Games using tangible projectile – Golf – Ball
Reexamination Certificate
2001-05-01
2002-12-31
Sewell, Paul T. (Department: 3711)
Games using tangible projectile
Golf
Ball
C473S373000, C473S357000, C473S376000
Reexamination Certificate
active
06500076
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
This invention relates to golf balls and, more particularly, to wound golf balls with high specific gravity centers.
BACKGROUND OF THE INVENTION
Conventional golf balls have been designed to provide particular playing characteristics. These characteristics are generally initial velocity, compression, and spin of the golf ball, and they can be optimized for various types of players. For instance, certain players prefer a ball that has a high spin rate in order to control the ball flight and stop the golf ball on impact with the greens. This type of ball, however, may not provide maximum distance. Other players prefer a ball that has a low spin rate and high resiliency to maximize distance.
Generally, golf balls have been classified as wound balls or solid balls. Wound balls are generally constructed from a liquid or solid center surrounded by an elastic thread wound in tension to form a wound core. This wound core is then surrounded by a cover. Wound balls are generally thought of as performance golf balls. When struck by a golf club, these balls have good resiliency, relatively high spin rate, and “soft” feel. Wound balls are generally more difficult to manufacture than solid golf balls.
Some early solid or non-wound golf balls contained metal. U.S. Pat. No. 4,995,613 to Walker discloses a practice golf ball with a dense metal-containing core surrounded with a thick layer of resilient material. To this, a fabric cover is bound. U.S. Pat. No. 5,104,126 to Gentiluomo discloses a non-wound ball that includes a dense center of steel surrounded by a molded encapsulating mass of a low density resilient synthetic elastomer composition. Both of these patents disclose solid or non-wound balls that include metal.
On the other hand, U.S. Pat. No. 1,946,378 to Young and U.S. Pat. No. 2,914,328 to Harkins disclose golf balls that include wound layers. For example, the Young patent discloses a spherical center weight of metal with an intermediate sphere of soft rubber thereon. Windings of rubber are disposed about the intermediate layer and an outer casing is formed thereon. Since high cis, polybutadiene was first introduced in 1956, the Young patent that was filed in 1931 and issued in 1934, did not disclose the use of such a compound. The commercial product related to the Harkins patent was the First Flight™ golf ball. The Harkins patent does not disclose the use of polybutadiene and the First Flight™ balls were not manufactured using polybutadiene.
TABLE I
Prior Art Steel Centered Golf Balls
Inner Sphere
Outer Sphere
Center
Name of Ball
Diameter
Weight
Hardness
Diameter
Weight
Side Stamp
Material
(in.)
(oz.)
Material
(Shore D)
(in.)
(oz.)
First Flight Reg 90
steel
0.343
0.096
NR
42.5
1.034
0.549
Steel Powered Center
First Flight Reg 100
steel
0.343
0.097
NR
36.1
1.057
0.541
Steel Powered Center
First Flight 90+
steel
0.342
0.096
SBR & NR
35.1
1.066
0.514
Steel Powered Center
Made in USA
Royce Chemical
steel
0.343
0.096
SBR & NR
51.1
1.005
0.514
Steel Flight
steel
0.314
0.074
NR
30.7
1.00
0.494
Steel Center
Byron Nelson
steel
0.346
0.100
NR
24.7
1.249
0.731
Steel Center
Plymoth
steel
0.343
0.097
SBR & NR
28.6
1.055
0.556
Championship
Steel Center
Butchart - Nicholls
steel
0.343
0.096
SBR & NR
37.1
1.005
0.526
Steel Master
Steel Center
Kroydon
steel
0.318
0.076
NR & SBR
48.1
1.24
0.720
Steel Center
U.S. Fortune
steel
0.343
0.096
SBR & NR
34.2
1.050
0.560
Steel Center
Long Wear
steel
0.348
0.102
NR
30.3
1.220
0.724
Steel Center
Bridgestone M
steel
0.345
0.097
NR & SBR
37.2
1.072
0.542
H.V. Metallic
The balls in Table I are formed with a steel inner sphere surrounded by an outer sphere or shell to form a center. The outer sphere is formed of natural rubber, designated NR, and possibly styrene butadiene rubber, designated SBR. No polybutadiene is used.
