JPH0938243A - Tennis racket frame - Google Patents

Abstract

PROBLEM TO BE SOLVED: To absorb and moderate transmission of an impact to wrist for holding a grip part in driving while keeping the driving directional bending rigidity as it is, and minimize the fatigue of the wrist. SOLUTION: A racket frame 1 is formed of a frame stringing part 2 for stretching a gut G; a shaft part 4 for supporting the base part 3 of the frame stringing part 2; and a grip part 5 for forming the terminal side part of the shaft 4. The torsional rigidity around central axis O-O of the shaft part 4 is set lower than the bending rigidity to the driving direction.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to, for example, an FRP.
Regarding a racket frame for tennis consisting of a strength member such as (fiber reinforced plastics) or a light alloy, particularly when the ball is hit at the time of hitting by reducing the torsional rigidity around the central axis of the shaft portion without changing the bending rigidity in the hitting direction. The torsion about the central axis of the shaft portion due to the rotational moment about the vertical axis of the frame string portion is absorbed, and the transmission of the impact to the wrist holding the grip portion is alleviated.

[0002]

2. Description of the Related Art When measuring the torsional rigidity (Nm / rad) of the shaft portion of a racket frame for tennis, the grip portion is usually fixed and the frame is rotated about the longitudinal axis, for example, with a radius of 200 mm. This is performed by applying an additional torque (20 N · m) by a weight of 10 kg to the body and measuring the twist angle (rad) of the frame tension string portion by this, about 400 N · m /
About rad, soft type is about 230 N ・ m / ra
d.

The holding torque (Nm) of a human hand and a wrist holding the grip portion is measured for a middle-class male player, and as a result, a maximum of about 8.0 Nm in the forward direction,
The maximum value was about 7.9 N · m in the opposite direction.

Therefore, when a player hits a ball at a position deviating from the longitudinal center axis of the frame string portion during play, as a result of measuring how much load is applied to the player's hand, the central axis of the shaft portion is generated instantaneously. It was found that the load due to the rotational torque around the maximum was about 36 N · m, which was far greater than the holding torque of the human hand and wrist described above.

[0005]

However, the conventional tennis racket frame has been devised so as to absorb and alleviate the twisting impact on the wrist due to the rotational torque about the central axis of the shaft portion at the time of hitting as described above. As the torsional rigidity of the shaft portion increases, the rotational torque inevitably increases, which results in
The wrist that grips the grip has a large impact, and the degree of fatigue on the wrist is severe.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to maintain bending rigidity in the ball striking direction as it is, absorb and relax the transmission of impact to the wrist holding the grip portion at the time of hitting, and reduce the fatigue level of the wrist. It is to provide a racket frame for tennis that can be played.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a frame tension string portion on which a gut is stretched, a shaft portion supporting a base portion of the frame tension string portion, and a terminal side of the shaft portion. In addition to the grip portion forming the portion, the torsional rigidity around the central axis of the shaft portion is set to be lower than the bending rigidity in the ball striking direction.

[0008]

That is, according to the present invention, since the torsional rigidity around the central axis of the shaft portion is set lower than the bending rigidity in the ball striking direction by adopting the above configuration,
The transmission of the impact to the wrist holding the grip portion at the time of hitting the ball is absorbed and relaxed, and the degree of fatigue of the wrist can be reduced. The torsional rigidity around the central axis of the shaft part is a value obtained by adding a slight margin to the rotational torque generated when a ball is hit at a portion deviated from the longitudinal central axis of the frame tension string part, for example, 40 N · m / rad or less. It is preferable that

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings. FIGS. 1 and 2 show a first embodiment of a tennis racket frame according to the present invention. In the figure, 1 is a straight shaft type racket frame.

