EP0296471B1 - Method and device for changing the course of the stitch rows in a knitted tube - Google Patents

Description

Tubular textile goods are generally produced on circular knitting machines, a large number of knitting needles being arranged on the circumference of a cylinder, which are actuated in a cyclic sequence and then each form a stitch. In addition to the forwarding of the thread in the circumferential direction, the axial feed is approximately one mesh size. If the machine has a hundred needles on the circumference, this feed is a total of 100 mm with a mesh size of 1 mm. When the hose is laid flat, half the slope of e.g. 50 mm reached.

In the case of tubular goods, the individual mesh paths thus run in a spiral or helical manner over the entire circumference. Although this does not appear particularly in the case of single-colored goods, especially when working with thin threads, it has a particularly disruptive effect, the thicker the thread and the better the individual "transverse webs" can be seen, in particular, therefore Differences in brightness or color, as are particularly high-contrast in fashionable striped goods, stockings, pullovers or the like is used.

To remedy this, the finished knitted "spiral hose" was previously cut along a surface line, the entire web wall was folded into one plane and the slit edges were then shifted in the longitudinal direction of the hose by the size of a slope. The goods were now processed on a single surface, that is, brought to the cutting table.

This may be the case in artisanal practice, but the effort required for this in terms of mechanical engineering is very considerable, and even in this case the production output is limited. Incidentally, it is a hardly technical process. Since such a textile web is a very unstable structure, it was almost impossible to completely remove the slope and thus to produce items of clothing in which the strip runs exactly horizontally, in particular it was not possible to cover the strip exactly bring.

The invention is based on the preamble of claim 1 in accordance with US Pat. No. 2,737,700 from a method for changing the initially spiral course of stitch paths into a textile tube, for example from circular knitted striped goods, the textile tube being continuously advanced in its longitudinal direction and thereby under Forming two slit edges is slit along a surface line; whereupon the two slit edges are offset in the longitudinal direction to one another, merged again transversely to the conveying direction, and are fixedly connected again in their relative arrangement to one another during the further conveyance in the offset position reached, and deals with the task of the whole process for converting the initially spiral course of stitch paths in a textile tube in a different way than in the prior art with less time and effort to design inexpensively and precisely that the textile tube is fed in its original spiral form to a workstation, passes through it and leaves with circular meshes.

• a) in einer Querebene zur Transportrichtung einander entsprechende Gestaltungsmerkmale beider Schlitzränder optisch ertastet und
• b) aus Größe und ggf. Richtung der Abweichungen beider Gestaltungsmerkmale ein Korrektursignal abgeleitet wird, und daß
• c) die Festigkeit der Verbindung zwischen beiden Schlitzrändern nach ihrer erneuten Zusammenführung überprüft wird und
• d) ein Fehlersignal ausgelöst und/oder die Vorschubbewegung des Textilschlauches unterbrochen wird, wenn die überprüfung einen Mangel der wiederhergestellten Verbindung ergeben hat.

This is done according to the invention to achieve the object in that

• a) optically palpated corresponding design features of both slot edges in a transverse plane to the transport direction and
• b) a correction signal is derived from the size and possibly the direction of the deviations of the two design features, and that
• c) the strength of the connection between the two slot edges is checked after their reunification, and
• d) an error signal is triggered and / or the feed movement of the textile hose is interrupted if the check has revealed a defect in the restored connection.

So you can work continuously with feeding until delivery. The longitudinal seam finally used can consistently be designed in such a way that it does not appear to the outside of the tube material, and the correction of the spiral strips from elongated rhombuses to a rectangular shape is consistently informal. The method according to the invention is therefore expediently inserted into the production process. This requires little time and effort, can be accomplished with relatively simple means and is therefore extremely inexpensive to perform. It enables an exact correction of the thread course and is particularly suitable for use in automatic operation on a modern technical machine.

The goods in tubular form are much more stable than in single-layer form. It is therefore easier and more precise to correct the spiral slope or to align the ends of a strip. This tube shape also makes processing much easier and cheaper. Above all, less expensive devices can be used.

• a) Tastmittel (72,73) zum Ertasten des Versatz-Istwertes zwischen beiden Schlitzrändern,
• b) Vergleichseinrichtungen (74) zum Vergleichen des Versatz-Istwertes mit einem Vorgabe-Istwert und
• c) eine Naht-Prüfeinrichtung und
• d) ein Signalgeber vorgesehen sind, der ein Fehlersignal auslöst oder eine Abschaltung der Vorrichtung oder ihres Vorschubantriebes steuert, wenn er einen Fehler der Verbindung erkennt.

