Elastic body and bat

Abstract

To provide an elastic body capable of reducing energy loss in the elastic body and improving repulsive force.SOLUTION: An elastic body for attachment to a ball hitting part 13 of a bat 1 for a ball game, includes: an outer annular part 23 arranged on a radially outer side; an inner annular part 21 arranged on a radially inner side; a spring part 19 which supports the outer annular part 23 relative to the inner annular part 21 in a radial direction, and is deflectable in a circumferential direction and the radial direction; and a space part 25 which is defined between the outer annular part 23 and the inner annular part 21, and enables deformation of the outer annular part 23 to the radially inner side while allowing deflection of the spring part 19.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an elastic body used in a bat for ball games and a bat using the same. [Background technology]

[0002] Conventional bats of this type include, for example, those described in Patent Document 1, in which a hitting portion is formed by integrating a cylindrical elastic body with a columnar base member.

[0003] This bat suppresses deformation of the ball by deforming the elastic body when hitting the ball, and imparts a repulsive force to the ball when the elastic body returns to its original shape, thereby improving the flight distance of the hit ball.

[0004] However, in conventional bats, the elastic body is a viscoelastic body such as foamed polyurethane, which results in a large energy loss due to viscous damping in the viscoelastic body, limiting the rebound force and, as a result, limiting the distance the ball can travel. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-19236 Summary of the Invention [Problem to be solved by the invention]

[0006] The problem to be solved was that the energy loss in the elastic body was large and the repulsive force was limited. [Means for solving the problem]

[0007] The present invention relates to a bat for ball games. Attached to the core material of Ball hitting club as Used , which is more likely to deform than the core material when it hits the ball.Provided is an elastic body comprising: an outer annular portion arranged radially outward; an inner annular portion arranged radially inward; a spring portion that supports the outer annular portion relative to the inner annular portion in the radial direction and is flexible in the radial direction; and a space portion partitioned between the outer annular portion and the inner annular portion that allows the spring portion to flex while enabling the outer annular portion to deform radially inward.

[0008] The present invention also provides a bat that includes the above elastic body and a core to which the elastic body is attached. [Effects of the Invention]

[0009] In the present invention, when a ball collides with the elastic body, the space between the outer and inner annular portions allows the spring portion to flex while allowing the outer annular portion to deform radially inward, thereby suppressing the volumetric change of the elastic body upon impact with the ball, thereby suppressing energy loss due to viscous damping and improving the repulsive force of the elastic body. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view showing a bat according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a longitudinal cross-sectional view of the bat of FIG. [Figure 3] 3A is a cross-sectional view taken along line III-III in FIG. 2 according to Example 1, and FIG. 3B is a cross-sectional view taken along line III-III in FIG. 2 according to a comparative example. [Figure 4] 4A is a cross-sectional view of Example 1 taken along line III-III in FIG. 2 when hitting a ball, and FIG. 4B is a cross-sectional view of a comparative example taken along line III-III in FIG. 2 when hitting a ball. [Figure 5] FIG. 5 is a cross-sectional view corresponding to line III-III in FIG. 2 according to the first modification of the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view corresponding to the line III-III in FIG. 2 according to the second modification of the first embodiment. [Figure 7]FIG. 7 is a cross-sectional view taken along line III-III in FIG. 2 according to the third modification of the first embodiment. [Figure 8] FIG. 8 is a cross-sectional view corresponding to the line III-III in FIG. 2 according to the fourth modification of the first embodiment. [Figure 9] FIG. 9 is a cross-sectional view corresponding to line III-III in FIG. 2 according to the second embodiment of the present invention. [Figure 10] FIG. 10 is a cross-sectional view taken along line III-III in FIG. 2 according to the third embodiment of the present invention. [Figure 11] FIG. 11 is a cross-sectional view taken along line III-III in FIG. 2 according to the fourth embodiment of the present invention. [Figure 12] FIG. 12 is a cross-sectional view of a modified example of the fourth embodiment taken along line III-III in FIG. [Figure 13] FIG. 13 is a cross-sectional view of a modified example of the fourth embodiment taken along line III-III in FIG. [Figure 14] FIG. 14 is a cross-sectional view of a modified example of the fourth embodiment taken along line III-III in FIG. [Figure 15] FIG. 15 is a cross-sectional view taken along line III-III in FIG. 2 according to the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] The objectives of reducing energy loss in the elastic body and improving repulsion force are achieved by using an elastic body in which the outer and inner ring portions are supported by a spring portion and a space is defined between the outer and inner ring portions.

