Badminton shuttlecock

Abstract

This badminton shuttlecock includes a base portion, a plurality of feathers, and a connection ring. Each feather has a root portion, an intermediate portion, and a tip portion. The base portion has a plurality of fixing holes, into each of which the root portion is inserted and fixed. The connection ring has a plurality of insertion holes, into each of which a feather shaft portion is inserted. The connection ring mutually connects the intermediate portions to integrally connect the plurality of feathers so that the plurality of feathers spread radially from the base portion. The plurality of fixing holes have a first positioning surface for positioning the root portion in a rotation direction around an axis. The plurality of insertion holes have a second positioning surface for positioning the intermediate portion in the rotation direction around the axis.

Description

Badminton Shuttlecock CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This international application claims priority to Patent Cooperation Treaty International Application PCT / JP2023 / 031926, filed with the Japan Patent Office on August 31, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to badminton shuttlecocks.

[0003] Badminton shuttlecocks (hereinafter referred to as "badminton shuttlecocks") have been known which have a base and a plurality of feathers fixed to the base so that the feathers radiate from the base. For such badminton shuttlecocks, a method of connecting the feathers with strings to position them relative to the base is known.

[0004] In Patent Document 1, in a badminton shuttlecock, the rachis of each of the multiple feathers is attached to a base and connected to each other with an overlocking thread so that the multiple feathers spread out radially. The base, rachis, and overlocking thread are then fixed with an adhesive.

[0005] JP 2014-166233 A

[0006] In a badminton shuttlecock, in order to achieve appropriate flight characteristics of the shuttlecock, it is necessary to adjust the multiple feathers so that they spread uniformly radially from the base. In the badminton shuttlecock described in Patent Document 1, the rachis portions are planted in the base and connected with an overlocking thread, thereby adjusting the spread of the multiple feathers. Furthermore, in a badminton shuttlecock, the rachis portions are positioned in the rotational direction around the axis. When the rachis portions are planted in the base and connected to each other with an overlocking thread, a worker has to manually position the rachis portions in the rotational direction around the axis. As a result, assembling a badminton shuttlecock can sometimes be difficult.

[0007] In one aspect of the present disclosure, it is desirable to improve the efficiency of assembling a badminton shuttlecock by facilitating the positioning of the rachis in the rotational direction around the axis.

[0008] One aspect of the present disclosure is a badminton shuttlecock comprising a base portion, a plurality of feathers, and a first connecting ring. Each of the plurality of feathers is fixed in an annular shape to the base portion, and each of the plurality of feathers has a feather portion and a rachis portion. The feather portion is attached to the rachis portion. The rachis portion has a root portion, a tip portion, and an intermediate portion. The root portion is the portion fixed to the base portion. The tip portion is the portion to which the feather portion is attached. The intermediate portion is the portion sandwiched between the root portion and the tip portion. The base portion has a plurality of fixing holes, and the root portions are inserted into and fixed to each of the plurality of fixing holes, so that the fixing positions of the plurality of root portions on the base portion form a ring shape. The first connecting ring is annular and has a plurality of insertion holes formed in the circumferential direction, and a rachis portion is inserted into each of the plurality of insertion holes. The first connecting ring interconnects the intermediate portions to integrally connect the multiple blades so that they radiate from the base portion. The first connecting ring has a thickness within a predetermined range in the direction of the shuttle axis, with the axis connecting the center of the ring shape formed by the fixing positions of the multiple root portions on the base portion and the center of the first connecting ring being the shuttle axis. Each of the multiple fixing holes has a first positioning surface for positioning the root portion in the rotational direction about its axis. The multiple insertion holes have a second positioning surface for positioning the intermediate portion in the rotational direction about its axis.

[0009] Note that the relative positions of the feathers in each of the multiple feathers can be determined as a result of positioning the rachis section in the rotational direction around its axis. For example, in a side view of the badminton shuttlecock, adjacent feathers in the multiple feathers may overlap, or may not overlap. In the following description, the term "side of the badminton shuttlecock" refers to a direction perpendicular to the shuttlecock axis of the badminton shuttlecock. Here, "overlapping feathers" may mean that adjacent feathers that appear to overlap in a side view of the badminton shuttlecock are in contact with each other. Alternatively, "overlapping feathers" may mean that adjacent feathers that appear to overlap in a side view of the badminton shuttlecock are not in contact with each other.

[0010] With this configuration, when each root portion is fixed to the base portion, the root portion contacts the first positioning surfaces in the multiple fixing holes in the base portion, which are used to position the root portion in the rotational direction about its axis. This prevents rotation of the root portion around its axis. Furthermore, when the first connecting ring connects the intermediate portions to each other, the intermediate portions contact the second positioning surfaces in the multiple insertion holes in the first connecting ring, which are used to position the intermediate portion in the rotational direction about its axis. This prevents rotation of the intermediate portion around its axis. This allows for a badminton shuttlecock that is easy to position in the rotational direction about its axis for the root portion and intermediate portion.

[0011] In one aspect of the present disclosure, the badminton shuttlecock may further include a second connecting ring in addition to the first connecting ring. The second connecting ring may be annular and have multiple insertion holes formed in the circumferential direction, with rachis sections inserted into each of the multiple insertion holes. The first connecting ring may connect the rachis sections to each other, thereby connecting the multiple feathers together. The second connecting ring may have a thickness within a predetermined range in the direction of the shuttle shaft over the entire circumference. The center of the second connecting ring may be at a different position on the shuttle shaft from the center of the annular shape formed by the fixing positions of the multiple root sections on the base section. The second connecting ring may connect the intermediate sections to each other at a position different from that of the first connecting ring in the direction of the shuttle shaft, so that the first connecting ring connects the intermediate sections to each other, thereby maintaining the shape of the badminton shuttlecock in which the multiple feathers are connected together and radiating out from the base section. The plurality of insertion holes in the first ring may have second positioning surfaces for positioning the intermediate portion in a rotational direction about the axis, and the plurality of insertion holes in the second ring may have third positioning surfaces for positioning the intermediate portion in a rotational direction about the axis.

[0012] With this configuration, when the second connecting ring connects the intermediate portions to each other, the intermediate portions contact third positioning surfaces in the multiple insertion holes of the second connecting ring, which positions the intermediate portions in the rotational direction about their axes. This suppresses rotation of the intermediate portions about their axes. Furthermore, a badminton shuttlecock can be obtained in which the intermediate portions are easily positioned in the rotational direction about their axes, and the multiple shuttlecocks can be connected more stably and firmly in the radial spread direction of the multiple shuttlecocks. Furthermore, by adjusting the distance between the first connecting ring and the second connecting ring in the direction of the shuttlecock axis, it is possible to adjust the radial spread of the multiple shuttlecocks on the badminton shuttlecock.

[0013] In one aspect of the present disclosure, the cross-sectional shape of each rachis portion of the plurality of blades taken perpendicular to the axial direction may have a recess.

[0014] With this configuration, the amount of material that makes up the rachis section is reduced compared to when no recesses are formed in the cross-sectional shape of each rachis section. This makes it possible to reduce the weight of each of the multiple feathers, thereby reducing the weight of the badminton shuttlecock as a whole.

[0015] In one aspect of the present disclosure, a first claw portion may be provided on a surface of each rachis portion of the plurality of feathers that faces the first connection ring, and the first claw portion may engage with the first connection ring to position the first connection ring in the axial direction of the rachis portion.

[0016] With this configuration, when the first connecting ring connects the intermediate sections to each other, the first claws on the surface facing the first connecting ring engage with the first connecting ring, thereby restricting axial movement of the intermediate sections of the first connecting ring, making it easy to position the first connecting ring in the axial direction of the rachis section.

[0017] In one aspect of the present disclosure, each rachis section of the plurality of feathers may have a first claw section on a surface facing the first connection ring and a second claw section on a surface facing the second connection ring, and the first claw section may engage with the first connection ring to position the first connection ring in the axial direction of the rachis section, and the second claw section may engage with the second connection ring to position the second connection ring in the axial direction of the rachis section.

[0018] With this configuration, as described above, the first claws make it easy to position the first connecting ring in the axial direction of the rachis section. In addition, when the second connecting ring connects the intermediate sections to each other, the second claws on the surface facing the second connecting ring engage with the second connecting ring. This prevents the intermediate section of the second connecting ring from moving in the axial direction. This makes it easy to position the second connecting ring in the axial direction of the rachis section.

[0019] On the other hand, when the cross-sectional shape of each rachis section perpendicular to the axial direction has a recess, it may be preferable to increase the robustness of the rachis section in order to ensure the impact resistance of the badminton shuttlecock.

[0020] In order to achieve such enhanced robustness, in one aspect of the present disclosure, a plurality of first ribs may be provided in the recess in each rachis section of a plurality of feathers, the first ribs extending in a direction approximately perpendicular to the axial direction of the rachis section.

[0021] According to this configuration, the structure of each rachis section is reinforced by providing multiple first ribs within the recess in each rachis section. This increases the robustness of each rachis section, thereby ensuring the impact resistance of the badminton shuttlecock.

[0022] Furthermore, in order to obtain the desired feel of hitting a badminton shuttlecock, it may be effective to provide a plurality of first ribs within the recess. By providing a plurality of first ribs within the recess of each rachis section, the structure of each rachis section is reinforced, and the desired robustness and feel of hitting a badminton shuttlecock can be achieved.

[0023] In one aspect of the present disclosure, a second rib may be provided within the recess in each rachis section of a plurality of feathers, and the second rib may extend in the axial direction of the rachis section within the recess and be provided on part of the axial direction of the rachis section within the recess.

[0024] According to this configuration, the structure of each rachis section is reinforced by providing a second rib within the recess in each rachis section. This increases the robustness of each rachis section, thereby ensuring the impact resistance of the badminton shuttlecock.

[0025] Furthermore, in order to obtain the desired hitting feel, it may be effective to provide a second rib. By providing a second rib within the recess of each rachis section, the structure of each rachis section is reinforced, and the desired robustness and hitting feel of a badminton shuttlecock can be achieved.

[0026] Furthermore, when both the first rib and the second rib are provided in the rachis section of each of a plurality of feathers, the robustness of each rachis section can be further improved compared to when only one of the first rib or the second rib is provided.

[0027] In one aspect of the present disclosure, the cross-sectional shape perpendicular to the axial direction of each rachis section of the multiple feathers is generally U-shaped, and the rachis section may have a base and two sidewalls extending from the base and facing each other. The thickness of the base may be constant along the axial direction of the rachis section, or may vary along a portion of the axial direction. Here, the strength required to achieve the desired feel of hitting a badminton shuttlecock (i.e., the degree of resistance to plastic deformation) may differ at each portion of the rachis section along the axial direction. In the rachis section, the thickness of the base in the portion requiring strength is preferably thicker than in other portions. On the other hand, the thickness of the base in the portion not requiring strength can be thinner than in other portions. In one aspect of the present disclosure, the thickness of the base may be thinner over the range from the connection position by the second connecting ring in the middle portion to the tip portion, including this connection position, compared to the portion outside this range.

