Claims:We claim:
1. A yarn joining mechanism (100) that joins a yarn end of a first yarn (YA) on a downstream side and a yarn end of a second yarn (YB) on an upstream side, the yarn joining mechanism (100) comprising:
a yarn joining section (50) that joins the yarn end of the first yarn (YA) and the yarn end of the second yarn (YB);
a yarn catching device (7, 12) that includes a catching section (7a, 12a) that catches the yarn end of the first yarn (YA) or the yarn end of the second yarn (YB) and that is movable between a catching position positioned on one side of the yarn joining section (50) and a first position positioned on other side of the yarn joining section (50);
a holding section (60A, 60B) that is arranged on one side of the yarn joining section (50), and holds the yarn end;
a cutting section (70A, 70B) that cuts the yarn end and that is arranged on the other side of the yarn joining section (50) between the first position and the yarn joining section (50); and
a tension applying unit (110) that acts at least on the yarn end present on the first position side of the holding section (60A, 60B), and applies tension on the yarn end present between the holding section (60A, 60B) and the cutting section (70A, 70B).

2. The yarn joining mechanism (100) as claimed in Claim 1, wherein the tension applying unit (110) includes a controlling section (16) that controls an operation of the yarn catching device (7, 12); and
the controlling section causes the catching section (7a, 12a) that is at the first position to move in a direction away from the holding section (60A, 60B) before the yarn end is cut by the cutting section (70A, 70B) and applies tension on the yarn end between the holding section (60A, 60B) and the cutting section (70A, 70B).

3. The yarn joining mechanism (100) as claimed in Claim 2, wherein the controlling section (16) causes the catching section (7a, 12a) to stop at a second position, which is farther from the holding section (60A, 60B) than the first position.

4. The yarn joining mechanism (100) as claimed in any one of Claims 1 to 3, wherein the yarn catching device (7) includes a clamping mechanism (35) that is arranged on the catching section (7a) and that holds the yarn end.

5. The yarn joining mechanism (100) as claimed in any one of Claims 1 to 4, wherein the yarn catching device (7) is a second yarn catching device (7) that catches the second yarn (YB), and the yarn catching device (7) sucks and catches the yarn end by action of a suction current generated inside the second yarn catching device (7).

6. The yarn joining mechanism (100) as claimed in any one of Claims 1 to 4, wherein the yarn catching device (12) is a first yarn catching device (12) that catches the first yarn (YA), and the yarn catching device (12) sucks and catches the yarn end by action of a suction current generated inside the first yarn catching device (12).

7. A yarn winding device (1) comprising:
the yarn joining mechanism (100) as claimed in any one of Claims 1 to 6;
a yarn supplying section (2) that supplies a yarn; and
a winding section (13) that winds the yarn.

8. The yarn winding device (1) as claimed in Claim 7 further comprising an unwinding suppressing member (3A) that is arranged in the yarn supplying section (2), and suppresses unwinding of the yarn from the yarn supplying section (2).

9. A yarn joining method that joins a yarn end of a first yarn (YA) on a downstream side and a yarn end of a second yarn (YB) on an upstream side by using a yarn joining section (50), the yarn joining method comprising:
a catching step of catching a yarn end of the first yarn (YA) or a yarn end of the second yarn (YB) with a yarn catching device (7, 12) including a catching section (7a, 12a) that catches the yarn end at a catching position positioned on one side of the yarn joining section (50);
a moving step of moving the yarn catching device (7, 12) with the yarn end caught in the catching section (7a, 12a) to a first position positioned on other side of the yarn joining section (50);
a holding step of holding the yarn end with a holding section (60A, 60B) arranged on one side of the yarn joining section (50);
a tension applying step of applying tension on the yarn end between a cutting section (70A, 70B) and the holding section (60A, 60B) by acting at least on the yarn end present on the first position side of the holding section (60A, 60B); and
a cutting step of cutting the yarn end with the cutting section (70A, 70B) arranged between the first position and the yarn joining section (50).

10. The yarn joining method as claimed in Claim 9, wherein the tension applying step includes applying the tension to the yarn end between the holding section (60A, 60B) and the cutting section (70A, 70B) by moving the catching section (7a, 12a) that is at the first position in a direction away from the holding section (60A, 60B).

11. The yarn joining method as claimed in Claim 10, wherein the tension applying step includes moving the catching section (7a, 12a) to a second position that is farther than the first position from the holding section (60A, 60B).
, Description:BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a yarn joining mechanism, a yarn winding device, and a yarn joining method.

2. Description of the Related Art
A lower yarn catching device for an automatic winder has been disclosed in Japanese Patent Application Laid-open No. H7-81849. The conventional lower yarn catching device includes a relay pipe, and a clamper that is mounted so as to face a suction port arranged at a tip end of the relay pipe. When the relay pipe moves from a lower yarn catching position to a standby position in an upward direction, the clamper mechanically clamps and retains a yarn end of a lower yarn. This prevents trapping errors that occur due to removal of a yarn end from the suction port due to insufficient suction force during the ascending movement of the relay pipe.
Recently, for example, yarns having elasticity such as spandex are being used occasionally. Such yarns are called elastic fibers. When a yarn having such elasticity is being joined by using a yarn joining device, while the yarn is being supplied to the yarn joining device by a yarn catching device, the yarn expands and contracts, and the yarn tends to easily slacken. If the yarn is joined in a slackened state, the state of a joint (for example, appearance, strength, and the like) becomes unstable. In this manner, in the conventional device, a stable yarn joining becomes difficult when the yarn is slackened.

SUMMARY OF THE INVENTION
It is an object of the present invention to provide a yarn joining mechanism, a yarn winding device, and a yarn joining method that are capable of performing a stable yarn joining by removing slack of a yarn during yarn joining.
A yarn joining mechanism that joins a yarn end of a first yarn on a downstream side and a yarn end of a second yarn on an upstream side according to one aspect of the present invention, includes a yarn joining section that joins the yarn end of the first yarn and the yarn end of the second yarn; a yarn catching device that includes a catching section that catches the yarn end of the first yarn or the yarn end of the second yarn and that is movable between a catching position positioned on one side of the yarn joining section and a first position positioned on other side of the yarn joining section; a holding section that is arranged on one side of the yarn joining section, and holds the yarn end; a cutting section that cuts the yarn end and that is arranged on the other side of the yarn joining section between the first position and the yarn joining section; and a tension applying unit that acts at least on the yarn end present on the first position side of the holding section, and applies tension on the yarn end present between the holding section and the cutting section.