[0012] As shown in the figures, elastic body 5 of the present invention is an elastic body used in ball-hitting portion 13 of bat 1 for ball games, and includes outer annular portion 23, inner annular portion 21, spring portion 19, and space portion 25. Outer annular portion 23 is disposed radially outward, and inner annular portion 21 is disposed radially inward. Spring portion 19 supports outer annular portion 23 relative to inner annular portion 21 in the radial direction and is configured to bend radially. Space portion 25 is defined between outer annular portion 23 and inner annular portion 21 and allows outer annular portion 23 to deform radially inward while allowing spring portion 19 to flex.

[0013] The spring portion 19 may be formed of a plurality of springs 19a, a honeycomb structure, a three-dimensional mesh, or the like, as long as its material, shape, structure, dimensions, and arrangement are set so as to support the outer annular portion 23 relative to the inner annular portion 21. The plurality of springs 19a may extend radially from the inner annular portion 21 toward the outer annular portion 23, and may be formed of leaf springs or the like. The leaf springs 19a may be made of fiber-reinforced plastic, metal, rubber, or resin.

[0014] The spring portion 19 may function as a spacer by being interposed between the outer annular portion and the inner annular portion without being joined thereto.

[0015] The elastic body 5 may also have an outer tube 29 in which the outer annular portion 23 is fitted or an outer shell 29 that is integral with the outer annular portion 23 .

[0016] Bat 1 equipped with such elastic body 5 has core material 3 to which elastic body 5 is attached.

[0017] In this bat 1, inner annular portion 21 of elastic body 5 may be attached to core 3 or may be integral with core 3. When integral with core 3, inner annular portion 21 may be attached to core 3 and then bonded to the core, or may be integrally formed to constitute a part of core 3. [Example]

[0018] [Bat structure] Fig. 1 is a perspective view showing a bat according to Example 1 of the present invention. Fig. 2 is a longitudinal cross-sectional view showing the bat of Fig. 1. Fig. 3(A) is a cross-sectional view taken along line III-III in Fig. 2 according to Example 1, and Fig. 3(B) is a cross-sectional view corresponding to line III-III in Fig. 2 according to a comparative example.

[0019] Bat 1 of this embodiment is used for ball games such as baseball and softball, and includes a grip portion 7 and a ball-hitting portion 13.

[0020] The grip portion 7 is the portion that the batter grips, and is made up of a part of the core material 3.

[0021] The core 3 is a hollow rod-shaped body with a circular cross-sectional shape. The cross-sectional shape of the core 3 is constant from the tip end to the base end. However, the cross-sectional shape of the core 3 can be different by changing the diameter partially in the length direction (the length direction of the bat 1). Furthermore, the cross-sectional shape of the core 3 is not limited to a circle, and other shapes such as an ellipse can be used.

[0022] Fiber reinforced plastic (FRP), in the present embodiment, is used as the material for the core material 3. However, the material for the core material 3 is not limited to FRP, and metal, wood, etc. may also be used.

[0023] The thickness of the hollow core 3 can be partially thin or thick, and the core 3 can also be entirely or partially solid.

[0024] This core 3 integrally comprises, from the base end to the tip end in the axial direction, a grip portion 7, a hitting area 9, and a head portion 11. However, any one of the grip portion 7, the hitting area 9, and the head portion 11 may be selected and configured as a separate member, or all of these portions may be configured as separate members, and these separate members may be integrally joined to form the core 3. It is also possible to omit the head portion 11.

