阅读说明：本技术 一种运动服拉链的拉片生产方法及装置 (Method and device for producing zipper pulls of sportswear zippers ) 是由 洪冬晓 于 2021-07-29 设计创作，主要内容包括：本发明涉及拉链相关配件领域,具体涉及一种运动服拉链的拉片生产方法,包括以下步骤：a、取一连续输送的拉绳,同时设置具有注塑模腔的注塑模具；b、对连续输送的拉绳端部固定；c、设置一拉出机构将拉绳沿其输送方向的垂直方向拉出并形成第一绳端及第二绳端,所述第一绳端及第二绳端落入注塑模腔内；d、注塑模具进行注塑形成绳端固定部,并将所述第一绳端及第二绳端的部分嵌置在所形成的绳端固定部内；e、在靠近拉绳输入端的一侧设置切断机构将成型后的绳端固定部与连续输送的拉绳切断分离,形成单个拉片；f、而后拉绳继续输送,并重复上述步骤b、c、d以实现拉片的连续生产。(The invention relates to the field of accessories related to zippers, in particular to a production method of a zipper pull of a sports wear zipper, which comprises the following steps: a. taking a continuously conveyed pull rope, and simultaneously arranging an injection mold with an injection mold cavity; b. fixing the end part of a continuously conveyed pull rope; c. a pull-out mechanism is arranged to pull out the pull rope along the direction vertical to the conveying direction of the pull rope to form a first rope end and a second rope end, and the first rope end and the second rope end fall into an injection mold cavity; d. the injection mold performs injection molding to form a rope end fixing part, and the parts of the first rope end and the second rope end are embedded in the formed rope end fixing part; e. a cutting mechanism is arranged on one side close to the input end of the pulling rope to cut and separate the formed rope end fixing part from the continuously conveyed pulling rope to form a single pulling piece; f. and then the pulling rope continues to convey, and the steps b, c and d are repeated to realize continuous production of the pull tab.)

1. A production method of a pull tab of a sports wear zipper is characterized by comprising the following steps:

a. taking a continuously conveyed pull rope, and simultaneously arranging an injection mold (200) with an injection mold cavity (203);

b. fixing the end part of a continuously conveyed pull rope;

c. a pulling-out mechanism (400) is arranged to pull out the pulling rope along the direction vertical to the conveying direction of the pulling rope to form a first rope end (1) and a second rope end (2), and the first rope end (1) and the second rope end (2) fall into an injection molding die cavity (203);

d. the injection mold (200) performs injection molding to form a rope end fixing part (3), and the parts of the first rope end (1) and the second rope end (2) are embedded in the formed rope end fixing part (3);

e. a cutting mechanism is arranged on one side close to the input end of the pulling rope to cut and separate the formed rope end fixing part (3) from the continuously conveyed pulling rope to form a single pulling piece;

f. and then the pulling rope continues to convey, and the steps b, c and d are repeated to realize continuous production of the pull tab.

2. The method for producing a pull tab of a zipper for sports clothes according to claim 1, further comprising, between the steps c and d:

c1, taking a continuously conveyed metal strip, arranging a stamping die (300) in front of the injection die (200), and pulling out the pull rope by a pulling-out mechanism (400) and then passing through a stamping die cavity (303) of the stamping die (300);

c2, punching the metal strip to coat the outer surfaces of the first rope end and the second rope end to form a rope end fixing piece;

c3, pulling out the mechanism (400) to pull the first rope end and the second rope end with the rope end fixing piece into the injection mould cavity (203) of the injection mould (200).

3. The method for producing a pull tab of a slide fastener for sports clothes according to claim 2, characterized in that: in the step c3, the pulling-out mechanism (400) pulls the string end fixing piece to be wholly embedded into the injection mold cavity (203) of the injection mold (200) or partially extends out of the rear end of the injection mold cavity (203).

4. The method for producing a pull tab of a slide fastener for sports wear according to claim 3, further comprising a step e1, after said step e: after the individual pull tabs are formed, the pull-out mechanism (400) continues to act to pull the individual pull tabs back out for ejection and collection.

