CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of copending U.S. patent application Ser. No. 13/251,590, filed Oct. 3, 2011, which is a Divisional of copending U.S. patent application Ser. No. 12/262,464 filed Oct. 31, 2008, now U.S. Pat. No. 8,029,388, the disclosures of which are incorporated by reference herein in their entirety.
FIELD OF THE INVENTION

This invention relates to golf balls, particularly to golf balls having improved dimple patterns. More particularly, the invention relates to methods of arranging dimples on a golf ball by generating irregular domains based on polyhedrons, packing the irregular domains with dimples, and tessellating the domains onto the surface of the golf ball.
BACKGROUND OF THE INVENTION

Historically, dimple patterns for golf balls have had a variety of geometric shapes, patterns, and configurations. Primarily, patterns are laid out in order to provide desired performance characteristics based on the particular ball construction, material attributes, and player characteristics influencing the ball's initial launch angle and spin conditions. Therefore, pattern development is a secondary design step that is used to achieve the appropriate aerodynamic behavior, thereby tailoring ball flight characteristics and performance.

Aerodynamic forces generated by a ball in flight are a result of its velocity and spin. These forces can be represented by a lift force and a drag force. Lift force is perpendicular to the direction of flight and is a result of air velocity differences above and below the rotating ball. This phenomenon is attributed to Magnus, who described it in 1853 after studying the aerodynamic forces on spinning spheres and cylinders, and is described by Bernoulli's Equation, a simplification of the first law of thermodynamics. Bernoulli's equation relates pressure and velocity where pressure is inversely proportional to the square of velocity. The velocity differential, due to faster moving air on top and slower moving air on the bottom, results in lower air pressure on top and an upward directed force on the ball.

Drag is opposite in sense to the direction of flight and orthogonal to lift. The drag force on a ball is attributed to parasitic drag forces, which consist of pressure drag and viscous or skin friction drag. A sphere is a bluff body, which is an inefficient aerodynamic shape. As a result, the accelerating flow field around the ball causes a large pressure differential with highpressure forward and lowpressure behind the ball. The low pressure area behind the ball is also known as the wake. In order to minimize pressure drag, dimples provide a means to energize the flow field and delay the separation of flow, or reduce the wake region behind the ball. Skin friction is a viscous effect residing close to the surface of the ball within the boundary layer.

The industry has seen many efforts to maximize the aerodynamics of golf balls, through dimple disturbance and other methods, though they are closely controlled by golf's national governing body, the United States Golf Association (U.S.G.A.). One U.S.G.A. requirement is that golf balls have aerodynamic symmetry. Aerodynamic symmetry allows the ball to fly with a very small amount of variation no matter how the golf ball is placed on the tee or ground. Preferably, dimples cover the maximum surface area of the golf ball without detrimentally affecting the aerodynamic symmetry of the golf ball.

In attempts to improve aerodynamic symmetry, many dimple patterns are based on geometric shapes. These may include circles, hexagons, triangles, and the like. Other dimple patterns are based in general on the five Platonic Solids including icosahedron, dodecahedron, octahedron, cube, or tetrahedron. Yet other dimple patterns are based on the thirteen Archimedian Solids, such as the small icosidodecahedron, rhomicosidodecahedron, small rhombicuboctahedron, snub cube, snub dodecahedron, or truncated icosahedron. Furthermore, other dimple patterns are based on hexagonal dipyramids. Because the number of symmetric solid plane systems is limited, it is difficult to devise new symmetric patterns. Moreover, dimple patterns based some of these geometric shapes result in less than optimal surface coverage and other disadvantageous dimple arrangements. Therefore, dimple properties such as number, shape, size, and arrangement are often manipulated in an attempt to generate a golf ball that has better aerodynamic properties.

U.S. Pat. No. 5,562,552 to Thurman discloses a golf ball with an icosahedral dimple pattern, wherein each triangular face of the icosahedron is split by a three straight lines which each bisect a corner of the face to form 3 triangular faces for each icosahedral face, wherein the dimples are arranged consistently on the icosahedral faces.