Accordingly, a device according to the invention for changing the spiral shape of stitch paths in a textile tube, for example made of circular knitted striped goods, in particular for practicing the above-described method according to the regulation of claim 7, characterized in that

• a) sensing means (72, 73) for sensing the actual offset value between the two slot edges,
• b) comparison devices (74) for comparing the actual offset value with a preset actual value and
• c) a seam testing device and
• d) a signal generator is provided which triggers an error signal or controls a shutdown of the device or its feed drive if it detects an error in the connection.

Fig. 1

eine schematische Seitenansicht einer Vorrichtung zum erfindungsgemäßen Führen und Bearbeiten eines Textilschlauches,

Fig. 2

eine Ansicht dieser Vorrichtung von oben in Fig. 1 gesehen,

Fig. 3

einen Teilschnitt nach der Linie III/III in Fig. 1 mit einem einzigen Kreismesser,

Fig. 3a

eine Abwandlung zur Fig. 3 mit zwei auf der gleichen Welle angebrachten Kreismessern,

Fig. 4+5

Teilschnitte nach den Linien IV/IV und V/V in Fig. 1,

Fig. 6

eine vergrößerte Teil-Darstellung der Stelle VI in Fig. 1 und

Fig. 7

eine räumliche Darstellung der erfindungsgemäßen Vorrichtung.

Further refinements and advantages of the invention are explained in the subclaims and in the following description of an embodiment of the invention with reference to the drawing. Show it:

Fig. 1

2 shows a schematic side view of a device for guiding and processing a textile hose according to the invention,

Fig. 2

a view of this device seen from above in Fig. 1,

Fig. 3

a partial section along the line III / III in 1 with a single circular knife,

Fig. 3a

3 with two circular knives mounted on the same shaft,

Fig. 4 + 5

Partial sections along lines IV / IV and V / V in Fig. 1,

Fig. 6

an enlarged partial representation of the point VI in Fig. 1 and

Fig. 7

a spatial representation of the device according to the invention.

On the machine frame (1), which has two side stands, an inner stand (19) and an outer stand (20), the unwinding bale (3) of a textile tube (4) is stored in a roller basket (2) on the input side, which during the following processing is pulled over a spreader (5) to a receiving device (6). This receiving device has a winding bale (7) there, but can also be provided with a laying device for the table (8).

A support belt (11) for the spreader (5) forms a first feed element which is driven by the main motor (10) with a sewing machine (12) via traction mechanism gear (13).

A second feed device is formed by a pressure belt (14) which is driven by the additional feed motor (15) and can be held under adjustable tension by a tensioning device (16).

As can best be seen from FIGS. 2 and 4, the spreader (5) has two guide cheeks in the form of half-shells made of sheet metal or light metal casting, an inner cheek (17) and an outer cheek (18). The inner cheek (17) is in a manner not shown attached to the inner side stand (19) that it can move somewhat vertically. The outer cheek (18), however, is at the free ends (21) two telescopic tubes (22), the other end of which are firmly clamped to the inner stand (19), are fastened in such a way that they bend somewhat under the weight of the outer cheek (18). The telescopic tubes (22) are each stretched apart by a helical compression spring (23) arranged in them, which is supported on the inner tube (24) and is completely passed through to the inner end of the outer tube (25).

A wire rope (26) is connected to the free end (21) of each telescopic tube (22) and is guided via two deflection pulleys (27, 28) to a rope sheave (29) which is connected to the rope sheave of the other wire rope on a shaft (30 ) sits. This, in turn, as can be seen in FIG. 1, is connected via a gear train (31) to a gear motor (32), so that the spreader (5) can be expanded and contracted by pressing a button.

Both guide cheeks, as can best be seen from the illustration of the outer cheek (18) in FIG. 4, have a U-shaped cross section with a web (36) and two flanges (37). At the outflow ends, however, the U-profile runs out in a far protruding flat bar (38) until it is transferred to the guide rollers (39) upstream of the winding bale (7).

Shorter pull-on lugs (40) are attached to the end of the two guide carriages. A cutting device (41) is provided between this and the next telescopic tube (22), the motor shaft (42) of which enables the accommodation of a single circular knife (43) or two circular knives (44) provided with an axial spacing. For the passage of these circular knives through the web (36) of the inner cheek (17), three parallel slot openings (45) are formed in it. Otherwise, the entire cutting device (41) with the bearing plate (78) can be pivoted about the axis (79) and the height can be adjusted.