5. A production apparatus of the production method of a pull-tab of a slide fastener for sports clothes according to claim 1, characterized in that: the automatic drawing device comprises a rack (100), wherein a unreeling roller for conveying a pull rope, an injection mold (200) with an injection mold cavity (203) and a plurality of guide wheels for guiding the pull rope are arranged on the rack (100), the injection mold (200) is provided with an upper injection mold (201) and a lower injection mold (202) which can be separated from each other up and down, a pressing mechanism (101) for fixing the free end of the pull rope is arranged on the rack (100), a drawing mechanism (400) for drawing the pull rope along the vertical direction of the conveying direction of the pull rope is arranged on the rack (100), the pull rope is positioned between the upper injection mold (201) and the lower injection mold (202) when being drawn out and forms a first rope end and a second rope end, and when the upper injection mold (201) and the lower injection mold (202) are closed, the first rope end and the second rope end are embedded in the injection mold cavity (203); and a cutter mechanism for cutting off the pulling rope after injection molding through the injection mold (200) to separate the pulling rope into single pulling pieces is arranged on the machine frame (100) at one side of the pulling rope entering the injection mold (200).

6. The apparatus for producing a pull-tab of a slide fastener for sports clothes according to claim 5, characterized in that: be equipped with a metal strip on frame (100) and carry unwinding mechanism, be located be equipped with a stamping die (300) on injection mold (200) outer and frame (100) close to the input position of stay cord, the stay cord passes through behind pull-out mechanism (400) the die cavity of stamping die (300), metal strip is carried unwinding mechanism and is extremely carried the metal strip in stamping die (300) and make stamping die (300) process it in order to form the rope end stationary blade of fixed stay cord.

7. The apparatus for producing a pull-tab of a slide fastener for sports clothes according to claim 6, wherein: the stamping die (300) is provided with an upper stamping die (301) and a lower stamping die (302) which can be separated up and down, and the molding surfaces of the upper stamping die (301) and the lower stamping die (302) are two arc surfaces (304) which are sequentially connected, so that the metal strip is in an '∞' annular structure with an opening after being acted by the stamping die (300).

8. The apparatus for producing a pull-tab of a slide fastener for sports clothes according to claims 5 to 7, wherein: the pulling-out mechanism (400) comprises an expansion link (401), a driving motor (402) and a transmission assembly which are matched with the expansion link (401), and a mechanical claw (403) which is arranged at the end part of the expansion link (401) and used for grabbing the pull rope.

9. The apparatus for producing a pull-tab of a slide fastener for sports clothes according to claims 5 to 7, wherein: the cutter mechanism comprises a cutter cylinder with the output direction in the vertical direction and a high-temperature cutter (500) arranged at the output end of the cutter cylinder.

Technical Field

The invention relates to the field of accessories related to zippers, in particular to a method and a device for producing a zipper pull of a zipper of sports clothes.

Background

The pull tab of the zipper is typically formed from a metal sheet having an aperture in which a slider is mounted. These metal sheets are often too small to allow the zipper to slide easily; therefore, many manufacturers attach a rope having a larger handle to the end of the existing zipper handle, as shown in chinese patent CN2415646Y, a rope type zipper handle is composed of a pulling rope and a handle body, the handle body is a two-color flat body, the middle of the handle body is concave, and convex strips are arranged at the upper and lower parts of the concave part, and the pulling rope is fixed at the upper part of the handle body. Which shows the basic structure of a prior pull tab with a pull cord.

As shown in CN 110384314 a, a pull tab for a slide fastener includes: a connecting body capable of being connected to a slider, and a pull-tab body integrally attached to the connecting body, the connecting body including: an exposed portion exposed from the tab body, and an embedded portion embedded in the tab body, the tab body including: a first forming portion made of resin and including at least one or more annular end portions having an opening and capable of surrounding an end portion of the embedded portion adjacent to the exposed portion; and a second forming portion made of resin, which is formed on the first forming portion with the embedded portion disposed therebetween, the first forming portion and the second forming portion being integrated (formed integrally).

In the present invention, when the pull-tab body is integrally attached to the connecting body, first, the end of the embedded portion adjacent to the exposed portion in the connecting body is surrounded by the annular end of the first forming portion formed in advance. Next, a second forming portion is formed by injection molding a resin to the first forming portion with the embedded portion disposed therebetween. Thus, the pull-tab body including the first and second forming portions in which the embedded portion of the coupling body is embedded is formed, and the pull-tab is completed. In the injection molding of the second forming portion, the annular end portion is disposed at an end portion of a cavity of a molding die of the second forming portion, that is, at an end portion of a cavity of the coupling body adjacent to the exposed portion, and the end portion of the embedded portion of the coupling body adjacent to the exposed portion is surrounded by the annular end portion at the end portion of the cavity. The opening of the annular end portion is set to a size such that the annular end portion surrounds the end portion of the embedded portion adjacent to the exposed portion of the coupling body with as little clearance as possible. In this state, the second forming portion is formed by injecting a molten resin into the cavity of the forming die, the first forming portion and the second forming portion are integrated with the embedded portion disposed therebetween to constitute the tab body, and the ring-shaped end portion remains as an end portion of the tab body adjacent to the exposed portion of the coupling body.

