JP7585625B2 - racket - Google Patents

Description

The present invention relates to a racket used in tennis and other sports.

When a ball is hit with a tennis racket, vibrations are generated in the racket. These vibrations are transmitted to the player, causing discomfort to the player.

JP 2002-045444 A discloses a racket frame that includes a fiber-reinforced layer and a vibration-absorbing body inserted into the fiber-reinforced layer. This vibration-absorbing body can suppress vibrations that are transmitted to the player.

JP 2002-045444 A

The vibration absorbing material described in JP 2002-045444 does not adhere well to the fiber reinforced layer. This vibration absorbing material impairs the rigidity of the frame. A racket with poor rigidity also has poor resilience.

The objective of the present invention is to provide a racket that suppresses vibrations transmitted to the player and has excellent rigidity.

The racket according to the present invention has a frame. The frame has a fiber-reinforced layer and a vibration damper bonded to the fiber-reinforced layer. The fiber-reinforced layer includes a matrix based on epoxy resin and reinforcing fibers. The material of the vibration damper is a polymer composition based on styrene-isoprene-styrene block copolymer or acrylic elastomer.

The frame may have a head, two throats and a shaft. Preferably, each throat includes a vibration damper.

Preferably, the thickness of the vibration damper is 0.10 mm or more and 1.00 mm or less.

In the racket of the present invention, the vibration damper attenuates the vibrations generated in the frame. Therefore, the vibrations transmitted to the player using the racket can be suppressed. This player can obtain an excellent hitting feel. This vibration damper has excellent adhesion to the epoxy resin of the fiber reinforced layer. Therefore, this vibration damper does not significantly impair the rigidity of the racket. This racket achieves both a good hitting feel and rigidity.

FIG. 1 is a front view showing a racket according to an embodiment of the present invention. FIG. 2 is an enlarged exploded view of a portion of the racket of FIG. FIG. 3 is an enlarged front view of a portion of the racket of FIG. FIG. 4 is an enlarged cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a cross-sectional view taken along line VV in FIG. FIG. 6 is an enlarged cross-sectional view of a portion of the racket shown in FIG. FIG. 7 is a perspective view showing a part of the manufacturing process of the racket of FIG. FIG. 8 is a cross-sectional view showing a portion of a racket according to another embodiment of the present invention. FIG. 9 is a cross-sectional view showing a portion of a racket according to still another embodiment of the present invention. FIG. 10 is a cross-sectional view showing a portion of a racket according to still another embodiment of the present invention. FIG. 10 is a cross-sectional view showing a portion of a racket according to still another embodiment of the present invention. FIG. 12 is a front view showing a racket according to still another embodiment of the present invention. FIG. 13 is an enlarged cross-sectional view taken along line XIII-XIII in FIG. FIG. 14 is a front view showing a racket according to still another embodiment of the present invention.

The present invention will now be described in detail based on a preferred embodiment, with reference to the drawings as appropriate.

A tennis racket 2 is shown in Figures 1 and 2. This tennis racket 2 has a frame 4, a grip 6, an end cap 8, a grommet 10, and strings 12. This tennis racket 2 can be used for hard tennis. In Figure 1, the arrow X indicates the width direction of the tennis racket 2, and the arrow Y indicates the axial direction of the tennis racket 2.

The frame 4 has a head 14, two throats 16, and a shaft 18. The head 14 forms the outline of the face 20 (described in detail later). The front shape of the head 14 is approximately elliptical. The long axis direction of the ellipse coincides with the axial direction Y of the tennis racket 2. The short axis direction of the ellipse coincides with the width direction X of the tennis racket 2. One end of each throat 16 is continuous with the head 14. This throat 16 merges with the other throat 16 near the other end. The throat 16 extends from the head 14 to the shaft 18. The shaft 18 extends from the point where the two throats 16 merge. The shaft 18 is formed continuously and integrally with the throat 16. The portion of the head 14 sandwiched between the two throats 16 is the yoke 22. This frame 4 is hollow.

The main material of this frame 4 is fiber-reinforced resin. In this embodiment, the matrix resin of this fiber-reinforced resin is a thermosetting resin. A typical thermosetting resin is an epoxy resin. A typical fiber of the fiber-reinforced resin is a carbon fiber. This fiber is a long fiber.

As shown in FIG. 2, the head 14 has a grommet groove 24. This grommet groove 24 is recessed from the outer peripheral surface of the head 14. The grommet groove 24 is formed around almost the entire circumference of the head 14, except for the yoke 22.

