JP4672903B2 - Thread trimmer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thread trimming apparatus, and more particularly to a thread trimming apparatus that generates heat by passing an electric current through a heating element and cuts it by contacting the thread.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a thread trimming device for a sewing machine, a machine that mechanically cuts a thread by inserting a thread between a moving knife and a fixed knife is widely known. In such a mechanical cutting system, it is difficult to cut a thick thread, or the thread cutting part is scattered or frayed easily. (Hot wire thread trimming apparatus) is applied (for example, Japanese Patent Laid-Open No. 57-75691, Japanese Utility Model Publication No. 7-52700, Japanese Patent Laid-Open No. 11-114270, etc.).
[0003]
For the purpose of improving such a thermal thread trimming apparatus, the thread trimming apparatus proposed by the present inventor in Japanese Patent Application No. 2000-123785 will be described with reference to FIGS. The hot wire plate 1 is a thread trimming medium (heating element) that is heated by energization. The front end portion 1a of the heat ray plate 1 is a portion having the highest electrical resistance, and is a thread cutting portion that generates Joule heat. With this heat, the lower thread 7a can be melted and cut or burnt out.
[0004]
The lower thread pull-out plate 2 is a member that pulls out a thread necessary for the next sewing before thread trimming in advance, and captures and guides the lower thread 7a to the front end portion 1a of the heat ray plate 1 by the lower thread capturing portion 2a at the front end. The lower thread drawing plate 2 is fixed to a heat ray plate fixing base 3 made of an insulating member. The lower heating wire cord 4 is an electrical bundle that passes current to the heating wire plate 1 and is transmitted from a transformer (not shown). The hot wire plate 1 and the lower hot wire cord 4 are fixed to the hot wire plate fixing base 3 with fixing screws 5. The fixing screw 5 itself becomes a current-carrying body.
[0005]
A hot wire plate driving cylinder 6 and a thread trimming insulating plate 8 are fixed to the back surface of the needle plate 10. The rod 6 a of the hot wire plate driving cylinder 6 is connected to the hot wire plate fixing base 3. The hot wire plate 1 and the lower thread draw-out plate 2 fixed to the hot wire plate fixing base 3 are moved back and forth in the direction of arrow AB in the figure by the hot wire plate driving cylinder 6 at the time of thread trimming.
[0006]
The bobbin case 7 is a case in which a lower thread 7a necessary for sewing is stored, and is built in a sewing machine head (not shown). The thread trimming insulating plate 8 is a heat-resistant insulating member to be abutted against the heat ray plate 1, and a cut portion of the lower thread 7 a is sandwiched between the thread trimming insulating plate 8 and the heat ray plate 1. On the needle plate 10, a workpiece 9 to be sewn with the lower thread 7a is arranged. The needle plate 10 is formed with a needle hole 10 a that is a thread passage hole for supplying the lower thread 7 a to the sewing product 9.
[0007]
In the thread trimming device having the above-described configuration, first, after energization to the hot wire plate 1 is started, the hot wire plate driving cylinder 6 is actuated to extend the rod 6a, and the hot wire plate 1 and the lower thread drawing plate 2 are illustrated. The lower end 7a having Joule heat is brought into contact with the thread trimming insulating plate 8 with the lower thread 7a captured and guided by the lower thread capturing part 2a of the lower thread drawing plate 2. The lower thread 7a sandwiched between the tip 1a and the thread trimming insulating plate 8 is melted and cut or burned out. After the end of thread trimming, the rod 6a contracts and returns to the B direction, and the hot wire plate 1 and the lower thread drawing plate 2 reach the standby position.
[0008]
[Problems to be solved by the invention]
By the way, the melting point temperature of the yarn trimming medium of the thermal yarn trimming apparatus is about 1,400 ° C., whereas the melting point temperature of a general yarn is 260 ° C. or less. The temperature of the thread trimming medium increases as the energization time is increased, and reaches the melting point temperature of about 1,400 ° C. Therefore, as a thermal thread trimming apparatus, it is usual to set the energization time so that the thread trimming medium is 500 ° C. or lower and cut the thread.
[0009]
However, the melting temperature of the yarn varies 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 yarn trimming medium needs to be set higher. For this reason, depending on the type and thickness of the yarn, depending on the type and thickness of the yarn, the energization time is often set so long that the temperature of the thread trimming medium is 500 ° C. or higher. There was something to do.
