Golf clubs and weight adjustment components

Abstract

To provide a golf club and weight adjustment mechanism that allow for easy adjustment of the shaft's subtle weight balance. [Solution] The golf club 1 comprises a head 7, a shaft 5, and a grip 9. The shaft 5 is hollow with open ends and has a taper 5A formed on its inner surface. A weight adjustment body 10 is detachably press-fitted and fixed to the inner surface 5a of the shaft 5.

Description

Technical Field

[0001] The present invention relates to a golf club having a shaft with adjustable weight balance and a weight adjustment body.

Background Art

[0002] A golf club includes a head and a shaft, and a configuration in which a weight member is attached to the shaft to enable adjustment of the club balance is known. For example, Patent Document 1 discloses a configuration in which a cover made of a rubber-like elastic body covering a weight is attached to the grip end of the shaft on the grip side of the shaft. Further, for example, Patent Document 2 discloses a configuration in which a weight member is adhered to a predetermined position of a hollow shaft body. The weight member is fixed to the inner surface of the shaft by winding a cotton cloth agent impregnated with an adhesive.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since the golf club disclosed in Patent Document 1 described above has a structure in which the weight member is fixed only to one end side (grip end) of the shaft, delicate adjustment cannot be performed. Further, since the golf club disclosed in Patent Document 2 described above requires an adhesive for adhesion to the inner surface of the shaft, the attachment and detachment work is not easy.

[0005] An object of the present invention is to provide a golf club capable of easily adjusting a delicate weight balance (club balance) of a shaft and a weight adjustment body attached to the shaft.

Means for Solving the Problems

[0006] The golf club of the present invention comprises a head, a shaft, and a grip, wherein the shaft is hollow with open ends and has a tapered inner surface, and a weight adjustment body is detachably press-fitted and fixed to the inner surface of the shaft.

[0007] In the golf club with the above configuration, the weight adjustment element is removably press-fitted and fixed to the taper on the inner surface of the shaft. This allows the weight adjustment element to be positioned at any desired location according to the taper on the inner surface of the shaft, making it possible to finely adjust the weight balance of the shaft (hereinafter referred to as club balance). Furthermore, since the weight adjustment element is press-fitted and fixed to the inner surface of the shaft without the use of adhesive, it can be easily attached and detached.

[0008] Furthermore, the present invention provides a weight adjustment body that is press-fitted and fixed to the inner surface of a golf club shaft, characterized in that the weight adjustment body comprises a weight and a weight holder having an outer surface that can be press-fitted and fixed to the taper on the inner surface of the shaft and housing the weight.

[0009] Since these weight adjustment components can be attached to and detached from the shaft of any golf club, it is possible to optimally adjust the club balance according to the user when purchasing a golf club, or after purchasing one. [Effects of the Invention]

[0010] According to the present invention, a golf club in which the subtle weight balance of the shaft can be easily adjusted, and a weight adjustment body that can easily perform such adjustments can be obtained. [Brief explanation of the drawing]

