Sewing device

Abstract

To provide a sewing device keeping sewing strength while reducing load of sewing work.SOLUTION: When an upper looper 10 moves forward from outside of a cloth edge side to inside of a cloth edge side, a body of the upper looper 10 and a first yarn 20 coming out of a tip of the upper looper 10 bend and consequently a clearance occurs between the first yarn 20 and the upper looper 10 in a sewing device. The first needle 12 moves down inside the clearance while holding a second yarn 21. The second needle 13 moves down outside the clearance and the upper looper 10 starts to retreat. The sewing device is constituted so as to perform lock stitches while simultaneously forming overlock sewing so that a darning width on a front surface is located at a position of the first needle 12 and a darning width on a rear surface is located at a position of the second needle 13 in a state where sewing work is finished.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a sewing device for forming an overlock seam. [Background technology]

[0002] Generally, overlock stitching is performed to finish the edges of fabric and prevent unraveling. This overlock stitching is performed using a known overlock sewing machine having a sewing needle that moves up and down in conjunction with a main shaft, and an upper looper and a lower looper that reciprocate in conjunction with the main shaft, and uses a sewing thread passed through the sewing needle and a looper thread passed through the looper to form a seam (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3699094 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with conventional two-needle overlock stitching, if one of the four threads breaks, the other three threads are likely to come loose as well. Therefore, when used for workwear that requires a wide range of motion, it was necessary to do a lock stitch in addition to the overlock stitching. [Means for solving the problem]

[0005] In order to solve the above problem, the invention according to claim 1 comprises an upper looper arranged on the outside of the edge of the cloth along the sewing direction in which the cloth advances and reciprocating in a direction perpendicular to the sewing direction, a lower looper arranged on the inside of the edge of the cloth and reciprocating in a direction perpendicular to the sewing direction, and two needles arranged in parallel in a direction substantially perpendicular to the sewing direction in a horizontal plane relative to the sewing direction and reciprocating in a vertical direction, one of the two needles being a first needle arranged on the edge of the cloth and the other being a second needle arranged outside the edge of the cloth relative to the first needle, a first thread held near the tip of the upper looper, a second thread held near the tip of the lower looper, and a first needle. and a fourth thread held by the second needle, and when the upper looper advances from the outside of the cloth edge side to the inside of the cloth edge side, the first needle descends while holding the second thread inside a gap between the first thread and the upper looper, which is generated by bending the first thread coming out from the main body of the upper looper and the tip of the upper looper, and the second needle descends outside the gap while the upper looper begins to retreat, so that when the sewing operation is completed, an overlock stitch is formed with a stitch width on the front side at the position of the first needle and a stitch width on the back side at the position of the second needle, while a lock stitch is simultaneously performed.

[0006] The invention according to claim 2 is characterized in that the overlock stitch width on the front side is 5 to 6 mm, and the overlock stitch width on the back side is 9 mm. Effect of the Invention

[0007] According to the present invention, the sewing work can be shortened to steps, and sewing that is less likely to come undone can be achieved. [Brief description of the drawings]

