JP2002336583A - Thread cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thread cutter capable of preventing rupture of a thread cutting medium. SOLUTION: This thread cutter has heating elements 11a, 21a, and 31a having a heating part heated by an electric current supplied from a power source, a heating element holding member 11 having integrally or separately the heating elements, and a moving means 6 for moving thread 7a or the heating elements in the mutually abutting direction of both, and cuts the thread by heat of the heating elements, and has switch means 11b and 11c for allowing the electric current to flow to the heating elements by engaging the heating elements with the thread.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thread cutting device, and more particularly to a thread cutting device that cuts a heating element by causing an electric current to flow and contacting the thread.

[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 sandwiching the thread between a moving knife and a fixed knife is widely known. In such a mechanical cutting method, it is difficult to cut a thick thread,
A thermal thread cutting device using Joule heat (hot wire thread cutting device) has been applied as a remedy because the cut portion of the yarn tends to be loose or frayed.
7-75691, actual fair 7-52700, JP-A-11-
114270).

A thread cutting device proposed by the present inventor in Japanese Patent Application No. 2000-123785 for the purpose of improving such a thermal thread cutting device will be described with reference to FIGS. 11 and 12. FIG. The hot wire plate 1 is a thread cutting medium (heating element) heated by energization. The tip 1a of the hot wire plate 1 is a portion where the electric resistance is the highest and is a thread cutting portion that generates Joule heat. By this heat, the lower thread 7a can be melted and cut or burned off.

The lower thread pull-out plate 2 is a member for pulling out a thread necessary for the next sewing before thread cutting in advance. The lower thread catching portion 2a at its tip catches the lower thread 7a to the tip 1a of the hot wire plate 1. Induce. The lower thread drawer plate 2 is fixed to a hot wire plate fixing base 3 made of an insulating member. The lower heating wire cord 4 is an electric bundle for passing an electric current to the heating wire plate 1 and is transmitted from a transformer (not shown). The hot wire 1 and the lower hot wire cord 4 are fixed to the hot wire fixing base 3 by fixing screws 5. The fixing screw 5 itself becomes an electric conductor.

[0005] On the back side of the needle plate 10, a hot-wire plate driving cylinder 6 is provided.
And the thread cutting insulating plate 8 is fixed. The rod 6 a of the hot-wire drive cylinder 6 is connected to the hot-wire fixing base 3. The hot wire plate 1 and the lower thread pull-out plate 2 fixed to the hot wire plate fixing base 3 are integrally moved by the hot wire drive cylinder 6 in the direction of arrow AB in the figure at the time of thread cutting.

The bobbin case 7 is a case in which a bobbin thread 7a necessary for sewing is stored, and is incorporated in a sewing machine head (not shown). The thread cutting insulating plate 8 is a heat-resistant insulating member against which the heating wire 1 is abutted, and a cut portion of the lower thread 7 a is sandwiched between the thread cutting insulating plate 8 and the heating wire 1. A sewing object 9 to be sewn with the lower thread 7a is arranged on the needle plate 10. The needle plate 10 is formed with a needle hole 10a which is a thread path hole for supplying the lower thread 7a to the sewing product 9.

[0007] In the yarn cutting device having the above configuration,
After the sewing is completed, first, the energization of the hot wire plate 1 is started, and the hot wire drive cylinder 6 is operated to extend the rod 6a, so that the hot wire plate 1 and the lower thread pull-out plate 2 move in the direction A in the drawing to release Joule heat. The held tip portion 1a abuts the lower thread 7a captured and guided by the lower thread catching portion 2a on the lower thread drawer plate 2 against the thread cutting insulating plate 8. The lower thread 7a sandwiched between the distal end portion 1a and the thread cutting insulating plate 8 is melted and cut or burnt off. After the completion of the thread cutting, the rod 6a contracts and returns in the direction B, and the hot wire plate 1 and the lower thread pull-out plate 2 reach the standby position.

