JP2000093558A - Tennis racket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control a tennis ball well through two-step flexible effects similar to those produced by the human elbow and wrist to drive the ball at sharp angles by providing first flexible parts at the upper end of a shaft and second flexible parts at the lower end of a frame. SOLUTION: A tennis racket comprises a frame part 2, a shaft part 3, and a grip part 4, and first flexible parts 5a, 5b thinner than other parts in a direction perpendicular to a string stretching face are provided in positions closer to the frame part 2 than to the longitudinal center of the shaft part 3. Second flexible parts 6a, 6b thinner than the other parts in a direction perpendicular to the string stretching face are provided in positions closer to the shaft part 3 than to the longitudinal center of the frame part 2. The two flexible parts are formed of constricted parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a racket used for tennis competition. More particularly, the present invention relates to a tennis racket having two bent portions, and more particularly to a racket having high rebound, spin performance, and control performance by exhibiting a bending effect.

[0002]

2. Description of the Related Art As tennis rackets, those made of fiber reinforced resin are generally widely used. These racquets generally did not provide sufficient speed to the ball due to their high rigidity and difficulty in bending. In addition, spin performance and control performance were not sufficient.

On the other hand, in Japanese Utility Model Laid-Open Publication No. 1-80162 and Japanese Utility Model Laid-Open Publication No. 1-112868, the thickness is maximized near the center of the frame, and the minimum thickness is provided near the center of the shaft. Rackets have been proposed.

[0004]

However, these rackets cannot cope with recent high-speed tennis play, and there is a strong demand for a racket having excellent repulsion, spin performance and control performance. ing.

SUMMARY OF THE INVENTION An object of the present invention is to provide a tennis racket capable of responding to the speeding up of tennis play, having better rebound, and capable of hitting a ball at a higher speed in order to solve the conventional problems. .

[0006]

In order to achieve the above object, a tennis racket according to the present invention is a tennis racket having a frame, a shaft, and a grip, wherein the tennis racket has a longitudinal direction. At a position closer to the frame portion than the center portion of the first portion, the thickness of the string in the direction perpendicular to the tension surface is smaller than the other portions,
At a position closer to the shaft portion than a center portion in the length direction of the frame portion, a thickness in a direction perpendicular to a string extending surface is provided with a second bent portion smaller than other portions. I do.

In the racket, the thickness of the thinnest portion of the first bent portion is preferably in the range of 55 to 95% of the thickness of the lower end of the shaft portion. In the racket, the thickness of the thinnest portion of the second bent portion is preferably in the range of 52 to 98% of the thickness of the lower end of the shaft portion.

In the racket, it is preferable that the thickness of the first bent portion is smaller than the thickness of the second bent portion. In the racket, the length of each of the first bent portion and the second bent portion is 30.
It is preferably in the range of 70 mm.

[0009] In the racket, it is preferable that the frame portion has a shape having a maximum thickness at the front end, and the thickness gradually decreases from the front end to the lower end. According to the configuration of the tennis racket, since the tip of the frame portion is set to the maximum thickness, the weight of the tip of the frame portion becomes relatively heavier than its lower end portion (so-called “top heavy” state). become). For this reason, the bending effect and the top heavy effect act synergistically, and the swing speed is further increased as compared with a tennis racket having only a bending portion. As a result, it is possible to respond to recent speedups in tennis play, and to hit a tennis ball with higher speed. In addition, when the swing speed is increased, the resilience is dramatically improved, and a sharper angled ball can be hit. Further, in the racket, it is preferable that the first bent portion and the second bent portion are located at positions symmetrical to the left and right of the frame portion when viewed from the stretched surface of the string.

[0010] The tennis racket of the present invention is easy to bend,
When hitting the ball, the ball is held in the string to some extent, and a proper contact time with the ball can be secured. This gives the ball speed, makes it easier to spin, and also improves the ball controllability.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The racket frame of the present invention is manufactured, for example, from a fiber-reinforced resin. Examples of the reinforcing fiber include carbon fiber, boron fiber, alumina fiber, ultrafine iron wire, Ti-Si-CO fiber (trade name: Tyranno fiber),
Aramid fibers, polyarylate fibers, ultrahigh molecular weight polyethylene fibers, and the like can be used. In particular, the tensile modulus is 15 ton / mm ² or more, especially 20 to 40 ton /
mm ² is preferred. In terms of strength, elastic modulus, cost, and the like, a high-strength and high-elasticity type carbon fiber called HM graphite is desirable.

