Golf club shaft, golf club set, and golf putter shaft

Abstract

To provide a golf club shaft, a golf club set, and a golf putter shaft.SOLUTION: A golf wooden shaft has a hardness of 210-240 CPM (±5CPM), a tip end diameter of 8.4-9.4 mm, and a weight of 40-70 g (±3 g). When a torque is measured at a tip end of the shaft, it is adjusted to 8-6 degrees (±0.2deg), and a centroid point of the shaft is positioned at 55%-85% (±5 mm) from the tip end. If the centroid point of the shaft body and the grip body is displayed, a golf club with good swing centroid at hand can be manufactured using this shaft. This can provide a golf club that is friendly to not only a professional but also an amateur golfer.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a shaft for a golf club, a golf club set, and a shaft for a golf putter. [Background technology]

[0002] A number of golf clubs with different lengths are available depending on the driving distance. The center of gravity and spin effect of a golf club naturally change depending on the weight and center of gravity of the golf shaft itself, the weight and center of gravity of the grip and head, the stiffness of the shaft, and the torque. The conventional golf club disclosed in Patent Document 1 focuses on the center of gravity of the entire club, and does not indicate the center of gravity of the golf club shaft alone. The iron golf club shown in Patent Document 1 also focuses on the center of gravity, and the position of the center of gravity is set at 76.5% to 79.5% of the total length of the golf club, which is closer to the head side. When the center of gravity of the golf club shaft was actually measured, it was located closer to the head side in terms of the overall length of the shaft, except for the shorter ones in the range of 9 iron to 7 iron. Even for the shorter ones in the range of 9 iron to 7 iron, the center of gravity of the shaft was less than 60% from the head side at most.

[0003] In addition, a number of golf grips with different weights and lengths are available depending on the golf club.

[0004] FIG. 14 shows a conventional golf club grip. In a golf club grip 1 having a total length of 270 mm, the center of gravity G0 is located at a position 63% from the tip on the head side. In this way, the position of the center of gravity of the grip of a conventional golf club is 63% from the tip of the head, or a maximum of 60 to 65% including margin of error, because while it is formed from a uniform material, the shape of the grip is thicker toward the grip end. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2013-106839 A Summary of the Invention [Problem to be solved by the invention]

[0006] Regardless of the material, the center of gravity of golf clubs called irons and woods is located toward the head from the center of the club's overall length, except for short golf clubs. For advanced players, there are also golf clubs that intentionally have the center of gravity moved closer to the head by attaching weights to the golf shaft. In this way, if the position of the center of gravity is closer to the head side with respect to the overall length of the golf club, the golf club feels heavy when swung, making it difficult to control and repeat the swing. Except for professional golfers who have time to practice frequently, beginners and intermediate players find it difficult to hit accurate shots with longer golf clubs. For this reason, shorter irons in the 9 to 7 range are often used in iron sets, and longer irons below 6 are becoming less popular. Traditionally, it was not possible to adjust the center of gravity with the shaft of a golf club, so the sense of balance when swinging the golf club as a whole, specifically the numerical values ​​C5 to D5, was often used. In addition, the grip of a golf club is necessary not only to prevent slipping, but also to cushion the impact of the shaft when it is struck. The grip was only considered to cushion the impact and prevent slipping, and the position of the center of gravity was naturally determined by the material and shape, and there was no need to change it.

[0007] The center of gravity located closer to the head side from the center of the overall length is called the tip center of gravity, and the center of gravity located closer to the grip side from the center of the overall length is called the grip center of gravity.

[0008] To provide a golf club shaft, a golf club set, and a golf putter shaft that are easy to handle not only for beginners and intermediate players, but also for advanced players. [Means for solving the problem]

[0009] The golf club shaft of the present invention is a CFRP or GFRP golf club shaft having a main body weight of 50g to 140g and a total length of 36.5 inches or more, and is configured so that the position of the center of gravity in the longitudinal direction is located closer to the grip side from the center of the total length. In conventional golf clubs with a total length of 36.5 inches or more, the center of gravity is naturally located closer to the head side from the center of the total length. In the above configuration, the center of gravity in the length direction of the CFRP or GFRP golf club shaft is located closer to the grip side from the center of the total length. The conventional one is called the front center of gravity, and the one of the present invention is called the grip center of gravity.

[0010] Since the center of gravity is closer to the grip side than the center of the overall length, swing stability is improved, just like with golf clubs with an overall length of less than 36.5 inches. In another aspect of the present invention, the position of the center of gravity is within a range of 45 to 49% of the overall length from the grip side. In the above configuration, in order to improve the stability of the swing while keeping the center of gravity at the grip, the position of the center of gravity is set within a range of 45-49% of the total length from the grip side. Also, as a more preferable range for improving the stability, the position of the center of gravity may be set within a range of 46-49% of the total length from the grip side. Furthermore, as a more preferable range, the position of the center of gravity may be set within a range of 47-49% of the total length from the grip side.

[0011] In another embodiment of the present invention, the position of the center of gravity is adjusted at each predetermined portion in the length direction by using a resin or a metal with a large specific gravity that is impregnated into the blank tube. In the above configuration, in the case of a carbon shaft for a golf club with a main body weight of 50g to 140g and a total length of 36.5 inches or more, the center of gravity is naturally at the front according to conventional manufacturing methods. However, it is now possible to adjust the center of gravity position by adding a resin or a metal with a high specific gravity to be impregnated into the blank tube at predetermined positions in the length direction. In addition, since the center of gravity is adjusted by the impregnated prepreg, the shaft can maintain a perfect circle relative to the axis.

[0012] In another embodiment of the present invention, electroless plating is applied. In the above-mentioned structure, since the carbon shaft is made of bundled fibers, it is prone to twisting. However, by applying electroless plating to the surface, the shaft becomes less prone to twisting even though the inside is made of bundles of fibers.

