JPS5915656Y2 - Baseball hard ball - Google Patents

Description

[Detailed description of the invention] A spherical core made of hard synthetic resin, etc. is covered with a semi-hard covering, and a soft thin layer made of thread, etc. Hardball baseballs made of wood are well known.

When you hit a baseball like this with a bat, the force is
After compressing the soft thin layer and the semi-rigid envelope, it is transmitted to the hard core body and exerts a strong repulsive force.

Therefore, by varying the hardness and thickness of the soft thin layer and semi-rigid envelope, different repulsion forces can be obtained.

However, since the soft thin layer is intended to provide a desired feel when gripping or catching a ball,
Its hardness and thickness tolerances are not very large.

Therefore, in order to exert the required repulsion force and keep the flight distance when the ball is hit with a certain force within a certain limit set by regulations, etc., the hardness and thickness of the semi-hard enveloping body must be adjusted. However, if the hardness of the semi-hard cover is too high, the repulsive force will be excessive, and the external force associated with hitting the ball will be difficult to properly transmit to the core, making it more likely to break. There is a possibility that

Furthermore, if the thickness of the cover is made too large, there will be a problem in that if the thickness of the cover increases, the repulsion force will be reduced, the durability will be reduced, and the sound of the ball will be poor.

In view of these points, the present invention improves durability by reducing the thickness of the semi-rigid envelope itself as much as possible.
By making the ball perform essentially the same function as a semi-rigid envelope, it is possible to maintain the flight distance when hitting the ball within an appropriate range, and it has excellent durability, as well as being able to emit a pleasant sound when hitting the ball. The aim is to provide a baseball made from a variety of materials.

The figure shows an example of a baseball ball according to the present invention.
The following explanation will be based on this.

Reference numeral 1 denotes a spherical core made of hard synthetic resin, on the outer periphery of which a large number of small concave holes 2 of small diameter and constant depth are bored at approximately equal intervals and facing in the centripetal direction.

Note that the figure shows one cross-section, so the spacing between the small concave holes 2 appears to be a little large, but when you actually look at it from the outside, the spacing between the adjacent small concave holes 2. It's quite small.

The outer periphery of the core body 1 is covered with a semi-rigid covering body 3 made of, for example, rubber mixed with thread waste, felt, etc., and the insides of each of the small recesses 2 are left as voids 4.

The outer periphery of the semi-rigid envelope 3 is covered with a soft thin layer 5 made of thread or the like, and the outer periphery of the upper layer 5 is covered with a skin material 6 made of cowhide.

In the baseball ball of the present invention having the above-mentioned structure, a large number of small concave holes 2 of a constant depth and facing in the centripetal direction are bored in the outer circumference of the hard core body 1, and the inside of the concave holes 2 are bored. is the air gap 4
Since the core body 1 is left as it is, it appears as if the core body 1 has a porous spherical shell part (indicated by an imaginary line 1a in the figure) with a thickness corresponding to the depth D of the small concave hole 2 at its outer periphery. (the part between the outer circumferential surface of the core 1) and the solid sphere (
It can be regarded as consisting of a ball (shown by the imaginary line 1a).

Due to the presence of a large number of small concave holes 2, the spherical shell part has a slightly increased flexibility compared to the solid spherical part inside it, and has a lower apparent specific gravity and average stiffness. Rather, it has properties similar to the semi-rigid envelope 3.

In other words, this ball is in the same state as if the thickness of the semi-hard covering body 3 had been substantially increased, and even though the hardness of the covering body 3 itself was quite large, the flight distance could not be adjusted properly. It can be kept within the range.

Therefore, the spherical shell portion in the core body 1 is essentially
Since it is integrated with the solid spherical part on the inside thereof, the external force accompanying the ball being hit is transmitted to the solid spherical part, and the repulsive force is transmitted to the covering body 3 very well.

Therefore, according to the present invention, the diameter of the core body 1 is made as large as possible, and the thickness of the semi-rigid envelope 3 is made as small as possible,
It can exhibit the same characteristics as conventional baseball balls of this type.

Furthermore, since the covering body 3 can be made thinner, there is less risk that that part will sag or break as in the conventional case, and durability is also improved.

Furthermore, due to the presence of a large number of small concave holes 2, it is easy to make a pleasant sound when hitting the ball, and by selecting various numbers and depths of the small concave holes 2, the repulsion characteristics and weight can be set over a wide range.
Moreover, it is advantageous because it has a simple configuration and is easy to implement.

[Brief explanation of drawings]

The figure is a longitudinal sectional front view showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Core body, 2...Small concave hole, 3...Semi-hard enveloping body, 4...Void, 5...Soft thin layer, 6...Skin material.

Claims (1)

[Scope of utility model registration request] In a baseball made of a spherical core made of a hard synthetic resin material, which is covered with a semi-hard covering material, and then covered with a skin material, the outer periphery of the core has a certain depth facing in the centripetal direction. A baseball ball characterized by having a large number of small concave holes formed therein and leaving the inside as a void.