US20220023726A1

US20220023726A1 - Method for manufacturing golf club shaft

Info

Publication number: US20220023726A1
Application number: US17/381,322
Authority: US
Inventors: Yuma Yamamoto
Original assignee: Sumitomo Rubber Industries Ltd
Current assignee: Sumitomo Rubber Industries Ltd
Priority date: 2020-07-22
Filing date: 2021-07-21
Publication date: 2022-01-27
Also published as: JP2022021809A

Abstract

A method for manufacturing a golf club shaft comprises: a preparing step of preparing a shaft main body formed from a fiber reinforced resin; a mounting step of mounting a surface layer material on an outer peripheral surface of the shaft main body, wherein the surface layer material comprises a heat-shrinkable film base material and is provided with a display portion; and a fixing step of firmly fixing the surface layer material to the outer peripheral surface of the shaft main body by heat-shrinking the surface layer material.

Description

TECHNICAL FIELD

The present disclosure relates to a method for manufacturing a golf club shaft.

BACKGROUND ART

Generally, a golf club shaft formed from a fiber reinforced resin is manufactured through the following steps as disclosed in Patent Document 1 below, for example.
First, a prepreg, that is, a sheet of reinforcing fibers impregnated with a matrix resin, is cut into a predetermined shape (cutting step).
Next, the cut prepregs are wound around a mandrel as a core. Thereby, a wound body of the prepregs which are wound around the mandrel, is formed on the mandrel. (winding step)
Next, the wound body is heated to cure the matrix resin. Thereby, a hardened laminate body of the prepregs is obtained (curing step).
Next, the mandrel is pulled out from the hardened laminate body (removing step).
Next, the unevenness of the outer surface of the hardened laminate body is smoothed by polishing (polishing step), and then the polished outer surface of the hardened laminate body is coated with a paint to obtain the shaft (painting step).
Next, on the outer surface of the shaft, a portion for displaying a product name, a brand logo and the like, is formed by printing, transfer printing or the like.

Patent Document 1: Japanese Patent No. 6601583

SUMMARY OF THE DISCLOSURE

Problems to be Solved by the Disclosure

As explained above, the conventional manufacturing method requires many steps in order to manufacture a golf club shaft. Thus, improvement in the productivity has been desired.
The present disclosure was made in view of the above circumstances, and an object of the present disclosure is to provide a method for manufacturing a golf club shaft by which an improvement of the productivity is possible.
According to one aspect of the present disclosure, a method for manufacturing a golf club shaft comprises:
a preparing step of preparing a shaft main body formed from a fiber reinforced resin,
a mounting step of mounting a surface layer material on an outer peripheral surface of the shaft main body, wherein the surface layer material comprises a heat-shrinkable film base material and is provided with a display portion, and
a fixing step of firmly fixing the surface layer material to the outer peripheral surface of the shaft main body by heat-shrinking the surface layer material.

Effects of the Disclosure

According to the present disclosure, the productivity of the golf club shaft can be improved by adopting the above steps.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a shaft main body prepared in a first embodiment of the present disclosure.

FIG. 2 is a perspective view showing a front side of a surface layer material in the first embodiment.

FIG. 3 is an exploded perspective view of the surface layer material of FIG. 2 as viewed from the back side thereof.

FIG. 4 is a perspective view showing a state in which the surface layer material is mounted on the shaft main body.

FIG. 5 is a perspective view of a golf club shaft manufactured by the first embodiment.

FIG. 6 is a front view of a golf club comprising the golf club shaft.

FIG. 7 is a top view of the golf club shown in FIG. 6.

FIG. 8 is a perspective view of a modified example of the shaft main body.

FIG. 9 is a cross-sectional partial view thereof taken along the shaft axis.

FIG. 10 is a cross-sectional partial view showing a state in which the surface layer material is mounted on the modified example of the shaft main body.

FIG. 11 is a cross-sectional partial view showing a state in which the surface layer material is closely fixed to the modified example of the shaft main body.

FIGS. 12A, 12B and 12C are perspective views for explaining a method for manufacturing a golf club shaft according to a second embodiment of the present disclosure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present disclosure will now be described in detail in conjunction with accompanying drawings. The drawings may contain exaggerations and dimensional ratios different from the actual ratios in order to aid the understanding of the present disclosure. For the different embodiments, the same reference numerals are given to the same or common parts, and duplicate explanations are omitted. The specific configurations illustrated in the embodiments and the drawings are for understanding the present disclosure, and the present disclosure is not limited to such specific configurations.

