BADMINTON SHUTTLECOCK

Abstract

 A badminton shuttlecock having flight performance and durability equal to those of a shuttlecock with waterfowl feathers is provided. A synthetic shuttlecock includes a feather body portion (5) and a shaft (7) connected to the feather body portion (5), a plurality of artificial feathers (3) fixed to a base body to be annularly arranged and to overlap one another, and a netting cord body (13) for fixing the shafts (7) of the plurality of artificial feathers (3) to one another. An end portion of a projection portion (12) as a flexible member is arranged on at least a part of a surface of the shaft (7) facing the netting cord body (13), and the netting cord body (13) is connected and fixed to the end portion of the projection portion (12) through an adhesive material with the end portion of the projection portion (12) being deformed by being pressed by the netting cord body (13).

Description

TECHNICAL FIELD

[0001] The present invention relates to a badminton shuttlecock, and more particularly to a badminton shuttlecock with artificial feathers having flight performance and durability equal to those of a badminton shuttlecock with waterfowl feathers.

BACKGROUND ART

[0002] A shuttlecock with waterfowl feathers (natural shuttlecock) and a shuttlecock with synthetically manufactured features made of nylon resin and the like (synthetic shuttlecock) are conventionally known as badminton shuttlecocks. A natural shuttlecock is more expensive than a shuttlecock with synthetic features since it requires time and effort to obtain natural features of a certain level of quality. Therefore, shuttlecocks with synthetic features which are inexpensive and of constant quality have been proposed (see Japanese Patent Laying-Open No. 57-37464 (Patent Document 1) and Japanese Patent Laying-Open No. 53-40335 (Patent Document 2), for example).

[0003] Patent Document 1 discloses a shuttlecock artificial feather manufactured by preparing a feather portion from nonwoven fabric and integrally forming a feather shaft portion coupled to the feather portion by injection molding, and a synthetic shuttlecock with this artificial feather. Patent Document 2 discloses a shuttlecock artificial feather manufactured by bonding a feather portion to a feather shaft portion having a reinforcing member of high-strength fiber with an adhesive.

PRIOR ART DOCUMENTS

PATENT DOCUMENTS

[0004] 

Patent Document 1: Japanese Patent Laying-Open No. 57-37464

Patent Document 2: Japanese Patent Laying-Open No. 53-40335

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] According to experiments conducted by the inventors, however, the synthetic shuttlecocks with the shuttlecock artificial feathers disclosed in Patent Document 1 and Patent document 2 stated above were inferior in durability to a natural shuttlecock with waterfowl feathers, since a portion where the feather portion and the feather shaft portion were connected to each other became separated or broke due to stress concentration on this connection portion after actual use. In addition, a feather shaft portion of a synthetic shuttlecock has low rigidity and becomes highly deformed as compared to a feather shaft portion of a natural shuttlecock. For this reason, even if a fixing member for fixing feather shaft portions of a plurality of shuttlecock artificial feathers forming a synthetic shuttlecock to one another and an adhesive for bonding the feather shaft portions to the fixing member are the same as those used for a natural shuttlecock, it is difficult to reliably bond and fix the shuttlecock artificial feathers such that they are resistant to continuous smashing with rackets. If a material for a feather shaft portion is changed to a material having higher rigidity in order to improve durability, the feather shaft portion easily breaks instead when hit with a racket, thus not leading to improved durability, and also resulting in flight performance significantly different from that of a natural shuttlecock with waterfowl feathers.

[0006] A natural shuttlecock with waterfowl feathers is becoming increasingly expensive due to increased difficulty in obtaining the waterfowl feathers, however. There is thus a strong need for a synthetic shuttlecock with artificial feathers having flight performance and durability equal to those of a natural shuttlecock with waterfowl feathers.

[0007] The present invention was made to solve the above-described problems, and an object of the present invention is to provide a badminton shuttlecock having flight performance and durability equal to those of a shuttlecock with waterfowl feathers.

MEANS FOR SOLVING THE PROBLEMS

[0008] A badminton shuttlecock according to the present invention includes a hemispherical base body. This is a synthetic shuttlecock also including a plurality of artificial feathers fixed to the base body to be annularly arranged and to overlap one another, each of the artificial feathers including a feather portion and a shaft connected to the feather portion. The shuttlecock further includes a fixing member for fixing the shafts of the plurality of artificial feathers to one another. A flexible member is arranged on at least a part of a surface of the shaft facing the fixing member, and the fixing member is connected and fixed to the flexible member through an adhesive material with the flexible member being deformed by being pressed by the fixing member.

[0009] As stated above, the flexible member is arranged on the surface of the shaft of the artificial feather, and when the shafts of the plurality of artificial feathers are fixed to one another by the fixing member, the flexible member arranged on the surface of the shaft of the artificial feather is deformed by being pressed by the fixing member. With the flexible member arranged on the shaft, a contact area between the shaft having the flexible member arranged thereon and the fixing member is larger than in a case where an artificial feather including the shaft not having the flexible member arranged thereon is used. Moreover, since the flexible member is deformed by being pressed by the fixing member, a shape of a contact portion between the shaft having the flexible member arranged thereon and the fixing member (specifically, a shape of the deformed flexible member) becomes complicated. An adhesive material adheres to a surface of the flexible member of such complicated shape to connect and fix the fixing member to the flexible member, thereby further improving adhesion strength between the fixing member and the flexible member. Namely, adhesion strength between the fixing member, and the shaft of the artificial feather and the flexible member is higher than in a case where an artificial feather including the shaft not having the flexible member arranged thereon is used. Therefore, the synthetic shuttlecock including the flexible member can have substantially improved durability against continuous smashing with rackets.

[0010] A badminton shuttlecock according to the present invention includes a hemispherical base body. This is a synthetic shuttlecock also including a plurality of artificial feathers fixed to the base body to be annularly arranged and to overlap one another, each of the artificial feathers including a feather portion and a shaft connected to the feather portion. The shuttlecock further includes a fixing member for fixing the shafts of the plurality of artificial feathers to one another. A porous or fibrous reinforcing member is arranged on at least a part of a surface of the shaft facing the fixing member. The fixing member is connected and fixed to the reinforcing member through an adhesive material, and the reinforcing member is impregnated with at least a part of the adhesive material.

[0011] In this manner, when the shafts of the plurality of artificial feathers are fixed to one another by the fixing member, the porous or fibrous reinforcing member arranged on the surface of the shaft of the artificial feather is bonded and fixed to the fixing member through the adhesive material. In this case, with the reinforcing member arranged on the shaft, a contact area between the shaft and the fixing member is larger than in a case where an artificial feather including the shaft not having the reinforcing member arranged thereon is used. In addition, the adhesive material can enter and impregnate the porous or fibrous reinforcing member. Thus, adhesion strength between the adhesive material and the reinforcing member is improved. As a result, adhesion strength between the shaft and the fixing member can be substantially improved from that in a case where the reinforcing member is not arranged on the surface of the shaft.

[0012] In the synthetic shuttlecock including the reinforcing member stated above, it is preferable that the reinforcing member be fixed while being deformed by being pressed by the fixing member. This generates a synergetic effect of the effect of impregnating the reinforcing member with the adhesive material and the effect of improved adhesion strength between the fixing member and the reinforcing member owing to the complicated shape of the contact portion between the reinforcing member and the fixing member (shape of the reinforcing member) because of the deformed reinforcing member. Therefore, adhesion strength between the shaft and the fixing member can be further improved.

[0013] A badminton shuttlecock according to the present invention includes a hemispherical base body. This is a synthetic shuttlecock also including a plurality of artificial feathers fixed to the base body to be annularly arranged and to overlap one another, each of the artificial feathers including a feather portion and a shaft connected to the feather portion. The shuttlecock further includes a fixing member for fixing the shafts of the plurality of artificial feathers to one another. A flexible member is formed integrally with the shaft on at least a part of a surface of the shaft facing the fixing member. The fixing member is connected and fixed to the flexible member through an adhesive material with the flexible member being deformed by being pressed by the fixing member.

[0014] As stated above, the flexible member is formed integrally with the shaft on the surface of the shaft of the artificial feather, and when the shafts of the plurality of artificial feathers are fixed to one another by the fixing member, the flexible member formed on the surface of the shaft of the artificial feather is deformed by being pressed by the fixing member. With the flexible member formed on the shaft, a contact area between the shaft having the flexible member formed thereon and the fixing member is larger than in a case where an artificial feather including the shaft not having the flexible member formed to project from the surface of the shaft is used. Moreover, since the flexible member is deformed by being pressed by the fixing member, a shape of a contact portion between the shaft having the flexible member formed thereon and the fixing member (specifically, a shape of the deformed flexible member) becomes complicated. An adhesive material adheres to a surface of the flexible member of such complicated shape to connect and fix the fixing member to the flexible member, thereby further improving adhesion strength between the fixing member and the flexible member. Namely, adhesion strength between the fixing member and the flexible member (shaft of the artificial feather) is higher than in a case where an artificial feather including the shaft not having the flexible member formed thereon is used. Therefore, the synthetic shuttlecock with the artificial feather having the flexible member formed thereon can have substantially improved durability against continuous smashing with rackets.

[0015] In the badminton shuttlecock described above, it is preferable that the fixing member for fixing the shafts of the plurality of artificial feathers to one another include a cord body wound to tie the shafts of the plurality of artificial feathers to one another. By using the cord body, the shafts of the artificial feathers can be readily fixed to one another.

[0016] In the badminton shuttlecock described above, the fixing member may be made ofFRP. A feather shaft portion of a feather in a synthetic shuttlecock often has a higher mass than a feather shaft portion of a waterfowl feather in a natural shuttlecock. For this reason, it is preferable to use a material which is lightweight and has high rigidity for the fixing member so as not to affect its flight performance. Therefore, it is preferable that the fixing member (e.g., the cord body stated above) be made of FRP. It is further preferable that the fixing member stated above include thermosetting resin. Consequently, the fixing member can be readily arranged on the shuttlecock, and the fixing member can be readily made of FRP.

[0017] Although carbon has conventionally been used widely as a material having high rigidity, use of carbon for the fixing member of the badminton shuttlecock in the present invention may result in disadvantage in terms of impact resistance. That is, since a shuttlecock is subjected to very strong impact upon being hit, a fixing member made of carbon as stated above may break due to such impact. Further, when fibrous carbon is formed into a thread (carbon fibers are processed into a twisted thread), and operations such as winding this thread made of carbon fiber around a feather shaft portion of a feather or deforming this thread into a certain shape for use as a fixing member, this thread may easily cut, resulting in difficulty in performing the above operations. Therefore, it is preferable that the fixing member include a thread made of glass or aramid fiber. The glass or aramid fiber stated above exhibits favorable characteristics (high impact resistance) as compared to the carbon in terms of impact resistance, and does not cut easily during operation of processing it into a thread and winding it around a feather shaft portion (using it as a binding thread). Consequently, a fixing member which is lightweight and has high rigidity, and exhibits high impact resistance can be realized, and this thread can be readily used as a binding thread. In particular, a fixing member having high impact resistance can be realized by using aramid fiber for the fixing member.

[0018] It is preferable that the badminton shuttlecock described above further include a reinforcement fixing member connected to the fixing member and arranged to encircle outer surfaces of annularly arranged the plurality of artificial feathers. Consequently, the shafts of the plurality of artificial feathers can be further firmly fixed to one another.

[0019] It is further preferable that the badminton shuttlecock described above further include a cover member covering an outer surface of the fixing member. By arranging the cover member, the fixing member can be reinforced, thereby further improving durability of the badminton shuttlecock.

EFFECTS OF THE INVENTION

[0020] According to the present invention, a badminton shuttlecock with artificial feathers having flight performance and durability equal to those of a natural shuttlecock can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] 

Fig. 1 is a schematic diagram showing a shuttlecock according to a first embodiment of the present invention.

Fig. 2 is a schematic plan view showing an embodiment of a shuttlecock artificial feather according to the present invention, which forms the shuttlecock shown in Fig. 1.

Fig. 3 is a schematic cross-sectional view taken along the line III-III in Fig. 2.

Fig. 4 is a schematic cross-sectional view taken along the line IV-IV in Fig. 2.

Fig. 5 is a schematic cross-sectional view taken along the line V-V in Fig. 2.

Fig. 6 is a schematic cross-sectional view taken along the line VI-VI in Fig. 2.

Fig. 7 is a photograph showing appearance of a lower end portion of a feather shaft portion of the shuttlecock artificial feather shown in Fig. 2.

Fig. 8 is a photograph showing appearance of a central portion of the feather shaft portion of the shuttlecock artificial feather shown in Fig. 2.

Fig. 9 is a photograph showing appearance of a tip portion of the feather shaft portion of the shuttlecock artificial feather shown in Fig. 2.

Fig. 10 is a flowchart for illustrating a method of manufacturing the artificial feather shown in Fig. 2.

