JP2001198378A - Hemmer sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent cloth mis-alignment at high speed transport of each cloth. SOLUTION: In a hemmer sewing machine in which a number of cloths 1 are transported sequentially to a roll former 3 and a machine head 4, endless upper and under belts 5 and 6 are used for a transport conveyer that transport cloths. Each cloth is held between the upper and under belts and it is transported by the upper and under belts that are driven by a driving motor 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hem triple winding sewing machine which wraps and sews three hem fabrics such as pockets, pajamas, cuffs and the like.

[0002]

[Prior art and its problems] Pocket mouth, pajamas hem,
In a hem triple-wrap sewing machine, three hem fabrics such as cuffs are wound and sewn together, usually a large number of fabrics are sequentially sent to a three-roll former and a sewing head, and the hem of the fabric is guided by the three-wrap former. Deformed and wound three times. Thereafter, the hem is sewn together by the sewing head.

In the meantime, in the case of the hem triple winding sewing machine, there has conventionally been a problem associated with a feed conveyor for feeding cloth. Heretofore, a combination of an endless feed belt and a table has been used as a feed conveyor, and the feed belt has been arranged along the upper surface of the table and driven along the upper surface of the table. Then, each fabric is sandwiched between the feed belt and the table, each fabric is dragged by the feed belt, and this is slid along the upper surface of the table and sent, but frictional resistance occurs between the fabric and the table, and each fabric is removed. If the paper is fed at a high speed, a frictional resistance causes a displacement of the cloth, which cannot be accurately transmitted. For this reason, there is a problem that the speeding up is limited. In addition, when the hem of the fabric is guided by a three-roll former and deformed, and when it is wound three times, there is a case where large deformation resistance occurs depending on the material of the fabric. Dough misalignment may occur. In this case, the hem three-turn sewing machine cannot be used for the fabric, and the hem of the fabric cannot be wound three times by the hem three-turn sewing machine and stitched together.

[0004]

SUMMARY OF THE INVENTION Therefore, according to the present invention, a large number of fabrics are sequentially fed to a three-roll former and a sewing head, and the hem of the fabric is guided by the three-wind former, wound three times, and the hem is sewn by the sewing head. In a hem triple-wrap sewing machine of the type, even if each cloth is fed at a high speed, it does not cause a cloth displacement, and the hem of the cloth is guided by a three-roll former, deformed, The purpose of the present invention is to prevent the material from shifting even if the material of the material causes a large deformation resistance when the material is wound.

[0005]

According to the present invention, the endless upper and lower belts are used for the feed conveyor for feeding the dough,
The upper and lower belts are vertically opposed. further,
The drive motor drives the upper and lower belts,
Each fabric is sandwiched between the upper and lower belts, and each fabric is fed by the upper and lower belts.

A timing belt is used as each of the upper and lower belts, drive sprockets are respectively provided on the upper and lower belts, and the upper and lower belts are engaged with the respective drive sprockets, and a common drive motor is driven by the respective drive sprockets. Preferably, it is connected to a sprocket and each drive sprocket is rotated by a common drive motor to drive the upper and lower belts.

A timing belt is used as each of the upper belt and the lower belt. A plurality of upper guide sprockets are provided on the upper belt, and the upper guide sprockets are arranged at intervals in the fabric feeding direction. Engage with the sprocket and place the lower belt along the top surface of the plate. Further, the upper belt is provided with a plurality of elastic urging means such as a leaf spring and a piano wire, and each elastic urging means is applied to each upper guide sprocket to elastically apply each upper guide sprocket toward the lower belt and the plate. Preferably.

Alternatively, a plurality of lower guide sprockets are provided on the lower belt, each lower guide sprocket is opposed to each upper guide sprocket, and the lower belt is engaged with each lower guide sprocket. The upper guide sprocket may be elastically biased toward each lower guide sprocket.

Further, the upper and lower belts are intermittently driven at a constant pitch, and each fabric is intermittently fed at a constant pitch. At each intermittent feed, the needle of the sewing machine head is pierced into a hem having three turns. It is preferable that the hems are pulled out and then sewn together.

