JP2000116829A - Putter golf club - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the directivity of a ball hit at a position out of a sweet spot. SOLUTION: This putter golf club has the club head 3 with a face 6 with loft angle θ at the lower end of the club shaft 1. When the golf club is set at a determined lie angle α and the face 6 is projected downward in the vertical direction, the gravity center G of the head 3 is located within the projection range (a).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a putter golf club, and more particularly, to a putter golf club having improved directivity at the time of putting at a position off a face.

[0002]

2. Description of the Related Art A putter golf club is a club used for putting a golf ball in a hole cup on a green. Therefore, a performance that can accurately roll the ball in the aimed direction is required. In conventional putter golf clubs, the center of gravity of the face of the club head
When hitting at the so-called sweet spot, the ball can be rolled in the target direction and is excellent in directionality, but if hit at a position outside the sweet spot, side spin occurs on the ball and the target direction is There has been a problem that the ball rolls in a direction that is largely displaced and the directionality is impaired.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a putter golf club capable of improving the directionality of a golf ball when hit at a position deviating from a sweet spot.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a putter golf club equipped with a club head provided with a face having a loft angle at the lower end of a club shaft. The club head is set at an angle, and when the face is projected vertically downward, the center of gravity of the club head is positioned within the projection area.

[0005] By setting the position of the center of gravity of the head in the projection area vertically below the face surface in this manner, even when the sweet spot is removed, the contact point between the ball and the face surface is centered on the center of gravity of the head. Since the ball moves substantially rearward and does not move in an oblique direction that causes side spin, the ball rolls in a substantially targeted direction and the directionality of the ball can be improved.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail with reference to the accompanying drawings. 1 and 2 show an example of the putter golf club of the present invention, in which a grip 2 is provided at an upper end of a club shaft 1 and a club head 3 is mounted at a lower end. The club shaft 1 is connected to the club head 3 via a socket 5 at a hosel 4 projecting upward on the heel side of the club head 3.

The face surface 6 of the club head 3 is formed so as to have a loft angle θ of about 4 °, and the center of gravity G of the club head 3 becomes the lie angle α which sets the club as shown in FIG. Is set in such a manner that when the face surface 6 is projected downward in the vertical direction, it is positioned within the projection area a. Further, when the center axis O of the club shaft 1 projects the face surface 6 vertically upward in the state of the side view shown in FIG. 2, the center axis O is located within the projection area b.

The inventors of the present invention have made extensive studies on the fact that if the golf ball is put out of the sweet spot, the golf ball will be spun and the directionality will be impaired. It was found that the position of the head center of gravity G was closely related to the face surface 6.

That is, in the conventional putter golf club, the center of gravity G of the head is located at the center of the club head 13 as shown in FIG. Therefore, FIG.
As shown in FIG. 4A, when the ball B is removed and hit on the toe n side from the center of gravity G of the head, the club head 13 is instantaneously moved from a dotted line around the center of gravity G of the head as shown in FIG. The ball B rotates so as to open to the position indicated by the solid line, and accordingly, the contact point P between the ball B and the face surface 16 also rotates around the center of gravity G of the head, and the ball B corresponds to the moving direction of the contact point P. As a result of the generation of the oblique velocity vector S, the component force S1 in the face direction gives the ball B a counterclockwise side spin. Also, if the ball B is removed from the center of gravity G of the head toward the heel side and hit, a side spin opposite to the above occurs on the ball B.

Therefore, in the present invention, based on the above findings, the center of gravity G of the head is positioned in the projection area a vertically below the face surface 6 and the face surface 6 with which the ball B comes into contact is positioned.
It was near. Thereby, as shown in FIG.
Even if the ball is hit at a position where the head center of gravity G is removed, since the head center of gravity G is within the projected face surface 6, the moment the face surface 6 opens, the contact point P between the ball B and the face surface 6 moves the head center of gravity G. Although it rotates about the center, its movement direction is substantially backward, and does not become the above-described oblique direction. Therefore, since the velocity vector Y generated by the rotation only acts in a direction substantially opposite to the traveling direction of the ball B, the component force does not act in the direction of the face surface, and side spin can be prevented. Therefore, even if the ball is hit at any position on the face surface, the ball can be rolled in a substantially aimed direction.

