JP4833540B2 - Ground golf club - Google Patents

Description

  The present invention relates to a club for ground golf, and in particular, when playing on a normal ground, the ball does not rise upward, the ball rolling direction is stable and the ball is not damaged, and The present invention relates to a club that can obtain a hit feeling of hitting a ball with a core even when the club swings normally at the time of one hit or play on the lawn.

  Ground golf uses a wooden club and competes for the number of hits until it is hit by a plastic ball (or wooden ball), rolled and stopped during the ring of the hole post, for the purpose of promoting health and entertainment. It is said.

  The tools that can be used for ground golf are stipulated in the equipment standard rules of the Japan Ground Golf Association (hereinafter also simply referred to as equipment standard rules). For example, the club head has the longest width of 14 cm to 16 cm, the longest width of 7 cm to 8 cm, and the thickness of 4 cm to 4.5 cm. The ball is made of wood or synthetic resin and ground. It does not bounce above and is a perfect circle with a weight of 75g to 95g and a diameter of 6cm.

  By the way, a club is the most basic tool used in ground golf, and various types have been proposed. For example, since the club head is made of wood, the head hitting surface and bottom surface of the head are less likely to be damaged by impacts from hitting, and the head bottom surface is not easily worn by rubbing against the ground. A club has been proposed in which a reinforcing board is attached (Patent Document 1).

  A belt-like weight is attached to the bottom of the head, or weights are attached to both ends of the head toe and heel, and the center of gravity of the head is positioned on the center axis of the shaft and at the height of the center of gravity of the ball on the ground. Therefore, clubs have also been proposed in which a person who has no physical strength or a weak muscular strength can hit a ball accurately (Patent Documents 2 and 3).

  Usually, when hitting the first hit of each hole during play of ground golf, since the ball is hit on the ball stand of the start mat, the ball is lifted from the ground by a height of 25 mm of the ball stand. . In this case, since the diameter of the ball is 60 mm, the center of gravity of the ball is 55 mm from the ground.

  In addition, the number of people who enjoy ground golf has increased, and courses for ground golf have been established. The lawn course has recently increased, but in this lawn course, the ball floats on the lawn. The second and third shots will be performed.

JP-A-10-179830 Japanese Patent Laid-Open No. 11-267258 JP 2000-84132 A

  By the way, in normal golf, an angle (loft angle) is given to the ball striking surface of the club head for the purpose of flying the ball upward, but in ground golf, the ball has a heavy diameter of 60 cm and a weight of 75 g to 95 g, so that it jumps up. This is very dangerous, and the equipment standard rules stipulate that the club head should not be inclined.

  However, in the clubs described in Patent Document 2 and Patent Document 3, a weight is provided at the bottom of the head and the center of gravity of the head is set to a low center of gravity. Therefore, when the club is swung, the effective distance from the hand to the center of gravity of the head is long. As shown in FIG. 10 (a), the bottom of the head 100 is easier to run, the hitting surface 100A of the head 100 is inclined with respect to the ball 110, and even if the ball can be hit with a sweet spot, the hit ball is inevitable. Easy to fly upward.

  Further, when the ball 110 cannot be caught at the sweet spot, the ball 110 is likely to be hit with the corner 100B at the bottom of the head 100 as shown in FIG. 10B, and the rolling direction of the ball 110 is stable. In addition to not doing so, the ball 110 may be damaged.

  Further, in the clubs described in Patent Document 2 and Patent Document 3, when the club is swung as in normal play on the ground at the time of the first hit of each hole or on the lawn, the center of gravity of the head becomes the center of gravity of the ball. The player feels a sense of discomfort as if the player missed the ball.

  Of course, if you swing the club with a short shaft, or swing the club so that the head floats, you can hit the ball by matching the center of gravity of the head and the center of gravity of the ball. It is not a thing.

  In view of such problems, the present invention does not raise the ball upward when playing on a normal ground, and further, the direction in which the ball rolls is stabilized and the ball is not damaged. It is an object of the present invention to provide a club for ground golf that can obtain a feeling of hitting a ball with a core even when the club is normally swung at the time of playing on the lawn.

Therefore, in the ground golf club according to the present invention, the lower end of the shaft is connected to the upper end surface of the head, while the horizontal width of the head is larger than the vertical width and the head vertical width is the widest. In a ground golf club that hits a ball with a diameter of 6 cm and is defined as 7 cm or more and 8 cm or less, a weight balance portion having a specific gravity greater than that of the head material is provided on the head bottom portion and the head top portion. Has a belt-like portion that extends between the tip of the toe and heel on the bottom surface of the head and between the tip of the toe and heel on the top surface of the head, and is fixed to the bottom surface of the head and the top surface of the head. It is characterized by a weight balance that is unevenly distributed on the side and the upper side .

