JPH0994312A - Hard and soft tennis ball capable of injecting air by air injector with nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hold fixed internal pressure at all times by providing a check valve provided with an injection port for injecting air and a discharge port on the inner wall of a ball and injecting the air to the ball by an air injector with a nozzle. SOLUTION: In the process of manufacturing the ball, before adhering two rubber semi-spheres in the case of the hard tennis ball and before adhering the two or three sheets of rubber in the case of the soft tennis ball, the check valve 2 provided with the injection port 1 for injecting the air and the discharge port 3 is attached to the inner wall of the ball by an adhesive material. The check valve is provided with elasticity like the rubber of a rubber balloon and is closely adhered to the inner wall of the ball. The air injector is constituted by attaching the nozzle instead of the needle of the well-known air injector with the needle and the air is injected inside the ball after putting the nozzle in the injection port 1. When the air is injected too much, by slightly pushing up the check valve 2 through the injection port 1 and discharging the air to the outside of the ball, the internal pressure is appropriately adjusted.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hard and soft tennis ball in which air can be injected by an inflator with a nozzle even if the internal pressure of the ball is reduced. be able to.

[Prior Art] According to Treton's announcement,
As a result of a test by the Swedish National Institute for Materials Science, the decrease in the internal pressure of a hard tennis ball was
Company internal pressure decreased by 9% and Company B 21%. At present, the foaming agent and water are made to react in the ball while raising the temperature to increase the internal pressure of the ball, and even if the internal pressure of the ball decreases, air cannot be injected into the ball. A ball with an internal pressure reduced by around 20% has a very bad ball bound. Tennis players are extremely reluctant to use a ball with reduced internal pressure. Even if the melton (felt) on the ball is as good as new, the ball with reduced internal pressure is immediately discarded. For this reason, balls that have been thrown away because they cannot be used at any tennis club are piled up like a mountain, and they are in a state of trouble for disposal. In addition, since the internal pressure of the rigid tennis ball begins to decrease immediately after manufacturing, it is contained in a container to which pressure is applied, so this container is also a large amount of dust. In 1997, the "Packaging Container Recycling Law" was enacted, which imposes on businesses the recycling of containers such as cans and PET bottles. Ball manufacturers must bear tremendous costs, and hard tennis balls are still manufactured by manufacturers. The price of each item will be around 400 yen, but the price increase is unavoidable.Manufacturers have to deal with further environmental problems such as discarded balls and containers. On the other hand, in the case of soft tennis balls, A needle-inflator is used to attach the needle to the ball's navel to inject the air. This needle can be very dangerous and often gets stuck in the finger, and the same place on the navel to prevent air from leaking. To prevent the needle from sticking to the needle, the needle often bends or breaks while striking at an angle. It looks worse and there, and the last is at present, so that leakage of air from the navel.
Also, the navel itself is often stuck. When the navel is caught or is loose, the trajectory of the ball often swings and is not stable.

[Problems to be Solved by the Invention As described above, the life of the hard tennis ball is short. The problem to be solved by the present invention is to find out what means should be taken to increase the internal pressure of the ball again even if the internal pressure of the ball is reduced. Therefore, what kind of means should be taken to eliminate the need to collect the container? For soft tennis balls, what measures should be taken to inject air without using an inflator with dangerous needles, and thus to eliminate the need for a svelte navel? It is in.

[Means for Solving the Problems] In the process of making a ball, before bonding two rubber hemispheres in the case of a hard tennis ball, and in the case of a soft tennis ball, two or three rubbers. Before adhering, a check valve 2 having an inlet 1 for introducing air and an outlet 3 is attached to the inner wall of the ball with an adhesive. The positions of the inlet 1 and the outlet 3 are displaced. The check valve is elastic like the rubber of a rubber balloon and is in close contact with the inner wall of the ball. The check valve may have any shape as long as the gap between the inlet 1 and the outlet 3 can be secured. An elastic adhesive is recommended as the adhesive to withstand the impact at the time of impact. Also, the material of the check valve should be elastic like rubber so that it will not wrinkle or form a gap when adhered to the inner wall of the ball. In addition, the check valve is thicker than thin, and the check effect is higher. If a small amount of oil or other liquid is introduced through the injection port, the closeness of contact between the check valve and the inner wall of the ball will increase and the check effect will increase. Remove this needle from the inflator with the needle of the currently used soft tennis ball, attach a nozzle instead, and insert this nozzle into inlet 1 to inject air. A ring is attached to the base of this nozzle. When too much air is put in, this ring is removed, and the nozzle becomes longer by that amount, so if you raise the check valve a little from the inlet, the air will come out of the ball. The internal pressure of the ball can be adjusted because it comes out. In this case, air comes out through the hole in the rubber part of the inflator. The structure of this check valve is very simple, but even if the pressure in the ball suddenly increases due to impact, the air will push the check valve strongly and the air in the inlet 1 will be blocked with a strong force. Will never get out of the ball. Note that
You must use a material that does not turn over at the outlet 3 or wrinkle or make a gap in the check valve. It just needs to fit tightly to the inner wall of the ball. Further, this check valve can be applied to various things such as bicycle tubes, car tires, soccer balls, volleyballs, basketballs, etc., which need to contain air or gas to prevent its backflow. Moreover, it is smaller, simpler, and much cheaper than the check valves currently used. In water experiments, it also had the effect of non-return. Only the discharge port 3 of this check valve is not bonded. Further, as will be shown later in the embodiment, even if the entire circumference of the check valve is adhered and the discharge port 3 is provided at a position deviated from the injection port 1, the check effect is the same.