[0010]
The rupture is caused by the following reason. By increasing the energization time, the heating temperature of the medium inevitably rises, and thread trimming can be easily performed regardless of the type and thickness of the thread, but at the same time, the medium suddenly rises to near the melting point temperature, Heats red and softens. In this state, the yarn is directly pressed against the yarn, so that a load is applied to the portion, and as a result, the medium itself breaks.
As described above, in the thermal type thread trimming apparatus, the longer the energization time to the thread trimming medium, the more likely the medium itself to break (melt).
[0011]
Also, considering the certainty of thread trimming, there is an extra energization time before and after thread trimming, so the energization time is set longer than the time required for actual thread trimming, so that unnecessary energization Along with the time, the temperature increase of the thread trimming medium was further remarkable.
[0012]
Therefore, in order to avoid a sudden temperature rise, prepare a medium with a small electrical resistance value at the tip of the thread trimming, that is, by increasing the cross-sectional area of the metal to reduce the temperature rise speed and increase the strength of the medium itself. It was used properly according to the type and thickness. However, it has been troublesome to prepare several types of media and replace them each time.
[0013]
An object of the present invention is to provide a thread trimming apparatus capable of preventing the thread trimming medium (heating element) from being broken.
Another object of the present invention is to save the trouble of exchanging a medium (heating element) according to the type and thickness of the yarn, or exchanging with a new medium when the medium is broken or damaged. It is an object of the present invention to provide a thread trimming apparatus capable of performing the above-mentioned.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, there is provided a heat generating portion that generates heat due to a current applied from a power source. Made of spring steel Heating element (11a, 21a, 21c, 31a) And a heating element holding member having the heating element integrally or separately (11, 21, 31) When, A lower heating wire cord (4) that is connected to the heating element holding member and allows a current to flow through the heating element; Moving means for moving the yarn or the heating element in a direction in which both of them contact each other (6) In a yarn cutting device that cuts yarn by the heat of the heating element, An engagement body (8) that is disposed opposite to the heating element and engages with the thread so as to sandwich the thread between the heating element when cutting the yarn and is formed of an insulator, and the heating element holding member. The heat generating plate is formed while the heating element and the yarn are not in contact with each other, and is kept in a separated state. And a control unit (16) for energizing the lower heating wire cord, wherein the heating element is energized and heated by contact of the heating wire plate separation unit. A thread trimming device is provided.
[0015]
Further, according to the present invention, the heating element having a heating part that generates heat due to the current applied from the power source, the heating element holding member having the heating element integrally or separately, and the yarn or the heating element are mutually connected. A yarn cutting device that cuts the yarn by the heat of the heating element, wherein the yarn or heating element is moved onto the heating element holding member so as to be detachable from the heating element holding member. And arranged side by side in the moving direction of Count from the yarn side There is provided a thread trimming device comprising switch means for allowing a current to flow through the heating elements of the second and subsequent rows when the heating elements are engaged with the yarn.
[0016]
The plurality of heating elements may include heating elements having different electric resistance values. Preferably, the heating element holding member has a cutout portion or a groove portion between the arrangement positions of the plurality of heating elements.
More preferably, an engagement body is provided which is engaged with the yarn so as to sandwich the yarn with the heating element when the yarn is cut and is formed of an insulator.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the yarn trimming device of the present invention will be described based on the embodiment shown in the drawings.
First, the external configuration of the yarn cutting device according to the first embodiment will be described with reference to FIG. The thread trimming apparatus according to the present embodiment is different from the thread trimming apparatus shown in FIGS. 11 and 12 in that there is a structure of a heat ray plate heated by energization and a fitting groove for preventing lateral displacement of the heat ray plate. This is the point that the insulating plate 12 is provided.
[0018]
That is, the thread cutting tip (heating element) 11a of the separation type hot wire plate 11 (heating element holding member) made of spring steel is the part with the highest electrical resistance, and is the thread cutting point that generates Joule heat. A hot-wire plate separating portion (switch means) 11b is formed in the vicinity of the thread trimming tip portion 11a, and this hot-wire plate separating portion 11b is in a separated state while the separable hot-wire plate 11 is not touching the lower thread 7a. In the meantime, the separation type hot wire plate 11 is not energized.
