JP2002282565A - Zigzag lock stitch sewing machine and pintuck forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a worker to easily, efficiently and stably sew uniform and beautiful pin-tucks regardless of its skill by improving the stability stitch balancing thread tension, the feeding stability of a sewing matter (cloth), and the visual confirmability of seams in sewing in the formation of pin-tucks by use of a zigzag lock stitch sewing machine. SOLUTION: A throat plate 11a comprises a hole 12a located between the lateral needle locating positions 20a and 20b of one needle and extended long in the feeding direction S of a sewing matter 13. A guide plate 10 for freely inserted to the hole 12a from the upper surface side of the throat plate 11a is formed on the lower surface of a presser 8. A feed dog 14a has a U-shaped sectional U-groove 15a in a position opposed to the hole 12a to work a feeding force to a pin-tuck part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zigzag lockstitch sewing machine and a method for forming a pin tack using the same. In particular, for a zigzag lockstitch sewing machine, while swaying one needle left and right, the other thread lacing (i
(interlacing a thread with another thread or another loop).

[0002]

2. Description of the Related Art There is an increasing demand for a sewn product (cloth) to which a pin tack is applied because it has a function of expanding and contracting the sewn product (cloth) and a unique decorative property. A pin tack can be formed by folding back a sewn product (cloth) and stitching the opposing portion along the folded portion. The sewing thread may be left, but the pin tack is formed by basting, the sewn product (cloth) is heat-treated to fix the pin tack shape, the suture is removed by removing the sewing thread, and the pleated pin tack becomes semi-permanent. Formed. By applying a large number of such pin tacks, a material with good elasticity can be formed, and the surface of clothing and the like can be decorated and a unique material feeling can be obtained, and its popularity is high.

In general, when performing basting, simplicity of the operation of removing the basting thread is an important issue in production. Further, in the case where the pin tack is used as a decoration, the uniformity and the degree of freedom of design become problems, and a sewing machine capable of reliably sewing a uniform and beautiful pin tack regardless of the skill of a skilled worker is desired. In addition, if there is a sewing machine that can easily sew not only a straight line but also a curved pin tack without deteriorating its uniformity, the degree of freedom of design is widened and ideal. Generally, a sewing machine is required to have visibility of a seam at the time of sewing. That is, a sewing machine that allows the operator to visually check the state of the seam while the sewing operation is in progress is desirable.

Conventionally, in order to sew a pin tack formed by folding a sewn product (cloth) into a U-shape, an existing staggered sewing machine is modified and used for pin tack sewing, or an existing lockstitch sewing machine is used. Or was. At that time, sewing was performed by the following sewing method.

[Conventional Example 1] FIG. 11A shows a case in which an existing staggered sewing machine is modified and used (referred to as Conventional Example 1).
This will be described with reference to FIG. When the existing staggered sewing machine is modified and used, as shown in FIG. 11 (a), a needle bar 6 for two needles is attached to the lower end of the needle bar 1 of the existing staggered sewing machine, and The needle 2a and the needle 2b are attached. The upper thread (not shown) is passed through each of the needles 2a and 2b. A projection 7 is provided on the upper surface of the needle plate 4. Thereby, the sewn product (cloth) 3 is deformed into an inverted U-shape. The shape of the pin tack can be adjusted by the height of the projection 7. Use the zigzag sewing machine with the needle swing stopped. When the sewing product (cloth) 3 is set on the sewing machine, the sewing product (cloth) 3 has an inverted U-shaped pin tack shape along the protrusion 7 on the upper surface of the needle plate 4. When the sewing machine operates, the left and right needles 2a and 2b simultaneously penetrate the sewing product (cloth) 3, and the upper thread passed through the left and right needles 2a and 2b races with the lower thread of the shuttle 5. As a result, a pin tack is applied to the sewing product (cloth) 3.

[Conventional Example 2] When an existing lockstitch sewing machine is used (referred to as Conventional Example 2), as shown in FIG. 11 (b), a sewing product (cloth) 3 is folded, and a needle 2 is placed at a pin tack portion. After the sewing is completed, the sewing product (cloth) 3 is opened to secure the pin tack shape.

[0007]

However, the conventional example 1 in which the above-mentioned existing staggered sewing machine is modified and used has the following problems.

First, in the conventional example 1, the left and right hands 2a, 2b
The two upper threads passed through the lace are laced by the staggered sewing hook 5, so that the hook 5 scoops the left and right upper threads, but the two needles separated by the interval between the left and right needles 2a and 2b. Needle 5
It is difficult to scoop with the tip of the sword, and there is a problem that the exquisite sword tip alignment, such as the timing of scooping the left and right threads, is forced.