First Embodiment

According to a first embodiment, a method for manufacturing a golf club shaft comprises a preparing step, a mounting step, and a fixing step, described as follows.
[Preparing step]
In the preparing step, a shaft main body 10 formed from a fiber reinforced resin is prepared.
FIG. 1 shows an example of the shaft main body 10, which is manufactured in the form of a pipe having a hollow therein and substantially tapered toward one of ends thereof.
The shaft main body 10 is prepared, for example, through the cutting step, winding step, curing step and removing step as explained in the “Background art’ section above.
That is, the shaft main body 10 is manufactured as a cured interim product of laminated prepregs (not shown).
As the fiber reinforced resin constituting the shaft main body 10, carbon fiber reinforced resin (cFRP) is preferably used. But, it is not to be limited thereto.
In the first embodiment, the polishing process as explained in the “Background art” section is eliminated. Therefore, at least a part (all in the this embodiment) of the outer peripheral surface 10 a of the shaft main body 10 is not polished, and the outer peripheral surface 10 a at least partially has an unpolished portion.
Further, in the first embodiment, the shaft main body 10 prepared in the preparing step is not subjected to the painting step as explained in the “Background art” section.
Therefore, at least a part (all in this embodiment) of the outer peripheral surface 10 a of the shaft main body 10 is not painted, and the outer peripheral surface 10 a at least partially has an unpainted portion.
[Mounting step]
In the mounting step, on the outer peripheral surface 10 a of the shaft main body 10 prepared in the preparing step, a surface layer material 20 comprising a heat-shrinkable film base material is mounted.
FIG. 2 shows an example of the surface layer material 20 which is formed in a tubular shape before being mounted on the shaft main body 10.
As shown in FIG. 3, the surface layer material 20 is formed in a tubular shape by overlap jointing both side edge portions 25 a of a strip of a film base material 25.
For example, in order for the overlap jointing, a solvent-based or urethane resin-based adhesive is used.
Therefore, the surface layer material 20 has a joint 22 in which the film base material 25 is overlap jointed.
The joint 22 extends in the longitudinal direction of the surface layer material 20 corresponding to the axial direction of the shaft main body 10.
In order that the shaft main body 10 can be inserted into the tubular surface layer material 20, the inner diameter of the tubular surface layer material 20 is preferably set to be slightly larger than the outer diameter of the shaft main body 10.

[Film Base Material]

As the film base material 25, various film materials may be used as far as they are heat shrinkable
For example, suitably used for the film base material 25 is a resin film composed of one kind alone or a mixture of two or more kinds selected from: polyester resins such as polyethylene terephthalate; polyolefin resins such as polyethylene and polypropylene; polystyrene resins such as a styrene-butadiene copolymer; and thermoplastic resins such as polyvinyl chloride.
Further, the following may be used as the film base material 25:

a laminated body composed of two or more kinds of resin films which are laminated; and
a composite material composed of a resin film and one of a non-woven fabric, a metal vapor deposition sheet, an expanded sheet and the like, which are laminated.

From the viewpoint of flexibility, elasticity and the like, suitably used as the film base material 25 are a polyethylene terephthalate-based resin film, and a polystyrene-based resin film. Incidentally, the film base material 25 may be transparent or colored.
The thickness of the film base material 25 is preferably 10 micrometers or more, more preferably 20 micrometers or more, still more preferably 30 micrometers or more, but preferably 100 micrometers or less, more preferably 80 micrometers or less, still more preferably 50 micrometers or less. But it is not to be limited thereto.

[Display Portion]

The surface layer material 20 is provided with a display portion 23 for displaying various information, e.g. the manufacturer name, trademark, flex of the golf club shaft and the like. The display portion 23 may include not only characters but also decorative patterns, figures, and the like. Such information and the like to be displayed in the display portion 23 are provided on either one of the surfaces of the film base material 25 by various techniques such as gravure printing and flexographic printing, for example.
It is preferable that the display portion 23 is formed at a position on the surface layer material 20 on the opposite side to the joint 22 as shown in FIG. 3.
In this example shown in FIG. 3, the display portion 23 is separated from the joint 22 by an angle of 180 degrees around the shaft axis.