[0025] Grip portion 7 is a cylindrical portion that is gripped by the batter. In this embodiment, grip portion 3 is a hollow rod with a circular cross section that corresponds to the shape of core material 3. Grip tape 7a is wrapped around grip portion 7. A grip end 7b that protrudes radially is provided at the base end of grip portion 7. A ball-hitting area 9 is integrally provided at the tip of grip portion 7. The radial direction refers to the direction along the diameter of bat 1, but also includes a direction slightly oblique to the diameter.

[0026] The ball-hitting area 9 is part of the core material 3 that, together with the elastic body 5, constitutes the ball-hitting area 13, and has a substantially uniform, hollow, circular cross-sectional shape. The cross-sectional shape of the ball-hitting area 9 is not limited to a circle and can be other shapes. For example, the cross-sectional shape of the ball-hitting area 9 may be asymmetrical on one side and the other side in the radial direction relative to the center of the ball-hitting area 13, or may be elliptical. The head portion 11 is integrally formed on the tip side of the ball-hitting area 9.

[0027] Head portion 11 is formed in the shape of a hollow disk. However, head portion 11 may be solid. Head portion 11 bulges radially relative to hitting area 9. The outer diameter of head portion 11 is approximately the same as the outer diameter of hitting portion 13.

[0028] Hitting portion 13 is configured by attaching elastic body 5 to hitting portion region 9 of core material 3. Note that elastic body 5 of this embodiment can also be applied to bats that do not have hitting portion region 9. In this case, hitting portion 13 can be configured by axially joining elastic body 5 to grip portion 7 of core material 3.

[0029] Elastic body 5 deforms when hit, thereby suppressing deformation of ball B (see FIG. 4) and applying a repulsive force to ball B. Therefore, elastic body 5 deforms more easily than core material 3 when hit. Ball B is a rubber ball.

[0030] Flexible Body The elastic body 5 integrally comprises a cylindrical portion 15 and a tapered portion 17 in the longitudinal direction. The elastic body 5 may be formed from multiple pieces separated in the longitudinal direction and connected together. In this case, the multiple pieces of the elastic body 5 may be made to differ in material, shape, structure, dimensions, etc., so that the characteristics can be adjusted in the longitudinal direction.

[0031] Cylindrical portion 15 is configured as a sweet area that includes the impact center, or sweet spot, of ball-hitting portion 13. The outer diameter of ball-hitting portion 13, which is approximately the same as the outer diameter of head portion 11, is the outer diameter of cylindrical portion 15 of elastic body 5.

[0032] The tip of the cylindrical portion 15 of the elastic body 5 abuts against the head portion 11 of the core material 3, and the base end of the tapered portion 17 is prevented from coming off by a collar 27 on the core material 3 side.

[0033] The elastic body 5 integrally includes a spring portion 19, an inner annular portion 21, and an outer annular portion 23 in the radial direction, and a space 25 is provided between the inner annular portion 21 and the outer annular portion 23. The material of the elastic body 5 is, for example, CFRP, but any material can be used as long as it is more easily deformed than the core material 3. For example, the elastic body 5 can be made of FRP other than CFRP, other resin materials, elastomers such as rubber, or metal.

[0034] This elastic body 5 can be manufactured by injection molding, extrusion molding, a 3D printer, etc. Alternatively, the spring portion 19, the inner annular portion 21, and the outer annular portion 23 can be formed separately from the same material or different materials, and the spring portion 19 can be inserted lengthwise between the inner annular portion 21 and the outer annular portion 23 to join them. Various methods can be selected for joining, such as adhesive bonding or positioning using grooves.

[0035] Additionally, spring portion 19 may be interposed between inner annular portion 21 and outer annular portion 23 as a spacer rather than being bonded thereto. In this case, elastic body 5 is easy to disassemble and assemble, and is excellent in maintainability and customizability. Furthermore, by adjusting the number of leaf springs 19a (described below) in spring portion 19, it is possible to adjust not only the repulsion characteristics but also the weight, thereby adjusting the balance of not only the repulsion characteristics but also the weight of bat 1.