Secondly, in Conventional Example 1, after the sword of hook 5 is aligned,
Since the timing of thread removal of the left and right upper thread from the hook 5 is different, the sewing condition is not uniform, and the point at which the left and right upper thread passes through the hook 5 from the point at which the sword tip of the left and right upper thread scoops. Until then, the upper thread on both sides will interfere in the hook 5,
This causes a problem that the thread tension becomes unstable.

Thirdly, in Conventional Example 1, since the joining point of the thread is at the lower surface of the sewing product (cloth) 3 at the time of sewing, despite the unstable sewing condition, it is confirmed that the sewing condition is not correct. There was a problem that it was not possible to work. That is, the visibility of the seam is poor.

Fourthly, in the conventional example 1, there is a problem that wrinkles, twists and the like are generated in the pin tack shape and the pin tack shape becomes unstable. The reason is that the inverted U-shaped pin tack portion protrudes from the upper surface of the sewn product (cloth) 3 and is not in direct contact with the feed dog but is located far away from the feed dog. The point that the feeding force is hardly transmitted to the pin tack portion, the pressing (not shown) by the inverted U-shaped pin tack portion formed on the upper surface of the sewing product (cloth) 3 and the left and right needles 2a and 2b.
Are touched and easily interfered with each other, and a force acts in a direction that hinders the feed of the sewn product (cloth) 3, and the inverted U-shaped pin tack portion stands on the upper surface of the sewn product (cloth) 3. And the shape tends to be unstable due to the influence of gravity. In order to correct the pin-tuck shape, the worker has to work with both hands, pulling the sewing material (cloth) 3 in the feed direction and carefully guiding it. The uniformity of the product depends on the skill of the worker. It had been. Curved pin tacks, etc., also required the skill of the operator.

Fifthly, in the first conventional example, there is a problem that the thread removing operation cannot easily perform the butt sewing. Generally, in sewing machines, the tension of the lower thread is very weak relative to the tension of the upper thread,
It is difficult to sew the lower thread in a straight line even if the lower thread is strengthened. For this reason, in Conventional Example 1, the two upper yarns are provided in a straight line, and the lower yarns are provided in a staggered manner, making it difficult to pull out any of the yarns.

On the other hand, a conventional example 2 using an existing lockstitch sewing machine
Has the following problems. In other words, in the case of sewing with the lockstitch sewing machine, the sewn product (cloth) 3 is folded each time at the pin tack position, and the folded portion is sewn while the worker manually guides the folded portion. There is a problem that it is difficult to sew them evenly, for example, when sewing back (two or more) pin tacks. Further, in Conventional Example 2, the sewing product (cloth) 3 is bent, and the double sewing product (cloth) 3 near the bent portion is sewn with one upper thread and one lower thread, so that the pin tack becomes loop-shaped. As a result, there has been a problem that a U-shaped pin tack cannot be formed, and a thread removing operation cannot be easily performed without false sewing.

The present invention has been made in view of the above-mentioned problems in the prior art, and in forming a pin tack using a staggered lockstitch sewing machine, it is not necessary to force an exquisite sword tip, and the thread tension can be stabilized. Performance, stability of feed of the sewn product (cloth), and improved visibility of stitches at the time of sewing, enabling uniform, beautiful pin tack to be stitched easily, efficiently, and stably regardless of the skill of the operator. The task is to

[0015]

According to a first aspect of the present invention, there is provided a needle swing mechanism for swinging one needle 31 left and right, and a left and right swinging mechanism corresponding to the swing width of the needle 31. And a pair of horizontal shuttles 33, 3 rotating in opposite directions to each other.
4, a needle plate 11 disposed above an intermediate portion between the pair of horizontal shuttles 33, 34, a presser 8 for holding a sewing material 13 placed on the upper surface of the needle plate, A feed dog 14 which is provided below and feeds the sewing material 13 in a direction orthogonal to the needle swing direction in cooperation with the lower surface of the presser 8. The needle plate 11b has a groove 12b that is located between the drop positions 20a and 20b, extends in the feed direction S of the sewing product 13 and is open on the upper surface of the needle plate 11b. Guide plate 10 loosely inserted into groove 12b from the top side
Is provided on the lower surface of the presser 8.

