GOLF BALLS HAVING IMPROVED SHORT GAME PERFORMANCE

Abstract

Golf balls having three-dimensional shaped fret areas and methods of making the same are disclosed. The three-dimensional shaped fret areas have at least three edges that meet at an apex point or an apex surface. The three-dimensional shaped fret areas may have a three-dimensional irregular pyramid shape or a three-dimensional truncated irregular pyramid shape. The three-dimensional shaped fret areas create golf balls having increased traction upon impact with the playing surface.

Description

FIELD OF THE INVENTION

The present disclosure relates generally to golf balls. More particularly, the present disclosure relates to golf balls having fret areas that are designed to provide an increase in traction with a playing surface.

BACKGROUND OF THE INVENTION

A golf ball typically includes an outer spherical surface with depressions or dimples on the outer surface. The portions of the outer surface between the dimples are commonly referred to as fret areas and form the un-dimpled surface of the golf ball. The dimples perturb the air flow surrounding the golf ball and create air turbulence as the ball moves through the air. The dimples are intended to create the appropriate amount of turbulence to reduce the aerodynamic drag and optimize golf ball performance.

Unlike dimples on the golf ball, the fret areas have the same curvature as a phantom sphere of the same radius as the golf ball. This causes the golf ball fret area to have a smooth texture. Since the fret area is often the first part of the golf ball to impact the playing surface, a smooth fret area does not optimize a golf ball's ability to grip the playing surface and reduce roll out. This is why golf shoe outsoles are generally equipped with cleats (or metal spikes in some cases) that are intended to prevent slipping during a player's golf swing and provide improved traction while traversing hills on the golf course. If the aforementioned shoe outsoles were smooth, it would compromise the player's ability to grip the terrain and ultimately lead to slipping. Similar to smooth shoe outsoles, the smooth fret areas compromise the golf ball's ability to grip the playing surface and reduce roll out. Reducing the amount of roll is desirable especially on shots where the golfer wishes to stop the ball as close to its landing position as possible but is unable to impart a high spin rate on the golf ball due to undesirable conditions of the golf shot.

Accordingly, there remains a need for golf balls having fret areas that can reduce the amount of roll out on a playing surface compared to that of golf balls having traditional fret areas impacting the playing surface with similar landing conditions.

SUMMARY OF THE INVENTION

The problems expounded above, as well as others, are addressed by the following inventions, although it is to be understood that not every embodiment of the inventions described herein will address each of the problems described above.

In some embodiments, a golf ball having a substantially spherical surface is provided, the golf ball including a plurality of dimples on the spherical surface and a plurality of fret areas defined therebetween, wherein at least one fret area on the spherical surface includes a three-dimensional irregular pyramid shape having at least three edges meeting at an apex point, and wherein the three-dimensional irregular pyramid shape has a height defined as the radial distance between the apex point and a phantom sphere having a radius. In some embodiments, the three-dimensional irregular pyramid shaped fret area is surrounded by three dimples of the plurality of dimples. In other embodiments, the radius is greater than about 0.84 inches. In still other embodiments, the radius is less than about 0.84 inches and the sum of the radius and the height is greater than about 0.84 inches. In further embodiments, the three-dimensional irregular pyramid shape has a total surface area of about 0.001 square inches to about 0.008 square inches. In still further embodiments, the height ranges from about 0.002 inches to about 0.025 inches.

In other embodiments, a golf ball having a substantially spherical surface is provided, the golf ball including a plurality of dimples on the spherical surface and a plurality of fret areas defined therebetween, wherein at least one fret area on the spherical surface includes a three-dimensional truncated irregular pyramid shape having at least three edges meeting at an apex surface, wherein the apex surface is a planar surface having a center of mass coincident with an apex point of the three-dimensional truncated irregular pyramid shape, and wherein the three-dimensional truncated irregular pyramid shape has a height defined as the radial distance between the apex surface and a phantom sphere having a radius, and wherein the apex surface comprises a polygonal shape. In other embodiments, the apex surface has a polygonal shape formed of at least three edges. For example, the apex surface may have a triangular shape. In still other embodiments, the apex surface includes a non-polygonal shape formed of a combination of line segments and curvatures. In further embodiments, the apex surface has a surface area ranging from about 0.0002 square inches to about 0.001 square inches. The surface area of the apex surface may account for about 5 percent to about 15 percent of the total surface area of the three-dimensional truncated irregular pyramid shape. In still further embodiments, the three-dimensional truncated irregular pyramid shaped fret area is surrounded by three dimples of the plurality of dimples. In yet further embodiments, the height ranges from about 0.005 inches to about 0.020 inches. In some embodiments, the radius of the phantom sphere is (i) greater than about 0.84 inches or (ii) less than about 0.84 inches but the sum of the radius and the height is greater than about 0.84 inches.