U.S. Pat. No. 5,046,742 to Mackey discloses a golf ball with dimples packed into a 32sided polyhedron composed of hexagons and pentagons, wherein the dimple packing is the same in each hexagon and in each pentagon.

U.S. Pat. No. 4,998,733 to Lee discloses a golf ball formed of ten “spherical” hexagons each split into six equilateral triangles, wherein each triangle is split by a bisecting line extending between a vertex of the triangle and the midpoint of the side opposite the vertex, and the bisecting lines are oriented to achieve improved symmetry.

U.S. Pat. No. 6,682,442 to Winfield discloses the use of polygons as packing elements for dimples to introduce predictable variance into the dimple pattern. The polygons extend from the poles of the ball to a parting line. Any space not filled with dimples from the polygons is filled with other dimples.

A continuing need exists for a dimple pattern whose dimple arrangement results in a maximized surface coverage and desirable aerodynamic characteristics, including improved symmetry.
SUMMARY OF THE INVENTION

The present invention provides a method for arranging dimples on a golf ball surface that significantly improves aerodynamic symmetry and minimizes parting line visibility by arranging the dimples in a pattern derived from at least one irregular domain generated from a regular or nonregular polyhedron. The method includes choosing control points of a polyhedron, generating an irregular domain based on those control points, packing the irregular domain with dimples, and tessellating the irregular domain to cover the surface of the golf ball. The control points include the center of a polyhedral face, a vertex of the polyhedron, a midpoint or other point on an edge of the polyhedron and others. The method ensures that the symmetry of the underlying polyhedron is preserved while minimizing great circles due to parting lines from the molding process.

The present invention provides methods for generating an irregular domain based on two or more control points. These methods include connecting the control points with a nonlinear sketch line, patterning the sketch line in a first manner to create a first irregular domain, and optionally patterning the sketch line in a second manner to create a second irregular domain.

The present invention also provides methods for generating one or more irregular domains based on each set of control points. The center to vertex method, the center to midpoint method, the vertex to midpoint method, the center to edge method, and the midpoint to center to vertex method each provide a single irregular domain that can be tessellated to cover a golf ball. The center to center method, the midpoint to midpoint method, and the vertex to vertex method each provide two irregular domains that can be tessellated to cover a golf ball. In each case, the irregular domains cover the surface of the golf ball in a uniform pattern.
BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings which form a part of the specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:

FIG. 1A illustrates a golf ball having dimples arranged by a method of the present invention; FIG. 1B illustrates a polyhedron face; FIG. 1C illustrates an element of the present invention in the polyhedron face of FIG. 1B; FIG. 1D illustrates a domain formed by a methods of the present invention packed with dimples and formed from two elements of FIG. 1C;

FIG. 2 illustrates a single face of a polyhedron having control points thereon;

FIG. 3A illustrates a polyhedron face; FIG. 3B illustrates an element of the present invention packed with dimples; FIG. 3C illustrates a domain of the present invention packed with dimples formed from elements of FIG. 3B; FIG. 3D illustrates a golf ball formed by a method of the present invention formed of the domain of FIG. 3C;

FIG. 4A illustrates two polyhedron faces; FIG. 4B illustrates a first domain of the present invention in the two polyhedron faces of FIG. 4A; FIG. 4C illustrates a first domain and a second domain of the present invention in three polyhedron faces; FIG. 4D illustrates a golf ball formed by a method of the present invention formed of the domains of FIG. 4C;

FIG. 5A illustrates a polyhedron face; FIG. 5B illustrates a first domain of the present invention in a polyhedron face; FIG. 5C illustrates a first domain and a second domain of the present invention in three polyhedron faces; FIG. 5D illustrates a golf ball formed using a method of the present invention formed of the domains of FIG. 5C;

FIG. 6A illustrates a polyhedron face; FIG. 6B illustrates a portion of a domain of the present invention in the polyhedron face of FIG. 6A; FIG. 6C illustrates a domain formed by the methods of the present invention; FIG. 6D illustrates a golf ball formed using the methods of the present invention formed of domains of FIG. 6C;