Therefore, according to the first aspect of the present invention,
A needle swing mechanism for swinging one needle to the left and right, and a pair of horizontal shuttles disposed on the left and right corresponding to the swing width of the needle and rotating in opposite directions are provided. It is only necessary to scoop alternately with the knives of the left and right kettles, and there is no need to scoop two upper threads in one kettle, so that the sword tip can be easily adjusted and two threads are scooped in one kettle. The disturbance of the thread tension due to this is eliminated. Further, a groove is provided in the needle plate, which is located between the needle drop positions on the left and right of the needle, extends in the feed direction of the sewn product, and is opened on the upper surface of the needle plate. Since the guide plate is provided on the lower surface of the presser, a part of the sewn material is corrected into a U-shaped pin tack shape by the guide plate and guided into the groove, and the U-shaped pin tack portion hangs down on the lower surface of the sewn material. It is formed as follows. Thereby, regardless of the skill of the worker, the sewing product is sent uniformly, the pin-tuck shape is stable, and the pin-tuck shape does not generate sewing wrinkles or twists, and a uniform and beautiful pin-tack is easily and efficiently formed. It can be stably sewn.
For example, the pin-tuck shape is stabilized without the operator pressing the sewing material by hand. In addition, since the seam of the pin tack (the joint between the upper thread and the lower thread) is formed on the upper side of the sewing product, the sewing manufacturer can proceed with the pin tack sewing while checking the finished state of the pin tack seam. In addition, it is possible to quickly find a defect in suturing.

According to a second aspect of the present invention, in the first aspect of the present invention, for example, as shown in FIG.
The back surface of the needle plate 11b in a range corresponding to the formation range of the protrusion 2b is raised, the groove 12b is formed to the inside of the protrusion, and a hole 1 is formed in the feed dog 14b in a range opposed to the protrusion.
5b is formed.

Therefore, according to the second aspect of the present invention,
The back surface of the needle plate in a range corresponding to the formation range of the groove formed in the needle plate is raised, and the groove is formed to the inside of the protrusion, so that the groove is formed deeper than the plate thickness of the needle plate. Also, a pin tack having a rising height larger than the thickness of the needle plate can be formed. If the conventional feed dog is used as it is, the feed dog may contact the raised portion on the back surface of the throat plate and the feeding operation may not be performed properly. A hole was formed. Thus, contact with the raised portion can be avoided, and the feeding operation can be performed normally.

According to a third aspect of the present invention, there is provided a needle swing mechanism for swinging one needle 31 right and left, and a pair of right and left needle swing mechanisms arranged in the right and left directions corresponding to the swing width of the needle 31 and rotating in opposite directions. Horizontal hooks 33, 34, a needle plate 11 disposed above an intermediate portion of the pair of horizontal hooks 33, 34, a presser 8 for holding a sewing material 13 placed on an upper surface of the needle plates, A feed dog 14 provided below the needle plate 11 and cooperating with the lower surface of the presser 8 to feed the sewing material 13 in a direction orthogonal to the needle swinging direction. The needle plate 11a is located between the left and right needle drop positions 20a and 20b, and extends in the feed direction S of the sewn material 13 in a long direction.
And a guide plate 10 which is loosely inserted into the hole 12a from the upper surface side of the needle plate 11a is provided on the lower surface of the presser 8.

Therefore, according to the third aspect of the present invention,
A needle swing mechanism for swinging one needle to the left and right, and a pair of horizontal shuttles disposed on the left and right corresponding to the swing width of the needle and rotating in opposite directions are provided. It is only necessary to scoop alternately with the knives of the left and right kettles, and there is no need to scoop two upper threads in one kettle, so that the sword tip can be easily adjusted and two threads are scooped in one kettle. The disturbance of the thread tension due to this is eliminated. The needle plate is provided with a hole located between the left and right needle drop positions of the needle and extending in the feed direction of the sewn material, and a guide plate loosely inserted from the upper surface of the needle plate in this hole is provided on the lower surface of the presser foot. Therefore, a part of the sewn product is corrected into a pin tack shape having a U-shaped cross section and guided into the hole by the guide plate, and a U-shaped pin tack portion hangs down from the lower surface of the sewn product. Thereby, regardless of the skill of the worker, the sewing product is sent uniformly, the pin-tuck shape is stable, and the pin-tuck shape does not generate sewing wrinkles or twists, and a uniform and beautiful pin-tack is easily and efficiently formed.
It can be stably sewn. For example, the pin-tuck shape is stabilized without the operator pressing the sewing material by hand. Further, since the holes are provided in the needle plate, sewing can be performed even if the rising height of the pin tack to be sewn is relatively high with respect to the thickness of the needle plate. With it,
A feed force can be applied to the lower end of the pin tack portion penetrating the hole and descending below the lower surface of the needle plate by a feed dog provided below the needle plate, so that the feed force acts directly on the pin tack portion. And the entire sewing product can be sent more uniformly. Furthermore, since the seam of the pin tack (the joint point of the upper thread and the lower thread) is formed on the upper side of the sewing product, the sewing manufacturer can proceed with the pin tack sewing while checking the finished state of the pin tack seam. In addition, it is possible to quickly find a defect in suturing.

