WO2000074797A1

WO2000074797A1 - Golf ball with three dimple types

Info

Publication number: WO2000074797A1
Application number: PCT/US2000/040067
Authority: WO
Inventors: Matthew B. Stanczak; Lane D. Lemons
Original assignee: Dunlop Maxfli Sports Corporation
Priority date: 1999-06-08
Filing date: 2000-06-05
Publication date: 2000-12-14
Also published as: CA2376171A1; WO2000074794A1; EP1191981A4; JP2003501173A; AU5334300A; CA2307703A1; AU4815200A; EP1189665A4; EP1189665A1; JP2003529393A; EP1191981A1

Abstract

The present invention provides a golf ball (5) having a plurality of dimples (200, 202, 204) arranged on its outer surface, selected from three sets of dimples. The radius of each dimple set has a different value. The dimples (200, 202, 204) are arranged on the surface of the ball according to the rhombicosadodecahedron.

Description

GOLF BALL WITH THREE DIMPLE TYPES

BACKGROUND OF THE INVENTION

This invention relates to golf balls and more particularly to a surface

configuration of a golf ball.

DESCRIPTION OF THE PRIOR ART

For many years golf balls have been made with surface

indentations or depressions, called dimples, to improve their aerodynamic properties in flight. Many efforts have been made to select the optimum

number, size and shape of dimples as well as their disposition around the

outer surface of a generally spherically shaped golf ball.

Dimples on golf balls are typically circular in elevation cross section,

but a number of other designs are also utilized, including truncated cones,

dimples within dimples, elliptical surfaces, hemispherical (or single radius)

dimples, and dual radius dimples. For example, U.S. Patent No. 4,979,747

shows dimples having a frusto-contical elevation view cross section, and U.S.

Pat. No. 5,005,838 shows dimples having complex shapes.

Different dimple shapes have different aerodynamic properties, and

therefore, result in different performance characteristics. For example, a

single radius dimple provides a more gradual entry of the airflow into the

dimple, while a dual radius dimple provides a more abrupt entry of the airflow into the dimple. (A single radius dimple is one in which the elevation

cross sectional shape of the dimple can be described by one radius, and dual

radius dimple is one in which the elevation cross section is described by two radii.)

It has been found that the single radius dimple is the most optimal

dimple shape for a high performance three-piece wound golf ball. By

contrast, the dual radius dimple is the most optimal shape design for two- piece distance balls for providing the desired golf ball flight trajectory. These

dimple choices are based on the current view that the higher spinning

performance balls require a more gradual entry of the airflow into the dimple

to create the desired aerodynamic effects, whereas the low spinning distance

ball requires a more abrupt entry of the airflow into the dimple to create the desired aerodynamic effect.

There are a number of hybrid type balls which do not fall squarely

within either the three-piece performance category or the two-piece distance

category. For example, two-piece performance balls and three-piece distance

balls are hybrid balls which behave like performance balls for certain shots

and like distance balls for other shots. As used herein the term "hybrid ball"

is used to refer to a two piece performance ball, a three-piece distance ball, or

any other ball which behaves like a performance ball for certain shots and

like a distance ball for other shots.

It has been found, for instance that a dimple pattern utilizing dual

radius dimples allows for a lower more boring trajectory for a distance two- piece ball, whereas a pattern utilizing single radius dimples allows for a more

consistent flight trajectory for high performance three-piece balls.

A need exists for a dimple pattern (and dimple shape) which takes into account the unique characteristics of the hybrid ball (i.e. the fact that it

performs as a distance ball for certain shots, and as a performance ball for

other shots) to provide optimum performance. The goal is to provide a ball

that (i) provides shghtly longer overall distance than a ball utilizing either all

single radius dimples or all dual radius dimples, and (h) has a significantly lower trajectory, as exhibited by the lower rear trajectory value.

Thus, it is an object of the present invention to provide a golf ball

dimple pattern that optimizes the performance characteristics of the hybrid ball.

It is another object of the present invention to provide a hybrid golf

ball that provides a shghtly longer overall distance and a lower trajectory than the prior art hybrid balls.

