JP2001347090A - Button sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a button sewing machine capable of preventing a thread from being cut before a movable scalpel and a fixed scalpel are engaged with each other after sewing a button and adjusting the length of the remaining thread. SOLUTION: The button sewing machine comprises a needle 410, a presser mechanism 110 for holding a button and a material to be sewn, a cloth sending mechanism 150 for moving the presser mechanism 110, a thread cutter 200 comprised of a fixed scalpel 230 and a movable scalpel 220 and a control device 300, and threads are cut after sewing a button. The control device 300 controls the cloth sending mechanism 150 so that a button is moved to a prescribed position relative to the fixed scalpel 230 after the completion of sewing and before the start of operation of the movable scalpel 220. The movable scalpel 220 has a guide member 260. The guide member 260 is for preventing the movable scalpel 220 from engaging with a thread while the thread is drawn in to the fixed scalpel 230 and preventing the thread from being in contact with an edge part 221 of the movable scalpel 220.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a button sewing machine for sewing a button on a workpiece while moving the button and the workpiece, and cutting the thread with a fixed knife and a moving knife after sewing the button. It is.

[0002]

2. Description of the Related Art A button sewing machine for sewing a button on a cloth (a material to be sewn) includes a presser plate on which a cloth is placed, and a button holding mechanism for holding the button, and a button supported by the button holding mechanism. The cloth is held between the presser plate and the presser plate. Then, when the button is sewn to the cloth by the seam, the button holding mechanism and the presser plate are integrally moved to perform needle dropping in a plurality of threading holes formed in the button in a predetermined order. In the case of a button sewing machine in which a button is sewn by single-ring stitching, a sewing thread laid over a pair of threading holes is knotted at a substantially central portion between the threading holes on the back side of the cloth. And at the nodule at the time of the last needle drop,
For example, a knot at the end of sewing is formed by a well-known method as described in U.S. Pat. No. 5,799,599. Therefore, in the case of sewing a button having two or more threading holes, the position of the knot portion is different from the button depending on the order of needle dropping into the threading hole.

For example, in the case of a four-hole button, FIG.
As shown in FIG. 7, a sewing pattern in which the thread between the holes 13a and 13c and the thread between the holes 13b and 13d intersect at the center of the button.
As shown in (b), between holes 13a, 13d, holes 13b, 1
There is a sewing pattern in which the threads between 3c are arranged in parallel.

In the case of the intersecting sewing pattern shown in FIG. 7 (a), the knot of the seam formed on the back of the cloth is located at a substantially central portion of the button 13, where the final knot is formed. It is formed. Further, in the case of the parallel sewing pattern shown in FIG. 7B, there are two locations substantially at the center between the two pairs of threading holes over which the stitch is passed, and the final knot is formed at one location. .

In the above-mentioned button sewing machine, as shown in FIGS. 7A and 7B, a fixed knife 11 fixedly supported by a needle plate (not shown), The moving knife 12 rotatably supported and the moving knife 1
2 is provided with a thread cutting device 10 which is provided with a thread dividing member 12A provided in the second device 2. After button sewing, moving knife 12
Is rotated, the thread splitting member 12A guides the needle thread connected to the cloth to the blade, and the thread is caught by the blade of the moving knife 12 and travels to the fixed knife 11, whereby the fixed knife 11 and the moving knife 12 are moved. The thread is cut by meshing with the thread.

[0006]

However, according to the thread cutting device 10 as described above, before the moving knife 12 and the fixed knife 11 are engaged with each other, the thread is pulled while the moving knife 12 is dragging the thread. Sometimes it was cut. In particular, as the position of the knot portion due to the final needle drop away from the fixed knife 11, the distance that the moving knife 12 approaches the thread to the fixed knife 11 becomes longer, so that the thread is moved before the fixed knife 11 and the moving knife 12 mesh with each other. There is a high possibility that the thread will be cut only by the moving knife 12 under tension. Fixed knife 11 and moving knife 12
If the thread is cut only by the moving knife 12 before the thread is engaged with the thread, the appearance of the cut end of the thread becomes poor.

Further, as described above, the stitch knot position of the final needle drop differs from the button due to the difference in the sewing pattern such as the X-shape in FIG. 7A or the parallel shape in FIG. 7B. Therefore, since the length of the thread guided from the threading hole of the button to the fixed knife varies depending on the sewing pattern, the length of the remaining thread extending from the button after cutting differs,
Decrease product value.

