JP2001300171A - Thread cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thread cutter which decreases the residual threads on a material to be sewn. SOLUTION: This thread cutter has a pair of thread cutters 14 and 33 which cut a needle thread 8 and a bobbin thread 50, at least one thread cutter of which is a heat type to pass current to heating elements 32 and 46 to cause the heat generation thereof and to cut one of the threads by bringing the elements into contact with one thread. The device has drawing out means 56 and 42 which draw the other thread out of the material to be sewn and a control section 76 for controlling respective mechanisms in such a manner that the other thread is cut by the other thread cutter after the one thread is cut by the one thread cutter and the other thread is drawn out of the material to be sewn by the drawing out means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thread cutting device,
In particular, the present invention relates to a thread cutting device having a thermal thread cutting device that cuts by applying a current to a heating element to generate heat and contact the yarn.

[0002]

2. Description of the Related Art Conventionally, as a thread cutting device of a sewing machine, a device that mechanically cuts a thread by inserting a thread between a moving knife and a fixed knife has been widely used. It is difficult to cut a thick thread by such mechanical cutting. Further, when cutting a yarn twisted with a plurality of single yarns, there is a problem that the yarns on the cut surface are frayed (separated) and the appearance of the cut portion is deteriorated.

[0003] For this reason, a thread cutting device that cuts by contacting the yarn with a heating element that generates heat by passing an electric current is used. For example, Japanese Utility Model Hei 3-76575, Tokuhei 7-
102270 Upper thread cutting device, Japanese Utility Model Publication No. 7-52700, lower thread cutting device,
114270 Upper and lower thread cutting device and the like. Such a thermal thread cutting device using Joule heat can cut a thick yarn, and can prevent fraying (split) between single yarns due to heat welding between the single yarns. Has features.

[0004]

However, in the conventional thermal thread trimming device, the end of the thread sewn on the workpiece always remains as a residual thread on the surface of the workpiece, and the remaining thread is long. Did not look good. In FIG. 16 (A) showing the state of the remaining yarn after thread trimming in the prior art, FIG.
Reference numerals c and 50c denote a needle thread and a lower thread which have been already sewn to the sewing object 12, respectively, and reference numerals 8b and 50b denote remaining threads remaining in the sewing object 12, respectively. Such a long remaining thread 8
The b and 50b remain because the upper thread and the lower thread are cut at the same time. For this reason, in a post-process, the remaining unnecessary yarn (remaining yarn) is cut with scissors or the like, or is melted by soldering.

Further, in the thermal thread cutting device, a fusing ball is formed at the end of the remaining yarns 8b and 50b by fusing, and there is an effect that the fusing ball prevents the thread from coming off the sewing object 12. However, since there is play 8D, 50D corresponding to the length of the remaining yarns 8b, 50b, when used as a sewn finished product as it is, the fusing ball portion gets caught on another object when coming into contact with another object, and conversely, the sewing thread This is accompanied by the danger that the yarn will easily come off. (Residual thread 8b, 50
b is pulled in the directions of arrows d1 and d2 in the figure. Therefore, the effect of preventing the thread sewn on the sewing object 12 from coming off is not perfect.

Further, when cutting the upper thread, the thread is trimmed as close as possible to the upper surface of the material to be sewn in order to reduce the amount of remaining thread after thread trimming. As a result, a variation in the thickness of the sewn object causes the heating element to come into contact with the sewn object and melts the sewn object, causing a fatal flaw as a sewn product. In addition, the amount of remaining yarn was different for each sewing process, and the appearance as a finished sewing was poor.

[0007] An object of the present invention is to provide a thread cutting device that can reduce the amount of residual thread on a sewing object.

Another object of the present invention is to provide a thread cutting device capable of completely preventing a thread from being sewn on an object to be sewn. It is still another object of the present invention to provide a thread cutting device that does not melt a workpiece. Still another object of the present invention is to provide a thread cutting device capable of keeping the remaining yarn amount constant.

[0009]

According to the first aspect of the present invention, there is provided a pair of thread cutting devices for cutting an upper thread and a lower thread, at least one of which is provided. In a thermal thread trimmer in which a device causes an electric current to flow through a heating element to generate heat and contact one of the yarns, the yarn trimmer cuts one of the yarns. It is characterized by comprising a control unit that controls each mechanism so that one thread is cut by a cutting device, the other thread is pulled out from the sewing object by a pulling unit, and then the other thread is cut by the other thread cutting device. Is provided.

