JP2000325513A - Shaft for golf club - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shaft for golf clubs which is adequately supple in at a swing, but is suppressed of the excessive deformation of the shaft and generates strong repulsive force in an impact, is thereby further improved in the initial speed and distance of a ball and is extremely suitable for use with low-centroid and large-sized club heads. SOLUTION: The shaft for golf clubs is constituted by building an arbor 6 consisting of a blank which is harder than the hollow shaft 1 and is less deformable into the shaft 1 over its entire length or across its front end along its axis, fixing a fixing part 62 of the arbor 6 to the bottom end of the shaft 1 and disposing an air bag 4 formed in such a manner that the repulsive force from compression is generated between the arbor 6 and the shaft 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a shaft for a golf club.

[0002]

2. Description of the Related Art Conventionally, a golf club has a shaft,
Using a high-strength high-elastic fiber (for example, carbon fiber) to form a hollow shape to reduce the weight, increase the head speed by deforming (bending) the material at the time of swing,
The initial speed and flight distance of the ball are improved by increasing the repulsive force generated when the deformed shaft returns to its original position. In addition, the tendency of recent golf clubs is to increase the size of the club head and lower the center of gravity. By increasing the deformation of the shaft, the head speed and repulsive force are increased to further increase the initial ball speed and flight distance. Is being improved.

[0003]

The factors that increase the flight distance are, in addition to the head speed and repulsion force, the center of gravity of the club head 100 as shown in FIG.
It is known that by hitting above the intersection with a perpendicular line lowered from 01 to the face surface, the initial velocity of the ball is more effectively improved and the flight distance is extended.

This is what is called a vertical gear effect. At the time of impact, when the ball 103 collides with the club head 100 advancing in the direction of the arrow 102 in the direction of the arrow 104, the club head 10
0, a counterclockwise couple 105 is generated.
Deforms the shaft 106 so as to crush the shaft 106 from the arrow 107.

That is, the correlation between the couple 105 of the club head 100 and the deformation of the shaft 106 is determined by the ball 10.
By rotating the club head 3 clockwise, the backspin affecting the flight distance is reduced and the launch angle is increased, so that the club head 100 is recently made larger in the vertical direction. I have.

[0006] However, as a result of the lowering of the center of gravity and the increase in the size of the club head 100 as described above, as shown in FIG.
6 becomes too large, and the energy loss due to the deformation of the shaft 106 becomes large.
It is difficult to increase the initial speed of the car.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances. It is an object of the present invention to suppress excessive deformation of a shaft at the time of impact and to generate a strong repulsive force while making the shaft proper at the time of a swing. Accordingly, it is an object of the present invention to provide a golf club shaft which improves the initial velocity of the ball, thereby further improving the flight distance, and is extremely suitable for using a low center of gravity and a large club head.

[0008]

The present invention employs the following technical means in order to achieve the above object.

[0009] The technical means of the present invention is that a mandrel made of a material that is harder and harder to deform than the shaft along its axis is built in over the entire length of the hollow shaft, and a lower end portion of the mandrel is provided. To the lower end of the shaft, and
A golf club shaft has an air bag disposed between the mandrel and the shaft so as to generate a repulsive force from compression.

According to the technical means of the first aspect, the mandrel and the air bag disposed inside the shaft act on the deformation of the shaft.

That is, a repulsive force is generated in the air bag compressed along the flexible shaft during the swing. Furthermore, regardless of the bending of the shaft, the mandrel that is hard to deform and is harder than the shaft keeps a substantially fixed position with little or no deformation, so that the air bag is crushed by the mandrel from the inside. Because the air bag is compressed, the air bag also has a repulsive force due to the compression.

At the time of impact, a strong repulsive force of the air bag acts on the shaft which is going to be deformed by the impact of the ball hitting the club head. This repulsive force suppresses excessive deformation (shake) that occurs when the shaft returns from the deformation. Therefore, the repulsive force is sufficiently utilized as a repulsive force to fly the ball, and the energy loss at impact is reduced.

According to the first aspect of the present invention, a mandrel and an air bag are arranged on the entire shaft.
The present invention is not limited to this configuration, and may be configured by filling a part of the shaft.

