JP7730441B1 - Badminton and soft badminton racket set suitable for elementary school students to adults - Google Patents

Abstract

[Problem] To provide a set of six sizes of badminton and soft badminton rackets for elementary school students, each individually tailored to the six classes of elementary school. [Solution] To accommodate the heights of elementary school students, the set includes six sizes for elementary school students, each with a racket outer size that is gradually reduced in size based on the outer size of an adult racket. [Selected Figure] Figure 1

Description

This invention relates to a set of rackets for badminton and soft badminton that are sized to accommodate the heights and physical strengths of elementary school children and adults. Furthermore, these rackets can also accommodate badminton squash shuttlecocks and shuttlecocks used for home practice.

<<The following provides information on the current situation regarding the only badminton racket used by people all over the world, from young children to adults, in accordance with the badminton rules.>>
Until now, there have been no unified regulations regarding the materials used in manufacturing badminton rackets, so each manufacturer has competed fiercely to master the materials and manufacturing techniques.As a result, even though the racket is a single racket (length x width) for adults, advances in materials and technological innovation have resulted in rackets being manufactured in nine different weight sizes (1U 98±2g, 2U 93±2g, 3U 88±2g, 4U 83±2g, 5U 78±2g, 6U 73±2g, 7U 68±2g, 8U 63±2g, 9U 58±2g).
For example, if a badminton racket is sized as "4U5," 4U indicates the weight, and 5 indicates the grip size. The racket's length and width are not specified because there is only one size for adults. Due to differences in the materials and thickness used to manufacture badminton rackets, the weight can vary even for the same shape and size.

Currently, there are three sizes of badminton rackets for first through sixth graders: 8LW/9U length 525mm for 6-7 year olds, 7LW/8U length 575mm for 8-9 year olds, and 6LW/7U length 625mm for 10-11 year olds. (The contents are disclosed in Prior Art Document 1.)
In addition, soft badminton and soft shuttlecocks were invented to introduce badminton to young children and schoolchildren, and are disclosed in Prior Art Document 2. The corresponding rackets are disclosed in Prior Art Document 1.
Furthermore, a home badminton practice device was invented in Patent No. 7470485 to allow badminton enthusiasts to practice at their leisure, and the corresponding racket for the practice ribbon shuttle is disclosed in Prior Art Document 1.
The racket set disclosed in Prior Art Document 1 is also applied to the newly invented sport of badminton and squash.

Japanese Patent Application Laid-Open No. 2020-048787 JP 2017-038754 A Japanese Patent Application Laid-Open No. 2022-106431 Japanese Patent Application Laid-Open No. 2023-058397 Patent No. 7470485 Japanese Patent Application Laid-Open No. 2018-038571

Roseddy badminton racket for kids, lightweight badminton set for kids, children's tennis badminton racket, children's badminton racket set for toddlers, badminton tennis racket for kids, badminton parent-child set, outdoor badminton sports.

The school aims to nurture perfect members of society through a three-round education consisting of intellectual, moral and physical education. Elementary school is an especially important period for children to cultivate the foundations for their lifelong development, so the school has a scientific, step-by-step education system with six grade levels according to the child's developmental stages, with each year leading up to a new level.
However, when it comes to physical education, all 19,525 elementary schools are equipped with impressive gymnasiums, swimming pools, and playgrounds. However, the badminton equipment in the gyms is 155cm high, with adult-sized net poles, making it unsuitable for elementary school students. The badminton courts are also too large for elementary school students. There are also no badminton rackets suitable for the physical needs of elementary school students. It's no wonder that elementary schools don't have badminton clubs.

Furthermore, amidst fierce competition in the global badminton racket manufacturing industry, weight reduction has become a key issue for adult carbon rackets, and the speed of manufacturing technology and material development has evolved day by day. The Power Shot Nano 9U 3DRAGON, weighing 9U (58±2g), is now the lightest racket available. However light it may be, its size is too large for elementary school students, making it difficult to use and causing stress.
Elementary school students are also using aluminum frame, steel shaft rackets, which are the same length and width as adult rackets, and weigh far more than adult carbon rackets.
There are rackets available for purchase online that only have a short shaft. For example, the racket listed in Non-Patent Document 1 is described as "(Compact size, ideal for children aged 6 to 12) A small racket measuring 44 cm in length and 22.5 cm in width, suitable for children 110 cm to 150 cm tall. ... (Lightweight and child-friendly) Each racket weighs just 100 g, so even children can use it without any stress. Children's bones are not yet fully developed, so do not force them to use an adult racket."
For adults, the most common weight sizes are 4U (83±2g) and 5U (78±2g). Comparing the two types of rackets, children's rackets for ages 6-12 weigh 100g. For adult rackets, the aforementioned weight size is 9U (58±2g), which is also the lightest racket available. The head width of children's rackets is 22.5cm wide. Most adult rackets have a head width of 20cm.
Forcing elementary school children to use rackets that are inappropriate for their developmental stage can put strain on their wrists, elbows, and shoulders, which can lead to early injuries or sports disorders.
In short, badminton is an adult sport. The badminton equipment manufacturing industry is working hard to develop rackets for adults, but no one is interested in badminton for young children.

……
However, the soft badminton racket set of Patent No. 6458211 uses only three sizes of rackets for elementary school students, which is suitable for sixth graders . This is like making a child climb two steps in one step, which feels strange. There is also the problem that the three sizes of rackets do not match the sixth grade.
Furthermore, there is a problem in that the rackets used by younger elementary school students are too long.

The soft badminton racket set includes a plastic racket for toddlers and a carbon fiber racket for elementary school students, junior high school students, and adults.
However, because the materials and manufacturing techniques used for plastic and carbon rackets are different, not categorizing them can be an obstacle to implementing the idea.

……
As described in paragraphs 0056 and 0057 of the specification of my previous patent application No. 6458211 , a shaft tube with a multi-layered carbon fiber sheet structure is used...

Regarding the two-stage raised curved grip for both offense and defense in my previous patent application No. 6458211 , the grip is configured in an embodiment of three paragraphs 0058, 0057, and 0060, as shown in Figure 15, front view 15-1, side view 15-2, and top perspective view 16-3 of the completed grip portion in Figure 16.
However, although the shape of the grip end portion in Figures 15 and 16 allows for gripping power to be exerted when hitting the ball, the middle part of the end bulges out significantly, and the end cap attached to the end surface is small, so there is a problem with the grip tape falling off.

In light of the badminton environment for young children mentioned above and my previous patent application No. 6458211, this invention aims to solve various problems and improve the badminton environment for elementary school students in order to popularize badminton among elementary school students. It aims to provide a good badminton environment for elementary school students with three pieces of equipment: a set of six rackets that can be replaced annually according to age and height, a badminton net support with a height-adjustable lifting device for elementary school students, and six sizes of badminton courts for elementary school students, thereby allowing elementary school students to progress one level each year in line with the six-year elementary school education system.

The six badminton racket sizes for elementary school students of the present invention are different from the racket sizes for adults set by each manufacturer, and six sizes are added to correspond to the age, height and physical strength of elementary school students.
For example, the racket size for a first grade elementary school student is written as "11L/11W/9G", where L is the total length, W is the width, and G is the grip size.
Weight is determined by the shape and size of the racket (total length and head width), frame thickness, shaft thickness, and grip size, but since the weight of similarly sized rackets varies depending on the manufacturing techniques and materials used by each manufacturer, this invention does not specify a weight size.