[0028] With this configuration, compared to when the thickness of the base of each rachis section is the same over the range from the connecting position at the middle with the second connecting ring to the tip, as it is outside this range, it is possible to reduce the weight of each of the multiple feathers while maintaining the strength of the rachis section itself, thereby making it possible to reduce the weight of the badminton shuttlecock as a whole.

[0029] It may be preferable to reinforce the structure of portions of each rachis section that are susceptible to impact when a badminton shuttlecock is hit with a badminton racket. To achieve this, in one aspect of the present disclosure, the cross-sectional shape perpendicular to the axial direction of each rachis section of the multiple feathers may be substantially U-shaped, and the rachis section may have a bottom and two side walls extending from the bottom and facing each other. The heights of the two side walls may be constant throughout the axial direction of the rachis section, or may differ over part of the axial direction in consideration of the impact expected when a badminton shuttlecock is hit with a badminton racket. In one aspect of the present disclosure, the heights of the two side walls may be higher over a range that includes the position at the middle where the second connecting ring is connected to the tip, compared to portions outside this range.

[0030] With this configuration, the structure of the parts that are likely to receive impact when the badminton racket hits the badminton shuttlecock is reinforced, thereby increasing the robustness of each rachis portion.

[0031] Furthermore, in order to obtain the desired hitting feel, it may be effective to increase the height of the two side wall sections. In each rachis section, the height of the two side wall sections is formed to be higher over the range from the connecting position at the middle section by the second connecting ring to the tip section compared to the parts outside this range, thereby reinforcing the structure of each rachis section and realizing the desired robustness and hitting feel of a badminton shuttlecock.

[0032] In one aspect of the present disclosure, in a badminton shuttle, each of the multiple fixing holes in the base portion may be arranged approximately parallel to the shuttle shaft, and the root portions of the multiple shuttlecocks may extend approximately parallel to the shuttle shaft.

[0033] With this configuration, the multiple fixing holes in the base and the roots of the multiple feathers are all approximately parallel to the shuttlecock shaft, so the insertion direction of all of the multiple feathers into the base is approximately uniform. Therefore, by simply inserting the roots of the multiple feathers into the multiple fixing holes in the base, the multiple feathers can become a badminton shuttlecock with a predetermined radial spread. This makes it easy to assemble the badminton shuttlecock.

[0034] FIG. 1A is a side view of a badminton shuttlecock according to the first embodiment. FIG. 1B is a front view of the badminton shuttlecock according to the first embodiment, viewed from the feathers toward the base. FIG. 1C is a perspective view of the badminton shuttlecock according to the first embodiment. FIG. 1B is a front view of one of the plurality of feathers according to the first embodiment, viewed from a direction perpendicular to the first feather surface and the second feather surface. FIG. 1C is a side view of one of the plurality of feathers according to the first embodiment. FIG. 4A is a cross-sectional view taken along line IVA-IVA in FIG. 2. FIG. 4B is a cross-sectional view taken along line IVB-IVB in FIG. 2. FIG. 4C is a cross-sectional view taken along line IVC-IVC in FIG. 2. FIG. 4D is a cross-sectional view taken along line IVD-IVD in FIG. 2. FIG. 5A is a side view of the base according to the first embodiment. FIG. 5B is a front view of the base, viewed from the rear of the base toward the front of the base, with the opening seen. 5C is a cross-sectional view of the cut portion indicated by the line VC-VC in FIG. 5B. FIG. 5C is a partially enlarged view of the front view of the base portion in the first embodiment. FIG. 7A is a front view of the connection ring in the first embodiment. FIG. 7B is a perspective view of the connection ring. FIG. 7B is a partially enlarged view of the front view of the connection ring in the first embodiment, viewed from the direction in which the rachis section 32 is inserted. FIG. 1B is a view of the case in which the base portion and multiple blades have been removed. FIG. 1C is an enlarged perspective view of one of the multiple insertion holes of the connection ring in the first embodiment. FIG. 1C is a view showing a state in which the width between the portion of the inner circumferential end facing the positioning surface and the positioning surface is locally narrowed in a connection ring of a modified example. FIG. 1C is also a view showing a state in which the width between the edge of the through hole on the inner circumferential side of the connection ring and the portion of the inner circumferential end facing the edge is locally narrowed. FIG. 12A is a front view of one of the multiple blades in the modified example. FIG. 12B is a partial side view of one of the multiple blades in the modified example.

[0035] DESCRIPTION OF SYMBOLS 1...badminton shuttlecock, 2...base portion, 3...feather, 4, 4a, 4b...connecting ring, 24...fixing hole, 31...feather portion, 32...rachis portion, 33...first rib, 34...second rib, 35...first claw portion, 36...second claw portion, 41...insertion hole, 42...through hole, 43...inner peripheral end portion, 241...positioning surface, 321...root portion, 322...middle portion, 323...tip portion, 323...recess, 325...bottom portion, 326...side wall portion, 411...positioning surface, 412...inner wall portion, 413...extending portion, 421...edge portion, 431...portion facing the positioning surface at the inner peripheral end portion, 432...edge portion of the through hole on the inner peripheral side of the connecting ring A...shuttle axis, C1...center of the ring shape formed by the fixed positions of multiple root portions on the base portion, C2...center of the first connecting ring, C3...center of the second connecting ring, H1-H4...height of the two side wall portions, L3, L4...width between the portion at the inner peripheral end of the connecting ring that faces the positioning surface and the positioning surface, L5, L6...width between the portion at the inner peripheral end of the connecting ring that faces the edge and the edge of the multiple through holes on the inner peripheral side of the connecting ring, R...ring shape formed by the fixed positions of multiple root portions on the base portion, T1-T4...thickness of the bottom portion.

[0036] 1. First Embodiment 1-1. Configuration A badminton shuttlecock 1 (hereinafter referred to as a badminton shuttlecock 1 ) shown in FIGS. 1A, 1B, and 1C includes a base portion 2 , a plurality of shuttlecocks 3 , and a connecting ring 4 .

[0037] Each of the multiple blades 3 has a blade portion 31 and a rachis portion 32 (see FIG. 2 ). The rachis portion 32 has a root portion 321, a tip portion 323, and an intermediate portion 322. The root portion 321 is the portion that is fixed to the base portion 2. The tip portion 323 is the portion to which the blade portion 31 is attached. The intermediate portion 322 is the portion sandwiched between the root portion 321 and the tip portion 323. In other words, the root portion 321, intermediate portion 322, and tip portion 323 are formed in the rachis portion 32 so that they extend continuously in that order. As will be described later, the connecting ring 4 connects the intermediate portions 322 of the multiple blades 3 to each other, thereby connecting the multiple blades 3 together.

[0038] 1 , for each of the plurality of blades 3, the root portion 321 of each of the plurality of blades 3 is inserted into and fixed to the base portion 2. Tracing the trajectory of the fixing positions of the root portion 321 of each of the plurality of blades 3 on the base portion 2 results in a ring shape R. Note that in FIG. 1B , the ring shape R on the base portion 2 is indicated by a dashed line.

[0039] The connecting ring 4 is an annular ring for connecting the rachis section 32 (i.e., the middle section 322). The number of connecting rings 4 in the badminton shuttlecock 1 is not particularly limited and may be, for example, one, two, three or more. In this embodiment, the badminton shuttlecock 1 includes two connecting rings 4, specifically a first connecting ring 4a and a second connecting ring 4b.

[0040] Here, the axis connecting the center C1 of the ring shape R formed by the respective fixed positions of the multiple root portions 321 on the base portion 2 and the center C2 of the first connecting ring 4a is defined as the shuttle axis A (see Figures 1A, 1B, and 1C).

[0041] Hereinafter, each of the above-mentioned components will be described in detail.

[0042] [A. Multiple Feathers 3] The multiple feathers 3 may be made of any material as long as it ensures the appropriate flight performance of the badminton shuttlecock 1. For example, the multiple feathers 3 may be artificial feathers made of an artificial material such as resin. The multiple feathers 3 may also be feathers from waterfowl such as geese (i.e., natural feathers).

[0043] In this embodiment, the blades 3 are made of resin, including, but not limited to, nylon resins such as nylon 12 and nylon 66, polypropylene (PP), polyacetal (POM), polyester-based resins, urethane-based elastomer resins, polyester-based elastomer resins, and styrene-based elastomer resins.

[0044] The badminton shuttlecock 1 of this embodiment can be used as a badminton shuttlecock 1 for competition or practice, and the number of shuttlecocks 3 can be, for example, 14 to 16. In this embodiment, the number of shuttlecocks 3 is 15. When the badminton shuttlecock 1 of this embodiment is used as a competition shuttlecock 1, the number of shuttlecocks 3 is desirably 16.

[0045] 2 , the blade portion 31 of each of the plurality of blades 3 has a first blade surface 311 and a second blade surface 312. The first blade surface 311 and the second blade surface 312 are attached to either side of the tip portion 323 of the rachis portion 32 so as to be located on the same plane. In this embodiment, the first blade surface 311 is formed in a substantially trapezoidal shape, and the second blade surface 312 is formed in a substantially mountain shape. Note that the shapes of the first blade surface 311 and the second blade surface 312 may be other shapes (for example, a substantially rectangular shape) as long as they achieve appropriate flight performance of the badminton shuttlecock 1.

[0046] The areas of the first and second blade surfaces 311 and 312 may be the same or different. In this embodiment, the area of ​​the second blade surface 312 is larger than that of the first blade surface 311 (see FIG. 2).

[0047] In the first blade surface 311 and the second blade surface 312, a plurality of notches 313 are formed over the entire surface (see FIG. 2 ). The plurality of notches 313 may have any shape. In this embodiment, the plurality of notches 313 are oval and obliquely formed with respect to the extension direction of the tip portion 323. In FIG. 2 , reference symbols are assigned to two representative notches 313 on each of the first blade surface 311 and the second blade surface 312. The plurality of notches 313 on each of the first blade surface 311 and the second blade surface 312 are formed substantially parallel to each other. The plurality of notches 313 may be formed only partially on each of the first blade surface 311 and the second blade surface 312. Alternatively, the plurality of notches 313 may be formed on only one of the first blade surface 311 and the second blade surface 312. By forming a plurality of notches 313 in first blade surface 311 and second blade surface 312, it is possible to reduce the weight of blade portion 31.