FIG. 7A illustrates a polyhedron face; FIG. 7B illustrates a domain of the present invention in the polyhedron face of FIG. 7A; FIG. 7C illustrates a golf ball formed by a method of the present invention;

FIG. 8A illustrates a first element of the present invention in a polyhedron face; FIG. 8B illustrates a first and a second element of the present invention in the polyhedron face of FIG. 8A; FIG. 8C illustrates two domains of the present invention composed of first and second elements of FIG. 8B; FIG. 8D illustrates a single domain of the present invention based on the two domains of FIG. 8C; FIG. 8E illustrates a golf ball formed using a method of the present invention formed of the domains of FIG. 8D;

FIG. 9A illustrates a polyhedron face; FIG. 9B illustrates an element of the present invention in the polyhedron face of FIG. 9A; FIG. 9C illustrates two elements of FIG. 9B combining to form a domain of the present invention; FIG. 9D illustrates a domain formed by the methods of the present invention based on the elements of FIG. 9C; FIG. 9E illustrates a golf ball formed using a method of the present invention formed of domains of FIG. 9D;

FIG. 10A illustrates a face of a rhombic dodecahedron; FIG. 10B illustrates a segment of the present invention in the face of FIG. 10A; FIG. 10C illustrates the segment of FIG. 10B and copies thereof forming a domain of the present invention; FIG. 10D illustrates a domain formed by a method of the present invention based on the segments of FIG. 10C; and FIG. 10E illustrates a golf ball formed by a method of the present invention formed of domains of FIG. 10D.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In one embodiment, illustrated in FIG. 1A, the present invention comprises a golf ball 10 comprising dimples 12. Dimples 12 are arranged by packing irregular domains 14 with dimples, as seen best in FIG. 1D. Irregular domains 14 are created in such a way that, when tessellated on the surface of golf ball 10, they impart greater orders of symmetry to the surface than prior art balls. The irregular shape of domains 14 additionally minimize the appearance and effect of the golf ball parting line from the molding process, and allows greater flexibility in arranging dimples than would be available with regularly shaped domains.

The irregular domains can be defined through the use of any one of the exemplary methods described herein. Each method produces one or more unique domains based on circumscribing a sphere with the vertices of a regular polyhedron. The vertices of the circumscribed sphere based on the vertices of the corresponding polyhedron with origin (0,0,0) are defined below in Table 1.

TABLE 1
Vertices of Circumscribed Sphere
based on Corresponding Polyhedron Vertices
Type of
Polyhedron
Vertices
Tetrahedron
(+1, +1, +1); (−1, −1, +1); (−1, +1, −1); (+1, −1, −1)
Cube
(±1, ±1, ±1)
Octahedron
(±1, 0, 0); (0, ±1, 0); (0, 0, ±1)
Dodecahedron
(±1, ±1, ±1); (0, ±1/φ, ±φ); (±1/φ, ±φ, 0); (±φ, 0, ±1/φ)*
Icosahedron
(0, ±1, ±φ); (±1, ±φ, 0); (±φ, 0, ±1)*
*φ = (1 + √5)/2

Each method has a unique set of rules which are followed for the domain to be symmetrically patterned on the surface of the golf ball. Each method is defined by the combination of at least two control points. These control points, which are taken from one or more faces of a regular or nonregular polyhedron, consist of at least three different types: the center C of a polyhedron face; a vertex V of a face of a regular polyhedron; and the midpoint M of an edge of a face of the polyhedron. FIG. 2 shows an exemplary face 16 of a polyhedron (a regular dodecahedron in this case) and one of each a center C, a midpoint M, a vertex V, and an edge E on face 16. The two control points C, M, or V may be of the same or different types. Accordingly, six types of methods for use with regular polyhedrons are defined as follows:

1. Center to midpoint (C→M);

2. Center to center (C→C);

3. Center to vertex (C→V);

4. Midpoint to midpoint (M→M);

5. Midpoint to Vertex (M→V); and

6. Vertex to Vertex (V→V).

While each method differs in its particulars, they all follow the same basic scheme. First, a nonlinear sketch line is drawn connecting the two control points. This sketch line may have any shape, including, but not limited, to an arc, a spline, two or more straight or arcuate lines or curves, or a combination thereof. Second, the sketch line is patterned in a method specific manner to create a domain, as discussed below. Third, when necessary, the sketch line is patterned in a second fashion to create a second domain.