[Mounting of Surface Layer Material on Shaft Main Body]

FIG. 4 shows a temporary assembly 30 of the shaft main body 10 and the surface layer material 20.
In the first embodiment, the temporary assembly 30 is obtained by inserting the shaft main body 10 into the hollow (or central hole) of the tubular surface layer material 20.
In another embodiment, the temporary assembly 30 can be obtained by winding a sheet of the surface layer material 20 around the outer peripheral surface 10 a of the shaft main body 10, and then jointing both side edge portions 25 a of the surface layer material 20 each other, into a tubular shape.
In the first embodiment, the surface layer material 20 has a length substantially equal to the overall length of the shaft main body 10.
In other embodiments, the surface layer material 20 can be shorter or longer than the overall length of the shaft main body 10, and the surface layer material 20 can be made up of a plurality of parts divided in the axial direction of the shaft main body 10.

[Fixing Step]

In the fixing step, the surface layer material 20 is closely fixed to the shaft main body 10 by heat-shrinking the surface layer material 20. This fixing step is performed, for example, by heating up the temporary assembly 30 to a predetermined temperature.
The heating can be performed in various ways, for example, such that the temporary assembly 30 is heated in a hot air chamber or a steam chamber adjusted to the predetermined temperature. Incidentally, the temperature is determined according to the material of the film base material 25.
For example, when the film base material 25 is made of PET, it is preferable that the temperature in the chamber is set in a range from about 160 to 180 degrees C.
The surface layer material 20 of the temporary assembly 30 heat-shrinks when heated, and firmly fixed to the outer peripheral surface 10 a of the shaft main body 10. And, the golf club shaft 1 as shown in FIG. 5 is manufactured.
Thus, this golf club shaft 1 includes the shaft main body 10 formed from the fiber reinforced resin, and the surface layer material 20 fixed to the outer peripheral surface 10 a of the shaft main body 10 and provided with the display portion 23.
As described above, by adopting the method of manufacturing a golf club shaft according to the first embodiment, it is possible to completely eliminate the polishing step and the painting step or simplify these steps if needed, therefore, the productivity of the golf club shaft 1 can be improved.
Further, in the first embodiment, the surface layer material 20 covers at least a part of the unpolished portion of the shaft main body 10.
In general, the surface of the shaft main body 10 formed from cured laminated prepregs is rough when not polished. In the first embodiment, in order to utilize such rough surface, the outer peripheral surface 10 a of the shaft main body 10 is provided with an unpolished portion. As a result, fine irregularities on the surface of the unpolished portion bite into the inner peripheral surface of the heat-shrieked surface layer material 20, and as a result, the displacement between the shaft main body 10 and the surface layer material 20 is effectively prevented.
From the above viewpoint, in the roughness curve of the outer peripheral surface 10 a of the shaft main body 10 measured along the axial direction, the ten-point average roughness (Rz jis) is preferably 3.0 micrometers or more, more preferably 4.0 micrometers or more, still more preferably 4.5 micrometers or more.

[Application to Golf Club]

FIG. 6 shows a front view of a golf club 100 manufactured by using the golf club shaft 1 shown in FIG. 5. FIG. 7 shows a top view of the golf club 100 shown in FIG. 6.
The golf club 100 can be manufactured by a golf club manufacturing method including a step of attaching a golf club head 40 to the golf club shaft 1 manufactured by the above manufacturing method.
The golf club 100 includes the golf club shaft 1, the golf club head 40 attached to the tip end of the golf club shaft 1, and a grip 50 attached to the butt end of the golf club shaft 1.
In FIG. 6, the golf club 100 is set in its reference state.
In the present specification, the reference state of a golf club is such that the golf club head 40 is placed on a horizontal plane HP so that score lines 42 formed on a club face 41 of the golf club head 40 become parallel with the horizontal plane HP, and the shaft axis (center line) CL of the golf club shaft 1 lies in a vertical plane (not shown) perpendicular to the horizontal plane HP.
The shaft main body 10 has a front side 10A and a back side 10B. The front side 10A is a part of the outer peripheral surface which is visible to a golfer when the golfer holds the golf club. The back side 10B is a part of the outer peripheral surface which is invisible to the golfer.
In the shaft main body 10 according to the first embodiment which is formed form the laminated prepregs, it may not be completely isotropic due to the presence of a spine or the like at which the prepregs overlap.
Such shaft main body 10 is managed to be used in a specific orientation when attached to the golf club head 40, therefore, the front side 10A and the back side 10B of the shaft main body 10 can be determined in advance of the assembling with the golf club head 40.
In the example of the shaft main body 10 shown in FIG. 1, a mark 10 b indicating the center of the front side 10A is provided. such mark 10 b is however, optional.
The front side 10A of the shaft main body 10 is defined as being located on a side “A” (shown in FIGS. 6 and 7) of a plane P which passes through the shaft axis (center line) CL and orthogonally to the above-mentioned vertical plane (not shown) perpendicular to the horizontal plane HP (namely, orthogonally to the paper surface of FIG. 6).
Therefore, the back side 10B of the shaft main body 10 is defined as being located on a side “B” of the plane P (as shown in FIGS. 6 and 7).
In the first embodiment, as shown in FIG. 6, the joint 22 of the surface layer material 20 is positioned on the back side 10B of the shaft main body 10. Thus, the joint 22 becomes out of sight when the golfer holds the golf club 100, therefore, the golf club shaft 1 can improve the appearance of the golf club 100.
On the other hand, the display portion 23 is positioned on the front side 10A at the opposite position to the joint 22 around the shaft axis, therefore, the display portion 23 which may impress the golfer when the golfer holds the golf club 100, can be put in the golfer's field of view (as shown in FIG. 7). This may improve the appearance of the golf club 100.