[0036] When the spring portion 19 is not coupled between the inner annular portion 21 and the outer annular portion 23, from the viewpoint of preventing rotation, it is preferable to provide grooves in the inner annular portion 21 and the outer annular portion 23 for engaging the leaf springs 19a. It is even more preferable to arrange at least one of the leaf springs 19a in the opposite direction in the circumferential direction.

[0037] The inner annular portion 21 is an annular member arranged radially inward. The outer annular portion 23 is an annular member arranged radially outward. In this embodiment, the inner annular portion 21 and the outer annular portion 23 are formed in annular shapes with a uniform thickness in cross section. The thickness of the inner annular portion 21 is the same as the thickness of the outer annular portion 23. Note that the thicknesses of the inner annular portion 21 and the outer annular portion 23 may be different from each other or may vary partially in the circumferential and axial directions.

[0038] The inner annular portion 21 has an outer diameter smaller than that of the outer annular portion 23 and is arranged concentrically with the outer annular portion 23. The outer diameter of the outer annular portion 23 at the cylindrical portion 15 is approximately twice the outer diameter of the inner annular portion 21. However, the relationship between these diameters can be selected in various ways. The outer annular portion 23 is supported radially relative to the inner annular portion 21 by the spring portion 19.

[0039] Inner annular portion 21 is configured to be able to be fitted onto the exterior of core material 3, and outer annular portion 23 is configured to be able to be fitted inside outer tube 29. That is, inner annular portion 21 is fitted onto the outer peripheral surface of ball-hitting region 9 of core material 3 and fixed thereto by appropriate means such as adhesive or fitting, thereby forming an integral exterior. Furthermore, outer annular portion 23 is fitted onto the inner peripheral surface of outer tube 29 and fixed thereto by adhesive or the like. This simplifies the manufacture of bat 1. It also makes it possible to adjust the balance of bat 1 depending on the weight of elastic body 5.

[0040] The outer tube 29 improves durability against impact with the ball B. In this embodiment, the outer tube 29 is formed in the shape of a cylindrical film made of a thermoplastic resin such as a polyurethane film. The outer tube 29 may be omitted.

[0041] The spring portions 19 are disposed between the inner annular portion 21 and the outer annular portion 23 at a mutual interval in the circumferential direction, and support the outer annular portion 23 in the radial direction relative to the inner annular portion 21. This support form is arbitrary, and in addition to integrally connecting the inner annular portion 21 and the outer annular portion 23 with the spring portions 19 as described above, the spring portions 19 may be interposed between the inner annular portion 21 and the outer annular portion 23 without being connected.

[0042] The spring portion 19 is made up of a plurality of springs that spread radially between the inner annular portion 21 and the outer annular portion 23. In this embodiment, the springs of the spring portion 19 are leaf springs 19a, but they may also be rod-shaped springs or the like. In this embodiment, the leaf springs 19a have a curved cross section.

[0043] Specifically, the spring portion 19 is configured with a plurality of, for example, 16, leaf springs 19a arranged at approximately equal intervals in the circumferential direction. The leaf springs 19a may also be arranged at uneven intervals. The number of leaf springs 19a can be changed as appropriate depending on the required elasticity, etc.

[0044] Each leaf spring 19a has the same shape. Each leaf spring 19a spans the entire length of the elastic body 5 between the inner annular portion 21 and the outer annular portion 23. However, the thickness of the leaf springs 19a only needs to be set so that they can deform when colliding with the ball B through cooperation between the leaf springs 19a and the outer annular portion 23. Note that some or all of the leaf springs 19a may be configured to have different thicknesses, lengths, etc. In the tapered portion 17, the dimensions of the leaf springs 19a are reduced in accordance with the reduced diameters of the inner annular portion 21 and the outer annular portion 23.

