JPS639487A - Yarn cutter in embroidering machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention aims to solve the following problems.

(Industrial Application Field) This invention is applicable to an embroidery sewing machine, in which the needle thread and the bobbin thread can be cut in order to make a major change in the embroidery stitching area or to finish embroidery stitching, or to cut the upper thread and bobbin thread in order to make a small change in the above-mentioned location or to change the embroidery stitching area. This invention relates to a thread cutting device for an embroidery sewing machine that cuts only the upper thread in order to change the color of the upper thread.

(Prior art) Conventional thread cutting devices that cut the upper thread and bobbin thread at the same time using a cutting blade that moves along the lower surface of the throat plate do not cut the needle thread and the bobbin thread at the same time. Even when changing the embroidery location or color, the bobbin thread is cut and many of the cut ends of the bobbin thread remain on the back side of the fabric, so the back side of the embroidered fabric is extremely clean. There was a problem with the situation. In addition, when cutting is performed as described above, the upper thread is cut at a position close to the needle, and the upper thread remaining on the needle side is scraped and shortened (as a result, as the needle rises, There was also the problem that the upper thread often fell out of the needle.

(Problems to be Solved by the Invention) This invention eliminates the above-mentioned conventional problems, and in the case of cutting only the needle thread, the needle thread on the side that is connected to the bobbin thread and the needle and has a shorter distance to the needle. A thread cutting device for an embroidery sewing machine that can cut only the upper thread on the side closer to the fabric exactly without cutting the upper thread, while also responding to requests for cutting both the upper thread and the lower thread. This is what we are trying to provide.

The configuration of the present invention is as follows.

(Means for Solving the Problems) The present invention takes the measures as described in the claims above, and its effects are as follows.

(Operation) When cutting only the upper thread, when the bobbin thread sweeper moves to the sweep position, the bobbin thread between the needle threading hole and the hook is swept out of the movement path of the cutting blade. be dismissed. Also, when the upper thread hooking piece is moved to the hooking position,
When the upper thread that has been lowered by the needle and passed through the hook is removed upward from the hook, it is caught in a loop shape by the upper thread hooking piece and is separated into the fabric side needle thread and the needle side needle thread. Thereafter, the cutting blade moves forward and cuts only the fabric side needle thread. On the other hand, when cutting both the upper thread and the bobbin thread, the bobbin thread wiper is held at the retracted position. Then, both the upper thread and the lower thread are cut by the cutting blade.

(Embodiments) The drawings showing the embodiments of the present application will be explained below. 1 is a throat plate having a metering hole 1a, 2 is a hook located below the throat plate 1, and includes an outer hook 3 which is designed to be rotated in the direction of the arrow; It is configured in a well-known manner with an inner pot 5 which is prevented from rotating by a stopper (not shown). Note that a bobbin case for a bobbin for bobbin thread is housed in the inner hook 5. Reference numeral 6 indicates a thread guide, and reference numeral 7 indicates a needle disposed above the throat plate l, which is configured to be vertically movable so as to be able to descend through the metering hole 1a, as is well known.

Next, reference numeral 8 denotes a bobbin thread wiper that is pivotally supported on the throat plate 1 via a pivot 13, and is moved by an operating mechanism 9 across the bobbin thread path between the needle hole 1a and the shuttle hook 2 as shown in FIG. The retreat position shown and the 14th
At the sweep-off position, the bobbin thread a is hooked on the thread hooking portion 8a and is swept away to a location away from the movement locus of the cutting blade, which will be described later. In the operating mechanism 9, 10 is a rotating shaft rotatably supported by the frame F, 11 is an operating arm fixed to the rotating shaft 10, and has an engagement groove 11a formed therein for its protection. 7?1l
At la, an engagement pin 8 is provided that protrudes from the lower surface of the bobbin thread sweeper piece 8.
b is engaged. Reference numeral 12 denotes a rotating arm fixed to the rotating shaft 10, and a connecting body 43 is attached to the tip end as shown in FIG.
is rotatably attached via a port 44. 1
Reference numeral 3 denotes a driving rod fixedly attached to the connecting body 43, and a driving means 50 is connected to this rod.

In the driving means 50, reference numeral 51 denotes a motor capable of forward and reverse rotation, and the rod 13 is pivotally attached to the distal end of an arm 52 attached to a rotating shaft 51a using a connector 53.

Therefore, by reciprocating the arm 52 of the driving means 50 as shown by the arrow, the bobbin thread removing piece 8 changes from the state shown in FIG. 1 to the state shown in FIG.
It is designed to reciprocate between the state shown in the figure.