In the present invention, as described above, the center axis O of the club shaft 1 is located in the projection area b vertically above the face surface 6 in side view, so that the wrist centering on the club shaft 1 is provided. Is returned,
You can hit the ball without giving side spin. That is, if the center axis O of the club shaft 1 is within the projection area b of the face surface 6, as shown in FIG.
(The club head 3 rotates around the center), and the velocity vector Z merely acts in a direction substantially opposite to the direction of travel of the ball, so that no side spin occurs. In contrast, FIG.
As shown in (b), when the center axis O of the club shaft 1 is out of the projection area of the face surface 6, the velocity vector Z acts in an oblique direction. Side spin occurs at the end.

In the present invention, in order to set the center of gravity G of the head within the projection area a of the face surface 6 as described above, for example, as shown in FIG. 2, the heel side of the club head 3 having the hosel 4 protruded therefrom. A protruding portion 3a protruding forward from the face surface 6 is provided, or a portion of the club head 3 on the face surface 6 side is made of a metal having a high specific gravity.
The protruding portion 3a can be made of a metal having a high specific gravity, but the technique is not particularly limited.

In the above embodiment, the golf club having a loft angle θ of about 4 ° has been described. However, the present invention is preferably applied to a putter golf club equipped with a club head 3 having a loft angle θ of −10 ° to 10 °. Can be used. If the loft angle θ is smaller than −10 °, the vertical rotation, so-called top spin rotation, becomes too strong, and after impact, the ball behaves as if it sinks into the turf once and repels by the reaction force. Could potentially have a negative impact on Conversely, if the angle exceeds 10 °, the so-called backspin rotation, which is reversely rotated in the vertical direction, becomes too strong, and the ball is likely to rise in the air, making it difficult to roll to the target location. Preferably, the loft angle θ is −5 ° to 7 °.

In the present invention, the position of the center of gravity of the club head can be measured by the following method. That is, FIG.
As shown in (a), the club head 3 is supported on the vertex 8 of the one-point support jig 7 so that the face surface 6 faces downward. It is preferable that the apex portion 8 be a complete apex such as a conical shape, but it is actually difficult to balance the apex with a perfect apex.
A flat portion may be provided at the vertex 8 in a shape such as a truncated cone as shown in FIG. When the vertex 8 has a truncated conical shape, the diameter Dt of the circular flat portion is desirably within 3 mm. If the diameter Dt exceeds 3 mm, it becomes difficult to measure the exact center of gravity. Further, when the flat portion of the vertex portion 8 is not circular, it is desirable that the area of the flat portion is 7 mm ² or less for the same reason.

Then, with the club head 3 balanced as described above, the point where the vertex 8 comes into contact with the face surface 6 is marked as shown in FIG. 7C. Then
As shown in FIG. 8, the club head 3 is placed on a flat surface, and a vertical auxiliary line 9 passing through the marked point and perpendicular to the leading edge is drawn on the face surface 6. 9 is extended to the upper surface of the club head 3.

Next, after the shaft 1 is inserted into the club head 3, as shown in FIG. 9, the shaft 1 is placed on a horizontal table 10 in a rotatable state around its axis. In such a state, the center of gravity stands still in a state of being located vertically below the shaft center axis. And FIG.
As shown in (a) and (b), an intersection 12 between an alternate long and short dash line 11 extending from the center axis of the shaft and the auxiliary line 9 is determined. If the intersection 12 does not exist in the face surface 6 as shown in FIG. 10A, it does not satisfy the requirements of the present invention. On the other hand, when the intersection 12 exists in the face surface 6 as shown in FIG. 10B, the condition of the present invention is satisfied.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The putters 1 and 2 of the present invention in which the center of gravity G of the head is located within the projection area a on the face surface, the comparative putter located ahead of the projection area a on the face surface, and the projection area a on the face surface Conventional putters 1 and 2 located at the rear were produced.

