JP4028910B2 - Soft tennis ball manufacturing method - Google Patents

Description

【００１５】
表１から明らかなように、バルブとバルブ周辺ゴムとを接着剤で接合していないものは、バルブが抜けたり、バルブ周辺から空気が漏洩したりしたが、バルブのスリットにシリコーンオイルを塗布したものは、接着剤によりスリットが接着されることがなかった。さらに、バルブのスリットにシリコーンオイルを塗布したものは、空気注入棒の挿入が容易であった。またこのときの送気弁の重量は０．６ｇで、飛翔性に問題はなかった。
【００１６】
また、表１の実験に使用したソフトテニスボールにおいて、送気弁の大きさを変えることにより、その重量のみを変え、その他の製造条件を変化させることなく、飛翔性の試験を実施した。その結果を表２に示す。
【００１７】
【表２】

【００１８】
表２から明らかなように、送気弁が１．５ｇ以上の重さになると、飛翔時のぶれが大きくなり、選手を惑わすので問題となる。
【００１９】
【発明の効果】
以上説明したように、本発明は、スリットを設けたバルブとその外周に嵌合したバルブ周辺ゴムとにより送気弁を構成させ、かつスリットに潤滑剤を塗布しているので、先端が尖った注射針を使用することなく、中空で棒状の空気注入器を使用してボールに空気を注入することができる。従って、注射針を使用する空気注入方法において問題であった、誤って人体に刺してしまう事故や、注射針をソフトテニスボールへの空気注入以外の用途に使用されること等を防止することができる。特に、カッターの刃先に潤滑剤を塗布してそのカッターによりスリットを形成するため、その成形時に、スリットに潤滑剤を塗布することができる。また、本発明は、送気弁の重量を１．５ｇ以下とすることにより、ボールの飛翔性に問題を生じる恐れはない。
【００２０】
また、本発明においては、ボールの空気注入穴を、明確に視認することができるので、ヘソ以外の個所に針を刺してボールをパンクさせるような事故を防止することが可能となる等の効果を有する。
【図面の簡単な説明】
【図１】 本発明の構成を示す縦断面図。
【図２】 本発明における空気注入状態を示す縦断面図。
【図３】 従来のソフトテニスボールの一例を示す縦断面図。
【符号の説明】
１ ボール本体
２ 送気弁
３ バルブ
４ スリット
５ 第２の穴
６ 潤滑剤
７ バルブ周辺ゴム
８ 第１の穴[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a soft tennis ball.
[0002]
[Prior art]
Soft tennis balls used in soft tennis have a breathable rubber material, and as time passes, the air in the ball decreases and its elasticity decreases. To restore elasticity. Therefore, conventionally, when air is injected into a soft tennis ball, it is injected into a thick and soft rubber block portion (usually referred to as “navel”, hereinafter referred to as navel) that is vulcanized and bonded to the inner wall of the ball. A method of penetrating a needle and supplying air into a ball by a pump is performed.
[0003]
However, this method is dangerous because it may accidentally pierce the finger with the needle when air is injected. In addition, the injection needle may be used for purposes other than the original purpose of injecting air into the ball, which is unfavorable in terms of customs. Furthermore, not only was it time-consuming to find the position of the navel by visual inspection, but there were various problems such as puncturing the ball with a needle other than the navel and puncturing the ball so that it could not be used later. .
[0004]
Therefore, in order to solve the above-described problems, it is considered to use a valve-type air supply valve with a hook, which is used in dodge balls, basketballs, volleyballs and the like as shown in FIG.
[0005]
The soft tennis ball configured in this manner can use a hollow rod-like air injector with no sharp tip when injecting air, so the use of an injection needle can be eliminated and the above problem can be solved. On the other hand, in the structure as described above, there is a problem that the valve may come off due to the impact applied to the ball at the time of striking with the racket, or air may leak from the peripheral portion of the valve, despite the presence of wrinkles. In addition, because of the presence of wrinkles, insertion work takes time and effort, and productivity is also problematic.
[0006]
[Problems to be solved by the invention]
The present invention has been made to solve the above-described problems, facilitates the air injection operation without using an injection needle, and allows the ball to be manufactured efficiently.
[0007]
[Means for Solving the Problems]
The present invention relates to a soft tennis ball manufacturing method including an air supply valve composed of a cylindrical valve and a valve peripheral rubber, and when the ball is manufactured, the valve peripheral rubber is added to a part of the inner wall of the ball body. The first hole is formed at the radial center of the valve peripheral rubber , and the second hole for inserting the injection rod of the air injector is formed at the radial center of the valve. And forming the valve by applying the lubricant to the slit by forming the slit connected to the second hole at the center of the valve in the radial direction by applying the lubricant to the blade edge of the cutter. characterized by inserting bonding said valve to said first bore of the valve surrounding rubber. In a preferred embodiment, the total weight of the valve and the rubber around the valve is 1.5 g or less, and the lubricant applied to the slit is lubricity such as silicone, fluorine oil or emulsion, liquid paraffin, and machine oil. Such a means is used to solve the above-mentioned problems.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a specific configuration of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a longitudinal sectional view showing a configuration of the present invention, FIG. 2 is a longitudinal sectional view showing an air injection state in the present invention, and FIG. 3 is a longitudinal sectional view showing an example of a conventional soft tennis ball.
