JP2000192363A - Top thread control mechanism for sewing machine - Google Patents

Abstract

(57) [Summary] (Modifications) [PROBLEMS] To form a ring seam with a plurality of needles and loopers arranged in parallel so that the heights of the respective needle tips are different, and to provide a fixed thread guide and an upper decoration. Spreader for guiding yarn
Accordingly, the upper decorative thread is reliably guided and sewn to the chain stitch on the upper surface of the cloth, thereby improving the commercial value of the product and providing an upper decorative thread control mechanism which is excellent in economic efficiency. A spreader for reciprocating from the starting point of movement on the upper surface of the cloth in a direction intersecting with the cloth feeding direction, catching the upper decorative thread connected to the fixed thread guide and the seam, and guiding the upper decorative thread to the needle, In a sewing machine in which an upper decorative thread is guided and sewn on a chain stitch on the upper surface of a cloth, the upper decorative thread is arranged in a path of the upper decorative thread connected to the seam, and the fixed thread guide and the spreader are caught near the upper dead center of the needle. A moving yarn guide 42 for forcibly moving the upper decorative yarn is provided so that the upper decorative yarn connected to the portion passes only under one needle point near the starting point of movement of the spreader in the cloth feeding direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixed thread guide which forms a circular seam with a plurality of needles and loopers and reciprocates in a direction intersecting a cloth feeding direction from a movement starting point on the upper surface of the cloth. The present invention relates to a control mechanism for an upper decorative thread of a sewing machine that sewes the upper decorative thread to a ring seam on the upper surface of a cloth by a spreader that catches the upper decorative thread connected to the seam and guides the upper decorative thread to the needle. .

[0002]

2. Description of the Related Art A control mechanism for a decorative thread in a conventional sewing machine of this type will be described with reference to FIG. 1 is a frame of the sewing machine, 2 is a thread tensioner fixed to the frame 1 for applying tension to the upper decorative thread 3, and 4 is a fixed thread having a thread hole 5 for guiding the upper decorative thread 3. The guide 6 is a thread guide whose base is fixed to the frame 1 of the sewing machine and has a U-shaped guide groove 7 at the tip, and 8a, 8b and 8c are needles (not shown) which move up and down in conjunction with the sewing machine mechanism. Needles 9 supported by a rod and arranged in parallel so that the height of each needle tip is different in a direction orthogonal to the cloth feeding direction, 9 has a hook portion 10 for catching the upper decorative thread 3 at the tip, and a base portion is provided for the sewing machine mechanism. In conjunction with this, the hook 10 is formed in an arc shape in a direction in which the needle 8a, which is the highest point of the plurality of needles 8a, 8b, 8c, starts moving and the cloth feed direction front side intersects the cloth feed direction (FIG. 16, FIG. (Shown by a two-dot chain line in FIG. 17).

[0003] When the sewing machine is driven, the needle bar moves up and down in cooperation with a looper (not shown) to form three ring stitches on the cloth, and the spreader-9 is controlled. Captures and releases the upper decorative thread 3a connected to the cloth below the thread guide 6, and sewes the upper decorative thread 3a while guiding the upper decorative thread 3a to the three ring stitches on the upper surface of the cloth.

In this state, as shown in FIG. 16, when the needles 8a, 8b, 8c are lowered to form three circular stitches on the cloth in cooperation with the looper, the spreader 9 moves to the left. The upper decorative yarn 3a which retreats to the starting point of the movement of the fixed yarn guide 4 and continues to the yarn hole 5 of the fixed yarn guide 4 and the cloth is moved to the upper decorative yarn 3a by the thread tensioner 2 and the positional relationship between the yarn hole 5 and the cloth. Due to the tension applied, the guide groove 7 of the thread guide 6 is located below the guide groove 7 in FIG.

In this state, when the needles 8a, 8b, 8c start to rise, the spreader 9 starts to move forward on the arc from the starting point of movement, and the hook 10 makes the upper decorative thread 3a continuous with the cloth.
To capture and move. Then, when the tips of the needles 8a, 8b, 8c fall out of the cloth, the cloth is fed, and the portion of the upper decorative thread 3a connected to the cloth moves in the cloth feeding direction. The tension of the upper decorative yarn 3a applied to the upper decorative yarn 3 by the thread tensioner 2 due to the movement of the catching position of the hook 10 of the spreader 9, the moving position of the catching position of the hook 10, and the fixing yarn Information 4
16 and the movement of the upper decorative thread 3a connected to the chain stitch by the cloth feed, the upper decorative thread 3a is moved near the upper dead center of the needles 8a, 8b, 8c into the guide groove 7 shown in FIG. From the position, the user slides in the guide groove 7 to get over the top of the guide groove 7 and moves to the position shown in FIG. 17, and as shown in FIG. 15, the one needle 8a near the starting point of movement of the spreader 9 Only the front lower part is passed in the cloth feeding direction.