[0008]

By the way, the melting point temperature of the thread cutting medium of the thermal thread cutting device is about 1,400 ° C., whereas the melting point temperature of a general thread is 260 ° C. or less. Then, the temperature of the thread cutting medium increases as the energizing time increases, and reaches the melting point temperature of about 1,400 ° C. Therefore, as a thermal thread cutting device, the thread cutting medium is 5
It is usual to cut the yarn by setting the energizing time so as to be 00 ° C. or less.

However, the melting point temperature of the yarn differs depending on the type of yarn (for example, Kevlar yarn does not melt unless it is 430 ° C. or higher). Further, as the yarn becomes thicker, the temperature of the thread cutting medium needs to be set higher. For this reason, depending on the market, depending on the type and thickness of the yarn, the energizing time is often set to be long so that the temperature of the thread cutting medium is 500 ° C. or more. There was something to do.

[0010] Such a break is caused by the following reason. By increasing the energization time, the heating temperature of the medium inevitably rises, and thread cutting can be easily performed regardless of the type and thickness of the thread, but at the same time, the medium sharply rises to near the melting point temperature, Heats red and becomes soft. In this state, since the pressing force is applied directly to the yarn, a load is applied to the portion, and as a result, the medium itself breaks. As described above, in the thermal thread cutting device, as the energizing time to the thread cutting medium becomes longer,
The medium itself is likely to break (melt).

Also, in consideration of the certainty of thread trimming, since an extra energizing time is provided before and after thread trimming, the energizing time is set longer than the time required for actual thread trimming. In addition to the wasteful energizing time, the temperature of the thread trimming medium has further increased remarkably.

Therefore, in order to avoid a sharp rise in temperature, a medium is prepared in which the electric resistance at the thread cutting end is reduced, that is, the cross-sectional area of the metal is increased to reduce the temperature rise rate and increase the strength of the medium itself. And used them according to the type and thickness of the yarn. However, it has been troublesome to prepare many types of media and replace them each time.

An object of the present invention is to provide a thread cutting device which can prevent the breakage of the thread cutting medium (heating element) as described above. Another object of the present invention is to eliminate the trouble of exchanging a medium (heating element) in accordance with the type and thickness of a thread, or exchanging a new medium when the medium is broken or damaged. The object of the present invention is to provide a thread cutting device capable of performing the above-mentioned.

[0014]

According to the present invention, there is provided a heating element having a heating portion for generating heat by a current supplied from a power supply, and a heating element having the heating element integrally or separately. A yarn cutting device that includes a body holding member, and a moving unit that moves the yarn or the heating element in a direction in which the two contact each other, wherein the heating element engages with the yarn Thus, there is provided a thread cutting device, comprising: a switch means for causing a current to flow through the heating element. The heating element may have a buffering property.

Further, according to the present invention, a heating element having a heating section which generates heat by a current applied from a power supply, a heating element holding member having the heating element integrally or separately, a thread or the heating element are provided. Moving means for moving the two in a direction in which they contact each other, wherein the yarn is cut by the moving means onto the heating element holding member so that the heating element can be detached. Or a switch means for arranging a plurality of heating elements in the moving direction of the heating elements and causing current to flow through the heating elements by engaging at least the heating elements in the second and subsequent rows with the yarn. A thread cutting device is provided.

The plurality of heating elements may include heating elements having different electric resistance values. Preferably, the heating element holding member has a cutout or a groove between each of the plurality of heating elements. More preferably, there is provided an engaging body formed of an insulator while engaging with the thread so as to sandwich the thread between the heating element and the thread when cutting the thread.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a thread cutting device according to the present invention. First, the external configuration of the thread cutting device according to the first embodiment will be described with reference to FIG. FIG. 1 shows a thread cutting device according to the present embodiment.
The difference from the thread cutting device shown in FIGS. 1 and 12 is that the device has a structure of a hot wire plate heated by energization and an insulating plate 12 with a fitting groove for preventing lateral displacement of the hot wire plate. .