The control unit cuts one thread by one thread cutting device, pulls out the other thread from the sewing object by the pulling means, and cuts the other thread by the other thread cutting device. By controlling the mechanism, one remaining thread is drawn into the sewing object when the other thread is pulled out from the sewing object. As a result, one of the remaining yarns can be shortened.

According to a second aspect of the present invention, in the thread cutting device according to the first aspect, the withdrawing means has a withdrawal amount adjusting means, and is capable of adjusting the withdrawal amount of the other thread to be extracted from the sewing object. Since there is a thread, it is possible to adjust the thread length necessary for the next sewing after cutting the thread. . According to the third aspect of the present invention, it is possible to prevent the material to be sewn from being melted and causing scratches.

According to the fourth aspect of the present invention, the third aspect is provided.
In the thread cutting device described above, the heating element includes a second non-heating member at a position facing the non-heating member. With such a configuration, it is possible to prevent the shape of the heating element from being collapsed and maintain a constant shape.

According to the fifth aspect of the present invention, the third aspect is provided.
In the thread cutting device according to the fourth aspect, the non-heating member includes a means for adjusting the gap, and by adjusting the gap, it is possible to adjust the amount of thread remaining on the sewing object.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

First, a first embodiment of the thread cutting device of the present invention will be described with reference to FIGS. The thread cutting device according to the present embodiment includes an upper heating device (thermal upper thread cutting device) shown in FIGS. 1 and 2, a lower heating device (thermal lower thread cutting device) shown in FIGS. The upper thread pulling device (upper thread pulling means) shown in FIG.

FIG. 1 is a front view of the upper heating device together with the sewing machine, and FIG. 2 is a perspective view of a main part of the upper heating device. FIG. 1 shows the apparatus standby position before and after thread trimming. The sewing machine head 2 is provided with a needle bar 4 below and an upper heating wire device 14 on a side surface. The needle bar 4 moves up and down in conjunction with a main shaft (not shown), and a needle 6 is fixed to the needle bar 4. The needle thread 8 is sewn to the sewing object 12 installed on the needle plate 10 by the vertical movement of the needle 6. The needle plate 10 has a needle hole 10a. In the drawings, only the needle plate 10 is shown in cross section.

The upper heating device 14 includes a heating rod driving cylinder 16.
Having. The heating rod driving cylinder 16 is used for the heating rod guide table 1.
8 and is fixed to a cylinder fixing plate 20. The cylinder fixing plate 20 is fixed to a side surface of the sewing machine head 2 via a hot wire device fixing stand 22.

The hot-wire drive cylinder 16 is connected to a hot-wire fixing stand 24 by a nut screw 16b at the tip of a cylinder rod 16a. Non-conductive heating wire rod fixing base 24
In the first embodiment, the upper ends 26a, 26a of the hot wire rods 26, 26 are fixed by upper hot wire cord fixing screws 28, 28, respectively. Further, the upper hot wire cord fixing screws 28, 28 have a function of fixing the upper hot wire cords 30, 30 to the hot wire rod fixing stand 24 and conducting the upper hot wire cords 30, 30 and the hot wire rods 26, 26. The upper heating wire cords 30, 30 are electric bundles for sending a current from a current source (not shown) to the heating wire rods 26, 26.

When the cylinder rod 16a expands and contracts due to the driving of the hot-wire drive cylinder 16, the hot-wire fixing stand 24 and the hot-wire rods 26, 26 fixed thereto reciprocate.

The hot wire rod guide base 18 is a non-conductive body and has a through hole through which the hot wire rods 26, 26 pass.
6 as a guide during reciprocating movement and the hot wire rods 26 and 2
6 has a function of preventing conduction from the outside to the outside.

The lower ends 26b, 26b of the hot wire rods 26, 26
, A strip-shaped upper heating wire (heating element) 32 is fixed.
The upper hot wire plate 32 is a current-carrying body having a higher electric resistance than the hot-wire rods 26, and generates red Joule heat when energized. The needle thread 8 can be melted by this heat.

FIG. 3 is a front view of the lower heating device, and FIG. 4 is a bottom view of the same. These figures show the apparatus standby positions before and after thread trimming. The lower heating device 33 has a heating plate driving cylinder 36 fixed to the lower surface of the needle plate 10 by a cylinder fixing plate 34. The hot wire drive cylinder 36 is connected to a hot wire fixing base 38 by a nut screw 36b at the tip of a cylinder rod 36a.