In further embodiments, a method of forming a three-dimensional shaped fret area on a golf ball is provided, the method including selecting a set of three neighboring dimples on a surface of the golf ball, wherein each dimple has a center; drawing a dimple line from the center of each dimple to the center of each of its neighboring dimples to form a triangle, wherein the triangle defines a fret area on the golf ball in which the three-dimensional shaped fret area will be formed; identifying an edge origin along each of the dimple lines of the triangle, wherein the edge origin is a point along the dimple line that is located outside the perimeters of each of the three neighboring dimples; identifying a centroid of the triangle, wherein the centroid defines an apex of the fret area; and drawing an edge line from each edge origin to the apex to form the three-dimensional shaped fret area. In some embodiments, the method further includes drawing an apex surface about the apex, wherein the apex surface is a planar surface having a center of mass coincident with the apex. In other embodiments, the apex surface has a polygonal shape comprising at least three edges. In still other embodiments, the step of drawing the edge line further includes drawing two or more edge lines from each edge origin to the apex. In yet other embodiments, the three-dimensional shaped fret area includes a three-dimensional irregular pyramid shape.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the invention can be ascertained from the following detailed description that is provided in connection with the drawings described below:

FIG. 1 is a front perspective view of a golf ball showing a plurality of dimples and fret areas.

FIG. 2 is a schematic diagram showing reaction forces of a playing surface on a golf ball.

FIG. 3 is an enlarged view of a portion of a golf ball surface having a three-dimensional shaped fret area designed in accordance with one embodiment of the present disclosure.

FIG. 4 is an enlarged view of a portion of a golf ball surface having a three-dimensional shaped fret area designed in accordance with another embodiment of the present disclosure.

FIG. 5 is an enlarged view of a portion of a golf ball surface having a three-dimensional shaped fret area designed in accordance with still another embodiment of the present disclosure.

FIG. 6 is an enlarged view of a portion of a golf ball surface having a three-dimensional shaped fret area designed in accordance with yet another embodiment of the present disclosure.

FIG. 7 is an enlarged view of a portion of a golf ball surface having a three-dimensional shaped fret area designed in accordance with still another embodiment of the present disclosure.

FIG. 8A is a schematic diagram illustrating the fret height H between a phantom sphere and an apex point of the three-dimensional shaped fret areas designed in accordance with the present disclosure.

FIG. 8B is a schematic diagram illustrating the fret height H between a phantom sphere and an apex surface of the three-dimensional shaped fret areas designed in accordance with the present disclosure.

FIG. 9A is a schematic diagram showing tangency lines drawn between two neighboring dimples.

FIG. 9B is a schematic diagram showing tangency lines drawn between two non-neighboring dimples.

FIG. 10 is an enlarged view of a portion of a golf ball surface showing a reference triangle formed by a set of three neighboring dimple lines with an apex point formed therein in accordance with an exemplary method of the present disclosure.

FIG. 11 is an enlarged view of the portion of the golf ball surface shown in FIG. 10 illustrating a three-dimensional shaped fret area designed in accordance with an exemplary method of the present disclosure.

FIG. 12 is an enlarged view of a portion of a golf ball surface showing a reference triangle formed by a set of three neighboring dimple lines with an apex surface formed therein in accordance with an exemplary method of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art of this disclosure. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well known functions or constructions may not be described in detail for brevity or clarity.

The terms “about” and “approximately” shall generally mean an acceptable degree of error or variation for the quantity measured given the nature or precision of the measurements.

Numerical quantities given in this description are approximate unless stated otherwise, meaning that the term “about” or “approximately” can be inferred when not expressly stated.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well (i.e., at least one of whatever the article modifies), unless the context clearly indicates otherwise.

