Method for removing an incorrectly inserted weft thread and air-jet weaving machine

Description

[0001] The invention relates to a method for removing an incorrectly inserted weft thread in an air-jet weaving machine and to such an air-jet weaving machine.

[0002] EP 0 310 804 B1 discloses such a method and such an air-jet weaving machine, in which weft threads are inserted into a shed formed by warp threads by means of a main jet nozzle arranged on an insertion side of the weft thread and several relay jets arranged along this shed. The shed, which is defined by a lower shed and an upper shed of correspondingly deflected warp threads, is created by a shedding device driven by a first drive. The shafts of the shedding device periodically shift the warp threads of the lower shed into the upper shed and vice versa after each weft insertion.After a weft thread has been inserted, the shed is moved into a closed position, and a reed driven by a second drive beats the weft thread to the binding point. The inserted weft thread is then separated from the weft thread supply by a separating device, particularly a cutting device, located on the insertion side. The first drive and the second drive are driven by a control system that ensures that the two drives always run synchronously with each other.

[0003] On the side facing away from the insertion side, hereinafter referred to as the discharge side, a thread monitor checks for faultless insertion of the weft threads. A faulty weft insertion, in which the weft thread passes the thread monitor, does not trigger an error signal. However, if a weft thread is inserted incorrectly – a scenario also referred to as a weft break – the thread monitor issues an error signal. This error signal causes the control system to stop the weaving machine. Since stopping cannot occur immediately, the incorrectly inserted weft thread is still beaten onto the tying point by the reed and must therefore subsequently be released from the tying point before being removed.

[0004] To remove the incorrectly inserted weft thread, the control system in the known method activates the first and second drives in such a way that, on the one hand, the shedding device moves the shed into an open position and, on the other hand, as a result of the synchronization and quite intentionally, the reed is pivoted away from the tying point. By pivoting this away, the incorrectly inserted weft thread still protruding from the main blower nozzle is lifted away from the tying point, at least on the insertion side, because the main blower nozzle, as well as any pre-nozzle and relay nozzles, are arranged together with the reed on the sley and are therefore pivoted away from the tying point with it. By activating the main blower nozzle and the relay nozzles (as well as any(existing pre-nozzle or pre-nozzles), the incorrectly inserted weft thread can then be released from the binding point over its entire length and transported, together with a released portion of the weft thread held ready on the insertion side, to the discharge side, where the weft thread end is stretched and held by a suction nozzle. This process is referred to as "blowing out" in the context of this description.

[0005] As an alternative to stretching the incorrectly inserted weft thread through the shed, designs are known in which an incorrectly inserted weft thread is pulled out of the shed on the insertion side by means of a mechanical device.

[0006] After the shed is closed and the reed is usually pivoted toward the binding point, the incorrectly inserted weft thread, stretched and held by the suction nozzle, is severed on the insertion side by a cutting device. The severed weft thread is then suctioned off on the discharge side with the shed reopened and the reed pivoted away from the binding point. In the above-mentioned variant of mechanically removing the weft thread from the shed on the insertion side, which is not described in EP 0 310 804 B1, this weft thread is also cut off on the insertion side and expediently removed from this insertion side.

[0007] A control step follows to verify whether the weft thread has actually been removed. To do this, the shed is closed and the reed is beaten onto the binding point. If the thread monitor then registers the presence of a weft thread, this means that the previously incorrectly inserted weft thread was not completely removed from the shed. In this case, this weft thread is removed manually with the shed opened.

[0008] A disadvantage of the air-jet weaving machine described in EP 0 310 804 B1 is that the repeated opening and closing of the shed during the successive steps of automatic weft break repair means that the warp threads are repeatedly stretched and, in addition, for longer periods of time (compared to normal weaving operation), which can then result in so-called start-up points in the finished fabric.

[0009] CN 105 401 311 B discloses a method for removing a faultily inserted weft thread. Upon detection of a faultily inserted weft thread, the weaving machine is stopped and the weft thread is cut. Subsequently, the warp threads in the lower and upper sheds, as well as the fabric, are shifted backward toward the warp beam. The lower and upper sheds are then lowered together, and the reeds are subsequently pivoted backward together with the relay nozzles. In this way, the cut, faultily inserted weft thread is pushed off the selvedge by the relay nozzles. The lower and upper sheds are then raised so that the relay nozzle openings can optimally engage and remove the weft thread to be discharged.

