JPH07136299A - Golf club - Google Patents

Abstract

PURPOSE:To stabilize a shot direction with a simple structure of the golf club distributed with the weight corresponding to a recessed part formed in a part of the rear surface of the club head around the recessed part by distributing the weight to the sole side and at least the upper part on the toe side among the upper part of the toe side and the lower part of the heel side. CONSTITUTION:A cavity 47 consists of a side wall part 47a corresponding to the difference in level on the outer periphery and a base part 47b which is flat and is almost parallel with the face surface on the front side. The outside shape of the base part 47b is formed to a square shape approximate to a rhombic shape in correspondence to the outer peripheral shape of the cavity 47 itself and the right and left sides of the square shape are made nearly parallel with the central axis 6a of a shaft. The weight corresponding to the cavity 47 is distributed around the cavity 47 by adjusting the thickness. The weight is thus distributed to the tow side weight distribution region 48c extending to the toe 42 side, the sole 49 itself and the heel side weight distribution region 48 extending to the heel 43 side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf club mainly made of iron, in which a cavity is formed on the back surface of a club head to expand a sweet area.

[0002]

2. Description of the Related Art FIG. 3 is a rear view showing a conventional cavity back iron club head. As shown,
Cavity 14 formed on the back surface of club head 104
7 is similar to the external shape of the club head 104, and has a structure that becomes deeper as it approaches the sole 149. As a result, the weight equivalent to the cavity 147 is mainly found on the sole 149 side and the toe 14 side of the cavity 147.
It will be distributed to the lower part on the 2nd side.

In the cavity back iron as described above, since the cavity 147 is provided to distribute the weight of the club head 104 to the peripheral portion thereof, the club head 1
The center of gravity of 04 becomes lower, the moment of inertia around the center of gravity of the club head 104 increases, the sweets area expands, and the directionality of the hit ball can be stabilized.

[0004]

However, in the cavity back iron as described above, the lower center of gravity causes
The hit ball tends to rise, but there is a problem that the hit ball loses momentum. Further, since the cavity 147 having a shape similar to that of the club head 104 is formed, the shaft 1
Due to the lie angle, the distance from the center axis of 05 to the center of gravity of the club head 104 becomes longer as it becomes a short iron, and unless the swing is changed for each club count, the shot is sliced with a long iron. However, there is a problem that the shots are easily hooked with a short iron, which causes a difference for each count.

FIG. 4 is a diagram for explaining this problem. The solid line shows the outer shape of the long iron, and the alternate long and short dash line shows the outer shape of the short iron when the shaft is aligned with the long iron. As shown in the figure, the centers of gravity of the long irons and the short irons are located at points A and A ', respectively, and the distances from the central axis 105a of the shaft 105 to the centers of gravity of the head portions of the long irons and the short irons are line segments, respectively. Corresponds to AB and line segment A'B '. Therefore, it is considered that the distance from the central axis 105a to the center of gravity of the club head 104 becomes longer as the short iron becomes shorter, and the shorter the iron becomes, the easier the hooking becomes.

In this case, a method of finely adjusting the position of the center of gravity by providing a protrusion or a groove in the cavity 147 is not inconceivable, but in such a method, the club head 104 is used.
However, there is a problem that the external design becomes complicated and the clean external design cannot be realized.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a golf club capable of stabilizing the shot direction with a simple structure.

[0008]

In order to achieve the above object, the golf club according to the present invention has a recessed portion formed on a part of the back surface of the club head, and the weight corresponding to the recessed portion is equal to the weight of the recessed portion. In the golf club distributed around, the weight distribution is mainly made on the sole side and at least the toe side upper part of the toe side upper part and the heel side lower part. is there.

In the above golf club, the weight distribution is made by forming a weight distribution region in which the club head wall thickness is increased, and the weight distribution region on the toe side is formed wider at the upper portion than at the lower portion on the toe side. It is preferable.

Further, in this case, it is preferable that the toe side wall portion of the recess is formed along a straight line extending substantially parallel to the central axis of the shaft.

Further, in the above golf club, it is preferable that the toe side side wall portion of the recess is formed at a position where the extension line intersects below the midpoint in the vertical direction of the toe side end of the face.