Fig. 11 is a flowchart for illustrating a method of manufacturing the shuttlecock shown in Fig. 1.

Fig. 12 is a schematic diagram for illustrating a step in the method of manufacturing the artificial feather shown in Fig. 10.

Fig. 13 is a schematic cross-sectional view taken along the line XIII-XIII in Fig. 12.

Fig. 14 is a schematic cross-sectional view taken along the line XIV-XIV in Fig. 12.

Fig. 15 is a schematic cross-sectional view taken along the line XV-XV in Fig. 12.

Fig. 16 is a flowchart illustrating an assembly step (S200) in detail.

Fig. 17 is a schematic diagram showing a state where a netting cord body is fixed to a flexible member forming the artificial feather.

Fig. 18 is an enlarged photograph for showing a detailed state of a substantial portion "XVIII" shown in Fig. 17.

Fig. 19 is a schematic diagram illustrating a detailed netting state where the netting cord body shown in the photograph of Fig. 18 fixes the artificial feather.

Fig. 20 is a schematic cross-sectional view at a bottom side of a shaft of the artificial feather.

Fig. 21 is a schematic cross-sectional view showing a state where the netting cord body applies pressure to the bottom side of the shaft of the artificial feather.

Fig. 22 is a schematic diagram showing an embodiment of the shuttlecock in Fig. 1 according to the first embodiment of the present invention, when viewed from a tip portion side of the shafts of the plurality of artificial feathers.

Fig. 23 is a schematic plan view showing a modified embodiment of the shuttlecock artificial feather according to the present invention, with a flexible member being arranged until an end portion at the bottom side of the shaft.

Fig. 24 is a schematic plan view showing another modified example of the artificial feather forming the shuttlecock.

Fig. 25 is a schematic plan view showing another modified example of the artificial feather forming the shuttlecock.

Fig. 26 is a schematic plan view showing another modified example of the artificial feather forming the shuttlecock.

Fig. 27 is a schematic plan view showing another modified example of the artificial feather forming the shuttlecock.

Fig. 28 is a schematic plan view showing another modified example of the artificial feather forming the shuttlecock.

Fig. 29 is a schematic plan view showing another modified example of the artificial feather forming the shuttlecock.

Fig. 30 is a schematic plan view showing another modified example of the artificial feather forming the shuttlecock.

Fig. 31 is a schematic plan view showing another modified example of the artificial feather forming the shuttlecock.

Fig. 32 is a schematic plan view showing another modified example of the artificial feather forming the shuttlecock.

Fig. 33 is a schematic cross-sectional view taken along the line XXXIII-XXXIII in Fig. 32.

Fig. 34 is a schematic perspective view showing a modified embodiment of the shuttlecock according to the present invention.
Fig. 35 is a schematic perspective view of the shuttlecock shown in Fig. 34, when viewed from a base body side.
Fig. 36 is a schematic plan view showing a modified embodiment of the shuttlecock artificial feather according to the present invention, which forms the shuttlecock shown in Figs. 34 and 35.
Fig. 37 is a schematic plan view showing another modified example of the artificial feather forming the shuttlecock.
Fig. 38 is a schematic plan view showing another modified example of the artificial feather forming the shuttlecock.
Fig. 39 is a schematic plan view showing another modified example of the artificial feather forming the shuttlecock.
Fig. 40 is a schematic plan view showing another modified example of the artificial feather forming the shuttlecock.
Fig. 41 is a schematic plan view showing another modified example of the artificial feather forming the shuttlecock.
Fig. 42 is a schematic plan view showing another modified example of the artificial feather forming the shuttlecock.
Fig. 43 is a schematic plan view showing another modified example of the artificial feather forming the shuttlecock.
Fig. 44 is a schematic plan view showing another modified example of the artificial feather forming the shuttlecock.
Fig. 45 is a flowchart illustrating the assembly step (S200) in Fig. 16 in detail from another viewpoint.
Fig. 46 is a schematic diagram showing a fixing member of a shuttlecock according to a second embodiment of the present invention.
Fig. 47 is a schematic diagram showing a shuttlecock in a modified example of the second embodiment of the present invention.

Fig. 48 is a schematic diagram showing a fixing member of a shuttlecock according to a third embodiment of the present invention.

Fig. 49 is a schematic diagram showing an embodiment of a binding thread portion, which is a fixing member of a shuttlecock according to a fourth embodiment of the present invention.

Fig. 50 is a schematic diagram showing a state where a netting cord body is fixed to a flexible member forming an artificial feather in the shuttlecock according to a fifth embodiment of the present invention.

Fig. 51 is a schematic cross-sectional view showing a state where the netting cord body applies pressure to a bottom side of a shaft of the artificial feather shown in Fig. 50.

Fig. 52 is a flowchart for illustrating a method of manufacturing the artificial feather shown in Fig. 50.

Fig. 53 is a flowchart for illustrating a step of forming the shaft included in a constituent member preparation step (S110) shown in Fig. 52.

Fig. 54 is a schematic cross-sectional view showing a state where the netting cord body applies pressure to a bottom side of a shaft of a modified example of the artificial feather shown in Fig. 50.

MODES FOR CARRYING OUT THE INVENTION

[0022] An embodiment and an example of the present invention will be described with reference to the drawings. It is noted that the same or corresponding parts have the same reference numerals allotted in the drawings, and description thereof will not be repeated.

(First Embodiment)

[0023] Referring to Figs. 1 to 9, an embodiment of a shuttlecock and a shuttlecock artificial feather according to the present invention will be described.

[0024] Referring to Fig. 1, a shuttlecock 1 according to the present invention includes a hemispherical base body (tip member), a plurality of shuttlecock artificial feathers 3 connected to a flat surface of the base body, and a netting cord body 13 (cord member) as a fixing member for fixing artificial feathers 3 to one another. The base body is formed from cork, for example. The plurality of (e.g. sixteen) artificial feathers 3 are annularly arranged on the flat surface of the base body. The plurality of artificial feathers 3 are arranged such that space among them is increased as distance from the base body increases (an inner diameter of a cylindrical portion formed by the plurality of artificial feathers 3 is increased as distance from the base body increases). As will be described later, netting cord body 13 is arranged to be entangled with shafts of the plurality of artificial feathers 3. Further, netting cord body 13 is made of FRP in which a cord body made of glass, aramid fiber or the like is impregnated with resin (e.g., thermosetting resin) and the resin is cured.

[0025] Referring to Figs. 2 to 9, artificial feather 3 forming shuttlecock 1 shown in Fig. 1 includes a feather body portion 5, and a shaft 7 connected to feather body portion 5. Shaft 7 includes a feather shaft portion 8 arranged to project from feather body portion 5, and a fixed shaft portion 10 connected to feather body portion 5 at a substantially central portion of feather body portion 5. Feather shaft portion 8 and fixed shaft portion 10 are arranged to extend in a line, to form one continuous shaft 7.

[0026] Feather body portion 5 is connected to a projection portion 12, which is held while being partially buried in feather shaft portion 8. Feather body portion 5 and projection portion 12 form a sheet-like member 9. Projection portion 12 is wider than feather shaft portion 8. That is, a width of projection portion 12 in a direction perpendicular to a direction in which feather shaft portion 8 extends is larger than a width of feather shaft portion 8 in the same direction. Thus, at each side of feather shaft portion 8, an end portion of substantially constant width of projection portion 12 is arranged along feather shaft portion 8. The end portions of projection portion 12 exposed at the sides of feather shaft portion 8 act as flexible members or reinforcing members for improving connection strength with netting cord body 13, as will be described later.

[0027] As shown in Fig. 3, a diameter of shaft 7 becomes gradually smaller from the bottom (right end portion in Fig. 3, or an end portion of feather shaft portion 8 opposite to a side thereof connected to fixed shaft portion 10) toward a tip portion (left end portion in Fig. 3, or an end portion of fixed shaft portion 10 opposite to a side thereof connected to feather shaft portion 8). As shown in Figs. 4 to 6, a cross-sectional shape of shaft 7 in a direction intersecting (orthogonal to) a direction in which shaft 7 extends is a quadrangular shape, and more specifically a rhombic shape. The cross-sectional shape of shaft 7 is not limited to such quadrangular shapes, but may be any shape. For example, the cross-sectional shape of shaft 7 may be an elliptical shape having a length in a direction intersecting a direction in which sheet-like member 9 extends (longitudinal direction in Fig. 4) longer than a length in the direction in which sheet-like member 9 extends (lateral direction in Fig. 4).

[0028] Sheet-like member 9 is buried in shaft 7 (sheet-like member 9 is buried to have an arc-shaped cross-sectional shape inside shaft 7) at a bottom side of shaft 7, as shown in Figs. 3, 4, and 7, and sheet-like member 9 is exposed at a surface of shaft 7 (sheet-like member 9 is in contact with and fixed to the surface of shaft 7) toward a tip portion side of shaft 7, as shown in Figs. 5, 6, 8, and 9. Further, as shown in Figs. 4 and 5, sheet-like member 9 is partially exposed at sides of shaft 7. Figs. 7 to 9 show photographs that were taken with an optical microscope with a magnification of 25 times.

[0029] Arrangement of sheet-like member 9 with respect to shaft 7 is not limited to the arrangement as shown in Figs. 3 to 9 where sheet-like member 9 is buried in shaft 7 at the bottom side of shaft 7, and is exposed at the surface of shaft 7 at a central portion and the tip portion side of shaft 7, but may be another arrangement. For example, sheet-like member 9 may be buried in shaft 7 at the bottom side and the central portion of shaft 7, and exposed at the surface of shaft 7 at the tip portion side of shaft 7. Alternatively, sheet-like member 9 may be buried in shaft 7 entirely at the bottom side, the central portion, and the tip portion side of shaft 7.

[0030] Referring now to Figs. 10 to 22, a method of manufacturing shuttlecock 1 and shuttlecock artificial feather 3 shown in Figs. 1 and 2 is described.

[0031] First, referring to Fig. 10, a method of manufacturing shuttlecock artificial feather 3 according to the present invention is described. As shown in Fig. 10, in the method of manufacturing artificial feather 3, a flexible member preparation step (S10) is performed first. A flexible member prepared in this step (S10) is sheet-like member 9 shown in Fig. 12, which has a plane shape as shown in Fig. 12 (a substantially quadrangular shape with rounded four corners). A thickness of sheet-like member 9 as the flexible member can be selected as appropriate in view of air resistance, mass balance and the like of artificial feather 3 to be formed. The flexible member (sheet-like member 9) can be made of nonwoven fabric made of chemical fiber such as polyester fiber and acrylic fiber. A nonwoven fabric having a basis weight of not less than 10 g/m² and not more than 90 g/m² may be used, for example. Alternatively, a nonwoven fabric made of polyester fiber having a basis weight of not less than 20 g/m² and not more than 80 g/m² and a thickness of not less than 0.07 mm and not more than 0.3 mm may be used, for example. Alternatively, a nonwoven fabric made of polyester fiber preferably having a basis weight of not less than 20 g/m² and not more than 60 g/m² and a thickness of not less than 0.08 mm and not more than 0.28 mm, and more preferably having a basis weight of not less than 30 g/m² and not more than 50 g/m² and a thickness of not less than 0.09 mm and not more than 0.25 mm may be used. Alternatively, a silk fabric, natural fiber such as cotton, cellulose fiber (i.e., paper), or those coated with resin and the like may be used instead of a nonwoven fabric. Still alternatively, a resin film (thickness: 50 to 100 µm) such as a polyamide resin film, a polyester resin film, and a PET film may be used instead of a nonwoven fabric. Further, a nonwoven fabric as described above with a coating layer formed on a surface thereof may be used. The coating layer may be formed by a method of laminating (coextrusion molding) a resin film or a foamed resin sheet on the nonwoven fabric, for example.
The coating layer such as a resin film may be formed on one surface or both surfaces of the nonwoven fabric. The coating layer may be partially formed on one surface or both surfaces. The foamed resin sheet may be fixed to a surface of the nonwoven fabric with an adhesive or a sticking agent.

[0032] Next, a step of arranging the flexible member in a mold (S20) is performed. In this step (S20), sheet-like member 9 made of nonwoven fabric or the like prepared in the above step (S10) is arranged in a mold for forming shaft 7 by injection molding or the like.

[0033] Next, a mold setting step (S30) is performed. Specifically, the mold in which the nonwoven fabric has been arranged is set such that resin which will form shaft 7 can be injected therein, and a temperature condition and the like of the mold are adjusted.

[0034] Next, a resin injection step (S40) is performed. Specifically, resin is injected into the mold through a resin inlet provided in the mold. As a result, shaft 7 in contact with and fixed to sheet-like member 9 made of nonwoven fabric is formed in the mold as shown in Fig. 12.

