EP0878570B1 - Method for forming a fabric with selvedges and at least one catch selvedge on looms and device for carrying out this method - Google Patents

Abstract

Fabric selvage is formed by a leno unit with two rotating bodies with controlled rotation and rotation reverse to form displaced fabric and catch selvages. In weaving the fabric edge, the selvage and catch selvage are each a full cross leno selvage. Rotation bodies give the leno selvage and catch selvage yarns with opposed twists. Also claimed is are: (1) an apparatus with an initial rotation leno selvage unit (12), with a leno yarn (12), has a rotating body (12-a) to form the fabric selvage (2); (2) a further leno selvage unit (13), with a catch selvage yarn (9), has a rotating body (13-a) to form a catch selvage (3); and (3) the fabric and catch selvages (2, 3) form full cross leno structures with the wefts (4), through a controlled rotation and direction of rotation at the rotation bodies (12-a, 13-a).

Description

The invention relates to methods for producing a fabric with fabric strips and at least one temporarily existing catch strip on weaving machines according to the preambles of claims 1 and 2. Such methods are known from GB-A-669 196.

According to GB-A-669 196, a rotary edge cutter is provided for producing the fabric strips, which permanently remain on the fabric, and the catch strip, which is intended only to prevent the weft yarn from springing back into the shed and is separated after the weaving process has been completed , The two rotary edge rotators have disc-shaped rotating bodies which are arranged coaxially next to each other at the edges of the resulting fabric web in the region of the shed. The axis of rotation of the rotating body is perpendicular to the direction of the warp threads.

The rotary bodies have in their peripheral area thread guide eyelets, through which the leno threads are passed to form the fabric strips or the Fangleisten threads to form the trap bar. It is expressly pointed out in GB-A-669 196 that the two rotary bodies can be operated either with controlled direction of rotation reversal or without reverse rotation. In the first case, the coils, from which the leno and Fangleisten threads are removed, may be arranged stationary; in the second case, it is necessary to store the coils on a rotary holder. In the preambles of claims 1 and 2 of the present application these two cases are taken into account.

GB-A-669 196 contains no information about how the drive of the two bodies of revolution should be realized constructively. After the age of this document, however, it can be assumed that the drive is derived mechanically from the main drive of the loom. This must necessarily mean that the two rotary edgebanders operate at a common speed, which is set once in the design of the loom, and that also the phases of the periodic change from forward to reverse rotation can be subsequently changed only with great effort. Furthermore, the possible speed of the conventionally driven rotary edger is not very high, so that they are limited in modern, high-speed running weaving machines.

From DE-A-44 05 776 and DE-A-44 05 777 rotary edge knives are already known, which are driven independently of the main drive of the loom by its own electric motor. Such a rotary edge cutter can be individually controlled and programmed. This applies, for example, to certain phases of forward and reverse rotation or to the selective setting of single bonds and bond misfires. The rotary edge twisters according to DE-A-44 05 776 and DE-A-44 05 777 have been proposed for forming the fabric strips or fabric edges on high-speed modern weaving machines and have proven themselves.

The catch strips, however, have previously been produced either with conventional edge turners such. B. Vierfaden-Kreuzdrehern, or it is working with canvas binding Fangleisten threads with at least 8 and up to 20 Fangleisten threads on each fabric bar. The latter was provided in the majority of the high-speed weaving machines. So it is a relatively broad and thus material-intensive catch bar produced.

A further disadvantage is that in the multi-filament crosswheels the Fangleisten threads are mechanically stressed very high, especially by deflections of the threads. It is therefore necessary to use safety catch threads of a tear-resistant material, for example of a synthetic material. The But brings with it the disadvantage that the cut-off catch strips do not form a sorted waste. The Fangleiste then consists of natural weft yarn, while the applied as Volldreherbindung Fangleisten threads made of a synthetic yarn. In addition, there is a risk that the conventional multi-filament crosshead wear prematurely at the high rotational speeds required today.