It is another object of the invention to provide a golf ball having a

dimple pattern that incorporates dimples of different sizes to maximize the aerodynamic qualities for each such dimple shape.

It is yet another object of the present invention to provide a golf ball having superior distance, trajectory and flight stability. SUMMARY OF THE INVENTION

These and other objectives of the present invention are accomplished

according to the present invention by providing a golf ball having a dimple pattern which incorporates dimples of different shapes to maximize the

aerodynamic properties of the ball. The dimple shapes may be selected from

any known dimple shapes, including but not limited to truncated cones, squares, triangles, dimples within dimples, elliptical surfaces, single radius

dimples, and dual radius dimples. The invention allows for the combination

of any of the possible dimple shapes into a single dimple pattern to allow a

more optimized golf ball flight trajectory.

The golf ball of the preferred embodiment is a hybrid ball in which the dimple pattern on the surface of the ball includes both single radius and dual radius dimples in order to achieve the most optimal flight performance. This

hybrid ball is allowed to best utilize the aspects of single rad us dimples for

shots where it behaves more like a performance three-piece ball, and the

aspects of dual radius dimples for shots where it behaves like a distance ball, while maintaining good flight performance and control with a combination of

both. The ball provides shghtly longer overall distance, and a significantly

lower trajectory than the prior art hybrid balls. This is a much desired

property for this type of ball.

The dimples are arranged by dividing the outer spherical surface of a golf ball into a plurality of polygonal configurations, including pentagons,

squares and triangles for locating a plurality of dimples on the outer surface of the golf ball. The polygonal configurations of this invention are preferably a combination of regular pentagons, squares and triangles to cover the outer

surface. This first plurality of polygonal configurations is generally referred to herein as a "rhombicosadodecahedron". The rhombicosadodecahedron is

further characterized by a uniform pattern of pentagons formed over the

outer surface each bounded by triangles and squares.

The preferred embodiment utilizes a pattern of 402 dimples arranged

in the construction of the rhombicosadodecahedron. A pair of first polygonal

configurations, each located on opposite sides of the outer surface, include

one of the two poles symmetrically arranged within its boundaries. The

outer surface has a plurality of dimples of different sizes. In one

embodiment, the dimples are of first, second and third sizes and are

generally located to have a first pattern associated with the pentagons, a second pattern associated with the squares, and a third pattern associated with the triangles.

In another embodiment of the invention, the outer surface of the golf

ball includes a plurality of parting lines along great circle paths of the ball for

further dividing the first plurality of polygonal configurations into a second plurality of polygonal configurations, each of which are smaller than the

polygonal configurations of the first polygonal configurations. The dimples

are arranged over the outer surface by being associated with both the first

and the second plurality of polygonal configurations. Description of the Drawings

The invention will be more readily understood from a reading of the

following specification and by reference to the accompanying drawings

forming a part thereof, wherein an example of the invention is shown and

wherein:

Figure 1 is an elevation view of the outer surface of a golf ball being

divided into a plurality of polygonal configurations according to the

invention;

Figure 2 is an elevation view of the golf ball of this invention showing

the relative locations of pentagons, squares and triangles formed on the outer surface with a pole at the center of a pentagon;

Figure 3 is an elevation view of the golf ball of this invention showing

the relative locations of pentagons, squares and triangles formed on the outer surface with a pole at the center of a square; Fig. 4 is an equatorial view of the ball of preferred embodiment of the

present invention.

Fig. 5 is a polar view of the ball shown in Fig. 4

Fig. 6 is an equatorial view of the ball shown in Fig. 4, and includes polygons projected thereon.

Fig. 7 is a polar view of the ball shown in Fig. 5 and include polygons

projected thereon.

