WO2021166671A1 - Racket string - Google Patents

Abstract

Provided is a racket string having a string-making structure for side threads, the racket string being capable of being easily manufactured and exerting a plurality of functions with a single string. A string (10) includes a core thread (11), a plurality of Z-winding-side threads (12a) wound in a Z-direction on the outer peripheral side of the core thread, and a plurality of S-winding-side threads (12b) wound in an S-direction on the outer peripheral side of the core thread, and extends in a predetermined direction. The Z-winding-side threads and the S-winding-side threads are woven into a string-making structure. Long core members (13) are incorporated so as to extend on the outside of the core thread.

Description

Racket string

The present invention relates to a racket string used for tennis, soft tennis, badminton, squash, etc.

Tennis and badminton rackets have strings stretched over the face in a mesh pattern. As a string for a racket, a string in which a monofilament serving as a core yarn or a monofilament serving as a thin side yarn is wound around the outside of a multifilament is widely used.

As such a string, as disclosed in Patent Document 1, a configuration in which a core yarn and a sheath yarn (side yarn) are integrated via a hot melt yarn has been proposed. Specifically, in the string of Patent Document 1, a hot melt yarn is spirally wound around a core yarn, a sheath yarn is woven on the surface of the core yarn, and the string-making yarn obtained by the cord-making is heated. By melting the hot melt yarn, the core yarn and the sheath yarn are heat-bonded and integrated.

JP-A-2018-187163

In the production of the string in Patent Document 1, the step of winding the hot melt yarn around the core yarn and the process of stringing the sheath yarn are carried out separately. Therefore, there is a problem that the string manufacturing process becomes complicated, takes a long time, and the manufacturing cost increases.

By the way, in the case of a string, various performances such as speed performance, spin performance, durability performance, and flying performance are required in the racket on which the string is stretched. Here, in order to make a single string have multiple functions in order to exert multiple functions with one racket, it is considered to use multiple types of sheath yarn materials with different physical characteristics in a single string. bottom. However, even if it is attempted to combine different materials having different physical characteristics with the sheath yarn, it is impossible to combine the yarns having different elongations because a large centrifugal force is applied to the sheath yarn during the string making process.

The present invention has been made in view of the above circumstances, and it is possible to facilitate manufacturing while making the side yarn a string-making structure, and it is possible to exert a plurality of functions with a single string. It is an object of the present invention to provide a string for a racket.

The racket string of the present invention includes a core yarn, a plurality of Z-wound side yarns wound in Z-winding on the outer peripheral side of the core yarn, and a plurality of S-winding wounds on the outer peripheral side of the core yarn. In a racket string that includes an S-wound side yarn and extends in a predetermined direction, the Z-wound side yarn and the S-winding side yarn are woven into a string-making structure, and a long core member is formed outside the core yarn. Is characterized by being extended and incorporated. Here, the long core member can be exemplified as a member extending in a thread shape.

According to the present invention, since the long core member is incorporated, the long core member can be integrally arranged outside the core thread in the string making process of each side thread. As a result, it is possible to suppress the complexity of manufacturing and the lengthening of time due to the provision of the long core member. Moreover, by providing the long core member, it is possible to add different functions due to the material, cross-sectional shape, etc. of the long core member to the string without the long core member. As a result, it is possible to give a single string a plurality of functions so that each of the plurality of functions can be exhibited, and at the same time, it is possible to suppress the complexity of manufacturing and the lengthening of time.

It is a partially enlarged front view of the string which concerns on embodiment. It is sectional drawing of the string which concerns on embodiment. It is explanatory drawing which simplified and represented the string making machine which draws the string. It is a partially enlarged front view which is the same as FIG. 1 of the string which concerns on a modification.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. The string of the present invention can be applied to various rackets such as badminton, soft tennis, tennis, squash, etc. as long as it is stretched over the frame of the racket to form a face.

FIG. 1 is a partially enlarged front view of the string according to the embodiment, and FIG. 2 is a cross-sectional view of the string according to the embodiment. As shown in FIGS. 1 and 2, the string 10 is provided with a core thread 11 which is located at the center and forms a substantially circular outer circumference in a cross section, and is spirally wound around the outer peripheral side of the core thread 11. It includes a Z-winding side thread 12a and an S-winding side thread 12b, and is configured to extend in a predetermined direction. Further, the string 10 includes a long core member 13 arranged outside the core thread 11. The outer shape of the string 10 is formed in a substantially circular shape in the cross section, and the core thread 11, the side threads 12a and 12b, and the long core member 13 are integrally bonded.