A yarn winding device according to another aspect of the present invention includes the above yarn joining mechanism; a yarn supplying section that supplies a yarn; and a winding section that winds the yarn.
A yarn joining method that joins a yarn end of a first yarn on a downstream side and a yarn end of a second yarn on an upstream side by using a yarn joining section according to still another aspect of the present invention includes a catching step of catching a yarn end of the first yarn or a yarn end of the second yarn with a yarn catching device including a catching section that catches the yarn end at a catching position positioned on one side of the yarn joining section; a moving step of moving the yarn catching device with the yarn end caught in the catching section to a first position positioned on other side of the yarn joining section; a holding step of holding the yarn end with a holding section arranged on one side of the yarn joining section; a tension applying step of applying tension on the yarn end between a cutting section and the holding section by acting at least on the yarn end present on the first position side of the holding section; and a cutting step of cutting the yarn end with the cutting section arranged between the first position and the yarn joining section.
The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a winding unit according to an embodiment of the present invention.
FIG. 2 is a front view of a yarn joining device shown in FIG. 1.
FIG. 3 is a side view of the yarn joining device shown in FIG. 2.
FIG. 4A is a perspective view of a lower yarn catching section shown in FIG. 1 with an open clamp cover, and FIG. 4B is a perspective view of the lower yarn catching section shown in FIG. 1 with the closed clamp cover.
FIG. 5 is a flowchart showing a process flow of a yarn joining step.
FIG. 6 is a side view of a configuration for explaining a catching step of a yarn end.
FIG. 7A is a view showing a state in which a first yarn catching device moves downward and supplies a yarn end of a first yarn to the yarn joining device, and FIG. 7B is a view showing a state in which a second yarn catching device moves upward.
FIG. 8A is a view showing a state in which the second yarn catching device moves upward and supplies a yarn end of a second yarn to the yarn joining device, and FIG. 8B is a view of a configuration for explaining a step of applying tension on the second yarn.
FIG. 9A is a front view corresponding to FIG. 8A, and FIG. 9B is a front view corresponding to FIG. 8B.
FIG. 10A is a view showing a state in which the first yarn and the second yarn are cut, and FIG. 10B is a view showing a state in which the second yarn catching device moves further upward.

DETAILED DESCRIPTION
Exemplary embodiments of the present invention are explained below with reference to the drawings. Identical elements, however, are indicated by the same reference symbols in the drawings and redundant explanation thereof is omitted.
An overall configuration of a winder unit (a yarn winding device) 1 that is equipped with a yarn joining device 10 according to a present embodiment is explained with reference to FIG. 1. The terms "upstream" and "downstream" refer to upstream and downstream in a traveling direction of a yarn during yarn winding respectively.
As shown in FIG. 1, the winder unit 1 winds a yarn Y supplied from a yarn supplying bobbin B onto a package P. The yarn supplying bobbin B is formed by a spinning frame in the previous stage, and the yarn supplying bobbin B, for example, is transported from the spinning frame while being set on a tray. Furthermore, an automatic winder, which is a textile machine, is configured by arranging a plurality of the winder units 1 side by side.
In the winder unit 1, a bobbin supporting section (a yarn supplying section) 2, a yarn unwinding assisting device 3, a pre-clearer 4, a tension applying device 5, a tension sensor 6, a lower yarn catching device (a second catching device) 7, the yarn joining device 10, a cutter 9, a yarn monitoring device 11, an upper yarn catching device (a first catching device) 12, and a winding device (a winding section) 13 are arranged in this order from upstream (here, on a lower side) along a traveling path of the yarn Y. Each of these structural components is mounted on a unit body 8. The upper yarn catching device (the first catching device) 12, and the lower yarn catching device (the second catching device) 7 are collectively called a yarn catching device.
The bobbin supporting section 2 supports the yarn supplying bobbin B in an upright posture so that the yarn Y can be supplied. The yarn unwinding assisting device 3 uses a cylindrical member arranged above the yarn supplying bobbin B to control a balloon of the yarn Y unwound from the yarn supplying bobbin B. The tension applying device 5 is a gate-type tenser that applies a predetermined tension on the traveling yarn Y by retaining the yarn Y in a zigzag manner with a pair of gates. The pair of the gates is constituted by a comb-teeth shaped fixed gate and a movable gate. The tension sensor 6 measures the tension of the yarn Y applied by the tension applying device 5.
As shown in FIG. 6, a kink preventer 3A (an unwinding suppressing member) is arranged in the bobbin supporting section 2. The kink preventer 3A includes a member (for example, a brush-shaped member) that comes in contact with the yarn supplying bobbin B and applies an unwinding resistance. The kink preventer 3A prevents, when the lower yarn catching device 7 sucks and unwinds the yarn Y from the yarn supplying bobbin B, any excessive unwinding of the yarn Y. The kink preventer 3A is not shown in FIG. 1.
As shown in FIG. 1, the pre-clearer 4 regulates with a pair of regulating members passage of a yarn having a defect such as a tangled yarn in which a thickness thereof is larger than a specified value. The regulating members are arranged at a predetermined distance across the traveling path of the yarn Y. The yarn monitoring device 11 detects yarn defects such as slub and the like during winding of the yarn Y. The cutter 9 cuts, when the yarn monitoring device 11 detects a yarn defect, the yarn Y. The yarn joining device 10 joins, when the yarn Y is cut by the cutter 9, when the yarn Y breaks, and the like, a yarn end of the yarn Y on a package P side and a yarn end of the yarn Y on the yarn supplying bobbin B side by the action of compressed air.
The lower yarn catching device 7, which is arranged below the yarn joining device 10, catches a yarn end of the yarn Y on the yarn supplying bobbin B side and guides the yarn end to the yarn joining device 10. The lower yarn catching device 7 is pivotably mounted on the unit body 8 with a as a pivotal axis. The lower yarn catching device 7 includes a relay pipe 7b, a suction port 7a (a catching section) arranged at a tip end (a pivoting end) of the relay pipe 7b, and as shown in FIGS. 4A and 4B, a clamp cover (a clamp mechanism) 35 that opens / closes the suction port 7a. The relay pipe 7b is caused to pivot by a driving source such as a stepping motor. An appropriate negative pressure source is connected to the relay pipe 7b. By the action of a suction current generated in the relay pipe 7b and at the suction port 7a, the lower yarn catching device 7 sucks and catches the yarn end of the yarn Y on the yarn supplying bobbin B side.