As the synthetic resin, a thermoplastic polyamide resin such as a thermosetting epoxy resin or a polyester resin is used. In order to manufacture the racket frame of the present invention, a plurality of prepreg sheets can be stacked on a mandrel, placed in a cavity having a desired frame shape of a mold, and can be prepared by a normal manufacturing method of performing a heat treatment.

When the thickness of the first bent portion exceeds 95% of the thickness of the lower end of the shaft portion, or when the thickness of the second bent portion exceeds 98% of the thickness of the lower end of the shaft portion,
The bending effect tends to be insufficient.

On the other hand, when the thickness of the first bent portion is less than 55% of the thickness of the lower end of the shaft portion, or the thickness of the second bent portion is less than 52% of the thickness of the lower end of the shaft portion, the bending is performed. Although the effect is sufficiently obtained, the control performance tends to be extremely reduced.

When the thickness of the first bent portion is equal to or less than the thickness of the second bent portion, a behavior similar to that of a human throwing a ball is exhibited. The ball can hit the opponent's court quickly, strongly and at an angle.

If the length of the bent portion is less than 30 mm, the bending effect is small, and if it exceeds 70 mm, the bending effect is large, but the control performance is extremely reduced, which is not preferable.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a tennis racket according to an embodiment of the present invention, FIG. 2 is a side view, and FIG. 3 is a partially enlarged view of FIG.

As shown in FIG. 1, the tennis racket 1
The frame part 2, the shaft part 3, and the grip part 4 are comprised, and the frame part 2 and the shaft part 3 are integrally formed by reinforced fiber reinforced resin. As the reinforcing fiber reinforced resin, for example, a carbon fiber reinforced resin, a glass fiber reinforced resin, or a synthetic fiber reinforced resin such as aramid can be used.

The first bent portion of the shaft portion 3, which is closer to the frame portion 2 than its center in the length direction, has a thickness in a direction perpendicular to the string extending surface smaller than other portions. Parts 5a and 5b are provided. A preferred position of the first bent portions 5a and 5b is near the upper end of the shaft portion 3. The thickness of the thinnest portion of the first bent portion is preferably in the range of 55 to 95% of the thickness of the lower end 3a of the shaft portion 3. The preferred length of the first bent portion is 30 to 70 m
m.

Next, at a position closer to the shaft portion 3 than the center portion in the longitudinal direction of the frame portion 2, a second bending portion 6a having a thickness in a direction perpendicular to the string extending surface is smaller than other portions. , 6b. Second bending parts 6a, 6
The preferred position of “b” is near the lower end of the frame portion 2.
The thickness of the thinnest portions of the second bent portions 6a and 6b is preferably 52 to 98% of the thickness of the lower end 3a of the shaft portion 3, and the preferred length is in the range of 30 to 70 mm. In the above, the thickness of the first bent portions 5a and 5b is preferably equal to or less than the thickness of the second bent portions 6a and 6b.

Next, as shown in FIG. 2, the front end 2a of the frame portion 2 is set to a maximum thickness, and the thickness gradually decreases from the front end portion toward the bending portion 6a.

FIG. 3 is a schematic enlarged view of the first bending portion 5a and the second bending portion 6a. The first bent portion 5a and the second bent portion 6a are both narrow and form a bent portion. Thus, the first bending portions 5a, 5
b and the second bending portions 6a and 6b, the tennis ball is satisfactorily formed by the effect of two steps of "force of force" (two steps of bending effect) similar to the elbow and wrist of the human body. It can be controlled, and an angled and sharp hit can be achieved.

As described above, the frame portion 2 has its tip 2a set to the maximum thickness and the bent portion 5
, The thickness of the frame portion 2 gradually decreases, and the weight of the front end 2a of the frame portion 2 is relatively heavier than that of the lower end portion (in a so-called “top heavy” state). For this reason, the bending effect of the first bending portions 5a and 5b and the second bending portions 6a and 6b (the effect of the force bending).
And the top heavy effect act synergistically to further increase the swing speed. As a result, it is possible to fully correspond to the recent speedup of tennis play,
It is possible to hit a tennis ball with higher speed. In addition, when the swing speed is increased, the resilience is dramatically improved, and a sharper angled ball can be hit.

