JP2646506B2 - Single thread chain stitching device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single thread and chain sewing machine applied to a single needle and single thread chain sewing machine called a single ring sewing machine.

[0002]

2. Description of the Related Art As is well known, a mechanism for performing chain stitching with a single needle and a single thread includes a sewing needle that operates vertically and a looper body that is positioned below a needle plate and performs a horizontal elliptical motion. And a fixed thread holder. The principle of the suturing operation is
The needle thread is captured by the looper body when the sewing needle is lowered, and the looper body operates in the needle thread capturing state in response to the rising of the sewing needle, and the captured needle thread is locked to the thread holder. Further, a needle thread loop is formed by the looper body and the thread holder by the operation of the looper body, a sewing needle is dropped into the needle thread loop, the thread is released from the looper body itself by the operation of the looper body, and the sewn cloth is sewn. The needle thread is released from the thread holding body by pulling the thread by the feeding operation of the above, the needle thread of the sewing needle that has passed through the needle thread loop and descended is captured again by the looper body, and the above operation is repeated, and Has been realized.

In particular, during the above-described suturing operation, if the catching thread is detached from the looper body, skipping occurs.
It has been proposed to provide a thread locking groove in a looper body (JP-A-3-123586).

[0004]

In the above-described single thread chain sewing apparatus, a looper body is provided at the upper end of a support arm whose lower end is rotatable like a universal joint, and the upper end is tilted and rotated by an upright support arm. Performs horizontal elliptical motion of the looper body.

In this horizontal elliptical movement of the looper body, the operation mechanism of the looper body becomes large, and the enlargement of the sewing machine itself is unavoidable, and the operation control of the support arm is complicated. As a countermeasure, when the looper body is driven by horizontal linear motion, the entire mechanism is simplified, but suturing errors are likely to occur. That is, the cause of the sewing error due to the single ring sewing machine is that the catching thread comes off from the looper body and that the catching thread cannot be locked to the thread holding body.
If the looper body is made to move horizontally and linearly, the catching yarn tends to come off from the looper body. However, even if the above-described conventional looper body is provided with the locking groove, it is not possible to reliably hold and release the capture thread with the looper body.

Further, since the thread holding member is provided in a fixed state, the detachment of the thread from the thread holding member is performed by pulling the locking thread by the feeding operation of the sewn cloth. If an inconvenience occurs in the cloth feeding such as skew of the seam, the locking thread will not come off, or the locking thread will come off and a thread loop will not be formed, resulting in so-called skipping. Therefore, the present invention proposes a looper body that can cope with a horizontal linear motion, and proposes a novel single-thread ring sewing device that realizes reliable sewing.

[0007]

SUMMARY OF THE INVENTION A single thread chain stitching apparatus according to the present invention includes a sewing needle that operates up and down, a looper body and a thread holder positioned below a needle plate. In particular, a looper body having a thread introduction section formed by the elastic wire body at the front end and a thread holding space portion at the base portion, in which an elastic wire body partly in contact with the looper body is attached to the looper body. And a drive unit for linearly operating the looper body in a horizontal plane approximately perpendicular to the direction of the sewing needle movement is provided.

[0008] In the above-mentioned apparatus, an operating portion for moving the thread holding body close to the looper body capturing the needle thread is provided.

[0009]

The suturing principle of the single thread and chain stitching device of the present invention is as follows.
When the threading portion at the leading end of the sewing needle is in the lower position of the needle plate, the looper body is advanced in the direction of the sewing needle, and the needle thread is guided into the thread holding space from the introduction portion and captured. Then, the looper body moves laterally in response to the upward movement of the sewing needle at the position above the needle plate, and subsequently moves backward, whereby the captured needle thread is securely locked to the thread holder. Further, when the looper body is retracted, the needle thread is formed into a loop between the thread holding space of the looper body and the thread holding body, and a sewing needle is dropped into the needle thread loop. When the thread comes off, the loop thread also comes off from the thread holding body, and the needle thread is captured again by the looper body by the advance operation of the next loop body, and this is repeated. Accordingly, the holding of the thread by the loop body performing the horizontal linear movement is reliably performed, and the formation of the thread loop for the single thread ring sewing is reliably realized.

In particular, when the approaching operation of the thread holding body in the direction of the looper body is performed, the loop body is retracted after the advancement (proximity operation) of the thread holding body. Since the thread holding body is retracted (separating operation) when the thread is required to be released further, the thread is released from the thread holding body regardless of the cloth feed.

[0011]

Next, an embodiment of the present invention will be described. The single thread chain stitching apparatus shown in the embodiment device includes a sewing needle 1, a looper body 2, and a thread holding body 3, and the sewing needle 1 has a thread a at a needle point like the conventional single ring sewing machine. Through the upper and lower portions of the needle plate, which is the moving position of the sewing object, to perform the vertical operation.

