JP2946684B2 - sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention is directed to cutting out a lower thread from a lower thread bobbin accommodated in a lower thread bobbin accommodating section provided in a bed section. Related to the sewing machine.

(Prior Art) For example, in a domestic sewing machine, when starting a sewing operation, a lower thread bobbin is accommodated in an inner hook, and a lower thread pulled out from the lower thread bobbin is provided in the inner hook. It is necessary to pass the lower thread through the tension generating section, and to draw the lower thread out of the required length from the tension generating section.

In this case, in the past, the lower thread was pulled upward from the needle hole of the needle plate to secure the required lead-out length.
In recent years, as shown in FIG. 8, a concave portion 3 formed on the upper surface of the bed portion 1 of the sewing machine is formed on the left side portion of the needle plate 2.
Provided with a cutting blade 4 therein. In this case, the lower thread 6 having passed through the tension generating section 5 is pulled out directly upward from a lower thread bobbin accommodating port 7 provided on the front side of the needle plate 2 in a state where the lower thread 6 has been drawn out in advance to be longer. While pressing the base side of the lower thread 6 with a finger, the middle side is pressed against the cutting blade 4 and the tip side is pulled, so that the tip of the lower thread 6 which is too long is cut off and set at an appropriate length. I can do it. Thus, the setting of the lower thread 6 is completed without pulling out the lower thread 6 from the needle hole 2a of the needle plate 2, and when the driving of the sewing machine is started in this state, the sewing needle moves up and down. As a result, the upper thread scoops the lower thread 6 and becomes stitched, so that a seam is formed on the work cloth and sewing is performed.

(Problems to be Solved by the Invention) However, in the above-described related art, since the cutting blade 4 is provided on the upper surface of the bed 1, the work cloth is hooked on the cutting blade 4 during the sewing operation, and the work cloth is cut. Feeding may not be performed properly. Further, since the cutting blade 4 is provided in an exposed state, the user may feel uneasy as to whether his / her finger may be cut by the cutting blade 4.

The present invention has been made in view of the above circumstances, and an object of the present invention is to facilitate the work of setting a lower thread, to feed a work cloth smoothly, and to use a cutting blade. An object of the present invention is to provide a sewing machine that can eliminate anxiety of an operator caused by the sewing machine.

[Structure of the Invention] (Means for Solving the Problems) The sewing machine of the present invention gives resistance to a lower thread bobbin removably accommodated in a bed portion and a lower thread derived from the lower thread bobbin in a pull-out direction. A tension generating section is provided, and a storage port for attaching and detaching the lower thread bobbin from the bed section is provided, and the lower thread is guided to a cutting blade covered with a cover section which is substantially flush with the bed section. A guide portion continuous with the accommodation port is fixedly provided, so that the lower thread derived from the lower thread bobbin is guided from the accommodation port to the cutting blade through the guide portion through the tension generating portion and pressed against the cutting blade. It is characterized in that it is cut by pulling operation.

(Operation) According to the above means, the lower thread is guided by the guide portion to the cutting blade by the user performing a pulling operation on the lower thread drawn out of the storage port, and is pressed and cut by the cutting blade.
Therefore, the user can easily cut the lower thread with one hand. In this case, the storage opening is open when the bobbin is stored, so that the bobbin thread can be drawn out without any effort, and can be displaced from or disengaged from the tension generating part when an excessive tensile force is applied to the bobbin thread. Can be easily checked, and the lower thread can be set without error. During the sewing operation, the accommodation opening is closed substantially flush with the bed portion and the cover portion covering the cutting blade is also provided substantially flush, so that the work cloth does not catch on the upper surface of the bed portion, and Since the cutting blade is not exposed, it is safe and does not give the user an uneasy feeling.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 7.