According to a fourth aspect of the present invention, in the third aspect of the present invention, for example, as shown in FIG.
A long groove 15a is provided in the feed dog 14d in the feed direction S of the sewn material 13 facing the feed tooth 2a.

Therefore, according to the fourth aspect of the present invention,
The needle plate is provided with a hole through which the pin tack portion of the sewn product is guided, and a long groove in the feed direction of the sewn material facing the hole is provided in the feed dog, so that the needle plate is provided with the groove. The entire depth of the pin tack formation groove consisting of the hole and the groove provided in the feed dog is deeper than the thickness of the needle plate, and sewing a pin tack with a rising height relative to the plate thickness of the needle plate Can be. Further, the lower surface of the pin tack portion that penetrates through the hole of the needle plate and hangs down below the lower surface of the needle plate comes into contact with the inner surface of the groove provided in the feed dog, so that the feed force can be directly applied to the pin tack portion. Thereby, the whole sewn material can be sent more uniformly. It is preferable that the inner surface of the groove has a U-shaped cross section along the pin tack shape. This is to increase the contact area with the pin tack portion. It is also effective to increase the frictional force by providing teeth on the inner surface of the groove, and to further increase the transmission efficiency of the feed force.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, for example, as shown in FIG.
The back surface of the feed dog 14a in a range corresponding to the formation range of 5a is raised, and the groove 15a is formed to the inside of the protrusion.

Therefore, according to the fifth aspect of the present invention,
The back surface of the feed dog in a range corresponding to the formation range of the groove formed in the feed dog is raised, and the groove is formed up to the inside of the protrusion, so that the rising height of the feed dog is larger than the thickness of the feed dog. Pin tack can also be formed.

According to a sixth aspect of the present invention, as shown in FIG. 10 (c), using the staggered lockstitch sewing machine according to any one of the first to fifth aspects, for example, as shown in FIG.
In contrast, a pin-tack forming method characterized by relatively increasing the tension of the needle thread Y1, sewing the needle thread Y1 linearly, and sewing the hook threads Y2, Y3 in a staggered manner.

Therefore, according to the invention of claim 6,
Since the stitches in which the needle thread is linear and the hook thread is staggered are formed, the needle thread can be easily pulled out, and unsealing can be easily performed. By using the staggered lockstitch sewing machine according to any one of claims 1 to 5, a sewing manufacturer can easily set an appropriate tension of the needle thread while checking the formation state of the stitch. it can.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The following is one embodiment of the present invention and does not limit the present invention. In the figure, arrow S
Indicates the feed direction. FIG. 1 is an exploded perspective view showing a main part configuration according to an embodiment of the present invention. As shown in FIG. 1, the zigzag lockstitch sewing machine according to the present embodiment includes a presser 8, a needle plate 11a, and a feed dog 14a as components having a characteristic structure of the present invention.

The presser 8 has a needle drop portion 9 at the center. The needle drop portion 9 has a role of passing a needle and a role of a window for visually recognizing a stitch. A guide plate 10 is vertically arranged on the lower surface of the presser 8. Here, the structure of the presser 8 will be described with reference to FIG. FIG. 2 shows a plan view (a), a front view (b), and a BB sectional view (c) of the presser 8. As shown in FIG. 2, the tip of the presser 8 is warped up, and a notch 18 is formed at the center thereof. A needle drop portion 9 is formed in the center of the presser 8. 20a, 2
0b indicates a needle drop position. A relief groove 21 is provided on the lower surface of the presser. The relief groove 21 is located on the front side in the feed direction of the needle drop portion 9. The relief groove 21 is provided to reduce the resistance when the balance pulls up the needle thread so that the thread can be pulled up smoothly. Guide plate 10
Is located on the lower surface of the presser 8 in the portion between the notch 18 and the needle drop portion 9, and is perpendicular to the lower surface of the presser 8 and forward along the center line 19 in the feed direction S in the feed direction S. Will be extended. As can be seen from FIG. 2A, the guide plate 10 is located between the needle drop positions 20a and 20b,
It extends from the needle drop positions 20a and 20b to the front in the feed direction S. The guide plate 10 has a predetermined height H, and the height H is selected according to the rising height of the pin tack.