[0035] Next, an aftertreatment step (S50) is performed. Specifically, sheet-like member 9 to which shaft 7 has been connected and fixed is taken out of the mold. Here, sheet-like member 9 and shaft 7 have cross-sections as shown in Figs. 13 to 15. That is, shaft 7 is connected to sheet-like member 9 over substantially the entire length thereof. As shown in Fig. 13, sheet-like member 9 is buried in shaft 7 at the bottom side of shaft 7 (at a lower end portion side in Fig. 12). Sheet-like member 9 extending from the sides (right and left sides) of shaft 7 shown in Fig. 13 will be projection portion 12 formed of a flexible member shown in Figs. 2 and 7, for example.

[0036] As shown in Figs. 14 and 15, sheet-like member 9 is exposed at a surface of shaft 7 toward the tip side of shaft 7 (an upper end portion side in Fig. 12). Sheet-like member 9 is fixed to the surface of shaft 7 at the tip side, as shown in Figs. 14 and 15. Such structure can be realized with a shape of a groove for forming shaft 7 in the mold, arrangement of the nonwoven fabric as sheet-like member 9, and the like.

[0037] In the aftertreatment step (S50), an unnecessary portion of sheet-like member 9 shown in Fig. 12 (portion other than a portion 6 which will be the feather body portion and the end portions of projection portion 12 extending outward from the sides of shaft 7) is cut and removed. Consequently, artificial feather 3 as shown in Fig. 2 can be obtained.

[0038] Referring now to Fig. 11, a method of manufacturing shuttlecock 1 shown in Fig. 1 is described. As shown in Fig. 11, a preparation step (S 100) is performed first. In this preparation step (S 100), constituent members of shuttlecock 1 such as the base body (tip member) of shuttlecock 1 and artificial feather 3 are prepared. The base body can be manufactured with a conventionally known method. Artificial feather 3 can be manufactured with the above-described manufacturing method shown in Fig. 10.

[0039] Next, an assembly step (S200) is performed. Referring to Fig. 16, in the assembly step (S200) of shuttlecock 1, a step of fixing the artificial feathers to the base body (step S21) is performed first. Specifically, the plurality of artificial feathers 3 stated above are connected to the flat surface portion of the base body. For example, holes in which end portions of shafts 7 of artificial feathers 3 will be inserted are formed in the flat surface portion of the base body, and then the end portions of shafts 7 of artificial feathers 3 (end portion opposite to the side where the feather body portion is arranged) are inserted in the holes. Then, an adhesive or the like is supplied to the holes to fix artificial feathers 3 to the base body. Alternatively, an adhesive or the like may be applied in advance to the end portions of shafts 7, and the end portions of shafts 7 may be inserted in the holes in the base body.

[0040] Next, a step of connecting the artificial feathers to one another by a fixing member (S22) is performed. Specifically, a cord body is successively wound around a predetermined position of shafts 7 of artificial feathers 3, to connect artificial feathers 3 to one another by the cord body as a fixing member. The connection (winding of the cord body) can be done with a conventionally well-known method. Here, the end portions of projection portion 12 acting as a flexible member extend from the sides of shaft 7. By winding the cord body around shaft 7, the end portions of projection portion 12 are deformed by being pressed by the cord body.

[0041] Next, a step of fixing the fixing member to the flexible member (S23) is performed. Specifically, an adhesive is applied to a portion of shaft 7 around which the cord body has been wound. As a result, the plurality of artificial feathers 3 are fixed to one another by the cord body. The cord body may be impregnated with thermosetting resin in order to increase strength of the cord body. After the cord body is impregnated with resin in this manner, the resin is cured by heating, for example. Consequently, an FRP member in which the cord body as a fixing member has been impregnated with resin and the resin has been cured can be obtained. Shuttlecock 1 shown in Fig. 1 can be manufactured in this manner.

[0042] The fixing member for fixing the plurality of artificial feathers 3 to one another is not limited to the cord body as stated above, but may be any member such as a ring-shaped member. Further, the fixing member can be made of any material such as resin and fiber. For example, a fixing member including a thread made of glass or aramid fiber to be described later may be used. Furthermore, it is preferable to provide the cord members as fixing members in two or more stages in a direction in which shaft 7 of artificial feather 3 (see Fig. 2) extends, as shown in Fig. 1, for example.

[0043] The method of fixing artificial feathers 3 to one another by the fixing member stated above is described in further detail with reference to Figs. 17 to 19. Although one artificial feather 3 is illustrated in Fig. 17, two artificial feathers 3 are fixed to each other by the cord body in a photograph of Fig. 18 and a schematic diagram of Fig. 19. As shown in Figs. 17, 18, and 19, it is preferable that the fixing member used for connecting shafts 7 of the plurality of artificial feathers 3 to one another include a cord body wound to tie shafts 7 of the plurality of artificial feathers 3 to one another. Particularly as shown in Fig. 19, netting cord body 13 repeatedly follows a trajectory of A→B→C→D→E→F→G to fix the plurality of artificial feathers 3 to one another as a binding thread.

[0044] As shown in Figs. 18 and 19, netting cord body 13 including one cord body is used as a fixing member to bind shaft 7 in a net-forming manner such that projection portion 12 which is a flexible member connected to shaft 7 (feather shaft portion 8) is deformed, to connect adjacent shafts 7 to each other. Netting cord body 13 thus presses the end portion of projection portion 12 (end portion extending from each side of shaft 7), so that the end portion of projection portion 12 is applied with pressure to move toward shaft 7 (feather shaft portion 8) and deformed, as shown in Figs. 17, 18, and 19. That is, with the end portions of projection portion 12 arranged at the sides of shaft 7, a contact area between shaft 7 having the end portions of projection portion 12 arranged thereon and netting cord body 13 is larger than in a case where an artificial feather including shaft 7 not having the end portions of projection portion 12 arranged thereon is used. Moreover, since the end portions of projection portion 12 are deformed by being pressed by netting cord body 13, a shape of a contact portion between shaft 7 with the end portions of projection portion 12 arranged at the sides thereof and netting cord body 13 (specifically, a shape of the deformed end portion of projection portion 12) becomes complicated as will be described later. An adhesive adheres to surfaces of the end portions of projection portion 12 of such complicated shape to connect and fix netting cord body 13 to the end portions of projection portion 12, thereby improving adhesion strength between netting cord body 13, and the end portions of projection portion 12 and shaft 7. Namely, adhesion strength between netting cord body 13, and shaft 7 of the artificial feather and the end portions of projection portion 12 is higher than in a case where an artificial feather including shaft 7 not having the end portions of projection portion 12 arranged at the sides thereof is used. Therefore, the synthetic shuttlecock including shaft 7 having the end portions of projection portion 12 arranged at the sides thereof can have substantially improved durability against continuous smashing with rackets.

[0045] Referring to Figs. 20 and 21, a structure of the contact portion between shaft 7 and netting cord body 13 stated above is described in further detail. Fig. 20 is basically identical to Fig. 4 which is a schematic cross-sectional view of a region including the bottom side (feather shaft portion 8) of shaft 7 and projection portion 12 stated above, and is provided for comparison with Fig. 21 showing a state where the end portions of projection portion 12 (end portions of sheet-like member 9) are deformed after netting cord body 13 is wound around shaft 7. As shown in the schematic cross-sectional view of Fig. 20, before netting cord body 13 is wound around shaft 7, the end portions of sheet-like member 9 (projection portion 12) extend from the sides of shaft 7 in a substantially horizontal direction (extend from the sides of shaft 7 in a direction substantially perpendicular to these sides of shaft 7). Yet as shown in Fig. 21, after projection portions 12 of sheet-like member 9 are deformed due to pressure applied by netting cord body 13, the end portions of sheet-like member 9 (projection portion 12) are deformed to bend in a direction along a direction in which two netting cord bodies 13 extend As a result, an adhesive adheres to surfaces of the end portions of sheet-like member 9 of complicated shape to connect and fix netting cord bodies 13 to the end portions of sheet-like member 9 (projection portion 12), thereby improving adhesion strength between netting cord body 13, and the end portions of sheet-like member 9 and shaft 7.

[0046] In the schematic cross-sectional view of Fig. 21, arrangement of netting cord bodies 13 with respect to shaft 7 is illustrated in a simplified manner. The actual arrangement of netting cord bodies 13 which fix shaft 7 of artificial feather 3 as a binding thread is shown in Figs. 18 and 19 described above.

[0047] From a different viewpoint, badminton shuttlecock 1 stated above includes the hemispherical base body. Shuttlecock 1 further includes the plurality of artificial feathers 3 fixed to the base body to be annularly arranged and to overlap one another. Each of the plurality of artificial feathers 3 includes feather body portion 5 as a feather portion, and shaft 7 connected to feather body portion 5. Shuttlecock 1 further includes netting cord body 13 as a fixing member for fixing shafts 7 of the plurality of artificial feathers 3 to one another. Further, the end portions of sheet-like member 9 as porous or fibrous reinforcing members are arranged on at least a part of a surface of shaft 7 facing netting cord body 13. Netting cord body 13 is connected and fixed to the end portions of sheet-like member 9 through an adhesive material (adhesive), with the end portions of sheet-like member 9 impregnated with at least a part of the adhesive.

[0048] In this manner, when shafts 7 of the plurality of artificial feathers 3 are fixed to one another by netting cord body 13, the end portions of porous or fibrous sheet-like member 9 arranged at the surfaces of shaft 7 of artificial feather 3 are bonded and fixed to netting cord body 13 through the adhesive material. In this case, with the end portions of sheet-like member 9 arranged at shaft 7, a contact area between shaft 7 and netting cord body 13 is larger than in a case where an artificial feather including shaft 7 not having the end portions of sheet-like member 9 extending outward from the sides thereof is used. Further, since the end portions of sheet-like member 9 are porous or fibrous, the end portions of sheet-like member 9 can be impregnated with the adhesive material. Thus, adhesion strength between the adhesive material and the end portions of sheet-like member 9 is improved. As a result, adhesion strength between shaft 7 and netting cord body 13 can be substantially improved from that in a case where the end portions of sheet-like member 9 described above are not arranged at the surfaces of shaft 7.

[0049] A feather shaft portion of a waterfowl feather in a natural shuttlecock is lightweight, and has a large cross-sectional area and high rigidity. When a natural shuttlecock is manufactured, therefore, a large contact area between a feather shaft portion and netting cord body 13 as a fixing member can be obtained to ensure high adhesion strength. Feather shaft portion 8 of artificial feather 3 in a synthetic shuttlecock has a specific gravity of about 1.2 when made of synthetic resin, for example, which is higher than a specific gravity of a feather shaft portion of a waterfowl feather. Thus, for a synthetic shuttlecock to have the same mass a natural shuttlecock, shaft 7 needs to be thinner than a feather shaft portion of a waterfowl feather. It thus becomes difficult to obtain a foamed or hollow structure of thinner shaft 7. Further, if shaft 7 is made of resin having high rigidity, thinner shaft 7 may break due to smashing.

[0050] When a waterfowl feather of a natural shuttlecock is used, a ratio of rigidity of a feather shaft portion of the waterfowl feather is higher than a ratio of rigidity of a cord body as a fixing member, for example, in a portion where they are fixed to each other. Yet for the reasons stated above, use of resin having high rigidity for shaft 7 in a synthetic shuttlecock poses difficulties. Accordingly, in a synthetic shuttlecock, it is preferable to increase rigidity of a binding thread which forms netting cord body 13 as a fixing member.

[0051] As stated above, feather shaft portion 8 of artificial feather 3 in the synthetic shuttlecock has a higher specific gravity (mass) than that of a feather shaft portion of a waterfowl feather. Thus, as the binding thread and the adhesive material for bonding netting cord body 13 to shaft 7 (feather shaft portion 8) increase in weight, the total mass of shuttlecock 1 becomes higher than that of a natural shuttlecock. This may cause flight performance of shuttlecock 1 to be substantially different from that of a natural shuttlecock.

[0052] For this reason, it is preferable that the binding thread as netting cord body 13 forming shuttlecock 1 having feather shaft portion 8 which is heavier than a feather shaft portion of a natural shuttlecock be more lightweight than a binding thread forming a natural shuttlecock. It is therefore preferable to use netting cord body 13 formed of a binding thread which is lightweight and has high rigidity as the fixing member forming shuttlecock 1. In order to satisfy these conditions, it is preferable that a member forming netting cord body 13 be made of FRP. This is because a member made of FRP improves strength and rigidity of netting cord body 13 as a fixing member. It is further preferable that thermosetting resin be used as the resin with which netting cord body 13 is impregnated to make netting cord body 13 of FRP (i.e., the fixing member in which netting cord body 13 is made of FRP include thermosetting resin). Consequently, the fixing member can be readily made of FRP with the thermosetting resin during a heating step and the like in a process for fixing netting cord body 13 to shaft 7. The thermosetting resin may be epoxy resin or phenolic resin, for example.

