AU2016293350A1

AU2016293350A1 - Weaving machine

Info

Publication number: AU2016293350A1
Application number: AU2016293350A
Authority: AU
Inventors: Andreas Rutz
Original assignee: Lindauer Dornier GmbH
Current assignee: Lindauer Dornier GmbH
Priority date: 2015-07-13
Filing date: 2016-06-22
Publication date: 2018-01-18
Also published as: WO2017009015A1; CA2990732A1; TWI599691B; JP2018524491A; US20180179675A1; EP3322845A1; CN107849761A; DE102015213015B3; KR20180030623A; TW201708648A; RU2018105076A

Abstract

The invention relates to a weaving machine with a shed forming device (10, 25) for forming sheds (3) between warp threads (1) drawn from a thread supply (9); a weft inserting device (20) for inserting weft threads (2) in the form of tapes into the formed sheds (3); and a drawing device (30) for drawing the fabric (4) made of warp and weft threads (1, 2) after the weft threads have been inserted. The weaving machine comprises a measuring device (40) for detecting geometric parameters, in particular the width, of a weft thread (2) prior to being inserted into the shed (3), and the weaving machine also comprises an analyzing device (45) for analyzing the detected measurement results. A controller (50) which is connected to the drawing device (30) is provided on the weaving machine in order to control the movement of the fabric (4), including the drawing process, on the basis of the analyzed measurement results.

Description

The invention relates to a weaving machine with a shed forming device (10, 25) for forming sheds (3) between warp threads (1) drawn from a thread supply (9); a weft inserting device (20) for inserting weft threads (2) in the form of tapes into the formed sheds (3); and a drawing device (30) for drawing the fabric (4) made of warp and weft threads (1,2) after the weft threads have been inserted. The weaving machine comprises a measuring device (40) for detecting geometric parameters, in particular the width, of a weft thread (2) prior to being inserted into the shed (3), and the weaving machine also comprises an analyzing device (45) for analyzing the detected measurement results. A controller (50) which is connected to the drawing device (30) is provided on the weaving machine in order to control the movement of the fabric (4), including the drawing process, on the basis of the analyzed measurement results.

(57) Zusammenfassung: Eine Webmaschine mit einer Fachbildeeinrichtung (10, 25) zum Bilden von Webfachem (3) zwischen von einem Fadenvorrat (9) abgezogenen Kettfiden (1), einer [Fortsetzung auf der nachsten Seite] wo 2017/009015 Al lllllllllllllllllllllllllllllllllllll^

Schusseintragseinrichtung (20) zum Eintragen von Schussfaden (2) in Form von Tapes in die gebildeten Webfacher (3), undeiner Abzugseinrichtung (30) zum Abziehen des von Kett-und Schussfaden (1, 2) gebildeten Gewebes (4) nach einem Schussfadeneintrag. Die Webmaschine umfasst eine Messeinrichtung (40) zur Erfassung von geometrischen Parametem, insbesondere der Breite, eines Schussfadens (2) vor seinem Eintrag indas Webfach (3), sowie eine Auswerteeinrichtung (45) zur Auswertung der erfassten Messergebnisse. An der Webmaschine ist eine mit der Abzugseinrichtung (30) in Verbindung stehende Steuereinrichtung (50) zur Steuerung einer Bewegung des Gewebes (4)einschlieBlich des Abzugs auf Grundlage der ausgewerteten Messergebnisse vorhanden.

Weaving Machine

The present invention relates to a weaving machine for processing tape-shaped weft threads - that is to say relatively wide and flat band-shaped textile units, according to the preamble of the claim 1. In this regard, the shedding arrangement or device, the weft insertion arrangement or device, as well as the essential parts of a drawing-off arrangement or device are known devices on weaving machines. The construction of a woven fabric of warp and weft threads in the form of tapes, for example of carbon or glass fiber tapes, is also known for some time. Such tapes are produced, for example, of carbon rovings, which are solidified with an impregnation in the spread-out, parallelized condition. The width of such tapes amounts to e.g. a few millimeters to more than one centimeter. Woven fabrics of carbon tapes are utilized, for example, for lightweight construction applications in the aircraft or motor vehicle field.