For example, as in the technical means of claim 2,
At the distal end of the hollow shaft, a mandrel made of a material that is harder and less deformable than the shaft along its axis is incorporated, and the lower end of the mandrel is fixed to the lower end of the shaft. An air bag is disposed between the shaft and the shaft, and the air bag is configured to generate at least a repulsive force from compression.

That is, since the tip portion of the shaft is the portion where deformation due to couple occurs most at the time of impact, and has the greatest influence on the flight distance and directionality, a mandrel and an air bag are provided at this portion. Thereby, the same operation as the first aspect is achieved.

As a specific range of the range of the front end portion, the range of the front end portion where the air bladder is disposed is changed to the end portion of the neck portion or the end portion of the neck portion. It is preferable to set the range from 30 cm to 40 cm from the vicinity of the end.

Further, the air bag may be adhered and fixed to the shaft as in the technical means of claim 4, whereby the repulsive force of the air bag acts on the torsion of the shaft. This makes it difficult to twist, and is effective in improving the directionality.

The air bladder is not limited to the whole which is bonded and fixed, but may be a part of which is bonded and fixed. For example, as in the technical means of claim 5, the upper end of the air bag is fixed to the shaft. Adhesive fixing is mentioned, and this configuration is
It is preferable that the air bag is disposed at the distal end of the shaft as in claims 2 and 3.

Further, the air bag may be filled with a soft foamed elastic body as in the technical means of claim 6, whereby a repulsive force due to the compression of the foamed elastic body is also applied.

Further, according to the technical means of claim 7,
One small-diameter vent at the upper end of the air bag, or
A plurality of holes may be opened.

According to the technical means of claim 7, since the air in the air bag is covered with the air bag at all parts except for the ventilation hole at the upper end, the air in the air bag or the air bag can be used. When the foamed airbag is filled with the foamed elastic body as shown in 6, the air in the foamed elastic body flows out from a narrow portion of only the ventilation hole. That is, the orifice effect acts on the ventilation hole.

In the orifice effect, a gentle force is applied to the shaft during the swing, so that the air bag,
Alternatively, since the air flows out of the ventilation hole without resistance due to the compression of the foamed elastic body, the bending of the shaft at the time of swing can be ensured.

Conversely, at the time of impact, the impact of the ball against the club head applies a sudden force to the shaft that is 100 to 1000 times faster than the force applied at the time of the swing. Is restricted. That is, a strong repulsive force due to the orifice effect acts on the air bag or the foamed elastic body on the shaft to be deformed. This repulsive force suppresses excessive deformation (shake) that occurs when the shaft returns from the deformation. Therefore, the repulsive force is sufficiently utilized as a repulsive force to fly the ball, and the energy loss at impact is reduced.

[0024] The air bag may be divided into a plurality of parts in a plan view. According to this technical means, a repulsive force can be applied to the shaft in other directions. In particular, an extremely high effect can be obtained with respect to the means for applying a repulsive force by the orifice effect.

The flexible foamed elastic material in the present invention includes polyurethane (foam obtained by mixing polyisocyanate and polyol), polyethylene (foam), polystyrene (foam), latex foam, foamed rubber,
Bouncing putty (impregnated with siloxane acid containing boron atom), butadiene-acrylonitrile copolymer, chloroprene polymer, ethylene propylene copolymer, acrylic copolymer, styrene-butadiene copolymer, isobutylene-isoprene , Polybutadiene, natural polyisoprene, synthetic polyisoprene, natural rubber, polyvinyl chloride rubber, polyamide rubber, polyvinyl chloride copolymer, polyolefin, synthetic rubber, propylene, nitrile, isoprene, silicone, urea And phenolic foams and foams selected from these.

In the shaft of the present invention, since the shaft is deformed as usual at the time of swing, it is preferable to increase the swing speed by using a material that is greatly deformed at the time of swing, and it is best to use a material that is as soft as possible. It is.