[0053] It is preferable that netting cord body 13 include a binding thread made of aramid fiber, for example. Aramid fiber is particularly lightweight and has high strength among fibers that can be used to make the fixing member of FRP. Thus, netting cord body 13 formed of a binding thread which is particularly lightweight and has high strength can be realized. Further, breakage and the like of artificial feather 3 can also be suppressed owing to the high strength, thereby improving durability and life of shuttlecock 1. For example, four aramid fibers of 400D model are formed into a twisted thread to form one netting cord body 13. Alternatively, netting cord body 13 formed of a binding thread made of glass instead of aramid fiber may be used.

[0054] Assume that shafts 7 of artificial feathers 3 are fixed to one another by netting cord body 13 in which four aramid fibers of 400D model are formed into a twisted thread as described above, for example. Netting cord bodies 13 arranged in two stages in the direction in which shaft 7 of artificial feather 3 extends have a mass of about 0.16 g. After each of netting cord bodies 13 of two stages is impregnated with a total of 0.2 g of epoxy resin as thermosetting resin, netting cord bodies 13 are heated for 90 minutes at 75°C. The epoxy resin is thus cured. This thermosetting resin may become an adhesive material, as will be described later. Such fixing member made of FRP (member made ofFRP including netting cord bodies 13 and the cured resin) has a total mass of 0.36 g. On the other hand, a binding thread forming a natural shuttlecock has a mass of 0.11 g and nitrocellulose which is an adhesive material has a mass of 0.4 g, resulting in a total mass of 0.51 g of the binding thread and the adhesive material. As such, the mass of the cord member (fixing member made of FRP) of shuttlecock 1 according to the present invention can be reduced by about 30% as compared to the total mass of a binding thread and an adhesive material forming a natural shuttlecock.

[0055] One netting cord body 13 shown in Fig. 22 annularly fixes the plurality of artificial feathers 3 as a binding thread, as shown in Figs. 18 and 19 described above. In this manner, one netting cord body 13 serving as a fixing member is wound to tie shafts 7 of the plurality of artificial feathers 3 to one another.

[0056] Referring to Fig. 23, artificial feather 3 according to the present invention is basically similar in structure to artificial feather 3 shown in Fig. 2, but has a different form at the bottom side of shaft 7. Specifically, in artificial feather 3 shown in Fig. 23, projection portion 12 as sheet-like member 9 is arranged until a tip at the bottom side of shaft 7 (feather shaft portion 8). Projection portion 12 having this structure can achieve a similar effect to that of projection portion 12 of artificial feather 3 shown in Fig. 2.

[0057] Referring to Figs. 24 to 32, modified examples of artificial feather 3 are described.

[0058] Referring to Fig. 24, another modified example of artificial feather 3 is basically similar in structure to artificial feather 3 shown in Fig. 2, but has a different plane shape of projection portion 12. Specifically, in artificial feather 3 shown in Fig. 24, projection portion 12 is not symmetrical with respect to shaft 7. Projection portion 12 on the left side of shaft 7 has a larger width in a direction substantially orthogonal to a central shaft of feather shaft portion 8 (horizontal direction in Fig. 24), and projection portion 12 on the right side of shaft 7 has a smaller width in the direction substantially orthogonal to the central shaft of feather shaft portion 8. Projection portion 12 having this shape can achieve a similar effect to that of projection portion 12 of artificial feather 3 shown in Fig. 2. Projection portion 12 may have a shape such that projection portion 12 on the right side of shaft 7 has a larger width in the horizontal direction and projection portion 12 on the left side of shaft 7 has a smaller width in the horizontal direction, for example. It is preferable that the width in the horizontal direction of larger projection portion 12 on the right or left side be not less than 1.1 times and not more than 3 times as large as the width in the horizontal direction of smaller projection portion 12 on the right or left side. It is further preferable that the larger width be not less than 1.2 times and not more than twice as large as the smaller width.

[0059] Referring to Fig. 25, another modified example of artificial feather 3 is basically similar in structure to artificial feather 3 shown in Fig. 2, but has a different plane shape of projection portion 12. Specifically, in artificial feather 3 shown in Fig. 25, four convex portions 41 are provided in two stages on right and left ridge lines (periphery) of projection portion 12. Feather body portion 5, projection portion 12, and convex portions 41 are formed from one sheet-like member 9. Consequently, convex portions 41 are pressed by netting cord bodies 13 provided in two stages in the direction in which shaft 7 of artificial feather 3 extends as shown in Fig. 1, for example, which leads to further increase in contact area and adhesion strength between netting cord bodies 13 and sheet-like member 9 (which includes projection portion 12 and convex portions 41).

[0060] Convex portion 41 of artificial feather 3 in Fig. 25 may have a height in a direction orthogonal to the central shaft of feather shaft portion 8 (height of convex portion 41 in a horizontal direction in Fig. 25 from the periphery of sheet-like member 9 other than convex portion 41) of more than 0 mm and not more than 3 mm, and more preferably not less than 0.5 mm and not more than 2.5 mm. Convex portion 41 may have a width in a direction along the central shaft of feather shaft portion 8 (width of convex portion 41 in a vertical direction in Fig. 25) of more than 0 mm and not more than 2 mm, and more preferably not less than 0.5 mm and not more than 1.5 mm. A width of a region between convex portions 41 of two stages in Fig. 25 (width in the vertical direction in Fig. 25) may be not less than 10 mm and not more than 20 mm, more preferably not less than 12 mm and not more than 18 mm, and still more preferably about 15 mm, for example. Although the periphery of convex portion 41 in Fig. 25 has an arc shape, a plane shape of convex portion 41 may be a quadrangular shape having a side orthogonal to the central shaft of feather shaft portion 8 shown in Fig. 25, another quadrangular shape (e.g., a trapezoidal shape, a parallelogram, a rhombic shape), a triangular shape, or a polygonal shape such as a pentagon or a hexagon.

[0061] Referring to Fig. 26, another modified example of artificial feather 3 is basically similar in structure to artificial feather 3 shown in Fig. 25, but has a different plane shape of projection portion 12. Specifically, in artificial feather 3 shown in Fig. 26, eight convex portions 41 shown in Fig. 25 are provided in four stages. As shown in Fig. 26, space between the first stage and the second stage and space between the third stage and the fourth stage are smaller than space between the second stage and the third stage. Netting cord bodies 13 may be arranged such that a region between convex portions 41 of the first stage and the second stage and a region between convex portions 41 of the third stage and the fourth stage are pressed by netting cord bodies 13 provided in two stages in the direction in which shaft 7 of artificial feather 3 extends as shown in Fig. 1, for example. A width of the region between convex portions 41 of the first stage and the second stage (width in a vertical direction in Fig. 26) may be not less than 1 mm and not more than 3 mm, and more preferably not less than 1.5 mm and not more than 2.5 mm, for example. Accordingly, netting cord bodies 13 come in contact with sheet-like member 9 at the regions of projection portion 12 between two convex portions 41, and at convex portions 41. A contact area between netting cord bodies 13 and sheet-like member 9 is thus increased, which leads to further increase in adhesion strength between them. Convex portion 41 in Fig. 26 can have a similar shape to convex portion 41 in Fig. 25.

[0062] Referring to Fig. 27, another modified example of artificial feather 3 is basically similar in structure to artificial feather 3 shown in Fig. 2, but has a different plane shape of projection portion 12. Specifically, in artificial feather 3 shown in Fig. 27, concave portions 42 are formed in two stages in the left periphery of projection portion 12. Consequently, concave portions 42 are pressed by netting cord bodies 13 provided in two stages in the direction in which shaft 7 of artificial feather 3 extends as shown in Fig. 1, for example, respectively, which leads to further increase in contact area and adhesion strength between netting cord bodies 13 and sheet-like member 9 (which includes projection portion 12 and concave portion 42). This is because, since the periphery of concave portion 42 is longer than a line segment connecting one end to the other end of concave portion 42, a contact area between netting cord body 13 and concave portion 42 is larger than a case where netting cord body 13 presses a place where concave portion 42 is not provided.

[0063] Concave portion 42 of artificial feather 3 in Fig. 27 may have a depth in the direction orthogonal to the central shaft of feather shaft portion 8 (depth in a horizontal direction in Fig. 27) of more than 0 mm and not more than 3 mm, and more preferably not less than 0.5 mm and not more than 2.5 mm. Concave portion 42 may have a width in the direction along the central shaft of feather shaft portion 8 (width in a vertical direction in Fig. 27) of more than 0 mm and not more than 2 mm, and more preferably not less than 0.5 mm and not more than 1.5 mm. A width of a region between concave portions 42 of two stages in Fig. 27 (width in the vertical direction in Fig. 27) may be not less than 10 mm and not more than 20 mm, more preferably not less than 12 mm and not more than 18 mm, and still more preferably about 15 mm, for example. Although the periphery of concave portion 42 of artificial feather 3 in Fig. 27 has an arc shape, a plane shape of concave portion 42 may be a quadrangular shape having a side orthogonal to the central shaft of feather shaft portion 8 shown in Fig. 27, another quadrangular shape (e.g., a trapezoidal shape, a parallelogram, a rhombic shape), a triangular shape, or a polygonal shape such as a pentagon or a hexagon.

[0064] Referring to Fig. 28, another modified example of artificial feather 3 is basically similar in structure to artificial feather 3 shown in Fig. 27, but has a different plane shape of projection portion 12. Specifically, in artificial feather 3 shown in Fig. 28, four concave portions 42 are provided in two stages in the periphery of the right and left sides of projection portion 12. Consequently, both right and left concave portions 42 are pressed by netting cord bodies 13, which leads to further increase in contact area and adhesion strength between netting cord bodies 13 and sheet-like member 9 (which includes projection portion 12 and concave portions 42). Concave portion 42 in Fig. 28 can have a similar shape to concave portion 42 in Fig. 27.

[0065] Referring to Fig. 29, another modified example of artificial feather 3 is basically similar in structure to artificial feather 3 shown in Fig. 2, but has a different plane shape of feather shaft portion 8. Specifically, unlike artificial feather 3 shown in Fig. 28, in artificial feather 3 shown in Fig. 29, four concave portions 42 are provided in two stages in right and left sides of feather shaft portion 8 rather than projection portion 12 (sheet-like member 9). Artificial feather 3 having this structure can achieve a similar effect to that of artificial feather 3 shown in Fig. 28. Concave portion 42 in Fig. 29 can have a similar shape to concave portion 42 in Fig. 28.

[0066] Referring to Fig. 30, another modified example of artificial feather 3 is basically similar in structure to artificial feather 3 shown in Fig. 25, but has different plane shapes of projection portion 12 and feather shaft portion 8. Specifically, in artificial feather 3 shown in Fig. 30, convex portions 41 are formed in parallel on the periphery on the right and left sides of projection portion 12 and the right and left sides of feather shaft portion 8, substantially orthogonally to the central shaft of feather shaft portion 8. Namely, a total of eight convex portions 41 are formed. Artificial feather 3 having this structure can achieve a similar effect to that of artificial feather 3 shown in Fig. 25. Convex portion 41 in Fig. 30 can have a similar shape to convex portion 41 in Fig. 25.

[0067] Referring to Fig. 31, another modified example of artificial feather 3 is basically similar in structure to artificial feather 3 shown in Fig. 26, but has different plane shapes of projection portion 12 and feather shaft portion 8. Specifically, in artificial feather 3 shown in Fig. 31, convex portions 41 are formed in parallel on the periphery of the right and left sides of projection portion 12 and the right and left sides of feather shaft portion 8, substantially orthogonally to the central shaft of feather shaft portion 8. Namely, a total of sixteen convex portions 41 are formed. Artificial feather 3 having this structure can achieve a similar effect to that of artificial feather 3 shown in Fig. 26. Convex portion 41 in Fig. 31 can have a similar shape to convex portion 41 in Fig. 26.

[0068] Referring to Fig. 32, another modified example of artificial feather 3 is basically similar in structure to artificial feather 3 shown in Fig. 2. All artificial feathers 3 described above including the one shown in Fig. 2 are formed such that sheet-like member 9 is at least partially buried in shaft 7 by using a mold. Yet in artificial feather 3 shown in Fig. 32, feather body portion 5 and/or projection portion 12 forming sheet-like member 9 are/is fixed to shaft 7 with an adhesive.

[0069] As shown in a schematic cross-sectional view of Fig. 33, feather body portion 5 and projection portion 12 of artificial feather 3 shown in Fig. 32 are later bonded to shaft 7 through an adhesive 34. It is preferable that adhesive 34 have adherence strong enough to sufficiently suppress separation from shaft 7 due to continuous smashing with rackets. For example, a rubber-based solvent-type adhesive (e.g., GP Clear manufactured by Konishi Co., Ltd.) is preferably used. Artificial feather 3 having this structure can achieve a similar effect to that of artificial feather 3 shown in Fig. 2. Not only artificial feather 3 shown in Fig. 2 but also all artificial feathers 3 described above can be formed by later bonding feather body portion 5 and projection portion 12, or only projection portion 12, as with artificial feather 3 shown in Fig. 32.