Furthermore, a photo sensor is arranged near the needle position of the sewing head, and when there is a fabric at the needle position of the sewing head, it is detected by the photo sensor and the sewing head is driven at a high speed. Further, when there is no fabric at the needle position of the sewing head, it is preferable to detect this by a photo sensor and drive the sewing head at a low speed.

Further, at a supply position where each dough is supplied between the upper and lower belts, upstream and downstream photosensors are arranged at intervals in the supply direction of the dough, and the rear end of the supplied dough is located on the downstream side. When the front end of the next fabric does not reach the upstream photo sensor installation position even after exceeding the photo sensor installation position, detect it by the upstream and downstream photo sensors and stop the upper and lower belts and the sewing machine head. Is preferred.

Further, a cutter is arranged at a downstream position of the sewing machine head, and a photo sensor is arranged at a downstream side of the cutter. When a rear end of a previous fabric of the adjacent pair of fabrics exceeds the installation position of the cutter, a photo sensor is provided. Preferably, the cutter is driven to drive the cutter, and the sewing machine cuts the hem sewing thread between the adjacent pair of fabrics.

Further, at the downstream position of the sewing machine head, the upstream and downstream cutters are arranged at intervals in the fabric feeding direction, the upstream photosensor is arranged upstream of the upstream cutter, and the downstream photosensor is connected to the downstream cutter. It is located downstream of the side cutter. Then, when the front end of the later fabric reaches the installation position of the upstream photosensor, the upstream photosensor detects the same and drives the upstream cutter, and the upstream fabric is used between the fabrics of the adjacent pair. Cut the hem sewing thread with the side cutter. After that, when the rear end of the previous fabric exceeds the installation position of the downstream photo sensor, it is detected by the downstream photo sensor, and the downstream cutter is driven,
The sewing thread of the hem may be cut by the downstream cutter between the adjacent pair of fabrics.

The cutter is arranged at the downstream position of the sewing machine head, and the upstream and downstream photosensors are arranged at the upstream and downstream sides of the cutter. When it exceeds the installation position, it is detected by the downstream photo sensor, and the cutter is driven,
Hem sewing threads are cut by a cutter between adjacent pairs of fabrics. After that, when the front end of the later fabric reaches the installation position of the upstream photo sensor, it is detected by the upstream photo sensor, the cutter is driven, and the sewing thread of the hem is cut again between the fabrics of the adjacent pair. Is also good.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.

In FIG. 1, this is a hem triple winding sewing machine in which three hems 2 of a cloth 1 such as a pocket mouth, pajamas, cuffs and the like are wound and sewn together. Have. The three-wind former 3 is for guiding the hem 2 of the fabric 1 and winding it three times. The sewing head 4 is for sewing the hem 2 wound three times. Then, many doughs 1 are sequentially sent to the three-wind former 3 and the sewing head 4.

Further, in this hem triple winding sewing machine, endless upper and lower belts 5 and 6 are used for a conveyor for feeding each fabric 1, and as shown in FIG. , 6 are opposed in the vertical direction. Further, the upper and lower belts 5 and 6 are driven by the drive motor 7, and each fabric 1 is sandwiched between the upper and lower belts 5 and 6, and each fabric 1 is sent by the upper and lower belts 5 and 6. .

Further, the upper and lower belts 5, 6 have one side edge 8 close to each other, but the upper belt 5 has a width smaller than that of the lower belt 6, and the other side edge 9 has a smaller width. Is located near the center of the lower belt 6. On the other hand, the three-wind former 3 is an elongated sleeve.
The sewing machine head 4 has a slit and extends along the adjacent side edges 8 of the upper and lower belts 5 and 6, and the sewing machine head 4 is disposed at a downstream position of the three-winding former 3. Therefore, each dough 1
Is sandwiched between the upper and lower belts 5 and 6, and when each fabric 1 is fed by the upper and lower belts 5 and 6, the hem 2 passes through the slit of the three-wind former 3 and passes through the slit of the three-wind former 3. The hem 2 of the fabric 1 is guided by the three-roll former 3, deformed, and wound three times. Thereafter, the hem 2 is sewn together by the sewing head 4.