Herein both the terms weft thread as well as tape are used, because the invention relates to the insertion of weft threads in the form of tapes.

Any desired threads can be used for the warp threads, for example also wide and/or thick threads, preferably however threads in the form of tapes.

For the insertion of weft threads in the form of tapes into an opened loom shed formed by lifted and lowered warp threads, gripping and clamping devices are provided, which grip or grasp the forward tape end either from the insertion side or coming from the opposite side (through the open loom shed) , and pull it through the loom shed.

In the embodiment according to EP 1 838 911 Al, the inserted tape is clamped in thread clamps at both sides of the loom shed and is transported against the rear fabric edge or against the binding or interlacing point of the woven fabric by movement of these thread clamps by a fixedly prescribed path distance in the weaving or drawing-off direction (machine direction) . Because only the outer ends of the tape-shaped weft thread are grasped and transported in the direction toward the fabric rear edge, in the method described in the EP 1 838 911 Al, in principle the danger exists that the tapes are brought against the fabric rear edge not absolutely straight or linearly over the weaving width, but rather that the area of the weft tapes lying at the center of the woven fabric forms a curve in the fabric plane. In the weaving machine according to EP 1 838 911 Al, it is attempted to reduce this effect in that the warp threads extend through the weaving machine in the vertical direction, whereby the weft tapes are similarly arranged with their width direction extending vertically and are inserted into the loom shed above the already existing fabric rear edge. The transport of the inserted tape-shaped weft treads to the fabric rear edge is thus supported by the gravity acting on the tapes.

The DE 10 2011 009 765 B3 discloses an apparatus and a method in which the woven fabric is moved back in the direction toward the just-inserted tape-shaped weft thread by a prescribed path distance contrary to the weaving direction, until the front longitudinal edge of the tape and the rear fabric edge lie in contact against one another.

In both cases, after the weft insertion, there follows a crossing-over of the warp threads with the weft threads by closing and opening the loom shed with the aid of the shed forming arrangement. The woven fabric which is now lengthened by one tape width is moved further or drawn off a small distance, in order to achieve space for the next weft insertion.

It can be disadvantageous in thusly produced woven fabrics, that after the weft insertion the subsequent positioning of the tape-shaped weft threads with respect to the fabric rear edge takes place independently of the actual momentary geometry of the tape .

In practice, tapes with widths of for example 20 mm to 50 mm also come into use. Such tapes have - caused by the manner of production - a certain - no longer negligible - spreading or scattering in the width over the length of the tape.

For certain application purposes it can also be advantageous, to use tape-shaped weft threads with purposely selected differing widths within one woven fabric in alternation or in a prescribed sequence .

There are also woven fabrics in which a certain predefined spacing distance shall remain between successive tape-shaped weft threads. With a varying or fluctuating width of the tapes, the danger exists that this spacing distance also does not uniformly comprise the predefined value.

The EP 1 838 911 Al discloses an apparatus with sensors that measures the width of the tapes in the weaving operation. Dependent on the measured width, special feed or supply devices for the warp threads are actuated in such a manner so that the winding-up of the woven fabric can take place in a tensionless manner or even with an excess of warp threads. An exact positioning of the longitudinal edge of the tape-shaped weft threads without spacing, or with a prescribed spacing to the rear fabric edge dependent on different widths of the tape-shaped weft threads, is thereby not possible.

It is the object of the present invention to provide a weaving machine in which the fabric formation through use of tape-shaped weft threads can be adapted to various different geometric parameters of the tapes, especially to various different widths.

