JP2003326004A - Twin needle sewing machine for corner sewing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a twin needle sewing machine for corner sewing capable of sewing without generating a crossing thread on an upper face of a fabric. <P>SOLUTION: The fabric is turned at the time of pausing of sewing by using right and left needles and a looper. When the fabric is sewed again after turning, a corner sewing is applied to the fabric. The twin needle sewing machine for corner sewing has an air blower which blows air to thread loops in a needle rear part so that the thread loops are separated from a looper orbit, and a hook for sliding the thread loops caught by the looper toward a looper base side. When the fabric is turned clockwise, the thread loops in a rear part of the right needle are separated from the looper orbit in a range from several stitches before turning of the fabric to several stitches after turning of the fabric. When the fabric is turned counterclockwise, the hook is advanced by several stitches before turning of the fabric, and the thread loops of the left needle caught by the looper are slid toward the looper base side and the thread loops of the left needle are caught by the right needle. The thread loops of the rear part of the left needle are separated from the looper orbit by several stitches after the turning of the fabric. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-needle sewing machine for square stitching, and more particularly to a sewing machine used for forming a double chain stitch like a decoration on the back surface of cloth.

[0002]

2. Description of the Related Art Conventionally, as a two-needle sewing machine for square stitching, a technique disclosed in Japanese Patent Laid-Open No. 186688/1988 is known. This sewing machine includes two left and right needles and a looper. The two needles individually pass the needle threads and penetrate the needle plate. The looper moves back and forth from the right along the needle penetration point of the needle plate. In this sewing machine, the looper captures the thread loop formed on the rear portion of the needle. The sewing operator turns the cloth when the sewing by the left and right needles and the looper is temporarily stopped, and performs the square stitch on the cloth by re-sewn after the turning of the cloth. In addition, this sewing machine forms a seam that looks like decoration on the front and back of the cloth. In this sewing machine, a double chain stitch can be formed without using the upper decorative thread.

[0003]

However, when square stitching is performed while forming a double chain stitch with a conventional two-needle sewing machine for square stitching, as shown in FIG. The overlapping portion of the first stitch S1 and the second stitch S2, that is, the crossover thread PT was conspicuous, and the appearance as a sewn product was poor. Therefore, an object of the present invention is to provide a two-needle sewing machine for square stitches in which a crossover thread is not generated on the upper surface of the cloth.

[0004]

In order to achieve the above object, the present invention inserts a needle thread into each of the left and right needles that penetrate the needle plate, and from the right along the needle penetration point of the needle plate. A looper that advances and retreats is provided so that the looper catches the thread loop formed at the rear part of the needle, the fabric is swung when the needle and the looper temporarily stop sewing, and the fabric is re-sewn after the fabric swivel to form a square shape on the fabric. In a two-needle sewing machine for square stitches that is sewn, an air blower that blows air to a thread ring formed at the rear portion of the needle to separate the thread wheel from the looper track, and can move forward and backward toward the looper. It is equipped with a hook that slides the thread loop captured by the looper to the base side of the looper, and when trying to rotate the fabric clockwise, several stitches after the fabric rotation than several stitches before the fabric rotation Right by operating the air blower for up to When the thread loop formed on the rear part of the fabric is disengaged from the looper track and the fabric is to be rotated counterclockwise, the hook is advanced a few stitches before the fabric is rotated, and the thread of the left needle caught by the looper is moved forward. Slide the loop to the base side of the looper, capture the left needle thread loop with the right needle, and then operate the air blower up to several stitches after the fabric has rotated, so that the loop of loops formed on the rear portion of the left needle is looped. It is characterized in that it is designed to be disengaged from the orbit.

It is desirable to arrange the air blower so that it can slide to the left and right and change the spraying position of the air blower according to the direction in which the cloth is swung.

[0006]

According to the present invention, when the cloth is to be rotated clockwise, it is formed on the rear portion of the right needle by operating the air blower from several needles before the cloth is rotated to several needles after the cloth is rotated. The thread loop from the looper track. As a result, a double chain stitch is formed on the fabric on the left needle side from a few stitches of the fabric turning to a few stitches after the fabric turning. Also,
When trying to turn the fabric counterclockwise, advance the hook a few stitches before turning the fabric, slide the left needle thread loop captured by the looper to the base side of the looper, and move the left needle thread loop to the right. Capture with a needle. After that, the air blower is operated up to several stitches after the fabric is swung, so that the thread loop formed at the rear portion of the left needle is disengaged from the looper track. As a result, a double chain stitch is formed on the fabric on the right needle side from a few stitches of the fabric turning to a few stitches after the fabric turning.