A further disadvantage is that in the case of an automatic weft breakage repair, which requires reopening (reverse weaving) of the previously closed shed, the catch wedge compartment setting the defective weft thread is not always released. Then, the weft breakage repair can not be performed in the required short time.

Finally, it is still to be noted as a disadvantage that conventional rotary devices often "prepare" the catch strip against the binding point of the shed or the stop edge of the fabric in the direction of the tether coil, and in particular on the weft extract or -ankunftsseite the shed. In this area, then compared to the weft insertion side of the weft less tensioned.

It is therefore not sufficient if, during the production of a fabric with fabric strips and at least one temporarily existing catch strip, although by the rotary edge cutter according to DE-A-44 05 776 and DE-A-44 05 777, a transition to higher engine speeds and thus an increase in performance in connection with a quality improvement is basically possible, while the disadvantages of conventional edge twister in the formation of the catch bar are maintained.

The invention is therefore based on the object to improve the aforementioned method with and without reversing the rotational body so that the high weaving speeds of modern weaving machines are achieved, at the same time the material used for the catch strips is reduced, the weft threads on both sides of the fabric reliable be held and yet after the separation of the catch strips a high quality, durable fabric strip of beautiful visual effect comes about.

This object is achieved by the method with the totality of the features specified in the claim 1 and 2 respectively.

By namely for both the fabric strips as well as for the catch strips rotary edgers are used with a drive that is independent of the drive of the loom, the rotational body of these rotary edge rotors can work with the highest possible speed, the formation of the tissue and Fangleisten adjusted and makes sense. Because despite the high speed when turning in a certain direction always Volldreherkanten come about, the weft threads are always tied and held reliable. This means in the case of the catch strips, that the number of Fangleisten threads and thus the use of materials can be reduced. Since the catch strips no longer have to be as wide as when using the conventional edge twister or in canvas binding catch strips, also required for the catch strips end portions of the weft threads are shorter and also achieved a material savings in the weft threads. On Greifenrvebmaschinen it was possible to save by the new construction about 25mm weft material per shot.

The lower mechanical stress of the Fangleisten threads by the present invention used according to the rotary edgers also leads to the fact that the Fangleisten threads in very many cases may consist of the same material as the weft threads, resulting in not only less, but also sorted waste. For example, in the manufacture of woolen fabric, wool tethers may also be used, while in the manufacture of synthetic fabric, synthetic tuck yarns are used. Since the waste is sorted, all separated catch strips can be fed virtually a workup and reuse, which means a cost savings for the weaving.

Of great importance for both methods according to claims 1 and 2 is further the flow .DELTA..alpha..sub.a of the rotation body leading the catch strip threads against the rotation body guiding the leno threads of the fabric strips, which is characterized by the free programmability of rotation and ggs. It is also possible to reverse the rotation of the rotating body. By this advance Δα namely can meet the conflicting demands that on the one hand the catch bar as early as possible, on the other hand, the fabric bar to set late. The early setting of the trap bar causes an early, reliable retention of taut weft thread by the relatively coarse Fangleistenfäden. The base fabric and the fabric strip consist of the much finer warp threads and leno threads; Therefore, the shed and the fabric strip tray should be kept open as long as possible so that warp threads and leno threads are not disoriented or even damaged by the penetration of the weft thread, for example by touching the gripper. By the flow .DELTA..alpha. Of the rotation body leading the catch strip threads to the rotation body guiding the leno threads allows to fulfill the two opposing requirements, the fabric strip visible after the separation of the catch strips is not only of high quality but also of good optical effect. At the same time prevents the flow Δα in the edge formation, the "preliminary work" of the trap bar against the binding point of the shed, as given by the former shorts a better leno thread training.