Figure 8 is an elevation view of the golf ball showing circular dimples

of three sizes being located on the outer surface of the golf ball to correspond with the polygonal configurations of Fig. 2; Figure 9 is an elevation view of the golf ball of Fig. 4 rotated to show

an equatorial great circle path defining a mold line;

Figure 10 is an elevation view of the outer surface of the golf ball being

further divided by a plurahty of parting lines of the polygonal configurations

to form another embodiment of the invention;

Figure 11 is an elevation view of the golf ball showing dimples located

on the outer surface of the golf ball to correspond with the polygonal

configurations and parting lines of Fig. 10;

Figure 12 is an elevation view of the golf ball showing dimples

associated with five parting lines on the outer surface of the golf ball to correspond with the polygonal configurations and parting lines of Fig. 2;

Figure 13 is an elevation view of the golf ball of Fig.12 rotated to show

an equatorial great circle path defining a mold line;

Figure 14 is an elevation view of the golf ball showing non-circular

dimples, being triangles and squares, located on the outer surface of the golf ball to correspond with the polygonal configurations of Fig. 2;

Figure 15 is an elevation view of the golf ball of Fig. 14 rotated to show

an equatorial great circle path defining a mold line;

Figure 16 is a cross sectional view cut through one of the dimples on the outer surface of the ball;

Figure 17 is a cross sectional view of a single radius dimple; and

Figure 18 is a cross sectional view of a dual radius dimple. DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now in more detail to the drawings, the invention will now

be described in more detail. The golf ball 5 may have a unit construction in a

single piece, molded from a suitable rubber or plastic composition; it may be

of a two-piece ball construction having a separately apphed cover apphed

around a core; it may be of a three piece wound ball with a liquid or solid

center; or it may be a multipiece solid golf ball. The cover is molded from a material suitable for golf balls. It may be molded as two separate

hemispherical half-shells which are then compression molded or injection

molded around the core.

The dimple configuration will normally be apphed to the ball during

the molding of the cover around the core by using appropriately shaped

negative molds containing the dimple pattern in reverse. The molded golf

ball having the desired dimple configuration may be then painted.

Alternately, painting may be unnecessary for one piece golf balls using a cover having a suitable compounding of the composition used.

Accordingly, the scope of this invention provides a golf ball mold whose

molding surface contains a uniform pattern to give the golf ball a dimple

configuration superior to those of the prior art. The invention is preferably described in terms of the golf ball that results from the mold, but could be

described within the scope of this invention in terms of the mold structure

that produces a golf ball.

To assist in locating the dimples on the golf ball, the golf ball 5 of this invention has its outer spherical surface partitioned by the projection of a plurahty of polygonal configurations onto the outer surface. That is, the formation or division that results from a particular arrangement of different

polygons on the outer surface of a golf ball is referred to herein as a "plurahty of polygonal configurations ." A view of one side of a golf ball 5 showing a

preferred division of the golf ball's outer surface 7 is illustrated in Fig. 1.

In the preferred embodiment, a polygonal configuration known as a

rhombicosadodecahedron is projected onto the surface of a sphere. A rhombicosadodecahedron is a type of polyhedron which contains thirty (30)

squares, twenty (20) polyhedra of one type, and twelve (12) polyhedra of

another type. The term "rhombicosadodecahedron" is derived from

"dodecahedron/' meaning a twelve (12) sided polyhedron; "icosahedron,"

meaning a twenty (20) sided polyhedron, and "rhombus" meaning a four

sided polyhedron.

The rhombicosadodecahedron of the preferred embodiment is

comprised of thirty (30) squares 12, twelve (12) pentagons 10, and twenty (20) triangles 14. It has a uniform pattern of pentagons with each pentagon

bounded by triangles and squares. The uniform pattern is achieved when

each regular pentagon 10 has only regular squares 12 adjacent to its five

boundary lines, and when a regular triangle 14 extends from each of the five

vertices of the pentagon. Five (5) squares 12 and five (5) triangles 14 form a

set of polygons around each pentagon. Two boundary lines of each square

are common with two pentagon boundary lines, and each triangle has its

vertices common with three pentagon vertices. The outer surface of the ball is further defined by a pair of poles and

an equatorial great circle path around the surface. A great circle path is

defined by the intersection between the spherical surface and a plane which passes through the center of the sphere. An infinite number of great circle paths may be drawn on any sphere. The equatorial great circle path in the

preferred embodiment corresponds to a mold parting line which separates

the golf ball into two hemispheres. The mold parting line is located from the poles in substantially the same manner as the equator of the Earth is located

from the North Pole and the South Pole.