Further, according to the present invention, the air blower is slidably arranged to the left and right, and the blowing position of the air blower is changed according to the turning direction of the cloth.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of an essential part of a two-needle sewing machine for corner sewing using the present invention. The cylinder bed 1 of this sewing machine is fixed to the feed dog 2 which moves the fabric in four directions up and down and forward and backward to feed the fabric in the arrow F direction, the looper 3 which swings in the direction intersecting the fabric feed direction F, and the screw hole 4. A needle plate 5 (see FIG. 2). A needle bar 9 to which a left needle 6 and a right needle 7 are attached via a needle stock 8 is arranged above the cylinder bed 1. Each of the needles 6 and 7 extends downward, and the tip of the needle penetrates the needle plate 5 by the vertical movement of the needle bar 9. The needle penetration points 5a, 5a of the needle plate 5 are on the base side of the needle plate claw 5b extending in the material feeding direction F, as shown in FIG.

The looper 3 is attached to a looper shaft 11 via a looper stand 10, and the looper shaft 11 moves forward and backward from the right side in conjunction with the rotation of a sewing machine main shaft (not shown). Looper shaft 1
The forward / backward direction of 1 is along the needle penetration points 5a, 5a of the needle plate 5, and the looper 3 moves forward and backward below the needle plate 5. As shown in FIG. 1, when the looper 3 is advanced from the right side, the tips of the needles 6 and 7 are located at the needle penetration point 5 of the needle plate 5.
It is in a state of being higher than a and 5a. Thread holes 6a for inserting needle threads 12 and 13 are provided at the tips of the needles 6 and 7,
7a is provided, and an eyelet 3a for inserting the looper thread 14 is provided at the tip of the looper 3.

On the left side of the feed dog 2 in FIG. 1, that is, on the tip side of the cylinder bed 1, there is provided a hook 15 for sliding the yarn wheel captured by the looper 3. The hook 15 has a groove portion 1a formed in the cylinder bed 1.
It is supported so that it can slide left and right. The hook 15 has a protrusion 15a on the base end side, and the protrusion 15a is fitted to a forked portion 16a formed at one end of the bell crank lever 16. The bell crank lever 16 is rotatably fixed to the cylinder bed 1 with a stepped screw 17.

An air cylinder 18 is arranged at the tip of the cylinder bed 1. An operating piece 19 is attached to the piston rod 18a of the air cylinder 18. The operating piece 19 is connected to the elongated hole 16b of the bell crank lever 16 via a stepped screw 20. The mounting position of the operating piece 19 on the piston rod 18a can be adjusted by the nut 21. The air cylinder 18 is connected to a high pressure air source (not shown) via a pipe 22. The working piece 1 at the tip of the piston rod 18a is generated by the aerodynamic force from the high pressure air source.
When 9 moves in the direction of arrow A, bell crank lever 16
Rotates around the stepped screw 17, and the hook 15 slides along the arrow B direction.

An air blower 23 is arranged behind the cylinder bed 1. The tip of the air blower 23 enters the inside of the cylinder bed 1 through the slot 1b. The blower outlet of the air blower 23 is directed toward the looper 3 side so that air is blown to the yarn wheel formed at the rear portion of the needle when the air blower 23 is raised. Also, this air blower 23
It is attached to a bracket 24 fixed to a piston rod (not shown) of a pen type air cylinder. When the piston rod of the pen-type air cylinder advances and retracts, the air blower 23 moves left and right along the arrow C direction. As a result, the blowing position of the air blower is changed. In addition, in order to prevent the lubricating oil supplied into the cylinder bed 1 from leaking, the groove hole 1b
Is equipped with a slitting oil draining member (not shown).

Next, the operation of the above-described sewing machine will be described with reference to FIGS.
This will be described with reference to FIG. In this sewing machine, the material W pressed against the needle plate 5 by a presser foot (not shown) is fed by the feed dog 2 in the direction of arrow F, and as shown in FIG. 7a and the needle threads 12 and 13 and the looper thread 14 which are respectively passed through the eyelet 3a of the looper 3 form a stitch (first stitch) S1 of a display symbol 406.

