JP2539638B2 - tennis racket - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a tennis racket having cushioning performance.

<Prior Art> A conventional tennis racket of this type has a hitting net surface for hitting a tennis ball and a grip portion for rotating the hitting net surface. Is a bar-shaped grip handle that is continuous as a single body.

The hitting net surface is stretched on an annular frame portion above the frame, and the rod-shaped grip handle portion having a grip portion is integrally connected to the annular frame portion. The annular frame portion and the grip handle portion The racket frame is constructed with <Problems to be solved by the invention> In such a tennis racket, since the annular frame portion and the grip portion are continuously formed by a hard grip handle portion, a hitting net surface is formed. The impact force when hitting the ball is transmitted to the palm directly from the frame and gives an impact to the hand and arm.

This impact force causes the shock wave to resonate strongly on the palm of the hand when the hitting net surface does not accurately hit the core of the ball and hit the ball.
In addition to causing many sports obstacles on the elbows, shoulders, etc., the impact force of a hit ball is generally propagated through a hard grip handle and reaches the palm, so that it is hardly attenuated, and for this reason, even a skilled person has a long time. There was a problem that sports practice often occurred due to time practice.

<Means for Solving Problems> According to the present invention, at least one buffer portion 30 is provided on one or both of the annular frame portion 11 and the grip handle portion 12 of the frame 10 of the tennis racket, and the buffer portion 30 is provided. A core layer 31 formed by filling a foamed synthetic resin, preferably a highly foamable synthetic resin, into the frame 30 of the frame, and a buffer layer 32 formed by polymerizing a gel substance in the core layer. Therefore, the buffer layer 32 is configured such that one surface thereof is in contact with the core layer 31 and the other surface is in contact with the inner surface 10 'of the skeleton of the frame 10.

<Operation> Since the tennis racket of the present invention has such a structure, the impact force generated on the hitting net surface 111 at the time of hitting is transmitted through the skeleton of the rigid frame to the palm of the human body from the grip 20.

However, in the tennis racket of the present invention, the buffer portion 30 is provided in the frame thereof, and the buffer portion 30 includes the core layer 31 of the expandable synthetic resin densely formed in the skeleton of the rigid frame, Since the core layer 31 and the buffer layer 32 of a gel-like substance are provided so as to be interposed between the core frame 31 and the rigid frame skeleton, they are generated on the hitting net surface and transmitted to the gripping portion of the frame. The shock wave is transmitted through the buffer layer 32.

The shock absorbing function of the shock absorbing layer 32 is performed by the inelastic or microelastic deformation characteristic of the gel-like substance and the diffusion characteristic similar to the liquid.

That is, when a shock wave is applied to the gel-like substance, it is distorted by this impact force and absorbs and attenuates impact energy by intermolecular frictional resistance due to the strain. Since the impact resilience due to the strain change is extremely small enough to be ignored, or is so small that it does not adversely affect the buffering operation, it is possible to prevent the generation of a new shock wave due to the impact resilience and the gel-like substance Since there is a characteristic of promptly dispersing and transmitting due to a propagation characteristic similar to that of a liquid, the shock wave transmitted to the buffer layer 32 via the core layer 31 or the frame skeleton is attenuated by this, and again the core layer 31 in the surroundings is attenuated. It is subdivided and propagated inside, and is also absorbed by the core layer 31.

Therefore, in the tennis racket of the present invention, the shock wave transmitted to the frame is effectively absorbed and attenuated in the buffer portion 30, and a large impact force is not transmitted to the grip portion.

<Examples> Fig. 1 is a front view showing an example of a tennis racket of the present invention. The frame 10 shown here is made by bending a rigid skeleton, and a hitting net surface 111 is provided on the upper part. An annular frame portion 11 for forming is provided, and a rod-shaped grip handle portion 12 integrally formed with the frame portion 11 is connected to the annular frame portion 11.

In this embodiment, the frame 10 is formed by bending one shaft material in an annular shape to form an annular frame portion 11, and the both ends of the annular frame portion 11 are combined to form a grip handle portion 12, so that the upper portion of the grip handle portion 12 is formed. Is bifurcated. The base end of the grip handle 12, that is, the lower portion in the figure, is configured as a grip 20.
As shown in FIG. 2, reference numeral 20 designates a base layer 21 made of a foaming synthetic resin formed on the peripheral surface of the handle 12 and a gel incorporated in the base layer 21 so as to be bonded to the handle 12. It is composed of a buffer layer 22 of a substance and a covering layer 23 which covers the outer surface of the base layer 21.