[0010] DE 10 2007 043142 A1 discloses a method for shutting down a weaving machine from weaving operation to a standstill due to a stop signal, wherein the shedding means are driven by a shedding machine through a secondary motor, while the reed is driven by the main motor of the weaving machine, and wherein for shutting down the synchronous drive of the shedding means and the reed is canceled and the reed is braked with its drive independently of the shedding machine.The method is characterized in that a) the process of shutting down the shedding machine includes the setting of the shed position desired when the shedding machine is at a standstill, b) in the event of an interruption of the weaving operation due to a weft thread break, the shedding machine is shut down on the basis of a specific stop signal in such a way that the shed with the broken weft is opened, and c) the removal of the weft break begins even before the shedding machine has come to a standstill.

[0011] It is an object of the present invention to provide an automated method for removing a faultily inserted weft thread in an air-jet weaving machine and such an air-jet weaving machine for the automatic weft breakage repair, in which contact points in the fabric are avoided or at least reduced.

[0012] This object is achieved by a method and a device having the respective features of the independent claims.

[0013] According to the invention, upon receiving an error signal from the thread monitor indicating a weft break, the control system of the air-jet loom cancels the synchronization between the first and second drives and then controls the two drives independently of one another. For this purpose, the two drives are mechanically separated from one another, i.e., they are not mechanically coupled at any time, but are electronically synchronized during normal operation. Alternatively, the two drives are mechanically coupled during normal operation and thus synchronized during normal operation, but can be decoupled from one another, e.g., by means of an appropriately designed coupling that can be controlled by the control system.

[0014] In order for the incorrectly inserted weft thread to be released from the tying point, the reed is pivoted away from the tying point by controlling the second drive - comparable to the known method for automatic weft break repair. Unlike in the prior art, the control system controls the second drive independently of the first drive in order to bring the reed into a first pivoted position pivoted away from the tying point. By pivoting it away, it is advantageously possible to lift the weft thread, which is still connected to the main blower nozzle, from the tying point on the insertion side and then - as also known from the prior art - to release it from the tying point over its entire length in the shed with the help of the at least one main blower nozzle and the relay nozzles.

[0015] Furthermore, according to the invention, the first drive is controlled by the control system independently of the second drive such that the weaving shed is moved into a first open position with a smaller opening angle compared to the maximum opening angle achieved during normal, i.e., continuous, weaving operation for blowing out and / or sucking in and / or mechanically removing the incorrectly inserted weft thread. The opening angle is defined as the angle formed between the lower shed and the upper shed, starting from the binding point.Since, due to its design, the shedding device always raises the lower shed and lowers the upper shed when the shed is reduced in size, the inventive design means that the relay nozzles, which are arranged together with the reed on the batten, now dip to a lesser extent from below through the lower shed into the shed, so that the relay nozzles hardly pose any obstacle to the weft thread to be removed and this can get caught on the relay nozzles less frequently or not at all. This makes it possible to remove incorrectly inserted weft threads from the shed with a significantly higher success rate. This advantage arises both from the stretching of the incorrectly inserted weft thread in the shed (by blowing out and / or suction) and from the mechanical removal of such a weft thread on the insertion side.

[0016] As indicated above, the first open position according to the invention with the relatively small opening angle can only be realized if the first and second drives are not mechanically coupled to one another or are at least decoupled during the process of removing the incorrectly inserted weft thread. According to the invention, both the shed opening and the reed position are therefore freely adjustable with respect to the shed, i.e., independently of one another. It is preferred that the two drives are each designed as individual drives, wherein these two individual drives are always decoupled but synchronized with one another by means of the control system during continuous weaving operation.When a weft break is detected, the reed is then pivoted into a first pivot position remote from the binding point, as in the prior art, while the shedding device, driven by the first drive, moves the shed into the said first open position.

[0017] The first open position is preferred, but not necessarily the one reached immediately after the synchronization of the two drives is canceled. However, the shed can also be moved to an intermediate position, although this would not be advantageous in most cases.

[0018] The basic steps of—after transferring the shed to the first open position according to the invention—subsequently blowing out and / or sucking in and / or mechanically removing the incorrectly inserted weft thread, cutting this weft thread, and finally removing it are advantageously carried out according to the state of the art, but particularly preferably with the synchronization of the two drives still suspended. The first and second drives are preferably synchronized with each other only upon resumption of normal weaving operation by appropriate control by the control system.