Accordingly, an object of the present invention is to prevent the thread from being cut before the moving knife and the fixed knife engage with each other. Another object is to adjust the length of the remaining yarn.

[0009]

In order to solve the above-mentioned problems, the invention according to claim 1 employs a holding means (a cloth presser mechanism 110) for holding a button and an object to be sewn, and a seam of a predetermined sewing pattern. Feeding means (cloth feeding mechanism 15) for moving the holding means so that the button is sewn on the workpiece.
0), a fixed knife (230), and a moving knife (220) that moves so as to cut the thread by cooperating with the fixed knife after the thread is pulled by operation, and is provided with a predetermined number of stitches. In a button sewing machine for cutting a thread after sewing a button, a control means (300) for controlling the cloth feeding means is provided so that the button for the fixed knife is moved to a preset position before the thread is cut. It is characterized by:

As described above, according to the first aspect of the present invention, before the thread is cut, the position of the button with respect to the fixed knife is adjusted, so that the distance between the knot portion due to the final needle drop and the fixed knife is adjusted. Can be. Therefore, the length of the remaining yarn after the yarn cutting can be arbitrarily changed. If the length of the remaining thread after thread cutting becomes longer, the knot becomes less likely to fray,
For example, buttons suitable for work clothing can be provided. On the other hand, if the length of the remaining yarn after the yarn cutting becomes shorter, the appearance of the knot becomes better, and for example, a button suitable for fashionable clothing can be provided. As described above, the sewing machine to which the thread cutting device according to the present invention is applied can attach a button to the sewing object according to the purpose of use of the sewing object.

After the sewing is completed, the position of the button can be brought closer to the fixed knife, and the knot portion by the final needle drop can be brought closer to the fixed knife. Therefore, when the moving knife draws the yarn, it is possible to prevent the yarn from being cut only by the moving knife.

According to a second aspect of the present invention, in the thread cutting device according to the first aspect, the control means keeps the distance from the knot portion of the thread at the final needle drop to the blade portion of the fixed knife always constant. Moving the button with respect to the fixed knife.

As described above, according to the second aspect of the invention, the distance from the knot portion of the thread to the blade portion of the fixed knife at the time of the final needle drop can be always constant based on the sewing pattern. Thus, the length of the remaining thread can be constant regardless of the sewing pattern.

According to a third aspect of the present invention, in the thread cutting device according to the first aspect, the control means changes a distance from a knot portion of the thread at the last needle drop to a blade portion of the fixed knife. The button is moved relative to the fixed knife so that the remaining thread length after the thread is cut can be freely changed.

As described above, according to the third aspect of the present invention, the distance from the knot portion of the thread to the blade portion of the fixed knife at the time of final needle drop can be changed based on the sewing pattern,
This makes it possible to freely change the remaining yarn length after the yarn is cut. If the length of the remaining yarn after the yarn cutting becomes longer, the knot becomes less likely to fray, and for example, a button suitable for working clothes can be provided. On the other hand, if the length of the remaining yarn after the yarn cutting becomes shorter, the appearance of the knot becomes better, and for example, a button suitable for fashionable clothing can be provided. As described above, the sewing machine to which the thread cutting device according to the present invention is applied can attach a button to the sewing object according to the purpose of use of the sewing object.
In particular, the sewing machine to which the thread cutting device according to the present invention is applied can be used for sewing objects having various purposes.

According to a fourth aspect of the present invention, in the thread cutting device according to the third aspect, a correction input means (309) for correcting the distance from the knot portion of the thread to the fixed knife at the final needle drop. It is characterized by having.

As described above, according to the fourth aspect of the present invention, the distance from the knot portion of the thread to the fixed knife at the time of final needle drop can be corrected, so that the size and type of the button are changed. Even if, for example, the position of the knot portion of the thread at the time of the final needle drop changes, the distance between the knot portion and the fixed knife can be suitably adjusted.

According to a fifth aspect of the present invention, there is provided the thread cutting device according to any one of the first to fourth aspects, wherein the thread is attached to the blade portion of the moving knife until the fixed knife and the moving knife engage with each other. Preventing means (guide member 26) for preventing
0) is provided on the moving knife.

According to the fifth aspect of the invention, it is possible to prevent the yarn from being cut only by the moving knife. As described above, since the yarn is prevented from being cut when the yarn is pulled, the appearance of the cut portion of the yarn is prevented from being deteriorated.

According to a sixth aspect of the present invention, in the thread cutting device according to the fifth aspect, the prevention means includes a guide portion (tip guide) which precedes a blade portion of the moving knife in a moving direction of the moving knife. 260A), wherein the guide section engages with the thread and guides the thread to the fixed knife.

