JPS6028464Y2 - metal racket - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a metal racket such as a tennis racket made of stainless steel or the like.

Generally, a racket such as a tennis racket has a frame that is curved into the shape of a racket and has string insertion holes, and the strings are passed through these holes and stretched on the frame surface.

However, when the bottom of the frame is made of metal such as stainless steel, if the guts are passed directly through the insertion holes, the guts will break at the edges of the insertion holes.For this reason, conventional metal rackets require various improvements to the insertion holes. I'm having a hard time.

For example, a metal or resin eyelet is attached to the insertion hole so that the eyelet does not come into direct contact with the edge of the insertion hole, or a so-called grommet is used, which is a strip of resin with cylindrical protrusions at predetermined intervals. There is also a grommet in which the protrusion is inserted into the insertion hole while the band-shaped part of the grommet is placed along the circumferential surface of the frame.

However, when metal eyelets are installed, the eyelets rub at the bends of the eyelets and are prone to breakage.The eyelets also loosen and make noises during use, which is unpleasant to the ears and has an appearance problem.

In addition, those using resin eyelets or grommets have a weak strength, and therefore have the disadvantage that the eyelets or grommets tend to be easily cut at the edges of the insertion holes.

The present invention was made in view of the above-mentioned circumstances, and its purpose is to provide a metal racket that prevents the gut from breaking, does not damage the eyelets, and has an excellent appearance.

Embodiments of the present invention will be described below based on the drawings.

Fig. 1 is a front view of a metal racket according to the present invention. This racket has a frame 1 which is made of stainless steel or the like and is curved into the shape of a racket, and a plurality of gutt insertion holes 2 are drilled into the frame 1. Further, metal eyelets 3 are attached to each of these gut insertion holes 2 by caulking with a hand press or the like.

As shown in FIGS. 2 and 3, this eyelet 3 has a flange 3a along the circumferential direction of the outer circumferential surface of the frame 1 in a substantially rectangular shape. along the direction of tension.

Furthermore, the inner wall of the metal eyelet 3 and the metal frame 1 described above.
A synthetic resin coating 4 is applied to the inner and outer circumferential surfaces of.

This threatening resin coating 4 is made of, for example, nylon, vinyl chloride, epoxy resin, or the like.

Among these resins, nylon resin is particularly suitable,
Practically speaking, the film thickness is preferably about 200 to 300 μm.

The above-described synthetic resin film 4 may be applied by, for example, a fluidized dipping method or an electrostatic coating method.

In the fluidized dipping method, the resin powder placed in the dipping tank is fluidized in an empty state, and 200 to 300
A coating film is formed by immersing a metal frame 1 heated to about °C.

The electrostatic coating method is a method in which synthetic resin powder is charged with ions, absorbed and coated onto the metal frame 1, and the metal frame 1 is heated in this state.

According to the metal racket having the structure described above, since the eyelet 3 is made of metal, the eyelet 3 will not be damaged, and the synthetic resin coating 4 may be provided on the inner circumference of the eyelet 3 and on the inner and outer circumferential surfaces of the frame 1. This acts as a cushion and prevents the gut 5 passing through the gut insertion hole 2 from breaking.

Further, when the synthetic resin coating 4 is applied, the radius of the corner increases, and this also prevents the guttering 5.

Furthermore, since the metal eyelet 3 is coated with the synthetic resin coating 4, the eyelet 3 will not become loose.

Furthermore, the appearance can be enhanced by hiding the eyelet 3 with the coating 4 and by making the coating 4 a desired color.

Furthermore, according to the above embodiment, the flange 3a of the metal eyelet 3 is lengthened in the direction of the tension of the eyelet 5, so the contact length between the eyelet 3 and the eyelet 5 is increased, and the force applied to the eyelet 5 is dispersed. to prevent the gut 5 from breaking.

Furthermore, when the ball is hit, the gut 5 moves along the eyelet 3, and in this case, the frictional force is similarly reduced to prevent the gut from breaking.

Next, an experimental example of the metal racket according to the present invention will be explained.

As shown in Fig. 4, gutt insertion holes 2 are bored at intervals of 10 to 20 wn in a stainless steel metal frame 1 having a concave cross-sectional shape.
．． 5rIr! A metal eyelet 3 having a flange 3a having a length of 8.5-Mn and a length of 8.5-Mn was attached, and then a nylon resin was applied to the metal eyelet to a thickness of 300 μm by a fluidized dipping method to produce a metal racket according to the present invention.

Through hole 2 of the metal racket obtained in this way, Z
A nylon string 5 with a diameter of 1.5 mφ and a breaking load of 140 kp was passed through in a U-shape and the string 5 was pulled, and the breaking load of the string 5 was measured and found to be 136 ko.

Also, Guttu 5 was frayed and broken.

On the other hand, a conventional metal racket was manufactured using conventional metal eyelets and without coating with nylon resin, and the breaking load of the gut 5 was measured in the same manner as in the above experimental example.

As a result, it broke at a low value of 113ko, and Guttu 5 looked as if it had been cut with a knife.

In addition, the breaking load of those using nylon resin eyelets instead of metal eyelets was 118 kg, and the breaking load of those using grommets was as low as 115 kg.Those using nylon, eyelets, and grommets were also damaged.

As is clear from the above results, the present invention has remarkable effects such as not damaging the eyelets, preventing the gut from breaking, and improving the appearance.

[Brief explanation of drawings]

Fig. 1 is a front view of a metal racket showing an embodiment of the present invention, Fig. 2 is a cross-sectional view taken along the line ■-■ in Fig. 1, and Fig. 3 is a cross-sectional view taken along the line ■-■ in Fig. 2. 4 are explanatory diagrams showing a gut rupture test on a metal racket according to the present invention. 1...Frame, 2...Gut insertion hole, 3...Metal eyelet, 4...Threat resin coating, 5...Gut.

Claims (2)

[Scope of utility model registration request] (1) In a metal racket in which a metal frame is curved in the shape of a racket and has a concave cross-section, a plurality of gutt insertion holes are bored and metal eyelets are attached to the holes, and the inner circumferential surface of the metal eyelets and the metal A metal racket with a synthetic resin coating applied to the inner and outer surfaces of the frame. (2) The metal racket according to claim 1, wherein the flange of the metal eyelet is shaped into a substantially rectangular shape along the circumferential direction of the outer peripheral surface of the frame.