[0019] Particularly preferably, the controller controls the first drive in response to the said error signal from the at least one thread monitor such that the shed, after being transferred to the first open position, remains in this first open position not only during the step of blowing out and / or sucking in and / or mechanically removing the incorrectly inserted weft thread, but also during the cutting of the incorrectly inserted weft thread. Furthermore, it is advantageous if the shed additionally remains in the first open position during the removal of the cut, incorrectly inserted weft thread. Furthermore, it is advantageous if the shed additionally remains in the first open position during a control step, preferably carried out with the thread monitor, for checking the successful removal of the incorrectly inserted weft thread.

[0020] In a particularly preferred embodiment, the shed remains in the first open position until the weaving machine is prepared and restarted with the first and second drives synchronized again. In this latter variant, after the synchronization is canceled, the shed is moved to the first open position and remains there throughout the entire weft break repair process, possibly including a control step, until the weaving machine's start-up process is initiated to commence weaving.

[0021] Preferably, the controller activates the second drive upon said error signal from the at least one thread monitor such that the reed, after pivoting into the first pivot position, remains in this first pivot position during blowing and / or suction and / or mechanical removal. The first pivot position is preferably as far away from the tying point as possible so that the incorrectly inserted weft thread can be released and stretched from the tying point by the main nozzle and the relay nozzles arranged on the sley.

[0022] To trim the incorrectly inserted weft thread, the weaving reed is then preferably moved into a second pivoting position by controlling the sley via the second drive. In this position, the weaving reed is close to the binding point, allowing the incorrectly inserted weft thread stretched in the shed to be trimmed in a controlled manner. By pivoting into this second pivoting position, the incorrectly inserted weft thread is preferably fed into a weft thread cutter.

[0023] During the removal of the cut, incorrectly inserted weft thread and / or to restart the weaving process with the first and second drives then synchronized again, the reed can be brought into the first pivot position or, as is preferred, is moved into a third pivot position in which the reed is preferably closer to the tying point than in the first pivot position and further away from the tying point than in the second pivot position. Pivoting the sley with the reed into such a third pivot position, which is closer to the tying point than the first pivot position, has the advantage that the reed has to travel a shorter pivoting distance in this third pivot position, starting from the second pivot position, and thus the duration of the automated process for removing an incorrectly inserted weft thread is shortened, which in turn reduces the downtime of the weaving machine after a weft break.In addition, the risk of the cut, incorrectly inserted weft thread getting caught during suction is further minimized, since the relay nozzles protrude even less into the shed in the third pivot position than in the first pivot position of the reed.

[0024] Particularly preferably, the first drive is activated by the control system upon an error signal from the at least one thread monitor such that the warp threads of the upper shed and the warp threads of the lower shed form an opening angle of less than 30°, preferably less than 15°, particularly preferably less than 12° in the first open position of the shed. These angular positions have proven advantageous for significantly less prone to weft break repair and for protecting the warp threads tensioned during weft break repair.

[0025] The control also particularly preferably controls the first drive in the event of an error signal from the at least one thread monitor such that the warp threads of the upper shed and the warp threads of the lower shed form an opening angle of more than 4°, preferably more than 6°, particularly preferably more than 7° in the first open position of the shed.

[0026] A relatively small opening angle in the first open position prevents excessive stretching of the warp threads, thus reducing the number of contact points in the finished fabric. At the same time, the relay jets, which are connected to the reed via the batten, penetrate less deeply into the shed through the lower shed.

[0027] Another advantage of a relatively small shed opening angle is the reduced distortion in the left and right spreader areas. The spreader bars serve to hold the fabric at its two edge areas running in the warp direction, preventing it from shrinking towards the center of the fabric due to mechanical tension. The smaller the shed opening or the opening angle of the shed, the lower the mechanical tension acting inward on the fabric edges, since the thread tension is hardly increased with a small shed, which ultimately leads to a more uniform tie-point line across the weaving width.

[0028] In preferred embodiments, it has proven advantageous if the opening angle is between 7° and 12°.

[0029] Preferably, the control system activates the first drive upon an error signal from the at least one thread monitor such that the relay nozzles, measured from the lower edge of the lowest blow opening of the relay nozzles, protrude no more than 6 mm through the plane of the warp threads of the lower shed into the shed in the first open position of the shed. The term "lowest blow opening" of each relay nozzle should also be understood to include the case where one or more relay nozzles have only a single blow opening. The aforementioned design has the advantage that the blow openings (or the single blow opening) protrude only a small height into the shed, and thus the relay nozzles hardly pose an obstacle to the weft thread approaching from the insertion side.