In each test putter, the thickness in the height direction is 25 mm, and the loft angle θ is 4 °.
The distance A from the leading edge to the center of gravity of the head and the distance B from the leading edge to the center axis of the club shaft are as shown in Table 1. However, each distance A, B is
The distance measured from the leading edge to the head rear side is +, and the distance measured to the head front side is-. The face surface is in a range from the leading edge to 1.7 mm.

An evaluation test of directionality was performed on each of these test putters under the following measurement conditions, and the results shown in Table 1 were obtained. Directivity evaluation test Each test putter is attached to the test hitting robot, and the center connecting the hole cup and the test hitting position when hit with a hole cup 10m away at a position 20mm away from the center of gravity of the head to the toe side. The distance (m) deviating left and right from the line was measured. Each test putter hit the golf ball 10 times, and the average distance is shown in Table 1. The smaller this value, the better the directionality.

[0020]

[Table 1]

As is apparent from Table 1, the putters 1 and 2 of the present invention, in which the center of gravity of the head is located in the area where the face surface is projected downward in the vertical direction, have an extremely small departure distance of 0.05 m or less. It can be seen that even if the golf ball is hit at a position out of the range, the ball can be rolled in a substantially targeted direction and the directionality can be improved.

When the face is projected upward in the vertical direction in side view, the putter 1 of the present invention, in which the center axis of the club shaft is located within the projection area, has a further reduced distance of 0.04 m. It can be seen that the directionality can be further improved.

[0023]

As described above, according to the present invention, in a putter golf club equipped with a club head provided with a face having a loft angle at the lower end of a club shaft, the club is set to have a set lie angle. When the face is projected downward in the vertical direction, the center of gravity of the club head is located in the projection area, so that even if the ball is hit at a position deviating from the sweet spot, the ball is directed in a substantially aimed direction. The golf ball can be rolled, and the directionality of the golf ball can be improved.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of a putter golf club of the present invention.

FIG. 2 is an enlarged side view of a main part of FIG.

FIG. 3 is a side view of a club head of a conventional putter golf club.

FIGS. 4A and 4B are explanatory diagrams for explaining that side spin occurs when hitting with a conventional putter golf club. FIG.

FIG. 5 is an explanatory view explaining that side spin does not occur when hitting with the putter golf club of the present invention.

FIGS. 6A and 6B are explanatory views showing the operation when the center axis of the club shaft is positioned in a region where the face surface is projected upward in the vertical direction when viewed from the side, and the operation when the center axis is deviated, respectively. It is.

7A is an explanatory view showing a method of measuring the center of gravity of the club head, FIG. 7B is a perspective view showing an example of a vertex of the one-point support jig, and FIG. 7C is a center of gravity on the face of the club head; It is a front view showing the state where a position was marked.

FIG. 8 is a perspective view showing a state where a line for measuring the center of gravity is drawn on the club head.

FIG. 9 is an explanatory diagram showing a method of measuring the position of the center of gravity of the club head.

FIGS. 10A and 10B are explanatory diagrams illustrating a method of measuring the position of the center of gravity of the club head.

[Explanation of symbols]

Reference Signs List 1 club shaft 2 grip 3, 13 club head 6, 16 face surface B golf ball G head center of gravity O center axis of club shaft P contact point a, b projection area α lie angle θ loft angle

Claims (2)

[Claims] 1. A putter golf club equipped with a club head having a face surface having a loft angle at a lower end of a club shaft, wherein the club is set to have a set lie angle, and the face surface is set in a vertical direction. A putter golf club in which, when projected downward, the center of gravity of the club head is located within the projected area. 2. The putter golf club according to claim 1, wherein a center axis of the club shaft is positioned within a projection area when the face is projected upward in a vertical direction in a side view.