  One of the features of the present invention is that weight balance portions are provided at the bottom and top of the head so that the head weight is unevenly distributed between the bottom and top, thereby realizing a weight balance in which the bottom and top of the head are heavy.

  As a result, the center of gravity of the head is not as low as that of the clubs described in Patent Document 2 and Patent Document 3, and the effective distance from the hand to the center of gravity of the head at the time of swing is compared to the clubs described in Patent Document 2 and Patent Document 3. Become shorter.

  As a result, the bottom part of the head is less likely to run faster than the top part, and the inclination of the head striking surface with respect to the ball becomes smaller and approaches the vertical direction. Almost never fly upwards, and you can guarantee safety during play. Further, since the ball is not hit at the corner of the bottom of the head, the rolling direction of the ball is stable and the ball is not damaged.

  The basic shape and dimensions of the ground golf club are stipulated in the equipment standard rules of the Japan Ground Golf Association, and it is not possible to adopt an abrupt shape or dimension. Therefore, it is practically difficult to set the center of gravity of the head at a height of 55 mm from the ground in consideration of the first hit in each hole or the play on the lawn.

  By the way, the ball hitting feeling can be considered as a problem of sweet spot. Patent Document 3 realizes a so-called toe-heel balance in which weights are unevenly distributed on the toe side and the heel side to make the toe side and the heel side heavy by attaching weights to both ends of the toe and heel of the head. Enlarging the sweet spot in the horizontal direction by increasing the moment of inertia around the vertical axis (Y axis) passing through the center of gravity of the head, and even if the ball is hit at a position shifted from the center of gravity of the head to the toe side or heel side, The concept of preventing force from being transmitted is described, but this toe-heel balance concept is when the ball is hit above the center of gravity of the head, such as when the first hit of each hole or when playing on the lawn. It is not possible to deal with the uncomfortable feeling of hitting.

  Another feature of the present invention resides in that a weight balance portion is provided in at least a central portion in the horizontal direction of the bottom portion of the head and at least a central portion in the horizontal direction of the top portion of the head. This makes it possible to achieve a weight balance in which the weight of the head is unevenly distributed on the bottom side and top side of the head and the bottom side and top side are heavy, and the moment of inertia around the horizontal axis (X axis) passing through the center of gravity of the head is Since it becomes large, even if it strikes the ball at a position shifted from the center of gravity of the head at the time of the first hit in each hole or play on the lawn, a large reaction force is not transmitted to the hand, and the player focuses on the ball A feeling of hitting is obtained, and it is rare to feel a sense of incongruity of hitting.

  Since the weight balance portion is provided in order to expand the sweet spot in the vertical direction as described above, it may be provided at least at the center portion in the horizontal direction of the head bottom portion and at least the center portion in the horizontal direction of the top portion of the head. Here, the “head center of gravity” refers to the center of gravity in a state where the head from which the shaft has been removed from the club is placed on a horizontal reference plane. The “center portion” is a desired range from the position of the center of gravity of the head toward the toe and heel in the contour shape in which the head with the shaft removed from the club is placed on a horizontal reference surface and the head is projected onto the reference surface. Say part.

  In many ground golf clubs, the shaft is fixed at an angle with respect to the head, and when the ball is hit at a position shifted upward from the center of gravity of the head as described above, the toe side or heel from the head center of gravity of the head striking surface Since the ball easily collides with the ball at a position shifted to the side, the head may turn around the Y axis passing through the center of gravity of the head, and the directionality of the ball may be deteriorated. Therefore, it is preferable that the weight balance portion is provided so as to extend between the toe and heel at the bottom of the head and between the toe and heel at the top of the head so as to expand the sweet spot in the left-right direction. As a result, the moment of inertia around the Y axis passing through the center of gravity of the head also increases, making it difficult for the head to turn around the Y axis and allowing the ball to roll accurately in the intended direction.

  The weight balance part may be configured by impregnating the head with a synthetic resin material, or by forming a recess in the head and embedding a metal piece, a synthetic resin piece, a carbon fiber reinforced material or a glass fiber reinforced material resin piece. Furthermore, a metal plate, a synthetic resin plate, a carbon fiber reinforced material, or a glass fiber reinforced material resin plate may be fixed with screws or an adhesive. That is, the weight balance portion has a belt-like portion and can be configured to be fixed to the bottom surface of the head and the top end surface of the head.

