JPH1157072A - Soft tennis ball and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a soft tennis ball and its manufacture which enable injection of air without using an injector with an pointed tip. SOLUTION: In this soft tennis ball 8, a recessed part is provided on the outer circumference of a shell part to be formed into a drum while a guide hole 3 is provided at the center part of the drum and, subsequently, a slit 4 is provided over the entire length along the length thereof. Moreover, a valve 1 made of a rubber built by fitting an O ring 7 into the outer circumference of the recessed part is bonded on the internal surface of the ball 8 while a tiny hole is bored by piercing a skin from outside the ball 8 to communicate with a guide hole 3 provided in the valve 1. In the manufacture of the soft tennis ball using the valve 1, air can be injected into the ball 8 without using the injector with a pointed tip. Moreover, this allows employing of the ball production process almost the same as the conventional process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a soft tennis ball and a method for manufacturing the same.

[0002]

2. Description of the Related Art In a ball used for soft tennis, since the rubber used as a material has air permeability, the air in the ball decreases with time and the elasticity decreases. Must be replenished to restore elasticity. For this reason, conventionally, when air is injected into a soft tennis ball, as shown in FIG. 8, a thick and soft rubber block portion (generally referred to as a "rubber") vulcanized and bonded to the inner wall of the ball. A method has been used in which a syringe needle is penetrated into a bellows, and air is supplied into a ball by a pump.

[0003] However, this method is dangerous because an injection needle may be accidentally stabbed in a finger when air is injected. Further, the injection needle may be used for a purpose other than injecting air into the ball, which is unfavorable due to morals. In addition, there are various problems, such as not only taking time to find the position of the navel visually, but also piercing the ball with a syringe needle at a location other than the navel to make the ball unusable for subsequent use. .

In order to solve the above-mentioned problems, a flanged, valve-type air supply valve used in dodgeballs, basketballs, volleyballs and the like as shown in FIGS. It is considered to be used.

[0005] In the soft tennis ball thus configured, a hollow rod-shaped air injector having a blunt tip can be used for injecting air, so that the use of an injection needle can be eliminated and the above problem can be solved. However, on the other hand, in the above-described structure, there is a problem that, despite the presence of the flange, the bulb is dropped by the impact applied to the ball when hit with the racket, or air leaks from the periphery of the valve. In addition, the presence of the collar requires labor and time for the manufacture of the valve and the work of mounting it on the ball, resulting in a problem in productivity and impractical.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and can easily perform an air injection operation without using a syringe needle. The manufacturing can be efficiently performed by the same mechanism and operation as in the case of the conventional navel.

[0007]

That is, the present invention provides a drum having a concave portion on the outer periphery of a body portion and a guide hole at a center portion, and has a length extending in the vertical direction following the guide hole. And a rubber valve formed by fitting an O-ring to the outer periphery of the concave portion, is bonded to the inner surface of the ball, and a guide hole provided in the valve through the skin from the outside of the ball. A soft tennis ball characterized by having a small hole communicating therewith, and the above-mentioned valve being coated with an adhesive and adhered to one of the rubber cloths, and then the ball is formed. A soft hole formed by drilling a small hole communicating with a guide hole provided in the valve, inserting a tip of a hollow pin of an air pump from the small hole into the ball through the slit, and injecting air. baud Relates to a method of manufacturing these by is obtained by achieving the above object.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a longitudinal side view of the soft tennis ball of the present invention, FIG. 2 is a perspective view of a valve used for the soft tennis ball of the present invention, FIG. 3 is an explanatory view sequentially showing the manufacturing process of the soft tennis ball of the present invention, and FIG. FIG. 5 is a longitudinal sectional side view showing a mode of injecting air into a container.
FIG. 6 is an enlarged vertical sectional side view of the main part, FIG. 6 is an enlarged vertical side view of the main part showing an example of a conventional valve, FIG.
FIG. 1 is a longitudinal side view showing a conventional soft tennis ball and its air injection mode.