First, FIG. 5 shows the entire main body 11 of the sewing machine according to the present embodiment. Here, the main body 11 of the sewing machine is integrally provided with an arm 13 above a bed 12. A needle bar 15 on which an extraction needle 14 is mounted is provided at a tip end of the arm portion 13. The needle bar 15 is moved up and down by a drive mechanism (not shown). On the other hand, on the upper surface of the bed portion 12, a metal needle plate 16 as shown in FIGS. 1 to 4 facing the needle bar 15 is substantially flush with the upper surface of the bed portion 12. Is provided. The plate needle 16 is formed with a needle hole 16a through which the sewing needle 14 penetrates and a plurality of elongated holes 16b for operating a feed dog (not shown). An opened lower thread bobbin accommodation port 17 is formed. In addition, a transparent slide lid 18 which is slidably inserted in a slide groove 17a formed on the left and right portions thereof so as to be slidable in the front-rear direction as a lid closed substantially flush with the needle plate 16 in the storage opening 17 is opened and closed. It is supposed to be.

Further, a cloth feed mechanism (not shown) for driving the feed dog in synchronization with the vertical movement of the needle bar 15 is provided in the bed portion 12, and the cloth feed mechanism is provided below the storage port 17 of the needle plate 16. A horizontal shuttle mechanism 19, which is located at a position and performs a sewing operation in cooperation with the sewing needle 14 while supplying a lower thread, is provided.
As shown in FIG. 4, the horizontal shuttle mechanism 19 includes an outer shuttle 20 having a sword point 20a and rotating in the horizontal direction in synchronization with the vertical movement of the needle bar 15, and a bed portion in the outer shuttle 20. It comprises an inner pot 21 and the like provided in a detented state with respect to 12.
The inner hook 21 is provided with a cylindrical container-shaped lower thread bobbin storage section 22 having a shaft portion 22a, facing the lower thread bobbin storage port 17, and further provided on the front side of the lower thread bobbin storage section 22. A tension generator 23 is provided on the inner wall. Although not shown in detail, the tension generating portion 23 is configured by attaching a thread tension plate 23a and a thread tension spring 23b, both of which are arc-shaped, in an overlapping state. On the other hand, on the lower surface side of the needle plate 16, a pressing plate 24 made of, for example, made of plastic is attached by screwing at the accommodation port 17 portion. This holding plate 24
The inner shuttle 21 has a circular opening corresponding to the lower thread bobbin accommodating portion 22 of the inner shuttle 21, and the inner shuttle 21 is in a state where it is prevented from being lifted up by the presser plate 24. With this, the lower thread bobbin 26 (see FIG. 4) formed by winding the lower thread 25 is detachably fitted to the lower thread bobbin accommodating portion 22 through the accommodation port 17 with the slide cover 18 opened. Is to be included. At this time, the lower thread bobbin 26 is
The shaft 22 is loosely inserted into the shaft 22a, and is housed in a rotatable state around the shaft 22a. The bobbin thread 25 led out of the bobbin bobbin 26 accommodated is passed between the thread tension plate 23a and the thread tension spring 23b of the tension generating section 23, and is appropriately pulled out by a frictional force therebetween. Resistance is given.

The horizontal shuttle mechanism 19 configured as described above is
Is rotated in the direction of arrow A (see FIG. 4) on the outer periphery of the inner hook 21 and the upper needle loop (not shown) formed below the needle hole 16a by the sewing needle 14 is captured by the blade point 20a. The upper thread loop is entangled with the lower thread 25 derived from the tension generating section 23 so as to pass through the inner hook 21 so that a seam is formed.

Now, the needle plate 16 is provided with a thread cutting portion 27 which is located on the left side of the accommodation port 17 and cuts the lower thread 25. The thread cutting portion 27 includes a guide groove 28 extending in a substantially S-shape on the upper surface of the needle plate 16, and cutting teeth 29 provided below the guide groove 28. Hereinafter, the thread cutting section 27 will be described in detail.

As shown in FIG. 4, the needle plate 16 is formed with a notch 30 in a substantially rectangular shape on the left side of the accommodating opening 17 so as to be continuous. Further, an arc-shaped portion 30a is cut out at the back side of the cut-out portion 30 so that a part thereof straddles the left end of the accommodation port 17. On the other hand, the notch
A cover 31 is provided integrally so as to cover 30.
The upper surface of the cover 31 is the upper surface of the needle plate 16 and thus the bed.
12 The flat surface is substantially flush with the upper surface. A guide groove 28 is formed in the cover 31 so as to be continuous with the storage port 17 and open vertically. In this case, the starting end portion of the guide groove 28 is formed by an arc-shaped portion 30a cut out of the needle plate 16 and a covering portion 31.
Is formed by a gap with the protruding portion 31a.

