JP2008086818A - Bat for baseball or softball, manufacturing method therefor, and bat base material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bat easily mounting an elastic body on a bat base material in the bat for baseball or softball coveringly integrating the elastic body on the surface of a ball hitting part, and to provide a manufacturing method therefor and the bat base material. <P>SOLUTION: This bat 1 is provided with the base material 2 and the elastic body 3. The base material 2 is provided with a recess part provided in a part to be the ball hitting part 5, a grip part 7, and a tapered part 6 positioned between the recess part and the grip part 7. The elastic body 3 is attached to the recess part surface of the base material 2 and forms the surface layer part of the ball hitting part 5. The maximum outside diameter of the tapered part 6 of the base material 2 is not less than 101% and not more than 140% of the minimum outside diameter of the recess part. The elastic body 3 has a cylindrical shape and, after being treated by softening or expanding processing, is fit into the recess part of the base material 2 from the grip part 7 side. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a baseball or softball bat (hereinafter also simply referred to as “bat”) and a method for manufacturing the same, and a base material for the bat, and in particular, a bat having an elastic body attached to the surface of a hitting ball, a method for manufacturing the bat, and the bat It relates to the base material.

In order to provide a bat that exhibits excellent durability and can extend the flight distance of a hit ball, a bat in which an elastic body is integrally coated on a concave portion of a hit ball portion is described in, for example, Japanese Patent Application Laid-Open No. 2003-19236 Has been.
JP 2003-19236 A

  If you actually use a bat with an elastic body covered and integrated in the concave part of the hit ball part, it is possible to extend the flight distance of the hit ball, but the elastic body is made of a relatively soft material, so compared to the base material The elastic body is easily damaged. Therefore, it is desired that the elastic body can be easily attached to and detached from the base material of the bat.

  Since the elastic body is made of a relatively soft material as described above, it can be removed relatively easily from the base material for the bat, but the work of actually attaching the elastic body to the recess of the base material for the bat is never It's not easy.

  As described in JP-A-2003-19236, in order to cover and integrate the synthetic resin into the concave portion of the hitting ball portion by injection molding or cast molding, equipment for this is required, which is a large-scale work. Therefore, it cannot be said that the elastic body can be easily attached to the base material of the bat.

  Further, a method of separately forming an elastic body and winding it around the concave portion of the hit ball portion is conceivable. However, in this case, there is a problem that the elastic body is cut and the elastic body is easily damaged from the cut.

  Japanese Patent Laid-Open No. 2003-19236 describes that the elastic body may be formed separately and bonded to the recess so as to match the shape of the recess of the base material for the bat. There is no description of a specific method that makes it possible to easily attach a cylindrical elastic body to a base material for use. Therefore, it is not easy for a person skilled in the art to come up with a specific method that allows a cylindrical elastic body to be mounted in the concave portion of the base material for bats only by disclosing the document.

  Accordingly, the present invention relates to a baseball or softball bat in which an elastic body is integrally coated on the surface of the hit ball portion, and the baseball or softball can be easily attached to the base material for the bat. An object of the present invention is to provide a bat for bat, a manufacturing method thereof, and a base material for bat.

  In one aspect, a baseball or softball bat according to the present invention has a recess provided in a portion to be a hitting ball portion, a grip portion, and a base material having a tapered portion positioned between the recess and the grip portion, And an elastic body attached to the surface of the concave portion and forming a surface layer portion of the hit ball portion. And the maximum outer diameter of the said taper part shall be 101% or more and 140% or less of the minimum outer diameter of a recessed part.

  By setting the maximum outer diameter of the tapered portion to a value within the above range with respect to the minimum outer diameter of the concave portion, the cylindrical elastic body is smoothly passed through the outer periphery of the tapered portion of the base material into the concave portion of the base material. Can be installed.

  In another aspect of the baseball or softball bat according to the present invention, the difference between the maximum outer diameter of the tapered portion and the minimum outer diameter of the concave portion is 0.3 mm or more and 20 mm or less.

  Even when the difference between the maximum outer diameter of the tapered portion and the minimum outer diameter of the concave portion is set to a value within the above range, the cylindrical elastic body is smoothly passed over the outer periphery of the tapered portion of the base material. It can be mounted in the recess.

  The elastic body is preferably formed of a cylindrical and integral thermoplastic elastomer or thermoplastic resin. More preferably, the elastic body is made of a cylindrical and integral thermoplastic polyurethane resin.