Accordingly, in this hem triple winding sewing machine, when a large number of cloths 1 are sequentially sent to the triple winding former 3 and the sewing head 4, each cloth 1 is sandwiched between the upper and lower belts 5, 6. , Upper and lower belt 5,
6, each dough 1 is sent. Therefore, each dough 1 can be accurately sent, and even if each dough 1 is sent at a high speed, the dough does not shift. As a result, it is possible to arbitrarily increase the speed of the hem triple winding sewing machine. When the hem 2 of the fabric 1 is guided, deformed, and wound three times by the three-turn former 3,
Even if a large deformation resistance occurs due to the material of the fabric 1, there is no problem because the fabric does not shift.

Further, in this embodiment, timing belts are used as the upper and lower belts 5, 6, respectively, and drive sprockets 10, 11 are provided on the upper and lower belts 5, 6, respectively. 5, 6 are engaged with the respective drive sprockets 10, 11. Further, a common drive motor 7 is connected to each drive sprocket 10, 11, and each drive sprocket 10, 11 is rotated by the common drive motor 7 to drive the upper and lower belts 5, 6. For example, the drive belt 7 connects the drive motor 7 and the drive sprocket 10, the gear 13 connects the drive motor 7 and the drive sprocket 11, and the drive motor 7, the timing belt 12 and the gear 13 drive each drive sprocket 1.
The upper and lower belts 5 and 6 are driven by rotation of 0 and 11. Therefore, the upper and lower belts 5 and 6 are driven by the common drive motor 7 to
It is not necessary to provide a drive motor for each of the upper and lower belts 5 and 6 to drive the upper and lower belts 5 and 6 individually, and the configuration is simple and the cost is low.

Further, a plurality of upper guide sprockets 14 are provided on the upper belt 5, and the upper guide sprockets 14 are arranged at intervals in the feed direction of the cloth 1, and the upper belt 5 engages with each upper guide sprocket 14. On the other hand, the lower belt 6 is arranged along the upper surface of the plate 15. Further, as shown in FIG. 3, a plurality of leaf springs 16 are provided on the upper belt 5, each leaf spring 16 is attached to the holder 17, and each upper guide sprocket 14 is attached to each leaf spring 16. Each upper guide sprocket 14 is supported by a leaf spring 16, and each leaf spring 16 acts on each upper guide sprocket 14, and each upper guide sprocket 14 is elastically urged toward the lower belt 6 and the plate 15. I have. Therefore, each upper guide sprocket 14 is pressed against the upper and lower belts 5, 6 and the plate 15, and the upper and lower belts 5, 6 are sandwiched between the upper guide sprocket 14 and the plate 15. As a result,
Each fabric 1 can be reliably sandwiched and sent between the upper and lower belts 5 and 6.

Further, the driving sprocket 10 is also used for the holder 1.
7 and supported by the cylinder 18
The holder 17 is provided between the carriage 7 and the carriage 19 and is connected to and supported by the cylinder 18 and the carriage 19.
Therefore, for example, when replacing the bobbin of the sewing machine head 4, the holder 18, the driving sprocket 10, the leaf spring 16 and the upper guide sprocket 14 can be pulled up by the cylinder 18, and the upper belt 5 can be lifted from the lower belt 6. Then, in that state, Carriage 1
9, the upper belt 5 can be displaced in its width direction, and the bobbin can be easily replaced.

FIG. 4 shows another embodiment. In this embodiment, the lower belt 6 has a plurality of lower guide sprockets 20.
Are provided, each lower guide sprocket 20 is opposed to each upper guide sprocket 14, and the lower belt 6 is engaged with each lower guide sprocket 20. And each leaf spring 16 acts on each upper guide sprocket 14,
Each upper guide sprocket 14 is elastically biased toward each lower guide sprocket 20. Therefore, each upper guide sprocket 14 is connected to the upper and lower belts 5,
6 and the lower guide sprocket 20,
Upper and lower belts 5,6 are sandwiched between upper and lower guide sprockets 14,20. Therefore, each fabric 1 can be reliably sandwiched and sent between the upper and lower belts 5 and 6.

