DE901856C - Method and device for producing a double chain stitch seam - Google Patents

Description

Method and device for producing a double chain stitch seam The invention relates to a method and a device for producing a double chain stitch seam on multi-needle machines. In MI-needle machines, such as B. Two-needle Drai, thread-over & maschinen, it has been shown that it is better to produce an even interlocking over long distances: to pull out the needle, thread loops by a mechanical means and hold it until the interlock is engaged ' is. Experience has shown that it is sufficient to lock only one of the two needle thread loops in order to prevent the seam from being pulled. can be separated in one piece. According to the invention, this is achieved by the simplest means in that, in the production of a me'hrn'adelüberdwcksnaht with, for example, a gripper for binding d: r Needle threads a needle thread loop from the nelenaIlstE'henden ', \ Tadel.spitz. recorded and firmly is held in such a way that it is around the adjacent N a-delfadLznschleife lies around and goes through from her is locked. In the drawing is the subject of the invention illustrated by exemplary embodiments. It shows Fig. 1 the bottom row, for example of a two- well, the drain thread overlap seam, Fig. 2 the underside as an example: a two needle-diameter tire overlap seam with something at the end attracted gri, thread ,. Fig.3 also with the locking of the Looper thread through the left needle thread, Fig. I desglaich_n with the locking of the lin- ken N a'del: thread through the looperfa-d # -n, Fig.5 the same with the locking of the reckoned needle thread by the looper thread, Fig. 6 a top view of the stitch plate tongue. Fig. 7 likewise to one in its form @; twas modified stitch plate tongue, Fig. 8 a view of the hook, Fig. 9 a top view of the hook with the needle threads and the needle plate tongue and thread holder, Fig. 10 a view of this hook with the needle threads without the thread holder, Fig. II a Look at the thread holder with. '#, U @ recesses for the needle.

The embodiment is of a two-needle cover machine started with a gripper, in which the gripper, coming from right to left, enters the needle thread loops. But it can also - just as well a three - or multi-needle machine.

In the seam pattern according to Fig. I: a., A. ', A "and a"' denote the piercings of the right needle thread A and b, b ', b " denote the piercings of the left needle thread B. The looper thread is denoted by C designated.

As the fig leaves. I recognize the left Nadelfadenschleifo B 'is held fixed while DER GreHerfaden C through the right Nadeilfadenschleife, A' through the right needle thread loop A free a, and then passes through the left NADE lfadenschleife B 'with d, at: b 'wraps around the link @ needle thread loop B "and then around the right needle thread loop A" at d. At a.' it emerges again from the left needle thread loop B ', also at a from the right needle thread loop A', in order to enter the next needle thread loop .4 "at ä. If a pull is now exerted on the looper thread in the direction of arrow e, it pulls the loop C 'the needle thread loop B "' back to the right (see Fig. a), and since it goes straight through the looper loop C , it can no longer be pulled up on the right; this is effectively locked (see Fig. 3).

If, on the other hand, the left needle thread B is pulled in the direction of the arrow f (see Fig. 4), the looper thread loop C is positioned across the needle hole and the needle thread cannot be pulled any further because it lies around the looper thread (see Fig.: F). The same applies to the right needle thread A (see Fig. 5); the needle thread loop A ″ is locked by the looper thread C passing through.

A separation of the seam is only possible if in the sequence Each loop is pulled individually to release the respective lock.

As is well known, the work cycle of a sewing machine begins when it goes down of the needles and the entry of the needles into the fabric. After the needles the deepest Have reached the point of the needle stroke and go up again, the needle loops are formed. in which in multi-needle machines with one looper per needle group the looper tip occurs one after the other. After this needle thread loop recording, through the looper g, while the needles continue to rise and their upper stroke end approach, the needle thread loops slide along the hook to its end, at which it is bent downward in the exemplary embodiment, and slide here in the case h (see Fig. 8 and i o). During this movement, the feed dog the fabric taken away, and the two needle thread loops were widened through the Throat plate tongue pulled apart over the short conical distance k (see Figs. 6 and 7), namely the left needle thread loop B to the left and the right needle thread loop A to the right. This ensures that the two needle thread loops do not ride on each other. can, which would lead to skipped stitches and that the thigh Z (see oj). 9 and. io) is so far to the left that the needle next to it on the right in right too. must pass it by. While the needle point o on the upper, Leg I passes, the loop B of the gripper trap h. so far after to the right. drawn that the point of the needle o must now pass through it; the right Needle thread loop A lies in its normal position to the right of the needle. The Gre-i.fer continues in the direction of arrow p; while he is on his right End stroke, approaches: the two needle thread loops fall off, have been pulled upwards, the needles go up again, form new loops, the hook points step a., and a new operation begins.

With needles lying particularly close to one another and certain; Thread types it is: possible that, despite the throat plate tongue widened to the left, the upper Thread legs of the left needle thread loop is caught by the right needle. Around to prevent this in a safe way, a suture holder q can be provided, as shown in Fig. 9. This thread holder prevents the thread legs can slide to the right. In Fig. I i thief is tip this. Thread holder. shown in one embodiment in which the thread holder is still used for the narrowest needle distances is provided with a recess r for the needle.

The needle plate tongue can, as in one embodiment in Fig. 7 is shown, also be designed so that after a short widening a normal width i is again obtained, which means that there is not too much looper thread is deducted.

In itself it would be possible to pull out the needle thread loop to bring about a specially added Schicidenziefier, but what an additional one Require the addition of machine elements and the machine only unnecessarily complicated would shape. According to the invention, this is achieved with the simplest means by that the steel plate tongue is held wider. is than the needle spacing, which is only at very closely spaced needles is possible, and by one on and for themselves known trap on your gripper, which is designed in such a way that it the, Nad.eifad2nschle: ife so far across that it comes from the one next to it Needle point is detected and then only released when the needle has passed through the loop is. With certain types of thread, it @ can also have a special thread holder be provided, which prevents the upper leg of the left needle thread loop slides too far to the right and is pierced by the right needle point.

The simple means provided according to the invention z. B. the left needle thread loop, pulled out so far that the needle next to it pierced through it and thereby locked. As is well known, the needle thread until the third; If the stitch is retightened, this left needle thread loop can now not: any longer under the necessary length through this. Nachzug can be reduced in size. By these simple remedies will have an absolutely safe mode of action and uniformity the locking achieved at the various speeds of the machine.

Claims (4)

PATENT CLAIMS: i. Process for the production of a double chain stitch on multi-needle machines, characterized in that a needle thread loop (B) is also grasped and held by the adjacent needle point (o) in such a way that it wraps around the adjacent needle thread loop (A ') and is thereby locked by it. 2. Device for performing the method according to claim i, characterized in that the stitch plate tongue (a @ at the stitch formation point! is essentially wider than the needle distance and tangentia.l by inclined surfaces connected to the pinholes while the hook (g) receives a trap (h), which in cooperation with the needle plate tongue (i) the left needle thread loop (B) so far to the one next to it. Needle (m) pulls over; that the top (o) of this Put the needle through the loop (B). 3. Apparatus according to claim 2, characterized marked that there is also a thread holder (q) between the two needles is attached that a rightward sliding of the upper thread leg of the left needle thread loop is prevented. 4. Apparatus according to claim 2 and 3, characterized in that hold the tip of the thread holder (q) for the tightest needle distances with a recess (r) is provided for the needle.