That is, the separating hot wire plate 1 made of spring steel
Thread cutting tip (heating element) 11a of 1 (heating element holding member)
Is a portion where the electric resistance is the highest, and is a thread cutting portion that generates Joule heat. A hot wire plate separating portion (switch means) 11b is formed near the thread cutting tip portion 11a, and the hot wire plate separating portion is formed. The section 11b keeps the separated hot wire plate 11 separated while the lower hot wire 11 is not in contact with the lower thread 7a, and the separate hot wire plate 11 is not energized during that time.

The insulating plate 12 fixed to the lower thread pull-out plate 2 by the set screw 12a has a fitting groove 12b for supporting the separation type hot wire plate 11, and the separation type hot wire plate 11 12b to prevent lateral displacement (vertical direction in FIG. 1A, lateral direction in FIG. 1B). The other components are the same as those in the example shown in FIGS. 11 and 12, and thus are denoted by the same reference numerals, and description thereof will be omitted.

Next, a control system according to the present embodiment will be described with reference to FIG. This control system is for controlling the thread cutting device, and includes a CPU 13, a RAM 14,
The control unit 16 includes a ROM 15. A start switch 17 of the sewing machine is connected to an input side of the control unit 16, and a hot-wire drive cylinder (moving means) is connected to an output side.
6, the transformer 18 and the sewing machine motor 19 are connected. When the operator turns on the start switch 17, the sewing machine motor 19 rotates to start sewing.

In the thread cutting device shown in FIGS. 11 and 12, transformers are prepared for the lower hot wire plate 21 and the upper hot wire plate 20 (not shown) for cutting the upper plate above the needle plate. In the embodiment, the upper and lower threads can be cut by only one transformer 18. That is, in FIG. 2A, the separation type hot wire plate 11 is connected to the transformer 18 via the lower hot wire cord 4, and the upper hot wire plate 20 for cutting the upper thread is also connected.

FIG. 2B is a timing chart showing the timing of energizing the separation type hot wire plate 11 and the hot wire drive cylinder 6 in this embodiment. This chart shows that the CPU 13 issues a drive signal to the hot-wire plate driving cylinder 6 in accordance with a program stored in the ROM 15 constituting the control unit 16 in FIG.
This is carried out by issuing an energization signal to. In the thread cutting device of FIGS. 11 and 12, the upper heating wire plate 20 (not shown) is energized and heated after the lower thread cutting is completed. And the upper heating wire plate 20 are energized simultaneously. Since the upper heating wire 20 has a low electric resistance and a low heating rate, the upper heating wire 20 is preheated at the time of cutting the lower thread. After the lower thread trimming is completed, Joule heat required for thread trimming has already been generated in the upper heating wire plate 20, so that the thread trimming of the upper and lower threads can be performed faster than the thread trimming apparatus of FIGS.

Next, the operation of the lower thread cutting device according to this embodiment will be described. First, while the sewing machine is being sewn, the rod 6a of the hot wire drive cylinder 6 is contracted,
And the separation type hot wire plate 11 is located in the direction B in FIG.
In standby state. When the sewing is completed and the thread trimming signal is turned ON, the control unit 16 sends an energizing signal to the transformer 18 to energize the lower heating wire cord 4 and the upper heating wire plate 20. At this time, since the separation type hot wire plate 11 is in a state of being separated by the hot wire plate separation portion 11b, no current flows through the separation type hot wire plate 11 and no heating is performed. However, the upper heating wire plate 20 is heated. At the same time, the hot wire drive cylinder 6 is also energized and its rod 6a
The lower thread drawer plate 2 and the separation type hot wire plate 11 move in the direction A in FIG. While paying out. This bobbin thread pull-out step is a step for previously securing a minimum length of the bobbin thread 7a necessary for the next sewing.