[0008] [Figure 1] 5 is an enlarged schematic view showing the operation of the sewing device according to the embodiment of the present invention; FIG. [Diagram 2] 5 is an enlarged schematic view showing the operation of the sewing device according to the embodiment of the present invention; FIG. [Diagram 3] 5 is an enlarged schematic view showing the operation of the sewing device according to the embodiment of the present invention; FIG. [Figure 4] 5 is an enlarged schematic view showing the operation of the sewing device according to the embodiment of the present invention; FIG. [Diagram 5] 5 is an enlarged schematic view showing the operation of the sewing device according to the embodiment of the present invention; FIG. [Figure 6] 5 is an enlarged schematic view showing the operation of the sewing device according to the embodiment of the present invention; FIG. [Figure 7] 5 is an enlarged schematic view showing the operation of the sewing device according to the embodiment of the present invention; FIG. [Figure 8] 5 is an enlarged schematic view showing the operation of the sewing device according to the embodiment of the present invention; FIG. [Figure 9] 5 is an enlarged schematic view showing the operation of the sewing device according to the embodiment of the present invention; FIG. [Figure 10] 1 is a schematic diagram showing a state of stitches sewn by a sewing device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0010] As shown in FIG. 1, an upper looper 10 is arranged on the outside of the edge of the cloth along the sewing direction in which the cloth 2 advances (hereinafter referred to as the "front side") and moves back and forth in a direction perpendicular to the sewing direction, a lower looper 11 is arranged on the inside of the edge of the cloth (hereinafter referred to as the "rear side") and moves back and forth in a direction perpendicular to the sewing direction, and two needles are arranged in parallel in a direction approximately perpendicular to the sewing direction in a horizontal plane and move back and forth in the vertical direction, one of the two needles is a first needle 12 arranged on the edge of the cloth, and the other is a second needle 13 arranged further back than the first needle 12. The thread held near the tip of the upper looper 10 is designated as a first thread 20, the thread held by the first needle 12 is designated as a second thread 21, the thread held by the second needle 13 is designated as a third thread 22, and the thread held near the tip of the lower looper 11 is designated as a fourth thread 23.

[0011] The operation of each part until the seam of the present invention is formed will be described below with reference to Figs.

[0012] From the state shown in Figure 1, the upper looper 10 moves from the front side to the back side while holding the first thread 20 near the tip of the upper looper 10 (hereinafter, the movement of the upper looper 10 from the front side to the back side will be referred to as "forward movement").

[0013] Then, as shown in FIG. 2, as the upper looper 10 moves forward, the first thread 20 coming out from the body of the upper looper 10 and the tip of the upper looper 10 is bent, creating a first gap 30 between the first thread 20 and the upper looper 10. The first needle 12 then descends while holding the second thread 21, inside the first gap 30, and the second needle 13 descends outside the first gap 30.

[0014] After that, as shown in Fig. 3, the upper looper 10 moves from the back side to the front side while hooking the first thread 20 on the first needle 12 (hereinafter, the movement of the upper looper 10 from the back side to the front side is referred to as moving backward), and the first needle 12, with the first thread 20 hooked at the first hooking point 40 shown in Fig. 3, penetrates the cloth 2 while holding the second thread 21 and descends to the bottom dead point. On the other hand, the second needle 13 descends outside the first gap 30, so that it does not have the first thread 20 hooked, but penetrates the cloth 2 while holding the third thread 22 and descends to the bottom dead point.

[0015] Then, as shown in FIG. 4, the first needle 12 and the second needle 13 begin to rise from the bottom dead center, causing the second thread 21 and the third thread 22 to bend, and the lower looper 11 moves inside the second gap 31 between the first needle 12 and the second thread 21 and the third gap 32 between the second needle 13 and the third thread 22 created by this bending, from the back side to the front side, while hooking the fourth thread 23 held near the tip of the lower looper 11 (hereinafter, the movement of the lower looper 11 from the back side to the front side will be referred to as "forward movement").

[0016] After that, as shown in Fig. 5, when the lower looper 11 advances while further hooking the second thread 21 and the third thread 22, the upper looper 10 also starts to advance, and advances inside the fourth gap 33 shown in Fig. 5 while hooking the fourth thread 23 above the upper looper 10 so as to scoop up the fourth thread 23 held near the tip of the lower looper 11 from below. In addition, when the two needles rise and penetrate the cloth 2, the upper looper 10 starts to advance, and the cloth 2 moves a predetermined distance L in the direction opposite to the sewing direction.

[0017] Thereafter, as the upper looper 10 further advances, as shown in FIG. 6, the fourth thread 23 advances while being hooked onto the first thread 20 from above the upper looper 10.

[0018] After that, as the upper looper 10 moves further forward, a first gap 30 is created between the first thread 20 and the upper looper 10 as shown in FIG. 2, and the lower looper 11 starts to move backward at the time when the first gap 30 is created.

