JPH09664A - Racket - Google Patents

Abstract

PURPOSE: To reduce an impact transmitted from a grip to the hand on smashing or receiving a ball by using a racket interposing a viscoelastic material between a top surfacing material and a part of a grip of the racket frame. CONSTITUTION: A racket frame 1 comprises a head part 2, a shaft part 3 and a grip 4 and is made of integrally formed a fiber reinforcing plastics as a whole. The grip 4 has a cross section of an octagon and the each faces of the octagon have a groove 5. A viscoelastic material is disposed in the groove on the each faces of the octagon and a tape 7 is wound on the peripheral surface of the grip. The viscoelastic material is preferably a material having an impact acceleration of 5-30G, more preferably 5-22G on a test piece made thereof having 10mm thickness. The viscoelastic material 6 is preferred to be formed flush with the surface of the grip part 4 surrounding the groove 5. The racket absorbs the impact for hitting a ball at the viscoelastic material 6 therefore the impact transmitted to the hand is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a racket used for tennis, badminton, or a sport similar thereto, and in particular, a racket frame made of FRP (fiber reinforced resin) is equipped with a cover material such as tape on a grip portion thereof. Regarding the racket.

[0002]

2. Description of the Related Art A racket in which tape is wound around a grip portion of an FRP racket frame is widely used. In a conventional racket, the entire outer surface of the grip portion of the FRP racket frame is covered with urethane, and a tape made of synthetic leather or the like is wound on the urethane.

[0003]

Since the urethane has a low impact absorption property, the conventional racket has a problem that the impact transmitted from the grip to the hand at the time of hitting the ball is relatively large.

[0004]

The racket according to claim 1 has the following features:
In a racket having a fiber-reinforced resin racket frame having a head portion, a shaft portion and a grip portion, and a cover material attached to the grip portion, a part of the interface between the cover material and the grip portion of the racket frame is adhered. It is characterized in that an elastic material is interposed.

A racket according to a second aspect of the present invention is the racket according to the first aspect, wherein, in the part of the interface, the cover material is in direct contact with the viscoelastic material, and the part other than the part. In this case, the cover material is in direct contact with the racket frame.

A racket according to a third aspect of the present invention is the racket according to the second aspect, wherein a recess is provided in a surface of the grip portion of the grip portion of the racket frame, and the viscoelastic material is provided in the recess. It is characterized by being arranged.

The racket of claim 4 is the racket of claims 1 to 3.
In the racket according to any one of items 1,
The impact acceleration per 0 mm thickness is 5 to 30 G.

[0008]

Function: By interposing a viscoelastic material at the interface between the grip portion of the racket frame and the cover material, the impact transmitted to the hand at the time of hitting the ball is reduced.

Since this viscoelastic material is interposed only in a part of the interface between the grip portion and the covering material, a part of the grip force of the hand is transmitted to the grip portion without passing through the viscoelastic material. Therefore, it is possible to sufficiently reduce the twisting and the movement of the racket in the pulling direction when the cover material is gripped and swung, and the racket is stably gripped.

In the racket of the second aspect, the cover material is in direct contact with the viscoelastic material in the part, and the impact transmitted to the cover material is extremely small in this part. In parts other than the above part, since the cover material is in direct contact with the racket frame, the grip force of the hand is directly transmitted from the cover material to the racket frame in this part, so that the grip of the racket becomes extremely stable. .

In the racket of claim 3, the surface of the viscoelastic material can be made flush with the surface of the grip portion (FRP portion) around the recess, and the grip shape is similar to that of the existing racket. Becomes Therefore, even a user who uses the racket for the first time can grip the racket without feeling discomfort.

The racket of claim 4 is extremely excellent in shock absorbing characteristics.

[0013]

EXAMPLES Examples will be described below with reference to the drawings. 1A and 1B are a front view and a side view of a racket frame according to an embodiment, FIG. 2 is an enlarged view of a grip portion, and FIG. 3 is a sectional view of the grip portion. FIG. 4 is a cross-sectional view of the grip portion of the racket.