Before the start of operation, the front end of the textile tube is first pulled off the unwinding bale (3), placed on the support roller (9) and, with the outer cheek (18) retracted, slipped over the pull-on tabs of the spreader until the front end of the tube hits the rear telescopic tube (22). The hose is expediently provided with a longitudinal slot (49) in the plane of the circular knife (43) from the front end to beyond the area of the cutting device (41), which initially remains pivoted out of the range of movement of the hose. The longitudinal slot (49) has already formed a lower slot edge (51) and an upper slot edge (52). The former (51) lies on the support belt (11) and is loaded by the inner cheek (17). The other (52) lies on the top (63) of the inner cheek.

Without a deflection device (54), the relation of the two slot edges with the definition of an axial spiral would be retained. The deflection device (54), which is arranged between the deflection rollers (55, 56) and has two club-shaped ramp levers (57), is used to deflect the upper slot edge (52). These sit in a common pivot bearing (58) and have a cutting edge (50) at their free ends, which lies on the top (63) of the inner cheek (17). The bearing (58) is attached to a vertical rod (59) which is held by a handwheel (60) or the like on a support (61) fixed to the frame according to the double arrow (62) and can be moved and locked.

The setting height of the bearing (58) and thus the deflection height h above the top (63) of the inner cheek (17) can be set on a scale (64) (Fig. 4). The pressure band (14) lying above the upper slot edge (52) runs between the two deflection rollers (65, 66) in the same direction to the right in FIG. 1 and over the deflection roller (68) which is arranged above the deflection device (54) and which, in principle, has to be arranged fixed to the frame is, but can also be mounted on the rod (59) according to the illustration.

The height h can be set as a function of the spiral pitch over the circumference of the textile tube, in particular as a function of the number and width of the individual mesh panels. After a short test run, this can be corrected by adjusting the handwheel (60). The offset obtained in this way is normally retained during further operation. However, if necessary, it can also be corrected automatically as a result of deviating touch values. The mechanical manual adjustment here can be replaced by a motor drive which is influenced, for example, by the control (75) mentioned later.

2 shows a rotating brush (46) serving as a scraper roller, which is driven by means of a friction roller (47), for example from the drive belt (48) of the additional feed motor (15) for the pressure belt (14). In this way, the outer part of the upper edge of the slit (52) is brushed outwards, thus counteracting the pulling out of this slit edge in the direction of the outer cheek (18).

The two slot edges (51, 52) are brought together again between the deflection rollers (66) of the pressure belt (14) and (67) of the support belt (11) and by the sewing machine (12) and a subsequent testing device (71) by the guide rollers (39 ) fed to the winding bale (7). As soon as the test device (71) provided with a signal transmitter detects an error in the previously made seam, it emits a signal and switches off the main motor (10).

In order to simplify the adjustment of the offset of the two slot edges (51, 52), contact-free scanning devices can be provided on both sides of these merged edges (72, 73) can be provided, which are connected to a comparison device (74) and the controller (75). This controls the additional feed motor (15) as a function of a remaining offset of the two slot edges and thereby also changes the speed of the upper slot edge (52) driven by it. The compensation can take place continuously or discontinuously.

As a rule, light / dark buttons are sufficient. If, however, a striped product has different colors with approximately the same light intensity, color sensors should be used that immediately recognize borders between adjacent color strips and then switch exactly.

Instead of firmly connecting the additional feed motor (15) to the roller (66) by means of the belt (48), a superimposed drive, for example with a differential gear, can also be provided. However, it seems more appropriate to use a stepper motor, to which a different number of control pulses are fed depending on the offset.

While the complete textile hose is generally only slit once with the circular knife (43) used there according to the illustration in FIG. 3, two circular knives (44) offset to the outside are in section according to FIG. 3a. In this way, wider intermediate strips can be cut out if, for some reason, it has been necessary to work with drop stitches on an edge part, which are now to be cut out.

The "overlock seam" produced by the sewing machine (12) has the advantage that the slotted edges (51, 52), which are brought together one above the other, can be sewn in this double layer and then swung out again around the common edge and joined together at the end. This takes place without special processes in the further course of the treatment.