[0011] [Figure 1] This diagram shows one embodiment of a golf club (a 7-iron), and indicates the position where the weight adjustment element is installed. [Figure 2] A cross-sectional view showing one example of a weight adjustment body that is press-fitted and fixed to the inner surface of a shaft. [Figure 3] (a) is a diagram showing a first modified example of the weight adjustment body, (b) is a diagram showing a second modified example of the weight adjustment body, and (c) is a diagram showing a third modified example of the weight adjustment body. [Figure 4] (a) and (b) are diagrams showing a fourth modified example of the weight adjustment body, where (a) is a cross-sectional view along the axial direction and (b) is a cross-sectional view along line AA in Figure (a). (c) and (d) are diagrams showing a fifth modified example of the weight adjustment body, where (c) is a cross-sectional view along the axial direction and (d) is a cross-sectional view along line BB in Figure (c). [Figure 5] The diagram shows a weight holder containing a weight, where (a) is a diagram showing a first configuration example of the retaining part, (b) is a diagram showing a second configuration example of the retaining part, (c) is a diagram showing a third configuration example of the retaining part, (d) is a diagram showing a fourth configuration example of the retaining part, and (e) is a diagram showing a fifth configuration example of the retaining part. [Figure 6] (a) is a diagram showing a golf club with weight adjustment elements installed at the tip and grip ends of the shaft, (b) is a diagram showing a golf club with weight adjustment elements installed at two locations on the tip end of the shaft, (c) is a diagram showing a golf club with weight adjustment elements installed at two locations on the butt end of the shaft, and (d) is a diagram showing a golf club with weight adjustment elements installed at four locations on the shaft. [Figure 7] Figure 1 shows a table illustrating the relationship between the position of the weight adjustment element on the golf club and the club balance. [Figure 8] A diagram showing a sixth modified example of the weight adjustment body. [Figure 9] (a) is a diagram showing a seventh modified example of the weight adjustment body, and (b) is a diagram showing an eighth modified example of the weight adjustment body. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments of the golf club of the present invention will be described with reference to the attached drawings. In the embodiments described below, an iron-type golf club (7-iron) will be used as an example.

[0013] As shown in FIGS. 1 and 2, the golf club 1 includes a shaft 5 and a head 7. The head 7 is formed with a hosel 7a for fixing the tip side of the shaft 5. A grip 9 is fixed to the base side of the shaft 5.

[0014] The shaft 5 is hollow with both ends open, and a taper 5A that tapers toward the tip side is formed on the inner surface 5a. The shaft 5 may be a steel shaft or a shaft made of fiber-reinforced resin (FRP) as long as a taper is formed on the inner surface so that a weight adjustment body can be press-fitted and fixed. Also, both ends of the shaft 5 are closed by fixing the head 5 and the grip 9. A weight adjustment body 10 is detachably press-fitted and fixed to the inner surface 5a of the shaft 5.

[0015] In this embodiment, the weight adjustment bodies 10 are press-fitted and fixed at a plurality of locations (four locations in the embodiment) at different positions in the axial direction on the inner surface of the shaft 5. Regarding the number of the weight adjustment bodies 10 disposed, it may be one location on the inner surface of the shaft 5, but by installing them at a plurality of locations, as will be described later, it is possible to perform delicate balance adjustment. In particular, in this embodiment, by disposing them at four positions (substantially equally spaced) of 200 mm, 350 mm, 550 mm, and 800 mm from the tip edge of the shaft 5, the balance adjustment can be performed finely.

[0016] Specifically, as disclosed in Patent Document 1 described above, in the configuration of disposing a weight at the grip end, since the added weight and the balance are proportional, the adjustment is limited. That is, when a weight is placed at the grip end, the heavier the weight is, the heavier the club weight becomes, and the lighter the balance becomes. Generally, as the club weight increases, it becomes more difficult to swing, and as the balance becomes lighter, the club becomes easier to swing. Thus, since the contrary effects affect each other simultaneously, the adjustment is limited in the configuration of attaching a weight at one location at the end of the grip. In this embodiment, by changing the position and the number of the weights disposed, as will be described later, the range of club balance adjustment becomes wider.

[0017] The weight adjustment body 10 may be constructed as a single weight structure (single material), but considering ease of handling and press-fitting and fixing to the inner surface of the shaft, it is configured as shown in Figure 2. The configuration of the weight adjustment body in this embodiment will be described below. In Figure 2, a magnified example of the weight adjustment body installed at a position 200 mm from the tip edge of the shaft 5 is shown, but weight adjustment bodies installed at other positions have a similar configuration.

[0018] The weight adjustment body 10 comprises a weight 11 and a weight holder 13 that houses the weight 11 and has a taper 13A formed on its outer surface 13a which is press-fitted into the taper 5A on the inner surface 5a of the shaft 5. The weight 11 is made of a metallic material such as lead or nickel. The weight holder 13 is preferably made of an elastic material that is elastically deformable and has good weather resistance and chemical resistance, such as an elastic member such as resin or elastomer. The weight 11 can be integrated with the weight holder 13 by press-fitting it, but the weight holder 13 can also be integrally formed with the weight 11 by insert molding or the like. When the two are integrated, the weight adjustment body 10 is formed, and the overall shape is approximately a frustoconical shape.

