JPH0425153Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field of the invention] This invention is based on fiber-reinforced plastics (hereinafter referred to as
This invention relates to a racket frame such as a tennis racket whose outer shell is FRP (abbreviated as FRP).

[Prior art and its problems]

Conventionally, in this type of racket frame,
As a means of increasing shock absorption when hitting a ball, we have introduced cushioning materials such as rubber in the grip, softened the material of the grip itself, and added string protection material to protect the strings attached to the stringed part of the frame. This may include creating a cushioning effect, or locally reducing the thickness of a part of the frame (for example, near the neck side of the shaft) or the number of FRP plies to provide flexibility (the bending of the entire racket frame). .

However, in the case of the above-mentioned conventional racket frame, the flex cannot be changed due to the structure in which the grip part and the gut protection material have a cushioning effect, and the flex cannot be changed, and in order to provide the flex, the racquet has to be locally tightened. Structures with reduced thickness or reduced number of FRP plies not only complicate manufacturing and increase costs, but also suffer from insufficient durability and strength.

[Purpose of invention]

This invention was made under the above circumstances, and its purpose is to be able to freely change the flex to improve shock absorption.
Moreover, it is an object of the present invention to provide a racket frame that is easy to manufacture and inexpensive in terms of cost.

[Summary of the idea]

In order to achieve the above object, this invention provides a racket frame in which a cushioning material is provided inside the FRP outer shell constituting the racket frame main body, and the cushioning material is placed around the neck of the racket frame main body. The structure is such that it is provided within an FRP outer shell corresponding to the ball-hitting surface side of an area that includes a part of the frame stringing part and a part of the shaft part.

In this case, the neck portion of the racket frame body refers to a portion of the frame that is interposed between the frame stringing portion and the shaft portion and connects the two.

Further, in this invention, the cushion material is provided within an FRP outer shell corresponding to the outer peripheral surface of the racket frame body in a direction perpendicular to the ball hitting surface side.

[Effect]

In other words, this idea uses cushioning material inside the FRP outer shell that makes up the racket frame body.
Since the flex points are arranged over a range that gives a soft feel at impact or a range that softens the feel at impact, manufacturing is easy, and the flex and to some extent the feel at impact can be freely changed. It is possible to reduce manufacturing costs and improve shock absorption properties.

[Example of idea]

This invention will be explained below based on illustrated embodiments.

1 and 2 show a first embodiment of the racket frame according to this invention, in which 1 is the racket frame main body, the frame stringing part 2 on which strings are stretched, the neck part 3 and the shaft part. It consists of 4. The racket frame body 1 includes a core layer 1 whose cross-sectional shape is made of a foam or honeycomb material made of urethane resin, polyethylene resin, etc.
FRP with reinforcing fibers such as glass fiber, carbon fiber, Kevlar or boron fiber around 1.
The ball-hitting surface side of an area A that has an outer shell structure with a closed cross section with a layer 12 added thereto, and includes a part of the frame stringing part 2 and the shaft part 4 centered on the neck part 3 shown with diagonal lines in FIG. As shown in FIG. 2, a cushion material 13 such as rubber, plastic elastomer, or sponge is disposed within the FRP outer shell in areas 1a and 1b, that is, areas containing flex points.

FIG. 3 shows a second embodiment of this invention, in which the cushioning material 13 in the first embodiment is arranged on the outer circumferential surface of the racket frame body 1 in a direction perpendicular to the ball-hitting surface. equivalent to 1c
It has a configuration in which it is disposed within the FRP outer shell 12 over the entire length in the frame circumferential direction, thereby imparting a cushioning effect particularly to the strings (not shown) stretched on the frame stringing section 2, This is expected to result in a softer feel at impact.

In each of the embodiments of this invention, the cushioning material is arranged in a range corresponding to the flex point or a range corresponding to the outer circumferential surface in a direction orthogonal to the ball-hitting surface, but the present invention is not limited to this. Of course, the cushion material may be placed in both areas.

Furthermore, in the above embodiments, the weaving and knitting form of the FRP reinforcing fibers forming the outer shell structure of the racket frame may be any one of roving, plain weave cloth, twill cloth, bias cloth, etc., or a combination of two or more of them. The effect of this structure can be obtained even when any type of reinforcing fiber is used alone or in a composite layer of two or more types. In addition, it is equally effective when the reinforcing fiber material in various forms is preferably carbon fiber, glass fiber, or high modulus organic fiber, either alone or in combination of two or more. be. Furthermore, the matrix synthetic resin impregnated into the reinforcing fibers is preferably an epoxy resin, an unsaturated polyester resin, or an epoxy acrylate resin.

[Effect of idea]

As explained above, according to this idea,
In addition to placing the cushion material inside the FRP outer shell,
Depending on the placement position of this cushion material, it is possible to reduce the rigidity of a specific part, and the cushion effect can absorb and alleviate the impact of the ball hitting the entire frame through the gut.
Flex points can be freely designed, which not only makes the feel of the ball softer, but also improves shock absorption, which is an excellent effect.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a racket frame according to this invention, Fig. 2 is an enlarged cross-sectional view of main parts taken along the line - Fig. 1, showing a first embodiment of this invention, and Fig. 3 is an explanatory diagram of a racket frame according to this invention. Figure 1 showing two embodiments-
FIG. 1...Racket frame body, 2...Frame stringing part, 3...Network part, 4...Shaft part, 1
2...FRP, 13...Cushion material, A...A range that includes a part of the frame stringing part centered on the neck part and a part of the shaft part.

Claims (1)

[Claims for Utility Model Registration] (1) In a racket frame in which a cushioning material is provided inside an FRP outer shell constituting the racket frame body, the cushioning material is placed around the neck of the racket frame body. A racket frame characterized in that it is provided within an FRP outer shell corresponding to the ball-hitting surface side in an area including a part of the frame stringing part and a part of the shaft part. (2) In a racket frame in which a cushioning material is provided inside the FRP outer shell that constitutes the racket frame body, the cushioning material is placed on the outer circumferential surface of the racket frame body in a direction perpendicular to the ball hitting surface side.
A racket frame characterized by being installed inside an FRP outer shell.