JPH01262877A - Tennis racket - Google Patents

Abstract

PURPOSE:To minimize an impact oscillation at the time of driving a ball propagated to the palm of a human being at a gripping part, to converge a tennis racket in a short time, and to obtain a comfortable ball driven feeling by stringing an elastic chord from a horizontal frame piece at the lower side of an annular frame part to the root of the forked part of a gripping handle part under a state in which the tension of the elastic chord is freely adjustable and fixing a mass body to the middle part of the elastic chord. CONSTITUTION:A frame 1 forms the ring frame part to be a ball driving part 2 by bending one shaft material into an annular shape. Further, the frame 1 forms a bar-shaped part to be a gripping handle part 3 by putting together both edges of this annular frame part. Therefore, the upper part of the gripping handle part is made into a forked part 31, and the lower part is composed as a gripping part 32 in which both the edges are overlapped and made into one. This gripping part 32 is formed with a base layer composed of a foaming synthetic resin stratified on the circumferential surface of a gripping handle base substance and a casting layer composed of either artificial leather bands or natural leather bands to coat the external surface of this base layer. Thus, the impact force generated at the ball driving part oscillates only the mass body under a suspended state by the elastic chord, and the amount of the impact force propagated to the palm of the human being gripping the tennis racket at the approximately tip of the gripping handle part can be extremely small.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a tennis racket.

2. Description of the Related Art Conventionally, a tennis racket has a ring-shaped ball-hitting part covered with a net in order to hit a tennis ball, and a handle part for rotating the ball-hitting part. The peduncle is a hard skeletal body that is integrally continuous with the peduncle. In particular, 1
When making a handle from book shaft material by combining both ends of the annular frame, the handle will be Y-shaped.
A substantially triangular space is formed between the horizontal frame piece, which is the lower side of the annular frame part, and the Y-shaped handle part.

Problems to be Solved by the Invention In such a tennis racket, since the ball-hitting part and the grip part are connected to each other by a hard skeleton that is a frame, the impact force generated on the ball-hitting surface at the time of hitting the ball is directly transmitted to the ball-hitting surface. It is often transmitted to the palm, causing a shock to the hand and arm.

If the impact force does not accurately hit the ball with the core of the ball hitting part, the shock waves will resonate and act strongly on the palm of the hand, which can cause sports injuries to the wrists, elbows, shoulders, etc. of beginners. In addition to the fact that there are many
In addition, the impact force from a batted ball generally propagates through the frame and reaches the palm of the hand, so there is almost no attenuation.
There is a problem in that even experienced athletes may develop sports injuries due to long hours of practice.

Means for Solving the Problems In order to solve the above-mentioned problems, the tennis racket of the present invention has a tennis racket frame including an annular frame portion and a Y-shaped handle portion. It is characterized in that an elastic value is stretched from the horizontal frame piece to the base portion of the handle portion so that its tension can be adjusted freely, and a mass body is fixed to the middle part of this elastic value.

Function: Since the tennis racket of the present invention is as described above, the impact force generated at the ball hitting portion only vibrates the mass suspended by the elastic value, and the tennis racket is gripped almost at the tip of the grip portion. Very little of it is transmitted to the palm of a person's hand.

In other words, since the mass body is supported by elasticity in the space between the horizontal frame side of the annular frame and the Y-shaped handle, vibrations caused by the impact of the ball are quickly transferred to this mass body. while the vibrations of the frame itself are quickly damped.

This is because if the weight of the mass body and the spring constant of the elastic value that supports the mass body match the weight of the frame, the natural frequency, etc., a configuration in which the mass body is fixed and the elastic value is stretched is so-called. This is because it acts as a dynamic vibration absorber, and the vibration of the frame is replaced by the vibration of the mass body. On the other hand, the unique structure in which a mass body is supported with elasticity in the space between the horizontal frame side of the annular frame part and the Y-shaped handle part tickles the playfulness of modern young people and stimulates their desire to purchase. bring about

Embodiment FIG. 1 is a front view of the main parts of a tennis racket (1) which is an embodiment of the tennis racket of the present invention.The frame shown here is made by bending a rigid skeleton, and the upper part has a It has an annular frame portion for forming a ball-hitting surface, and a rod-shaped portion integrally formed with the core portion is connected to the annular frame portion.