As shown in FIG. 1, the racket frame 1 includes a frame tension string portion 2 on which a gut G is stretched, and a shaft portion 4 which separately supports a base portion 3 of the frame tension string portion 2, As shown in FIG. 2, the strength member 41 of the shaft portion 4 is composed of a grip portion 5 that forms the end 4a side portion of the shaft portion 4, and has a thickness, for example, that maintains the bending rigidity in the ball striking direction as it is. It has an I-shaped cross-sectional shape with t of 6 mm or less, and the torsional rigidity about the central axis OO thereof is set to 40 N · m / rad or less.

FIG. 3 shows a second embodiment according to the present invention, in which the strength member 41 of the shaft portion 4 has a thin plate rectangular cross section with a thickness t of 6 mm or less, and a central axis O thereof. -O torsional rigidity of 40 N ・ m / r
It has a configuration configured to be equal to or less than ad.

FIG. 4 shows a third embodiment according to the present invention, in which the strength member 41 of the shaft portion 4 has an H-shaped cross section with a thickness t of 6 mm or less,
The torsional rigidity around the central axis O-O is 40 N ・ m / rad
The configuration has the following settings.

FIG. 5 and FIG. 6 show a fourth embodiment according to the present invention, in which two shafts 4 are separated from each other in parallel to the ball striking direction, which is separate from the frame tension string portion 2, in parallel to each other. The strength members 41 and 41 are formed, and the torsional rigidity around the central axis O-O is set to 40 N · m / rad or less. In this case, the strength members 41 and 41 are formed. End 41a, 41 of the grip
The a side may be connected and fixed by the grip end member 6.

7 and 8 show a fifth embodiment according to the present invention, in which the shaft portion 4 is separated from the frame tension string portion 2 in parallel with a vertical plane orthogonal to the ball striking direction. It is formed of two pipe-shaped strength members 41, 41, and the torsional rigidity about the central axis OO is 40%.
In this case, the grip members end 41a, 41a side of each of the strength members 41, 41 may be connected to each other by the grip end member 6.

FIGS. 9 to 11 show a sixth embodiment of an open throat type racket frame 11 according to the present invention, which comprises a frame tension string portion 12 and a shaft portion 14 including a throat portion 13. , The strength members 15 and 15 which are integrally extended from the frame string 12 to form the throat portion 13 and are joined to each other in a direction orthogonal to the ball striking direction. The strength members 15 and 15 in the parts are
For example, while having a U-shaped cross-sectional shape with a thickness of 3 mm or less, the end portion 15 on the side of the grip portion 16 from the base end 13a of the throat portion 13 of the strength member 15 joined to each other.
A portion having a thickness t of 6 mm or less is formed into an I-shaped cross-section, and the torsional rigidity about the central axis OO is set to 40 N · m / rad or less. Is.

FIG. 12 shows a seventh embodiment according to the present invention. In the fifth embodiment, the strength member 15 of the shaft portion 14 is a thin plate rectangular cross section having a thickness t of 6 mm or less. In addition, the torsional rigidity around the central axis OO is set to 40 N · m / rad or less.

FIG. 13 shows an eighth embodiment according to the present invention. In the fifth embodiment, the strength member 15 of the shaft portion 14 has an H-shaped cross section with a thickness t of 6 mm or less. , Its torsional rigidity around the central axis OO is 40N
-It has a configuration that is set to m / rad or less.

In the fifth to eighth embodiments, the base end 13a of the throat portion 13 of the shaft portion 14 is used.
Member 1 from the end to the end of the grip 16 side
5 has an I-shaped shape having a thickness t of 6 mm or less over the entire length,
Although the thin plate-shaped rectangular shape and the H-shaped cross section are used, only the portion corresponding to the entire length of the grip portion 16 or the portion corresponding to a part of the grip portion 16 has an I-shaped, thin-plate rectangular or H-shaped cross section. It may be shaped.

14 and 15 show a ninth embodiment according to the present invention.
In the embodiment, the strength members 15 and 15 of the shaft portion 14 in the fifth embodiment described above are made to face each other in a direction orthogonal to the ball striking direction and separated, and the strength members 15 and 15 15 has an I-shaped cross-section, and the torsional rigidity around the central axis OO is 40.
It has a configuration in which it is set to N · m / rad or less.