Referring to Fig. 2, the poles 70 are located at the center of a pentagon

10 on the top and bottom sides of the ball, as illustrated in this view of one

such side. The mold parting line 30 is at the outer edge of the circle in this planar view of the golf ball. In the embodiment shown in Fig. 3, the poles 72

are both located at the center of the square on the top and bottom of the golf

ball, as illustrated in this view of one such side. (The top and bottom views are identical.) The mold parting line 40 is at the outer edge of the circle in

this planar view of the golf ball.

Dimples are placed on the outer surface of the golf ball based on

segments of the plurahty of polygonal configurations described above. In the

preferred embodiment, three (3) dimples are associated with each triangle,

five (5) dimples are associated with each square, and sixteen (16) dimples are

associated with each pentagon. The term "associated" as used herein in

relation to the dimples and the polyhedra means that the polyhedra are used

as a guide for placing the dimples. The dimple configuration of the preferred embodiment is shown in

Figs. 4-7. It is based on the projection of the rhombicosadodecahedron shown

in Fig. 2. The ball has a total of 402 dimples. The plurahty of dimples on

the surface of the ball are selected from three sets of dimples, with each set having different sized dimples. Dimples 200 are in the first set, dimples 202

are in the second set, and dimples 204 are in the third set. Dimples are

selected from all three sets to form a first pattern associated with the

pentagon 10. All sides 206 of each pentagon are intersected by two dimples

200 from the first set of dimples and one dimple 202 from the second set of dimples. All pentagons 10 have the same general first pattern arrangement

of dimples.

Dimples 200, 202 and 204 (from all three sets of dimples) are also used to form a second pattern associated with the squares 12. All sides 208 of

each square 12 are intersected by dimples 202 from the second set of dimples,

and all squares have the same general second pattern arrangement of

dimples.

Dimples 202 from the second set of dimples form a third pattern

associated with the triangles 14. All sides 210 of each triangle are

intersected by a dimple 202 from this second set of dimples. All triangles

have this same general third pattern arrangement of dimples. The mold

parting line 30 is the only dimple free great circle path on this ball.

The ball of the preferred embodiment utilizes two different types of

dimples having two different cross sections, single radius dimples 200 and

204 and dual radius dimples 202. In the single rad us dimple (Fig. 17), a single radius (referred to as a major radius, or Radius 1) describes the shape of the bottom of the dimple. In other words, the major radius governs the

shape of the dimple toward the bottom of the dimple. In a dual radius dimple

(Fig. 18), on the other hand, two radii are used to describe the shape of the dimple. The major radius describes the bottom of the dimple, and a minor radius (Radius 2) describes the shape of the dimple about its circumference.

Dimple size is measured by a diameter and depth generally according

to the teachings of U.S. Patent No. 4,936,587 (the '587 patent), which is included herein by reference thereto. An exception to the teaching of the '587

patent is the measurement of the depth, which is discussed below. A cross-

sectional view through a typical single radius dimple 6 is illustrated in Fig.

16. The diameter Dd used herein is defined as the distance from edge E to edge F of the dimple. Edges are constructed in this cross-sectional view of the dimple by having a periphery 50 and a continuation thereof 51 of the dimple 6. The periphery and its continuation are substantially a smooth

surface of a sphere. An arc 52 is inset about 0.003 inches below curve 50-51-

50 and intersects the dimple at point E' and F'. Tangents 53 and 53' are

tangent to the dimple 6 at points E' and F' respectively and intersect periphery continuation 51 at edges E and F respectively. The exception to

the teaching of '587 noted above is that the depth d is defined herein to be the

distance from the chord 55 between edges E an F of the dimple 6 to the deepest part of the dimple cross sectional surface 6 (a), rather than a

continuation of the periphery 51 of an outer surface 50 of the golf ball. The dimple dimensions for the preferred embodiment are set forth

below:

It is understood that the following dimple size ranges are within the scope of this invention: dimples 200 from the first set may have a diameter in the

range of 0J50 inches to 0J60 inches; dimples 202 from the second set may

have a diameter in the range of 0J40 inches to 0.150 inches; dimples 204

from the third set may have a diameter in the range of 0J35 inches to 0.145 inches; all dimples, 200, 202 and 204 may have a depth in the range of 0.0056

inches to 0.0078 inches; the major radius may be in the range of 0.34 inches

to 0.80 inches; and the minor radius (for dimple 202) may be in the range of

0J0 inches to 0.12 inches.