[0012]

According to the golf club of the present invention, the weight distribution is mainly performed on the sole side and at least the toe side upper portion of the toe side upper portion and the heel side lower portion. Therefore, not only the sweet spot is widened, but the weight distribution to the upper part on the toe side of the club head is relatively increased compared to the lower part. As a result, firstly, the moment of inertia about the central axis of the shaft is relatively increased, and it is difficult for the club head to shake during the operation of returning the club head, and the shot can be stabilized. Secondly, the center of gravity of the club head can be made relatively high while maintaining the shape of the sole, which enables a smooth swing and a powerful shot in which the momentum of the ball is hard to lose.

In the above golf club, the weight distribution is made by forming a weight distribution region in which the club head wall thickness is increased, and the weight distribution region on the toe side is formed wider at the upper portion than at the lower portion on the toe side. In this case, the weight can be distributed without largely changing the outer shape of the club head, and the design of the club head is not damaged.

In the above golf club, when the toe side wall of the recess is formed along a straight line extending substantially parallel to the central axis of the shaft, the weight distribution of the club head is
It can be embodied as a good design of the recess.

In the above golf club, when the toe side side wall portion of the recess is formed at a position where the extension line intersects below the vertical midpoint of the toe side end of the face, the toe side of the club head This will effectively increase the weight distribution to the top. As a result, the distance from the center of gravity of the club head to the center axis of the shaft can be kept substantially constant, and the shot direction can be stabilized regardless of the lie angle. That is, the upper part of the club head on the toe side is in a direction substantially perpendicular to the center axis of the shaft starting from the lower end of the heel. The distance from the center of gravity to the center axis of the shaft does not fluctuate due to movement to the toe side. Therefore, from the short iron with a large lie angle to the long iron with a small lie angle, the distance from the center of gravity of the club head to the central axis of the shaft can be kept substantially constant, and the player can play the same fee for all the irons. You can hit the ball with the ring. That is, while keeping the shape of the club head of each club constituting the set similar, the return of the club head can be kept constant regardless of the club count,
It is possible to stabilize the shot direction between the clubs.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A cavity back iron which is an embodiment of a golf club according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a cavity back iron of the embodiment. FIG. 1A is a front view of a head casting portion of a middle 5 iron, and FIG. 1B is a front view of a head casting portion of a short 9 iron.

As shown in FIG. 1 (a), the head casting portion of the No. 5 iron has a hosel 2 having a relatively small lie angle α coaxially connected to a shaft (not shown), and a neck of the hosel 2. And a head 4 which is connected via 3. On the face surface 41 of the head 4, between the toe 42 and the heel 43, a plurality of parallel score lines 46 are formed from the top edge 44 to the leading edge 45. As will be described in detail below, the back side of the head 4 is formed with a quadrangular cavity 47 (illustrated by a dotted line) that is close to a rhombus.

As shown in FIG. 1 (b), the 9-iron has a shape similar to that of the 5-iron, so that the common parts are designated by the same reference numerals and the description thereof will be omitted.
However, in the case of the 9th iron, the lie angle β is relatively large corresponding to the relatively short shaft. Also, the line of the top edge 44 has a shape that slightly bulges upward when viewed from the front.

FIG. 2 shows a cavity provided in the cavity back iron of FIG. 2A is a back view of the head casting part of the 5 iron, and FIG. 2B is a back view of the head casting part of the 9 iron.

As shown in FIG. 2 (a), the fifth iron cavity 47 is composed of a side wall portion 47a corresponding to a step on the outer periphery thereof and a bottom surface portion 47b which is flat and substantially parallel to the front face surface 41. . The outer shape of the bottom surface portion 47b corresponds to the outer peripheral shape of the cavity 47 itself and is a quadrangle close to a diamond. The left and right sides of this rectangle are
Both are almost parallel to the central axis 6a of the shaft,
One matches the first parallel line 6b passing through the upper end of the heel side end 41a (dotted line) of the face surface 41, and the other matches the second parallel line passing through the lower end of the toe side end 41b (dotted line) of the face surface 41. It matches line 6c. Also, this bottom portion 47b
The upper and lower sides of the quadrangle substantially correspond to the lower end of the upper region 48 a along the top edge 44 and the upper end of the sole 49, and are formed substantially parallel to these.

