JP3247167U - tennis racket - Google Patents

Abstract

[Problem] To provide a tennis racket with improved resilience performance. [Solution] A tennis racket 1 according to one embodiment comprises a frame portion 2 on which strings 7 are stretched to form a ball-hitting surface 20, a grip portion 4, and a shaft portion 3 that connects the frame portion and the grip portion, and an inner peripheral surface 21 of the frame portion has at least a straight portion 5 on one side. [Selected Figure] Figure 1

Description

This invention relates to a tennis racket.

In recent years, there has been a high demand for tennis rackets that have high repulsion and can hit the ball with little force. The hitting surface of a tennis racket is formed by the strings stretched over it, and the vibration of these strings is closely related to the repulsion force.

One of the objectives of this invention is to provide a tennis racket with improved repulsion performance.

A tennis racket according to one embodiment includes a frame portion over which strings are stretched to form a hitting surface, a grip portion, and a shaft portion that connects the frame portion and the grip portion, and the inner circumferential surface of the frame portion has at least a straight portion.

In one embodiment, the frame portion has a generally elliptical shape. The frame portion also has a plurality of through holes for passing the string through, with at least three of the through holes being located in the straight portion.

For example, the string includes a plurality of first strings stretched in a first direction. In this case, the straight portion may include a pair of first straight portions facing each other in the first direction, and the plurality of through holes may include a plurality of first through holes located in each of the pair of first straight portions and through which the first strings are passed.

The string may include a second string stretched in a second direction perpendicular to the first direction. In this case, the straight portion may include a pair of second straight portions facing each other in the second direction, and the plurality of through holes may include a plurality of second through holes located in each of the pair of second straight portions and through which the second string is passed.

For example, the strings passing through the through holes located in the straight portion form the central region of the ball-striking surface.

The straight portion may also have a plane perpendicular to the ball-striking surface, narrower than the outer peripheral surface of the frame portion, and on which the through-holes are aligned, and a pair of inclined surfaces inclined relative to the ball-striking surface and connecting the outer peripheral surface and the plane.

For example, this invention can provide a tennis racket with improved repulsion performance.

FIG. 1 is a schematic perspective view of a tennis racket 1 according to an embodiment. FIG. 2 is a schematic plan view of the tennis racket 1. FIG. 3 is a schematic cross-sectional view of the tennis racket 1 taken along line III-III in FIG.

An embodiment will be described with reference to the drawings.
The present invention is not limited to the following description. In addition, various modifications and improvements can be made to the embodiments, and such modifications and improvements may also be included in the present invention.

Also, as shown in the drawings, the X, Y, and Z directions are defined as being orthogonal to one another. The Z direction is the normal direction of a plane that includes the X and Y directions. Also, viewing the tennis racket 1 parallel to the Z direction is referred to as a planar view.

Figure 1 is a schematic perspective view of a tennis racket 1 according to this embodiment. Figure 2 is a schematic plan view of the tennis racket 1. The tennis racket 1 comprises a frame portion 2, a shaft portion 3, and a grip portion 4. The frame portion 2 is a frame body having an inner peripheral surface 21 and an outer peripheral surface 22. A hitting surface 20 is formed by stretching strings 7 in the area surrounded by the inner peripheral surface 21 of the frame portion 2. This tennis racket 1 is for use in, for example, soft tennis. Note that the configuration disclosed in this embodiment can also be applied to rackets for hard tennis.

The frame portion 2 has a plurality of through holes 8 penetrating the inner peripheral surface 21 and the outer peripheral surface 22. A plurality of through holes 8 are formed in a line along the circumferential direction around the entire circumference of the frame portion 2. Each through hole 8 forms a pair with another through hole 8 facing in the X direction or Y direction.

The strings 7 are tensioned so as to pass through a pair of through holes 8. In other words, the string 7 that is passed through one of the pair of through holes 8 from the outer peripheral surface 22 side toward the inner peripheral surface 21 side is passed through the other of the pair of through holes 8 from the inner peripheral surface 21 side toward the outer peripheral surface 22 side. By passing the strings 7 in this manner, multiple first strings 71 extending in the X direction and multiple second strings 72 extending in the Y direction are tensioned on the frame portion 2.