The suction port 7a pivots between a point that is on an upper side of the yarn joining device 10 and a point that is on a lower side of the pre-clearer 4. The suction port 7a is at standby on the lower side of the pre-clearer 4. The lower yarn catching device 7 sucks, when the yarn Y is cut by the cutter 9, when the yarn Y breaks, and the like, the yarn end of the yarn Y on the yarn supplying bobbin B side through the suction port 7a. Then, the lower yarn catching device 7 causes the suction port 7a to pivot toward the upper side of the yarn joining device 10 to pass the yarn Y from the yarn supplying bobbin B side to the yarn joining device 10.
As shown in FIG. 4B, the clamp cover 35 that opens / closes the suction port 7a is arranged at the tip end of the relay pipe 7b. The clamp cover 35 is biased by a not-shown spring and the like so that a clamp section 35A that faces the suction port 7a closes the suction port 7a. The clamp cover 35 usually keeps the suction port 7a closed. In the present embodiment, it is necessary that the yarn Y pulled at a tension applying step (explained later in detail) is held firmly. Therefore, a spring having a spring constant that can withstand the tension is used.
As shown in FIG. 4A, when the relay pipe 7b is positioned at the lowest point, an opener cam 69B acts on a protrusion 35B formed on the clamp cover 35. With this action, the clamp cover 35 is caused to pivot in a direction that allows opening the suction port 7a. Furthermore, the opener cam 69B is fixed to the unit body 8 via a mounting section 69A. Moreover, FIG. 4A shows a state in which the relay pipe 7b is positioned at the lowest point; however, the suction port 7a is opened by the same mechanism as that of shown in the figure when the relay pipe 7b is positioned at the highest point (a third position explained later). With the lower yarn catching device 7 having this configuration, the yarn on the yarn supplying bobbin B side is sucked and caught, and by causing the relay pipe 7b to pivot with the yarn held in, the yarn from the yarn supplying bobbin B side is passed to the yarn joining device 10.
As shown in FIG. 1, the upper yarn catching device 12, which is arranged above the yarn joining device 10, catches a yarn end of the yarn Y from the package P side and guides the yarn end to the yarn joining device 10. The upper yarn catching device 12 is pivotably mounted on the unit body 8 with ß as a pivotal axis. The upper yarn catching device 12 includes a suction mouth 12b, and a suction port 12a (a catching section) arranged at a tip end (a pivoting end) of the suction mouth 12b. The suction mouth 12b is caused to pivot with a driving source, for example, that is constituted by a stepping motor. An appropriate negative pressure source is connected to the suction mouth 12b. By the action of a suction current generated at the suction mouth 12b and the suction port 12a, the upper yarn catching device 12 sucks and catches the yarn end of the yarn Y on the package P side.
The suction port 12a pivots between a lower side of the yarn joining device 10 and the winding device 13. The upper yarn catching device 12 causes, when the yarn Y is cut by the cutter 9, when the yarn Y breaks, and the like, the suction port 12a to pivot towards the winding device 13 side and suck the yarn end of the yarn Y on the package P side through the suction port 12a. Then, the upper yarn catching device 12 causes the suction port 12a to pivot toward the lower side of the yarn joining device 10 to pass the yarn Y from the package P side to the yarn joining device 10.
In the lower yarn catching device 7 and the upper yarn catching device 12 according to the present embodiment, a common negative pressure source is used. The suction force in the lower yarn catching device 7 is smaller than the suction force in the upper yarn catching device 12 because the pipe diameter of the relay pipe 7b is smaller than the pipe diameter of the suction mouth 12b. Because of the difference in the pipe diameters, the effect of a pipe friction increases in the relay pipe 7b, resulting in a pressure loss. As a result, the flow rate in the relay pipe 7b is lower than the flow rate in the suction mouth 12b.
The winding device 13 winds the yarn Y unwound from the yarn supplying bobbin B onto the package P to form a fully wound package P. The winding device 13 includes a winding drum 14 whereon a drum groove 14a is formed, and a cradle 15 that rotatably supports the package P. The cradle 15 causes the surface of the package P to come in contact with the surface of the winding drum 14 at an appropriate contact pressure. The winding device 13 causes the winding drum 14 to be driven to rotate by using a motor and consequently the package P is rotated following the rotation of the winding drum 14. With this action, the winding device 13 winds the yarn Y onto the package P while traversing the yarn Y at a predetermined width.
The unit body 8 includes a controlling section 16, an inputting section 17, and a displaying section 18. The controlling section 16 includes, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read-only Memory), an I/O port (Input / Output port), and a communication port. The ROM stores therein a computer program for controlling each structural component of the winder unit 1. The controlling section 16 sends to and receives from a host controlling section included in the automatic winder various information related to winding operations. The host controlling section manages the controlling section 16 in each of the winder units 1, thereby controlling the entire automatic winder. The controlling section 16 controls each of the structural components of the winder unit 1. The inputting section 17 is, for example, an operation button and the like, and is used by the operator to set various parameters for the controlling section 16. The displaying section 18 displays the operation status and the like of the winder unit 1.
A configuration of the yarn joining device 10 is explained below. In the following explanation, for the convenience, the package P side is referred to as an upper side, and the yarn supplying bobbin B side is referred to as a lower side. The traveling path side of the yarn Y with respect to the yarn joining device 10 is referred to as a front side, and an opposite side thereof is referred to as a back side. Moreover, the yarn Y on the package P side is referred to as an upper yarn (a first yarn on the downstream side) YA, and the yarn Y on the yarn supplying bobbin B side is referred to as a lower yarn (a second yarn on the upstream side) YB.
As shown in FIG. 2, the yarn joining device 10 includes an untwisting section 40, a yarn joining section 50, a yarn shifting lever pair 81, and a twist locking lever pair 82. The untwisting section 40 includes a first untwisting section 41A, and a second untwisting section 41B. Each of the first untwisting section 41A and the second untwisting section 41B includes a pipe member to catch the upper yarn YA and the lower yarn YB. The yarn shifting lever pair 81 swings so that the first untwisting section 41A and the second untwisting section 41B are interposed between the levers. The twist locking lever pair 82 swings so that the yarn joining section 50 is interposed between the levers. The yarn joining device 10 is mounted on the unit body 8 via a main body frame (main body) 20 that supports various structural components thereof.