[0013] In another embodiment of the present invention, the surface of the electroless plating is electroplated to form a double plating. In the above-mentioned structure, by applying electroless plating, it becomes possible to apply electroplating to the surface. The thickness can be easily increased by electroplating, and the core can take advantage of the light weight of the blank tube and can adjust the weight.

[0014] In another embodiment of the present invention, the electroplating is copper plating. In another aspect of the present invention, the electroplating is chrome plating.

[0015] In another aspect of the present invention, a golf club set includes a golf club formed with the shaft as described above. With the above configuration, the center of gravity of all golf clubs, from short to long, can be located near the grip, making the golf club set easy to swing. On the other hand, a carbon shaft for a golf club aimed at advanced players can be a CFRP or GFRP golf club shaft with a main body weight of 50g to 140g, and the position of the center of gravity in the longitudinal direction can be configured to be in the range of 43 to 49% of the total length from the tip side.

[0016] Also, in a CFRP or GFRP golf putter shaft, the surface of the underlying carbon shaft may be electrolessly plated, and electroplating may be added to the surface of that. The shaft is made of CFRP or GFRP, and the center of gravity and weight can be easily adjusted.

[0017] Furthermore, the shaft of the golf club of the present invention has a tip diameter of 8.4 to 9.4 mm, weighs 40 to 100 g (±3 g), and has the center of gravity located 55% to 85%, preferably 60% to 80% (±5 mm) from the tip. Since the position of the center of gravity is quite close to the grip side from the center of the overall length, by making the position of the center of gravity in the longitudinal direction within a range of 45 to 49% of the overall length from the grip side as in other embodiments, the stability of the swing is improved, but this club is still a little difficult for beginners and golfers with little strength to use. In another aspect of the present invention, the position of the center of gravity is within a range of 55% to 85%, preferably 60% to 80% (±5 mm) of the total length of the shaft body from the tip head side. However, by adjusting the position of the center of gravity and the kick point, it is possible to adjust the vertical position of the ball. As for the torque angle, for players with weak strength or those with a competitive oriented attitude, the torque angle range of 8 to 2 degrees makes it easier to adjust the left and right of the ball by using spin. In addition, the golf club shaft of another embodiment of the present invention has a tip diameter of 8.4 to 9.4 mm, weighs 40 to 100 g (±3 g), and has the center of gravity located 55% to 85% (±5 mm) from the tip. Furthermore, in the shaft of a wooden club according to another embodiment of the present invention, the hardness is 210 to 240 CPM (±5 cpm) and the weight is 40 to 70 g (±3 g). In addition, in the shaft of a wooden club according to another embodiment of the present invention, the hardness is 240 to 260 CPM (±5 cpm) and the weight is 50 to 80 g (±3 g). In addition, in the shaft of a wooden club according to another embodiment of the present invention, the hardness is 260 to 270 CPM (±5 cpm) and the weight is 60 to 100 g (±3 g). In addition, the shaft of the iron club according to another embodiment of the present invention has a hardness of 210 to 230 CPM (±5 cpm), a tip diameter of 9.4 mm, and a weight of 50 to 70 g (±3 g). In addition, the shaft of the iron club according to another embodiment of the present invention has a hardness of 220 to 240 CPM (±5 cpm), a tip diameter of 9.4 mm, and a weight of 60 to 90 g (±3 g). In addition, the shaft of the iron club according to another embodiment of the present invention has a hardness of 230 to 260 CPM (±5 cpm), a tip diameter of 9.4 mm, and a weight of 70 to 120 g (±3 g). In addition, a putter shaft according to another embodiment of the present invention has a tip diameter of 9.0 to 9.4 mm and a weight of 80 to 140 g (±3 g). In another embodiment of the present invention, the surface of the electroless plating is electroplated to form a double plating. In another aspect of the present invention, the electroplating is copper plating. In another aspect of the present invention, the electroplating is chromium plating. In still another embodiment of the present invention, the upper surface of the shaft is further subjected to ion plating. Furthermore, by adding a center of gravity on the grip side and two surface materials with different textures, it is possible to contribute to the sense of stability that differs from golfer to golfer.

[0018] In another aspect of the present invention, the position of the center of gravity is adjusted by adding glass to the resin with which the base tube is impregnated at predetermined positions in the length direction, and the position of the center of gravity is adjusted by adding a material with a high specific gravity, such as glass, to the resin with which the carbon fiber is impregnated at predetermined positions in the length direction. With conventional manufacturing methods, the center of gravity naturally begins near the center. However, by impregnating the blank tube with glass or heavy metal prepreg at specific locations along the length, the center of gravity can be adjusted. In addition, the shaft can be kept perfectly round relative to the axial core because it can be adjusted by the resin or metal used.

[0019] In another aspect of the present invention, a golf club set includes a golf club formed with the shaft as described above. With the above configuration, the center of gravity of all golf clubs, from short to long, can be located close to the grip, resulting in a golf club set that is easy to operate and swing. On the other hand, for the carbon shaft of a golf club aimed at advanced players, it is necessary to reinforce the shaft from near the center toward the head to make it stiffer.

[0020] The grip of the golf club of the present invention has a weight of 25 to 150 g and a center of gravity located within a range of 66 to 85% from the tip on the head side. In the above configuration, the grip weighs 25 to 150 g, and the center of gravity is located in the range of 66 to 85% from the tip on the head side. Therefore, compared to the 60% position of conventional grips, the center of gravity of a golf club using the golf grip of the present invention is located closer to the grip.