The outer peripheral surface 22 of the frame portion 2 is generally elliptical in shape, elongated in the Y direction in plan view. In this embodiment, "approximately elliptical" means that the maximum width in the Y direction is greater than the maximum width in the X direction, and also includes a shape that has only one axis of symmetry, such as an egg shape.

The inner circumferential surface 21 of the frame portion 2 has at least a straight line portion 5. In other words, the frame portion 2 in this embodiment is configured such that the contour line of the inner circumferential surface 21 surrounding the ball-striking surface 20 in a plan view is a straight line portion 5 and a curved line portion 6. The contour line is a line segment connecting the portion of the inner circumferential surface 21 located the innermost of the frame portion 2, and corresponds to the center of the inner circumferential surface 21 in the Z direction in one example. The multiple through holes 8 open at positions corresponding to the contour line. Note that "the contour line in a plan view is straight" means that the contour line is substantially straight, and also includes a case where the contour line has a curvature that is sufficiently small compared to the curvature of the curved line portion 6.

In the example of FIG. 2, the width of the portion of the frame 2 where the straight line portion 5 is provided is wider than the width of the portion where the curved line portion 6 is provided.

In the example of Figures 1 and 2, the tennis racket 1 has a pair of first straight line portions 51 facing each other in the X direction and a pair of second straight line portions 52 facing each other in the Y direction. The pair of first straight line portions 51 are parallel to each other. The pair of second straight line portions 52 are parallel to each other.

In this embodiment, a plurality of first through holes 81 are located in the first straight portion 51. Similarly, a plurality of second through holes 82 are located in the second straight portion 52. The number of first through holes 81 located in the first straight portion 51 is not particularly limited, but in one example, it is at least three, and preferably at least six. Similarly, the number of second through holes 82 located in the second straight portion 52 is not particularly limited, but in one example, it is at least three, and preferably at least six.

Between the pair of first straight sections 51, a plurality of first strings 71 are positioned, which are passed through first through holes 81 provided in the first straight sections 51. The lengths L1 of the first strings 71 are approximately the same. Similarly, between the pair of second straight sections 52, a plurality of second strings 72 are positioned, which are passed through second through holes 82 provided in the second straight sections 52. The lengths L2 of the second strings 72 are approximately the same.

In this embodiment, the length L1 refers to the length of the first string 71 between the openings of the paired first through holes 81 on the inner circumferential surface 21 side in a plan view. Additionally, the length L2 refers to the length of the second string 72 between the openings of the paired second through holes 82 on the inner circumferential surface 21 side in a plan view.

The first string 71 passing through the first through hole 81 is preferably a string that forms the central region 20A of the ball striking surface 20. Also, the second string 72 passing through the second through hole 82 is preferably a string that forms the central region 20A of the ball striking surface 20.

In this case, the lengths L1 of the first strings 71 forming the central region 20A are approximately the same, and the lengths L2 of the second strings 72 are approximately the same.

The central region 20A is the region that forms the so-called sweet spot, and has a higher repulsive force than the vicinity of the frame portion 2. For example, the central region 20A is formed in the area surrounded by the dashed line in FIG. 1, and in this embodiment, the spacing between adjacent strings 7 in the same direction becomes narrower as they approach the central region 20A.

Figure 3 is a cross-sectional view of the tennis racket 1 taken along line III-III in Figure 2. In the example of Figure 3, the straight line portion 5 (first straight line portion 51) has a pair of inclined surfaces 9 and a flat surface 10. The inclined surface 9 is inclined with respect to the striking surface 20 (X-Y plane) and connects the outer peripheral surface 22 and the flat surface 10. The flat surface 10 is narrower in width in the Z direction than the outer peripheral surface 22 of the frame portion 2 and is perpendicular to the striking surface 20. In addition, a plurality of through holes 8 (first through holes 81) are arranged in the flat surface 10. Note that the inclined surface 9 and the flat surface 10 are not essential. The cross-sectional structure of the frame portion 2 including the second straight line portion 52 is the same as that of the example of Figure 3.