Which shows a way of forming a pull tab with a resin structure.

However, the existing pulling-on piece, in particular to the pulling-on piece of the zipper applied to the sports wear, has the following problems:

firstly, due to the production limitation of a resin pull piece structure, the connection between a pull rope and pull pieces is excessively inconsistent, so that the positions of two ends of the pull rope on the pull pieces are not uniform, and the attractiveness of a product is influenced;

secondly, the quality of the existing production process is poor, and the situation that the pull rope is separated from the pull piece is easy to occur;

and thirdly, the resin pull piece is light in weight, lacks the texture of the metal pull piece and influences the hand feeling during pulling.

At present, the zipper pull product cannot be efficiently produced.

Disclosure of Invention

Therefore, the invention provides a production method and a related production device for a zipper pull of sports clothes, and solves the problem that the existing resin zipper pull cannot be efficiently produced.

In order to achieve the purpose, the invention is realized by the following technical scheme:

a production method of a pull tab of a sports wear zipper comprises the following steps:

a. taking a continuously conveyed pull rope, and simultaneously arranging an injection mold with an injection mold cavity;

b. fixing the end part of a continuously conveyed pull rope;

c. a pull-out mechanism is arranged to pull out the pull rope along the direction vertical to the conveying direction of the pull rope to form a first rope end and a second rope end, and the first rope end and the second rope end fall into an injection mold cavity;

d. the injection mold performs injection molding to form a rope end fixing part, and the parts of the first rope end and the second rope end are embedded in the formed rope end fixing part;

e. a cutting mechanism is arranged on one side close to the input end of the pulling rope to cut and separate the formed rope end fixing part from the continuously conveyed pulling rope to form a single pulling piece;

f. and then the pulling rope continues to convey, and the steps b, c and d are repeated to realize continuous production of the pull tab.

Preferably, the steps c and d further include:

c1, taking a continuously conveyed metal strip, arranging a stamping die in front of the injection die, and pulling out the pull rope by a pulling-out mechanism to penetrate through a stamping die cavity of the stamping die;

c2, punching the metal strip to coat the outer surfaces of the first rope end and the second rope end to form a rope end fixing piece;

c3, the pulling mechanism continues to act, and the first rope end and the second rope end which are provided with the rope end fixing pieces after being punched are pulled into an injection mould cavity of the injection mould.

Preferably, in the step c3, the pulling-out mechanism pulls the string end fixing piece to be wholly inserted into the injection mold cavity of the injection mold or partially protrudes from the rear end of the injection mold cavity.

Preferably, step e1 is further included after step e: after the single pull piece is formed, the pulling-out mechanism continues to act to pull the single pull piece to be output backwards so as to realize demoulding and collection.

A production device for the production method of the pulling piece of the sports wear zipper comprises a rack, wherein a unreeling roller for conveying the pulling rope, an injection mold with an injection mold cavity and a plurality of guide wheels for guiding the pulling rope are arranged on the rack, the injection mold is provided with an upper injection mold and a lower injection mold which can be separated up and down, a pressing mechanism for fixing the free end of the pulling rope is arranged on the rack, a pulling mechanism for pulling the pulling rope out along the vertical direction of the conveying direction of the pulling rope is arranged on the rack, the pulling rope is positioned between the upper injection mold and the lower injection mold when being pulled out and forms a first rope end and a second rope end, and when the upper injection mold and the lower injection mold are closed, the first rope end and the second rope end are embedded in the injection mold cavity; and a cutter mechanism for cutting off the pull rope subjected to injection molding by the injection mold to separate the pull rope into single pull pieces is arranged on the rack on one side of the pull rope entering the injection mold.

Preferably, be equipped with a metal strip transport unwinding mechanism in the frame, be located outside the injection mold and be provided with a stamping die in the frame of the input end position that is close to the stay cord, the stay cord passes through behind the pulling mechanism pulling stamping die's die cavity, metal strip transport unwinding mechanism carries the metal strip extremely in the stamping die and make it processes the rope end stationary blade in order to form fixed stay cord to the stamping die.