Further, when the needles 8a, 8b and 8c start descending, the spreader 9 starts moving backward, the spreader 9 returns to the starting point of movement, and the upper decorative thread 3a returns to the position shown in FIG. Is repeated each time the needle moves up and down, so that the upper decorative thread 3a is sewn while being guided on the upper surface of the cloth with respect to the three loop stitches.

[0007]

However, the conventional mechanism for controlling the decorative yarn has the following problems. That is, in the conventional control mechanism of the decorative yarn,
The tension of the upper decorative yarn 3 applied to the upper decorative yarn 3 by the thread tensioner 2 due to the movement of the hook portion 10 of the spreader 9 by the movement, the arc-shaped moving position of the hook position of the hook portion 10, and the fixed yarn The needle 8a, 8b, 8c is moved by the position of the thread hole 5 of the guide 4 and the movement of the upper decorative thread 3a connected to the chain stitch by the cloth feed.
In the vicinity of the top dead center, the upper decorative thread 3a is slid in the guide groove 7 from the position of the guide groove 7 shown in FIG. 16 to move over the top of the guide groove 7 to the position shown in FIG. As shown in (1), only the lower part of one needle 8a near the starting point of movement of the spreader 9 is passed in the cloth feeding direction.

For this reason, the coefficient of friction varies depending on the type of the decorative yarn, the thickness of the decorative yarn, etc., and the tension of the decorative yarn 3 applied to the decorative yarn 3 by the thread tensioner 2 changes, If the feed amount changes or the guide groove 7 is damaged, the upper decorative thread 3 does not climb over the top of the guide groove 7 near the top dead center of the needle as shown in FIG.
Does not pass below the tip of the single needle 8a near the starting point of movement of the spreader 9 in the cloth feeding direction, or the guide groove 7 of the thread guide 6 is formed by the hook 10 of the spreader 9 as shown in FIG. Phenomena such as the upper decorative thread 3 being unable to be caught below occur, and the upper decorative thread 3 cannot be accurately sewn into the chain stitch, resulting in a decrease in the commercial value of the product or an increase in the thread tensioner 2 Adjustment of the tension of the decorative thread 3, trial sewing, and the like are required, and there is a problem that sewing efficiency is reduced.

[0009]

In order to solve the above-mentioned problems, the present invention according to the first aspect of the present invention provides a ring seam comprising a plurality of needles and loopers arranged in parallel so that the heights of the respective needle tips are different. And a spreader that reciprocates from the starting point of movement on the upper surface of the cloth in a direction crossing the cloth feeding direction, catches the upper decorative thread connected to the fixed thread guide and the seam, and guides the upper decorative thread to the needle. In a sewing machine in which an upper decorative thread is sewn to the chain stitch on the upper surface of the cloth, the upper decorative thread is arranged in the path of the upper decorative thread connected to the fixed thread guide and the seam, and the fixed thread guide and the catcher of the spreader are located near the top dead center of the needle. The moving yarn guide for forcibly moving the upper decorative yarn is provided so that the continuous upper decorative yarn passes only under one needle point near the starting point of movement of the spreader in the cloth feeding direction.

According to the first aspect of the present invention, since the upper decorative yarn is forcibly moved by the movable yarn guide, the friction coefficient changes depending on the type of the upper decorative yarn, the thickness of the upper decorative yarn, and the like.
Even if the tension of the upper decorative thread 3 applied to the upper decorative thread 3 by the thread tensioner 2 changes, or if the cloth feed amount changes,
In the vicinity of the top dead center of the needle, the upper decorative thread 3 is spreader-9.
The upper decorative thread 3 can be sewn accurately to the chain stitch by reliably passing the needle 8a near the starting point of the lower part of the needle 8a in the cloth feeding direction, thereby reducing the commercial value of the product. In addition to the above, there is no need to adjust the tension of the upper decorative thread 3 by the thread tensioner 2 or to perform trial sewing, thereby improving the sewing efficiency.