The looper body 2 is mounted on a predetermined drive mechanism 4 which operates in synchronization with the vertical movement of the sewing needle 1. The looper body 2 has a tough and suitable elasticity like a piano wire below the sword-shaped main body 21. In particular, the elastic wire body 22 is attached, and the thread introduction portion 23 is formed by bending the tip of the elastic wire body, and a part thereof is further brought into contact with the looper body (the contact portion 24). The yarn holding space portion 25 is provided. Further, the operation of the looper body 2 by the drive mechanism 4 is performed in a direction perpendicular to the suturing direction, behind the operating position of the sewing needle 1 (suturing end direction).
From a plane where at least the thread holding space portion 25 advances forward from the needle position, then laterally moves to the front of the needle position, then retreats and returns to the initial position by lateral movement at the end of retreat. When you look at it, it becomes an elongated rectangular motion.

The thread holding member 3 is located on the opposite side of the sewing machine 1 in a direction orthogonal to the operation direction of the looper body 1, and moves in a sewing direction at a position adjacent to the vertical position of the needle in the sewing direction. A curved concave portion 31 is formed at the tip end portion so as to be suitable for locking and releasing the thread.

Next, the execution of single thread chain sewing by the above-mentioned apparatus will be described. For convenience of explanation of the direction, the supply side of the sewing object is set to the front, the sewing end direction is set to the rear, and the operation start position of the looper body 2 is set to the right. Single thread chain stitching, as is well known, forms a loop at the lower side of the sewing object, and the thread of the loop comes out above the sewing object, passes through the sewing object again, forms the next loop through the loop. Is sequentially repeated, and the thread is sewn into a chain.

Specifically, the suturing operation according to the present invention is performed by lowering the sewing needle 1 so that the thread a2 is inserted into the loop a1 formed earlier.
With the sewing needle 1 penetrated (FIG. 3: A, FIG. 4:
(A: The sewing needle 1 is located at the bottom dead center), and the looper body 2 advances from right to left at a position behind and behind the sewing needle 1. By this advance operation, the yarn a2 is guided from the introduction portion 23 into the yarn holding space portion 25 and captured (FIG. 3: B). Further, the yarn a2 advances to the left in the captured state, and the yarn holding space 25 advances to the left further than the position of the yarn holder 3.

Next, the thread holding member 3 is advanced to the rear side, and the yarn holder 3 is advanced over the looper body 2 and advanced to the rear side (FIG. 3: C:
The sewing needle 1 is moved to the upper dead center position, and the looper body 2 is further laterally moved forward (by the rotational movement of the drive unit 4) and retracted to the right. Then, the tip of the thread holding body 3 is
Is necessarily located on the right side and the rear side of the yarn a2 captured by the looper 2, and the looper body 2 is securely locked by the retreat operation.

When the looper body 2 is retracted, the thread a2 is prevented from coming off from the thread holding space 25 of the looper body 2 by the contact portion 24. Then, the end of the thread holder 3 is locked to form a loop a3. By the descending operation of the next sewing needle 1, the sewing needle 1 passes through the thread loop a3 with the thread a4 forming the next loop. At the same time, when the looper body 2 further retreats, the loop thread a3 comes off from the thread holding space and the thread holder 4 also retreats forward, so that the loop thread a3 also comes off. Next, the looper 2 moves sideways to return to the initial state, and enters the operation of catching the next thread a4 by advancing to the left, and repeats the above-mentioned operations, thereby realizing a reliable single thread chain stitch. is there.

The driving means for the loop body and the thread holding body is as follows.
There is no particular limitation as long as it performs a predetermined operation, and a mechanism may be appropriately employed.

[0019]

As described above, according to the present invention, in a single thread chain sewing device, a looper body for forming a thread loop is formed in a predetermined shape capable of securely catching a thread when necessary and realizing release of thread catch. The elastic wire is attached to the looper, and the thread loop can be formed by the horizontal linear motion of the looper body, which realizes the miniaturization and simplification of the whole device, and also reliably eliminates the occurrence of sewing errors. It is.

In particular, since the thread holding body is operated to reliably release the thread at a predetermined timing, reliable sewing can be performed regardless of the cloth feeding state.

[Brief description of the drawings]

FIG. 1 is a front view of a looper body according to an embodiment of the present invention.

FIG. 2 is a perspective view of a main part of the apparatus of the embodiment.

FIG. 3 is an explanatory view of the suturing principle.

FIG. 4 is an explanatory diagram of the operation of each unit viewed from a plane.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sewing needle 2 Looper body 21 Sword-shaped main body 22 Elastic wire body 23 Thread introduction part 24 Contact part 25 Thread holding space part 3 Thread holding body 31 Curved concave part 4 Drive device

Claims (2)

(57) [Claims] 1. A sewing needle which vertically moves through a needle plate, which is a moving position of a sewing object, and a looper body which is located below the needle plate and catches a needle thread when the sewing needle descends. In a single thread ring sewing device that includes a thread holding body that locks a capture needle thread by operation of a looper body and drops a sewing needle into a needle thread loop formed by the looper body and the thread holding body, a part of the looper body is used. The looper body is provided with a thread introduction section formed by the elastic wire body at the front end of the looper body, and a looper body having a thread holding space at the base. A single thread ring sewing device characterized in that a drive unit is provided which makes a linear operation in a horizontal plane approximately perpendicular to the direction of movement of the sewing needle. 2. The single thread chain sewing device according to claim 1, wherein
A single thread chain stitching device comprising an operating portion for causing a thread holder to move closer to a looper body that has captured a needle thread.