[0030] The invention also relates to a device according to the independent device claim with the corresponding device features that follow directly from the above. This also applies to the dependent device claims.

[0031] Advantageous further developments of the invention result from the features of the subclaims.

[0032] The invention is explained in more detail with reference to the figures. They show: Figure 1 shows an air-jet loom in a schematic side view; Figure 2 shows a front view of a reed and pneumatic devices of the air-jet loom; Figure 3 shows a side view of a reed in a first pivoting position and a shed, shown on the one hand with a first opening angle α and on the other hand with an opening angle α' according to the prior art; Figure 4 shows a side view of the reed of the Figure 3in a second pivoting position, and Figure 5 a side view of the reed of the Figures 3 and 4 in a third swivel position.

[0033] In the Figure 1 , essential elements of an air-jet loom 1 are shown in a very schematic side view. Two shafts 23 of a shedding device 22, arranged one behind the other, take up warp threads 2 in a known manner, wherein the two shafts 23 are moved up and down in counter-phase by means of a first drive 20. As a result, the warp threads 2 form a lower shed 62 and an upper shed 64, which together create a shed 60, which opens and closes as a result of the warp threads 2 constantly alternating from the lower shed 62 to the upper shed 64 and vice versa. When the shed 60 is open, a weft thread 3 is shot through the shed 60 in the weft direction SR, which runs orthogonal to the warp direction KR (see Figure 2), whereupon the shed 60 is closed by means of the shedding device 22 and a reed 32 strikes the binding point 66 of the fabric 67. The reed 32 is arranged on a sley 36, which is periodically pivoted toward and away from the binding point 66 by a second drive 30 during normal weaving operation.

[0034] The first drive 20 and the second drive 30 are both controlled by a controller 50 via corresponding signal lines 51, 52. It is particularly preferred that both drives 20, 30 be designed as individual drives, which the controller 50 can control separately from one another. During normal weaving operation, the two drives 20, 30 are controlled such that they run synchronously with one another in order to ensure the repeated, precise movement sequence of shed formation and reed beat-up required for a weaving cycle.

[0035] From the front view of the Figure 2the process of weft insertion into the shed 60 becomes apparent. On the insertion side 8, at least one main blow nozzle 6 is arranged, to which weft thread material is fed from a corresponding weft thread accumulator (not shown). It should be mentioned here that there are various configurations and arrangements of one or more main blow nozzles 6. Thus, it is possible for one or more main blow nozzles 6 to be arranged on the sley 36 and to be pivoted with it. There are also variants in which one or two (or more) main blow nozzles are arranged on the sley, while one or two (or more) stationary main blow nozzles are provided, which are not pivoted with the sley. In the present case, it is assumed that there is at least one main blow nozzle 6, which is arranged here on the sley 36 and pivoted with it, which according to Figure 2 is connected to the sley 36 via a connecting piece 7.

[0036] The weaving reed 32 is arranged on the sley 36 driven by the second drive 30, whereby in the present case only some of its reed teeth 33 are shown on the outer sides. Furthermore, several relay nozzles 40, spaced apart in the weft direction SR, are arranged on a holder 38 on the sley 36, one or more of whose blowing openings 42 are directed towards a channel 34 running in the weft direction SR, which is formed by indentations in the reed teeth 33 (see the Figures 3-5). The at least one main blow nozzle 6 inserts a weft thread 3 on the insertion side 8 into the shed 60, which is then transported by the relay nozzles 40 in the channel 34 through the shed 60 and sucked in by a suction device 45 arranged on the discharge side 9. Subsequently, the shed 60 is closed by the shedding device 22, the inserted weft thread 3 is beaten onto the binding point 66 by the reed 32 and subsequently cut off by a cutting device 68 on the insertion side 8.

[0037] On the discharge side 9, a thread monitor 48, which in this case consists of an optical transmitter and an optical receiver, checks the faultless insertion of each weft thread 3. The thread monitor 48 only emits an error signal if a weft thread 3 is inserted incorrectly and does not reach the thread monitor 48. This scenario is also referred to as a weft break. The present invention relates to an improved method and an improved device for automatically correcting weft breakage. Such an error signal from the thread monitor 48 causes the controller 50 connected to the thread monitor 48 to initially stop the normal weaving operation of the air-jet loom 1. According to the invention, the synchronization between the first and second drives 20, 30 is then canceled by the controller 50. The controller 50 now controls the second drive 30 such that the reed 32 assumes a first pivoted position pivoted away from the binding point 66, see. Figure 3. However, prior to this, the reed 32 – due to the impossibility of stopping the moving elements immediately after the machine stop – pushed the incorrectly inserted weft thread 3 toward the tying point 66. If the at least one main blower nozzle 6 is arranged on the sley 36, as is usual, and is deflected with it, the incorrectly inserted weft thread 3 can be released from the tying point 66, at least in the area of the main blower nozzle 6, by pivoting the reed 32 into the first pivot position.