This object is achieved by the features of the claim 1. In this solution, the advantages are especially seen in that the actual width and especially the width fluctuations of the tapes to be inserted into the woven fabric can be taken into consideration, because the tape and the woven fabric can be moved toward one another, on the basis of the evaluated measurement results, with a varying - and not according to the prior art with a fixedly prescribed - motion or distance feed advance. Thereby, for example, a tighter or more-closed fabric appearance can be obtained, for example in the case that the momentary width of the tape to be inserted should be reduced.

Overall, through the invention, the flexibility for the weft insertion is increased considerably, because on the basis of the evaluated measurement results, commands for the weaving feed advance can be given via the control arrangement to the drawing-off arrangement, which commands take into consideration the respective actual tape width.

Alternatively, but preferably in addition to the width detection, the measuring arrangement is embodied for the detection of other geometric measured values, for example of holes and/or splices in the weft thread, whereby the latter arise due to separations of individual or several filaments out of the tape composite.

According to an advantageous embodiment of the invention, the measuring arrangement is based on an optical measuring method. In this regard, it can especially involve an optically scanned measuring field which preferably extends over the width of the tape. A corresponding measuring arrangement is, for example, an optical precision micrometer.

According to an alternative, the measuring arrangement works acoustically, especially with the aid of ultrasound. Depending on the wave propagation of the ultrasound, a conclusion can be reached about the width of the scanned tape.

Also conceivable is a line camera with combined pattern recognition software.

A further measuring method is based, for example, on a tactile and thus not contactless - probing or scanning of the weft thread (tape) to be inserted.

Especially preferably, the measuring arrangement is embodied in such a manner so that the width of the weft thread to be measured is continuously detected before and/or during its insertion. In this manner, a continuous measurement is possible, in which all fluctuations relating to the tape width can be detected. Thereby, the corresponding evaluation possibilities are considerably expanded.

The measuring arrangement according to the invention is preferably arranged in such a manner so that it is able to measure the width values of the next to be inserted and/or the momentarily inserted weft thread, whereby the measurement can be carried out on the moving weft thread over the entire length to be inserted. Through this measurement, directly following after the weft insertion on the basis of the evaluated measurement, the woven fabric can be moved against this tape by a motion or path distance dependent on the evaluation result.

Thereafter, the woven fabric including the previously inserted tape is advanced in the warp direction. For these transport processes, a drivable drawing-off roll and advantageously also a woven fabric clamp are provided as part of the drawing-off arrangement. The fabric clamp is advantageously arranged in the area of the fabric rear edge extending in the weft direction, and during the fabric's sliding displacement prevents a sliding displacement of the tape-shaped weft threads last inserted into the woven fabric.

In the case that the abovementioned relative motion of the tape and the fabric toward one another is not carried out (for example because the spacing distance between tape and fabric is already as desired), the drawing-off arrangement can further move or advance the fabric including the previously inserted tape immediately in the drawing-off direction by a distance dependent on the evaluation result.

For producing a reversing fabric sliding displacement it is advantageous to provide an oscillating or swinging motion of deflecting rolls intermediately positioned in the warp thread path or in the fabric path, instead of a reversible rotation of the drawing-off roll. In this case, the drawing-off arrangement encompasses an oscillatingly or swingingly supported and reversibly drivable deflecting roll that is arranged in the fabric path between the loom shed or between the fabric clamp and the drivable drawing-off roll.

Preferably the measuring arrangement is arranged on the insertion side of the weft thread or tape, and in this regard is advantageously oriented in the warp thread direction, i.e. transversely or perpendicularly to the weft thread direction. Thus the measuring arrangement can be accommodated also in a limited or cramped space and is nonetheless in the position to reliably detect the entire width of the weft threads.

Alternatively, the measuring arrangement is arranged below and above the warp threads, and in this regard advantageously in the area of that fabric longitudinal edge that is first crossed by the tape during the weft insertion. In this manner, the tape that is just now pulled through the loom shed can be measured with regard to its width nearly over its entire length.

