JPH0454976A - Backet - Google Patents

Abstract

PURPOSE:To transmit efficiently energy to a ball by shaping a gut stretching section into a nearly rhomboid shape, stretching two sets of guts respectively nearly parallel to the sides of the gut stretching section and nearly equalizing the lengths of the stretched guts to each other at any positions. CONSTITUTION:A gut stretching section 2 providing a main part of a frame 1 is shaped into a nearly rhomboid shape symmetrical about the longitudinal center axis of the frame 1. Also, since two sets of guts 3 are stretched nearly parallel to the sides of the frame 1, respectively, the respective guts intersect obliquely each other and have the nearly equal length. Thus, since the gut stretching section 2 is shaped into the nearly rhomboid shape and the guts 3 are stretched obliquely, the deformation of the frame 1 in the direction perpendicular to that of a shot ball is enlarged. Thus, the energy of the ball can be more accumulated, the deformation mode coincides with the timing of deflection of the gut and the frame also restores the original state as soon as the ball leaves the gut, so that the accumulated energy is efficiently returned to provide a first shot ball.

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to improvements in rackets for tennis, squash, racket games, and the like.

<Conventional Technology> In recent years, various rackets have been proposed in which the width of the shaft, guttack, or entire length of the racket is increased to increase rigidity, with the aim of hitting the ball with higher speed. ing.

The purpose of these rackets is to increase the rigidity of the frame in the ball-hitting direction to more efficiently transmit energy to the ball.

<Problems to be Solved by the Invention> Originally, the entire frame of a racket when hitting a ball bends in the direction of the ball, and at the same time deforms in a direction perpendicular to the ball. In other words, immediately after contact with the ball, the gut tensioned part deforms into a vertically elongated shape,
The ball recovers at about the same time as it leaves Gatsuto.

The energy given to the ball by the frame mainly depends on the restoring forces of these two deformation modes.

At this time, if the flex of the racket frame in the ball hitting direction is too large, the frame will not restore at the same timing when the ball leaves the gut, and the energy of the flex will not be sufficiently converted into the ball. Therefore, if the width of the frame is increased partially or over the entire length to increase the rigidity, the above-mentioned timing deviation will be reduced and the ball hitting speed will be increased.

However, with this method, the contact time between the ball and the gut is short, and controllability and spin performance are reduced. Therefore, it has the disadvantage that it is not liked by athletes, especially first-class athletes such as professional athletes.

To this end, it has been proposed that the maximum width of the racket frame, which was originally 30 mm or more, be reduced to around 25 mm, but the above-mentioned problems have not been solved.

According to the inventor's experiments, the mechanism of collision between the racket and the ball is as follows. First, the ball collides with Gatsuto and begins to deform together. At this time, the gut tension part receives a force in the direction of the center of the plane perpendicular to the batted ball,
Transforms vertically. At the same time, the frame begins to deform in the direction of the ball.

At this time, the ball and gutt will return to their original positions after reaching their maximum displacement, but since the guttating part is linked to the movement of the gutt,
As Gatsuto is restored, it will move back from vertical to normal.

On the other hand, the frequency of the frame in the ball hitting direction is considerably lower than the frequency of the deformation of the ball and the string, and the frequency of the string extension.
It has not been restored at this point. Even if the frame width is increased, the timing shift in this direction cannot be completely corrected.

As described above, the deformation of the guttating part in the direction perpendicular to the ball hit always coincides with the timing of the deflection of the gutt, so if this deformation is increased, the contact time between the gutt and the ball will be shortened. It turns out that it is possible to give more energy to the ball without having to do so.

<Means for solving the problem> Therefore, in order to solve the problem of conventional rackets, the width of the frame was increased compared to the length in the longitudinal direction without increasing the rigidity. In order to increase the deformation of the frame in the direction perpendicular to the ball hitting direction, the shape of the gut extension part is formed into a substantially diamond shape.

Furthermore, instead of the conventional racket's guts being stretched in the vertical and horizontal directions and crossing at right angles, they are stretched parallel to each side of the diamond shape of the frame.

Furthermore, by making the length of the guts almost the same at all positions, we have devised a way to increase frame deformation in this direction.

<Function> By forming the string extension part into a nearly diamond shape and by extending the strings so that they cross diagonally, this racket is more effective than a conventional racket in which the strings are stretched vertically across an elliptical frame. As a result, deformation in the longitudinal direction when the ball is hit is large and smooth.

At the same time, since the length of the gut is almost the same at every position, the tension of the gut is also almost uniform, which prevents the ball speed from decreasing dramatically when the ball is hit off center.

<Example> An example of the racket according to the present invention will be described below based on the drawings.

First, the racket frame 1 is made of FRP, as shown in FIG.
(fiber-reinforced synthetic resin) or the like by a known method, and is composed of a gut extension part 2, a shaft part 4, a grip part 5, and the like.

The string extension part 2, which is the main part of the frame 1, has a rhombic shape with the longitudinal center line of the frame 1 as the axis of symmetry. The long axis of the rhombus in this example is 400 m
m and the minor axis are 250 mm, but the ratio of the major axis to the minor axis (major axis l minor axis) may be changed. In this case, the larger the ratio, the greater the deformation in the direction perpendicular to the batted ball, resulting in higher repulsion, but care must be taken because the area of the guttation part becomes smaller, which may impede play. should not.

In addition, each vertex and each side of the rhombus are curved to increase the strength when strung. The radius of curvature is preferably 360 mm at the side A, 50 mm at the apex on the vertical axis side, and 125 mm at the horizontal axis C, but if these are also strong enough depending on the type of constituent materials and molding method, You can freely adjust its length.

Gatsuto 3 has no distinction between warp and weft as before, but the first
As shown in the figure, two sets of guts 3 are stretched substantially parallel to each frame. As a result, each gut crosses diagonally,
Also, the lengths of all the guts are approximately equal.

As shown in FIG. 2, the width d of the frame is maximum at the center of the stringed part 2, has a slope toward both ends, and is minimum at the tip.

The maximum width and minimum width are preferably 24mm and 518m.
Let it be m.

<Effects of the Invention> As described above, in the present invention, the shape of the string extension portion is approximately rhombic, and the string is stretched diagonally, thereby increasing the deformation of the frame in the direction perpendicular to the ball when the ball is hit.

Therefore, more energy can be stored in the ball, and since this deformation mode coincides with the timing of the deflection of the gut, the frame will also restore itself at the moment the ball leaves the gut, so the stored energy can be used efficiently. It returns well and allows you to hit the ball fast. At this time, the rigidity of the frame in the ball hitting direction remains the same as that of conventional rackets, so the contact time with the ball is not shortened and spin and controllability are not impaired.

[Brief explanation of the drawing]

FIG. 1 is a front view of a tennis racket as an embodiment of the present invention, and FIG. 2 is a side view. 1... Racket frame 2... Gut tension part 3
...Gut 4...Shaft part 5.
...Grip handle part a...Side part b...Apex (vertical axis side) C...Apex (horizontal axis side) d...Radius 31 Fig. 42

Claims (1)

[Claims] 1. In a tennis racket having at least a stringed part with strings stretched thereon, and a handle part, the shape of the said stringed part is approximately diamond-shaped, and two sets of strings each have a stringed part. A racket characterized in that the strings are stretched substantially parallel to each side of the racket, and the length of each stringed string is approximately the same at any position.