JP2001218990A - Single yarn circularly sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a needle-shaking type single yarn circularly sewing machine having a simple constitution capable of securely sewing. SOLUTION: This sewing machine is provided with a main shaft 10, a needle bar moving up and down and at the same time moving laterally and provided with a needle, a looper shaft 17, and a looper 18. The needle bar is moved up and down once according to one rotation of the main shaft 10 to carry out sewing by cooperation of the needle with the looper 18. The rotational speed during one rotation of the loooer shaft 17 is varied against the rotational speed of the main shaft 10 to make the rotational speed of the looper shaft 17 faster than that of the main shaft 10 when catching needle yarn by the looper 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a needle swing type single thread ring stitch sewing machine having a needle swing mechanism.

2. Description of the Related Art As a sewing method using a sewing machine, a so-called single thread ring sewing method is known. The sewing machine that performs the single thread ring stitch is provided with a needle that moves up and down and moves in a predetermined direction, a needle thread hanging on the needle, and a sewing thread provided below the sewing surface of the sewing machine. It has a looper for catching, and a thread shift portion for shifting the needle thread by swinging. Hereinafter, a method of single thread ring sewing will be described.

[0002] First, with the needle dropped below the sewing surface,
A looper captures the needle thread to form a first thread loop.
Next, while the needle falls from the next needle drop position to below the sewing surface, the thread shift portion pulls the first thread loop in the direction opposite to the traveling direction of the needle, and the looper makes one rotation. And the needle falls below the sewing surface avoiding the first thread loop,
The looper catches the needle thread hanging on the needle. And
As the needle rises, the needle thread captured by the looper is passed through the first thread loop to form a second thread loop,
Further, the looper rotates, and the first yarn loop separates from the looper. Hereinafter, by repeating this operation sequentially, single thread ring sewing is performed.

If the single-thread ring stitch sewing machine having the above-described structure is provided with a needle swinging function of reciprocating the needle left and right in substantially the same plane as the rotation surface of the looper, the following problem occurs. That is, in this single thread and chain stitch sewing machine, the looper makes one rotation for one vertical movement of the needle, while the needle drop position changes to the left and right. The timing when the needles meet is shifted.

For example, as shown in FIG. 10, when the needle 1 drops to the needle drop position 1a, the looper 2 is at the position 2a, so that the needle 1 and the looper 2 meet with good timing. When the needle 1 has dropped to the needle drop position 1b which is separated from the needle drop position 1a by the distance r, the looper 2 is still at the position 2a. The rotation angle of the looper corresponding to r)
Just need to rotate. That is, when the needle 1 drops to the needle drop position 1b, the timing at which the looper 2 encounters the needle 1 is delayed (shifted). Then, due to this timing shift, the vertical position of the needle with respect to the looper, that is, the vertical position of the needle thread, changes, and the looper may not be able to accurately capture the needle thread.

As a method of solving such a problem, a method of increasing the length from the blade point of the looper to the rotation axis (the rotation radius of the looper) can be considered. Referring to FIG. 10, if the rotation radius R of the looper 2 is increased, the rotation angle a of the looper 2 corresponding to the deviation width r of the needle drop position can be reduced. Even when rotated at the same angular velocity as in the case, the looper 2 can encounter the needle 1 faster. That is, according to this method, it is possible to reduce the difference in the timing at which the looper 2 and the needle 1 meet.

However, in this method, since the radius of rotation of the looper becomes large, the needle thread is pulled out longer than usual when the looper capturing the needle thread rotates. This increases the loosening of the seam immediately after the loop is formed by the cooperation of the looper and the needle, and the cloth must be pulled back longer than usual by a balance in order to reduce the loosening. Further, for the above-described reason, the amount of the needle thread passing through the hole of the needle increases, so that the needle thread is squeezed more. Therefore, troubles such as skipping and thread breakage are likely to occur.

In view of such problems, conventionally, as a needle swing type single thread ring stitch sewing machine, a looper is always arranged below a needle by interlocking a looper with swinging of the needle. A single-thread chain stitch sewing machine of a type and a needle swing type single-thread chain stitch sewing machine having two loopers are also used.
The needle swing type single thread chain stitch sewing machine having two loopers performs the single thread chain stitch by the following method.

First, the needle falls near one of the two loopers, and the needle thread is caught by one of the loopers and moved toward the other looper to form a first thread loop. Next, the needle moves up to the next needle drop position, and falls below the sewing surface so as to enter the first thread loop. The second thread loop is captured by the other looper and moved toward the first looper while passing the needle thread through the first thread loop to form a second thread loop. In other words, the two loopers alternately capture the needle thread for each stitch to form a thread loop sequentially, and the needles are sequentially inserted into the thread loop to perform single thread ring sewing.

[0009]

However, the needle swing type single thread ring stitch sewing machine has the following problems. That is, in the former needle swing type single thread ring stitch sewing machine, in addition to the mechanism for rotating the looper, a mechanism for reciprocating the looper in conjunction with the reciprocating movement of the needle is required, so that the structure of the sewing machine is complicated. And the cost of the sewing machine increases. In addition, the weight of a series of mechanisms for driving the looper increases, and the inertial force generated by driving the looper increases, which makes it difficult to drive the sewing machine at high speed.

Also, in the latter needle swing type single thread ring stitch sewing machine, the needles are alternately shifted left and right to correct positions so as to be inserted into a thread loop formed alternately by left and right loopers. Therefore, there is a problem that the position of the needle drop is restricted.

The limitation of the needle drop position will be described with reference to FIG. 11. The looper 3 is formed on one side of the shaft 3a of the looper 3 along the longitudinal direction of the shaft 3a. And has a recessed groove 3b and moves back and forth within a certain range. Here, when the next needle is dropped to the thread loop 4 formed by capturing the needle thread of the needle dropped at the needle drop position 5a by the looper 3, the looper 3 returns when the needle is dropped to the right of the looper 3. When it hits a needle,
It is necessary to drop the needle 1 to the left of the looper 3 and inside the thread loop 4, that is, at a position 5b between the groove 3b and the thread loop 4. As is apparent from this figure, the concave groove 3b and the yarn loop 4
Very narrow between. An object of the present invention is to provide a needle swing type single thread stitch sewing machine having a simple structure, which can perform sewing surely even when a swing width of a needle is changed.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an invention according to claim 1 includes a main shaft rotatably supported by a sewing machine frame, a vertical movement in conjunction with the main shaft, and a right and left movement. A needle bar that swings and has a needle, a looper shaft that is pivotally supported by the sewing machine frame and rotates in conjunction with the main shaft, and a thread loop that is attached to the looper shaft and supplements the needle thread to form a thread loop. A needle swing type single thread ring stitch that performs sewing in cooperation with the needle and the looper by moving the needle bar up and down once for one rotation of the main shaft and rotating the looper shaft once. In the sewing machine, by changing the rotation speed of the looper shaft during one rotation with respect to the rotation speed of the main shaft, the rotation speed of the looper shaft is made higher than the rotation speed of the main shaft when the looper captures the needle thread. It is characterized in.

