JP6452072B1 - Practice bat - Google Patents

Abstract

An object of the present invention is to provide a practice bat that can be used in batting practice in which a ball is actually hit.
A practice bat 100 includes a weight 130 disposed in a space formed inside a bat main body 120, and a biasing means for applying a biasing force to the weight 130. The weight 130 is movable between an initial position and a tip position within a space formed inside the bat body 120. The tip position is a position closer to the tip 140 of the practice bat 100 than the initial position along the longitudinal axis direction of the practice bat 100. The urging means is configured such that, when the weight 130 is at the tip position, the urging force in a direction returning from the tip position to the initial position acts on the weight 130.
[Selection] Figure 2B

Description

  The present invention relates to a practice bat, and more particularly, to a practice bat that can be used in a batting practice such as toss batting, tee batting, and free batting (that is, batting practice in which a ball is actually hit).

  Conventionally, bats that are heavier than ordinary bats (so-called mascot bats) have been known as practice bats. It is known that swinging with a mascot bat helps to improve swing speed.

  Conventionally, a product called “Power Slugger” sold by Uchida Sales System Co., Ltd. as a practice bat is known (see Non-Patent Document 1). When swinging with this product, you can move the weight and practice to be able to sound at the timing of impact, so you can acquire a swing that can transmit force to the ball at the moment of impact It is supposed to be attached.

Uchida Sales System, “PRODUCT-BASEBALL Baseball Training Equipment”, [online], [Search May 12, 2018], Internet <URL: http: // www. uchida-power. jp / product / baseball / # power>

  However, the conventional practice bats are limited to those used for “swing”. That is, it was not possible to perform batting practice of hitting a ball using a conventional practice bat. For this reason, even if the desired swing can be obtained using the conventional practice bat, it is necessary to hit the ball with a bat different from the conventional practice bat when hitting the ball in actual batting practice. was there. For this reason, in actual batting practice, there is a problem that it is difficult to realize whether or not the player is hitting with a desirable swing that can be obtained and whether or not the hit ball has changed.

  The present invention has been made to solve this problem, and a training bat that can be used in batting practice such as toss batting, tea batting, and free batting (that is, batting practice that actually hits a ball). The purpose is to provide.

  The practice bat of the present invention includes a grip portion and a bat body, and a space is formed in at least a part of the bat body, and the bat body is formed in the bat body. A weight disposed in the space; and a biasing means for applying a biasing force to the weight, wherein the weight has an initial position and a tip in the space formed inside the bat body. The tip position is a position closer to the tip of the practice bat than the initial position along the longitudinal axis direction of the practice bat, and the biasing means is When the weight is at the tip position, an urging force in a direction returning from the tip position to the initial position is applied to the weight. Thereby, the object mentioned above is achieved.

  The biasing means may be configured so that biasing force does not act on the weight when the weight is in the initial position.

  The biasing means includes a coiled tension spring, and one end of the tension spring is connected to the weight, and the other end of the tension spring is connected to the bat body or the grip portion. Good.

  The biasing means further includes a coiled compression spring, one end of the compression spring is connected to the weight, and the other end of the compression spring is connected to the tip of the practice bat. Good.

The practice bat further includes a core rod extending from the tip of the practice bat, the core rod is disposed in the space formed inside the bat body, A front through hole is provided so that the core rod can pass through the weight,
The biasing means includes a coiled tension spring, and the core rod is configured to pass through the through hole of the weight and the coil of the tension spring.
One end of the tension spring may be connected to the weight, and the other end of the tension spring may be connected to the core rod, the grip portion, or the bat body.

  The biasing means further includes a coiled compression spring, and the core rod is configured to pass through the coil of the compression spring, the through hole of the weight, and the coil of the tension spring. May be.

  The core rod is provided with a protrusion, and the other end of the tension spring is fixed to the core rod by hooking the coil of the tension spring on the protrusion in the vicinity of the other end of the tension spring. May be.

  The core rod is provided with a guide portion, and the guide portion is configured to guide the core rod so that the longitudinal axis direction of the core rod coincides with the longitudinal axis direction of the practice bat. May be.

  The compression spring may be a conical coiled compression spring, and the compression spring may be configured such that the radius of the coil of the compression spring monotonously increases as the tip of the practice bat approaches.

  The tip of the practice bat is configured to be openable and closable, and the practice bat is configured to be able to exchange the weight while the tip of the practice bat is open. Also good.