"This invention is not about improving the materials or manufacturing techniques of badminton rackets, but about reforming the racket's external size and structure. The racket of this invention is compatible with the manufacturing techniques and materials of various manufacturers. For example, the Power Shot Nano 9U 3DRAGON weighs 9U (58±2g). If it were manufactured using the lightest manufacturing techniques and materials, it would be the lightest! "
In order to solve the above problems, the present invention aims to reform the badminton environment for elementary school students by providing a set of six sizes of rackets for elementary school students, all individually tailored to the six grades, and using a three-item set of free-climbing badminton net poles for elementary school students and six-size badminton competition courts for elementary school students, thereby popularizing elementary school badminton from Japan to the world.
Badminton and soft badminton rackets for elementary school students to adults
It is a set
The competitive rackets used by elementary school students from the age of 6, when they can start playing racket sports, to adult players, are manufactured using lightweight, highly elastic, and extremely strong carbon fiber material.
As elementary school students grow, the size of the racket changes, so there are six sizes of rackets.
In order to accommodate the height of elementary school students, the racket has six sizes for elementary school students, which are gradually reduced in size based on the outer size of an adult racket.
Table 1 shows the recommended racket set sizes for different ages.
Eight sizes of rackets as listed in Table 1 above are provided.
A badminton and soft badminton racket set suitable for everyone from elementary school students to adults .

In addition, in the above-mentioned invention, there is provided a racket set for badminton and soft badminton suitable for children from elementary school students to adults , which comprises:
The racket set for elementary school students has a head frame that is reduced in size step by step to reduce the weight of the racket,
The internal spaces of all the head frames of the above sizes are provided with the same inner diameter dimension, and the wall thickness is made thinner step by step, so that the outer diameter is made thinner step by step.
In order to increase the elasticity of the head guard and the power of the shot, the number of vertical and horizontal strings is reduced according to the size.
In order to exert the hitting force of the head girder surface in all directions equally, the head girder surface has a square-woven girder hitting surface where vertical and horizontal strings intersect,
The square mesh girt hitting surface is formed so that it expands in two stages from a large size racket to a small size racket in order to accommodate elementary school children,
The hammer portion of the racket for adult men is formed by disposing a soft lead weight of 3 to 7 g inside the hollow interior of the front end of the head frame of the 4U/5G size racket for adult men,
Each racket head configuration has the size shown in Table 2 below.
A badminton and soft badminton racket set suitable for everyone from elementary school students to adults .

In addition, in the above-mentioned invention, there is provided a racket set for badminton and soft badminton suitable for children from elementary school students to adults , which comprises:
The racket for elementary school students has an inner diameter of a shaft supporting an annular head that is gradually tapered in two stages in order to gradually reduce the weight of the racket to a smaller size,
The thickness of the shaft is made thinner in two stages based on the thickness of the racket size for adults,
The outer diameter of the shaft is tapered in two steps depending on the inner diameter and wall thickness of the shaft,
Furthermore, the length of the shaft is set to be gradually shorter for elementary school students according to the size stages,
The racket shaft has the dimensions of each part listed in Table 3 below.
In order to increase the bending elasticity of the racket shaft of the racket size 8, the neck portion of the racket, which is the front end of the shaft cylinder, is deformed into an elliptical shape, and the long axis of the elliptical shape is set parallel to the hitting surface,
The elliptical bending elastic neck has the sizes of each part shown in Table 4 below,
A shaft having an elliptical bending elastic neck is formed using a jig core rod and a case-type die for forming the shaft,
A badminton and soft badminton racket set suitable for everyone from elementary school students to adults .

This invention has also been developed for a jig core rod and case-type mold for forming a shaft with an elliptical bending elastic neck, and provides two methods for forming the shaft for the convenience of manufacturers.
A method for forming the shaft of a badminton and soft badminton racket set suitable for children from elementary school students to adults, using a jig core rod and a case-type mold,
The forming method using a jig mandrel and a case-type die for forming a shaft having an elliptical bending elastic neck uses the jig mandrel of the first or second proposal,
The first proposal includes a jig mandrel corresponding to each mandrel outer diameter size listed in Table 4, which can be used to form a jig mandrel for forming a shaft,
The second proposal involves preparing two metal core rods of appropriate length and short length, each having an outer diameter similar to the inner diameter of the shaft, and when winding the shaft into a cylindrical shape using a resin sheet, inserting a rod-shaped heat-foamable resin into the elliptical portion, and arranging the long and short core rods at both ends to form shaft jig core rods corresponding to the core rod outer diameter sizes listed in Table 4.
The two types of jig mandrels of the first or second proposals for forming a shaft having an elliptical bending elastic neck have the sizes listed in Table 5 below,
The jig core rod of the first embodiment for forming the elliptical bending elastic neck portion of the racket shaft comprises a metal core rod having an outer diameter similar to the inner diameter of the shaft, and a 2 mm diameter elliptical forming portion machined by a lathe at the front end of the metal core rod.
Further, a sliding cylindrical core rod portion having an inner diameter of 2 mm and an outer diameter similar to that of the rear end portion of the core rod is provided,
The case-type mold of the shaft jig described above has a shape for forming a three-stage shaft in which a semi-elliptical shape is formed on both sides of a half pipe and a semi-cylindrical shape is provided on both ends thereof,
In addition, a device is provided for connecting the forming molds in parallel and opening and closing them using three stages of semi-cylindrical, semi-elliptical and semi-cylindrical shapes on both sides,
Furthermore, the method has a structure in which lid-type stoppers are provided on both ends of the case-type mold in which both pieces forming the shaft are formed in the shape of a half pipe,
a device lock is provided to prevent the shaft forming device from being opened after being closed;
A forming method using a jig core rod and a case-type mold for forming a shaft having an elliptical bending elastic neck portion, characterized in that:

In addition, in the above-mentioned invention, there is provided a racket set for badminton and soft badminton suitable for children from elementary school students to adults , which comprises:
The grip part for manipulating the racket has an octagonal shape at the front, and the widths of the four diagonal corners are narrowed to widen the widths of the two sides facing the ball-hitting surface and the two sides facing the side, creating a raised shape that is optimal for gripping with the hand.
The total length of the grip and the size of the eight sides of the quick operation part have the total length and size listed in Table 6 below,
By cutting out about two-thirds of the grip from the front end, the width of the eight sides is narrowed, making it thinner, and it has auxiliary operating parts for the ring finger and little finger.
The cross-sectional size of the auxiliary operating portion of the grip for the ring finger and little finger has the size listed in Table 7 below,
The grip has an end portion provided with a power end portion, which is an egg-shaped grip portion that protrudes more than the front half portion,
The cross-sectional size of the power end portion provided at the end portion of the grip has the size listed in Table 8 below,
The raised agile operation part, the thin auxiliary operation parts for the ring finger and little finger, and the raised power end part form a curved shape like a two-stage protrusion, providing both offensive and defensive functions with agile operation and striking power.
A badminton and soft badminton racket set that is suitable for everyone from elementary school students to adults.

This invention is a set of six sizes of rackets for elementary school students, all individually tailored to the sixth grade , and a free-rising badminton net support for elementary school students...

In addition, the rackets are suitable not only for badminton and soft badminton, but also for badminton squash and as a home practice facility, and are effective in helping young children improve their badminton skills.

By reducing the number of grommets on the badminton racket head, not only is it lighter, but the head frame is also more durable.
In addition, by reducing the number of strings, the hard hitting surface becomes flexible, increasing the rebound force and reducing air resistance, shortening the swing time and increasing the shuttlecock speed.
Furthermore, by providing a hammer portion at the front end of the head frame of the racket for adult men, the power of the hit ball can be greatly increased.