According to the first aspect of the present invention, the rotation speed of the looper shaft during one rotation is changed with respect to the rotation speed of the main shaft. Since the rotation speed is higher than the rotation speed of the main shaft, the vertical position of the needle with respect to the looper, that is, the vertical position of the needle thread, is significantly changed even when the needle drop position changes and the timing at which the needle and the looper meet is shifted. Instead, the looper and the needle can be met. Therefore, the looper can accurately capture the needle thread, so that sewing can be reliably performed, and the needle drop position can be changed to some extent within a range where the looper can capture the needle thread.

Further, by changing the rotation speed of the looper shaft during one rotation with respect to the rotation speed of the main shaft, the rotation speed of the looper shaft is made smaller than the rotation speed of the main shaft when the looper captures the needle thread. Since the speed may be set to a high speed, the looper can be swung together with the needle, and the configuration of the single thread ring stitch sewing machine can be simplified as compared with the case where two loopers are used. Here, one of the looper shafts
In order to change the rotation speed during rotation with respect to the rotation speed of the main shaft, for example, the invention described in claims 2 to 4 may be adopted.

According to a second aspect of the present invention, in the first aspect of the present invention, there is provided a transmission mechanism for transmitting a driving force from the main shaft to the looper shaft and having at least a pair of non-circular gears. The rotation speed of the looper shaft during one rotation is changed with respect to the rotation speed of the main shaft by meshing the gears with each other.

According to the second aspect of the present invention, the non-circular gears mesh with each other to form one of the looper shafts.
The rotation speed during rotation can be reliably changed with respect to the rotation speed of the main shaft, and the single-thread ring stitch sewing machine is simply provided with a transmission mechanism, simplifying the configuration of the single-thread ring stitch sewing machine. it can.

Here, in order to provide the transmission mechanism in a single-thread ring stitch sewing machine, for example, the following may be performed. That is, the intermediate shaft is rotatably supported on the sewing machine frame and parallel to the main shaft, non-circular gears are provided on each of the main shaft and the intermediate shaft, and these non-circular gears are meshed with each other. What is necessary is just to rotate in conjunction with an intermediate shaft.

According to a third aspect of the present invention, in the first aspect of the present invention, a motor for driving the looper shaft is provided, and the rotation speed of the looper shaft is controlled during one rotation of the motor by controlling the rotation speed of the motor. The speed is changed with respect to the rotation speed of the main shaft.

According to the third aspect of the invention, by controlling the rotation speed of the motor, the rotation speed of the looper shaft during one rotation is changed to the rotation speed of the main shaft regardless of the rotation of the main shaft. In addition, the configuration can be changed, and the configuration of the single thread ring stitch sewing machine can be simplified because only the motor is provided in the single thread ring stitch sewing machine. Here, a known motor whose speed can be changed may be used as the motor.

According to a fourth aspect of the present invention, in the first aspect, there is provided a motor for driving the looper shaft, and at least a pair of non-circular gears for transmitting the driving force of the motor to the looper shaft. A looper transmission mechanism is provided, and the rotation speed of the looper shaft during one rotation is changed with respect to the rotation speed of the main shaft by meshing the non-circular gears with each other.

According to the fourth aspect of the present invention, the rotation speed of the looper shaft during one rotation is adjusted only by adjusting the speed of the motor to the speed of the main shaft by meshing the pair of non-circular gears. In addition to being able to reliably change the rotation speed of the main shaft, the structure of the single thread ring stitch sewing machine can be simplified because only the looper transmission mechanism is provided in the single thread ring stitch sewing machine.

According to a fifth aspect of the present invention, there is provided a main shaft rotatably supported by a sewing machine frame, a needle bar which moves up and down in conjunction with the main shaft, swings right and left, and has a needle.
Two loopers that swing in the same direction as the swing direction of the needle bar and alternately capture a needle thread to form a thread loop. A thread shifter is provided, which reciprocates once in a substantially horizontal direction with respect to vertical movement, and pulls a part of a thread loop formed by the looper out of a region where the looper swings. .

According to the fifth aspect of the present invention, the yarn loop formed by the looper reciprocates substantially horizontally once over two loopers in response to two vertical movements of the needle bar. Since the thread puller is provided so as to partially pull out of the area where the looper swings, the needle is dropped inside a part of the thread loop avoiding the area where the looper swings. The needle thread passed through the needle can be captured by the looper. Therefore, the needle drop position can be arbitrarily changed and the needle drop position does not need to be so accurate, so that sewing can be performed easily and reliably. Here, in order to make the looper easy to catch the needle thread, and to prevent the looper from colliding with the needle when the looper operates in the opposite direction to the catch, the looper catches the needle thread among the constituent parts of the looper. It is desirable that the portion to be bent is bent toward the needle drop position.

According to a sixth aspect of the present invention, in the invention according to the fifth aspect, the thread holding portion of the looper holding the thread loop and the thread puller holding the thread loop held by the looper are applied. The thread holding portion is disposed at a position sandwiching a plane on which the needle is swung when the needle descends.

According to the invention described in claim 6, the thread holding portion of the looper holding the thread loop and the thread holding portion of the thread shifter holding the thread loop held by the looper are formed. When the needle is lowered, it is arranged at a position sandwiching the plane on which the needle is swung, so that the inside of a part of the thread loop intersects with the plane on which the needle is swung. Therefore, the needle can be easily dropped inside a part of the thread loop, and sewing can be performed more easily and reliably.

According to a seventh aspect of the present invention, there is provided a main shaft rotatably supported by a sewing machine frame, a needle bar which moves up and down in conjunction with the main shaft, swings right and left, and has a needle.
A looper shaft pivotally supported by the sewing machine frame and rotating in conjunction with the main shaft, and a looper attached to the looper shaft to form a thread loop by supplementing a needle thread,
A needle swing type single thread ring stitch sewing machine that moves the needle bar up and down once per rotation of the main shaft and rotates the looper shaft once to perform sewing in cooperation with the needle and the looper.
An auxiliary looper provided with an auxiliary sword tip that swings one reciprocation for one vertical movement of the needle bar and moves faster than the sword tip of the looper to capture the needle thread, and first captures the needle thread; Needle thread captured by the auxiliary sword tip of the auxiliary looper,
The sword of the looper is captured.

