where IV is the initial velocity in ft/sec and SC is the surface coverage in the decimal form of percentage and 0 < SC < 1.
28 . The golf ball of claim 24 , wherein the rubber formulation further comprises polyisoprene, ethylene propylene rubber, styrene-butadiene rubber, or combinations of two or more thereof.
29 . The golf ball of claim 24 , wherein the rubber formulation comprises polybutadiene rubber having a 1,4 cis-bond content of greater than 80%.
30 . The golf ball of claim 24 , wherein the pattern has a surface coverage of about 50 percent or less.
31 . The golf ball of claim 24 , wherein the average of all the edge angles (θ µ ) is related to the surface coverage according to the following equation:
88.8
S
C
2
−
116.9
S
C
+
47.7
≤
θ
μ
≤
170.0
S
C
2
−
242.5
S
C
+
106.6
where SC is the surface coverage in the decimal form of percentage and 0 < SC < 1.
32 . A golf ball, comprising:
a core layer comprising a rubber formulation, the rubber formulation comprising a blend of polybutadiene rubber and butyl rubber, and
a cover layer comprising a plurality of dimples disposed thereon, wherein the dimples are arranged in a tetrahedral pattern consisting of four substantially identical dimple sections, wherein each dimple section is defined by a spherical triangle,
wherein the dimples in each of the four substantially identical dimple sections have a corresponding dimple diameter and a corresponding edge angle and the dimples in each of the four substantially identical dimple sections comprise:
(i) four or more different dimple diameters including a minimum dimple diameter, a maximum dimple diameter, and at least two additional dimple diameters, wherein each of the four or more different dimple diameters range from about 0.050 inches to about 0.180 inches, and
(ii) substantially identical edge angles,
wherein the pattern has a surface coverage of about 65 percent or less and the pattern results in at least three dimple-free great circles on the golf ball, and
wherein the surface coverage is related to the amount of polybutadiene rubber present in the rubber formulation according to the following equation:
BR
1
−
SC
≤
2.0
where SC is the surface coverage in the decimal form of percentage and 0 < SC < 1, and BR is the weight percent of polybutadiene rubber, in decimal form, based on the total weight of rubber in the rubber formulation and 0 ≤ BR ≤ 1.
33 . The golf ball of claim 32 , wherein the polybutadiene rubber has a 1,4 cis-bond content of greater than 90%.
34 . The golf ball of claim 32 , wherein the pattern has a surface coverage of about 60 percent or less.
35 . The golf ball of claim 32 , wherein the golf ball has a coefficient of restitution (COR) and the COR is related to the surface coverage according to the following equation:
C
O
R
1
−
S
C
≤
2.0
where COR is the coefficient of restitution and 0 < COR < 1 and SC is the surface coverage in the decimal form of percentage and 0 < SC < 1.
36 . The golf ball of claim 32 , wherein the golf ball comprises an initial velocity and the initial velocity is related to the surface coverage according to the following equation:
I
V
1
−
S
C
≤
700
where IV is the initial velocity in ft/sec and SC is the surface coverage in the decimal form of percentage and 0 < SC < 1.