In the present embodiment, the core yarn 11 is composed of multifilaments, although not shown, but the number of the core yarns 11 is not limited and does not prevent the core yarns 11 from being composed of monofilaments. Further, in FIG. 2, the core thread 11 is formed in a circular shape in a cross section, but the cross section is not limited to this, and the cross section may be a polygon (for example, a pentagon).

On the outer peripheral side of the core yarn 11, the Z-wound side yarn 12a is wound in Z-winding and the S-winding side yarn 12b is wound in S-winding, and they are woven into a braided string-like structure. .. In the present embodiment, the Z-winding side yarn 12a, the S-winding side yarn 12b, and the long core member 13 are formed into a band or flat shape by aligning a plurality of yarns (long members) into one set. .. In FIG. 1, the lines at the boundary portions of the plurality of threads constituting the side threads 12a and 12b and the long core member 13 are omitted. The Z-winding side thread 12a, the S-winding side thread 12b, and the long core member 13 are not limited to the above shapes, and the cross section may be formed into a circular shape, an elliptical shape, or a polygonal shape (for example, a pentagonal shape). Further, in the present embodiment, a 16-stroke string-making structure is provided in which eight Z-winding side yarns 12a and eight S-winding side yarns 12b are provided, but the number of these yarns may be a plurality of four. It may be braided as another number, such as having an 8-stroke string-making structure provided for each.

In the string-making structure of the present embodiment, two Z-winding side yarns 12a and two S-winding side yarns 12b are woven in a two-way jump where two yarns intersect in the radial direction of the string 10. The Z-winding side yarn 12a and the S-winding side yarn 12b have an inclination angle of 45 ° with respect to the extension direction of the string 10, but the angle and the number of jumps are arbitrary as long as the string can be made, such as 30 °. Can be set to.

The long core member 13 is incorporated by being woven between the forming layer of the Z winding side yarn 12a and the forming layer of the S winding side yarn 12b. Therefore, in the radial direction of the string 10, at the position where the Z-winding side thread 12a is on the outside and the S-winding side thread 12b is on the inside and intersects, the long core member 13 is inside the Z-winding side thread 12a and on the S-winding side. It is arranged so as to be sandwiched outside the thread 12b. On the contrary, at the position where the Z-winding side thread 12a is on the inside and the S-winding side thread 12b is on the outside and intersects, the long core member 13 is outside the Z-winding side thread 12a and from the S-winding side thread 12b. It is placed sandwiched inside. Further, the long core member 13 is exposed to the outside at a position where the Z winding side thread 12a and the S winding side thread 12b do not intersect. The method of weaving the long core member 13 will be described later.

The long core member 13 extends parallel to the extending direction of the string 10. Therefore, as shown in FIG. 1, when the string 10 extends linearly in the vertical direction in the figure, the long core member 13 also extends linearly in the vertical direction. Here, "parallel" does not mean strict parallelism, but is a concept that includes manufacturing errors and slight deformation due to unintended external factors. Further, a plurality of long core members 13 are provided at predetermined angles in the circumferential direction of the core thread 11. In the present embodiment, eight long core members 13 are provided and arranged at equal angles of about 45 ° in the circumferential direction of the core yarn 11. It should be noted that the number of the long core members 13 does not prevent the number of the long core members 13 from being a plurality of other members such as four or being one.

A surface coating layer 15b is formed after the internal coating layer 15a is formed around the side yarns 12a and 12b and the long core member 13 knitted on the outer peripheral side of the core yarn 11 (both are shown in FIG. 1). Not shown). A general thermoplastic resin can be used for each of the coating layers 15a and 15b, and it is particularly desirable to use a polyamide-based resin and a polyurethane-based resin. In the present embodiment, the internal coating layer 15a and the surface coating layer 15b are separated, but they may not be separated. Further, each of the layers 15a and 15b may be a plurality of layers.