While the basic scheme is consistent for each of the six methods, each method preferably follows different steps in order to generate the domains from a sketch line between the two control points, as described below with reference to each of the methods individually.
The Center to Vertex Method

Referring again to FIGS. 1A1D, the center to vertex method yields one domain that tessellates to cover the surface of golf ball 10. The domain is defined as follows:

 1. A regular polyhedron is chosen (FIGS. 1A1D use an icosahedron);
 2. A single face 16 of the regular polyhedron is chosen, as shown in FIG. 1B;
 3. Center C of face 16, and a first vertex V_{1 }of face 16 are connected with any nonlinear sketch line, hereinafter referred to as a segment 18;
 4. A copy 20 of segment 18 is rotated about center C, such that copy 20 connects center C with vertex V_{2 }adjacent to vertex V_{1}. The two segments 18 and 20 and the edge E connecting vertices V_{1 }and V_{2 }define an element 22, as shown best in FIG. 1C; and
 5. Element 22 is rotated about midpoint M of edge E to create a domain 14, as shown best in FIG. 1D.

When domain 14 is tessellated to cover the surface of golf ball 10, as shown in FIG. 1A, a different number of total domains 14 will result depending on the regular polyhedron chosen as the basis for control points C and V_{1}. The number of domains 14 used to cover the surface of golf ball 10 is equal to the number of faces P_{F }of the polyhedron chosen times the number of edges P_{E }per face of the polyhedron divided by 2, as shown below in Table 2.

Domains Resulting from Use of Specific Polyhedra When Using the Center to Vertex Method

Number
Type of
of Faces,
Number of Edges,
Number of Domains
Polyhedron
P_{F}
P_{E}
14
Tetrahedron
4
3
6
Cube
6
4
12
Octahedron
8
3
12
Dodecahedron
12
5
30
Icosahedron
20
3
30
The Center to Midpoint Method

Referring to FIGS. 3A3D, the center to midpoint method yields a single irregular domain that can be tessellated to cover the surface of golf ball 10. The domain is defined as follows:

 1. A regular polyhedron is chosen (FIGS. 3A3D use a dodecahedron);
 2. A single face 16 of the regular polyhedron is chosen, as shown in FIG. 3A;
 3. Center C of face 16, and midpoint M_{1 }of a first edge E_{1 }of face 16 are connected with a segment 18;
 4. A copy 20 of segment 18 is rotated about center C, such that copy 20 connects center C with a midpoint M_{2 }of a second edge E_{2 }adjacent to first edge E_{1}. The two segments 16 and 18 and the portions of edge E_{1 }and edge E_{2 }between midpoints M_{1 }and M_{2 }define an element 22; and
 5. Element 22 is patterned about vertex V of face 16 which is contained in element 22 and connects edges E_{1 }and E_{2 }to create a domain 14.

When domain 14 is tessellated around a golf ball 10 to cover the surface of golf ball 10, as shown in FIG. 3D, a different number of total domains 14 will result depending on the regular polyhedron chosen as the basis for control points C and M_{1}. The number of domains 14 used to cover the surface of golf ball 10 is equal to the number of vertices P_{V }of the chosen polyhedron, as shown below in Table 3.