When the cloth W is to be swung clockwise, as shown in FIG. 4, the blowing position of the air blower 23 is changed to the right needle 7 side from a few stitches before the cloth is swung, and the air blower 23 is moved. Activate. When the air blower 23 operates,
The thread loop formed on the rear portion of the right needle 7 is disengaged from the track of the looper 3 during the ascent. Therefore, when the looper 3 advances from the right side in this state, as shown in FIG. 5, the loop of loops formed on the rear part of the right needle is not captured by the looper 3 and the loop of loops formed on the rear part of the left needle. Only capture. Then, the left needle 6 descending after passing through the top dead center, the looper 3 retreating to the left, the looper thread 14 reaching the cloth W from the eyelet 3a of the looper 3, and the thread loop 12L of the left needle captured by the looper 3. Enter the triangle formed by. Then, the looper yarn 14a in the triangle is captured by the left needle 6 as shown in FIG. At this time, the right needle 7 is simply the cloth W
Will be penetrated.

When the sewing machine is driven in this state, the needle thread 12 inserted into the thread hole 6a of the left needle 6 as shown in FIG.
With the looper thread 14 inserted through the eyelet 3a of the looper 3, the seam Sa of the display symbol 401 is formed on the cloth W. Then, after the driving of the sewing machine is stopped with the needles 6 and 7 at the top dead center (see FIG. 8), the fabric W is swung clockwise by a predetermined angle around the base end portion SS of the seam ( (See FIG. 9). After this turning, the material W is pressed against the needle plate 2 by a presser foot (not shown), and sewing with the sewing machine is restarted. At this time, the operation of the air blower 23 is continued for several stitches,
The seam Sa of the display symbol 401 is formed on the cloth W so as to be continuous with the base end portion SS of the seam. After that, air blower 23
The air blowing is stopped, and the seam (second seam) S2 of the initial display symbol 406 is continuously formed as shown in FIG. As a result, regarding the corner surface of the seam,
Only the outside is the sewing line (seam Sa of the display symbol 401,
Sa) remains, and the transition yarn is not generated.

When the cloth W is to be rotated counterclockwise, the hook 15 is operated when the looper 3 has moved forward for several stitches before the cloth is rotated. As a result, each of the yarn wheels 12L and 13L captured by the looper 3 is slid to the base end side of the looper 3 as shown in FIG.
When the looper 3 retreats to the left, the left needle 6 that descends via the top dead center is the looper 3 and the looper thread 14 that reaches the cloth W from the eye hole 3a of the looper 3 and the left needle that is captured by the looper 3. It enters into the triangle formed by 12L of the thread loop. At this time, the right needle 7 captures the left needle thread loop 12L captured by the looper 3 and the looper thread 14 reaching the cloth W through the looper 3 and the eye hole 3a of the looper 3 and the right captured by the looper 3. It enters into the triangle formed by the needle wheel 13L. Thread loop 12L for the left needle captured by the right needle 7
Is disengaged from the looper 3 that retracts when the hands 6 and 7 descend,
As shown in FIG. 12, the left needle thread ring 12LL that is disengaged from the looper 3 is lifted to the fabric W side while being caught by the right needle 7.

After that, the blowing position of the air blower 23 is changed to the left needle 6 side and the air blower 23 is operated. When the air blower 23 is actuated, the yarn wheel formed on the rear portion of the left needle 6 is disengaged from the track of the looper 3 when rising. Therefore, when the looper 3 advances from the right side in this state,
As shown in FIG. 3, the loop formed on the rear part of the right needle is caught by the looper 3, but the loop formed on the rear part of the left needle is not captured by the looper 3. Needle 6, descending after passing through top dead center
As shown in FIG. 14, the looper 7 is retracted to the left and the looper thread 14 reaching the cloth W from the eyelet 3a of the looper 3
And enters the triangle formed by the loop 13L of the right needle captured by the looper 3. When the sewing machine is driven as it is, as shown in FIG. 15, the thread hole 7 of the right needle 7
A stitch Sa of a display symbol 401 is formed on the cloth W by the needle thread 13 inserted in a and the looper thread 14 inserted in the eye hole 3 a of the looper 3.

Then, after the driving of the sewing machine is stopped with the needles 6 and 7 at the top dead center (see FIG. 16), the material W is rotated counterclockwise by a predetermined angle around the base end portion SS of the seam. (See FIG. 17). After the fabric W is turned, the fabric W is pressed against the needle plate 2 by a presser foot (not shown), and the sewing with the sewing machine is restarted. At this time, the operation of the air blower 23 is continued for several stitches, and the seam Sa of the display symbol 401 is formed on the cloth W so as to be continuous with the base end portion SS of the seam.
After that, the air blow of the air blower 23 is stopped, and
As shown in FIG. 5, the seam (second seam) of the initial display symbol 406 is subsequently formed. As a result, regarding the corner surface of the seam, only the outer side is the sewing line (display symbol 4
No. 01 stitches Sa, Sa) remain and no crossover thread is generated.

