JPS6033981Y2 - hollow baseball bat - Google Patents

Description

[Detailed description of the invention] The present invention relates to a hollow baseball bat made of a metal member such as an aluminum alloy, which has the same flexibility as a wooden bat, and has a striking point that is the center of impact (center of impact). This relates to a bat that can be detected.

In general, the structure of currently used hollow baseball bats, such as metal bats, is such that the ball hitting part, taper part, and grip part are formed with a uniform thickness (simply called S) due to the manufacturing process such as drawing processing. It is something.

For this reason, for example, the ball hitting part has a structure (thick wall) that can withstand external pressure.
If this is adopted, the repulsive force caused by the bending phenomenon in the grip will be inferior.On the other hand, if the grip is made thin to maximize the repulsive force, the ball hitting part will be brittle and easily dented by impact. This causes a defect.

In addition, with a hollow bat of uniform thickness, not only does it result in an increase in weight as a whole, but it is also difficult to intuitively determine the impact center (center of impact) position of the ball-hitting part, and from this point of view, batting technique is also important. This is a bat that is difficult to demonstrate.

That is, in order to obtain the maximum repulsion force, it is necessary to hit the ball with appropriate deflection and follow-through technique only when it hits the center of impact.

For this reason, it is necessary to intuitively know the position of the center of impact.

Here, the hitting part of a bat is the so-called area where the ball hits, and when the batter hits the ball in this position, the ball can be hit most strongly and far without giving any unnatural impact sensation to the hand. This point of impact is called the impact center, and detecting the impact center quickly will lead to a more effective impact.

Furthermore, the grip section refers to a small-diameter portion extending from the hitting section through a tapered part (intermediate section) for gripping the hand, and the grip section is the part that flexes the most when the ball hits the hitting section.

In this deflection action, it is possible to obtain a deflection equivalent to that of a conventional wooden bat that can exhibit the follow-through effect, but at present no bat has appeared that focuses on this point.

The present invention has been developed in view of the above circumstances, and its configuration will be described below with reference to drawings of embodiments.

Reference numeral 1 denotes a hollow bat body made of a metal member or the like, and an inner wall portion 1a at the impact center 2' of the ball hitting portion 2 of the bat body 1.
The wall thickness of one part of the bat body is a (usually about 2.5 to 3.
01rrI4) A partial raised part 2a' having a thicker wall b (for example, 5rrgn) is formed, and the grip part 4 passing through the tapered part 3 connected to the ball hitting part 2 is connected to the hitting side of the grip part 4. The distal end portion is made into a gripping flexible portion 4' having a thickness C (for example, 1.5 mm) thinner than the bat body wall thickness a, and the grip end portion 4'', which is the proximal end side of the gripping portion 4, is made from a base. The bat body has a tapered wall thickness d that gradually becomes thicker toward the end.

In other words, this bat body has a thick wall portion at the distal end serving as the impact center portion 2', and a tapered thick wall portion at the grip end portion at the base end, resulting in a well-balanced bat.

Note that the tapered portion 3, which is the intermediate portion, causes some deflection during the swing, but this portion mainly serves as a transmission portion that transmits the impact force of the ball received by the ball hitting portion 2 to the grip portion 4, and the taper portion 3 The wall thickness e of the portion 3 may be equal to the wall thickness a of the bat body 1 (main body).

To explain this effect now, first of all, when the grip part 4 of the bat body 1 is grasped when batting, the ball hitting part 2 of the bat body 1 has a thick-walled impact center part 2' that moves the center of gravity toward the impact center. As a result, the swing balance is good, and the impact center 2' receives a partial thick-walled load that becomes the raised part 2a', so that just by gripping the grip part 4, the impact center 2' You can see where it is located.

That is, since the position of the impact center 2' in the ball-hitting portion 2 can be sensed and reliably determined, it is only necessary to try to hit the ball there.

In this case, the raised part 2a', which becomes the impact center part 2', has a constant width (10oTIr in a standard bat).
! 1), the position of the impact center 2' can be found intuitively even if the grip position is slightly shifted up or down depending on the batter's preference.

Here, if the ball hits the impact center 2' of the ball hitting part 2, this impact will be transmitted to the grip part 4 and it will bend, and at the moment of this impact, the ball will be deformed ( The ball is crushed) so that it comes into close contact with the impact center 2' and does not advance together with the bat body 1.

At this time, the force of the ball and the force of the bat combine, causing the bat's elasticity to momentarily stop.

In other words, the batter's force is transmitted to the ball and generates a repulsive force only when the ball is in the first elasticity stop state.

At this time, the first half of the grip part 4, which is the hitting side, has a gripping flexible part 4' having a thickness C thinner than the thickness a of the bat body 1, so that the gripping flexible part 4' is sufficiently flexible and the ball can be held. The bat does not leave the bat body 1 sooner than necessary, and the ball can be hit with a high level of batting technique known as follow-through.