[0021] Furthermore, in the present invention, the main composition on the head side is different from the main composition on the end side. The position of the center of gravity can be changed by changing the material of the golf grip. Note that the material of the grip end is often different, so the material is changed at the part that comes into contact with the side of the golf shaft. The main composition of the head side is different from the main composition of the end side, and by making the main composition of the head side lighter and the main composition of the end side heavier, the position of the center of gravity can be changed. The change in material can also change the coefficient of friction of the surface, as described below. This also includes making the golf grip into separate parts for the head side and the grip end side. In this case, the center of gravity can be determined as an integrated part.

[0022] In addition, the present invention is configured such that the center of gravity is located within a range of 66 to 80% from the tip of the head side. Furthermore, the present invention is configured such that the coefficient of friction of the surface is smaller on the tip side in at least a range of up to 40% from the tip on the head side and in at least a range of up to 60% from the end side. The present invention is also configured such that the coefficient of friction of the surface is smaller on the tip side in at least a range up to 30% from the tip on the head side than in at least a range up to 70% from the end side.

[0023] Furthermore, the present invention is configured such that at least a maximum of 40% of the surface from the tip on the head side is made of leather or synthetic leather, and at least a maximum of 60% of the surface from the end side is made of rubber or silicone. In addition, the present invention is configured such that the leather or synthetic leather on the head side is lighter than the rubber or silicone on the end side. Furthermore, the present invention is configured so that the weight is 25 to 150 g, the grip has a center of gravity located in the range of 66 to 85% from the tip on the head side, and the center of gravity is located at a position more than 50% toward the grip side of the total length of the golf club. In this way, according to the present invention, the center of gravity of the grip alone can be shifted toward the grip end, and the center of gravity of the entire club can be shifted toward the grip end. Since the center of gravity of the golf club is closer to the grip, the operability and reproducibility when swinging the golf club are improved. On the other hand, if a counterbalance is attached, the center of gravity can be shifted toward the grip end, but this increases the weight of the entire club. In the present invention, the center of gravity is shifted toward the grip end without changing the weight of the grip alone. Effect of the Invention

[0024] According to the present invention, it is possible to provide a golf club shaft, a golf putter shaft, a golf club grip, and a golf club set that are easy to handle for beginners and intermediate players. [Brief description of the drawings]

[0025] [Figure 1] FIG. 2 is a diagram showing a swing and the position of the center of gravity of a shaft. [Diagram 2] FIG. 1 is a diagram showing a carbon shaft for an iron set according to one embodiment of the present invention. [Diagram 3] FIG. 1 is a diagram showing a carbon shaft for a conventional iron set. [Figure 4] FIG. 13 is a diagram showing a carbon shaft for an iron set according to another embodiment. [Diagram 5] FIG. 1 is a diagram showing a carbon shaft for a wood set according to one embodiment of the present invention. [Figure 6] FIG. 13 is a diagram showing a carbon shaft for an iron set with the center of gravity at the front. [Figure 7] FIG. 13 is a diagram showing a carbon shaft for a wood set according to another embodiment. [Figure 8] FIG. 2 is a diagram showing the configuration of a putter shaft. [Figure 9] 1 is a schematic diagram showing a grip of a golf club according to an embodiment of the present invention. [Figure 10] 1 is a schematic diagram showing a grip of a golf club according to an embodiment of the present invention. [Figure 11] 1 is a schematic diagram showing a grip of a golf club according to an embodiment of the present invention. [Figure 12] 1 is a schematic diagram showing a grip of a golf club according to an embodiment of the present invention. [Figure 13] FIG. 2 is a schematic diagram showing a golf club to which a golf club grip is applied. [Figure 14] FIG. 1 is a schematic diagram showing a conventional golf club grip. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a swing and the position of the center of gravity of a shaft, FIG. 2 shows a carbon shaft for an iron set according to one embodiment of the present invention, and FIG. 3 shows a carbon shaft for a conventional iron set. In the following, a golf club means a single club, a golf club set means a set including several iron or wood golf clubs, an iron set means a set including several iron golf clubs, and a wood set means a set including several wood golf clubs.

[0027] In sumo and golf, it is more important to stabilize the center of gravity (the position of the waist) than to increase body weight. In golf clubs, the change in the center of gravity rather than the weight of the shaft contributes to the stability of the swing, and is a very important factor. The inventor has confirmed from his experience in golf for over 50 years, particularly from data obtained from professional and competitive golfers, that the center of gravity near the grip is not only an important factor in the stability (operability) of the swing, but also the need to adjust the ball's spin, lateral deviation, and ease of catching the ball.

[0028] In the case of golf clubs, because the swing rotation motion creates complex movements, we confirmed that it is particularly meaningful to prioritize the stability (operability) of the shaft at the grip, which is an important part of the contact point between the golf club and the body, and the rhythm of the swing. In other words, we focused on the center of gravity of the shaft body, which has a strong effect on the operability of the golf club, and created it. In the present invention, in order to respond to the subtle sensitivities of individual golfers, attention is paid to the center of gravity rather than the weight or weightiness of the golf club shaft.

[0029] Figure 1 shows a simplified view of a golfer's swing planes P1 and P2. In the figure, G indicates the center of gravity, CD indicates the position of the shaft at the time of impact, and CU indicates the position of the shaft during the process of swinging it up. Since the center of gravity G is the central point when the shaft is pushed down by gravity, the distance from the grip during the swing has a large effect on maneuverability. It can be understood that the distance from the grip is experienced as the stability (maneuverability) of the shaft at the hand.

[0030] <First Example> FIG. 2 shows a carbon shaft for an iron set according to one embodiment of the present invention. It shows the total length, center position, center of gravity position, center of gravity position ratio, and distance from the center. The right side of the drawing is the head side, and the left side of the drawing is the grip side. Center of gravity G represents the length from the head side. Therefore, if center of gravity G is longer than the center, center of gravity G will be closer to the grip side, and will be the hand center of gravity. On the other hand, if center of gravity G is shorter than the center, center of gravity G will be closer to the head side, and will be the tip center of gravity.

