JP2001025516A - Ball for regulation baseball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ball for regulation baseball which has the characteristics similar to an ordinary regulation ball and has excellent waterproofness. SOLUTION: The outermost layer of the ball for regulation baseball which is provided with a layer 13 consisting of woolen yarn on the outer periphery of a rubber core 12 internally having baked cork and is provided with the outermost layer 15 via a layer 14 consisting of cotton yarn on its outer periphery is composed of a water impermeable resin. The ball is provided with a cotton layer 16 having density of 10 to 75% of the woolen yarn layer between the rubber core and the woolen yarn layer. The entire weight of the ball is specified to 142 to 148 g.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball used for a rigid baseball.

[0002]

2. Description of the Related Art As shown in FIG. 2, a rigid ball currently used in professional baseball, high school baseball, etc. has a fired cork 1 inside.
A layer 3 made of wool is provided on the outer periphery of the rubber core 2 having a layer, and an outermost layer made of cowhide 5 is provided on the outer periphery of the layer 3 via a layer 4 made of cotton yarn.

[0003] In this ball, the outermost layer of cowhide is easily damaged and easily deformed by impact such as impact. That is,
Since the cowhide is not uniform in density, strength and restoring force, irregularities are generated each time the impact is repeated, and it is difficult to restore the irregularities. For these reasons, the service life of the ball is not very long. Further, in this hard ball, the stitched portion of cowhide is the portion having the weakest strength. For this reason, when an impact such as a blow is applied to this portion, the sewing thread may be cut, or the cowhide in the peripheral portion may be broken and become unusable.

[0004] In addition, the hard ball is more likely to soak in water such as rainwater than the seam of cowhide. When the water penetrates into the hard ball, the yarn is impregnated with the water and causes deterioration of the yarn. For this reason, when the ball is hit, shrinkage occurs.
Further, as described above, since the hard ball is more easily permeated by rainwater or the like than the seam of the cowhide, moisture flows in and out depending on the use environment, that is, the weather and humidity, and the weight of the whole ball is significantly changed.

As a solution to this problem, there are known a top ball, practice ball and the like in which the outermost layer is covered with a resin. As shown in FIG. 3, the top ball has a fired cork layer 7 provided around a foamed polyurethane core 6 and a resin elastomer layer 8 provided around its periphery. The practice ball is a ball for a hardball baseball practice for rainy weather. As shown in FIG. 4, the practice ball is provided with a resin elastomer layer 10 on the outer periphery of the core of the fired cork layer 9.

Since these balls have a resin elastomer layer as the outermost layer, they have excellent waterproofing properties and can resist deformation due to impact.

[0007]

However, the above-mentioned top ball is not approved for use in hardball baseball, but is used for semi-hardball baseball. In addition, the weight of the above-mentioned top ball and practice ball is heavier than that of a normal hard ball. For this reason, it gives a sense of incongruity to a player or the like, and is hardly used as a substitute for a normal hard ball, even for practice. Further, the ratio of the density of the outer peripheral portion to the density of the core portion of the above-described top ball or practice ball is larger than the ratio of the density of the outer peripheral portion to the density of the core portion of a normal hard ball. For this reason, when the ball is given a rotation, changes in curves and the like are likely to occur,
And it changes greatly.

Further, in the above-mentioned top ball and practice ball, the outermost resin elastomer layer has a higher elasticity and repulsive force than a normal hard ball, so that the hit distance increases the flight distance and the bounce tends to increase.

In order to overcome the difference in weight and make the weight of the top ball or practice ball equal to that of a normal hard ball, it is conceivable to reduce the weight of the outermost resin elastomer layer.

In this case, the thickness of the outermost layer decreases, and the strength of the outermost layer relatively decreases. For this reason, it is conceivable that the outermost resin elastomer layer is deformed and ruptured as the use is repeated, and the waterproof property is lost.

It is an object of the present invention to provide a ball for a hardball baseball having the same characteristics as a normal hardball and having excellent waterproof properties.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the invention according to the ball for a rigid baseball is provided with a layer made of wool around an outer periphery of a rubber core having a fired cork therein.
In a ball for a rigid baseball having an outermost layer provided through a layer made of cotton yarn on the outer periphery thereof, the outermost layer is made of a water-impermeable resin, and between the rubber core and the yarn layer, A cotton layer having a density of 10 to 75% of the wool layer is provided, and the total weight is 142 to 148 g.