The terms “first,” “second,” “third,” and the like are used herein to describe various features or elements, but these features or elements should not be limited by these terms. These terms are only used to distinguish one feature or element from another feature or element. Thus, a first feature or element discussed below could be termed a second feature or element, and similarly, a second feature or element discussed below could be termed a first feature or element without departing from the teachings of the present disclosure.

Golf Balls Having Three-Dimensional Shaped Fret Areas

Referring to FIG. 1, a golf ball 10 having a spherical core (not shown) and a cover 4 is shown. Numerous dimples 6 are formed on the cover 4 of the golf ball 10. The upper curved portion of the cover 4 extending from dimple to dimple is known as a fret area 8. The present disclosure provides golf balls having a secondary surface texture in the fret areas of the golf ball. In some embodiments, the fret areas have a three-dimensional shape. The three-dimensional shaped fret areas create golf balls having increased traction upon impact with the playing surface. As illustrated in the free body diagram of FIG. 2, F represents the force a golf ball exerts on the ground, while FN and traction force FT represent the reaction forces of the playing surface on the golf ball. By increasing the traction force FT with the use of three-dimensional shaped fret areas, the golf ball can better grip the playing surface upon impact. This is especially desirable for shots where the golfer wishes to minimize the amount of roll but is unable to impart a high spin rate on the golf ball.

In some embodiments, the fret areas of the present disclosure are designed as three-dimensional irregular pyramids. As used herein, a “three-dimensional irregular pyramid” refers to a fully enclosed three-dimensional shape having one or more faces that resemble a polygon and a base having curved edges. The regions where two faces of the shape meet to form a line segment are known as the edges and the points where two or more edges meet are known as the vertices of the shape. In some embodiments, the three-dimensional irregular pyramid shaped fret areas have at least three edges. In other embodiments, the three-dimensional irregular pyramid shaped fret areas may have four or more edges. In still other embodiments, the three-dimensional irregular pyramid shaped fret areas may have six or more edges. In yet other embodiments, the three-dimensional irregular pyramid shaped fret areas may have nine or more edges. In still further embodiments, the three-dimensional irregular pyramid shaped fret areas may have twenty or more edges. The three-dimensional irregular pyramid shaped fret areas can generally have any number of edges depending on the desired appearance of the fret area.

The three-dimensional irregular pyramid shaped fret areas may also have any number of vertices, one of which is an apex (i.e., the highest point of the shape). In some embodiments, the three-dimensional irregular pyramid shaped fret areas have three or more vertices. In still other embodiments, the three-dimensional irregular pyramid shaped fret areas have five or more vertices. In yet other embodiments, the three-dimensional irregular pyramid shaped fret areas have ten or more vertices. In still other embodiments, the three-dimensional irregular pyramid shaped fret areas have twenty or more vertices. As will be appreciated by one of ordinary skill in the art, the total number of vertices of the three-dimensional irregular pyramid shaped fret areas will depend on the number of edges utilized.

Each of the three-dimensional irregular pyramid shaped fret areas has an apex. The apex is defined as the vertex at the top of the three-dimensional irregular pyramid shaped fret area (opposite the base or the surface of the golf ball). In some embodiments, the apex of the three-dimensional irregular pyramid shaped fret area is a point. That is, the edges of the three-dimensional irregular pyramid shape meet at an apex point.

FIGS. 3 and 4 illustrate various three-dimensional irregular pyramid shaped fret areas having an apex point according to the present disclosure. FIG. 3 shows a three-dimensional irregular pyramid shaped fret area 20 positioned between three neighboring circular dimples D₁, D₂, D₃ on the surface of the golf ball 10. The three-dimensional irregular pyramid shaped fret area has three edges. The three edges meet at a single apex point A. As illustrated in FIG. 3, the three-dimensional irregular pyramid shaped fret area 20 resembles a pyramid shape. FIG. 4 shows a three-dimensional irregular pyramid shaped fret area 30 positioned between three neighboring circular dimples D₁, D₂, D₃ on the surface of the golf ball 10 according to another embodiment. The three-dimensional irregular pyramid shaped fret area 30 has nine total edges, six of which form faces resembling that of a triangle. The three remaining edges connect the edges forming the triangular-like faces to a single apex point A.