By adjusting the thickness of the cavity 47, the weight corresponding to the cavity 47 is distributed. Specifically, the weight is distributed to the toe side weight distribution region 48c extending to the toe 42 side, the sole 49 itself, and the heel side weight distribution region 48d extending to the heel 43 side. Since the lateral width of the toe-side weight distribution region 48c is wide on the upper side, effective weight distribution to the upper portion on the toe 42 side is possible. Further, since the lateral width of the heel side weight distribution region 48d is widened on the lower side, the heel 4
Enables effective weight distribution to the lower part on the 3 side. In addition,
In the fifth iron embodiment, the first and second parallel lines 6
The distance A between b and 6c is about 34 mm, and the second parallel line 6
The distance B from c to the upper end of the toe side end 41b of the face surface 41 was about 23 mm, and the distance C from the central axis 6a to the first parallel line 6b was about 20 mm.

As shown in FIG. 2 (b), the 9-iron has a cavity shape similar to that of the 5-iron, and therefore the common parts are designated by the same reference numerals and the description thereof will be omitted. However, the bottom surface portion 47b of the cavity 47
Since the inclination angle of the side of the quadrangle is larger corresponding to the lie angle β, the shape of the bottom surface portion 47b, that is, the outer peripheral shape of the cavity 47 itself is a quadrangle whose both sides are more upright. . More specifically, the left and right sides of this quadrangle are both substantially parallel to the central axis 6a of the shaft with a large lie angle β, and one side is
The first parallel line 6b passing through the upper end of the heel side end 41a of the face surface 41 is matched with the second parallel line 6c passing through the lower end of the toe side end 41b of the face surface 41. That is, the extension lines on both sides of the quadrangle of the bottom surface portion 47b of the cavity 47 are not limited to the lie angles, and
The upper end of the first heel side end 41a and the lower end of the toe side end 41b of the face surface 41 pass through.

In the ninth iron embodiment, the distance A'between the first and second parallel lines 6b and 6c is set to about 37 mm, and the upper end of the toe side end 41b of the face surface 41 is separated from the second parallel line 6c. Is about 20 mm, and the distance C ′ from the central axis 6a to the first parallel line 6b is 21 mm.
It was about degree.

A shot using the cavity back iron of the embodiment will be described. In the cavity back iron of the embodiment, since the toe side weight distribution region 48c is provided for both the 5th and 9th irons, effective weight distribution to the upper portion on the toe 42 side is possible, and the center of the shaft during swinging is achieved. The moment of inertia about the axis 6a increases. As a result, the return of the head 4 becomes stable,
In particular, the face 41 is less likely to shake at the time of impact, and the shot becomes relatively stable. In addition, tow 42
By distributing the weight to the upper part of the side, the center of gravity of the head 4 can be easily increased while maintaining the shape of the sole 49 such as the width (which is lower than that of a conventional iron, but less than that of a conventional cavity iron). (Slightly higher), a smooth swing that makes the best use of the sole 49 is possible, and a powerful shot is possible in which the ball rises and the momentum of the raised ball is hard to lose.

Further, the toe side weight distribution region 48c extends in a direction substantially perpendicular to the shaft center axis 6a, starting from the lower end of the heel side end 41a of the face surface 41 through which the shaft center axis 6a passes regardless of the lie angle. is there. Therefore,
The distance from the central axis 6a of the shaft to the comparatively heavy toe side weight distribution area 48c hardly changes between the clubs of the 5th iron and the 9th iron of the same set in which the shape of the head 4 is similar, and The distance from the shaft 6a to the center of gravity of the head 4 can be kept substantially constant. As a result, the moment of inertia around the central axis 6a of the shaft can be kept constant between the clubs, and the return of the head 4 at the time of a shot can be kept constant in both clubs.
That is, both clubs can swing at the same timing, and the shot direction can be stabilized.

On the other hand, in the cavity back iron of the embodiment, the heel side weight distribution region 48d is provided for both the 5th and 9th irons to further enhance the cavity effect.
In this case, since the lower portion of the head 4 on the heel 43 side is located closest to the center axis 6a of the shaft, the moment of inertia about the center axis 6a of the shaft between the 5th iron and 9th iron clubs is increased. Can be kept substantially constant, and the return of the head 4 during the shots of both clubs can be kept uniform.

Although the present invention has been described with reference to the embodiments, the present invention is not limited to the above embodiments. For example, in the above embodiment, the weight is distributed to the upper portion on the toe 42 side by the outer peripheral shape of the cavity 47, but a metal having a high specific gravity may be embedded in the upper portion on the toe 42 side.

