JPH07185048A - Golf club - Google Patents

Abstract

(57) [Abstract] [Purpose] In a golf club, the impact resistance of the joint portion between the shaft and the head is improved, and the risk of breakage of the end portion to which the shaft is connected is reduced. The shaft mounting zone (3) comprises at least one first part (30) in which a static connection is realized between the female part (10) and the male part (20), and said female part (3). 10) and at least one second part (31) in which at least one flexible and elastically deformable layered element (6) is inserted between the male part (20).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to improvements in golf clubs, and more particularly to golf clubs including vibration damping devices.

[0002]

BACKGROUND OF THE INVENTION Golf clubs are ball striking tools that generally consist of a metal or composite shaft and a head connected to the lower end of the shaft within a shaft mounting zone. Many means for fixing the head to the end of the shaft have already been developed. For example, US Patent No. 1
No. 818553 discloses that the end of a threaded shaft is screwed into a threaded hole in the neck of the head. Also, US Pat.
No. 27848 discloses that the end of a shaft covered with a winding of thread impregnated with an adhesive is fitted into a hole provided in a head.

Further, in US Pat. No. 5,163,682, the head is not provided with a hosel, but the hollow end of the shaft closed by a bush is inserted into a cylindrical through hole (bore through system) provided in the head. Has been done. Further, it is disclosed that the sleeve is maintained in a predetermined position by adhesion, and a plastic ring is adhered to the upper limit portion of the region where the shaft is penetrated.

[0004]

SUMMARY OF THE INVENTION In the above-mentioned conventional golf club, there is a problem that the joint between the shaft and the head is rapidly deteriorated by a slight difference due to the impact when the ball is hit and the repeated impact. there were. There is also a problem that the connecting end of the shaft is frequently damaged.
It should be noted that this phenomenon can frequently occur in the case of the hoselless head described in US Pat. No. 5,163,682.

Therefore, an analysis of the vibration phenomenon that occurs in the conventional golf club has revealed that the end portion of the shaft is the region in which the deformation energy is the largest in the vibration mode excited after impact. This vibration acts to break the joint between the shaft and the head and reduce the strength of the connecting end of the shaft. Based on experience, the vibration felt by the player causes discomfort when hitting a ball, which reduces the player's confidence in his or her tool. Therefore, it is important to damp this vibration.

Regarding damping of vibrations occurring in golf clubs, mention may be made of the applicant's British patent application No. 2259861 or Australian patent application No. 20964/92. In the former case, a damping device added on the structure of the shaft is proposed, and in the latter case, a damping device built in due to the structure of the shaft is proposed. These damping devices are placed at the nodes of vibration and provide great comfort for the player, but increase the strength of the joint between the shaft and the head and reduce the risk of breakage of the connecting end of the shaft. Does not contribute to. The present invention has been made based on the above circumstances. An object of the present invention is to provide a golf club which can improve impact resistance of a connecting portion between a shaft and a head and reduce a risk of breakage of a connecting end portion of the shaft as compared with a conventional golf club. .

[0007]

SUMMARY OF THE INVENTION The present invention is directed to improvements in golf clubs, and more particularly to golf clubs that include a vibration damping device, and the above-described object of the present invention is to provide a female portion and a male portion that define a shaft mounting zone. A golf club including a head and a shaft assembled together by interfitting the portions, wherein the shaft attachment zone has at least one first connection wherein a static coupling is realized between the female portion and the male portion. And at least one second part in which at least one flexible and elastically deformable layered element is inserted between said female part and said male part.

According to a more specific aspect, the female part is a hole reaching at least a part of the head and the male part is an end of the shaft. According to an advantageous aspect, the first part is in the lower part of the shaft mounting zone and the second part is in the upper part of the shaft mounting zone, and the first part and the second part are The shaft mounting zone between is provided with a space between the female and male portions. According to a particular aspect, the cross-sectional area of the hole is reduced within the first portion in relation to the second portion. Thus, a conventionally shaped shaft can be mounted on the head according to the invention. According to a different aspect, the cross-sectional area of the hole is substantially constant and the end of the shaft includes an enlarged portion at the lower portion of the shaft mounting zone.
In this case, the shape of the shaft is adapted for mounting on a conventional head. Preferably, the damping constant, which characterizes the vibration absorbing capacity of the viscoelastic material constituting the flexible element, is the maximum in the frequency range of 4 Hz to 200 Hz at 20 ° C. and is 0.6 or more.

[0009]

In the present invention, since the second portion is provided in the shaft mounting zone, the coupling strength and durability of the fitting portion can be effectively increased, and the player can be comforted based on experience. Therefore, it contributes to the damping of vibration. Further, the upper portion of the shaft mounting zone is a portion that receives the largest bending and torsional stress under normal conditions. The interposition of a flexible element at this location has the effect of absorbing most of the stress due to the deformation of the element, which contributes to effectively protecting the lower part of the shaft from any risk of breakage.