According to a second aspect of the present invention, in this type of sewing machine, the fixed thread guide and the spreader are trapped near the top dead center of the needle by disposing the fixed thread guide and the upper decorative thread in a path connected to the seam. The upper decorative yarn is forcibly moved so that the upper decorative yarn connected to the upper portion passes only under one needle point near the starting point of movement of the spreader in the cloth feeding direction, and the catcher of the spreader moves upward. During the period of catching the decorative thread, the upper decorative thread connected to the fixed thread guide and the seam is spreader.
The moving yarn guide is positioned within the reciprocating locus of the catching section.

According to the second aspect of the present invention, the upper decorative yarn is guided by the movable yarn guide, and the upper decorative yarn connected to the fixed yarn guide and the catcher of the spreader near the top dead center of the needle is spreader-shaped. The upper decoration thread is forcibly moved so as to pass in the cloth feeding direction only below one needle tip close to the starting point of the movement of the needle, and the fixed thread guide and the seam are used during the period when the catcher of the spreader captures the upper decoration thread. The movable yarn guide for forcing the upper decorative yarn connected to the position within the reciprocating locus of the catcher of the spreader is forcibly moved.

For this reason, the coefficient of friction changes depending on the type of the decorative yarn, the thickness of the decorative yarn, etc., and even if the tension of the decorative yarn 3 applied to the decorative yarn 3 by the thread tensioner 2 changes, Even when the cloth feed amount changes, the upper decorative thread 3 is reliably passed in the cloth feed direction below the needle tip of one needle 8a near the starting point of movement of the spreader 9 near the top dead center of the needle. At the same time, the catch of the upper decorative thread by the catcher of the spreader is also ensured, and the upper decorative thread 3 can be sewn more accurately to the chain stitch, thereby improving the commercial value of the product and improving the thread tension. There is no need to adjust the tension of the upper decorative thread 3 by the container 2 or to perform trial sewing, and the sewing efficiency is improved.

According to a third aspect of the present invention, in the first and second aspects of the present invention, the movable yarn guide is provided with a driving body that swings about a horizontal axis in conjunction with the vertical movement of the needle. , A swing arm that can swing about the vertical axis, a connecting rod that connects the driver and the swing arm and transmits the swing of the driver to the swing arm, and is linked with the swing of the swing arm A drive plate that swings about a vertical axis and a yarn guide that moves substantially along the cloth feed direction in conjunction with the drive plate and has a yarn guide formed at the end.

According to the third aspect of the present invention, in addition to the effects of the first and second aspects, a conventional chain stitch sewing machine having a spreader for guiding an upper decorative thread is provided with this mechanism. By attaching a, the conventional problems can be solved, and therefore, there is an effect of being excellent in applicability. According to a fourth aspect of the present invention, there is provided a driving body which swings around a horizontal axis in conjunction with a vertical movement of a needle, and a swing arm which can swing around a vertical axis and supports a spreader at one end. A connecting rod that connects the driving body and the other end of the swinging arm to transmit the swing of the driving body to the swinging arm, and a drive that swings about a vertical axis in conjunction with the swinging of the swinging arm. It is composed of a plate and a yarn guide body that moves substantially along the cloth feed direction in conjunction with the drive plate and has a yarn guide formed at the end.

According to the fourth aspect of the present invention, by attaching this mechanism to a conventional chain stitch sewing machine having no spreader for guiding an upper decorative thread, a general chain stitch sewing machine can be mounted on a ring on a cloth upper surface. Since the sewing machine can be modified to sew the upper decorative thread at the seam, the use of the sewing machine is expanded and the versatility is excellent, and there is no need to provide a complicated spreader drive mechanism, so the cost is low and the economy is excellent. And so on.

Further, the invention described in claim 5 is the third invention.
Each component described in claim 4 is configured to be mounted on a mounting base that is detachable from the sewing machine arm.
According to the fifth aspect of the present invention, this mechanism can be easily attached to a conventional chain stitch sewing machine having no spreader for guiding the upper decorative thread, and therefore does not have a guide mechanism for the upper decorative thread. The chain stitch sewing machine can be modified into a sewing machine that sews a decorative thread on the chain stitch on the upper surface of the cloth, and the use of the sewing machine is expanded, which has excellent versatility. Since a seam to be embedded can be formed, there are effects such as excellent economic efficiency.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. First, the configuration of the first embodiment will be described with reference to FIGS. The sewing machine described below has a thread tensioner for applying tension to the upper decorative thread and a fixed thread guide, as in the related art. Further, the same parts as those in the related art will be described with the same reference numerals.