A first guide plate 21 is arranged on the upper side of the first untwisting section 41A and the second untwisting section 41B. A second guide plate 22 is arranged on the lower side of the first untwisting section 41A and the second untwisting section 41B. The first guide plate 21 and the second guide plate 22 face each other in a vertical direction, interposing the yarn joining section 50 therebetween. A guide groove 21A and a guide groove 21B are formed in the first guide plate 21. A guide groove 22A and a guide groove 22B are formed in the second guide plate 22. The guide groove 21A of the first guide plate 21 faces the guide groove 22A of the second guide plate 22 in the vertical direction. The guide groove 21B of the first guide plate 21 faces the guide groove 22B of the second guide plate 22 in the vertical direction.
The upper yarn YA guided by the upper yarn catching device 12 and then pulled by the yarn shifting levers 81 is guided into the vertically facing guide grooves 21A and 22A. The lower yarn YB guided by the lower yarn catching device 7 and then pulled by the yarn shifting levers 81 is guided into the vertically facing guide grooves 21B and 22B.
An upper yarn holding section 60A is arranged on the upper side of the first guide plate 21, and a lower yarn cutting section 70B is arranged on the lower side of the first guide plate 21. A lower yarn holding section 60B is arranged on the lower side of the second guide plate 22, and an upper yarn cutting section 70A is arranged on the upper side of the second guide plate 22. The upper yarn holding section 60A holds (or grasps) the upper yarn YA guided into the guide groove 21A. While the upper yarn YA is being held by the upper yarn holding section 60A, the upper yarn cutting section 70A cuts the upper yarn YA guided into the guide groove 22A. The lower yarn holding section 60B holds (or grasps) the lower yarn YB guided into the guide groove 22B. While the lower yarn YB is being held by the lower yarn holding section 60B, the lower yarn cutting section 70B cuts the lower yarn YB guided into the guide groove 21B. The lower yarn cutting section 70B and the upper yarn cutting section 70A are collectively called a cutting section.
While the upper yarn YA is being held by the upper yarn holding section 60A, the first untwisting section 41A draws and untwists a yarn end of the upper yarn YA cut by the upper yarn cutting section 70A. While the lower yarn YB is being held by the lower yarn holding section 60B, the second untwisting section 41B draws and untwists a yarn end of the lower yarn YB cut by the lower yarn cutting section 70B.
The yarn joining section 50 twists together the yarn end of the upper yarn YA untwisted by the first untwisting section 41A and the yarn end of the lower yarn YB untwisted by the second untwisting section 41B, and joins the yarn end of the upper yarn YA and the yarn end of the lower yarn YB. When the yarn ends are being twisted together in the yarn joining section 50, the upper yarn YA is held by the upper yarn holding section 60A, and the lower yarn YB is held by the lower yarn holding section 60B. Then, the yarn shifting levers 81 pull the yarn end of the upper yarn YA from the first untwisting section 41A and pull the yarn end of the lower yarn YB from the second untwisting section 41B, and the twist locking levers 82 position the tip end of the yarn end of the upper yarn YA and the tip end of the yarn end of the lower yarn YB near the yarn joining section 50. The upper yarn holding section 60A and the lower yarn holding section 60B are collectively called a holding section.
As shown in FIGS. 2 and 3, a driving motor 23 is mounted on the main body frame 20 as a common driving source for the yarn shifting lever pair 81 and the twist locking lever pair 82. The driving motor 23 is, for example, a stepping motor. An arm 25 is fixed to a driving axis 24 of the driving motor 23. A rear end part of a coupling member 26 is rotatably connected to the arm 25. A base end part of the yarn shifting levers 81 is rotatably connected to a front end part of the coupling member 26. The yarn shifting levers 81 are rotatably supported by a support shaft 27 fixed to the main body frame 20.
As shown in FIGS. 2 and 3, the twist locking levers 82 are rotatably supported by the support shaft 27. The twist locking levers 82 are biased toward the first untwisting section 41A side and the second untwisting section 41B side by using a torsion coil spring 28 that is rotatably mounted on the support shaft 27. Accordingly, the twist locking levers 82 pivot to move toward the first untwisting section 41A and the second untwisting section 41B along with the yarn shifting levers 81. However, when a tip end of a not-shown stopper bolt that is screwed to a base end part of the twist locking levers 82 has come in contact with a part of the main body frame 20, only the yarn shifting levers 81 are caused to pivot toward the first untwisting section 41A and the second untwisting section 41B.
A driving motor 31 that functions as a common driving source of the upper yarn holding section 60A, the lower yarn holding section 60B, the upper yarn cutting section 70A, and the lower yarn cutting section 70B is mounted on the main body frame 20. The driving motor 31 is, for example, a stepping motor. A first transmission mechanism 90A is coupled to the upper yarn holding section 60A and the lower yarn cutting section 70B. A second transmission mechanism 90B is coupled to the lower yarn holding section 60B and the upper yarn cutting section 70A.
As shown in FIG. 3, the first transmission mechanism 90A includes a first arm 91A and a first coupling member 92A, and transmits a driving force from a first driving shaft 32A of the driving motor 31 to the upper yarn holding section 60A and the lower yarn cutting section 70B. The first arm 91A is fixed to the first driving shaft 32A. A rear end part of the first coupling member 92A is rotatably coupled to the first arm 91A.
As shown in FIG. 2, the lower yarn cutting section 70B includes a fixed part 71 and a movable part 72. The fixed part 71 is fixed to the first guide plate 21. The movable part 72 is rotatably supported by a not-shown support shaft fixed to the first guide plate 21. A front end part of the first coupling member 92A is rotatably coupled to a not-shown arm that extends from a base end part of the movable part 72. The upper yarn holding section 60A includes a base member 61 and a sub member 62. In the upper yarn holding section 60A, the upper yarn YA is held by the base member 61 and the sub member 62.
As shown in FIG. 3, the second transmission mechanism 90B includes a second arm 91B and a second coupling member 92B, and transmits the driving force from a second driving shaft 32B of the driving motor 31 to the lower yarn holding section 60B and the upper yarn cutting section 70A. The second arm 91B is fixed to the second driving shaft 32B. A rear end part of the second coupling member 92B is rotatably coupled to the second arm 91B.