[0070] Referring to Figs. 34 to 36, a modified embodiment of the shuttlecock and the shuttlecock artificial feather according to the present invention is described.

[0071] Referring to Figs. 34 and 35, shuttlecock 1 according to the present invention is basically similar in structure to shuttlecock 1 shown in Fig. 1, but has a partially different structure of artificial feather 3. Specifically, shuttlecock 1 shown in Figs. 34 and 35 is different from shuttlecock 1 shown in Fig. 1 in that a flap portion 31 projecting outward from a side of feather shaft portion 8 of artificial feather 3 (see Fig. 36) is formed. Artificial feather 3 shown in Fig. 36 is basically similar in structure to artificial feather 3 shown in Fig. 2, but includes flap portion 31 having a triangular plane shape. More specifically, the plane shape of flap portion 31 is a triangular shape having a side extending in a direction substantially perpendicular to the central shaft of feather shaft portion 8, and a side obliquely intersecting the central shaft of feather shaft portion 8. A vertex of the plane shape of flap portion 31 (farthest end from the surface of feather shaft portion 8) may be positioned on the feather body portion 5 side as shown in Fig. 36, or may be arranged in another position.

[0072] In addition to flap portion 31, an edge portion 32 is formed at each side of feather shaft portion 8 of artificial feather 3 shown in Fig. 36. Edge portions 32 extend at both sides of flap portion 31, and are arranged along the central shaft of feather shaft portion 8. Edge portion 32 is also formed at a side of feather shaft portion 8 opposite to the side at which flap portion 31 is formed. Edge portions 32 are formed of a part (end portions) of sheet-like member 9. A width L2 of edge portion 32 is substantially constant in any position of feather shaft portion 8 in the direction along the central shaft of feather shaft portion 8. Width L2 may be more than 0 mm and not more than 2 mm, and more preferably not less than 0.5 mm and not more than 1 mm, for example. Flap portion 31 may be formed without forming edge portions 32. Feather body portion 5, flap portion 31, and edge portions 32 are positioned in substantially the same plane. Edge portions 32 positioned at both sides of feather shaft portion 8 have the same width.

[0073] A length L1 of flap portion 31 in the direction along the central shaft of feather shaft portion 8 may be not less than 5 mm and not more than 15 mm, more preferably not less than 7 mm and not more than 12 mm, and still more preferably about 10 mm, for example. It is preferable to set a size of flap portion 31 such that flap portion 31 can be arranged between netting cord bodies 13 of two stages as a fixing member for fixing the plurality of artificial feathers 3 to one another, as shown in Figs. 34 and 35. Namely, it is preferable that length L1 of flap portion 31 be shorter than a distance between the two cord bodies. Further, concave portions 42 around which netting cord bodies 13 will be wound are formed in the periphery of projection portion 12 to sandwich flap portion 31 in the direction along the central shaft of feather shaft portion 8. Shuttlecock 1 with artificial feathers 3 having this structure can achieve a similar effect to that of shuttlecock 1 shown in Fig. 1. Moreover, with flap portion 31 formed in artificial feather 3, rotation performance of shuttlecock 1 can be maintained.

[0074] Flap portion 31 may be positioned anywhere in the direction along the central shaft of feather shaft portion 8, and is preferably formed in a region between the center of feather shaft portion 8 and feather body portion 5. With such arrangement, a possibility that flap portion 31 will be hidden behind the base body of shuttlecock 1 during flight of shuttlecock 1 can be lowered. Therefore, the rotation performance of shuttlecock 1 can be reliably maintained by flap portion 31.

[0075] Further, in shuttlecock 1 shown in Figs. 34 and 35, it is preferable to arrange flap portion 31 such that flap portion 31 can be seen outside of the hemispherical base body when viewed from the base body side. With such arrangement, air can be directly supplied to flap portion 31 without being blocked by the base body. Therefore, rotation of shuttlecock 1 can be effectively maintained by flap portion 31.

[0076] Furthermore, in each of the plurality of artificial feathers 3 arranged annularly (to surround a central axis of feather shaft portions 8 passing through the base body) in shuttlecock 1 shown in Figs. 34 and 35, flap portion 31 is preferably formed at a side toward the central axis of feather shaft portions 8 passing through the base body (inner side) between the sides of feather shaft portion 8. With such arrangement, rotation of shuttlecock 1 can be more effectively maintained.

[0077] Referring to Figs. 37 to 44, modified examples of artificial feather 3 are described.

[0078] Referring to Fig. 37, another modified example of artificial feather 3 is basically similar in structure to artificial feather 3 shown in Fig. 36, but has a different plane shape of flap portion 31. Specifically, in artificial feather 3 shown in Fig. 37, flap portion 31 has a rectangular (quadrangular) plane shape. Flap portion 31 having this shape can achieve a similar effect to that of flap portion 31 of artificial feather 3 shown in Fig. 36. The plane shape of flap portion 31 may be a quadrangular shape having a side orthogonal to the central shaft of feather shaft portion 8 as shown in Fig. 37, another quadrangular shape (e.g., a trapezoidal shape, a parallelogram, a rhombic shape), or a polygonal shape such as a pentagon or a hexagon.

[0079] Referring to Fig. 38, another modified example of artificial feather 3 is basically similar in structure to artificial feather 3 shown in Fig. 36, but has a different plane shape of flap portion 31. Specifically, in artificial feather 3 shown in Fig. 38, the plane shape of flap portion 31 has a curved periphery. Flap portion 31 having this shape can achieve a similar effect to that of flap portion 31 of artificial feather 3 shown in Fig. 36. In flap portion 31 shown in Fig. 38, a central portion of the periphery of feather shaft portion 8 in the direction along the central shaft of feather shaft portion 8 is the farthest portion from the center of feather shaft portion 8. Alternatively, the position of this farthest portion in flap portion 31 in the direction along the central shaft of feather shaft portion 8 may be moved from the central portion toward feather body portion 5 or to a side opposite to the side where feather body portion 5 is positioned, depending on flight performance required of shuttlecock 1.

[0080] Referring to Fig. 39, another modified example of artificial feather 3 is basically similar in structure to artificial feather 3 shown in Fig. 36, but has a different plane shape of flap portion 31. Specifically, in artificial feather 3 shown in Fig. 3 9, rectangular flap portion 31 is formed from one side of feather shaft portion 8 over the entire length of feather shaft portion 8 along the central shaft of feather shaft portion 8. A width L3 of flap portion 31 is substantially constant over the entire length of feather shaft portion 8. With such flap portion 31 formed over substantially the entire length of feather shaft portion 8, the effect of generating rotating force of shuttlecock 1 by flap portion 31 can be increased from case where flap portion 31 is formed only partially in feather shaft portion 8 in the direction along the central shaft of feather shaft portion 8 as shown in Fig. 36 and the like. As shown in Fig. 39, concave portion 42 formed in flap portion 31 has a different size from concave portion 42 formed in edge portion 32. Specifically, a depth and a width of the concave portion formed in flap portion 31 are greater than a depth and a width of concave portion 42 formed in edge portion 32 on the opposite side.

[0081] Width L3 of flap portion 31 may be not less than 1 mm and not more than 3 mm, and more preferably not less than 1.5 mm and not more than 2.5 mm, for example. In flap portion 31 and edge portion 32, concave portions 42 are formed in positions where netting cord bodies 13 in two stages shown in Figs. 34 and 35 should be fixed.

[0082] Referring to Fig. 40, another modified example of artificial feather 3 is basically similar in structure to artificial feather 3 shown in Fig. 36, but is different in that in addition to flap portion 31, another flap portion 33 is formed on a side of feather shaft portion 8 opposite to the side where flap portion 31 is formed. Flap portion 33 has a triangular plane shape. A vertex of the triangular plane shape of flap portion 33 (farthest end from feather shaft portion 8) is positioned on a side opposite to the side where feather body portion 5 is positioned. That is, the vertex of flap portion 33 is positioned opposite to the vertex of flap portion 31 with respect to feather shaft portion 8 in the direction along the central shaft of feather shaft portion 8. With two flap portions 31 and 33 thus provided, the effect of generating rotating force of shuttlecock 1 by flap portions 31 and 33 can be increased. Concave portions 42 are formed to sandwich flap portion 33.

[0083] Referring to Fig. 41, another modified example of artificial feather 3 is basically similar in structure to artificial feather 3 shown in Fig. 40, but has different shapes of flap portions 31 and 33. That is, flap portions 31 and 33 of artificial feather 3 shown in Fig. 41 have rectangular plane shapes. The plane shapes of flap portions 31 and 33 may be any quadrangular shape as with flap portion 31 shown in Fig. 37. This structure can achieve a similar effect to when artificial feather 3 shown in Fig. 40 is applied to shuttlecock 1.

[0084] Referring to Fig. 42, another modified example of artificial feather 3 is basically similar in structure to artificial feather 3 shown in Fig. 40, but has different shapes of flap portions 31 and 33. That is, the plane shapes of flap portions 31 and 33 of artificial feather 3 shown in Fig. 41 have curved peripheries as with flap portion 31 shown in Fig. 38. Further, flap portion 31 has a relatively large area with respect to flap portion 33. This structure can achieve a similar effect to when artificial feather 3 shown in Fig. 40 and the like is applied to shuttlecock 1.

[0085] Referring to Fig. 43, another modified example of artificial feather 3 is basically similar in structure to artificial feather 3 shown in Fig. 40, but has different shapes of flap portions 31 and 33. That is, in artificial feather 3 shown in Fig. 43, rectangular flap portions 31 and 33 are formed over the entire length of feather shaft portion 8 along the central shaft of feather shaft portion 8. Flap portions 31 and 33 have substantially the same widths. This structure can achieve a similar effect to when artificial feather 3 shown in Fig. 40 is applied to shuttlecock 1. Alternatively, flap portions 31 1 and 33 may have widths different from each other.

[0086] Referring to Fig. 44, another modified example of artificial feather 3 is basically similar in structure to artificial feather 3 shown in Fig. 36, but has a different plane shape of feather body portion 5 from that of artificial feather 3 shown in Fig. 36. That is, in artificial feather 3 shown in Fig. 44, feather body portion 5 is asymmetrical with respect to fixed shaft portion 10. By controlling the shape of feather body portion 5 in this manner and applying such feather body portion 5 to shuttlecock 1, the degree of freedom for controlling flight performance of shuttlecock 1 can be increased. In the structure having feather body portion 5 of asymmetric shape as shown in Fig. 44, flap portions 31 and 33 may not be formed. Alternatively, in the structure having feather body portion 5 of asymmetric shape, flap portions 31, 33 and edge portion 32 of any shape as shown in Figs. 37 to 43 may be formed.

[0087] Although edge portion 32 is formed in addition to flap portion 31 and/or flap portion 33 in the modified examples of artificial feather 3 described above, only flap portion 31 and/or flap portion 33 may be formed without forming edge portion 32. In this case, netting cord body 13 is arranged to overlap an end portion of flap portion 31 and/or flap portion 33.

[0088] In shuttlecock 1 with artificial feather 3 having flap portions 31 and 33, flap portions 31 and 33 are arranged in a region other than a portion where netting cord bodies 13 of two stages are fixed to feather shaft portion 8 (e.g., a region between netting cord bodies 13 of two stages, or a region other than the region between netting cord bodies 13 of two stages). Consequently, occurrence of deformation of flap portion 31 caused by formation of flap portion 31 to overlap a portion where netting cord body 13 is fixed to feather shaft portion 8 can be suppressed.

[0089] In shuttlecock 1 described above, flap portions 31 and 33 may be hardened by impregnating flap portions 31 and 33 with resin such as an adhesive, or by coating flap portions 31 and 33 with resin or a film. Consequently, the shapes of flap portions 31 and 33 can be maintained over a prolonged period during use of shuttlecock 1. Edge portion 32 may also be hardened in a similar manner.

[0090] Although artificial feather 3 includes one or two of flap portions 31 and 33 in shuttlecock 1 described above, three or more flap portions 31 and 33 may be formed depending on required flight performance. By forming the plurality of flap portions 31 and 33 in this manner, the degree of freedom for adjusting flight performance of shuttlecock 1 can be further increased.

[0091] Further, in shuttlecock 1 described above, flap portions 31 and 33 may be formed in positions different from each other in the direction along the central shaft of feather shaft portion 8. In addition, one or a plurality of flap portions 31 may be formed only on one side of feather shaft portion 8, or one or a plurality of flap portions 31 and one or a plurality of flap portions 33 may be formed on both sides of feather shaft portion 8. Further, flap portions 31 and 33 may have sizes and shapes different from each other in shuttlecock 1 described above.

