JPH0135739Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is based on the upper looper, which operates in an intersecting manner with the sewing machine needle and the lower looper to stitch the edges of the fabric, and has two threads per needle and three threads per needle. This invention relates to an upper looper device for an overlock sewing machine which can be switched to overlocking.

Conventional Technology This type of overlock sewing machine is equipped with an upper looper 2 and a lower looper in the sewing machine bed that operate in synchronization with the rise and fall of the sewing machine needle, and each needle has three threads that are threaded through the upper and lower loopers respectively. In some cases, overlock stitching is performed, and in other cases, two-thread overlock stitches per needle are performed, in which the loop thread is passed only through the lower looper and the loop thread is received by the thread hooking part of the upper looper. In a conventional overlock sewing machine, a latch piece that can swing along the upper looper is provided, and when three threads per needle are being stitched, this latch piece is moved to the inactive position, and when two threads per stitch are being stitched, the latch piece is moved to the inoperative position. When the main thread is being stitched, a switching means is provided so as to form a thread receiver for the loop thread of the lower looper by aligning the hooking piece along the upper looper and bringing the thread hooking part provided at the tip into contact with the upper looper. (For example, special public service in 1984
−13478 Publication, Utility Model Application Publication No. 15386, No. 1983, Publication No. 60−
Publication No. 18771, Publication No. 60-18772).

Problems to be Solved by the Invention The upper looper device attached to the above-mentioned conventional sewing machine has a hook piece formed separately from the upper looper fixed to the upper looper shaft, which is attached to the base of the upper looper or the upper looper holder. On the other hand, since it was configured to be swingably attached via a fulcrum shaft,
The number of parts increases by the amount of the fulcrum shaft, which requires more effort to assemble, and the position of the locking piece tends to become unstable during use. Therefore, it has been desired to improve the upper looper device of an overlock sewing machine so that the structure is simple and the switching operation can be performed easily and reliably.

Means to Solve the Problems Therefore, the present invention has developed an upper looper that operates in an intersecting manner with the sewing machine needle and the lower looper to stitch the edge of the fabric, and has two threads per needle and three threads per needle. In the upper looper device of the overlock sewing machine, which is provided so that it can be switched, the upper looper for sewing three threads per needle, which is equipped with a thread passage hole and a thread hooking part, is fixed to the upper looper shaft. Separately, the tip is provided with a locking protrusion that fits into the threading hole, the base end has a U-shaped fitting part that fits on both sides of the base of the upper looper, and the side surface of the base has an elastic The upper looper is provided with a latching part that engages the fitting part with a concave and convex engagement, and has a threading part at the tip of the upper edge to form an upper looper for stitching two threads per needle. 1 through the latching protrusion, the fitting part, and the latching part.
To provide an upper looper device for an overlock sewing machine, characterized in that the upper looper for three-needle thread overlocking is detachably provided.

Function As mentioned above, the looper device according to the present invention has 1 needle and 3 needles.
The upper looper for main thread overlocking and the upper looper for 1-needle, 2-thread overlocking are manufactured separately, and the former is fixed to the upper looper shaft and the latter is attached to and detached from the former to perform edge overlocking. Since it is designed to be switched, the fulcrum shaft of the hanging piece can be omitted, simplifying the structure.
In addition, the upper looper for one-needle two-thread stitching has a latch protrusion that fits into the thread passing hole formed in the upper looper for one-needle three-thread stitching, and a fitting part and a hook, respectively. Since the switch is attached and detached through the section, the switching operation can be performed easily and reliably.

Embodiments Examples of the present invention will be described below with reference to the drawings.

In the figure, 1 is an upper looper shaft that operates with a conventionally known structure, and 2 is an L-shaped base 2' fixed to the upper end of the upper looper shaft 1 by a set screw 3. The upper looper 4 is a thread passage hole for the upper loop yarn b provided in the upper looper 2;
As shown in FIG. 1, 5 is a thread hooking part for receiving the loop thread a formed by the lower looper (not shown), and 6 is an upper looper for stitching two threads per needle, which is formed separately from the upper looper 2. be. The upper looper 6 is
As shown in FIG. 1, the distal end is provided with a locking protrusion 7 that projects laterally, and the proximal end is provided with a fitting portion 8 having a U-shaped cross section.
and a hemispherical hooking part 10 that elastically engages with the round hole 9 provided in the base part 2',
As shown in the figure, by fitting and removing the locking protrusion 7 into the thread passing hole 4 and the fitting part 8 and the locking part 10 into the base 2', the upper looper 2 for stitching three threads per needle is formed. It is configured so that it can be attached to and detached from it. 11 is formed at the tip of the upper edge of the upper looper 6, and the second
As shown in the figure, this is a thread hooking section that receives the loop thread a formed by the lower looper in the case of one-needle, two-thread stitching. In the figure, reference numeral 12 indicates a fitting positioning projection formed at the upper end of the base portion 2'.

When using the overlock sewing machine to stitch three threads per needle, the upper looper 6 for stitching two threads per needle is separated, as shown in Fig. When using the upper looper 2 for stitching 3 threads per needle as shown in Figure 2.
The upper looper 6 for stitching two threads per needle is used by superimposing them together.

Effects of the invention According to the invention configured as described above and adapted to be used as described above, a looper is formed separately from the upper looper for stitching three threads per needle, which is provided with a thread passing hole and a thread hooking part. By attaching and removing the upper looper for 1-stitch, 2-thread overlocking, you can switch between overlocking stitches.
The switching operation is simple and reliable. Also, when attaching the upper looper for one-needle, two-thread stitching to one fixed upper looper,
This is done by fitting the latching protrusion at the tip, the fitting part and the latching part at the base end into the thread passing hole and the base of the upper looper for one-needle, three-thread stitching, so the latching piece Compared to the conventional device that switches by swinging, it is possible to omit the provision of a fulcrum shaft, reducing the number of parts, and has the practical effect of firmly holding the upper looper in its mounting position.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention. Fig. 1 is an exploded perspective view showing the state of use in which one stitch of three threads is stitched, and Figure 2 is a perspective view of the used state in which one needle and two threads are threaded. FIG. 3 is a longitudinal sectional view of the proximal end of the upper looper for one-needle, two-thread stitching. 1...Upper looper shaft, 2...Upper looper for stitching 3 threads per needle, 3...Set screw, 4...Thread passage hole, 5...Threading section, 6...Setting thread 2 threads per needle Upper looper for use, 7... Latching protrusion, 8... Fitting part, 9
... Round hole, 10 ... Latching part, 11 ... Positioning protrusion, a, b ... Loop thread.

Claims (1)

[Scope of utility model registration request] An upper looper device of an overlock sewing machine, in which the upper looper, which operates in an intersecting manner with the sewing machine needle and lower looper to overlock the edges of fabric, can be switched between 2 threads per needle and 3 threads per needle. , an upper looper 2 for stitching three threads per needle is provided with a thread passing hole 4 and a thread hooking part 5 on an upper looper shaft 1.
Separately from the upper looper 2, the tip is provided with a locking protrusion 7 that fits into the threading hole 4, and the proximal end has a cross section that fits on both sides of the base 2' of the upper looper 2. It has a U-shaped fitting part 8 and a hooking part 10 that engages the fitting part 8 elastically with unevenness on the side surface of the base 2', and has a thread hooking part at the tip of the upper edge. 11
An upper looper 6 for stitching two threads per needle is formed with An upper looper device for an overlock sewing machine, characterized in that the upper looper device is detachably attached to an upper looper 2.