In the embodiment shown in FIGS. 3 and 4, a plurality of piano wires may be provided on the upper belt instead of the leaf spring 16, and each upper guide sprocket 14 may be elastically biased by each piano wire. Each upper guide sprocket 14 may be elastically urged by another elastic urging means.

Further, in this hem triple winding sewing machine, the control device 21 controls the drive motor 7 and the sewing machine head 4
Are connected to the drive motor 7 by the control device 21.
Is controlled, the upper and lower belts 5 and 6 are intermittently driven at a constant pitch, and each fabric 1 is intermittently fed at a constant pitch. Further, the sewing machine head 4 is controlled by the control device 21, and every time the fabric 1 is intermittently fed, the needle of the sewing machine head 4 pierces the hem 2 wound three times and is pulled out. Therefore, the needle of the sewing head 4 can be smoothly pierced and extracted. Thus, the hem 2 wound three times is sewn.

Further, the photo sensor 22 is
And a control device 21 is connected to the photo sensor 22. When the fabric 1 is at the needle position of the sewing machine head 4, it is detected by the photo sensor 22, and based on the detection signal, the control device 21 The speed of the sewing machine head 4 is changed by 21 and the sewing machine head 4 is driven at a high speed. By this, the hem 2 wound three times is sewn. When the fabric 1 is not present at the needle position of the sewing head 4, it is detected by the photo sensor 22 and based on the detection signal, the controller 21 The head 4 is shifted, and the sewing head 4 is driven at a low speed. Therefore, even if it is sewn empty between each fabric 1,
This does not cause thread breakage of the sewing machine.

Further, in this embodiment, the starting end of the upper belt 5 is located downstream of the starting end of the lower belt 6,
The lower belt 6 is covered by the cover 23, thereby forming a supply position 24 for the cloth 1. Further, as shown in FIG. 5, at the supply position 24 of the dough 1, the ruler plates 25 are arranged and fixed in place, and each dough 1 is placed on the cover 23 and brought into contact with the side surface of the ruler plate 25. It can be supplied between the upper and lower belts 5,6. Further, at the supply position 24, for example, a window 26 is formed on the upper surface of the three-wind former 3, and the upstream and downstream photosensors 27 and 28 are arranged at an interval L0 in the supply direction of the dough 1. Winding former 3
The control device 21 is connected to the upstream and downstream photosensors 27 and 28. Even if the rear end of the supplied fabric 1 exceeds the installation position of the downstream photosensor 28, the next fabric When the front end of the first photo sensor 1 does not reach the installation position of the upstream photo sensor 27, the upstream and downstream photo sensors 2
It is detected by 7,28. Further, based on the detection signal, the upper and lower belts 5 and 6 and the sewing machine head 4 are controlled by the control device 21 and stopped. Then, the front end of the next dough 1 is
Is reached by the upstream photo sensor 27, the upper and lower belts 5, 6 and the sewing machine head 4 are controlled and driven by the controller 21 based on the detection signal, and the upper and lower Each fabric 1 is sent by the side belts 5 and 6. As a result, the interval L1 between the doughs 1 is limited. Therefore,
The distance L1 between the upstream and downstream photo sensors 27, 2
8, the number of blank stitches between the respective fabrics 1 is small when the respective fabrics 1 are sequentially sent to the three-winding former 3 and the sewing machine head 4.

In addition, in the case of the hem triple winding sewing machine, the cutter 29 is arranged at a position downstream of the sewing machine head 4. As shown in FIGS. 6 and 7, the cutter 29 is of a scissors type and includes an upper blade and a lower blade, and the position thereof corresponds to the hem 2 of the fabric 1, and the hem 2 is the upper blade and the lower blade of the cutter 29. Sent through and sent. Further, the photo sensor 30 is disposed downstream of the cutter 29, and the control device 21 is connected to the photo sensor 30. The rear end of the previous cloth 1 in the adjacent pair of cloths 1 exceeds the installation position of the photo sensor 30. The cutter 29 is driven by the control device 21 based on the detection signal, and the upper blade is lowered toward the lower blade. Therefore, the sewing thread 31 of the hem 2 is sandwiched between the upper blade and the lower blade of the cutter 29 between the pair of cloths, and the sewing thread 31 of the hem 2 is cut by the cutter 29. Then, cutter 29
The upper blade rises again, and the hem 2 of the fabric 1 is fed between the upper blade and the lower blade.