The method of arranging the air bag and the mandrel on the shaft is arbitrary. The mandrel may be inserted into the shaft with the air bag attached to the mandrel, or may be fixed inside the shaft after the mandrel is fixed to the shaft. An air bag formed in a corresponding shape may be inserted.

[0028]

According to the present invention, by applying a repulsive force to the shaft, excessive deformation of the shaft (shaft deflection) at the time of impact is suppressed, and the repulsive force sufficiently acts as a repulsive force for flying the ball. Therefore, it is possible to provide a golf club shaft having an extremely improved initial ball speed and flight distance.

According to the fourth and fifth aspects of the present invention, the repulsive force can also act on the deformation of the shaft in the torsional direction, which is extremely effective in stabilizing the directionality of the ball. The golf club shaft is extremely excellent not only in the initial ball speed and the flight distance but also in the directionality.

According to the sixth aspect of the present invention, since the repulsive force of the foamed elastic body is also applied, it is effective in improving the ball initial speed and the flight distance.

According to the seventh aspect of the present invention, further repulsion can be expected, which is effective in improving the ball initial speed and the flight distance.

Further, the invention of claim 8 has an effect that it can cope with deformation of the shaft in multiple directions.
A repulsive force is obtained by an orifice effect.
An extremely large effect can be obtained for the invention of (1).

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1A and 1B show a golf club A using a golf club shaft 1 according to the present invention. Is shown. First, the configuration of the golf club A will be described.

This embodiment uses a shaft according to claim 7 in which a repulsive force is obtained by an orifice effect.

The shaft 1 has a hollow structure formed by winding a high-strength high-elasticity fiber impregnated with a synthetic resin (for example, carbon fiber) or a high-strength high-elasticity filament impregnated with a synthetic resin. This structure is well known and will not be described in detail.

Reference numeral 2 denotes a club head, which is formed in a predetermined shape using a known material (for example, titanium), and has a shaft 1 inserted and fixed in a neck portion 3 provided integrally on the upper surface.

Reference numerals 4... 4 are air bladders, reference numerals 5... 5 are foamed elastic bodies filled in the air bladders 4, and reference numeral 6 is a mandrel.

The air bladders 4... 4 are made of a material which has elasticity and does not allow air to pass through, and is formed in a substantially fan-shaped planar shape having the same shape. These air bags 4 are arranged in quadrants around the mandrel 61 of the mandrel 6 with their opposing surfaces adhered. The air bladders 4 ... 4
The mandrel 61 has the same length as the entire length thereof, and is disposed so as to adhere from the lower end to the upper end of the mandrel 61.

The foamed elastic bodies 5 are tightly fitted by filling the air bladders 4 in a compressed state. Also, small-diameter ventilation holes 51 are formed at the upper end of the air bag. These orifices 51 generate an orifice effect that increases or decreases the repulsive force against the deformation by the speed of the deformation force applied to the shaft 1.

The mandrel 6 is made of a material (for example, metal, carbon fiber, glass fiber, or the like) that is harder than at least the foamed elastic bodies 5 and has a tension sufficient to compress the elastic bodies.
It is composed of the mandrel 61 and a fixing portion 62 integrally formed at the lower end of the mandrel 61 using a hard synthetic resin or the like.

The mandrel 61 has a length of 30 cm. The fixing portion 62 is formed to have the same length as the length of the neck portion 3 and an outer diameter substantially matching the inner diameter of the shaft 1.

The air bags 4 integrated in this manner are:
4. The foamed elastic members 5... 5 and the mandrel 6 are inserted into the shaft 1 from the upper end (not shown), and the entire periphery of the fixing portion 62 and the entire periphery of the upper portion of the air bags 4. Is fixed by using an adhesive 7 over the entire circumference of.

In this arrangement, the fixing portion 62 is connected to the shaft 1
5 are located on the same plane as the lower end surface 11 of the neck portion 3, and are arranged within a range of 30 cm from the upper end portion 31 of the neck portion 3.

Next, with reference to FIGS. 2 and 3, a description will be given of a series of deformation states of the shaft 1 when the ball 6 is hit with the golf club A configured as described above.