[0031] In this embodiment, a carbon shaft (CFRP) is used as the shaft of the golf club as an example. The shaft with the center of gravity from the tip to the grip may be a GFRP shaft other than the carbon shaft. The center of gravity position ratio indicates the ratio of the distance from the grip side of the center of gravity G to the total length. The distance from the center indicates the distance between the center of gravity G and the center.

[0032] The carbon shafts are available in five different weights (90g, 100g, 110g, 120g, and 130g). These weights are generally found in golf clubs called iron sets. The weight of the carbon shaft can also be as low as 140g.

[0033] Total length (inches / cm) Center position Center of gravity position Center of gravity position ratio Distance from center Center of gravity classification 39.0 / 99.1 49.5cm 51.0cm 48.5% 1.5cm Center of gravity at hand 38.5 / 97.8 48.9cm 50.5cm 48.4% 1.6cm Center of gravity at hand 38.0 / 96.5 48.3cm 50.0cm 48.2% 1.7cm Center of gravity at grip 37.5 / 95.3 47.6cm 49.5cm 48.0% 1.9cm Center of gravity at hand 37.0 / 94.0 47.0cm 49.0cm 47.9% 2.0cm Center of gravity at hand 36.5 / 92.7 46.4cm 48.5cm 47.7% 2.1cm Center of gravity at grip

[0034] Average golfers are inexperienced in terms of both the amount of practice and sensibility. The center of gravity at the grip is the center of gravity that prioritizes operability. Therefore, it is desirable to design each club so that the center of gravity at the grip is located at this position.

[0035] In terms of whether the center of gravity is at the grip or at the tip, even in the carbon shaft of a relatively short golf club, which had the center of gravity at the grip according to conventional manufacturing methods, there is little deviation in the position ratio of the center of gravity from the carbon shaft of a longer golf club to the carbon shaft of a shorter golf club, and the distance from the grip end to the center of gravity position becomes shorter in proportion to the length, making it easier to operate.

[0036] In this way, the carbon shaft of the golf club has a total length of 36.5 inches or more, and the position of the center of gravity in the length direction is closer to the grip side than the center of the total length. In this embodiment, the main body weight is 90g to 130g, but this is for an iron set as described above. For a wood set to be described later, a lighter one is desired, so a main body weight of 50g to 90g was created.

[0037] Also, the position of the center of gravity is within a range of 47-49% of the total length from the grip side. In this embodiment, the weight is placed on stability and the range is set to 47-49%. However, from the viewpoint of yield, it is possible to widen the range while keeping the center of gravity at the grip side. Therefore, the position of the center of gravity can be set within a range of 46-49% of the total length from the grip side, or further, the position of the center of gravity can be set within a range of 45-49% of the total length from the grip side. If the range is widened in this way, the yield during manufacturing can be improved.

[0038] Figure 3 shows a conventional carbon shaft for an iron set. Conventionally, the shaft is woven with carbon material and is evenly impregnated with liquid resin, and then molded by applying a certain pressure in a mold. As shown in the figure, conventional carbon shafts for golf clubs with a total length of 36.5 inches or more have the center of gravity at the front. Carbon shafts for golf clubs with a total length of 36 inches or less have the center of gravity at the grip. This is the natural result of evenly impregnating the woven carbon shaft with liquid resin.

[0039] However, even with such a conventional position of the center of gravity G, professional golfers who are competitive have a lot of practice and a lot of sensitivity, so there is no particular need to change the position of the center of gravity G for each club. However, for average golfers, it has to be said that with the conventional carbon shafts with inconsistent center of gravity positions, it is difficult to achieve both distance and operability.

[0040] Total length (inches / cm) Center position Center of gravity position Center of gravity position ratio Distance from center Center of gravity classification 39.0 / 99.1 49.6cm 47.4cm 54.3% 3.0cm Tip center of gravity 38.5 / 97.8 48.7cm 46.7cm 53.0% 1.6cm Tip center of gravity 38.0 / 96.5 48.3cm 46.7cm 52.1% 1.0cm Tip center of gravity 37.5 / 95.3 47.6cm 46.6cm 51.7% 0.2cm Tip center of gravity 37.0 / 94.0 47.0cm 46.5cm 50.0% -0.5cm Tip center of gravity 36.5 / 92.7 46.4cm 46.0cm 49.7% -1.6cm Tip center of gravity

[0041] As shown in the figure, the center of gravity position ratio of the carbon shaft of a conventional golf club changes over a wide range from 46.7% to 54.3%. Furthermore, the center of gravity, which was near the grip on the short side, changes to the tip on the long side, and this change is a major factor that makes long golf clubs difficult to operate for average golfers.

[0042] <Second Example> FIG. 4 shows a carbon shaft for an iron set according to another embodiment. Total length (inches / cm) Center position Center of gravity position Center of gravity position ratio Distance from center Center of gravity classification 39.0 / 99.1 49.5cm 50.6cm 48.9% 1.1cm Center of gravity at hand 38.5 / 97.8 48.9cm 49.7cm 49.2% 0.8cm Center of gravity 38.0 / 96.5 48.3cm 49.3cm 49.0% 1.0cm Center of gravity at hand 37.5 / 95.3 47.6cm 48.7cm 48.9% 1.0cm Center of gravity at hand 37.0 / 94.0 47.0cm 48.0cm 48.9% 1.0cm Center of gravity at hand 36.5 / 92.7 46.4cm 47.0cm 49.3% 0.7cm Center of gravity at grip

[0043] In this iron set, the center of gravity is located near the grip and the position ratio of the center of gravity is within a range of 48.9% to 49.3% from the grip side (51.1% to 50.7% from the tip side). For average golfers, both the amount of practice and sensibility are still inexperienced, so it is desirable to design the center of gravity closer to the grip for ease of use, and to keep the position of the center of gravity G constant. "Constant" here means that the range of variation is very narrow, which in this example is approximately 51%.