  The practice bat may be a metal bat.

  According to the present invention, it is possible to provide a practice bat that can be used in batting practice such as toss batting, tea batting, and free batting (that is, batting practice that actually hits a ball).

The figure which shows an example of the internal structure of the practice bat 100 when the weight 130 exists in an initial position. The figure which shows an example of the internal structure of the practice bat 100 when the weight 130 exists in a front-end | tip position. The figure which shows another example of the internal structure of the bat 100 for practice when the weight 130 exists in an initial position. The figure which shows another example of the internal structure of the bat 100 for practice when the weight 130 exists in a front-end | tip position. The figure which shows another example of the internal structure of the bat 100 for practice when the weight 130 exists in an initial position. The figure which shows another example of the internal structure of the bat 100 for practice when the weight 130 exists in a front-end | tip position. The figure which shows a state when a batter holds the practice bat 100 and made the top position The figure which shows the mode of the moment when the batter swings out the practice bat 100 The figure which shows the mode of the moment when a batter hits the ball with the practice bat 100

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1. Practice bat of the present invention will be described below practice bat 100 as an example of a practice bat of the present invention. The practice bat 100 is a hardball baseball practice bat, but the present invention is not limited to this. The present invention can also be applied to semi-rigid baseball practice bats and soft baseball practice bats. The present invention can also be applied to a softball practice bat.

  The practice bat 100 includes a grip portion 110 and a bat body 120. The grip portion 110 is a base portion of the practice bat 100 and is a portion gripped by hand (usually a portion around which cloth or rubber is wound to prevent slipping). The bat body 120 is a portion other than the grip portion 110 of the practice bat 100. A space is formed inside at least a part of the bat body 120. The present invention uses such a space formed inside the bat body 120.

  The practice bat 100 further includes a weight 130. The weight 130 is disposed in a space formed inside the bat main body 120. The weight 130 is movable between an initial position and a tip position within a space formed inside the bat body 120. Here, the initial position is defined as a position where the weight 130 is positioned when the practice bat 100 is erected with the grip portion 110 facing down. The tip position is defined as a position closer to the tip 140 of the practice bat 100 than the initial position along the longitudinal axis direction of the practice bat 100.

  It does not matter how the weight 130 is molded. For example, the weight 130 may be a processed metal lump. Alternatively, the weight 130 may be obtained by encapsulating metal powder in a tubular member made of polyvinyl chloride.

  The practice bat 100 further includes a biasing means for applying a biasing force to the weight 130. This urging means is configured so that the urging force does not act on the weight 130 when the weight 130 is in the initial position. Further, this urging means is configured such that, when the weight 130 is at the tip position, the urging force in the direction returning from the tip position to the initial position acts on the weight 130.

  Hereinafter, an example of the internal structure of the practice bat 100 when the coiled tension spring 150 functions as the biasing means will be described with reference to FIGS. 1A and 1B.

  In the example shown in FIGS. 1A and 1B, one end of the tension spring 150 is connected to the weight 130, and the other end of the tension spring 150 is fixed to the grip portion 110. At this time, the other end of the tension spring 150 may be directly fixed to the grip portion 110, or may be indirectly fixed to the grip portion 110 via a wire. Alternatively, one end of the tension spring 150 may be connected to the weight 130 and the other end of the tension spring 150 may be fixed to the bat body 120. At this time, the other end of the tension spring 150 may be directly fixed to the bat main body 120, or may be indirectly fixed to the bat main body 120 via a wire.

  When the weight 130 is in the initial position, the tension spring 150 does not expand. Therefore, when the weight 130 is in the initial position, the urging force by the tension spring 150 does not act on the weight 130. The extension of the tension spring 150 allows the weight 130 to move from the initial position to the tip position. Therefore, when the weight 130 is at the distal end position, an urging force by the tension spring 150 (that is, a force in a direction returning from the distal end position to the initial position and proportional to the extension of the tension spring 150). Acts on the weight 130. The tension spring 150 may be a single spring or a combination of a plurality of springs.

  FIG. 1A shows an example of the internal structure of the practice bat 100 when the weight 130 is in the initial position.