Preferably, the stamping die is provided with an upper stamping die and a lower stamping die which can be separated up and down, and the forming surfaces of the upper stamping die and the lower stamping die are two arc surfaces which are sequentially connected, so that the metal strip is in an '∞' annular structure with an opening after being acted by the stamping die.

Preferably, the pulling-out mechanism comprises a telescopic rod, a driving motor and a transmission assembly which are matched with the telescopic rod, and a mechanical claw which is arranged at the end part of the telescopic rod and used for grabbing the pull rope.

Preferably, the cutter mechanism comprises a cutter cylinder with the output direction in the vertical direction and a high-temperature cutter arranged at the output end of the cutter cylinder.

By adopting the technical scheme, the invention has the beneficial effects that:

according to the technical scheme, the pull-tab product structure is designed according to a corresponding pull-tab product structure, and a pull-out mechanism vertical to the conveying direction of the pull rope is arranged to match with a corresponding injection mold and a corresponding cutter mechanism, so that the purpose of automatic production of the pull-tab with the pull rope is achieved; meanwhile, the product has strong consistency and better appearance, and products such as clothes using the pull piece product can also keep consistency.

Drawings

FIG. 1 is a schematic top view of an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of another state of the embodiment of the present invention in a top view;

FIG. 3 is a schematic structural diagram of a front view direction according to an embodiment of the present invention;

FIG. 4 is a schematic view of a pull tab in an embodiment of the present invention;

FIG. 5 is a schematic cross-sectional view of the pull tab of FIG. 5;

FIG. 6 is a schematic view of another structural pull tab in accordance with an embodiment of the present invention;

FIG. 7 is a schematic view of another structural pull tab in accordance with embodiments of the present invention.

Description of the drawings: 1. a first rope end; 2. a second rope end; 3. a rope end fixing part; 31. a groove; 32. a protrusion; 33. an arc-shaped slot; 34. anti-skid lines; 4. a rope end fixing piece; 5. a light-reflecting sheet; 100. a frame; 101. a pressing mechanism; 200. injection molding a mold; 201. injection molding an upper die; 202. injection molding a lower die; 203. an injection molding die cavity; 300. a stamping die; 301. stamping an upper die; 302. stamping a lower die; 303. stamping a die cavity; 304. an arc-shaped surface; 400. a pull-out mechanism; 401. a telescopic rod; 402. a drive motor; 403. a gripper; 500. a high temperature cutter; A. pulling a rope; and B, metal strips.

Detailed Description

The following detailed description will be provided for the embodiments of the present invention with reference to specific embodiments, so that how to apply the technical means to solve the technical problems and achieve the technical effects can be fully understood and implemented.

Examples

Referring to fig. 1, 2 and 3, a method for producing a pull tab of a zipper for sportswear, comprising the steps of:

a. taking a continuously conveyed pull rope, and simultaneously arranging an injection mold 200 with an injection mold cavity 203;

b. fixing the end part of a continuously conveyed pull rope;

c. a pulling-out mechanism 400 is arranged to pull out the pulling rope along the direction vertical to the conveying direction of the pulling rope and form a first rope end 1 and a second rope end 2, and the first rope end 1 and the second rope end 2 fall into the injection molding die cavity 203;

d. the injection mold 200 performs injection molding to form a rope end fixing part 3, and the parts of the first rope end 1 and the second rope end 2 are embedded in the formed rope end fixing part 3;

e. a cutting mechanism is arranged on one side close to the input end of the pulling rope to cut and separate the formed rope end fixing part 3 from the continuously conveyed pulling rope to form a single pulling piece;

f. and then the pulling rope continues to convey, and the steps b, c and d are repeated to realize continuous production of the pull tab.

Meanwhile, in production, the step e is followed by a step e 1: after a single pull piece is formed, the pulling-out mechanism 400 continues to act to pull the single pull piece to be output backwards so as to realize demoulding and collection; thus, different production functions can be achieved by merely adding one stroke to the pulling mechanism 400.

According to the technical scheme, the pull-tab product structure is designed according to the corresponding pull-tab product structure, the pull-out mechanism 400 vertical to the conveying direction of the pull rope is arranged to match with the corresponding injection mold 200 and the cutter mechanism, so that the purpose of automatic production of the pull-tab with the pull rope is achieved, compared with the traditional pull-tab structure with a combined structure, the pull-tab structure with the pull rope has the advantages that the production process is fully automatic, the labor cost is reduced, and the production efficiency is improved; meanwhile, the product has strong consistency and better appearance, and products such as clothes using the pull piece product can also keep consistency.