[0009]
As shown in FIGS. 1 and 2, the soft tennis ball according to the manufacturing method of the present invention has a valve peripheral rubber 7 vulcanized and bonded to a part of the inner wall of the ball body 1, and the valve peripheral rubber 7 has a radial center. and forming a hole 8 in part, radially central portion with a hole 5 for inserting a hollow injection rod 12 of the air injector 11, forming a slit 4 connecting to the hole 5, and at the time of forming the slits 4 The valve 3 in which the lubricant 6 is previously applied to the slit 4 is inserted and bonded into the hole 8 formed in the valve peripheral rubber 7 to constitute the air supply valve 2. In addition, in the air supply valve 9 in the conventional ball | bowl shown in FIG. 3, 10 is a cage | basket and the valve 3 is rubber | gum like the valve in the well-known air supply valve.
[0010]
In the present invention, as described above, the air supply valve 2 is constituted by the valve peripheral rubber 7 bonded to a part of the inner wall of the ball body 1 and the valve 3 fitted and bonded to the valve peripheral rubber 7, and further the air supply valve 2. Lubricant 6 is applied in advance to the slit 4 provided in the valve 3 of the air valve 2. In the present invention having the air supply valve 2 configured as described above, in order to inject air into the ball main body 1, the hollow injection rod 12 of the air injector 11 is inserted into the ball main body 1 as shown in FIG. 2. The slit 4 is pushed open by being inserted into a hole 5 formed in the cylindrical valve 3 of the air supply valve 2, and smoothly enters the inner surface of the ball body 1 by the lubricating action of the lubricant 6 applied to the slit 4. Thereafter, the air injector 10 can be operated.
[0011]
In the case of a known ball having such a structure, an adhesive is applied to the surface of the air supply valve 2 in order to bond the valve 3 and the valve peripheral rubber 7 at the time of manufacture. However, in the present invention, the cutter 4 is used to form the slit 4 in which the lubricant is previously applied to the cylindrical valve 3 of the air supply valve 2. For example, a silicone-based, fluorine-based oil or emulsion, fluidized ball fin, machine oil, or the like is used to apply a lubricant 6 mainly composed of a highly lubricious substance. Lubricant 6 is applied to the forming surface (opposite surface forming the slit), and as a result, even if the adhesive is used, the intrusion of the adhesive into the slit 4 is prevented thereafter. Sky It will exert a lubricating action upon entry into the hollow slit 4 of the injection rod 12 of the injector 11.
[0012]
As the adhesive used in the present invention, for example, Aron Alpha (registered trademark), ThreeBond 1521 (registered trademark), and other adhesives for joining rubbers can be appropriately used.
[0013]
【Example】
Next, examples of the present invention will be described.
A rubber with a hardness of 60 degrees (JIS-A hardness meter) is used to make a cylindrical valve peripheral rubber with an outer diameter of 8 mm, an inner diameter of 5 mm, and a height of 10 mm, and vulcanized and bonded to the inner wall of the ball body. A valve made by drilling a hole at the position of the inner diameter, further drilling a hole with an outer diameter of 6 mm and a length of 10 mm, a diameter of 2 mm and a depth of 3 mm in the hole, and cutting a slit from the hole. A soft tennis ball with an air supply valve was created. Experiments were conducted by actually hitting the ball created as described above with a racket in order to investigate valve omission, air leakage from the periphery of the valve, flightability, and the like. The results are shown in Table 1.
[0014]
[Table 1]