[Modification of Shaft Main Body]

FIG. 8 shows a modification of the shaft main body 10, and FIG. 9 is a cross-sectional partial view thereof taken along the shaft axis CL.
The shaft main body 10 in this example is a cured interim product obtained by curing the laminated prepregs similar to the above, but the outer peripheral surface 10 a of the shaft main body 10 is provided with a convex pattern 10 c extending spirally therearound.
After the above-mentioned winding step of winding the cut prepregs around a mandrel to form a wound body of the prepregs, the convex pattern 10 c is formed by spirally winding a wrapping tape (not shown) around the outer peripheral surface of the wound body while applying a tension (tape wrapping step), and then hardening the wound body together with the wrapping tape wound thereon. Then, the wrapping tape is removed. As a result, on the outer peripheral surface 10 a of the shaft main body 10, a mark of the spirally wound wrapping tape is remained. The mark is used as the convex pattern 10 c in this example.
Incidentally, the wrapping tape can prevent the prepregs from unwinding, which is useful to maintain the shape of the wound body.
As shown in FIG. 10, the surface layer material 20 is mounted on the shaft main body 10 shown in FIGS. 8 and 9 in the same way as described above (mounting step).
At this time, the surface layer material 20 is attached so as to cover at least a part of the convex pattern 10 c.
Thereby, a temporary assembly 30 of the shaft main body 10 and the surface layer material 20 mounted thereon, is obtained.
Next, the temporary assembly 30 is heated (fixing step). Thereby, the surface layer material 20 on the outside of the shaft main body 10 is heat-shrieked to closely fixed to the shaft main body 10.
By the above steps, the golf club shaft 1 as shown in FIG. 11 is manufactured, wherein the spirally extending convex pattern 10 c of the shaft main body 10 bites into the inner peripheral surface of the surface layer material 20, and as a result, the joint between the shaft main body 10 and the surface layer material 20 becomes stronger. This effectively prevents the displacement between the shaft main body 10 and the surface layer material 20.
Preferably, the protruding height h of the convex pattern 10 c is 20 micrometers or more, more preferably 25 micrometers or more. However, if the protruding height h becomes excessively large, there is a possibility that the surface layer material 20 is broken. From this point of view, the protruding height h is preferably 50 micrometers or less, more preferably 45 micrometers or less.