As shown in FIG. 2, when seen from the front side, the configuration of the upper yarn cutting section 70A has a relationship of point symmetry with the configuration of the lower yarn cutting section 70B, with the yarn joining section 50 at the center. Similarly, when seen from the front side, the configuration of the lower yarn holding section 60B has a relationship of point symmetry with the configuration of the upper yarn holding section 60A, with the yarn joining section 50 at the center.
The winder unit 1 of the present embodiment, for example, has a suitable configuration to wind the yarn Y having elasticity such as spandex. Particularly, the winder unit 1 includes a yarn joining mechanism 100 that prevents slacking of the lower yarn YB at the time of yarn joining in the yarn joining section 50 of the yarn joining device 10. The yarn joining mechanism 100 is explained below.
The yarn joining mechanism 100 includes the yarn joining device 10, the lower yarn catching device 7, and the upper yarn catching device 12 explained above. The yarn joining device 10 includes the yarn joining section 50, the upper yarn holding section 60A and the lower yarn cutting section 70B that are arranged above the yarn joining section 50, and the lower yarn holding section 60B and the upper yarn cutting section 70A that are arranged below the yarn joining section 50. The yarn joining mechanism 100 further includes a tension applying mechanism (a tension applying unit) 110 that applies tension on the yarn end of the lower yarn YB during the yarn joining. The tension applying mechanism 110 includes a function of the controlling section 16 that controls the pivoting operation of the lower yarn catching device 7.
The lower yarn catching device 7 is controlled by the controlling section 16 to pivot and stop the suction port 7a at at least four positions. Specifically, the suction port 7a is movable between a catching position that is positioned below the yarn joining section 50 and a first position P1 (refer to FIG. 8A) that is positioned above the yarn joining section 50. The first position P1 is a position of the suction port 7a that corresponds to a timing when the lower yarn YB is held by the lower yarn holding section 60B during the yarn joining. The suction port 7a is capable of moving to a second position P2 that is positioned further upward (in other words, away from the lower yarn holding section 60B) than the first position P1. The second position P2 is a position of the suction port 7a that corresponds to a timing when tension is applied to the lower yarn YB during the yarn joining. Furthermore, the suction port 7a is capable of moving to a third position P3 that is positioned further upward (in other words, away from the lower yarn holding section 60B) than the second position P2. The third position P3 is a position of the suction port 7a that corresponds to a timing when the clamp cover 35 explained above opens the suction port 7a.
Accordingly, when causing the relay pipe 7b to pivot and move upward, the controlling section 16 controls the lower yarn catching device 7 so as to stop the suction port 7a at positions of three stages, the first position P1, the second position P2, and the third position P3. Particularly, when the suction port 7a is moving from the first position P1 to the second position P2, cutting of the lower yarn YB by the lower yarn cutting section 70B is not performed. After the suction port 7a has reached the second position P2, the cutting of the lower yarn YB by the lower yarn cutting section 70B is performed.
Operation of the yarn joining mechanism 100 (in other words, a yarn joining method implemented in the yarn joining mechanism 100) is explained next with reference to FIGS. 5 and 6 onwards. Each of the following operations is controlled by the controlling section 16 by execution of the computer program stored in the controlling section 16.
First, when a yarn Y is cut by the cutter 9 upon detection of a yarn defect, or a yarn breakage of the yarn Y occurs because of excessive tension (Step S01), the upper yarn catching device 12 and the lower yarn catching device 7 guide the upper yarn YA and the lower yarn YB to the yarn joining device 10 respectively. More specifically, the relay pipe 7b that is at the downward catching position catches a yarn end of the lower yarn YB through the suction port 7a (Step S02: Catching step).
Next, as shown in FIG. 6, the suction mouth 12b moves upward to catch a yarn end of the upper yarn YA on the package P side through the suction port 12a (Step S03). Then, as shown in FIG. 7A, the suction mouth 12b moves downward while holding the yarn end of the upper yarn YA by the action of suction, and supplies the yarn end of the upper yarn YA to the yarn joining section 50 of the yarn joining device 10 (Step S04). At this time, because the suction mouth 12b has a sufficient suction force, slack does not occur in the upper yarn YA.
The relay pipe 7b that is holding the yarn end of the lower yarn YB in the catching position moves upward while holding the yarn end of the lower yarn YB by clamping, and causes the suction port 7a to move to the first position P1 (refer to FIG. 8A) that is above the yarn joining section 50 (First ascending step: Moving step). Accordingly, the yarn end of the lower yarn YB is supplied to the yarn joining section 50 of the yarn joining device 10 (Step S05). At this time, because the relay pipe 7b is holding the yarn end of the lower yarn YB by clamping, even if slack occurs in the lower yarn YB, the slack cannot be removed by using a suction. Furthermore, because the kink preventer 3A arranged on the bobbin supporting section 2 is only in contact with a part of the bobbin tip end, the slack in the lower yarn YB occurred due to ascending of the relay pipe 7b cannot be removed. Therefore, as shown in FIG. 7B, the lower yarn catching device 7 supplies to the yarn joining device 10 the lower yarn YB that is slackened.
Then, the yarn shifting levers 81 swing toward the first untwisting section 41A side and the second untwisting section 41B side causing the yarn end of the upper yarn YA guided by the upper yarn catching device 12, and the yarn end of the lower yarn YB guided by the lower yarn catching device 7 to be drawn toward the first untwisting section 41A side and the second untwisting section 41B side. Accordingly, the yarn end of the upper yarn YA is guided into the guide groove 21A of the first guide plate 21, the guide groove 22A of the second guide plate 22, and a yarn joining nozzle 51 of the yarn joining section 50. Similarly, the yarn end of the lower yarn YB is guided into the guide groove 21B of the first guide plate 21, the guide groove 22B of the second guide plate 22, and the yarn joining nozzle 51 of the yarn joining section 50. When being guided into the yarn joining nozzle 51, the yarn end of the upper yarn YA and the yarn end of the lower yarn YB are placed in a collecting section 52 via a guide inclining section 53 (see FIGS. 2, 9A, and 9B).