Next, as shown in FIG. 3, the leading end 11a comes into contact with the lower thread 7a captured and guided by the lower thread catcher 2a of the lower thread drawer plate 2, and the lower thread 7a is separated by the thread cutting insulating plate 8 Hit it. That is, for the first time, the thread cutting tip 11a comes into contact with the lower thread 7a, but the hot wire separator 11b comes into contact with the lower thread 7a in a pressed manner.
(Point C in FIG. 2B). This energization heats the thread cutting tip 11a to generate Joule heat, and the lower thread 7a sandwiched between the thread cutting tip 11a and the thread cutting insulating plate 8.
Is melted or burnt off and cut.

As described above, the thread cutting tip 11a is connected to the lower thread 7a.
Since the heating is started by contact with the thread, the heating time of the thread trimming tip 11a is the minimum time required for thread trimming, and it is possible to prevent the temperature of the thread trimming medium from rising and to reduce the thread trimming tip. 11a does not hit the lower thread 7a in a heated red color and becomes soft, so that the effect of preventing breakage of the thread cutting medium can be obtained. it can. Further, the hot wire separating portion 1 of the separation type hot wire 11 made of spring steel.
1b plays a role of absorbing the impact when the lower thread 7a comes into contact, thereby reducing the load due to direct impact, thereby further obtaining the effect of preventing the thread cutting medium itself from breaking.

After the cutting of the lower thread 7a is completed, the power supply from the control unit 16 to the hot wire drive cylinder 6 is stopped, the rod 6a contracts, and the lower thread pull-out plate 2 and the separation type hot wire 11 move in the direction B at the standby position. Return. At the same time, the thread cutting tip 11a is separated from the thread cutting insulating plate 8, and the separation type hot wire 11 is again in the separated state, so that the power supply to the separation type hot wire 11 is automatically cut off (FIG. 2B). D point).

Thereafter, an upper thread trimming step is performed, and the energization signal to the transformer 18 is stopped. The upper heating wire plate 20
Has a structure in which the heating rate is slower than that of the separation type hot wire plate 11 (the medium itself has a large cross-sectional area and low electric resistance).

Next, a thread cutting device according to a second embodiment of the present invention will be described with reference to FIGS. In the separation type hot wire plate 11 of the first embodiment, only one hot wire plate separating portion 11b is provided, but the thread cutting device according to the present embodiment is provided with a plurality thereof. The illustrated example shows an example in which two hot wire plate separation units are provided. That is, a first hot wire separating portion 21b is formed in the vicinity of the first thread cutting tip portion 21a of the separating hot wire plate 21, and the first hot wire separating portion 21b is formed behind the hot wire separating portion 21b. Behind)
Are further formed with a second thread cutting tip portion 21c and a second hot wire plate separating portion 21d.

The total length of the separate hot wire plate 21 is the first
It is made longer than the separation type hot wire plate 11 of the embodiment, a long groove 21f is formed at the rear end thereof, and furthermore, between the first thread cutting tip 21a and the second thread cutting tip 21c. A notch (notch or groove) 21e is formed. By applying a force to the vicinity of the distal end of the separation-type hot wire plate 21, the hot plate 21 can be cut at the cut portion 21e.
Further, the fixing screw 5 and the long groove 21f for fixing the separation-type hot wire plate 21 to the hot-wire plate fixing base 3 enable the position of the separation-type hot wire plate 21 to be adjusted by sliding forward and backward.

The thread cutting operation of this embodiment is the same as that of the first embodiment. At the time of thread cutting, as shown in FIG. 5, the second hot-wire separating portion 21d is separated from the surroundings. Only the first hot wire plate separating portion 21b is in contact with the first hot wire separating portion 21b, so that electric heating can be performed.

When the first thread cutting tip 21a is broken, the second thread cutting tip 21c can be used. That is, the cutting portion 21e of the separation type hot wire plate 21 is cut by applying a bending load to the first thread cutting tip portion 21e.
After removing a, the separable hot wire plate 21 is slid along the insulating plate 12 using the fixing screw 5 and the long groove 21f, and is advanced until the second thread cutting tip portion 21c reaches a predetermined position. As a result, the state shown in FIG.
Can be used as a thread cutting portion that generates Joule heat.