Further, although the outer peripheral shape of the cavity 47 is a quadrangle in the above embodiment, the shape of the cavity 47 can be arbitrary as long as the toe side weight distribution region 48c is widened from the lower side to the upper side. However, cavity 4
It is easier to adjust the moment of inertia around the shaft center axis 6a and to achieve a simple appearance by forming the side wall of the toe 42 side of the shaft 7 in parallel with the shaft center axis 6a. Also on the heel 43 side of the cavity 47, the shape is arbitrary as long as the heel side weight distribution region 48d is widened from the upper side to the lower side, but from the viewpoint of adjusting the moment of inertia and the simple appearance, the side wall portion on the heel 43 side. Is preferably formed parallel to the central axis 6a of the shaft.

In the above embodiment, the cavity 47 is
The upper end of the heel side end 41a of the face surface 41 and the face 4
A pair of parallel lines 6b passing through the lower end of the toe side end 41b of No. 1,
It is formed between 6c, but it is not necessarily limited to this. Therefore, in order to adjust the moment of inertia about the shaft center axis 6a according to the shape and thickness of the head 4, the distance from the shaft center axis 6a to the side wall portion of the cavity 47 on the toe 42 side and the shaft center The distance from the shaft 6a to the side wall portion of the cavity 47 on the heel 43 side can be appropriately changed. However, tow 43
By forming the side wall portion on the side at a position where the extension line intersects below the center of the toe side end 41b of the face surface 41, weight distribution to the upper portion on the toe 42 side becomes effective.

Furthermore, the shape of the sole 49 is also arbitrary.
However, the weight distribution to this is the toe side weight distribution area 48.
In order to enhance the effect of c and the heel side weight distribution region 48d, it is preferable not to make it extremely large.

Further, in the above embodiment, the cavity 47
Although it has an open structure, it may be sealed to form a hollow structure having a simple appearance.

[0033]

As described above, according to the golf club of the present invention, the weight distribution is mainly the sole side and at least the toe side upper portion of the toe side upper portion and the heel side lower portion. It is done by. Therefore, not only the sweet spot is widened, but the weight distribution to the upper part on the toe side of the club head is relatively increased compared to the lower part. As a result, firstly, the moment of inertia about the central axis of the shaft is relatively increased, and it is difficult for the club head to shake during the operation of returning the club head, and the shot can be stabilized. Second
In addition, the center of gravity of the club head can be made relatively high while maintaining the shape of the sole, which enables a smooth swing and a strong shot in which the momentum of the ball is hard to lose.

Further, weight distribution is possible without largely changing the outer shape of the club head, and the design of the club head is not damaged.

Furthermore, the weight distribution of the club head can be embodied as a good design of the recess.

Further, the distance from the center of gravity of the club head to the central axis of the shaft can be kept substantially constant, and the shot direction can be stabilized regardless of the lie angle.

[Brief description of drawings]

FIG. 1 is a front view of a pair of cavity back irons according to an embodiment.

FIG. 2 is a back view of a pair of cavity back irons according to the embodiment.

FIG. 3 is a back view of a conventional cavity back iron.

FIG. 4 is a diagram showing the relationship between the count and the center of gravity of a conventional cavity back iron.

[Explanation of symbols]

 4 Head 42 Toe 43 Heel 47 Cavity 48c, 48d Weight Distribution Area 49 Sole

Claims (4)

[Claims] 1. A golf club in which a recessed portion is formed on a part of the back surface of a club head, and a weight corresponding to the recessed portion is distributed around the recessed portion, wherein the weight distribution is mainly on the sole side. And a toe-side upper part and at least a toe-side upper part of the heel-side lower part. 2. The weight distribution is made by forming a weight distribution region in which the club head wall thickness is increased, and the weight distribution region on the toe side is wider at the upper portion than at the toe side lower portion. The golf club according to claim 1, wherein the golf club is formed. 3. The golf club according to claim 2, wherein the toe-side side wall portion of the recess is formed along a straight line extending substantially parallel to the central axis of the shaft. 4. The toe-side side wall portion of the recessed portion is formed at a position where the extension line intersects below the midpoint in the vertical direction of the toe-side end of the face. Golf club.