As described above, according to the sixth aspect of the present invention, since the guide section is provided on the moving knife with the guide section preceding the blade section of the moving knife, the guide section is engaged with the thread first. Accordingly, it is possible to prevent the blade portion of the moving knife from coming into contact with the thread. Therefore, it is possible to prevent the thread from being cut only by the moving knife before the fixed knife and the moving knife start to mesh with each other. Since the cutting of the yarn is prevented when the yarn is pulled, the appearance of the cut portion of the yarn is prevented from being deteriorated.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

The sewing machine with a single thread ring stitch button according to the present embodiment has a general frame structure including a bed, a footnote, and an arm, and includes a feeding device 100 as shown in FIG.
A thread cutting device 200 as shown in FIG. 2 is provided.

Looper 420 disposed in the bed
(FIG. 3) operates in synchronization with the vertical movement of the needle 410 fixed to the lower end of the needle bar, captures the thread T of the needle 410, and forms the thread loop formed first and the thread loop formed next to the thread loop. A single thread ring seam is formed by the thread loop. Button B (Figure 8)
Needle 41 alternately between the two threading holes B1 and B2 (FIG. 8).
0 penetrates to form a single thread ring seam, and
8) Sewing buttons. And at the time of the last needle drop,
An operation of forming a final knot at substantially the same location as the previous needle drop is performed to form a knot of the thread, and then the moving knife 260 of the thread cutting device 200 is connected to the looper 420 and the cloth on the side connected to the cloth. The thread Ta is caught and cut in cooperation with the fixed knife 230.

As shown in FIG. 1, the feeding device 100 includes a cloth pressing mechanism 110 (holding means) for holding a button and holding a workpiece, and a cloth feeding mechanism 150 (feeding means) for moving the cloth pressing mechanism 110. ).

The cloth feeding mechanism 150 has the following configuration. That is, a first drive motor 151 and a second drive motor 152, which are pulse motors, are arranged in the bed on the side of the vertical trunk side symmetrically left and right with respect to the feed base 161. The first drive motor 151 and the second drive motor 152 are arranged such that their output shafts 153 and 154 project upward from the upper surface of the bed.

The output shaft 153 has an eccentric member 155 fixed to the output shaft 153, an eccentric shaft 157 eccentric to the axis of the output shaft 153 and fixed to the eccentric member 155, and one end of the eccentric shaft 157. Link member 1 rotatably supported
A first connecting mechanism 59 is provided. The output shaft 154 has an eccentric member 15 having the same configuration as the eccentric member 155, the eccentric shaft 157, and the link member 159.
6, a second connecting mechanism including an eccentric shaft 158 and a link member 160 is provided. The first and second coupling mechanisms are disposed symmetrically left and right with respect to the feed base 161.

The feed base 161 has a base end connected to the link member 15.
9 and 160, are rotatably connected to and supported by the other end portions, respectively, and extend along the bed surface so that the front end is disposed at the front end of the bed portion. At the center of the slide 161, a slide 161 is provided.
An elongated hole-shaped guide hole 162 is formed along the longitudinal direction. A guide member 163 rotatably supported on the bed portion about a support shaft 163A is slidably engaged with the guide hole 162 in the longitudinal direction. The feed base 161 is connected to the support shaft 16 of the guide member 163.
3A and the guide member 163 and the guide hole 1
By being guided by 62, it is configured to be able to swing around the support shaft 163 </ b> A within the longitudinal direction range of the guide hole 162.

The cloth presser mechanism 110 comprises a feed plate 111 for supporting a workpiece, and a knob 112 for clamping a button and pressing the workpiece. The feed plate 111 is fixed to the tip of the feed base 161 and the feed plate 11
1 is provided with a long hole 111A (FIG. 8) at least in a direction orthogonal to the extension direction of the feed base 161.
A needle 410 penetrates A.

The knob device 112 has its base end moved to the feed base 1 so that the tip end thereof can be raised and lowered with respect to the feed base 161.
It has a support plate 113 rotatably supported with respect to 61, and a button clamp mechanism 114 provided at the tip of the support plate 113 to clamp and support a button. The knob device 112 is urged downward by a spring (not shown), and the button clamp mechanism 114 is pressed against the feed plate 111 by this urging force, and clamps the workpiece. A driving device 312 (shown in FIG. 4) using a solenoid, a motor, or the like as a driving source.
Thus, the grip device 112 is lifted against the urging force to release the clamp of the sewing object.