A lower thread pull-out plate (lower thread pull-out means) 42 is fixed to the hot-wire plate fixing base 38 by a screw (lower thread pull-out amount adjusting means) 40 and the lower hot-wire cord set screw 4 is fixed.
4 fixes a lower heating wire (heating element) 46 of the current-carrying body. The distal end 42a of the lower thread pull-out plate 42 has a V-shape. The fixed end 42b of the lower thread pullout plate 42 on the side fixed to the hot wire plate fixing base 38 is formed with a groove 42c, and the screw 40 is loosened to move the lower thread pullout plate 42 along the groove 42c. Thereby, the position of the distal end portion 42a can be adjusted. The lower heat wire cord set screw 44 fixes the lower heat wire cords 48, 48 to the hot wire plate fixing base 38 and conducts the lower heat wire cords 48, 48 and the lower heat wire plate 46. The lower heating wire cords 48, 48 are electric bundles for sending a current from a current source (not shown) to the lower heating wire plate 46.
The hot wire plate fixing base 38 is a non-conductive body, and prevents external power supply.

When the cylinder rod 36a of the hot-wire drive cylinder 36 expands and contracts, the hot-wire fixing base 38 and the lower thread pull-out plate 42 and the lower hot-wire plate 46 fixed thereto reciprocate.

The lower heating wire plate 46 is formed in a plate shape, and the cross-sectional area of only the tip end portion 46a is reduced. Since the distal end portion 46a has a large electric resistance, red Joule heat is generated when electricity is supplied. With this heat, the lower thread 50 can be melted.

Below the needle hole 10a of the needle plate 10, a bobbin case 52 containing a lower thread 50 necessary for sewing is installed. On the lower surface of the needle plate 10 near the needle hole 10a, a columnar thread cutting insulating plate 54 made of a non-conductive material and made of a heat-resistant material is fixed. The thickness of the thread cutting insulating plate 54 is formed to be smaller than the distance between the upper surface of the lower thread drawer plate 42 and the lower surface of the needle plate. That is, the tip of the lower thread pull-out plate 42 is in contact with the thread cutting insulating plate 54 so that the movement is not restricted.

When the cylinder rod 36a is extended by driving the hot wire drive cylinder 36, the lower thread drawer 42 and the lower hot wire 46 move. First, the V-shaped tip 42a of the lower thread drawer 42 is moved to the needle plate. 10 and bobbin case 52
During the sewing, the amount of the lower thread 50 necessary for the next sewing after thread trimming is drawn out from the bobbin case 52 in advance, and the lower thread 50 is guided to a predetermined position for thread trimming. Next, the tip 46a of the lower heating wire plate 46 abuts against the thread cutting insulating plate 54, and the lower thread 50 is cut by Joule heat.
For this reason, the distal end portion 46 a of the lower heating wire plate 46 has a shape that matches the outer shape of the thread cutting insulating plate 54. The amount of the lower thread 50 to be fed out for the next sewing can be adjusted by the screw 40.

FIG. 5 is a front view of the upper thread pulling-out device shown together with the sewing machine. This figure shows a state immediately before the thread is pulled out. The yarn fed out by the needle thread pulling device is a needle 6
And the needle thread 8a between the workpiece 12 and the sewing object 12. The lower thread 50b indicated by a broken line is a final thread remaining portion after the sewing is completed, and is a terminal portion of the lower thread 50 immediately after thread trimming, that is, a portion serving as a remaining thread.

The upper thread extracting device 56 is provided with the cylinder fixing plate 5.
8 has a needle thread pull-out cylinder 60 fixed to the side surface of the sewing machine head 2. The upper thread pull-out cylinder 60 is connected to the link arm connecting plate 62 by a nut screw 60b at the tip of a cylinder rod 60a. Cylinder rod 6
The stroke amount 0a can be adjusted by a stroke end stopper screw (upper thread withdrawal amount adjusting means) 60c, and thereby the amount of withdrawal of the needle thread 8a between the needle 6 and the workpiece 12 required for the next sewing is adjusted. Is done.

