EP0259563B1 - Flat bed knitting machine - Google Patents

Description

The invention relates to a flat knitting machine with a lanyard and with stripping and / or stitch hold-down elements, such as those e.g. is known from DE-A-2 707 637.

The knitted fabric pull-off devices conventionally arranged below the needle beds in flat knitting machines have variously proven to be disadvantageous. In the manufacture of shaped knitwear, uneven draw-off tensions result in the knitted fabric, if not all knitted areas can be grasped by the take-off elements at the same time. Disadvantages also arise in the case of knitted fabrics with patterns due to different stitch formation, if, for example, heap accumulations occur, or also in the case of knitting methods for forming spikes in the knitted fabric. In order to avoid these known drawbacks, attempts have been made to fully or partially effect the action of conventional extraction devices by the action of Carriage of the flat knitting machine with moving strippers, which plunge into the comb gap of the flat knitting machine, and to be replaced by the action of stationary barb-like stitch hold-downs in the comb gap. The purpose of these devices is to keep the old stitches down in the comb gap of the machine when the needles are being driven out to form new stitches or tuck handles or to be transferred. These devices bring about a noticeable improvement because they act directly on the knitted fabric hanging in the needles and thereby bring about better tension compensation of the stitch formations piled up side by side on the needles.
Strip-in and / or mesh hold-down elements are to be understood as elements, for example, from GB-PS 844 186, 10 53 477, GB-OS 21 20 684, DE-GM 80 19 179, DE-OS 30 13 145, 34 23 564 and 34 28 059 can be seen.

Even with these arrangements, however, it cannot be entirely avoided, especially at high knitting speeds, that some stitches are less pulling than other stitches and inevitably result in a more flexible mobility of these stitches, which can lead to knitting errors in high-speed machines that , especially in the case of very long stitches, mesh heads, for example, do not or only partially spliced into the hook of the accepting needle when transferring, or, when the transferring or knitting needle is withdrawn, also fully or only partially slide back into the hook again over the opened needle tongue.

The invention has for its object to ensure in these flat knitting machines provided with stripping and / or stitch retaining elements for holding down stitches in the comb gap area that despite the lower stitch tensions present, safe processing of the thread and treatment of the stitches by the knitting tools remains ensured even with high-speed machine.

The object is achieved in a flat knitting machine of the type mentioned according to the invention in that it is provided with latch needles, the tongue of which, in a manner known per se, has two stable positions in its swiveling range, one of which is before the full closed position and the other before the full Open position of the tongue and from which the tongue can be pressed against the restoring force of a spring in the full closed position or the full open position.

Through the use of such tongue needles known from hand knitting apparatuses in modern flat knitting machines of the type mentioned at the outset, the needle tongue advantageously resting with its tongue end near the joint on a rod-shaped spring inserted into the tongue guide slot of the needle shaft and with its ends resting on the ends of the tongue guide slot and that The end of the tongue has two flattenings which determine the two stable positions, is a safe interplay between mesh heads even in the case of high-speed machines and also when setting large mesh lengths and handle heads and the latch needles even in the absence of the tension exerted by a pull-off device on the stitches formed.

When these known needles were used to solve the problem, the prejudice was overcome that these special latch needles could no longer fulfill the function of taking two stable pivot positions of the latch at the high expulsion and withdrawal speeds, and that the stress caused by the movement of the latch was no longer possible a spring acting on the tongue is too large to be borne by a relatively weak spring due to its dimensions. Contrary to these prejudices, it has been shown that the tongue needles can be filled with sufficiently strong springs, which ensure both the maintenance of the two stable positions mentioned when the needle tongue is not under pressure and a sufficiently long service life of the needles.

With the spring tongue needles known from a hand knitting apparatus, there was no possibility of transferring them. The use of the needles in the partially open position of their tongue for safely inserting a stitch to be transferred into the hook of the receiving needle during the transfer process has not been described anywhere and has not been used.