Since the outermost layer of the ball is made of a water-impermeable resin, the ball is waterproof and can suppress the deterioration of the ball due to the intrusion of water and the fluctuation of the weight of the ball.

Further, the obtained ball can be reduced in weight except for the outermost layer, as compared with a normal hardball baseball. For this reason, as the water-impermeable resin of the outermost layer,
Since a weight larger than the weight of the outermost cowhide of a normal official baseball ball can be used, a thicker one can be used. Therefore, the strength of the outermost layer can be increased, breakage can be prevented, and waterproofness can be maintained.

Further, as the water-impermeable resin, a resin having a taper abrasion of more than 0 mg and 200 mg or less can be selected.

With this configuration, the outermost resin layer is unlikely to be damaged, broken, thermally deformed, or burned. For this reason, the life of the ball can be extended.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

A ball for a hardball baseball (hereinafter referred to as a "new ball") according to the present invention, as shown in FIG.
A layer 13 made of wool is provided on the outer periphery of a rubber core 12 having a baked cork 11 inside, and a layer 15 made of a water-impermeable resin is provided as an outermost layer on the outer periphery via a layer 14 made of cotton yarn. is there.

A cotton layer 16 having a predetermined density is provided between the rubber core 12 and the yarn layer 13.

Specific examples of the resin used for the water-impermeable resin layer 15 constituting the outermost layer of the new ball include polyethylene, polypropylene, polystyrene, polyamide resin, epoxy resin, thermoplastic polyurethane resin, polyester resin, and acetic acid. Examples include thermoplastic resins such as vinyl resins, ABS resins, and acrylic resins, thermosetting resins, and thermoplastic resin elastomers. Among these,
A polyamide resin, an epoxy resin, a thermoplastic polyurethane resin, a polyamide elastomer, a thermoplastic polyurethane vulcanized elastomer and the like are preferable, and a thermoplastic polyurethane resin, a thermoplastic polyurethane vulcanized elastomer and the like are particularly preferable.

The water-impermeable resin layer 15 may be in the form of a resin itself, or may be in the form of synthetic leather or artificial leather.

The water-impermeable resin constituting the water-impermeable resin layer 15 preferably has properties such as tapered wear, hardness, breaking strength, and softening temperature.

The taper abrasion measured by JIS K 7311 is preferably more than 0 mg and not more than 1000 mg, more preferably not more than 200 mg, and preferably not more than 100 mg.
It is more preferred that: Furthermore, in order to prevent the resulting new ball from being damaged or broken, and to further improve the durability, the taper abrasion is 0 mg.
More preferably, 15 mg or less,
0.1 mg or more and 10 mg or less are still more preferable,
Particularly preferred is 0.1 mg to 1 mg. 200mg
If it exceeds, the outermost layer is likely to be damaged or broken.

The hardness is JIS K 7311 type A
Is preferably 50 to 100, more preferably 60 to 100, and still more preferably 80 to 95. If it is less than 50, deformation is easily caused by impact, and
If it exceeds 100, it is too hard, and a feeling equivalent to that of a conventional ball cannot be obtained.

The breaking strength is preferably from 10 to 100 MPa, more preferably from 40 to 100 MPa, as measured by JIS K 7311.
a is more preferable, and 50 to 100 MPa is further preferable. If it is less than 10 MPa, the outermost layer is likely to be damaged or broken. Further, the pressure may exceed 100 MPa, but there is no particular need to have such a performance.

The softening temperature is preferably from 50 to 300 ° C., more preferably from 80 to 300 ° C., even more preferably from 90 to 300 ° C., as measured by JIS K 7206.
300 ° C. is even more preferred. If the temperature is lower than 50 ° C., burning tends to occur due to friction caused by the use of a pitching machine and friction caused by batting. In addition, the temperature may exceed 300 ° C., but there is no particular need to have performance up to that.

If the above characteristics are satisfied, sufficient strength is exhibited within the range of normal ball use such as baseball games, batting practice, and practice with a pitching machine.