The material of the core yarn 11 and the side yarns 12a and 12b is not particularly limited, but for example, polyamide, polyester and the like are used. It should be noted that the core yarn 11 and the side yarns 12a and 12b do not prevent the use of polyester (polybutylene terephthalate, polyethylene terephthalate, etc.), polyolefin, polyphenylene sulfide, polyetheretherketone, etc. Further, hollow fibers may be used for the core yarn 11 and the side yarns 12a and 12b.

Here, the production of the string 10 in the present embodiment will be described with reference to FIG. FIG. 3 is an explanatory diagram showing a simplified string-making machine for string-making the string. The string making machine 20 shown in FIG. 3 is used for manufacturing the string 10 of the present embodiment. In the string making machine 20, the Z-winding bobbin 21 (shown by a solid circle) around which the Z-winding side thread 12a (not shown in FIG. 3) is wound and the S-winding side thread 12b (not shown in FIG. 3) are wound. It is equipped with an S-winding bobbin 22 (shown by a broken line circle). The Z-winding bobbin 21 and the S-winding bobbin 22 are provided with eight weights each according to the number of Z-winding side threads 12a and S-winding side threads 12b (8 threads).

Further, the string making machine 20 has a Z winding groove 23 (shown by a thick solid line) for guiding the progress of the Z winding bobbin 21 and an S winding groove 24 (with a thick broken line) for guiding the progress of the S winding bobbin 22. (Illustrated). Each of the grooves 23 and 24 meanders and surrounds the core thread 11 directed in the vertical direction (direction orthogonal to the paper surface) in a closed loop shape. In the string making by the string making machine 20, the Z winding bobbin 21 is guided along the Z winding groove 23, and the S winding bobbin 22 is guided along the S winding groove 24 in the direction of the arrow in the drawing. By the progress of each of the bobbins 21 and 22, a string-making structure is formed in which the Z-winding side yarn 12a and the S-winding side yarn 12b are woven on the outer peripheral side of the core yarn 11.

In the string making machine 20, the Z winding groove 23 and the S winding groove 24 intersect at predetermined intervals in the circumferential direction of the core thread 11, and Z is formed between two adjacent intersecting positions in the circumferential direction. The winding groove 23 and the S winding groove 24 form a closed loop shape (circular shape). The long core member 13 is arranged in the center of the closed loop-shaped portion in a direction intersecting the paper surface of FIG. By disposing the long core member 13 in this way, the long core member 13 can be arranged between the Z winding side thread 12a and the S winding side thread 12b in the radial direction of the string 10.

As the bobbins 21 and 22 proceed along the grooves 23 and 24, the side threads 12a and 12b receive centrifugal force. On the other hand, since the long core member 13 does not travel in the circumferential direction like the side threads 12a and 12b, the long core member 13 receives no centrifugal force or hardly receives centrifugal force when the side threads 12a and 12b are crocheted. The core member 13 can be integrally woven. Further, the long core member 13 can be knitted into the side yarns 12a and 12b in the same process as the knitting of the side yarns 12a and 12b.

As described above, according to the present embodiment, the long core member is knitted with the Z winding side yarn 12a and the S winding side yarn 12b so as to extend in the same direction as the core yarn 11 without winding around the core yarn 11. 13 can also be woven.

Here, in a structure in which a hot melt yarn is spirally wound around a core yarn having a conventional structure and then a side yarn is woven on the surface thereof, two steps of winding and lacing are required. On the other hand, in the present embodiment, the core yarn 11 and the side yarns 12a and 12b are formed by applying the hot melt yarn to the long core member 13 in one step of stringing the side yarns 12a and 12b. And the long core member 13 can be integrated. As a result, in the present embodiment, it is possible to suppress the manufacturing process of the string 10 from becoming complicated and lengthening, and to suppress an increase in the manufacturing cost.

Also, as a comparative structure, it is conceivable to mix side yarns that exhibit different characteristics without making all the side yarns have the same characteristics. However, since the bobbins 21 and 22 proceed at high speed in the above-mentioned string making machine 20 and are string-made while receiving centrifugal force, all of the plurality of Z-wound side threads 12a and S-wound side threads 12b are formed. If the tension is not uniform, string making cannot be performed. Therefore, in the comparative structure in which the side yarns having different characteristics are mixed, the elongation and the like differ between the side yarns, and it is not realistic to make the side yarns uniform.