[0015]
As is clear from Table 1, when the valve and the rubber around the valve were not joined with an adhesive, the valve was pulled out or air leaked from around the valve, but silicone oil was applied to the valve slit. As for thing, the slit was not adhere | attached by the adhesive agent. Further, in the case where the silicone oil was applied to the slit of the valve, it was easy to insert the air injection rod. In addition, the weight of the air supply valve at this time was 0.6 g, and there was no problem in flight characteristics.
[0016]
Further, in the soft tennis ball used in the experiment of Table 1, the flying property test was carried out by changing the size of the air supply valve, changing only its weight, and changing other manufacturing conditions. The results are shown in Table 2.
[0017]
[Table 2]

[0018]
As can be seen from Table 2, when the air supply valve weighs 1.5 g or more, there is a problem because the flying during the flight becomes large and the player is confused.
[0019]
【The invention's effect】
As described above, in the present invention, the air supply valve is constituted by the valve provided with the slit and the valve peripheral rubber fitted to the outer periphery thereof, and the lubricant is applied to the slit, so that the tip is sharp. Without using a needle, air can be injected into the ball using a hollow, rod-shaped air injector. Therefore, it is possible to prevent accidents that may be accidentally stabbed into the human body, which is a problem in the air injection method using the injection needle, and that the injection needle is used for purposes other than air injection into the soft tennis ball. . In particular, since the lubricant is applied to the blade edge of the cutter and the slit is formed by the cutter, the lubricant can be applied to the slit during the molding. Further, in the present invention, there is no possibility of causing a problem in the flying property of the ball by setting the weight of the air supply valve to 1.5 g or less.
[0020]
Further, in the present invention, since the air injection hole of the ball can be clearly seen, it is possible to prevent an accident such as a puncture of the ball by inserting a needle into a portion other than the thigh. Have
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a configuration of the present invention.
FIG. 2 is a longitudinal sectional view showing an air injection state in the present invention.
FIG. 3 is a longitudinal sectional view showing an example of a conventional soft tennis ball.
[Explanation of symbols]
1 Ball body 2 Air supply valve 3 Valve 4 Slit 5 Second hole 6 Lubricant 7 Valve peripheral rubber 8 First hole

Claims (3)

In a method for producing a soft tennis ball comprising an air supply valve composed of a cylindrical valve and a rubber around the valve,
When manufacturing the ball, the valve peripheral rubber is vulcanized and bonded to a part of the inner wall of the ball main body, a first hole is formed in the radial center of the valve peripheral rubber , and
A second hole for inserting the injection rod of the air injector is formed in the central portion of the valve in the radial direction, and the slit connected to the second hole is formed by the cutter with the lubricant applied to the blade edge of the cutter. wherein the by forming a radial center portion of the valve by applying a lubricant to the slit forming the valve, characterized by inserting bonding said valve to said first bore of said valve peripheral rubber Production method.   The method for producing a soft tennis ball according to claim 1, wherein the total weight of the valve and the rubber surrounding the valve is 1.5 g or less.   2. The method for producing a soft tennis ball according to claim 1, wherein the lubricant applied to the slit is mainly composed of a material having high lubricity such as silicone-based, fluorine-based oil or emulsion, liquid paraffin, or machine oil. .

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