The use of the special latch needles in connection with movable sinkers arranged between the latch needles has proven to be particularly advantageous, the sinkers of the two needle beds facing each other and lying in a front position with the formation of bridges with projections spanning the comb gap, that no old stitch can move up from the comb gap along the shafts of the expelling needles. Here the sinkers form the stitch hold-down elements, whereby the knitting machine can additionally be provided with a stripper.

In the following, an embodiment of a latch needle used and an embodiment of a double-bed, trigger device-free flat knitting machine provided with the latch needles and with adjustable sinkers are explained in more detail with reference to the attached drawing.

Fig. 1

einer Seitenansicht des Kopfbereiches einer verwendeten Zungennadel, teilweise im zentralen Längsschnitt;

Fig. 2

einen Teilquerschnitt durch die beiden Nadelbetten einer V-Bett-Flachstrickmaschine, die mit Zungennadeln und Platinen bestückt ist, im Bereich des Kammspaltes der Flachstrickmaschine;

Fig. 3 - 9

der Fig. 2 entsprechende Darstellungen bei unterschiedlichen Relativstellungen von Nadeln und Platinen im Verlauf der Herstellung eines doppelflächigen Gestrickes oder beim Umhängevorgang.

In detail show:

Fig. 1

a side view of the head area of a latch needle used, partially in the central longitudinal section;

Fig. 2

a partial cross section through the two needle beds of a V-bed flat knitting machine, which is equipped with latch needles and sinkers, in the area of the comb gap of the flat knitting machine;

3 - 9

2 corresponding representations with different relative positions of needles and sinkers in the course of the production of a double-layer knitted fabric or during the transfer process.

The tongue needle 21 shown in FIG. 1 has an inserted spring rod 11 in its tongue slot 10, which extends over the needle opening 12 and is supported with its ends on the needle shaft 13. The tongue 14 of the tongue needle 21 lies with its end near the tongue axis 15 against the spring rod 11 and is provided with two flats 16 and 17 at this end. These flattenings result in two stable positions for the tongue 14 within its swivel range, from which it can only be moved by bending the spring rod 11. In Fig. 1, the tongue 14 is shown in one of these stable positions, in which the flat 16 rests on the spring rod 11, with a solid line. In this stable position, a gap 18 remains between the tongue spoon 19 and the needle head 20. The full closed position of the tongue 14, in which the tongue spoon 19 lies against the tip of the needle head 20 and which is shown in FIG. 1 with a thin dash-dotted line, can be achieved against the restoring force of the spring rod 11 by pressure on the tongue spoon 19, such as is exerted by a stitch when knocking off. In the other stable position of the needle tongue 14, in which the flat 17 abuts the spring rod 11, the tongue 14 forms a relatively wide gap 18ʹ with the needle shaft 13. This second stable position is shown in FIG. 1 with a thick dash-dotted line. The full open position of the latch needle 21, in which the latch 14 bears against the end of the latch slot 10, is indicated by a thin dash-dotted line. The tongue can be in this full end position 14 press against the restoring force of the spring rod 11 by means of a stitch sliding over the tongue onto the needle shaft.

2 to 7 show a schematic cross section through the comb gap area 30 of a V-bed flat knitting machine with a front needle bed 22 and a rear needle bed 23, which with needles 21 and 21.1 of the type shown in FIG. 1 and with sinkers 33 and 33.1 are busy. The sinkers 33 or 33.1 of the front needle bed 22 or of the rear needle bed 23 are each lined up on a common pivot axis 24 or 25 together with stitch pattern projections 26 and 27. Each circuit board also has an arcuate slot 28 or 28.1 designated in FIG. 3, through which a wire 29 or 29.1 which forms the stitch wiping edge of the relevant needle bed 22 or 23 is guided. The arcuate slot 28, 28.1 limits the pivoting movement of the boards 33, 33.1 about the pivot axes 24 or 25. Each board is provided with a projection 31 or 31.1, and the projections of two opposing boards 33 and 33.1 can abut against each other according to FIG. 3 brought so that they form a bridge spanning the comb gap 30.