The head 14 further has a number of holes 26. Each hole 26 penetrates the head 14. The number of holes 26 is arranged around almost the entire circumference of the head 14.

The grip 6 is formed by a tape wound around the shaft 18. The grip 6 prevents the player's hand from slipping against the tennis racket 2 when the tennis racket 2 is swung. An end cap 8 is attached to the end of the grip 6.

As shown in FIG. 2, the grommet 10 has a base 28 and multiple pipes 30. The base 28 has a belt shape. Each pipe 30 is integrally formed with the base 28. The pipes 30 stand upright from the base 28. The grommet 10 is typically made of a synthetic resin that is softer than the frame 4. The tennis racket 2 may have multiple grommets 10. The grommets 10 may be spaced apart from the adjacent grommets 10. The number of pipes 30 in each grommet 10 may be one.

The grommet 10 is attached to the head 14. When the grommet 10 is attached to the head 14, the base 28 is housed in the grommet groove 24. A portion of the base 28 may protrude from the grommet groove 24. Furthermore, when the grommet 10 is attached to the head 14, the pipe 30 passes through the hole 26.

As shown in FIG. 1, the strings 12 are strung on the head 14. The strings 12 are strung along the width direction X and the axial direction Y. The strings 12 form a number of threads. The portion of the string 12 that extends along the width direction X is referred to as the horizontal thread 32a. The portion of the string 12 that extends along the axial direction Y is referred to as the vertical thread 32b. The multiple horizontal threads 32a and the multiple vertical threads 32b form the face 20. The face 20 generally extends along the XY plane. The face 20 may be formed from two or more strings 12.

Figure 3 is an enlarged front view showing a portion of the tennis racket 2 in Figure 1. Figure 3 shows the frame 4 in the vicinity of the throat 16. Figure 3 shows a pair of left and right throats 16. Figure 4 is an enlarged cross-sectional view taken along line IV-IV in Figure 3. Figure 5 is a cross-sectional view taken along line V-V in Figure 4. Figure 4 shows the right throat 16. The left throat 16 has a shape that is the left-right inverse of the shape in Figure 4. Figure 5 shows the right throat 16. The left throat 16 has a shape that is the left-right inverse of the shape in Figure 5.

Figures 4 and 5 show a fiber-reinforced layer 34 and a vibration damper 36. The fiber-reinforced layer 34 has a plurality of reinforcing fibers and a matrix. A typical reinforcing fiber is carbon fiber. The matrix material is a resin composition with an epoxy resin as the base material.

In this embodiment, the vibration damper 36 is layered. The vibration damper 36 is surrounded by a fiber-reinforced layer 34. The vibration damper 36 is biased toward the outside in the width direction of the throat 16 (right side in FIG. 4). The vibration damper 36 may be biased toward the inside in the width direction of the throat 16 (left side in FIG. 4).

The vibration damper 36 is formed from a polymer composition. The polymer composition includes a base polymer. The polymer composition may include additives, if desired.

A typical base polymer for the vibration damper 36 is a styrene-isoprene-styrene block copolymer. The styrene-isoprene-styrene block copolymer contains a polystyrene block as a hard segment and a polyisoprene block as a soft segment. An example of a sheet molded from a styrene-isoprene-styrene block copolymer is the product name "KRAIBON" from Gummiwerk KRAIBURG GmbH & Co. KG.

The vibration damper 36, which is based on a styrene-isoprene-styrene block copolymer, has excellent damping performance. When a ball is hit with the tennis racket 2, vibrations occur in the frame 4. The vibration damper 36 gradually reduces the amplitude of this vibration. With this tennis racket 2, the amplitude of the vibration transmitted to the player is small. The player is less likely to feel uncomfortable when hitting the ball. This tennis racket 2 has an excellent hitting feel.

As mentioned above, in this embodiment, the vibration damper 36 is located in the throat 16. When the ball is struck by the face 20, the vibrations generated in the head 14 are attenuated by the throat 16 and transmitted to the player.

Since styrene-isoprene-styrene block copolymer has excellent vibration damping properties, even if the vibration damper 36 is thin, the vibration damper 36 can contribute to the hitting feel. The thin vibration damper 36 does not significantly impair the rigidity of the frame 4.

Styrene-isoprene-styrene block copolymer has excellent adhesion to epoxy resin. Therefore, this vibration damper 36 can be firmly bonded to the fiber reinforced layer 34. The strong bond can contribute to the rigidity of the frame 4. A tennis racket 2 with excellent rigidity has excellent resilience performance. A player can hit fast shots using this tennis racket 2. The strong bond can also contribute to the durability of the tennis racket 2.