In this case, the grip end portion 4″ which becomes the base end of the grip portion 4
has a tapered wall thickness d that gradually increases in thickness, and on the other hand, in order to restrict the bending phenomenon, the gripping force on the shaft arm does not change, and the ball can be accurately hit on the impact center 2' (proximal side (If the ball flexes too much, it will be difficult to hit the ball accurately at the center of impact 2').

In order to improve the acoustic effect, it is possible to arrange a cushioning member such as urethane inside the impact center part 2' as necessary, and a reinforcing member (not shown in the figure) can also be provided in the grip part 4. It is also possible to insert

For example, if the ball accidentally hits a position that is significantly off the center of impact 2', an unexpected force will be applied to the bat's grip 4, potentially causing the grip 4 to break. Reinforcing members are provided to ensure this.

Of course, this reinforcing member uses a member having flexibility that can follow the degree of bending of the grip portion 4.

If we compare the amount of distortion during impact between the bat of the present invention, a commercially available wooden bat, and a commercially available metal bat, the curves shown in FIG. 6 will be obtained.

In this case, the measurement method is to attach a strain gauge G to the end of the grip part 4 of the bat body 1 shown in FIG. The bat was swung and batted, and the amount of distortion of the bat was measured.

A shows a curve of a commercially available wooden bat, B shows a curve of a metal bat of the present invention, and C shows a curve of a commercially available metal bat.

Now, the maximum value of the amount of strain, which is the amount of deflection of the bat before the moment of impact I when the ball hits the center of impact 2', is:
A bat is 740 (unit is strain amount (×1o-6),
After a little delay, the distortion amount of B bat becomes 706, and after further delay, the distortion amount of B bat becomes 706.
The amount of distortion of the bat was 370.

That is, the B bat of the present invention appears as a curve comparable to the strain curve of the wooden A bat, and it can be seen that the B bat has a deflection similar to that of the wooden A bat.

Next, after the impact, the C bat's push back point appears first, and the amount of push is small.

That is, the amount of deflection of the metal C bat is small, and the so-called follow-through width is small, indicating that the ball quickly leaves the bat.

This means that a strong person can hit the ball, while a weak person can hit the ball, but a weak person cannot make the ball fly. ing.

In contrast, the B bat of the present invention has a push-back point opening that is close to the push-back point A of the wooden A bat.

That is, it can be seen that the amount of deflection is large and therefore has a width that allows for good follow-through.

As mentioned above, in the bat of the present invention, the impact center of the ball-hitting part has a stepped raised part that is thicker than the thickness of the conventional metal bat body, and the grip part has a thin part that is flexible and the base end. The grip end has a tapered wall thickness, so you can easily sense the impact center position on the bat just by grasping it, and the first half of the grip (hitting side) is thinner to increase the amount of deflection, making it easier to use a wooden bat. Obtains the same deflection as that of the ball, enables follow-through shots, and obtains the maximum repulsion force.

Moreover, in this case, the grip end (for example, about 12 cm width from the end) has a tapered wall thickness that gradually becomes thicker, which not only improves the balance of the bat as a whole, but also reduces the bending phenomenon in this part. On the other hand, since the bending force is suppressed to the contrary, it is possible to prevent the transmission of bending to the gripping part of the shaft arm, allowing a secure grip to be maintained, and making it possible to complete the swing (this grip end part bends). It has been experimentally proven that being difficult to hit is effective for hitting).

In addition, since the impact center part is made thick, it has practical effects such as providing impact resistance against balls and making the bat durable without denting the surface.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a side view;
Fig. 2 is a vertical sectional side view of the same, Fig. 3 is a sectional view taken along line II in Fig. 2, Fig. 4 is a sectional view taken along line ■-■ in Fig. 2, and Fig. 5 is a sectional view taken along line ■-■ in Fig. 2. A cross-sectional view of the line, Figure 6 is a curve diagram showing the amount of strain, and Figure 7 is a curve diagram showing the amount of strain.
The figure is an explanatory diagram showing the measurement position. 1... Bat body, 2... Ball hitting part, 2
'... Impact center, 2a'... Raised part, 3... Taper part, 4... Grip part, 4'... ...Grip bending part, 4z...Grip end part, a...Thickness, b...Thick wall, C...Thin wall.

Claims (1)

[Scope of utility model registration request] In a baseball bat made of metal, an impact center portion 2 having a narrow width of a ball hitting portion 2 of a hollow bat body 1 having a predetermined wall thickness a.
A thick stepped raised part 2a' is formed around the entire circumference on the inner wall only at the ' position, and the grip part 4 passing through the tapered part 3 connected to the ball hitting part 2 is connected to the first half part on the ball hitting part side. The grip flexible part 4' has a thickness C that is thinner than the bat body thickness a, and the grip end part 4'' has a taper wall thickness d that is thicker than the bat body thickness a at the end of the rear half part that becomes the grip end side. A hollow shaped baseball bat.