Reference numeral 20 denotes a mounting base, which includes a vertical mounting portion 21 which is attached to and detached from the frame of the sewing machine, a support portion 23 which is bent in a U-shape to form a vertical hole 22, and extends sideways. An extended vertical support portion 24 is provided. Reference numeral 25 denotes a support body. The center part is fixed to the vertical surface of the mounting base 20 with screws 26, and the left lower part is bent forward to form a receiving surface 27, and the right lower part is formed rearward. It is bent to form the link receiving portion 28.

Reference numeral 29 denotes a V-shaped driving body whose base is rotatably connected to the support 24 of the mounting section 21 by a shaft 30 and which has a needle bar (not shown) which moves up and down at the tip. An interlocking connection shaft 31 is provided. A swing arm 32 has a base fixed to a shaft 33 rotatably supported in the hole 22 of the mounting base 20, and a fork 34 is formed at an intermediate portion.

Reference numeral 35 denotes a drive plate, the base of which is rotatably supported on the upper surface of the link receiving portion 28 of the support 25 around a shaft 36, and is loosely fitted to the fork 34 of the swing arm 32 at an intermediate portion. A pin 37 is provided. Reference numeral 38 denotes a connecting rod, one end of which is ball-connected to an intermediate portion of the driving body 29, and the other end of which is ball-connected to the tip of the swing arm 32.

Numeral 39 designates a yarn guide as a movable yarn guide. The base is rotatably supported at the tip of the drive plate 35 by a shaft 40, and a thread guide 42 having a hole 41 at the tip is provided. The guide 39 is provided on the receiving portion 2 of the support 25.
7 is placed on the upper surface. Reference numeral 43 denotes a guide, which fixes the base portion on the lower surface of the receiving portion 27, and loosely fits the thread guide 39 in a portion bent upward in a U-shape.
7 guides the yarn guide body 39 placed on the upper surface so as not to move in the left-right direction when moving in the front-rear direction. Reference numeral 44 denotes a cloth presser.

Next, the operation of the first embodiment will be described with reference to FIGS.
This will be described below. FIGS. 4 and 6a show a state in which the sewing machine needle is almost at the bottom dead center. In this state, the connecting shaft 31 of the driving body 29 in FIG. 2 is pushed down most downward by the needle bar. For this reason, the thread guide 39 is located at the forward position as shown in FIG. 6A, and the spreader 9 is located at the movement start point.

When the main shaft (not shown) of the sewing machine rotates from this state, the needle starts to rise at first, the connecting shaft 31 of FIG. 2 is pushed up, and the driving body 29 rotates clockwise about the shaft 30. start. This rotation is transmitted to the swing arm 32 in FIG. 4 via the connecting rod 38, and the swing arm 32 starts to rotate counterclockwise about the shaft 33. The counterclockwise rotation of the swing arm 32 is transmitted to the pin 37 via the fork 34,
The drive plate 35 is rotated counterclockwise about the shaft 36, whereby the yarn guide 39 starts to move backward from the forward position shown in FIGS. 4 and 6a by the guide 43, and the spreader 9 moves. Start moving to the right from the starting point.

Then, as shown in FIG. 6B, the catcher 10 of the spreader 9 catches the upper decorative thread 3a connected to the thread hole 41 of the thread guide 42 and the seam. Further, while the needle continues to rise, the spreader 9 continues to advance, and the thread hole 41 of the thread guide 42 also continues to retreat with the upper decor thread 3a passing through the thread hole 41, forcing the upper decor thread 3a. Move.

When the needle tips of the needles 8a, 8b and 8c come out of the cloth, the cloth starts to be fed, and when the needle reaches the vicinity of the top dead center, the spreader 9 which has captured the upper decorative thread 3a as shown in FIG. 6a. Due to the positional relationship between the position of the catching section 10 and the position of the yarn hole 41 of the yarn guide 42 through which the upper decorative yarn 3a passes, as shown in FIG. Only the needle 8a is forced to pass under the needle tip in the cloth feeding direction.

When the needle reaches the top dead center, the spreader 9 and the thread guide 42 move as shown in FIG. 5 so that the spreader 9 reaches the most advanced position and the thread guide 42 retracts to the most retracted position. I do. Next, when the needle starts to descend, the driving body 29
Starts rotating counterclockwise about the shaft 30 in FIG. 2 in the opposite direction to the above, and swinging arm 3 in FIG.
The swing arm 32 starts rotating clockwise about the axis 33 in FIG. The clockwise rotation of the swing arm 32 about the shaft 33 causes the drive plate 35 to rotate counterclockwise about the shaft 36, thereby moving the thread guide 39 from the forward position in FIG. At the same time as the retreat starts, the spreader 9 starts returning to the left.