[0048] In this embodiment, the feather section 31 and the rachis section 32 may be integrally formed by injection molding. Furthermore, in order to approximate the performance of a natural feather (for example, weight, durability, and hitting feel with a badminton racket), the thickness of the first feather surface 311 and the second feather surface 312 may be adjusted in this embodiment. Furthermore, for this purpose, the number or shape of the multiple notches 313 in the first feather surface 311 and the second feather surface 312 may be adjusted in this embodiment.

[0049] There are no particular restrictions on the cross-sectional shape of the rachis section 32 perpendicular to the axial direction, as long as it is a shape that, as will be described later, prevents rotation of the root section 321 about its axis when the root section 321 is fixed to the base section 2, and that prevents rotation of the intermediate sections 322 about their axis when the connecting ring 4 connects the intermediate sections 322 to each other. Note that the cross-sectional shape of the rachis section 32 perpendicular to the axial direction may be the same over the entire length of the rachis section 32, or may be partially different.

[0050] A cross section of the rachis section 32 perpendicular to the axial direction may have a recess 324 over the entire length of the rachis section 32 (see FIGS. 4A to 4D). In this case, the two apexes 326a (see FIG. 4A) of the recess 324 in the intermediate section 322 come into two-point contact with the positioning surfaces 411 (see FIG. 7) of the multiple insertion holes 41 of the connecting ring 4. Furthermore, the two apexes of the recess 324 in the base section 321 come into two-point contact with the positioning surfaces 241 (see FIG. 5B) of the multiple fixing holes 24 of the base section 2, which will be described later. Note that the recess 324 in the base section 321 is not shown in FIGS. 4A to 4D. However, in reality, the recess 324 in the base section 321 has a similar shape to the recess 324 in the intermediate section 322 in the sense that it has two apexes. Therefore, the shape of the two apexes 326a of the recess 324 in the intermediate portion 322 can be referred to for the shape of the two apexes of the recess 324 in the base portion 321. The shape of the recess 324 in a cross section perpendicular to the axial direction of the rachis portion 32 may be, for example, a substantially U-shape, a substantially V-shape, a substantially H-shape, a substantially C-shape, a substantially J-shape, or the like. In this embodiment, the cross section perpendicular to the axial direction of the rachis portion 32 is substantially U-shaped over the entire length of the rachis portion 32 (see FIGS. 4A to 4D). The rachis portion 32 has a bottom portion 325 and two side walls 326 that extend from the bottom portion 325 and face each other.

[0051] Note that the cross section of the rachis section 32 perpendicular to the axial direction may have an outer shape that is, for example, a straight line connecting the two apexes 326a of the recess 324 of the rachis section 32 described above. The cross section of the rachis section 32 perpendicular to the axial direction may have this straight line portion over the entire length of the rachis section 32. In this case, the straight line portion of the intermediate section 322 may be in surface contact with positioning surfaces 411 of multiple insertion holes 41 of the connecting ring 4 described below. The straight line portion of the base section 321 may also be in surface contact with each positioning surface 241 of multiple fixing holes 24 of the base section 2 described below. The cross section of the rachis section 32 perpendicular to the axial direction may have an outer shape that is, for example, an approximately semicircular shape in which the outer shape other than the above-mentioned straight line portion is formed into an arc, or may be an approximately polygonal shape (for example, a triangle, a rectangle, or a pentagon) that has the above-mentioned straight line portion in part.

[0052] 4A to 4D, in this embodiment, the two side wall portions 326 have approximately the same height from the bottom portion 325. However, the two side wall portions 326 may have different heights from the bottom portion 325. For example, one of the two side wall portions 326 may have a higher height from the bottom portion 325 than the other.

[0053] In this embodiment, as will be described later, the second connecting ring 4b connects the intermediate portions 322 of the plurality of blades 3 to each other (see FIGS. 1A to 1C). Here, in the rachis section 32, the range from the connecting position of the second connecting ring 4b in the intermediate portion 322 to the tip portion 323 is defined as a first range Q1 (see FIGS. 2 and 3). In this embodiment, the first range Q1 is the range from the connecting position to the tip point 37 of the tip portion 323. The two side wall portions 326 are formed higher in the first range Q1 than the portions of the rachis section 32 outside the first range Q1 (see FIGS. 4A to 4D). Specifically, in FIGS. 4A to 4D, the heights H1-H3 of the two side wall portions 326 are formed higher than H4. Note that H1-H3 indicate the heights of the two side wall portions 326 from the bottom 325 at locations within the first range Q1, and H4 indicates the heights of the two side wall portions 326 from the bottom 325 at locations outside the first range Q1.

[0054] The heights of the two side wall portions 326 from the bottom portion 325 may be partially different across the axial direction of the rachis section 32. In this embodiment, the heights of the two side wall portions 326 from the bottom portion 325 are partially different within the first range Q1. Specifically, as shown in Fig. 3, at the tip point 37 of the tip portion 323, the heights of the two side wall portions 326 are formed lower than the other portions within the first range Q1.

[0055] The thickness of the bottom 325 may be the same or different in the axial direction of the rachis section 32. In this embodiment, the bottom 325 is formed thinner in the first range Q1 compared to the portion of the rachis section 32 outside the first range Q1. Specifically, the thickness of the bottom 325, T1-T3, is formed thinner than T4. Note that T1-T3 indicate the thickness of the bottom 325 at a location within the first range Q1, and T4 indicates the thickness of the bottom 325 at a location outside the first range Q1.

[0056] Furthermore, as shown in FIG. 3 , in this embodiment, the thickness of the bottom portion 325 gradually increases from a boundary portion 329 between the base portion 321 and the intermediate portion 322 toward a tip point 38 of the base portion 321, as compared to the boundary portion 329. Such a gradually increasing portion 39 is indicated by a dashed line in FIG. 3 . Each of the multiple feathers 3 in this embodiment can be manufactured by injection molding. In this case, the tip point 38 of the base portion 321 may serve as a gate for pouring in a resin or the like. Here, in the badminton shuttlecock 1 of this embodiment, the wall thickness of the rachis portion 32 of each of the multiple feathers 3 can be formed thin throughout its entire length for purposes such as weight reduction. In such a case, when manufacturing each of the multiple feathers 3 by injection molding, the cross-sectional area of ​​the flow passage for introducing a material such as a resin is relatively small, making it difficult to distribute the material throughout the entire length of the rachis portion 32. Therefore, when a gate section is provided at the tip point 38 of the base section 321, by providing a section 39 in the rachis section 32 where the thickness of the bottom 325 gradually increases near the gate section, the thickness of the bottom 325 at this section 39 increases, making it easier to flow the material in. In other words, by having the section 39 in the rachis section 32 where the thickness of the bottom 325 gradually increases, it is easier to ensure the amount of material that flows in when flowing the material, and to increase the fluidity of the material, compared to when this section 39 is not provided.

[0057] In each of the plurality of blades 3, tip portion 323 is bent at a predetermined angle relative to intermediate portion 322. Specifically, with respect to axis E extending linearly through intermediate portion 322, tip portion 323 is curved in direction α parallel to first blade surface 311 and second blade surface 312 (see FIG. 2 ), and is also curved in direction β perpendicular to first blade surface 311 and second blade surface 312 (see FIG. 3 ).

[0058] The root portion 321 is bent relative to the intermediate portion 322 (see FIG. 3). As a result, the root portion 321 extends substantially parallel to the shuttle axis A.

[0059] In this embodiment, in each rachis section 32 of the multiple feathers 3, multiple first ribs 33 extending in a direction approximately perpendicular to the axial direction of the rachis section 32 are provided within the recess 324 (see FIG. 2 ). Specifically, multiple first ribs 33 are provided at approximately equal intervals in the intermediate section 322 and the tip section 323. The intervals between the first ribs 33 may vary. For example, in parts of the rachis section 32 that are likely to receive impact when hitting the badminton shuttlecock 1 with a badminton racket, the first ribs 33 may be provided at closer intervals. The thicknesses of the multiple first ribs 33 in the axial direction of the rachis section 32 may be different or approximately the same.

[0060] In this embodiment, a second rib 34 is provided within the recess 324 of each rachis section 32 of the multiple feathers 3 (see FIG. 2 ). The second rib 34 extends within the recess 324 in the axial direction of the rachis section 32, and is provided within the recess 324 on a portion of the axial direction of the rachis section 32. Such a second rib 34 may be provided in a portion of the rachis section 32 that is likely to receive an impact when the badminton shuttlecock 1 is hit with the badminton racket. For example, such a portion that is likely to receive an impact includes the connection position of the second connecting ring 4 b in the middle section 322 of the rachis section 32, and the range from this connection position to approximately the midpoint of the tip section 323 is defined as a second range Q2 (see FIG. 2 ). In this embodiment, the second rib 34 is provided in the second range Q2 within the recess 324.

[0061] The height and thickness of the second rib 34 may vary within the recess 324. For example, in Figures 4A to 4C, the second rib 34 shown in Figure 4A is formed to be lower and thicker than the second rib 34 shown in Figures 4B and 4C. However, the shapes of the second rib 34 shown in Figures 4A to 4C are merely examples, and the shape is not limited to these.

[0062] In this embodiment, a plurality of first ribs 33 and a plurality of second ribs 34 are both provided within the recess 324 of the rachis section 32, but for example, only one of the plurality of first ribs 33 and the plurality of second ribs 34 may be provided.

[0063] 3, in this embodiment, a first claw portion 35 is provided on the surface facing the first connecting ring 4a of each rachis section 32 (i.e., the intermediate portion 322) of the multiple blades 3. The first claw portion 35 engages with the first connecting ring 4a to position the first connecting ring 4a in the axial direction of the rachis section 32.

[0064] In this embodiment, second claws 36 are provided on the surface facing the second connecting ring 4b of each rachis section 32 (i.e., the intermediate section 322) of the multiple blades 3. The second claws 36 engage with the second connecting ring 4b to position the second connecting ring 4b in the axial direction of the rachis section 32.

[0065] [B. Base Portion 2] As described above, the base portion 2 fixes the root portion 321 of each of the plurality of blades 3 in an annular shape.

[0066] The base portion 2 can be formed from any material. Preferably, the base portion 2 is formed from an artificial material such as resin. Examples of resins include nylon resins such as nylon 12 and nylon 66, polypropylene (PP), polyacetal (POM), polyester-based resins, urethane-based elastomer resins, polyester-based elastomer resins, and styrene-based elastomer resins. Furthermore, to reinforce the base portion 2, a resin containing reinforcing fibers such as glass fiber, carbon fiber, cellulose fiber, and aramid fiber may be used. The base portion 2 may also be formed from a natural material such as cork.