In the case of the method according to claim 1, ie with controlled reversal of rotation of the rotary body brings the freely programmable direction of rotation reversal in the rotation taking place with rotating rotation of the rotary body a further advantage. In fact, it is inevitable that the binding of the leno or catch strip threads, which occurs at the moment of turning back, is only a half-turn binding, in which the threads do not wrap around each other but run parallel to one another. The Halbdreherbindung keeps the weft far less good than the Volldreherbindung. When the rotating body leading the catching strip threads rotates in the same phase with the rotating body guiding the leno threads, the moment of reversing occurs both at the leno threads as well as the Fangleisten threads a Halbdreherbindung concluded; the set weft threads are in this case held less firmly than those weft threads, which are tied with an unchanged direction of rotation of the rotating body. This can mean a deterioration in quality and is avoided by ensuring by the freely programmable time of reversal of rotation, that there is always a half-turn binding only at the fabric bar or the catch bar, but never at both at the same time.

The invention also relates to the apparatus required for carrying out the method, which are specified in claims 3 and 4. The relevant and taken into account in the preambles of claims 3 and 4 prior art is again the GB-A-669 196th

In addition to the advantages that can be achieved with the methods, the advantages of a particularly compact construction are added to the devices.

Advantageous embodiments of the devices are given in the dependent claims.

The invention will be explained in more detail with reference to embodiments shown in the drawings.

Figur 1

die aus zwei Rotations-Kantendrehern bestehende Vorrichtung wobei jeder Rotations-Kantendreher einen separaten Fremdantrieb besitzt,

Figur 2

die aus zwei Rotations-Kantendrehern bestehende Vorrichtung, wobei jeder Rotations-Kantendreher einen separaten integralen Antrieb besitzt und wobei die Vorrichtung von einer Trageinrichtung aufgenommen ist,

Figur 3

die als Ring ausgebildeten Dreherscheiben der Rotations-Kantendreher gemäß Figur 2, mit drehwinkelversetzten Fadenführungsösen,

Figur 4

die aus zwei Rotations-Kantendrehern bestehende Vorrichtung, wobei der eine Kantendreher einen Fremdantrieb und der andere Kantendrehern einen integralen Antrieb besitzt,

Figur 5

die aus zwei Rotations-Kantendrehern bestehende Vorrichtung gemäß Figur 5, wobei die Rotationskörper der Kantendreher die Drehrichtungsumkehr unabhängig voneinander ausführen,

Figur 6

die eintragsseitige Fangleiste,

Figur 7

die eintragsseitige Gewebeleiste mit Bindungsaussetzern.

In the drawings show:

FIG. 1

the device consisting of two rotary edgers with each rotary edger having a separate external drive,

FIG. 2

the device consisting of two rotary edgers, each rotary edger having a separate integral drive and the device being received by a support,

FIG. 3

the trained as a ring leno wheels of the rotary edge cutter according to Figure 2, with rotational angle offset yarn guide eyelets,

FIG. 4

the device consisting of two rotary editors, one edge-driver having an external drive and the other edge-turning device having an integral drive,

FIG. 5

the device consisting of two rotary edgebanders according to FIG. 5, wherein the rotational bodies of the edge drivers execute the direction of rotation reversal independently of one another,

FIG. 6

the entry-side fishing line,

FIG. 7

the entry-side fabric strip with binding misfires.

According to FIG. 1, the device consists of a first rotary edge cutter 12 and of a second rotary edge cutter 13. The construction, the arrangement and the mode of action of both edge twisters are comprehensively described in DE 44 05 777 C1, so that at this point repetitions are described is waived.

Each of the edge twisters 12, 13 has a leno threads 7 or a Fangleisten threads 9 leading rotary body 12a with not visible here Fadensführungsösen 12b and a rotating body 13a with Fangleisten threads leading Fadenführungsösen 13b.

Both edge twisters 12, 13 are rotatably drivable with one rotary drive 14 in each case. The rotary actuators 14 are driven by a drive control 15.

By one half turn of the rotating body 12a, 13a, about the center axis 25 of the rotary body forms 12a with the leno threads 7 a fabric strip tray 8 and the rotating body 13a a Fangleistenfach 10 about synchronously to form the shed 6 with the warp threads 5.

The means for forming the shed 6 are not shown here, because generally known.

In the open compartments 6, 8, 10, at least one weft thread 4 is entered from the entry side of the shed 6 to the arrival or withdrawal side by means of pneumatic or mechanical entry members.