In the embodiment, the grip portion 20 is ten bases of the grip handle portion 12.
It is provided in cm, and an artificial or natural leather band is wound as the outer cover layer 23.

The annular frame portion 11 and the handle 12 of the frame 10 are integrally made of a shaft material of glass fiber reinforced plastic having a core material of expandable synthetic resin.

To make the frame 10 having such a one-body structure, there is a method of winding a fiber reinforced plastic prepreg around a material that has been bent and formed into a frame shape in advance and heating and curing it in a mold. Separately, a rod material of expandable synthetic resin is used as a core material, and a prepreg, which is a material for molding glass fiber reinforced plastic, is wound around the core material to obtain one rod-shaped shaft material, which is then bent and bent. There is also a method of fitting the resin into a mold and subjecting it to overheating and hardening treatment. Such a molding method is disclosed in Japanese Patent Laid-Open No. 51-141045.

A horizontal frame piece 112 for fixing the thread end is installed as a part of the annular frame portion 11 on the bifurcated portion of the frame 10, and the thread end of the hitting net surface 111 is fixed to the horizontal frame piece 112.

The frame 10 is provided with at least one buffer portion 30, and the buffer portion 30 includes the annular frame portion 11 and the grip handle portion 12.
It is provided inside one or both of the above.

In the embodiment shown in FIG. 1, the buffer portion 30 is the grip handle portion 12 described above.
The bifurcated portion 121 and the top portion of the annular frame portion 11 and the horizontal frame piece 112 are arranged, but the most effective position is the top portion of the annular frame portion 11. The buffer portion 30 is densely formed in the hard skeleton of the frame 10, and as shown in FIG. 2, a core layer 31 of expandable synthetic resin and a gel-like substance formed by polymerization on the core layer 31. And a buffer layer 32.

The core layer 31 of the buffer portion 30 may be provided only at the buffer portion disposition portion of the frame 10, but in the embodiment, the core material of the shaft material is used as the core layer 31 of the shaft. Besides being easy to manufacture, there is an advantage that the core layer 31 can be closely packed in the frame 10.

As shown in FIGS. 2 to 5, the buffer layer 32 is formed so that one surface thereof is in contact with the core layer 31 and the other surface thereof is in close contact with the inner surface 10 'of the frame skeleton. It is provided so as to be in contact with the frame skeleton outer inner surface 10 'as shown, the frame skeleton top portion upper inner surface 10' as shown in FIG. 3 or the frame skeleton top portion lower inner surface 10 'as shown in FIG.

Further, the buffer layer 32 may be provided in parallel with the opposing inner surfaces 10 ', 10' of the frame skeleton as shown in FIG. 5, in which case all or part of the core layer 31 is a pair of buffer layers. It will be sandwiched between 32.

In the embodiment shown in FIG. 2, since the shaft material is bent into a racket shape and cured to form the frame 10, the buffer portions 30 are symmetrically arranged on the left and right sides of the central partition wall 122 of the bifurcated portion 121. However, when the buffer portion 30 is provided on the annular frame portion 11, it is sufficient to superpose one buffer layer 32 on the core layer 31, as shown in FIG.

Silicone gel is well suited as the gel-like substance used for the buffer layer 32 of the buffer portion 30 because of its stability as a material, and among them, JIS K 2530-1976- (50 g load).
The silicone gel having a penetration of about 50 to 200 as measured by, and a composite silicone gel obtained by mixing such hollow silicone spheres as a base material with micro hollow spheres are most preferable.

Since such silicone gel materials are also particularly excellent in buffering and anti-vibration ability, the intended purpose can be easily achieved by using these silicone gel materials.

As such a material, for example, trade name Toray Silicone CF5027 manufactured by Toray Silicone Co., Ltd. and trade name KE-1051 manufactured by Shin-Etsu Chemical Co., Ltd. are used. Examples of spheres include Philite (registered trademark) manufactured by Nippon Philite Co., Ltd. and Expancel (registered trademark) sold by the same. Silicone gel mixed with micro hollow spheres is disclosed in Japanese Patent Application No. Sho 60.
-297677.

The gel-like substance for forming the buffer layer 32 may be used without attaching the outer cover. However, when the gel-like substance is used as it is, when the gel-like substance is a silicone gel, an oil component is internally generated. May exude and destabilize the position of the buffer layer 32.To prevent this, the buffer layer 32 is covered with a gel-like substance, for example, a 0.1 mm urethane film or a 0.3 mm vinyl chloride film. What you have done is good.