[0019]
The insulating plate 12 fixed to the lower thread drawing plate 2 by the set screw 12a has a fitting groove 12b for supporting the separation type heat ray plate 11, and the separation type heat ray plate 11 is placed in the fitting groove 12b. By being fitted, a lateral shift (a vertical shift in FIG. 1A and a horizontal shift in FIG. 1B) is prevented.
Other parts are the same as those shown in FIGS. 11 and 12, and therefore, the same reference numerals are given and description thereof is omitted.
[0020]
Next, the control system in the present embodiment will be described with reference to FIG. This control system is for controlling the thread trimming device and includes a control unit 16 including a CPU 13, a RAM 14, and a ROM 15. A sewing machine start switch 17 is connected to the input side of the controller 16, and a hot-wire plate driving cylinder (moving means) 6, a transformer 18 and a sewing machine motor 19 are connected to the output side. When the operator turns on the start switch 17, the sewing machine motor 19 rotates and sewing starts.
[0021]
11 and 12, a transformer is prepared for each of the lower heating wire plate 21 and the upper heating wire plate 20 (not shown) that cuts the upper plate above the needle plate, but in this embodiment, The upper and lower threads can be cut with only one transformer 18. That is, in FIG. 2 (A), to the transformer 18, the separation type heat ray plate 11 is connected via the lower heat ray cord 4 and the upper heat ray plate 20 for cutting the upper thread is also connected.
[0022]
FIG. 2B is a timing chart showing the energization timing to the separation type heat ray plate 11 and the heat ray plate driving cylinder 6 in the present embodiment. This chart is implemented by the CPU 13 issuing a drive signal to the hot-wire plate drive cylinder 6 and an energization signal to the transformer 18 according to a program stored in the ROM 15 constituting the control unit 16 of FIG. Is done. 11 and 12, the upper heating wire plate 20 (not shown) is energized and heated after the completion of the lower thread cutting. In the present embodiment, the lower heating wire cord 4 is formed by one transformer 18. And the upper heating wire plate 20 are energized simultaneously. Since the upper heating wire 20 has a low electric resistance and a slow heating rate, the upper heating wire 20 is preheated when cutting the lower thread. After the completion of the lower thread trimming, Joule heat necessary for the thread trimming has already been generated on the upper heating wire plate 20, so that the upper and lower threads can be trimmed faster than the thread trimming apparatus shown in FIGS.
[0023]
Next, the operation of the lower thread trimming device according to this embodiment will be described. First, during sewing of the sewing machine, the rod 6a of the heat ray plate driving cylinder 6 is contracted, and the lower thread drawing plate 2 and the separation type heat ray plate 11 are located in the B direction of FIG. 1 and are in a standby state. When sewing is completed and the thread trimming signal is turned ON, the control unit 16 sends an energization signal to the transformer 18 and energizes the lower heating wire cord 4 and the upper heating wire plate 20. At this time, since the separation type heat ray plate 11 is separated by the heat ray plate separation part 11b, no current flows through the separation type heat ray plate 11 and it is not heated. However, the upper heating wire plate 20 is heated. At the same time, the heat ray plate driving cylinder 6 is energized and its rod 6a extends, and the lower wire drawing plate 2 and the separation type heat ray plate 11 together with the heat ray plate fixing base 3 move in the direction A in FIG. The lower thread pull-out plate 2 is fed out while being guided by the lower thread capturing portion 2a. This lower thread drawing process is a process for securing in advance a minimum amount of the lower thread 7a necessary for the next sewing.
[0024]
Next, as shown in FIG. 3, the front end portion 11 a comes into contact with the lower thread 7 a that is caught and guided by the lower thread catching portion 2 a of the lower thread drawing plate 2, and this lower thread 7 a is abutted against the thread trimming insulating plate 8. . That is, for the first time, the thread trimmer tip 11a comes into contact with the lower thread 7a. However, since the hot wire plate separating part 11b comes into contact with the lower thread 7a, the separation type hot wire plate 11 is energized (FIG. 2). (C point of (B)). By this energization, the thread trimming tip 11a is heated to generate Joule heat, and the lower thread 7a sandwiched between the thread trimming tip 11a and the thread trimming insulating plate 8 is melted or burned off and cut.