The here in the subjects 6, 8, 10 registered weft thread 4 is to hit by the reed 27 to the stop edge 1a, 2a of the fabric 1 and the fabric strip 2 and by the Hilfswebblatt 28 to the stop edge 3a of the catch strip 3 and to Bonding by the shedding organs on the side of the shed 6 held by the weft insertion member 26.

After setting of the weft thread 4, a shed 6 and by a respective half turn of the rotary body 12a, 13a again a Gewebeleisten- and Fangleistenfach 8, 10 is formed by synchronous control by the Webfachbildeorgane, in which again at least one weft thread is entered. This creates a fabric 1 with a fabric strip 2 and spaced to a temporarily present catch strip. 3

In the manufacture of the fabric strip 2 and the catch strip 3, it is essential to the invention that the rotary bodies 12a, 13a are replaced by a multiplicity of successive half-turns, e.g. in which one direction of rotation, and preferably by the same multiplicity of successive half-turns in the other direction of rotation, form both the fabric strip 2 and the catch strips 3 as a fixed full-turn edge.

The device shown here is arranged on the right side in the loom rotary edge twister 12 and 13; another device of the same construction is arranged on the left side in the weaving machine, as shown for example in FIGS. 4 and 5.

In order to be able to supply the free ends of the weft threads 4 arranged in the catch strip of a tissue width holding device, not shown here, at least one holding or stretching device 29, 30 (see Figures 4 and 5) is provided on both sides of the fabric 1.

Due to the coaxial arrangement of the two rotary edge twister 12, 13 a fabric or cutting lane 16 is formed between the fabric strip 2 and the catch strip 3, see also Figure 4, in which a separator 17 engages and the catch strip at the appropriate time of the fabric. 1 separates.

Since each rotary edge twister 12,13 of the device is equipped with its own rotary drive 14, it is possible, each rotary edge twister 12, 13 individually, especially with regard to the reversal of the direction of rotation and the time for setting the weft threads 4 to form the exhaust side fishing line 3, to control.

The catch strip threads 9 for the catch strip 3 are, like the leno threads 7 for the fabric strip 2, withdrawn from holders 19 and 18 arranged on coils 21 and 20, wherein the holders 18,19 are mounted stationary.

In the event that a reversal of rotation of the rotary body 12a, 13a is not provided, the coils 20, 21 are arranged on a, not shown, rotationally driven coil holder. Such a rotary-driven bobbin holder is required, first, to prevent any mutual wraps of the leno threads 7 and, secondly, no mutual wraps of the suture strip threads 9 on the path between the rotary bodies 12a, 13a and the coils 20, 21.

In FIG. 2, the device consists of a first rotary edge cutter 12 and a second rotary edge cutter 13. The construction, arrangement and mode of action of both edge twisters are disclosed in DE 44 05 776 C1. It is essential here that both rotational bodies 12a, 13a are the rotors of an electromotive actuator. Here too, both edge twisters form a structural unit which is received by a carrying device 22.

The formation of the Gewebeleisten- and Fangleistenfaches 8, 10 is analogous to the operation of the device of Figure 1. About the drive control 15 each edge twister 12,13 is individually controlled and operated in accordance with the shedding.

The support device 22 as a whole can be connected via the elongated holes 22d by corresponding machine elements with the weaving machine and positioned in the direction of the double arrow 32. At least a second and third component 22b, 22c is connected to the first component 22a. The third component 22 c is arranged in a plane alone in the direction of the double arrow 33 about a vertical axis 23 pivotally. The combined to a structural unit rotary edge twister 12, 13 are connected to the third component 22c such that the unit along the center axis 24 of the component 22c slidably and about this central axis 24 is pivotable.

With webbings folded over, the pivotability of the structural unit is of particular advantage. The leno threads 7 and the Fangleisten threads 9 are also deducted from coils 20, 21, as already shown in Figure 1.

FIG. 3 shows two rotational bodies 12a, 13a which can be rotated about the center axis 25 with thread guiding eyelets 12b, 13b. The rotary bodies 12a, 13a are formed according to the device according to FIG. 1 or 2.