This frame is made by bending a single shaft material into an annular shape to create an annular frame that spans the ball-striking part, and by bringing together both ends of this annular frame to create a rod-shaped part that is the grip handle 3. The upper part is a bifurcated part 31, and the lower part has both ends overlapped to form a grip part 32. In the embodiment, this grip part 32 is formed by layering on the circumferential surface of the grip handle base. It consists of a base layer of foamable synthetic resin and an outer covering layer of artificial or natural skin covering the outer surface of this base layer.

The above frame is integrally made of a shaft material made of glass fiber reinforced plastic with a core material made of foamable synthetic resin. There is a method of wrapping prepreg, which is a fiber-reinforced plastic molding material, around the material and molding it under heat and pressure in a mold.Another method is to wrap prepreg around a rod-shaped core material to form a single rod-shaped shaft. After obtaining the shaft material, there is also a method of bending the shaft material and fitting it into a mold to form the shaft material under heat and pressure. A horizontal frame piece 21 is installed at the upper end of the bifurcated portion 31 of the handle portion 3 as the lower side of the annular frame portion, and on this horizontal frame piece 21 are threads of catgut lines and guts 22 made of nylon thread, which will become the ball-hitting surface. The ends are locked. In addition, this horizontal frame piece 2! There is a method in which prepreg is wrapped around a core material installed as the lower side of the annular frame so that it is molded at the same time as the annular frame during heating and pressure molding, and another method is to wrap the prepreg together with the annular frame. There is a method of fixing the horizontal frame pieces with screws, adhesive, etc.

In the embodiment, the M@body 5 is disposed in the space 4 surrounded by the horizontal frame piece 21, which is the lower side of the annular frame, and the bifurcated portion 31 of the grip handle. , an elasticity value of 6 is stretched from the horizontal frame piece 21 to the bifurcated part 31,
The MR body 5 is supported in the middle of its elasticity value 6.

For the elasticity value 6, piano wire is used, the upper and lower parts are divided at one point in the middle, and a spiral groove is carved in each part.
A turnbuckle 7 is screwed into this portion, and by rotating the turnbuckle 7, the tension of the piano wire can be adjusted. In addition, both ends of the piano wire may be directly locked to a reinforced frame with aggregate, etc., but in this embodiment, they are attached as attachments using hook-shaped locking pieces 8182. I have to. Note that the shape and structure of the locking pieces 81 and 82 can be designed as appropriate, as long as they have a structure that can secure an elasticity value of 6.

Therefore, when a tennis ball is hit using such a tennis racket 1, the impact force generated on the ball hitting surface is sequentially transmitted from the ball hitting portion 2b) of the frame, which is a rigid skeleton, to the grip portion 3. However, the street attack wave propagates to the mass body 5 through the elasticity value 6, causing the mass body 5 to vibrate. This vibration of the mass body 5 is caused by the weight of the mass body 5 at that time, the elasticity value 6,
In the embodiment, when the spring constant etc. of the piano wire matches the weight, natural frequency etc. of the frame, the configuration in which the M mass 5 is fixed and the elastic value is stretched acts as a so-called dynamic vibration absorber. However, by minimizing the vibration of the frame, most of the vibrations propagated to the mass body 5 are absorbed in this part so that they are not returned to the frame.

For example, if you have just installed Guttu 22,
The natural frequency of the frame will be relatively high, and even if it matches the weight of the mass body 5, the spring constant of elasticity value 6, the weight of the frame, the natural frequency, etc. at this point, as it is used, Since the guts become loose and the natural frequency of the frame changes slightly, it may be difficult for the structure in which the mass body 5 is suspended to function efficiently as a dynamic vibration absorber, and may even have the opposite effect. If such a situation occurs,
By rotating the turnbuckle 7 to further tighten the elasticity value 6, balanced and efficient vibration absorption can be achieved again. This does not only depend on the tension of the cut, but also on various conditions such as gripping position, arm length, grip strength, arm strength, and even temperature and humidity on that day. Uniqueness when viewed (
Similarly, it is possible to balance changes in the number of rotations.

