DE104963C - Device for extending the thread loops on double chain stitch sewing machines - Google Patents

Description

IMPERIAL

PATENT OFFICE.

The subject of the present invention is a device on double chain stitch sewing machines, by which the loops of the bobbin thread are suitably widened for the entry of the needle, without the swaying one Loops need to be moved sideways. Here the guiding thought was to avoid such means for widening the bobbin thread loops, which special Movements and operational parts need for themselves what the construction and working method of the Machine would make it difficult.

In the accompanying drawing, FIG. 1 shows a front view and FIG. 2 shows a top view of the part of a two-needle sewing machine embodying the invention; Figures 3 and 4 are Perspectivische bottom views of the throat plate. Through FIGS. 5 to 9 are different positions of a loop former in relation to a needle and a catch hook.

On the oscillating shaft A (Fig. 2, 5 and 6 a) sit as many loop patterns a as there are needles. Each loop pattern has a shoulder 3 on the side 2 facing the needle, which is used to widen the thread loops and is provided with a shoulder 4. On the underside of the throat plate b , a catch hook b ^{l is} arranged next to each needle hole, the tip of which shows in the opposite direction to the tip of the loop former α working with it (FIG. 4). The loop of the bobbin thread is caught by this hook while the loop former is making the first part of its return movement, and is detached again while the loop former is making the last part of its return movement and after the needle has entered the extended loop.

The shaft A is provided with an arm c , which is arranged between two up and down moving thread lifters with guide eyes dd ¹ and works with these (Fig. 1 and 2). The thread lifters receive their up and down movement from the shaft E, which moves the feeder rod e horizontally in a known manner. One arm e ^{l of} the shaft E fafst in a fork of the lever D on the shaft E ¹ and the lever D contains said guide eye d, while the other ^{eye 1 is located} in an arm d ' ² on the lever D (Fig. 1 and 2).

When the shaft E moves the material slide rod e horizontally, the lever D is moved up and down by the arm e ^l , and these movements will always correspond to the material slide movements, so that when the material movement changes, the lifting of the bobbin thread or threads through the eyes dd ^l changes accordingly.

The operation of the machine described above is as follows:

When a needle has reached its lowest position, raised a little and thus formed a thread loop in the usual way, the loop former α, swinging back and forth in the direction of the movement of the fabric, steps and guides its thread into the needle thread loop (Fig. 5). If the

Has reached its foremost position, its shoulder 4 has stepped in front of the eye of the needle and the catch hook b ^{1 of} the needle plate b , so that the thread, which is led from the front eye of the looper through the needle hole to the work piece, has passed behind the shoulder and is held taut (Fig. 6 a and 6 b). When the loop pattern recedes, the shoulder 4 pushes the loop sideways onto the attachment 3, which feeds it to the catch hook b ¹ (Fig. Yes and 7 b). The loop is held back by this and widened (FIGS. 8a and 8b) until the descending needle has inserted its thread into the widened loop. If the latter has happened and the loop former swings back completely, it pulls its thread down from the hook again (Fig. 9a and 9b), and the lower thread loop is then drawn into the stitch.

The facility described above works Use for both single and multi-needle machines to simultaneously use several To be able to produce rows of seams next to each other.

As a result, lateral movements of the loop pattern are unnecessary and widen with it special movements and drives are avoided, the working mechanism is like this it has become simple, that the machine can work at the greatest speed. Further enables the simple swinging movement of the loop patterns, in planes parallel to the shifting of the fabric to be able to use any number of loop patterns like needles.

Claims (1)

Patent claim: Device for widening the thread loops in double chainstitch sewing machines with a catch hook fixed under the throat plate and next to the needle hole, characterized in that each loop pattern (α) swinging in the direction of the shifting of the fabric has a lateral attachment (3) facing the needle with a sloping shoulder (4) possesses and through this approach its thread loop to the catch hook (b ^l j feeds, which expands the loop for the purpose of passage of the needle when the loop pattern recedes. 1 sheet of drawings.