With regard to the timing of the setting of the weft threads in the catch strip 3, it is essential to the invention that the catch strip pocket 10 sets the weft thread 4 by a few degrees of rotation Δα in front of the fabric strip pocket 8. In other words, the rotation of the rotation body 13b leads the rotation of the rotation body 12b both in the flow according to arrow 34 and after reversal of direction in the return according to arrow 35 ahead. The degree of anticipatory rotation, i. the amount Δα, is freely programmable in the drive control 15.

Figure 4 shows an entry side of the shed 6 arranged device with different rotary actuators. While to form the fabric strip 2 a first rotary edge cutter 12 is provided with integral rotary drive, so the rotary body 12a is the rotor of an electric motor actuator, the catch strip 3 is formed by means of a foreign-driven rotary body 13a (rotary drive 14).

The drives of the two edge twisters 12, 13 are controlled by a drive control 15. On the entry side of the shed 6, analogously to the arrival or withdrawal side of the shed 6, the ends of the set weft threads 4 are preferably held pneumatically stretched by a holding or stretching device 30 to the inlet into a spreading device, not shown.

FIG. 5 shows a device as already shown in FIG. Here, according to the method of forming a cloth sheet 2 and a trap 3 according to the present invention, the ratio of the number of reversals of rotation of the rotary bodies 12a, 13a per section of fabric 31 is different from one, that is. not after each weft insertion is a reversal of the direction of rotation of the rotary body 12a, 13a.

To produce a high-quality fabric strip 2 on fabrics 1 for the clothing industry, it is for example advantageous if the reversal of the direction of rotation of the rotating body 12a for the fabric strip 2 after the production of more than 20 Volldreherabbindungen done while the direction of rotation of the rotating body 13a for the production the catch strip 3 after less than ten Volldreherabbindungen done. This ensures that the fabric strip is visually beautiful and the catch strip 3 may have a relatively higher weft density, as it can be reached with any other known leno system.

It is therefore essential to the invention that the ratio of the reversals of rotation of a device consisting of two rotary edge twisters 12, 13 for forming a fabric strip 2 and a catch strip 3 can be varied as desired for each fabric section 31, or that the variation can be freely programmed.

Figure 6 shows Fangleisten threads 9, which form the ends of the weft threads 4 by means of Volldreherabbindungen to a catch strip 3 by rotation of the rotating body 13a in one direction. In the catch strip 3 as well as in the fabric strip 2, the point of reversal of the direction of rotation is not visually recognizable. In the present example, therefore, it is not shown that a reversal of the rotational direction of the rotational body 13a has been carried out.

FIG. 7 shows the leno threads 7, which in one direction form the ends of the weft threads 4 by means of rotation of the rotation body 12a into a fabric strip 2 by means of full-turn ties. Due to the free programming of the rotary edge twister 12, 13, taping variants for the weft threads 4 are conceivable, such as e.g. so-called binding misfires that are equally feasible in the fabric strip 2 and 3 in the catch bar.

In summary, it can be stated that the technology known per se for producing a full-turn fabric strip 2 can be used without restrictions for producing a temporary catch strip 3. It can further be seen that by the combination of two rotary edge twisters 12, 13 into one structural unit and using the full-turn technology, in addition to material savings for forming the catch strips 3, material savings per weft thread 4 can be achieved. The saving in weft material is made possible by the fact that, in particular on rapier weaving machines, the thread-indicating units and the weft scissors 17 can be positioned closer to the reed 27 by the reduced width of a conventionally produced catching strip 3. Further, it is thereby possible to set the start position of the weft insertion members (donor and taker grippers) closer to the reed 27.

