JPH0611032Y2 - Table tennis racket core - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a table tennis racket core, and more specifically, a plurality of pieces of plate material are arranged so that the grain direction of the plate surface and the wood grain surface is in a specific direction. Regarding things that are butted and bonded together.

<Prior Art> When a ball is returned in a range outside a so-called sweet spot of a table tennis racket, for example, in a peripheral portion such as a side portion or a tip portion (hereinafter, abbreviated as peripheral portion), the user feels discomfort such as numbness or twisting in his hand. The directionality of the hit ball is also bad. It is considered that the collision with the ball causes a twist that causes the racket to rotate around its center of gravity, or causes vibration. Therefore, in order to enlarge the sweet spot, it is necessary to eliminate or at least reduce the twist and vibration at the time of hitting the ball.

Conventionally, the following are examples of table tennis rackets in which the sweet spot has been expanded by focusing on the fiber direction of the wooden board.

There is one in which a plurality of wooden thin plates with a fixed fiber direction are laminated with their fiber directions orthogonal to each other (Fig. 11, Jikken Sho 53-32698). Reference numeral 23 is a front board whose fiber direction is vertical, 24 is a horizontal attachment board, and 25
Shows the vertical center core thin plates.

The striking plate part of the racket is divided into three parts in the vertical direction, and both side parts 26,
28 is a hard plate material, and the central portion 27 is a flexible plate material (Fig. 12, Jikken 53-13503).

<Problems to be solved by the present invention> In all conventional table tennis rackets, although the sweet spot expansion effect such as reduction of vibration is recognized as such,
Twisting still occurs around the racket and its effect is insufficient. This is because the grain direction of the grain surface is not taken into consideration.

That is, since the one obtained by laminating a large number of thin plates having the same grain direction is used, the repulsive force is constant and the moment of inertia around the center of gravity is constant in any part of the ball striking face. Therefore, even if the sweet spot can be slightly enlarged as a whole, it is not possible to particularly improve only the tip portion and side portions of the racket, and it is not possible to change the repulsion direction of only a part such as the tip portion.

It is considered that the sweet spot can be slightly expanded in order to increase the moment of inertia about the centerline vertical axis of the racket to some extent and to reduce the twist about the same vertical axis to some extent. However, it cannot be expected that the sweet spot will expand at the bottom of the racket or at the tip, and the repulsion direction of the ball cannot be changed.

<Means for Solving Problems> The table tennis racket core of the present invention comprises a plurality of small pieces of wood board material having a constant grain direction, a board surface of each piece (a board material surface, the same applies hereinafter) and a wood mouth surface. Both wood grain directions are oriented in a desired direction, and they are abutted and bonded. By the action of the grain of wood, the twist and vibration generated in the racket due to the collision with the sphere are reduced, and the sweet spot is enlarged.

That is, the present invention laterally divides the upper grip portion to the tip portion into at least three parts such as an upper part, a central part, and a lower part, and further divides at least one part of each of the laterally divided parts in the vertical direction to obtain a wooden board. A table tennis racket core configured to constitute each of the above-mentioned divided parts by abutting and adhering a plurality of plate material pieces having a constant grain direction to the surface (hereinafter, abbreviated as plate surface) and the wood mouth surface, The angle α with respect to the plate surface in the wood grain direction of each of the small pieces is approximately 45 ° to 135
A table tennis racket core, in which the above-mentioned small pieces are arranged so as to be in a range of °.

The wood used in the present invention is required to have wood grain (annual ring) formed from spring wood which is sparse and soft and has weak repulsion, and autumn wood which is dense and hard and has high repulsion.
Examples of these woods include scallops, kaya, cypress, cedar, fir, asunaro, sawara, hemlock, yew, red pine, hiba, koyamaki, wig, himekomatsu and the like.

The grain direction of the plate surface of the small piece of plate material is, for example, the grip portion of the racket core as the upper portion, and the grip portion to the lower end portion as the upper portion,
When divided into four parts, the central part, the lower part and the tip part, usually, the racket core upper part is in the vertical direction, the central part is in the vertical or horizontal direction, the both sides are in the vertical direction, and the lower part, the tip part (the lower end part), etc. Then the horizontal direction is appropriate. However, in the peripheral portion, especially at the tip portion, the sweet spot expansion effect becomes higher when the grain direction of the plate surface is substantially perpendicular to the center of the racket striking surface, that is, about 45 ° with respect to the vertical direction of the racket.