[0025]
Since heating starts when the thread trimming tip 11a contacts the lower thread 7a in this way, the heating time of the thread trimming tip 11a is the minimum time necessary for thread trimming, and the temperature of the thread trimming medium rises. In addition, the thread trimming tip 11a does not hit the lower thread 7a in a state of being heated red and soft, and an effect of preventing breakage of the thread trimming medium can be obtained, and further, the energization time is reduced. It is possible to achieve the power saving effect. Further, since the heat ray plate separating portion 11b of the separation type heat ray plate 11 made of spring steel plays a role of shock absorption when contacting the lower thread 7a, the load due to direct impact is reduced. The effect of preventing breakage is obtained.
[0026]
After the cutting of the lower thread 7a is completed, the energization from the control unit 16 to the hot wire plate driving cylinder 6 is stopped, the rod 6a is contracted, and the lower thread drawing plate 2 and the separation type hot wire plate 11 return to the B direction of the standby position. At the same time, the thread trimming tip portion 11a is separated from the thread trimming insulating plate 8, and the separation type heat ray plate 11 is again separated, so that the energization to the separation type heat ray plate 11 is automatically cut off (see FIG. 2B). D point).
[0027]
Thereafter, the 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 heating wire plate 11 (the medium itself has a large cross-sectional area and a low electric resistance), so that the overall heating is longer than the lower thread trimming. It's time.
[0028]
Next, a thread trimming apparatus according to a second embodiment of the present invention will be described with reference to FIGS. In the separation-type heat ray plate 11 of the first embodiment, only one heat ray plate separation portion 11b is provided, but the yarn cutting device according to the present embodiment is provided with a plurality of them. The illustrated example shows an example in which two heat ray plate separation portions are provided. That is, a first heat ray plate separating portion 21b is formed in the vicinity of the first thread trimming tip portion 21a of the separation type heat ray plate 21, and behind this heat ray plate separation portion 21b (the moving direction of the separation type heat ray plate 21). Further, a second thread trimming tip 21c and a second heat ray plate separating part 21d are formed on the rear side.
[0029]
Further, the total length of the separation type heat ray plate 21 is made longer than that of the separation type heat ray plate 11 of the first embodiment, a long groove 21f is formed at the rear end portion, and the first thread trimming tip portion 21a is further formed. A notch (notch or groove) 21e is formed between the first and second thread trimming tips 21c. By applying a force in the vicinity of the distal end portion of the separation type heat ray plate 21, it is possible to cut the cut portion 21e. The position of the separation type heat ray plate 21 can be adjusted by sliding it back and forth by the fixing screw 5 and the long groove 21f for fixing the separation type heat ray plate 21 to the heat ray plate fixing base 3.
[0030]
The thread trimming operation of the present embodiment is the same as that of the first embodiment. At the time of thread trimming, the second heat ray plate separating portion 21d is separated from the surroundings as shown in FIG. Only the heat ray plate separating portion 21b is in contact and can be heated by energization.
[0031]
If the first thread trimming tip 21a is broken, the second thread trimming tip 21c can be used. That is, after applying the bending load to the cut portion 21e of the separation type heat ray plate 21 and cutting it to remove the first thread trimming tip portion 21a, the separation type heat ray plate 21 using the fixing screw 5 and the long groove 21f. Is slid along the insulating plate 12 and moved forward until the second thread trimming tip 21c reaches a predetermined position. Thereby, it will be in the state shown in FIG. 6, and the 2nd thread trimming front-end | tip part 21c can be used as a thread trimming location which emits Joule heat.
[0032]
In the present embodiment, when the cross-sectional areas of the first thread trimming tip 21a and the second thread trimming tip 21c are the same (the same resistance value), the sewing conditions using the same type of lower thread 7a Below, even if the first thread trimming tip 21a is broken or not replaced with a new heat ray plate, the second thread trimming tip 21c can be used. Moreover, it is not necessary to replace the heat ray plate, and it is only necessary to loosen the fixing screw 5 and slide the separation type heat ray plate 21. Therefore, since it can be set easily and quickly, time loss due to breakage can be prevented as much as possible. When three or more thread trimming tip portions and hot wire plate separation portions are provided, each thread trimming tip portion can be used in turn. In addition, the position adjustment of the separation type heat ray plate 21 is not limited to only by sliding / fixing the mounting position using the long hole 21f, but the configuration is such that the stroke of the moving means of the moving means is changed or a plurality of fixing positions are provided. It is good.