The evaluating arrangement is preferably embodied in such a manner so that it is able to calculate the minimum width and/or the maximum width of the weft thread to be inserted. These extreme values can be determined in a simple manner from all detected measurement data for one weft thread, in order to correspondingly actuate the drawing-off arrangement depending on the desired fabric image, for example for producing a desired constant spacing between the respectively successive weft threads. For this, the maximum width of the current weft thread is determined, and the fabric transport in the forward direction (if applicable with previous transport in the rearward or reverse direction toward the tape) is adjusted corresponding to the desired spacing distance.

- 8 Alternatively or additionally, the evaluating arrangement is advantageously embodied in such a manner so that it is able to calculate a mixed value based on several measured values of a weft thread to be inserted or that has been inserted, especially the width average value thereof. With the use of this average value, the drawing-off arrangement can be actuated in such a manner so that a uniform optical weaving pattern with a spacing of the current last-inserted weft thread or tape to the fabric rear edge, is obtained, wherein this spacing is adapted to the said average value. In this regard, this spacing can also be adjusted so that the applicable weft thread lies against the fabric rear edge corresponding to the determined mixed value, depending on the width fluctuations of the tape and the contour of the rear fabric edge, if applicable with gaps.

Alternatively to, or following on, a relative motion of the last inserted weft thread and the fabric, before insertion of the next weft thread, the fabric can be moved further by means of the actuated drawing-off arrangement in such a manner so that the next weft thread is inserted, over its entire weft length, without any gap formation with the fabric rear edge or with a spacing distance to the fabric rear edge.

In the presence of width fluctuations of the tape, fabric images are also realizable in which the tapes with both of their longitudinal edges contact against the neighboring tapes in certain regions, while narrower tape sections form corresponding gaps .

Advantageously the evaluating arrangement and/or the control arrangement are embodied and configured in such a manner at least to stop the further weft insertion and the drawing-off arrangement and/or to output a prescribed signal upon exceeding and/or falling below prescribed weft thread widths. The evaluating unit and/or the control arrangement are thus preferably in the position to stop the weaving process based on determined extreme values with respect to the tape width, and thereby to avoid a faulty production.

Comparably to this, the evaluating arrangement is preferably embodied in such a manner so that it is able to recognize faults of the weft to be inserted, for example holes and/or splices, in order to trigger a prescribed action of the weaving machine in its such case. Such an action can for example be the stopping of the weft insertion arrangement and/or the outputting of a signal, for example in order to summon machine operating personnel.

In the following the invention will be described in further detail in connection with an example embodiment. It is shown by:

Fig. 1 a schematic top plan view onto a weaving machine,

Fig. 2 a schematic view of the weaving machine according to

Fig. 1 from the supply side of the warp threads,

Fig. 3 a schematic cross-section through the weaving machine according to Figs. 1 and 2 with a view direction in the weft direction.

In Figures 1, 2 and 3, a weaving machine for warp and weft threads in the form of tapes is schematically illustrated. The tapes consist, for example, of carbon and/or glass fibers. Such a weaving machine is also termed a tape weaving machine.

The embodiment of the weaving machine described here can alternatively also be used for such woven fabrics in which merely the weft threads are present in the form of tapes, while the warp threads are utilized in a typical thread form, preferably however in the form of coarse, that is to say thick and/or wide threads.

Several warp threads 1 running next to one another are provided in rotating supply bobbins 9 and are transported in the warp direction 6 (also named the machine direction or the weaving direction) to a shedding arrangement 10, 25. This encompasses heddles, which are not shown in further detail, and through which the warp threads 1 are threaded-through. The heddles are preferably inserted or combined together in heald frames 25 - schematically illustrated as frames - and are alternately lifted or lowered with the aid of a drive 11, so that the warp threads 1 guided through the heddles form a loom shed 3 between themselves in a known way and manner. When one half of the warp threads 1 are deflected in their upper maximum position and the other half are deflected in their lower maximum position, a weft thread 2 can be guided through the thusly formed loom shed 3.