When the racket of the present invention is used for badminton, the large square mesh of the net-like hitting surface allows the shuttlecock face to penetrate the mesh of the hitting surface in a large area when used for a cut hitting technique, resulting in great spike performance, and the diagonal change flight allows for a large change in width.
Regarding the difficult technique of executing a hairpin shot, it is more effective to hold the racket horizontally, lightly rotate the shuttlecock by cutting it sideways or back and forth, and then use a spin net to have it drop vertically just over the net, and even better results can be achieved by using a larger mesh on the hitting surface.

The racket's bending elastic neck greatly amplifies the flex, suppressing and damping vibrations and resonance when hitting, and also blocking the impact force, making it less likely to be transmitted to the player's hands, reducing strain on the wrists and elbows.
In addition, the provision of a bending elastic neck at the front end of the shaft narrows the bending range of the shaft to one point at the front end, further improving operability.
Furthermore, the resilience is greatly increased, enabling high repulsive impact force.

The grip section is equipped with a two-stage raised curved shape and two-point operation multi-function, allowing the user to twist the grip with the pads of the thumb, index finger, and middle finger, allowing for easy and agile operation to freely change the hitting surface.
The end of the grip is a large, raised, flattened oval shape that allows for a two-point grip. This extends the distance between the gripping end and the hitting surface when smashing, further increasing the power of the shot.
In particular, the hammer striking force of a 4U.5G size racket for adult men can be combined with the high elasticity of the bending elastic neck and the power of the power end to achieve explosive striking force.

<<In this invention, because the external shape of all eight rackets is the same, drawings of adult men's 4U and 5G size rackets are submitted as representative drawings, and drawings of rackets of other sizes are omitted. This application is a continuation of the previous patent application 6458211, and uses all drawings as they are, except for the additional drawings. The invention is implemented using drawings 1 to 13.>>
1 is a diagram showing the size of the steps on the outer surface of an eight-stick racket according to the present invention, suitable for children from elementary school students to adults. FIG. 1 is a front view showing the position of each part of a racket structure according to the present invention. Fig. 3-1 is a side view of the racket, and Fig. 3-2 is a front view explaining the structure of the head part. Enlarged views of Fig. 3-3, Fig. 3-4, and Fig. 3-5 explain the structure of the hammer part for adult men. Fig. 4-1 is a front view of the racket shaft, Fig. 4-2 is a top view of the elliptical neck (enlarged), Fig. 4-3 is a side view, and Fig. 4-4 shows a cross section of the elliptical neck (enlarged). Figure 5-1 is a design drawing of the jig mandrel for forming the shaft. Figure 5-1 explains the configuration of the shaft jig mandrel of the first proposal. Figure 5-2 explains the state in which both the left and right mandrel sets are placed in a case-type mold. Figure 5-3 is a diagram showing the shape of the mandrel of the second proposal. 6-1, 6-2, and 6-3 are explanatory diagrams showing the structure of three parts of a shaft jig case type mold for forming an elliptical shape. 7-2 is a cross-sectional view of the ellipse-forming portion of the case-type mold. 8-1, 8-2, and 8-3 show the appearance of a special jig case type mold for forming an elliptical shaft. 9-1, 9-2, 9-3, 9-4, and 9-5 explain the process of forming a shaft using a shaft jig core rod and a case-type mold. This paper explains the process of forming a shaft using a shaft jig core rod and a case-type mold in the second type shaft forming method. 11-1 is a front view, FIG. 11-2 is a side view, and FIG. 11-3 is a cross-sectional view showing the curved shape of the two-stage protrusion of the offensive and defensive grip portion of the racket in FIG. 3 is a perspective plan view of the grip portion of the racket of FIG. 2, showing the double-protruding shape for both offense and defense, which provides quick handling and striking power. 3 is a side view of the racket shown in FIG. 2, showing the state of bending that occurs when an external force is applied to the bending elastic neck of the racket.

The badminton and soft badminton racket set according to the embodiment of the present invention is embodied in 13 drawings.
The structure of a carbon material competitive racket according to an embodiment will be explained with reference to 13 drawings. The rackets start with the reference number 100. The racket 100 will be explained in the embodiment.
<<I created a list of eight items to make the invention easier to explain and understand, and all eight items are listed in the paragraph on means for solving the problem.
Eight tables with similar content are attached to the detailed description of the invention. Please note that they are duplicated.

<<Overview of the configuration of the racket 100 according to this embodiment>>
The present invention is a competitive badminton and soft badminton racket made of carbon fiber material suitable for hitting badminton and soft badminton shuttlecocks (it may be made entirely of aluminum for leisure use, or with a carbon head and aluminum shaft). The present invention is based on a badminton racket, which is light, thin, short and small in size due to its scalability, and has been evolved for elementary school students, with six racket sizes corresponding to the growth stages of elementary school students from 1st to 6th grade, plus two for junior high school students and above, and for adult men, for a total of eight sizes, and the racket has seven external sizes according to age stages, and since the external shape and structure are the same even though the sizes of each part are different, the structure of the racket 100 will be explained using Figures 1 to 13 of a 4U and 5G size racket as a representative diagram.

This embodiment provides a size chart (see Figure 1) for reference in selecting a racket for children from 6 years old to adult males, according to their developmental stage.
Unlike the badminton racket sizes listed above, the six-racket badminton racket for elementary school students in this invention has six sizes that correspond to the age, height, and physical strength of elementary school students. For example, the racket size for a first grade elementary school student is written as "11L, 11W, 9G," where L is the total length, W is the width, and G is the grip size.
Weight is determined by the racket's shape and size (total length and head width), frame thickness, shaft thickness, and grip size, but the weight of similarly sized rackets varies depending on the manufacturing techniques and materials used by each manufacturer. Therefore, this invention does not set weight sizes.
The length of the racket is set to be shortened in stages to 35 mm from the total length of 675 mm for adults.
In addition, the head width is set to be shortened in stages from 205 mm for adult rackets to 7 mm.
The external steps of the eight rackets in the set can be seen in Figure 1.

<<A schematic explanation of each component of the racket 100.>>
Figure 1 shows the length and width of an eight-racket set. (A racket set size chart is provided.)
2 is a front view showing the configuration of the racket 100. The racket 100 has a head portion 120, a shaft portion 130, and a grip portion 140.
The racket 100 has a total length of 675 mm and a width of 205 mm. The thickness 121B of the frame 121 (ball-hitting surface frame) of the annular head 120 is set to about 1.0 mm.
By placing a weight of about 3 to 7 g made of soft lead material 128 inside the hollow interior of the front end (only for adult men's rackets), a hammer section 122 is formed that can exert hammer-like hitting power. To improve the hitting surface, grommets and strings are added, and the main string section 123 and cross string section 124 are connected to the frame section 121, and a square-woven mesh hitting surface is formed by alternating cross-knit strings.
A T-shaped joint 125 (see Figure 3-2) is provided inside the T-shaped intersection formed to connect the lower end of the head portion 120 and the front end 131-F of the shaft portion 130 (a conventional method for firmly joining badminton rackets). A bendable elastic neck portion 132, which is deformed into an oval shape for 15 to 30 mm, is provided at the front end of the joined shaft where it comes into contact with the neck of the racket.
The rear end 131 of the shaft 130 is connected to the grip 140 for manipulating the racket. To achieve harmony between the thick grip and the thin shaft, the front end of the grip 140 is tapered, and a similarly shaped shaft cap 133 is attached to the tapered portion. The grip body is shaped like a flat octagonal curved rod, and a large, protruding elongated oval is formed in the center of the front half, forming a quick operation portion 140A. By narrowing the four diagonal surfaces 143, the thumb force application points on both the front and rear planes 141 are wider than the large planes of a normal grip.
The grip has a thin operating portion 140C for the ring finger and little finger at the waist.
The end of the grip is formed into a power end 140R with a large raised egg shape, forming an oblate octagon, allowing for gripping and hitting the ball, and an end cap 144 is attached to the end of 140R. The grip 140 has a two-stage raised curved shape, providing a dual grip for both offense and defense. A badminton and soft badminton racket set suitable for children from elementary school to adults can be constructed with the above components.