In the embodiment shown in FIG. 6, two sewing threads 3
The hem 2 of the fabric 1 is sewn together by 1. Therefore, the two sewing threads 31 are cut by the cutter 29, but the hem 2 of the fabric 1 may be sewn by one sewing thread 31, and the single sewing thread 31 may be cut by the cutter 29.

FIG. 8 shows another embodiment. In this embodiment, at the downstream position of the sewing head 4, the upstream and downstream cutters 32, 33 are arranged at intervals in the feeding direction of the fabric 1. Upstream and downstream cutters 32,
33 is the same as the cutter 29, and its position corresponds to the hem 2 of the fabric 1, and the hem 2 is the upstream and downstream cutters 3.
The paper is fed between the upper blade and the lower blade of 2,33. Further, an upstream photo sensor 34 is disposed upstream of the upstream cutter 32, a downstream photo sensor 35 is disposed downstream of the downstream cutter 33, and the control device 21 is connected to the upstream and downstream photo sensors 34, 35. ing. The front end of the next fabric 1 of the adjacent pair of fabrics 1 is the upstream photo sensor 3.
4 is reached by the upstream photo sensor 34, the upstream cutter 32 is driven by the control device 21 based on the detection signal, the upper blade descends toward the lower blade, and Between the pair of fabrics 1,
The sewing thread 31 of the hem 2 is sandwiched between the upper blade and the lower blade of the upstream cutter 32, and the sewing thread 3 of the hem 2 is
1 is disconnected. Thereafter, the upper blade of the upstream cutter 32 rises again, and the hem 2 of the fabric 1 passes between the upper blade and the lower blade,
Sent. Further, above the hem 2, a suction duct 36 is disposed between the upstream and downstream cutters 32 and 33, and after the sewing thread 31 is cut, the suction duct 36 is moved.
Is sucked into, and each dough 1 is sent in that state,
When the rear end of the previous fabric 1 exceeds the installation position of the downstream photo sensor 35, it is detected by the downstream photo sensor 35, and based on the detection signal, the downstream cutter 33 is driven by the control device 21, and The blade descends toward the lower blade, and the sewing thread 31 of the hem 2 is sandwiched between the upper blade and the lower blade of the downstream cutter 33 between the adjacent pair of fabrics 1, and the sewing thread 31 of the hem 2 is moved by the downstream cutter 33. Be cut off. After that, the upper blade of the downstream cutter 33 rises again, and the hem 2 of the fabric 1 is fed between the upper blade and the lower blade. Accordingly, in this case, first, the sewing thread 31 of the hem 2 is cut by the upstream cutter 32 near the front end of the fabric 1, and thereafter, the sewing thread 31 of the hem 2 is cut by the downstream cutter 33 near the rear end of the fabric 1. It can be cut precisely and the length of the cut end can be minimized.

In the embodiment shown in FIG. 9, the cutter 37 is disposed at the downstream position of the sewing machine head 4, the upstream and downstream photo sensors 38 and 39 are disposed at the upstream and downstream of the cutter 37, and the control device 21 is disposed at the upstream side. The downstream photosensors 39 and 39 are connected to the downstream and upstream photosensors 38 and 39, and when the rear end of the previous fabric 1 in the adjacent pair of fabrics 1 exceeds the installation position of the downstream photosensor 39, it is detected by the downstream photosensor 39. The cutter 37 is driven by the control device 21 based on the detection signal, and the sewing thread 31 of the hem 2 is cut by the cutter 37 between the adjacent pair of fabrics 1. Further, below the hem 2, a suction duct 40 is arranged on the downstream side of the cutter 37, and after cutting the sewing thread 31, it is sucked into the suction duct 40, and each fabric 1 is sent in that state, and thereafter, When the front end of the subsequent fabric 1 reaches the position where the upstream photo sensor 38 is installed, the upstream photo sensor 38 detects this, and the cutter 21 is driven by the control device 21 based on the detection signal, and the fabric of the adjacent pair is In one interval, the sewing thread 31 of the hem 2 is cut again. Therefore, first, the sewing thread 31 of the hem 2 is cut near the rear end of the fabric 1 by the cutter 37, and thereafter, the sewing thread 31 of the hem 2 is cut near the front end of the fabric 1. Cut,
The length of the cut end can be kept to a minimum.