Then, the needle pierces the cloth for the first time when the needle descends while the upper decorative thread 3a is in the state shown in FIG. 7, the spreader 9 starts to move backward, and the thread guide 42 inserts the upper decorative thread 3a into the thread hole 41 thereof. When the needle starts to retreat while passing through the needle and reaches the bottom dead center, the spreader 9 and the thread guide 42 are connected to each other as shown in FIG.
Return to the exercise start point shown in. As the spreader 9 and the thread guide 42 repeat the above-mentioned reciprocating motion in conjunction with the vertical movement of the needle, the upper decorative thread 3a is sewn to the ring stitch on the upper surface of the cloth.

Next, the structure and operation of the second embodiment of the present invention will be described with reference to FIGS. The present invention
The thread hole 41 of the thread guide 42 for guiding the upper decorative thread 3a of the first embodiment is configured as a hook-like portion 45, and the hook-like portion 45 is formed.
The mechanism and the spreader 9 for driving are the same as those of the first embodiment.

Therefore, when the needle is at the bottom dead center, the hook 45, the spreader 9, and the upper decorative thread 3a are at the positions indicated by the solid lines in FIGS.
Starts moving forward from the movement start point, and the hook-shaped portion 45 begins to retreat. As a result, the catcher 10 of the spreader 9 is
Catches the upper decorative thread 3a and moves forward, and
5 forcibly moves the upper decorative thread 3a as shown by the two-dot chain line in FIG.

When the cloth is fed and the needle reaches the vicinity of the top dead center, the hook-like portion 45 and the catching portion 10 of the spreader 9 are located at the positions indicated by the two-dot chain lines in FIGS. 10 and 9, respectively. As a result, the upper decorative thread 3a is forced to pass only in the cloth feeding direction below the needle tip of one needle 8a close to the start point of movement of the spreader. Thereafter, when the needle reaches the top dead center, the spreader 9 and the thread guide 42 reach the most advanced position, and the hook 45 of the thread guide 42 retreats to the most retracted position.

While the needle is descending for the first time while the upper decorative thread 3a is in the state shown in FIG.
9 starts a backward movement, the thread guide 42 starts to retreat, and when the needle reaches the bottom dead center, the spreader 9 and the thread guide 42
It returns to the exercise starting point shown in FIG. As the spreader 9 and the thread guide 42 repeat the above-mentioned reciprocating motion in conjunction with the vertical movement of the needle, the upper decorative thread 3a is sewn to the ring stitch on the upper surface of the cloth.

Next, the structure and operation of the third embodiment of the present invention will be described with reference to FIGS. According to the present invention, a spreader is provided integrally with the swing arm 32 of the first embodiment.
The configuration is such that the arm 32a is formed, and the other configuration is the same as the configuration and operation of the first embodiment. The tip of the spreader arm 32a has a hole 46 inclined with respect to the horizontal plane.
And a groove 47 communicating with the hole 46 is formed. This hole 4
6 has a groove 49 and a hole 4 of the E-ring 48 at the left end shown in FIG.
6 and a hole 50 orthogonal to the axis of
Is loosely fitted.

As shown in FIGS. 11 and 12, the upper end of the spreader 9 having the catching portion 10 is fixed to the right end screw 51 of the shaft 52 with a nut 53, and the spreader arm 32a is fixed to the hole 50. Groove 4 formed at the tip of
7, the shaft 52 is loosely fitted into the hole 46 at the tip of the spreader arm 32a from the right side so that the pin 54 is loosely fitted into the groove 47, and the left end of the shaft 52 is It protrudes to the left of the hole 46 as shown in FIG. First, a spring 55 is loosely fitted onto the protruding shaft 52, and then the seat 5
The spring 55 is compressed by 6 to fit the E-ring 48 into the groove 49.

Therefore, the left end face of the spreader 9 is always pressed against the distal end face of the spreader arm 32a by the elastic force of the spring 55, but in the axial direction against the elastic force of the spring 55. Since the pin 54 can be moved and the pin 54 is loosely fitted in the groove 47, no rotation about the shaft 52 occurs. Next, the operation of the third embodiment will be described with reference to FIGS.

FIG. 13 shows a state in which the needle of the sewing machine is almost at the bottom dead center.
1 is pushed down most downward by the needle bar. Therefore, the yarn guide 39 is located at the forward position as shown in FIG. 13, and the spreader 9 is located at the movement start point. When the main shaft (not shown) of the sewing machine rotates from this state, the needle starts to rise at first, the connecting shaft 31 is pushed up, and the driving body 29 starts rotating around the shaft 30. This rotation is the connecting rod 3
8 to the swing arm 32 of FIG.
Starts rotating counterclockwise about the axis 33.