The link arm connecting plate 62 is connected to an upper thread pull-out arm 66 via a link arm 64. Link arm 64
Is composed of three arms 64a, 64b, 64c, and the starting force from the link arm connecting plate 62 is the arms 64a, 64b, 64c.
are transmitted in the order of c. An upper thread pull-out arm mounting base 68 is fixed to the lower end of the sewing machine head 2. The upper thread pull-out arm 66 has its upper end rotatably attached to the upper thread pull-out arm mounting base 68 by a step screw 68a, and the tip end 66a is shaped to be able to catch the needle thread 8. When the actuation force from the link arm 64 is transmitted to the upper thread pull-out arm 66, the upper thread pull-out arm 66 rotates around the step screw 68a, and captures and feeds out the needle thread 8a at the tip end 66a. As a result, the needle thread 8a is pulled out to secure an amount of the needle thread 8a necessary for the next sewing. As a result of feeding out the needle thread 8a in this manner, the lower thread 5 already knotted with the needle thread 8 will be described later.
The zero remaining thread 50b is pulled upward.

Next, the operation at the time of thread trimming by the thread trimming device having the above configuration will be described. FIG. 6 shows the upper heating device 14,
The procedure of the thread cutting operation by the lower heating device 33 and the upper thread drawing device 56 is shown, and the operation is performed from A to F in the figure. The operation will be briefly described with reference to FIG.
Is driven from the standby state (A) to return to the standby state (A) after the lower thread is pulled out and the lower thread is cut (B). Next, the upper thread drawing device 56 is driven from the standby state (C), and after the upper thread drawing (D) is performed, the state returns to the standby state (C). Finally, the upper heating device 14 is driven from the standby state (E) to perform the upper thread cutting (F), and then the standby state (E).
Return to

FIG. 7A is a block diagram of a control system according to the present embodiment. This control system is for controlling each mechanism (the upper heating wire device 14, the lower heating wire device 33 including the lower thread pulling plate 42, and the upper thread pulling device 56).
The control unit 78 includes a U72, a RAM 74, and a ROM 76. A start switch 80 of the sewing machine is connected to an input side of the control unit 78, and an output side for flowing a current to the hot wire rod driving cylinder 16, the upper thread drawing cylinder 60, the hot wire plate driving cylinder 36, and the upper hot wire plate 32. Transformer 82, transformer 8 for flowing current to lower heating wire plate 46
4. The sewing machine motor 86 is connected. When the operator presses the start switch 80, the sewing machine motor 86 rotates to start sewing.

FIG. 7B is a timing chart showing the timing of energizing the upper hot wire plate 32, the lower hot wire plate 46, the hot wire drive cylinder 36, the upper thread drawing cylinder 60, and the hot wire rod drive cylinder 16 in this embodiment. It is.
This chart corresponds to R which constitutes the control unit 78 of FIG.
The CPU 72 according to the program stored in the OM 76
Is performed by issuing a drive signal to each of the cylinders 16, 36, 60 or a heating signal to the transformers 82, 84.

The operation of the lower heating device 33 will be described in detail with reference to the block diagram of FIG. 7, a timing chart, and FIGS. First, during sewing of the sewing machine, the lower heating wire device 33 is in a standby state shown in FIGS. When the sewing is completed and the thread trimming signal is turned on as shown in FIG.
By transmitting a heating signal to the transformer 84, the lower hot wire plate 46 is energized through the lower hot wire cords 48, 48.
At the same time, electric power is supplied to the hot wire driving cylinder 36 so that the lower wire pull-out plate 42 and the lower hot wire 4
6 moves, and the lower thread 50 is moved to the leading end 4
It unfolds while capturing and guiding in 2a. Then, the lower thread 50 is abutted against the thread cutting insulating plate 54 as shown in FIG. FIG.
FIG. 9 is an enlarged view of a main part of FIG. 8. This drawing-out step is a step for ensuring the minimum length of the lower thread 50 necessary for the next sewing.

Next, the lower heating wire plate 4 already having Joule heat
6, the lower end 50a of the bobbin case 52 is cut off from the remaining yarn 50b on the cloth side and the lower yarn 50a on the bobbin case 52 by Joule heat. Then, FIG.
As shown at 0, the lower heating device 33 returns to the standby position. Finally, since the lower thread 50 is cut at the lower portion of the needle hole 10a, the needle plate 10
And remains as a residual yarn 50b. Further, at the end of each of the lower thread 50a on the bobbin case side and the remaining thread 50b on the needle side, a fused ball in which the thread is melted in a spherical shape is formed.