In this embodiment, when the first thread cutting tip 21a and the second thread cutting tip 21c have the same sectional area (the same resistance value), the same type of lower thread 7a is used. Under the sewing conditions, the first thread cutting tip 21
Even if a is broken, the second hot wire
Can be used. Moreover, there is no need to replace the hot wire plate, and it is only necessary to loosen the fixing screw 5 and slide the separate hot wire plate 21. Therefore, the setting can be performed easily and quickly, so that time loss due to breakage can be prevented as much as possible. When three or more thread cutting end portions and the hot wire plate separating portion are provided, each thread cutting end portion can be used in order. Further, the position adjustment of the separation-type hot wire plate 21 is not limited to the one by sliding / fixing the mounting position using the long hole 21f, but a configuration in which the longitudinal movement stroke of the moving means is changed or a plurality of fixing positions are provided. It may be.

On the other hand, in the present embodiment, when the cross-sectional area of the second thread cutting tip 21c is larger than that of the first thread cutting tip 21a (the resistance value is reduced to reduce the heating rate), The thread cutting tip can be selected according to the resistance value suitable for the lower thread 7a to be cut. When a yarn having a relatively high melting point temperature or a thick yarn is used, the first thread cutting tip portion 21a is likely to be broken due to excessive heating in order to prolong the heating time. Therefore, in order to prevent the breakage, the cross-sectional area is increased to alleviate the temperature rise and the strength of the medium itself is increased, so that the break-resistant second thread cutting tip 21c can be used. . That is, when a normal thread is used, the first thread cutting tip 21a is used,
When a yarn having a relatively high melting point or a thick yarn is used, the separation-type hot wire plate 21 is cut at the cut portion 21e to remove the first thread cutting tip portion 21a, and the second thread cutting tip portion 21 is removed.
Use c. As described above, even if different hot wire plates are not prepared in advance in accordance with the type of yarn, it is possible to cope with one separate hot wire plate 21. Also in this case, it is not necessary to replace the hot wire plate, and it is only necessary to loosen the fixing screw 5 and slide the separate hot wire plate 21. Therefore, the setting can be performed easily and quickly, so that the time loss due to the replacement can be prevented as much as possible. .

In the case where the cross-sectional areas of the first thread cutting tip 21a and the second thread cutting tip 21c are made the same or different, the stock of the normal hot wire sheet is reduced. In the event that the thread has been lost, the second, third or subsequent thread cutting end can be used as a substitute in an emergency.

Next, a thread cutting device according to a third embodiment of the present invention will be described with reference to FIG. In this embodiment, the sectional shape of the thread cutting tip 31a of the separation type hot wire plate 31 is changed. The other points are the same as the first embodiment. (B) is a YY sectional view of (A). For comparison, FIG. 8A shows a tip 1a of the hot wire plate 1 by the thread cutting device shown in FIGS. 11 and 12, and FIG.
It is shown in (B).

In each of the cross-sectional shapes shown in FIGS. 7B and 8B, the lengths in the direction in which the hot wire plates 1 and 31 move (AB direction) are a1 and a31, and the lengths in the direction perpendicular thereto are a1 and a31. t1, t
Assuming that the sectional area is the same, a31 × t31 =
a1 × t1, but t31> t1. t1, t
Since 31 is the thickness of the surface where the thread cutting tips 1a and 11a are in contact with the lower thread 7a, the area of contact with the lower thread 7a is better for the separation type hot wire plate 31 of the present embodiment in FIG. 8 is wider than the example. Since the cross-sectional areas are the same, the heating rates are the same.

At the time of heating the thread trimming, the tip of the thread trimming becomes soft, so that the thread gradually deforms along the shape of the lower thread 7a each time the thread trimming is repeated. The tip portion 1a of the hot wire plate 1 of the thread cutting device shown in FIGS. 11 and 12 is deformed as shown in FIG. 9 (A) and does not hinder the thread cutting. Time was a bit late.