Another suitable base polymer for the vibration damper 36 is an acrylic elastomer. The acrylic elastomer contains acrylic resin blocks as hard segments and soft segments. An example of a sheet molded from an acrylic elastomer is "PIEZON" manufactured by Titex Japan Co., Ltd.

The vibration damper 36, which is based on an acrylic elastomer, has excellent damping performance. When a ball is hit with the tennis racket 2, vibrations occur in the frame 4. The vibration damper 36 gradually reduces the amplitude of this vibration. With this tennis racket 2, the amplitude of the vibration transmitted to the player is small. The player is less likely to feel uncomfortable when hitting the ball. This tennis racket 2 has an excellent hitting feel.

Acrylic elastomers have excellent vibration damping properties, so even if the vibration damper 36 is thin, it can still contribute to the feel of the impact. The thin vibration damper 36 does not significantly impair the rigidity of the frame 4.

Acrylic elastomers have excellent adhesion to epoxy resins. Therefore, the vibration damper 36 can be firmly bonded to the fiber-reinforced layer 34. The strong bond can contribute to the rigidity of the frame 4. A tennis racket 2 with excellent rigidity has excellent resilience performance. A player can use this tennis racket 2 to hit fast shots. The strong bond can also contribute to the durability of the tennis racket 2.

Figure 6 is a further enlarged cross-sectional view of the tennis racket 2 of Figure 5. Figure 6 shows the throat 16. In Figure 6, the arrow Ti indicates the thickness of the vibration damper 36. The thickness Ti is preferably 0.10 mm or more and 1.00 mm or less. A vibration damper 36 having a thickness Ti of 0.10 mm or more can achieve an excellent hitting feel. From this perspective, the thickness Ti is more preferably 0.20 mm or more, and particularly preferably 0.30 mm or more. A vibration damper 36 having a thickness Ti of 1.00 mm or less does not significantly impair the rigidity of the frame 4. From this perspective, the thickness Ti is more preferably 0.80 mm or less, and particularly preferably 0.60 mm or less.

In FIG. 3, the arrow Le indicates the length of the vibration damper 36. From the viewpoint of vibration damping properties, the length Le is preferably 30 mm or more, more preferably 50 mm or more, and particularly preferably 60 mm or more.

The total length Le of all vibration dampers 36 in the tennis racket 2 is preferably 50 mm or more, more preferably 80 mm or more, and particularly preferably 100 mm or more.

The Shore A hardness of the vibration damper 36 is preferably 40 or more and 95 or less. A vibration damper 36 with a hardness of 40 or more does not significantly impair the rigidity of the frame 4. From this perspective, a hardness of 45 or more is more preferable, and 50 or more is particularly preferable. A vibration damper 36 with a hardness of 95 or less can achieve an excellent hitting feel. From this perspective, a hardness of 90 or less is more preferable, and 87 or less is particularly preferable. The hardness is measured on a test piece made of the same material as the vibration damper 36. The measurement is performed in accordance with the provisions of "JIS K 6253-3".

The elongation at break of the vibration damper 36 is preferably 200% or more. A vibration damper 36 with an elongation of 200% or more can achieve an excellent feel on impact. From this perspective, an elongation of 240% or more is more preferable, and 260% or more is particularly preferable. The elongation is measured by a tensile test. The tensile test is performed in accordance with the provisions of "JIS K 6251".

Hereinafter, with reference to FIG. 7, an example of a method for manufacturing a tennis racket 2 according to the present invention will be described. In this manufacturing method, a mandrel, a tube, a plurality of prepregs 38, and two films are prepared. Each prepreg 38 is made of a plurality of reinforcing fibers arranged in parallel and a matrix resin. In this manufacturing method, a mandrel is first inserted into a tube. The prepregs 38 are wound around the tube in sequence. By being wound, the prepregs 38 assume a cylindrical shape. FIG. 7 shows a cylindrical prepreg 38a and a sheet-like prepreg 38b. Two films 40 are placed on the sheet-like prepreg 38b. In FIG. 7, the mandrel and the tube are omitted.

As the mandrel is rotated, prepreg 38b is wound on top of prepreg 38a. This winding causes prepreg 38b to assume a cylindrical shape. Each film 40 is sandwiched between prepreg 38a and prepreg 38b. Another prepreg 38 is wound on top of prepreg 38b as necessary.

