JP2004105531A - Racket frame - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a racket frame which is especially suitable for regulation-ball tennis and has good flipping. <P>SOLUTION: A high stiffness board 20 is adhered to the front of the racket frame from the shaft section side of a grip part 4 to a midway in the longitudinal direction of a shaft section 3 and an elastic body 30 is laid between the end vicinity on the face section side of this high stiffness board 20 and the shaft section 3. Also, a soft material 40 for vibration absorption is laid between the side edge of the high stiffness board 20 and the shaft section 3 and the grip part 4. The high stiffness board 20 consists of a compound material formed by impregnation of a synthetic resin to a woven fabric of high resilience fibers of carbon, and the like. The raised section 32 of the elastic body 30 is fitted to an opening 23 of the high stiffness board 20. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a racket frame for tennis, badminton or the like, and more particularly to a racket frame suitable for hard tennis.
[0002]
[Prior art]
As is well known, a racket frame such as a tennis racket frame includes a face part on which a gut is stretched, a grip part gripped by a player, and a shaft part that connects these parts.
[0003]
Conventional racket frames are made of metal such as FRP, aluminum, and titanium. A racket is constructed by putting a gut (string) on the face portion of the racket frame.
[0004]
Japanese Patent Application Laid-Open No. 2000-61005 is characterized in that in a fiber reinforced synthetic resin racket frame having a reinforcing metal plate, the strip-like metal plate having a specific gravity of 5 or less is embedded in at least the shaft portion. A racket frame is described.
[0005]
The racket frame of the same publication has a light metal plate with a specific gravity of 5 or less embedded in at least the shaft portion, and the shaft portion has high strength and rigidity.
[0006]
[Patent Document 1]
JP 2000-61005 A
[Problems to be solved by the invention]
When a metal plate is embedded in the shaft portion as described in JP 2000-61005 A, the rigidity of the entire shaft portion is increased. Thus, the racket frame in which the rigidity of the entire shaft portion is increased tends to be insufficient in flexure when used by a general-level player whose swing speed is not so fast.
[0008]
An object of the present invention is to provide a racket frame which is effective in bending, has a good hitting speed and has a high hitting speed even when used by a general level player.
[0009]
[Means for Solving the Problems]
The racquet frame of the present invention is a racquet frame having a face portion, a grip portion, and a pair of shaft portions connecting the face portion, and the front surface of the racquet frame extending from at least the end on the shaft portion side to the middle portion of the shaft portion. A high-rigidity plate is fixed to the side, and an elastic body made of rubber or elastomer is interposed between the tip portion on the face portion side of the high-rigidity plate and the shaft portion.
[0010]
The front portion of the racket frame is the side facing the surface parallel to the face surface of the face portion of the outer surface of the racket frame. The racket frame has a fore side and a back side, and a high-rigidity plate and an elastic body are disposed on the front portions on both sides thereof.
[0011]
In such a racket frame, when the ball is hit, the face portion and the shaft portion bend (bend) so that the face portion and the shaft portion are warped. At this time, an elastic body (but on the side opposite to the striking surface) disposed between the shaft portion and the high-rigidity plate on the face portion side of the shaft portion is sandwiched between the shaft portion and the high-rigidity plate. Elastically compressed. When the face part and the shaft part are restored from the warp, the elastic body elastically tries to restore the original shape, assists the restoration of the face part, and restores the face part to the restoring speed (the bending return speed). ). For this reason, the hitting speed of the ball is increased, and a good hitting feeling can be obtained.
[0012]
In the present invention, the elastic body is preferably disposed on the face side with respect to the middle in the longitudinal direction of the shaft portion. In this case, the length of the elastic body in the longitudinal direction of the shaft portion is 20 to 20 times the total length of the shaft portion. It is preferably 40%.
[0013]
The high-rigidity plate is preferably made of a composite material obtained by impregnating a synthetic resin into a high-elastic fiber woven fabric or an alloy material having a low specific gravity.
[0014]
In order to manufacture the racket frame of the present invention, for example, an expandable tube is used as a core material, and an FRP prepreg is distributed around the tube, and the tube is expanded in a mold, shaped into a product shape and heated. Then, the prepreg may be cured.
[0015]
As the synthetic resin constituting the FRP, epoxy resin, nylon, vinyl ester and the like are preferable, but epoxy resin is preferable in terms of strength, durability and price. If a soft resin is used, a vibration absorbing effect can be obtained.