In the configuration of the present embodiment, a thread (long member) having different characteristics and performance for each side thread 12a and 12b can be used for the long core member 13. As a result, the core thread 11 and the side threads 12a and 12b can exert a predetermined function, and the long core member 13 can add a function different from the function. As a result, a single string 10 can have a plurality of functions and can exert each of them. In other words, it is possible to exert each of a plurality of functions in a state where the same string 10 is stretched between the warp and the weft.

The plurality of functions by providing the long core member 13 in the string 10 of the present embodiment can have variations in the combination by selecting the long core member 13 having various characteristics, materials, and sizes. .. A combination of such a plurality of functions will be described below with specific examples. In the following description, the case where the string 10 is stretched on the badminton racket will be mainly described, but the same function can be exhibited in tennis and the like.

(1) Speed Performance and Spin Performance Here, the speed performance is defined as the performance that can be exhibited mainly by the material and thickness of the core yarn 11 and the side yarns 12a and 12b. By demonstrating the speed performance, it is possible to easily give the player a feeling of hitting a ball at a high speed, and it is possible to improve the speed of the shuttle hit. The speed performance is the same in the following, and the description may be omitted.

For spin performance, the long core member 13 is woven as described above, and in particular, the thickness of the long core member 13 is formed to be thicker than the side threads 12a and 12b to form irregularities on the surface of the string 10, and the string 10 and the string 10 are formed. It is said to be a performance that can be demonstrated by increasing the friction with the shuttle. If the surface of the string 10 can be made uneven, it does not prevent the long core member 13 from being formed thinner than the side threads 12a and 12b. By demonstrating the spin performance, it is possible for the player to easily apply a spin and to increase the spin (rotation speed) of the hit shuttle. With the above configuration, it is possible to demonstrate spin performance in addition to speed performance.

(2) Speed performance and power performance In terms of power performance, the long core member 13 is made of a material different from that of the side threads 12a and 12b, and the elastic modulus of the long core member 13 is formed higher than the elastic modulus of the side threads 12a and 12b. By doing so, it is said that the performance can be demonstrated. The elastic modulus means to include at least one of the elastic modulus of the material itself and the elastic modulus of the thread (the same shall apply in the claims). By demonstrating the power performance, it becomes easier to give the player a feeling of hitting a powerful ball, and it is possible to increase the force applied to the shuttle by crushing the shuttle at the time of a smash shot or the like. With the above configuration, it is possible to demonstrate power performance in addition to speed performance.

(3) Speed Performance and Durability Performance Durability is a performance that can be exhibited by coating the long core member 13 with a low-friction fluorine-based resin or the like to make the strings 10 that intersect at the time of hitting slippery. In addition to the coating with the fluororesin, the fluororesin itself may be used as a raw yarn. Further, the yarn may be coated with a material other than fluorine, which has higher wear resistance than the side yarns 12a and 12b, and made into a raw yarn. Abrasion resistance is synonymous with low frictional resistance, and high wear resistance means that frictional resistance is reduced (the same applies within the scope of claims). By demonstrating durability performance, it becomes difficult to scrape the intersections of the strings 10 and it becomes difficult to form grooves called notches, and it is possible to suppress cutting of the strings 10 and extend the service life. .. With the above configuration, it is possible to demonstrate durability performance in addition to speed performance.

(4) Speed Performance and Flying Performance In terms of flying performance, the long core member 13 is made of a material different from the side threads 12a and 12b, and the long core member 13 has a smaller elastic modulus than the side threads 12a and 12b and has elastic force. By forming it with elastic fibers, it is said that the performance can be exhibited. By demonstrating the flying performance, it becomes easy to give the player a feeling of hitting the shuttle so that the shuttle can easily fly, and the shuttle is easily repelled by the string 10 at the time of hitting. The long core member 13 made of elastic fibers has a large area covered by the side threads 12a and 12b, and its durability can be kept good. With the above configuration, it is possible to demonstrate flying performance in addition to speed performance.

The elastic fiber is made of synthetic fiber, which has low rubber elasticity (for example, 10 MPa or less) and expands and contracts greatly with a small force. Specific examples include polyurethane fibers, polyether-ester copolymer fibers, and polytrimethylene terephthalate fibers.