The operation of the upper thread pulling device 56 will be described with reference to the block diagram of FIG. 7, a timing chart, and FIGS.
2 will be described in detail. Fig. 6 Until the end of bobbin thread trimming
Is in the standby state shown in FIG. When the bobbin thread trimming operation is completed, the controller 78 energizes the upper thread drawing cylinder 60. Thus, the upper thread drawing operation shown in FIG. 11 is performed through the state where the upper thread is being drawn in FIG.
The needle thread 8a is caught and fed at the tip end 66a of No.6. As a result of this withdrawal, after the thread is cut, the needle thread 8a necessary for the next sewing remains on the needle side as described above.

The remaining thread 5 of the lower thread when the upper thread is pulled out
The state of 0b will be described with reference to FIG. FIG. 12A shows the formation of the stitch just before the needle thread 8a is unreeled upward, and the state of the remaining thread 50b immediately after the lower thread trimming.
FIG. 12B shows a state at the time of the upper thread pull-out operation in FIG. By pulling the needle thread 8a in the direction of the arrow (upward) by the tip 66a of the upper thread pull-out arm 66, the knot 70 between the needle thread 8 and the lower thread 50 is lifted,
As a result, the remaining thread 50b of the lower thread is drawn into the sewing object 12. Since a fused ball in a melted state is formed at the thread end of the bobbin thread 50, the fused ball serves as a stopper and is caught on the bottom surface of the sewing object 12.
To prevent it from falling upward. As described above, since the remaining thread 50b is absorbed into the sewing object 12, the remaining thread processing step of the lower thread 50 can be omitted.

The operation of the upper heating device 14 will be described in detail with reference to the block diagram of FIG. 7, a timing chart, and FIGS. As shown in FIG. 7, when the current supply to the upper thread drawing cylinder 60 is completed, the control
2, a heating signal is issued to energize the upper hot wire plate 32 and energize the hot wire rod drive cylinder 16. as a result,
The hot wire rods 26, 26 and the upper hot wire plate 32 move in the direction F in FIG. 13, and the upper hot wire plate 32 having Joule heat comes into contact with the knot portion 70 between the needle thread 8 and the lower thread 50 as shown in FIG. I do.
The needle thread 8 comes into contact with the upper heating wire plate 32, and as shown in FIG.
Is cut off by the side needle thread 8b. At this time, the needle thread 8 on the needle 6 side
A melted ball is formed at the thread end of the needle thread 8b on the side of the sewing object 12a. In particular, the needle thread 8 on the side of the workpiece 12
b is welded to the needle thread 8c already sewn on the sewing object 12 and the sewing object 12, and the remaining thread of the needle thread 8 is described in the same manner as described in the above description of the operation of the upper thread drawing device 56. Processing steps can be omitted.

As described above, in the present embodiment,
The upper heating device 14 and the lower heating device 33 are operated at different timings to cut the upper and lower yarns.
Before cutting the needle thread, the needle thread 8 is drawn out by the needle thread pull-out device 56 and the needle thread 8 is pulled out from the sewing object 12. Residual yarn can also be reduced. In particular, the remaining thread 50b remaining on the sewn object 12 after the lower thread 50 is cut by the upper thread drawing device 56 is sewn until the fusing ball portion at the end of the thread comes into contact with the surface of the sewn object 12 and becomes a stopper. If the thread is pulled into the object 12 and the remaining thread 50b is made invisible from the outside of the sewing object 12, the remaining thread 8b, 50b of the upper and lower threads can be reduced to almost zero.

FIGS. 16A and 16B are explanatory views showing the state of the remaining yarn after thread trimming according to the present embodiment in comparison with that of the prior art, wherein FIG. 16A shows the prior art, and FIG. 16B shows the state of the present embodiment. Indicates the status. In the prior art, there is a play 8D, 50D of the remaining threads 8b, 50b, so that there is a danger that the thread will easily come off as described above. On the other hand, in the present embodiment, such play can be completely eliminated or minimized, so that the danger can be avoided.

In the above, the operation procedure of each device is as follows. First, the lower thread is pulled out and cut by the lower heating device 33, then the upper thread is pulled out by the upper thread puller 56, and finally the upper thread is pulled out. Although an example in which the upper thread is cut by the hot wire device 14 has been described, instead of this, first, the upper thread is pulled out by the upper thread drawer 56, then the upper thread is cut by the upper hot wire device 14, and finally, the lower hot wire is cut. Device 3
3, the lower thread can be pulled out and the lower thread cut, and in this case, the same effect as in the above-described operation procedure can be obtained.