  In one aspect, the method for manufacturing a baseball or softball bat according to the present invention includes the following steps. A cylindrical and integral elastic body is formed. The elastic body is softened. A softened cylindrical elastic body is formed on the taper portion from the grip portion side of the base material for the bat, which has a recess provided in a portion to be a hitting ball portion, a grip portion, and a taper portion located between the recess and the grip portion. It fits into a recess via.

  Since the elastic body is softened as described above, the cylindrical elastic body can be smoothly moved from the grip portion side of the bat base material toward the concave portion via the tapered portion.

  In another aspect, the method for manufacturing a baseball or softball bat according to the present invention includes the following steps. A cylindrical and integral elastic body is formed. The elastic body is expanded. An expanded cylindrical elastic body is formed on the taper portion from the grip portion side of the base material for the bat having a recess provided in a portion to be a hitting ball portion, a grip portion, and a taper portion positioned between the recess and the grip portion. It fits into a recess via.

  Also in the case of this aspect, since the elastic body is expanded, the cylindrical elastic body can be smoothly moved from the grip portion side of the bat base material toward the concave portion via the tapered portion.

  In another aspect, the method for manufacturing a baseball or softball bat according to the present invention includes the following steps. A cylindrical and integral elastic body is formed. The surface of the concave portion, the surface of the tapered portion, the surface of the tapered portion, and the elastic body of the base material for a bat having a concave portion provided in a portion to be a hitting ball portion, a grip portion, and a tapered portion located between the concave portion and the grip portion. Apply lubricant to at least one location with the inner surface. The cylindrical elastic body is fitted into the concave portion from the grip portion side of the bat base material via the tapered portion.

  Also in this aspect, since the lubricant is applied to at least one of the surface of the concave portion of the base material for the bat, the surface of the tapered portion, and the inner surface of the elastic body, the grip portion side of the base material for the bat Thus, the cylindrical elastic body can be smoothly moved toward the concave portion via the taper portion.

  The maximum outer diameter of the tapered portion is larger than the minimum inner diameter of the elastic body in the initial state (for example, 1.01 times or more of the minimum inner diameter of the elastic body) and 1.4 times or less of the minimum inner diameter of the elastic body. Is preferred. Moreover, it is preferable to make the minimum inner diameter of the elastic body in the initial state smaller than the minimum outer diameter of the recess. Here, the “initial state” is a state in which an elastic body is integrally formed in a cylindrical shape, and refers to a state before the process of softening or expanding the elastic body or applying a lubricant.

  In one aspect, the base material for a bat according to the present invention includes a concave portion provided in a portion serving as a hitting portion of a baseball or softball bat, a grip portion, and a tapered portion positioned between the concave portion and the grip portion. And the maximum outer diameter of the tapered portion is set to be 101% or more and 140% or less of the minimum outer diameter of the concave portion.

  By setting the maximum outer diameter of the tapered portion of the base material for the bat within the above range with respect to the minimum outer diameter of the concave portion, the base for the bat can be smoothly installed when the cylindrical elastic body is attached to the concave portion of the base material for the bat. It can be passed over the taper of the material.

  In another aspect of the base material for a bat according to the present invention, a difference between the maximum outer diameter of the tapered portion and the minimum outer diameter of the concave portion is set to 0.3 mm or more and 20 mm or less.

  Even when the difference between the maximum outer diameter of the taper portion of the base material for the bat and the minimum outer diameter of the concave portion is within the above range, when attaching the cylindrical elastic body to the concave portion of the base material for the bat, It can pass over the taper part of the base material for bats.

  According to the present invention, since the cylindrical elastic body can be easily attached to the concave portion of the base material by smoothly passing over the tapered portion of the base material for the bat, the surface of the hit ball portion is covered with the elastic body. The replacement work of the elastic body can be easily performed in the integrated bat.

  Hereinafter, a baseball or softball bat, a manufacturing method thereof, and a base material for a bat in an embodiment of the present invention will be described. The bat in the present embodiment mainly includes a base material (core material) and an elastic body, which will be described later.

  The base material has a tip portion, a concave portion provided in a portion serving as a hitting ball portion, a grip portion, and a tapered portion located between the concave portion and the grip portion. The tip of the base material becomes the tip of the bat, the portion where the elastic body is attached to the concave portion of the base material becomes the hitting portion of the bat, the taper portion of the base material becomes the taper portion of the bat, and the grip portion of the base material becomes the bat It becomes the grip part.