In the above embodiment, the piano wire is stretched from the base of the bifurcated portion 31 to the horizontal frame piece 21 so as to extend across the frame, and the mass body 5 is supported by the piano wire. However, the present invention is not limited to this, and for example, as shown in FIG. 2, elasticity 6 like a guitar string may be strung, and one end thereof may be freely wound by a winding device 9 consisting of a combination of a gear and a pinion. In this case, an attachment such as a guitar can be used as the winding tool 9, and a third
As shown in the figure, if a guitar string with an elasticity value of 6 is bent and passed through the mass body 5, the elasticity value 6 can be fixed in a fixed position when tensioned, and when the mass body 5 is slightly loosened,
Since it can be moved up and down, the fixed position at the elasticity value of 6 can be changed, and the frequency can be further adjusted.

In the above embodiments, glass fiber-reinforced plastic was used as the rigid frame material of the frame, but the present invention is not limited to this, and carbon fiber-reinforced materials may also be used. Laminated wood, reinforced with fiber-reinforced plastic, drawn from aluminum or other alloys, molded from other metals, injection molded, transfer molded, or compression molded from thermoplastic or thermosetting resin, or a combination of these. It goes without saying that it can be applied in the same way even if it is made of other materials.

In addition, in the above embodiment, the elasticity values of guitar strings and piano wires are used, but the elasticity values are not limited to so-called string-shaped strings. It also includes resin threads, wires, etc.

Furthermore, with the mass body 5 fixed at a predetermined position above and below the elasticity value 6, a gel layer based on silicone gel may be placed around the 117 body 5, or a gel layer may be placed to cover this gel layer. You can freely cover the front and back with transparent plastic plates, and when attaching a gel layer based on silicone gel, JIS K 2530-
Penetration measured by 1976-(50g load) is 5
0 to 200 silicone gel itself or a composite silicone gel in which microscopic hollow spheres are mixed are suitable.For such materials, for example, Toray Silicone CF3027 manufactured by Toray Silicone Co., Ltd. or Shin-Etsu Chemical KE-1051 manufactured by Kogyo Co., Ltd., and micro hollow spheres mixed therein include Phyllite (registered trademark) manufactured by Nippon Philite Co., Ltd. and Expancel (registered trademark) sold by the same company. Of course, the material is not limited to this, and may be reinforced with silica or the like.

Effects of the Invention As described above, according to the tennis racket of the present invention, the structure in which the mass body is fixed and the elastic strings are stretched acts exactly as a so-called dynamic vibration absorber, and the impact vibration at the time of hitting is absorbed by the mass body. Since it can be replaced with fanning, there is very little transmission to the palm of the person's hand at the gripping part, and it converges in a short time, providing a comfortable hitting feeling and solving the problem of sports injuries. becomes possible. on the other hand,
The strange structure in which a mass body is supported by elastic strings in the space between the horizontal frame side of the annular frame and the Y-shaped handle part tickles the playful spirit of modern young people and creates a desire to purchase. You can also do that.

[Brief explanation of the drawing]

Fig. 1 is a front view showing the main parts of one embodiment of the tennis racket of the present invention, Fig. 2 is a perspective view of the main parts of another embodiment, and Fig. 3 is an embodiment of the mass body fixing structure. FIG.

Claims (1)

[Claims] In a tennis racket frame consisting of an annular frame part and a Y-shaped handle part, an elastic string is stretched from the horizontal frame piece which is the lower side of the annular frame part to the base of the bifurcated part of the grip part so that its tension can be freely adjusted. The tennis racket is also characterized in that a mass body is fixed to the middle part of the elastic string.