Next, the yarn end of the upper yarn YA guided into the guide groove 21A of the first guide plate 21 is held by the upper yarn holding section 60A near the guide groove 21A (Step S06). Similarly, the yarn end of the lower yarn YB guided into the guide groove 22B of the second guide plate 22 is held by the lower yarn holding section 60B near the guide groove 22B (Step S06: Holding step). In FIG. 8A, the upper yarn holding section 60A and the lower yarn holding section 60B are shown in holding state, and therefore are indicated with black-ink-filled rectangles. The upper yarn holding section 60A and the lower yarn holding section 60B are shown in the similar manner in FIGS. 8B and 10A.
As shown in FIGS. 8A and 9A, slack has occurred in the yarn end of the lower yarn YB when the lower yarn YB is mechanically held by the clamp cover 35 of the suction port 7a and the lower yarn holding section 60B. At this point, the controlling section 16 performs the following tension applying step, instead of performing a cutting step in which the upper yarn cutting section 70A and the lower yarn cutting section 70B perform cutting.
As shown in FIG. 8B, the controlling section 16 causes the relay pipe 7b to move further upward to move the suction port 7a, which is at the first position P1, in a direction away from the lower yarn holding section 60B (Step S07: Second ascending step, in other words, tension applying step). More specifically, the controlling section 16 causes the relay pipe 7b to pivot only for an additional pivoting angle ?1 to stop the suction port 7a at the second position P2 that is farther from the lower yarn holding section 60B than the first position P1. Accordingly, the tension is applied on the yarn end of the lower yarn YB, thereby removing the slack in the lower yarn YB in an area that is above the lower yarn holding section 60B. In other words, the tension applying mechanism 110 acts at least on the yarn end of the lower yarn YB present on the first position P1 side of the lower yarn holding section 60B (more specifically, on the first position P1 side of the lower yarn cutting section 70B). The tension applying mechanism 110 draws up the lower yarn YB. However, in an area that is below the lower yarn holding section 60B, the slack of the lower yarn YB remains.
In this manner, the tension applying mechanism 110 includes a part of functions of the controlling section 16 that causes the relay pipe 7b to perform additional pivoting operation. The additional pivoting for the angle ?1 performed at the tension applying step is set in advance on the basis of the amount of the slack predicted in accordance with the elasticity of the yarn Y, the winding speed, and the like. Such an additional pivoting operation can be controlled, for example, by determining the rotation quantity and the rotational speed of the stepping motor for each computer program.
After performing the tension applying step, as shown in FIG. 9B, the yarn end of the lower yarn YB is regulated by the guide groove 22B, the collecting section 52 of the yarn joining section 50, and the guide groove 21B, and is being extended substantially linearly therebetween. Consequently, the length of the lower yarn YB between the lower yarn holding section 60B and the lower yarn cutting section 70B is controlled to be a certain length. The length of the upper yarn YA that is regulated by the guide groove 21A, the collecting section 52 of the yarn joining section 50, and the guide groove 22A between the upper yarn holding section 60A and the upper yarn cutting section 70A is similarly controlled to be a certain length.
Next, as shown in FIG. 10A, the yarn joining step is performed again, and the yarn end of the upper yarn YA guided into the guide groove 22A of the second guide plate 22 is cut by the upper yarn cutting section 70A near the guide groove 22A, while being held by the upper yarn holding section 60A (Step S08). Similarly, the yarn end of the lower yarn YB guided into the guide groove 21B of the first guide plate 21 is cut by the lower yarn cutting section 70B near the guide groove 21B, while being held by the lower yarn holding section 60B (Step S08: Cutting step). In FIG. 10A, the upper yarn cutting section 70A and the lower yarn cutting section 70B are shown in a cutting state, and therefore are indicated in black color.
Then, by injecting air for untwisting, the first untwisting section 41A captures and untwists the yarn end of the upper yarn YA cut by the upper yarn cutting section 70A while being held by the upper yarn holding section 60A. Similarly, by injecting air for untwisting, the second untwisting section 41B captures and untwists the yarn end of the lower yarn YB cut by the lower yarn cutting section 70B while being held by the lower yarn holding section 60B. The yarn shifting levers 81 draw, by further swinging to the first untwisting section 41A side and the second untwisting section 41B side, the yarn end of the upper yarn YA from the first untwisting section 41A, and draw the yarn end of the lower yarn YB from the second untwisting section 41B. The twist locking levers 82 that have swung along with the yarn shifting levers 81 press down the tip end of the yarn end of the upper yarn YA and the tip end of the yarn end of the lower yarn YB near the yarn joining section 50. The yarn joining section 50 injects the air for yarn joining inside the collecting section 52 from an exhaust port to twist together the yarn end of the upper yarn YA untwisted by the first untwisting section 41A, and the yarn end of the lower yarn YB untwisted by the second untwisting section 41B (Step S09: Yarn joining step). At this time, the yarn end of the upper yarn YA is in a state of being held by the upper yarn holding section 60A, and the yarn end of the lower yarn YB is in a state of being held by the lower yarn holding section 60B. Because the yarn end of the upper yarn YA and the yarn end of the lower end YB having a certain length with the holding sections 60A and 60B as the reference are untwisted and joined, the state of a joint such as appearance and strength is kept stable.
Subsequently, as shown in FIG. 10B, the controlling section 16 causes the relay pipe 7b to move further upward to move the suction port 7a that is at the second position P2 in the direction further away from the lower yarn cutting section 70B (Step S10: Third ascending step). More specifically, the controlling section 16 causes the relay pipe 7b to pivot only an additional pivoting angle of ?2, and stop at the third position P3. Accordingly, the clamp cover 35 comes in contact with a stopper 120 that is fixed to the unit body 8, and opens the suction port 7a. When the suction port 7a opens, the remaining yarn end of the lower yarn YB (refer to FIG. 10A) is sucked and removed.
Then, the yarn shifting levers 81 and the twist locking levers 82 swing in a reverse direction, and the upper yarn holding section 60A and the lower yarn holding section 60B release the hold. Accordingly, the yarn Y that is spliced by joining the yarn end of the upper yarn YA and the yarn end of the lower yarn YB returns on a yarn path on the front side of the yarn joining device 10.