When the eccentric members 155 and 156 rotate around the respective output shafts 153 and 154 by the driving of the first drive motor 151 and the second drive motor 152, the link members 159 supported by the eccentric shafts 157 and 158. , 1
60 is oscillatingly displaced. As a result, the feed table 161 moves back and forth within the longitudinal direction range of the guide hole 162, and swings right and left around the support shaft 163A, whereby the feed plate 111 and the button clamp mechanism 114 also move back and forth and left and right. That is, the feed plate 111 and the button clamp mechanism 114 are moved to arbitrary positions on the XY plane by controlling the rotation direction and the rotation amount of the first drive motor 151 and the second drive motor 152 separately. I do.

Thus, the feed base 111 and the button clamp mechanism 11 are set in accordance with the type and size of the button supported by the button clamp mechanism 114 and the sewing pattern.
By moving the button 4 on the XY plane, the needle 410 penetrates the threading hole of the button B in a predetermined order, a single thread ring stitch is formed, and the button B is sewn to the workpiece W.

Next, the thread cutting device 200 will be described. 2 and 3 (a),
As shown in (b), the needle plate 210, the moving knife 220,
Fixed knife 230, thread cutting arm 240, thread dividing member 25
0, a guide member 260 and the like.

The needle plate 210 fixed to the bed portion is disposed below the feed plate 111 so as to be opposed thereto, and has a horizontally long needle hole 211 having substantially the same shape as the hole 111A of the feed plate 111.

The fixed knife 230 having the blade portion 231 is shown in FIG.
As shown in FIG. 8, the needle hole 211 is fixed to the lower surface of the needle plate 210 so as to face one end in the longitudinal direction. Moving knife 220
The support shaft 2 fixed to the needle plate 210 as shown in FIG.
It is supported rotatably around 20A. The moving knife 220 is rotatably connected to a thread cutting arm 240 to which a driving device 313 (shown in FIG. 4) having a driving source such as a solenoid or a motor is connected. When the arm 240 is actuated, the moving knife 220 rotates about the support shaft 220A, and the blade portion 221 is moved to the needle hole 21.
1 along the longitudinal direction of the blade 1 of the fixed knife 230
Move toward 31. Then, by the rotation of the moving knife 220, the thread Ta captured by the looper 420 and connected to the looper 420 and the cloth is captured and approached to the fixed knife 230, and the thread Ta is cut by engaging the blade portion 221 with the fixed knife 230. I do. The drive device 313 for driving the moving knife 220 uses the same solenoid as the drive device 312 for raising the knob device 112 as a drive source.
2 may be configured to release the clamping of the workpiece W.

Further, as shown in FIG.
Numeral 0 is arranged on the lower surface of the moving knife 220, and the guide member 260 is arranged on the upper surface of the moving knife 220, and is fixed to the moving knife 220, respectively. The thread splitting member 250 has the same configuration as the conventional one shown in FIG. 7, and when the moving knife 220 moves, the thread splitting member 250 handles the thread so as to capture only the thread to be cut. To the blade portion 221 of FIG.

The guide member 260 constituting the prevention means includes:
As shown in FIG. 8 and FIG. 9, the distal end guide portion 260 </ b> A is arranged so as to extend above the blade portion 221 of the moving knife 220. When the moving knife 220 moves toward the fixed knife 230, the yarn captured by the yarn dividing member 250 is guided to the blade portion 221.
The zero tip guide 260A contacts the thread above the blade 221 to prevent the thread from contacting the blade 221.

The operation of the above-described thread cutting device 200 will be described. After the sewing is completed, the thread cutting arm 240 operates, and the moving knife 220 starts rotating. Moving knife 22
0 rotates, the thread dividing member 250 causes the thread Ta to be cut.
Is guided to the blade portion 221 of the moving knife 220, and the guide member 260 is engaged with the thread Ta to prevent the thread Ta from coming into contact with the blade portion 221. Further, the rotation of the moving knife 220 causes the guide member 260 to guide the thread Ta to the fixed knife 230, and the moving knife 220 and the fixed knife 230 engage to cut the thread Ta. The gripping of the sewing object W by the knob device 112 is released after the cutting of the thread Ta is completed.

As described above, the guide member 260 prevents the thread Ta from contacting the blade portion 221 of the moving knife 220, and guides the guide member 260 to the fixed knife 230, so that the blade portion 221 of the moving knife 220 is fixed. Until the blade Ta of the moving knife 220 starts to engage with the blade 231 of the knife 230, the thread Ta
21 does not come into contact with the thread Ta only with the moving knife 220.
Is prevented from being cut.