That is, after cutting the upper thread and before cutting the lower thread, the lower thread drawing plate 42 is driven by the lower heating wire device 33 so that the lower thread 50 is driven.
As a result, the lower thread 50 is pulled out downward. Therefore, the knot 7 between the needle thread 8 and the lower thread 50 in the sewing object 12 is
0 is drawn downward, and as a result, the remaining thread 8b of the upper thread is drawn into the sewing object 12. Since a fusing ball in a melted state is formed at the yarn end of the remaining yarn 8b,
The blown ball serves as a stopper, which is caught on the upper surface of the sewing object 12 and prevents the needle thread 8a from falling off. As described above, since the remaining thread 8b is absorbed into the sewing object 12, the remaining thread processing step of the upper thread 8 can be omitted.

Next, a second embodiment of the thread cutting device of the present invention will be described with reference to FIGS. The thread cutting device according to the present embodiment is different from the first embodiment only in the configuration of the upper heating device, and the configuration of the other devices is the same.

FIG. 17 is a diagram showing the upper heating device 114 of the present embodiment in a standby state before thread cutting, and FIG. 18 is a diagram showing the upper heating device 114 in a thread cutting state. The upper heating device 114 according to the first embodiment is different from the upper heating device 1 according to the first embodiment in that the hot wire thread cutting guide 116 is fixed to the upper heating wire plate 32 by the hot wire guide set screw 118.
4 and the other configuration is the same, and the description is omitted. The hot wire thread cutting guide 116 is
This is a current-carrying body having a lower electric resistance than that of the second member, and is a component for preventing the red heating portion of the upper hot wire plate 32 from directly touching the sewing object 12 at the time of thread cutting.

FIG. 19 is a view showing the hot-wire thread cutting guide 116, FIG. 20 is an enlarged view of a part of FIG. 18, and FIG.
(A) is a diagram viewed from the direction A in FIG. 20, and FIG. 21 (B) is a diagram viewed from the direction B in FIG. Heat wire thread cutting guide 11
Reference numeral 6 denotes a concave or V-shaped distal end portion 116a, and a long groove for fixing by a hot wire guide set screw 118 is formed at a fixed end 116b on the side fixed to the upper hot wire plate 32. The concave or V shape of the distal end portion 116a is
This is for guiding the needle thread 8a so as not to escape when it is hit against the needle thread 8a and melted. Further, the mounting position of the hot wire thread cutting guide 116 can be adjusted vertically by the long groove of the fixed end 116b and the hot wire guide set screw 118.

The operation of the upper heating device 114 having the above configuration will be described. First, the process proceeds from FIG. 17 in the thread cutting standby state to FIG. 18 in the thread cutting state. At that time hot wire thread cutting guide 1
16 is grounded on the sewing object 12 while guiding the needle thread 8a by the concave portion of the tip portion 116a.

At this time, as shown in FIG. 20, a gap H is secured between the red heating portion of the upper hot wire plate 32 and the workpiece 12 by the hot wire thread cutting guide 116, and the upper hot wire plate 32 and the workpiece are secured. Since the contact with the sewing object 12 is prevented, the sewing object 12 is not melted and scratched. The gap H can be adjusted according to the required amount of the remaining thread 8b remaining on the workpiece 12 by the hot wire thread cutting guide 11.
6 can be adjusted by the hot-wire guide set screw 118 to project downward from the upper hot-wire plate 32. For example, when it is desired to shorten the remaining yarn length, the hot wire thread cutting guide 116 is raised to reduce the gap H. Conversely, if it is necessary to increase the remaining thread length after thread trimming, the hot wire thread trimming guide 116 is lowered to increase the gap H.

Next, the upper heating wire 32 heated in red is
a, and the needle thread 8a is cut at the contact point 8d as shown in FIG. FIG. 22 (A) is an enlarged view of a part of FIG. 21 (B), and FIG. 22 (B) is a view showing the state of the sewing object 12 and the thread after the completion of the thread trimming. FIG.
In (A), the upper hot wire plate 32 is shown by a virtual line in order to clearly represent the contact point 8d. As a result, the aforementioned gap H
The remaining thread 8b and the fusing ball having a length corresponding to the above-mentioned length remain. By reducing the gap H, the thread 12b can be reduced to almost zero without melting the sewing object 12.