In other embodiments, the three-dimensional irregular pyramid shaped fret areas can have an apex surface. In this embodiment, the fret areas may be referred to as three-dimensional truncated irregular pyramid shaped fret areas. The truncated irregular pyramid shaped fret areas include a surface having a center of mass that is positioned at the apex point. The edges of the shape can meet at the perimeter of the apex surface such that the truncated irregular pyramid shaped fret area has a planar upper portion (as opposed to a peak formed by the apex point discussed above). The apex surface may have any shape that allows for the surface to be centered at the apex point of the shape. In some embodiments, the apex surface is a polygonal shape having at least three edges. Suitable polygonal shapes for the apex surface include, but are not limited to, triangles, quadrilaterals, pentagons, hexagons, heptagons, octagons, nonagons, decagons, hendecagons, dodecagons, triskaidecagons, tetradecagons, pentadecagons, hexadecagons, heptadecagons, octadecagons, nonadecagons, icosagons, and the like. In further embodiments, the apex surface can have a non-polygonal shape. For instance, the apex surface may have a shape including one or more curvatures, such as a circle. Other suitable curved shapes include, but are not limited to, elliptical, parabolic, conic, hyperbolic, sinusoidal, or any combination of these curves. In still other embodiments, the apex surface may have a shape including one or more line segments and one or more curvatures. The size of the apex surface may vary so long as the area of the apex surface is less than that of the area of the truncated irregular pyramid shaped fret area.

FIGS. 5, 6, and 7 illustrate various three-dimensional truncated irregular pyramid shaped fret areas having an apex surface according to the present disclosure. FIG. 5 shows a truncated irregular pyramid shaped fret area 40 positioned between three neighboring circular dimples D₁, D₂, D₃ on the surface of the golf ball 10. The truncated irregular pyramid shaped fret area 40 has three edges. However, rather than the edges meeting at a single apex point, the edges of the truncated irregular pyramid shaped fret area 40 meet at an apex surface S. In the illustrated embodiment, the apex surface S has a triangular shape, the perimeter of which is formed by three straight edges. The edges of the truncated irregular pyramid shaped fret area 40 meet at the perimeter of the apex surface S.

FIG. 6 shows a three-dimensional truncated irregular pyramid shaped fret area 50 positioned between three neighboring circular dimples D₁, D₂, D₃ on the surface of the golf ball according to another embodiment. Similar to the truncated irregular pyramid shaped fret area shown in FIG. 5, the truncated irregular pyramid shaped fret area 50 has three edges that meet at the perimeter of an apex surface S that is triangular shaped. The apex surface S illustrated in FIG. 6 however has a smaller area than the apex surface S illustrated in FIG. 5 due to shorter edge lengths.

FIG. 7 shows a three-dimensional truncated irregular pyramid shaped fret area 60 positioned between three neighboring circular dimples D₁, D₂, D₃ on the surface of the golf ball according to still another embodiment. The truncated irregular pyramid shaped fret area 60 has six edges that meet at the perimeter of an apex surface S. The apex surface S has a non-polygonal shape including both line segments and curvatures. As illustrated in FIG. 7, the apex surface S has six sides, three of which are straight edges and three of which are curvatures.

The irregular pyramid shaped and the truncated irregular pyramid shaped fret areas may have any dimensions, for example, height and surface area, so long as the fret areas do not interfere with the dimples arranged on the golf ball. In one embodiment, the irregular pyramid shaped and the truncated irregular pyramid shaped fret areas have a fret height H. The fret height H can be defined as the height of the apex, for instance, the apex point or apex surface, on the three-dimensional irregular pyramid shaped and the truncated irregular pyramid shaped fret areas. As depicted in FIG. 8A, the fret height H (or the height of the apex) is the radial distance between a phantom sphere 12 and the apex point A. The phantom sphere 12 is defined as the spherical surface containing fret area 8 if there were no dimples or three-dimensional shaped fret areas. In another embodiment, as depicted in FIG. 8B, the fret height H (or the height of the apex) is the radial distance between the phantom sphere 12 and the apex surface S. The phantom sphere 12 has a radius R. In one embodiment, the radius R of the phantom sphere 12 is greater than about 0.84 inches. In another embodiment, the radius R of the phantom sphere 12 is less than about 0.84 inches and the sum of the radius R and the fret height H is greater than about 0.84 inches.