[0067] The base portion 2 is a hollow member having a hemispherical portion 21 configured in a substantially hemispherical shape (see FIGS. 5A to 5C). An inner surface 25 of the hemispherical portion 21 defines an internal space. The hemispherical portion 21 of the base portion 2 has an opening 22 that faces rearward in the flight direction of the badminton shuttlecock 1. In FIGS. 5A and 5C, the flight direction of the badminton shuttlecock 1 is indicated by an arrow.

[0068] Here, the apex 21a side of the hemispherical portion 21 is the front side of the base portion 2, and the opening 22 side is the rear side of the base portion 2. When the badminton shuttlecock 1 is hit with a badminton racket, the badminton shuttlecock 1 takes flight starting from the front side of the base portion 2. At the rear of the base portion 2, a thick portion 23 is provided between the inner surface 25 and the outer surface 26 of the hemispherical portion 21, where the thickness is increased.

[0069] Here, the front of the base portion 2 refers to the direction when the opening 22 is viewed from the rear of the base portion 2 toward the front of the base portion 2. In the front view of the base portion 2, the thick portion 23 is formed in an annular shape (see FIG. 5B ).

[0070] A plurality of fixing holes 24 are formed in the thick-walled portion 23. The same number and shape of fixing holes 24 as the number of shuttlecocks 3 used in the badminton shuttlecock 1 are formed in the thick-walled portion 23 of the base portion 2. Each of the fixing holes 24 may have any shape, but may be formed to fit the cross-sectional shape perpendicular to the axial direction of the base portion 321. Note that in Figure 5B, reference symbols are assigned to three representative fixing holes 24. The bottom portion 242 of each of the fixing holes 24 is formed in a tapered shape.

[0071] The root portions 321 of the blades 3 are inserted into and fixed to the respective fixing holes 24. When viewed from the front of the base 2, the path of the fixing positions of the root portions 321 of the blades 3 on the base 2 forms a ring shape R (see FIG. 5B ).

[0072] The base portion 2 and the root portion 321 can be fixed together by any method. For example, after the root portion 321 is inserted into the fixing hole 24 of the base portion 2, the root portion 321 may be fixed to the inner wall of the fixing hole 24 via an adhesive. Examples of the adhesive that can be used include, but are not limited to, a cyanoacrylate adhesive, an epoxy resin adhesive, a silicone adhesive, a vinyl acetate adhesive, and a UV adhesive.

[0073] Each of the multiple fixing holes 24 has a positioning surface 241 for positioning the root portion 321 in the rotational direction around the axis. In this embodiment, the positioning surface 241 in each fixing hole 24 is formed as a flat surface on part of the inner wall of the fixing hole 24. Specifically, the positioning surface 241 in each fixing hole 24 is formed as a surface that appears linear in a front view of the base portion 2 (see FIG. 5B ). When each root portion 321 is fixed in each of the multiple fixing holes 24, the apexes of the two side wall portions 326 in a cross section perpendicular to the axial direction of each root portion 321 (see FIGS. 4A-4D ) come into contact with the positioning surface 241 in each fixing hole 24 at two points. This suppresses rotation of the root portion 321 around the axis. Note that, for example, the cross section perpendicular to the axial direction of the rachis section 32 may have an outer shape that is a straight line connecting the two apexes 326 a of the recesses 324 of the rachis section 32 described above. In this case, the linear portion of the base portion 321 may come into surface contact with the positioning surface 411 of each fixing hole 24 .

[0074] As shown in Figure 6, in each of the multiple fixing holes 24, the positioning surface 241 is formed so that the angle (e.g., θ1, θ2, θ3) between the line connecting the center C1 of the ring shape R formed by the fixing positions of the multiple root portions 321 on the base portion 2 and the middle (e.g., M1, M2, M3) of the positioning surface 241 in each of the multiple fixing holes 24 is the same as the angle between the line connecting the line and each positioning surface 241 (e.g., θ1, θ2, θ3).

[0075] The widths F1 and F2 between the positioning surface 241 of each fixing hole 24 and the inner surface 25 of the thick portion 23 are formed to be approximately constant. The widths F1 and F2 can be made as narrow as possible as long as the base portion 2 is not damaged when the badminton shuttlecock 1 is hit, etc.

[0076] If the inner surfaces 25 of the thick-walled portions 23 that face the positioning surfaces 241 of each fixing hole 24 are connected by the shortest distance and a similar design is performed for all fixing holes 24, the shape of the inner surfaces 25 of the thick-walled portions 23 will be a gear-like shape G when viewed from the front (see Figure 5B).

[0077] Each of the plurality of fixing holes 24 in the base portion 2 is provided substantially parallel to the shuttle axis A (see the relationship between the shuttle axis A and the direction X in which the plurality of fixing holes 24 extend in FIG. 5C).

[0078] [C. Connecting ring 4] Connecting ring 4 interconnects the intermediate portions 322, thereby integrally connecting the multiple feathers 3 so that they spread out radially from base portion 2. Here, "the multiple feathers 3 spread out radially" means that the diameter of the ring shape formed by the multiple feathers 3 increases as the multiple feathers 3 move away from base portion 2 in the direction of shuttlecock axis A. In other words, badminton shuttlecock 1 is formed in a substantially conical shape with base portion 2 as its apex.

[0079] As shown in FIG. 1A, by shortening the distance L1 between the base portion 2 and the first connecting ring 4a in the direction of the shuttle axis A, the radial spread of the multiple blades 3 relative to the shuttle axis A can be increased.

[0080] The center C3 of the second connecting ring 4b is located on the shuttle axis A. In other words, when the badminton shuttle 1 is viewed from the feather 31 toward the base 2, the center C1 of the ring shape R formed by the respective fixing positions of the multiple root portions 321 on the base 2, the center C2 of the first connecting ring 4a, and the center C3 of the second connecting ring 4b substantially coincide on the shuttle axis A (see FIG. 1B ).

[0081] The center C3 of the second connecting ring 4b is at a different position on the shuttle axis A from the center C1 of the ring shape R formed by the fixed positions of the multiple root portions 321 on the base portion 2, and the center C2 of the first connecting ring 4a. Specifically, the center C2 is located between the centers C1 and C3 (see FIG. 1A ). Furthermore, the second connecting ring 4b connects the intermediate portions 322 to each other at a different position from the first connecting ring 4a in the direction of the shuttle axis A, so that the shape of the badminton shuttlecock 1 in which the multiple shuttlecocks 3 are connected together so as to radiate out from the base portion 2 is maintained by the first connecting ring 4a connecting the intermediate portions 322 to each other.

[0082] The distance L2 between the first connecting ring 4a and the second connecting ring 4b in the direction of the shuttlecock axis A is set to an appropriate distance so that the first connecting ring 4a interconnects the intermediate portions 322, thereby maintaining the shape of the badminton shuttlecock 1 in which the multiple feathers 3 are connected together so as to spread radially from the base portion 2. By adjusting L2, it may be possible to adjust the radial spread of the multiple feathers 3 in the badminton shuttlecock 1.

[0083] Hereinafter, the configuration of the connection ring 4 in this embodiment will be described with reference to Figures 7A and 7B. Note that the first connection ring 4a and the second connection ring 4b differ in details such as the diameter of the rings, but share a basic configuration. The same reference numerals are used to designate components common to the first connection ring 4a and the second connection ring 4b. Hereinafter, the configuration of the connection ring 4 will be described using the second connection ring 4b as an example. The fact that the first connection ring 4a and the second connection ring 4b share a basic configuration will be described later with reference to Figure 9.

[0084] The second connecting ring 4b can be formed from any material. Preferably, the second connecting ring 4b is made of resin. Examples of such resins include nylon resins such as nylon 12 and nylon 66, polypropylene (PP), polyacetal (POM), polyester-based resins, urethane-based elastomer resins, polyester-based elastomer resins, and styrene-based elastomer resins. Furthermore, to reinforce the second connecting ring 4b, a resin containing reinforcing fibers such as glass fiber, carbon fiber, cellulose fiber, and aramid fiber may be used. In this embodiment, the first connecting ring 4a and the second connecting ring 4b may be made of different materials.

[0085] The second connecting ring 4b has a thickness within a predetermined range in the direction of the shuttlecock axis A. The thickness can be set appropriately depending on the material used so that the second connecting ring 4b can withstand the impact and deformation when the badminton shuttlecock 1 is struck with a badminton racket. The second connecting ring 4b may also be flat and have a uniform thickness around its entire circumference.

[0086] The second connecting ring 4b has a plurality of insertion holes 41 around its entire circumference. A rachis section 32 is inserted into each of the plurality of insertion holes 41, and the second connecting ring 4b interconnects the rachis sections 32 (i.e., the intermediate sections 322), thereby integrally connecting the plurality of feathers 3 so that they radiate from the base section 2. The second connecting ring 4b is provided with a plurality of insertion holes 41 of the same number and shape as the plurality of feathers 3 used in the badminton shuttlecock 1. The shape of each of the plurality of insertion holes 41 may be formed to fit the cross-sectional shape of the rachis section 32 perpendicular to the axial direction. Note that in Figures 7A and 7B, reference symbols are assigned to three representative insertion holes 41.

[0087] An adhesive may be used when connecting the intermediate portion 322 with the second connecting ring 4b. Specifically, the adhesive may be applied to the inner wall portion 412 of the connecting ring 4 and brought into contact with the intermediate portion 322. The inner wall portion 412 is a portion that constitutes the inner wall of each of the multiple insertion holes 41. Examples of the adhesive that can be used include, but are not limited to, a cyanoacrylate adhesive, an epoxy resin adhesive, a silicone adhesive, a vinyl acetate adhesive, and a UV adhesive.

[0088] Each of the insertion holes 41 has a positioning surface 411 for positioning the intermediate portion 322 in the rotational direction around its axis. The positioning surface 411 is formed as a flat surface on a portion of the inner wall 412 of each insertion hole 41. In the following description, the direction in which each intermediate portion 322 is inserted into the second connection ring 4b is referred to as the front surface of the second connection ring 4b. In this embodiment, the positioning surface 411 is formed as a surface that appears linear in a front view of the second connection ring 4b (see FIG. 7A ). When each intermediate portion 322 is inserted into each of the insertion holes 41, the tops 326a of the two side wall portions 326 of each intermediate portion 322 in a cross section perpendicular to the axial direction make two-point contact with the positioning surface 411 of each insertion hole 41. This suppresses rotation of the intermediate portion 322 around its axis. Note that the cross section perpendicular to the axial direction of the rachis section 32 may have an outer shape that is, for example, a straight line connecting the two apexes 326a of the recess 324 of the rachis section 32 described above. In this case, the straight line portion of the intermediate section 322 may come into surface contact with the positioning surface 411 of each insertion hole 41.

