JPH0970457A - Golf club - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to impart spin to a ball so as to enable a golfer using a two-piece ball to hit the ball to a dead stop on a green and to suppress the flawing of the cover of the ball. SOLUTION: Several lines of grooves having a groove width L in a range from 0.9 to 0.700, groove depth D from 0.50 to 0.35mm and the angle θU formed by the face and the groove depth D direction from 100 to 110 deg. and an angle θD formed by the groove depth D direction and the groove base 4A from 90 to 100 deg. are arranged in the impact area 3 of the face of a head 1.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a golf club,
In particular, the present invention relates to a golf club in which a groove (grooving or score line) formed on the face surface of the head is devised.

[0002]

2. Description of the Related Art As shown in FIG. 2, it is permitted to mark a groove 4, a punch mark, or the like on an impact area 3 of a face surface 2 of a head 1 of a golf club. It is restricted. To summarize the rules for the groove, it is possible to add several straight grooves 4 having the same left and right cross-section with an expanded upper part as illustrated in FIGS. It is stated that the faces must be generally constant over the front face of the club face and the length of the groove 4, respectively. Furthermore, the roundness of the edge of the groove 4 is a circle with a radius of 0.5 mm or less, and the width L of the groove 4 is the internal rule of R & A "30 degree measuring method".
(See Fig. 6) It must be 0.9mm or less.
Also, the distance between the adjacent grooves 4 must be at least three times the width L of the groove 4 and at least 1.9 mm. Also, groove 4
Depth D must be less than 0.5 mm. Therefore,
The groove 4 on the face surface 2 of the golf club is designed and manufactured within limits.

On the other hand, in recent years, two-piece golf balls have dramatically increased their market share. The characteristics of the two-piece ball are that it is more difficult to bend than the thread-wound balata ball and has a longer flight distance, but on the other hand, due to its material structure, it is difficult to spin on approach shots and it is difficult to stop the ball on the green. Has disadvantages. In order to solve this disadvantage, spin type two-piece balls have been provided by improving the cover material. However, the spin performance has not reached the level of the wound balata ball. In addition, this improvement sacrifices some of the advantages of conventional two-piece balls on driver shots.

On the other hand, in order to spin on a two-piece ball that is hard to spin, the groove shape of the face of a golf club, especially a short iron, is manufactured within the limit of the above-mentioned golf rules, so-called square groove 4 (see FIG. 4). ) Is provided as.

[0005]

A golf club having a square groove engraved thereon has a spin property higher than that of a normal groove, but at the same time has a drawback that the cover of the ball is significantly damaged.

Therefore, the present invention provides a golf club which gives a spin to a golfer who uses a two-piece ball so that he or she can place the ball on the green and stop it tightly, while suppressing damage to the cover of the ball. To aim.

[0007]

In order to achieve the above object, the present invention has a groove width L in the range of 0.90 mm to 0.70 mm and a groove depth D of 0 in the impact area of the face surface of the head. A number of .50 mm to 0.35 mm, an angle θ _U formed between the face surface and the groove depth direction is 100 to 110 °, and an angle θ _D formed between the groove depth direction and the groove bottom is 90 to 100 ° The groove is arranged.

[0008]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, a plurality of grooves 4 are formed in the impact area 3 of the face surface 2 of the head 1, the groove width L of the grooves 4 is 0.90 to 0.70 mm, and the groove depth D is 0.5
The angle θ _U formed by the face surface 2 and the direction of the groove depth D is 100 to 110 °, and the groove depth D is 0 to 0.35 mm.
And the groove bottom 4A makes an angle θ _D of 90 to 100 °.

In the golf club, as shown in FIG. 2, a shaft 6 is attached to a hosel 5 of a head 1, and the shaft 6 is attached.
A grip 7 is attached to the base end of the. The groove 4 is called a grooving or score line. The tip side of the area where these grooves 4 are engraved is a toe, the hosel side is a heel, the lower edge of the face surface 2 is a leading edge,
The upper edge is called the top edge. Although FIG. 2 shows an iron club, similar grooves 4 or punch marks are formed on the face surface of the wood club.