  The tip of the bat is the tip (one end) on the hitting ball side of the bat and the vicinity thereof. For example, a portion in the range of about 50 mm from the tip on the hitting ball side of the bat corresponds to the tip. For example, a cap member may be attached to the tip portion.

  The hitting part of the bat is a part that is actually planned to hit the ball from the beginning. For example, a part in the range of about 250 mm to 300 mm from the end part on the grip part side of the tip part to the grip part side. Corresponds to the hit ball part.

  The taper portion of the bat is a portion that is located between the hit ball portion and the grip portion, and whose outer diameter gradually decreases from the hit ball portion toward the grip portion. For example, a portion in a range of about 150 mm to 220 mm from the end on the grip portion side of the hitting ball portion to the grip portion side corresponds to the taper portion.

  The grip portion of the bat is a portion that the batter is scheduled to hold by hand, and the portion from the end of the tapered portion on the grip portion side to the other end (grip end) of the bat corresponds to the grip portion. The grip end is typically composed of an enlarged diameter portion. The grip end may be formed integrally with the base material, but may be formed separately from the base material and separately attached to the base material.

  As a material of the above-mentioned base material, for example, a material that can be used for the bat such as wood, metal, fiber reinforced plastic, and the like can be adopted.

  The elastic body is attached to the concave surface of the base material and forms a surface layer portion of the hitting portion of the bat. The elastic body typically has a cylindrical shape, is integrally formed, and is fixed to the concave portion of the substrate using, for example, an adhesive or a double-sided tape.

  Although it is necessary to secure an adhesive strength that does not hinder the ball when hit, it is possible to easily remove the elastic body from the base material using an adhesive or double-sided tape. It is preferable to take care that the strength does not become too high.

  In addition, it is preferable to apply a lubricant to at least one of the surface of the concave portion of the base material for the bat, the surface of the tapered portion of the base material for the bat, and the inner surface of the elastic body. What can be fitted in the concave portion of the base material while moving the integral elastic body in a cylindrical shape so as to slide on the surface of the base material from the grip portion side of the base material via the taper portion If so, any lubricant can be used. For example, various adhesives such as epoxy adhesives, urethane adhesives, rubber adhesives, silicon adhesives, primers, and the like can be used as the lubricant. Moreover, wax, oil, petroleum jelly, silicone oil, water, solvent, etc. can be considered as a lubricant having no adhesiveness.

  Although the thickness of the elastic body can be arbitrarily set, it is preferable to set the thickness within a range of, for example, about 4 mm to 25 mm in view of the function of the elastic body and considering strength, mass, and detachability. If the thickness of the elastic body is less than 4 mm, depending on the material, it may be difficult to ensure the function and strength of the elastic body, and the elastic body may be easily damaged. On the other hand, when the thickness of the elastic body exceeds 25 mm, the mass of the elastic body increases, and the outer diameter of the concave portion of the base material decreases, so that the durability may decrease.

  The elastic body is thickest at or near the sweet spot of the bat, and gradually decreases from this thickest portion toward both ends in the longitudinal direction.

The material of the elastic body may be any material that has a low energy loss rate when restored after elastic deformation. For example, thermoplastic elastomers such as ionomers and butadiene rubber, thermoplastic resins, and the like can be used. . Preferably, a thermoplastic polyurethane resin is used as the material of the elastic body. Also, considering the mass, energy loss rate, manufacturing cost, and ease of molding, the hardness is 20-80 in JIS C hardness, the specific gravity is 0.25-0.70, and the tensile stress at 300% elongation is It is conceivable to employ a foamed polyurethane of 1.0 MPa to 4.0 MPa. In the present specification, “JIS C hardness” means JIS.
The hardness measured in accordance with the spring hardness test type C test method of K7312, Annex 2.

  In the present embodiment, the maximum outer diameter of the tapered portion of the base material (bat) is set to be 101% or more and 140% or less of the minimum outer diameter of the concave portion of the base material (butt). Preferably, the content is 101% or more and 125% or less. If the above value is less than 101%, after attaching the cylindrical elastic body to the concave portion of the base material, there is a high possibility that the elastic body will come out of the concave portion and be displaced to the grip side. For example, it is not easy to move the cylindrical elastic body from the grip side by hand to pass the outer periphery of the tapered portion.