A grommet 11 that supports the string 7 is attached to the frame portion 2. The shape of the grommet 11 is not particularly limited, but in one example, it has a base 11a that extends circumferentially around the frame portion 2 along a groove provided in the outer peripheral surface 22, and multiple tubes 11b that extend from this base toward the inner peripheral surface 21 and through which the string 7 passes. Each tube 11b passes through a through hole 8.

In the present embodiment described above, by providing the straight line portion 5 on the inner peripheral surface 21, the lengths of the multiple strings 7 extending in the same direction are approximately the same. This reduces the variation in the natural frequency of each string 7.

As a result, the vibrations applied to the strings 7 when the ball collides with the ball-striking surface 20 are uniform, improving the repulsion characteristics of the tennis racket 1. For the same reason, the range of the sweet spot of the ball-striking surface 20 can be expanded compared to a tennis racket that does not have a straight portion 5.

When the first straight portion 51 is provided, the first string 71 that forms the central region 20A of the ball striking surface 20 is shorter than the second string 72 that also forms the central region 20A of the ball striking surface 20, so that the resilience performance is likely to improve when the lengths of the strings 7 are made the same. In order to obtain the above-mentioned effect, it is preferable to provide both the first straight portion 51 and the second straight portion 52.

Furthermore, in this embodiment, the area of the hitting surface 20 is slightly reduced by providing the straight section 5. This makes it easier for the ball to hit the straight section 5 when hitting the ball. If the straight section 5 did not have an inclined surface 9 and the flat surface 10 had the same width as the outer peripheral surface 22, the ball would be more likely to bounce in an unintended direction when it hits the corner of the flat surface 10.

In this regard, by providing an inclined surface 9, even if the ball collides near the corner of the flat surface 10, this unintended rebound can be suppressed.

As is clear from the above description, this embodiment can provide a tennis racket with improved repulsion performance.

The present invention is not limited to the above-described embodiments, and these new embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. Furthermore, these embodiments and their modifications are included within the scope and spirit of the invention, and are included in the scope of the invention and its equivalents set forth in the scope of the utility model registration claims.

1...tennis racket, 2...frame, 20...ball-hitting surface, 20A...center area, 21...inner surface, 22...outer surface, 3...shaft, 4...grip, 5...straight section, 51...first straight section, 52...second straight section, 7...string, 71...first string, 72...second string, 8...through hole, 81...first through hole, 82...second through hole, 9...inclined surface, 10...flat surface

Claims (7)

The golf club has a frame portion on which a string is stretched to form a hitting surface, a grip portion, and a shaft portion connecting the frame portion and the grip portion,
The inner circumferential surface of the frame portion has at least a linear portion.
tennis racket. The tennis racket according to claim 1, wherein the frame portion has a generally elliptical shape. The frame portion has a plurality of through holes for passing the strings through,
At least three of the through holes are located in the straight portion.
3. A tennis racquet as claimed in claim 2. The strings include a plurality of first strings stretched in a first direction,
The straight portion includes a pair of first straight portions opposed to each other in the first direction,
The plurality of through holes include a plurality of first through holes that are located in each of the pair of first straight portions and through which the first string is passed.
4. A tennis racquet as claimed in claim 3. The strings include a second string stretched in a second direction perpendicular to the first direction,
the straight line portion includes a pair of second straight line portions opposed to each other in the second direction,
The plurality of through holes include a plurality of second through holes that are located in each of the pair of second straight portions and through which the second string is passed.
5. A tennis racquet as claimed in claim 4. The tennis racket according to any one of claims 3 to 5, wherein the strings passing through the through holes located in the straight portion form a central region of the ball-striking surface. The straight portion is
a plane perpendicular to the ball-hitting surface, narrower than an outer peripheral surface of the frame portion, and in which the through holes are arranged;
A pair of inclined surfaces inclined with respect to the ball striking surface and connecting the outer circumferential surface and the flat surface;
having
A tennis racket according to any one of claims 3 to 5.

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