JP6525745B2 - racket - Google Patents

Description

  The present invention relates to a racquet, in particular a racquet for soft tennis.

  Rackets are used in sports such as soft tennis, hard tennis, squash, and badminton. As a racket for soft tennis, one having a structure in which a frame and a grip are connected by a single shaft (hereinafter also referred to as a single shaft) and one having a structure in which a shaft is bifurcated and joined to a frame (Hereafter, it is also called an open throat) is known (for example, refer to patent documents 1).

JP, 2009-261914, A

  The open throat racket has good surface stability and good ball repulsion, but has less flex and twist. For this reason, it is difficult to control the ball and the feel at impact is hard.

  On the other hand, the single-shaft racket has a large amount of bending and twisting. This makes it easy to hold the ball well. In particular, in soft tennis, twisting is important because rotation is applied using twisting. Therefore, there are many players who are particular about the shape of a single shaft.

  However, a single-shaft racket has a problem that it is difficult to swing and it is difficult for the ball to fly.

  The present invention has been made in view of such circumstances, and an object of the present invention is to improve the swing-out property while maintaining the bending and twisting of a single shaft.

The main invention to achieve the above object is
With the shaft,
A frame joined to one end side in the longitudinal direction of the shaft, in which a plurality of longitudinal strings parallel to the longitudinal direction are stretched at intervals in the width direction orthogonal to the longitudinal direction, and in the width direction A frame in which a plurality of parallel horizontal strings are stretched at intervals in the longitudinal direction to form a striking surface;
A grip joined to the other end of the shaft in the longitudinal direction;
A racket with
It has an opening at the junction of the shaft and the frame,
Among the plurality of vertical strings, the first vertical string and the second vertical string closest to the center in the width direction in the hitting surface are folded back at the opening and are outside the first vertical string. A third vertical string adjacent to the second vertical string, and a fourth vertical string adjacent to the second vertical string outward on the outer circumferential surface of the frame ;
The shaft has a top surface in a thickness direction orthogonal to the longitudinal direction and the width direction, and sloped surfaces provided on both sides in the width direction of the top surface.
In the joint portion, the top surface of the shaft sandwiching the opening in the width direction is provided closer to the opening.
It is a racket characterized by.

  Other features of the present invention will become apparent from the description of the present specification and the drawings.

  According to the racket of the present invention, the swing-off property can be improved.

It is the top view and side view of the racket 1 of this embodiment. 5 is an enlarged view of a shaft 30 and a yoke portion 13 of the racket 1. FIG. 3A to 3C are cross-sectional views at each position of FIG. 3A is an A-A cross section of FIG. 2, FIG. 3B is a B-B cross section of FIG. 2, and FIG. 3C is a C-C cross section of FIG. It is explanatory drawing of a structure of grommet 60. As shown in FIG. It is a schematic explanatory drawing of the structure of the racket 100 (one shaft). It is a schematic explanatory drawing of the structure of the racket 200 (open throat). It is the figure which compared the dimension of the racket 1 and the racket 200. FIG. It is a figure which shows the result of the characteristic comparison of each racket.

=== Overview of Disclosure ===
At least the following matters will be made clear by the present specification and the description of the drawings.

A shaft and a frame joined to one end side in the longitudinal direction of the shaft, and a plurality of longitudinal strings parallel to the longitudinal direction are stretched at intervals in the width direction orthogonal to the longitudinal direction, and A frame in which a plurality of transverse strings parallel to the width direction are stretched at intervals in the longitudinal direction to form a hitting surface, and a grip joined to the other end side in the longitudinal direction of the shaft A racket, having an opening at a joint portion between the shaft and the frame, and a first vertical string and a second vertical closest to the center in the width direction of the hitting surface among the plurality of vertical strings. The string is folded back at the opening, and a third vertical string adjacent to the first vertical string on the outer side, and a fourth vertical string adjacent to the second vertical string to the outer side. Ring is folded back at the outer peripheral surface of the frame, it becomes clear racket characterized by.
According to such a racket, it is possible to improve the swing-out property while maintaining the bending and twisting of the single shaft.

In such a racket, the shaft has a top surface in a thickness direction orthogonal to the longitudinal direction and the width direction, and an inclined surface provided on both sides in the width direction of the top surface, and the joining is performed. In the portion, it is desirable that the top surface of the shaft sandwiching the opening in the width direction be provided closer to the opening.
According to such a racket, the width of the top surface can be reduced, and the air resistance can be reduced.