[0092] Furthermore, like artificial feathers 3 shown in Figs. 36 to 44, it is preferable to provide concave portion 42 similar to that of artificial feather 3 in Fig, 28 described above, for example. Consequently, the contact area and adhesion strength between netting cord bodies 13 and sheet-like member 9 can be increased as with artificial feather 3 in Fig. 28. Concave portion 42 of artificial feather 3 in Fig. 36 preferably has a height (horizontal direction in the drawing) and a width (vertical direction in the drawing) similar to those of artificial feather 3 in Fig. 28, and these sizes may be changed depending on width L2 of edge portion 32. The structure shown in Figs. 36 to 44 including concave portion 42 similar to that of artificial feather 3 in Fig. 28 is merely illustrative. That is, other than concave portion 42 similar to that of artificial feather 3 in Fig. 28, concave portion 42 or convex portion 41 shown in Figs. 25 to 31 can be combined in any way to increase the contact area and adhesion strength.

[0093] As described above, in shuttlecock 1 with artificial feather 3 having flap portions 31 and 33, flap portions 31 and 33 are arranged in a region other than a portion where netting cord bodies 13 of two stages are fixed to feather shaft portion 8 (e.g., a region between netting cord bodies 13 of two stages, or a region other than the region between netting cord bodies 13 of two stages). Consequently, occurrence of deformation of flap portion 31 caused by formation of flap portion 31 to overlap a portion where netting cord body 13 is fixed to feather shaft portion 8 can be suppressed. Accordingly, when artificial feather 3 including flap portions 31 and 33 includes convex portions 41 or concave portions 42, it is preferable to provide convex portions 41 or concave portions 42 such that flap portions 31 and 33 are arranged in a region between convex portions 41 or concave portions 42 of two stages, as shown in Figs. 36 to 44. If netting cord bodies 13 are arranged in three or more stages or netting cord body 13 is arranged only in one stage, arrangement and the number of convex portions 41 or concave portions 42 are preferably determined depending on the number of stages of netting cord bodies 13. Further, although only convex portions 41 or concave portions 42 are formed in one artificial feather 3 described above, both of convex portions 41 and concave portions 42 may be formed in one artificial feather 3. Here, convex portions 41 and concave portions 42 may be formed in the same position in the direction along the central shaft of shaft 7, or convex portions 41 may be formed on one side and concave portions 42 may be formed on the other side when viewed from shaft 7. Alternatively, both of convex portions 41 and concave portions 42 may be formed on the same side when viewed from shaft 7.

[0094] Referring to Fig. 45, in the assembly step (S200) of shuttlecock 1, a step of fixing the artificial feathers to the base body (S25) is performed first. Specifically, this step is similar to the step (S21) shown in Fig. 16, where the plurality of artificial feathers 3 stated above are connected to the flat surface portion of the base body. Next, a step of connecting the artificial feathers to one another by a fixing member (S26) is performed. This step (S26) is basically similar to the step (S22) shown in Fig. 16. The end portions of projection portion 12 of artificial feather 3, which can be made of nonwoven fabric made of chemical fiber such as polyester fiber and acrylic fiber as described above, are flexible members and act as porous or fibrous reinforcing members in this case.

[0095] When an adhesive material is applied to projection portion 12 which is a flexible member as in the step (S22) described above, at least a part of the applied adhesive material enters and impregnates projection portion 12. This is because the adhesive material can readily enter a gap in tissue (space between holes or fibers) of porous or fibrous projection portion 12.

[0096] Next, an impregnation and bonding step (S27) is performed. Specifically, in a manner similar to the step (S23) shown in Fig. 16, an adhesive material is applied to a contact portion between the end portion of projection portion 12 which is a reinforcing member and netting cord body 13 which is a fixing member, for example. Consequently, the adhesive material enters a surface of the end portion of projection portion 12 and impregnates projection portion 12. That is, the adhesive material exists between netting cord body 13 and the end portion of projection portion 12 and also inside projection portion 12, in the contact portion. The contact portion is then heated. Consequently, the adhesive material is hardened while existing both on the surface of projection portion 12 and inside projection portion 12 and being in contact with netting cord body 13. With the adhesive material existing both on the surface of projection portion 12 and inside projection portion 12, netting cord body 13 and the end portion of projection portion 12 can be firmly bonded to each other. Further, since the cord member which is a fixing member (netting cord body 13) is made of a fibrous material such as aramid fiber, at least a part of the applied adhesive material can enter and impregnate netting cord body 13 as well. Furthermore, by impregnating netting cord body 13 which is a fixing member with epoxy resin which is thermosetting resin as described above, for example, this resin can also be utilized as an adhesive material. This synergetic effect allows very firm bonding between projection portion 12 and netting cord body 13.

[0097] As described above, the adhesion strength can be improved by the adhesive material that has entered and impregnated projection portion 12 and netting cord body 13. As further described above, when netting cord body 13 presses projection portion 12 which is a reinforcing member, the reinforcing member is deformed to increase the contact area between projection portion 12 and netting cord body 13. Thus, the adhesion strength between projection portion 12 and netting cord body 13 is further increased, which leads to further improved durability of shuttlecock 1.

[0098] Both of the flowchart in Fig. 45 and the flowchart in Fig. 16 illustrate the same assembly process of shuttlecock 1, with different viewpoints. Specifically, in Fig. 16, netting cord body 13 presses and deforms the end portion of projection portion 12 which is a flexible member, to complicate the shape of projection portion 12 in the contact portion between netting cord body 13 and projection portion 12, thereby increasing the adhesion strength between netting cord body 13 and projection portion 12. In Fig. 45, on the other hand, the adhesive material supplied to the surface of projection portion 12 and/or the impregnating thermosetting resin to make netting cord body 13 of FRP are/is arranged on the surfaces thereof by heating, and enter(s) and impregnate(s) them, thereby bonding netting cord body 13 and projection portion 12 to each other.

(Second Embodiment)

[0099] Referring to Fig. 46, shuttlecock 1 according to a second embodiment of the present invention is basically similar in structure to shuttlecock 1 shown in Fig. 1. Yet shuttlecock 1 shown in Fig. 46 further includes an encircling cord body 14 as a reinforcement fixing member, which is connected to netting cord body 13 as a fixing member and arranged to encircle outer surfaces of the plurality of annularly arranged artificial feathers 3. Shuttlecock 1 shown in Fig. 46 is different from shuttlecock 1 shown in Fig. 1 in this respect.

[0100] Encircling cord body 14 is arranged to be in contact with one of netting cord bodies 13 provided in two stages in the direction in which shaft 7 extends in Fig. 46, which is on the tip portion side of shaft 7 of artificial feather 3 (on the feather body portion 5 side). Thus, the fixing members are provided in two stages as a whole as with shuttlecock 1 in Fig. 1.

[0101] Separation of a fixed portion of netting cord body 13 due to continuous smashing with rackets as stated above tends to occur particularly in one of netting cord bodies 13 provided in two stages, which is at the tip portion side of shaft 7 of artificial feather 3. For this reason, it is preferable to arrange encircling cord body 14 as a reinforcement fixing member to be in contact with netting cord body 13 at the tip portion side of shaft 7 of artificial feather 3, as shown in Fig. 46. With this arrangement, netting cord body 13 at the tip portion side of shaft 7 of artificial feather 3 is reinforced by encircling cord body 14 in contact therewith, thereby suppressing occurrence of separation of a fixed portion of netting cord body 13.

[0102] For encircling cord body 14, it is preferable to form a twisted thread from four aramid fibers of 400D model, for example, and use one or a plurality of the twisted threads, when forming one cord member forming netting cord body 13. Encircling cord body 14 may be arranged to be in contact with and overlap netting cord body 13 at the tip portion side of shaft 7 of artificial feather 3, as described above. Alternatively, encircling cord body 14 may be arranged to be in contact with the periphery of overlap netting cord body 13 at the tip portion side of shaft 7 of artificial feather 3. That is, the aramid fibers forming encircling cord body 14 encircle along the periphery of overlap netting cord body 13 to overlap the periphery. Accordingly, encircling cord body 14 forms a ring shape by encircling the annular periphery formed by shafts 7 of the plurality of artificial feathers 3 as with netting cord body 13, thereby reinforcing netting cord body 13 and shaft 7. As a result, shaft 7 of artificial feather 3 is more resistant to breakage, and breakage of a fixed portion of netting cord body 13 and the like can be suppressed.

[0103] Encircling cord body 14 is made of FRP with aramid fiber and resin as with netting cord body 13. The resin may be thermosetting resin. Consequently, as with netting cord body 13 stated above, the thermosetting resin that has entered and impregnated encircling cord body 14 also impregnates the end portion of projection portion 12 of artificial feather 3 (see Fig. 2), thereby improving adhesion strength between projection portion 12 and encircling cord body 14. Further, netting cord body 13 made of FRP by being impregnated with the thermosetting resin as described above and encircling cord body 14 impregnated with the thermosetting resin are fixed to each other while being in contact with each other. Accordingly, the thermosetting resin that has impregnated encircling cord body 14 acts as an adhesive material with the thermosetting resin that has impregnated netting cord body 13. Therefore, adhesion strength between netting cord body 13 and encircling cord body 14 can be further increased.

[0104] Moreover, when encircling cord body 14 is arranged on shuttlecock 1, netting cord body 13 is already made of FRP and has high rigidity. It is therefore possible to wind the fibers forming encircling cord body 14 to encircle the outer portions of artificial feathers 3 while applying high tension to encircling cord body 14. When winding encircling cord body 14, it is preferable to fix a starting point and an ending point of encircling cord body 14 by hooking the points on a knot of the binding thread of netting cord body 13. This allows easy winding of encircling cord body 14.

[0105] The aramid fibers of 400D model, for example, used for encircling cord body 14 are wound around the annular periphery formed by shafts 7 of the plurality of artificial feathers 3 three times to five times, and more preferably four times. Consequently, sufficient strength as a reinforcing member for netting cord body 13 can be maintained.

[0106] Referring to Fig. 47, another modified example of shuttlecock 1 is basically similar in structure to shuttlecock 1 shown in Fig. 46, but has a third netting cord body 13 encircling along the upper netting cord body 13 instead of encircling cord body 14. Shuttlecock 1 having this structure can achieve a similar effect to that of shuttlecock 1 shown in Fig. 46.

[0107] The second embodiment of the present invention described above is only different from the first embodiment of the present invention in the respects stated above. That is, the second embodiment of the present invention is similar to the first embodiment of the present invention in all respects such as structure, condition, procedure and effect not described above.

(Third Embodiment)

[0108] Referring to Fig. 48, shuttlecock 1 according to a third embodiment of the present invention is basically similar in structure to shuttlecock 1 shown in Fig. 1. However, netting cord bodies 13 are provided in three stages in the direction in which shafts 7 of the plurality of artificial feathers 3 extend. Shuttlecock 1 shown in Fig. 48 is different from shuttlecock 1 shown in Fig. 1 in this respect.

[0109] As compared to shuttlecock 1 shown in Fig. 1 in which netting cord bodies 13 are provided in two stages in the direction in which shafts 7 of the plurality of artificial feathers 3 extend, shuttlecock 1 shown in Fig. 48 in which netting cord bodies 13 are provided in three stages can have further improved strength and rigidity. Consequently, shuttlecock 1 can have further improved durability and life.

[0110] Convex portions 41 or concave portions 42 provided in projection portion 12 of artificial feather 3 shown in Figs. 25 to 31 described above are all formed to correspond to a case where the cord bodies such as netting cord bodies 13 are provided in two stages in the direction in which shaft 7 of artificial feather 3 extends. In artificial feather 3 of shuttlecock 1 in which the cord members are provided in three stages as shown in Fig. 48, however, it is preferable to form convex portions 41 or concave portions 42 in three stages to correspond to the arrangement of the cord members of three stages. More specifically, if the artificial feathers having the structures shown in Figs. 25, 27, 28, 29, and 30 are used with cord members provided in three stages, it is preferable to provide convex portions 41 or concave portions 42 in three stages, and if the artificial feathers having the structures shown in Figs. 26 and 31 are used, it is preferable to provide convex portions 41 or concave portions 42 in six stages. In this case, it is preferable that the sizes such as height and width of convex portion 41 and concave portion 42 be the same as those in the first embodiment of the present invention. Further, it is preferable that a width of each region among convex portions 41 of three stages in the direction in which shaft 7 extends have a value in consideration of the space among netting cord bodies 13.

[0111] The third embodiment of the present invention is only different from the first embodiment of the present invention in the respects stated above. That is, the third embodiment of the present invention is similar to the first embodiment of the present invention in all respects such as structure, condition, procedure and effect not described above.

(Fourth Embodiment)

[0112] Referring to Fig. 49, shuttlecock 1 according to a fourth embodiment of the present invention is basically similar in structure to shuttlecock 1 shown in Fig. 1, but further includes a cover member covering an outer surface of a binding thread structure of netting cord body 13. Netting cord body 13 indicating a binding thread portion of the shuttlecock shown in Fig. 49 is different from netting cord body 13 indicating a binding thread portion in the first embodiment of the present invention in this respect.