  The tension spring 150 is configured so that a biasing force does not act on the weight 130 when the weight 130 is in the initial position. For example, when the practicing bat 100 is upright with the grip portion 110 facing down, the weight 130 of the support member (eg, a second spring (not shown) having a diameter larger than the inner diameter of the grip portion 110). By being supported on the weight 130, the weight 130 may be disposed at the initial position in a state where the tension spring 150 is not stretched.

  FIG. 1B shows an example of the internal structure of the practice bat 100 when the weight 130 is in the tip position.

  When the weight 130 is at the tip position, the tension spring 150 is configured such that a biasing force in a direction returning from the tip position to the initial position acts on the weight 130. As will be described later, when the practice bat 100 is swung, a centrifugal force acts on the weight 130. The spring coefficient of the tension spring 150 is designed in advance so that the centrifugal force acting on the weight 130 and the biasing force acting on the weight 130 are balanced.

  In the example shown in FIGS. 1A and 1B, the grip portion 110 and the bat main body 120 are formed so as to be hollow, but the internal structures of the grip portion 110 and the bat main body 120 are not limited thereto. As long as a space is formed in at least a part of the bat body 120 and the weight 130 can move between the initial position and the tip position in the space, the bat body 120 has an arbitrary internal structure. It is possible.

  Furthermore, in the example shown in FIGS. 1A and 1B, the tension spring 150 has been described as an example of the urging means for generating the urging force, but the present invention is not limited to this. Instead of the tension spring 150, any biasing means that generates a biasing force can be used.

  Hereinafter, an example of the internal structure of the practice bat 100 when the coiled tension spring 150 and the conical coiled compression spring 160 function as biasing means will be described with reference to FIGS. 2A and 2B.

  In the example shown in FIGS. 2A and 2B, one end of the tension spring 150 is connected to the weight 130, and the other end of the tension spring 150 is fixed to the bat body 120. One end of the compression spring 160 is connected to the weight 130, and the other end of the compression spring 160 is fixed to the tip 140 of the practice bat 100.

  When the weight 130 is in the initial position, the tension spring 150 does not expand and the compression spring 160 is not compressed. Therefore, when the weight 130 is in the initial position, the urging force by the tension spring 150 and the urging force by the compression spring 160 do not act on the weight 130. When the tension spring 150 is extended and the compression spring 160 is compressed, the weight 130 can move from the initial position to the tip position. Therefore, when the weight 130 is in the tip position, the biasing force by the tension spring 150 (that is, a force in a direction returning from the tip position to the initial position and proportional to the extension of the tension spring 150) and A biasing force by the compression spring 160 (that is, a force in a direction returning from the tip position to the initial position and proportional to the magnitude of compression of the compression spring 150) acts on the weight 130. Note that both the tension spring 150 and the compression spring 160 may be a single spring or a combination of a plurality of springs.

  FIG. 2A shows another example of the internal structure of the practice bat 100 when the weight 130 is in the initial position.

  The tension spring 150 and the compression spring 160 are configured so that a biasing force does not act on the weight 130 when the weight 130 is in the initial position. For example, when the practicing bat 100 is erected with the grip portion 110 down, the weight 130 is supported on the tension spring 150 in an unstretched state, so that the tension spring 150 is not stretched. In addition, the weight 130 may be disposed at the initial position in a state where the compression spring 160 is not compressed.

  FIG. 2B shows another example of the internal structure of the practice bat 100 when the weight 130 is in the tip position.

  The tension spring 150 and the compression spring 160 are configured such that when the weight 130 is at the distal end position, an urging force in a direction returning from the distal end position to the initial position acts on the weight 130. As will be described later, when the practice bat 100 is swung, a centrifugal force acts on the weight 130. The spring coefficient of the tension spring 150 and the spring coefficient of the compression spring 160 are designed in advance so that the centrifugal force acting on the weight 130 and the biasing force acting on the weight 130 are balanced.

  Hereinafter, with reference to FIGS. 3A and 3B, another example of the internal structure of the practice bat 100 when the coiled tension spring 150 and the conical coiled compression spring 160 function as biasing means will be described. To do.

  The practice bat 100 further includes a core rod 170 extending from the tip 140 of the practice bat 100. The core rod 170 is disposed in a space formed inside the bat main body 120. The weight 130 is provided with a through hole so that the core rod 170 can pass through the weight 130. The core rod 170 is configured to pass through the coil of the compression spring 160, the through hole provided in the weight 130, and the coil of the tension spring 150 in this order.