  The band-shaped part of the weight balance part may be extended to a part between the tip of the toe and heel including the position of the center of gravity of the head at the bottom and top of the head, but the above-mentioned horizontal sweet spot should be widened. In consideration, it is preferable to extend the entire tip between the toe and heel. Therefore, it is preferable that the belt-like portion of the weight balance portion has a shape extending between the toe and heel tips on the bottom surface of the head and between the toe and heel tips on the top surface of the head. In the weight balance portion, the belt-like portion on the bottom surface of the head extends between the tip of the toe and heel on the bottom surface of the head, and the belt-like portion on the top surface of the head is formed between the tip of the toe on the top surface of the head and the vicinity of the shaft connection portion. It is also possible to have a shape extending between the gap and the tip of the heel and the vicinity of the shaft coupling portion.

  In addition, the band-shaped portion of the weight balance portion including the position of the center of gravity of the head on the bottom surface and the top surface of the head and extending all or part between the tips of the toe and heel may be the full width in the head thickness direction. It is good also as the width of a part. For example, the belt-like portion on the upper end surface of the head can be viewed from above by the player, so that it can be designed to look good. For example, in the weight balance part, the head upper end surface and / or the belt-like portion on the bottom surface of the head has a dimension in the head thickness direction from the end on the toe side to the mounting site of the shaft and from the end on the heel side to the mounting site of the shaft. The shape can be gradually reduced or gradually increased.

  The material of the weight balance part is not particularly limited as long as it has a higher specific gravity than the material of the head. For example, an appropriate metal material such as an aluminum alloy or a magnesium alloy, or a synthetic resin material such as polypropylene (powder having a high specific gravity) A synthetic resin material in which is dispersed), a carbon fiber reinforced material, and a glass fiber reinforced material.

  Here, “the weight balance portion includes a belt-shaped portion” means that a component other than the belt-shaped portion is included. For example, when the weight balance part is manufactured by die-casting an aluminum-based alloy, distortion is easily generated in the band-shaped part. Therefore, a longitudinal rib for preventing distortion may be formed on the back surface of the band-shaped part. Further, if the belt-like portion of the weight balance portion is fixed to the head with only the screws, the belt-like portion may be peeled off from the head due to impact or the like during play. In view of this, columnar fixing protrusions may be formed at appropriate locations on the back surface of the belt-like portion, and fitted into recesses formed in the bottom and upper end surfaces of the head to prevent the strip-like portion from peeling off.

  Further, the hitting surface of the head is not particularly limited. For example, the head striking surface may be composed of a head material, preferably a coated head material. A head made of resin material, carbon fiber reinforced material or glass fiber reinforced material may be attached to increase the durability of the head.

  Hereinafter, the present invention will be described in detail based on specific examples shown in the drawings. 1 to 4 show a preferred embodiment of a ground golf club according to the present invention. In the figure, the club 10 is composed of a wooden shaft 20 and a head 30, and the head 30 is basically manufactured using wood, and a grip 21 is provided on the upper portion of the shaft 20.

  As shown in FIG. 1, the head 30 includes a hitting surface 31, a back surface 32, a bottom surface 33, and an upper end surface 34. A circular mounting hole is formed obliquely toward the inside of the head 30 on the upper end surface 34. The shaft 20 is inserted into the head 20 through the mounting hole and fixed in a state of being inclined with respect to the head 30.

  Further, a metal plate (weight balance portion) 40 is annularly covered on the bottom surface 33 and the upper end surface 34 of the head 30, and is fixed to the bottom surface 33 and the upper end surface 34 with screws 41, and the shaft 20 is inserted into the metal plate 40. An attachment hole 42 is formed in communication with the attachment hole in the upper end surface 34 of the head 30.

  The metal plate 40 is made of a metal material such as an aluminum-based alloy or a magnesium-based alloy, and is manufactured in a shape that is divided into two at the top and bottom at the tip of the toe 35 and the tip of the heel 36 of the head 30 by die casting or cutting. An annular shape is formed by covering the bottom surface 33 and the upper end surface 34 of the head 30.

  Further, the portion 40A of the upper end surface 34 and the portion 40B of the bottom surface 33 of the head 30 of the metal plate 40 extend between the tip of the toe 35 and the tip of the heel 36 of the head 30 and extend to the full width of the head 30 in the thickness direction. It is striped. Further, a plurality of concave grooves are formed in the portion 40B of the bottom surface 33 of the head 30 of the metal plate 40 so as to extend in the thickness direction of the head 30, thereby improving the slidability between the ground, the weeds or the lawn.