Next, the width L and the depth D of the groove 4, the distance S between the edges of the groove 4, and the angles θ _U and θ _D are changed to change the loft angle. Are shown in Table 1.

[0012]

[Table 1]

Table 2 shows Comparative Examples 1 to 6.

[0014]

[Table 2]

Table 3 shows the results of measuring the spin rates of Examples 1 to 3 and Comparative Examples 1 to 6. The unit of spin amount is r.
pm. Iron heads having the groove and the loft angle shown in the above-described Examples and Comparative Examples were produced, assembled into a club, and the following measurements were performed. Specifically, Example 1, Comparative Example 1, Comparative Example 4 and Comparative Example 6 are pitching wedges, Example 2 and Comparative Example 2 are 9 irons, and Example 3, Comparative Example 2 and Comparative Example 5 are 7 irons. Was used as an experiment. Also, the test ball A is a thread-wound balata ball,
Ball B is a spin type two-piece ball which is a soft type ionomer cover, and ball C is a hard cover type two-piece ball. The amount of spin is measured by
For each club using a striking robot, first, using a thread-wound balata ball, another two-piece ball was measured according to the spin condition at the time of actual striking by a person. The head speed at this time is 35 m / sec for the pitching wedge,
The 9th iron is 37m / sec, and the 7th iron is 40m
m / sec. In the dry state and the wet state, the former is a state in which a normal club face is dry, and in the latter, a wet state is set by wiping the club face with a wet cloth.

[0016]

[Table 3]

Next, scratches on the cover surface of the ball were measured. In this measuring method, the state of scratches formed during the above-described spin amount measurement was ranked according to a 10-point method and scored. Here, the higher the score, the better the state of surface scratches. Table 4 shows the results.

[0018]

[Table 4]

From the measurement results shown in Tables 3 and 4, it is clear that the present invention improves the spin rate by suppressing surface scratches on the two-piece ball. When comparing in more detail, in the dry state between Example 1 and Comparative Example 1, the state of scratches is the same, but the spin amount of the two-piece ball is clearly shown in Example 1.
Is increasing. Further, in Example 1, the spin amount was maintained at the same level as in the dry state even in the wet state, whereas in Comparative Example 1, it was found that the spin amount was significantly reduced and the flyer phenomenon occurred. Next, looking at a comparative example in which the groove width L is widened to improve the spinnability or a comparative example in which the angle is set, the former is more effective than the comparative example 1, but it is a step forward,
The latter has a considerably improved spin performance, but it can be seen that the surface scratches on the cover are significantly deteriorated. From the above, it is apparent that the present invention has a groove shape suitable for minimizing the scratches on the surface of the cover of the two-piece ball and improving the spin property.

[0020]

As described above, in the golf club of the present invention, it is possible to directly hit the green and hit a ball that stops tightly, and when the club face is dry even if it is wet due to rain or the like. A ball with the same spin can be shot, and the damage to the cover of the ball is suppressed, so the life of the ball can be extended.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of a face surface showing a preferred embodiment of the present invention.

FIG. 2 is a front view of a golf club.

FIG. 3 is a cross-sectional view showing a conventional groove.

FIG. 4 is a cross-sectional view showing another conventional groove.

FIG. 5 is a sectional view showing still another conventional groove.

FIG. 6 is a cross-sectional view showing a groove measuring method.

[Explanation of symbols]

 1 Head 2 Face Surface 3 Impact Area 4 Groove 4A Groove Bottom L Groove Width D Groove Depth S Distance between Groove Edges

Claims (2)

[Claims] 1. The impact width of the face surface of the head has a groove width L in the range of 0.90 mm to 0.70 mm and a groove depth D of 0.50 mm to 0.35 mm. A golf club characterized by arranging several grooves having an angle θ _U of 100 to 110 ° and an angle θ _D of 90 to 100 ° formed with the groove bottom in the depth direction of the groove. 2. The golf club according to claim 1, wherein the loft angle is 35 ° or more.