  In the example shown in FIGS. 3A and 3B, one end of the tension spring 150 is connected to the weight 130, and the other end of the tension spring 150 is fixed to the core rod 170. Specifically, the core rod 170 is provided with a protrusion 180. The compression spring 160, the weight 130, and the tension spring 150 are passed through the core rod 170 in this order, and the tension spring 150 is rotated in the vicinity of the other end of the tension spring 150 while rotating the weight 130 and the tension spring 150 around the core rod 170. It is possible to fix the other end of the tension spring 150 to the core rod 170 by hooking the coil on the protrusion 180 of the core rod 170. The protrusions 180 may be provided over the entire circumference of the core rod 170 or may be provided only on a part of the circumference of the core rod 170. The protrusion 180 may have any shape as long as it has a protrusion for hooking the coil of the tension spring 150. Alternatively, one end of the tension spring 150 may be connected to the weight 130, and the other end of the tension spring 150 may be fixed to the grip portion 110 or the bat body 120 instead of the core rod 170.

  In the example shown in FIGS. 3A and 3B, one end of the compression spring 160 is a free end, and the other end of the compression spring 160 is also a free end. In other words, both ends of the compression spring 160 need not be connected or fixed to anything. Because the movement of the compression spring 160 is regulated by the core rod 170, one end of the compression spring 160 does not need to be connected to the weight 130, and the other end of the compression spring 160 is fixed to the tip 140 of the practice bat 100. It is not necessary to be done.

  One end of the core rod 170 is fixed to the tip 140 of the practice bat 100, but a guide portion 190 is provided at the other end of the core rod 170. The guide portion 190 is configured to guide the core rod 170 so that the longitudinal axis direction of the core rod 170 matches the longitudinal axis direction of the practice bat 100. In the example shown in FIGS. 3A and 3B, the guide portion 190 is configured as a brim portion that protrudes outward from the core rod 170. The function of guiding the core rod 170 so that the longitudinal axis direction of the core rod 170 coincides with the longitudinal axis direction of the practice bat 100 by such a brim portion coming into contact with the grip portion 110 or the inner wall of the bat main body 120. Because it can be fulfilled. The weight 130 is configured to be movable between the initial position and the tip position along the longitudinal axis direction of the core rod 170. Accordingly, the weight 130 can move between the initial position and the tip position along the longitudinal axis direction of the practice bat 100.

  The core rod 170 is preferably formed integrally with the practice bat tip 140 from the same material as the practice bat tip 140, but is not limited thereto. For example, the core rod 170 is a separate member from the tip 140 of the practice bat, and the core rod 170 and the tip 140 of the practice bat may be bonded to each other.

  When the weight 130 is in the initial position, the tension spring 150 does not expand and the compression spring 160 is not compressed. Therefore, when the weight 130 is in the initial position, the urging force by the tension spring 150 and the urging force by the compression spring 160 do not act on the weight 130. When the tension spring 150 is extended and the compression spring 160 is compressed, the weight 130 can move from the initial position to the tip position. Therefore, when the weight 130 is in the tip position, the biasing force by the tension spring 150 (that is, a force in a direction returning from the tip position to the initial position and proportional to the extension of the tension spring 150) and A biasing force by the compression spring 160 (that is, a force in a direction returning from the tip position to the initial position and proportional to the magnitude of compression of the compression spring 150) acts on the weight 130. Note that both the tension spring 150 and the compression spring 160 may be a single spring or a combination of a plurality of springs.

  FIG. 3A shows another example of the internal structure of the practice bat 100 when the weight 130 is in the initial position.

  The tension spring 150 and the compression spring 160 are configured so that a biasing force does not act on the weight 130 when the weight 130 is in the initial position. For example, when the practicing bat 100 is erected with the grip portion 110 down, the weight 130 is supported on the tension spring 150 in an unstretched state, so that the tension spring 150 is not stretched. In addition, the weight 130 may be disposed at the initial position in a state where the compression spring 160 is not compressed.

  FIG. 3B shows another example of the internal structure of the practice bat 100 when the weight 130 is in the tip position.

  The tension spring 150 and the compression spring 160 are configured such that when the weight 130 is at the distal end position, an urging force in a direction returning from the distal end position to the initial position acts on the weight 130. As will be described later, when the practice bat 100 is swung, a centrifugal force acts on the weight 130. The spring coefficient of the tension spring 150 and the spring coefficient of the compression spring 160 are designed in advance so that the centrifugal force acting on the weight 130 and the biasing force acting on the weight 130 are balanced.