According to the seventh aspect of the invention, since the speed of the auxiliary looper is faster than that of the looper, the timing at which the needle meets the auxiliary sword tip hardly changes even when the needle drop position changes, and the needle thread is reliably captured. Since the needle thread is previously captured by the auxiliary sword tip of the auxiliary looper, the looper can capture the needle thread previously captured by the auxiliary sword tip. Therefore, the looper can reliably capture the needle thread, so that sewing can be reliably performed, and the needle drop position can be changed to some extent within a range where the auxiliary sword tip can capture the needle thread. Further, since it is only necessary to provide the auxiliary looper on the single thread ring stitch sewing machine, the configuration of the single thread ring stitch sewing machine can be simplified.

According to an eighth aspect of the present invention, in the invention according to the seventh aspect, the auxiliary sword tip of the auxiliary looper has a substantially inverted U-shaped cross section, and the auxiliary sword tip for supplementing the needle thread has a substantially inverted cross-sectional shape. In the concave part formed by making it U-shaped,
The needle thread of the looper captures the needle thread captured by the auxiliary blade tip of the auxiliary looper by inserting the blade tip of the looper.

According to the eighth aspect of the present invention, the tip of the looper is inserted into a recess formed by making the sectional shape of the auxiliary sword tip for supplementing the needle thread into a substantially inverted U-shape. Since the needle point of the looper can catch the needle thread captured by the auxiliary point of the auxiliary looper,
The looper can more easily and reliably catch the needle thread. Therefore, sewing can be performed more easily and reliably.

According to a ninth aspect of the present invention, there is provided a main shaft rotatably supported by a sewing machine frame, a needle bar which moves up and down in conjunction with the main shaft, swings right and left, and has a needle.
A looper shaft pivotally supported by the sewing machine frame and rotating in conjunction with the main shaft, and a looper attached to the looper shaft to form a thread loop by supplementing a needle thread,
A needle swing type single thread ring stitch sewing machine that moves the needle bar up and down once per rotation of the main shaft and rotates the looper shaft once to perform sewing in cooperation with the needle and the looper.
The looper includes a sword tip for supplementing a needle thread, and a holding part for holding the needle thread supplemented by the sword tip behind the sword tip with the rotation of the looper, wherein the holding part comprises a held needle thread. Is formed on the opposite side of the point of the sword from the center of rotation of the looper so as not to go to the opposite side of the needle from the center of rotation of the looper.

According to the ninth aspect of the present invention, the holding portion is formed on the opposite side of the blade point from the rotation center of the looper so that the held needle thread does not go on the opposite side of the needle from the rotation center of the looper. That is, at the time of sewing, the needle thread caught by the looper is not disposed on the opposite side of the needle from the center of rotation of the looper. The needle thread caught by the above is not excessively long. Therefore, the radius of rotation of the looper can be increased to some extent.

By increasing the rotation radius of the looper, the rotation angle of the looper corresponding to the shift distance of the needle drop position becomes smaller, so that the looper can encounter the needle earlier even if the needle drop position changes. be able to. Therefore, since the looper can accurately capture the needle thread, sewing can be performed reliably, and the needle drop position can be changed to some extent within a range where the looper can capture the needle thread. Also, since it is only necessary to change the shape of the looper of the single thread ring stitch sewing machine, the configuration of the single thread ring stitch sewing machine can be simplified.

[0033]

Embodiments of the present invention will be described below in detail with reference to the drawings. [First Embodiment] First, the configuration will be described. The needle swing type single thread chain stitch sewing machine according to the present invention is the same as the conventional needle swing type single thread chain stitch sewing machine having one conventional looper except that it has a transmission mechanism 20 as shown in FIG. (The looper shape is simplified for easy explanation). That is, as shown in FIG. 1, the needle swing type single thread and ring sewing machine according to the present invention includes a main shaft 10, a needle bar (not shown), a looper 18, and a transmission mechanism 20. Sewing is performed by cooperation of the provided sewing needle and the looper 18.

The main shaft 10 is rotatably supported by a sewing machine frame (not shown). A drive unit (not shown) for rotating the main shaft 10 in the direction of arrow G at a constant speed is provided at a base end of the main shaft 10. The needle bar moves up and down once for one rotation of the main shaft 10 in conjunction with the main shaft 10, while a needle bar swing mechanism (not shown)
It can swing right and left. Further, a sewing needle is provided at the tip of the needle bar.

The transmission mechanism 20 includes a first non-circular gear 11,
Intermediate shaft 12, second non-circular gear 13, pulley 14.1
6, a timing belt 15, and a looper shaft 17. The first non-circular gear 11 is provided on the base end side of the main shaft 10. The intermediate shaft 12 is provided below the main shaft 10 so as to be rotatable on the sewing machine frame and parallel to the main shaft 10. A pulley 14 is provided on a distal end side of the intermediate shaft 12, and a second non-circular gear 13 having the same shape as the first non-circular gear 11 is provided on a proximal end side. The second non-circular gear 13 is a first non-circular gear 11
And the intermediate shaft 12 makes one rotation in the direction of the arrow H by one rotation of the main shaft 10.

The looper shaft 17 is rotatable on the sewing machine frame below the sewing surface of the sewing machine and the main shaft 1 is rotated.
0 is provided in parallel. A pulley 16 is provided on the base end side of the looper shaft 17. A timing belt 15 is stretched over a pulley 14 and a pulley 16, and the rotation of the looper shaft 1
7 makes one rotation in the direction of arrow J. That is, the looper shaft 17 rotates in conjunction with the main shaft 10 via the intermediate shaft 12. The looper 18 is provided at the tip of the looper shaft 17. The looper 18 is a known looper that captures a needle thread to form a thread loop.
8 at the tip.

Next, the functions of the first non-circular gear 11 and the second non-circular gear 13 will be described. First non-circular gear 11
Rotates at a constant rotation speed with the rotation of the main shaft 10. On the other hand, the second non-circular gear 13 rotates at the same rotational speed as the first non-circular gear 11, but changes its rotational speed during one rotation.

More specifically, the first non-circular gear 11 and the second non-circular gear 13 do not have a constant distance (diameter) from the center of rotation to the outer peripheral portion. In a state where the long part and the part with the short diameter of the second non-circular gear 13 mesh (the state shown in FIG. 1), the first
The rotation angle of the non-circular gear 11 per unit time
The rotation angle of the non-circular gear 13 per unit time increases. That is, in this state, the second non-circular gear 13 rotates faster than the first non-circular gear 11.

Conversely, a state where the short diameter portion of the first non-circular gear 11 and the long diameter portion of the second non-circular gear 13 are engaged (from the state of FIG.
In a state where the first non-circular gear 11 is rotated by 0 degrees), the rotation angle of the second non-circular gear 13 per unit time is smaller than the rotation angle of the first non-circular gear 11 per unit time. That is, in this state, the second non-circular gear 13 rotates slower than the first non-circular gear 11.