After the mandrel is removed from the tube, the tube and prepreg 38 are set in a mold. Inside the mold, the tube is filled with gas, causing it to expand. This expansion presses the prepreg 38 against the cavity surface of the mold. The prepreg 38 is heated, causing the matrix resin to harden. A molded body is obtained as a result of the hardening. The molded body has a shape that is the inverse of the shape of the cavity surface.

Holes 26 are drilled in this molded body. The molded body is then subjected to surface polishing, painting, and other processes to obtain the frame 4. The grip 6, grommets 10, and other components are attached to this frame 4. Strings 12 are then strung on this frame 4 to complete the tennis racket 2. The vibration damper 36 for the left throat 16 is formed from one film 40. The vibration damper 36 for the right throat 16 is formed from the other film 40.

Figure 8 is a cross-sectional view showing a portion of a tennis racket according to another embodiment of the present invention. Figure 8 shows a cross-section of the right throat 42. The left throat has a shape symmetrical to the cross-sectional shape of the right throat 42. The configuration of the tennis racket other than the throat is the same as that of the tennis racket 2 shown in Figure 1.

This tennis racket has a fiber reinforced layer 44, a first vibration damper 46, and a second vibration damper 48. The fiber reinforced layer 44 has a plurality of reinforcing fibers and a matrix. A typical reinforcing fiber is carbon fiber. The matrix material is a resin composition with an epoxy resin as a base material. The first vibration damper 46 is surrounded by the fiber reinforced layer 44. The second vibration damper 48 is surrounded by the fiber reinforced layer 44. The fiber reinforced layer 44 is present between the first vibration damper 46 and the second vibration damper 48. The second vibration damper 48 is spaced apart from the first vibration damper 46.

The material, thickness, and physical properties of the first vibration damper 46 are the same as those of the vibration damper 36 shown in FIG. 4. This first vibration damper 46 is firmly attached to the fiber-reinforced layer 44. The material, thickness, and physical properties of the second vibration damper 48 are the same as those of the vibration damper 36 shown in FIG. 4. This second vibration damper 48 is firmly attached to the fiber-reinforced layer 44.

When a ball is hit with this tennis racket, vibrations occur in the frame. The first vibration damper 46 and the second vibration damper 48 gradually reduce the amplitude of this vibration. With this tennis racket, the amplitude of the vibration transmitted to the player is small. The player is less likely to feel uncomfortable when hitting the ball. This tennis racket has an excellent hitting feel.

Figure 9 is a cross-sectional view showing a portion of a tennis racket according to yet another embodiment of the present invention. Figure 9 shows a cross-section of the right-side throat 50. The left-side throat has a shape symmetrical to the cross-sectional shape of the right-side throat 50. The configuration of the tennis racket other than the throat is the same as that of the tennis racket 2 shown in Figure 1.

This tennis racket has a fiber-reinforced layer 52, a first vibration damper 54, and a second vibration damper 56. The fiber-reinforced layer 52 has a plurality of reinforcing fibers and a matrix. A typical reinforcing fiber is carbon fiber. The matrix material is a resin composition with an epoxy resin as a base material. The first vibration damper 54 is surrounded by the fiber-reinforced layer 52. The first vibration damper 54 is located on the outer side in the width direction (right side in FIG. 9) of the center of the throat 50. The second vibration damper 56 is surrounded by the fiber-reinforced layer 52. The second vibration damper 56 is located on the inner side in the width direction (left side in FIG. 9) of the center of the throat 50.

The material, thickness, and physical properties of the first vibration damper 54 are the same as those of the vibration damper 36 shown in FIG. 4. This first vibration damper 54 is firmly attached to the fiber-reinforced layer 52. The material, thickness, and physical properties of the second vibration damper 56 are the same as those of the vibration damper 36 shown in FIG. 4. This second vibration damper 56 is firmly attached to the fiber-reinforced layer 52.

When a ball is hit with this tennis racket, vibrations occur in the frame. The first vibration damper 54 and the second vibration damper 56 gradually reduce the amplitude of this vibration. With this tennis racket, the amplitude of the vibration transmitted to the player is small. The player is less likely to feel uncomfortable when hitting the ball. This tennis racket has an excellent hitting feel.

Figure 10 is a cross-sectional view showing a portion of a tennis racket according to yet another embodiment of the present invention. Figure 10 shows a cross-section of the right throat 58. The left throat has a shape symmetrical to the cross-sectional shape of the right throat 58. The configuration of the tennis racket other than the throat is the same as that of the tennis racket 2 shown in Figure 1.