TABLE 3
Domains Resulting From Use of Specific Polyhedra
When Using the Center to Midpoint Method
Type of Polyhedron
Number of Vertices, P_{V}
Number of Domains 14
Tetrahedron
4
4
Cube
8
8
Octahedron
6
6
Dodecahedron
20
20
Icosahedron
12
12
The Center to Center Method

Referring to FIGS. 4A4D, the center to center method yields two domains that can be tessellated to cover the surface of golf ball 10. The domains are defined as follows:

 1. A regular polyhedron is chosen (FIGS. 4A4D use a dodecahedron);
 2. Two adjacent faces 16 a and 16 b of the regular polyhedron are chosen, as shown in FIG. 4A;
 3. Center C_{1 }of face 16 a, and center C_{2 }of face 16 b are connected with a segment 18;
 4. A copy 20 of segment 18 is rotated 180 degrees about the midpoint M between centers C_{1 }and C_{2}, such that copy 20 also connects center C_{1 }with center C_{2}, as shown in FIG. 4B. The two segments 16 and 18 define a first domain 14 a; and
 5. Segment 18 is rotated equally about vertex V to define a second domain 14 b, as shown in FIG. 4C.

When first domain 14 a and second domain 14 b are tessellated to cover the surface of golf ball 10, as shown in FIG. 4D, a different number of total domains 14 a and 14 b will result depending on the regular polyhedron chosen as the basis for control points C_{1 }and C_{2}. The number of first and second domains 14 a and 14 b used to cover the surface of golf ball 10 is P_{F}*P_{E}/2 for first domain 14 a and P_{V }for second domain 14 b, as shown below in Table 4.

TABLE 4
Domains Resulting From Use of Specific Polyhedra
When Using the Center to Center Method
Number of
Number
Number of
Number of
First
Number
of
Second
Type of
Vertices,
Domains
of Faces,
Edges,
Domains
Polyhedron
P_{V}
14a
P_{F}
P_{E}
14b
Tetrahedron
4
6
4
3
4
Cube
8
12
6
4
8
Octahedron
6
9
8
3
6
Dodecahedron
20
30
12
5
20
Icosahedron
12
18
20
3
12
The Midpoint to Midpoint Method

Referring to FIGS. 5A5D, the midpoint to midpoint method yields two domains that tessellate to cover the surface of golf ball 10. The domains are defined as follows:

 1. A regular polyhedron is chosen (FIGS. 5A5D use a dodecahedron);
 2. A single face 16 of the regular polyhedron is chosen, as shown in FIG. 5A;
 3. The midpoint M_{1 }of a first edge E_{1 }of face 16, and the midpoint M_{2 }of a second edge E_{2 }adjacent to first edge E_{1 }are connected with a segment 18;
 4. Segment 18 is patterned around center C of face 16 to form a first domain 14 a, as shown in FIG. 5B;
 5. Segment 18, along with the portions of first edge E_{1 }and second edge E_{2 }between midpoints M_{1 }and M_{2}, define an element 22; and
 6. Element 22 is patterned about vertex V which is contained in element 22 and connects edges E_{1 }and E_{2 }to create a second domain 14 b, as shown in FIG. 5C.

When first domain 14 a and second domain 14 b are tessellated to cover the surface of golf ball 10, as shown in FIG. 5D, a different number of total domains 14 a and 14 b will result depending on the regular polyhedron chosen as the basis for control points M_{1 }and M_{2}. The number of first and second domains 14 a and 14 b used to cover the surface of golf ball 10 is P_{F }for first domain 14 a and P_{V }for second domain 14 b, as shown below in Table 5.

TABLE 5
Domains Resulting From Use of Specific Polyhedra
When Using the Center to Center Method
Number of
Number of
Second
Type of
Number of
Number of First
Vertices,
Domains
Polyhedron
Faces, P_{F}
Domains 14a
P_{V}
14b
Tetrahedron
4
4
4
4
Cube
6
6
8
8
Octahedron
8
8
6
6
Dodecahedron
12
12
20
20
Icosahedron
20
20
12
12
The Midpoint to Vertex Method

Referring to FIGS. 6A6D, the midpoint to vertex method yields one domain that tessellates to cover the surface of golf ball 10. The domain is defined as follows:

 1. A regular polyhedron is chosen (FIGS. 6A6D use a dodecahedron);
 2. A single face 16 of the regular polyhedron is chosen, as shown in FIG. 6A;
 3. A midpoint M_{1 }of edge E_{1 }of face 16 and a vertex V_{1 }on edge E_{1 }are connected with a segment 18;
 4. Copies 20 of segment 18 is patterned about center C of face 16, one for each midpoint M_{2 }and vertex V_{2 }of face 16, to define a portion of domain 14, as shown in FIG. 6B; and
 5. Segment 18 and copies 20 are then each rotated 180 degrees about their respective midpoints to complete domain 14, as shown in FIG. 6C.