  Further, a difference between the maximum outer diameter of the tapered portion and the minimum outer diameter of the concave portion is set to 0.3 mm or more and 20 mm or less. Preferably, it is 0.3 mm or more and 12.5 mm or less. If the value of the difference is less than 0.3 mm, there is a high possibility that the elastic body will come out of the recess and be displaced to the grip side after the cylindrical elastic body is mounted in the recess of the base material. If it is larger, for example, it will not be easy to move the cylindrical elastic body from the grip side by hand and pass it over the outer periphery of the tapered portion.

  By setting the relationship between the maximum outer diameter of the taper portion of the base material (bat) and the minimum outer diameter of the concave portion within the above range, the cylindrical elastic body can be smoothly attached to the concave portion of the base material. The cylindrical elastic body can be easily mounted in the concave portion of the base material by passing over the taper portion of the base material, and the displacement of the elastic body after mounting and the decrease in the fixing strength can also be suppressed. .

  Next, a method for manufacturing a baseball or softball bat in the present embodiment having the above-described structure will be described.

  First, a cylindrical and integral elastic body is produced. For example, when an elastic body is made of a thermoplastic elastomer or a thermoplastic resin, a core material is installed in the outer mold, and a liquid material is poured into a space (cavity) between the core material and the outer mold. The elastic body can be produced by later curing and releasing the molded product.

  While the elastic body is produced in this manner, the base material for the bat is produced. For example, when producing a base material for a bat made of fiber reinforced plastic, wrap a carbon fiber reinforced resin prepreg sheet around the core, remove the core from the tip side, insert an elastic tube from the tip side, and insert the tip. A base for a bat having the above-described structure by closing the prepreg sheet and setting it to the outer mold, applying internal pressure to the prepreg sheet through the elastic tube with the outer mold sandwiched between press machines, and then removing the prepreg sheet from the outer mold. A material can be produced (internal pressure manufacturing method).

  Next, the elastic body is softened or expanded. As a technique for softening or expanding the elastic body, a technique for immersing the elastic body in a liquid such as a certain solvent can be cited. This solvent is preferably volatile. Thereby, the solvent can be volatilized after the elastic body is attached, and the hardness of the elastic body can be prevented from remaining lowered. For example, when the elastic body is composed of a thermoplastic polyurethane resin, the elastic body can be softened or expanded by immersing (swelling) the elastic body in white gasoline.

  On the other hand, an adhesive means such as a double-sided tape for adhering the elastic body to the concave portion of the bat base material is installed in the concave portion of the bat base material. In addition, when using a double-sided tape, it is desirable to apply | coat said solvent on this double-sided tape.

  Next, the cylindrical elastic body to which softening, expansion, or lubricant is applied is fitted into the recess from the grip portion side of the bat base material via the taper portion. When the elastic body is softened, the elastic body can be easily deformed in the radial direction by a manual operation by an operator and allowed to pass through the tapered portion. The taper portion can be passed only by slightly expanding in the radial direction in the above state or by manual work by the operator. The lubricant may be applied to at least one of the concave portion or taper portion of the base material for the bat and the inner surface of the elastic body, and when the elastic body is subjected to the above softening or expansion treatment or not In any case, it can be applied, but by applying a lubricant, it is possible to easily pass the tapered portion while sliding the elastic body on the surface of the base material for the bat by an operator's manual operation or the like. it can. By softening or expanding the elastic body or applying a lubricant in this way, the cylindrical elastic body can be smoothly moved from the grip portion side of the bat base material toward the concave portion via the tapered portion. it can. Therefore, the cylindrical elastic body can be easily attached to the concave portion of the base material.

  Note that the maximum outer diameter of the taper portion of the base material for the bat is larger than the minimum inner diameter of the elastic body before the process of softening or expanding the elastic body or applying the lubricant (initial state) (for example, the minimum of the elastic body) The inner diameter is preferably 1.01 times or more of the inner diameter) and 1.4 times or less of the minimum inner diameter of the elastic body. By setting it within this range, the diameter of the elastic body can be expanded and the tapered portion can be easily passed through without impairing the characteristics of the elastic body.