Second Embodiment

FIGS. 12A, 12B and 12C are perspective views illustrating a method for manufacturing a golf club shaft according to a second embodiment.
In the first embodiment, the shaft main body 10 is prepared as a cured interim product obtained by curing the laminated prepregs in the preparing step.
In the second embodiment, the shaft main body 10 is prepared as an uncured interim product obtained by laminating prepregs.
As shown in FIG. 12A, the shaft main body 10 is formed by winding prepregs 10P around the mandrel M as the metal core to form the uncured shaft main body 10 on the mandrel M, wherein the prepregs 10P are cut into predetermined shapes (preparing step).
Next, as shown in FIG. 12B, the surface layer material 20 is mounted on the uncured shaft main body 10 wound on the mandrel M (mounting step). Also in this example, the surface layer material 20 is formed into a tubular shape in advance, and the shaft main body 10 is inserted into the surface layer material 20 together with the mandrel M.
Thereby, a temporary assembly 30 in which the surface layer material 20 is mounted on the shaft main body 10 is obtained.
Next, the temporary assembly 30 is heated to a predetermined temperature in an oven or the like (fixing step). Thereby, the prepregs of the shaft main body 10 start to harden, and the surface layer material 20 start to heat-shrink. Accordingly, the surface layer material 20 is firmly fixed to the shaft main body 10.
with the above steps, the golf club shaft 1 is manufactured on the mandrel M as shown in FIG. 12C. In this embodiment, since the curing of the shaft main body 10 and the heat-shrinking of the surface layer material 20 are performed at the same time, it is possible to further improve the productivity of the golf club shaft 1.
Further, similarly to the wrapping tape, the surface layer material 20 can prevent the wound prepregs from loosening since the shaft main body 10 is held from the outside during curing. Thus, the shape of the shaft main body 10 is maintained.
While detailed description has been made of preferable embodiments of the present disclosure, the present disclosure is not limited to the illustrated embodiments, and the present disclosure can be embodied in various forms within the scope of the technical idea described in the claims.
Meanwhile, the manufacturing method according to the above-described first and second embodiments and modifications can provide the following golf club shafts and golf club:

EXAMPLE 1

The golf club shaft 1, which comprises the shaft main body 10 made from the fiber reinforced resin, and the surface layer material 20 closely fixed to the outer peripheral surface 10 a of the shaft main body 10 by the heat shrinkage of the surface layer material 20, and which is provided with the display portion 23;

EXAMPLE 2

The golf club shaft 1 of the above EXAMPLE 1, in which the shaft main body 10 is the cured laminated prepregs; at least a part of the outer peripheral surface 10 a has an unpolished portion; and the surface layer material 20 covers at least a part of the unpolished portion;

EXAMPLE 3

The golf club shaft 1 of the above EXAMPLE 1 or 2, in which the outer peripheral surface 10 a of the shaft main body 10 is provided with the spirally extending convex pattern 10 c, and the surface layer material 20 covers at least a part of the convex pattern 10 c;

EXAMPLE 4

The golf club shaft 1 of the above EXAMPLE 1, 2 or 3, in which the shaft main body 10 is not painted;

EXAMPLE 5

The golf club shaft 1 of the above EXAMPLE 1, 2, 3 or 4, in which the shaft main body 10 has the front side 10A visible to a golfer and the back side 10B invisible to the golfer when the golfer holds the golf club; the surface layer material 20 has the joint 22 extending in the axial direction of the shaft main body 10; and the joint 22 is located in the back side 10B of the shaft main body 10;

EXAMPLE 6

The golf club 100 which comprises the golf club shaft 1 of the above EXAMPLE 1, 2, 3, 4 or 5, and a golf club head 40 attached to the golf club shaft 1.

Statement of the Present Disclosure

The present disclosure is as follows:

Disclosure 1: A method for manufacturing a golf club shaft comprising:

a preparing step of preparing a shaft main body formed from a fiber reinforced resin,
a mounting step of mounting a surface layer material on an outer peripheral surface of the shaft main body, wherein the surface layer material comprises a heat-shrinkable film base material and is provided with a display portion, and
a fixing step of firmly fixing the surface layer material to the outer peripheral surface of the shaft main body by heat-shrinking the surface layer material.