The description will be continued with reference to FIG. Needle plate 11
A long hole 12a is formed in the center of a in the feed direction of the sewing product 13. The hole 12a is located at the left and right needle drop positions 20.
a, 20b, and extends in the feed direction S of the sewing product 13 in a long manner. The needle plate 11a has needle penetrating portions 22a, 2
2b are provided corresponding to the left and right needle drop positions 20a and 20b. At the time of sewing, the needle that swings and moves up and down at predetermined positions on the left and right passes through the needle penetration portions 22a and 22b.
FIG. 1 shows a case where the needle penetration portions 22a, 22b and the hole 12a are continuous, but the invention is not limited to this, and the needle penetration portions 22a, 22b,
Each of the holes 22b may be an independent needle hole that is not continuous with the hole 12a. Feed dog 1 facing hole 12a
A U groove 15a is formed at the center of 4a. Feed dog 1
The teeth 17 formed on the needle plate 4a are inserted into holes 16 formed on the needle plate 11a.

Next, a description will be given with reference to FIGS. 3 is a sectional view taken along line AA in FIG. 1, and FIG. 4 is a sectional view taken along line CC in FIG. As shown in FIGS. 3A and 3B, the tooth 17 of the feed dog 14a or 14d is inserted into the hole 16 provided in the needle plate 11a. A sewing product (cloth) 13 is placed on the upper surface of the needle plate 11a. As shown in FIGS. 3A and 3B, the U groove 15a is a groove having a U-shaped cross section. U groove 1
The inner surface of 5a is formed so as to be continuous with the inner surface of hole 12a. In FIG. 3B, the back side of the feed dog 14a is raised, and a U-groove 15a is formed to the inside of the raised portion. The hole 12a and the U groove 15a constitute the entire pin tack forming groove for introducing the pin tack portion of the sewing product (cloth) 13.

As shown in FIG. 3, the lower surface of the presser 8 presses the upper surface of the sewing product (cloth) 13. At the center, the guide plate 10 presses the sewn (cloth) 13 to correct the sewn (cloth) 13 into a U-shaped pin-tuck shape, and the hole 12a is formed.
And the U-groove 15a. As shown in FIG. 4, the sewing material (cloth) 13 flowing on the needle plate 11a is bent downward by the guide plate 10 attached to the lower surface of the presser 8, and the holes 12a and
It is guided into the groove formed by the groove 15a. Arrow a in FIG.
As shown by 1 to a4, the feed dog 14a makes a specific feed motion that repeats the feed a1, the lowering a2, the return a3, and the raising a4. As a result, the tooth portions 17 act on the sewn product (cloth) 13 as in the related art, and the feed force is transmitted to the sewn product (cloth) 13. In addition, in the present embodiment, the U groove 15a
Also acts on the sewn (cloth) 13, and the feed force is transmitted directly to the pin tack portion. By the above, the sewing product (cloth) 13
Is transferred in the feed direction S. In FIG. 4, C-
The position of the sewing product (cloth) 13 in the C section is shown. 31 is a needle. Sewing product (cloth) in CC section
An arbitrary point 13 first strikes the guide plate 10, infiltrates into the hole 12a, and subsequently into the U-groove 15a, and after suturing, floats on the needle plate 11a from the end of the hole 12a. As a result, a pin tack is formed.

Here, another form of the needle plate and the feed dog will be described with reference to FIG. FIG. 5 is a cross-sectional view corresponding to FIG. 3 for explaining another embodiment of the present invention. In the above-described configuration, the needle plate 11a having the hole 12a and the feed dog 14a or 14d having the U groove 15a are used. However, a combination of the needle plate 11b and the feed dog 14b as shown in FIG. May be used. As shown in FIG. 5A, the center of the needle plate 11b is not a hole but a U-shaped groove 12 having a U-shaped cross section.
b is formed. The center of the back surface of the needle plate is raised, and a U-shaped groove 12b is formed inside the raised portion. A hole 15b is provided in the center of the feed dog 14b instead of the U groove, and the feed dog 1
4b The projection on the back surface does not contact the feed dog.

Further, as shown in FIG.
A combination of a and the feed dog 14c may be used. The needle plate 11a has the hole 12a as described above. The feed dog 14c is located at a position facing the hole 12a.
This is an existing feed dog with no special grooves or the like. Such a configuration is also possible when the height of the pin tack is low. Although it cannot cope with a pin tack having a high rising height, there is an advantage that an existing feed dog can be used as it is.

Next, a sewing method using a zigzag lock stitch sewing machine having the above-described presser, needle plate, and feed dog will be described.

The zigzag lockstitch sewing machine according to the present embodiment, together with the presser 8, the needle plate 11a, and the feed dog 14a,
As shown in FIG. 7, one needle 31, a needle swing mechanism including a needle bar 32 that swings the needle 31 left and right, and a needle swing mechanism that is disposed on the left and right corresponding to the swing width of the needle 31, A pair of rotating horizontal shuttles 33 and 34 are provided. Needle plate 11a is horizontal hook 3
It is arranged above the middle part of 3,34. The sewing method described below is disclosed in Japanese Patent Application Laid-Open No. 9-299631.