  Moreover, it is preferable to make the minimum inner diameter of the elastic body in the initial state smaller than the minimum outer diameter of the recess. Thereby, even when a simple bonding method such as a double-sided tape is employed, the adhesive force of the elastic body can be ensured.

  After the elastic body is fitted into the concave portion of the bat base material as described above, the elastic body is dried. Accordingly, the elastic body itself is cured or contracted to give an appropriate tightening force to the concave portion of the bat base material, and the elastic body can be fixed to the concave portion of the bat base material by an adhesive means such as a double-sided tape. .

  As described above, according to the present embodiment, the cylindrical elastic body can be easily mounted in the recess of the base material, so that the elastic body can be easily replaced when the elastic body is damaged. . In addition, damage to the bat due to a repair error can be avoided.

  Furthermore, the replacement work of the elastic body is simplified, so that the final shape of the bat can be made different by attaching an elastic body having a different external shape without changing the shape of the base material (core material) for the bat. You can also. In this case, it is possible to produce bats having variously shaped hitting parts by purchasing only one bat base material.

  In addition, it is possible to easily change the outer shape of the hit ball portion by inserting some member between the elastic body and the base material for the bat, or by increasing the thickness of the adhesive layer entirely or locally. In this case, the shape of the hit ball portion according to the user's preference can be obtained without changing the type of the elastic body.

Embodiments of the present invention will be described below with reference to FIGS.
As shown in FIG. 1, a baseball or softball bat 1 in this embodiment mainly includes a base material 2 and a cylindrical elastic body 3.

  As shown in FIGS. 1 and 2, the base material 2 includes a tip portion 4, a concave portion 8 provided in a portion that becomes the hitting ball portion 5, a grip portion 7, and a taper positioned between the concave portion 8 and the grip portion 7. Part 6 and made of fiber-reinforced plastic. The tip portion 4, the taper portion 6 and the grip portion 7 of the base material become the tip portion 4, the taper portion 6 and the grip portion 7 of the bat 1, respectively. The hitting ball portion 5 of the bat 1 is mainly composed of a portion of the base material 2 provided with a recess 8 and an elastic body 3 to be described later.

  The length of the base material 2 is about 840 mm which is the same as the entire length of the bat 1, the length of the tip portion 4 is about 50 mm, the length of the hitting ball portion 5 is about 280 mm which is substantially the same as the length of the concave portion 8, The length of the taper portion 6 is about 260 mm, and the length of the grip portion 7 is about 250 mm.

  As shown in FIG. 2, the maximum outer diameter D2 of the taper portion 6 in the substrate 2 is about 49 mm, and the minimum outer diameter D1 of the recess 8 is about 40 mm. Therefore, in this example, the difference between the maximum outer diameter D2 of the tapered portion 6 and the minimum outer diameter D1 of the concave portion 8 is about 9 mm, and the maximum outer diameter D2 of the tapered portion 6 is about the minimum outer diameter D1 of the concave portion 8. 123%.

  The elastic body 3 has a cross-sectional structure shown in FIG. 3 and is made of a thermoplastic polyurethane resin. The elastic body 3 is bonded to the concave portion 8 of the substrate 2 through a double-sided tape.

  As shown in FIG. 3, the elastic body 3 has a first opening 9 and a second opening 10 at both ends in the longitudinal direction. The first opening 9 is disposed on the tip portion 4 side of the bat 1, and the second opening 10 is disposed on the grip portion 7 side of the bat 1. In the example of FIG. 3, the inner diameter D4 of the first opening 9 is about 62 mm, the inner diameter D5 of the second opening 10 is about 42 mm, and the inner diameter D4 of the first opening 9 is larger than the inner diameter D5 of the second opening 10. Is also getting bigger.

  Further, in this example, the minimum inner diameter D3 of the elastic body 3 is about 40 mm, which is about the same as the minimum outer diameter D1 of the recess 8, but the minimum inner diameter D3 of the elastic body 3 is set to the minimum outer diameter of the recess 8. It may be smaller than D1. Further, the maximum outer diameter D2 of the taper portion 6 of the substrate 2 is about 1.23 times the minimum inner diameter D3 of the elastic body 3.

  As shown in FIG. 3, the elastic body 3 has a maximum thickness in a portion about 40 mm from the first opening 9, and the thickness of the elastic body 3 gradually increases from the first opening 9 toward this maximum thickness portion. Increases, and the thickness of the elastic body 3 gradually decreases from the maximum thickness portion toward the second opening 10. In the example of FIG. 3, the thickness of the maximum thickness portion of the elastic body 3 is about 13 mm.