  2A, 2B, 3A, and 3B, the compression spring 160 is configured so that the radius of the coil of the compression spring 160 monotonously increases as it approaches the tip 140 of the practice bat 100 (that is, Coil radius is equal or increased). By using such a compression spring 160 together with the tension spring 150, the weight 130 is slowly moved to the practice bat compared to the case where only the tension spring 150 is used (ie, the case shown in FIGS. 1A and 1B). The moving speed of the weight 130 can be gradually decreased as the weight 130 approaches the front end 140 of the practice bat 100.

  In the example shown in FIGS. 2A, 2B, 3A, and 3B, the grip portion 110 is solid and a part of the bat body 120 is hollow. The internal structure of 110 and bat main body 120 is not limited to this. As long as a space is formed in at least a part of the bat body 120 and the weight 130 can move between the initial position and the tip position in the space, the bat body 120 has an arbitrary internal structure. It is possible.

  Furthermore, in the example shown in FIGS. 2A, 2B, 3A, and 3B, the tension spring 150 and the compression spring 160 have been described as an example of the urging means that generates the urging force, but the present invention is not limited to this. Instead of the tension spring 150, any biasing means that generates a biasing force can be used. Alternatively, any biasing means that generates a biasing force (for example, a conical non-coiled compression spring) can be used instead of the compression spring 160.

  Further, in the practice bat 100 shown in FIGS. 1A, 1B, 2A, 2B, 3A, and 3B, the distal end 140 of the practice bat 100 may be configured to be openable and closable. In this case, the weight 130 may be configured to be replaceable while the tip 140 of the practice bat 100 is open. For example, it is preferable that the weight 130 is easily removable from the tension spring 150 by placing one end of the tension spring 150 on the hook of the weight 130. For example, weights of various weights (for example, 500 g, 250 g, 100 g) are prepared as the weight 130, and by making these exchangeable, one practice bat 100 can be replaced with a plurality of different weights. It can be used as if it were a practice bat. In addition, the structure which enables opening and closing of the front-end | tip 140 of the practice bat 100 does not ask | require. For example, the tip 140 of the practice bat 100 is made detachable, and the screw thread (or screw groove) formed in the tip 140 is engaged with the screw groove (or screw thread) formed in the bat body 120. Alternatively, the convex portion formed at the tip 140 may be pushed into the concave portion formed in the bat main body 120.

  Furthermore, the practice bat 100 is typically a metal bat. Since the metal bat is originally hollow in both the grip portion and the bat body, it does not require a step of forming a space inside the bat body. Therefore, it can be said that the metal bat is suitable for manufacturing the practice bat of the present invention. However, the practice bat of the present invention is not limited to a metal bat. The practice bat of the present invention may be a bat formed of any material as long as a space is formed inside at least a part of the bat body. For example, the practice bat of the present invention may be a wooden bat in which a space is formed by hollowing out at least a part of the bat body.

2. Batting practice using the practice bat of the present invention The practice bat 100 having the internal structure shown in FIGS. 1A and 1B is identical in appearance to a normal bat. Therefore, it is possible to perform batting exercises such as toss batting, tea batting, and free batting (that is, batting exercises for actually hitting a ball) using the practice bat 100 as in the case of a normal bat. The same applies to the practice bat 100 having the internal structure shown in FIGS. 2A and 2B. The same applies to the practice bat 100 having the internal structure shown in FIGS. 3A and 3B.

  4A to 4C show how the batter holds the practice bat 100, swings out, and swings.

  FIG. 4A shows a state where the batter holds the practice bat 100 and creates the top position. At this time, the weight 130 is in the initial position inside the practice bat 100. Immediately before swinging the bat from the top position shown in FIG. 2A, the batter swings the practice bat 100 in the longitudinal axis direction of the practice bat 100 (the direction of arrow A shown in FIG. 4A) for a moment. . By this operation, the weight 130 inside the practice bat 100 moves from the initial position toward the tip position. At this time, an urging force acts on the weight 130 in a direction to return from the tip position to the initial position. At the same time, when the batter swings out the practice bat 100, a centrifugal force acts on the weight 130. In this way, the urging force acting on the weight 130 balances with the centrifugal force acting on the weight 130, so that the weight 130 remains in the vicinity of the tip position. Thus, the batter swings the practice bat 100 while feeling the weight near the tip 140 of the practice bat 100 after the practice bat 100 is swung out until the ball is hit and the follow-through is finished. Is possible.

