JPH08238336A - Golf ball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf ball for excellent flying performance by providing a convex in the center of dimple and a concavity of which the deepest depth is a particular value around the dimple, and providing a particular ratio of the width along the convex surface to the width from the one side of the concavity rim to the others along the line goes through the center of the convex. SOLUTION: The dimple 14 has the central convex part 16 and the concavity part 18 which surrounds the convex part 16, and the convex part 16 extends out from the concavity part 18 to the position of the spherical surface 12 or to the approximate position to make a ringed form. As the deepest depth of the dimple concavity part 18 is about 0.38 mm, the largest scale of the dimple convex part (d) is always shorter than one second of the dimple scale D. The minimum valid capacity of the dimple is 344.13 mm<3> . As a result, the performance of the golf ball is improved, and its outlook is also improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf ball, and more particularly to improvement of a golf ball having dimples on its surface.

[0002]

BACKGROUND OF THE INVENTION Golf balls are generally designed to fit the mold in the sense that the specifications of the American Golf Association are edited from the viewpoint of parameters such that the minimum outer diameter is 42.67 mm (1.680 in). easy.

The dimple shape of a conventional golf ball is
It is usually circular, rectangular or pentagonal, but can take on various other geometric shapes. The maximum center depth of dimples is about 0.20 mm (0.008 in) to about 0.38.
It is in the range of mm (0.015 in). It has been previously recognized that changes in the dimple geometry, size and depth, and changes in its pattern on the surface of the golf ball affect the performance of the golf ball.

Various dimple patterns designed to enhance the performance characteristics of golf balls are described in US Pat. No. 4,932,664 to Pocklington et al. And assigned to a common assignee; No. 5,201,522. The entire contents of this patent are described here.

Proposals for a central portion and other dimple patterns having recesses around the central portion have been proposed by Hagen in US Pat. No. 1,666,699 and Fotheringham.
U.S. Pat. No. 1,716,435.

US Patent No. 1,666,699 to Hagen
The dimple structure shown in the issue can be described as a truncated cone with a spherical portion protruding from the truncated point of the cone. When the radius of the spherical portion is overlapped with that of the golf ball, the spherical portion has a radius such that the surface of the spherical portion and the surface of the golf ball overlap and meet at one point. As a result, multiple dimples
It will form a plurality of annular portions that are concave and spaced apart from the surface of the golf ball. In the case of fosseling ham, the concave portion is formed by preparing a plurality of narrow annular rings on the surface of the golf ball at intervals.

The flight distance of a golf ball is determined by the number and depth of dimples on the surface of the ball. More specifically, the total effective volume of the dimples contributes to the flight performance of the ball. Golf balls with various structural characteristics have different spin rates and therefore different climbing performance. However, it is not possible to select one particular number for the total available volume of the dimples that will give maximum performance.

[0008]

However, in spite of this, the total effective volume of the dimples is at least about 344.13 mm ³ with respect to the present structural specifications of golf balls.
It has been concluded that it must be (0.021 in ³ ). Below this value, the flight performance of the golf ball becomes unsatisfactory. The golf ball proposed by Hagen and Foselingham is an example of such an unsatisfactory design.

In view of the above points, the present invention provides a golf ball having excellent flight performance.

[0010]

The plurality of dimples provided on the golf ball of the present invention have a new design. That is, the dimple has a central convex portion and a concave portion completely surrounding the convex portion, and the concave portion has a depth of 0.2.
It is in the range of 0 mm (0.008 in) to 0.38 mm (0.015 in). Further, the central convex portion projects to the height of the arc formed in the common region of the outer surface of the golf ball, or almost to that height.

The golf ball may have all of its dimples of a new design, or the dimples of this new design may be mixed with standard dimples. Further, the convex portion and the concave portion of the dimple may have the same shape or different shapes. For example, either or both of the shapes of the concave portion and the convex portion may be a circle, a rectangle, a pentagon, a rhombus, an ellipse, or other geometric shapes. The geometry of these recesses and protrusions may be altered to enhance the performance of the golf ball as well as the appearance of the golf ball. In a preferred embodiment of the present invention, the shape of the central convex portion is circular.