As a rule, the whole "repeat" should be balanced. But it is also conceivable that one only wants to change the slope of the spiral by only compensating for part of the offset. This offset can be felt continuously or discontinuously, as can the correction in one way or another. In principle, it is also possible to make corrections exclusively by changing the detour, for example by pivoting the pivot bearing (58) under the action of the control (75).

Another possibility of correction is that only the speed of one slot edge is designed so differently from the other, for example up to the point of merging, that approximately one pitch of the spiral is just compensated for. In principle, you can get by with linear guides, even if under certain circumstances an intermediate transverse deflection should be necessary to maintain the conveying tension.

Instead of scanning the normal mesh paths, separate signal transmitters, for example made of radiant or metallic conductive material, can also be worked into the longitudinal wall and felt, e.g. a thread of signal material drawn into a spiral-shaped mesh.

While you are usually guided by the actual offset of the two slot edges, you can also feel the offset difference or its change. Most of the time, the direction of correction is also recorded. However, this may also result from a comparison between two consecutive keying operations.

Claims (22)

1. A method for modifying the initially helical course of lines of meshes in an item of hosiery, as for instance a circularly knitted and circularly striped fabric, in the case of which the item of hosiery is continuously fed in its longitudinal direction and, with the formation of two cut edges, is slit along a line thereon, following which the two cut edges are offset in relation to each other, are moved back towards each other transversely in relation to the direction of feed and during such common feed are permanently joined together in the attained offset position in a relative position to each other, characterized in that:

   a) the design features of the two cut edges corresponding to each other in a plane which is transverse in relation to the feed direction are optically sensed and

   b) from the size and if appropriate the direction of the departures of the two design features a correction signal is derived and

   c) the strength of the connection between the two cut edges is checked after they have been brought together again and

   d) an error signal is produced and/or the feed movement of the hosiery is interrupted, if the check shows that there is a defect in the remade connection.
2. The method as claimed in claim 1, characterized by sensing of at least individual points on mesh lines or boundary lines between differently designed and initially helically extending transverse stripes.
3. A method for modifying the initially helical course of lines of meshes in an item of hosiery, as for instance a circularly knitted and circularly striped fabric, more particularly as claimed in claim 1 or claim 2, in the case of which in the sensed areas of the two cut edges respectively the visible coloration is sensed and if appropriate is measured.
4. The method as claimed in any one of the preceding claims 1 through 3, in the case of which readily detected separate signal producing means, as for instance material able to radiate or metallic material are worked into the longitudinal edges.
5. The method as claimed in claim 4, in the case of which at least one thread of a signal material incorporated in a helical mesh line.
6. The method for modifying the initially helical course of lines of meshes in an item of hosiery, as claimed in any one of the preceding claims 1 through 5, characterized in that the two intermediately separated cut edges are sewn together by overlock or loop stitching.
7. An apparatus for modifying the initially helical course of lines of meshes in an item of hosiery, as for instance a circularly knitted and circularly striped fabric, more particularly foil use in the above described method as claimed in any one of the preceding claims 1 through 6, comprising an apparatus frame (1), an inner guide (5) mounted thereon for the hosiery (4) and at least one feed device (11) for continuously feeding the hosiery over the inner guide (5), and furthermore a cutting device (41), mounted adjacent to the inner guide (5) for sitting the hosiery (4) in the direction of feed, separate guides for guiding the two cut edges (51 and 52) bordering the longitudinal slot (49) along feed paths of different length and/or at different speeds in order to offset these cut edges (51 and 52) out of their previous relative position in relation to each other and for then bringing together the cut edges in the offset position, a connecting device or sewing machine (12) for renewed connecting together of the returned cut edges (51 and 52) into a hose form during further feed and a seam checking device (71) following the connecting device (12), characterized in that

   a) a sensing device (72 and 73) for sensing the actual value of the offset between the two cut edges,

   b) a comparison device (74) for comparison of the actual value of the offset with a set value,

   c) a seam checking device and

   d) a signal producing means are provided, which produces an error signal or causes a switching off of the device or of its feed drive (11 and 14), if it detects an error in the connection.
8. An apparatus for modifying circularly striped fabric, more particularly as claimed in claim 7 comprising correcting means (75) for correcting offset values after comparison with set values.
9. The apparatus as claimed in claim 8, whose sensing device comprises

   a) at least two optical sensing elements (72 and 73)

   b) for sensing mutually corresponding features of the two cut edges (51 and 52) without making contact.
10. The apparatus as claimed in claim 8 or claim 9 comprising the following features:

    a) the provision of an additional device, an additional drive or an additional control (75) for allowing for the offset differential,

    b) this additional device is adapted to modulate the feed drive (10 and 15) for one cut edge (51 and 52),

    c) it also controls the direction of the allowance for offset.
11. The apparatus as claimed in claim 10 comprising

    a) sensing elements for radiation other than visible light being either

    b) inherent radiation from signal elements arranged in the hosiery (4),

    c) outside radiation modified by the signal elements or deflected thereby.
12. The apparatus as claimed in claim 7, whose inner guide

    a) has a spreader (5) with two lateral guide cheeks (17 and 18),

    b) which are arranged for adjustment in relation to each other transversely in relation to the direction of feed over a support surface (11),

    c) and one of the two guide cheeks, that is to say the inner cheek (17), is associated with the machine frame (1)

    d) and has at least one recess (45) extending in the direction of feed for the passage of a slitting knife (43 and 44) of the cutting device (41).
13. The apparatus as claimed in claim 12 comprising the following features:

    a) the inner cheek (17) is directly mounted on the machine frame (1),

    b) and is connected with the outer cheek (18) by the intermediary of telescoping tubes (22) extending cantilever-fashion from it in a transverse direction,

    c) which receive compression springs acting between the two guide cheeks (17 and 18).
14. The apparatus as claimed in claim 15 comprising the following features:

    a) on the outer cheek (18) two flexible traction elements (25) are connected,

    b) which extend through the telescoping tubes (22) outwards, and

    c) are connected with a common setting member (30) which is preferably driven by a servo motor (32).
15. The apparatus as claimed in claim 12 comprising the following:

    a) the cutting device (41) comprises a rotary slitting knife, a circular knife (43)

    b) which is offset from a sitting motor in rotation and

    c) is guided in parallelism to a or its plane for movement into the hosiery (4),

    d) and holding means being provided on the knife shaft (42) bearing the sitting knife (33), for at least two slitting knives (43) to be arranged with a spacing between them.
16. The apparatus as claimed in any one of the preceding claims 12 through 15 comprising the following features:

    a) at least the inner cheek (17) is designed in the form of a hollow dish opening towards the outer guide cheek (18),

    b) it consists of a dimensionally stable material such as sheet metal or cast metal,

    c) for the selective cutting of one or two longitudinal slots (49) in the hosiery (4) with a spacing between them there are three parallel slot-like openings (45) in the wall of the dish.
17. The apparatus as claimed in claim 12 with the following features:

    a) underneath the range of movement of the spreader (5) a broad support belt (11) is arranged,

    b) which is more particularly driven at the feed speed of the hosiery (4),

    c) the lower slot edge (51) is loaded and held by the weight of the spreader (5) of the support belt (11),

    d) while the upper cut edge (52) is thrust by a separate advancing means (14) against the upper side of the inner guide cheek (17).
18. The apparatus as claimed in claim 17 comprising the following features:

    a) the upper advancing means is in the form of an endless flexible traction means (14),

    b) which is held taut by a tensioning means such as a spring or gravity loaded tensioning pulley (65), and

    c) its lower run is rested on the upper cut edge (52), which is on the inner cheek (17) of the spreader (5), of the hosiery (4).
19. The apparatus as claimed in claim 18 comprising the following features:

    a) the flexible traction element is a flat pressing belt (14),

    b) whose lower run is guided, more particularly between two bend pulleys, over a deflector projection (57 and 58) extending transversely away from the main support surface (63),

    c) such projection leads to a deflected path, different to the feed path of the support belt, for the upper advancing means (14) in order to constitute an offset between the two cut edges (51 and 52).
20. The as claimed in claim 19 comprising the following features:

    a) the defecting projection is constituted by a double ramp with an upper rounded part,

    b) two club-like ramp levers (57) are arranged so that their thicker, rounded ends are held in a common deflecting bearing (58) about an axis which is transverse in relation to the main direction of feed, and

    c) their free ends (50) are pointed to be in the form of wedges and they lie underneath the upper cut edge on the inner cheek (17) of the spreader.
21. The apparatus as claimed in claim 20, whose deflecting bearings (58) is arranged adjustably in relation to the support (63 and 17) of the upper cut edge (52).
22. The apparatus as claimed in claim 18 in the case of which at least one coating roll (46) is associated with the upper cut edge (52) and acts on the cut edge away from the outer cheek (18).

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