JPS625385A - Empty link stitching apparatus of two-needle overlock sewingmachine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention involves forming an empty ring of a predetermined length after completing the formation of an overlock seam on a fabric, cutting this empty ring on the fabric side, This invention relates to an empty chain sewing device for a two-needle overlock sewing machine, which holds the side leading to the needle and sews it into a newly formed overlock seam during the next sewing.

[Prior art]

Overlock stitches using an overlock sewing machine are formed using needle thread, upper looper thread, and lower looper thread. After forming the overlock stitch on the fabric, an empty ring is formed to a predetermined length, and then the fabric is sewn. Change direction with the empty ring to the operator side, stretch the empty ring, cut and clamp the fabric side end with an empty ring holding/cutting device, etc., and place the side of the empty ring that reaches the needle against the throat plate surface. Sewing is performed by holding the empty ring in this state and sewing it into a newly formed overlock seam at the time of the next sewing.

By the way, this type of sewing machine is usually equipped with two loopers as a means of providing thread for forming seams on the fabric, and when performing overlock stitching, one looper (lower louver) is attached to the bottom of the fabric. The needle moves from the needle to the edge of the fabric in a direction perpendicular to the seam line, and another looper (upper looper) moves from the edge of the fabric to the top of the fabric so as to cross the needle, and by the action of these loopers, the thread An overlock seam is formed beyond the edge of the fabric.

The two-needle overlock sewing machine has two sewing needles, as shown in FIG. 1, and each manufacturer has an inner claw and an outer claw on one side of the needle drop. In other words, in Fig. 0, where the inner and outer claws are often arranged in parallel on both sides of the needle drop part of the outer sewing needle, 1 is the throat plate, 2 is the outer claw, and 3 is the needle drop part (M needle) on both sides. )N1. The inner claw with N2, 4, is an empty ring holding and cutting device.

Then, when the sewing work on the fabric is finished, the operator carries the fabric and the empty ring connected to it to the front (turn pack).
When the empty ring is cut and clamped by the empty ring holding/cutting device 4, the empty ring is held on the throat plate 1 in the state shown in FIG.

In the figure, A indicates an empty ring.

[Problem that the invention seeks to solve]

However, since the empty ring A is held in the above state, when the needle descends at the beginning of sewing, the empty ring A is pulled toward the needle by the needle thread, so that the outer sewing thread (N2)
If this happens, there is a problem in that subsequent sewing is not performed and most of the empty loops remain in a protruding state beyond the sewing start portion. In addition, as mentioned above, in overlock stitching, the upper looper forms a loop with the louver thread on the top surface of the fabric edge, and the sewing thread from the sewing needle engages with this loop to perform sewing. This prevents loop formation by the upper looper.

To explain this with reference to Fig. 3, the thread triangle (loop) B formed by the upper looper 5 is pulled by the empty ring A as shown in the figure, and is placed on the opposite side of the sewing needles Nl and N2 (in the figure) across the upper looper 5. Since the stitches are located below the upper looper 5, a problem arises in that stitch skipping occurs.

[Means for solving problems]

The present invention attempts to solve the above-mentioned problems by providing an engaging portion for locking the empty ring at the end of the throat plate or the outer pawl of the presser foot.

〔Example〕

An embodiment of the present invention will be described based on the drawings from FIG. 4 onwards. Note that the same parts as in the conventional example are denoted by the same reference numerals, and redundant explanation will be omitted.

FIG. 4 is an enlarged view of the main part of this embodiment, and in FIG. 4, reference numeral 2a denotes a notch serving as an engagement portion of a hollow ring formed at the end of the outer claw 2. In FIG. In this embodiment, the notch 2a is a semicircular recess, but it goes without saying that any structure may be used as long as it allows the empty ring to enter and exit smoothly.

Next, the operation will be explained with reference to FIGS. 5 and 6.

When the sewing of the fabric is completed, the empty ring connected to the fabric is locked in the empty ring engaging part 2a at the end of the outer claw 2, turned to the operator side, and brought to the operator side, and the end on the fabric side is held by the empty ring holding/cutting device 4. Cut and clamp. Then, when sewing the next fabric C starts, the empty ring A is held in the proper position by the engaging part 2a without being involved with the outer needle N2, so the empty ring A is sewn smoothly into the overlock seam. It will be done. (See Fig. 5) Also, as shown in Fig. 6, the empty ring A
a, and is pulled from this point and clamped to the empty ring holding/cutting device, so no unnecessary force is applied to the loop formation of the upper looper 5, so that the loop can be formed in the proper position, i.e. In the figure, the thread triangle B (loop) is located above the upper looper 5, so the sewing needles Nl and N2 accurately complement it. Furthermore, FIGS. 7 to 9 are diagrams showing other embodiments of the present invention. In FIG. 7, a notch is provided at the left end of the throat plate outer claw 2 to form an engaging portion 2a, which locks the empty ring A by cooperation with the outer claw 6a of the presser foot 6. There is. In FIG. 8, the engaging portion 2a is composed of the left end of the throat plate outer claw 2 and the right end of the presser foot outer claw 6a. In other words, the engagement portion 2a is formed by a gap formed between the right end of the straight presser foot outer claw 6a and the left end of the throat plate outer claw 2 which is shaped to expand downward.

In FIG. 9, an engaging portion 2a is formed by a recess provided at the tip of the outer claw 6a of the presser foot. In these embodiments the operation does not differ from that described above.

〔Effect of the invention〕

As explained above, this invention has a structure in which an engaging portion for locking the empty ring is formed on the outer claw of the throat plate, so that the relative position of the empty ring and the sewing needle is accurately regulated, and the overlapping of the empty ring When sewing into the lock seam, the sewing needle does not sew on the empty ring, so the work of sewing the empty ring at the beginning of the fabric is smooth.

done accurately. Furthermore, since the loops of the upper looper are formed accurately, there is an effect that skipped stitches can be reliably prevented at the overlock seam.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the main parts of the device in the conventional example, Fig. 2 is an explanatory diagram showing the holding state of the empty ring in the conventional example, and Fig. 3 is a diagram showing the relationship between the loop formation by the upper looper and the empty ring in the conventional example. Figure 4 is an enlarged view of the main part of an embodiment of the present invention,
FIG. 5 is a diagram showing the sewing state of the empty loop in the embodiment of the present invention, FIG. 6 is an explanatory diagram showing the relationship between the loop formation by the upper looper and the empty loop, and FIGS. 7 to 9 are other illustrations. It is a figure showing an example of.

Claims (1)

[Claims] An empty ring holding/cutting device is provided on the front side of the needle drop part, and an engaging part of the empty ring is formed at the end of the needle plate or presser claw provided on the outside of the two sewing needles to sew the fabric. A two-needle overlock sewing machine characterized in that when the fabric is carried to the operator side after finishing, the needle-side end of a hollow ring formed in a continuous manner with the fabric is locked in the engaging part. Ring sewing device.