  A reinforcing rib or a fixing protrusion may be formed on the back surface of the metal plate 40. The weight distribution of the portion 40A on the upper end surface side of the metal plate 40 and the portion 40B on the bottom surface side of the head depends on the size of the sweet spot in the vertical direction, the height of the center of gravity of the head, or the weight of the head. It is better to decide in consideration of such factors. For example, in this example, the head upper end surface side portion 40A and the head bottom surface side portion 40B have substantially equal weight distribution.

  When starting the first shot in each hole, as shown in FIG. 3, the ball 60 is placed on the ball stand 51 of the start mat 50, the grip 21 of the shaft 20 is held with both hands, and normal play on the ground is performed. As in the case of, the club 10 is swung, and the ball 60 is hit by the head 30 and rolled.

  At this time, the ball 60 is placed on the ball stand 51, and the center of gravity of the ball is 55 mm above the ground and is higher than the head center of gravity CG. However, in the club 10 of this example, the metal plate 40 is disposed around the head 30. Since the weight is unevenly distributed around the head 30, the sweet spot is widened not only in the horizontal direction but also in the vertical direction as shown by the oblique lines in FIG.

  As a result, most of the momentum F of the head 30 is transmitted to the ball 60, while the reaction force R from the ball 60 is small, and the player feels that the ball 60 is hit with the core, and feels uncomfortable with the hit. There is nothing.

  In addition, when playing on the lawn course, the player feels a hit feeling like hitting the ball 60 with the core as described above, and does not feel uncomfortable.

  Furthermore, since the head center of gravity CG is not as low as the clubs described in Patent Document 2 and Patent Document 3, the effective distance from the hand to the head center of gravity CG during swing is the same as that of the clubs described in Patent Document 2 and Patent Document 3. The bottom of the head 30 does not run faster than the top of the head 10. As a result, since the inclination of the hitting surface 31 of the head 30 with respect to the ball 60 during play on the normal ground is reduced, the hitting ball does not fly upward, and safety during play can be guaranteed.

  Further, since the ball 60 is not hit at the corner of the bottom portion of the head 30, the rolling direction of the ball 60 is stable and the ball 60 is not damaged.

  FIG. 5 shows a second embodiment. In the example shown in FIG. 5A, a concave portion is formed in the central portion of the bottom surface 33 of the head 30 and the central portion of the upper end surface 34, and metal plates (weight balance portions) 70 and 71 are fitted and fixed with screws. Thus, even if the metal plates 70 and 71 are provided only at the central portions of the bottom surface 33 and the upper end surface 34 of the head 30, the sweet spot can be expanded in the vertical direction. Instead of the metal plate, a synthetic resin plate having a specific gravity larger than that of the material of the head 30 (which may be a dispersion of powder particles having a high specific gravity), a resin plate made of carbon fiber reinforced material or glass fiber reinforced material is used. You can also.

  In the example shown in FIG. 5 (b), a plurality of recesses are formed in the upper and bottom central portions of the head 30 (or the back surface 32) of the head 30 to embed a metal piece 72, and the sweet spot is formed in the vertical direction. I try to expand it. Thus, you may make it comprise a weight balance part using a metal piece instead of a metal plate. Instead of the metal piece, a synthetic resin piece having a larger specific gravity than that of the material of the head 30 (which may be obtained by dispersing powder particles having a higher specific gravity) may be used. In addition, the concave portion is formed over the entire circumference of the top and bottom of the ball striking surface 31 (or the back surface 32) of the head 30, and a metal piece or a synthetic resin piece (including a resin piece of carbon fiber reinforced material or glass fiber reinforced material). It may be embedded.

In the reference example shown in FIG. 5C, the weight balance portion 73 heavier than the head material is configured by impregnating the central portion of the top and bottom of the head 30 with a synthetic resin material. Thus, you may comprise a weight balance part by the impregnation of resin. Further, the weight balance portion may be configured by impregnating resin over the entire circumference of the upper portion and the bottom portion of the head 30.

  FIG. 6 shows a third embodiment, in which the same reference numerals as those in FIGS. 1 to 4 denote the same or corresponding parts. In this example, the metal plate 40A covering the upper end surface 34 of the head 30 is a belt-shaped portion 40A of the upper end surface 34 of the head 30 and the dimension of the head 30 in the thickness direction is the mounting hole (attachment site) of the shaft 20 from the end on the toe 35 side. 42 and the heel 35 end shape toward the attachment hole (attachment part) 42 of the shaft 20 is gradually reduced. As described above, the metal plate 40 may have a width that covers a part of the head 30 in the thickness direction. Instead of the metal plate 40, a synthetic resin plate (including a carbon fiber reinforced material or a glass fiber reinforced material resin plate) may be employed.