In some embodiments, the fret height H may range from about 0.002 inches to about 0.025 inches. In other embodiments, the fret height H may range from about 0.005 inches to about 0.02 inches. In still other embodiments, the fret height H may range from about 0.01 inches to about 0.015 inches. In some embodiments, the three-dimensional shaped fret areas on the golf ball may all have the same fret height H. In other embodiments, the three-dimensional shaped fret areas used on the golf ball may have varying fret heights H. For instance, some three-dimensional shaped fret areas may be shorter or taller than others on the golf ball.

In one embodiment, the total surface area (SA) of a single three-dimensional shaped fret is between about 0.001 square inches and about 0.008 square inches. In another embodiment, the total surface area (SA) of a single three-dimensional shaped fret area is between about 0.002 square inches and about 0.006 square inches. In some embodiments, the three-dimensional shaped fret area has an apex surface S and the surface area of the apex surface S is between about 0.0002 square inches and 0.001 square inches. In other embodiments, the three-dimensional shaped fret area has an apex surface S and the surface area of the apex surface S is between about 0.0004 square inches and about 0.0008 square inches. In still other embodiments, the surface area of the apex surface S accounts for about 5 percent to about 15 percent of the total surface area (SA) of the three-dimensional shaped fret area. For example, the surface area of the apex surface S accounts for about 10 percent of the total surface area (SA) of the three-dimensional shaped fret area.

In some embodiments, the three-dimensional shaped fret areas may be used at all of the fret areas on a golf ball. That is, all of the land areas on the golf ball may utilize the three-dimensional shaped fret areas disclosed herein. In other embodiments, the three-dimensional shaped fret areas may be used at only one fret area on the golf ball. In still other embodiments, the three-dimensional shaped fret areas may be used at a portion of the fret areas on a golf ball. For example, the three-dimensional shaped fret areas may be used in specific locations on the golf ball or a collection of specific locations. In one embodiment, at least about 10 percent of the fret areas on a golf ball are designed with the three-dimensional shapes described herein. In some embodiments, at least about 20 percent of the fret areas on a golf ball are designed with the three-dimensional shapes described herein. In other embodiments, at least about 50 percent of the fret areas on a golf ball are designed with the three-dimensional shapes described herein. In still other embodiments, at least about 75 percent of the fret areas on a golf ball are designed with the three-dimensional shapes described herein. In yet other embodiments, at least about 90 percent of the fret areas on a golf ball are designed with the three-dimensional shapes described herein. Indeed, as will be appreciated by one of ordinary skill in the art, the more fret areas designed with the three-dimensional shapes described herein, the greater the traction force applied to the golf ball upon impact with a playing surface.

The three-dimensional shaped fret areas may be used on golf balls having varying dimple geometries. In some embodiments, the three-dimensional shaped fret areas of the present disclosure may be used on golf balls with dimples having a circular plan shape. A “plan shape,” as used herein, refers to the perimeter of the dimple as seen from a top view of the dimple, or the demarcation between the dimple and the outer surface of the golf ball or fret surface. In this embodiment, the three-dimensional shaped fret areas are generally surrounded by a set of three neighboring dimples, as will be described in more detail below. In other embodiments, the three-dimensional shaped fret areas may be used on golf balls with dimples having non-circular plan shapes. For example, the plan shape may be any one of a circle, square, triangle, rectangle, oval, or other geometric or non-geometric shape. In some embodiments, the dimples on the golf ball may have a square plan shape. In this embodiment, the three-dimensional shaped fret areas are generally surrounded by a set of four neighboring dimples. In still other embodiments, the dimples on the golf ball may have a plan shape defined by low frequency or high frequency periodic functions.

The three-dimensional shaped fret areas may also be used on golf balls having different dimple patterns. Suitable dimple patterns include, but are not limited to, polyhedron-based patterns (e.g., icosahedron, octahedron, dodecahedron, icosidodecahedron, cuboctahedron, and triangular dipyramid), phyllotaxis-based patterns, spherical tiling patterns, triangular dipyramids, quadrilateral dipyramids, pentagonal dipyramids, hexagonal dipyramids, and random arrangements.