[0033]
On the other hand, in the present embodiment, when the cross-sectional area of the second thread trimming tip 21c is larger than the first thread trimming tip 21a (lowering the resistance value and decreasing the heating rate), the lower thread to be used The thread trimming tip can be selected according to the resistance value appropriate for 7a. When a yarn having a relatively high melting temperature or a thick yarn is used, the heating energization time is lengthened, so that the first thread trimming tip 21a is easily broken due to excessive heating. Therefore, in order to prevent the breakage, the second thread trimming tip 21c having breakage resistance can be used by increasing the cross-sectional area to alleviate the temperature rise and increasing the strength of the medium itself. . That is, the first thread cutting tip 21a is used when using a normal thread, and the separation type heat ray plate 21 is cut at the notch 21e when using a thread having a relatively high melting point or a thick thread. The first thread trimming tip 21a is removed by cutting, and the second thread trimming tip 21c is used. Thus, it is possible to cope with one separation-type heat ray plate 21 without preparing different heat ray plates according to the type of yarn in advance. Also in this case, it is not necessary to replace the heat ray plate, and it is possible to simply and quickly set since it is only necessary to loosen the fixing screw 5 and slide the separation type heat ray plate 21, thereby preventing time loss due to exchange as much as possible. .
[0034]
In addition, when the cross-sectional area of the 1st thread trimming front-end | tip part 21a and the 2nd thread-trimming front-end | tip part 21c is made the same, when it makes it different, the case where the stock of a normal heat ray board is lost For the emergency, the second or third and subsequent thread trimming tips can be used as a substitute in an emergency.
[0035]
Next, a thread trimming apparatus according to a third embodiment of the present invention will be described with reference to FIG. In this embodiment, the cross-sectional shape of the thread trimming tip 31a of the separable heat ray plate 31 is changed. Other points are the same as those of the first embodiment. (B) is a YY sectional view of (A). For comparison, FIG. 8A shows a front end portion 1a of the hot wire plate 1 by the yarn cutting device shown in FIGS. 11 and 12, and FIG. 8B shows a ZZ sectional view thereof.
[0036]
7B and 8B, the length in the direction (AB direction) in which the heat ray plates 1 and 31 move is a1, a31, and the length in the direction perpendicular thereto is t1, t31. Then, a31 × t31 = a1 × t1 is set so that the cross-sectional areas are the same, but t31> t1. Since t1 and t31 are the thicknesses of the surfaces where the thread trimming tips 1a and 11a are in contact with the lower thread 7a, the contact area with the lower thread 7a is equal to that of the separation type hot wire plate 31 of the present embodiment in FIG. Is wider than the example of FIG. Since the cross-sectional areas are the same, the heating rate is the same.
[0037]
When the thread trimming is heated, the leading end of the thread trimming is soft, so that it gradually deforms along the shape of the lower thread 7a every time the thread trimming is repeated. The tip 1a of the hot wire plate 1 of the thread trimming device shown in FIGS. 11 and 12 is deformed as shown in FIG. 9A, and there is no hindrance to thread trimming, but until the lower thread 7a is completely cut. The time was a little late.
[0038]
Therefore, in the present embodiment, the modification is used. That is, by reducing the plate thickness a31 in the moving direction (AB direction) of the heat ray plate 31, it becomes easier to deform as shown in FIG. 9B, and the thread trimming so as to surround the outer periphery of the lower thread 7a. The tip 31a is deformed. According to the present embodiment, the contact area between the lower thread 7a and the thread trimming tip 31a is enlarged, and faster and more reliable thread trimming is possible.
[0039]
As mentioned above, although the thread trimming apparatus of this invention was demonstrated based on embodiment shown in drawing, this invention is not limited to these embodiment, A various deformation | transformation is possible.