The dimensions of the dimples and the dimensions of the convex portions and the concave portions are controlled to enhance the performance of the golf ball and the uniformity of the appearance. The size of the dimples typically depends on the number of dimples. Thus, the greater the number of dimples, the smaller their dimensions. Further, the size of the dimple depends on the geometrical shape of the dimple and the distance between the dimples defined as the closest distance between the edges of the adjacent dimples. Dimple dimensions will typically vary from about 1.91 mm (0.075 in) to about 4.45 mm (0.175 in). The distance between dimples is approximately 1.78 mm (0.07 mm).
0 in) or less.

[0013]

EXAMPLE An outer surface 12 of a golf ball 10 shown in FIG. 1 contains dimples 14 according to the present invention.

As best seen in FIGS. 2 and 3, the dimple 14 has a central convex portion 16 and a concave portion 18 that completely surrounds the convex portion 16.

According to FIG. 4, the convex portion 16 extends outwardly from the concave portion 18 to the position of the spherical outer surface 12 or almost to that position to form an annular body shape 20.
The maximum depth of the concave portion 18 of the dimple is about 0.2.
0 mm (0.008 in) to about 0.38 mm (0.015 in)
Is in the range.

As shown in FIG. 5, the dimple 24 formed on the spherical outer surface 22 has a side 28 of a quadrangle of equal length, and a central convex portion 26 is surrounded by a concave portion 30. The convex portion 26 and the concave portion 30 are both quadrangular. According to FIG. 6, the convex portion 26 projecting from the concave portion 30 reaches the height of the spherical outer surface 22, or almost the height thereof.

According to currently known embodiments of the invention, the raised and recessed portions are circular as shown in FIGS. And the maximum depth of the circular recess is about 0.25.
mm (0.010 in), three different diameters, namely about 4.06 mm (0.160 in) and about 3.94 mm (0.1
55 in) and about 3.43 mm (0.135 in).
The diameter of the circular convex portion is about 0.89 mm (0.035 in). With this configuration, about 432 dimples are provided on the spherical outer surface with a spacing of about 1.78 mm (0.070 in).

In the case of the square-shaped dimple shown in FIGS. 5 and 6, it is preferable that the concave portion 30 has a side length of about 4.06 mm (0.160 in). The maximum depth of the concave portion 30 is about 0.25 mm (0.010 in). Further, the size of the rectangular convex portion 26 reaching the spherical outer surface 22 is preferably about 0.89 mm (0.035 in).

When the dimples 34 are formed in a diamond shape as shown in FIG. 7 in the spherical outer surface, the concave portion 36 is formed.
Has a diamond shape, and the convex portion 38 also has a diamond shape.

When the dimples 40 are formed in a pentagonal shape on the outer surface of the spherical shape as shown in FIG.
4 has a pentagonal shape, and the convex portion 46 also has a pentagonal shape.

Obviously, other dimple shapes can be used in the present invention. Circles, squares, pentagons, diamonds and similar shapes can be used for either or both of the convex and concave portions. Thus, the cross-sectional shape of the convex portion orthogonal to the radius of the golf ball may be circular, quadrangular, pentagonal, rhombic and similar shapes, and the cross-sectional shape of the concave portion orthogonal to the radius of the golf ball is also circular. , Squares, pentagons, rhombuses and similar shapes. The geometric shapes of the above-mentioned convex portion and concave portion may be the same, or may be different as shown in FIGS.

For example, referring to FIG. 9, the dimple 4 according to the present invention.
In No. 8, the concave portion 50 orthogonal to the radius of the golf ball has a circular sectional shape, and the convex portion 52 orthogonal to the golf ball radius has a rectangular sectional shape.

Next, referring to FIG. 10, in the dimple 54 according to the present invention, the concave portion 56 orthogonal to the radius of the golf ball is a quadrangle, and the convex portion 5 orthogonal to the radius of the golf ball.
The cross-sectional shape of 8 is circular.

Further, in the dimple 60 shown in FIG. 11, the concave portion 62 orthogonal to the radius of the golf ball has a pentagonal sectional shape, and the convex portion 64 has a circular sectional shape. It will be apparent to those skilled in the art that various other combinations can be made by blending with other specific shapes.