FIG. 2 shows a relative position of the needles 21, 21.1, in which an old stitch hangs in the heads of the needles 21 and 21.1, which are connected to one another via a connecting thread arch 49. The tongues 14 and 14.1 of the needles 21 and 21.1 are in their stable partially open position, in which, according to FIG. 1, the flattened portion 17 of the tongue 14 rests on the spring rod 11.

Fig. 3 shows the position of the knitting tools before the start of the needle drive. The plates 33 and 33.1 of both needle beds 22 and 23 are pivoted into their front position, in which their projections 31 and 31.1 lie against each other, so that when the needles 21 or 21.1 are subsequently driven out into the position shown in FIG. 4, the position held by the respective needle old stitch cannot slide up from the comb gap 30. When the needles 21, 21.1 are driven out into the position shown in FIG. 4, the old stitches 48 and 48.1 have slipped over the tongues 14, 14.1 onto the needle shaft, whereupon the tongues 14 and 14.1 spring back into their stable, partially open position.

When the needles 21 or 21.1 are subsequently removed, the plates 33 and 33.1 are pivoted back before the thread insertion position shown in FIG. 5 is reached, with the opening of the comb gap 30. Even loose old stitches 48 cannot jump over the tongues 14 and 14.1 of the needles 21 and 21.1 protruding from the needle shaft, but instead reach the gap 18 'shown in FIG. 1, so that when the needles are pulled further into the one from FIGS. 6 and 7 visible stitch formation position the tongues 14 and 14.1 are closed with certainty. Fig. 6 shows the take-off position in which the old stitches 48 and 48.1 slide over the closed needle head and thereby press the needle tongues into their full closed position. The tongues spring after the release through the old stitches 48 and 48.1 back into the stable partial closed position, in which, according to FIG. 1, the flat 16 of the tongue 14 rests on the spring rod 11 and which can be seen from FIG. 7, which shows the needles in the lowest trigger position shows in which new stitches 51 and 52 have formed which hang in the partially open needle heads.

Fig. 8 shows a transfer position of the knitting tools, in which the needle 21.1 takes the position of the transferring needle and the needle 21 the position of the receiving needle. The stitch 55 in the throat of the transferring needle 21.1 or on the needle hook of the taking over needle 21, which is spread by the needle spring 56, is caused by the raising of the needle 21 in the direction of arrow II with certainty that it is in the raised position needle tongue 14.

Fig. 9 shows the dropping of the stitch 55 in the transfer process. The stitch 55 in the needle hook of the needle 21 and at the same time on the needle shaft of the needle 21.1 causes the needle tongue 14.1 to pass underneath the movement of the needle 21.1 in the direction of the arrow III and thereby close it, in order to subsequently slide over the needle hook.

Claims (3)

1. Flat knitting machine having a transfer device and having inserting and/or stitch holding-down elements, and equipped with latch needles (21), the latch (14) of which has two stable positions in its pivoting range, characterised in that one stable position is in front of the fully closed position and the other in front of the fully open position of the latch (14), and in that the latch (14) can be pressed respectively out of these positions into the fully closed position or the fully open position counter to the restoring force of a spring (11).
2. Flat knitting machine according to Claim 1, characterised in that the latch (14) of the latch needles (21) bears in a known way with its latch end near the joint against a bar-shaped spring (11) introduced into the latch guide slot (10) and supported with its ends on the ends of the latch guide slot, and in that the latch end has two flattenings (16, 17) determining the two stable positions.
3. Two-bed flat knitting machine according to Claim 1 or 2, characterised in that the latch needles (21) having stable latch positions interact with sinkers (33, 33.1) arranged between them, the sinkers (33, 33.1) of the two needle beds (22, 23) being opposite one another and, in a front position, being located against one another with projections (31, 31.1) acting as stitch holding-down elements, to form bridges spanning the comb gap (30).

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