[0016]
Reinforcing fibers include carbon fiber, boron fiber, alumina fiber, ultrafine iron wire, Ti-Si-CO-based fiber (trade name Tyranno fiber), aromatic polyamide fiber, aromatic polyester fiber, ultrahigh molecular weight polyethylene fiber However, carbon fiber is preferable from the viewpoint of cost.
[0017]
The high-rigidity plate is preferably bonded with an adhesive from the shaft portion to the grip portion of the racket frame (racket frame main body), and at this time, an elastic body is interposed between the tip portion of the high-rigidity plate and the shaft portion.
[0018]
By setting the elastic body mounting portion of the shaft portion as a recess, the thickness of the elastic body can be increased.
[0019]
It is preferable to provide an opening at the tip of the high-rigidity plate, and provide a convex portion on the elastic body, and fit the convex portion to the opening. By doing so, the elastic body can be positioned. In addition, it is possible to prevent displacement and deformation of the attached elastic body.
[0020]
In the present invention, a vibration-absorbing soft material may be interposed between the side edge of the high-rigidity plate, the grip portion, and the shaft portion. Thereby, the vibration at the time of a ball hit is attenuated.
[0021]
In the present invention, a rib may be erected on the side edge of the high-rigidity plate, and the rib may be engaged with the corner edge of the grip portion and the shaft portion. Thus, by providing a rib in a highly rigid board, the rigidity (secondary moment of a section) of a highly rigid board can be raised. Further, by engaging the rib with the corner edge of the grip portion and the shaft portion, the edge portion of the high-rigidity plate is prevented from being turned up, and the durability of the racket frame is improved.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments will be described with reference to the drawings.
[0023]
1 is an exploded perspective view of a hard tennis racket frame according to an embodiment, FIG. 2 is an enlarged view of a part of FIG. 1, FIG. 3 is a perspective view of the vicinity of the shaft portion of the racket frame, FIG. 5 is a cross-sectional view taken along the line VV in FIG. 3, FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. 3, FIG. 7 is a front view of the high-rigidity plate, and FIGS. ), (C), and (d) are cross-sectional views along line A-A, line B-B, line C-C, and line DD in FIG.
[0024]
The racket frame 1 includes a face portion 2 on which a gut is stretched, a grip portion 4 held by a player, and a shaft portion 3 that connects the grip portion 4 and the face portion 2. The face portion 2 has a substantially oval or egg-shaped annular shape, and the grip portion 4 has a straight bar shape. A pair of shaft portions 3 are provided so as to open in a V shape from the face side end of the grip portion 4. The extending direction of the shaft portion 3 is a substantially tangential direction of the face portion 2.
[0025]
The face portion 2 is provided with a number of gut insertion holes 6 that communicate the outer peripheral side and the inner peripheral side. A groove 7 extends in the circumferential direction on the outer peripheral surface of the face portion 2, and the gut protection members 10 and 12 are attached so as to engage with the groove 7. Although not shown, a gut protection member may also be provided on the face bottom portion.
[0026]
The gut protection member 10 is disposed on the face top side, and the gut protection member 12 is disposed on both face side portions. Each of the gut protection members 10 and 12 has a structure in which the cylindrical portions 10a and 12a inserted through the gut insertion holes 6 are integrated via the band portions 10b and 12b.
[0027]
A high-rigidity plate 20 is fixed to the front surface of the racket frame from the shaft portion side of the grip portion 4 in the middle of the longitudinal direction of the shaft portion 3. 3 and the elastic body 30 is interposed between them. A vibration absorbing soft material 40 is interposed between the side edge of the high-rigidity plate 20 and the shaft portion 3 and the grip portion 4.
[0028]
The high-rigidity plate 20 has a substantially Y shape having a base portion 21 that overlaps with the grip portion 4 and arm portions 22 and 22 that are connected to the base portion 21 and overlap a pair of shaft portions 3 and 3. The high-rigidity plate 20 is made of a composite material formed by impregnating a woven fabric of high-elasticity fibers such as carbon with a synthetic resin such as epoxy, unsaturated polyester, or vinyl ester. The fibers of the woven fabric may be carbon fibers, aramid fibers, glass fibers, or the like, or two or more types of these fibers.
[0029]
The high-rigidity plate may be a low specific polymerization gold having a specific gravity of about 1.8 to 5.0, such as a titanium alloy, a magnesium alloy, or an aluminum alloy. As the low specific polymerization gold, an aluminum alloy or a magnesium alloy (specific gravity 1.8 to 2.8) having a small specific gravity is particularly preferable.