The racket frame 1 includes a head portion 2,
F as a whole having the shaft portion 3 and the grip portion 4
It consists of an integrally molded RP. The grip portion 4 has an octagonal cross section, and recesses 5 are provided on each of eight surfaces.

A viscoelastic material 6 is arranged in each of the recesses 5, and a tape 7 is wound around the outer periphery of the viscoelastic material 6 to form a racket.

In the present embodiment, the recess 5 is extended in the longitudinal direction of the grip portion 4, but in the case of such a configuration, the length L _{2 of the} recess 5 is longer than the length L ₁ of the grip portion 4. Is 50
-80%, especially 60-70% is preferable. The position of the recess 5 on the grip end side is the length L from the grip end.
_It is preferable that ₃ is 10 ± 5% of the length of L ₁ .

The width W _{2 of the} recess 5 is preferably 90 to 40%, especially 70 to 50% of the width W ₁ of the one surface of the octagon in which the recess 5 is provided.

The depth of the recess 5 is preferably 0.3 to 2.5 mm, more preferably 0.8 to 1.5 mm.

The grip portion 4 is preferably in the shape of a hollow shell as shown in the drawing, and the thickness of the grip portion corresponding to the thickness of the shell is 0.8 to 3.0 mm, particularly 1.0 to 2.0 mm. .

5A and 5B are a front view and a side view of a grip portion 4A of a racket frame used in another embodiment. The grip portion 4A is provided with a concave portion 8 that circulates. The length L ₄ of the recess 8 in the grip portion longitudinal direction is preferably 50 to 80%, and particularly preferably 60 to 70% of the length L ₁ of the entire grip portion. Further, the length L ₅ from the recess 8 to the grip end is preferably 5 to 30% of L ₁ , and particularly preferably 15 to 25%. The depth of the recess 8 is 0.8 to
1.5 mm is preferable.

Epoxy resin, nylon and the like are preferable as the synthetic resin of the FRP constituting the racket frame, but epoxy resin is preferable in terms of strength, durability and cost.

As the reinforcing fiber, carbon fiber, boron fiber, alumina fiber, ultrafine iron wire, Ti-Si-C-
O-based fibers (trade name Tyranno fiber), aromatic polyamide fibers, aromatic polyester fibers, ultra-high molecular weight polyethylene fibers, and the like can be used, but carbon fibers are preferable in terms of cost.

This racket frame can be manufactured by the same method as the conventionally known racket frame manufacturing method. That is, a member obtained by laying up a fiber-reinforced synthetic resin prepreg made of a desired material may be provided in the mold cavity, and heated and pressed.

As the viscoelastic material 6 arranged in the recess,
It is preferable to use a test piece having a thickness of 10 mm and an impact acceleration of 5 to 30 G, especially 5 to 22 G. Here, G means gravitational acceleration. This impact acceleration is measured as follows.

On a test piece having a thickness of 10 mm, a weight body of 5 kg to which an acceleration sensor is attached is freely dropped from a height of 5 cm. At this time, the acceleration applied to the weight when the weight collides with the test piece is read by the sensor. The weight body is set so that the contact area with the test piece is 9 cm ² (3 × 3 cm). The test shall be conducted at 20 ° C.

When the impact acceleration of the viscoelastic material exceeds 30 G,
It does not absorb the impact of hitting the ball well. Further, if it is less than 5 G, there are problems in the shape retention of the grip portion and the like.

A suitable viscoelastic material 6 is disclosed in Japanese Patent Laid-Open No. 62-
No. 225335 discloses that the impact resilience at 20 ° C. is 25% or less and the density is 0.05 to 0.9 g / c.
m ³ , a foam having a hardness of 50 ° or less by SRIS, a tensile strength of 100 kg / cm ² or more, and an elongation at break of 50.
% Or more, hardness (JIS A) is 60 ° or more, and thickness is 10
Examples of the shock absorbing material include a synthetic resin film having a thickness of ˜2000 μm and / or a molded product of the film having a large number of closed cells.