In the above process, the structure of the grip 20 may be the same as the conventional structure, but as shown in the embodiment, if the base layer 21 and the buffer layer 22 are included, the grip 20 can also absorb and attenuate the shock wave. There is an advantage that you can do things.

In the tennis racket of the present invention, when a ball is hit by this, the impact vibration at the time of hitting the hitting net surface 111 is transmitted to the palm through the frame 10.

Since this shock vibration is always subjected to the buffering action of the buffer section 30 before being transmitted to the palm, the buffer layer 32 of the gel-like substance is provided on the palm.
The shock wave after being transmitted to and attenuated here is applied.

Here, the deformation of the gel-like substance forming the buffer layer 32 is an inelastic deformation, does not cause repulsion elasticity, and propagates rapidly over a wide area, so that the vibration is attenuated and absorbed in the whole gel-like substance. However, what is transmitted to the palm is extremely low compared to the conventional one, and it will converge in a short time.

As a result, when the tennis racket of the above-mentioned embodiment and the conventional tennis racket were compared, a significant improvement was seen in both the impact force transmitted to the palm and the vibration convergence time. Particularly, in the convergence time, 30% to 50% A reduction of about% was recognized.

The inelastic deformation referred to in the specification of the present application means that strong elastic deformation such as rubber and spring is not caused, and does not mean that elastic deformation is not caused at all.

Similarly, the absence of impact resilience means that strong impact resilience such as rubber and spring is not exhibited, and does not mean that the impact resilience is absolutely zero.

As the gel-like substance constituting the above-mentioned buffer layer 32, in addition to the gel-like substance in a pure state as described in the above-mentioned examples, JP-A-61-51035 and JP-A-62-138 are used.
As disclosed in Japanese Unexamined Patent Publication No. 39436/1988, after gel hardening, the degree of cross-linking of the surface is further increased to form a non-adhesive skin layer only on the surface, or as disclosed in JP-A-61-21436. , Enclosed in an exterior body such as urethane film, or
Those filled in a hose-shaped film, and Shokai Sho 61
As disclosed in JP-A-89534, it is possible to use a ball-shaped cured product.
Regenerated gel and its molded products produced by the production method disclosed in No. 132849 can be arbitrarily selected and used.

Further, the gel-like substance may be mixed with fine particles having a large weight in place of the fine hollow spheres, for example, fine powder particles of lead, and thus the weight of the buffer layer 32 becomes large. It is possible to increase the cushioning effect when it is provided at the top position of the frame.

That is, in the tennis racket of the present invention, it can be said that the deformation of the gel-like material is the fundamental operation of vibration damping.
This is because it is preferable to dispose the buffer layer 32 having a large absorbed energy at the top position of the frame with the most vibration.

<Effects of the Invention> As described above, the tennis racket of the present invention has the frame
At least a part of 10 is provided with a buffer portion 30, and the buffer portion 30 is provided with a buffer layer 32 of a gel-like substance such that one surface thereof is in direct contact with the inner surface of the frame skeleton. Since the core layer 31 made of a foamable synthetic resin is in contact with the other surface, the impact at the time of impact is directly absorbed by the buffer layer 32 and dispersed and absorbed by the core layer 31, which adversely affects the palm. There is an effect that vibration can be largely eliminated.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the tennis racket of the present invention, FIG. 2 is an enlarged sectional view showing a main part of the tennis racket shown in FIG. 1, and FIG. 3 is a top portion of a frame of the same tennis racket. FIG. 4 is a vertical sectional front view showing another embodiment of the top portion of the same frame, and FIG. 5 is a transverse plan view of the top portion showing another embodiment of the frame of the tennis racket of the present invention. . In the figure, 10 is a frame, 11 is an annular frame portion, 111 is a hitting net surface, 12 is a grip handle portion, 20 is a grip portion, 30 is a buffer portion, 31 is a core layer,
32 indicates a buffer layer.

Claims (2)

(57) [Claims] 1. A frame having an annular frame portion for forming a hitting net surface and a grip handle portion connected to the annular frame portion is provided with at least one buffer portion, and the buffer portion is a skeleton of the frame. The core layer is made of a foamable synthetic resin filled in the core layer, and a buffer layer formed by polymerizing a gel-like substance on the core layer. One of the buffer layers is in contact with the core layer and the other surface. A tennis racket characterized by being configured so as to come into contact with the inner surface of the skeleton of the frame. 2. The tennis racket according to claim 1, wherein the buffer portion is provided at the top position of the frame.