[0010]

1 is a plan view showing a first example of a golf club of the present invention. This golf club is face 1
1, a head 1 having a heel 12 and a toe 13 and a substantially conical shaft 2, and the lower end of the shaft 2 forming the male part 20 passes through a hole forming the female part 10 to form the head 1. Mounted within the heel 12 of the. Hole 1
0 is coaxially provided in the neck 4 of the head 1. The mutual fitting of the male part 20 and the female part 10 forms the shaft mounting zone 3. The shaft 2 extends upward along the axis OO ′ by a certain length, and the upper end 21 is covered with a grip 22.
Within the shaft mounting zone 3, the male portion 20 is typically joined to the female portion 10 by gluing, screwing, welding or the like. The shaft 2 and the head 1 are made of metal, plastic, composite material, or the like.

FIG. 2 is a partial sectional plan view showing a detailed example of the golf club of the present invention shown in FIG. 1, and FIG.
A sectional view and FIG. 4 are exploded partial sectional plan views thereof. The head 1 includes a neck 4 extending upward from the heel 12. The neck 4 is provided with a coaxial cylindrical bore 10 in which the lower end 20 of the tubular shaft 2 is mounted in the bore 10 over a length corresponding to the shaft mounting zone 3. This shaft mounting zone 3
The tip of the lower end portion 20 of the shaft 2 includes a first portion 30 which is integrated with the head 1 by a coupling means. The cross-sectional area of the tip of the lower end portion 20 of the shaft 2 substantially corresponds to the cross-sectional area of the hole 10 so that the first portion 30 can be fitted together, except for dimensional tolerances. This fit is
It may be an interference fit or there may be some play. In this example, the layers are bonded via the adhesive layer 5, and the layer thickness is within the range of 0.2 mm.

The shaft mounting zone 3 includes a second portion 31 in the upper portion adjacent to the first portion 30. An annular space 310 is provided in the second portion 31 between the inner surface of the hole 10 and the outer surface of the lower end portion 20 of the shaft 2. This annular space 310 is partially occupied by the flexible, elastically deformable element 6. This element 6 is tubular in shape and is composed of a layer of viscoelastic material. The thickness e of this element 6 is such that it is the annular space 3
When it is housed inside 10, it is 0.4 mm to 3 mm. The element 6 may be slightly prestressed in the thickness direction inside the annular space 310. Preferably, this element 6 is glued to the outer surface of the lower end 20 of the shaft 2 and the inner surface of the bore 10. This makes it possible to avoid vertical movement and rotational movement of the element 6 and also to avoid the annular space 3
It is possible to improve the absorbability of vibration in shear, compression and tension inside 10. The upper part of the neck 4 in the second part 31 acts as the damper's mandrel. The constituent material of element 6 has a Young's modulus E of 0.5 GPa or less and an attenuation constant of 0.6 or more at 20 ° C. and 4 Hz to 200 Hz. For example, "VITON GF" or "VA
Mention may be made of "M" type materials.

FIG. 5 is a partially sectional plan view showing a second example of the golf club of the present invention. The hole 10 penetrates the head 1. With such a structure, the neck is unnecessary. Therefore, the mass can be reduced, and the mass distribution of other parts of the head 1 can be made advantageous. The lower end 20 of the shaft 2 is inserted over the entire length of the hole 10. The element 6 has a tubular portion 61 which creates an interface between the bore 10 and the lower end 20 of the shaft 2 and an expanded portion 60 which covers the upper lip 110 of the bore 10 to improve hermeticity and finish.

FIG. 6 is a partially sectional plan view showing a third example of the golf club of the present invention, and FIG. 7 is an exploded partial sectional plan view thereof. The lower end portion 20 of the shaft 2 has an upper portion 2
It includes a lower portion 200 having an enlarged and partially cut-away cross section in relation to 10. The upper part 210 is
It is surrounded by an element 6 which can be assembled and glued before mounting in the head 1.

FIG. 8 is a partial sectional plan view showing a fourth example of the golf club of the present invention. Lower end 20 of shaft 2
The connection between the and the hole 10 of the head 1 is made by the bush 7 in the fitting part, which is the first part 30.
The bush 7 includes an internal hole 70 into which the tip of the lower end 20 of the shaft 2 is inserted and which is statically coupled. The bush 7 is integrated inside the hole 10 of the head 1. The bush 7 includes a shoulder 71 located in the counterbore 111 having a shape complementary to the hole 10 to facilitate positioning during installation.

FIG. 9 is a perspective view showing a fifth example of the golf club of the present invention, and FIG. 10 is a sectional view taken along the line BB '.
The neck 4 includes a plurality of slits 40, 41, 42, 43 extending longitudinally along the axis OO '. Each slit 40, 41, 42, 43 extends from the upper end of the neck 4 toward the heel 12 of the head 1 over a certain length. By making these slits 40, 41, 42, 43 it is possible to improve the effect of the core plate which the neck 4 plays in the damping device. The number of slits is 2
It is optional from books to six. The element 6 arranged between the lower end 20 of the shaft 2 and the neck 4 is continuous over the entire circumference of the shaft 2.