In this way, the second non-circular gear 13 is
The rotation speed of the second non-circular gear 13 is changed during rotation, but the rotation of the second non-circular gear 13 is transmitted to the looper shaft 17 via the intermediate shaft 12. It is designed to rotate at the same rotational speed as. That is, the looper shaft 17 rotates faster or slower than the main shaft 10.

Next, how the looper shaft 17 rotates during sewing will be described with reference to FIGS. 2 (a) to 2 (d). First, as shown in FIG.
When the rotation angle is 0 degrees, the sewing machine needle reaches the bottom dead center, while the looper 18 is in the state shown in FIG.
Degree). At this time, the looper 18 has a first thread loop formed by the looper 18 catching the needle thread at the previous needle drop.

Then, with the rotation of the main shaft 10, the looper 18 rotates to catch the needle thread of the sewing needle. At this time, the looper shaft 17 rotates faster than the main shaft 10, and the looper 18 rotates 120 degrees when the main shaft rotates 90 degrees and the sewing machine needle reaches the vicinity of the sewing surface (FIG. 2).
(B)). That is, when the looper 18 captures the needle thread, the rotation speed of the looper shaft 17 is faster than the rotation speed of the main shaft 10.

Thereafter, the looper shaft 17 rotates slower than the main shaft 10, and when the main shaft rotates further 90 degrees from the state of FIG. 2B and the sewing machine needle reaches the top dead center, the looper shaft 17 is rotated. 17 further rotates 60 degrees (FIG. 2)
(C)). Similarly, from the state of FIG.
When the sewing machine needle reaches the vicinity of the sewing surface after the rotation of 0 by 90 degrees, the looper shaft further rotates by 60 degrees (FIG. 2).
(D)). Here, the first thread loop is separated from the looper 18 while the looper 18 rotates from the state shown in FIG. 2B to the state shown in FIG.

That is, when the yarn loop separates from the looper 18, the rotation speed of the looper shaft 17 becomes lower than the rotation speed of the main shaft 10, and the yarn loop separates from the looper 18 at the same timing as in the related art. I have.

Thereafter, the looper shaft 17 rotates again faster than the main shaft 10, and the main shaft 10 further rotates 90 degrees from the state shown in FIG. 2D, and the sewing machine needle dies at the next needle drop position. When the point is reached, the looper shaft 17 rotates further 120 degrees and returns to the state of FIG. That is, when the looper 18 catches the needle thread of the sewing machine needle which has fallen from the next needle drop position, the looper shaft 17 rotates again faster than the main shaft 10.

As described above, in the first embodiment, the rotation speed of the looper shaft 17 during one rotation is changed with respect to the rotation speed of the main shaft 10 so that the looper 18 captures the needle thread. Since the rotation speed of the looper shaft 17 is higher than the rotation speed of the main shaft 10, even if the needle drop position changes and the timing at which the needle and the looper 18 meet is shifted, the vertical position of the needle with respect to the looper 18, that is, the vertical movement of the needle thread The looper 18 can be brought into contact with the needle without significantly changing the position. Therefore, the looper 18 can accurately capture the needle thread, so that sewing can be reliably performed, and the needle drop position can be changed to some extent within a range where the looper 18 can capture the needle thread.

Further, by meshing the non-circular gears 11 and 13 with each other, the rotation speed of the looper shaft 17 during one rotation can be reliably changed with respect to the rotation speed of the main shaft 10, and single thread ring sewing can be performed. Since the sewing machine is merely provided with the transmission mechanism 20 that changes the rotation speed of the looper shaft 17 during one rotation with respect to the rotation speed of the main shaft 10, the looper can be swung with the needle, or two loopers can be used. The configuration of the single thread and ring stitch sewing machine can be simplified as compared with the case where the sewing machine is provided.

[Second Embodiment] Next, a second embodiment of the present invention will be described.
An embodiment will be described. The single thread chain stitch sewing machine according to the present embodiment is different from the single thread chain stitch sewing machine according to the first embodiment in that the single thread chain stitch sewing machine according to the first embodiment includes a first non-circular gear 11, Intermediate shaft 12 and second non-circular gear 1
3, the pulleys 14 and 16, the timing belt 15,
While the transmission mechanism 20 including the looper shaft 17 is provided, the single thread ring stitch sewing machine of the present embodiment is provided with a motor for driving the looper shaft instead of the transmission mechanism. Therefore, the difference will be described in detail below.

First, the configuration of the single-thread ring stitch sewing machine according to the present embodiment will be described. The single thread ring stitch sewing machine according to the present embodiment
It has a main shaft, a needle bar, a looper shaft and a looper,
These configurations and arrangement positions are the same as in the first embodiment. The single-thread ring stitch sewing machine according to the present embodiment includes a motor that drives a looper shaft. This motor is a known motor whose speed can be changed, and by controlling the rotation speed of this motor, the rotation speed during one rotation of the looper shaft is changed with respect to the rotation speed of the main shaft, The looper shaft rotates in the same manner as in the first embodiment (see FIG. 2).

Therefore, according to the second embodiment, not only the same effects as in the first embodiment can be obtained, but also advantageous effects as compared with the first embodiment can be obtained. . That is, by controlling the rotation speed of the motor, the rotation speed of the looper shaft during one rotation can be changed with respect to the rotation speed of the main shaft irrespective of the rotation of the main shaft. Further, since the motor is merely provided in the single thread ring stitch sewing machine, the configuration of the single thread ring stitch sewing machine can be simplified.

[Third Embodiment] Next, a third embodiment of the present invention will be described.
An embodiment will be described. The difference between the single-thread chain stitch sewing machine of the present embodiment and the single-thread chain stitch sewing machine of the first embodiment is that the transmission mechanism 20 of the single-thread chain stitch sewing machine of the first embodiment has The first non-circular gear 11 and the second non-circular gear 13 of the intermediate shaft 12 mesh with each other so that the main shaft 10
Is transmitted to the intermediate shaft 12 and the rotation of the intermediate shaft 12 is transmitted to the looper shaft 17 via the timing belt 15 and the like. On the other hand, the single thread ring stitch sewing machine according to the present embodiment has such a configuration. The point is that a transmission mechanism different from the transmission mechanism 20 is provided. Therefore, the difference will be described in detail below.

This transmission mechanism includes a first non-circular gear, an intermediate shaft, a second non-circular gear, and a looper shaft.
The configurations and arrangement positions of the main shaft, the needle bar, and the looper are the same as those in the first embodiment. The intermediate shaft is provided on the sewing machine frame below the main shaft so as to be rotatable and parallel to the main shaft. A first non-circular gear is provided on the intermediate shaft, and a motor for driving the intermediate shaft at a constant rotation speed is provided at a base end of the intermediate shaft. And
The intermediate shaft is rotated by this motor at the same rotational speed as the main shaft.