[0045] The radially inner and outer edges of each leaf spring 19a are joined to the inner annular portion 21 and the outer annular portion 23 of the elastic body 5 at approximately the same radius. The cross section of each leaf spring 19a is formed by bending at the middle portion in the radial direction. The bent shapes of the leaf springs 19a are arranged so that the bending direction is in the same direction in the circumferential direction of the elastic body 5. The leaf springs 19a can also be arranged in pairs with bent shapes facing each other and spaced apart in the circumferential direction.

[0046] The bending angle of the leaf spring 19a may be set so that the leaf spring 19a and the outer annular portion 23 cooperate to deform when colliding with the ball B. In this embodiment, the bending angle of the leaf spring 19a is constant, but the bending angle may be varied in part or all of the leaf spring 19a.

[0047] The spaces 25 allow each leaf spring 19a of the spring portion 19 to flex radially between the inner annular portion 21 and the outer annular portion 23. The leaf springs 19a of this embodiment are also allowed to flex in the circumferential direction. This flexure of the leaf springs 19a allows the outer annular portion 23 to deform radially inward relative to the inner annular portion 21.

[0048] The space 25 is defined between the outer annular portion 23 and the inner annular portion 21, and allows the outer annular portion 23 to deform radially inward while allowing the spring portion 19 to flex. In this embodiment, the space 25 exists between the leaf springs 19a that are adjacent in the circumferential direction between the inner annular portion 21 and the outer annular portion 23 in the radial direction.

[0049] This space 25 is open at the longitudinal end of the elastic body 5. However, it is also possible to close both ends of the elastic body 5 to form the space 25 in a sealed state. In this case, various gases can be sealed in the space 25.

[0050] The space 25 may have any size, arrangement, shape, structure, etc. that can be appropriately set as long as it allows the outer annular portion 23 to deform radially inward while allowing the spring portion 19 to bend.

[0051] [Bat Action] 4A is a cross-sectional view taken along line III-III in FIG. 2 at the time of hitting a ball, and FIG. 4B is a cross-sectional view taken along line III-III in FIG. 2 at the time of hitting a ball according to a comparative example.

[0052] As shown in FIG. 3(B), the bat 1 of the comparative example has an elastic body 5 in which a viscoelastic body (urethane) 19 is tightly interposed between an inner annular portion 21 and an outer annular portion 23 without leaving any spaces.

[0053] 4(A), when bat 1 of this embodiment hits a ball, that is, when hitting portion 13 collides with ball B, deformation of elastic body 5 suppresses deformation of ball B and generates a repulsive force against ball B. At this time, leaf spring 19a of elastic body 5 around the point of impact of ball B is deflected within space 25 via outer annular portion 23.

[0054] When the leaf springs 19a are bent, the leaf springs 19a closest to the point of impact of the ball B are deformed relatively largely in the radial direction. At this time, the tip of the bend in the leaf spring 19a can be displaced in the circumferential direction within the space 25, allowing the leaf springs 19a to bend. Similarly, the tip of the bend in the leaf springs 19a on both sides of the leaf spring 19a in the circumferential direction can be displaced in the circumferential direction within the space 25, allowing the leaf springs 19a to bend. However, the amount of bending of the leaf springs 19a is relatively small.

[0055] In the longitudinal direction of bat 1, leaf spring 19a is largely deflected within space 25 at a location close to the impact point of ball B, and the deflection within space 25 decreases as the distance from ball B increases.

[0056] The deflection of leaf spring 19a due to space 25 reduces the volume change of elastic body 5 during deformation, suppressing viscous damping. This reduces the energy loss when the deformation energy accumulated in hitting area 13 is converted into the kinetic energy of ball B. Therefore, in this embodiment, elastic body 5 has a good resilience characteristic value, which means that the resilience of elastic body 5 is improved, thereby improving the flight distance of ball B.

[0057] Furthermore, in this embodiment, as shown in FIG. 4(A), there is no or limited contact between the leaf springs 19a when the spring portion 19 is deformed, so that energy loss due to such contact does not occur or is limited.