The racket is characterized in that the other end side in the longitudinal direction of the shaft has a protruding portion provided so as to project in the thickness direction, and the length in the width direction of the top surface is the same as that of the racket. Preferably, the length is smaller than the length in the width direction on the other end side in the longitudinal direction of the raised portion.
According to such a racket, the rigidity can be increased while reducing the air resistance.

  In this racket, it is preferable that a boundary between the inclined surface and the top surface is connected to a boundary between the ridge and the inclined surface at the one end side in the longitudinal direction of the ridge. .

=== Embodiments ===
<Structure of racket>
FIG. 1 is a plan view and a side view of a racket 1 of the present embodiment. In the drawings, the left side is a plan view and the right side is a side view. FIG. 2 is an enlarged view of the shaft 30 and the yoke portion 13 of the racket 1. In FIG. 2, for convenience of explanation, the vertical strings 12 a are numbered (numbers in parentheses). 3A to 3C are cross-sectional views at each position of FIG. 3A is an A-A cross section of FIG. 2, FIG. 3B is a B-B cross section of FIG. 2, and FIG. 3C is a C-C cross section of FIG.

  As shown in FIG. 1, the racket 1 has a head 10 which is a part to hit a ball, a grip 20 which is a part to which the player grips the racket 1, and a shaft 30 which integrally connects the head 10 and the grip 20. Have. In the following description, the side where the head 10 is located in the longitudinal direction of the racket 1 is referred to as the tip end (corresponding to one end side), and the side where the grip 20 is located is referred to as the rear end (corresponding to the other end). In addition, a direction orthogonal to the longitudinal direction on the strike surface (plane along the strike surface) of the racquet 1 is taken as a width direction, and a direction orthogonal to the strike face of the racquet 1 (ie, a direction orthogonal to the longitudinal direction and the width direction) Thickness direction.

  The head 10 has an oval frame 11 extending in the longitudinal direction of the racket 1, a string 12 stretched inside the frame 11, and a yoke portion 13 connecting lower portions (rear end portions) of the frame 11. And. Grooves 11 a are provided on the outer peripheral surface of the frame 11 along the circumferential direction of the frame 11. Further, a plurality of through holes (not shown) penetrating from the inner circumferential surface to the outer circumferential surface of the frame 11 are provided in the groove portion 11 a along the circumferential direction of the frame 11. Furthermore, two through holes are formed in the yoke portion 13 as well. These through holes are holes for inserting the string 12.

  Inside the frame 11 (and the yoke portion 13), a “vertical string 12a” which is a portion of the string 12 is spaced along the longitudinal direction (parallelly) and in the width direction through the plurality of through holes. There are a number of empty bottles. Furthermore, a plurality of "horizontal strings 12b", which are portions of the strings 12, are stretched along the width direction (parallelly) and at intervals in the longitudinal direction so as to intersect the vertical strings 12a. Thus, a net-shaped strike face is formed. A grommet (not shown) is attached to the outer peripheral surface (groove portion 11a) of the frame 11 in order to protect the string 12 and to dampen the vibration at the time of hitting a ball. And string 12 (vertical string 12a, horizontal string 12b) is folded back via this grommet. In the yoke portion 13, the vertical string 12a is folded back via a grommet 60 described later.

<About the shaft 30>
The shaft 30 bifurcates toward the tip end in the longitudinal direction, as viewed in the thickness direction. The bifurcated portion (the joint portion between the shaft 30 and the frame 11) is referred to as a throat portion 40. As described above, since the shaft 30 is bifurcated, the throat portion 40 is formed with an opening 50 which is open in the thickness direction. In other words, the racket 1 has the opening 50 at the junction between the shaft 30 and the frame 11. However, in the racket 1 of this embodiment, the sizes of the throat 40 and the opening 50 are smaller than those of the open throat racket (see FIG. 6). Specifically, the opening 50 has such a size that the vertical string 12a is folded back only once. For this reason, the shape (contour) of the outer shape including the shaft 30 of the racket 1 is substantially the same as that of the single-shaft racket (see FIG. 5), whereby the single-shaft racket is bent or twisted. (See the example described later). Moreover, in the racket 1 of the present embodiment, by providing the opening 50, weight reduction and reduction of air resistance can be achieved as compared with a single-shaft racket. The weight reduced by providing the opening 50 as described above is distributed to the frame 11 and the grip 20 to maintain the weight balance and improve the swing-out property.