In FIG. 3-1 of Drawing 3, a side view of the racket is schematically illustrated. Upper and lower grommet portions 126 and large sized grommets 127 are fitted at intervals on the side of the frame portion 121.
The two-tiered curved side of the grip 140 connected to the rear end of the shaft 130 can be seen. Comparing it to the front view, it can be seen that the flat surface 142 on both sides of the grip is narrower than the width of the front surface 141, forming a flat octagonal shape.
In addition, an end cap portion 144 is attached to the end surface portion 140L and has a peripheral edge extending out by 1.5 mm (to serve as a guard for the grip tape), and 144 is integrally molded using hard plastic. Competitive badminton and soft badminton rackets made of carbon material can be constructed with the above-mentioned components.

A typical badminton racket has 76 grommets that fit into the head frame, 22 vertical strings, and 23 horizontal strings.
Regarding the size of the head portion 120 in 3-2 of Figure 3, the number of strings used for the eight rackets is divided into five sizes to accommodate the growth stages of elementary school students, and the following list of head portion configuration sizes (2) is listed excluding grommets.
In FIG. 3-2, the size of the head portion 120 will be described with reference to the attached table (2).
To make rackets lighter and easier for children of all ages to use, the rackets are divided into six grade levels, with the head size reduced accordingly. To reduce the weight of the head frame of the six sizes of rackets for elementary school students, the thickness of the 121B has been reduced. The thickness of the 121B frame for adult players is approximately 1.0 mm, and each subsequent level is approximately 0.08 mm thinner. (These are reference values; thickness is determined by the technology and materials of each manufacturer.)
The internal space of the head frame portion 121 has the same inner diameter (which may be gradually reduced), and the thickness is gradually reduced by the wall thickness 121B (not shown).
By reducing the size of the head and thinning the 121B wall thickness, or by making the outer shape thinner, the head frame becomes considerably lighter, making it possible to create a lighter, thinner, shorter and smaller racket.
The lighter, thinner, and shorter rackets reduce air resistance during swings. They can be used by children of all ages and are effective in preventing wrist and elbow pain.
Elementary school students start using small rackets from an early age and gradually switch to larger rackets as they grow. The smaller hitting surface requires more accurate hitting, and as the nervous system is developing at a young age, it develops a higher level of concentration and develops accurate timing for hitting the ball, reducing the chance of hitting the ball out of bounds throughout their life in badminton.

<<A method for forming the hammer portion 122 of the racket head for adult men will be explained in 3-3, 3-4, and 3-5 of FIG. 3>>
A soft lead of an appropriate weight (3 to 7 g) is formed into a rectangle of appropriate thickness, width, and length, and this rectangular lead plate is bent into a semicircular shape as shown in Figure 3-3 to form the soft lead member part 128.
In addition, the annular frame portion 121 of the head portion 120 is formed by a conventional processing method in which a carbon fiber sheet is wrapped around it in multiple layers, and a foamable resin rod-shaped core portion HAP, which is heated and foamed at the same time, is placed and wound into a cylindrical shape to form a resin sheet cylindrical portion 121U.When the cylindrical shape is formed by wrapping the sheet, the shape of the soft lead material portion 128 is reduced in the vertical direction of the foamable resin rod-shaped core portion HAP at the part that corresponds to the inside of the sheet at the center of the front end of the annular frame, and the soft lead material portion 128 formed as shown in Figure 3-3 is placed, and the carbon fiber reinforced sheet is wrapped around portion 128 and the foamable resin rod-shaped core portion HAP as shown in Figure 3-4 to form the resin sheet cylindrical portion 121U.
The resin sheet cylindrical portion 121U is bent into a ring shape and placed in a mold with both ends butted together, and then heated and pressurized, causing the foamable resin rod-shaped core portion HAP to foam and expand within the frame, thereby forcing the resin sheet cylindrical portion 121U to expand along the mold, and at the same time, the soft lead member portion 128 is also formed into the desired shape shown in Figure 3-5 along the mold in the same shape as the cylindrical portion 121U. The soft lead member portion 128 should preferably be in the range of 2 to 7 g.
The racket can be configured with a hammer portion 122 that increases the power of a 4U.5G size racket for adult men.
In addition, a second proposal has been made to reduce the manufacturing process for the hammer part 122, in which the method for forming the soft lead member part 128 is changed to a method of mixing soft lead pellets and a thermosetting adhesive.
Small pellets of soft lead are made and an appropriate amount of lead pellets are mixed into a thermosetting adhesive that hardens at about 120°C. The opening is sealed inside a sheet tube bag of 128 parts of the same thickness, and when the sheet is rolled into a cylindrical shape, the sheet tube bag containing the lead pellets mixed with the thermosetting adhesive is placed at the 128th position inside the center of the front end of the annular frame. The sheet is rolled into a cylindrical shape, bent into a ring shape, placed in a mold and molded using heat and pressure.
The racket can be configured with a hammer portion 122 that increases the power of a 4U.5G size racket for adult men.
The reason for attaching weights to the head frame of a racket can be understood by observing common sense. For example, the force generated when hitting an object with a wooden-handled hammer is determined by the weight of the hammer head; a light hammer head is weak, a heavy hammer head is strong. By following this tip, you can increase the striking power of a hammer by attaching weights to the head frame of a racket. (Note: Hammer rackets are not recommended for elementary school students and adult women, as their weak muscles make them prone to wrist and elbow injuries.)

As part of the measures taken to improve the racket's cutting and power performance, the present invention reduces the number of strings used to enlarge the mesh on the hitting surface. First, the head of a 4U.5G size racket has 18 vertical strings 123 and 19 horizontal strings 124 (20 is acceptable), interlaced to form an even 10mm square mesh hitting surface. The mesh is enlarged for the following sizes, as shown in Table 2. Reducing the number of strings accordingly also requires a corresponding reduction in the number of grommets and a corresponding change in their placement.
By reducing the number of grommets and strings and enlarging the weave as a result of the above-mentioned measures on the hitting surface, even young players can swing lightly and at high speed.