According to the present embodiment, even when there is a variation in the thickness of the workpiece 12, the constant gap H between the upper heating wire 32 and the workpiece 12 when the upper heating wire 32 cuts the thread. Is kept. For this reason, the upper heating wire plate 32 is
, And no flaw is caused by melting the sewing object 12. Further, the amount of the remaining thread 8b on the sewing object 12 is also constant corresponding to the gap H.

Next, a third embodiment of the thread cutting device of the present invention will be described with reference to FIGS. The thread cutting device according to the present embodiment is configured such that the hot wire thread cutting guide 11 is
6 and the second hot wire thread trimming guide 122 is moved to the side opposite to the hot wire thread trimming guide 116.
24. The other points are the same as those of the first and second embodiments, and the description thereof will be omitted. When configured as in this embodiment, the upper hot wire plate 32
Can be protected. In addition, it is possible to prevent the upper hot wire plate 32 from being deformed and maintain a constant shape.

When the second hot wire thread cutting guide 122 is moved in the direction P as shown in FIG. 24, the upper hot wire plate 32 is moved by the tip 122a of the second hot wire thread cutting guide 122.
23 is deformed so as to be pushed out in the M direction and the E direction, and the gap h between the red heating portion of the upper hot wire plate 32 and the sewing object 12 is smaller than the gap H before deformation in FIG. That is, the second hot wire thread cutting guide 122 allows fine adjustment of the amount of downward projection of the upper hot wire plate 32, and thus fine adjustment of the remaining yarn amount. In the case of the present embodiment, the upper heating wire 32 is made of a material that can be restored to the original shape, for example, spring steel.
FIG. 24B is a diagram viewed from the direction B in FIG.

Although the present invention has been described based on the embodiments shown in the drawings, the present invention is limited to these embodiments and can be variously modified. For example, the upper thread trimmer 1
Only one of the thread cutting device 4 and the lower thread cutting device 33 can be a thread cutting device using a heating element, and the other can be a mechanical thread cutting device.

[0053]

According to the first aspect of the present invention, the control section cuts one of the threads by one of the thread cutting devices, and
The other thread is pulled out of the sewing object by the pulling means,
By controlling each mechanism so that the other thread is cut by the other thread cutting device, one of the remaining threads is drawn into the sewing object when the other thread is pulled out from the sewing object. As a result, one of the remaining threads can be shortened, so that it is possible to omit the remaining thread processing such as cutting or melting by soldering the remaining thread and improve the appearance of the sewn product. it can.

According to the second aspect of the present invention, the pull-out means has the pull-out amount adjusting means, and the pull-out amount of the other thread drawn from the sewing object can be adjusted.
The thread length required for the next sewing after the thread is cut can be adjusted. .

According to the third aspect of the present invention, the non-heating member between the heating element and the sewing object maintains a gap between the sewing object and the heating element when the heating element contacts the thread. Therefore, contact between the heating element and the sewing object can be prevented. Therefore, it is possible to prevent the material to be sewn from being melted and damaged.

According to the fourth aspect of the present invention, since the heating element has the second non-heating member at a position facing the non-heating member, the heating element can be protected.
Further, it is possible to prevent the shape of the heating element from being collapsed and maintain a constant shape.

According to the fifth aspect of the present invention, since the non-heating member is provided with a means for adjusting the gap, it is possible to adjust the amount of thread remaining on the sewing object.

[Brief description of the drawings]

FIG. 1 is a front view of an upper heating device of a first embodiment of a thread cutting device according to the present invention.

FIG. 2 is a perspective view of a main part of FIG.

FIG. 3 is a front view of the lower heating device of the first embodiment.

FIG. 4 is a bottom view of the lower heating device.

FIG. 5 is a front view of the upper thread pulling device according to the first embodiment.

FIG. 6 is a diagram illustrating an operation procedure according to the first embodiment.

FIG. 7A is a block diagram of a control system according to the first embodiment, and FIG. 7B is a timing chart illustrating operation timing of each device according to the first embodiment.

FIG. 8 is a front view during operation of the lower hot-wire device of the first embodiment.

FIG. 9 is an enlarged view of a main part of FIG. 8;

FIG. 10 is a front view of the lower heating device of the first embodiment at the time of standby.

FIG. 11 is a front view of the needle thread pulling device according to the first embodiment in operation.

FIG. 12 is a diagram illustrating a state of the remaining yarn when the upper yarn is pulled out in the first embodiment.

FIG. 13 is a front view during operation of the upper heating device of the first embodiment.

FIG. 14 is an enlarged view of a main part of FIG.