Therefore, in the present embodiment, the modification is used. That is, by reducing the plate thickness a31 in the direction (AB direction) in which the hot wire plate 31 moves,
As shown in FIG. 9 (B), the lower thread 7a
Is deformed so as to surround the outer periphery of the thread cutting end 31a. According to the present embodiment, the contact area between the lower thread 7a and the thread cutting tip 31a is increased, and faster and more reliable thread cutting can be performed.

The thread cutting device of the present invention has been described based on the embodiments shown in the drawings. However, the present invention is not limited to these embodiments and can be variously modified.

For example, the heating element according to the present invention is constituted by the distal end portions 11a, 21a, 31a of the separation-type heating wire plates 11, 21, 31 and the separation-type heating wire plates 11, 21 having the heating element integrally with the heating element holding member. , 31, but the heating element can be formed separately from the heating element holding member. Further, in the present invention, the switch means for causing a current to flow through the heating element by engagement with the thread is constituted by the hot wire plate separating portions 11b, 21b, 31b, but may be constituted by a separate component from the separate hot wire plate 11. it can.

The tips 11a, 21a and 31a are moved in the direction in which they come into contact with the lower thread 7a.
You may move in the direction which contacts 1a, 21a, 31a.

Further, in the second embodiment, an example is shown in which two switch means, that is, a first hot wire plate separation portion 21b and a second hot wire plate separation portion 21d are provided.
As shown in FIG. 7, the first row of heating elements, that is, the first thread cutting tip 21a engages with the yarn, and thereby the tip 21a
The switch is not provided with a switch means for causing a current to flow through the second row of heating elements, that is, a switch for allowing a current to flow through the second thread cutting tip 21c by engaging with the thread. You may comprise so that only the means 21d may be provided. In the case where a thread cutting tip is provided in the third and subsequent rows, switch means corresponding to each thread cutting tip is provided.

[0043]

According to the present invention, a heating element having a heating section which generates heat by a current supplied from a power supply, a heating element holding member having the heating element integrally or separately, a thread or the heating element are provided. A moving means for moving the two in a direction in which they contact each other, wherein the yarn is cut by the heat of the heat generating element. A thread cutting device comprising a switch means. When the heating element engages with the thread, a current flows through the heating element and the heating element is heated.Thus, the minimum heating time required for thread trimming is required, and the temperature of the heating element can be prevented from rising. Since it does not engage with the yarn in a softened state, the breakage of the heating element can be prevented. In addition, since the heating time (energization time) can be minimized, a power saving effect can be obtained.

When the heating element has a buffering property, the load due to the impact caused by the engagement with the yarn is reduced, so that the effect of preventing the heating element from breaking can be further obtained.

Further, according to the present invention, a heating element having a heating section which generates heat by a current applied from a power supply, a heating element holding member having the heating element integrally or separately, a thread or the heating element are provided. Moving means for moving the two in the direction in which they contact each other, wherein the yarn cutting device cuts the yarn by the heat of the heating element, wherein the heating element on the heating element holding member, the yarn or the heating element by the moving means A thread cutting device provided with a plurality of switches arranged side by side in the movement direction and a switch means for causing a current to flow through the heating elements by engaging the heating elements in at least the second and subsequent rows with the threads. In the case of this invention, in addition to the effect of the first invention,
By arranging a plurality of heating elements in the moving direction of the thread or the heating element, for example, when the heating element in the first row is broken, the heating element in the second row is used by removing the heating element. For example, the sewing operation can be continued without the need to replace the heating element.

When the plurality of heating elements include heating elements having different electric resistance values, when using a yarn having a different melting point temperature or a yarn having a different thickness, the heating energizing time is changed. A heating element having an appropriate electric resistance value can be selected and used.