First, a prerequisite sewing method will be described with reference to FIG. 6, FIG. 7, and FIG. The stitches on this sewing machine
As shown in FIG. 6, it is constituted by three yarns of one needle yarn (upper yarn) Y1 and two bobbin yarns (lower yarn, shuttle yarn) Y2 and Y3. The needle thread Y1 alternately interlaces with each of the bobbin threads Y2 and Y3 while swinging left and right, and interlacing (intersecting the thread with another thread or another loop).
That is, the loop of the needle thread Y1 passes through the cloth F from the needle side, and the other side is laced with one bobbin thread Y2 on the back surface. Thereafter, the needle thread Y1 is pulled up so that the intersection of the needle thread Y1 and the bobbin thread Y2 comes to the middle part of the thickness of the cloth F.
Next, the needle thread Y1 is swung to the side corresponding to the other bobbin thread Y3, passes through the cloth F, and laces the other thread with the bobbin thread Y3 on the back surface. Thereafter, the needle thread Y1 is pulled up so that the intersection of the needle thread Y1 and the bobbin thread Y3 is located in the middle of the thickness of the cloth.

When the above operation is continuously performed with the cloth feed pitch being set quantitatively, the front surface has a zigzag stitch shape and the back surface has a two-needle lock stitch shape. In the example shown in FIG. 6, the left and right swing widths of the needle thread Y1 are constant, but may be changed regularly.

The sewing machine used has an arm capable of zigzag stitching and having a needle swing mechanism for swinging a needle bar 32 having one needle 31 shown in FIG. 7 to the left and right. At the corresponding positions, a horizontal shuttle 33 rotating clockwise and a horizontal shuttle 34 rotating counterclockwise are provided. The arm itself having the above-described needle swing mechanism is widely known, and a detailed description thereof will be omitted.

First, in the arm, the swing width of the needle 31 is set in the same manner as that having a conventional needle swing mechanism.
Then, as shown in FIG. 8, the right hook 33 is positioned so that the blade point 33a passes through the right side of the needle drop position as in the conventional two-needle sewing machine.

Further, the needle 31 is moved to the left as shown by the alternate long and short dash line in FIG. At this time, in the conventional two-needle sewing machine, since the edge portions of the respective needles are on the outside of each other and the needle thread loop is formed on the outside of each of the needles, the blade point 34a passes through the left side of the needle drop position. It should have been aligned with. However, in this sewing machine in which the needle 31 is swung right and left with one needle 31, the edge 31a of the needle 31 is on the right side no matter which way it is swung, and the needle thread loop can be formed on the right side of the needle at any position. , Sword point 3
As shown in FIG. 8, it is necessary to align the position 4a so as to pass to the right of the needle drop position. That said, not only that (the conventional kettle) but also the kettle 34
Must be able to descend to the left side of the sword tip 34a. That is, it is necessary that the tip of the sword 34a is floated outside and that the gap between the sword tip 34a and the main body is made to be relatively long so that the sword tip 34a does not hit the needle 31 during scooping of the needle thread loop. There is. Note that A1 and B1 in FIG. 7 are the sword tips 33a and 34a, respectively.
Is the passing position.

In the sewing machine having such a configuration, for example, when the needle 31 swings to the right and slightly passes through the cloth, a needle thread loop is formed on the edge 31a side of the needle 31. The needle thread 33a of the right hook 33 scoops the needle thread loop, and the needle thread passes around the hook 33 with the rotation of the tip 33a, and the bobbin thread (Y
Race with 2) and other yarns. Thereafter, the needle thread is lifted by raising the needle 31 and the balance, and the intersection of the needle thread and the bobbin thread moves to an intermediate portion of the cloth thickness. Next, the needle 31
Swings to the left and performs the same operation as on the right, but the needle drop position is, as shown in FIG.
4 is the gap on the left side of the tip 34a, and the needle thread loop is scooped by the tip 34a. And soon needle 3
Since 1 rises, the sword tip 34a can rotate counterclockwise without hitting the needle 31. Other operations are the same as those on the right side. The needle thread is laced with the bobbin thread (Y3) in the shuttle 34, and the crossover part moves to the middle part of the cloth thickness. By repeating this series of operations continuously, the stitches shown in FIG. 6 are formed.

Next, a method of forming a pin tack will be described with reference to FIGS.

As shown in FIG. 9A, the above-described sewing operation is performed with the left and right sides of the pin tack portion formed into a U-shaped pin tack shape by the guide plate 10 as needle drop positions. That is, the range of the swing width G is adjusted so that the pin tack portion runs. The swing width G is adjusted, and the above-described sewing operation is performed. Then, as shown in FIG. 9B, a stitch is formed in which the needle thread Y1 is sewn in a zigzag shape. At the time of execution of sewing, the formed stitch can be visually recognized from the needle drop portion 9 in real time.