When the small pieces of the plate material are arranged such that the angle α with respect to the plate surface of the small piece in the grain direction of the wood mouth surface is approximately 45 ° to 135 °, a suitable sweet spot expansion effect is obtained. The angle α is preferably a right angle in the central portion and the lower portion of the racket core, and an appropriate acute angle (for example, 45 °) or an obtuse angle (for example, 135 °) in the peripheral portion. However, to be exact, it is determined depending on the use of the table tennis racket. For example, when the main core is used for a racket that is mainly used on one side and uses a lot of drive striking methods such as a pen holder type, an acute angle is suitable for the angle α at the peripheral portion of the racket core. On the other hand, in the case of a shake hand type racket that uses both the drive striking method and the cut striking method and uses both sides, two cores for the above pen holder type can be pasted together and used, but In order to increase the sweet spot expansion effect with the core, it is preferable to increase the number of plate material pieces constituting the racket peripheral portion and arrange each piece so that the angle α alternates between an acute angle and an obtuse angle.

If the number of small pieces of plate material used is too small, it will be difficult to enhance the sweet spot expansion effect, and if too many, the number of bonded parts will increase and the hardness will increase too much, and the manufacturing cost will also increase. The number of sheets used depends on the purpose, but usually 5
About 20 pieces is suitable.

<Example> An example of the present invention will be described with reference to FIGS. Hereinafter, the parallel thin lines in the figure show the grain.

Example 1 [Production of core (i) for table tennis racket] In Figs. 1 and 2, the table tennis racket core material was divided into four blocks of an upper part, a central part, a lower part and a tip part in the lateral direction, and a plate surface was formed on the upper part. The small pieces 2 of the plate material are arranged such that the wood grain is in the vertical direction and the wood grain surface is in the direction perpendicular to the surface. The central part is vertically on the left side,
It is divided into three parts, the central part and the right part, and in the central part, there is arranged a small piece of plate material 4 having a vertical wood grain direction and a right angle α formed by the wood grain direction and the wood grain surface, and at the center thereof. Small pieces 3 and 5 with the wood grain direction being vertical and the angle α of about 45 ° on both left and right sides of the section
Are arranged symmetrically. At the bottom, the grain direction is horizontal and α
Arrange the small pieces 6 at right angles. Furthermore, the tip part is divided into two parts on the left and right, a small piece 7 with a horizontal grain direction and an α of 45 ° is arranged on the left side, and a small piece 8 with a horizontal grain direction and an α of about 45 ° is arranged on the lower right side of the same. To do. Then, all the plate material pieces 2 to 8 are brought into contact with the wood edges, the wood mouths, etc., and the contact portions are bonded to obtain the table tennis racket core (i) 1.

Example of use 1 FIG. 3 shows a core (i) 1 with front and back plates 9 and 9
It is a pen holder type racket with 10 attached. Code 11
Is a rubber, 12 is a cork board, and 13 is a grip. The sweet spot on the racket surface (ball striking surface) is enlarged.

USE EXAMPLE 2 FIG. 4 shows a shake hand type racket in which two cores (i) 1 are symmetrically used. Reference numeral 14 indicates a rubber sheet with protrusions. The shot feeling and directionality are good on both sides of the racket, and the sweet spot is enlarged on both sides.

USE EXAMPLE 3 FIG. 5 shows a pen holder type racket using the core (i) 1 as a front plate. Reference numeral 15 indicates a kerat substrate. The sweet spot on the racket surface is enlarged.

Example 2 As shown in FIG. 6, a small piece of plate material 1 at the tip of the racket core material
This is an example configured in the same manner as in Example 1 except that the grain directions of the plate surfaces 7 and 18 are oriented substantially at right angles to the racket center (that is, approximately 45 ° with respect to the longitudinal direction of the racket core). . The small piece 17 and the small piece 18 are bilaterally symmetrical. Compared to the first embodiment, the sweet spot at the tip of the racket is enlarged.

Example 3 [Production of racket core (ii)] As shown in FIGS.
It is divided and the wood grain direction is vertical from the top on the left side and the angle α
Is an obtuse angle (approx. 135 °, the same applies below), small piece 3a, acute angle (approx. 45
° and so on. ) 3b, obtuse angle 3c, and acute angle 3d are sequentially arranged, and similarly obtuse angle 5a, acute angle 5b, obtuse angle 5c, and acute angle 5d are arranged on the right side. Furthermore, the tip is divided into four vertically, and from left to right, a small piece with a horizontal grain direction and an obtuse angle α.
a, an acute angle 7b, an obtuse angle 8a, and an acute angle 8b are arranged one after another, but after arranging the small pieces of plate material in the same manner as in Example 1, butting the wood edges, the mouths, etc. of the small pieces of plate material, Bonding was performed to obtain a racket core (ii) 19 for table tennis.