For supplying the weft thread 2, present as a tape, a supply bobbin or spool 7 rotating about a rotation axis 8 is provided, which supply bobbin 7 is located on one side of the weaving machine. The warp threads 1 can alternatively, instead of the supply bobbin 9, also be provided on a common supply arrangement, e.g. a warp beam.

For insertion of a weft thread 2 into a loom shed 3, a weft insertion arrangement or device 20 is provided, which encompasses a drive 22, a gripper rod or rapier 24 connected with the drive 22, and a gripper head 23 provided on the free end of the gripper rod 24. The gripper rod 24 is drivable by means of the drive 22 back and forth through the opened sheds 3. Instead of a gripper rod 24 it is alternatively also possible to use a gripper band or tape, which, however, under certain circumstances must be guided on its path through the loom shed.

Before the weft insertion, first the weft thread 2 that has been prepared or presented from the weft thread bobbin 7 is tightly held in the area of its free end by means of a clamping and cutting arrangement or device 21 that is only schematically illustrated, whereupon the gripper head 23 drives or moves through the loom shed 3 and grasps and clamps this free end of the weft thread 2. On its part, the clamping and cutting arrangement 21 lets go the free end of the weft thread 2, so that the gripper head 23 can pull the weft thread 2 through the loom shed 3. Then the loom shed 3 is closed in that the warp threads 1 are moved downwards or upwards respectively. Moreover, the clamping and cutting arrangement 21 clamps the weft thread 2 on the side of the weft thread bobbin 7 and separates the previously inserted weft thread 2 from the endless weft thread 2 supplied from the weft thread bobbin 7.

In Fig. 2, the loom shed 3 is schematically illustrated from the rear side of the weaving machine, which loom shed 3 is formed by warp threads 1 that are alternately moved up and down, so that weft thread 2 subsequently or followingly supplied from the weft thread bobbin 7 can be conveyed through the loom shed 3. For clamping and releasing, the clamping jaws of the gripper head 23 comprise a pivot point 29 that is only schematically indicated. Of course, purely linear motions of the clamping jaws of the gripper head 23 are also conceivable. Clamping and releasing of the clamping jaws can occur, for example, with the aid of a mechanical control arrangement that is arranged outside of the loom shed; however pneumatic or electro-mechanical control arrangements are also possible.

In an alternative that is not illustrated, the weft thread 2 is gripped by a gripper that is previously not driven or moved through the loom shed in the direction of the weft thread, but rather is arranged on the side of the weft thread bobbin, there grasps the weft thread end, transports it through the loom shed, lets go the weft thread, and then moves back in the direction of the weft thread bobbin without the weft thread.

The inserted weft thread 2 is still to be bound onto the woven fabric 4. For this purpose, before or during the closing of the loom shed 3, the fabric rear edge or the binding or interlacing point 5 with the woven fabric 4 is moved in the direction toward the inserted weft thread 2. For this, the woven fabric 4 over its entire width is pushed contrary to the warp direction 6 by a rearward or reverse path distance 38 to the previously inserted weft thread 2, until, for example, the fabric rear edge 5 lies in contact on the longitudinal edge of the said weft thread 2. Preferably in that regard, the woven fabric 4 is clamped by means of a fabric clamp 36 driven by a drive 35 (see Figures 1 and 3) . Next, the clamping by the fabric clamp 36, which exists if applicable, is released, and this clamp is pushed or advanced still further contrary to the warp direction 6 so far that the fabric clamp 36 can also grasp and clamp the said weft thread 2.

Next the fabric clamp 36 together with the clamped woven fabric 4 is moved in the warp direction 6 by the forward path distance so that the next loom shed 3 can be formed.

The thereby constantly growing woven fabric 4 is rolled or wound up on a drawing-off roll 32 that is rotationally driven by a drive 31 about a rotation axis 33. In order to produce the forwards and backwards motion of the woven fabric 4, in the present example embodiment an oscillating or swinging motion of intermediately arranged deflecting rolls 34, 37 is realized in the warp thread path or course or in the woven fabric path or course. This oscillating or swinging motion of the deflecting rolls 34, 37 is presently realized actively with a reversing oscillating drive (not illustrated in the figures) that synchronously moves both deflecting rolls 34, 37.