FIG. 15 is a diagram illustrating a state of the upper thread cut by the upper heating device according to the first embodiment.

FIG. 16 is an explanatory diagram showing the state of the remaining yarn after thread trimming according to the first embodiment in comparison with that of the related art;
(A) shows the state of the art, and (B) shows the state according to the present embodiment.

FIG. 17 is a view showing the upper heating device of the second embodiment in a standby state before thread cutting.

FIG. 18 is a diagram illustrating a thread cutting state of the upper heating device of the second embodiment.

FIG. 19 is a view showing a hot wire thread cutting guide of the upper heating device of the second embodiment.

20 is an enlarged view of a part of FIG. 18;

21 (A) is a view as viewed from a direction A in FIG. 20,
(B) is a diagram viewed from the direction B in FIG. 20.

22 (A) is an enlarged view of a part of FIG. 21 (B), and FIG. 22 (B) is a view showing a state of a sewing material and a thread after thread trimming is completed.

FIG. 23 is a view showing an upper heating device of a third embodiment of the thread cutting device of the present invention.

24A and 24B are diagrams illustrating the upper heating device according to the third embodiment, wherein FIG. 24A is a diagram viewed from the same direction as FIG. 23, and FIG. 24B is a diagram viewed from the B direction of FIG. .

[Explanation of symbols]

H, h Clearance between the sewing object and the heating element
2 sewing machine head 4 needle bar 6 needle 8
Needle thread 8D Play of the needle thread remaining on the sewing product 8a
Needle thread on needle side 8b Needle thread (remaining thread) 8c Needle thread sewn 8d Point where upper hot wire plate contacts 10 Needle plate 1
0a Needle hole 12 Sewing object 14 Upper heating wire device (thermal upper thread cutting device) 16 Hot wire rod driving cylinder 18 Hot wire rod guide stand 20 Cylinder fixing plate 22 Hot wire device fixing stand 24 Hot wire rod fixing stand 26,26 Hot wire rod 30, Reference Signs List 30 upper heating wire cord 32 upper heating wire plate (heating element) 33 lower heating wire device (thermal lower thread cutting device) 34 cylinder fixing plate 36 heating wire plate driving cylinder 38 heating wire plate fixing base 40 screw (lower thread drawing amount adjusting means) 42 lower Thread pulling plate (lower thread pulling means) 46
Lower heating wire plate (heating element) 46a Tip 48,48 Lower heating wire cord
50 bobbin thread 50a bobbin side bobbin thread 50b residual thread 50c
Sewing of lower thread 50D Play of lower thread remaining on the sewing product 52D
Bobbin case 54 Thread cutting insulating plate 56 Needle thread pull-out device (needle thread pull-out means) 58 Cylinder fixing plate 60 Needle thread pull-out cylinder 60c Stroke end stopper screw (needle thread pull-out amount adjusting means) 62 Link arm connecting plate 64 Link arm 6
6 Upper thread pull-out arm 70 Knot part 78 Control part 1
14 Upper hot wire device 116 Hot wire thread cutting guide 118 Hot wire guide set screw 122 Second hot wire thread cutting guide 124 Hot wire guide set screw

Claims (5)

[Claims] A pair of thread cutting devices for cutting an upper thread and a lower thread, wherein at least one of the thread cutting devices applies a current to a heating element to generate heat and contact one of the threads. And a pull-out means for pulling out the other thread from the workpiece, and one thread cutting device for cutting one thread and pulling out the other thread from the workpiece by pull-out means. A thread cutting device, comprising: a control unit that controls each mechanism so that the other thread is cut by the other thread cutting device. 2. The thread trimming device according to claim 1, wherein said pulling-out means has a pulling-out amount adjusting means, and is capable of adjusting a pulling-out amount of the other thread to be pulled out from the sewing material. apparatus. 3. A thread cutting device for cutting by making an electric current flow through a heating element and causing the heating element to come into contact with a thread, wherein a non-heating member is provided between the heating element and the sewing object. A thread cutting device characterized in that a gap is maintained between a sewing object and a heating element at the time of contact between a body and a thread, thereby preventing contact between the heating element and the sewing object. 4. The thread cutting device according to claim 3, wherein the heating element has a second non-heating member at a position facing the non-heating member. 5. The thread cutting device according to claim 3, wherein the non-heating member has a means for adjusting the gap, and adjusting the gap to adjust the amount of thread remaining on the sewing object. A thread cutting device characterized in that it is possible.