Further, in this hem triple winding sewing machine, two receiving plates 41 are arranged at a downstream position of the lower belt 6. Further, the end of the upper belt 5 is located downstream of the end of the lower belt 6, and
After the cutting, the dough 1 is sent by the upper belt 5, and the dough 1 reaches each receiving plate 41. After that, each receiving plate 41
Swings around the support shaft 42 and opens downward, and the fabric 1
Falls on the stacker 43.

[0033]

As described above, according to the present invention, when a large number of fabrics 1 are sequentially sent to the three-winding former 3 and the sewing head 4, each fabric is placed between the upper and lower belts 5, 6. Each fabric is sandwiched and fed by the upper and lower belts. Therefore, each dough can be sent accurately, and even if each dough is sent at a high speed, there is no problem because the dough does not shift. As a result, it is possible to arbitrarily increase the speed of the hem triple winding sewing machine. When the hem 2 of the fabric is guided by the three-wind former and is deformed and wound three times, even if a large deformation resistance is caused by the material of the fabric, there is no problem because the fabric is not misaligned. The purpose of the term can be achieved.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a side view of the hem triple winding sewing machine of FIG. 1;

FIG. 3 is a partially enlarged view of FIG. 2;

FIG. 4 is a partially enlarged view showing another embodiment.

FIG. 5 is a partially enlarged view of FIG. 1;

FIG. 6 is an explanatory diagram of the cutter shown in FIG. 1;

FIG. 7 is a side view of the cutter of FIG. 6;

FIG. 8 is a side view showing another embodiment.

FIG. 9 is a side view showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fabric 2 Hem 3 Three winding former 4 Sewing head 5 Upper belt 6 Lower belt 7 Drive motor 10,11 Drive sprocket 14 Upper guide sprocket 15 Plate 16 Plate spring 20 Lower guide sprocket 22 Photosensor 24 Supply position 27 Upstream photosensor 28 Downstream Photosensor 29 Cutter 30 Photosensor 29 Cutter 31 Sewing Thread 32 Upstream Cutter 33 Downstream Cutter 34 Upstream Photosensor 35 Downstream Photosensor 37 Cutter 38 Upstream Photosensor 39 Downstream Photosensor

Claims (10)