Further, as disclosed in JP-A-5-239256, a high molecular weight organic material and a low molecular weight organic material are contained as main components, and the content ratio of the high molecular weight organic material is lower than that of the low molecular weight organic material. Is a low polymer blend material,
There is also a polymer blend material characterized in that the polymer organic material has a three-dimensional continuous network skeleton structure.

Further, a silicone gel type shock absorbing material, polyvinyl chloride, urethane type elastomer, amide type elastomer, EVA and composite materials thereof can be used.

As shown in FIG. 4, the viscoelastic material 6 is preferably distributed in the recess 5 so as to be flush with the surface of the grip 4 around the recess 5.

The viscoelastic material having the above dimensions and materials is
The total of eight pieces is about 15 to 20 g, which is significantly smaller than the weight (about 30 g) of urethane in the grip portion of the currently marketed racket.

An ordinary grip tape can be used as the surface mounting material on which the viscoelastic material 6 is mounted on the outer periphery of the grip portion arranged in the recess 5.

The tape has a thickness of 0.1 to 3.0 m.
It is preferable that the material of m is synthetic leather, natural leather, rubber, soft plastic or the like.

In this racket, since the impact at the time of hitting the ball is absorbed by the viscoelastic material 6, the impact transmitted to the hand is significantly reduced. Further, when grasping this racket, a part of the grip force is directly transmitted from the tape 7 to the FRP portion of the grip portion 4 or 4A, so that the grip of the racket becomes stable.

In particular, in the embodiment shown in FIGS. 1 to 4, a plurality of viscoelastic materials 6 are arranged in an elongated shape, FRP portions extend between the viscoelastic materials 6, and the FRP portions are arranged. Occupies the octagonal edge portion of the grip portion, and the FRP portion and the viscoelastic material are flush with each other, so that twisting of the grip portion and movement in the longitudinal direction are surely ensured when the grip portion is grasped. This prevents the racket from being held very stably.

Although the embodiment of the present invention has been described in detail with reference to the accompanying drawings, the present invention is not limited to this and various modifications can be made. For example, as shown in FIG. 6, the viscoelastic material 6 may be arranged at the corners of the grip skeleton 7 having a polygonal cross section. The tape is omitted in FIG.

[0037]

According to the racket of the present invention, the impact transmitted to the hand when hitting a ball is significantly reduced. Also, the weight of the grip portion can be reduced. A viscoelastic material is partially distributed in the grip portion of this racket, and the deformation of the viscoelastic material is small when the grip portion is twisted or an external force in the longitudinal direction is applied,
The grip is also good.

The racket of claim 2 has a very good grip feeling, and the racket of claims 3 and 4 has an even better grip feeling.

[Brief description of drawings]

FIG. 1 is a front view and a side view of a racket frame according to an embodiment.

FIG. 2 is a front view of a grip portion of the racket according to the embodiment.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a sectional view of a grip portion of the racket according to the embodiment.

FIG. 5 is a front view and a side view of a grip portion of a racket frame according to another embodiment.

FIG. 6 is a cross-sectional view of a grip portion of a racket frame according to another embodiment.

[Explanation of symbols]

 1 Racket frame 2 Head part 3 Shaft part 4, 4A Grip part 5, 8 Recessed part 6 Viscoelastic material 7 Tape

Claims (4)

[Claims] 1. A racket having a fiber reinforced resin racket frame having a head portion, a shaft portion and a grip portion, and a cover material mounted on the grip portion, wherein an interface between the cover material and the grip portion of the racket frame is provided. A racket in which a viscoelastic material is interposed in a part of the racket. 2. The surface material according to claim 1, wherein the cover material is in direct contact with the viscoelastic material in the part of the interface, and the part of the interface is in the part other than the part. A racket in which the cover material is in direct contact with the racket frame. 3. The grip according to claim 2, wherein a recess is provided on a surface of the grip of the grip of the racket frame, and the viscoelastic material is disposed in the recess. Racket characterized by. 4. The racket according to claim 1, wherein the impact acceleration per 10 mm thickness of the viscoelastic material is 5 to 30 G.