In the present embodiment, the hook 15 is used for each thread loop 1
2L and 13L were slid to the base side of the looper 3, but not limited to this, only the left needle thread ring 12L can be caught so that the descending right needle 7 can catch the left needle thread ring 12L. You may slide it. Further, in the present embodiment,
Although the turning angle of the dough is set to 90 °, the turning angle is not limited to this, and the turning can be performed at any angle. Furthermore,
In the present embodiment, the blowing position of the air blower is changed by the pen type air cylinder, but the present invention is not limited to this, and it may be changed by a foot pedal, a knee switch, or a manual operation.

[0020]

As described above, according to the present invention, since a crossover thread is not generated on the corner surface of the seam formed on the cloth, the sewn product looks good. In particular, when trying to turn the fabric counterclockwise, slide the left needle thread loop captured by the looper to the base side of the looper a few stitches before the fabric rotation, and let the left needle thread loop be captured by the right needle. As a result, there is no fraying from the corners of the seams formed in the fabric. Further, since the blowing position of the air blower is changed according to the turning direction of the cloth, the number of parts arranged in the sewing machine can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view of an essential part showing a two-needle sewing machine for square stitching applied to the present invention.

FIG. 2 is a perspective explanatory view showing a needle plate shape of the sewing machine.

FIG. 3 is a perspective view showing a first step of a square stitching process by the sewing machine.

FIG. 4 is a perspective view showing a second step of the square stitching process by the sewing machine.

FIG. 5 is a perspective view showing a third step of the corner sewing process by the sewing machine.

FIG. 6 is a perspective view showing a fourth step of the square stitching process by the sewing machine.

FIG. 7 is a perspective view showing a fifth step of the corner sewing process by the sewing machine.

FIG. 8 is a schematic plan view showing a planar state of the fifth step.

FIG. 9 is a schematic plan view showing a sixth step of the corner sewing step by the sewing machine.

FIG. 10 is a schematic plan view showing a seventh step of the corner sewing step by the sewing machine.

FIG. 11 is a perspective view showing another first step of the corner sewing step by the sewing machine.

FIG. 12 is a perspective view showing another second step of the square stitching process by the sewing machine.

FIG. 13 is a perspective view showing another third step of the square stitching process by the sewing machine.

FIG. 14 is a perspective view showing another fourth step of the corner sewing step by the sewing machine.

FIG. 15 is a perspective view showing another fifth step of the corner sewing step by the sewing machine.

FIG. 16 is a schematic plan view showing a planar state of the another fifth step.

FIG. 17 is a schematic plan view showing another sixth process of the corner sewing process by the sewing machine.

FIG. 18 is a schematic plan view showing another seventh step of the square stitching process by the sewing machine.

FIG. 19 is a schematic plan view showing a finished state of a corner sewing process using a conventional sewing machine.

[Explanation of symbols]

3 looper 5 needle plate 5a Needle penetration point 6 left needle 7 right needle 12,13 needle thread 12L, 13L thread loop 15 hooks 23 Air blower W fabric

Claims (2)

[Claims] 1. A thread loop formed on the rear portion of the needle, comprising left and right needles that individually insert needle threads and penetrate the needle plate, and a looper that moves forward and backward along the needle penetration point of the needle plate. In the two-needle sewing machine for square stitching, the looper is caught, the cloth is swung when the sewing by the needle and the looper is temporarily stopped, and the cloth is square stitched by re-sewing after the cloth is swung. An air blower that blows air to the loop of loops formed at the rear portion of the needle to separate the loop from the looper track, and a looper that is arranged so as to be able to move forward and backward toward the looper and that is trapped by the looper. When the fabric is to be rotated clockwise, it is equipped with a hook that slides to the back and is formed on the rear part of the right needle by operating the air blower from several stitches before the fabric rotation to several stitches after the fabric rotation. Remove the loop from the looper track, When trying to turn the fabric counterclockwise, advance the hook a few stitches before turning the fabric, slide the left needle thread loop captured by the looper to the base side of the looper, and move the left needle thread loop. For square stitching, characterized by catching with the right needle and then operating the air blower up to several stitches after turning the fabric so that the thread loop formed at the rear part of the left needle is disengaged from the looper track. 2 needle sewing machine. 2. A two-needle sewing machine for square stitches according to claim 1, wherein the air blower is slidably arranged to the left and right, and the blowing position of the air blower is changed according to the turning direction of the material.