Disclosure 2: The method for manufacturing a golf club shaft according to Disclosure 1, wherein the surface layer material is formed in a tubular shape prior to being mounted on the shaft main body.
Disclosure 3: The method for manufacturing a golf club shaft according to Disclosure 1 or 2, wherein the shaft main body is formed from cured laminated prepregs.
Disclosure 4: The method for manufacturing a golf club shaft according to Disclosure 3, wherein
at least a part of the outer peripheral surface of the shaft main body has an unpolished portion, and
in the mounting step, the surface layer material is mounted so as to cover at least a part of the unpolished portion.
Disclosure 5: The method for manufacturing a golf club shaft according to Disclosure 3 or 4, wherein
at least a part of the outer peripheral surface of the shaft main body has an unpainted portion, and
in the mounting step, the surface layer material is mounted so as to cover at least a part of the unpainted portion.
Disclosure 6: The method for manufacturing a golf club shaft according to any one of Disclosure 1 to 5, wherein the shaft main body has a front side visible to a golfer and a back side invisible to the golfer when the golfer holds the shaft, the surface layer material has a joint where the film base material is overlap jointed, and
in the mounting step, the surface layer material is mounted so that the joint is positioned on the back side of the shaft main body.
Disclosure 7: The method for manufacturing a golf club shaft according to any one of Disclosure 1 to 6, wherein the outer peripheral surface of the shaft main body is provided with a convex pattern extending spirally therearound, and
in the mounting step, the surface layer material is mounted so as to cover at least a part of the convex pattern.
Disclosure 8: The method for manufacturing a golf club shaft according to any one of Disclosure 1 to 7, wherein the thickness of the film base material is in a range from 10 to 100 micrometers.
Disclosure 9: The method for manufacturing a golf club shaft according to Disclosure 1 or 2, wherein the shaft main body is formed from uncured laminated prepregs.
Disclosure 10: A method for manufacturing a golf club comprises: a step of attaching a golf club head to the golf club shaft manufactured by the method according to any one of Disclosure 1 to 9.

DESCRIPTION OF THE REFERENCE SIGNS

1 golf club shaft
10 shaft main body
10A front side
10B back side
10 a outer peripheral surface
10 c convex pattern
20 surface layer material
22 joint
23 display portion
25 film base material
40 golf club head
100 golf club

Claims

1. A method for manufacturing a golf club shaft comprising:

a preparing step of preparing a shaft main body formed from a fiber reinforced resin,

a mounting step of mounting a surface layer material on an outer peripheral surface of the shaft main body, wherein the surface layer material comprises a heat-shrinkable film base material and is provided with a display portion, and

a fixing step of firmly fixing the surface layer material to the outer peripheral surface of the shaft main body by heat-shrinking the surface layer material.

2. The method for manufacturing a golf club shaft according to claim 1, wherein

the surface layer material is formed in a tubular shape prior to being mounted on the shaft main body.

3. The method for manufacturing a golf club shaft according to claim 1, wherein

the shaft main body is formed from cured laminated prepregs.

4. The method for manufacturing a golf club shaft according to claim 2, wherein

the shaft main body is formed from cured laminated prepregs.

5. The method for manufacturing a golf club shaft according to claim 3, wherein

at least a part of the outer peripheral surface of the shaft main body has an unpolished portion, and

in the mounting step, the surface layer material is mounted so as to cover at least a part of the unpolished portion.

6. The method for manufacturing a golf club shaft according to claim 4, wherein

7. The method for manufacturing a golf club shaft according to claim 3, wherein

at least a part of the outer peripheral surface of the shaft main body has an unpainted portion, and

in the mounting step, the surface layer material is mounted so as to cover at least a part of the unpainted portion.

8. The method for manufacturing a golf club shaft according to claim 4, wherein

9. The method for manufacturing a golf club shaft according to claim 5, wherein

10. The method for manufacturing a golf club shaft according to claim 6, wherein

11. The method for manufacturing a golf club shaft according to claim 1, wherein

the shaft main body has a front side visible to a golfer and a back side invisible to the golfer when the golfer holds the shaft,

the surface layer material has a joint where the film base material is overlap jointed, and

in the mounting step, the surface layer material is mounted so that the joint is positioned on the back side of the shaft main body.

12. The method for manufacturing a golf club shaft according to claim 1, wherein

the outer peripheral surface of the shaft main body is provided with a convex pattern extending spirally therearound, and

in the mounting step, the surface layer material is mounted so as to cover at least a part of the convex pattern.

13. The method for manufacturing a golf club shaft according to claim 2, wherein

14. The method for manufacturing a golf club shaft according to claim 3, wherein

15. The method for manufacturing a golf club shaft according to claim 5, wherein

16. The method for manufacturing a golf club shaft according to claim 7, wherein

17. The method for manufacturing a golf club shaft according to claim 1, wherein

the thickness of the film base material is in a range from 10 to 100 micrometers.

18. The method for manufacturing a golf club shaft according to claim 1, wherein

the shaft main body is formed from uncured laminated prepregs.

19. The method for manufacturing a golf club shaft according to claim 2, wherein

the shaft main body is formed from uncured laminated prepregs.

20. A method for manufacturing a golf club comprises:

a step of attaching a golf club head to the golf club shaft manufactured by the method according to claim 1.