[0019] In this case, it is preferable to form an upper wall portion 13b and a lower wall portion 13c (retaining portion) perpendicular to the axial direction on the tip side and base side of the weight holder 13, respectively, so that the weight 11 does not come out of the weight holder 13.

[0020] The weight adjustment body 10 is press-fitted and fixed to the taper 5A formed on the inner surface 5a of the shaft 5. Press-fitting and fixing here means inserting the weight adjustment body 10 from the opening at the base of the shaft 5 and fixing it in the predetermined position, specifically, a state of fixation such that it will not come off even if the base of the shaft 5 is struck against the ground or the like and subjected to impact. For this reason, the taper 13A on the outer surface 13a of the weight holder 13 is set to be the same as the taper 5A of the shaft 5 so that it can make a tight fit when the weight holder 13 is pressed in, and the fixing position can be specified by changing the outer diameter D of the tip.

[0021] Furthermore, regarding the weight holder 13, if it is too soft, the weight 11 will easily come off, and if it is too hard, it will not make close contact with the taper 5A of the shaft 5. Therefore, it is preferable that the hardness of the weight holder 13 be in the range of Shore A hardness 30 to 100. By making it this hard, when it makes close contact with the inner surface 5a of the shaft 5, it is possible to prevent slippage or detachment and prevent the generation of abnormal noise. Since the hard metal weight 11 is tightly housed inside the soft weight holder 13, when the weight holder 13 is pushed in the axial direction, the weight holder 13 deforms due to the reaction force acting on the weight holder 13 from the inner surface 5a of the shaft 5. At that time, the presence of the hard weight 11 inside the weight holder 13 suppresses the deformation of the weight holder 13, and the weight holder 13 can be more firmly fixed in the predetermined position on the inner surface 5a of the shaft 5. Therefore, it is preferable that the weight 11, which is made of a metal material, has its sides covered by the weight holder 13.

[0022] Furthermore, the axial length L of the weight holder 13 should be approximately 10 to 60 mm to ensure a sufficient contact area, and its wall thickness should be approximately 0.8 to 2.0 mm to prevent it from coming loose and to avoid generating noise. In this case, it is preferable that the wall thickness of the side wall 13B having the outer surface 13a be tapered, with the tip being thinner than the base. This structure makes it possible to use a cylindrical weight 11 regardless of the taper of the inner surface of the shaft 5.

[0023] The weight adjustment body 10 described above can be inserted through the opening at the base of the shaft 5 and pressed into place using a jig (not shown) to fix it in place. To remove the press-fitted weight adjustment body 10, a jig can be inserted through the opening at the tip of the shaft 5 and pushed out towards the opening at the base of the shaft 5, or a jig can be inserted through the opening at the base of the shaft 5 and hooked onto the weight adjustment body 10 to pull it out.

[0024] The weight adjustment body can be deformed, for example, as shown in Figures 3(a) to 3(c). Examples of modified weight adjustment bodies are given below. In the following drawings, components similar to those in Figure 2 are given the same reference numerals, and detailed explanations are omitted.

[0025] The weight 11A shown in Figure 3(a) is configured as a cylindrical shape with a through hole 11a formed in the axial direction. With this configuration, it is possible to reduce the weight of the weight 11A without changing the shape of the weight holder 13. In addition, a jig can be inserted into the through hole 11a, making the extraction work easier.

[0026] The weight 11B shown in Figure 3(b) is configured in the same way as in Figure 3(a), with a cylindrical shape having a through hole 11a formed in the axial direction, and an internal thread 11b formed on its inner surface. With this configuration, a jig with an internal thread formed on the internal thread 11b can be screwed onto it to press-fit and fix the weight adjustment body 10 in a predetermined position, or to pull it out, thus making attachment and detachment operations easy.