  Moreover, as shown to the CC cross section of FIG.2 and FIG.3, the shaft 30 has the inclined surface 31, the top surface 32, and the protruding part 35. As shown in FIG. As can be seen from FIGS. 1 and 3, in the racket 1 of the present embodiment, the front side and the rear side are symmetrical with respect to the center in the thickness direction. Hereinafter, although the structure of the one side (here front side) of thickness direction is demonstrated, the structure of the other side (rear side) is also the same.

  The top surface 32 is an end surface on the front side in the thickness direction from the raised portion 35 to the bifurcated branch portion of the shaft 30.

  The inclined surfaces 31 are provided on both sides in the width direction sandwiching the top surface 32 (and the raised portions 35), and are formed such that the thickness decreases as approaching the end in the width direction. In addition, the inclination of the inclined surface 31 on either side is the same, and the top surface 32 is formed in the center part of the width direction of the shaft 30 (refer FIG.2 and FIG.3C).

  Further, in the racket 1 of the present embodiment, the shaft 30 is bifurcated at the throat portion 40. Therefore, as shown in FIG. 2, the top surface 32 is also bifurcated (two top surfaces 42). doing. Moreover, the outer side inclined surface 41 continuous with the inclined surface 31 is formed in the outer side of the top surface 42, and the inner side inclined surface 43 is formed from the branch position inside. Here, as shown in FIG. 3B, the inner inclined surface 43 is shorter in length in the width direction than the outer inclined surface 41 (that is, the inclination is steep), and the position of the top surface 42 in the width direction is inner (opening The part 50 side is closer. This makes it possible to reduce the width (length in the width direction) of the top surface 32 where the top surfaces 42 of the two throats 40 join together, and further, on both sides in the width direction of the top surface 32, a wide inclination The surface 31 can be formed. As described above, in the racket 1 of the present embodiment, the width of the top surface 32 of the shaft 30 is small, and furthermore, since the inclined surfaces 31 are formed on both sides in the width direction of the top surface 32, air resistance is reduced. be able to.

  The raised portion 35 is provided on the rear end side (grip 20 side) in the longitudinal direction of the shaft 30 so as to be continuous with the top surface 32 in the longitudinal direction. The ridges 35 are formed to protrude (project) in the thickness direction as the rear side is approached, and to widen in width. For this reason, the width (length in the width direction) of the top surface 32 is smaller than the width (length in the width direction) on the rear end side (junction with the grip 20) in the longitudinal direction of the raised portion 35. Further, on the tip side in the longitudinal direction of the raised portion 35, the boundary between the top surface 32 and the inclined surface 31 is connected to the boundary between the raised portion 35 and the inclined surface 31. With such a configuration, it is possible to increase the rigidity at the time of hitting while reducing the air resistance.

<About Grommet 60>
A grommet 60 is provided on the yoke portion 13 (the end portion on the tip end side in the longitudinal direction of the opening 50) of the racket 1 of the present embodiment. Then, the string 12 (vertical string 12 a) is folded back via the grommet 60.

  FIG. 4 is an explanatory view of the configuration of the grommet 60. As shown in FIG. The upper left figure is a front view (left half is a sectional view), and the lower left figure is a side view. Also, the figure on the right side is a cross-sectional view of each position in the figure on the upper left. In the present embodiment, the grommet 60 is formed of a transparent material (resin). Thereby, when the grommet 60 is attached to the yoke part 13, the grommet 60 can be made inconspicuous. The grommet 60 is not limited to transparent, and may be translucent, for example.

  The grommet 60 has two cylindrical portions 61 in which a hollow portion 61 a is formed, and a strip-like base portion 62 connecting the two cylindrical portions 61 and communicating with the hollow portion 61 a in the cylindrical portion 61. The grommet 60 is attached to the yoke portion 13 by causing the tip end of the cylindrical portion 61 to pass through the through hole from the outer peripheral surface side (i.e., the opening 50 side) of the yoke portion 13. The grommet 60 is symmetrical in the left-right direction, and when the grommet 60 is attached to the yoke portion 13, the center position in the width direction of the grommet 60 is aligned with the center position in the width direction of the frame 11 (see FIG. 2).

  The base 62 of the grommet 60 has a bottom 62a, a pair of side walls 62b, and a groove 62c.

  The bottom portion 62 a is a portion where the two cylindrical portions 61 are provided, and an opening communicating with the hollow portion 61 a of each cylindrical portion 61 is formed.