The following test data illustrates the improved performance of the

dimple pattern of the present invention. All balls identified below are hybrids

As shown above, the ball of the present invention, which utilizes both single radius and dual radius dimples, provides shghtly longer overall

distance than a ball utilizing either all single radius dimples or all dual

radius dimples, and it has a significantly lower trajectory, as exhibited by the

lower rear trajectory value. This is a much desired property for the hybrid

ball.

Fig. 8 shows another embodiment of the present invention. The

dimples are arranged on the surface of the ball based on the projection of the

rhombicosadodecahedron as shown in Fig. 2. The poles are located at the center of the pentagons on the top and bottom of the balls (Fig. 8). The mold parting (30) line is the only great circle path on the ball that is not

intersected by a dimple. A rotated view of the ball shown in Fig. 8 is shown in

Fig. 9. A mold parting surface 80 adjacent the mold parting line 30 is formed

by defining a great circle path void of dimples. The mold parting line 30 runs through certain of the squares 12a and triangles 14a projected onto the surface. The dimples adjacent the mold line 30 help to form boundaries of

the mold parting surface.

The plurahty of dimples on the surface of the ball shown in Fig. 8 are

selected from three sets of dimple of three different sizes. Dimples 60 are

from a first set of dimples, dimples 61 are from a second set, and dimples are

62 from a third set. Dimples 60 and 62 form a first pattern associated with

the pentagons 10. All sides 11 of each pentagon 10 are intersected by

dimples 61 from the second set and all pentagons 10 have the same general

first pattern of dimples. All sides 13 of each square 12 are intersected by third dimples 62, and all squares 12 have the same general second pattern arrangement of dimples. The first dimples 60 form a third pattern associated

with the triangles 14. All sides 15 of each triangle 14 are intersected by first

dimples 60 and all triangles have the same general third pattern

arrangement of dimples. In this embodiment, the dimples 60 are larger

than the dimples 61, which in turn, are larger than the dimples 62. The sizes

of the dimples 60, 61, and 62 correspond to the sizes of the dimples 200, 202, and 204, respectively, as described above.

A secondary partitioning of the outer surface of the golf ball is

superimposed on the rhombicosadodecahedron previously described, as illustrated in Fig. 10. For this embodiment the two poles 72 are located at

the center of squares and the mold line 40 is formed as illustrated in Fig. 3.

This second partitioning is realized by forming parting lines or bisectors 20

along great circle paths that essentially divide each pentagon 10 into ten (10) smaller triangles 36 of equal size. These parting lines 20 also divide each square into four (4) smaller squares 32 and each triangle 14 into six smaller

triangles 34. This further division of the outer surface of the golf ball allows

the location of dimples over a greatly expanded number of polygonal

configurations. It further allows a mold line 40 to be selected to correspond with any one of the parting lines 20 to create a true mold line and fourteen

false mold lines.

A possible dimple pattern for the polygonal configuration of Fig. 10 is

illustrated in Fig. 11. For this embodiment the dimples are located within all

fifteen of the parting lines 70. That is, none of the parting lines are intersected by any dimple. Three different dimple sizes are shown in Fig. 11;

with the largest sized dimples located within the squares. This arrangement

of dimples is illustrative of having no dimples intersect parting lines. The number of dimples in each of the smaller triangles and squares can be

substantially different from the number shown, within the scope of this

invention. Dimples are, once again, formed and measured as illustrated in

Fig. 16.

Another embodiment of the polygonal configurations including certain

parting lines is illustrated in Fig. 12. This embodiment uses only five parting

lines 70a and 70b of the fifteen parting lines 20 illustrated in Fig. 10 These certain parting lines are not intersected by any dimples. The mold parting

line corresponds to one great circle path 70b, as illustrated in the rotated

view of the golf ball of Fig. 13. The dimple layout in parts of the outer surface

adjacent the five great circle paths may be substantially different than the

dimple layout in parts of the outer surface not adjacent the five great circle

paths. One example of a dimple layout having dimples approximately equal

in size is illustrated in Figs. 12 and 13.