[0038] Furthermore, according to the invention, the control 50 controls the first drive 20 in such a way that the shedding device 22 transfers the shed 60 into a first open position, wherein the opening angle α of this first open position - starting from the binding point 66 and measured between the lower shed 62 and the upper shed 64 - is smaller than the maximum opening angle α' of the open position reached during the continuous weaving operation, see also Figure 3In any case, however, by transferring the reed 32 to the first pivot position in conjunction with the shed 60, which has been brought into a first open position by the shedding device 22, the possibility arises that the incorrectly inserted weft thread 3 can ultimately be removed from the shed 60. In this first open position of the shed with the first opening angle α, the air-jet weaving machine 1 shown in the figures then carries out the known step of blowing out the incorrectly inserted weft thread. The term "blowing out" means that the weft thread 3, still connected to the weft thread supply on the insertion side 8, is transported toward the discharge side 9 by activating at least one main blower nozzle 6 and the relay nozzles 40 (and possibly one or more pre-nozzles), where it is stretched by the suction device 45.To allow the weft thread end to reach the suction device 45, a piece of the weft thread is released from the weft thread storage device. In the aforementioned stretched position, the incorrectly inserted weft thread 3 can be cut by the cutting device 68 on the insertion side 8 and finally removed. This is conveniently done by suction using the suction device 45 on the discharge side 9.

[0039] However, other variants than the blowing out are also conceivable, for example the mechanical removal of the incorrectly inserted weft thread 3 from the shed 60 by means of a pulling device on the insertion side 8 (this variant is not shown).

[0040] In all variants, the incorrectly inserted weft thread 3 is finally cut off and finally removed by means of the cutting device 68.

[0041] Coming back to the Figure 3It can be seen from this that the shed 60 formed by the lower shed 62 and the upper shed 64, in its first open position, assumes an opening angle α of approximately 10°, with the opening angle α preferably being between 7° and 12°. In contrast, the opening angle α' between the lower shed 62' and the upper shed 64' (see Figure 3 ) with the shed 60 in its maximum open position during normal weaving operation at over 30°.

[0042] The small opening angle α offers the particular advantage that the warp threads 2 deflected by the shafts 23 are only slightly stretched, at least during the phase of blowing out and / or sucking in and / or mechanically removing the incorrectly inserted weft thread 3. Furthermore, Figure 3It can be seen that the relay nozzles 40 protrude only slightly through the lower shed 62 into the shed 60 when the shed 60 is first opened. This means that the incorrectly inserted weft thread 3 - regardless of whether it is stretched toward the discharge side 9 or pulled out on the insertion side 8 - can hardly get caught on the relay nozzles 40, thereby achieving a higher success rate in the automatic weft breakage repair.

[0043] In the Figure 3 It is also indicated that the lower edge of a blowing opening 42—shown here only as an individual one—which is arranged at the free ends of each relay nozzle 40, protrudes only slightly through the lower shed 62, preferably no more than 6 mm. This still ensures the functionality of blowing out the incorrectly inserted weft thread 3, but with minimal obstruction to its freedom of movement on its way to the discharge side 9 or the insertion side 8.

[0044] In the Figure 4 The reed 32 is pivoted into a second pivot position near the binding point 66 by controlling the second drive 30 by means of the control 50, in order to then cut off the incorrectly inserted weft thread 3. Due to the canceled synchronization between the two drives 20, 30, the shed can remain in the said first open position, so that the warp threads 2 continue to be stretched only slightly.

[0045] In the Figure 5Finally, the reed 32 is transferred to a third pivot position, in which the reed 32 is located between the first and second pivot positions, such that the reed 32 only has to travel a relatively short pivoting distance, starting from the second pivot position. The shed 60, on the other hand, can continue to remain in the aforementioned advantageous first open position with the opening angle α. In these positions of the reed 32 and the shed 60, the incorrectly inserted and meanwhile cut weft thread 3 is preferably removed, preferably by suction using the suction device 45. The risk of the cut weft thread 3 getting caught during suction is further minimized by this third pivot position, since here the relay nozzles 40 protrude even less into the lower shed 62 compared to the first pivot position.Transferring the reed 32 into the third pivoting position described also leads to time savings in the automatic weft breakage repair process and to short downtimes of the weaving machine.