When domain 14 is tessellated to cover the surface of golf ball 10, as shown in FIG. 6D, a different number of total domains 14 will result depending on the regular polyhedron chosen as the basis for control points M_{1 }and V_{1}. The number of domains 14 used to cover the surface of golf ball 10 is P_{F}, as shown in Table 6.

TABLE 6
Domains Resulting From Use of Specific Polyhedra When Using the
Midpoint to Vertex Method
Type of Polyhedron
Number of Faces, P_{F}
Number of Domains 14
Tetrahedron
4
4
Cube
6
6
Octahedron
8
8
Dodecahedron
12
12
Icosahedron
20
20
The Vertex to Vertex Method

Referring to FIGS. 7A7C, the vertex to vertex method yields two domains that tessellate to cover the surface of golf ball 10. The domains are defined as follows:

 1. A regular polyhedron is chosen (FIGS. 7A7C use an icosahedron);
 2. A single face 16 of the regular polyhedron is chosen, as shown in FIG. 7A;
 3. A first vertex V_{1 }face 16, and a second vertex V_{2 }adjacent to first vertex V_{1 }are connected with a segment 18;
 4. Segment 18 is patterned around center C of face 16 to form a first domain 14 a, as shown in FIG. 7B;
 5. Segment 18, along with edge E_{1 }between vertices V_{1 }and V_{2}, defines an element 22; and
 6. Element 22 is rotated around midpoint M_{1 }of edge E_{1 }to create a second domain 14 b.

When first domain 14 a and second domain 14 b are tessellated to cover the surface of golf ball 10, as shown in FIG. 7C, a different number of total domains 14 a and 14 b will result depending on the regular polyhedron chosen as the basis for control points V_{1 }and V_{2}. The number of first and second domains 14 a and 14 b used to cover the surface of golf ball 10 is P_{F }for first domain 14 a and P_{F}*P_{E}/2 for second domain 14 b, as shown below in Table 7.

TABLE 7
Domains Resulting From Use of Specific Polyhedra
When Using the Vertex to Vertex Method
Number of
Number
Number of
Second
Type of
Number of
of First
Edges per Face,
Domains
Polyhedron
Faces, P_{F}
Domains 14a
P_{E}
14b
Tetrahedron
4
4
3
6
Cube
6
6
4
12
Octahedron
8
8
3
12
Dodecahedron
12
12
5
30
Icosahedron
20
20
3
30

While the six methods previously described each make use of two control points, it is possible to create irregular domains based on more than two control points. For example, three, or even more, control points may be used. The use of additional control points allows for potentially different shapes for irregular domains. An exemplary method using a midpoint M, a center C and a vertex V as three control points for creating one irregular domain is described below.
The Midpoint to Center to Vertex Method

Referring to FIGS. 8A8E, the midpoint to center to vertex method yields one domain that tessellates to cover the surface of golf ball 10. The domain is defined as follows:

 1. A regular polyhedron is chosen (FIGS. 8A8E use an icosahedron);
 2. A single face 16 of the regular polyhedron is chosen, as shown in FIG. 8A;
 3. A midpoint M_{1 }on edge E_{1 }of face 16, Center C of face 16 and a vertex V_{1 }on edge E_{1 }are connected with a segment 18, and segment 18 and the portion of edge E_{1 }between midpoint M_{1 }and vertex V_{1 }define a first element 22 a, as shown in FIG. 8A;
 4. A copy 20 of segment 18 is rotated about center C, such that copy 20 connects center C with a midpoint M_{2 }on edge E_{2 }adjacent to edge E_{1}, and connects center C with a vertex V_{2 }at the intersection of edges E_{1 }and E_{2}, and the portion of segment 18 between midpoint M_{1 }and center C, the portion of copy 20 between vertex V_{2 }and center C, and the portion of edge E_{1 }between midpoint M_{1 }and vertex V_{2 }define a second element 22 b, as shown in FIG. 8B; 5. First element 22 a and second element 22 b are rotated about midpoint M_{1 }of edge E_{1}, as seen in FIGS. 8C, to define two domains 14, wherein a single domain 14 is bounded solely by portions of segment 18 and copy 20 and the rotation 18′ of segment 18, as seen in FIG. 8D. When domain 14 is tessellated to cover the surface of golf ball 10, as shown in FIG. 8E, a different number of total domains 14 will result depending on the regular polyhedron chosen as the basis for control points M, C, and V. The number of domains 14 used to cover the surface of golf ball 10 is equal to the number of faces P_{F }of the polyhedron chosen times the number of edges P_{E }per face of the polyhedron, as shown below in Table 8.