As shown in FIG. 4, the sewing machine constructed as described above has a feeding device 100 and a thread cutting device 20.
0 is provided with a control device 300 for controlling the operation of the control signal. The controller 300 starts the thread cutting device 20 after the sewing is completed.
The position of the button with respect to the fixed knife 230 is changed by controlling the operation of the feeding device 100 until the operation of the button 0 is performed. The control device 300
Is also used as a control device of the sewing machine, and controls sewing of the sewing machine.

The control device 300 has a CPU (Centra
l Processing Unit) 301 and RO
M (Read Only Memory) 302 and R
AM303 (Random Access Memory)
y), drive circuits 304, 305, 306, 307;
A start pedal 308 and an operation panel 309 are provided, and each unit is connected to each other via a system bus so that data can be input and output therebetween.

According to the control program and control data stored in the ROM 302 and the signals input by the start pedal 308 and the operation panel 309, the CPU 3
01 performs control of the entire control device and various data processing. R
The AM 303 is a storage unit used as a work area or the like of the CPU 301, and stores the contents stored in the ROM 302 or the result of the arithmetic processing of the CPU 301.

The drive circuit 304 is connected to the sewing machine motor 310 and controls the drive of the sewing machine motor 310 based on the result of the arithmetic processing of the CPU 301. By driving the sewing machine motor 310, the needle 410 moves up and down or the looper 420 rotates to form a stitch.

The driving circuit 305 is connected to driving devices 312 and 313 for driving the thread cutting device 200 and the pinching device 112, and controls the driving of the driving devices 312 and 313 based on the result of arithmetic processing by the CPU 301.

The drive circuit 306 includes a first drive motor 151
And controls the driving of the first drive motor 151 based on the result of the arithmetic processing by the CPU 301. Drive circuit 3
07 is connected to the second drive motor 152, and CP
The second drive motor 152 is calculated based on the calculation result of U301.
To control the drive of.

When the start pedal 308 is depressed, it outputs an operation signal to the CPU 301 or the like, whereby the sewing machine motor 310 operates.

The operation panel 309 outputs an operation signal to the CPU 301 or the like by operating a switch. Information relating to sewing can be input from the operation panel 309, and the CPU 301 performs arithmetic processing based on the information.
With the operation panel 309, setting of a sewing pattern,
The distance L (FIG. 8) between the knot portion formed at the final needle drop and the fixed knife 230 can be set.

FIG. 5 shows an example of the operation panel 309. As shown in FIG. 5, by operating the selection switch 321 of the operation panel 309, a sewing pattern of the button B to be sewn to the workpiece W can be set. By operating the selection switch 321, the LED 322 corresponding to the sewing pattern is turned on. In the present embodiment, for the four-hole button, three sewing patterns such as an X-shape or a side-by-side pattern and a sewing pattern for the two-hole button can be selected. When a sewing pattern is selected by operating the operation panel 309, the CPU 301 reads a sewing program corresponding to the sewing pattern from the ROM 302 based on an operation signal from the operation panel 309. The sewing machine motor 310, the first drive motor 151, and the second drive motor 152 are controlled based on the sewing program, and the button B is sewn to the workpiece W in the selected sewing pattern.

The selection switch 323 sets the distance L between the knot formed at the last needle drop and the fixed knife 230. In this embodiment, this distance is “far”
It is configured so that it can be set to five levels of “slightly far”, “normal”, “slightly close”, and “close”.
The ED 324 is arranged. Each time the selection switch 323 is operated, the selection is shifted, and the LED 324 corresponding to the distance is turned on accordingly.
The distance data between the nodule and the fixed knife 230 at each stage is stored as a distance (numerical value) in the ROM 302, and the CPU 301 reads the distance data from the ROM 302 by selecting the selection switch 323. The first drive motor 151 and the second drive motor 152 are controlled based on the distance data, and the center position of the button B with respect to the fixed knife 230 is adjusted. The distance data between the knot portion and the blade portion 231 of the fixed knife 230 at each stage is the same for any sewing pattern.

In this embodiment, furthermore, it is configured so that fine adjustment can be made between the respective stages. That is, the operation panel 30
By operating the 9 fine adjustment switch 325, the distance data stored in the ROM 302 in advance is corrected. The value L1 of the correction by the fine adjustment switch 325 is displayed on the display unit 326.

