JPH07178202A - Badminton racket - Google Patents

Abstract

PURPOSE:To improve deflectiveness and to decrease the twists around an axis by forming at least a part of a shaft to such an irregular shape that the section thereof perpendicular to the axial line of the shaft has a major axis along a gut surface and is not a polygonal shape. CONSTITUTION:This badminton racket is composed of the gut 3 extended on the frame 2 and the grip 4 mounted at the base end of the shaft 1. In such a case, a part of the shaft 1 is formed to such irregular shape that the section thereof perpendicular to the axial line of the shaft has the major axis along the gut surface and is not the polygonal shape. Namely, the irregular shape at the section of the shaft 1 is formed to a substantially elliptic shape. The major axis (a) of the section is set at 8 to 12mm and the minor axis (b) to 6 to 11mm, respectively and these axes are specified at a relation a>b. Further, the irregularly shaped part at the section of the shaft 1 is formed nearer the gut surface side than the central part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a badminton racket, and more particularly to a badminton racket which has good flexibility and little twist, and is excellent in controllability.

[0002]

2. Description of the Related Art Conventional badminton racket shafts are disclosed in Japanese Utility Model Publication No. 55-175455 and Japanese Utility Model Publication No. 6
The one described in Japanese Patent Laid-Open No. 31-4686 is known. The former is one in which the cross section of the shaft is square or rectangular, and the shaft is formed by a metal hollow pipe, and the latter is the cross section of the hollow shaft is circular, and a protrusion protruding inward is formed on the inner peripheral surface. It was done.

[0003]

In both of the above-mentioned two conventional examples, the flexibility of the shaft is poor and it is not pliable.
The shaft described in Japanese Utility Model Laid-Open No. 61-31468 is difficult to manufacture because the projection is formed on the inner peripheral surface.

Therefore, an object of the present invention is to provide a badminton racket provided with a shaft which has good flexibility and can resist twisting around an axis at the time of impact.

[0005]

In order to achieve the above-mentioned object, the present invention has a different-diameter shape in which at least a part of a shaft has a cross section perpendicular to its axis having a major axis in a direction along a gut surface. In addition, it is configured so as not to have a polygonal shape.

[0006]

When the shaft has a perfectly circular cross section, the torsion about the shaft axis is large at the time of impact, and when it has a rectangular shape, the flexibility is poor. However, the shaft having a major axis in the direction along the gut surface of the present invention. In that case, there is little twist, and the shaft has sufficient flexibility unless it has a polygonal shape such as an elliptical cross section.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

1 to 3 are cross-sectional views of the shaft 1 of the badminton racket shown in FIG. 4, taken along the line AA. The badminton racket is attached to the gut 3 stretched on the frame 2 and the base end side of the shaft 1. It consists of a grip 4.
The shaft 1 shown in FIG. 1 is formed such that the cross section perpendicular to the axis of the shaft 1 has a different diameter shape having a major axis a in the direction along the surface of the gut 3 and is not polygonal. The cross-sectional shape shown in FIG. 1 is elliptical and has a major axis a.
Is preferably 8 to 12 mm and the minor axis b is 6 to 11 mm. Such a cross-sectional shape may be formed closer to the surface of the gut 3 than the central portion of the shaft 1, or the cross-sectional shape of the entire shaft 1 may be an elliptical shape as shown in FIG. The opposite ends may have different shapes, and the other ends may have an elliptical shape as shown in FIG.

The sectional shape of the shaft 1 shown in FIG. 2 is an intermediate shape between an elliptical shape and a rectangular shape. If the cross-sectional shape of the shaft 1 is rectangular, the flexibility will deteriorate.

The cross-sectional shape of the shaft 1 shown in FIG. 3 has a major axis a.
The central part of the has a concave shape. 2 and 3
Similar to the embodiment of FIG. 1, the sectional shape shown in FIG. 2 may be the whole or a part of the shaft 1.

The material for forming the shaft 1 may be aluminum or another metal material, and a fiber reinforced resin material can be preferably used. When the fiber reinforced resin material is used, it is preferable to use a composite material in which carbon or the like is mixed with boron or the like. Further, in the cross-sectional shape of the shaft 1 shown in FIGS. 1 to 3, all the shafts 1 are hollow, but they are not necessarily hollow shafts. Further, the shaft 1 and the frame 2 can be integrally molded when they are molded with a resin material, but the frame 2 and the shaft 1 are molded separately, and the shaft 1
May be joined to the frame 2.

[0012]

As described above, according to the present invention, at least a part of the shaft has a different diameter shape such that the cross section perpendicular to the axis has a major axis in the direction along the gut surface, and the polygonal shape is obtained. Since it is configured so as not to have a shape, twisting around the axis of the shaft is reduced, and the flexibility is also improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view taken along the line AA of FIG.

FIG. 2 is a cross-sectional view showing another example of the cross-sectional shape of the shaft.

FIG. 3 is a sectional view showing still another example of the sectional shape of the shaft.

FIG. 4 is a front view of a badminton racket.

[Explanation of symbols]

 1 shaft 3 gut

Claims (4)

[Claims] 1. A badminton racket characterized in that at least a part of the shaft has a different diameter shape such that a cross section perpendicular to the axis has a major axis in a direction along the gut surface, and is not a polygonal shape. 2. The badminton racket according to claim 1, wherein the different-diameter cross section of the shaft has a substantially elliptical shape. 3. The badminton racket according to claim 2, wherein the major axis a of the cross section is 8 to 12 mm, the minor axis b is 6 to 11 mm, and a> b. 4. The badminton racket according to any one of claims 1 to 3, wherein the shaft portion having a different diameter cross section is formed on the gut surface side with respect to the central portion of the shaft.