Next, reference numeral 40 denotes a low-lead solenoid fixed to the frame F, which will be exemplified as driving means for the upper thread hooking piece 14, which will be described next. , 41 is rotary solenoid 4
The swinging arm 42 is fixed to the rotation shaft 40a of 0, and the operating arm 42 is fixed to the swinging arm 41.

Reference numeral 14 denotes an upper thread hooking piece provided at the tip of the operating arm 42, which is located at a retracted position away from the hook 2 as shown in FIG. 1 and facing into the hook 2 as shown in FIG. It is arranged so as to be movable between the hooking position and the hooking position, and at the hooking position, the loop-shaped upper thread thread passing through the shuttle hook 2 is hooked in the process of being pulled upward. Further, the upper thread hooking piece 14 is formed wide in the horizontal direction, and the right upper thread bl of the loop-shaped upper thread hooked on itself is formed wide.
(meaning the needle thread bl on the side connected to the cloth 15) and needle thread b2 (meaning the needle thread b2 on the side connected to the needle 7) are spaced from each other.

Next, reference numeral 16 denotes an operating arm of the thread trimmer, which is pivotally supported on the needle plate 1 via a pivot 17, and a movable blade 18 constituting a cutting blade is provided at the tip. The operating arm 16 is rotated by a predetermined amount when necessary by an operating mechanism 19, which will be described later, to move the movable blade 18 between a retracted position away from the hook 2 as shown in FIG. 1 and an operating position shown in FIG. It's like letting them do it. In the above-mentioned movable blade 1B, reference numeral 20 denotes a thread hooking part extending in the direction of rotation toward the operating position, and a thread guide part 20a formed so as to move away from the center of rotation as it goes rearward from the front end. and a hook recess 20b that is depressed from the rear end of the thread guide 20a toward the center of rotation.

21 is a cutting hole formed near the front end of the thread hooking part 20;
Reference numeral 22 denotes a cutting edge portion formed on the upper edge of the front end side of the cutting hole 21, and is formed by providing a spherical bulge portion 23 around the front end side of the cutting hole 21. 24 is the above-mentioned hook recess 20
A thread guide groove is formed extending from b to the cutting hole 21.

In the operating mechanism 19, 25 is a rotating shaft rotatably supported by the frame F, 26 is an operating arm that is properly attached to the rotating shaft 25, and has an engaging groove 26a formed therein. A retaining pin 16a that protrudes from the lower surface of the operating arm 16 is engaged with the matching groove 26a. Reference numeral 27 denotes a rotating arm fixed to the rotating arm 25, and a connecting body 29 is rotatably attached to the tip of the rotating arm via a bolt 45, as shown in FIG. Reference numeral 28 denotes a driving rod fixedly attached to the connecting body 29, and a driving means 60 is connected to one end thereof. Since the driving means 60 has the same structure as the driving means 50, each member is given the same reference numeral as the driving means 50, and redundant explanation will be omitted.

Next, reference numerals 30 and 31 designate a pair of upper and lower blade housing arms that are fixedly attached to the throat plate 1, and a housing space 32 at the distal end of the arms that accommodates the movable blade 18 in the retracted position is provided between the arms as shown in FIG. is formed. Reference numeral 33 denotes a fixed blade formed on the upper blade housing arm 30, which is provided with a cutting blade part 34 on the artificial side edge that cooperates with the cutting blade part 22 of the movable blade 18 to make an uncut cut. There is. 5
Reference numeral 5 denotes a control device that gives operating commands to the motor 51 of each drive means 50, 60 and the rotary solenoid 40.

In the case of the above structure, the upper thread a is passed through a total of seven holes,
When the bobbin for the bobbin thread is set in the bobbin case and the embroidery sewing machine is operated, the needle 7 moves up and down through the needle hole la and the outer hook 3 rotates in the direction of the arrow, thereby sewing embroidery on the fabric in a well-known manner. can be administered.

Next, when cutting both the upper thread b1 and the bobbin thread a on the right side of the upper thread when moving on to embroidery sewing another pattern after finishing embroidery sewing of one pattern, each member is It operates as shown in FIGS. 6 to 13. In this case, no command is given to the drive means 50, and the bobbin thread wiper piece 8 remains stationary at the retracted position.

First, at point (a) when the cycle angle is 0 degrees as shown in FIG. The piece 14 is located in the retracted position shown in FIG. 1. At the point (b) when the cycle angle is 25 degrees, the needle 7 starts to descend and the tip 3a of the outer hook 3 is positioned directly above. Ru.