[0044] <Third Example> FIG. 5 shows a carbon shaft for a wood set according to one embodiment of the present invention. Total length (inches / cm) Center position Center of gravity position Center of gravity position ratio Distance from center Center of gravity classification 46.0 / 116.8 58.4cm 58.7cm 49.8% 0.2cm Center of gravity at hand 42.0 / 106.7 53.3cm 53.6cm 49.8% 0.2cm Center of gravity

[0045] In this wood set, the center of gravity is located at the grip side, which is 49.8% from the grip side (50.2% from the tip side). The weight of the main body is in the range of 50g to 90g. Like the iron set, the center of gravity is close to the grip and the center of gravity position ratio is constant, so it improves rhythm stability and operability for average golfers.

[0046] On the other hand, by adjusting the center of gravity by adding glass to the resin that is impregnated into the base tube at specific locations along the length, it is possible to make adjustments that are more suitable for advanced players rather than one that emphasizes stability for average golfers.

[0047] <Fourth Example> FIG. 6 shows a carbon shaft for an iron set with the center of gravity at the front. Total length (inches / cm) Center position Center of gravity position Center of gravity position ratio Distance from center Center of gravity classification 39.0 / 99.1 49.6cm 44.6cm 55.0% -4.9cm Tip center of gravity 38.5 / 97.8 48.7cm 43.8cm 55.2% -5.2cm Tip center of gravity 38.0 / 96.5 48.3cm 43.5cm 55.0% -4.8cm Tip center of gravity 37.5 / 95.3 47.6cm 43.0cm 54.9% -4.6cm Tip center of gravity 37.0 / 94.0 47.0cm 42.3cm 55.0% -4.7cm Tip center of gravity 36.5 / 92.7 46.4cm 41.5cm 55.2% -4.9cm Tip center of gravity

[0048] In this iron set, the center of gravity is located at the front, with the center of gravity position ratio falling within a range of 54.9% to 55.3% from the grip side (54.7% to 55.1% from the tip side). This iron set has the center of gravity at the front, not at the grip. Even inexperienced golfers who are weak or do not practice much prefer to prioritize distance. A set with a front center of gravity has a good head movement, making it lighter overall, which is preferable for average golfers and those with little strength. For this reason, in order to improve operability while still having a front center of gravity, the club is designed to be as light as possible with a front center of gravity.

[0049] The thickness, length, and weight of the carbon shaft will be the same as before, but the weight position has been adjusted to make the center of gravity at the front.

[0050] <Fifth Example> FIG. 7 shows a carbon shaft for a wood set according to another embodiment. Wood sets are golf clubs that are primarily suited to competitive golfers, as they emphasize directionality and operability. However, front-heavy sets have a head that moves well, making them lighter overall and more suitable for average golfers and those with little strength. The thickness, length, and weight of the carbon shaft will be the same as before, but the position of the weight has been adjusted so that the center of gravity is closer to the grip and at the tip.

[0051] Total length (inches / cm) Center position Center of gravity position Center of gravity position ratio Distance from center Center of gravity classification 46.0 / 116.8 58.4cm 56.0cm 52.1% 2.4cm Tip center of gravity 42.0 / 106.7 53.3cm 47.3cm 55.7% 6.0cm Tip center of gravity

[0052] In this wood set, the center of gravity is at the front, with a center of gravity position ratio of 52.1 to 55.7% from the grip side (44.3 to 47.9% from the tip side). In this example, it is 45 to 48%, and it may be set to 43 to 49% in consideration of processing errors.

[0053] <Sixth Example> FIG. 8 is a diagram showing the configuration of a putter shaft. This carbon shaft for putters is made by electroless plating the surface of the carbon shaft body, and then electroplating the surface with copper. The surface of this copper plating can be decorated as desired without affecting the thickness of the copper plating. In other words, from the surface, it is composed of an electroplated (copper plated) portion, an electroless plated portion, a carbon shaft body (bare tube), and an electroless plated portion.

[0054] Carbon shafts, as an example of CFRP or GFRP, have a soft feel and a light image. In this embodiment, the carbon shaft for putters was first electroless plated on the front and back sides. By applying electroless plating, it becomes possible to apply metal plating afterwards. In this embodiment, copper plating was applied to the surface of the carbon shaft for putters that had been electroless plated. By applying copper plating, it is possible to ease concerns about the carbon shaft for putters being "light" and to make it feel like it is halfway between steel and carbon, with a weight that is somewhat similar to that of steel.

[0055] It also has a carbon feel, which, unlike steel, allows you to feel the weight of the head, preventing you from hitting the ball too early and preventing pushing and hooking. Furthermore, carbon has a tendency to bend, which allows the ball to roll more easily. However, using carbon alone is not desirable because it can twist. In this embodiment, copper plating is applied to the surface, and the thickness is adjusted to suppress twisting. This allows the ball to be hit with the sensation of hitting a steel ball, and improves directional control. When using a putter, the ball is often hit off-center, so being resistant to deviations in the impact point can help prevent mistakes and have a positive effect on improving scores. Next, an embodiment of a golf club shaft in which the position of the center of gravity is within a range of 15 to 45% of the total length from the grip side, ie, within a range of 55 to 85% of the total length from the head side, will be described.