[0046] After initiating this removal of the cut-off, incorrectly inserted weft thread 3, a control step can follow, in which it is checked whether the said weft thread 3 has actually been finally removed. For this purpose, the shed 60 remains in its previously moved open position with its relatively small opening angle, while the reed 32 is moved close to the binding point 66 (comparable to the position of the shed 60 and the reed 32 according to the Figure 4). If the thread monitor 48 still registers the presence of a weft thread 3 and emits a corresponding signal (here, signaling the presence of a weft thread), this means that the previously incorrectly inserted weft thread 3 was not completely removed from the shed 60. In this case, this weft thread 3 is preferably removed manually when the shed 60 is then opened.

[0047] Even until the preparation for the renewed start-up of the air-jet loom 1, in which the first drive 20 and the second drive 30 then run in synchronized operation again by control by the control 50, the shed 60 is preferably still in the first open position with opening angle α. The reed 32, however, is advantageously moved by means of the second drive 30 controlled by the control 50 into a position similar to that in the Figure 5described third pivoting position or remains in this third pivoting position after the removal of the incorrectly inserted weft thread 3, with the above-described effect of saving time in the automatic weft breakage repair and the associated reduction in downtimes. With regard to the shed 60, the control 50 is accordingly configured such that it preferably controls the first drive 20 upon an error signal from the at least one thread monitor 48 such that the shed 60, after being transferred to the first open position, can remain in this first open position until the continuous weaving operation is restarted.Only then are preferably the reed 32 and / or the shafts 23 of the shedding device 22 brought into the position necessary for continuous weaving operation with the associated synchronization of the shedding device 22 and the reed 32, whereupon the weaving operation can then be continued.

[0048] The aforementioned long dwell time in the first open position with the reduced opening angle has the advantage that the warp threads 2 are only slightly stretched during the entire process of removing the weft thread 3. Further advantages of the invention due to the relatively small and preferably constant opening angle of the shed are reduced distortion in the temple area and a uniform tying point. The free, independent adjustability of the opening angle of the shed on the one hand and the position of the reed relative to the opened shed on the other hand allows for a higher success rate in automatic error correction.

[0049] The present invention is not limited to the illustrated and described embodiments.

[0050] Thus, the first open position of the shed 60 does not have to be reached immediately after the machine stops; one or more intermediate positions are also possible beforehand. It is also possible that after the incorrectly inserted weft thread 3 has been blown out and / or sucked in and / or mechanically removed, the shed 60 is moved into one or—then successively—several other open positions, which preferably also have a relatively small opening angle of less than 30°. Additional thread monitors can also be arranged at other positions relative to the shed 60; furthermore, the thread monitor 48 and / or other thread monitors can be based on functional principles other than optical detection. List of reference symbols

[0051] 1 Air-jet loom 2 Warp thread 3 Weft thread 6 Main nozzle 7 Connecting piece 8 Entry side 9 Discharge side 20 First drive 22 Shedding device 23 Shafts 30 Second drive 32 Reed 33 Reed tooth 34 Channel 36 Sliding 38 Holder 40 Relay nozzles 42 Blowing opening 45 Suction device 48 Thread monitor 50 Control system 51 Signal line 52 Signal line 60 Shed 62, 62' Lower shed 64, 64' Upper shed 66 Tying point 67 Fabric 68 Cutting device SR Weft direction KRCaution direction α Opening angle α' Opening angle (state of the art)