In the present embodiment, the angles α in the wood grain direction of the plate material pieces 3a to 8b at the side portions and the lower end portions may be such that the acute angle and the obtuse angle are interchanged, and the left and right are not necessarily the same arrangement.

USE EXAMPLE 4 An example of a shake hand type table tennis racket using the core (ii) 19 obtained in Example 3 is shown in FIG. There is a sweet spot expansion effect on both sides of the racket.

<Operation> Fig. 10 shows an enlarged example of the grain of the grain surface of the core for this racket. The wood grain is composed of hard autumn wood 21 and soft spring wood 22. In Fig. 10, the angle α in the grain direction of the grain surface is symmetric with respect to the plate surface in (1) and (3) around the racket.
It is 45 ° and 90 ° in the central part (2). Now
When the ball 20 collides with the peripheral part of the racket, (1) or (3), the collision force of the ball transmitted through the spring material 22 is directed by the action of the autumn material 21 in the arrow direction, that is, the racket central part (2) direction. As force is generated and the racket twists and vibrates when hitting the ball, it seems that a comfortable hitting feeling and a sweet spot expansion effect can be obtained.

<Effect> In the core material of the present invention, the grain of the plate and the grain of the wood are properly oriented. Therefore, if the main core is used as a part of the components of the table tennis racket, even if the ball is hit around the periphery of the racket. , The uncomfortable vibration and the twist are hard to receive, and the sweet spot is enlarged considerably.

By appropriately selecting the hardness and number of small pieces of plate material, the grain direction of the plate surface and the wood surface, racket cores with various characteristics can be obtained, so the main core can be used on both sides (shaking hand) type (Mainly a pen holder) When used as a board material for table tennis rackets (main body, core) such as a backing plate, front plate, back plate, etc., it has optimum characteristics according to the user's battle pattern, batting method, technology and taste. We can provide a table tennis racket.

Further, since the plate material constituting the present racket core may be a small piece, end materials and the like can be utilized, and the part is well retained, which is economical.

[Brief description of drawings]

FIG. 1 shows a racket core (i) of the present invention. 2 (A) to (D) show sectional views taken along the lines AA to DD in FIG. 1, respectively. 3 to 5 show examples of use of the racket lead (i) shown in FIG. FIGS. 6 to 7 show another embodiment, and FIGS. 8 (A) to 8 (H) respectively show A- in FIG.
The AH line sectional view is shown. FIG. 9 shows an example of use of the racket lead (ii) shown in FIG. FIG. 10 is a view exemplifying the action of the grain of the plate material piece in the present invention. 11th ~
Figure 12 shows a conventional example. 1 ... Table tennis racket core (i), 2 to 8 (subscripts a to d)
, 18, 18 …… Small plate material, 16 …… Racquet core (ii), 19 …… Racquet core (iii)

Claims (5)

[Scope of utility model registration request] 1. An upper part, a central part, a lower part, etc. are laterally divided into at least three parts from an upper grip part to a tip part, and at least one part of each of the laterally divided parts is further longitudinally divided.
A ping-pong racket core configured to form each of the above-mentioned divided parts by abutting and adhering a plurality of small pieces of plate material having a constant grain direction on the surface of a wooden board (hereinafter abbreviated as a board surface) and the surface of a wood mouth. A core for a table tennis racket, characterized in that the small pieces are arranged such that an angle α of the small pieces with respect to the plate surface in the grain direction of the wood mouth is in the range of approximately 45 ° to 135 °. 2. A racket core according to claim 1, wherein the upper grip, the grip, and the tip are laterally divided into four parts, an upper part, a central part, a lower part and a tip part. . 3. The center part is vertically divided into three parts and the tip part is vertically divided into two parts, and the grain of the plate surface of the plate material piece is vertically at the center part of the racket core and both left and right parts thereof, and the lower part and the left and right end parts are left and right. Then, the racket core according to claim 2, wherein the small pieces of the plate material are abutted and bonded in a horizontal direction. 4. The center part is vertically divided into three parts, the tip part is vertically divided into two parts, and the grain of the plate surface of the small plate material is arranged vertically in the center part and the left and right parts of the racket core and horizontally in the lower part. 3. The racket core according to claim 2, characterized in that the small pieces of the plate material are butted and adhered to each other in a right-and-left symmetry with respect to the vertical direction and at an angle of about 45 ° with respect to the vertical direction. 5. The angle α is about 90 ° in the central portion and the lower portion of the racket core, and about 45 ° or 135 ° in at least a part of the peripheral portion.
The racket core according to any one of claims 2 to 4, characterized in that each small piece is butted and adhered so that