TABLE 8
Domains Resulting From Use of Specific Polyhedra When Using the
Midpoint to Center to Vertex Method
Type of
Number of
Number of Edges,
Number of Domains
Polyhedron
Faces, P_{F}
P_{E}
14
Tetrahedron
4
3
12
Cube
6
4
24
Octahedron
8
3
24
Dodecahedron
12
5
60
Icosahedron
20
3
60

While the methods described previously provide a framework for the use of center C, vertex V, and midpoint M as the only control points, other control points are usable. For example, a control point may be any point P on an edge E of the chosen polyhedron face. When this type of control point is used, additional types of domains may be generated, though the mechanism for creating the irregular domain(s) may be different. An exemplary method, using a center C and a point P on an edge, for creating one such irregular domain is described below.
The Center to Edge Method

Referring to FIGS. 9A9E, the center to edge method yields one domain that tessellates to cover the surface of golf ball 10. The domain is defined as follows:

 1. A regular polyhedron is chosen (FIGS. 9A9E use an icosahedron);
 2. A single face 16 of the regular polyhedron is chosen, as shown in FIG. 9A;
 3. Center C of face 16, and a point P_{1 }on edge E_{1 }are connected with a segment 18,
 4. A copy 20 of segment 18 is rotated about center C, such that copy 20 connects center C with a point P_{2 }on edge E_{2 }adjacent to edge E_{1}, where point P_{2 }is positioned identically relative to edge E_{2 }as point P_{1 }is positioned relative to edge E_{1}, such that the two segments 18 and 20 and the portions of edges E_{1 }and E_{2 }between points P_{1 }and P_{2}, respectively, and a vertex V, which connects edges E_{1 }and E_{2}, define an element 22, as shown best in FIG. 9B; and
 5. Element 22 is rotated about midpoint M_{1 }of edge E_{1 }or midpoint M_{2 }of edge E_{2}, whichever is located within element 22, as seen in FIGS. 9B9C, to create a domain 14, as seen in FIG. 9D.

When domain 14 is tessellated to cover the surface of golf ball 10, as shown in FIG. 9E, a different number of total domains 14 will result depending on the regular polyhedron chosen as the basis for control points C and P_{1}. The number of domains 14 used to cover the surface of golf ball 10 is equal to the number of faces P_{F }of the polyhedron chosen times the number of edges P_{E }per face of the polyhedron divided by 2, as shown below in Table 9.

TABLE 9
Domains Resulting From Use of Specific Polyhedra
When Using the Center to Edge Method
Type of
Number of
Number of Edges,
Number of Domains
Polyhedron
Faces, P_{F}
P_{E}
14
Tetrahedron
4
3
6
Cube
6
4
12
Octahedron
8
3
12
Dodecahedron
12
5
30
Icosahedron
20
3
30

Though each of the above described methods has been explained with reference to regular polyhedrons, they may also be used with certain nonregular polyhedrons, such as Archimedean Solids, Catalan Solids, or others. The methods used to derive the irregular domains will generally require some modification in order to account for the nonregular face shapes of the nonregular solids. An exemplary method for use with a Catalan Solid, specifically a rhombic dodecahedron, is described below.
A Vertex to Vertex Method for a Rhombic Dodecahedron