[0030]
As shown in FIGS. 8A to 8C, the high-rigidity plate 20 stands up from the portion disposed on the front side of the shaft portion 3 and the grip portion 4 and the edge of the portion. 3 and a rib portion 20 </ b> R that engages with the corner edge of the grip portion 4.
[0031]
Openings 23 are provided on the distal end sides of the respective arm portions 22 of the high-rigidity plate 20. The opening 23 is a long hole extending in the longitudinal direction of the shaft portion 3.
[0032]
In this embodiment, the distal end sides of the arm portions 22, 22 extend to the face portion 2 side rather than the middle in the longitudinal direction of the shaft portion 3. The elastic body 30 is interposed between the tip portions of the arm portions 22 and 22 and the shaft portion 3.
[0033]
A portion of the front portion of the shaft portion 3 to be mounted with the elastic body 30 is a recess 3a, and the elastic body 30 is fitted and disposed in the recess 3a.
[0034]
The entire back surface of the elastic body 30 is in contact with the shaft portion 3. Protruding portions 31 are provided along both side edges of the elastic body 30, and the elastic bodies 30 are fitted into the recesses 3a so that the outer surface of the protruding portion 31 is substantially flush with the outer surface of the shaft portion 3. Combined.
[0035]
The recess 3 a and the elastic body 30 engaged with the recess 3 a are disposed on the face portion 2 side with respect to the middle in the longitudinal direction of the shaft portion 3. The length in the longitudinal direction of the shaft portion 3 of the elastic body 30 and the recess 3a is preferably about 20 to 40%, particularly about 25 to 35% of the total length of the shaft portion 3. The total length of the shaft portion 3 is the intersection of the shaft portion 3 and the face portion 2 from the root of the pair of shaft portions 3 and 3 (the valley portion of the intersection of both) (the valley portion of the intersection of the two). ).
[0036]
The elastic body 30 is preferably a rubber or elastomer such as NR, SBR, silicon rubber, urethane elastomer, styrene elastomer, olefin elastomer, etc., and its hardness at normal temperature (Shore A hardness, hereinafter the same) is 30 to 30. In particular, about 40 to 60 is preferable.
[0037]
A convex portion 32 is provided at the center on the front side of the elastic body 30 (the center in the longitudinal direction of the shaft portion 3 and the center in the width direction). The convex portion 32 has a shape and size that fits into the opening 23 of the high-rigidity plate 20.
[0038]
A region from the periphery of the convex portion 32 to the ridge portion 31 is a shallow region 33 that is one step lower than the ridge portion 31. The highly rigid plate 20 is engaged with the shallow region 33. In addition, the protrusion part 31 does not need to be provided. That is, only the shallow region 33 other than the convex portion 32 may be used.
[0039]
A step portion is provided on a side edge from the shaft portion 3 to the grip portion 4, and the soft material 40 is distributed along the step portion. The soft material 40 is made of rubber or elastomer (for example, a composition containing butyl rubber) having a Shore A hardness of about 40 to 60, and is adhered or adhered to the shaft portion 3 and the grip portion 4.
[0040]
The tips of the rib portions 20 </ b> R of the high-rigidity plate 20 are in contact with the soft material 40.
[0041]
The high-rigidity plate 20 is bonded to the shaft portion 3 and the grip portion 4 with a high-strength adhesive such as epoxy or acrylic resin.
[0042]
The rear end side of the high-rigidity plate 20 extends to the middle of the grip part 4, but may extend to the rear end (grip end) of the grip part 4. The rear end of the high-rigidity plate 20 preferably extends from the intersection of the shaft portion 3 and the grip portion 4 to a location separated by 50% or more, particularly 80% or more of the entire length of the grip portion 4.
[0043]
In the racket frame 1 configured in this way, when the ball is hit, the face portion 2 bends and warps, and the elastic body 30 is pinched between the shaft portion 3 and the high-rigidity plate 20, Elastically compressed.
[0044]
When the face portion 2 and the shaft portion 3 are restored, the restoring force of the elastic body 30 acts on the shaft portion 3, assisting the restoration of the face portion 2, and the bending return speed of the face portion 2 increases. This increases the repulsive force applied to the ball and increases the hitting speed. As a result, the racket frame 1 has a so-called good playing performance. Further, by providing the high-rigidity plate 20, the torsional rigidity is increased from the shaft portion 3 to the grip portion 4, and ball controllability is improved.
[0045]
In particular, in this embodiment, since the high-rigidity plate is obtained by impregnating a woven fabric of high-elasticity fibers such as carbon fibers with a synthetic resin, it is lightweight and highly elastic. For this reason, the increase in the weight of the racket frame due to the provision of the high-rigidity plate is extremely small.