[0113] As described above, it is preferable that netting cord body 13 be made of FRP to be lightweight and have high rigidity. However, even if the binding thread structure shown in Fig. 19 described above, for example, is formed as netting cord body 13 which is a fixing member made of FRP, a connection portion between netting cord bodies 13 and a connection portion between netting cord body 13 and feather shaft portion 8 may break (portions of netting cord bodies 13 that have been fixed to each other may become separated, or the connection portion between netting cord body 13 and feather shaft portion 8 may become separated) due to continuous smashing with rackets. Upon occurrence of such breakage, coupling of a ring-shaped portion firmly coupled (fixed) as the binding thread of netting cord body 13 shown in Fig. 19 and coupling between netting cord body 13 and feather shaft portion 8 are loosened. This results in difficulty in maintaining the shape of artificial feather 3 in shuttlecock 1, causing significant deformation of the arrangement and shape of artificial feather 3 (i. e., the shape of shuttlecock 1) during the course of smashing of shuttlecock 1.

[0114] For this reason, in the shuttlecock shown in Fig. 49, a cover member 35 is formed to cover the outer surface of netting cord body 13 (cover the outer surface of the binding thread structure). As shown Fig. 49, the binding thread structure of one netting cord body 13 forming the fixing member of the shuttlecock according to the fourth embodiment of the present invention is similar to the binding thread structure of netting cord body 13 shown in Fig. 19 according to the first embodiment of the present invention.

[0115] Specifically, as shown in Fig. 49, cover member 35 is arranged to fill a gap between netting cord body 13 and shaft 7 (feather shaft portion 8) of each of the plurality of artificial feathers 3 (e.g., near a region H in Fig. 49), a gap between netting cord bodies 13 crossing each other when fixing shaft 7 (feather shaft portion 8) (e.g., near a region I in Fig. 49), and the entire peripheral surface of netting cord body 13 (e.g., near a region J in Fig. 49), and to coat netting cord body 13.

[0116] It is preferable to use a material capable of forming a coating, such as nitrocellulose, for cover member 35. This allows efficient coating.

[0117] By coating the entire region near region H, near region I, and near region J stated above with cover member 35 as stated above, cover member 35 can suppress deformation of the gap near region H and the gap near region I, and deformation of netting cord body 13 near region J as well. Artificial feather 3 can thus be reinforced more reliably by netting cord body 13. Therefore, shuttlecock 1 can have improved durability during continuous smashing of shuttlecock 1 with rackets.

[0118] Furthermore, since a fixed state of netting cord body 13 is maintained by cover member 35, occurrence of faults such as separation of a fixed portion in netting cord body 13 shown in Fig. 22 or a fixed portion between netting cord body 13 and shaft 7 can also be suppressed, for example. Therefore, a phenomenon such as change (increase) in flight distance due to reduction in air resistance during flight of shuttlecock 1 resulting from change in shape of shuttlecock 1 can be suppressed as well.

[0119] The fourth embodiment of the present invention is only different from the first embodiment of the present invention in the respects stated above. That is, the fourth embodiment of the present invention is similar to the first embodiment of the present invention in all respects such as structure, condition, procedure and effect not described above.

(Fifth Embodiment)

[0120] Referring to Figs. 50 and 51, a fifth embodiment of the shuttlecock according to the present invention is basically similar in structure to shuttlecock 1 shown in Fig. 1, but has a different structure of artificial feather 3 from shuttlecock 1 shown in Fig. 1. Namely, artificial feather 3 shown in Figs. 50 and 51 includes feather body portion 5, and shaft 7 connected to feather body portion 5. Shaft 7 includes feather shaft portion 8 arranged to project from feather body portion 5, and fixed shaft portion 10 connected to feather body portion 5 at a substantially central portion of feather body portion 5. Feather shaft portion 8 and fixed shaft portion 10 are arranged to extend in a line, to form one continuous shaft 7. As shown in Fig. 51, a cross-sectional shape of shaft 7 in a direction substantially perpendicular to the direction in which shaft 7 extends is a cross shape. That is, as shown in Fig. 51, in the cross-sectional shape of shaft 7, thick rib portions 22a having a relatively large thickness (thickness in a horizontal direction in Fig. 51 (or a circumferential direction of a concentric circle around central shaft portion 21)) are formed to project from a central shaft portion 21 in a vertical direction in Fig. 51.

[0121] In addition, thin rib portions 22b having a relatively small thickness (thickness in the vertical direction in Fig. 51 (or a circumferential direction of a concentric circle around central shaft portion 21)) are formed to project from central shaft portion 21 in the horizontal direction in Fig. 51. Two thick rib portions 22a stated above are formed to extend in opposite directions from central shaft portion 21. Two thin rib portions 22b stated above are also formed to extend in opposite directions from central shaft portion 21. Thin rib portion 22b is formed to extend in a direction intersecting (more specifically, orthogonal to) a direction in which thick rib portion 22a extends. Thick rib portions 22a and thin rib portions 22b form a rib portion 22. The plurality of portions of rib portion 22 and central shaft portion 21 form a body portion 23 of shaft 7. A cross-sectional shape of body portion 23 is a so-called cross shape.

[0122] Further, as shown in Fig. 51, a thin portion 24 is formed on an outer end portion of thin rib portion 22b (i.e., to project from a side wall of body portion 23). Thin portion 24 as a flexible member has an even smaller thickness than the above thickness of thin rib portion 22b. Thin portion 24 is formed integrally with thin rib portion 22b. Thin portion 24 is formed such that a surface of thin portion 24 forms substantially the same plane with a side surface of thin rib portion 22b (upper side surface in Fig. 51). The thickness of thin portion 24 may be not less than 0.03 mm and not more than 0.1 mm, and more preferably not less than 0.04 mm and not more than 0.07 mm, for example. A width of thin portion 24 (before deformation) may be not less than 0.1 mm and not more than 0.5 mm, and more preferably not less than 0.2 mm and not more than 0.3 mm, for example.

[0123] To summarize the structure of the shuttlecock with artificial feather 3 described above according to the present invention, the shuttlecock includes hemispherical base body 2, the plurality of artificial feathers 3, and netting cord body 13 as a fixing member. Each of artificial feathers 3 includes feather body portion 5 and shaft 7 connected to feather body portion 5, and artificial feathers 3 are fixed to base body 2 to be annularly arranged and to overlap one another. Netting cord body 13 fixes shafts 7 of the plurality of artificial feathers 3 to one another. Thin portion 24 as a flexible member is formed integrally with shaft 7, on at least a part of a surface of shaft 7 facing netting cord body 13. With netting cord body 13 pressing thin portion 24 as a flexible member, netting cord body 13 and deformed thin portion 24 are connected and fixed to each other through an adhesive material.

[0124] From a different viewpoint, shuttlecock artificial feather 3 according to the present invention includes feather body portion 5, and shaft 7 connected to feather body portion 5. The cross-sectional shape of shaft 7 in a plane perpendicular to the direction in which shaft 7 extends (see Fig. 51, for example) may be a cross shape (see Fig. 51) or a T-shape (see Fig. 54 to be described later). In shaft 7, thin portion 24 as a flexible member having a thickness smaller than that of body portion 23 forming the cross shape or T-shape in cross section is formed integrally with body portion 23 to project from the side surface of body portion 23.

[0125] With thin portion 24 as a flexible member formed integrally with shaft 7 on the side surface of shaft 7, when netting cord body 13 as a fixing member fixes shaft 7 as will be described later, thin portion 24 can be deformed to improve adhesion strength between netting cord body 13, and thin portion 24 and shaft 7.

[0126] In the artificial feather shown in Figs. 50 and 51, the cross-sectional shape of body portion 23 of shaft 7 is substantially a cross shape, thereby improving rigidity of shaft 7 while suppressing increase in total mass of shaft 7. Further, by forming thin portion 24 to project from the side surface of body portion 23 of shaft 7, air resistance of artificial feather 3 for controlling flight performance of shuttlecock 1 can be adjusted as appropriate. Since thin portion 24 is thinner than body portion 23, increase in mass of shaft 7 can be suppressed. Consequently, rigidity of shaft 7 of artificial feather 3 is improved and air resistance of artificial feather 3 is adjusted while increase in mass of artificial feather 3 is suppressed, thereby realizing artificial feather 3 forming shuttlecock 1 having excellent flight performance.

[0127] A width of shaft 7 in the direction in which thin rib portions 22b extend (horizontal direction in Fig. 51) is the sum of a width of thin portion 24 and a width W3 of body portion 23. This width of shaft 7 is larger than a width (height) T of shaft 7 in the direction in which thick rib portions 22a extend (vertical direction in Fig. 51).

[0128] The width of one (left) thin portion 24 and the width of the other (right) thin portion 24 in Fig. 51 may have the same value, or different values. Thin portion 24 may be formed over the entire length of shaft 7, and is preferably formed at least in feather shaft portion 8 which is exposed to the outside. Thin portion 24 may be formed only on one side, or may be formed not over the entire length of shaft 7 but partially (e.g., intermittently) in the direction in which shaft 7 extends.

[0129] Feather body portion 5 includes a foam layer and a shaft fixing layer arranged to sandwich fixed shaft portion 10, and a bonding layer arranged with fixed shaft portion 10 between the foam layer and the shaft fixing layer for fixing the foam layer to the shaft fixing layer. That is, in feather body portion 5, the foam layer and the shaft fixing layer are stacked to sandwich fixed shaft portion 10. In feather body portion 5, the bonding layer is further arranged for connecting the foam layer to the shaft fixing layer and for connecting and fixing fixed shaft portion 10 to the foam layer and the shaft fixing layer. From a different viewpoint, in feather body portion 5, the bonding layer is stacked on the foam layer positioned on an outer peripheral side when shuttlecock 1 is formed.

[0130] On this bonding layer, fixed shaft portion 10 is arranged in a substantially central portion of this bonding layer and the foam layer. Here, fixed shaft portion 10 is arranged such that a direction in which thick rib portion 22a projects from central shaft portion 21 is substantially perpendicular to a surface of the bonding layer (such that a direction in which thin rib portion 22b projects from central shaft portion 21 is along the surface of the bonding layer). Another bonding layer is arranged to extend from fixed shaft portion 10 to the bonding layer. The shaft fixing layer is further arranged on this bonding layer.

[0131] In artificial feather 3, shaft 7 is warped toward the foam layer (i.e., outer side of shuttlecock 1). From a different viewpoint, shaft 7 is warped to be convex toward the shaft fixing layer. In addition to artificial feather 3 being warped toward the foam layer in the direction in which shaft 7 extends as described above, feather body portion 5 may be warped toward the foam layer (i.e., feather body portion 5 may be warped to be convex toward the shaft fixing layer) in a direction intersecting the direction in which shaft 7 extends (e.g., a width direction perpendicular to the direction in which shaft 7 extends and along the surface of feather body portion 5). In this case, warping of artificial feather 3 in the direction in which shaft 7 extends and warping of feather body portion 5 in the direction intersecting the direction in which shaft 7 extends as described above may occur together, or only one of the warpings may occur. Such warping can be realized with a conventionally well-known method, such as subjecting the materials for shaft 7 and feather body portion 5 to heat treatment, or originally forming the materials for shaft 7 and feather body portion 5 in a warped state.

[0132] The foam layer forming feather body portion 5 can be made of resin foam, for example, and more specifically polyethylene foam, for example. The shaft fixing layer can be made of resin foam as well. The shaft fixing layer can be made of a film made of resin and the like, or any material such as nonwoven fabric, for example, other than polyethylene foam.

[0133] The bonding layer may be double-faced tape, for example. In artificial feather 3 shown in Figs. 50 and 51, the foam layer and the shaft fixing layer are preferably made of polyethylene foam. It is preferable that an extrusion direction of this polyethylene foam be a direction indicated with an arrow 95 in Fig. 50. In this case, shaft 7 is connected and fixed to feather body portion 5 in a direction intersecting the extrusion direction of the polyethylene foam indicated with arrow 95, thus reducing a possibility of occurrence of faults such as splitting of feather body portion 5 in the direction in which shaft 7 extends.

[0134] A method of fixing artificial feather 3 shown in Figs. 50 and 51 by a fixing member (netting cord body 13) is basically similar to the method of fixing artificial feathers 3 shown in Figs. 17 to 19 by the fixing member. That is, netting cord body 13 including one cord body is used as a fixing member to bind shaft 7 in a net-forming manner such that thin portion 24 which is a flexible member formed integrally with shaft 7 (feather shaft portion 8) is deformed, to connect adjacent shafts 7 to each other. Netting cord body 13 thus presses an end portion of thin portion 24 (end portion extending from the side of shaft 7), so that thin portion 24 is applied with pressure to move toward shaft 7 (feather shaft portion 8) and deformed, as shown in Fig. 51. That is, with thin portion 24 formed on the side of shaft 7, a contact area between shaft 7 having thin portion 24 formed on the side thereof and netting cord body 13 is larger than in a case where an artificial feather including shaft 7 not having thin portion 24 formed on the side thereof is used. Moreover, since thin portion 24 is deformed by being pressed by netting cord body 13, a shape of a contact portion between shaft 7 having thin portion 24 formed on the side thereof and netting cord body 13 (specifically, a shape of deformed thin portion 24) becomes complicated as will be described later. An adhesive adheres to a surface of thin portion 24 of such complicated shape to connect and fix netting cord body 13 to thin portion 24, thereby improving adhesion strength between netting cord body 13, and thin portion 24 and shaft 7. Namely, adhesion strength between netting cord body 13, and shaft 7 of the artificial feather and thin portion 24 is higher than in a case where an artificial feather including shaft 7 having thin portion 24 formed on the side thereof is used. Therefore, the synthetic shuttlecock including shaft 7 having thin portion 24 formed on the side thereof can have substantially improved durability against continuous smashing with rackets.