[0056] <Seventh Example> The measurement values ​​of the golf club shaft in this embodiment are as follows. - Golf wood shaft stiffness 210~240CPM(±5cpm) Tip diameter: 8.4~9.4mm Weight: 40~70g (±3g) Torque is measured at the tip of the shaft and adjusted to 8~6 degrees (±0.2deg). The center of gravity of the shaft is located 55%~85% (±5mm) from the tip. By using such a golf club shaft, it is possible to manufacture a golf club with a center of gravity close to the grip that is easy to swing. Incidentally, torque measurement is shown as a more preferable example.

[0057] <Eighth Example> The measurement values ​​of the golf club shaft in this embodiment are as follows. - Golf wood shaft stiffness 240~260CPM(±5cpm) Tip diameter: 8.4~9.4mm Weight: 50~80g (±3g) Torque is measured at the tip of the shaft and adjusted to 5~4 degrees (±0.2deg). The center of gravity of the shaft is located 55%~85% (±5mm) from the tip. By using such a golf club shaft, it is possible to manufacture a golf club with a center of gravity close to the grip that is easy to swing. Incidentally, torque measurement is shown as a more preferable example.

[0058] <Ninth Example> The measurement values ​​of the golf club shaft in this embodiment are as follows. - Golf wood shaft stiffness 260~270CPM(±5cpm) Tip diameter: 8.4~9.4mm Weight: 60~100g (±3g) Torque is measured at the tip of the shaft and adjusted to 3~2 degrees (±0.2deg). The center of gravity of the shaft is located 55%~85% (±5mm) from the tip. By using such a golf club shaft, it is possible to manufacture a golf club with a center of gravity close to the grip that is easy to swing. Incidentally, torque measurement is shown as a more preferable example.

[0059] <Tenth Example> The measurement values ​​of the golf club shaft in this embodiment are as follows. -Golf iron shaft stiffness 210~230CPM(±5cpm) Tip diameter 9.4mm Weight: 50-70g (±3g) Torque is measured at the tip of the shaft and adjusted to 8~6 degrees (±0.2deg). The center of gravity of the shaft is located 55%~85% (±5mm) from the tip. By using such a golf club shaft, it is possible to manufacture a golf club with a center of gravity close to the grip that is easy to swing. Incidentally, torque measurement is shown as a more preferable example.

[0060] <Eleventh Example> The measurement values ​​of the golf club shaft in this embodiment are as follows. -Golf iron shaft stiffness 220~240CPM(±5cpm) Tip diameter 9.4mm Weight: 60-90g (±3g) Torque is measured at the tip of the shaft and adjusted to 5~4 degrees (±0.2deg). The center of gravity of the shaft is located 55%~85% (±5mm) from the tip. By using such a golf club shaft, it is possible to manufacture a golf club with a center of gravity close to the grip that is easy to swing. Incidentally, torque measurement is shown as a more preferable example.

[0061] <Twelfth Example> The measurement values ​​of the golf club shaft in this embodiment are as follows. -Golf iron shaft stiffness 230~260CPM(±5cpm) Tip diameter 9.4mm Weight: 70~120g (±3g) Torque is measured at the tip of the shaft and adjusted to 3~2 degrees (±0.2deg). The center of gravity of the shaft is located 55%~85% (±5mm) from the tip. By using such a golf club shaft, it is possible to manufacture a golf club with a center of gravity close to the grip that is easy to swing. Incidentally, torque measurement is shown as a more preferable example.

[0062] <Thirteenth Example> The measurement values ​​of the golf club shaft in this embodiment are as follows. Golf putter shaft tip diameter 9.0~9.4mm Weight: 80~140g (±3g) Torque is measured at the tip of the shaft and adjusted to 8~2 degrees (±0.2deg). The center of gravity of the shaft is located 55%~85% (±5mm) from the tip. By using such a putter club shaft, it is possible to manufacture a golf putter that is easy to control with the center of gravity close to the grip and easy to swing. Incidentally, torque measurement is shown as a more preferable example.

[0063] <14th Example> A suitable grip for use with the above golf club shaft is as follows. The measurement values ​​of the grip of the golf club in this embodiment are as follows. Grip weight: 25-150g -Center of gravity position is within 65~85% (±5mm) from the tip 70% of the grip from the rear end is made of rubber-related materials. 30% of the grip from the tip is made of leather-related materials, including artificial leather. Since carbon shafts are made of fiber as the basic material, they tend to twist easily. For this reason, professional and other competitive golfers tend to use steel shafts, which tend to have less twist, not only for putters but for many of their golf clubs.

[0064] In addition, heavy steel shafts are recommended not only for competitive golfers but also for amateur golfers. This is undesirable in terms of the various health hazards that come with swinging a heavy club for a long period of time, including practice. It's no secret that much of the buzz around the world is focused on making shafts and grips lighter to increase distance for beginner, junior and senior golfers. Also, many people see or hear about golf clubs used by professional or competitive golfers who practice a lot on a daily basis, and mistakenly believe that if they use those clubs, even beginners will improve their game in a flash, as if by magic, ignoring the center of gravity of the club or shaft, and rush out to buy the new product.

[0065] In addition, the torque angle of the shaft can be easily adjusted, specifically from 2 to 8 degrees, by using low to high elasticity carbon fiber windings or boron fiber in the internal design of the carbon shaft, making it possible to adjust the torque angle to suit the power and swing speed of each individual golfer. Conventional clubs with a forward center of gravity, especially with a light shaft and grip, make the whole club lighter. The head moves well and the distance is great, so it looks spectacular, but the ball swings from side to side and doesn't quite go the way you want it to.