In each of the above-mentioned embodiments, the static connection between the hole of the head and the lower end of the shaft in the fitting part means all the connections between the two parts to be joined which do not allow any degree of freedom. Say. For example, gluing, screwing, welding, interference fitting, etc. or a combination of two or more thereof. Also, the second part, where the elements are, is located close to the part of the shaft that is the node of vibration. The vibration node is one point of the shaft, and the deformation of the shaft is the maximum there, so that the second portion is effective in damping the vibration.
The present invention is not limited to the above embodiment. For example, metal fittings may be mounted around the shaft mounting zone. The fitting is preferably secured to the shaft mounting zone with a plastic material, such as nylon, which has no vibration damping. This fitting has an aesthetic function and serves to cover the top of the shaft mounting zone.

[0018]

As described above, according to the golf club of the present invention, the impact resistance of the connecting portion between the shaft and the head is improved and the risk of breakage of the connecting end portion of the shaft is reduced as compared with the conventional golf club. Therefore, it is possible to make the play comfortable by damping the vibration, and to improve the player's confidence in his or her own tool.

[Brief description of drawings]

FIG. 1 is a plan view showing a first example of a golf club of the present invention.

FIG. 2 is a partial cross-sectional plan view showing a detailed example of the golf club of the present invention shown in FIG.

FIG. 3 is a sectional view taken along the line AA ′ of the golf club of the present invention shown in FIG.

4 is an exploded partial cross-sectional plan view of the golf club of the present invention shown in FIG.

FIG. 5 is a partial cross-sectional plan view showing a second example of the golf club of the present invention.

FIG. 6 is a partial cross-sectional plan view showing a third example of the golf club of the present invention.

7 is an exploded partial cross-sectional plan view of the golf club of the present invention shown in FIG.

FIG. 8 is a partial cross-sectional plan view showing a fourth example of the golf club of the present invention.

FIG. 9 is a perspective view showing a fifth example of the golf club of the present invention.

FIG. 10 is a BB ′ of the golf club of the present invention shown in FIG.
FIG.

[Explanation of symbols]

 1 Head 2 Shaft 3 Shaft Attachment Zone 4 Neck 6 Element 7 Bushing 10 Female Part (Hole) 11 Face 12 Heel 13 Toe 20 Male Part (Lower End of Shaft 2) 21 Upper End of Shaft 22 Grip 30 First Part 31 Second part 40, 41, 42, 43 Slit 60 Expansion part 61 Tubular part 70 Inner hole 110 Upper lip of hole 10 111 Counterbore 200 Lower part of lower end 20 of shaft 2 210 Lower end of shaft 2 Upper part 310 Annular space

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Vou Jean-Luc France 74170 Lumiley Rude La Courdy 39

Claims (9)

[Claims] 1. A golf club comprising a head (1) and a shaft (2) assembled together by mutual fitting of a female part (10) and a male part (20) constituting a shaft mounting zone (3). , In the shaft mounting zone (3) at least one first part (30) in which a static coupling is realized between the female part (10) and the male part (20); 10) and at least one second part (31) in which at least one flexible and elastically deformable layered element (6) is inserted between the male part (20). And a golf club. 2. The female part (10) is a hole reaching at least a part of the head (1), and the male part (2).
The golf club according to claim 1, wherein 0) is an end portion of the shaft (2). 3. The first portion (30) is in the lower portion of the shaft mounting zone (3) and the second portion (31) is in the upper portion of the shaft mounting zone (3). A space (31) between the female part (10) and the male part (20) in the shaft mounting zone (3).
0) are provided, and the element (6) is provided in the space (310).
The golf club according to claim 2, wherein the golf club is stored. 4. The cross-sectional area of the hole is such that the second portion (3
The golf club according to claim 3, wherein the golf club is reduced in size in the first portion (30) in relation to (1). 5. The method according to claim 3, wherein the cross-sectional area of the hole is substantially constant and the end of the shaft (2) includes an enlarged portion (200) in the lower portion of the shaft mounting zone (3). The listed golf club. 6. The thickness (e) of the element (6) is 0.4.
The golf club according to claim 1, 2, 3, 4, or 5, having a size of mm to 3 mm. 7. The damping constant of said element (6) at 20 ° C. is at least 0.6 in the frequency range of 4 Hz to 200 Hz, according to claim 1, 2, 3, 4, 5 or 6. Golf club. 8. Golf according to claim 2, 3, 4, 5, 6 or 7, wherein the head (1) is laterally extended by a neck (4) in which the hole is provided coaxially. club. 9. The static connection of the first part (30) comprises:
The golf club according to claim 2, 3, 4, 5, 6, 7 or 8, which is realized by bonding, screwing, welding or interference fitting or a combination of two or more thereof.