[0019] 7, when the first needle 12 descends, the upper looper 10 moves backward while hooking the first thread 20 on the first needle 12. At this time, the lower looper 11 releases the second thread 21 and the third thread 22 that were hooked on the lower looper 11, and moves backward while hooking the fourth thread 23 held near the tip of the lower looper 11 in the second gap 31 and the third gap 32.

[0020] Then, as shown in FIG. 8, the second thread 21 and the third thread 22 released from the lower looper 11 are pulled upward together with the fourth thread 23 hooked on the inside of the second gap 31 and the third gap 32 as the first needle 12 and the second needle 13 pass through the cloth 2 and descend, and the upper looper 10 releases the fourth thread 23 that was hooked on the inside of the fifth gap 34 shown in FIG. 8 and retreats with the first thread 20 hooked below the fourth thread 23.

[0021] Thereafter, as shown in FIG. 9, the lower looper 11 moves forward while hooking the inside of the second gap 31 and the third gap 32 created by the descent of the first needle 12 and the second needle 13, and as the lower looper 11 moves forward, the fourth thread 23 is pulled, eliminating the fifth gap 34 shown in FIG. 8, and at the same time, the upper looper moves backward, pulling the first thread 20.

[0022] By repeating the above-described steps, as shown in Fig. 10, the overlock stitch on the front side is formed with the overhang width of the first thread 20 at the seam allowance (A) of the first needle 12, and on the outside of that, the lock stitch is formed with the third thread 22 at the seam allowance (B) of the second needle 13. The overlock stitch on the back side is formed with the overlock width of the fourth thread 23 at the seam allowance (A) of the second needle 13.

[0023] The seam allowances for the overlock stitching on the front side and the overlock stitching on the back side may be specified as 5 to 6 mm and 9 mm, respectively.

[0024] According to the present invention, by hooking the first thread only on the first needle 12 of the two needles, overlock stitching and lock stitching can be performed simultaneously in one process, and since the overlock stitching and lock stitching are sewn independently on the surface, even if either the lock stitching or the overlock stitching comes undone, the other is sewn independently, so there is no risk of them coming undone in a chain reaction and they are less likely to come undone. [Explanation of symbols]

[0025] 1 Overlock sewing machine 2 cloth 10 Upper Looper 11 Lower Looper 12 The First Needle 13 The Second Needle 20 The First Thread 21 The Second Thread 22 The Third Thread 23 The Fourth Thread 30 The First Gap 31 The Second Gap 32 The Third Gap 33 The Fourth Gap 34 The Fifth Gap 40 First hook point

Claims

1. an upper looper that is disposed on the outer side of the edge of the cloth along the sewing direction in which the cloth advances and that reciprocates in a direction perpendicular to the sewing direction; a lower looper that is disposed on the inside of the edge of the cloth and reciprocates in a direction perpendicular to the sewing direction; The sewing machine has two needles which are arranged in parallel in a direction substantially perpendicular to the sewing direction in a horizontal plane and move up and down, one of the two needles being a first needle arranged on the edge side of the cloth, and the other being a second needle arranged on the outer side of the edge side of the cloth than the first needle; a first thread held near a tip of the upper looper, a second thread held near a tip of the lower looper, a third thread held by the first needle, and a fourth thread held by the second needle; When the upper looper advances from the outside of the cloth edge side to the inside of the cloth edge side, the first needle descends while holding the second thread inside a gap between the upper looper and the first thread generated by bending the first thread coming out of the main body of the upper looper and the tip end of the upper looper, and the second needle descends outside the gap, and the upper looper starts to retreat, This sewing device is characterized in that, when the sewing work is completed, an overlock stitch is formed in which the overlock width on the front side is the position of the first needle and the overlock width on the back side is the position of the second needle, while simultaneously performing a lock stitch.

2. 2. The sewing device according to claim 1, wherein the overlock stitch width on the front side is 5 to 6 mm, and the overlock stitch width on the back side is 9 mm.

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