The operation panel 309 has a setting switch 328. By operating the setting switch 328, the CPU 301 outputs to the CPU 301 the selection of the setting state by the pattern selection switch 321, the distance selection switch 323, and the fine adjustment switch 325.

The operation panel 309 has a reset switch 327. By operating the reset switch 327, the data set by the pattern selection switch 321, the distance selection switch 323, and the fine adjustment switch 325 are reset to a default value. Can be set.

Next, the flow of sewing by the operation of the single-ring stitch sewing machine with a button according to the present embodiment will be described with reference to the flowchart of FIG. In the setting state where the setting switch 328 is operated (step S1), when the reset switch 327 is operated, the default value set at the factory shipment stage is set (step S2-S3). When the pattern selection switch 321 is operated (step S
4) A sewing pattern is selected and set according to the button hole of the button B (step S5). Also, a distance selection switch 3
When the operation of No. 23 is operated (Step S6), the distance L between the knot portion and the blade portion 231 of the fixed knife 230 at the time of final needle drop is selectively set (Step S7). When the fine adjustment switch 325 is operated as needed (Step S)
8) Based on the setting, the distance L between the knot portion and the blade portion 231 of the fixed knife 230 is corrected (L ± L1) (step S9). Various setting values are output to the CPU 301. When the start switch (not shown) is operated after the setting or when the setting switch 328 is not operated (step S10), a sewing program is started to perform a sewing operation (step S11).

In this sewing operation, the sewing machine motor 3
10, first drive motor 151 and second drive motor 15
2, the cloth presser mechanism 110 is moved in the XY direction so that the needles drop into the holes B1, B2, etc. of the button B according to the selected sewing pattern, and the predetermined number of stitches is A thread loop seam and a final needle drop thread knot are formed. During the sewing program, when a needle down position signal is generated from the well-known needle position detecting means 314 at the time of thread knotting of the last needle drop, the cloth feed of the distance L is performed in the rotation direction of the first drive motor 151 and the second drive motor 152. Then, the position of the button with respect to the fixed knife 230 is adjusted (step S12). Next, the driving device 313 is operated (step S13), and the thread cutting device 2
The moving knife 220 of 00 starts to move. Thereby, moving knife 2
Before the thread 20 captures the thread Ta, the guide member 260
Is captured, the captured thread Ta is moved toward the fixed knife 230, and the moving knife 220 is further moved, so that the blade 221 of the moving knife 220 is moved to the blade 2 of the fixed knife 230.
The thread Ta is cut by meshing with the thread 31. Thereafter, the driving device 312 operates to raise the knob device 112 (step S14).

The first feature of this embodiment is that when the sewing operation of the button B to the workpiece W is completed, strictly speaking, after the final needle drop is completed and before the moving knife 220 is operated. The position of the button B is adjusted by moving the button B with respect to the fixed knife 230 by the feeding device 100. For example, if “close” is set in step S6, the feeding device 1
When the button B is moved closer to the fixed knife 230 after the sewing is completed, the knot portion and the fixed knife 23 during the thread trimming operation are moved.
The distance L to 0 can be reduced. This allows
The remaining thread Ta which is cut and continues from the threading hole B1 of the button B
Becomes shorter. Therefore, the appearance of the knot is improved, and buttons suitable for fashionable clothing can be provided. Further, by bringing the knot portion by the final needle drop closer to the fixed knife, no tension is applied to the thread Ta while the moving knife 220 moves, and even if the guide member 260 is not provided, the moving knife is not moved. 220
The moving knife 22 when the blade portion 221 of the
It is possible to prevent the yarn from being cut only by zero. Therefore, the appearance of the cut portion of the yarn is prevented from being deteriorated.

For example, if "far" is set in step S6, the length of the remaining thread can be increased by releasing the button with respect to the fixed knife 230 after the feeding device 100 has finished sewing. If the length of the remaining yarn after the yarn cutting becomes longer, the knot becomes less likely to be frayed, and for example, it is possible to perform buttoning suitable for work clothing that does not need to care about appearance.