Methods of Forming Three-Dimensional Shaped Fret Areas

The present disclosure also provides methods for forming the three-dimensional shaped fret areas on a golf ball surface. In some embodiments, the method of the present disclosure involves selecting three neighboring dimples on the golf ball. Neighboring dimples may be determined by first drawing two tangency lines from the center of a first dimple to the center of a potential nearest neighboring dimple. In addition, a line segment is drawn connecting the center of the first dimple to the center of the potential nearest neighboring dimple. If there is no line segment that is intersected by another dimple, or portion of a dimple, then those dimples are considered to be nearest neighbors. For example, FIG. 9A shows a case where the two tangency lines and the line from one dimple center to the other dimple center do not intersect any other dimple edges, so dimple 1 and dimple 2 are considered nearest neighbors. Alternatively, FIG. 9B shows a case where the two tangency lines and the line from one dimple center to the other dimple center intersect an alternative dimple, so dimple 1 and dimple 2 are not considered nearest neighbors. Those skilled in the art will recognize that the line segments described above do not actually have to be drawn on the golf ball. Rather, it is desirable for a computer modeling program to be capable of performing this operation automatically.

Once each dimple's neighboring dimples are identified, the method of the present disclosure includes drawing a line from the center of each dimple to the center of each of its neighboring dimples. Each line connecting the center of one dimple to the center of a neighboring dimple is referred to as a dimple line. The dimple lines for the set of the three neighboring dimples form a triangle. The resulting triangle defines the fret area in which the three-dimensional shaped fret area will be formed. In the next step, the method of the present disclosure includes identifying a centroid of the area enclosed by the resulting triangle. The centroid of the triangle is the point that defines the apex of the fret area.

FIG. 10 is an illustration of three neighboring dimples on the golf ball surface and the corresponding triangle formed by a set of three neighboring dimple lines with an apex point defined therein. As shown in FIG. 10, three neighboring dimples D₁, D₂, and D₃ on the golf ball surface 10 are selected. A dimple line L₁ is drawn connecting the center of the dimple D₁ to the center of the dimple D₂. As can be seen in FIG. 10, dimples D₁ and D₂ are considered to be “neighboring” dimples since two tangency lines (not shown) and the dimple line L₁ do not intersect another dimple (or portion thereof). Dimple line L₂ is drawn connecting the center of the dimple D₂ to the center of the dimple D₃. Dimples D₂ and D₃ are considered to be “neighboring” dimples since two tangency lines (not shown) and the dimple line L₂ do not intersect another dimple (or portion thereof). Dimple line L₃ is drawn connecting the center of the dimple D₃ to the center of the dimple D₁. Dimples D₃ and D₁ are considered to be “neighboring” dimples since two tangency lines (not shown) and the dimple line L₃ do not intersect another dimple (or portion thereof). As illustrated, dimple lines L₁, L₂, and L₃ for the set of three neighboring dimples, D₁, D₂, and D₃, form a triangle 70. The triangle 70 defines the fret area in which the three-dimensional shaped fret area will be formed. The area enclosed by the triangle 70 has a centroid 72. The centroid 72 is the point that defines an apex of the three-dimensional shaped fret area.

Once the centroid of the triangle, for example, the apex point, is identified, the method of the present disclosure involves determining the edge origins of the triangle. An “edge origin,” as used herein, refers to any point along a dimple line that is located outside of the perimeter of any one of the neighboring dimples. An edge origin is not considered an edge of the three-dimensional shaped fret area. To form an edge of the three-dimensional shape, the method includes drawing an edge line from an edge origin to the apex point. The edge line drawn from the edge origin to the apex point forms one edge of the shape. Any number of edges and vertices may be drawn from the various edge origins to the apex point depending on the desired shape of the three-dimensional formation, as discussed above.