[0027] The weight holder 13C of the weight adjustment body shown in Figure 3(c) does not have a tapered outer surface, but rather has a stepped shape 13e that narrows in diameter towards the tip. Thus, the outer surface of the weight holder 13 may not be in close contact with the inner surface of the shaft, but rather may be in point contact at multiple corners 13e' and fixed by press-fitting. With such a configuration, the contact force when press-fitting can be weakened, and the weight adjustment body 10 can be easily removed.

[0028] Figures 4(a) and 4(b) show a fourth modified example of the weight adjustment body, where (a) is a cross-sectional view along the axial direction and (b) is a cross-sectional view along line AA in Figure (a). In this embodiment, the weight holder 13D of the weight adjustment body has an outer layer 13f integrally formed on the radially outer side of the outer surface 13a, having a taper similar to that of the taper 13A, and a plurality of grooves 13f' are formed in the outer layer 13f, extending axially at approximately equal intervals over 360°.

[0029] This groove 13f' functions as a passage for air to flow back to the base of the shaft when the weight adjustment body is pressed into the shaft from the base to the tip, thus making the press-fitting operation of the weight adjustment body easier.

[0030] Figures 4(c) and 4(d) show a fifth modified example of the weight adjustment body, where (a) is a cross-sectional view along the axial direction and (b) is a cross-sectional view along line BB in Figure (a). In this embodiment, the weight holder 13E of the weight adjustment body has a projection 13g formed on the tip side of the outer surface 13a over a 360° range, and the weight holder 13E is press-fitted and fixed by making contact at two points: the projection 13g and the corner portion 13a' on the base side of the outer surface 13a. With this configuration, the contact force when press-fitted can be weakened, making it easier to remove the weight adjustment body. can.

[0031] Figure 5 shows a weight holder 13 containing a weight 11, and illustrates an embodiment in which a retaining portion 20 is formed on at least one of the weight 11 and the weight holder 13 to prevent the weight 11 from coming out of the weight holder 13.

[0032] As illustrated in Figures 5(a) to (d), the retaining portion 20 can be constructed by forming one or more protrusions 11c and / or recesses 11d on the outer circumferential surface of the weight 11 over a 360° range, and forming one or more recesses 13h and / or protrusions 13i on the corresponding positions of the weight holder 13 over a 360° range, and then fitting the two together. Such a configuration can be created by forming the protrusions 11c and / or recesses 11d on the weight 11 and then insert molding the weight holder 13.

[0033] Furthermore, by forming the retaining portion 20 in this manner, the weight 11 will not come out of the weight holder 13. Therefore, as shown in Figure 5(e), the weight 11 may protrude axially from the weight holder 13.

[0034] Next, with reference to Figures 6 and 7, the placement position of the weight adjustment body 10 described above, and the resulting state of the club balance, will be explained for the golf club of this embodiment.

[0035] As described above, in this embodiment, the weight adjustment bodies 10 are intended to be installed at four locations spaced apart in the axial direction of the shaft 5 (200 mm, 350 mm, 550 mm, and 800 mm from the tip edge of the shaft). The placement position, number, and weight of the weight adjustment bodies 10 can be appropriately changed depending on the type of club, the length of the shaft, etc. Below, an example of the placement state of the weight adjustment bodies 10 and the club balance will be described.

[0036] As shown in Figure 6(a), by placing weight adjustment elements 10 at 200mm and 800mm (on both sides) from the tip edge of the shaft 5, a counterbalancing effect is created, allowing the golf club to be swung through easily. Also, as shown in Figure 6(b), by placing weight adjustment elements 10 at 200mm and 350mm from the tip edge of the shaft 5, the weight is shifted to the tip, allowing for a smooth and relaxed swing. Furthermore, as shown in Figure 6(c), by placing weight adjustment elements 10 at 500mm and 850mm from the tip edge of the shaft 5, the weight is shifted to the butt, allowing for a firm and rigid feel and a speedy swing. Finally, as shown in Figure 6(d), by placing weight adjustment elements 10 at all positions, the club can be swung through with a stable motion while still feeling the weight.