Until now, the shaft supporting the annular head of a racket has been manufactured using conventional methods, with a hollow cylindrical shape made by winding multiple layers of carbon fiber prepreg. However, this requires the material to be extremely rigid, which has the problem of making it difficult to flex. It is extremely difficult for a single shaft to simultaneously achieve both of these performance characteristics.
However, the present invention solves the problem of compatibility by providing an elliptical bending elastic neck portion 132, making it possible to simultaneously exhibit rigidity and flexibility performance in a single shaft.
The shaft portion 130 is divided into three sections to provide an oval shape at 132: a front end 131-F, a bending elastic neck portion 132, and a rear end 131 in the shaft center.
The structure of the shaft portion 130 in FIG. 4 will be briefly described below.
4-1 is a front view of the shaft. An elliptical bending elastic neck 132 is provided at the front end of the center-rear end 131 of the cylindrical shaft, followed by the shaft front end 131F. The protrusions on both sides of the elliptical portion 132 from the shaft portion 131 indicate the major axis 134 of the elliptical shape 132.
4-2 is an enlarged view showing the state where the cylindrical shaft front end portion 131F overlaps the elliptical bending elastic neck portion 132, as seen from above. 134 is the major axis of the elliptical portion 132, and 136 is the hollow portion of the shaft.
FIG. 4C is a diagram showing the ratio of the minor axis of the elliptical portion 132 to the thickness of the shaft middle butt end 131 as viewed from the side of the shaft.
The enlarged view of FIG. 4-4 shows the state where 132 and 131 overlap as viewed from the cross section of 132.
The shaft sizes for each racket size are listed in Table (3).
<Note: It is understood that the standard inner and outer diameters of the shaft are approximately 3.5-4.0 mm and 7.0-8.0 mm, respectively. However, in this invention, the bending elasticity range of the shaft is limited to the elliptical bending elasticity neck at the front end of the shaft, and the inner diameter of the shaft has been expanded to 4.2 mm in order to achieve bending rigidity in other parts.>
As shown in the table above, in order to accommodate the growth stages of elementary school students, each part of the shaft structure is gradually shortened, the wall thickness is made thinner, and the outer diameter is made narrower from large size to small size.

To connect the front end 131F of the shaft to the racket head frame 121, conventional manufacturing techniques are used, with both horizontal ends of an adhesive-applied T-shaped joint inserted into the hollow of the annular frame, and the lower vertical end inserted into the hollow portion 136 of the front end 131F of the shaft, and the connection can be achieved by wrapping FRP resin tape around the outer periphery of the joint between the frame and the shaft.
To enhance the resilience of the racket when hitting, and to improve its flexibility, an elliptical bending elastic neck 132 is provided below the joint. Because the elliptical bending elastic neck 132 has both a major axis and a minor axis, the major axis parallel to the hitting surface is strengthened in rigidity and does not distort, while the minor axis facing the hitting surface has weaker bending rigidity, greatly amplifying the bending flexibility.
The flexibility of the club dampens and suppresses the vibration and resonance of the ball, blocking the impact force on the wrists and elbows of young children, reducing the strain on the hands, necks and elbows.
In addition, the explosive rebound force at the moment the elliptical bending elastic neck returns to its original shape significantly increases the power of the ball.
The following is a list (3) of the sizes of the elliptical bending elastic neck portion 132.
(The elliptical bending elastic neck is formed using a shaft forming jig, which will be described later.)
The lowermost end of the center butt end 131 of the shaft is inserted into a hole formed in the front end of the grip 140 and glued thereto, thereby being integrally joined to the racket.

In the above invention, a jig for forming an elliptical bendable elastic neck of a shaft of a racket set for badminton and soft badminton,
This invention has also been developed for a jig core rod and case-type mold for forming a shaft with an elliptical bending elastic neck, and provides two methods for forming the shaft for the convenience of manufacturers.
With reference to Table 5, the structure of the shaft jig core rod will be explained in the order of Figures 5-1, 5-2, and 5-3 of Drawing 5.
In the present invention, in order to form the shaft jig core rod portion 200 into an elliptical shape, unlike conventional core rods, a three-stage shape is provided, consisting of the core rod central rear end portion 211, the elliptical shape forming portion 212, and the sliding cylindrical core rod portion 213.
In the first method, the shaft thickness for elementary school students is divided into three stages, with two shafts per stage, and is gradually made thinner, so there are four stages in the core rod thickness size (one type for adults).Since the structure is the same, the core rod drawing for adults in Figure 5-1 will be used as a representative diagram for explanation.The core rod drawing for elementary school students will be omitted.
The structure of the shaft jig core rod will be explained in (1), (2), and (3) of Figure 5-1.
(1) is a metal rod (which may be stainless steel) with high bending rigidity, formed into two thicknesses, and an oval-shaped portion 212 with a diameter of 2 mm is machined and formed at the front end of a rear end portion 211 of a core rod with a diameter of 4.2 mm by a lathe machining method, and 212 is made long so that a sliding cylindrical core rod portion 213 can be attached.
(2) shows the slide cylindrical core rod portion 213 having a diameter of 4.2 mm formed at the shaft front end 131F. 213H is the hollow portion of the cylindrical core rod portion 213.
(3) The front end 212 of the central rear end 211 can be inserted into the hollow portion 123H of the slide cylindrical core rod portion 213 to form a shaft jig core rod configuration.
The second method will be explained in Fig. 5-2. Two metal core rods of appropriate length are formed, one at the rear end 211X and the other at the front end 213V, with an outer diameter similar to the inner diameter of the size shaft.
When winding the shaft using resin sheet 130S, a heat-foamable resin rod-shaped core portion HAP can be placed in an elliptical area between the middle rear end portion 211X and the front end portion 213V, resulting in a second shaft jig core rod configuration.
Figure 5-3 shows the half shape of the jig case type mold for the shaft, 241 is the forming part of the front end part 131F of the shaft, 242 is the forming part of the elliptical bending elastic neck part 132 of the shaft, 243 is the forming part of the middle rear end part of the shaft, and 245 are the lid type stopper parts at both ends of the jig case.
The shaft jig core rod portion 200 is inserted into the half mold, and the front and rear end faces of the core rod are fastened to the lid-type stopper portions 245 on both ends of the mold.

<<The configuration of the jig case type die part 240 for the shaft will be explained in outline with reference to Figures 6, 7, and 8.>>
FIG. 6 shows a three-part exploded perspective plan view of a 240-case mold section with a two-half vertically split cylindrical forming device opened.
Figure 6-1 shows that a case-type mold edge portion 244 is provided on the outside, and adjacent to it are a portion 241 for forming the front end 132 of the shaft, a portion 242 for forming the oval shaft, and a portion 243 for forming the middle rear end 131 of the shaft, and that lid-type stoppers 245 are provided on both ends of 241 and 243. (245 is a stopper that fixes the position of the core rod.)
Also, a shaft cylinder portion 253 is provided at the center to connect both the half forming devices, and a one-sided shaft forming device is configured.
Figure 6-2 shows a one-sided shaft forming device having three case-type mold locking sections 260 provided on the edge section 244 of the outer case-type mold, 260 having a lock rotation shaft section 261, a lock manual operation lever section 262, and a lock hook stopper section 263 (since the middle and rear sections of the device are long, 260 may also be provided in one location). Adjacent sections are provided with a shaft front end 131F forming section 241, a shaft oval forming section 242, and a shaft middle and rear end 131 forming section 243, with lid-type stoppers 245 provided on both ends of 241 and 243, and a shaft tube section 253 attached to the center to connect both half forming devices.
In Figure 6-3, an opening and closing device (hinge) part 250 for the left and right half forming devices of the case-type mold is provided in the center of the left and right half forming devices, and a core rod head part 251 of the opening and closing device and a rotating shaft part 252 for opening and closing the left and right half forming devices are provided.
The above is a diagram showing the layout of each part of the case-type mold for the shaft forming device.
Referring to FIG. 7, the structure of the jig case type die part 240 for the shaft will be described.
As shown in Figure 7-1, it is desirable to alternately fit the shaft tube portions 253 attached to the center of the left and right piece forming devices, insert the core rod head 251 into the hollow of 253 using the rotating shaft portion 252 up to the end of 253, and attach a nut-shaped stopper to the protruding portion of the rotating shaft portion 252 from the other end of the shaft tube portion 253 to prevent it from being pulled out (not shown).
FIG. 7-2 is a cross-sectional view of the ellipse forming position of the case-type mold, showing the half-cylinder shapes of the ellipse forming portion 142 and 141, 143.
The shaft jig case type mold 240 can be configured by the above-mentioned parts.