In the case where the heating element holding member has a cutout or a groove at each position between the plurality of heating elements, the force for manually bending the heating element holding member is applied. Thereby, it is possible to easily cut from a portion where the strength is weakened by the notch or the groove.

When the yarn is interposed between the heating element and the heating element at the time of cutting the thread, the yarn is engaged with the heating element, and the engagement member formed of an insulator is provided. Therefore, the yarn can be reliably cut.

[Brief description of the drawings]

1A and 1B show a thread cutting device according to a first embodiment of the present invention, wherein FIG. 1A is a plan view, FIG. 1B is a sectional view taken along line XX of FIG. 1A, and FIG.

FIG. 2A is a block diagram of a control system according to the present embodiment, and FIG. 2B is a timing chart illustrating timing of energizing a separation-type hot wire and a hot wire drive cylinder according to the present embodiment.

3A and 3B show a state of cutting the lower thread in the thread cutting device of FIG. 1, wherein FIG. 3A is a plan view and FIG.

FIG. 4 is a view showing a thread cutting device according to a second embodiment of the present invention.

FIG. 5 shows a first example of the thread trimming device shown in FIG.
It is a figure which shows the state of the 2nd hot wire separation part.

6 is a view showing a state in which a first thread cutting tip is cut and removed in the thread cutting device of FIG. 4;

FIG. 7A is a view showing a thread cutting tip of a thread cutting device according to a third embodiment of the present invention, and FIG. 7B is a view showing Y in FIG.
It is -Y sectional drawing.

8 (A) shows a thread cutting tip of the thread cutting device of FIG. 11, and FIG. 8 (B) is a sectional view taken along the line Z-Z of FIG. 8 (A).

9A is a view showing a thread cutting tip of the thread cutting device of FIG. 11 at the time of thread cutting, and FIG. 9B is a similar view of the thread cutting device of FIG. 4;

FIG. 10 is a view showing a modification of the thread cutting device according to the second embodiment of the present invention.

FIG. 11 is a plan view showing a thread cutting device previously proposed by the present inventors.

FIG. 12 is a side view showing the thread cutting device proposed earlier by the present inventor, where (A) shows a state at a standby position,
(B) shows the state at the thread cutting position.

[Explanation of symbols]

6 Hot wire plate driving cylinder (moving means) 7a Lower thread 8 Thread cutting insulating plate (engaging body) 11, 21, 31 Separable heating wire plate (heating element holding member) 11a, 21a, 21c, 31a Thread cutting tip (heating element) 11b, 21b, 21d, 31b Hot wire separating part (switch means) 21e Notch (notch or groove)

Claims (6)

[Claims] 1. A heating element having a heating section that generates heat by a current applied from a power supply, a heating element holding member having the heating element integrally or separately, and a direction in which the thread or the heating element abuts each other. A yarn cutting device that cuts a yarn by the heat of the heat generating element, wherein a switch means for causing a current to flow through the heat generating element by engaging the heat generating element with the yarn. A thread cutting device characterized by the above-mentioned. 2. The thread cutting device according to claim 1, wherein said heating element has a buffering property. 3. A heating element having a heating section which generates heat by a current applied from a power supply, a heating element holding member having the heating element integrally or separately, and a direction in which the thread or the heating element abuts each other. A threading device that cuts a thread by the heat of the heating element, wherein a direction in which the thread or the heating element is moved by the moving means onto the heating element holding member so that the heating element can be detached. And a switch means for causing a current to flow through the heating element by engaging at least the heating element in the second and subsequent rows with the yarn. 4. The thread cutting device according to claim 3, wherein the plurality of heating elements include heating elements having different electric resistance values. 5. The thread cutting device according to claim 3, wherein the heating element holding member has a notch or a groove between each of the plurality of heating elements. Thread trimming device. 6. The thread cutting device according to claim 1, further comprising an engaging body formed of an insulator while engaging with the thread so as to sandwich the thread between the heating element and the thread when the thread is cut. A thread cutting device characterized by the above-mentioned.