FIG. 10 is a perspective view of the pin tack after suturing.
FIG. 10A is a plan view of the seam shown in FIG. FIG.
(C) shows a stitch when the tension of the needle thread Y1 is increased to make the needle thread Y1 straight. As shown in FIGS. 10 (a) and 10 (b), a stitch in which the needle thread Y1 is staggered (zigzag) on the back surface of the pin tack 40, and bobbin threads Y2, Y3 on both sides of the pin tack 40 are sewn on a straight line, respectively. Become.
When the tension of the needle thread (upper thread) Y1 is set higher and the tension of the bobbin threads (lower thread, hook thread) Y2 and Y3 are set lower, as shown in FIG. A stitch in which the right bobbin thread Y2 and the left bobbin thread Y3 alternately cross the needle thread Y1. In the case of the present invention, the stitch is formed on the upper surface of the sewing product (cloth) 13 and the stitch can be confirmed from the needle drop portion 9, so that the needle thread Y1 necessary to make the straight line should be loaded. The tension can be adjusted easily and quickly. Such a suturing method is easy to unravel and can be used as a basting stitch. After using as a basting stitch, first, the needle thread Y1 can be easily pulled out by pulling the end of the needle thread Y1, and then the right bobbin thread Y2 and the left bobbin thread Y3 can be easily unstitched. Can be. The pin tack shape can be fixed by performing a predetermined heat treatment in a state where the basting stitch is applied, and then the pin tack can be formed by unraveling.

The suturing method that is difficult to unravel is shown in FIG.
As shown in (b), the intersection (node) between the needle thread Y1 and the right bobbin thread Y2 and the intersection (node) between the needle thread Y1 and the left bobbin thread Y3 are sewn (cloth) 13. This is a method of forming a stitch positioned at the center of the thickness of the stitch. Needle thread Y
1. It can be realized by adjusting the tension of the right bobbin thread Y2 and the left bobbin thread Y3.

The above stitches can be visually recognized from the needle drop portion 9 which is a window formed in the center of the presser 8, so that the operator can work while checking the stitch balance.
In addition, there is an advantage that the yarn tension can be adjusted while checking. Therefore, according to the present embodiment, stitches that are easy to unravel as shown in FIG. 10C or stitches that are difficult to unravel as shown in FIG.

[0047]

As described above, according to the invention described in each of the claims, a part of the sewn product is corrected into a U-shaped pin tack shape by the guide plate, and the U-shaped pin tack portion is sewn. Is formed so as to hang down on the lower surface of the sewing machine, whereby the sewing product is uniformly fed regardless of the skill of the operator, the pin-tack shape is stabilized, and the wrinkle is formed in the pin-tack shape.
There is an effect that uniform and beautiful pin tack can be easily, efficiently and stably sewn without twisting or the like. Further, not only a straight line but also a curved pin tack can be easily sewn without breaking its uniformity.
Furthermore, since the seam of the pin tack (the joint point of the upper thread and the lower thread) is formed on the upper side of the sewing product, the sewing manufacturer can proceed with the pin tack sewing while checking the finished state of the pin tack seam. This has the effect that a defect in the suturing can be quickly found. Also, since two upper threads are not scooped in one kettle, sword tip alignment can be easily performed, and disturbance of thread tension due to scooping of two threads in one kettle is eliminated. This has the effect.

According to the second aspect of the present invention, the groove is formed deeper than the thickness of the needle plate, and a pin tack having a rising height larger than the thickness of the needle plate can also be formed. effective.

According to the third aspect of the present invention, the hole formed on the needle plate for forming the pin tack is provided.
Even if the rising height of the pin tack to be sewn is relatively high with respect to the thickness of the needle plate, sewing can be performed, and feed force can be given to the lower end of the pin tack portion by a feed dog, The feed force can be directly applied to the pin tack portion, and there is an effect that the entire sewn product can be sent more uniformly.

According to the fourth aspect of the present invention, the depth of the entire pin tack forming groove formed by the hole provided in the needle plate and the groove provided in the feed dog is greater than the thickness of the needle plate. There is an effect that it is possible to sew a pin tack which is deep and has a high rising height with respect to the thickness of the needle plate. Also,
The inner surface of the groove provided in the feed dog contacts the lower end of the pin tack portion, and the feed force can be directly applied to the pin tack portion, so that the entire sewing product can be fed more uniformly.

Further, according to the fifth aspect of the present invention, since the groove is formed deeper than the thickness of the feed dog, there is an effect that a pin tack having a high rising height can be formed.