This tennis racket has a fiber-reinforced layer 60 and a vibration damper 62. The fiber-reinforced layer 60 has a plurality of reinforcing fibers and a matrix. A typical reinforcing fiber is carbon fiber. The matrix material is a resin composition with an epoxy resin as a base material. In the cross section of FIG. 10, the vibration damper 62 forms a loop. The vibration damper 62 is surrounded by the fiber-reinforced layer 60. The material, thickness, and physical properties of the vibration damper 62 are the same as those of the vibration damper 36 shown in FIG. 4. The vibration damper 62 is firmly bonded to the fiber-reinforced layer 60.

When a ball is hit with this tennis racket, vibrations occur in the frame. The vibration damper 62 gradually reduces the amplitude of this vibration. With this tennis racket, the amplitude of the vibration transmitted to the player is small. The player is less likely to feel uncomfortable when hitting the ball. This tennis racket has an excellent hitting feel.

Figure 11 is a cross-sectional view showing a portion of a tennis racket according to yet another embodiment of the present invention. Figure 11 shows a cross-section of the right-side throat 64. The left-side throat has a shape symmetrical to the cross-sectional shape of the right-side throat 64. The configuration of the tennis racket other than the throat is the same as that of the tennis racket 2 shown in Figure 1.

This tennis racket has a fiber-reinforced layer 66 and a vibration damper 68. The fiber-reinforced layer 66 has a plurality of reinforcing fibers and a matrix. A typical reinforcing fiber is carbon fiber. The matrix material is a resin composition with an epoxy resin as a base material. The vibration damper 68 is laminated on the inner surface of the fiber-reinforced layer 66. The material, thickness, and physical properties of the vibration damper 68 are the same as those of the vibration damper 36 shown in FIG. 4. The vibration damper 68 is firmly bonded to the fiber-reinforced layer 66.

When a ball is hit with this tennis racket, vibrations occur in the frame. The vibration damper 68 gradually reduces the amplitude of this vibration. With this tennis racket, the amplitude of the vibration transmitted to the player is small. The player is less likely to feel uncomfortable when hitting the ball. This tennis racket has an excellent hitting feel.

Figure 12 is a front view showing a tennis racket 70 according to yet another embodiment of the present invention. This tennis racket 70 includes a vibration damper 74 in the head 72. The vibration damper 74 is disposed over almost the entire head 72 except for the yoke 76. This tennis racket 70 does not have a vibration damper in the throat 78. This tennis racket 70 may have a vibration damper 74 in the head 72 and also have a vibration damper in the throat 78.

Figure 13 is an enlarged cross-sectional view taken along line XIII-XIII in Figure 12. The head 72 has a fiber-reinforced layer 80 and a vibration damper 74. The fiber-reinforced layer 80 has a plurality of reinforcing fibers and a matrix. A typical reinforcing fiber is carbon fiber. The matrix material is a resin composition with an epoxy resin as the base material. The vibration damper 74 is surrounded by the fiber-reinforced layer 80. The material, thickness, and physical properties of the vibration damper 74 are the same as those of the vibration damper 36 shown in Figure 4. This vibration damper 74 is firmly bonded to the fiber-reinforced layer 80.

When a ball is hit with this tennis racket 70, vibrations occur in the frame. The vibration damper 74 gradually reduces the amplitude of this vibration. With this tennis racket 70, the amplitude of the vibration transmitted to the player is small. The player is less likely to feel uncomfortable when hitting the ball. This tennis racket 70 has an excellent hitting feel.

Figure 14 is a front view showing a tennis racket 82 according to yet another embodiment of the present invention. This tennis racket 82 includes a first vibration damper 86 and a second vibration damper 88 in a head 84. The first vibration damper 86 is located to the right of the center of the head 84. The second vibration damper 88 is located to the left of the center of the head 84. The second vibration damper 88 is symmetrical to the first vibration damper 86.

The material, thickness, and physical properties of the first vibration damper 86 are the same as those of the vibration damper 36 shown in FIG. 4. This first vibration damper 86 is firmly attached to the fiber-reinforced layer. The material, thickness, and physical properties of the second vibration damper 88 are the same as those of the vibration damper 36 shown in FIG. 4. This second vibration damper 88 is firmly attached to the fiber-reinforced layer.