[0058] Furthermore, when the leaf spring 19 rebounds, the leaf springs 19a at the center of the impact with the ball B and at three points on both sides of the center are in a rebound state, so that the ball B can be stably and accurately launched.

[0059] On the other hand, as shown in Figure 4(B), in the bat 1 of the comparative example, when the hitting portion 13 collides with the ball B, the viscoelastic body (urethane) 19 bends radially inward, suppressing deformation of the ball B and generating a repulsive force against the ball B.

[0060] At this time, in the comparative example, the viscoelastic body 19 is pressed by the ball B and is compressed and deformed, causing a change in volume of the viscoelastic body 19. Therefore, in the comparative example, energy loss occurs due to viscous damping of the viscoelastic body 19, which results in limiting the resilience characteristic value.

[0061] [Variations] 5 to 8 relate to Modifications 1 to 4 of the embodiment, and are cross-sectional views corresponding to line III-III in FIG. 2, respectively.

[0062] In Modification 1 of FIG. 5, each leaf spring 19a of the spring portion 19 of the elastic body 5 is a radially linear leaf spring. The joints between each leaf spring 19a and the inner annular portion 21 and the outer annular portion 23 are offset from each other in the circumferential direction. As a result, each leaf spring 19a is arranged so as to be inclined relative to the radial direction. The circumferential spacing between adjacent leaf springs 19a is approximately the same, and each spacing increases radially outward. The number of leaf springs 19a and other factors are set to the same as in Example 1.

[0063] In this first modification, the leaf spring 19a is not bent, which makes manufacturing easier.

[0064] In the second modification shown in Fig. 6, each leaf spring 19a of the spring portion 19 of the elastic body 5 is formed in a leaf spring shape that is folded back in multiple stages in the radial direction. The joints between each leaf spring 19a and the inner annular portion 21 and the outer annular portion 23 are set on approximately the same radius. The number of leaf springs 19a is set to be the same as in the first embodiment shown in Fig. 3(A).

[0065] In this second modification, the rebound characteristics can be changed by adjusting the number of folds of the leaf spring 19a.

[0066] In Modification 3 of FIG. 7, each leaf spring 19a of the spring portion 19 of the elastic body 5 is an arc-shaped leaf spring with a radially intermediate portion that is convex in the circumferential direction. The joints between each leaf spring 19a and the inner annular portion 21 and the outer annular portion 23 are set on approximately the same radius. The number of leaf springs 19a is fewer than in the embodiment, with six leaf springs 19a arranged at equal intervals in the circumferential direction. However, the number of leaf springs 19a in Modification 3 can also be the same as in the embodiment of FIG. 3(A).

[0067] 8, each leaf spring 19a of the spring portion 19 of the elastic body 5 is connected to an adjacent leaf spring 19a and arranged on the same imaginary circle. In this modification, eight circular leaf springs 19a are connected in series in the circumferential direction between the inner annular portion 21 and the outer annular portion 23.

[0068] The circular leaf springs 19a are in contact with each other in the circumferential direction, and their outer peripheries are integrally formed with or integrally joined to the outer periphery of the inner annular portion 21 and the inner periphery of the outer annular portion 23. The circular leaf springs 19a can also be spaced apart in the circumferential direction. The circular leaf springs 19a can also be elliptical, which is a form of a circle, so that the number of circular leaf springs 19a in the circumferential direction can be increased or decreased.

[0069] In this fifth modification, circular leaf spring 19a stabilizes deformation, and a relatively uniform repulsion characteristic value can be obtained around the outer periphery of bat 1. [Example]

[0070] Fig. 9 is a cross-sectional view of Example 2 of the present invention, taken along line III-III in Fig. 2. Note that the basic structure of this example is similar to that of Example 1, and therefore the same reference numerals are used to designate corresponding components, and redundant explanations will be omitted. For the overall structure, refer to Figs. 1 and 2.

[0071] In this embodiment, the spring portion 19 of the elastic body 5 is made of a honeycomb structure.