  FIG. 4B shows the moment when the batter swings out the practice bat 100, and FIG. 4C shows the moment of impact when the batter hits the ball with the practice bat 100. FIG.

  According to the batting practice using the bat 100 for practice, the batter can acquire “feeling to feel the weight near the tip of the bat just before swinging out the bat and swinging the bat while feeling the weight”. Is possible. This sense is important. This is because by wearing this feeling, the trajectory of the bat swing and the bat swing can be improved.

  In particular, according to the practice bat 100 having the internal structure shown in FIGS. 2A, 2B, 3A, and 3B, the presence of the conical coiled compression spring 160 causes the internal structure shown in FIGS. 1A and 1B. Compared to the practice bat 100 having a structure, the weight 130 can be slowly moved toward the tip 140 of the practice bat 100, and the weight 130 approaches the tip 140 of the practice bat 100. It is possible to gradually decrease the moving speed of the. Thereby, according to the practice bat 100 having the internal structure shown in FIGS. 2A, 2B, 3A, and 3B, even after the batter swings the practice bat 100 out of the top position, It is possible to continue to feel the weight near the tip of the bat. Therefore, according to the practice bat 100 having the internal structure shown in FIGS. 2A, 2B, 3A, and 3B, compared to the practice bat 100 having the internal structure shown in FIGS. 1A and 1B, the bat It is possible to acquire a sense of shaking the bat while feeling the weight longer while feeling the weight near the tip of the. As described above, in the process of swinging from the bat swinging out, it is important that the time for feeling the weight near the tip of the bat is long. This is because by wearing this feeling, the trajectory of the bat swing and the bat swing can be further improved.

  The inventor has served as the director of the All Hirakata Boys Elementary School for many years, teaching batting from the first grade to the sixth grade. Since there is a clear difference in power between children in the upper grades and children in the lower grades, it has been a long-standing concern how to teach batting of children in the lower grades. The present invention is based on the result of continuing to consider how batting should be instructed in order to solve the problem of seeing that batting of children in the lower grades of elementary school tends to be pushed by the momentum of the ball. Is.

  By repeating batting practice using the bat 100 for practice, even a low-grade elementary school child can strike back a ball thrown by an elementary school child. This is because a swing that conveys force to the ball without waste is completed by wearing a feeling of feeling the weight near the tip of the bat and swinging the bat while feeling the weight just before swinging the bat. It is thought to be from. Of course, batting practice using the practice bat 100 is not only useful for elementary school students, but is useful for all baseball players such as junior high school students, high school students, university students, and adults. This is because a swing that transmits force to a ball without waste is useful to all baseball players regardless of whether or not there is power.

  The swing completed in this way is different from the swing that is good to put out the bat at the shortest distance to the impact with the inside-out that was used as a conventional example, but the bat seems to come out rather detouring It can be said that it is a swing that runs well at the tip of the bat and reaches the impact. Such a swing is far from conventional baseball common sense and should be a “swing revolution” following the “flyball revolution”. By completing batting practice using the practice bat 100, a completed swing based on a new swing theory can be obtained.

  As mentioned above, although this invention has been illustrated using preferable embodiment of this invention, this invention should not be limited and limited to this embodiment. It is understood that the scope of the present invention should be construed only by the claims. It is understood that those skilled in the art can implement an equivalent range based on the description of the present invention and the common general technical knowledge from the description of specific preferred embodiments of the present invention.

  INDUSTRIAL APPLICABILITY The present invention is useful for providing an exercise bat that can be used in batting practice such as toss batting, tea batting, and free batting (that is, batting practice that actually hits a ball).