[0066] With such clubs, it is possible to get the ball to fly somewhat straighter and with the desired trajectory through rigorous practice, but if you have no choice but to practice hard, in order to enjoy golf, you must either devote yourself to golf practice, even if it means spending a lot of money, or you must be one of the wealthy golfers, otherwise it will be difficult to enjoy golf. Conventional clubs with a center of gravity that is located slightly closer to the grip than the tip or center are a natural design, and the current situation is that shafts are manufactured without regard for the issue of the center of gravity. In the past and present, there are no shafts in the world that specify the location of the center of gravity as a key specification for the manufacturing of golf shafts. In the shaft of the present invention, by using a club centered on the base of the specifications for the center of gravity at the grip, and adjusting the weight, hardness, and torque, it becomes a club that allows you to fully enjoy golf without excessive practice. Next, an embodiment of a grip for a golf club will be described. FIG. 9 is a schematic diagram showing a grip of a golf club according to one embodiment of the present invention. In the figure, the grip 10 of the golf club of the present invention has a tip diameter of 15 to 16 mm and a weight of 40 to 100 g (±3 g). The position of the center of gravity of the grip 10 is at the tip of the grip, that is, at a position 66% to 85% from the head side. The weight of the grip can be in the range of 25 to 150 g.

[0067] However, it is not easy to move the center of gravity toward the grip end without increasing the weight of the grip alone, so more realistically, the position of the center of gravity of the grip of the present invention may be in the range of 66% to 80% from the head side. The center of gravity is located quite close to the end of the grip's overall length, improving swing stability. When moving the center of gravity toward the grip end in this manner, it is preferable to move the center of gravity without increasing the overall weight.

[0068] As an example of this technique, the one shown in Fig. 10 has a grip 20 with a composition that is partially, i.e., partially different in the length direction. That is, a head side region 21 is formed of a light composition, and a grip end side region 22 is formed of a heavy composition.

[0069] Also, in the example shown in FIG. 11, two compositions 31, 32 having different specific gravities are intertwined like a double thread to form a single grip 30. In this case, rather than changing the material in the length direction, the center of gravity is shifted by partially changing the composition ratio. That is, composition 32 has a higher composition ratio than composition 31 on the head side, and composition 31 has a higher composition ratio than composition 32 on the grip end side. Even in this way, it can be said that the main composition on the head side is different from the main composition on the end side.

[0070] In addition, in parallel with these, for example, when forming anti-slip grooves on the surface, making the grooves larger on the head side and smaller on the grip end side also contributes to shifting the center of gravity. Specifically, by making the head side a so-called concave finish and the grip end side a so-called convex finish, the center of gravity can be shifted to the grip end side.

[0071] Next, FIG. 12 shows a schematic diagram of a golf club grip having partially different surface materials. In this grip 40, the surface material of the tip side 41 of the grip 40 is leather, synthetic leather, etc., and the grip end side 42 is a rubber product or silicone product. Changing the surface material also contributes to moving the center of gravity to the grip end side. In this example, the leather, synthetic leather, etc. may be lighter in weight than the rubber product on the grip end side.

[0072] In addition to shifting the center of gravity, the surface material on the tip of the grip can be changed to leather, synthetic leather, etc., and added to the head side on two sides, which contributes to more stable control. By using leather products for the tip 41 of the grip 40, rather than rubber products that are slip-resistant, we found a tendency to prefer using the subtle sensation of the fingertips. Specifically, it is difficult to feel the smooth flow of the swing with your fingertips using rubber products.

[0073] The flow of a golf swing is the same as that of smoothly steering a car, and we have found that using leather products on the parts where the fingertips come into contact helps to ensure a smooth grip, resulting in a comfortable sensation in the fingertips and palm of the hand. As a specific example of such a sensation, leather or synthetic leather is used on the head side, but the friction coefficient of the surface may be made different between the head side and the end side, with the friction coefficient being smaller on the tip side. Specifically, this can be achieved by changing the material or the anti-slip pattern on the surface.

[0074] For the sake of center of gravity movement, for example, the coefficient of friction of the surface is made smaller on the tip side at least in the range from the tip to a maximum of 40% on the head side and at least in the range from the end to a maximum of 60%. If necessary, the coefficient of friction of the surface may be made smaller on the tip side at least in the range from the tip to a maximum of 30% on the head side and at least in the range from the end to a maximum of 70%.

[0075] By the way, in sumo and golf, it is more important to stabilize the center of gravity (position of the waist) than to increase body weight. In golf clubs, the change in the center of gravity rather than the weight of the shaft contributes to the stability of the swing and is a very important factor. In the case of golf clubs, because the swing rotation motion creates complex movements, we found that it is particularly meaningful to prioritize stability (operability) of the shaft in the hand, which is an important part of the contact point between the golf club and the body.

[0076] However, the heavier the grip, the closer the center of gravity of the golf club will move to the grip, which is the ideal position. In this case, the center of gravity will be closer to the ideal position, but not only will the weight of the grip increase, but the club itself will also become heavier, which will cause you to lose strength faster and your swing speed to drop. In addition, the center of gravity of the club will move even closer to the head, which will cause instability in not only operability but also distance.

[0077] Furthermore, not only does it slow down your swing speed, but over a long period of time it also drains your physical strength, which means that not only the distance but also the direction of the ball becomes unstable. The present invention reduces the weight of the grips that golfers have traditionally used, as much as possible, while moving the center of gravity of the club toward the grip end, making the swing easier, improving not only operability but also the sense of rhythm, and resulting in greater distance.

[0078] In other words, while the premise is to make the club as light as possible, if the center of gravity is not located toward the grip end, not only will the controllability decrease but the flight distance will also decrease. In addition, it is not only the center of gravity of the shaft body that has a strong influence on the operability of a golf club; furthermore, in order to respond to the subtle sensitivities of each golfer's fingertips and palms, attention was paid not only to the weight and weightiness of the golf club shaft, but also to the center of gravity of the shaft, the center of gravity of the grip, and two types of texture (rubber and leather materials).