Next, at time (c) when the cycle angle is 120 degrees, a total of seven needle tips enter the needle through hole 1a, and the tip 3a of the outer hook 3 is positioned directly below. Next, at point (d) when the cycle angle is 180 degrees, a total of seven needle tips are positioned at the bottom dead center, and then at point (e) when the cycle angle is 205 degrees, the needle tips start to rise slightly. At the same time, the tip 3a of the outer hook 3 is positioned directly above again, and at this point, the tip 3a of the outer hook 3 catches the needle thread fed out by the needle 7. Thereafter, the low-kly solenoid 40 is energized, and as a result, the t8 moving bowl 4
1 and the operating arm 42 are swung to move the upper thread hooking piece 14 to the hooking position shown in FIGS. 6 and 7. As a result, the tip of the upper thread hooking piece 14 enters into the hook 2 as shown in FIG. Next, when the cycle angle reaches 290 degrees, a total of seven needle tips are raised to near the rising end, and the tip 3a of the outer hook 3 is rotated directly downward again, so that the tip 3a is raised upward. Hook the thread and transport. In this process, the upper thread b1 on the right side of the upper thread holder comes into contact with the upper thread hooking piece 14, and the upper thread holder also passes through the inner hook 5. Then, with a cycle angle of 353 degrees (
At point (g), the needle thread has finished passing through the inner hook 5, and the tip 3a is rotated directly to the side and faces upward.
At this point, the upper thread comes off the tip 3a and is pulled upwards (
(by the scales) As a result, the needle-side needle thread b2 of the needle thread stop is caught on the needle thread catch piece 14, and the needle thread stop becomes triangular between the needle hole 1a and the needle thread catch piece 14, as shown in FIG. .

Further, at the above point (g), the drive rod 28 begins to be moved to the left in FIG. 1 by the drive means 60. As a result, the rotating arm 27 and the operating arm 26 are swung, and the movable blade 18 begins to be swung from the retracted position shown in FIG. 1 to the operating position shown in FIG. 1O. When the movable blade 18 is swung toward the operating position, first, as shown in FIG. b2, and at a subsequent point in time, due to the swinging of the movable blade 18, the thread guide section 20a moves the right upper thread b1 and the lower thread a by the rotation of the movable blade 18, as shown in FIG. Move it away from the center. Thereafter, when the movable blade 18 reaches the operating position as shown in FIG.
It comes off and enters the hook recess 20b. After that, movable blade 1
8 is returned to the retracted position, the hooking recess 20b hooks and moves the right upper thread bl and lower thread a as shown in FIG. ．．
a enters the thread guide groove 24. Thereafter, when the movable blade 18 is housed in the blade housing arm 30.31, the cutting edge portion 22 of the movable blade 18 and the cutting edge portion 34 of the fixed blade 33 as shown in FIG.
pinches and cuts both yarns bl and a.

Energization to the rotary solenoid 40 is stopped after the right upper thread bl and lower thread a are cut,
The needle thread hooking piece 14 is returned to the retracted position.

After that, the cloth is moved laterally and embroidery begins at a new point on the cloth, but in this case, the needle-side upper thread b2 is not cut and there is a sufficient length of thread below the total 7. Therefore, it is possible to prevent the upper thread from coming off from the needle 7 at the time of starting sewing, and embroidery sewing can be started without any accidents.

Next, if you want to cut only the right side needle thread b1 of the needle thread when moving on to embroidery stitching of another pattern after finishing embroidery stitching of one pattern, as shown in Figs. 14 to 20. It operates to cut only the right needle thread b1. In this case, first, (
(b) Near the point in time, the drive rod 13 is slowly moved to the left in FIG. Slowly rock vj into position. As a result, the thread hooking part 8a of the bobbin thread sweeper piece 8 hooks the bobbin thread a, moves it slowly to the side so as not to break the thread, and (
c) At around the time point, as shown in FIG. 14, the lower thread a between the needle hole 1a and the hook 2 is moved to the upper thread pulling piece 14 side of the operating position. Thereafter, the operation is the same as in the case of cutting both threads bl and a, and at time (1), the needle thread hook is hooked on the needle thread hooking piece 14 as shown in FIG. As shown in the figure, the tip of the movable blade 18 enters between the bobbin thread a and the right upper thread b1, which have been shifted to the side.
guides only the right upper thread bl, and at point (N), only the right upper thread b1 enters the hooking recess 20b as shown in FIG. Then, at the point (l), only the right needle thread b1 is cut, as shown in FIG. 19. The bobbin thread wiper piece 8 is returned to the retracted position after the right needle thread b1 is cut.