  FIG. 7 shows a fourth embodiment, in which the same reference numerals as those in FIGS. 1 to 4 denote the same or corresponding parts. In this example, a reinforcing plate portion 43 made of a metal plate is formed at right angles and integrally with a metal plate 40B covering the bottom surface 33 of the head 30, while a concave portion is formed in the striking surface 31 of the head 30, and the reinforcing plate is formed in this concave portion. The portion 43 is fitted and fixed to the hitting surface 31 with a screw 41. The reinforcing plate part is not made of metal but can be made of synthetic resin (including carbon fiber reinforced material or resin made of glass fiber reinforced material), and is manufactured separately from the metal plate 40B. Then, it may be fixed to the hitting surface 31.

  8 and 9 show the fifth and sixth embodiments, in which the same reference numerals as those in FIGS. 1 to 4 denote the same or corresponding parts. In the example shown in FIGS. 8 and 9, the metal plate 40A covering the upper end surface 34 of the head 30 is placed between the tip end 35 of the toe and the vicinity of the shaft attachment hole (shaft connection portion) 42, and from the tip end 36 of the heel to the shaft attachment hole 42. Are provided extending in the vicinity of each other and fixed by screws 41.

  In the example shown in FIG. 8, the width of the head 30 in the thickness direction of the metal plate 40A is gradually reduced from the toe tip 35 toward the shaft mounting hole 42. In the example shown in FIG. The width in the thickness direction of the head 30 is formed to be a constant width shorter than the thickness of the head 30 from the shaft toward the shaft mounting hole 42.

  In each of the above examples, the metal plate (weight balance part) 40 is manufactured in a form that is divided into two vertically and is attached to the bottom surface 33 and the upper end surface 34 of the head 30. It may be formed integrally with the form and externally fitted to the head 30 from the side.

It is a principal part perspective view which shows preferable embodiment of the club for ground golf which concerns on this invention. It is a figure which shows the bottom face in the said embodiment. It is a figure which shows the state of the start of the 1st hit | damage of each hole in Grundo golf. It is a figure for demonstrating the effect | action of the said embodiment. It is a figure which shows 2nd Embodiment. It is a figure which shows 3rd Embodiment. It is a figure which shows 4th Embodiment. It is a figure which shows 5th Embodiment. It is a figure which shows 6th Embodiment. It is a figure for demonstrating the subject which invention will solve.

Explanation of symbols

10 club 20 shaft 30 head 31 hitting surface 32 back surface 33 bottom surface 34 upper end surface 40 metal plate (weight balance portion)
43 Reinforcement board part 70, 72 Metal plate (weight balance part)
72 Metal piece (weight balance part)
73 Weight balance

Claims (5)

While the lower end of the shaft is connected to the upper end surface of the head, the horizontal width of the head is larger than the vertical width, and in order to strike a ball having a diameter of 6 cm, the head has the widest vertical width of 7 cm to 8 cm. In a ground golf club, wherein the ball striking face is formed substantially parallel to the back surface and substantially perpendicular to the bottom surface ,
The head bottom and top have weight balance parts with a specific gravity greater than the head material. The weight balance part extends between the toe and heel tips on the bottom surface of the head and between the toe and heel tips on the top surface of the head. A ground golf club characterized by having a belt-shaped portion and a weight balance in which the head weight is unevenly distributed on the head bottom side and the top side by being fixed to the head bottom surface and the head top surface.   In the weight balance portion, the belt-like portion on the bottom surface of the head has a shape extending between the tip of the toe heel on the bottom surface of the head, and the belt-like portion on the top surface of the head is formed between the tip of the toe on the top surface of the head and the vicinity of the shaft connection portion. 2. The golf club for ground golf according to claim 1, wherein the club is formed in a shape extending between the gap and the tip of the heel and the vicinity of the shaft connecting portion.   Among the above-mentioned weight balance portions, the head-shaped top band and / or the band-shaped portion on the bottom surface of the head gradually decreases in the thickness direction from the end on the toe side to the shaft mounting site and from the heel side to the shaft mounting site. The club for ground golf according to claim 1, wherein the club is configured to gradually increase.   2. The club for ground golf according to claim 1, wherein the weight balance portion is made of a metal material, a synthetic resin material, a carbon fiber reinforced material, or a glass fiber reinforced material.   2. The club for ground golf according to claim 1, wherein a reinforcing plate made of a metal material, a synthetic resin material, a carbon fiber reinforced material, or a glass fiber reinforced material is attached to the hitting surface of the head.

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