[0089] In this embodiment, the positioning surface 411 is provided on the inner peripheral side IS of the second connection ring 4b, which is closer to the center C3 (i.e., the inner peripheral side IS), and on the side farther from the center C3 of the second connection ring 4b (i.e., the outer peripheral side OS) (see FIGS. 2A and 2B ). However, the positioning surface 411 may be provided on the outer peripheral side OS of the second connection ring 4b.

[0090] In this embodiment, protrusions 44 are formed on the outer circumferential side OS of the second connection ring 4b in portions facing the respective insertion holes 41 (see FIG. 7A ). This allows the thickness of the second connection ring 4b between the outer circumferential side OS and the respective insertion holes 41 to be increased, thereby improving the durability of the second connection ring 4b.

[0091] However, such a protrusion 44 does not have to be formed on the outer circumferential surface OS of the second connection ring 4b. For example, the outer circumferential surface OS of the second connection ring 4b may be substantially circular. Therefore, hereinafter, a second connection ring 4b having a substantially circular outer circumferential surface OS will be described as an example.

[0092] Hereinafter, explanations will be made using FIG. 8 in addition to FIG. 7A and FIG. 7B . In each of the multiple insertion holes 41, the positioning surfaces 411 are formed so that the angles (e.g., θ4, θ5, θ6) formed between the positioning surfaces 411 and a line connecting the center C3 of the second connecting ring 4b and the middle point (e.g., M4, M5, M6) of the positioning surfaces 411 in each of the multiple insertion holes 41 are the same (see FIG. 3 ). Positioning of the rachis section 32 in the rotational direction around the axis can determine the relative positions of the feathers 31 in each of the multiple feathers 3. For example, in a side view of the badminton shuttlecock 1 ( FIG. 1A ), adjacent feathers 31 in the multiple feathers 31 may or may not overlap. Here, "overlapping feathers 31" may mean that adjacent feathers 31 that appear to overlap in a side view of the badminton shuttlecock 1 are in contact with each other. Alternatively, "the feathers 31 overlap" may mean that adjacent feathers 31 do not touch each other, although they appear to overlap in a side view of the badminton shuttlecock 1. In this embodiment, as shown in Fig. 1C in addition to Fig. 1A, adjacent feathers 31 do not touch each other, although they appear to overlap in a side view of the badminton shuttlecock 1.

[0093] In addition, in this embodiment, the blade portions 31 of adjacent blades 3 partially overlap each other, and when the badminton shuttlecock 1 is viewed from the blade portion 31 in the direction of the base portion 2, the shape of the blade portion 31 is approximately circular (see Figure 1B).

[0094] It is preferable that the angles θ4, θ5, θ6 of the multiple insertion holes 41 of the second connecting ring 4b described above are the same as the angles θ1, θ2, θ3 of the multiple fixing holes 24 of the base portion 2 described above. This makes it possible to easily position the rachis section 32 simply by inserting the rachis section 32 into the base portion 2 and the second connecting ring 4b, without any extra fine adjustments or the like.

[0095] The second connection ring 4b has a plurality of through holes 42 around its entire circumference. In this embodiment, the second connection ring 4b has a plurality of insertion holes 41 and a plurality of through holes 42 alternately arranged around its entire circumference. In Figures 7A and 7B, reference symbols are assigned to three representative through holes 42.

[0096] The multiple through holes 42 may have any shape. For example, the multiple through holes 42 may be circular, such as a perfect circle or an ellipse, or may be polygonal, such as a triangle, a rectangle, or a pentagon. If the multiple through holes 42 are polygonal, it is preferable that each corner is rounded. In this embodiment, the multiple through holes 42 are substantially triangular in shape with rounded corners. The second connecting ring 4b may deform due to the impact when the badminton shuttlecock 1 is struck with a badminton racket.

[0097] As described above, the first connecting ring 4a and the second connecting ring 4b have different details such as ring diameter, but have a common basic configuration.

[0098] For example, Figure 9 shows a front view of the badminton shuttlecock 1 of this embodiment, viewed from the vane section 31 toward the base section 2, with the base section 2 and multiple feathers removed. At the positions in the rachis section 32 where the intermediate section 322 is connected by the first connecting ring 4a and the second connecting ring 4b, the cross-section perpendicular to the axial direction of the rachis section 32 has the same shape and size. Therefore, between the first connecting ring 4a and the second connecting ring 4b, each of the multiple insertion holes 41 has the same shape and size (see Figure 9). Of course, depending on the cross-sectional shape perpendicular to the axial direction of the rachis section 32, the multiple insertion holes 41 in the first connecting ring 4a and the second connecting ring 4b may have different shapes or sizes.

[0099] The through holes 42 have different shapes and sizes between the first connecting ring 4 a and the second connecting ring 4 b (see FIG. 9 ). However, the through holes 42 may have the same shape and size between the first connecting ring 4 a and the second connecting ring 4 b.

[0100] The other configurations (for example, the positioning surface 411, etc.) of the first connecting ring 4a and the second connecting ring 4b are common to each other, but may be modified as appropriate.

[0101] As shown in Figure 10, each of the multiple insertion holes 41 has an extension portion 413 in a part of the contact portion with the intermediate portion 322 on the inner wall portion 412 of the insertion hole 41, which is configured to be thicker in the direction of the shuttle axis A than other parts of the contact portion in order to contact the intermediate portion 322.

[0102] Here, the contact portion refers to, for example, a portion of the inner wall portion 412 that directly contacts the feather middle portion 322 so that the position of the middle portion 322 is maintained by friction. However, the contact portion may also be, for example, a portion of the inner wall portion 412 that contacts the middle portion 322 via an adhesive. Furthermore, the contact portion may also be, for example, a portion of the inner wall portion 412 that comes into contact with the middle portion 322 only after the second connecting ring 4b is deformed when the badminton shuttlecock 1 is hit.

[0103] Incidentally, extension portion 413 may be configured to increase in thickness in the insertion direction of feathers 3, which are configured to spread radially from base portion 2 (see FIGS. 1A, 1B and 1C) when intermediate portion 322 is inserted into insertion hole 41. Here, the "insertion direction of feathers 3" refers, as an example, to the direction shown as axis B for the feather 3 located at the bottom of the multiple feathers 3 of badminton shuttlecock 1 in FIG. 1A.

[0104] 10, the extending portion 413 may be configured such that a rectangular parallelepiped extending portion 413 is attached to the inner wall portion 412 of the insertion hole 41. In this case, the extending portion 413 and the inner wall portion 412 form a step inside the insertion hole 41. However, the extending portion 413 is not limited to such a configuration, and may be configured such that the inner wall portion 412 extends in the direction of the shuttle axis A, and the extending portion 413 and the inner wall portion 412 are continuous without any step. Furthermore, the positioning surface 411 may be extended in the direction of the shuttle axis A to function as the extending portion 413.

[0105] In this embodiment, two extension portions 413 are provided in each of the multiple insertion holes 41, and in each of the multiple insertion holes 41, the two extension portions 413 are provided at positions facing each other on the inner wall portion 412. Specifically, in a front view of the second connecting ring 4b, the two extension portions 413 are provided at both ends D1 and D2 of the positioning surface 411 so as to be approximately perpendicular to the positioning surface 411 and to face each other. In addition to the positioning surface 411, the extension portions 413 arranged at both ends D1 and D2 of the positioning surface 411 can further suppress rotation around the axis of the intermediate portion 322 in surface contact with the positioning surface 411. This can make it even easier to position the intermediate portion 322 in the rotational direction around the axis.

[0106] It should be noted that each of the plurality of insertion holes 41 may be provided with one or more extension portions 413 .

[0107] 8 , the inner peripheral end 43 of the second connecting ring 4b is configured so that widths L3 and L4 between a portion 431 (hereinafter referred to as the first portion 431) facing the positioning surface 411 and the positioning surface 411 are substantially constant. Specifically, the first portion 431 has a portion configured to extend substantially parallel to the positioning surface 411 while maintaining a substantially constant distance from the positioning surface 411. In this embodiment, the first portion 431 refers to a portion of the inner peripheral end 43 sandwiched between intersections D3 and D4 of perpendicular lines P1 and P2 drawn from both ends D1 and D2 of the positioning surface 411 of each of the multiple insertion holes 41 to the inner peripheral end 43.

[0108] Furthermore, widths L5 and L6 between a portion 432 (hereinafter referred to as the second portion 432) facing the edge portions 421 of the through holes 42 at the inner peripheral end portion 43 of the second connecting ring 4b and the edge portions 421 are configured to be approximately constant relative to the edge portions 421 of the multiple through holes 42 on the inner peripheral side IS of the second connecting ring 4b. Specifically, the second portion 432 has a portion configured to extend approximately parallel to the edge portions 421 of the inner peripheral side IS of the through holes 42 while maintaining an approximately constant distance from the edge portions 421, within a range that does not change the widths L3 and L4 between the first portion 431 and the positioning surface 411. In this embodiment, the second portion 432 refers to a portion of the inner peripheral end 43 on the inner peripheral side IS of the second connecting ring 4b, which is sandwiched between the intersections D7 and D8 of the perpendicular lines P3 and P4 with the inner peripheral end 43 when perpendicular lines P3 and P4 are drawn from any two points D5 and D6 on the edge 421 of each of the multiple through holes 42 to the inner peripheral end 43.

[0109] The widths L3 and L4 between the first portion 431 and the positioning surface 411, and the widths L5 and L6 between the second portion 432 and the edge 421 can be set appropriately depending on the material of the second connecting ring 4b used. If these widths L3, L4, L5, and L6 are too wide, air resistance will increase when the badminton shuttlecock 1 is launched, and it may not be possible to achieve appropriate flight performance. On the other hand, if these widths L3, L4, L5, and L6 are too narrow, the second connecting ring 4b may be damaged.

[0110] In this embodiment, the widths L3 and L4 of the first portion 431 are the same as those of the positioning surface 411. Furthermore, the widths L5 and L6 of the second portion 432 are the same as those of the edge portion 421 of the through-hole 42.

[0111] It is also possible that the widths L3 and L4 between the first portion 431 and the positioning surface 411 and / or the widths L5 and L6 between the second portion 432 and the edge 421 of the through-hole 42 are different. For example, a modified example of this embodiment is disclosed in FIG. 11 .

[0112] In this modification, the widths L3 and L4 of the first portion 431 and the positioning surface 411 are different, with the width L4 being narrower than the width L3. Furthermore, the widths L5 and L6 of the second portion 432 and the edge 421 of the through-hole 42 are different, with the width L6 being narrower than the width L5.