According to the sixth aspect of the present invention, since the stitches in which the needle thread is linear and the hook thread is staggered are formed, the needle thread can be easily pulled out, and the sewing can be easily performed. You can do basting. By using the staggered lockstitch sewing machine according to any one of claims 1 to 5,
There is an effect that the sewing manufacturer can easily set an appropriate tension of the needle thread while checking the formation state of the stitch.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a configuration of main parts according to an embodiment of the present invention.

FIG. 2 is a plan view (a), a front view (b), and a BB cross-sectional view (c) of the presser 8 according to the embodiment of the present invention.

FIG. 3 is a sectional view taken along line AA in FIG. 1;

FIG. 4 is a sectional view taken along line CC in FIG.

FIG. 5 is a diagram for explaining another embodiment of the present invention;
It is sectional drawing corresponding to FIG.

FIG. 6 is a perspective view of a sewing seam according to the embodiment of the present invention.

FIG. 7 is a perspective view of a shuttle portion of the sewing machine for sewing the sewing seam according to the embodiment of the present invention.

FIG. 8 is a plan view of a shuttle portion of the sewing machine for sewing the sewing seam according to the embodiment of the present invention.

FIG. 9 is a perspective view for explaining a method of forming a pin tack in one embodiment of the present invention.

FIG. 10 is a perspective view (a), a plan view (b) of a seam, and a plan view (c) of another seam after sewing in an embodiment of the present invention.

FIG. 11 is a perspective view illustrating a conventional example of a pin tack formation method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Needle bar 2 ... Needle 3,13 ... Sewn product (cloth) 4,11 ... Needle plate 5 ... Hook 6 ... Needle 7 ... Protrusion 8 ... Holding 9 ... Needle drop part 10 ... Guide plate 12a ... Hole 12b ... U Grooves 14a, 14b, 14c: feed dog 15a: U-groove 15b: hole 16: hole 17: tooth portion 18: notch 19: center line 20a, 20b: needle drop position 21: relief groove 22a, 22b: needle penetrating portion 31: Needle 32 ... Needle bar 33 ... Right hook 34 ... Left hook 33a, 34b ... Sword point Y1 ... Needle thread Y2 ... Right bobbin thread (Right hook thread) Y3 ... Left bobbin thread (Left hook thread)

Claims (6)

[Claims] 1. A needle swing mechanism for swinging one needle to the left and right, a pair of horizontal shuttles disposed to the left and right corresponding to the swing width of the needle, and rotating in opposite directions to each other; A needle plate disposed above an intermediate portion of the horizontal shuttle, a presser for holding a sewing product placed on the upper surface of the needle plate, and a presser provided below the needle plate;
A feed dog, which cooperates with the lower surface of the presser to feed a sewn product in a direction orthogonal to the needle swing direction, wherein the stitch is located between the left and right needle drop positions of the needle. A groove extending in the feed direction of the object and opening in the upper surface of the needle plate is provided in the needle plate, and a guide plate loosely inserted into the groove from the needle plate upper surface side is provided on the lower surface of the presser. A staggered lockstitch sewing machine characterized by the following. 2. The back surface of the needle plate in a range corresponding to the formation range of the groove is raised, the groove is formed to the inside of the protrusion, and a hole is formed in the feed dog in a range opposed to the protrusion. The staggered lockstitch sewing machine according to claim 1, wherein 3. A needle swing mechanism for swinging one needle to the left and right, a pair of horizontal shuttles disposed to the left and right corresponding to the swing width of the needle, and rotating in opposite directions to each other; A needle plate disposed above an intermediate portion of the horizontal shuttle, a presser for holding a sewing product placed on the upper surface of the needle plate, and a presser provided below the needle plate;
A feed dog, which cooperates with the lower surface of the presser to feed a sewn product in a direction orthogonal to the needle swing direction, wherein the stitch is located between the left and right needle drop positions of the needle. A zigzag lock stitch sewing machine, characterized in that a hole extending in the feed direction is provided in the needle plate, and a guide plate loosely inserted into the hole from the needle plate upper surface side is provided on the lower surface of the presser. . 4. The staggered lockstitch sewing machine according to claim 3, wherein a long groove is provided in the feed dog in a feed direction of the sewing material facing the hole. 5. The staggered lock stitch according to claim 4, wherein a back surface of the feed dog in a range corresponding to a formation range of the groove is raised, and the groove is formed to the inside of the protrusion. sewing machine. 6. The staggered lockstitch sewing machine according to any one of claims 1 to 5, wherein the tension of the needle thread is relatively increased with respect to the hook thread, and the needle thread is linearly moved. A pin-tack forming method characterized by sewing a hook thread in a staggered manner.