Claims

1. A method for removing an incorrectly inserted weft thread (3) on an air jet weaving machine (1), which has at least one main blowing nozzle (6) in the weft direction (SR) and a plurality of relay nozzles (40), which each have one or more blowing openings (42) and are arranged along a weaving sley (36), wherein a first drive (20) drives a shed forming device (22) for opening and closing a weaving shed (60) defined by warp threads (2), wherein the weaving shed (60) is formed by a lower shed (62) and an upper shed (64), and wherein the at least one main blowing nozzle (6) and the relay nozzles (40) transport the respective weft threads (3) through the weaving shed (60), and wherein a second drive (30) drives the weaving sley (36) together with a weaving reed (32) arranged on the weaving sley (36), so that the latter periodically strikes the interlacing point (66) of the fabric (67), wherein a control (50) controls the first drive (20) and the second drive (30) in such a way that they are operated in synchronism with one another during normal weaving operation, wherein the method comprises the following steps: detecting a weft thread (3) incorrectly inserted into the weaving shed (60) with at least one thread monitor (48), which generates a corresponding error signal and forwards it to the control (50), subsequently cancelling the synchronism between the first and the second drive (20, 30) by the control (50) after reception of the error signal, subsequently controlling the second drive (30) by the control (50) in such a way that the weaving reed (32) assumes a first pivot position pivoted away from the interlacing point (66), and controlling the first drive (20) by the control (50) in such a way that the shed forming device (22) transfers the weaving shed (60) into a first open position by raising the lower shed and lowering the upper shed, the opening angle (α) of which formed by the lower shed (62) and the upper shed (64) starting from the interlacing point (66) is smaller than the opening angle (α') of the maximum open position of the weaving shed (60) reached during the continuous weaving operation, subsequently blowing out and / or suctioning in the incorrectly inserted weft thread (3) on the insertion side (8) or the outlet side (9) of the weft thread (3) and / or mechanically eliminating the incorrectly inserted weft thread (3) from the weaving shed (60) in the respectively said first open position of the weaving shed (60), subsequently cutting off the incorrectly inserted weft thread (3) on the insertion side (8), and subsequently removing the incorrectly inserted and cut-off weft thread (3).

2. The method according to claim 1, characterized in that the control (50) controls the first drive (20) in the case of said error signal of the at least one thread monitor (48) in such a way that the weaving shed (60), after its transfer into the first open position, remains in this first open position not only during the blowing out and / or suctioning in and / or mechanical eliminating, but also during at least one of the following steps: - during the cutting off of the incorrectly inserted weft thread (3), - during the cutting off and the removing of the incorrectly inserted weft thread (3), - during the cutting off and the removing of the incorrectly inserted weft thread (3) and a control step, preferably carried out with the thread monitor (48), for checking the successful removal thereof, or - during the cutting off and the removing of the incorrectly inserted weft thread (3), an optional control step and until the restart of the weaving process in the synchronized operation of the first and second drive (20, 30).

3. The method according to claim 1 or 2, characterized in that the control (50) controls the second drive (30) in such a way that the weaving reed (32) for the cutting off of the incorrectly inserted weft thread (3) is brought into a second pivot position close to the interlacing point (66) and / or that the weaving reed (32) for the removing of the incorrectly inserted weft thread (3) from the weaving shed (60) and / or for the restart of the weaving process in the synchronized operation of the first and second drive (20, 30) is brought into a third pivot position, which lies between the first and a second pivot position close to the interlacing point (66).

4. The method according to one of the preceding claims, characterized in that the control (50) in the case of said error signal of the at least one thread monitor (48) controls the first drive (20) in such a way that the warp threads of the lower shed (62) and the warp threads of the upper shed (64) form an opening angle of less than 30°, preferably less than 15°, particularly preferably less than 12° in the first open position of the weaving shed (60).

5. The method according to one of the preceding claims, characterized in that the control (50) in the case of said error signal of the at least one thread monitor (48) controls the first drive (20) in such a way that the warp threads of the lower shed (62) and the warp threads of the upper shed (64) form an opening angle of more than 4°, preferably more than 6°, particularly preferably more than 7° in the first open position of the weaving shed (60).

6. The method according to one of the preceding claims, characterized in that the control (50) in the case of said error signal of the at least one thread monitor (48) controls the first drive (20) in such a way that the relay nozzles (40), measured from the bottom edge of the blowing region of the relay nozzles (40), in the first open position of the weaving shed (60) project no more than 6 mm through the plane of the warp threads of the lower shed (62) into the weaving shed (60).