Meanwhile, the steps c and d further include:

c1, taking a continuously conveyed metal strip, arranging a stamping die 300 in front of the injection die 200, and pulling out the pull rope by a pulling-out mechanism 400 to pass through a stamping die cavity 303 of the stamping die 300;

c2, punching the metal strip to coat the outer surfaces of the first rope end 1 and the second rope end 2 to form a rope end fixing piece 4;

c3, the pulling mechanism 400 continues to pull the first rope end 1 and the second rope end 2 with the rope end fixing piece 4 into the injection mold cavity 203 of the injection mold 200 after punching.

Meanwhile, in the step c3, the pulling mechanism 400 pulls the string end fixing piece 4 to be wholly inserted into the injection mold cavity 203 of the injection mold 200 or partially protrudes the string end fixing piece 4 out of the rear end of the injection mold cavity 203, as shown in fig. 4, 5, 6 and 7, showing three different pull tab product structures.

Meanwhile, the technical proposal provides a correspondingly used device, and particularly refers to fig. 1, 2 and 3, the production device of the production method of the zipper pull of the sports clothes zipper comprises a frame 100, the frame 100 is provided with a unwinding roller for conveying the pull rope, an injection mold 200 with an injection mold cavity 203 and a plurality of guide wheels for guiding the pull rope, the injection mold 200 has an upper injection mold 201 and a lower injection mold 202 which can be separated from each other, the frame 100 is provided with a pressing mechanism 101 for fixing the free end of the pull rope, the frame 100 is provided with a pulling mechanism 400 for pulling the pull rope out along the direction vertical to the conveying direction of the pull rope, the pull rope is positioned between the injection upper die 201 and the injection lower die 202 when being pulled out, forming a first rope end 1 and a second rope end 2, and when the injection upper die 201 and the injection lower die 202 are closed, the first rope end 1 and the second rope end 2 are embedded in the injection die cavity 203; a cutter mechanism for cutting off the pulling rope after injection molding through the injection mold 200 to separate the pulling rope into individual pulling pieces is arranged on the machine frame 100 at one side of the pulling rope entering the injection mold 200.

In this embodiment, a metal strip conveying and unwinding mechanism is arranged on the frame 100, a stamping die 300 is arranged on the frame 100, which is located outside the injection mold 200 and close to the input end of the pulling rope, the pulling rope passes through the die cavity of the stamping die 300 after being pulled by the pulling mechanism 400, and the metal strip conveying and unwinding mechanism conveys the metal strip into the stamping die 300 and enables the stamping die 300 to process the metal strip to form a rope end fixing piece 4 for fixing the pulling rope.

In this embodiment, the stamping die 300 has an upper stamping die 301 and a lower stamping die 302 which can be separated vertically, and the molding surfaces of the upper stamping die 301 and the lower stamping die 302 are two arc surfaces 304 connected in sequence, so that the metal strip is in an '∞' ring structure with an opening after being acted by the stamping die 300.

In this embodiment, the pulling-out mechanism 400 includes an expansion link 401, a driving motor 402 and a transmission assembly adapted to the expansion link 401, and a gripper 403 disposed at an end of the expansion link 401 for gripping the pulling rope.

In this embodiment, the cutter mechanism includes a cutter cylinder with an output direction in a vertical direction and a high temperature cutter 500 installed at an output end of the cutter cylinder.

Correspondingly, the technical scheme shows the structure of the produced related product:

referring to fig. 4 and 7, a pull tab of a zipper of sportswear comprises a pull rope with a first rope end 1 and a second rope end 2, wherein the first rope end 1 or the second rope end 2 passes through the slider to be connected with the slider (the specific structure of the slider is not shown in the figure);

a rope end fixing part 3 made of resin for fixing the first rope end 1 and the second rope end 2;

a rope end fixing piece 4 embedded in the rope end fixing part 3 and keeping the first rope end 1 and the second rope end 2 flat, wherein the rope end fixing piece 4 is made of metal;

the rope end fixing piece 4 is of an open infinity-shaped annular structure and clamps the first rope end 1 and the second rope end 2; specifically, the rope end fixing part 3 is of a cylindrical structure, and the first rope end 1 and the second rope end 2 are fixed at the axial end parts of the cylindrical structure;