The previous embodiments illustrate dimples which are formed as

generally circular in a plan view of each dimple. Other embodiments of the

present invention include dimples which are non-circular in form, as

illustrated in Figs. 14 and 15. These illustrations show the use of the

polygonal configurations of Fig. 2; where the pentagons 10 have twenty (20)

triangular shaped dimples, the squares 12 have four square shaped dimples

and the triangles 14 have four triangular shaped dimples. The triangular shaped dimples have a height in the range of 0.037 inches to 0J49 inches,

and a base in the range of 0.037 inches to 0J49 inches. The squared shaped

dimples have a height in the range of 0.037 inches to 0.224 inches and a width in the range of 0.037 inches to 0.224 inches.

Dimples at the equatorial great circle path defining a mold parting

line 30 are divided into two parts, as illustrated in Fig. 9. Each one of the

parts appears in a single one of the polygonal configurations. For the

embodiment illustrated, the mold line divides certain square shaped dimples 100 within the squares 12 into two parts 102 and 104. A mold parting

surface 30a is formed by partially eliminating the depression of the certain

square shaped dimples adjacent to the mold parting line without changing

the general shape or location of these dimples. For example, the two parts 102 and 104 of a parted square dimple are essentially the same size and

shape as the square dimple 100. The mold parting surface becomes bounded

by parted dimples. The irregular shaped dimples are measured on the basis

of spherical shaped dimples having equivalent surface areas and cross sectional areas as set forth above.

The dimples may be placed on the outer surface of the golf ball to

intersect all of the parting hnes constructed on the outer surface, none of the

parting lines, or only some of the parting lines on the outer surface. When

great circle paths are not intersected by dimples they become true parting

lines for defining the dimple pattern. Fig. 8 shows all of the parting lines intersected by dimples; Fig. 11

shows none of the parting lines intersected by dimples; and Fig. 12 shows ten

of the parting lines intersected by dimples.

While a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it

is to be understood that changes and variations may be made without

departing from the spirit or scope of the following claims. For example, it is understood that the invention is not hmited to a dimple pattern defined by the rhombicosadodecahedron.

Claims

What is claimed is:

1. A golf ball comprising an outer surface, and a plurahty of dimples

arranged on the outer surface to form a dimple pattern, the plurahty of

dimples including a first»set of dimples, with each dimple in the first set having a single

radius cross section;

a second set of dimples, with each dimple in the second set having a dual radius cross section; and a third set of dimples, with each dimple in the third set having a single

radius cross section.

2. The golf ball of claim 1 wherein

the dimples in the first set of dimples have a diameter of 0.156 inches

and a major radius of 0.4148 inches;

the dimples in the second set of dimples have a diameter of 0J45

inches, a major radius of 0.7874 inches, and a minor radius of 0.1181 inches; and

the dimples in the third set of dimples have a diameter of 0.140 inches

and a major radius of 0.3535 inches.

3. The golf ball of claim 2 wherein the dimples in the first set of dimples have a diameter in the range of

0J50 inches to 0J60 inches, and a major radius in the range of 0.34 inches to

0.80 inches; the dimples in the second set of dimples have a diameter in the range

of 0J40 inches to 0.150 inches, a major radius in the range of 0.41 inches to

0.80 inches; and a minor radius in the range of 0J0 inches to 0J2 inches;

and the dimples in the third set of dimples have a diameter in the range of

0J35 inches to 0J45 inches, and a major radius in the range of 0.34 inches to

0.80 inches.

4. The golf ball of claim 1 wherein the outer surface is divided into a

plurahty of polygonal configurations which include pentagons, squares and triangles, wherein a first pattern of dimples is associated with each triangle, a second pattern of dimples is associated with each pentagon, and a third

pattern of dimples is associated with each square.

5. The golf ball of claim 1 wherein the dimples in the first set of dimples have a different size than the dimples in the third set of dimples.

6. The golf ball of claim 1 wherein said outer surface is divided into a

polyhedron defined as a rhombicosadodecahedron and dimples are arranged using that pattern.