FIG. 11 is an illustration of a three-dimensional irregular pyramid shaped fret area designed by drawing three edge lines from edge origins to the apex point of the fret area. As shown in FIG. 11, edge lines can originate at any of the edge origins on the triangle 70. The edge origins along triangle 70 include any point along dimple line L₁ that is located outside of the perimeter of each of neighboring dimples D₁ and D₂; any point along dimple line L₂ that is located outside of the perimeter of each of neighboring dimples D₂ and D₃; and any point along dimple line L₃ that is located outside of the perimeter of each of neighboring dimples D₃ and D₁. In the illustrated embodiment, edge line E₁ is drawn from an edge origin along dimple line L₁ to an apex point A. Edge line E₂ is drawn from an edge origin along dimple line L₂ to the apex point A. Edge line E₃ is drawn from an edge origin along dimple line L₃ to the apex point A. The three edge lines E₁, E₂, and E₃ form a three-dimensional irregular pyramid shaped fret area 80 having three edges that meet at the apex point A.

In further embodiments, the method of the present disclosure may include forming an apex surface about the centroid of the triangle. After the centroid of the triangle, for example, the apex, is identified, an apex surface may be drawn about the apex. In this embodiment, the apex surface has a center of mass coincident with the apex point. The apex surface may be drawn to have any shape discussed above in the preceding section. In some embodiments, the apex surface has a polygonal shape. Once the apex surface is drawn such that its center of mass is coincident with the apex point, edge lines can be drawn from the edge origins to the perimeter of the apex surface (rather than to the apex point as described above).

FIG. 12 is an illustration of an apex surface defined within the triangle 70. After the centroid 72 of the area enclosed by the triangle 70 is identified, an apex surface S is drawn about the centroid 72 such that its center of mass is coincident with the centroid 72 (e.g., the apex point). In the illustrated embodiment, the apex surface S is a triangle. The edges of the triangle are formed around the centroid 72 so that the triangle's center of mass is positioned at the centroid 72. Edge lines can then be drawn from any edge origin along dimples lines L₁, L₂, and L₃ to the perimeter of the apex surface S. Examples of resulting three-dimensional truncated irregular pyramid shaped fret areas formed in accordance with this embodiment of the present disclosure are illustrated in FIGS. 5, 6, and 7 (which are described in detail above).

The steps of the methods described herein may be repeated to form additional three-dimensional shaped fret areas on the golf ball surface. For instance, the steps may be repeated to form three-dimensional shaped fret areas over one or more portions of the surface of the golf ball. In other embodiments, the steps may be repeated to form three-dimensional shaped fret areas over the entire surface of the golf ball.

The methods disclosed herein have been illustrated with golf ball surfaces utilizing dimples having a circular plan shape. In the illustrated embodiments, the three-dimensional shaped fret areas are designed by using three neighboring dimples. However, as will be appreciated by those skilled in the art, the methods described herein can be adapted for use on golf ball surfaces having various other dimple geometries. Indeed, any number of neighboring dimples may be used to design three-dimensional shaped fret areas depending on the dimple geometry. For example, the methods disclosed herein can be utilized to form three-dimensional shaped fret areas on golf ball surfaces with dimples having a rectangular plan shape. In this embodiment, the three-dimensional shaped fret areas may be designed by using four neighboring dimples.

Golf Ball Construction

The three-dimensional shaped fret areas according to the present disclosure may be used with practically any type of ball construction. For instance, the golf ball may have a two-piece design, a double cover, or veneer cover construction depending on the type of performance desired of the ball. Other suitable golf ball constructions include solid, wound, liquid-filled, and/or dual cores, and multiple intermediate layers.

Different materials may be used in the construction of golf balls according to the present disclosure. For example, the cover of the ball may be made of a thermoset or thermoplastic, a castable or non-castable polyurethane and polyurea, an ionomer resin, balata, or any other suitable cover material known to those skilled in the art. Conventional and non-conventional materials may be used for forming core and intermediate layers of the ball including polybutadiene and other rubber-based core formulations, ionomer resins, highly neutralized polymers, and the like.

The golf balls of the present disclosure may be formed using a variety of application techniques. For example, the golf ball layers may be formed using compression molding, flip molding, injection molding, retractable pin injection molding, reaction injection molding (RIM), liquid injection molding (LIM), casting, vacuum forming, powder coating, flow coating, spin coating, dipping, spraying, and the like. Conventionally, compression molding and injection molding are applied to thermoplastic materials, whereas RIM, liquid injection molding, and casting are employed on thermoset materials.