When a ball is hit with this tennis racket 82, vibrations occur in the frame. The first vibration damper 86 and the second vibration damper 88 gradually reduce the amplitude of this vibration. With this tennis racket 82, the amplitude of the vibration transmitted to the player is small. The player is less likely to feel uncomfortable when hitting the ball. This tennis racket 82 has an excellent hitting feel.

The effects of the present invention will be explained below by way of examples, but the present invention should not be interpreted in a restrictive manner based on the description of these examples.

[Example 1]
A tennis racket as shown in FIG. 1-6 was obtained. This racket has a fiber-reinforced layer and a vibration damper. The fiber-reinforced layer contains a matrix based on epoxy resin and reinforcing fibers. A commercially available sheet (the aforementioned product name "KRAIBON") was used as the vibration damper. The material of this vibration damper is a polymer composition based on a styrene-isoprene-styrene block copolymer. The thickness of the vibration damper is 0.5 mm.

[Example 2]
A tennis racket of Example 2 was obtained in the same manner as in Example 1, except that another commercially available sheet (product name "PIEZON") was used as the vibration damper. The material of this vibration damper was a polymer composition having an acrylic elastomer as a base material.

[Comparative Example 1]
A tennis racket of Comparative Example 1 was obtained in the same manner as in Example 1, except that another commercially available sheet was used as the vibration damper. The material of this vibration damper was a polymer composition having a chlorinated polyethylene base material.

[Comparative Example 2]
A tennis racket of Comparative Example 2 was obtained in the same manner as in Example 1, except that no vibration damper was provided.

[Examples 3-8]
Tennis rackets of Examples 3-8 were obtained in the same manner as in Example 1, except that the positions of the vibration dampers were as shown in Table 2 below.

[evaluation]
A player was made to play a rally with each tennis racket. The player was made to evaluate the repulsion performance (flight), vibration absorption performance, hitting feeling, and control performance. The results are shown in Tables 1 and 2 below. The higher the value, the more favorable the evaluation.

As is clear from Tables 1 and 2, the tennis rackets of the examples have an excellent balance of performance. These results clearly show the superiority of the present invention.

The racket of the present invention can be used in a variety of sports, including soft tennis, squash, and badminton.

2, 70, 82...Tennis racket 4...Frame 10...Grommet 12...String 14, 72, 84...Head 16, 42, 50, 64...Throat 20...Face 34, 44, 52, 66, 80...Fiber reinforced layer 36, 68, 74...Vibration damper 38...Prepreg 40...Film 46, 54, 86...First vibration damper 48, 56, 88...Second vibration damper

Claims (4)

It has a frame,
The frame has a fiber reinforced layer and a vibration damper joined to the fiber reinforced layer,
The fiber reinforced layer includes a matrix based on an epoxy resin and reinforcement fibers,
The material of the vibration damper is a polymer composition having a base material of a styrene-isoprene-styrene block copolymer or an acrylic elastomer,
the frame having a head, two throats and a shaft;
Each throat includes the vibration damper;
the vibration damper is surrounded by a fiber-reinforced layer;
The vibration damper is disposed on the outer side of the throat in the width direction of the racket. It has a frame,
The frame has a fiber reinforced layer and a vibration damper joined to the fiber reinforced layer ,
The fiber reinforced layer includes a matrix based on an epoxy resin and reinforcement fibers,
The material of the vibration damper is a polymer composition having a base material of a styrene-isoprene-styrene block copolymer or an acrylic elastomer,
the frame having a head, two throats and a shaft;
Each throat includes the vibration damper;
the vibration damper is surrounded by a fiber-reinforced layer;
The vibration damper is disposed on the inner side of the throat in the width direction of the racket . It has a frame,
the frame has a fiber reinforced layer and a first vibration damper and a second vibration damper joined to the fiber reinforced layer ,
The fiber reinforced layer includes a matrix based on an epoxy resin and reinforcement fibers,
the first vibration damper and the second vibration damper are made of a polymer composition having a base material of a styrene-isoprene-styrene block copolymer or an acrylic elastomer;
the frame having a head, two throats and a shaft;
Each throat includes the first vibration damper and the second vibration damper,
Each of the first vibration damper and the second vibration damper is surrounded by a fiber reinforced layer,
The first vibration damper is disposed on the outer side of the throat in the width direction,
The second vibration damper is disposed on the inner side of the throat in the width direction of the racket . 4. The racket according to claim 1 , wherein the vibration damper has a thickness of 0.10 mm or more and 1.00 mm or less.

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