The maximum dimple depth of a golf ball within the preferred range of the present invention is generally 0.25 mm.
(0.010 in). Further, in the case of such a preferable mode, the maximum dimension d of the dimple convex portion shown in FIG.
Is always smaller than 1/2 of the dimple dimension D.

Next, the convex portion and the concave portion are shown in FIGS.
When it is circular as shown in Fig. 3, the above dimensions d and D
Is constant no matter where it is measured, but when these take other shapes, it depends on the position of a straight line drawn from one outer edge of the concave portion to the other outer edge through the center of the convex portion, One or both of these dimensions will vary. In the present invention, even in such a case, the maximum lateral dimension of the convex portion is smaller than 1/2 of the maximum lateral dimension of the concave portion.

The total effective volume of the dimples on the surface of the golf ball can be controlled by using the above parameters. Thus, as noted in the introductory portion of this specification, the performance characteristics of a golf ball will vary depending on the total available volume of dimples formed in the golf ball. And the minimum value is 344.13 mm ³ (0.02
It is believed that 1 in ³ ) is necessary for satisfactory performance. Such a golf ball is shown in FIGS. Also, a golf ball having the above-mentioned dimensions is about 760.95 mm ³ (0.046436 in ³ )
Preferably having a total effective volume of

The above volume can be calculated by considering that the dimples shown in FIGS. 1 to 4 have an annular shape or a donut shape. Maximum dimple depth is 0.
25 mm (0.010 in), the average diameter of the dimples is 3.
Assuming 68 mm (0.145 in) and 432 dimples, the depth h is 0.25 mm (0.010 in) from FIG.
Is. Assuming that the diameter of the convex portion is 0.89 mm (0.035 in), the dimensions a and c shown in FIG.

[0029]

[Equation 1]

[0030]

[Equation 2]

Therefore, a is 0.70 mm (0.027
5 in) and c are 1.14 mm (0.045 in).

According to the Pappus theory, the volume of the rotating body is given by the following equation.

Volume of annular body = 2πcA

Here, c is the distance between the center of the plane of rotation A and the center of rotation. The rotation surface A is the hatched portion 70 in the figure.

The plane of rotation A can be obtained using the Pythagorean theorem. First, considering the radius γ in FIG. 3,

Γ ² = (γ-h) ² + a ²

Γ ² = γ ² -2γh + h ² + a ²

2γh = h ² + a ²

[0039]

(Equation 3)

The area Ac of a circle of radius γ is

Ac = πγ ²

Therefore, the fan-shaped area whose central angle is θ shown in FIG. 13 is θ / 360 (πγ ² ). Regarding the central angle θ,

[0043]

[Equation 4]

[0044]

(Equation 5)

[0045]

(Equation 6)

Next, in order to obtain the area of the rotating surface A, the area At of the triangle having the apex angle θ is obtained in FIG.

At = a (γ-h)

Therefore, A = θ / 360 (πγ ² ) -a (γ-h) = 2 (sin ⁻¹ a / γ) / 360 (πγ ² ) -a (γ-h)

As described above, h = 0.25 mm (0.01
0 in) and a = 0.70 mm (0.0275 in),

Γ ² = (γ-0.25) ² + (0.70) ² ∴γ = 1.0874 mm

When the area of the rotating surface A is calculated,

[0052] A = 0.24mm ² (0.003762in ²⁾

Therefore, the volume of the annular body is

2πcA = 2 (3.1416) (1.14) (0.24) = 1.744mm ³ (0.0001064in ³ )

Therefore, since the total effective volume of the dimples is 432 dimples,

Total effective volume = 432 (1.744) = 75
3.23 mm ³ (0.045965 in ³ )

Other examples of the golf balls having the shapes shown in FIGS. 1 to 4 are shown in the table below.