First, during the downswing, the shaft 1
Since a moderate deformation force acts on the
The air contained in the air flows out of the air holes 51 without any resistance. This makes the shaft 1 easy and
It is correct, and this bending increases the head speed.

Next, at the time of impact, as shown in FIG.
A couple D is generated in the club head 2 due to the impact in the direction of the arrow C2 at the time of collision, and the couple D exerts a sharp deformation force on the shaft 1 such that the shaft 1 is crushed from the arrow E.

The time required for the shaft 1 to deform at the time of impact is about 100 to 1000 times faster than the time required for the shaft 1 to perform at the time of downswing. A force is added to a large deformation force.

The sudden deformation force causes a compression force from the outside by the shaft 1 to be deformed and a compression force from the inside by the mandrel 61 having a smaller deformation than the shaft 1. This compressive force tends to compress and deform the foamed elastic bodies 5... 5, but due to the orifice effect, the ventilation holes 51.
51 to provide resistance to the outflow of air from the
… 5 generates a strong repulsive force, and this repulsive force is
Of the shaft 1 is suppressed by minimizing the deformation of the shaft 1. That is, the loss of energy at impact is reduced, and the repulsive force of the shaft 1 can be concentrated on the ball, so that the initial speed of the ball and the flight distance are improved.

Further, since the elastic body 4 is bonded to the shaft 1, a repulsive force acts on the shaft 1 even when the shaft 1 is deformed in the torsion direction, so that a stable directivity is realized.

In this embodiment, the air bag is filled with a foamed elastic body, and the shaft is configured to obtain a repulsive force by an orifice effect. A shaft configured to obtain a repulsive force only with the bag may be used. Also, the air bag is described as a shaft disposed at the tip of the shaft.
The shaft may be arranged on the entire shaft so as to correspond to the above. (All are not shown.)

In this embodiment, the golf clubs are all wood types, but the present invention is not limited to this type and golf clubs may be iron types. In the case of this iron type (not shown), a long iron type used when a flight distance is required is optimal.

[Brief description of the drawings]

FIG. 1A is a partially cutaway side view showing a main part of a golf club using a golf club shaft according to the present invention. (B) is an enlarged sectional view taken along the line (b)-(b) of (a).

FIG. 2 is an operation diagram showing a deformed state of a shaft from a downswing to an impact.

FIG. 3 is a partially cutaway side view showing a deformed state of a shaft at the moment of impact.

FIG. 4 is an operation diagram showing a deformed state of the conventional shaft from a downswing to an impact.

FIG. 5 is a side view showing a deformation state of the conventional shaft at the moment of impact.

[Explanation of symbols]

 1: Shaft 2: Club head 3: Neck 4: Air bag 5: Foam elastic body 6: Mandrel 51: Vent 61: Mandrel 62: Fixed part A: Golf club

Claims (8)

[Claims] 1. A mandrel made of a material that is harder and harder to deform than the shaft along its axis along the entire length of the hollow shaft, and a lower end of the mandrel is fixed to a lower end of the shaft. A golf club shaft comprising an air bag disposed between the mandrel and the shaft so as to generate a repulsive force from compression. 2. A hollow mandrel made of a material that is harder and less deformable than the shaft along its axis at the tip of the hollow shaft, and the lower end of the mandrel is fixed to the lower end of the shaft. And between the mandrel and the shaft,
A golf club shaft provided with an air bag in such a manner that at least a repulsive force from compression is generated. 3. The golf club shaft according to claim 2, wherein a range of the tip portion where the air bag is disposed is set to a range of 30 cm to 40 cm from an end portion of the neck portion or a vicinity of the end portion. 4. The golf club shaft according to claim 1, wherein the air bag is adhesively fixed to the shaft. 5. The golf club shaft according to claim 2, wherein an upper end portion of the air bag is adhesively fixed to the shaft. 6. The golf club shaft according to claim 1, wherein the air bag is filled with a soft foamed elastic body. 7. A small-diameter ventilation hole is provided at an upper end of the air bag.
The golf club shaft according to any one of claims 1 to 6, wherein one or a plurality of holes are formed. 8. The golf club shaft according to claim 1, wherein the air bag is divided into a plurality in a plan view.