As an example, a carbon fiber reinforced resin is used as a material for the frame portion, the shaft portion and the grip portion, and the length of the frame portion is 341 mm (of which the length of the second bent portion is 34 mm and the thickness is 34 mm). 22.6 mm (94% of the thickness at the lower end of the shaft), the thickness at the tip (maximum thickness) is 2
The length of the shaft portion is 174 mm (the length of the first bent portion is 34 mm), and the thickness of the lower end is 2 mm.
3.1 mm, the thickness of the first bent portion is 21.7 mm (94% of the thickness of the lower end of the shaft), and the length of the grip portion is:
Each was set to 188 mm, and a tennis racket was produced by a known method.

The tennis racket thus obtained exhibits a good bending effect and a top heavy effect,
When I actually hit a tennis ball, I was able to return a fast ball. In the present embodiment,
The second bent portion in the frame portion is provided near the lower portion of the frame portion, but the bent portion may be located at a position closer to the shaft portion than the center in the length direction of the frame portion.

As described above, according to an embodiment of the present invention, the weight of the front end of the frame portion is relatively heavier than that of its lower end portion because the front end of the frame portion is set to the maximum thickness. , A so-called top heavy state. For this reason, the bending effect and the top heavy effect act synergistically, and the speed of the face surface of the racket is further improved as compared with a tennis racket having only the bending effect.
As a result, it is possible to cope with recent high-speed play.

[0027]

As described above, the tennis racket of the present invention is a tennis racket including a frame portion, a shaft portion, and a grip portion. In a position close to the portion, the first bent portion having a thickness in a direction perpendicular to the stretch surface of the string is smaller than the other portions, and is closer to the shaft portion than the center in the length direction of the frame portion. In the position, the thickness in the direction perpendicular to the tension surface of the string has a second bent portion smaller than the other portions, so that the tennis ball can be successfully controlled by a two-step bending effect), A sharp hit with an angle is possible. As a result, the tennis racket of the present invention is easily bent, and when hitting the ball, the ball is held to a certain extent in the string, so that a proper contact time with the ball can be secured. This gives the ball speed, makes it easier to spin, and also improves the ball controllability.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a tennis racket according to an embodiment of the present invention.

FIG. 2 is a side view showing a tennis racket according to the embodiment of the present invention.

FIG. 3 is a partially enlarged view of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tennis racket 2 Frame part 2a Tip of frame part 3 Shaft part 3a Lower end of shaft part 4 Grip part 5a, 5b First bending part 6a, 6b Second bending part

Claims (7)

[Claims] 1. A tennis racket comprising a frame portion, a shaft portion, and a grip portion, wherein a string extending surface is provided at a position closer to the frame portion than a center portion in a longitudinal direction of the shaft portion. A first bent portion having a thickness in a direction perpendicular to the other portion is smaller than the other portion, and is perpendicular to the string extending surface at a position closer to the shaft portion than a center portion in a length direction of the frame portion. A tennis racket having a second bent portion having a smaller thickness in a direction than other portions. 2. The tennis racket according to claim 1, wherein the thickness of the thinnest portion of the first bent portion is in the range of 55 to 95% of the thickness of the lower end of the shaft portion. 3. The tennis racket according to claim 1, wherein the thickness of the thinnest portion of the second bent portion is in the range of 52 to 98% of the thickness of the lower end of the shaft portion. 4. The tennis racket according to claim 1, wherein the thickness of the first bent portion is equal to or less than the thickness of the second bent portion. 5. The first flexible part and the second flexible part each have a length in the range of 30 to 70 mm.
The tennis racket described in. 6. The tennis racket according to claim 1, wherein the frame portion has a maximum thickness at the front end, and the thickness gradually decreases from the front end toward the lower end. 7. The tennis racket according to claim 1, wherein the first bent portion and the second bent portion are located at positions symmetrical to the left and right of the frame portion when viewed from the stretched surface of the string.