[0072] The spring portion 19 has approximately two stages of honeycomb-shaped wall portions 19a arranged radially between the inner annular portion 21 and the outer annular portion 23. The wall portions 19a constituting the honeycomb shape are each leaf spring-shaped, and adjacent spaces 25 share the wall portions 19a to form the honeycomb shape. The number of honeycomb shapes can be freely set.

[0073] In the second embodiment, when the hitting portion 13 collides with the ball B, the spring portion 19 bends at a position corresponding to the ball B, so as to crush the honeycomb structure.

[0074] At this time, the wall portions 19a of the honeycomb structure are deflected in the circumferential and radial directions in the honeycomb-shaped space portions 25. The deflection of the wall portions 19a gradually decreases with increasing distance from the impact point of the ball B, thereby increasing the dispersion of the force.

[0075] As a result, a relatively uniform resilience characteristic value can be obtained around the outer periphery of bat 1. In addition, in Example 2, the same effects as those in Example 1 can be achieved. [Example]

[0076] Fig. 10 is a cross-sectional view of Example 3 of the present invention, taken along line III-III in Fig. 2. Note that the basic structure of this example is similar to that of Example 1, and therefore the same reference numerals are used to designate corresponding components, and redundant explanations will be omitted. For the overall structure, refer to Figs. 1 and 2.

[0077] In this embodiment, the spring portion 19 of the elastic body 5 is formed of a three-dimensional mesh. The spring portion 19 is formed by crossing leaf spring-like or linear mesh components 19a having spring properties, and lattice-like spaces 25 are defined three-dimensionally in the radial and longitudinal directions. In a cross section, both ends of each mesh component 19a are integrally connected to the inner annular portion 21 and the outer annular portion 23, or abut between the inner annular portion 21 and the outer annular portion 23 without being connected.

[0078] In the third embodiment, when the hitting portion 13 collides with the ball B, the spring portion 19 bends at a position corresponding to the ball B, so that the three-dimensional mesh is crushed.

[0079] At this time, in this embodiment, the mesh components 19a bend in the circumferential and radial directions in the mesh-shaped spaces 25. This bending of the mesh components 19a gradually decreases as they move away from the part where the ball B hits. This improves the force dispersion capability of the mesh components 19a. This bending of the mesh components 19a generates a repulsive force against the ball B.

[0080] In Example 3, the force distribution by leaf spring 19a is improved, and a relatively uniform repulsion characteristic value can be obtained around the outer periphery of bat 1. In addition, this example also has the same effects as Example 1. [Example]

[0081] Fig. 11 is a cross-sectional view of Example 4 of the present invention, taken along line III-III in Fig. 2. Note that the basic structure of this example is similar to that of Example 1, and therefore the same reference numerals are used to designate corresponding components, and redundant explanations will be omitted. For the overall structure, refer to Figs. 1 and 2.

[0082] In this example, core material 3 of bat 1 equipped with elastic body 5 is eccentric. The rest is the same as Example 1. That is, the center of ball-hitting area 9 of core material 3 is radially offset from the center of ball-hitting area 13.

[0083] The radial length of the leaf spring 19a of the spring portion 19 varies depending on the eccentricity. The amount of deformation of the leaf spring 19a can be increased on the side where the gap between the inner annular portion 21 and the outer annular portion 23 is widened due to the eccentricity.

[0084] If the spring portion 19 is interposed as a spacer between the inner annular portion 21 and the outer annular portion 23 without being joined, it is possible to make the spring portion 19 of Example 1 eccentric as in this example by simply replacing the spring member 19a.

[0085] [Variations] 12 to 14 are cross-sectional views corresponding to the line III-III in FIG. 2, each relating to a modification of the fourth embodiment.

[0086] In the modification of Fig. 12, each leaf spring 19a of the spring portion 19 of the elastic body 5 is connected to an adjacent leaf spring 19a and arranged on the same imaginary circle, as in the modification 4 of the embodiment 1 of Fig. 8. The rest is the same as the embodiment 4.

