JP2000317014A - Golf ball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a carry by overlapping dimples on each other in such a manner that an overlap area attains a specific area ratio with respect to the total area of a ball. SOLUTION: For example, the dimples 2 of a diameter larger than the diameter of the dimples 1 are partially overlapped on these dimples 1. The area of the overlapped parts 3 is specified to a range of 5 to 55% of the total area of the ball. The diameters of the dimples 1 and 2 may be same. Also, the shapes may be circular or non-circular shapes, such as elliptic shapes and the depth thereof may be ordinary. At <5%, the dimples are the same as the dimples free of the substantial overlapping portions and at >=55%, the ball diameter at which a cross-sectional surface below a standard value occurs is obtd. and the ball is no longer usable as an officially recognized ball. Aerodynamic characteristics are improved and the carry is improved by the constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to aerodynamic characteristics (drag,
The present invention relates to a golf ball having improved flight distance by improving lift.

[0002]

2. Description of the Related Art Conventionally, a plurality of dimples are arranged on the surface of a golf ball to improve aerodynamic characteristics (reducing drag and increasing lift). Various improvements have been made to this dimple. For example, the surface shape of the dimple may be made non-circular such as elliptical (Japanese Patent Laid-Open No. 8-191905), or the dimple may be provided with a convex portion or a concave portion to provide a double dimple. (JP-A-8-238336), connecting dimples with grooves (JP-A-8-276035), and the like have been proposed. However, in recent years, further improvement in aerodynamic characteristics has been demanded.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a golf ball having improved aerodynamic characteristics and improved flight distance by devising dimples.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a golf ball having a plurality of dimples on its surface, wherein the dimples partially overlap each other, and the area of the overlap portion is reduced to 5 to 55% of the total surface area of the ball. It is characterized by having done.

Since the dimples partially overlap each other as described above, an overlap portion which is recessed from the virtual surface of the ball (the surface of the golf ball when no dimple is provided on the golf ball) is formed. Since the same effect as the reduction is obtained, the drag can be reduced, the flight distance can be increased, and the area of the overlap portion is 5 to 55% of the total surface area of the ball. Compared to the conventional design that prevents overlapping, the degree of freedom in designing dimples is increased, and the dimple occupation area occupying the ball surface area can be increased without increasing the number of dimples, so the drag is small. And the lift increases.
Therefore, it is possible to improve the flight distance.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 2, conventionally, dimples 1 having a circular surface shape are provided on the surface of a golf ball so as not to overlap each other.

In the present invention, as shown in FIG. 1, a dimple 1 having a larger diameter partially overlaps a dimple 1 to form an overlap portion 3. These dimples 1 and 2 may have the same diameter in the surface shape or may be different as shown in FIG. These dimples 1 and 2 are
The surface shape need not be circular, and may be non-circular such as elliptical. The depth of these dimples 1 and 2 is
A normal dimple depth conventionally arranged on the surface of a golf ball may be used.

The area of the overlap portion 3 is 5 to 55% of the total surface area of the ball. Here, the total surface area of the ball refers to the total surface area of the virtual surface of the ball. If the area of the overlapping portion 3 is less than 5% of the total surface area of the ball, the area is too small to substantially cause an overlapping portion, while if it exceeds 55%, the actual ball diameter is smaller than the standard value. This is because the cross section becomes smaller and the ball cannot be recognized as an officially recognized ball.

[0009] The number of dimples to be overlapped is preferably 20 to 80% of the total number of dimples. 2
If it is less than 0%, the dimples to be wrapped will be biased, and will not conform to the standard that defines the symmetry of the ball. If it exceeds 80%, a cross section in which the actual ball diameter is smaller than the standard value is formed, and the ball cannot be recognized as an officially recognized ball.

[0010]

EXAMPLE A two-piece golf ball was manufactured with the occupation rate (%), the total number of dimples (pieces), the wrap number rate (%), and the wrap rate (%) shown in Table 1 (ball diameter 42.67).
mm, Examples 1 to 8 and Comparative Examples 1 and 2) and the golf balls were evaluated for flight distance as follows. Table 1 shows the results.

Here, the occupancy (%) is the area occupied by dimples in the total surface area of the virtual surface of the ball, the total number of dimples (pieces) is the number of dimples provided on the ball surface, and the wrap number ratio (%) is The ratio of the overlapped dimples to the total number of dimples, and the wrap ratio (%) refers to the ratio of the area of the overlap portion to the total surface area of the ball.

Flying distance : The flying distance was measured by setting a driver having a loft of 11 ° in a swing robot made by Miyama and averaging the flying distance when hitting a ball at a head speed of 40 m / s with N = 10. The result was evaluated by an index with the flight distance of 200 m of Comparative Example 1 as 100.
The larger the index value, the better the flight distance.

[0013]

[Table 1]

In Table 1, Comparative Example 1 shows the case where the dimples do not overlap, and Comparative Example 2 shows that the dimples overlap, but the lap ratio (%) is 3% out of the range of the present invention. (5 to 55% in the present invention). As is clear from Table 1, in the case of the present invention (Examples 1 to 8), the flight distance is superior to Comparative Examples 1 and 2. Also in the case of the present invention, when the wrap number ratio (%) is lower (Examples 1, 3, and 6) than when the wrap number ratio (%) is 40% (Examples 2 and 4), and When the distance is high (Examples 5 and 8), the flight distance is reduced.

[0015]

As described above, according to the present invention, in a golf ball having a plurality of dimples on the surface,
The dimples partially overlap each other,
The area of the overlap portion is 5 to 55 of the total surface area of the ball.
%, It is possible to improve the aerodynamic characteristics and improve the flight distance. In addition, the degree of freedom in design is improved as compared with the conventional dimple arrangement in which no overlap occurs.

[Brief description of the drawings]

FIG. 1 is an explanatory plan view showing an example of an arrangement of dimples in a golf ball of the present invention.

FIG. 2 is an explanatory plan view showing an example of a dimple arrangement in a conventional golf ball.

[Explanation of symbols]

 1 Dimple 2 Dimple 3 Overlap

Claims (2)

[Claims] 1. A golf ball having a plurality of dimples on its surface, wherein the dimples partially overlap each other so that the area of the overlapped portion is 5 to 55% of the total surface area of the ball. 2. The golf ball according to claim 1, wherein the number of overlapping dimples is 20 to 80% of the total number of dimples.