In addition, among the above-mentioned characteristics, if at least the requirement of the taper wear is satisfied, the water-impermeable resin layer 15 used for the new ball is prevented from being scratched, rubbed, broken, thermally deformed, burned, and the like. Is more preferable.

When the water-impermeable resin layer 15 as described above is used, the new ball is prevented from being damaged or broken, and has a waterproof property. Therefore, it is possible to withstand use in rainy weather. Further, since the water-impermeable resin layer 15 has a uniform density, strength, and restoring force in any portion, unevenness is unlikely to occur even if the impact is repeated.

The method of manufacturing the new ball by coating the water-impermeable resin layer 15 as the outermost layer is a method of coating by injection molding using a mold, and the above synthetic leather or artificial leather is bonded as the outermost layer. Any method can be adopted, such as a method of covering the boundary and fusing the boundary with the same resin. Since the new ball of the present invention does not have a seam, a weak portion does not occur. For this reason, the sewing thread is not cut by the impact and the outermost layer around the sewing thread is not broken, so that the life of the ball is extended.

The cotton layer 16 is a layer lighter than the yarn layer 13 forming the outer layer, that is, a layer having a lower density. The density of the cotton layer 16 is 10 to 7 of the density of the yarn layer 13.
5% by weight is preferable, 30 to 70% by weight is preferable, and 40 to
65% by weight is more preferred, and 50-63% by weight is even more preferred. If the weight is more than 75% by weight, the thickness of the outermost water-impermeable resin layer 15 must be reduced in order to keep the weight of the new ball within a predetermined range described later, and scratches and breaks may occur. is there. It may be lighter than 10% by weight,
Such cotton has not been found.

The cotton constituting the cotton layer 16 is not particularly limited as long as the density of the cotton layer 16 satisfies the above conditions. In particular, cotton collected from the seeds of Panha has a density of the cotton layer 16 formed when a new ball is manufactured using the same, and a density of 50 to 63 times that of the yarn layer 13.
% By weight. The cotton collected from the seeds of the panya is cotton, commonly called kapok, and is collected in tropical regions of Southeast Asia. The density of the cotton layer 16 and the density of the yarn layer 13 can be measured after manufacturing the above-mentioned new ball. That is, the manufactured new ball is divided in half, the volume occupied by the cotton layer 16 and the yarn layer 13 is calculated, and the density can be measured from this and the amount of the used cotton and yarn.

The cotton layer 16 is formed by pressing the kapok into a predetermined shape at a pressure of about 30 kg / cm ² and then heat-treating the entire mold at 240 to 260 ° C. for 2 minutes to 2 minutes 30 seconds. It is manufactured by

The total weight of the new ball is 142 to 148
g. This is the same as the standard of a hard ball (hereinafter, referred to as a “conventional ball”) whose outermost layer is made of cowhide as shown in FIG. 2, which is usually used in professional baseball, high school baseball, and the like. is there.

Of the configuration of the above-mentioned new ball, the baked cork 11
For the rubber core 12, the yarn layer 13, and the cotton layer 14 having a rubber ball, a rubber core, a wool, and a cotton yarn having a baked cork used in professional baseball or high school baseball are used. For this reason, the new ball is the same as the conventional ball except for the cotton layer 16 formed between the rubber core 12 and the yarn layer 13 and the outermost water-impermeable resin layer 15.

The cotton layer 16 and the water-impermeable resin layer 15
In addition to the weight that satisfies the range of the total weight of the new ball, the density ratio between the core and the outer periphery of the new ball is equal to the density ratio between the core and the outer periphery of the conventional ball. It is preferable that By doing so, there is no difference in the change due to rotation between the new ball and the conventional ball.

It is desirable that the new ball has a predetermined repulsive force. This repulsive force can be measured by a conventional ball rebound test. In this rebound test, a ball to be measured is dropped on marble from a height of 13 feet and 5 inches (approximately 4.09 m), and the height of the ball is measured. The repulsive force at this time, that is, the height that jumped up is 4 feet 7 inches (about 1.397 m)
Conventional ball rebound test standards fall within the range of ボ ー ル 4 feet and 9 inches (about 1.448 m). When the repulsive force of the new ball falls within this range, the new ball has the same repulsive force as the conventional ball, and can be handled in the same manner as the conventional ball.