FIG. 8 shows an external view of the shaft jig case type mold 240.
In FIG. 8-1, the position and shape of each component can be seen from the side of the case-type mold 240 in the closed state.
In FIG. 8-2, the layout positions of each part and the shape of each part device can be seen from the front of the case-type mold 240.
8-3 is a cross-sectional view of the middle part of the ellipse-shape forming portion 242 of the case-type die 240. The structure of each part of the shaft jig case-type die can be seen.
The shaft jig case type mold 240 is configured as shown in the three drawings of Drawing 6, Drawing 7, and Drawing 8.
Alternatively, it is preferable to use a material that can withstand high temperatures and does not deform at high temperatures as the material for the shaft jig case type mold.

<<In addition, the method and procedure for forming a shaft provided with an elliptical bending elastic neck portion 132 using the jig core rod portion 200 and case-type mold portion 240 of the shaft of the first construction method will be explained with reference to Figure 9.>>
The formation of the shaft 130 using the shaft jig core rod portion 200 and shaft jig case mold portion 240 thus constructed will now be described.
As shown in Figure 9-1, the connection state of the core rod rear end 211 that forms the middle rear end 131 of the shaft, the elliptical bending elastic neck forming core rod portion 212, and the sliding cylindrical core rod portion 213 that forms the front end of the shaft is confirmed, and the winding work using the resin sheet portion 130S is started.
As shown in Figure 9-2, a heat-foamable resin part HA is placed on the outer periphery of an elliptical bending elastic neck-forming core rod part 212, and a sheet part 130S containing carbon fiber, carbon nanotubes, and a binder is wound around the outer periphery of the connected core rod part 200 as shown in Figure 9-2 to form a shaft resin sheet cylindrical part 130U having a thickness of 1.2 mm to 1.4 mm.
The formation of the elliptical bending elastic neck 132 is explained in Fig. 9-3. In Fig. 9-2, the formed resin sheet cylindrical portion 130U is placed in the case-type mold 240 while still attached to the shaft mandrel 200 (opened as in Fig. 7-1, the case-type mold is opened), and the mold is closed using the opening/closing device 250 and locked using the operating lever 262 of the locking portion 260. This is the state shown in Fig. 9-3.
Depending on the state in which the elliptical forming portion 242 of the case-type mold is clamped, the shaft resin sheet cylindrical portion 130U is formed into an irregular elliptical shape, and by heating the mold in a high-temperature chamber, the foamable resin portion HA provided on the outer periphery of 212 is expanded by the force of foaming, and the elliptical resin sheet cylinder is pushed out to fit the mold, and the elliptical bending elastic neck portion 132 is formed regularly.
9-4 is a cross-sectional view of the ellipse forming portion 242 of the case-type mold, and shows the ellipse-shaped bending elastic neck portion 132 enclosed by the semi-ellipse 242 on both the upper and lower halves. The cross-section of the ellipse-shaped bending elastic neck forming core rod portion 212 at the center is also confirmed. It can be seen that the ellipse shape of the bending elastic neck portion 132 exactly matches the shape of the ellipse forming portion 242 of the case-type mold.
Figure 9-5 shows how the locking portion 60 of the case-type mold is unlocked to open the case-type mold, the shaft tube attached to the core rod portion 200 is removed, and the core rod rear end portion 211 and the sliding cylindrical core rod portion 213 are pulled out from both ends of the shaft resin tube 130U, thereby forming the shaft portion 130.

The reason for submitting the second proposal is that increasing the elasticity of the elliptical bending elastic neck 132 is the most effective way to shorten the minor axis of the ellipse. It is thought that it would be impossible to make the core rod 212 that forms the elliptical bending elastic neck thinner than the 2 mm diameter proposed in the first proposal.
The minor diameter of the ellipse shape can be adjusted by replacing the core rod 212 with a heat-foamable resin rod-shaped core part HAP and shortening or enlarging the minor diameter of the ellipse-forming part 242 of the case-type mold. (The thickness of the heat-foamable resin rod-shaped core part HAP must be adjusted appropriately.)≫
Next, the shaft jig core rod portion 200 of the second construction plan is composed of three stages: the core rod rear end portion 211X (the elliptical bending elastic neck forming core rod portion 212 of the first construction plan is eliminated and a heat-foamable resin rod-shaped core body portion HAP is inserted instead), the heat-foamable resin rod-shaped core body portion HAP, and the front end core rod portion 213V. The formation of the shaft 130 using the core rod and the shaft jig case mold portion 240 will be explained in brief.
As shown in Figure 10,
In FIG. 10-1, only the front end 213V and the rear end 211X of the core rod portion 200 are visible, but it is confirmed that the elliptical bending elastic neck forming core rod portion 212 has been eliminated.
FIG. 17-2 shows the operation of winding the core rod rear end 211X, the heat-foamable resin rod-shaped core body HAP, and the front end core rod 213V in a connected state using a sheet 130S containing carbon fiber, carbon nanotubes, and a binder.
10-3 shows a cylindrical shaft resin sheet portion 130U having a thickness of 1.2 mm to 1.4 mm, which is formed by wrapping multiple layers of resin sheet 130S around the outer periphery of the connected core rod portion 200. The oval-shaped portion is confirmed to be a heat-foamable resin rod-shaped core portion HAP.
10-4 shows that the resin cylindrical portion 130U wound around the shaft jig core rod portion 200 is fitted into a case-type mold 240. In this state, it can be heated and formed in a high-temperature chamber.
FIG. 10-5 shows the completed state of the shaft portion 130 after heat hardening.
The second method for forming the shaft is the same except that the core rod portion 212 is eliminated and a heat-foamable resin rod-shaped core portion HAP is inserted instead, so the explanation of the flow of the manufacturing process will be omitted.
The shaft portion 130 having the elliptical bendable elastic neck portion 132 can be formed by the above two shaft forming methods.
The elliptical shape of the racket's elastic neck greatly amplifies flexibility, suppressing and damping vibrations and resonance when hitting, and also blocking the impact force, making it less likely to be transmitted to children's hands, reducing strain on the wrists and elbows.
In addition, by providing a bending elastic neck at the tip of the shaft, the bending range of the shaft is narrowed to one point at the tip, further improving operability.
Furthermore, the repulsion force is greatly increased, making it possible to hit the ball with high repulsion.