[0040]
For example, the heating element according to the present invention is constituted by the distal end portions 11a, 21a, 31a of the separation type heat ray plates 11, 21, 31, and the separation type heat ray plates 11, 21, 31 having the heating element holding member integrally. Although comprised, a heat generating body can be comprised separately from a heat generating body holding member. Further, in the present invention, the switch means in which the current flows through the heating element by engagement with the yarn is configured by the heat ray plate separation portions 11b, 21b, 31b, but may be constituted by a component separate from the separation type heat ray plate 11. it can.
[0041]
Moreover, although the front-end | tip parts 11a, 21a, and 31a are moved in the direction contact | abutted with the lower thread | yarn 7a, you may move a thread | yarn in the direction contact | abutted with the front-end | tip parts 11a, 21a, and 31a.
[0042]
Further, in the second embodiment, an example in which two switch means, that is, a first heat ray plate separation part 21b and a second heat ray plate separation part 21d are provided, but as shown in FIG. The second row of heating elements, ie, the second heating element, ie, the second heating element, ie, the second thread heating element, ie, the second row of heating elements, ie, the second heating element, ie, the second row heating element, ie, the second heating element, ie, the second heating element, ie, the second heating element. Only the switching means 21d that allows the current to flow through the tip 21a by engaging the thread cutting tip 21c with the yarn may be provided. In the case where the thread trimming tips are also provided in the third and subsequent rows, switch means corresponding to the respective thread trimming tips are provided.
[0043]
【The invention's effect】
According to the present invention, the heat generating portion that generates heat due to the current applied from the power source is provided. Made of spring steel Heating element (11a, 21a, 21c, 31a) And a heating element holding member having the heating element integrally or separately (11, 21, 31) When, A lower heating wire cord (4) that is connected to the heating element holding member and allows a current to flow through the heating element; Moving means for moving the yarn or the heating element in a direction in which both of them contact each other (6) In a yarn cutting device that cuts yarn by the heat of the heating element, An engagement body (8) that is disposed opposite to the heating element and engages with the thread so as to sandwich the thread between the heating element when cutting the yarn and is formed of an insulator, and the heating element holding member. The heat generating plate is formed while the heating element and the yarn are not in contact with each other, and is kept in a separated state. And a control unit (16) for energizing the lower heating wire cord, wherein the heating element is energized and heated by contact of the heating wire plate separation unit. A thread trimming device is provided. When the heating element engages with the yarn, current flows through the heating element and heats it, so the minimum heating time required for thread trimming is sufficient, and the temperature of the heating element can be prevented from rising, and the heating red color Since the yarn does not engage with the yarn in the softened state, the heating element can be prevented from being broken. Further, since the heating time (energization time) can be minimized, a power saving effect can also be obtained.
[0044]
The heating element is Made of spring steel Since the load due to the impact accompanying the engagement with the yarn is reduced, the effect of preventing the heat generating element from being broken can be further obtained.
[0045]
Further, according to the present invention, the heating element having a heating part that generates heat due to the current applied from the power source, the heating element holding member having the heating element integrally or separately, and the yarn or the heating element are mutually connected. And a moving means that moves in the abutting direction, wherein the heating element is cut on the heating element holding member in a moving direction of the yarn or the heating element by the moving means. While arranging multiple, side by side, Count from the yarn side There is provided a thread trimming apparatus comprising switch means for causing a current to flow through the heating elements when the heating elements of the second and subsequent rows engage with the yarn. 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 yarn or the heating element, for example, when the heating element in the first row breaks, the heating element By removing the, the sewing work can be continued without the need to replace the heating elements, such as using the heating elements in the second row.
[0046]
In the case where the plurality of heating elements include heating elements having different electric resistance values, when using yarns having different melting point temperatures or yarns having different thicknesses, it is suitable for changing the heating energization time. A heating element having an electric resistance value can be selected and used.
[0047]
When the heating element holding member is configured to have a cutout portion or a groove portion between the plurality of heating element arrangement positions, by applying a force to bend the heating element holding member manually, It can be easily cut from a portion whose strength is weakened by the notch or the groove.
[0048]
When the yarn is cut, the yarn is sandwiched between the heating element so as to engage with the yarn and an engagement body formed of an insulator is provided, so that the yarn is surely brought into contact with the heating element. The yarn can be cut reliably.
[Brief description of the drawings]
1A and 1B show a yarn trimming apparatus according to a first embodiment of the present invention, in which FIG. 1A is a plan view, FIG. 1B is a sectional view taken along line XX in FIG. 1A, and FIG.