FIG. 16 shows a tenth embodiment according to the present invention, in which the shaft portion 1 in the ninth embodiment described above is used.
The strength members 15 and 15 of No. 4 have a thin plate-shaped rectangular cross-sectional shape, and the torsional rigidity around the central axis O--O is 40.
It has a configuration in which it is set to N · m / rad or less.

FIG. 17 shows an eleventh embodiment according to the present invention, which is the shaft portion 1 in the ninth embodiment.
The strength members 15, 15 of No. 4 have a forward and reverse U-shaped cross section, and the torsional rigidity around the central axis OO is 40 N ·
It has a configuration set to m / rad or less.

In the ninth to eleventh embodiments described above, the terminal portions 15a, 15a on the grip portion 16 side of the respective strength members 15, 15 are separated, but within a range of 50 mm or less from the grip end. You may connect.

18 and 19 show a first embodiment according to the present invention.
In the second embodiment, the strength members 15 and 15 of the shaft portion 14 in the above-described ninth embodiment have a hollow cross-sectional shape, and a sponge, a soft rubber or a viscoelastic body is provided between the respective strength members 15 and 15. The elastic member 17 such as the above is interposed, and the torsional rigidity around the central axis OO is set to 40 N · m / rad or less.

FIG. 20 shows a thirteenth embodiment according to the present invention, in which sponge, soft rubber, viscoelastic body or the like is formed around the strength members 15 and 15 of the shaft portion 14 of the twelfth embodiment. The elastic member 17 is interposed, and the torsional rigidity around the central axis OO is set to 40 N · m / rad or less.

FIG. 21 shows a fourteenth embodiment according to the present invention, which has a structure in which the strength members 15, 15 of the shaft portion 14 are opposed to each other in the ball striking direction in the twelfth embodiment. is there.

22 to 25 show a first embodiment according to the present invention.
5 shows the fifth embodiment, the shaft portion 24 and the grip portion 2
6 is formed as a separate body, and the insertion holding mechanism 25 is made of an elastic rubber rotating spring inserted in the shaft portion 24.
Into the grip portion 26, the connecting rod 27 is inserted, and the shaft portion 24 is elastically rotatably joined so that the torsional rigidity around the central axis O-O is set to 40 N · m / rad or less. It has the following structure.

In the above embodiment, the reinforcing members 15 and 15 of the shaft portion 14 have a closed cross-section structure such as an I-shape, a thin plate rectangular shape, or an H-shape, but may have an open cross-section structure. .

[0028]

As is apparent from the above description, according to the present invention, the frame tension string portion on which the gut is stretched, the shaft portion supporting the base portion of the frame tension string portion, and the end side portion of the shaft portion are formed. In addition to the grip part, the torsional rigidity around the central axis of the shaft part is set to be lower than the bending rigidity in the ball striking direction, so the transmission of impact to the wrist holding the grip part at the time of hitting is absorbed and mitigated. Therefore, the degree of fatigue of the wrist can be reduced.

[Brief description of drawings]

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

FIG. 2 is an enlarged cross-sectional view taken along line AA of FIG.

FIG. 3 is an enlarged sectional view showing a second embodiment according to the present invention.

FIG. 4 is an enlarged sectional view showing a third embodiment according to the present invention.

FIG. 5 is an explanatory view showing a fourth embodiment according to the present invention.

6 is an enlarged cross-sectional view taken along the line BB of FIG.

FIG. 7 is an explanatory diagram showing a fifth embodiment according to the present invention.

8 is an enlarged cross-sectional view taken along the line CC of FIG.

FIG. 9 is an explanatory view showing a sixth embodiment according to the present invention.

10 is an enlarged cross-sectional view taken along the line DD of FIG.

11 is an enlarged cross-sectional view taken along the line EE of FIG.