When the swing arm 32 rotates counterclockwise, the swing arm 32 is first transmitted to the pin 37 via the fork 34,
The drive plate 35 is rotated clockwise about the shaft 36, whereby the thread guide 39 starts to retreat from the advanced position in FIGS. 4 and 6a, and the spreader arm 32a also rotates counterclockwise, The spreader 9 starts moving forward to the right from the movement start point.

As shown in FIG. 6B, the catch 10 of the spreader 9 catches the upper decorative thread 3a connected to the thread hole 41 of the thread guide 42 and the seam, as in the first embodiment. In addition, the needle keeps rising and spreader
9 continues to advance, and the yarn hole 41 of the yarn guide 42 is also
Continues to retreat with the upper decorative thread 3a passing through the upper decorative thread 3a.
Force to move.

When the needle tips of the needles 8a, 8b and 8c come out of the cloth, the cloth starts to be fed, and when the needle reaches the vicinity of the top dead center, as shown in FIG. 6a, the spreader 9 catches the upper decorative thread 3a. Due to the positional relationship between the position of the catching section 10 and the position of the yarn hole 41 of the yarn guide 42 through which the upper decorative yarn 3a passes, as shown in FIG. Only the needle 8a is forced to pass under the needle tip in the cloth feeding direction.

When the needle reaches the top dead center, the swing arm 3
2 stops rotating counterclockwise, and these spreaders 9
And the thread guide 42, as shown in FIG.
9 reaches the most advanced position, and the yarn guide 42 retreats to the last retreat position. Next, when the needle starts to descend, the driving body 29 starts rotating in the opposite direction to the above, and the driving body 29 is connected via the connecting rod 38 in FIG.
4 is transmitted to the swing arm 32, and the swing arm 32 starts rotating clockwise about the shaft 33. By rotating the swing arm 32 clockwise about the axis 33, the drive plate 35
6, the thread guide 39 starts to move forward from the retracted position in FIG. 14, and the spreader arm 32a rotates clockwise, and the spreader arm 32a rotates clockwise.
9 starts returning to the left.

Then, while the needle starts descending and pierces the cloth while the upper decorative yarn 3a is in the state shown in FIG. 7, the spreader 9 starts to return, and the yarn guide 42 inserts the upper decorative yarn 3a into the yarn hole 41. When the needle starts to move forward while passing the needle and the needle reaches the bottom dead center, the spreader 9 and the thread guide 42 are connected to each other as shown in FIG.
Return to the exercise start point shown in. As the spreader 9 and the thread guide 42 repeat the above-mentioned reciprocating motion in conjunction with the vertical movement of the needle, the upper decorative thread 3a is sewn to the ring stitch on the upper surface of the cloth.

Accordingly, in the third embodiment, the spreader 9 and the thread guide 42 are reciprocated by the driving body 29 which reciprocates in conjunction with the vertical movement of the needle. Further, in the above-described embodiment, the thread guide 42 is moved back and forth in conjunction with the vertical movement of the needle. However, the forward and backward movement of the thread guide 42 is not limited to the vertical movement of the needle, but is linked with the main shaft of the sewing machine. Of course, it can be replaced by another mechanism.

Further, in the above-described embodiment, the embodiment in which the thread guide 42 is moved back and forth by a mechanism interlocked with the main shaft of the sewing machine is shown. However, the forward and backward movement of the thread guide 42 is synchronized with the rotation angle of the main shaft of the sewing machine. An arbitrary actuator can be operated by the electric signal to thereby move the yarn guide 42 back and forth.

[0044]

As described above, according to the present invention, the upper decorative yarn is forcibly moved by the movable yarn guide, so that the coefficient of friction changes depending on the type of the upper decorative yarn, the thickness of the upper decorative yarn, etc. 2, the spreader 9 moves the upper decorative thread 3 near the top dead center of the needle even if the tension of the upper decorative thread 3 applied to the upper decorative thread 3 or the cloth feed amount changes. The upper decorative thread 3 can be sewn accurately to the chain stitch by reliably passing the needle 8a near the starting point below the tip of the needle 8a in the cloth feeding direction, thereby improving the commercial value of the product. At the same time, there is no need to adjust the tension of the upper decorative thread 3 by the thread tensioner 2 or to perform trial sewing, thereby improving the sewing efficiency.