  The pair of side wall portions 62 b is provided so as to protrude in the longitudinal direction rear end side along the width direction at both ends in the thickness direction of the bottom portion 62 a. As shown in FIGS. 4 and 3A, the outer sides of the pair of side wall portions 62b are formed in a curved shape so as to be integrated with the yoke portion 13 when the grommet 60 is attached to the yoke portion 13. . Thereby, the air resistance at the time of hitting can be reduced. On the other hand, the inner side of the pair of side wall portions 62b is formed in a linear shape. Thereby, the strings 12 (vertical strings 12a) can be reliably sandwiched, and the position can be prevented from shifting.

  The groove portion 62c is a portion where the string 12 (vertical string 12a) is folded back, and is formed along the width direction between the pair of side wall portions 62b. As shown in the figure, the size of the groove 62c is not constant, and at the middle point of the two cylindrical portions 61 (the position of the A-A cross section), the groove is more than the position of the cylindrical portion 61 (the position of the B-B cross section) 62c is formed to be small.

  As shown in FIG. 2, two vertical strings 12 a near the center in the width direction among the plurality of vertical strings 12 a formed on the striking surface are passed through the grommet 60. That is, the vertical string 12a (1) on the left side and the vertical string 12a (2) on the right side with respect to the center of FIG. 2 are separated by the grommet 60 at the opening 50 (one hollow 61a of the grommet 60, the groove 62c). , Through the other cavity 61a).

  On the other hand, the vertical string 12a (3) adjacent to the left (outside) with respect to the vertical string 12a (1) and the vertical string 12a (4) adjacent to the right (outside) with respect to the vertical string 12a (2) As illustrated, the outer peripheral surface of the frame 11 is folded back (through a grommet (not shown)). The vertical string 12a (1), the vertical string 12a (2), the vertical string 12a (3), and the vertical string 12a (4) are respectively the first vertical string, the second vertical string, the third vertical string, and the fourth. It corresponds to a vertical string.

  As described above, the racket 1 of the present embodiment has the opening 50 in the throat portion 40 (the joint portion between the shaft 30 and the frame 11). However, in the racket 1 of the present embodiment, the sizes of the throat 40 and the opening 50 are small, and the vertical string 12 a is folded back only once at the opening 50. As a result, it is possible to improve the swing-off property while maintaining the bending and twisting of the single shaft.

<Example>
The racket 1 of this embodiment was compared with the racket 100 with a single shaft and the racket 200 with an open throat.

  FIG. 5 is a schematic explanatory view of the configuration of the racket 100 (single shaft). The racket 100 includes a head 110 having a hitting surface, a grip 120, and a shaft 130 connecting the head 110 and the grip 120. Since the racket 100 is a single-shaft type, the shaft 130 is not bifurcated. The cross section perpendicular to the longitudinal direction of the shaft 30 is substantially rectangular. The outer shape (contour) of the racket 100 is substantially the same as that of the racket 1 of the present embodiment.

  FIG. 6 is a schematic explanatory view of the configuration of the racket 200 (open throat). The racket 200 has a head 210 formed with a hitting surface, a grip 220, and a shaft 230 connecting the head 210 and the grip 220. The shaft 230 of the racket 200 is bifurcated and a throat portion 240 is formed. The racket 200 is one of the open throat type rackets commercially available in which the shape of the bifurcated portion (throat portion 40) is the smallest. Specifically, in the racket 200, four vertical strings are passed through the opening of the throat portion 40 (that is, there are two folds of the vertical string at the opening). For this reason, in the racket 200, two grommets (not shown) are provided at the opening, and the center position in the width direction of the racket 200 and the center position in the width direction of each grommet are not aligned.

  FIG. 7 is a view comparing dimensions of the racket 1 and the racket 200. As shown in FIG. As shown in the lower part of FIG. 7, the shaft length (length in the longitudinal direction) is M, and the shaft width (length in the width direction) is W. Further, the length of the throat portion (length in the longitudinal direction) is set to Ma, and the width of the throat portion is set to Wa.

  The smaller the shaft width W, the easier it is to twist. In FIG. 7, while the shaft width W of the racket 200 is 85 mm, the shaft width W of the racket 1 is 76 mm. Thus, the racket 1 has a shaft width W smaller than that of the racket 200 (that is, the racket 1 is easier to twist than the racket 200).

  Also, the larger the shaft length M, the easier it is to bend. In FIG. 7, while the shaft length M of the racket 200 is 140 mm, the shaft length M of the racket 1 is 181 mm. Thus, the racket 1 has a shaft length M larger than that of the racket 200 (that is, the racket 1 bends more easily than the racket 200).

  Also, as the coefficient M / Wa is larger, it becomes easier to bend and twist. In FIG. 7, while the coefficient M / Wa of the racket 200 is 2.9, the coefficient M / W of the racket 1 is 5.5. Thus, the racket 1 has a coefficient M / W larger than that of the racket 200 (that is, the racket 1 is more easily bent and twisted than the racket 200).