[0079] In this way, the present invention is designed not only to prevent the center of gravity, but also to prevent the hand from slipping during the swing by dividing the palm and the fingertips. It was felt that it was necessary to improve the surface of the grip body by dividing it into the palm and the fingertips. Specifically, it is best to design a plain, light material with no irregularities for the area of ​​50-70% from the tip where the thumb, index finger, and middle finger touch. This is because many people are very dexterous with their fingertips, and they tend to use unnecessary force against the flow of the swing, so it is necessary to make them as slippery as possible.

[0080] On the other hand, it is desirable to design the remaining rear end part to have bumps and to use a hard material and a soft material on one side of the bumps. This will minimize the palm slippage as much as possible, making the grip more stable and less likely to shake when operating, making it easier to move smoothly.

[0081] A suitable grip for use with the above golf club shaft is as follows. The measurement values ​​of the grip of the golf club in this embodiment are as follows. Grip weight: 25-150g -Center of gravity position is within 65~80% (±1mm) from the tip -60~70% of the rear end of the grip is made of rubber-related materials. - 30-40% of the grip from the tip is made of leather-related materials, including synthetic leather.

[0082] FIG. 13 is a schematic diagram showing a golf club to which the golf club grip is applied. It is assumed that the grip 51 of this golf club 50 has a center of gravity Gg1 that is shifted toward the grip end side relative to the center of gravity Gg0 of a conventional grip, without any increase in weight. As a result, the center of gravity of the golf club 50 to which this grip 51 is attached also moves from the conventional center of gravity Gc0 to center of gravity Gc1 as the center of gravity of the grip 51 moves without increasing in weight. This golf club 50 weighs 25 to 150 g and is equipped with a grip whose center of gravity is located within a range of 66 to 85% from the tip on the head side, and the center of gravity is located 50% or more toward the grip side relative to the overall length of the golf club.

[0083] By applying the present invention, the center of gravity at the grip can be concentrated at the grip together with the grip, rather than being realized by the shaft of the golf club alone, to produce the effect of the center of gravity at the grip.

[0084] It goes without saying that the present invention is not limited to the above-mentioned embodiment. -Appropriately change and apply the mutually replaceable members and configurations disclosed in the above embodiments. · Appropriately replacing members and configurations that are not disclosed in the above embodiments but are publicly known and can be mutually substituted for the members and configurations disclosed in the above embodiments, and changing the combinations thereof for application. - Substitute members and configurations, etc. that are not disclosed in the above embodiments but that a person skilled in the art could imagine as substitutes for the members and configurations, etc. disclosed in the above embodiments based on publicly known techniques, and change and apply the combinations. is disclosed as one embodiment of the present invention. [Explanation of symbols]

[0085] P1, P2...swing plane, G...center of gravity position, 10...grip, 20...grip, 21...head side region, 22...grip end side region, 30...grip, 31, 32...composition, 40...grip, 41...tip side, 42...grip end side, 50...golf club, 51...grip.

Claims

1. A golf club shaft having a tip diameter of 8.4 to 9.4 mm, a weight of 40 to 100 g (±3 g), and a center of gravity located at a position 55% to 85% (±5 mm) from the tip.

2. 2. The golf club shaft according to claim 1, which is a shaft for a wooden club, characterized in that the hardness is 210 to 240 CPM (±5 cpm) and the weight is 40 to 70 g (±3 g).

3. 2. The golf club shaft according to claim 1, which is a shaft for a wooden club, characterized in that the hardness is 240 to 260 CPM (±5 cpm) and the weight is 50 to 80 g (±3 g).

4. 2. The golf club shaft according to claim 1, which is a shaft for a wooden club, characterized in that the hardness is 260 to 270 CPM (±5 cpm) and the weight is 60 to 100 g (±3 g).

5. The golf club shaft according to claim 1, characterized in that it is an iron club shaft, has a hardness of 210 to 230 CPM (±5 cpm), a tip diameter of 9.4 mm, and a weight of 50 to 70 g (±3 g).

6. The golf club shaft according to claim 1, characterized in that it is an iron club shaft, has a hardness of 220 to 240 CPM (±5 cpm), a tip diameter of 9.4 mm, and a weight of 60 to 90 g (±3 g).

7. The golf club shaft according to claim 1, characterized in that it is an iron club shaft, has a hardness of 230 to 260 CPM (±5 cpm), a tip diameter of 9.4 mm, and a weight of 70 to 120 g (±3 g).

8. 2. The golf club shaft according to claim 1, wherein the tip diameter of the putter shaft is 9.0 to 9.4 mm, and the weight is 80 to 140 g (±3 g).

9. 2. The golf club shaft according to claim 1, characterized in that it is electroless plated.

10. 10. The golf club shaft according to claim 9, wherein the surface of the electroless plating is electroplated to form a double plating.

11. 11. The golf club shaft of claim 10, wherein the electroplating is a copper plating.

12. 11. The golf club shaft of claim 10, wherein the electroplating is a chrome plating.

13. 2. The shaft for a golf club according to claim 1, further comprising an ion plating process on an upper surface of the shaft.

14. A golf club set comprising a golf club formed with the shaft according to any one of claims 1 to 13.

15. The shaft of the golf club is characterized in that the main body weight is 50g to 140g, the shaft is made of CFRP or GFRP, and the position of the center of gravity in the longitudinal direction is within a range of 43 to 49% of the total length from the tip side.

16. A golf putter shaft made of CFRP or GFRP, characterized in that the surface of the base shaft is electrolessly plated and electroplated on the surface.

Images