[0113] In this way, if there are areas where the width is locally narrow, such as widths L4 and L6, stress will be concentrated at those areas when the badminton shuttlecock 1 is deformed, which may lead to breakage.

[0114] If the first portion 431 and the second portion 432 at the inner peripheral end portion 43 are extended and connected, and if a similar design is performed for all of the multiple insertion holes 41 and multiple through holes 42 in the second connecting ring 4b, the shape of the inner peripheral end portion 43 will be a star-shaped polygon 433 (see Figure 7A).

[0115] In this embodiment, when viewed as a whole, the second connecting ring 4b may form a rigid frame bridge. This can increase the rigidity of the second connecting ring 4b even when the second connecting ring 4b is made of synthetic resin. Furthermore, even when a badminton shuttlecock 1 having the second connecting ring 4b is hit with a badminton racket, breakage of the second connecting ring 4b is suppressed, and the multiple shuttlecocks 3 in the badminton shuttlecock 1 can be kept firmly held together.

[0116] In this embodiment, the second connection ring 4b may be formed by injection molding. Alternatively, the second connection ring 4b may be formed by cutting out the shape of the second connection ring 4b according to this embodiment from a single flat plate.

[0117] [2. Effects] According to the embodiment described above in detail, the following effects are achieved.

[0118] (2a) In the badminton shuttlecock 1, the multiple fixing holes 24 provided in the base portion 2 have positioning surfaces 241 for positioning the root portion 321 in the rotational direction about its axis. With this configuration, when each root portion 321 is fixed to the base portion 2, the root portion 321 comes into contact with the positioning surfaces 241 in the multiple fixing holes 24 of the base portion 2 for positioning the root portion 321 in the rotational direction about its axis. Specifically, the tops of the two side wall portions 326 in a cross section of the root portion 321 perpendicular to the axial direction come into contact with the positioning surfaces 241 in the multiple fixing holes 24 at two points. This prevents the root portion 321 from rotating about its axis. This makes it easier to position the root portion 321 in the rotational direction about its axis.

[0119] Furthermore, in the badminton shuttlecock 1, the multiple insertion holes 41 provided in the second connecting ring 4b have positioning surfaces 411 for positioning the intermediate portions 322 in the rotational direction about their axes. With this configuration, when the connecting ring 4 connects the intermediate portions 322 of the multiple shuttlecocks 3 to each other, the intermediate portions 322 come into contact with the positioning surfaces 411 in the multiple insertion holes 41 of the second connecting ring 4b for positioning the intermediate portions 322 in the rotational direction about their axes. Specifically, the tops 326a of the two side wall portions 326 in a cross section perpendicular to the axial direction of the intermediate portions 322 come into contact with the positioning surfaces 411 in the multiple insertion holes 41 at two points. This suppresses rotation of the intermediate portions 322 about their axes. This makes it easier to position the intermediate portions 322 in the rotational direction about their axes.

[0120] Furthermore, the badminton shuttlecock 1 includes a first connecting ring 4a in addition to the second connecting ring 4b. The positioning surfaces 411 of the first connecting ring 4a and the second connecting ring 4b enable positioning in the rotational direction around the axis of the middle portion 322, making this positioning more efficient. Furthermore, the first connecting ring 4a and the second connecting ring 4b each connect the middle portions 322 of the multiple feathers 3 to each other, making it possible to connect the multiple feathers 3 in the badminton shuttlecock 1 more stably and firmly in the radial direction of the multiple feathers 3.

[0121] (2b) A cross section perpendicular to the axial direction of each rachis section 32 of the multiple feathers 3 has a recess 324 over the entire length of the rachis section 32. With this configuration, the amount of material constituting the rachis section 32 can be reduced compared to when no recess 324 is formed in the cross-sectional shape of each rachis section 32. This makes it possible to reduce the weight of each of the multiple feathers 3. As a result, the weight of the badminton shuttlecock 1 as a whole can be reduced.

[0122] (2c) In each rachis section 32 of the multiple blades 3, a second claw section 36 is provided on the surface facing the second connecting ring 2b. When the second connecting ring 2b connects the intermediate sections 322 to each other, the second claw section 36 on the surface facing the second connecting ring 2b engages with the second connecting ring 2b. This prevents the intermediate sections 322 of the second connecting ring 2b from moving in the axial direction. This makes it easy to position the second connecting ring 2b in the axial direction of the rachis section 32.

[0123] Furthermore, a first claw 35 is provided on the surface of each rachis section 32 of the multiple blades 3 that faces the first connecting ring 4a. The first claw 35 engages with the first connecting ring 4a to position the first connecting ring 4a in the axial direction of the rachis section 32. When the first connecting ring 4a connects the intermediate sections 322 to each other, the first claw 35 on the surface that faces the first connecting ring 4a engages with the first connecting ring 4a. This prevents the intermediate sections 322 of the first connecting ring 4a from moving in the axial direction. This makes it easy to position the first connecting ring 4a in the axial direction of the rachis section 32.

[0124] (2d) In each rachis section 32 of the multiple feathers 3, multiple first ribs 33 extending in a direction approximately perpendicular to the axial direction of the rachis section 32 are provided within the recess 324. This reinforces the structure of each rachis section 32. This makes it possible to increase the robustness of each rachis section 32. This ensures the impact resistance of the badminton shuttlecock 1.

[0125] Furthermore, by providing a plurality of first ribs 33 within the recess 324 in each rachis section 32, the structure of each rachis section 32 is reinforced, and the desired robustness and hitting feel of the badminton shuttlecock 1 can be achieved.

[0126] (2e) A second rib 34 is provided within the recess 324 in each rachis section 32 of the multiple feathers 3. The second rib 34 extends within the recess 324 in the axial direction of the rachis section 32, and is provided in a first range Q1 within the recess 324. By providing such a second rib 34 in each rachis section 32, the structure of each rachis section 32 is reinforced. This makes it possible to increase the robustness of each rachis section 32. This ensures the impact resistance of the badminton shuttlecock 1. Furthermore, by providing such a second rib 34 in the rachis section 32, the structure of each rachis section 32 is reinforced, and the desired robustness and hitting feel of the badminton shuttlecock 1 can be achieved.

[0127] (2f) The thickness of the base 325 in the cross-sectional shape perpendicular to the axial direction of each rachis section 32 of the multiple feathers 3 (i.e., a substantially U-shape) may be constant in the axial direction of the rachis section 32, or may vary over part of the axial direction. Here, the strength required to obtain the desired feel of hitting the badminton shuttlecock 1 (i.e., the degree of resistance to plastic deformation) may differ between different parts of the rachis section 32 in the axial direction. In the rachis section 32, the thickness of the base 325 in parts where strength is required is preferably thicker than in other parts. On the other hand, the thickness of the base 325 in parts of the rachis section 32 where strength is not required can be thinner than in other parts.

[0128] The thickness of the bottom portion 325 is thinner over the first range Q1 compared to the portion outside said range Q1. With this configuration, compared to a case where the thickness of the bottom portion 325 of each rachis section 32 is the same over the first range Q1 as the portion outside said range Q1, it is possible to reduce the weight of each of the multiple feathers 3 while maintaining the strength of the rachis section 32 itself. This allows the badminton shuttlecock 1 to be made lighter as a whole.

[0129] (2g) The height of the two side walls 326 in the cross section perpendicular to the axial direction of each rachis section 32 of the multiple blades 3 (i.e., a substantially U-shape) is higher over the first range Q1 than the parts outside said range Q1. This reinforces the structure of the parts that are likely to receive impact when the badminton shuttlecock 1 is hit with the badminton racket. This makes it possible to increase the robustness of each rachis section 32.

[0130] Furthermore, in order to obtain the desired hitting feel, it may be effective to increase the height of the two side wall portions 326. By forming the height of the two side wall portions 326 of each rachis section 32 to be higher over the first range Q1 compared to the portions outside said range Q1, the structure of each rachis section 32 is reinforced, and the desired robustness and hitting feel of the badminton shuttlecock 1 can be achieved.

[0131] (2h) In the badminton shuttlecock 1, each of the multiple fixing holes 24 in the base portion 2 is provided substantially parallel to the shuttle axis A, and the root portions 321 of the multiple feathers 3 extend substantially parallel to the shuttle axis A. With this configuration, the multiple fixing holes 24 in the base portion 2 and the root portions 321 of the multiple feathers 3 are all substantially parallel to the shuttle axis A, so the insertion direction of all of the multiple feathers 3 into the base portion 2 is substantially uniform. Therefore, simply by inserting the root portion 321 of each of the multiple feathers 3 into each of the multiple fixing holes 24 in the base portion 2, the multiple feathers 3 can become a badminton shuttlecock 1 with a predetermined radial spread. This makes it easy to assemble the badminton shuttlecock 1.

[0132] (2i) The base portion 2 is a hollow member having a hemispherical portion 21 that is configured in a substantially hemispherical shape. With this configuration, the weight of the base portion 2 can be reduced compared to when the base portion 2 is a solid member. This allows the weight of the entire badminton shuttlecock to be reduced.

[0133] (2j) The second connection ring 4b has a plurality of through holes 42 formed in the circumferential direction, and the plurality of insertion holes 41 and the plurality of through holes 42 are arranged alternately in the circumferential direction. With this configuration, the second connection ring 4b is hollowed out by providing the plurality of through holes 42 in the second connection ring 4b. This reduces the weight of the second connection ring 4b.

[0134] The second connecting ring 4b may form a rigid frame bridge when viewed as a whole. This can increase the rigidity of the second connecting ring 4b even when the second connecting ring 4b is made of synthetic resin. Furthermore, even when a badminton shuttlecock 1 having the second connecting ring 4b is hit with a badminton racket, breakage of the second connecting ring 4b is suppressed, and the multiple shuttlecocks 3 of the badminton shuttlecock 1 can be kept firmly held together.

[0135] (2k) Each of the multiple insertion holes 41 has an extending portion 413 that is thicker in the direction of the shuttle axis A than the other portions of the contact portion at a portion of the contact portion of the inner wall portion 412 of the insertion hole 41 where the intermediate portion 322 contacts. With this configuration, when the second connection ring 4b connects the intermediate portions 322 to each other, the intermediate portions 322 come into contact with the extending portion 413 of the second connection ring 4b. Therefore, the contact area between the second connection ring 4b and the intermediate portions 322 is increased compared to when the extending portion 413 is not provided. This suppresses rotation of the intermediate portions 322 around their axes, allowing for optimal positioning of the intermediate portions 322 in the rotational direction around their axes.

[0136] Furthermore, in a front view of the second connecting ring 4b, the extending portion 413 is provided so as to be approximately perpendicular to the positioning surface 411. Therefore, in addition to the positioning surface 411, the extending portion 413, which is provided so as to be approximately perpendicular to the positioning surface 411, can further suppress rotation around the axis of the intermediate portion 322, which is in contact with the positioning surface 411 at two points. This can make it even easier to position the intermediate portion 322 in the rotational direction around the axis.