[0037] In this type of adjustment, making the tip of the golf club shaft heavier results in a heavier club balance, a slower return of the shaft's flex, a slower swing tempo, and a feeling of "scooping" the ball (using the shaft's flex to scoop it from below). Furthermore, the ball flight tends to be more of a draw. Such a shaft balance is suitable for golfers with slower swing speeds.

[0038] Furthermore, making the butt end of a golf club shaft heavier results in a lighter club balance, a firmer flex, a faster swing tempo, and a better feeling of hitting the ball. It also tends to produce a fade shot. Such a shaft balance is suitable for golfers with high swing speeds.

[0039] In fact, the results of measuring the club balance when the weight adjustment body 10 described above is placed at one or more of the four locations on the shaft 5 will be explained with reference to Figure 7. The club used was a 7-iron with a shaft length of 902 mm and a shaft weight of 70 g, and one weight The weight of adjustment unit 10 was set to 5g. Club balance was measured using a high-performance swing balancer from Sanko Seikojo. The table in Figure 7 shows the measurement results for 16 shafts: shaft No. 1 (no weight adjustment element), shafts No. 2 to No. 15 (with a weight adjustment element installed in one or more locations), and shaft No. 16 (with a weight adjustment element installed in all locations).

[0040] As shown in the table in Figure 7, depending on how the weight adjustment elements 10 are arranged for shafts No. 2, No. 7, and No. 13, the club balance can be kept approximately constant while only the weight is changed. Furthermore, depending on how the weight adjustment elements 10 are arranged for shafts No. 3, No. 4, and No. 5, the club balance can be changed while the added weight remains constant (5g). In addition, depending on how the weight adjustment elements 10 are arranged for shafts No. 8, No. 9, and No. 10, the weight distribution can be changed while keeping the club balance approximately constant and the added weight constant (10g).

[0041] In this way, by press-fitting and fixing the weight adjustment body 10 to the taper on the inner surface of the shaft 5 in a detachable manner, the weight adjustment body can be positioned at any desired location according to the taper on the inner surface of the shaft, making it possible to finely adjust the club balance and swing feel. Furthermore, since the weight adjustment body 10 is press-fitted to the inner surface of the shaft without the use of adhesive, attachment and detachment work can be easily performed.

[0042] In particular, since the weight adjustment body 10 can be easily press-fitted and fixed to the inner surface of the shaft 5 at multiple different positions in the axial direction, it becomes possible to finely adjust the club balance. Furthermore, positions other than those in the above-described embodiment, as well as the weight of the weight adjustment body 10, can be set as appropriate, allowing the user to make finer and wider adjustments.

[0043] In the embodiment described above, the weight adjustment body 10 is composed of a weight 11 and a weight holder 13, but it is also possible to construct it as a single weight structure (single material). For example, in the weight adjustment body shown in Figure 8 (sixth modified example), the weight adjustment body 50 itself is composed of a weight 51 that is directly press-fitted and fixed to the taper 5A on the inner surface 5a of the shaft 5.

[0044] The weights 51 that make up such a weight adjustment body 50 can be made of a resin material in which metal powder is mixed in, for example, with elastomer as the main material. Specifically, the main material can be silicone rubber (1.0 g / cm³). 3 ) and here, stainless steel (7.8 g / cm³) is used as the compounding material, which is a metal powder. 3 It can be molded by kneading (the density after kneading is preferably 1.2 to 3.0). Alternatively, the main material can be urethane rubber (1.1 g / cm³). 3 ) and here, as the compounding material which is a metal powder, tungsten alloy (18 g / cm³) 3 ) can be kneaded and molded (the density after kneading is preferably 1.4 to 6.0). Thus, the weight adjustment body can be constructed from a single material, rather than being held in a weight holder as described above, and can be directly press-fitted and fixed to the tapered inner surface of the shaft.