Referring to FIGS. 10A10E, a vertex to vertex method based on a rhombic dodecahedron yields one domain that tessellates to cover the surface of golf ball 10. The domain is defined as follows:

 1. A single face 16 of the rhombic dodecahedron is chosen, as shown in FIG. 10A;
 2. A first vertex V_{1 }face 16, and a second vertex V_{2 }adjacent to first vertex V_{1 }are connected with a segment 18, as shown in FIG. 10B;
 3. A first copy 20 of segment 18 is rotated about vertex V_{2}, such that it connects vertex V_{2 }to vertex V3 of face 16, a second copy 24 of segment 18 is rotated about center C, such that it connects vertex V_{3 }and vertex V_{4 }of face 16, and a third copy 26 of segment 18 is rotated about vertex V_{1 }such that it connects vertex V_{1 }to vertex V_{4}, all as shown in FIG. 10C, to form a domain 14, as shown in FIG. 10D;

When domain 14 is tessellated to cover the surface of golf ball 10, as shown in FIG. 10E, twelve domains will be used to cover the surface of golf ball 10, one for each face of the rhombic dodecahedron.

After the irregular domain(s) is created using any of the above methods, the domain(s) may be packed with dimples in order to be usable in creating golf ball 10. There are no limitations on how the dimples are packed. There are likewise no limitations to the dimple shapes or profiles selected to pack the domains. Though the present invention includes substantially circular dimples in one embodiment, dimples or protrusions (brambles) having any desired characteristics and/or properties may be used. For example, in one embodiment the dimples may have a variety of shapes and sizes including different depths and widths. In particular, the dimples may be concave hemispheres, or they may be triangular, square, hexagonal, catenary, polygonal or any other shape known to those skilled in the art. They may also have straight, curved, or sloped edges or sides. To summarize, any type of dimple or protrusion (bramble) known to those skilled in the art may be used with the present invention. The dimples may all fit within each domain, as seen in FIGS. 1A and 1D, or dimples may be shared between one or more domains, as seen in FIGS. 3C3D, so long as the dimple arrangement on each independent domain remains consistent across all copies of that domain on the surface of a particular golf ball. Alternatively, the tessellation can create a pattern that covers more than about 60%, preferably more than about 70% and preferably more than about 80% of the golf ball surface without using dimples.

In other embodiments, the domains may not be packed with dimples, and the borders of the irregular domains may instead comprise ridges or channels. In golf balls having this type of irregular domain, the one or more domains or sets of domains preferably overlap to increase surface coverage of the channels. Alternatively, the borders of the irregular domains may comprise ridges or channels and the domains are packed with dimples.

When the domain(s) is patterned onto the surface of a golf ball, the arrangement of the domains dictated by their shape and the underlying polyhedron ensures that the resulting golf ball has a high order of symmetry, equaling or exceeding 12. The order of symmetry of a golf ball produced using the method of the current invention will depend on the regular or nonregular polygon on which the irregular domain is based. The order and type of symmetry for golf balls produced based on the five regular polyhedra are listed below in Table 10.

TABLE 10
Symmetry of Golf Ball of the Present Invention
as a Function of Polyhedron
Type of Polyhedron
Type of Symmetry
Symmetrical Order
Tetrahedron
Chiral Tetrahedral Symmetry
12
Cube
Chiral Octahedral Symmetry
24
Octahedron
Chiral Octahedral Symmetry
24
Dodecahedron
Chiral Icosahedral Symmetry
60
Icosahedron
Chiral Icosahedral Symmetry
60

These high orders of symmetry have several benefits, including more even dimple distribution, the potential for higher packing efficiency, and improved means to mask the ball parting line. Further, dimple patterns generated in this manner may have improved flight stability and symmetry as a result of the higher degrees of symmetry.

In other embodiments, the irregular domains do not completely cover the surface of the ball, and there are open spaces between domains that may or may not be filled with dimples. This allows dissymmetry to be incorporated into the ball.

While the preferred embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not of limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. For example, while the preferred polyhedral shapes have been provided above, other polyhedral shapes could also be used. Thus the present invention should not be limited by the abovedescribed exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.