In FIGS. 1 and 2, reference numeral 1 denotes a valve made of vulcanized rubber containing natural rubber, which has a concave portion 2 formed on the outer periphery of its body and a drum-shaped member having a guide hole 3 in the center. A slit 4 is provided along the entire length of the valve 1 in the longitudinal direction following the guide hole 3, and an O-ring 7 is fitted on the outer periphery of the concave portion 2. Therefore, the opposing surfaces of the slits 4 are always in close contact with each other due to the tightening force of the O-ring 7.
Numeral 5 denotes an adhesive surface of the bulb 1 with the inner surface of the ball 8, and numeral 6 denotes a tip of the bulb 1. Reference numeral 9 denotes a small hole that penetrates the rubber of the ball 8 and communicates with the guide hole 3. Reference numeral 10 denotes a drill having a cone 11 at the tip for drilling a small hole 9 communicating with the guide hole 3 on the surface of the ball 8.
4 and 5, reference numeral 12 denotes a pump for injecting air, reference numeral 13 denotes a hollow pin, the tip of which is formed as a curved surface, and a hole 14 is provided at the center. 6 and 7
In the conventionally known valve for a soft tennis ball shown in FIG. 1, reference numeral 15 denotes a valve adhered to the inner wall of the ball 8, which is provided with an injection hole 16 in the center and a slit 18 having a radius following the injection hole 16 and a flange 17 on the side surface thereof. It is provided. In the conventional ball and pump 12 for injecting air into the conventional ball shown in FIG. 8, reference numeral 19 denotes an injection needle, and reference numeral 20 denotes a navel for injecting air.

According to the present invention, a cylindrical vulcanized rubber containing natural rubber is used as a material, a concave portion 2 is provided on the outer periphery of a body portion thereof, and a drum having a guide hole 3 in a central portion is formed. And the O-ring 7 is fitted around the outer periphery of the recess 2 to form the bulb 1. The bulb 1 is attached to the ball 8 with an adhesive adhered to the adhesive surface 5 thereof. Glue to the inner wall of Drill 10 from outside of ball 8
The guide hole 3 penetrates through the skin of the ball by using a cone 11 of
The ball 8 is formed by providing a small hole 9 communicating with the ball. Then, as shown in FIG. 4, when the hollow pin 13 of the pump 12 for injecting air is inserted into the ball 8 from the small hole 9 provided in the ball 8, the tip of the hollow pin 13 passes through the guide hole 9 and faces the opposite side. Vertical slits 4 whose faces are close to each other
Is pushed open against the tightening force of the O-ring 7, and the ball 8
Exposure inside. Then, the pump 12 for injecting air is operated to send air into the ball 8 from the hole 14. When the hollow pin 13 of the pump 12 for injecting air is withdrawn after a predetermined amount of air has been supplied, the opposing surfaces of the slit 4 of the valve 1 come into close contact with each other due to the suppression of the O-ring 7.
The ball 8 is configured without the air in the ball 8 leaking to the outside.

The size of the drum-shaped bulb 1 in the present invention is 10 mm in diameter of the bonding surface 5 and 8 m in diameter of the tip 6.
m, a height of 8 mm, and a diameter of the recess 2 of about 5.5 mm are appropriate. Further, the guide hole 3 at the center portion is provided so that the tip of the drill 11 of the drill 10 is formed in order to prevent the drill from damaging the valve 1 when drilling the small hole 9 from the outside of the ball 8. This is to detect the phenomenon that the cutting force changes suddenly at the moment of passing through the skin.
It is appropriate that the depth is about 1.5 mm and the width of the slit 4 is about 2.2 to 2.5 mm. Further, the O-ring 7 fitted into the concave portion 2 of the valve 1 is made of rubber, and its inner diameter is suitably about 4.5 mm smaller than the diameter of the concave portion 2. The diameter of the distal end portion 6 of the bulb 1 is set to about 8 mm as described above because the O-ring 7 has an inner diameter of 1 so that the O-ring 7 does not come off the concave portion 2 due to the deformation of the racket due to impact.
This is because it is necessary to make it about 60%. Also, the weight of the valve should be 0.45g or less to reduce the difference between the ball center of gravity and the center of gravity of the ball, and to prevent rotational shake during use. The total weight of the valve and the O-ring should not exceed 0.5g. It is necessary to The small hole 9 drilled from the outside of the ball 8 toward the guide hole 3 of the bulb 1 is suitably about 1.5 mm in diameter.

Next, a method of manufacturing the ball of the present invention will be described with reference to FIG. First, as described above, a drum-shaped drum having a cylindrical portion formed of vulcanized rubber containing natural rubber and having a concave portion 2 formed on the outer periphery of its body is formed. A guide hole 3 having a depth of about 0.5 mm and a depth of about 1.5 mm is provided.
Next, using a cutter, a slit 4 having a width of 2.2 to 2.5 mm is formed in the longitudinal direction following the guide hole 3 over the entire length of the drum. Further, in the concave portion 2 provided on the outer periphery of the drum shape,
Using a pipe jig (not shown),
The valve 1 is formed by fitting the ring. Therefore, the contact surface 5 of the bulb 1 is attached to the inside of the ball 8 to form the ball 8. At this time, the position of the guide hole 3 of the valve 1 on the outer surface of the ball 8 is marked,
Then, using the drill 10 or the like as a target, the small hole 9 which penetrates the skin of the ball 8 and communicates with the guide hole 3 provided in the valve 1 adhered to the inner surface of the ball 8 is drilled using the drill 10 or the like. Set up.