The drawing-off roll 32 as well as the fabric clamp 36 and if applicable the deflecting roll 34 are part of a drawing-off arrangement or device 30, whereby the drives of these devices must be exactly adapted to one another. This is carried out by a control arrangement 50 (in this regard see below in connection with the explanation of the invention).

The deflecting roll 34 is arranged in the fabric path between the loom shed 3 and the drawing-off roll 32. The fabric clamp 36 is also located in this area, and is preferably arranged in the area of the fabric rear edge 5.

The optional deflecting roll 37 is arranged in the rear area or region of the weaving machine between the heald frames 25 and the supply bobbins 9.

In principle it is also possible to avoid an oscillating or swinging motion of the deflecting rolls 34 and 37, whereby then the forward and backward motion of the woven fabric 4 must be achieved by corresponding control of the drive 31 for the drawing-off roll 32. For the compensation in the rear area of the machine, then e.g. corresponding drives for the supply bobbins 9 would be required.

It has now been found that especially the width of the weft threads 2 fluctuates due to the production thereof, so that non-uniform fabric appearances arise with fixedly prescribed path distances 38 (for the reverse or reward motion) and 39 (for the subsequent forward motion), which is not desirable for all applications .

Therefore, according to the invention, a measuring arrangement 40 for detecting geometric parameters, especially the width, of the weft threads 2 before their insertion in the respective formed loom shed 3 is provided. In the present example embodiment, the measuring arrangement 40 is provided between the weft thread bobbin 7 and the clamping and cutting arrangement 21 below the weft thread 2.

The measuring arrangement 40 presently is based on an optical measuring principle and in this regard probes or scans the weft thread 2. For example the measuring arrangement 40 can be embodied as an optical precision micrometer. The optical signals reflected back from the weft thread 2 are received by the measuring arrangement 40. Alternatively or additionally, a receiver 41 (shown in dashed lines in Fig. 2) is arranged above the weft thread 2. In principle, measuring arrangements 40 for detecting geometric parameters of an elongated surfacially shaped structure, such as that of a tape, are known and do not need to be explained in further detail here.

The measurement values or measurement results detected by the measuring arrangement 40 are presently provided further to an evaluating arrangement or device 45, which evaluates the measurement results and provides the results of the evaluation (which are presently also referred to as evaluated measurement results) further to a control arrangement or device 50. The control arrangement 50 is connected with the drawing-off arrangement 30 and controls the motions of the woven fabric 4 in that it controls the oscillating or swinging back and forth motion of the deflecting rolls 34, 37 and if applicable of the fabric clamp 36 and also controls the winding or rolling up of the woven fabric 4 onto the drawing-off roll 32. In this regard, the control arrangement 50 is connected with the drive for the oscillating motion of the deflecting rolls 34, 37 and if applicable with the drive 35 that drives the fabric clamp 36, as well as also with the drive 31 that drives the drawing-off roll 32.

Generally it is noted that the signal and control lines in Figs. 1 and 2 are illustrated with dash-dotted lines.

The measuring arrangement 40 is preferably embodied for the continuous measurement of the geometry of the weft thread 2. Thereby all deviations from the ideal form or shape (width, holes, lateral chipping or spalling) are reliably detected. In this regard, the measurement is preferably carried out when the weft thread 2 is guided past the measuring arrangement 40.

In this regard, the continuous measurement suitably also encompasses the measurement values of that section of the weft thread 2 located in the measurement area, which belongs to the weft thread 2 that is to be inserted next), while this is still clamped by the clamping and cutting arrangement 21. The measured values in this regard are preferably also taken into consideration by the evaluating arrangement 45, so that measured values are present over the entire length of the next to-be-inserted weft thread 2.

The evaluating arrangement 45 is preferably embodied in such a manner so that it is able to calculate the minimum width and/or the maximum width of the weft thread to be inserted.