The looper shaft is provided on the sewing machine frame below the sewing surface of the sewing machine so as to be rotatable and parallel to the main shaft. A second non-circular gear is provided on the looper shaft. The shapes of the first non-circular gear and the second non-circular gear are the same as in the first embodiment.
The first non-circular gear and the second non-circular gear are meshed with each other, so that one rotation of the intermediate shaft makes one rotation of the looper shaft. Further, a looper is provided at the tip of the looper shaft.

The functions of the first non-circular gear and the second non-circular gear are the same as in the first embodiment. That is, the first non-circular gear rotates at a constant rotation speed with the rotation of the intermediate shaft. On the other hand, the second non-circular gear rotates at the same rotational speed as the first non-circular gear, but changes its rotational speed during one rotation. That is, the looper shaft rotates at a constant rotation speed in conjunction with the intermediate shaft, but changes the rotation speed during one rotation so that the looper shaft rotates in the same manner as in the first embodiment. (Fig. 2
reference).

Therefore, according to the third embodiment, the same effects as those of the second embodiment can be obtained, and more advantageous effects can be obtained as compared with the second embodiment. . That is, by engaging the pair of non-circular gears, the rotation speed of the looper shaft during one rotation can be reliably changed with respect to the rotation speed of the main shaft without controlling the rotation speed of the motor. In addition, since only the looper transmission mechanism is provided on the single thread ring stitch sewing machine, the configuration of the single thread ring stitch sewing machine can be simplified.

[Fourth Embodiment] Next, a fourth embodiment of the present invention will be described.
The embodiment will be described with reference to FIGS. 3 and 4. FIG. The single thread chain stitch sewing machine according to the present embodiment has the same configuration as a needle swing type single thread chain stitch sewing machine provided with two conventional loopers, except for having a mechanism as shown in FIG. I have.

That is, the single thread ring stitch sewing machine according to the present embodiment comprises a main shaft rotatably supported by a sewing machine frame,
It has a needle bar that moves up and down in conjunction with the main shaft, swings right and left at the same time, and has a needle, and a mechanism as shown in FIG. Hereinafter, the mechanism shown in FIG. 3 will be described.
The description of the main shaft and the needle bar having the same configuration as the conventional one will be omitted.

The mechanism shown in FIG. 3 is arranged below the sewing surface, and includes a thread pulling drive mechanism for driving the thread puller 27 having the thread puller 27 and a looper driving mechanism for driving the loopers 30 and 31. It is configured. The looper drive mechanism is substantially the same as the conventional single thread ring stitch sewing machine except for the shape of the loopers 30 and 31.

That is, the loopers 30 and 31 are connected to the looper shafts 28 and 29, respectively.
When the looper shaft 29 is rotated by the drive mechanism (not shown) in the direction of arrow E (which is the same direction as the swinging direction of the needle bar), the loopers 30 and 31 swing in the direction of arrow E. The loopers 30 and 31 alternately supplement the needle thread to form a thread loop. Further, the loopers 30 and 31 are disposed closer to the looper shafts 28 and 29 than the plane 32 on which the needle is swung.

The looper 30 has a thread holding section 30a for holding a thread loop, and a thread catching section (sword point) 30b for catching a needle thread.
It is composed of The thread holding section 30a is connected to the looper shaft 28.
Is a bar-shaped portion. The yarn catching portion 30b is a portion extending laterally from the distal end of the yarn holding portion 30a, and becomes thinner toward the distal end, and is bent toward the flat surface 32 on which the needle is swung, that is, toward the needle drop position. Shape. Looper 31
Has a symmetrical shape with the looper 30.

The yarn pulling drive mechanism includes a rotating shaft 21, an eccentric cam 22, a rod 23, a pin 24, a swing shaft 25,
A yarn puller support 26 and a yarn puller 27 are provided. The rotation shaft 21 is disposed outside the looper shaft 28 and the looper shaft 29 and rotates in the direction of arrow K in conjunction with the main shaft. A rod 23 is connected to the rotating shaft 21 via an eccentric cam 22, and the rod 23 moves left and right substantially along a direction orthogonal to the rotating shaft 21.

On the other hand, below the looper shaft 28 and the looper shaft 29, the swing shaft 25 is supported by the sewing machine frame in parallel with the rotation shaft 21. At the tip end of the swing shaft 25, a thread pulling support portion 26 has an upper end portion of 2
It is provided so as to be arranged above the two loopers 30 and 31 and to be rotatable and swingable. And the rod 23
Are connected to each other by a pin 24. Note that the pin 24 is rotatable with respect to the rod 23 and the yarn pulling support portion 26. Further, a yarn shifter 27 is fixed to the upper end of the yarn shift supporting portion 26.

With such a mechanism, the yarn shift supporting portion 26
The swing of the rod 23 is transmitted via the pin 24,
Since the swinging shaft 25 swings in the direction of the arrow L about the fulcrum, the yarn puller 27 reciprocates in the direction of the arrow L. Here, the reciprocating speed is, for two vertical movements of the needle bar,
It makes one reciprocation in a substantially horizontal direction.

The yarn puller 27 pulls a part of the yarn loop 35 formed by the loopers 30 and 31 so as to come out of the region where the loopers 30 and 31 swing. This yarn puller 27 is plate-shaped, and its tip end is
It is fixed to the yarn approaching support portion 26 so as to protrude toward the fifth side. A yarn holding portion 27a for holding the yarn loop 27 on the yarn puller 27 is provided at the distal end. The thread holding portion 27a has a flat surface 32 on which the needle is swung.
It is arranged on the opposite side of the loopers 30 and 31. That is, the yarn holding portions 30a and 31a of the loopers 30 and 31
And the yarn holding portion 27a of the yarn shifter 27 are disposed at positions sandwiching the plane 32 on which the needle is swung when the needle is lowered.

The single-thread ring stitch sewing machine performs sewing as follows. That is, as shown in FIG. 4, the needle first falls on a needle drop position (not shown) near the looper 31 in the plane 32 on which the needle is swung, and the needle thread is caught by the looper 31 and To the looper 30 side to form a first thread loop 35, and the thread shifter 27 moves in the direction of the arrow L1 to hook the thread loop 35 on the thread holding portion 27a. 31 is pulled out of the swinging area.

Next, the next needle falls inside a part of the thread loop 35. Here, the needle drop position can be arbitrarily selected from a range intersecting a part of the inner part of the thread loop 35 and the plane 32 on which the needle is swung, that is, between a needle drop position 33 and a needle drop position 34. . When the next needle drops, the looper 30 catches this needle thread, and moves the needle thread through the thread loop 35 toward the looper 31 to form a second thread loop. Moves in the direction of arrow L2 to hook the second yarn loop 35 on the yarn holding portion 27a, and pulls a part of the second yarn loop so as to come out of the region where the loopers 30 and 31 swing. By this series of operations, a stitch for one stitch is formed.