[0137] Furthermore, when adhesive is used to connect the intermediate portion 322 with the second connecting ring 4b, applying the adhesive to the extending portion 413 increases the area to which the adhesive is applied in the direction of the shuttle axis A compared to when the extending portion 413 is not provided. This increases the adhesive strength. This allows the intermediate portion 322 to be connected more firmly with the second connecting ring 4b.

[0138] When the intermediate portions 322 are connected to each other by strings, adhesive is used, and the entire string must be soaked in the adhesive to increase the hardness of the strings. This requires the use of a larger amount of adhesive, which can result in a longer drying time. However, with the configuration of this embodiment, adhesive is applied only to the necessary portions of the second connecting ring 4b (i.e., the contact portion between the intermediate portion 322 and the inner wall portion 412 of the insertion hole 41 and the extension portion 413). This allows for a smaller amount of adhesive to be used compared to using strings, and as a result, the drying time of the adhesive can be shortened. This prevents the badminton shuttlecock 1 from becoming heavier due to the increased amount of adhesive.

[0139] (2l) Each of the multiple insertion holes 41 has multiple extending portions 413, and in each of the multiple insertion holes 41, the multiple extending portions 413 are provided at positions facing each other on the inner wall portion 412. With this configuration, the intermediate portion 322 is sandwiched between the extending portions 413 of the second connection ring 4b and comes into contact with each of the extending portions 413. This further increases the adhesive area between the second connection ring 4b and the intermediate portion 322, and allows for optimal positioning of the intermediate portion 322 in the rotational direction around its axis.

[0140] Furthermore, when viewed from the front of the second connecting ring 4b, each of the two extending portions 413 is disposed at both ends of the positioning surface 411 so as to be substantially perpendicular to the positioning surface 411 and so as to face each other. Therefore, in addition to the positioning surface 411, the extending portions 413 disposed at both ends of the positioning surface 411 can further suppress rotation around the axis of the intermediate portion 322, which is in contact with the positioning surface 411 at two points. This can make it even easier to position the intermediate portion 322 in the rotational direction around the axis.

[0141] (2m) The positioning surfaces 411 of the multiple insertion holes 41 are provided on the inner circumferential side IS of the second connecting ring 4b. The widths L3 and L4 between the first portion 431 at the inner circumferential end 43 and the positioning surface 411 are configured to be approximately constant. Furthermore, the widths L5 and L6 between the second portion 432 at the inner circumferential end 43 and the edge 421 of the through hole 42 are configured to be approximately constant. This configuration reduces the amount of material required to mold the second connecting ring 4b compared to a second connecting ring 4b in which the widths L3 and L4 between the first portion 431 at the inner circumferential end 43 and the positioning surface 411 exceed a substantially constant width and / or the widths L5 and L6 between the second portion 432 at the inner circumferential end 43 and the edge 421 of the through hole 42 exceed a substantially constant width. This allows for a reduction in the weight of the second connecting ring 4b.

[0142] Furthermore, there are no locally narrowed widths L3, L4 between the first portion 431 at the inner circumferential end 43 and the positioning surface 411, and widths L5, L6 between the second portion 432 at the inner circumferential end 43 and the edge 421 of the through hole 42. This prevents damage or tearing of the second connecting ring 4b when the badminton shuttlecock 1 is struck, etc. This can improve the durability of the badminton shuttlecock 1.

[0143] (2n) All components of the badminton shuttlecock 1 can be formed from artificial materials such as resin. This makes it possible to obtain a badminton shuttlecock 1 with improved assembly ease, as described above. For example, if the base portion 2 and / or the multiple shuttlecocks 3 are formed from natural materials, the performance (e.g., flight performance and impact resistance) of the resulting badminton shuttlecock 1 may not be consistently determined depending on the properties (e.g., material and shape) of the natural materials used. If all components of the badminton shuttlecock 1 are formed from artificial materials such as resin, it is possible to obtain a badminton shuttlecock 1 with uniformly determined performance.

[0144] (2o) The positioning surfaces 241 in the multiple fixing holes 24 of the base portion 2 and the positioning surfaces 411 in the multiple insertion holes 41 of the connecting ring 4 make it easy to position the root portion 321 and middle portion 322 of each of the multiple feathers 3 in the rotational direction about the axis. Furthermore, with this configuration, as a result of positioning the rachis portion 32 in the rotational direction about the axis, the positional relationships between the feather portions 31 in each of the multiple feathers 3 can be determined. And when the multiple feathers 3 of this embodiment 1 are used, the flight performance of the badminton shuttlecock 1 can be improved.

[0145] 3. Other Embodiments In the first embodiment, the connecting ring 4 connects the middle portions 322 of the multiple feathers 3 to each other. However, the middle portions 322 of the multiple feathers 3 may be connected by a thread or string instead of the connecting ring 4. In this case, as shown in FIG. 12A , a first plurality of protrusions 327 and a second plurality of protrusions 328 may be provided in the middle portions 322 of the multiple feathers 3 instead of the first claw portions 35 and the second claw portions 36. For example, when connecting the middle portions 322 with two threads or strings, one of the two threads or strings can be hooked between the first plurality of protrusions 327 and the other can be hooked between the second plurality of protrusions 327. This suppresses axial movement of the middle portions 322 of each of the threads or strings. This makes it easy to position the thread or string in the axial direction of the rachis portion 32, which can facilitate assembly of the badminton shuttlecock 1.

[0146] In this case, the base portion 2 and the plurality of feathers 3 may be those exemplified in the first embodiment. As exemplified in the first embodiment, the positioning surfaces 241 in the plurality of fixing holes 24 of the base portion 2 may prevent rotation of each of the plurality of feathers 3 about the axis of the base portion 321. This makes it easy to position the base portion 321 in the direction of rotation about the axis. Therefore, even if the connecting ring 4 is not used in the badminton shuttlecock 1, the efficiency of assembling the badminton shuttlecock 1 can be improved by facilitating positioning of the base portion 321 in the direction of rotation about the axis.

[0147] In the first embodiment, a configuration was illustrated in which the bottoms 242 of the respective fixing holes 24 were tapered (see FIG. 5B ). However, the roots 321 of the respective blades 3 may be formed to fit such a tapered shape. Specifically, as shown in FIG. 12B , the roots 321 of the respective blades 3 may be formed in a tapered shape near the tip 38 similar to the bottoms 242 of the fixing holes 24. With this configuration, when the roots 321 of the respective blades 3 are inserted into the respective fixing holes 24, the respective roots 321 fit into the respective fixing holes 24. This allows the roots 321 of the respective blades 3 to be more firmly fixed to the respective fixing holes 24 of the base portion 2.

[0148] In the first embodiment, a configuration with two connecting rings 4 is exemplified, but the number of connecting rings 4 may be one, or three or more. When multiple connecting rings 4 are used, the multiple connecting rings 4 may have a common configuration, or different configurations. For example, it is desirable that the shapes and sizes of the multiple insertion holes 41 among the multiple connecting rings 4 be the same, depending on the cross-sectional shapes perpendicular to the axial direction of the rachis sections 32 of the multiple blades 3 used. On the other hand, other configurations may be different among the multiple connecting rings 4. Furthermore, the multiple connecting rings 4 may be made of different materials.

[0149] In the first embodiment, the second connecting ring 4b is provided with a plurality of through holes 42 around its entire circumference, but for example, the plurality of through holes 42 may be provided in a portion of the circumference of the connecting ring 4. Also, at least one plurality of through holes 42 may be provided. Furthermore, in the connecting ring 4, the plurality of through holes 42 do not have to be arranged alternately with the plurality of through holes 42. For example, there may be no through holes 42 between adjacent insertion holes 41, or there may be a plurality of through holes 42.

[0150] In the first embodiment, the cross section of the intermediate portion 322 perpendicular to the axial direction has a recess 324. Furthermore, the tops 326a of the two side wall portions 326 in the cross section perpendicular to the axial direction of the intermediate portion 322 contact at two points with a positioning surface 411, which is formed as a surface that appears linear in a front view of the second connection ring 4b. This suppresses rotation of the intermediate portion 322 around its axis, making it easy to position the intermediate portion 322 in the rotational direction around its axis. However, the method for positioning the intermediate portion 322 in the rotational direction around its axis is not limited to this method. For example, the positioning surface 411 may have a protrusion in a front view of the second connection ring 4b. Furthermore, when the intermediate portion 322 is inserted into each of the multiple insertion holes 41, the protrusion on the positioning surface 411 may engage with the recess 324 in the intermediate portion 322. In this case, this engagement can suppress rotation of the intermediate portion 322 around its axis.