[0046]
In this embodiment, since the recess 3 a is provided in the shaft portion 3, the protruding portion of the high-rigidity plate 20 is small even if the thickness of the elastic body 30 is large. The thickness in the shallow region 33 of the elastic body 30 is preferably about 2 to 5 mm, particularly about 2.5 to 4.5 mm.
[0047]
In this embodiment, the elastic body 30 is provided with a convex portion 32, and the convex portion 32 is fitted in the opening 23 of the high-rigidity plate 20, so that the high-rigidity plate 20 and the elastic body 30 can be easily positioned. It is. Further, even when stress is applied to the elastic body 30 in the direction of the surface of the shaft portion when the racket frame is used, the stress is counteracted by the engagement between the convex portion 32 and the opening 23, so that the elastic body 30 is displaced. Is prevented.
[0048]
In this embodiment, the soft material 40 is interposed between the side edge of the shaft portion 3 and the grip portion 4 and the rib portion 20R, and the vibration along the surfaces of the shaft portion 3 and the grip portion 4 is caused by the vibration. Absorbed by the soft material 40, the burden on the elbow and shoulder of the player is reduced. The elastic body 30 also has a similar vibration absorbing action.
[0049]
In this embodiment, since the rib portion 20R is arranged so as to cover the corner edges of the shaft portion 3 and the grip portion 4, a human body or an object is caught on the edge of the high-rigidity plate 20, and the force in the peeling direction is exerted. Will not be added. For this reason, the durability of the racket frame is good.
[0050]
The above-described embodiment is an example of the present invention, and the present invention can take other forms than shown.
[0051]
【The invention's effect】
As described above, according to the present invention, a racket frame that is easy to play is provided.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a hard tennis racket frame according to an embodiment.
FIG. 2 is an enlarged view of a part of FIG.
FIG. 3 is a perspective view of the vicinity of a shaft portion of a racket frame.
FIG. 4 is a perspective view of a highly rigid plate and an elastic body.
5 is a cross-sectional view taken along line VV in FIG.
6 is a cross-sectional view taken along the line VI-VI in FIG. 3;
FIG. 7 is a front view of a highly rigid plate.
8 (a), (b), (c), and (d) are cross-sectional views taken along lines AA, BB, CC, and DD in FIG. Figure).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Racket frame 2 Face part 3 Shaft part 4 Grip part 20 High-rigidity board 20R Rib part 21 Base part 22 Arm part 23 Opening 30 Elastic body 31 Projection part 32 Convex part 33 Shallow area 40 Soft material

Claims (12)

In a racket frame having a face part, a grip part, and a pair of shaft parts connecting them,
A high-rigidity plate is fixed to the front side of the racket frame from at least the end on the shaft portion side of the grip portion to the middle portion of the shaft portion,
A racket frame, characterized in that an elastic body made of rubber or elastomer is interposed between a tip portion on the face portion side of the high-rigidity plate and a shaft portion. 2. The racket frame according to claim 1, wherein the elastic body is disposed closer to the face portion than the middle in the longitudinal direction of the shaft portion. The racket frame according to claim 2, wherein the length of the elastic body in the longitudinal direction of the shaft portion is 20 to 40% of the entire length of the shaft portion. The racket frame according to any one of claims 1 to 3, wherein the elastic body has a Shore A hardness of 30 to 70. The racket frame according to any one of claims 1 to 4, wherein the elastic body has a thickness of 2 to 5 mm. 6. The racket frame according to claim 1, wherein the high-rigidity plate is made of a composite material obtained by impregnating a woven fabric of high-elasticity fibers with a synthetic resin or an alloy material having a low specific gravity. 7. The racket frame according to claim 1, wherein the high-rigidity plate is bonded to the grip portion and the shaft portion with an adhesive. 8. The racket frame according to claim 7, wherein the adhesive is an epoxy or acrylic adhesive. 9. The racket frame according to claim 1, wherein a portion of the shaft portion to which the elastic body is attached is a recess. In any one of Claims 1 thru | or 9,
An opening is provided at the tip of the high-rigidity plate,
A racket frame, wherein the elastic body is provided with a convex portion fitted into the opening. 11. The racket frame according to claim 1, wherein a vibration-absorbing soft material is interposed between the side edge of the high-rigidity plate, the grip portion, and the shaft portion. The rib according to any one of claims 1 to 11, wherein a rib is erected on a side edge of the high-rigidity plate, and the rib is engaged with a corner edge of the grip portion and the shaft portion. And racket frame.

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