FIG. 2A is a block diagram of a control system in the present embodiment, and FIG. 2B is a timing chart showing energization timings to the separation type heat ray plate and the heat ray plate drive cylinder in the present embodiment.
FIGS. 3A and 3B show a state at the time of cutting a lower thread in the thread trimming apparatus of FIG. 1, FIG. 3A is a plan view, and FIG.
FIG. 4 is a view showing a yarn cutting device according to a second embodiment of the present invention.
FIG. 5 is a diagram showing a state of first and second heat ray plate separating portions at the time of thread trimming in the yarn trimming apparatus of FIG. 4;
6 is a view showing a state where a first thread trimming tip is cut and removed in the thread trimming device of FIG. 4; FIG.
7A is a view showing a thread trimming tip portion of a thread trimming device according to a third embodiment of the present invention, and FIG. 7B is a YY sectional view of FIG.
8A shows a thread trimming tip of the thread trimming device of FIG. 11, and FIG. 8B is a ZZ sectional view of FIG.
9A is a front view of a thread trimmer when the thread trimmer of FIG. 11 is thread trimmed, and FIG. 9B is a similar view of the thread trimmer of FIG.
FIG. 10 is a view showing a modification of the yarn cutting device according to the second embodiment of the present invention.
FIG. 11 is a plan view showing a thread trimming apparatus previously proposed by the present inventor.
FIGS. 12A and 12B are side views showing the thread trimming device previously proposed by the present inventor, wherein FIG. 12A shows a state at a standby position, and FIG. 12B shows a state at a thread trimming position.
[Explanation of symbols]
6 Hot wire plate drive cylinder (moving means)
7a Lower thread
8 Thread trimming insulation plate (engagement body)
11, 21, 31 Separable heat ray plate (heating element holding member)
11a, 21a, 21c, 31a Thread trimmer tip (heating element)
11b, 21b, 21d, 31b Hot wire plate separation part (switch means)
21e Notch (notch or groove)

Claims (6)

Have a heating unit that generates heat by from the applied current power supply, a heating element made of spring steel,
A heating element holding member having the heating element integrally or separately;
A lower heating wire cord that is connected to the heating element holding member and flows current to the heating element;
Moving means for moving the yarn or the heating element in a direction in which both of them contact each other,
In a yarn cutting device for cutting yarn by the heat of the heating element,
An engagement body that is disposed opposite to the heating element and engages with the thread so as to sandwich the thread between the heating element when cutting the yarn and is formed of an insulator;
A heat ray plate separating portion that is formed on the heating element holding member and maintains a separated state while the heating element and the yarn are not in contact with each other, and is pressed and contacts when the heating element and the thread are engaged,
A control unit for energizing the lower heating wire cord by a thread trimming signal;
The yarn cutting device , wherein the heating element is energized and heated by the contact of the heat ray plate separating section . The thread trimming device according to claim 1,
A lower thread pull-out plate fixed to the heat ray plate fixing base and pulling out a thread necessary for the next sewing in advance before thread trimming;
A thread trimming device comprising: an insulating plate having a fitting groove that is fixed to the lower thread drawing plate and supports the heating element holding member in one direction . A heating element having a heating part that generates heat due to a current applied from a power source;
A heating element holding member having the heating element integrally or separately;
Moving means for moving the yarn or the heating element in a direction in which both of them contact each other,
In a yarn cutting device for cutting yarn by the heat of the heating element,
A plurality of the heating elements are arranged side by side in the moving direction of the yarn or the heating element on the heating element holding member so as to be detachable from the heating element,
A thread trimming apparatus comprising switch means for causing a current to flow through the heating elements when the heating elements in the second and subsequent rows counting from the yarn side are engaged with the yarns. In the thread trimming device according to claim 3,
The plurality of heating elements include heating elements having different electric resistance values. In the thread trimming device according to claim 3 or 4,
The thread cutting device according to claim 1, wherein the heating element holding member has a notch portion or a groove portion between the arrangement positions of the plurality of heating elements. In the thread trimming device according to any one of claims 3 to 5 ,
A thread trimming apparatus comprising: an engagement body formed by an insulator and engaging with the thread so as to sandwich the thread between the heating element when the thread is cut.

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