In conventional balls, when polybutadiene forms a core layer of the golf ball it typically includes enough high density fillers to alter the weight of such a layer. The amount of high density fillers used is, however, less than about 10 parts per hundred based upon 100 parts per hundred of polybutadiene. These fillers have two unfortunate side effects, they increase the hardness of the center and reduce the ball's resiliency.
Therefore, a need exists for a golf ball with lower hardness or compression but with greater resiliency. The improved golf balls of the present invention to provide as disclosed herein provides such a golf ball.
SUMMARY OF THE INVENTION
The present invention is directed towards an improved golf ball that includes a high-specific gravity central sphere encapsulated in a soft and resilient shell layer.
In one embodiment, the sphere is formed of metal and the soft-resilient shell is formed of polybutadiene rubber molded thereon. This shell is subsequently wound with thread that is preferably elastic to form a wound core. This wound core is then covered. One feature of the metal sphere is that it has a specific gravity of at least about 6.0.
In this embodiment, the sphere has a sphere diameter less than about 0.5 inches and the subassembly with the shell has a shell diameter equal to or greater than about 1.3 inches. Further in this embodiment, the wound core can include a wound core diameter of greater than about 1.55 inches.
Preferably, the inventive golf ball has a compression of less than about 90, and more preferably the compression is between about 40 and about 80.
Preferably, the wound layer is formed of at least one spun elastic thread, and the sphere is formed of a solid metallic material. In this embodiment, the metallic material is formed from one of the following: tungsten, steel, brass, titanium, lead, zinc, copper, iron, silver, platinum, gold, or alloys thereof.
In another embodiment, the sphere is molded of high-specific gravity powder retained in a binding material. Preferably, the binding material is a thermoplastic compound, and the high specific gravity filler is metallic powder. A soft-resilient layer is disposed on the sphere and preferably is formed of polybutadiene rubber molded thereon. This layer is subsequently wound with thread that is preferably elastic to form a wound core. This wound core is then covered.
In yet another embodiment, the binding material can be a thermosetting compound.
According to one feature of this embodiment, the metallic powder is formed from one of the following: steel, brass, titanium, lead, zinc, copper, tungsten, bismuth, nickel, molybdenum, iron, bronze, cobalt, silver, platinum, gold, or alloys thereof. In addition, the sphere has a mass, the metallic powder forms a first percentage of the mass, the binding material forms a second percentage of the mass, and the first percentage is greater than the second percentage.
According to another embodiment, the wound golf ball of the present invention comprises a sphere having a specific gravity of above about 6.0, at least one molded shell, a wound layer, and a cover. The molded shell is formed around the sphere to form a center. The center has a diameter equal to or greater than about 1.25 inches. The wound layer is disposed about the center to form a wound core, and the cover surrounds the wound core.
In alternative embodiments, the center has a diameter of greater than about 1.3 inches or greater than about 1.4 inches.
In this embodiment, the sphere can be formed of a solid metallic material or of metallic powder retained in a binding material.
In yet another embodiment, the center further includes a first shell disposed on the sphere and a second shell disposed on the first shell, wherein the first shell is a molded layer and the second shell is a wound layer. According to one feature of this embodiment, the first shell has a first Shore D hardness and the second shell has a second Shore D hardness different from the first Shore D hardness by at least 5. The first Shore D hardness can be greater than or less than the second Shore D hardness.
The present invention is further directed to a wound golf ball that comprises a solid sphere formed of a metal material, at least one molded
Jones Douglas E.
Morgan William E.
Acushnet Company
Hunter, Jr. Alvin A.
Sewell Paul T.
Swidler Berlin Shereff & Friedman, LLP
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