As described above, according to the fourth embodiment,
Since the yarn puller 27 is provided, the needle is dropped inside a part of the yarn loop 35 avoiding the region where the loopers 30 and 31 swing, and the needle thread passed through the needle is captured by the loopers 30 and 31. Can be done. Therefore, the needle drop position can be arbitrarily changed and the needle drop position does not need to be so accurate, so that sewing can be performed easily and reliably.

Here, the yarn holding portions 3 of the loopers 30 and 31
0a 31a and the yarn holding portion 27a of the yarn shifter 27
When the needle is lowered, it is arranged at a position sandwiching the plane on which the needle swings, so that the inside of a part of the thread loop 35 intersects with the plane 32 on which the needle swings. Therefore, the needle can be easily dropped inside a part of the thread loop 35.

[Fifth Embodiment] Next, a fifth embodiment of the present invention will be described.
The embodiment will be described with reference to FIGS. 5 and 6. FIG. The needle swing type single thread ring stitch sewing machine according to the present invention is shown in FIG.
Except that the auxiliary looper 40 is provided with the same configuration as that of a conventional single swing ring sewing machine provided with one conventional looper.
Will be described.

The auxiliary looper 40 is provided in the vicinity of the looper 49, and includes a rotating shaft 41, an eccentric cam 42,
Rod 43, pin 44, arm 45, fulcrum shaft 46
And an auxiliary sword tip 47. The rotation shaft 41 is rotatably supported by the sewing machine frame so as to extend in a direction perpendicular to the rotation surface of the looper 49, and is rotated in the direction of arrow N by a drive mechanism (not shown). A rod 4 is attached to the tip of the rotating shaft 41 via an eccentric cam 42.
3 are connected. Therefore, the rod 43 swings in the direction of the arrow P with the rotation of the rotating shaft 41. On the other hand, a fulcrum shaft 46 is provided above the tip of the rod 43.
Are fixed in parallel with the rotation shaft 41, and the fulcrum shaft 46
Arm 45 is swingably connected to the arm.

The arm 45 has a shape in which both ends are bent at substantially right angles and the both ends extend in opposite directions to each other, and a bent portion at one end is connected to the fulcrum shaft 46 at one end. It is rotatably swingably connected, and is connected at one end to the tip of a rod 43 via a pin 44. Therefore, the arm 45 can swing in the direction of the arrow M with the rotation of the rotation shaft 41.

The auxiliary sword tip 47 is provided at the other end of the arm 45. This auxiliary sword tip 47 has a substantially inverted U-shaped cross section. Further, a holding portion 47a for holding a needle thread captured by the auxiliary sword tip 47 is formed at a rear portion of the auxiliary sword tip 47. Here, the swing speed of the auxiliary looper 40 having such a structure makes one reciprocation for one vertical movement of the needle bar, and the auxiliary sword tip 47 is higher than the sword tip 50 that supplements the needle thread of the looper 49. Move fast and move first to needle thread 52
Can be supplemented.

The single-thread ring stitch sewing machine provided with the auxiliary looper 40 performs sewing as follows. That is, when the needle 51 falls, the auxiliary sword tip 47 moves in the direction of the arrow M1 to catch the needle thread 52 before the looper 49. Next, the tip 50 of the looper 49 rotating in the direction of arrow A is inserted into the recess 48 formed by making the cross-sectional shape of the auxiliary sword tip 47 substantially U-shaped.
The needle thread 52 of the looper 49 catches the needle thread 52 that has been captured earlier, and forms a thread loop.

Next, the auxiliary sword tip 47 moves in the direction of the arrow M2, and the looper 49 rotates. When the next needle drops, the auxiliary sword tip 47 moves again in the direction of arrow M1 and the needle thread 5
2 is captured before the looper 49. Next, the sword tip 50 of the looper 49 is inserted into the concave part 48 of the auxiliary sword tip 47, and the needle thread 52 captured first by the
The sword 50 of the ninth catches and passes the needle thread 52 through the thread loop formed earlier. By repeating this operation, sewing is performed.

As described above, according to the fifth embodiment, since the speed of the auxiliary looper 40 is faster than that of the looper 49, even if the needle drop position changes, the needle and the auxiliary looper 40 can be moved.
The timing at which the auxiliary sword tip 47 encounters almost no change, the needle thread can be reliably captured, and the auxiliary looper 4
Since the needle thread 52 is previously captured by the zero auxiliary sword tip 47, the looper 49 can capture the needle thread 52 previously captured by the auxiliary sword tip 47. Therefore, since the looper 49 can reliably capture the needle thread 52, sewing can be performed reliably, and
The needle drop position can be changed to some extent within a range in which the auxiliary sword tip 47 can catch the needle thread 52.

Here, by inserting the sword tip 50 of the looper 49 into the recess 48 of the auxiliary sword tip 47, the needle thread 52 captured by the auxiliary sword tip 47 can be captured by the sword tip 50 of the looper 49. As a result, the looper 49 can more easily and reliably catch the needle thread 52.
Further, since it is only necessary to provide the auxiliary looper 40 on the single thread ring stitch sewing machine, the configuration of the single thread ring stitch sewing machine can be simplified.

[Sixth Embodiment] Next, a sixth embodiment of the present invention will be described.
The embodiment will be described with reference to FIGS.
As shown in FIGS. 7 and 8, the needle swing type single thread stitch sewing machine of the present embodiment is different from the looper 60 in shape, as shown in FIGS. Since the configuration is the same as that of the thread stitch sewing machine, the shape of the looper 60 will be described.

The rotation radius R1 of the looper 60 is larger than that of the conventional looper. In addition, the looper 60 rotates the looper 60 with the sword 61 for supplementing the needle thread 64 and the needle thread 64 supplemented by the sword 61. A holding portion 62 is provided behind the sword tip 61, and a connecting portion (rotation center) 63 extends from the holding portion 62 toward the rotation axis and is connected to the rotation shaft. The holding portion 62 is formed on the opposite side of the sword tip 61 from the connecting portion 63 so that the held needle thread 64 does not go on the opposite side of the needle from the connecting portion 63 of the looper 60.

The side wall 65 of the looper 60 on the side of the sword 61 is slightly recessed toward the other side wall. This is because the needle thread 64 captured by the looper 60 at the time of sewing travels along the side wall 65 on the side of the sword tip 61 and moves rearward of the sword tip 61 as the looper 60 rotates, as described later. At this time, the looper 60
This is to reduce the length of the needle thread 64 pulled out as much as possible so that the needle thread 64 can be just received in the holding portion 62.