  The data shown in FIG. 7 is an example, and the size of each part is not limited to this. For example, the shaft length M of the racket 1 is desirably 170 to 195 (mm), and the shaft width W is desirably 72 to 82 (mm). The throat length Ma is preferably 20 to 30 (mm), and the throat width Wa is preferably 25 to 30 (mm). Within these ranges, the factor M / Wa is between 4.5 and 7.8, which is greater than the factor M / Wa of the racket 200 (= 2.9).

  FIG. 8 is a diagram showing the results of characteristic comparison of the respective rackets. Here, deformation rates due to bending and twisting are compared.

  As can be seen from the figure, the single-shafted racket 100 is more distorted and twisted than the open-shafted racket 200. In particular, while the racket 200 is 145, the twist is 173 for the racket 100, and the racket 100 is significantly larger.

  As shown in FIG. 8, the racket 1 of this embodiment achieves bending and twist equal to or greater than that of the single-shaft racket 100. Furthermore, the racket 1 has the opening 50 at the joint portion between the shaft 30 and the frame 11, so that the weight and air resistance can be reduced more than the racket 100. Thereby, the swing-through property can be improved.

=== Others ===
The above embodiments are for the purpose of facilitating the understanding of the present invention, and are not for the purpose of limiting the present invention. It goes without saying that the present invention can be modified and improved without departing from the gist thereof, and the present invention includes the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 racket 10 head 11 frame 11a groove 12 string 12a vertical string 12b horizontal string 13 yoke part 20 grip 30 shaft 31 inclined surface 32 top surface 35 raised part 40 throat part 41 outer inclined surface 42 top surface 43 inner inclined surface 50 opening 60 Grommet 61 Tube part 61a Hollow part 62 Base part 62a Bottom part 62b Side wall part 62c Groove part 100 Racket (single shaft)
110 head 120 grip 130 shaft 200 racket (open throat)
210 head 220 grip 230 shaft 240 throat part

Claims (3)

With the shaft,
A frame joined to one end side in the longitudinal direction of the shaft, in which a plurality of longitudinal strings parallel to the longitudinal direction are stretched at intervals in the width direction orthogonal to the longitudinal direction, and in the width direction A frame in which a plurality of parallel horizontal strings are stretched at intervals in the longitudinal direction to form a striking surface;
A grip joined to the other end of the shaft in the longitudinal direction;
A racket with
It has an opening at the junction of the shaft and the frame,
Among the plurality of vertical strings, the first vertical string and the second vertical string closest to the center in the width direction in the hitting surface are folded back at the opening and are outside the first vertical string. A third vertical string adjacent to the second vertical string, and a fourth vertical string adjacent to the second vertical string outward on the outer circumferential surface of the frame ;
The shaft has a top surface in a thickness direction orthogonal to the longitudinal direction and the width direction, and sloped surfaces provided on both sides in the width direction of the top surface.
In the joint portion, the top surface of the shaft sandwiching the opening in the width direction is provided closer to the opening.
A racket characterized by With the shaft,
A frame joined to one end side in the longitudinal direction of the shaft, in which a plurality of longitudinal strings parallel to the longitudinal direction are stretched at intervals in the width direction orthogonal to the longitudinal direction, and in the width direction A frame in which a plurality of parallel horizontal strings are stretched at intervals in the longitudinal direction to form a striking surface;
A grip joined to the other end of the shaft in the longitudinal direction;
A racket with
It has an opening at the junction of the shaft and the frame,
Among the plurality of vertical strings, the first vertical string and the second vertical string closest to the center in the width direction in the hitting surface are folded back at the opening and are outside the first vertical string. A third vertical string adjacent to the second vertical string, and a fourth vertical string adjacent to the second vertical string outward on the outer circumferential surface of the frame;
The shaft has a top surface in a thickness direction orthogonal to the longitudinal direction and the width direction, and sloped surfaces provided on both sides in the width direction of the top surface.
The other end side in the longitudinal direction of the shaft has a protruding portion provided so as to project in the thickness direction,
The length in the width direction of the top surface is smaller than the length in the width direction at the other end side of the protrusion in the longitudinal direction,
A racket characterized by The racket according to claim 2 , wherein
A boundary line between the inclined surface and the top surface is connected to a boundary line between the raised portion and the inclined surface at the one end side in the longitudinal direction of the raised portion.
A racket characterized by

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