Therefore, as shown in FIG. 4, a hollow pin 13 of a pump 12 for injecting air is pierced into the small hole 9, and a guide hole 3 and a slit 4 of the valve 1 are
The slit 4 is pushed out and expanded against the tightening force of
The tip of the hollow pin 1 is projected through the slit 4 into the ball 8 and the air injection pump 12 is operated.
Air is blown into the ball 8 from the hole 14 provided at the tip of the nozzle 3. After a predetermined amount of air is supplied, a pump 1 for injecting air
When the second hollow pin 13 is pulled out, the air in the ball 8 does not leak because the slit 4 closes and closes due to the tightening force of the O-ring 7. Thus, the ball 8 can be manufactured.

In the soft tennis ball of the present invention configured as described above, the O-ring 7 moves in the direction of the distal end surface 6 of the bulb 1 in response to the impact caused by the impact of the racket, and acts to tighten the O-ring 7.

[0015]

As described above, according to the present invention, the valve is formed in the shape of a drum, a slit is provided at the center thereof, and an O-ring is fitted around the outer periphery of the valve. Since the valve is closed, air can be injected from the valve into the ball using a hollow rod-shaped air injector without using a sharp-pointed injection needle. Therefore, accidents such as accidentally stabbing the human body, which had been a problem in the conventional air injection method using a needle, and the use of the injection needle for purposes other than air injection into a soft tennis ball, etc., have been considered. Can be prevented. Further, according to the present invention, since the small hole is formed on the outer surface of the ball, the air injection hole of the ball can be clearly recognized, and an accident such as puncturing the ball by inserting a needle into a portion other than the navel can be prevented. This can be prevented.

Further, according to the present invention, the valve can be bonded to the inner wall of the ball by using substantially the same process as the conventional method for manufacturing a soft tennis ball, so that productivity in the ball manufacturing process is not hindered. It has excellent effects such as efficient production.

[Brief description of the drawings]

FIG. 1 is a longitudinal side view of a soft tennis ball of the present invention.

FIG. 2 is a perspective view of a valve used for the soft tennis ball of the present invention.

FIG. 3 is an explanatory view sequentially showing a manufacturing process of the soft tennis ball of the present invention.

FIG. 4 is a longitudinal side view showing a mode of injecting air into the soft tennis ball of the present invention.

FIG. 5 is an enlarged vertical sectional side view of a main part thereof.

FIG. 6 is an enlarged vertical sectional side view of a main part showing an example of a conventional valve.

FIG. 7 is a bottom view of the same.

FIG. 8 is a longitudinal sectional side view showing a conventional soft tennis ball and a mode of air injection thereof.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 valve 2 recess 3 guide hole 4 slit 5 bonding surface 6 tip 7 O-ring 8 ball 9 small hole 10 drill 11 cone 12 air injection pump 13 hollow pin 14 hole 15 valve 16 injection hole 17 flange 18 slit 19 injection needle 20 belly button

Claims (2)

[Claims] 1. A drum-shaped part having a concave portion provided on the outer periphery of a body portion, and a guide hole and a slit extending over the entire length in the vertical direction are provided at a central portion of the drum shape. A rubber valve formed by fitting an O-ring around the outer periphery of the ball is adhered to the inner surface of the ball, and a small hole that penetrates the skin from the outside of the ball and communicates with the guide hole provided in the valve is formed. Soft tennis ball characterized by becoming. 2. A concave portion is provided on the outer periphery of the body portion, a drum having a guide hole is formed at the center portion, and a slit is provided over the entire length in the vertical direction following the guide hole, and the outer periphery of the concave portion is provided. A rubber valve formed by fitting an O-ring to the surface is coated with an adhesive and adhered to one side of a rubber material, and then a ball is formed. A guide hole provided in the outside of the ball and the valve is provided. A method of manufacturing a soft tennis ball, characterized in that a small hole communicating with the air hole is formed, and a tip of a hollow pin of an air pump is inserted into the ball from the small hole through the slit, and air is injected.