According to the yarn joining mechanism 100 and the yarn joining method explained above, the yarn end of the lower yarn YB is caught by the lower yarn catching device 7. When the lower yarn catching device 7 is moved to the first position P1, the yarn end is supplied to the yarn joining section 50. At this time, when the slack occurs in the lower yarn YB, the yarn end is in slackened state while being held by the lower yarn holding section 60B (refer to FIGS. 8A and 9A). In this state, before the yarn end is cut by the lower yarn cutting section 70B, the tension applying mechanism 110 acts on at least the yarn end present on the first position P1 side of the lower yarn holding section 60B. Specifically, the lower yarn YB is drawn up. Accordingly, the tension is applied on the yarn end between the lower yarn holding section 60B and the lower yarn cutting section 70B to remove the slack in the yarn end (FIGS. 8B and 9B). Then, when the yarn end of the lower yarn YB is cut by the lower yarn cutting section 70B, the yarn end of the certain length is roughly aligned between the lower yarn holding section 60B and the lower yarn cutting section 70B. A stable yarn joining can be performed by joining the yarn end of the lower yarn YB of a substantially certain length and the yarn end of the upper yarn YA of a substantially certain length by the yarn joining section 50. This point is particularly beneficial for a yarn Y having elasticity such as spandex (in other words, easily slackening yarns).
Even in the conventional yarn joining devices such as the yarn joining device disclosed in Japanese Patent Application Laid-Open No. H7-81849, if the yarn has low elasticity, a satisfactory yarn joining is possible. In the case of a yarn having high elasticity, however, a stable yarn joining by using the conventional yarn joining devices is difficult. The yarn joining mechanism 100 according to the present embodiment produces advantageous effects from the perspective of a stable yarn joining.
In the yarn joining mechanism 100, by merely causing the lower yarn catching device 7, which is used for catching a yarn end and supplying the yarn end to the yarn joining section 50, to perform an additional operation, tension can be applied on the yarn end. Consequently, without making the configuration complicated, the slack in the lower yarn YB during the yarn joining can be removed.
In the yarn joining mechanism 100, the controlling section 16 causes the suction port 7a to stop at the second position P2. Depending on the degree of elasticity of the yarn, the slacking state of the yarn end in the yarn joining section 50 changes. For example, depending on the degree of elasticity of the yarn, the winding speed, and the like, the suction port 7a is caused to move to the second position P2, resulting in a precise removal of the slack. Moreover, by setting in advance the second position P2 at which the suction port 7a is caused to stop, the slack can be removed precisely.
Because the lower yarn catching device 7 includes the clamp cover 35 arranged on the suction port 7a, the yarn end of the lower yarn YB can be firmly held by the clamp cover 35. On the other hand, even when the tension applying mechanism 110 acts on the yarn end of the lower yarn YB, drawing of that yarn end from the suction port 7a can be prevented, and tension can be appropriately applied on the yarn end.
In the yarn joining mechanism 100, with the action of a suction current generated inside the relay pipe 7b, a yarn end is sucked and caught. If the diameter of the relay pipe 7b is small and the suction force is comparatively small, the slack can occur easily in the lower yarn YB. However, by using the tension applying mechanism 110 for the lower yarn YB, a stable yarn joining is possible. This point is particularly advantageous for yarns having elasticity such as spandex.
According to the winder unit 1 equipped with the yarn joining mechanism 100, a stable yarn joining can be performed.
In the winder unit 1, the kink preventer 3A is arranged on the bobbin supporting section 2. Because the kink preventer 3A presses down the yarn with a comparatively weak force, and is in contact with only a part of the yarn supplying bobbin B, the yarn having elasticity such as spandex can be easily slackened. Removal of the slack by the tension applying mechanism 110 is particularly advantageous for the yarns having elasticity.
The embodiments of the present invention are explained above. The present invention, however, is not limited to the above embodiments. For example, even if in the above embodiments, as a tension applying unit, a mechanism that applies tension on a yarn end by causing the yarn catching device to perform additional operation (further pivoting operation) is cited as an example, other mechanisms can be employed. For example, on the first position P1 side of the holding section, an external force can be applied on a yarn end in the direction intersecting a yarn path. In such a case, for example, by using a cylindrical member that can be moved with an actuator, and moving the cylindrical member on a plane that intersects the yarn path, a yarn end can be pushed in a direction in which it is pressed to a guide plate. When a yarn end is pushed on the outer surface (outside the range between the holding section and the cutting section) of the yarn joining device, tension acts on the entire yarn end on the first position side of the holding section, and the tension is transmitted to a yarn end portion that is opposite to the yarn joining section. In such a case, because the yarn end portion extends linearly, there is almost no change in the dimension of the yarn end portion.
After the first ascending step, it is not necessary to stop the yarn catching device at the second position until the yarn end is cut. The yarn end can be cut by the cutting section at an appropriate timing during the first ascending step (the yarn catching device is operating at this time), and then moved to the third position. In other words, the yarn catching device can be continuously moved from the first position to the third position without stopping.
It is not necessary that the relay pipe be equipped with a clamping mechanism. The relay pipe can apply tension on a yarn end only by using the suction force. In such a case, after the yarn end is held by the holding section, the suction force generated inside the relay pipe can be increased, and the tension can be applied on the yarn end with the increased suction force. However, it does not mean that a sucking state at which the yarn end is held simply continues. It is necessary to change the form of suction action on the yarn end before and after the yarn end is mechanically held by the holding section of the yarn joining device. In other words, "tension applying unit" and "tension applying step" involve applying a further tension on the yarn end (in other words, applying additional tension). In other words, "tension applying unit" and "tension applying step" are states in which the slack occurs in the yarn end before the yarn end is mechanically held by the holding section, and after the yarn end is mechanically held by the holding section, tension is applied on the yarn end at a sucking state different than the sucking state at which the yarn end is caught.
In the above embodiments, a configuration in which the tension applying unit is arranged only in the lower yarn catching device 7 (the second yarn catching device) is explained. The present invention, however, is not limited to such a configuration. The tension applying unit can be arranged in the upper yarn catching device 12 (the first yarn catching device) that catches the upper yarn YA. When the suction force in the upper yarn catching device 12 is comparatively small, slacking of the upper yarn YA in the yarn joining section 50 can be prevented by arranging the tension applying unit. In this configuration, the upper yarn catching device 12 can move from the catching position to the first position, and then move to the second position at the tension applying step, similar to the operation of the lower yarn catching device 7 of the embodiments explained above.
It is allowable to arrange the tension applying unit in both of the lower yarn catching device 7 (the second yarn catching device) and the suction mouth 12b (the first yarn catching device).