[0087] The diameter of the circular leaf spring 19a is set to a large or small value depending on the eccentricity of the core material 3. Note that the thickness of the leaf spring 19a can be increased on the side where the gap between the inner annular portion 21 and the outer annular portion 23 widens due to the eccentricity.

[0088] In the modified examples of FIGS. 13 and 14, the leaf spring 19a on the side where the gap between the inner annular portion 21 and the outer annular portion 23 is narrowed due to eccentricity is omitted from the fourth embodiment of FIG. 11 and the modified example of FIG. [Example]

[0089] Fig. 15 is a cross-sectional view of Example 5 of the present invention taken along line III-III in Fig. 2. Note that the basic structure of this example is similar to that of Example 1, and therefore the same reference numerals are used to designate corresponding components, and redundant explanations will be omitted. For the overall structure, refer to Figs. 1 and 2.

[0090] In this embodiment, spring portion 19 of bat 1 is formed integrally with hitting area 9 of core material 3 and outer tube 29. In other words, inner annular portion 21 is core material 3, and outer annular portion 23 is outer tube 29. Spring portion 19 may be formed integrally with either hitting area 9 or outer tube 29, and may be externally or internally mounted on the other, as in Example 1. Also, outer tube 29 may be omitted from this embodiment.

[0091] In the fifth embodiment, the spring portion 19 is integrally formed with the outer tube 29 and the core member 3, which makes it easier to handle and reduces the number of parts. In addition, the same effects as those of the first embodiment can be achieved. [Explanation of symbols]

[0092] 1 bat 3 Core material 5 Elastic Body 13 Ball batting club 19 Spring section 19a Leaf springs, walls, mesh components 21 Inner annular section 23 Outer Ring 25 Space section 29 Outer tube

Claims

1. An elastic body that is attached to a core material of a bat for a ball game and used as a hitting portion, and that is more easily deformed than the core material when colliding with a ball, an outer annular portion disposed radially outward; an inner annular portion disposed radially inside; a spring portion that supports the outer annular portion relative to the inner annular portion in the radial direction and is flexible in the radial direction; a space portion defined between the outer annular portion and the inner annular portion, the space portion allowing the outer annular portion to deform radially inward while allowing the spring portion to bend; An elastic body comprising:

2. The elastic body of claim 1, The spring portion includes a plurality of springs extending radially from the inner annular portion to the outer annular portion. Elastic body.

3. The elastic body of claim 2, The spring is a leaf spring. Elastic body.

4. The elastic body of claim 3, The leaf spring is made of fiber-reinforced plastic. Elastic body.

5. The elastic body of claim 3, The leaf spring is made of metal. Elastic body.

6. The elastic body of claim 3, The leaf spring is made of rubber. Elastic body.

7. The elastic body of claim 3, The leaf spring is made of resin. Elastic body.

8. The elastic body of claim 1, The spring portion is a honeycomb structure. Elastic body.

9. The elastic body of claim 1, The spring portion is a three-dimensional mesh. Elastic body.

10. An elastic body used in the hitting portion of a bat for ball games, an outer annular portion disposed radially outward; an inner annular portion disposed radially inside; a spring portion that supports the outer annular portion relative to the inner annular portion in the radial direction and is flexible in the radial direction; a space portion defined between the outer annular portion and the inner annular portion, the space portion allowing the outer annular portion to deform radially inward while allowing the spring portion to bend; An elastic body comprising: the spring portion is interposed between the outer annular portion and the inner annular portion without being coupled thereto and functions as a spacer. Elastic body.

11. The elastic body according to any one of claims 1 to 10, An outer tube in which the outer annular portion is installed, Elastic body.

12. The elastic body according to any one of claims 1 to 10, An outer tube integral with the outer annular portion, Elastic body.

13. A bat having the elastic body of any one of claims 1 to 12, A core material to which the elastic body is attached is provided. bat.

14. 14. The bat of claim 13, The inner annular portion is sheathed on the core material. bat.

15. 15. The bat of claim 13 or 14, The inner annular portion is integral with the core material. bat.

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