7. An air jet weaving machine (1) with a device for removing an incorrectly inserted weft thread (3), with at least one main blowing nozzle (6) and a plurality of relay nozzles (40), which each have one or more blowing openings (42) and are arranged along a weaving sley (36), wherein at least the at least one main blowing nozzle (6) and the relay nozzles (40) transport the respective weft threads (3) through a weaving shed (60) defined by warp threads (2), wherein the weaving shed (60) is formed by a lower shed (62) and an upper shed (64), with a first drive (20) for driving a shed forming device (22) for opening and closing the weaving shed (60), a second drive (30) for periodically beating a weaving reed (32) arranged on the weaving sley (36) against the interlacing point (66), with at least one thread monitor (48) for detecting a weft thread (3) incorrectly inserted into the weaving shed (60) and for generating a corresponding error signal, with a control (50), designed for controlling the first and second drive (20, 30) so that they are operated in synchronism with one another in the normal weaving operation, and for receiving a said error signal from the at least one thread monitor (48), wherein at least the at least one main blowing nozzle (6) and the relay nozzles (40) and / or a suction device (45) and / or a mechanical elimination device stretch the incorrectly inserted weft thread (3) in the weaving shed (60) or transport it away from the weaving shed (60) on the insertion side (8) of the weft thread (3), with a cutting device (68) for cutting off the incorrectly inserted weft thread (3) on the insertion side (8), and with a device for removing the incorrectly inserted and cut-off weft thread (3), characterized in that the control (50) is set up in such a way that it firstly cancels the synchronism between the first and the second drive (20, 30) on reception of a said error signal of the thread monitor (48), in that it subsequently furthermore controls the second drive (30) in such a way that the weaving reed (32) assumes a first pivot position pivoted away from the interlacing point (66), and furthermore controls the first drive (20) in such a way that it transfers the weaving shed (60) into a first open position for blowing out and / or suctioning in the incorrectly inserted weft thread (3) by raising the lower shed and lowering the upper shed, wherein the opening angle (α) of the said first open position formed by the lower shed (62) and the upper shed (64) starting from the interlacing point (66) is smaller than the opening angle (α') of the maximum open position of the weaving shed (60) reached during the continuous weaving operation.

8. The air jet weaving machine (1) according to the preceding device claim, characterized in that the control (50) is set up in such a way that it controls the first drive (20) in the case of said error signal of the at least one thread monitor (48) in such a way that the weaving shed (60) remains in the first open position not only during the blowing out and / or suctioning in and / or mechanical eliminating of the incorrectly inserted weft thread (3), but also: - during the cutting off of the incorrectly inserted weft thread (3), or - during the cutting off and the removing of the incorrectly inserted weft thread (3), or - during the cutting off and the removing of the incorrectly inserted weft thread (3) and a control step, preferably carried out with the thread monitor (48), for checking the successful removal thereof, or - during the cutting off and the removing of the incorrectly inserted weft thread (3), an optional control step and until the restart of the weaving process in the synchronized operation of the first and second drive (20, 30).

9. The air jet weaving machine (1) according to one of the preceding device claims, characterized in that the control (50) is set up in such a way that it controls the second drive (30) in such a way that the weaving reed (32) for the cutting off of the incorrectly inserted weft thread (3) is brought into a second pivot position close to the interlacing point (66) and / or that the weaving reed (32) for the removing of the incorrectly inserted weft thread (3) from the weaving shed (60) and / or for the restart of the weaving process in the synchronized operation of the first and second drive (20, 30) is brought into a third pivot position, which lies between the first and a second pivot position close to the interlacing point (66).

10. The air jet weaving machine (1) according to one of the preceding device claims, characterized in that the control (50) is set up in such a way that it controls the first drive (20) in the case of said error signal of the at least one thread monitor (48) in such a way that the warp threads (2) of the lower shed (62) and the warp threads (2) of the upper shed (64) form an angle (α) of less than 30°, preferably less than 15°, particularly preferably less than 12° in the first open position of the weaving shed (60).

11. The air jet weaving machine (1) according to one of the preceding device claims, characterized in that the control (50) is set up in such a way that it controls the first drive (20) in the case of said error signal of the at least one thread monitor (48) in such a way that the warp threads (2) of the lower shed (62) and the warp threads (2) of the upper shed (64) form an angle of more than 4°, preferably more than 6°, particularly preferably more than 7° in the first open position of the weaving shed (60).

12. The air jet weaving machine (1) according to one of the preceding device claims, characterized in that the control (50) is set up in such a way that it controls the first drive (20) in the case of said error signal of the at least one thread monitor (48) in such a way that the relay nozzles (40), measured from the bottom edge of the bottommost blowing opening (42) of the relay nozzles (40), in the first open position of the weaving shed (60) project no more than 6 mm through the plane of the warp threads of the lower shed (62) into the weaving shed (60).

13. The air jet weaving machine (1) according to one of the preceding device claims, characterized in that the first drive (20) and the second drive (30) are individual drives.