[0045] Figure 9(a) shows a seventh modified example of the weight adjustment body. In this modified example, the weight 51 of the weight adjustment body 50 is made of a single material, similar to the configuration shown in Figure 8, and has a stepped 51e on its outer surface that narrows in diameter towards the tip, similar to the configuration shown in Figure 3(c). Thus, the outer surface of the weight 51 may be fixed by press-fitting, not by making full contact with the inner surface of the shaft, but by making point contact at multiple corners 51e'.

[0046] Figure 9(b) shows an eighth modified example of the weight adjustment body. In this modified example, the weight 51 of the weight adjustment body 50 is made of a single material, similar to the configuration shown in Figure 8, and protrusions 51g are formed on the front and base ends of its outer surface, extending 360°. These two protrusions 51g make point contact with the inner surface 5a of the shaft 5, causing the weight adjustment body 50 to be press-fitted and fixed to the inner surface of the shaft. Thus, the outer surface of the weight 51 may have a structure in which multiple protrusions 51g are formed so that it is press-fitted and fixed to the inner surface of the shaft at multiple points.

[0047] Although embodiments of the present invention have been described above, the present invention can be applied not only to iron clubs but also to wood-type golf clubs and putters. Furthermore, while the weight adjustment body may be provided as a weight on its own, as described above, providing it in a weight holder improves ease of attachment and detachment. In addition, the shape of the weight and weight holder can be modified as appropriate. [Explanation of Symbols]

[0048] 1 Golf Club 5 shafts 7 heads 9 Grips 10,50 Weight adjustment body 11,11A,11B weight 13, 13C, 13D, 13E Weight holder 20 Retaining part

Claims

1. In a golf club, which consists of a head, shaft, and grip, The aforementioned shaft is hollow with both ends open and has a tapered inner surface. A golf club characterized in that a weight adjustment body is detachably press-fitted and fixed to the inner surface of the shaft.

2. The golf club according to claim 1, characterized in that the weight adjustment body is made of a single material.

3. The golf club according to claim 2, characterized in that the single material is mainly an elastomer, and is formed by mixing a metal powder compound therein.

4. The golf club according to claim 1, characterized in that the weight adjustment body comprises a weight and a weight holder having an outer surface that is press-fitted into the taper on the inner surface of the shaft and housing the weight.

5. The golf club according to claim 4, characterized in that the weight holder is formed of an elastic material, and the thickness of the side wall having the outer surface is tapered, with the tip side being thinner than the base side.

6. The golf club according to claim 4, characterized in that the weight is made of a metal material and its sides are covered by the weight holder.

7. The golf club according to claim 1, characterized in that the weight adjustment body has a passage formed therein that allows air inside the shaft to circulate towards the base when it is pressed in from the base to the tip of the shaft.

8. The golf club according to claim 1, characterized in that the weight adjustment body is press-fitted and fixed to the inner surface of the shaft at multiple or more different positions in the axial direction.

9. A weight adjustment body that is press-fitted and fixed to the inner surface of a golf club shaft, A weight adjustment body characterized by comprising a weight and a weight holder having an outer surface that can be press-fitted and fixed into the tapered inner surface of the shaft, and which houses the weight.

10. The aforementioned weight holder is made of an elastic material, The weight adjustment body according to claim 9, characterized in that at least one of the weight holder and the weight has a retaining portion formed therein to prevent the weight from coming out in the axial direction of the shaft.

11. The weight holder is characterized in that the weight adjuster according to claim 9 has a tapered shape in which the thickness of the side wall having an outer surface that is press-fitted into the inner surface of the shaft is thinner at the tip end than at the base end.

12. A weight adjustment body that is press-fitted and fixed into the taper on the inner surface of a golf club shaft, A weight-adjusting body characterized by being formed by mixing an elastomer as the main material with a metal powder compounding agent.

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