As described above, by adjusting the position of the button B with respect to the fixed knife 230 on the basis of the sewing pattern, the seam knot portion at the time of thread trimming is cut from the blade 2 of the fixed knife 230.
The distance L with respect to 31 is changed. That is, based on the sewing pattern selected in step S4, step S6
The control device 300 drives the feed device 100 after the end of the sewing so that the distance L becomes the distance L selected in. Therefore, the length of the remaining yarn after the yarn cutting can be arbitrarily changed. Thereby, according to the purpose of use of the sewing object,
A button can be attached to the sewing object. Also,
As in the above-described embodiment, the movement of the button for changing the distance L from the seam knot portion to the blade portion 231 of the fixed knife 230 starts when the needle lower position is detected by the final needle drop, and the needle moves to the upper position. The cycle time can be shortened when the adjustment is performed before the ascent is stopped. Further, the movement start timing may be set such that the movement of the button is completed before the blade portion 211 of the moving knife 210 or the distal end guide portion 260A of the guide member 260 engages with the thread Ta.

The second feature of this embodiment is that the position of the button with respect to the fixed knife 230 is adjusted based on the sewing pattern, so that the connection between the knot portion of the thread at the time of the final needle drop and the blade portion 231 of the fixed knife 230 is made. The purpose is to keep the distance L constant. The fixed knife 23 is set based on the selected sewing pattern so as to have the distance L selected in step S6.
By adjusting the button position with respect to 0, no matter what sewing pattern is selected, the distance between the knot portion of the thread and the blade portion 231 of the fixed knife 230 at the time of the final needle drop is always the distance selected in step S6. L.

For example, in a four-hole button, the needle 410
Selects a sewing pattern in which two stitches formed through the threading holes B1 and B2 of the button B become parallel stitches that are parallel to each other, and when “close” is selected in step S6, the ROM 302 The distance L between the seam knot portion and the blade portion 231 of the fixed knife 230 is controlled so that the distance data corresponds to “close” stored in the scalpel.
On the other hand, in the case of the four-hole button, an X-shaped sewing pattern in which the two stitches formed by the needle 410 passing through the threading holes B1 and B2 of the button B intersect each other at the center of the button B is selected. When "close" is selected in step S6, the distance L is controlled so as to be distance data corresponding to "close" stored in the ROM 302. Since the distance data between the knot portion and the blade portion 231 of the fixed knife 230 at each stage is the same for any sewing pattern, the distance L is always constant regardless of which sewing pattern is selected. it can. Therefore, no matter which sewing pattern is selected, the remaining thread length is always constant.

The third feature of this embodiment is that the operation panel 3
09 by the fine adjustment switch 325
By finely adjusting the distance L between the blade portion 231 and the knot portion, the distance L selected in step S8 is corrected (L
± L1). Thus, the fixed knife 230
By correcting the distance L between the blade portion 231 and the knot portion, even if the position of the knot portion changes due to a change in the size or type of the button or the like, the blade portion 231 of the knot portion and the fixed knife 230 changes. Can be suitably adjusted.

In the above-described embodiment, it is needless to say that the specific detailed structure can be variously changed without departing from the gist thereof. By moving the feed plate 111 and the knob device 112 back and forth and left and right, X
The cloth feeding mechanism 150 is not limited to the above-described configuration as long as it can be moved in the −Y direction. For example, the feed plate 111 and the knob device 112 are moved back and forth by one drive motor, and the feed plate 111 is moved by another drive motor.
The knob device 112 may be moved left and right. Further, in the present embodiment, the distance L between the blade portion 231 of the fixed knife 230 and the seam knot portion is set by five-stage selection, but the numerical value is directly input and set from the operation panel. Is also good.

[0062]

As described above, according to the first aspect of the present invention, the length of the remaining yarn after the yarn cutting can be arbitrarily changed. If the length of the remaining yarn after the yarn cutting becomes longer, the knot becomes less likely to fray, and for example, a button suitable for working clothes can be provided. On the other hand, if the length of the remaining yarn after the yarn cutting becomes shorter, the appearance of the knot becomes better, and for example, a button suitable for fashionable clothing can be provided. As described above, the sewing machine to which the thread cutting device according to the present invention is applied can attach a button to the sewing object according to the purpose of use of the sewing object. Further, the knot portion caused by the last needle drop of the sewing machine can be brought closer to the blade portion of the fixed knife. Therefore, when the moving knife draws the yarn, it is possible to prevent the yarn from being cut only by the moving knife. Therefore, the appearance of the cut portion of the yarn is prevented from being deteriorated.

Further, according to the second aspect of the present invention, the distance from the knot portion of the thread to the blade portion of the fixed knife at the time of the final needle drop can be always kept constant based on the sewing pattern. Even with a sewing pattern, the length of the remaining thread can be made constant.

