JP2571332B2 - Golf shaft - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf club shaft.

[0002]

2. Description of the Related Art Conventional golf club shafts use materials such as wood, steel, glass, and other composite materials that are more expensive than synthetic graphite materials. In recent years, from the viewpoint of flight distance, directionality, shot feeling, and the like. Research has been done on strength, weight, weight distribution, flexibility, torsion, size, length, diameter, wall thickness, taper, step, etc., and improvements have been made.

[0003]

Various materials have been developed, and the use of these materials has been used to cover the shaft axis of the shaft over the entire length of the shaft. In this way, just covering the entire length of the shaft makes use of the characteristics of each material.For example, if it is a boron fiber, it has the effect of increasing the flight distance, but the effect of the material used alone is Had the disadvantage of ending. The present invention has been achieved as a result of taking full advantage of the characteristics of the plurality of materials and taking into consideration the kick points generated by the different materials.

[0004]

In order to solve the above-mentioned problems, a golf shaft according to the present invention is characterized in that a boron fiber extends from a grip side to a central portion of a shaft axis made of a highly elastic carbon fiber, and an aramid fiber extends from a head side to a central portion. And the reinforcement ratio is the borrow of the total external surface area of the shaft core.
The area covered with the fiber and the area without the
The gist is that the covering area ratio of the lamid fiber is 5: 4: 3, and that the outer layer is coated with high-strength carbon fiber over the entire length of the shaft.

Here, the carbon fiber forming the shaft core is H
A highly elastic carbon sheet such as M40 is preferred. The outer layer carbon fibers are preferably high-strength carbon. The ratio of the reinforcing member is determined by dividing the total surface area of the innermost carbon fiber shaft core by a boron fiber coated portion: a portion having no reinforcing member (exposed carbon fiber portion of the inner layer): an aramid fiber coated portion of 5: 4:
It has been found that the case of 3 has an excellent effect.

[0006]

In the golf shaft of the present invention, if attention is paid to the intermediate layer of the coating layer, boron fiber, carbon fiber, and aramid fiber (Kevlar (registered trademark)) are sequentially placed on the shaft center of the shaft from the grip of the club. Because it covers
There are two joining and switching points for the three materials, and the degree of flexing, strength, and elasticity differs depending on the material. Therefore, the two joining points form two kick points when hit.

Further, all the characteristics of each material are appropriately provided. Boron fiber is lighter than aluminum and has both excellent strength and rigidity. In addition, since the boron fiber is a metallic fiber using ultrafine tungsten for the core wire, it has excellent vibration transmission properties. Therefore, at the time of impact, a powerful shot feeling close to steel can be fully enjoyed. In addition, when hitting, the part immediately below the grip receives the most impact, but by arranging a strong compressive boron fiber at that point, it withstands the impact received at impact and absorbs the impact and conveys numbness to the hand It also protects the surrounding graphite fibers and helps prevent club damage.

Next, the carbon fiber has a specific gravity of 1.7 to 1.
8, which is several times as rigid as glass fiber. High tensile strength, small deflection, high rigidity,
It is a fiber that can be made highly elastic. Finally, aramid fibers have high specific strength and specific elastic modulus, and have many properties such as thermal stability, dimensional stability, fatigue resistance, and excellent vibration absorption ability. If high-strength carbon fibers are used for the outermost layer, it is possible to prevent the club from breaking. In addition, by using a highly elastic carbon fiber for the shaft core, torque (rotational force) can be suppressed low.

[0009]

【Example】

Embodiment 1 An embodiment of a club shaft according to the present invention will be described with reference to the drawings. FIG. 1 is a front view of a club shaft main body of the present invention. Club is grip 2 and head 3
And a shaft 1 for connecting the two. FIG.
FIG. 3 is an exploded view of a shaft forming covering member. (A) shows a mandrel 5 which becomes a mold of a hollow portion when molding a club shaft. (B) is, for example, HM40 which covers the mandrel 5
Sheet-like high-elasticity carbon fibers 6 such as (c)
(D) shows a sheet-like aramid fiber 7 and a sheet-like boron fiber 8 which further cover the carbon fiber (b), and (e) shows a sheet-like carbon fiber 9 which further forms an outer layer thereof. ing. In the usual way, the mandrel 5 is extended over the entire length of the shaft (about 1118 mm),
6, high elastic carbon fiber (AP 45 °), then the grip 2 side is covered with boron fiber 8 and the head side is covered with arasidic fiber 7, and the whole is further covered with high strength carbon fiber 9 (SP
0 °) to complete the club shaft of the present invention.
At this time, the shape of the reinforcing sheet is such that the grip side and the head side are covered with the covering member over the entire outer periphery, and the leading ends 7a8a are such that the covering area decreases toward the center.
Is preferred.

The aramid fiber sheet 7 and the boron fiber sheet 8 of the covering member are wound around the inner layer carbon fiber, and the covering state is indicated by a dotted line in FIG.
At this time, X and Y around the leading end 7a8a of each sheet are kick points (bending points). The kick point automatically moves according to the head speed. It has the function of an automatic kick point.

FIGS. 3A and 3B are sectional views of the thus formed club shaft of the present invention taken along line AA and BB in FIG. As is apparent from the above manufacturing method and the drawings, the head side is formed of aramid fiber and the grip side is formed of boron fiber in the intermediate layer of the three-layer coating layer of the shaft. The results of measuring the vibration amplitude using the club shaft thus formed are shown in FIGS.
(D). (A) is a steel shaft, which shows that the vibration amplitude of the shaft at the time of impact is large. (B) is a metal carbon shaft, whose vibration amplitude is slightly smaller and improved than that of a steel shaft. (C) is the vibration amplitude of the conventional carbon shaft.

As is apparent from the results, the club shaft (d) of the present invention has a significantly smaller vibration amplitude than the conventional club shafts (a) to (c). This is because aramid fiber is a material originally used for bulletproof garments, which has excellent vibration proofing and can absorb instantaneous powerful shocks.

It is generally said that a moment of impact receives a shock of one ton, but the material absorbs a small amount of shock and transmits to the hand, so that the hand is completely numb.
It is absorbed instantly as shown in FIG. Then, the impact force is transmitted to the club shaft without waste, and it is understood that the club shaft has excellent flight distance, directionality, and shot feeling.

[0014]

As described above, according to the club shaft of the present invention, the shaft intermediate coating layer is composed of three materials, and two kick points are formed at the switching points of these materials, so that the swing of the player can be improved. According to the present invention, it is possible to provide a flexural rigidity and a flexural characteristic which are low in torque, have a very long flight distance, and have good directivity.

[Brief description of the drawings]

FIG. 1 is a front view of a club shaft showing one embodiment of the present invention.

FIG. 2 is an exploded development view of each covering member of the club shaft in one embodiment of the present invention.

FIG. 3 is a sectional view taken along line AA and a line BB in FIG. 1;

FIG. 4 is a comparison diagram of vibration amplitude between a conventional club shaft and a club shaft of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Club shaft 2 Grip 3 Head 6 Carbon fiber 7 Arashid fiber 8 Boron fiber

Claims (1)

(57) [Claims] 1. A boron fibers toward the center portion from the grip side to the shaft axis made of a high modulus carbon fiber, toward the center portion from the head-side coated reinforced with aramid fibers, the
Reinforcement ratio is the surface covered with boron fiber in the total outer surface area of the shaft core.
Area and the area without the coating reinforcing member
A golf club shaft having a covering area ratio of 5: 4: 3 and an outer layer covered with high-strength carbon fibers over the entire length of the shaft.