Further, the upper decorative yarn is guided by the movable yarn guide, and the upper decorative yarn connected to the fixed yarn guide and the catcher of the spreader near the top dead center of the needle is a single needle close to the starting point of movement of the spreader. The upper decoration thread is forcibly moved so as to pass only in the lower portion of the upper end in the cloth feeding direction, and the upper decoration thread connected to the fixed thread guide and the seam is spread while the catcher of the spreader captures the upper decoration thread. The moving yarn guide positioned within the reciprocating locus of the capturing unit is forcibly moved.

Therefore, the coefficient of friction varies depending on the type of the decorative yarn, the thickness of the decorative yarn, etc., and even if the tension of the decorative yarn 3 applied to the decorative yarn 3 by the thread tensioner 2 changes, Even if the cloth feed amount changes, the upper decorative thread 3 is reliably passed in the cloth feed direction below the needle tip of one needle 8a near the starting point of movement of the spreader 9 near the top dead center of the needle. At the same time, the catch of the upper decorative thread by the catcher of the spreader is also ensured, and the upper decorative thread 3 can be sewn more accurately to the chain stitch, thereby improving the commercial value of the product and improving the thread tension. There is no need to adjust the tension of the upper decorative thread 3 by the container 2 or to perform trial sewing, and the sewing efficiency is improved.

Also, a driving body that swings the movable yarn guide around a horizontal axis in conjunction with the vertical movement of the needle, a swing arm that can swing about a vertical axis, a driving body and a swing arm And a connecting plate that transmits the swing of the driving body to the swing arm by connecting the swinging arm, a driving plate that swings about the vertical axis in conjunction with the swing of the swing arm, A thread guide that moves along the cloth feed direction and has a thread guide formed at the end thereof is attached to a conventional chain stitch sewing machine having a spreader for guiding an upper decorative thread. The upper decorative thread 3 can be sewn more accurately, thereby improving the commercial value of the product and eliminating the need for adjusting the tension of the upper decorative thread 3 by the thread tensioner 2 and performing trial sewing. It has the effect of improving the sewing efficiency and has the effect of being excellent in applicability.

Also, a driving body that swings about a horizontal axis in conjunction with the vertical movement of the needle, a swing arm that can swing about a vertical axis and supports a spreader at one end, A connecting rod that connects the other end of the moving arm to transmit the swing of the driving body to the swing arm, a driving plate that swings about a vertical axis in conjunction with the swing of the swing arm, and a driving plate And a thread guide body having a thread guide formed at the end thereof, which moves substantially along the cloth feed direction in conjunction with, so that this mechanism can be applied to a conventional chain stitch sewing machine which does not have a spreader for guiding an upper decorative thread. By attaching, a general chain stitch machine can be modified to a sewing machine that sews a decorative thread on the chain stitch on the upper surface of the cloth, so the use of the sewing machine is expanded, it is excellent in versatility, and it is necessary to provide a complicated spreader drive mechanism Cost is lower and economy is better There is an effect such as that.

Further, each of the drive mechanism for the thread guide and the drive mechanism for the spreader, which is linked to the drive linked to the vertical movement of the needle, is mounted on a mounting base which can be attached to and detached from the sewing machine arm. Therefore, this mechanism can be easily attached to a conventional chain stitch sewing machine that does not have a spreader that guides a top decoration thread. The sewing machine can be remodeled to sew the upper decorative thread on the chain stitch, and the use of the sewing machine is expanded and it has the effect of being excellent in versatility.Since a single sewing machine can form the ring seam and the seam for sewing the upper decorative thread, There are effects such as excellent economic efficiency.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a control mechanism for a decorative yarn.

FIG. 2 is a perspective view from the right where the control mechanism of the upper decorative thread is assembled.

FIG. 3 is a perspective view from the left in which a control mechanism for an upper decorative thread is assembled.

FIG. 4 is a top view of the control mechanism of the upper decoration thread, in a state where the needle is near the bottom dead center.

FIG. 5 is a top view of the control mechanism of the upper decorative thread, in a state where the needle is near the top dead center.

FIG. 6 is an explanatory diagram for explaining the operation of the control mechanism of the upper decorative thread.

FIG. 7 is a perspective view showing the state of the needle and the upper decoration thread near the top dead center in the control mechanism of the upper decoration thread.

FIG. 8 is a partial plan view of the second embodiment, in which the needle is near the bottom dead center.

FIG. 9 is a partial side view of the second embodiment and is an explanatory diagram showing a state of an upper decorative thread.

FIG. 10 is a partial plan view of the second embodiment, showing a state where the needle is near the top dead center.

FIG. 11 is an exploded perspective view of the third embodiment.

FIG. 12 is a partial sectional view of the third embodiment.