[Claims] 1. A three-roll former for guiding a hem of a fabric and winding the hem three times, a sewing machine head for sewing the three-folded hem, and a large number of fabrics are sequentially sent to the three-wind former and the sewing head. In a hem triple winding sewing machine including a feed conveyor, an endless upper and lower belts are used for the feed conveyor, and the upper and lower belts are vertically opposed to each other, and the upper and lower belts are driven by a drive motor. Drive the belt,
A three-fold hem stitch sewing machine, wherein each of the fabrics is sandwiched between the upper and lower belts, and the fabrics are fed by the upper and lower belts. 2. A timing belt is used as each of the upper and lower belts, a drive sprocket is provided on each of the upper and lower belts, and the upper and lower belts are engaged with the respective drive sprockets, and The drive motor according to claim 1, wherein the drive motor is connected to the drive sprockets, and the drive sprockets are rotated by a common drive motor to drive the upper and lower belts. Twin-stitch sewing machine. 3. A timing belt is used as each of the upper belt and the lower belt, a plurality of upper guide sprockets are provided on the upper belt, and the upper guide sprockets are arranged at intervals in a feed direction of the cloth.
Engaging the upper belt with each of the upper guide sprockets, arranging the lower belt along an upper surface of a plate, and further comprising a plurality of leaf springs on the upper belt;
Elastic urging means such as a piano wire is provided, each of the elastic urging means acts on each of the upper guide sprockets, and each of the upper guide sprockets is elastically urged toward the lower belt and the plate. 3. The hem triple winding sewing machine according to claim 1. 4. A timing belt is used as each of the upper and lower belts, a plurality of upper guide sprockets are provided on the upper belt, and the respective upper guide sprockets are arranged at intervals in a feeding direction of the cloth.
The upper belt is engaged with each of the upper guide sprockets, a plurality of lower guide sprockets are provided on the lower belt, the lower guide sprockets are opposed to the upper guide sprockets, and the lower belt is The upper belt is engaged with each of the lower guide sprockets, and the upper belt is provided with a plurality of elastic urging means such as a leaf spring, a piano wire, and the elastic urging means is acted on each of the upper guide sprockets. The hem triple winding sewing machine according to claim 1, wherein the guide sprocket is elastically biased toward each of the lower guide sprockets. 5. A hem in which the upper and lower belts are intermittently driven at a constant pitch, the respective fabrics are intermittently fed at a constant pitch, and the needle of the sewing head is wound three times at each intermittent feed. 3. The hem triple-wound sewing machine according to claim 1, wherein the hem is pierced into the hem, pulled out, and stitched with the hem thus wound. 6. A photo sensor is disposed near a needle position of the sewing machine head. When the fabric is present at a needle position of the sewing machine head, the fabric sensor detects the cloth and drives the sewing machine head at a high speed. 3. The hem triple winding sewing according to claim 1, wherein when there is no cloth at the needle position of the sewing head, the photo sensor detects the cloth and drives the sewing head at a low speed. sewing machine. 7. In a supply position for supplying each of the doughs between the upper and lower belts, upstream and downstream photosensors are arranged at intervals in a supply direction of the dough,
Even if the rear end of the supplied dough exceeds the installation position of the downstream photo sensor, when the front end of the next dough does not reach the installation position of the upstream photo sensor, it is detected by the upstream and downstream photo sensors. 3. The three-fold hem stitch sewing machine according to claim 1, wherein the upper and lower belts and the sewing head are stopped. 8. A cutter is arranged at a downstream position of the sewing machine head, and a photosensor is arranged at a downstream side of the cutter, and a rear end of a previous fabric in an adjacent pair of fabrics exceeds the installation position of the cutter. The hem sewing machine according to claim 1, wherein the photo sensor detects the hem, drives the cutter, and cuts the sewing thread of the hem by the cutter between the adjacent pair of fabrics. Twin-stitch sewing machine. 9. At a downstream position of the sewing head,
Upstream and downstream cutters are arranged at intervals in the dough feeding direction, an upstream photosensor is arranged upstream of the upstream cutter, and a downstream photosensor is arranged downstream of the downstream cutter, When the front end of the later fabric of the fabric of the adjacent pair reaches the installation position of the upstream photosensor,
The upstream photo sensor detects it, drives the upstream cutter, and cuts the sewing thread of the hem by the upstream cutter between the adjacent pair of fabrics. When the position of the side photo sensor is exceeded, the downstream photo sensor detects it, drives the downstream cutter, and cuts the sewing thread of the hem by the downstream cutter between the fabrics of the adjacent pair. 3. The hem triple winding sewing machine according to claim 1, wherein 10. A cutter is disposed at a downstream position of the sewing machine head, and an upstream and a downstream photosensor are disposed at an upstream and a downstream of the cutter.
When the rear end of the previous fabric exceeds the installation position of the downstream photosensor, the downstream photosensor detects it, drives the cutter, and, between the fabrics of the adjacent pair, the sewing thread of the hem by the cutter. Then, when the front end of the later fabric reaches the installation position of the upstream photosensor, it is detected by the upstream photosensor, the cutter is driven, and the hem is placed between the adjacent pair of fabrics. The hem triple winding sewing machine according to claim 1, wherein the sewing thread is cut again.