The raised shape at the rear end of the grip dates back to the ancient sword grips, and is now widely used in tool grips and various hand levers.
Until now, racket operation has been limited to a single point grip, due to the straight, flat, octagonal rod-shaped grip, making it difficult to exert sufficient hitting power.
Furthermore, when attempting to achieve a curved flight, it is necessary to create an oblique face by pronating and supinating the wrist and elbow, which can result in insufficient hitting power and can cause pain in the elbow and wrist.
The offensive and defensive grip of the present invention uses a two-stage raised curved shape and has a multi-operation function of a two-point grip.
The structure of the grip portion 140 will be comprehensively and briefly explained below with reference to the front view of FIG. 11-1 and the side view of FIG. 11-2 in FIG. 11 and the plan perspective view of the grip portion 140 of FIG. 11-3 and FIG.
In order to ensure harmony between the thick grip portion and the thin shaft portion connected to it, the front end of the grip 140 is formed into a tapered shape, and a shaft cap portion 133 of a similar shape is attached in a tapered shape, and the rear end portion 131 of the shaft portion 130 is inserted into and joined to a hole formed at the front end of the grip portion 140.
The quick operation portion 140A of the grip portion 140 will be described below.
In the front half of the non-tapered part of the grip, the diagonal width part 143 of the deformed octagonal bar is narrowed to four planes, so that the width of the two planes parallel to the hitting surface, the thumb force application point part 141 and both side parts 142, is wide, and an agile operation part 140A is provided for twisting the grip using the thumb, index finger and middle finger, and because the diagonal part 143 is narrow, the corner parts protrude clearly, so the direction of the hitting surface can be accurately controlled by the sense of the fingers, and the fingertips do not slip when twisting, making it easy to make instant changes to the hitting surface during an intense game.
Below is a list (6) of the total length of each racket grip and the size of the quick operation part 140A.
In addition, the width of the eight sides of the grip is narrowed by cutting it into the lower part of the grip, and a thin auxiliary operating section 140C for the ring finger and little finger is provided.
By narrowing the 140C portion, the front and rear ends of the grip bulge out greatly, forming a two-stage curved shape.
The front of the grip is formed with a large, almost elongated oval shape and a large protrusion that fits perfectly to the shape of the palm of the hand, providing an optimal, agile control section 140A. During a match, the ring finger and little finger hold 140C securely, and the thumb, index finger, and middle finger twist and turn 140A, switching the racket face from side to side to change the flight, allowing for effective, subtle manipulation.
A list showing the cross-sectional size of the grip portion 140C of each racket was submitted.
Next, the power end portion provided at the rear end of the grip portion 140 will be described.
The end portion R of the grip is formed in a flat octagonal, egg-shaped shape with a large protrusion, and this protrusion shape fits perfectly with the shape of the palm, making it optimal for gripping, and by providing a power end portion 14R that can fully exert hitting power, the grip portion 140 is configured with a curved grip with two protrusions and a dual grip that combines offensive and defensive functions.
The cross-sectional size of the grip portion 140R of each racket is listed in a table.
In addition, the peripheral edge of the hard plastic end cap portion 144 attached to the end 140L extends 1.5 mm beyond the end surface 140L, which helps prevent the grip tape from slipping off. This allows the wrapped grip tape to remain in good condition even after long-term use.

The functions of each part of the grip will be explained with reference to Figures 11 and 12.
First, when using 140A to operate the racket, the 140C portion is thin and slightly circular, so during a match, you hold and stabilize the 140C portion with your ring finger and little finger, and twist and turn 140A with your thumb, index finger, and middle finger, which makes it easier to rotate the racket, allowing you to freely change the hitting surface to the left or right at the moment of impact, allowing for fine and skillful operation.
In addition, since the diagonal surface portion 143 is narrow, the corner portion protrudes clearly, so the direction of the hitting surface can be accurately controlled by the sense of the fingers, and the fingertips do not slip when twisted, making it easy to make instant changes to the hitting surface during an intense game.
Furthermore, the 140A mid-ridge elongated oval shape fits perfectly with the palm of your hand, allowing you to fully exert your hitting power.
Grip styles can be broadly divided into three types: Eastern grip, Western grip, and thumbs up. Each grip has its own advantages and disadvantages, so you can easily and freely switch between the three grip styles depending on the flight during an intense match.

Furthermore, 60% of the defensive range is occupied by the thumb operating part 141, and the power of the thumb is used to hit back cross shots, course changes, etc. The technique involves holding the racket steady with the ring finger and little finger at part 140C, twisting the racket with the thumb using the wide width of part 141 and the index finger and middle finger using part 143. The greatest feature is that the axis of rotation is small, allowing the racket to rotate quickly. For applied flights, it is easier to receive smashes and pushes with the thumb up. Furthermore, it can be easily used for situations that require a quick change in racket face direction.
In particular, when dropping the shuttlecock from the middle or back of the court to sink it into both sides of the front of the opponent's court, you can quickly change the face angle to cut the shuttlecock and send it flying diagonally.
Furthermore, from the rear left of your court, you can aim at the left side of your opponent's court and perform a cut smash by quickly changing the angle of the face at the moment of impact without having to pronate your wrist or elbow.The biggest feature is that the hitting surface changes at the moment of impact, making it difficult to tell where the ball will hit until just before it is hit, making it difficult for the opponent to read the course.

Furthermore, the role of the grip end of the conventional badminton racket is to prevent the racket from slipping out of the hand, making it extremely difficult to hit the ball with a proper grip.
The end portion 140R of the racket grip of the present invention is a flat octagonal, large raised egg shape that fits snugly in the palm of the hand. The advantage of gripping this end portion is that the mid-distance between the end portion where the hand applies force and the point of application of force on the hitting surface is extended by approximately 50 to 60 mm, which increases the shuttle's impact point and shortens the flight between the impact point and the landing point, shortening the time difference and also enabling greater hitting power.
In addition, by holding the 140R, you can further increase the success rate of the most aggressive smash, which is an overhead stroke that is hit at an acute angle towards the opponent's court.
Furthermore, the power end 140R allows not only singles players but also doubles players to grip the club at the moment of impact and hit the ball. Gripping the end increases the distance between the end where the hand applies force and the hitting surface, greatly increasing the impact power.
By using the above elements, we can provide a racket set for badminton and soft badminton that can be used by people from elementary school students to adults.

<<A conventional cylindrical shaft has the same bending rigidity in all directions when an external force is applied, so it cannot bend in just one direction.>>
However, the elliptical bending elastic neck is different in that it has both a major axis and a minor axis. Because the major axis parallel to the hitting surface has increased rigidity and does not distort, while the minor axis facing the hitting surface has weaker bending rigidity, greatly amplifying the flex range. This significantly increases the explosive repulsion and hitting power when the elliptical bending elastic neck recovers its original shape. Figure 13 shows the racket bending elastic neck 132 when an external force is applied, and the bending rigidity of the center-rear portion 131. This solves the problem of a single shaft being unable to simultaneously achieve both rigidity and flex performance. By simultaneously achieving both rigidity and flex performance in a single shaft, controllability is effectively improved and the power of the shot is significantly increased.
In addition, the bending elastic neck portion 132 causes the bending reaction point of the shaft portion to be concentrated at one point at the front end, increasing the rigidity of the middle and rear portions, making it easier to control the racket.
Furthermore, the adult male competitive racket has the above-mentioned reform of the hitting surface, the provision of an elliptical bending elastic neck at the tip of the shaft, an improved structure with a two-stage raised curved grip, plus the provision of a hammer section at the tip of the head frame, which realizes destructive striking power like a hammer, making it possible to provide the strongest racket ever equipped with offensive and defensive capabilities.

This badminton and soft badminton racket set, suitable for children from elementary school to adults, is also suitable as sports education equipment for elementary schools.