List of reference numbers

1

tissue

1 a

Stop edge of the fabric

2

Gewebeleiste

2a

Stop edge of the fabric strip

3

stop profile

3a

stop edge

4

weft

5

warp

6

shed

7

leno thread

8th

Fabric selvedge shed

9

Catch selvedge thread

10

Catch selvedge shed

12

first rotary edge cutter

12a

body of revolution

12b

thread guiding eye

13

second rotary edge cutter

13a

body of revolution

13b

thread guiding eye

14

rotary drive

15

drive control

16

Tissue or cutting alley

17

Separating device (weft scissors)

18

holder

19

holder

20

Kitchen sink

21

Kitchen sink

22

support means

22a

first component

22b

second component

22c

third component

22d

Long hole

23

vertical axis

24

mid-axis

25

common center axis

26

Weft insertion member

27

reed

28

Hilfswebblatt

29

Holding or stretching device

30

Holding or stretching device

31

fabric section

32

double arrow

33

double arrow

34

arrow

35

arrow

Δα

angle of rotation

Claims (13)

1. Method for the production on looms of a fabric (1) having fabric selvedges (2) and at least one temporarily present catch selvedge (3), according to which at least one weft thread (4) is introduced into a shed (6) formed from warp threads (5), into a fabric selvedge shed (8) formed from leno threads (7) and into a catch selvedge shed (10) formed from catch selvedge threads (9), thereupon the weft thread (4) is beaten up to the fell (1a, 2a, 3a) of the fabric (1), the fabric selvedge (20) and the catch selvedge (3), is subsequently bound in by the warp threads (5), the leno threads (7) and the catch selvedge threads (9) and thereafter is cut by means of at least one weft thread cutting device (17) from a weft thread (4) held in readiness, wherein the fabric selvedge (2) and the catch selvedge (3) are each formed as a full-cross leno selvedge by means of rotation of a respective rotating body (12a, 13a) guiding the leno threads (7) and the catch selvedge threads (9) of a first and a second rotary leno mechanism (12, 13) having a controlled reversal of rotation direction,
   characterised in that
   the rotating bodies (12a, 13a) are driven and are controlled independently of the drive of the loom and in that the rotation and the reversal of the rotation direction of each rotating body (12a, 13a) is freely programmable, wherein on the weft thread exit side and arrival side respectively of the shed (6) an advance Δα of the rotating body (13a) guiding the catch selvedge threads (9) with respect to the rotating body (12a) guiding the leno threads (7) is freely programmable, whereby with an advance Δα of several angular degrees the catch selvedge shed (10) is closed ahead of the fabric selvedge shed (8) and this advance Δα is maintained when reversal of the rotation direction is effected.
2. Method for the production on looms of a fabric (1) having fabric selvedges (2) and at least one temporarily present catch selvedge (3), according to which at least one weft thread (4) is introduced into a shed (6) formed from warp threads (5), into a fabric selvedge shed (8) formed from leno threads (7) and into a catch selvedge shed (10) formed from catch selvedge threads (9), thereupon the weft thread (4) is beaten up to the fell (1a, 2a, 3a) of the fabric (1), the fabric selvedge (20) and the catch selvedge (3), is subsequently bound in by the warp threads (5), the leno threads (7) and the catch selvedge threads (9) and thereafter is cut by means of at least one weft thread cutting device (17) from a weft thread (4) held in readiness, wherein the fabric selvedge (2) and the catch selvedge (3) are each formed as a full-cross leno selvedge by means of rotation of a respective rotating body (12a, 13a) guiding the leno threads (7) and the catch selvedge threads (9) of a first and a second rotary leno mechanism (12, 13) with no reversal of the rotation direction, and wherein both the leno threads (7) and the catch selvedge threads (9) are drawn from spools arranged on a rotatably driven holder,
   characterised in that
   the rotating bodies (12a, 13a) are driven and are controlled independently of the drive of the loom and in that the rotation of each rotating body (12a, 13a) is freely programmable, wherein on the weft thread exit side and arrival side respectively of the shed (6) an advance Δα of the rotating body (13a) guiding the catch selvedge threads (9) with respect to the rotating body (12a) guiding the leno threads (7) is freely programmable, whereby with an advance Δα of several angular degrees the catch selvedge shed (10) is closed ahead of the fabric selvedge shed (8).
3. Apparatus for carrying out the method according to claim 1, comprising:

   a first rotary leno mechanism (12) having a rotating body (12a) guiding leno threads (7) to form a fabric selvedge (2),