FIG. 13 is a plan view of the third embodiment, showing a state where the needle is near the bottom dead center.

FIG. 14 is a plan view of the third embodiment, in which the needle is near the top dead center.

FIG. 15 is a perspective view of a control mechanism of a conventional decorative yarn.

FIG. 16 shows a state in which the needle of the conventional upper decorative thread control mechanism has the needle near the bottom dead center.

FIG. 17 shows a state in which the needle of the control mechanism of the conventional upper decoration thread has the needle near the top dead center.

FIG. 18 is an explanatory view showing one of the problems of the control mechanism of the conventional decorative yarn.

FIG. 19 is an explanatory view showing another problem of the conventional control mechanism of the upper decoration thread.

[Explanation of symbols]

 2 Thread tensioner 3 Upper decorative thread 4 Fixed thread guide 8a needle 8b needle 8c needle 9 spreader 10 capture unit 20 mounting base 29 driver 32 swinging arm 32a spreader arm 35 drive plate 38 connecting rod 39 thread guide 42 thread guide

Claims (5)

[Claims] 1. A loop seam is formed by a plurality of needles and loopers which are arranged in parallel so that the heights of the respective needle tips are different from each other, and a direction intersecting a cloth feed direction from a movement starting point on an upper surface of the cloth. A sewing machine that reciprocates at a fixed thread guide and catches the upper decorative thread connected to the seam and guides the upper decorative thread to the needle, and sews the upper decorative thread to the ring seam on the upper surface of the cloth. And placed in the path of the upper decorative thread connected to the seam,
In the vicinity of the top dead center of the needle, the upper decorative yarn connected to the fixed yarn guide and the catcher of the spreader is moved upward only so as to pass in the cloth feeding direction only below one needle tip close to the starting point of movement of the spreader. An upper thread control mechanism for a sewing machine, comprising a movable thread guide for moving a decorative thread. 2. A loop seam is formed by a plurality of needles and loopers arranged in parallel so that the heights of the respective needle tips are different from each other, and a direction intersecting the cloth feed direction from a movement starting point on the upper surface of the cloth. A sewing machine that reciprocates at a fixed thread guide and catches the upper decorative thread connected to the seam and guides the upper decorative thread to the needle, and sews the upper decorative thread to the ring seam on the upper surface of the cloth. And placed in the path of the upper decorative thread connected to the seam,
In the vicinity of the top dead center of the needle, the upper decorative yarn connected to the fixed yarn guide and the catcher of the spreader is moved upward only so as to pass in the cloth feeding direction only below one needle tip close to the starting point of movement of the spreader. A moving thread guide for moving the decorative thread and for positioning the upper decorative thread connected to the fixed thread guide and the seam within the reciprocating path of the catcher of the spreader during a period in which the catcher of the spreader captures the upper decorative thread. An upper thread control mechanism for a sewing machine, which is provided. 3. A driving body, wherein the moving yarn guide swings around a horizontal axis in conjunction with a vertical movement of a needle, a swing arm that can swing around a vertical axis, and the driving body. A connecting rod that connects the arm and transmits the swing of the driving body to the swing arm, a drive plate that swings about the vertical axis in conjunction with the swing of the swing arm, and a linkage with the drive plate 3. An upper thread control mechanism for a sewing machine according to claim 1, further comprising a thread guide body which moves substantially along a cloth feed direction and has a thread guide formed at a leading end thereof. 4. A loop seam is formed by a plurality of needles and loopers arranged in parallel so that the heights of the respective needle tips are different from each other, and a direction intersecting a cloth feed direction from a movement starting point on the upper surface of the cloth. In a sewing machine that reciprocates at a fixed thread guide and catches the upper decorative thread connected to the seam and guides the upper decorative thread to the needle, the sewing machine sewes the upper decorative thread to the ring seam on the upper surface of the cloth. A driver that swings about a horizontal axis in conjunction with movement, and a spreader that can swing about a vertical axis at one end.
A swinging arm supporting the swinging arm, a connecting rod connecting the driving body and the other end of the swinging arm to transmit the swinging of the driving body to the swinging arm, and a vertical axis interlocking with the swinging of the swinging arm. The sewing machine comprises a drive plate that swings around a center, and a thread guide body that moves substantially along the cloth feed direction in conjunction with the drive plate and has a thread guide formed at the end thereof. mechanism. 5. The sewing machine according to claim 3, wherein each of the component parts according to claim 3 and 4 is mounted on a mounting base detachable from the sewing machine arm. Top decoration thread control mechanism.