The lower surface side portion of the cover portion 31 inside the bulge on the trouble side of the guide groove 28 is a mounting portion 32 for mounting the cutting blade 29. As shown in FIGS. 6 and 7,
The left and right and front wall surfaces of the mounting portion 32 are formed so as to taper downward, and a cutting blade 29 is provided at a lower end portion of the mounting portion 32.
The cutting edge 29a is fixed in a substantially vertical state with the cutting edge 29a facing forward. Thus, the cutting blade 29 is provided in the bed portion 12 with its upper portion covered by the cover portion 31.

With such a thread trimming section 27, the lower thread bobbin 26 is set in the lower thread bobbin accommodating section 22, the lower thread 25 is passed through the tension generating section 23, and then the lower thread 25 is suitable for starting a sewing operation. The tip part can be cut off in a state where only the length is pulled out. That is, as shown in FIG. 1, the lower thread 25 led upward from the accommodation port 17 through the tension generating section 23 is
The lower thread 25 is pulled from the starting end of the guide groove 28 so as to pass through the inside of the guide groove 28 along the S-shape.
28, the space around the mounting portion 32 is guided, and once turned back to the near side at the start end of the guide groove 28, then turned back to the back side by the cutting blade 29, so that the cutting blade 29 Cutting edge 29
It is pressed by a and cut. Therefore, the guide portion according to the present invention is fixedly formed in the space around the guide groove 28 and the mounting portion 32.

Next, an operation procedure for newly setting the lower thread bobbin 26 in the lower thread bobbin accommodating portion 22 and starting the sewing operation in the above configuration will be described.

First, the user removes the lower thread bobbin 26 from the accommodation port 17 and removes the lower thread bobbin 26 from the accommodation port 17 in a state where the slide lid 18 is removed.
And set it. Next, the bobbin thread 25 pulled out from the bobbin bobbin 26 is passed through the tension generating section 23, and the leading end thereof is inserted into the accommodation port.
Pull upward from 17. At this time, the lower thread 25 is previously drawn out longer. Then, as shown in FIG. 2 and FIG.
While lowering the lower thread 25 slightly
Turn to draw a character. Then, the middle portion of the lower thread 25 first enters the opening end of the guide groove 28, and the guide groove 28 is gradually guided. At this time, the bobbin thread 25 enters the space around the mounting portion 32 from the guide groove 28 as shown in FIGS. 6 and 7, and finally reaches the guide groove 28 as shown in FIG. The cutting blade 29 is guided to be folded at the start end portion and the cutting blade 29, and is pressed against the cutting edge 29a of the cutting blade 29 to be cut. Thereby, the tip of the lower thread 25 is cut off in a state where the lower thread 25 is pulled out from the tension generator 23 by a predetermined length. Further, at this time, the cutting blade 29 is so-called sharp so that the lower thread 25 is cut with a weak tensile force such that the lower thread 25 is not pulled out from the tension generating portion 23.

Thereafter, the slide cover 18 is closed, and the bed 12 (the needle plate 1) is closed.
6) Set a work cloth (not shown) on the top and drive the sewing machine. Then, at the first stitch, by the cooperation of the sewing needle 14 and the horizontal shuttle mechanism 19, the loop of the upper thread scoops out the lower thread 25 which is led out while being given appropriate pull-out resistance from the tension generating part 23. The sewing is performed in view of this. In this case, the path of the bobbin thread 25 from the tension generating section 23 to the cutting blade 29 is substantially constant, and the bobbin thread 25 is cut at an appropriate drawing length. The sewing operation can be started without any trouble without the drawer length being too long or too short.

Also, during this sewing operation, most of the thread cutting portion 27 except the guide groove 28 is covered with the covering portion 31 which is flush with the needle plate 16, so that the thread cutting portion 27 is smoothly caught without being caught. The work cloth can be fed, and the cutting blade 29 is not exposed on the upper surface of the needle plate 16 whose upper part is covered by the cover part 31, so that it is excellent in safety and gives anxiety to the user. There is no.