[Operation] A nozzle of an inflator with a nozzle is put in the inlet 1 and air is introduced while manually checking the internal pressure of the ball. When too much air is put in, remove the ring at the base of the nozzle, put it in through inlet 1 and push up the check valve a little, and air will come out of the ball. Air comes out from the round hole in the rubber part of the inflator.

[First Embodiment] FIG. 1 is a plan view of a check valve 2 showing a first embodiment. The structure and adhesion of the check valve are exactly the same for both hard and soft tennis balls.
The other portion is bonded to the inner wall of the ball without bonding only the discharge port 3 around the check valve. Inlet 1 is not visible and is shown by the dotted line. The positions of the inlet 1 and the outlet 3 are displaced. The air injected from the inlet 1 enters the ball via the outlet 3. Despite the fact that the discharge port 3 is not adhered, the air inside the ball does not flow backward and exit the ball through the injection port. This is probably because the check valve 2 is pressed by the pressure of the air in the ball and the inlet 1 is strongly blocked.

[Second Embodiment] FIG. 2 is a plan view of a check valve 2 showing a second embodiment. The area around the check valve is completely bonded, and the discharge port 3 is provided at a position offset from the injection port 1.

[Advantages of the Invention] According to a test by the National Institute for Materials Science, Sweden, in the case of hard tennis balls, the internal pressure decreased by 9% for Company A and 21% for Company B one week after the ball was purchased. In this way, the life of the balls is very short, and a large number of balls are thrown away and turned into garbage. Also, since the internal pressure begins to decrease immediately after the ball is manufactured, it must be placed in a PET bottle or can under pressure. Since the "Packaging Container Recycling Law" will come into effect in 1997, the burden on manufacturers will be heavy and it will be a major environmental problem. The ball with the check valve of the present invention can be filled with air many times, so that the life of the ball is extended. Since the player can easily inflate the ball, there is no need to put it in a high-pressure PET bottle or can, and therefore, to collect them, and the ball can be simply wrapped in a plastic bag. It can be said that it is an environmentally friendly ball. The check valves currently used for soccer balls and basketball are so large and heavy that they cannot be used for small balls. The check valve according to the present invention has a very simple structure and has almost no weight of the check valve. Therefore, the trajectory of the ball does not fluctuate, it can be applied to any ball that is filled with air, and it is very inexpensive. There is no need for the work to perform the reaction of the foaming agent for obtaining the pressure of the ball and the water while raising the temperature and the device that is currently performed, and the work to put the ball in a PET bottle or a can and pressurize them and the device. Therefore, there is no need to collect PET bottles and cans, and the products can be sold in simple packaging, so that the manufacturing cost of balls can be significantly reduced. At a school where I practice every day or at a tennis school, it costs about 400 yen each, so I was sick of the budget. Since a ball with a check valve can be filled with air many times, it doesn't have to be thrown away as before, and it can be used for a long time. If used in combination with the felt protection cover (mesh-shaped cover made of thin nylon, etc.) that I applied for earlier, the life of the ball can be greatly extended. On the other hand, in the case of a soft tennis ball, if this check valve is provided, it does not require the navel currently used and is much lighter than the navel, so the trajectory of the ball does not swing. It's very safe because you don't need to use needles to inflate the air, which also improves the image of soft tennis. In addition, the ball does not have to be stuck in the navel many times, so the life of the ball and its appearance are good. Also, this check valve can be made cheaper than the navel.

[Brief description of drawings]

FIG. 1 is a plan view of a check valve 2 showing a first embodiment of the present invention.

FIG. 2 is a plan view of a check valve 2 showing Embodiment 2 of the present invention.

FIG. 3 is a perspective view showing a state where the check valve 2 of the present invention is adhered to the inner wall of the ball. Inlet 1 is not visible and is shown in dotted lines.

[Explanation of symbols]

 1 is inlet 2 is check valve 3 is outlet

Claims (1)

[Claims] 1. A hard and soft tennis ball having an inlet 1 for introducing air and a check valve 2 provided with an outlet 3 on the inner wall of the ball so that the air can be injected by an inflator with a nozzle.