According to one aspect of the present invention, a yarn joining mechanism that joins a yarn end of a first yarn on a downstream side and a yarn end of a second yarn on an upstream side includes a yarn joining section that joins the yarn end of the first yarn and the yarn end of the second yarn; a yarn catching device that includes a catching section that catches the yarn end of the first yarn or the yarn end of the second yarn and that is movable between a catching position positioned on one side of the yarn joining section and a first position positioned on other side of the yarn joining section; a holding section that is arranged on one side of the yarn joining section, and holds the yarn end; a cutting section that cuts the yarn end and that is arranged on the other side of the yarn joining section between the first position and the yarn joining section; and a tension applying unit that acts at least on the yarn end present on the first position side of the holding section, and applies tension on the yarn end present between the holding section and the cutting section.
In the yarn joining mechanism, the yarn catching device catches the yarn end of the first yarn or the yarn end of the second yarn. When the yarn catching device is moved to the first position, the caught yarn end is supplied to the yarn joining section. At this time, when slack occurs in the yarn, the yarn end is in slackened state while being held by the holding section. In this state, before the yarn end is cut by the cutting section, the tension applying mechanism acts on at least the yarn end present on the first position side of the holding section. Accordingly, the tension is applied on the yarn end between the holding section and the cutting section to remove the slack in the yarn end. Then, when the yarn end is cut by the cutting section, the yarn end of a certain length is roughly aligned between the holding section and the cutting section. A stable yarn joining can be performed by joining the yarn end of a substantially certain length and the other yarn end by the yarn joining section. This point is particularly beneficial for a yarn having elasticity such as spandex (in other words, easily slackening yarns).
In the yarn joining mechanism according to the above aspect, the tension applying unit includes a controlling section that controls an operation of the yarn catching device; and the controlling section causes the catching section that is at the first position to move in a direction away from the holding section before the yarn end is cut by the cutting section and applies tension on the yarn end between the holding section and the cutting section. In this case, by merely causing the yarn catching device, which is used for catching a yarn end and supplying the yarn end to the yarn joining section, to perform an additional operation, tension can be applied on the yarn end. Without making the configuration complicated, the slack in the yarn during the yarn joining can be removed.
In the yarn joining mechanism according to the above aspect, the controlling section can cause the catching section to stop at a second position, which is farther from the holding section than the first position. Depending on the degree of elasticity of the yarn, slacking state of the yarn end in the yarn joining section changes. For example, by setting in advance the second position at which the catching section is caused to stop depending on the degree of elasticity of the yarn, the winding speed, and the like, the slack can be removed precisely.
In the yarn joining mechanism according to the above aspect, the yarn catching device includes a clamping mechanism that is arranged on the catching section and that holds the yarn end. In this case, the yarn end can be firmly held by the clamping mechanism. On the other hand, even when the tension applying unit acts on the yarn end, drawing of that yarn end from the catching section can be prevented, and tension can be appropriately applied on the yarn end.
In the yarn joining mechanism according to the above aspect, the yarn catching device is a second yarn catching device that catches the second yarn, and the yarn catching device can suck and catch the yarn end by action of a suction current generated inside the second yarn catching device. If the diameter of the second yarn catching device is small and the suction force is comparatively small, the slack can occur easily in the yarn. However, by using the tension applying unit for the second yarn, a stable yarn joining is possible. This point is particularly advantageous for yarns having elasticity such as spandex.
In the yarn joining mechanism according to the above aspect, the yarn catching device is a first yarn catching device that catches the first yarn, and the yarn catching device can suck and catch the yarn end by action of a suction current generated inside the first yarn catching device. If the suction force of the first yarn catching device is comparatively small, by using the tension applying unit for the first yarn, a stable yarn joining is possible.
According to another aspect of the present invention, a yarn winding device includes the above yarn joining mechanism; a yarn supplying section that supplies a yarn; and a winding section that winds the yarn. According to the yarn winding device, a stable yarn joining can be performed.
The yarn winding device according to the above aspect further includes an unwinding suppressing member that is arranged in the yarn supplying section, and suppresses unwinding of the yarn from the yarn supplying section. The unwinding suppressing member presses down the yarn with a comparatively weak force. Accordingly, even if the unwinding suppressing member is provided, the yarn having elasticity such as spandex can be easily slackened. Removal of the slack by the tension applying unit is particularly advantageous for the yarns having elasticity.
According to still another aspect of the present invention, a yarn joining method that joins a yarn end of a first yarn on a downstream side and a yarn end of a second yarn on an upstream side by using a yarn joining section, includes a catching step of catching a yarn end of the first yarn or a yarn end of the second yarn with a yarn catching device including a catching section that catches the yarn end at a catching position positioned on one side of the yarn joining section; a moving step of moving the yarn catching device with the yarn end caught in the catching section to a first position positioned on other side of the yarn joining section; a holding step of holding the yarn end with a holding section arranged on one side of the yarn joining section; a tension applying step of applying tension on the yarn end between a cutting section and the holding section by acting at least on the yarn end present on the first position side of the holding section; and a cutting step of cutting the yarn end with the cutting section arranged between the first position and the yarn joining section.
In the yarn joining method according to the above aspect, for the same reason as explained in relation to the above yarn joining mechanism, the tension is applied on the yarn end between the holding section and the cutting section to remove the slack in the yarn end. Then, when the yarn end is cut by the cutting section, the yarn end of a certain length is roughly aligned between the holding section and the cutting section. A stable yarn joining can be performed by joining the yarn end of a substantially certain length and the other yarn end by the yarn joining section.
In the yarn joining method according to the above aspect, the tension applying step can include applying the tension to the yarn end between the holding section and the cutting section by moving the catching section that is at the first position in a direction away from the holding section. In this case, by merely causing the yarn catching device, which is used for catching a yarn end and supplying the yarn end to the yarn joining section, to perform an additional operation, tension can be applied on the yarn end. Without making the configuration complicated, the slack in the yarn during the yarn joining can be removed.
In the yarn joining method according to the above aspect, the tension applying step can include moving the catching section to a second position that is farther than the first position from the holding section. Depending on the degree of elasticity of the yarn, slacking state of the yarn end in the yarn joining section changes. For example, by moving the catching section to the second position depending on the degree of elasticity of the yarn, the winding speed, and the like, the slack can be removed precisely.
According to some of the aspects of the present invention, a stable yarn joining is possible by removing the slack in the yarn during the yarn joining.
In the above explanation, the meaning of "a plurality of" also includes "a predetermined number of".
Although the invention has been explained with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the scope of the claims.