Alternatively or additionally, the evaluating arrangement 45 can calculate, for example, a mixed value based on several measured values of a weft thread 2, especially the width average value thereof .

Based on the evaluations of the evaluation arrangement 45, the drive of the deflecting rolls 34, 37 and if applicable the drive 35 of the fabric clamp 36 can be actuated by the control arrangement 50, in order to drive or move the woven fabric 4 back by an adapted path distance 38 contrary to the warp direction 6 based on the determined weft thread width (for example based on the determined extreme values relating to the weft thread width or a mixed value) . The subsequent counter motion 39 of the woven fabric 4 in the warp direction 6 is also correspondingly adapted, so that the forward path distance 39 just like the rearward path distance 38 varies depending on the evaluation. Contrary to the prior art, thus no constant prescribed motions of the woven fabric 4 are provided after each weft insertion, but rather motions that are adapted to the actual width of the respective previously inserted weft thread. Also the winding or rolling-up of the woven fabric 4 onto the drawing-off roll 32 as well as the oscillating motion of the deflecting roll 34 between drawing-off roll 32 and fabric clamp 36 are controlled dependent on the actual current determined weft thread width.

The drives with which the various different motions of the previously described structural assemblies of the weaving machine are controlled are preferably embodied as individually actuatable motors or as motor-transmission combinations, which preferably receive their signals from the control arrangement 50. These drives are embodied so that they - as needed - carry out reversing pivoting, rotating or linear motions.

The control arrangement 50 can actuate the drawing-off arrangement 30, especially the deflecting roll 34 and the fabric clamp 36, in such a manner so that the woven fabric 4 is positioned in the most varied manner before the next weft insertion. For example in this regard it is possible that the woven fabric 4 - through continuous consideration of the width of the respective weft threads 2 - comprises no gaps. Alternatively, the woven fabric 4 is positioned before the respective next weft thread insertion in such a manner so that a spacing distance of each weft thread 2 relative to the fabric rear edge 5 is always present, so that a fabric appearance with gaps between successive weft threads 2 results. Corresponding to a further alternative, the drawing-off arrangement 30 is controlled in such a manner so that along the currently inserted weft thread 2 that fluctuates in its width, one or more gaps are formed with the fabric rear edge 5, whereby in the remaining areas this weft thread 2 contacts against the fabric rear edge 5 and/or even forms overlapping regions with the fabric rear edge 5.

Mixed forms of the abovementioned fabric appearances are also possible without difficulty through corresponding adjustment of the control arrangement 50.

The evaluating arrangement 45 and/or the control arrangement 50 are preferably embodied and configured in such a manner so as at least to stop the further weft insertion as well as the drawing-off arrangement 30 in the event of exceeding and/or falling below prescribed weft thread widths, and/or to output a prescribed signal. Similarly it is advantageous if the evaluating arrangement 45 can recognize faults of the weft thread 2 to be inserted, for example holes and/or splices, and can trigger a prescribed action of the weaving machine, especially via the control unit 50.

The present invention is not limited to the illustrated and described example embodiments. Derivations or modifications within the scope of the patent claims are also possible just like a combination of the features, even when these are illustrated and described in different example embodiments.

Reference Number List 1 warp threads weft threads (tapes) loom shed woven fabric fabric rear edge warp thread direction weft thread bobbin rotation axis supply bobbins shedding arrangement drive for shedding arrangement weft insertion arrangement clamping and cutting arrangement drive for gripper gripper head gripper rod heald frame pivot point drawing-off arrangement drive for drawing-off roll drawing-off roll rotation axis deflecting roll drive for fabric clamp fabric clamp deflecting roll rearward path distance forward path distance measuring arrangement receiver evaluating arrangement control arrangement

Claims

Patent Claims:

1. Weaving machine with a shedding arrangement (10) for forming loom sheds (3) between warp threads (1) pulled off from a thread supply (9), a weft insertion arrangement (20) for inserting weft threads (2) in the form of tapes into the formed loom sheds (3), and a drawing-off arrangement (30) for drawing-off the woven fabric (4) formed of warp and weft threads (1, 2) after a weft thread insertion, characterized by a measuring arrangement (40) for detecting geometric parameters, especially the width, of a weft thread (2) before its insertion into the formed loom shed (3), by an evaluating arrangement (45) for evaluating the detected measurement results, as well as by a control arrangement (50) connected with the drawing-off arrangement (30) for controlling a motion of the woven fabric (4) including the drawing-off on the basis of the evaluated measurement results.
2. Weaving machine according to claim 1, characterized in that the measuring arrangement (10) is based on at least one of the following measuring methods:

an optical measuring method, wherein the measuring arrangement (10) is preferably embodied in the form of an optical precision micrometer, and/or an acoustic measuring method, especially operating by means of ultrasound, and/or a tactile measuring method.
3. Weaving machine according to at least one of the preceding claims, characterized in that the measuring arrangement (40) is embodied and configured to continuously detect the width of a weft thread (2).
4. Weaving machine according to at least one of the preceding claims, characterized in that the measuring arrangement (40) is arranged in such a manner so that it is able to measure the width values of the weft thread (2) that is next to be inserted or of a weft thread (2) during its insertion, wherein the measurement can be carried out on the moving weft thread (2) .
5. Weaving machine according to at least one of the preceding claims, characterized in that the measuring arrangement (40) is arranged on the insertion side of the weft thread (2) .
6. Weaving machine according to at least one of the preceding claims, characterized in that the evaluating arrangement (45) is embodied to calculate the minimum width and/or the maximum width of a measured weft thread (2) .
7. Weaving machine according to at least one of the preceding claims, characterized in that the evaluating arrangement (45) is embodied to calculate a mixed value on the basis of several measured values of a weft thread (2) to be inserted or of a weft thread (2) during its insertion, especially its width average value.
8. Weaving machine according to at least one of the preceding claims, characterized in that the drawing-off arrangement (30) encompasses a drivable drawing-off roll (32).
9. Weaving machine according to claim 8, characterized in that the drawing-off arrangement (30) encompasses an oscillatingly or swingingly drivable deflecting roll (34) that is arranged in the fabric path between the loom shed (3) and the drivable drawing-off roll (32) .
10. Weaving machine according to at least one of the preceding claims, characterized in that the drawing-off arrangement (30) comprises a fabric clamp (36), and in that the drawing-off arrangement (30) is actuatable in such a manner by the control arrangement (50) so that the woven fabric (4) together with the fabric clamp (36) is moved back contrary to the weaving direction by a prescribed path distance (38), which is preferably determined based on the evaluated measurement results, preferably until contacting against the previously inserted weft thread (2).
11. Weaving machine according to at least one of the preceding claims, characterized in that by controlling the drawing-off arrangement (30) the woven fabric (4) can be positioned before the next weft insertion in such a manner so that the weft thread (2) is insertable according to one of the following manners:

over its entire weft length without any gap formation with the fabric rear edge (5), or over its entire weft length with a gap relative to the fabric rear edge (5), or over its entire weft length while forming one or more gaps with the fabric rear edge (5), and namely with area-wise contacting on the fabric rear edge (5) and/or overlapping with the fabric rear edge (5) .
12. Weaving machine according to at least one of the preceding claims, characterized in that the evaluating arrangement (45) and/or the control unit (50) are embodied at least to stop the further weft insertion and the drawing-off arrangement (30) upon exceeding and/or falling below prescribed weft thread widths and/or to output a prescribed signal.
13. Weaving machine according to at least one of the preceding claims, characterized in that the evaluating arrangement (45) is embodied to recognize faults of the weft thread (2) to be inserted, for example holes and/or splices, and to trigger a prescribed action of the weaving machine.

1/3

Fig. 1 i

2/3

Fig. 2

3/3

1^co