FIG. 12 is an enlarged sectional view showing a seventh embodiment according to the present invention.

FIG. 13 is an enlarged sectional view showing an eighth embodiment according to the present invention.

FIG. 14 is an explanatory view showing a ninth embodiment according to the present invention.

FIG. 15 is an enlarged sectional view taken along line FF in FIG.

FIG. 16 is an enlarged sectional view showing a tenth embodiment according to the present invention.

FIG. 17 is an enlarged sectional view showing an eleventh embodiment of the present invention.

FIG. 18 is an explanatory view showing a twelfth embodiment according to the present invention.

19 is an enlarged cross-sectional view taken along the line GG of FIG.

FIG. 20 is an enlarged sectional view showing a thirteenth embodiment according to the present invention.

FIG. 21 is an enlarged sectional view showing a fourteenth embodiment according to the present invention.

FIG. 22 is an explanatory view showing a fifteenth embodiment according to the present invention.

FIG. 23 is an enlarged perspective view of the insertion holding mechanism on the shaft side as well.

FIG. 24 is an exploded perspective view showing a joined state of the shaft portion and the grip portion.

FIG. 25 is an explanatory view showing elastically rotating states of the shaft portion and the grip portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Racket frame, 2 ... Frame tension string part, 3 ... Base part, 4 ... Shaft part 4a ... Shaft end, 41 ... Strength member, 5 ... Grip part, OO ... Shaft center axis.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuhiro Ishigaki 10-1 Nakazawa-machi, Hamamatsu City, Shizuoka Prefecture Yamaha Stock Company

Claims (12)

[Claims] 1. A frame tension string portion on which a gut is stretched,
A shaft portion that supports the base of the frame string and a grip portion that forms a terminal side portion of the shaft portion, and the torsional rigidity around the central axis of the shaft portion is set lower than the bending rigidity in the ball striking direction. This is a racket frame for tennis. 2. The tennis racket frame according to claim 1, wherein the shaft portion is made of a single strength member that is separate from the frame tension string portion. 3. The tennis racket frame according to claim 1, wherein the strength member of the shaft portion has an I-shaped or thin plate-shaped rectangular shape or H-shaped cross-sectional shape. 4. The tennis racket frame according to claim 1, wherein the shaft portion is composed of two strength members which are separate from the frame stringing portion and are separated from each other. 5. The tennis racket frame according to claim 1 or 4, wherein each of the strength members of the shaft portion that are separated from each other is connected to the grip portion end side. 6. The tennis racket frame according to claim 1, wherein the shaft portion is composed of two strength members joined together to form a throat portion by integrally extending from the frame tension string portion. 7. A portion corresponding to at least all or a part of the grip portion of the strength member extending from the throat portion base ends joined to each other of the shaft portion to the end portion of the shaft portion is I-shaped or thin plate-shaped rectangular or H-shaped. The tennis racket frame according to claim 1 or 6, wherein the racket frame has a mold cross-sectional shape. 8. The tennis racket frame according to claim 1, wherein the shaft portion is composed of two separate strength members that extend integrally from the frame stringing portion to form a throat portion. 9. The cross-sectional shape of each of the strength members in the portion from the base end of the throat portion separating from each other of the shaft portion to the end side of the shaft portion is I-shaped, thin-plate rectangular, or forward / reverse U-shaped. The racket frame for tennis according to claim 1 or 8. 10. The tennis racket frame according to claim 1, wherein the respective strength members of the shaft portion that are separated from each other are connected to the grip portion end side. 11. An elastic member is interposed between respective strength members which are separated from each other at a portion from the base end of the throat portion of the shaft portion to the end side of the shaft portion. Racket frame for tennis described in. 12. The shaft-side grip portion on the terminal side is formed at least partially as a separate body, and the grip portion is joined to the shaft portion so as to be elastically rotatable in a rotation direction around a central axis of the shaft portion. Claims 1, 2, 4, 6
Or the racket frame for tennis according to 8.