The single-thread ring stitch sewing machine performs sewing by operating as follows at the time of sewing. As shown in FIG. 9A, the looper 60 rotates in the direction of arrow Q, and when the needle drops, the needle thread 64 catches the needle thread 64 to form a thread loop. Next, as the looper 60 rotates, the needle thread 64 travels along the side wall 65 on the side of the sword tip 61 and moves rearward of the sword tip 61, and the needle thread 64 is held by the holding portion 62. Then, as shown in FIG. 9B, when the looper 60 rotates about 180 degrees, the needle thread 64 is pulled out to the same degree as the conventional looper. More looper 6
0 rotates, and when the next needle falls, the needle thread 64
Is captured by the blade 61, and the needle thread 64 is passed through the thread loop formed earlier. Repeat the above operation,
Perform sewing.

Therefore, in the sixth embodiment,
The holding section 62 controls the looper 6 so that the held needle thread 64 does not go to the opposite side of the needle from the rotation center 63 of the looper 60.
Since it is formed on the opposite side of the sword tip from the center of rotation of 0,
That is, at the time of sewing, the needle thread 64 captured by the looper 60 is not disposed on the opposite side of the needle from the rotation center of the looper 60. Therefore, the rotation radius of the looper 60 can be increased to some extent without the needle thread 64 being pulled out for a long time.

By increasing the rotation radius R1 of the looper 60, the rotation angle of the looper 60 corresponding to the distance of the needle drop position becomes smaller. You can meet the needle without changing the needle. Therefore, the looper 60 can accurately capture the needle thread 64, so that sewing can be reliably performed, and the needle drop position can be changed to some extent within a range where the looper 60 can capture the needle thread 64. . Also, since it is only necessary to change the shape of the looper 60 of the single thread ring stitch sewing machine, the configuration of the single thread ring stitch sewing machine can be simplified.

In the first embodiment, the intermediate shaft 12 is used to transmit the driving force from the main shaft 10 to the looper shaft 17 in the first embodiment.
The present invention is not limited to this. By providing a non-circular gear on the looper shaft and meshing the non-circular gear with the non-circular gear of the main shaft, the looper shaft 1 can be directly driven from the main shaft 10.
7 may be used to transmit the driving force. Further, the rotation speed of the looper shaft in the first to third embodiments is arbitrary as long as the rotation speed of the looper shaft is higher than the rotation speed of the main shaft when the looper captures the needle thread.

[0084]

According to the first aspect of the present invention, the rotation speed of the looper shaft during one rotation is changed with respect to the rotation speed of the main shaft, so that when the looper captures the needle thread, the looper shaft is rotated. Since the rotation speed of the shaft is higher than the rotation speed of the main shaft and the rotation speed of the looper is larger than the vertical movement speed of the needle bar, the needle drop position changes and the timing at which the needle meets the looper Even if the position is shifted, the vertical position of the needle with respect to the looper, that is, the vertical position of the needle thread, can be brought into contact with the looper without much changing. Therefore, the looper can accurately capture the needle thread, so that sewing can be reliably performed, and the needle drop position can be changed to some extent within a range where the looper can capture the needle thread.

Also, by changing the rotation speed of the looper shaft during one rotation with respect to the rotation speed of the main shaft, the rotation speed of the looper shaft can be made smaller than the rotation speed of the main shaft when the looper captures the needle thread. Since the speed may be set to a high speed, the looper can be swung together with the needle, and the configuration of the single thread ring stitch sewing machine can be simplified as compared with the case where two loopers are used.

According to the second aspect of the invention, the same effect as that of the first aspect can be obtained, and the rotation of the looper shaft during one rotation can be achieved by meshing the non-circular gears with each other. The speed can be reliably changed with respect to the rotation speed of the main shaft. In addition, since only the transmission mechanism is provided on the single thread ring stitch sewing machine, the configuration of the single thread ring stitch sewing machine can be simplified.

According to the third aspect of the present invention, the same effects as those of the first aspect can be obtained, and of course, by controlling the rotation speed of the motor, regardless of the rotation of the main shaft. The rotation speed of the looper shaft during one rotation can be changed with respect to the rotation speed of the main shaft. In addition, since only the motor is provided on the single thread ring stitch sewing machine, the configuration of the single thread ring stitch sewing machine is provided. Can be simplified.

According to the fourth aspect of the invention, the same effect as that of the first aspect can be obtained, and the speed of the motor can be reduced by engaging the pair of non-circular gears. Only by adjusting to the speed, the rotation speed of the looper shaft during one rotation can be reliably changed with respect to the rotation speed of the main shaft. Also, since only the single-thread ring stitch sewing machine is provided with the looper transmission mechanism, In addition, the configuration of the single-thread ring stitch sewing machine can be simplified.

According to the fifth aspect of the present invention, the needle is
The looper can be dropped inside a part of the thread loop avoiding the swinging area, and the looper can catch the needle thread passed through the needle. Therefore, the needle drop position can be arbitrarily changed and the needle drop position does not need to be so accurate, so that sewing can be performed easily and reliably.

According to the sixth aspect of the present invention, the same effects as those of the fifth aspect can be obtained, and the needle holding portion of the looper and the yarn holding portion of the yarn shifter can be provided with the needle. When the needle descends, it is arranged at a position sandwiching the plane on which the needle is swung, so that the inside portion of a part of the yarn loop intersects with the plane on which the needle is swung. Therefore, the needle can be easily dropped inside a part of the thread loop, and sewing can be performed more easily and reliably.

According to the seventh aspect of the invention, since the speed of the auxiliary looper is high, the timing at which the needle meets the auxiliary sword tip hardly changes even if the needle drop position changes, and the needle thread can be reliably captured. The looper can capture the needle thread previously captured by the auxiliary sword tip. Therefore, the looper can reliably capture the needle thread, so that sewing can be performed reliably,
The needle drop position can be changed to some extent within a range where the auxiliary sword tip can catch the needle thread. Further, since it is only necessary to provide the auxiliary looper on the single thread ring stitch sewing machine, the configuration of the single thread ring stitch sewing machine can be simplified.

According to the eighth aspect of the present invention, the same effect as that of the seventh aspect can be obtained, and the auxiliary looper is inserted into the concave portion of the auxiliary sword by inserting the tip of the looper. The needle thread of the looper can catch the needle thread captured by the auxiliary sword tip, so that the looper can more easily and reliably capture the needle thread. Therefore, sewing can be performed more easily and reliably.

According to the ninth aspect, at the time of sewing, the needle thread captured by the looper is not disposed on the side opposite to the needle from the center of rotation of the looper. Even if it is increased, the needle thread captured by the looper does not become excessively long. Therefore, the radius of rotation of the looper can be increased to some extent.