according to the technical scheme, the structure with the rope end fixing piece 4 is adopted, so that the positions of two ends of the pull rope which is difficult to position can be fixed, the positions of the first rope end 1 and the second rope end 2 are kept when the rope end fixing part 3 is used for injection molding, and the position deviation caused by the expansion and contraction of materials or the vibration of a machine table is not easy to occur, so that the position deviation of the two rope ends is not easy to occur, and the integral attractiveness of the pull piece is influenced;

secondly, the first rope end 1 and the second rope end 2 are clamped in advance through the rope end fixing piece 4 and then are connected with the rope end fixing part 3 into a whole through injection molding, so that the connecting structure is more stable, and the condition that a single saint rope end on a pull rope is separated from the rope end fixing part 3 independently can not occur;

thirdly, the rope end fixing sheet 4 is additionally arranged, so that the quality of the whole pulling piece can be slightly increased, but the rigidity is not too strong as that of a metal pulling piece, the characteristics of wear resistance and skid resistance of a resin material and easiness in pulling are kept, meanwhile, the sinking feeling during pulling is increased, and the texture of the whole pulling piece is improved;

in this embodiment, the surface of the rope end fixing portion 3 is provided with a groove 31; the structure of the groove 31 is arranged, and the concave structure of the outer surface of the rope end fixing part 3 is added, so that the anti-skidding and pulling are facilitated; meanwhile, conditions are provided for adding functional structures in the subsequent grooves 31; specifically, the reflective sheet 5 is embedded in the groove 31; the addition of the reflector 5 can increase the reflection effect on the rope end fixing part 3, thereby not only being practical, but also improving certain aesthetic effect;

in this embodiment, the length of the string-end fixing piece 4 embedded in the string-end fixing portion 3 is 4/5; the length ratio can be adjusted according to the weight requirement and raw materials of production, and can be in the range of 1/2-4/5. The weight of the whole pulling piece is adjusted through the different widths of the rope end fixing pieces 4; when the rope end fixing part occupies 4/5 of the length of the rope end fixing part 3, the weight distribution is more uniform, and the situation that one end is heavy is avoided;

in this embodiment, the string-end fixing piece 4 is integrally embedded in the string-end fixing portion 3; thus, in appearance, the structure of the pull piece is not greatly different from that of the traditional pull piece with the pull rope, but the effects of increasing the quality and enhancing the pulling hand feeling can be realized;

meanwhile, as shown in fig. 1, the rope end fixing piece 4 has a certain compression effect on the pulling rope in the production process, so that when the rope end fixing part 3 is formed, a corresponding connecting surface with an irregular section can be formed on the outer surface of the pulling rope embedded in the rope end fixing piece, and the rope end fixing piece and the pulling rope are more stable and can bear larger pulling force when being connected.

Referring to fig. 6 again, compared with the above structure, a pull tab structure with a different shape is designed, specifically: the rope end fixing part 3 is a long strip-shaped structure with a round-corner rectangular cross section, and the upper end surface and the lower end surface of the rope end fixing part are provided with a bulge 32 and an arc-shaped groove 33 which are convenient for fingers to pull; the structure improves the convenience and the skid resistance when in pulling;

meanwhile, in order to enhance the effect, the rope end fixing part 3 is provided with anti-slip threads 34 at one side end away from the first rope end 1 and the second rope end 2, and specifically, the anti-slip threads 34 are arranged on the outer surface of the protrusion 32;

corresponding improvement needs to be made on the internal structure, specifically, the rope end fixing piece 4 is embedded between the end part of the rope end fixing part 3 and the arc-shaped groove 33; thus, the width of the string-end fixing piece 4 is reduced, but the amount of resin used is also reduced in the resin structure at the rear, and the weight of the string-end fixing piece 3 at a position not including the string-end fixing piece 4 is reduced, and the weight can be kept uniform to a certain extent.

Referring to fig. 7 again, compared with the above structure, another structure is designed, specifically, the rope end fixing piece 4 is partially embedded in the rope end fixing part 3; this kind of structure is in order to guarantee that first rope end 1, second rope end 2 are closely connected with rope end fixed part 3, has avoided the junction separation of first rope end 1 with second rope end 2, also avoids appearing the condition appearance that stay cord and resin's rope end fixed part 3 appear separating.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.