[0038]

[Manufacture of balls]

(Production Example) 10 g of Kapok (produced by Kanematsu Co., Ltd. from Southeast Asia) was placed in a female mold of a hemispherical mold, and a male mold having a hemispherical protrusion was pressed from above with a gauge pressure of 26 kg / cm ² . Next, the mold was heated at 240 to 260 ° C. for 2 minutes to obtain a kapok molded body. This molded article was used as a cotton layer. The density of the above-mentioned Kapok molding is 0.33 g /
cm ³ . The above-mentioned kapok molded article, a rubber core having a baked cork used for a rigid ball for professional baseball, a wool,
Using a cotton thread, a new ball was produced as shown in FIG. That is, the above-mentioned two kapok moldings were covered around the rubber core, the wool was wound therearound, and the cotton yarn was wound therearound. Next, this was put in a mold, and a molten thermoplastic polyurethane resin (3537, manufactured by Kuraray Co., Ltd.) was poured around the mold and cooled, thereby producing a ball having a structure as shown in FIG. The average weight of ten of the balls obtained was 146 g, and all balls were in the range of 142-148 g. Also, divide one of the obtained balls in half and apply a cotton layer (Kapok molded body layer)
And the density of the yarn layer were measured. As a result, the density of the cotton layer (the layer of the formed compact) was 0.33 g / cm ^3, which was not changed from the density at the time of manufacturing the formed kapok. The density of the yarn layer was 0.53 g / cm ³ . In addition, the tapered abrasion of the used thermoplastic polyurethane resin (JIS
K 7311, H-22 used as wear wheel) 1 mg,
The hardness (JIS K 7311 Type A) was 90, the breaking strength (JIS K 7311) was 57 MPa, and the softening temperature (JIS K 7206) was 116 ° C. (Example 1) A repulsion test was performed using ten new balls produced in the production example. That is, a new ball was dropped on marble from a height of 13 feet 5 inches (about 4.09 m), and the repulsive force, that is, the height of the jump was measured. As a result, the maximum repulsion is 4 feet 9 inches and the minimum is 4 feet 8
The average of ten inches was about 8.5 feet (about 1.435 m). The value of the repulsive force is from 4 feet 7 inches (about 1.397 m) to 4 feet 9 inches (about 1.44) which is a standard of a conventional ball.
8m), it is possible to receive the same handling as a conventional ball.

[0039]

According to the present invention, the ball obtained is
The surface is not easily scratched or broken, and the ball itself is not easily deformed or burned. For this reason, the life of the ball can be extended.

Further, since the obtained ball is waterproof, it is possible to suppress the deterioration of the ball due to the intrusion of water and the fluctuation of the weight of the ball. For this reason, it can be used for training in rainy weather.

Further, since the obtained ball has the same standard as the conventional official baseball for both the total weight and the rebound,
The same handling as a conventional official baseball can be performed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a ball according to the present invention.

FIG. 2 is a sectional view showing an example of a conventional ball.

FIG. 3 is a cross-sectional view of a top ball.

FIG. 4 is a sectional view of a practice ball.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 baked cork 2 rubber core 3 wool layer 4 cotton thread layer 5 cowhide 6 expanded polyurethane core 7 baked cork layer 8 resin elastomer layer 9 baked cork layer 10 resin elastomer layer 11 baked cork 12 rubber core 13 wool layer 14 cotton thread layer 15 water impervious Resin layer 16 Cotton layer

Claims (3)

[Claims] 1. A ball for a hardball baseball comprising a layer made of wool provided on an outer periphery of a rubber core having a burnt cork therein, and an outermost layer provided on the outer periphery thereof via a layer made of cotton yarn, wherein the outermost layer is made of water. While being made of impermeable resin,
Between the rubber core and the yarn layer, 10 to 75 of the yarn layer
% Cotton layer, with a total weight of 142-148
g. A baseball for hardball. 2. The ball according to claim 1, wherein the cotton layer is made of cotton collected from panya seeds. 3. The ball according to claim 1, wherein the water-impermeable resin has a taper abrasion of more than 0 mg and 1000 mg or less.