[0151] In the above embodiments, multiple functions of one component may be realized by multiple components, or one function of one component may be realized by multiple components. Furthermore, multiple functions of multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Furthermore, part of the configuration of the above embodiments may be omitted. Furthermore, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments. [Technical Ideas Disclosed in this Specification] [Item 1] A badminton shuttlecock comprising a base portion, a plurality of feathers, and a first connecting ring, each of the plurality of feathers being fixed in an annular shape to the base portion, each of the plurality of feathers having a feather portion and a rachis portion, the feather portion being attached to the rachis portion, the rachis portion having a root portion which is the portion fixed to the base portion, a tip portion which is the portion to which the feather portion is attached, and an intermediate portion which is a portion sandwiched between the root portion and the tip portion, the base portion having a plurality of fixing holes, the root portion being inserted into and fixed to each of the plurality of fixing holes, and the fixing positions of the plurality of root portions on the base portion forming a ring shape, a first connecting ring having a ring shape and a plurality of insertion holes formed in the circumferential direction, the rachis portion being inserted into each of the plurality of insertion holes, the first connecting ring interconnecting the intermediate portions and thereby integrally connecting the plurality of feathers so that the plurality of feathers spread radially from the base portion, the first connecting ring having a thickness within a predetermined range in the direction of the shuttle axis over its entire circumference, the axis connecting the center of the ring shape formed by the fixing positions of the plurality of root portions on the base portion and the center of the first connecting ring being the shuttle axis, each of the plurality of fixing holes having a first positioning surface for positioning in the rotational direction around the axis of the root portion, and the plurality of insertion holes having a second positioning surface for positioning in the rotational direction around the axis of the intermediate portion.[Item 2] The badminton shuttlecock further comprises a second connecting ring in addition to the first connecting ring, the second connecting ring being annular and having a plurality of insertion holes formed in the circumferential direction, the rachis sections being inserted into each of the plurality of insertion holes, the first connecting ring connecting the intermediate sections to each other thereby connecting the plurality of feathers together, the second connecting ring having a thickness within a predetermined range in the direction of the shuttle shaft over the entire circumference, the center of the second connecting ring being at a position on the shuttle shaft different from that of the first connecting ring, the center of the annular shape formed by the fixing positions of the plurality of root sections on the base section being at a position different from that of the first connecting ring, in the direction of the shuttle shaft, so that the first connecting ring connecting the intermediate sections to each other maintains the shape of the badminton shuttlecock in which the plurality of feathers are connected together so as to radiate out from the base section, The badminton shuttlecock according to item 1, wherein the plurality of insertion holes in the first connecting ring have second positioning surfaces for positioning in the rotational direction about the axis of the intermediate section, and the plurality of insertion holes in the second connecting ring have third positioning surfaces for positioning in the rotational direction about the axis of the intermediate section. [Item 3] The badminton shuttlecock according to item 1, wherein the cross-sectional shape perpendicular to the axial direction of each rachis section of the plurality of feathers has a recess. [Item 4] The badminton shuttlecock according to item 2, wherein the cross-sectional shape perpendicular to the axial direction of each rachis section of the plurality of feathers has a recess. [Item 5] The badminton shuttlecock according to item 3 or 4, wherein each rachis section of the plurality of feathers has a first claw portion on a surface facing the first connecting ring, and the first claw portion engages with the first connecting ring to position the first connecting ring in the axial direction of the rachis section.[Item 6] The badminton shuttlecock according to Item 4, wherein each rachis section of the plurality of feathers has a first claw portion on a surface facing the first connecting ring and a second claw portion on a surface facing the second connecting ring, the first claw portion engaging with the first connecting ring to position the first connecting ring in the axial direction of the rachis section, and the second claw portion engaging with the second connecting ring to position the second connecting ring in the axial direction of the rachis section. [Item 7] The badminton shuttlecock according to any one of Items 3 to 6, wherein each rachis section of the plurality of feathers has a plurality of first ribs provided in the recessed portion, the first ribs extending in a direction approximately perpendicular to the axial direction of the rachis section. [Item 8] The badminton shuttlecock according to any one of items 3 to 7, wherein a second rib is provided within the recess in each rachis section of the plurality of feathers, the second rib extending within the recess in the axial direction of the rachis section and being provided within the recess on a portion of the axial direction of the rachis section. [Item 9] The badminton shuttlecock according to item 4 or 6, wherein the cross-sectional shape perpendicular to the axial direction of each rachis section of the plurality of feathers is substantially U-shaped, the rachis section has a bottom and two side walls extending from the bottom and facing each other, and the thickness of the bottom includes the position at the intermediate section where the second connecting ring connects, and is thinner over the range from the position to the tip section than the portion outside this range. [Item 10] The badminton shuttlecock according to item 4 or 6, wherein the cross-sectional shape perpendicular to the axial direction of each rachis portion of the plurality of feathers is substantially U-shaped, the rachis portion has a bottom and two side wall portions extending from the bottom and facing each other, the height of the two side wall portions including the position at the intermediate portion where the second connecting ring connects the second connecting ring and is higher over the range from the position at the connecting position to the tip portion than the portions outside the range. [Item 11] The badminton shuttlecock according to any one of items 1 to 10, wherein in the badminton shuttlecock, each of the plurality of fixing holes in the base portion is provided substantially parallel to the shuttle shaft, and each root portion of the plurality of feathers extends substantially parallel to the shuttle shaft.[Item 12] A connecting ring for a badminton shuttlecock, wherein the badminton shuttlecock comprises a base portion and a plurality of feathers, each of the plurality of feathers being fixed to the base portion in an annular shape, each of the plurality of feathers having a feather portion and a rachis portion, the feather portion being attached to the rachis portion, the rachis portion having a root portion that is fixed to the base portion, a tip portion that is the portion to which the feather portion is attached, and an intermediate portion that is a portion sandwiched between the root portion and the tip portion, the connecting ring is annular and has a plurality of insertion holes formed in the circumferential direction, the rachis portions are inserted into each of the plurality of insertion holes, and the connecting ring connects the intermediate portions to each other to connect the plurality of feathers together so that the plurality of feathers spread radially from the base portion, A connecting ring, wherein an axis connecting the center of the ring-shaped configuration formed by the fixing positions of the plurality of rachis sections on the base section and the center of the connecting ring is defined as a shuttle axis, and the connecting ring has a thickness within a predetermined range in the direction of the shuttle axis over the entire circumference, and the plurality of insertion holes have positioning surfaces for positioning the intermediate section in the rotational direction about the axis. [Item 13] The connecting ring according to Item 12, wherein the connecting ring has a plurality of through holes formed in the circumferential direction, and the plurality of insertion holes and the plurality of through holes are provided alternately in the circumferential direction. [Item 14] The connecting ring according to Item 12 or 13, wherein each of the plurality of insertion holes has an extension portion configured to be thicker in the direction of the shuttle axis in a part of a contact portion with the intermediate section on an inner wall portion of the insertion hole compared to other portions of the contact portion in order to bring the intermediate section into contact. [Item 15] The connecting ring according to Item 14, wherein each of the plurality of insertion holes has a plurality of the extension portions, and in each of the plurality of insertion holes, the plurality of extension portions are respectively provided at positions facing each other on the inner wall portion.[Item 16] The positioning surfaces in the multiple insertion holes are provided on the inner circumferential side of the connecting ring, and the width between the positioning surface and a portion of the inner circumferential end of the connecting ring that faces the positioning surface is configured to be approximately constant, and the width between the edge of the multiple through holes on the inner circumferential side of the connecting ring and a portion of the inner circumferential end of the connecting ring that faces the edge is configured to be approximately constant.

Claims

1. A badminton shuttlecock comprising a base portion, a plurality of feathers, and a first connecting ring, each of the plurality of feathers is fixed in an annular shape to the base portion, each of the plurality of feathers has a feather portion and a rachis portion, the feather portion is attached to the rachis portion, the rachis portion has a root portion which is fixed to the base portion, a tip portion which is the portion to which the feather portion is attached, and an intermediate portion which is a portion sandwiched between the root portion and the tip portion, the base portion has a plurality of fixing holes, the root portion is inserted into and fixed into each of the plurality of fixing holes, and the fixing positions of the plurality of root portions on the base portion form a ring shape, the first connecting ring is annular and has a plurality of insertion holes formed in the circumferential direction, the rachis portion is inserted into each of the plurality of insertion holes, and the first connecting ring connects the intermediate portions to each other to integrally connect the plurality of feathers so that the plurality of feathers radiate out from the base portion, A badminton shuttle, wherein the shuttle axis is an axis connecting the center of the ring shape formed by the fixing positions of the multiple root portions on the base portion and the center of the first connecting ring, the first connecting ring has a thickness within a predetermined range in the direction of the shuttle axis around its entire circumference, each of the multiple fixing holes has a first positioning surface for positioning in the rotational direction about the axis of the root portion, and the multiple insertion holes have a second positioning surface for positioning in the rotational direction about the axis of the intermediate portion.

2. The badminton shuttlecock further comprises a second connecting ring in addition to the first connecting ring, the second connecting ring is annular and has a plurality of insertion holes formed in the circumferential direction, the rachis section is inserted into each of the plurality of insertion holes, the first connecting ring connects the intermediate sections together to integrally connect the plurality of feathers, the second connecting ring has a thickness within a predetermined range in the direction of the shuttle axis over the entire circumference, the center of the second connecting ring is at a different position on the shuttle axis from the center of the ring shape formed by the fixing positions of the plurality of root sections on the base section and the center of the first connecting ring, and the second connecting ring connects the intermediate sections together at a different position from the first connecting ring in the direction of the shuttle axis so as to maintain the shape of the badminton shuttlecock in which the plurality of feathers are integrally connected so as to radiate out from the base section by connecting the intermediate sections together with each other, The badminton shuttlecock of claim 1, wherein the multiple insertion holes in the first connecting ring have a second positioning surface for positioning the intermediate portion in a rotational direction about the axis, and the multiple insertion holes in the second connecting ring have a third positioning surface for positioning the intermediate portion in a rotational direction about the axis.

3. The badminton shuttlecock according to claim 1, wherein a cross-sectional shape perpendicular to the axial direction of each of the rachis portions of the multiple feathers has a recess.

4. The badminton shuttlecock according to claim 2, wherein a cross-sectional shape perpendicular to the axial direction of each of the rachis portions of the multiple feathers has a recess.

5. The badminton shuttlecock according to claim 1, wherein a first claw portion is provided on a surface of each of the rachis sections of the plurality of feathers that faces the first connecting ring, and the first claw portion engages with the first connecting ring to position the first connecting ring in the axial direction of the rachis section.

6. A badminton shuttlecock according to claim 2, wherein each rachis section of the plurality of feathers has a first claw portion on a surface facing the first connecting ring and a second claw portion on a surface facing the second connecting ring, the first claw portion engaging with the first connecting ring to position the first connecting ring in the axial direction of the rachis section, and the second claw portion engaging with the second connecting ring to position the second connecting ring in the axial direction of the rachis section.

7. A badminton shuttlecock according to claim 3 or claim 4, wherein a plurality of first ribs extending in a direction approximately perpendicular to the axial direction of the rachis portion are provided within the recess in each of the rachis portions of the plurality of feathers.

8. A badminton shuttlecock according to claim 3 or claim 4, wherein a second rib is provided within the recess in each rachis section of the plurality of feathers, the second rib extending within the recess in the axial direction of the rachis section and provided within the recess on a portion of the axial direction of the rachis section.

9. A badminton shuttlecock according to claim 4, wherein the cross-sectional shape perpendicular to the axial direction of each of the rachis portions of the multiple feathers is approximately U-shaped, the rachis portion has a bottom portion and two side wall portions extending from the bottom portion and facing each other, and the thickness of the bottom portion includes the connection position at the intermediate portion by the second connecting ring, and is thinner over the range from the connection position to the tip portion compared to the portion outside said range.

10. A badminton shuttlecock as claimed in claim 4, wherein the cross-sectional shape perpendicular to the axial direction of each of the rachis portions of the multiple feathers is roughly U-shaped, the rachis portion has a bottom and two side wall portions extending from the bottom and facing each other, and the height of the two side wall portions includes the connection position by the second connecting ring at the intermediate portion, and is higher over the range from the connection position to the tip portion compared to the parts outside said range.

11. The badminton shuttlecock according to claim 3 or 4, wherein each of the plurality of fixing holes in the base portion is provided approximately parallel to the shuttle shaft, and each of the root portions of the plurality of feathers extends approximately parallel to the shuttle shaft.

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