[0135] In the schematic cross-sectional view of Fig. 51, arrangement of netting cord bodies 13 with respect to shaft 7 is illustrated in a simplified manner as with Fig. 21. The actual arrangement of netting cord bodies 13 which fix shaft 7 of artificial feather 3 as a binding thread is shown in Figs. 18 and 19 described above.

[0136] Although the cross-sectional shape of shaft 7 is a cross shape in artificial feather 3 shown in Figs. 50 and 51, another cross-sectional shape may be employed. That is, the cross-sectional shape of shaft 7 may be another shape as long as thin portion 24 formed integrally with shaft 7 is provided. For example, shaft 7 may have a cross-sectional shape as shown in Figs. 4 to 6. Further, thin portion 24 may be formed only on one side of shaft 7. Alternatively, a plurality of thin portions 24 may be formed on the sides of shaft 7. For example, three or more thin portions 24 may be formed instead of two thin portions 24 as shown in Fig. 51.

[0137] Referring now to Figs. 52 and 53, a method of manufacturing artificial feather 3 shown in Figs. 50 and 51 and a shuttlecock with artificial feather 3 is described.

[0138] First, referring to Fig. 52, a method of manufacturing shuttlecock artificial feather 3 shown in Figs. 50 and 51 is described. As shown in Fig. 52, in the method of manufacturing artificial feather 3, a constituent member preparation step (S110) is performed first. In this step (S110), shaft 7 forming artificial feather 3, the sheet-like member forming the foam layer and the shaft fixing layer which will be feather body portion 5, and the double-faced tape which will be the bonding layer forming feather body portion 5 are prepared. The sheet-like member and the double-faced tape may have any plane shapes as long as they are larger than the size of feather body portion 5 shown in Fig. 50. As a material for the sheet-like member which will be the foam layer, polyethylene foam (polyethylene foam which has been formed like a sheet) having a thickness of 1.0 mm and a basis weight of 24 g/m² may be used, for example. As a material for the sheet-like member which will be the shaft fixing layer, polyethylene foam having a thickness of 0.5 mm and a basis weight of 20 g/m² may be used. The double-faced tape which will be the bonding layers may have a basis weight of 10 g/m².

[0139] In a process of manufacturing shaft 7 described above, a mold preparation step (S111) is prepared first, as shown in Fig. 53. In this step (S111), a mold for forming shaft 7 by injection molding or injection compression molding is prepared. The mold prepared in this step is divided into an upper mold and a lower mold, which include a recess corresponding to the shape of shaft 7 in surfaces of the mold facing each other. This recess includes a portion for forming body portion 23 of shaft 7, and a gap for forming thin portion 24 at an outer portion of the portion for forming body portion 23.

[0140] Next, a molding step (S112) is performed. In this step (S112), the mold thus prepared is set in a device for injecting resin into the mold (the recess) such as an injection molding machine (mold setting step). Next, a resin injection step is performed. That is, resin is injected into the recess in the mold through a resin inlet provided in the mold. The resin may be thermosetting resin, for example. As a result, a shaft is formed inside the mold. Since the gap for forming thin portion 24 is formed in the recess of the mold, as described above, obtained shaft 7 has thin portion 14 projecting from a side of shaft 7. The molding step (S 112) is performed in this manner. Then, shaft 7 is taken out of the mold. Consequently, shaft 7 forming artificial feather 3 can be obtained.

[0141] Next, an affixation step (S120) is performed as shown in Fig. 52. In this step (S120), the double-faced tape which will be the bonding layer is affixed to a main surface of the sheet-like member which will be the foam layer. Then, fixed shaft portion 10 of shaft 7 is arranged on the double-faced tape. Further, on fixed shaft portion 10, the sheet-like member which will be the shaft fixing layer, which has double-faced tape which will be another bonding layer affixed on a surface facing fixed shaft portion 10, is stacked and affixed. Consequently, a structure can be obtained in which fixed shaft portion 10 of shaft 7 is sandwiched and fixed between the sheet-like member which will be the foam layer and the sheet-like member which will be the shaft fixing layer.

[0142] Next, an aftertreatment step (S130) is performed. Specifically, an unnecessary portion of the stacked and arranged sheet-like members which will be feather body portion 5 (i.e., a region other than a portion which will be feather body portion 5) is cut and removed. As a result, artificial feather 3 as shown in Figs. 50 and 51 can be obtained. Then, heat treatment such as application of heat from the foam layer side is performed on artificial feather 3, to constrict the foam layer and the like. As a result, shaft 7 and feather body portion 5 can be warped toward one surface (toward the foam layer) of feather body portion 5. Another method can be used to warp shaft 7 and feather body portion 5 in this manner. For example, shaft 7 having an originally warped shape may be used.

[0143] Next, a method of manufacturing a shuttlecock with artificial feather 3 shown in Figs. 50 and 51 is described. This method of manufacturing a shuttlecock is basically similar to the method of manufacturing a shuttlecock shown in Fig. 11. That is, as shown in Fig. 11, the preparation step (S100) is performed first. In this preparation step (S100), constituent members of shuttlecock 1 such as base body 2 (tip member) of shuttlecock 1 and artificial feather 3 described above are prepared.

[0144] Base body 2 can be manufactured with a conventionally known method. For example, base body 2 can be made of a natural material such as cork. Alternatively, base body 2 can be made of synthetic resin or the like. When base body 2 is made of synthetic resin, base body 2 can be formed with a conventionally well-known processing method. For example, a block of a material for base body 2 is prepared, which is subjected to a cutting process to have a rough shape. This processing is performed in consideration of a height of the hemispherical portion at the tip portion. Then, a cutting process may be further performed to form holes in which artificial feathers 3 will be inserted. The synthetic resin stated above may be ionomer resin foam, EVA (ethylene-vinyl acetate copolymer), polyurethane, PVC (polyvinyl chloride), polyethylene, polypropylene, or the like. In addition, artificial feather 3 can be manufactured with the manufacturing method shown in Figs. 52 and 53.

[0145] Next, the assembly step (S200) is performed as shown in Fig. 11. During the assembly step (S200), in the step of fixing the artificial feathers to the base body (step S21), the bottoms of shafts 7 of the plurality of artificial feathers 3 described above are inserted and fixed in the insertion holes in the fixing surface portion of the base body. Then, in the step of connecting the artificial feathers to one another with a fixing member (S22), the plurality of artificial feathers 3 are fixed to each other by a cord member. Feather body portions 5 are arranged to partially overlap one another among adjacent artificial feathers 3. In order to maintain the overlapping state of feather body portions 5, a thread may arranged by stitching to encircle fixed shaft portion 10 connected to feather body portion 5 of one artificial feather 3, pass through an overlapping portion between two feather body portions 5 to reach fixed shaft portion 10 of another adjacent artificial feather 3, and encircle this fixed shaft portion 10. As a result, shuttlecock 1 having the structure shown in Fig. 1 can be manufactured with artificial feather 3 shown in Figs. 50 and 51.

[0146] The fixing member stated above can be made of any material such as resin and fiber, as already described. For example, it is preferable to use a fixing member made of FRP in which aramid fiber or glass fiber is used for a cord member, the aramid fiber or the glass fiber is impregnated with resin (e.g., thermosetting resin), and the resin is cured. Such fixing member made of FRP can have improved strength and rigidity. The thermosetting resin may be epoxy resin or phenolic resin. By using thermosetting resin for FRP in this manner, the fixing member can be readily made of FRP with the thermosetting resin during a heating step and the like in a process for fixing the fixing member to shaft 7.

[0147] Referring to Fig. 54, a modified example of the artificial feather shown in Figs. 50 and 51 according to the present invention is described. Fig. 54 corresponds to Fig. 51.

[0148] An artificial feather including a shaft shown in Fig. 54 is basically similar in structure to artificial feather 3 shown in Figs. 50 and 51, but has a different cross-sectional shape of body portion 23 of shaft 7. Specifically, body portion 23 of shaft 7 shown in Fig. 54 includes two thin rib portions 22b extending in a horizontal direction from central shaft portion 21, and thick rib portion 22a extending only in one direction from a lower side of central shaft portion 21. Thin portion 24 as a flexible member is formed integrally with body portion 23 on an outer end portion of thin rib portion 22b. Thin portion 24 is bent by being pressed by netting cord body 13. This artificial feather having the shaft in which body portion 23 has a so-called T-shaped cross-section can achieve a similar effect to that of artificial feather 3 shown in Figs. 50 and 51. In the shuttlecocks in the embodiments described above, the structures used in the other embodiments can be combined and applied as appropriate. For example, encircling cord body 14 as a reinforcement fixing member of the shuttlecock in the second embodiment may be applied to the shuttlecocks in the third to fifth embodiments. Alternatively, cover member 35 in the fourth embodiment may be applied to the shuttlecocks in the embodiments other than the fourth embodiment.

[0149] It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

INDUSTRIAL APPLICABILITY

[0150] The present invention is advantageously applied to a badminton shuttlecock with artificial feathers having flight performance and durability equal to those of a badminton shuttlecock with waterfowl feathers.

DESCRIPTION OF THE REFERENCE SIGNS

[0151] 1 shuttlecock; 3 artificial feather; 5 feather body portion; 6 portion which will be feather body portion; 7 shaft; 8 feather shaft portion; 9 sheet-like member; 10 fixed shaft portion; 12 projection portion; 13 netting cord body; 14 encircling cord body; 21 central shaft portion; 22 rib portion; 22a thick rib portion; 22b thin rib portion; 23 body portion; 24 thin portion; 31, 33 flap portion; 32 edge portion; 34 adhesive; 35 cover member; 41 convex portion; 42 concave portion.

Claims

1. A badminton shuttlecock comprising:

a hemispherical base body;

a plurality of artificial feathers fixed to said base body to be annularly arranged and to overlap one another, each of said artificial feathers including a feather portion and a shaft connected to said feather portion; and

a fixing member for fixing said shafts of said plurality of artificial feathers to one another,

a flexible member being arranged on at least a part of a surface of said shaft facing said fixing member, and

said fixing member being connected and fixed to said flexible member through an adhesive material with said flexible member being deformed by being pressed by said fixing member.

2. A badminton shuttlecock comprising:

a hemispherical base body;

a plurality of artificial feathers fixed to said base body to be annularly arranged and to overlap one another, each of said artificial feathers including a feather portion and a shaft connected to said feather portion; and

a fixing member for fixing said shafts of said plurality of artificial feathers to one another,

a porous or fibrous reinforcing member being arranged on at least a part of a surface of said shaft facing said fixing member,

said fixing member being connected and fixed to said reinforcing member through an adhesive material, and

said reinforcing member being impregnated with at least a part of said adhesive material.

3. The badminton shuttlecock according to claim 2, wherein
said reinforcing member is fixed while being deformed by being pressed by said fixing member.

4. A badminton shuttlecock comprising:

a hemispherical base body;

a plurality of artificial feathers fixed to said base body to be annularly arranged and to overlap one another, each of said artificial feathers including a feather portion and a shaft connected to said feather portion; and

a fixing member for fixing said shafts of said plurality of artificial feathers to one another,

a flexible member being formed integrally with said shaft on at least a part of a surface of said shaft facing said fixing member, and

said fixing member being connected and fixed to said flexible member through an adhesive material with said flexible member being deformed by being pressed by said fixing member.

5. The badminton shuttlecock according to any one of claims 1 to 4, wherein said fixing member includes a cord body wound to tie said shafts of said plurality of artificial feathers to one another.

6. The badminton shuttlecock according to any one of claims 1 to 4, wherein said fixing member is made of FRP.

7. The badminton shuttlecock according to any one of claims 1 to 4, wherein said fixing member includes thermosetting resin.

8. The badminton shuttlecock according to any one of claims 1 to 4, wherein said fixing member includes a thread made of glass or aramid fiber.

9. The badminton shuttlecock according to any one of claims 1 to 4, further comprising a reinforcement fixing member connected to said fixing member and arranged to encircle outer surfaces of annularly arranged said plurality of artificial feathers.

10. The badminton shuttlecock according to any one of claims 1 to 4, further comprising a cover member covering an outer surface of said fixing member.

Drawing