   a second rotary leno mechanism (13) having a rotating body (13a) guiding catch selvedge threads (9) to form a catch selvedge (3),

   wherein the fabric and catch selvedges (2, 3) are producible by full-cross leno interlacings of the weft threads (4) by means of controlled reversal of the rotation direction of the rotating bodies (12, 13),

   characterised in that

   each rotating body (12a, 13a) has a rotary drive (14), which is independent of the main drive of the loom, and in that both rotary drives (14) are controllable independently of one another, wherein on the weft thread exit side and arrival side respectively of the shed (6) an advance Δα of the rotating body (13a) guiding the catch selvedge threads (9) with respect to the rotating body (12a) guiding the leno threads (7) is freely programmable, whereby with an advance Δα of several angular degrees the catch selvedge shed (10) is closed ahead of the fabric selvedge shed (8) and this advance Δα is maintained when reversal of the rotation direction is effected.
4. Apparatus for carrying out the method according to claim 2, comprising:

   a) a first rotary leno mechanism (12) having a rotating body (12a) guiding leno threads (7) to form a fabric selvedge (2),

   b) a second rotary leno mechanism (13) having a rotating body (13a) guiding catch selvedge threads (9) to form a catch selvedge (3),

   c) the fabric and catch selvedges (2, 3) are producible by full-cross leno interlacings of the weft threads (4) without reversal of the rotation direction of the rotating bodies (12a, 13a) and

   d) a holder rotatably driven with spools for the leno and catch selvedge threads,

   characterised in that
   each rotating body (12a, 13a) has a rotary drive (14), which is independent of the main drive of the loom, and in that both rotary drives (14) are controllable independently of one another, wherein on the weft thread exit side and arrival side respectively of the shed (6) an advance Δα of the rotating body (13a) guiding the catch selvedge threads (9) with respect to the rotating body (12a) guiding the leno threads (7) is freely programmable, whereby with an advance Δα of several angular degrees the catch selvedge shed (10) is closed ahead of the fabric selvedge shed (8).
5. Apparatus according to one of claims 3 and 4, characterised in that the first and the second rotary leno mechanism (12, 13) together form a structural unit in the form of a modular construction system.
6. Apparatus according to any one of claims 3 to 5, characterised in that each rotating body (12a, 13a) is in the form of a preferably annular leno disc and has thread guiding eyes (12b, 13b).
7. Apparatus according to any one of claims 3 to 6, characterised in that at least one of the two rotating bodies (12a, 13a) is the rotor of an electromotive actuator.
8. Apparatus according to claim 3, characterised in that per fabric section or weft sequence the number and the times of the reversal of rotation direction and the number of rotations of each rotating body (12a, 13a) are freely programmable by means of a drive control system (15).
9. Apparatus according to claim 4, characterised in that per fabric section or weft sequence the number of rotations of each rotating body (12a, 13a) is freely programmable by means of a drive control system (15).
10. Apparatus according to claim 5, characterised in that the structural unit formed by the rotary leno mechanisms (12, 13) is position-adjustable within the loom by means of a carrier arrangement (22).
11. Apparatus according to claim 10, characterised by a carrier arrangement (2) having the following features:

    a) at least one first structural component (22a) fixedly arranged on the loom and adjustable in at least one plane,

    b) at least one second and third structural component (22b, 22c) connected to the first structural component (22a), the third structural component (22c) being arranged to be pivotable about a vertical axis (23) in a single plane and
    wherein

    c) the structural unit is connected to the third structural component (22c) in such a way that the unit is slidable along and is pivotable about the centre line (24) of the third structural component.
12. Apparatus according to claim 11, characterised in that the first and the second rotary leno mechanisms (12, 13) of the structural unit are received by the third structural component (22c) in such a way that their rotating bodies (12a, 13a) rotate about a common centre line (25).
13. Apparatus according to claims 12, characterised in that in an operative state of the structural unit, the centre line (25) lies approximately parallel to the fell (1a, 2a, 3a) of the fabric (1), the fabric selvedge and the catch selvedge (3).

Images