In addition, in both operations shown in FIGS. 13 and 20 above,
The upper thread hooking piece may be moved from the retracted position to the operating position at any point within the range indicated by A.If the movement of the movable blade 18 is changed as shown by the two-dot chain line, the movable blade 18 can be moved slowly. The arm 52 of the drive means 50 is equipped with a knob for manual scraping, and by operating the knob, the arm 52 of the drive means 50 can be moved as shown in FIG. The bobbin thread wiper may be moved between the solid line position and the 2-point!3\ line position, and the bobbin thread wiper piece may be moved between the retracted position and the retracted position, or it may be stopped at the solid line position and then at the retracted position. .

(Effects of the Invention) As described above, in the present invention, after finishing embroidery of one pattern, when moving to another G4-like embroidery stitch at a nearby position, the needle thread only needs to be threaded. If you want to cut the lower thread a, use the bobbin thread sweeper 8 on the lower side of the throat plate 1 to actively sweep the bobbin thread a away from the locus of movement of the cutting blade, and use the needle thread catcher 14 to remove the bobbin thread b1 from the needle. Since the needle thread b2 is separated from the needle thread b2 and the cutting blade advances in this state, the lower thread a and the needle thread b
It has the feature that only the right needle thread b1 can be accurately cut with the cutting blade without cutting the thread b1. This has the effect of helping to solve the conventional problems.

Furthermore, in the above case, even if there is slack in the bobbin thread due to the sewing speed, the tension of the bobbin thread, or the properties of the bobbin thread itself, and this slack could cause the bobbin thread to enter the locus of movement of the cutting blade, Since the bobbin thread is actively brushed away by the bobbin thread sweeper 8 as described above, there is also the advantage that the accurate cutting effect of only the right side needle thread b1 as described above can be maintained.

On the other hand, if you want to cut both the upper thread and the bobbin thread a, such as when the embroidery stitches have a large jump or when the embroidery stitches are finished, the bobbin thread sweeper piece 8 should be kept stationary at the retracted position. By doing so, it has the advantage that both threads A and A can be cut together by the cutting blade.

This has the advantage of preventing long bobbin threads from remaining on the underside of the fabric, resulting in a beautiful finish on the embroidered fabric.

[Brief explanation of the drawing]

The drawings show an embodiment of the present application, and Fig. 1 is a plan view of the main parts of the embroidery sewing machine, Fig. 1 is a cross-sectional view taken along the line l-1, and Fig. 2 is a cross-sectional view of a part of Fig. 1. The front view shown in Figure 3 is ll.
l-1
The figure is a sectional view taken along line V-V, Figure 6 is a plan view showing the operation of the upper thread hooking piece, Figure 7 is a front view as well, and Figures 8 to 11 are both threads of the upper thread and lower thread on the right side. An operation explanatory diagram showing the cutting operation, Fig. 12 is a sectional view showing the operation of the cutting blade, Fig. 13 is a time chart showing the operation for cutting both threads, and Figs. 14 to 1.
FIG. 9 is an operation explanatory diagram showing the operation for cutting only the right upper thread, and FIG. 20 is a time chart diagram as well. l... Throat plate, 1a... Needle hole, a... Lower thread, b
... Upper thread, bl... Right side upper thread, b2... Needle side upper thread, 8... Lower thread removing piece, 14... Needle thread hooking piece, 18.
...Movable blade (cutting blade). Figure 3 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 14 Figure 1d Figure 16 Figure 17 Figure 18 Figure 19

Claims (1)

[Claims] A hook is provided below the needle plate having a needle through hole, and a vertically movable meter is provided above the needle plate so as to be able to move downward toward the hook through the needle hole. In an embroidery sewing machine in which embroidery stitches are performed on cloth by moving the needle up and down, the needle thread is fed out through the needle and the bobbin thread is fed out from the shuttlecock. The bobbin thread sweeper piece, which is used to sweep away the bobbin thread between the shuttle and the above-mentioned hook to a location that is out of the travel trajectory of the cutting blade, is moved back and forth between the sweep position and the retracted position, and remains stationary at the retracted position. The upper thread hooking piece is arranged to be selectively operable, and is positioned within the loop of the upper thread when the upper thread passes through the hook and is pulled upward in a looped state. and a retracted position, and the upper thread hooking piece is arranged so that the upper thread on the fabric side and the upper thread on the needle side are separated from each other when the upper thread is located in the looped upper thread. It is formed to be wide, and further below the throat plate, when the loop-shaped needle thread is caught on the needle thread hooking piece, the expected position of the fabric-side needle thread in the loop-shaped needle thread and the A thread cutting device for an embroidery sewing machine, characterized in that a cutting blade is provided that can advance through the position where the lower thread is expected to exist to cut the upper thread and the lower thread on the fabric side.