L indicates length. W indicates width. T indicates side. G indicates grip size.
120 Head portion. 121 Frame portion. 121U Cylindrical resin sheet portion. 121B Frame thickness. 122 Hammer portion. 123 Longitudinal strings. 124 Cross strings. 125 Joint portion. 126 Small size grommet portion. 127 Large size grommet portion. 128 Soft lead member portion. HAP Heat-foamable resin rod-shaped core portion.
130 Shaft portion. 130S Resin sheet portion. 130U Cylindrical resin portion of shaft. 130B Shaft wall thickness. 131F Front end portion of shaft. 131 Middle rear end portion of shaft. 132 Elliptical bending elastic neck portion. 133 Shaft cap portion. 134 Major axis of elliptical neck portion. 135 Minor axis of elliptical neck portion. 136 Hollow portion of shaft.
140 Grip section. 140A Quick operation section for twisting the grip using the tips of the thumb, index finger, and middle finger. 140C Auxiliary operation section for the ring finger and little finger, 140R Power end section. 140L End end surface section. 141 Thumb force application point section on both the front and back planes. 142 Both left and right side sections of the grip. 143 Diagonal surface section. 144 End cap section.
200 Shaft jig core rod portion. 211 Core rod rear end portion. 212 Elliptical bending elastic neck forming core rod portion. 213 Sliding cylindrical core rod portion. 213H Cylindrical core rod hollow portion. 211X Core rod rear end portion. 213V Core rod front end portion. HA Heat-foamable resin portion.
240 Shaft jig case type mold part 241 Shaft front end outer shape protection part 242 Shaft oval forming part 243 Shaft middle rear end outer shape protection part 244 Edge part of case type mold 245 Lid type stopper parts on both ends of jig case
250 Opening and closing device part of double-piece forming device of case-type mold. 251 Core rod head part of opening and closing device. 252 Rotating shaft part of double-piece forming device. 253 Shaft cylinder part attached for connecting the double-piece forming devices.
260 Lock part of case type mold 261 Rotating shaft part of lock 262 Manual operation lever part of lock 263 Hook stop part of lock

Claims (5)

Badminton and soft badminton rackets for elementary school students to adults
It is a set
The competitive rackets used by elementary school students from the age of 6, when they can start playing racket sports, to adult players, are manufactured using lightweight, highly elastic, and extremely strong carbon fiber material.
As elementary school students grow, the size of the racket changes, so there are six sizes of rackets.
In order to accommodate the height of elementary school students, the racket has six sizes for elementary school students, which are gradually reduced in size based on the outer size of an adult racket.
Table 1 shows the recommended racket set sizes for different ages.
Eight sizes of rackets as listed in Table 1 above are provided.
A badminton and soft badminton racket set suitable for everyone from elementary school students to adults . 2. The badminton and soft badminton racket set according to claim 1, suitable for use by elementary school students through adults ,
The racket set for elementary school students has a head frame that is reduced in size step by step to reduce the weight of the racket,
The internal spaces of all the head frames of the above sizes are provided with the same inner diameter dimension, and the wall thickness is made thinner step by step, so that the outer diameter is made thinner step by step.
In order to increase the elasticity of the head guard and the power of the shot, the number of vertical and horizontal strings is reduced according to the size.
In order to exert the hitting force of the head girder surface in all directions equally, the head girder surface has a square-woven girder hitting surface where vertical and horizontal strings intersect,
The square mesh girt hitting surface is formed so that it expands in two stages from a large size racket to a small size racket in order to accommodate elementary school children,
The hammer portion of the racket for adult men is formed by disposing a soft lead weight of 3 to 7 g inside the hollow interior of the front end of the head frame of the 4U/5G size racket for adult men,
Each racket head configuration has the size shown in Table 2 below.
A badminton and soft badminton racket set suitable for everyone from elementary school students to adults . 2. The badminton and soft badminton racket set according to claim 1, suitable for use by elementary school students through adults ,
The racket for elementary school students has an inner diameter of a shaft supporting an annular head that is gradually tapered in two stages in order to gradually reduce the weight of the racket to a smaller size,
The thickness of the shaft is made thinner in two stages based on the thickness of the racket size for adults,
The outer diameter of the shaft is tapered in two steps depending on the inner diameter and wall thickness of the shaft,
Furthermore, the length of the shaft is set to be gradually shorter for elementary school students according to the size stages,
The racket shaft has the dimensions of each part listed in Table 3 below.
In order to increase the bending elasticity of the racket shaft of the racket size 8, the neck portion of the racket, which is the front end of the shaft cylinder, is deformed into an elliptical shape, and the long axis of the elliptical shape is set parallel to the hitting surface,
The elliptical bending elastic neck has the sizes of each part shown in Table 4 below,
A shaft having an elliptical bending elastic neck is formed using a jig core rod and a case-type die for forming the shaft,
A badminton and soft badminton racket set suitable for everyone from elementary school students to adults . A method for forming a shaft of a badminton and soft badminton racket set suitable for use by elementary school students through adults, using a jig core rod and a case-type mold, as set forth in claim 3,
The forming method using a jig mandrel and a case-type die for forming a shaft having an elliptical bending elastic neck uses the jig mandrel of the first or second proposal,
The first proposal includes a jig mandrel corresponding to each mandrel outer diameter size listed in Table 4, which can be used to form a jig mandrel for forming a shaft,
The second proposal involves preparing two metal core rods of appropriate length and short length, each having an outer diameter similar to the inner diameter of the shaft, and when winding the shaft into a cylindrical shape using a resin sheet, inserting a rod-shaped heat-foamable resin into the elliptical portion, and arranging the long and short core rods at both ends to form shaft jig core rods corresponding to the core rod outer diameter sizes listed in Table 4.
The two types of jig mandrels of the first or second proposals for forming a shaft having an elliptical bending elastic neck have the sizes listed in Table 5 below,
The jig core rod of the first embodiment for forming the elliptical bending elastic neck portion of the racket shaft comprises a metal core rod having an outer diameter similar to the inner diameter of the shaft, and a 2 mm diameter elliptical forming portion machined by a lathe at the front end of the metal core rod.
Further, a sliding cylindrical core rod portion having an inner diameter of 2 mm and an outer diameter similar to that of the rear end portion of the core rod is provided,
The case-type mold of the shaft jig described above has a shape for forming a three-stage shaft in which a semi-elliptical shape is formed on both sides of a half pipe and a semi-cylindrical shape is provided on both ends thereof,
In addition, a device is provided for connecting the forming molds in parallel and opening and closing them using three stages of semi-cylindrical, semi-elliptical and semi-cylindrical shapes on both sides,
Furthermore, the method has a structure in which lid-type stoppers are provided on both ends of the case-type mold in which both pieces forming the shaft are formed in the shape of a half pipe,
a device lock is provided to prevent the shaft forming device from being opened after being closed;
A forming method using a jig core rod and a case-type mold for forming a shaft having an elliptical bending elastic neck portion, characterized in that: 2. The badminton and soft badminton racket set according to claim 1 , suitable for use by elementary school students through adults ,
The grip part for manipulating the racket has an octagonal shape at the front, and the widths of the four diagonal corners are narrowed to widen the widths of the two sides facing the ball-hitting surface and the two sides facing the side, creating a raised shape that is optimal for gripping with the hand.
The total length of the grip and the size of the eight sides of the quick operation part have the total length and size listed in Table 6 below,
By cutting out about two-thirds of the grip from the front end, the width of the eight sides is narrowed, making it thinner, and it has auxiliary operating parts for the ring finger and little finger.
The cross-sectional size of the auxiliary operating portion of the grip for the ring finger and little finger has the size listed in Table 7 below,
The grip has an end portion provided with a power end portion, which is an egg-shaped grip portion that protrudes more than the front half portion,
The cross-sectional size of the power end portion provided at the end portion of the grip has the size listed in Table 8 below,
The raised agile operation part, the thin auxiliary operation parts for the ring finger and little finger, and the raised power end part form a curved shape like a two-stage protrusion, providing both offensive and defensive functions with agile operation and striking power.
A badminton and soft badminton racket set suitable for everyone from elementary school students to adults.