Games using tangible projectile – Golf – Ball
Reexamination Certificate
2001-03-05
2003-03-04
Sewell, Paul T. (Department: 3711)
Games using tangible projectile
Golf
Ball
C473S378000, C473S379000, C473S380000, C473S381000, C473S382000, C473S383000
Reexamination Certificate
active
06527653
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
The present invention generally relates to golf balls, and more particularly, to a golf ball having unique dimple patterns.
BACKGROUND OF THE INVENTION
Golf balls were originally made with smooth outer surfaces. In the late nineteenth century, players observed that the guttie golf balls traveled further as they got older and more gouged up. The players then began to roughen the surface of new golf balls with a hammer to increase flight distance. Manufacturers soon caught on and began molding non-smooth outer surfaces on golf balls.
By the mid 1900's, almost every golf ball being made had 336 indents arranged in an octahedral pattern. Generally, these balls had about 60% of their outer surface covered by dimples. In 1983, Titleist introduced the TITLEIST 384, which had 384 dimples that were arranged in an icosahedral pattern. About 76% of its outer surface was covered with dimples. Today's dimpled golf balls travel nearly two times farther than a similar ball without dimples.
The dimples on a golf ball are important in reducing drag and providing lift. Drag is the air resistance that acts on the golf ball in the opposite direction from the balls flight direction. As the ball travels through the air, the air surrounding the ball has different velocities and, thus, different pressures. The air exerts maximum pressure at the stagnation point on the front of the ball. The air then flows over the sides of the ball and has increased velocity and reduced pressure. At some point it separates from the surface of the ball, leaving a large turbulent flow area called the wake that has low pressure. The difference in the high pressure in front of the ball and the low pressure behind the ball slows the ball down. This is the primary source of drag for a golf ball.
The dimples on the ball create a turbulent boundary layer around the ball, i.e., the air in a thin layer adjacent to the ball flows in a turbulent manner. The turbulence energizes the boundary layer and helps the turbulent boundary layer stay attached to the ball's surface further around the ball to reduce the area of the wake. This greatly increases the pressure behind the ball and substantially reduces the drag.
Lift is the upward force on the ball that is created from a difference in pressure on the top of the ball to the bottom of the ball. The difference in pressure is created by a warpage in the air flow resulting from the ball's back spin. Due to the back spin, the top of the ball moves with the air flow, which delays the separation to a point further rearward. Conversely, the bottom of the ball moves against the air flow, moving the separation point forward. This asymmetrical separation creates an arch in the flow pattern, requiring the air over the top of the ball to move faster, and thus have lower pressure than the air underneath the ball.
Almost every golf ball manufacturer researches dimple patterns in order to increase the distance traveled by a golf ball. A high degree of dimple coverage is beneficial to flight distance, but only if the dimples are of a reasonable size. Dimple coverage gained by filling spaces with tiny dimples is not very effective, since tiny dimples are not good turbulence generators. Most balls today still have many large spaces between dimples or have filled in these spaces with very small dimples that do not create enough turbulence at average golf ball velocities.
There are many patents directed to dimple patterns. U.S. Pat. No. 5,201,522 discloses a golf ball with a dimple pattern that includes a pentagon formation of dimples at each of the poles and has five equally-spaced triangular formations of a plurality of dimples between each polar pentagon formation and the equator.
There continues to be a need for dimple patterns that increase lift and decrease drag. More particularly, there continues to be a need for dimple patterns that have the same lift and drag from all orientations.
SUMMARY OF THE INVENTION
The present invention provides a golf ball with an outer surface that has dimples positioned according to a pentagonal hexecontahedron.
The present invention also provides for a golf ball with an outer surface that has dimples positioned on each hemisphere of the golf ball surface according to a portion of a pentagonal hexecontahedron, which extends from each pole to the parting line.
The present invention further provides a method of packing dimples on the outer surface of a golf ball according to a pentagonal hexecontahedron.
The present invention comprises a golf ball dimple pattern based upon a pentagonal hexecontahedron. A preferred embodiment is comprised of a three-dimensional geometric structure composed of 92 vertices that are connected by 150 edges to form 60 pentagonal regions. The 92 vertices are composed of 12 V
5
vertices, where each V
5
vertex is a vertex shared by five adjacent pentagonal regions, and 80 V
3
vertices, where each V
3
vertex is a vertex shared by three adjacent pentagonal regions. Preferably, the total number of dimples is about 200 to about 700. More preferably, the total number of dimples is about 300 to about 500. The diameter and depth of the dimples that make up the dimple patterns of the present invention may be substantially the same or the diameter and depth of the dimples may vary. The dimples may have a diameter of about 0.09 inches to 0.2 inches. More preferably, the dimples may have a diameter of about 0.11 inches to 0.19 inches. Most preferably, the dimples may have a diameter of about 0.13 inches to 0.19 inches. Based upon the size of the dimples positioned according to the pentagonal hexecontahedron pattern, dimples may be centered at the vertices, along the edges, and on or in proximity to the pentagonal regions.
Orientation of the pentagonal hexecontahedron pattern can be positioned any where on the golf ball's outer surface. The pattern may also be oriented based upon the parting line. The parting line is located at the equator of the outer surface, there by dividing the outer surface into the two hemispheres. Each hemisphere has a pole positioned at the furthest point on the outer surface from the parting line. The pentagonal hexecontahedron may originate at and extend toward the parting line from a pole with a V
5
vertex. A first set of dimples, which may vary in size, may be centered on the ball surface at selected vertices and edges of the pentagonal hexecontahedron except where, if dimples were placed, the dimples would intersect or cross the parting line. When space on the edges is available, additional dimples may also be centered along the edges except where, if dimples were placed, the dimples would intersect or cross the parting line. The remaining uncovered surface may then be filled with dimples that have sizes large enough to aid in reducing drag and providing lift. Preferably, the percentage of the golf ball surface covered by dimples ranges is greater than about 68%.
An embodiment of the present invention is a golf ball with an outer surface having 322 dimples according to the pentagonal hexecontahedron pattern. Dimples used to create the pattern may be of a first, a second, a third, and a fourth size. Based upon the diameter of the golf ball, a pentagonal hexecontahedron pattern may extend from the poles towards the parting line of the outer surface with a V
5
vertex and a first size dimple centered at each pole. A second size dimple may then be centered at each of the other vertices of the pentagonal hexecontahedron only if the centered dimple would not intersect the parting line. Where space is available, additional second size dimples may also be centered along the edges of the pentagonal hexecontahedron. To minimize the portion of the outer surface that is not dimpled, reduce drag, and increase lift, the remainder of the golf ball surface may then be covered with the second, third, and fourth size dimples only at positions where the dimples do not intersect or cross the parting line.
Another embodiment of the present invention is a golf ball surface having 33
Aoyama Steven
Winfield Douglas C.
Acushnet Company
Duong Tom
Sewell Paul T.
Swidler Berlin Shereff & Friedman, LLP
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