According to the third aspect of the present invention, if the length of the remaining yarn after the yarn cutting becomes longer, the knot becomes less likely to fray and, for example, a button suitable for working clothes can be provided. On the other hand, if the length of the remaining yarn after the yarn cutting becomes shorter, the appearance of the knot becomes better, and for example, a button suitable for fashionable clothing can be provided. As described above, the sewing machine to which the thread cutting device according to the present invention is applied can attach a button to the sewing object according to the purpose of use of the sewing object.

According to the fourth aspect of the present invention, even if the size or type of the button is changed and the position of the knot portion of the thread at the time of the final needle drop changes, the knot portion and the fixed knife are changed. Can be suitably adjusted.

According to the fifth aspect of the present invention, it is possible to prevent the yarn from being cut only by the moving knife. As described above, since the yarn is prevented from being cut when the yarn is pulled, the appearance of the cut portion of the yarn is prevented from being deteriorated.

According to the sixth aspect of the present invention, it is possible to prevent the guide portion from squeezing the yarn and thereby contact between the blade portion of the moving knife and the yarn. Therefore, it is possible to prevent the thread from being cut only by the moving knife before the fixed knife and the moving knife start to mesh with each other. Since the cutting of the yarn is prevented when the yarn is pulled, the appearance of the cut portion of the yarn is prevented from being deteriorated.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of a feed device and a thread cutting device according to an embodiment.

FIG. 2 is a perspective view showing a main part of the thread cutting device in a see-through manner.

FIG. 3 is a perspective view showing a main part of the thread cutting device.

FIG. 4 is a block diagram illustrating a control device of the sewing machine according to the embodiment.

FIG. 5 is a plan view showing an operation panel provided in the sewing machine according to the embodiment.

FIG. 6 is a flowchart illustrating a flow of an operation of the sewing machine according to the embodiment.

FIG. 7 is a drawing schematically showing a thread cutting device provided in a conventional sewing machine.

FIG. 8 is a schematic cross-sectional view of a thread cutting device and a suturing portion in a thread cutting operation state according to the present embodiment.

FIG. 9 is a front view showing a main part of the thread cutting device of the sewing machine according to the embodiment.

[Explanation of symbols]

 Reference Signs List 110 cloth holding mechanism (holding means) 150 cloth feeding mechanism (feeding means) 200 thread cutting device 220 moving knife 221 blade section 230 fixed knife 231 blade section 260 guide member (preventing means) 260A tip guide section (guide section) 300 controller (Control means) 309 Operation panel (correction input means) 410 stitches

Continuation of front page (72) Inventor Fumihiko Yoshida 8-term, Kokuryo-cho, Chofu-shi, Tokyo 1 Juke Co., Ltd. F term (reference) 3B150 AA04 AA23 BA06 BB02 CE01 CE04 CE27 FH02 FH06 FH09 FH12 FH20 GF02 GF03 JA02 JA03 JA11 LA53 LA73 LB02 NA12 NA20 NA48 NB07 NB16 NC03 NC11 QA06 QA07 QA08

Claims (6)

[Claims] 1. A holding means for holding a button and an object to be sewn; a feeding means for moving the holding means so as to sew the button to the object to be sewn by a stitch of a predetermined sewing pattern; A moving knife that moves so as to cut the thread by cooperating with the fixed knife after the thread is unraveled,
In a button sewing machine for cutting a thread after sewing a button with a predetermined number of stitches, a control means for controlling the cloth feeding means so as to move the button for the fixed knife to a preset position before cutting the thread. A sewing machine with a button, comprising: 2. The control means moves the button with respect to the fixed knife so that the distance from the knot portion of the thread at the final needle drop to the blade portion of the fixed knife is always constant. The sewing machine with a button according to claim 1. 3. The control means changes the distance from the knot portion of the thread at the final needle drop to the blade portion of the fixed knife so that the remaining length of the thread after cutting the thread can be freely changed. 2. The sewing machine according to claim 1, wherein the button is moved with respect to the fixed knife. 4. A sewing machine with a button according to claim 3, further comprising correction input means for correcting the distance from the knot portion of the thread at the last needle drop to the fixed knife. 5. The apparatus according to claim 1, further comprising means for preventing the thread from coming into contact with the blade of the moving knife until the fixed knife engages with the moving knife. The sewing machine with a button according to any one of 1 to 4. 6. A method according to claim 6, wherein said preventing means has a guide portion which precedes a blade portion of said moving knife in a moving direction of said moving knife, said guide portion engaging with a thread and guiding to said fixed knife. The sewing machine with a button according to claim 5, wherein