By increasing the rotation radius of the looper, the rotation angle of the looper corresponding to the distance of the needle drop position becomes smaller, so that the looper can meet the needle earlier even if the needle drop position changes. be able to. Therefore, the looper can accurately capture the needle thread, so that sewing can be reliably performed, and the needle drop position can be changed to some extent within a range where the looper can capture the needle thread. Also, since it is only necessary to change the shape of the looper of the single thread ring stitch sewing machine, the configuration of the single thread ring stitch sewing machine can be simplified.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a configuration of a transmission mechanism of a single thread and ring stitch sewing machine according to a first embodiment of the present invention.

FIG. 2 is a front view showing a mode of rotation of the looper of FIG. 1;

FIG. 3 is a perspective view showing a yarn shift driving mechanism and a looper driving mechanism according to a fourth embodiment.

FIG. 4 is a plan view showing a mode of an operation of a looper and a yarn shifter of FIG. 3;

FIG. 5 is a front view showing a mode of sewing by a single thread ring stitch sewing machine according to a fifth embodiment.

FIG. 6 is a longitudinal sectional view showing a position of a looper blade tip with respect to the auxiliary blade tip of FIG. 5;

FIG. 7 is a front view showing a looper according to a sixth embodiment.

FIG. 8 is a side view of FIG. 7;

FIG. 9 is a front view showing a mode of capturing a needle thread by a looper.

FIG. 10 is a front view showing a mode of sewing by a single thread ring stitch sewing machine provided with one conventional looper.

FIG. 11 is a plan view showing a mode of sewing by a single thread ring stitch sewing machine provided with two conventional loopers.

[Explanation of symbols]

 Reference Signs List 10 Main shaft 11 First non-circular gear (non-circular gear) 13 Second non-circular gear (non-circular gear) 17 Looper shaft 18 Looper 20 Transmission mechanism 27 Thread shift 27a Thread holding unit 30/31 Looper 30a / 31a Thread holding unit 35 Needle thread 40 Auxiliary looper 47 Auxiliary sword point 48 Recess 49 Looper 50 Sword point 51 Needle 52 Needle thread 60 Looper 61 Sword point 62 Holder 64 Needle thread

Claims (9)

[Claims] A main shaft rotatably supported by a sewing machine frame;
A needle bar having a needle, a looper shaft pivotally supported by the sewing machine frame and rotating in conjunction with the main shaft, and a looper attached to the looper shaft to form a thread loop by supplementing a needle thread. A needle swing type single thread stitch sewing machine that moves the needle bar up and down once per rotation of the main shaft and rotates the looper shaft once to perform sewing in cooperation with the needle and the looper; By changing the rotation speed of the looper shaft during one rotation with respect to the rotation speed of the main shaft, the rotation speed of the looper shaft is higher than the rotation speed of the main shaft when the looper captures the needle thread. And single thread ring stitch sewing machine. 2. A transmission mechanism for transmitting a driving force from the main shaft to the looper shaft and having at least a pair of non-circular gears, wherein the non-circular gears mesh with each other to make one rotation of the looper shaft. 2. The single thread stitch sewing machine according to claim 1, wherein the rotation speed during the rotation is changed with respect to the rotation speed of the main shaft. 3. A motor for driving the looper shaft is provided, wherein a rotation speed of the looper shaft during one rotation is changed with respect to a rotation speed of the main shaft by controlling a rotation speed of the motor. The single thread ring stitch sewing machine according to claim 1, characterized in that: 4. A motor for driving the looper shaft, and a looper transmission mechanism for transmitting a driving force of the motor to the looper shaft and having at least a pair of non-circular gears, and the non-circular gears mesh with each other. The single thread stitch sewing machine according to claim 1, wherein the rotation speed of the looper shaft during one rotation is changed with respect to the rotation speed of the main shaft. 5. A main shaft rotatably supported by a sewing machine frame, vertically moving in conjunction with said main shaft, and simultaneously swaying left and right,
A needle bar provided with a needle, and two loopers swinging in the same direction as the swing direction of the needle bar and alternately capturing a needle thread to form a thread loop. A thread that reciprocates once in a substantially horizontal direction in response to two vertical movements of the needle bar, and pulls a part of a thread loop formed by the looper out of an area where the looper swings. A single thread ring stitch sewing machine characterized by having a shift. 6. The thread holding section of the looper holding the thread loop and the thread holding section of the thread shifter holding the thread loop held by the looper when the needle descends. The single thread ring stitch sewing machine according to claim 5, wherein the sewing machine is arranged at a position sandwiching a plane on which the needle is swung. 7. A main shaft rotatably supported by a sewing machine frame, vertically moving in conjunction with the main shaft, and simultaneously swinging left and right,
A needle bar having a needle, a looper shaft pivotally supported by the sewing machine frame and rotating in conjunction with the main shaft, and a looper attached to the looper shaft to form a thread loop by supplementing a needle thread. A needle swing type single thread ring stitch sewing machine that moves the needle bar up and down once per rotation of the main shaft and rotates the looper shaft once to perform sewing in cooperation with the needle and the looper; An auxiliary looper provided with an auxiliary sword tip for reciprocating one reciprocation for one vertical movement of the needle bar, moving faster than the sword tip for capturing the needle thread of the looper, and supplementing the needle thread first, The needle thread captured by the auxiliary sword tip of the auxiliary looper is
A single thread ring stitch sewing machine characterized in that the point of the looper catches. 8. A concave portion formed by making the cross-sectional shape of the auxiliary sword tip of the auxiliary looper substantially U-shaped and making the cross-sectional shape of the auxiliary sword tip for supplementing the needle thread substantially U-shaped.
The single thread ring stitch sewing machine according to claim 7, wherein the needle point of the looper captures the needle thread captured by the auxiliary blade point of the auxiliary looper by inserting the blade point of the looper. 9. A main shaft rotatably supported by a sewing machine frame, vertically moving in conjunction with the main shaft, and simultaneously swaying left and right,
A needle bar having a needle, a looper shaft pivotally supported by the sewing machine frame and rotating in conjunction with the main shaft, and a looper attached to the looper shaft to form a thread loop by supplementing a needle thread. A needle swing type single thread ring stitch sewing machine that moves the needle bar up and down once per rotation of the main shaft and rotates the looper shaft once to perform sewing in cooperation with the needle and the looper; The looper is provided with a sword tip for supplementing the needle thread, and a holding part for holding the needle thread supplemented by the sword tip behind the sword tip with the rotation of the looper. A single thread ring stitch sewing machine formed on the opposite side of the blade point from the rotation center of the looper so as not to be on the opposite side of the needle from the rotation center of the looper.