DESCRIPTION OF SYMBOLS 100 Practice bat 110 Grip part 120 Bat body 130 Weight 140 Tip of practice bat 150 Tension spring 160 Compression spring 170 Core rod 180 Projection part 190 Guide part

Claims (11)

A practice bat, wherein the practice bat is
A grip part,
A bat body, wherein a space is formed inside at least a part of the bat body; and
A weight disposed in the space formed inside the bat body;
Biasing means for applying a biasing force to the weight, and
The weight is movable between an initial position and a tip position in the space formed inside the bat body, and the tip position is located along the longitudinal axis direction of the practice bat. It is a position closer to the tip of the practice bat than the initial position,
The biasing means is configured such that when the weight is at the tip position, a biasing force in a direction returning from the tip position to the initial position acts on the weight .
The practice bat further includes a core rod extending from a tip of the practice bat, the core rod is disposed in the space formed inside the bat body, and the weight includes the weight A through hole is provided so that the core rod can pass through the weight,
The biasing means includes a coiled tension spring, and the core rod is configured to pass through the through hole of the weight and the coil of the tension spring.
One end of the tension spring is connected to the weight, and the other end of the tension spring is connected to the core rod or the grip portion or the bat body,
The core rod has a protrusion, and the other end of the tension spring is fixed to the core rod by hooking the coil of the tension spring on the protrusion in the vicinity of the other end of the tension spring. A practice bat.   2. The practice bat according to claim 1, wherein the biasing means is configured so that a biasing force does not act on the weight when the weight is in the initial position. 3. The biasing means further includes a coiled compression spring, and the core bar is configured to pass through the coil of the compression spring, the through hole of the weight, and the coil of the tension spring. The practice bat according to claim 1 or 2 . The compression spring is a conical coiled compression spring, and the compression spring is configured such that the radius of the coil of the compression spring monotonously increases as the tip of the practice bat approaches. The practice bat according to 3 . A practice bat, wherein the practice bat is
A grip part,
A bat body, wherein a space is formed in at least a part of the bat body. The body,
A weight disposed in the space formed inside the bat body;
A biasing means for applying a biasing force to the weight;
With
The weight is movable between an initial position and a tip position in the space formed inside the bat body, and the tip position is located along the longitudinal axis direction of the practice bat. It is a position closer to the tip of the practice bat than the initial position,
The biasing means is configured such that when the weight is at the tip position, a biasing force in a direction returning from the tip position to the initial position acts on the weight.
The biasing means includes a coiled tension spring, one end of the tension spring is connected to the weight, and the other end of the tension spring is connected to the bat body or the grip part,
The biasing means further includes a coiled compression spring, one end of the compression spring is connected to the weight, and the other end of the compression spring is connected to a tip of the practice bat,
The compression spring is a conical coiled compression spring, and the compression spring is configured so that the radius of the coil of the compression spring monotonously increases as the tip of the practice bat approaches. bat. A practice bat, wherein the practice bat is
A grip part,
A bat body, wherein a space is formed inside at least a part of the bat body; and
A weight disposed in the space formed inside the bat body;
A biasing means for applying a biasing force to the weight;
With
The weight is movable between an initial position and a tip position in the space formed inside the bat body, and the tip position is located along the longitudinal axis direction of the practice bat. It is a position closer to the tip of the practice bat than the initial position,
The biasing means is configured such that when the weight is at the tip position, a biasing force in a direction returning from the tip position to the initial position acts on the weight.
The practice bat further includes a core rod extending from a tip of the practice bat, the core rod is disposed in the space formed inside the bat body, and the weight includes the weight A through hole is provided so that the core rod can pass through the weight,
The biasing means includes a coiled tension spring and a coiled compression spring, and the core rod is disposed in the coil of the compression spring, in the through hole of the weight, and in the coil of the tension spring. Configured to pass through,
One end of the tension spring is connected to the weight, and the other end of the tension spring is connected to the core rod or the grip portion or the bat body,
The compression spring is a conical coiled compression spring, and the compression spring is configured so that the radius of the coil of the compression spring monotonously increases as the tip of the practice bat approaches. bat. The practice bat according to claim 5 or 6, wherein the biasing means is configured so that a biasing force does not act on the weight when the weight is in the initial position. The core rod has a protrusion, and the other end of the tension spring is fixed to the core rod by hooking the coil of the tension spring on the protrusion in the vicinity of the other end of the tension spring. The practice bat according to claim 6 . The core rod is provided with a guide portion, and the guide portion is configured to guide the core rod so that a longitudinal axis direction of the core rod coincides with a longitudinal axis direction of the practice bat. The practice bat according to any one of claims 1, 6 , and 8.   The tip of the practice bat is configured to be openable and closable, and the practice bat is configured to allow the weight to be exchanged while the tip of the practice bat is open. The practice bat according to any one of claims 1 to 9.   The practice bat according to claim 1, wherein the practice bat is a metal bat.