The golf balls and methods described and claimed herein are not to be limited in scope by the specific embodiments herein disclosed, since these embodiments are intended as illustrations of several aspects of the disclosure. Any equivalent embodiments are intended to be within the scope of this disclosure. Indeed, various modifications of the golf balls and the methods in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims. All patents and patent applications cited in the foregoing text are expressly incorporated herein by reference in their entirety. Any section headings herein are provided only for consistency with the suggestions of 37 C.F.R. § 1.77 or otherwise to provide organizational queues. These headings shall not limit or characterize the invention(s) set forth herein.

Claims

1. A golf ball having a substantially spherical surface, comprising:

a plurality of dimples on the spherical surface and a plurality of fret areas defined therebetween,

wherein at least one fret area on the spherical surface comprises a three-dimensional irregular pyramid shape having a base formed of curved edges, the curved edges corresponding to edges of the dimples surrounding the fret area, and at least three edges extending continuously upwardly from the base formed of the curved edges and meeting at an apex point, and

wherein the three-dimensional irregular pyramid shape has a height defined as the radial distance between the apex point and a phantom sphere having a radius.

2. The golf ball of claim 1, wherein the three-dimensional irregular pyramid shaped fret area is surrounded by three dimples of the plurality of dimples.

3. The golf ball of claim 1, wherein the radius is greater than about 0.84 inches.

4. The golf ball of claim 1, wherein the radius is less than about 0.84 inches and the sum of the radius and the height is greater than about 0.84 inches.

5. The golf ball of claim 1, wherein the three-dimensional irregular pyramid shape has a total surface area of about 0.001 square inches to about 0.008 square inches.

6. The golf ball of claim 1, wherein the height ranges from about 0.002 inches to about 0.025 inches.

7. A golf ball having a substantially spherical surface, comprising:

a plurality of dimples on the spherical surface and a plurality of fret areas defined therebetween,

wherein at least one fret area on the spherical surface comprises a three-dimensional truncated irregular pyramid shape having at least three edges meeting at an apex surface, wherein the apex surface is a planar surface having a center of mass coincident with an apex point of the three-dimensional truncated irregular pyramid shape, and

wherein the three-dimensional truncated irregular pyramid shape has a height defined as the radial distance between the apex surface and a phantom sphere having a radius.

8. The golf ball of claim 7, wherein the apex surface has a polygonal shape formed of at least three edges.

9. The golf ball of claim 8, wherein the apex surface has a triangular shape.

10. The golf ball of claim 7, wherein the apex surface comprises a non-polygonal shape formed of a combination of line segments and curvatures.

11. The golf ball of claim 7, wherein the apex surface has a surface area ranging from about 0.0002 square inches to about 0.001 square inches.

12. The golf ball of claim 7, wherein the three-dimensional truncated irregular pyramid shaped fret area is surrounded by three dimples of the plurality of dimples.

13. The golf ball of claim 7, wherein the height ranges from about 0.005 inches to about 0.020 inches.

14. The golf ball of claim 11, wherein the surface area of the apex surface accounts for about 5 percent to about 15 percent of the total surface area of the three-dimensional truncated irregular pyramid shape.

15. The golf ball of claim 7, wherein the radius of the phantom sphere is (i) greater than about 0.84 inches or (ii) less than about 0.84 inches but the sum of the radius and the height is greater than about 0.84 inches.

16.-20. (canceled)

21. A golf ball having a substantially spherical surface, comprising:

a plurality of dimples on the spherical surface and a plurality of fret areas defined therebetween,

wherein at least one fret area on the spherical surface comprises a three-dimensional irregular pyramid shape having a base formed of curved edges, the curved edges corresponding to edges of the dimples surrounding the fret area, and at least three edges extending continuously upwardly from the base formed of the curved edges and meeting at an apex point.

22.-23. (canceled)

24. The golf ball of claim 21, wherein the three-dimensional irregular pyramid shape has a height defined as the radial distance between the apex point and a phantom sphere having a radius, and the height ranges from about 0.002 inches to about 0.025 inches.

25. (canceled)

26. The golf ball of claim 21, wherein the three-dimensional irregular pyramid shaped fret area is surrounded by three dimples of the plurality of dimples.