[0058]

[Table 1]

FIG. 14 shows another mode of the present invention.
Here, the dimples 82 having the shapes shown in FIGS. 1 to 4 are used only as a part of all the dimples of the golf ball. The number of dimples 84 to dimples 82 is of conventional design, as described, for example, in the above-referenced US Pat. No. 5,201,522. The dimples 82 are arranged in a hexagonal shape, and each array has one dimple 82 at the center thereof. In this example, 152 dimples 82 are combined with 228 dimples 82.

Although the present invention has been described with reference to the above several embodiments, the above embodiments are not intended to limit the present invention, and various modifications can be made based on the technical idea of the present invention. Is.

[0061]

Since the present invention has the above-mentioned structure,
The performance of the golf ball can be improved and the appearance of the golf ball can be improved.

[Brief description of drawings]

FIG. 1 is a front view of a golf ball according to the present invention.

FIG. 2 is a fragmentary perspective view of the dimple shape of the golf ball shown in FIG.

FIG. 3 is a plan view of a dimple of the present invention having a circular shape.

FIG. 4 is a fragmentary sectional view taken generally along the line 4-4 in FIG.

FIG. 5 is a plan view of a dimple according to the present invention having a rectangular shape in a rectangular shape.

FIG. 6 is a fragmentary cross-sectional view taken generally along line 6-6 of FIG.

FIG. 7 is a plan view of a diamond dimple according to the present invention.

FIG. 8 is a plan view of a pentagonal dimple according to the present invention.

FIG. 9 is a plan view of a dimple according to the present invention having a circular concave portion and a square convex portion.

FIG. 10 is a plan view of a dimple according to the present invention having a square concave portion and a circular convex portion.

FIG. 11 is a plan view of a dimple according to the present invention having a pentagonal concave portion and a circular convex portion.

FIG. 12 is a plan view of the dimple described in FIGS. 1 to 4 showing a general dimensional relationship.

FIG. 13 is a fragmentary cross-sectional view of the dimple shown in FIGS. 1 to 4 showing a general dimensional relationship.

FIG. 14 is a front view of a golf ball in which the dimples of the present invention and standard dimples are mixed.

[Explanation of symbols]

10,80
Golf balls 12,22,32,42
Outer surface 14, 24, 34, 40, 48, 54, 60, 82, 8
4 dimples 16, 26, 38, 46, 52, 58, 64
Center convex part 18, 30, 36, 44, 50, 56, 62
Surrounding recessed portion-More than-

Claims (7)

[Claims] 1. A plurality of dimples have spherical outer surfaces arranged at intervals, and the dimples have a central convex portion protruding to the height of the outer surface, or approximately to that height, and The maximum depth is about 0.38 mm (0.015 in), and the lateral length of the convex portion along the outer surface is the straight line passing through the center of the convex portion. The total effective volume of the dimples, which is smaller than 1/2 minimum value of the lateral length from the outer edge to the outer edge of the concave portion and accumulates the concave portion volume of each dimple on the outer surface, is about 344.13 mm ³ (0.021
A golf ball larger than in ³ ). 2. The total available volume is at least about 344.13.
The golf ball according to claim 1, having a size of mm ³ (0.021 in ³ ). 3. It has at least about 380 circular dimples, and the diameter of said central circular convex portion is about 0.89 mm (0.0
35 in) and the diameter of the recess is approximately 3.43 mm.
The golf ball of claim 2, having a range of (0.135 in) to 4.06 mm (0.160 in). 4. The golf ball according to claim 1, wherein the convex portion which penetrates the convex portion and is orthogonal to the radius of the golf ball has a circular cross-sectional shape. 5. A cross-sectional shape of a concave portion orthogonal to the radius of a golf ball penetrating the concave portion is circular.
The described golf ball. 6. The cross-sectional shape of the convex portion which penetrates the convex portion and is orthogonal to the radius of the golf ball is any one of a circle, a minor diameter, a pentagon and a rhombus, and a concave portion which penetrates the concave portion and is orthogonal to the radius of the golf ball. The golf ball according to claim 1, wherein the sectional shape of the portion is any of a circle, a minor axis, a pentagon, and a rhombus. 7. The golf ball according to claim 1, wherein a part of the dimples on the surface of the golf ball is a dimple composed of the convex portion and the concave portion around the convex portion.