Next, a method for manufacturing the bat 1 of this embodiment will be described with reference to FIGS.
First, the elastic body 3 is produced. In order to produce the elastic body 3, as shown in FIG. 4, the first core material 12 whose surface is coated with polytetrafluoroethylene in advance is set in an outer mold 11 heated to 50 ° C. A liquid thermoplastic polyurethane resin material is poured into the mold 11. Thereafter, the second core material 13 whose surface is coated with polytetrafluoroethylene in advance is set in the outer mold 11 so as to be combined with the first core material 12, the lid 14 is closed, and left for 10 minutes, for example. Thereby, the elastic material 3 can be molded by curing the resin material. After the molding of the elastic body 3 is completed, the lid 14 is opened, the second core material 13 is taken out, and the first core material 12 together with the molded product of the elastic body 3 is taken out from the outer mold 11. Thereby, the elastic body 3 can be produced. On the other hand, the base material 2 having the shape shown in FIG.

  Next, a double-sided tape is affixed to the bottom surface of the recess 8 of the substrate 2. Thereafter, the elastic body 3 is immersed in white gasoline or white gasoline is applied to the elastic body 3 to swell the white gasoline in the elastic body 3. Thereby, the elastic body 3 is softened or expanded. On the other hand, white gasoline is also applied on the double-sided tape affixed to the recess 8 of the substrate 2.

  Next, as shown in FIG. 5, the softened or expanded cylindrical elastic body 3 is manually mounted on the outer periphery of the base material 2 from the end portion (grip end) of the base material 2 on the grip part 7 side. . More specifically, a cylindrical elastic body 3 that has been softened or expanded from the grip end onto the grip portion 7 is externally fitted, and the elastic body 3 is moved toward the concave portion 8 in accordance with the arrow in FIG. Let it pass. At this time, since the elastic body 3 is softened or expanded, the elastic body 3 can be easily moved on the outer peripheral surface of the substrate 2 by expanding the diameter of the elastic body 3 by hand. Then, the elastic body 3 is fitted into the concave portion 8 of the base material 2.

  After the elastic body 3 is fitted into the concave portion 8 of the substrate 2 as described above, the elastic body 3 is dried. Thereby, the elastic body 3 itself is cured or contracted to give an appropriate tightening force to the concave portion 8 of the base material 2, and the elastic body 3 can be fixed to the concave portion 8 of the base material 2 with a double-sided tape.

  After the elastic body 3 is softened or expanded, or without softening or expanding the elastic body 3, an epoxy adhesive is applied to the inner surface of the elastic body 3, and the grip portion 7 of the base material 2 is manually operated. The elastic body 3 may be mounted on the outer periphery of the substrate 2 from the side end (grip end).

  Although the embodiments and examples of the present invention have been described above, the embodiments and examples disclosed this time should be considered as illustrative in all points and not restrictive. . The scope of the present invention is defined by the terms of the claims, and includes meanings equivalent to the terms of the claims and all modifications within the scope.

  The present invention is applied to a baseball or softball bat.

It is a top view of the baseball or softball bat in the Example of this invention. It is a top view of the base material for bats in the Example of this invention. It is sectional drawing of the elastic body in the Example of this invention. It is sectional drawing which shows an example of the manufacturing apparatus of the elastic body in the Example of this invention. It is a schematic diagram which shows a mode that the elastic body is mounted | worn with the base material for bats.

Explanation of symbols

  1 Bat (baseball or softball bat), 2 base material, 3 elastic body, 4 tip, 5 hitting ball, 6 taper, 7 grip, 8 recess, 9 1st opening, 10 2nd opening, 11 outside Mold, 12 first core material, 13 second core material, 14 lid.

Claims (1)

A base having a concave portion (8) provided in a portion to be the hitting ball portion (5), a grip portion (7), and a tapered portion (6) positioned between the concave portion (8) and the grip portion (7). Material (2),
An elastic body (3) attached to the surface of the concave portion (8) and forming a surface layer portion of the hitting ball portion (5);
A baseball or softball bat in which the maximum outer diameter (D2) of the tapered portion (6) is 101% to 140% of the minimum outer diameter (D1) of the concave portion (8).

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