(5) Performance and Durability of Natural Fiber By using natural fiber for the long core member 13, the long core member 13 has the side threads 12a and 12b while obtaining the shot feeling and characteristics peculiar to the natural fiber. By being covered, the durability performance of the long core member 13 can be kept good.

(6) Designability The color tones can be made different by the plurality of long core members 13, and various color tones can be combined by the long core members 13 extending in parallel with the extending direction of the string 10. Designability can be further exhibited in addition to the above-mentioned functions.

The present invention is not limited to the above embodiment, and can be modified in various ways. In the above embodiment, the size, shape, direction, etc. shown in the attached drawings are not limited to this, and can be appropriately changed within the range in which the effects of the present invention are exhibited. In addition, it can be appropriately modified and implemented as long as it does not deviate from the scope of the object of the present invention.

For example, the string-making structure using the Z-winding side thread 12a and the S-winding side thread 12b may be changed to the configuration shown in FIG. FIG. 4 is a partially enlarged front view similar to FIG. 1 of the string according to the modified example. In the modified example of FIG. 4, the Z-winding side yarn 12a and the S-winding side yarn 12b are woven one by one in a staggered manner intersecting each other in the radial direction of the string 10.

Further, in FIGS. 1 and 4, the core yarn 11 is exposed through between the knitted Z-wound side yarn 12a and the S-winding side yarn 12b, but the distance between the side yarns 12a and 12b is reduced or eliminated. The core thread 11 may not be exposed by the above. In this configuration, the long core member 13 is also provided so as not to be exposed by the side threads 12a and 12b.

Further, in the braiding of the long core member 13, the long core member 13 may be changed to the position indicated by the alternate long and short dash line in FIG. In other words, the long core member 13 may be arranged inside both the Z winding groove 23 and the S winding groove 24 to tie the side threads 12a and 12b. Also by this, while incorporating the long core member 13 on the outer peripheral side of the core thread 11, the long core member 13 can be arranged in the extending direction of the string 10 at the same time as the stringing of the side threads 12a and 12b.

Further, the long core member 13 may be in the form of a thread, a string, a band, or an elongated sheet or a long member in the form of a film. Further, the long core member 13 can be selected from the above materials that can be used for the core thread 11 and the side threads 12a and 12b, as well as animal fibers such as sheep intestine, wool, silk thread and spider thread, cotton, seaweed and the like. It may be a natural material to be used as the plant fiber of the above, or it may be a product obtained by subjecting it to a predetermined process.

The racket string of the present invention has the effect that the side yarn has a string-making structure and can be easily manufactured, and a single string can exert a plurality of functions.

This application is based on Japanese Patent Application No. 2020-026224 filed on February 19, 2020. All of this content is included here.

Claims (6)

1. A core yarn, a plurality of Z-wound side yarns wound in Z-winding on the outer peripheral side of the core yarn, and a plurality of S-winding side yarns wound in S-winding on the outer peripheral side of the core yarn are provided. In a racket string that extends in a predetermined direction
   The Z-wound side yarn and the S-winding side yarn are woven into a string-making structure.
   A string for a racket, characterized in that a long core member extends outward from the core thread and is incorporated.
2. The racket string according to claim 1, wherein the long core member is woven between the Z-winding side yarn forming layer and the S-winding side yarn forming layer.
3. The racket string according to claim 1 or 2, wherein the long core member extends parallel to the extension direction of the racket string.
4. The racket string according to any one of claims 1 to 3, wherein a plurality of the long core members are provided at predetermined angles in the circumferential direction of the core yarn.
5. The long core member has a structure in which the thickness is formed thicker than the Z-wound side thread and the S-wound side thread, a structure made of a material different from the Z-wound side thread and the S-wound side thread, and the Z-wound. Uses a structure in which the elasticity is higher than that of the side yarn and the S-wound side yarn, a structure in which the yarn is coated or made into a raw yarn with a material having higher wear resistance than the Z-winding side yarn and the S-winding side yarn, and a natural material. The racket string according to any one of claims 1 to 4, characterized in that it has at least one structure among the structures configured in the above.
6. The racket string according to any one of claims 1 to 5, wherein the string-making structure is such that the Z-winding side yarn and the S-winding side yarn are woven in a two-pronged manner.

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