As described above, according to the present embodiment, the operation of cutting the lower thread 25 is performed by pulling out the lower thread 25 passing through the tension generating portion 23 above the accommodation port 17 and turning the lower thread 25 so as to draw an S-shape. It can be done very easily by a series of smooth movements with one hand, which passes through 28, and a storage port for leading out the lower thread 25
17 is open when the bobbin bobbin 26 is attached and detached, so that it can be performed without any effort.
Since the setting state of the lower thread 25 through 23 is clear at a glance,
Even if the position of the lower thread 25 with respect to the tension generating section 23 due to excessive pulling of the lower thread 25 can be corrected in advance.

In the present embodiment, unlike the conventional one in which the cutting blade 4 is exposed on the upper surface of the bed 1, the upper part of the cutting blade 29 is formed by a covering part 31 whose upper surface is substantially flush with the needle plate 16. Since the cover 17 is covered and the storage opening 17 is also closed by a slide cover 18 which can be opened and closed in the same manner, the work cloth can be smoothly fed, and, at the same time, the user is excellent in safety and excellent in safety. Can eliminate the feeling of anxiety. In addition, since the cutting blade 29 can be made so-called sharp with the excellent safety, there is also obtained an advantage that the cutting operation of the lower thread 25 can be performed easily without applying much force. Things. Further, when cutting the lower thread 25, only the tip pinched by the finger on the cut side is pulled out to the upper surface of the bed portion 12, so that the base portion does not get caught at the start of sewing.

In the above embodiment, the cover portion 31 is provided integrally with the presser plate 24. However, the cover portion may be provided by another member, or the cover portion may be constituted by the needle plate 16, for example. Further, the guide groove 28 is not limited to the S-shape, and may be formed in a simple arc shape. Further, the cutting blade 29 may be provided not in a vertical shape but in a substantially horizontal blade edge 29a. The lower thread may be configured to be guided by the guide portion and pressed against the cutting blade by the operation of the lower thread above.

In addition, the present invention can be appropriately modified and implemented without departing from the gist.

[Effects of the Invention] As is apparent from the above description, according to the sewing machine of the present invention, the work for setting the lower thread can be facilitated. And an excellent effect of eliminating the user's anxiety due to the cutting blade.

[Brief description of the drawings]

1 to 7 show an embodiment of the present invention. FIG. 1 is a perspective view of the main part, and FIGS. 2 and 3 show the state of the main part in order of a lower thread cutting operation. FIG. 4 is an exploded perspective view of a horizontal shuttle mechanism, FIG. 5 is a perspective view of a sewing machine main body, and FIG.
The figure is a vertical front view of the guide section, and FIG. 7 is a vertical side view of the guide section. FIG. 8 is a perspective view of a main part showing a conventional example. In the drawing, 12 is a bed portion, 16 is a needle plate, 17 is a storage port, 29 is a horizontal shuttle mechanism, 21 is an inner shuttle, 22 is a lower thread bobbin storage section, 23 is a tension generating section, 24 is a presser plate, and 25 is The lower thread 26 is a lower thread bobbin, 27 is a thread cutting section, 28 is a guide groove (guide section), 29 is a cutting blade, 31 is a cover section, and 32 is a mounting section.

Continuation of the front page (56) References JP-A-2-74286 (JP, A) JP-A-53-106146 (JP, U) Patent 2819685 (JP, B2) JP-B-56-20876 (JP, B2) JP 61-10631 (JP, Y2) JP-61-8852 (JP, Y2) JP-56-54946 (JP, Y2) JP-B 46-9625 (JP, B1)

Claims (1)

(57) [Claims] A lower thread bobbin accommodating section provided in a bed section for detachably accommodating a lower thread bobbin, and an openable and closable lid opened to the bed section for detachably operating the lower thread bobbin, and the bed section is substantially formed. A storage port that is closed at the same time, a tension generating unit that provides resistance to pulling out a lower thread drawn from the lower thread bobbin,
A cutting blade provided in the bed portion, a covering portion provided substantially flush with the bed portion for covering the cutting blade, and a lower thread fixedly provided in the bed portion so as to be continuous with the accommodation port. And a guide part for guiding the lower thread to the cutting blade.The lower thread is led out from the lower thread bobbin in a state where the storage port is opened, and the lower thread is guided from the storage port through the guide part through the tension generating part. A sewing machine characterized in that the sewing machine is guided to a cutting blade and is cut by a pulling operation so as to press against the cutting blade.