EP0039009B1 - Process and apparatus for pneumatic insertion of the weft in the shuttles of multiple looms - Google Patents

Abstract

PCT No. PCT/DE81/00064 Sec. 371 Date Dec. 11, 1981 Sec. 102(e) Date Dec. 11, 1981 PCT Filed Apr. 18, 1981 PCT Pub. No. WO81/03037 PCT Pub. Date Oct. 29, 1981.A method for the pneumatic insertion of the weft thread (24, 24a) into the shuttles (9) of a multi-feed weaving loom. The weft thread (24, 24a), of a respectively predetermined length, is inserted by means of an air flow in an injector (23) into the weft thread magazine (29) of a shuttle (9) traveling in a continuous movement past the injector (23). In order to be able to supply the shuttles (9) rapidly with the particular weft thread required for the fabric panel width in a multi-feed weaving loom, without thereby causing an impermissible strain on the weft thread or being required to extend the length of the weft thread magazine (29) of the shuttles (9), the injector (23) is moved conjointly with the shuttle, e.g. by a gear coupling (34-38) beginning at a start position (I) but, at a slower speed than the shuttle and over shorter distance during the insertion of the thread (24, 24a) into the weft thread magazine (29). At the end of this distance the injector is rapidly returned to the start position by a spring (42).

Description

The invention relates to a method for the pneumatic insertion of the weft into the weft magazine of the weft carrier of a multi-system weaving machine, in which the weft magazines of the weft carrier are each successively loaded with a cut weft piece in such a way that the weft piece is conveyed into the weft magazine by means of an air jet is, the air jet is moved during loading with the weft thread carrier.

In addition, the invention relates to a device for performing this method, with an injected with compressed air injector to which the weft thread can be fed from a thread measuring and delivery device and which is arranged close to the path of movement of the weft thread carrier of a multi-system weaving machine and along part of this path of movement in the same direction as a weft thread carrier movably mounted and coupled with a correspondingly directed movement driving device which is synchronized with the movement of the weft thread carrier.

In a device known from DE-B-1287526 for loading loomers of weaving machines, multi-armed deflection wheels are provided in the path of movement of the loomers, and their arms are designed to accommodate one loomer, each rotating around parallel axes. The shooters picked up by the arms of the revolving deflection wheels are moved synchronously over a certain angular arc of, for example, 120 or 180 °, so that the mouth of an outlet nozzle lying in one arm of the deflection wheel is opposite a thread inlet opening of the assigned shooter and is fed with a cut weft piece can. The weft piece is conveyed into the weft magazine by means of an air jet while the weaving machine is running, the outlet nozzle and thus the air jet being moved with the weaving machine during loading.

Since each weaving shifter necessarily moves at the same speed as the associated outlet nozzle during the loading of its weft magazine, the inserted weft thread is piled up in the weft magazine and compressed into a plug consisting of zigzag-like thread loops. The result of this is that there is a risk that the weft thread will not be pulled smoothly out of the weft thread magazine during the weaving in, but that the individual thread loops of the stopper will get caught in one another and form knots.

In the case of a multi-system weaving machine, in which a plurality of fabric webs are produced side by side, it is desirable to assign a separate weft thread supply to each fabric web, in order to open up the possibility of supplying each fabric web with its own different weft thread. When using the device known from DE-B-1287526 on such a multi-system weaving machine, however, the shooters would have to be led out of the chain for each fabric web and brought back in a loop to the beginning of their path of movement because of the multi-arm deflection wheels used for loading the weft thread, which is already done Due to lack of space.

The invention has for its object to feed the weft carrier of a multi-system weaving machine pneumatically within a short, lying between two adjacent fabric sections or webs of movement of the weft carrier with the weft thread required for the respective fabric section width, without thereby accumulating the weft at one point Weft magazine of a weft thread carrier or an inadmissible strain on the weft thread would occur or an extension of the weft thread magazine of the individual weft thread carriers would be necessary.

To solve this problem, we proceed according to the invention in such a way that the air jet, starting from an initial position, moves with the weft thread carrier over a predetermined path length at a lower speed during the loading of a weft thread magazine and returns it to the starting position at the end of this path after the loading is completed becomes.

Because the air jet conveying the weft thread is moved at a lower speed than the weft thread carrier during the loading of a weft thread magazine, it executes a relative movement to the weft thread carrier, with the result that the weft thread is distributed evenly over the individual chambers of the weft thread magazine in which separate thread sheets are stored, which can not intertwine. This prevents the weft thread from being compressed into a stopper. This relative movement of the air jet to the weft carrier during the loading of the weft magazine also ensures that a longer time is available for loading the weft magazine compared to an air jet coming from a stationary injector, which can be used for this purpose without undue stress of the weft thread either increase the speed of the weft thread carrier, and thus the work performance of the entire weaving machine, significantly and / or insert longer weft thread pieces and thus produce particularly wide fabric webs.

Basically, the difference between the speed of each weft thread gers and the slower moving air jet in such a way that - as mentioned - no accumulation of the weft occurs at one point of the weft magazine, but there is a uniform distribution of the weft in the weft magazine. In order to utilize the entire magazine length, it is expedient for the air jet to be shifted relative to the weft thread carrier by an amount corresponding to the length of the weft magazine during the insertion of the weft thread into the weft thread magazine.

In order to avoid that the weft thread is thrown out of the air jet during the rapid return of the air jet to the starting position, it may be expedient in certain cases that the weft yarn is at least partially guided laterally on its way to the air jet, which happens, for example, as a result can that the thread path runs through a preferably transparent plastic tube or a plastic hose.

In the manufacture of woven goods which contain different weft threads, it is possible to use at least two air jets, each of which is associated with its own weft thread, one of the air jets from the starting position for inserting the weft thread into the weft thread magazine with the weft thread carrier is moved while the other air jet (s) is or are kept ineffective. This results in very simple conditions if the ineffective air jet (s) is or are held laterally next to the path of movement of the weft thread carriers and the air jet to be moved is transferred to the corresponding starting position for the co-movement before the insertion of the weft thread into the weft thread magazine. For example, according to the desired color repeat, the air jets can be selected according to the program for inserting the weft into the weft magazine. An electronic repeat control can be used for this.

The use of two air jets can also save time when filling the weft magazine of the respective weft carrier. After the insertion of the weft into a weft magazine has ended, the air jet takes a certain time to return to its starting position; if only an air jet is used, this return time cannot be used to fill a weft magazine. With two air jets, however, one can proceed in such a way that during the return of the moving air jet after completion of the insertion of the weft into the weft magazine, the second air jet is transferred to the starting position for moving with the next following weft carrier, so that immediately upon completion of the weft insertion in that a weft magazine can already be started with the weft insertion - by means of the second air jet - into the weft magazine of the subsequent weft carrier.

When the insertion of the weft into the weft magazine is completed, the weft is cut off at the edge of the fabric; It is particularly expedient if its end is automatically retracted into an injector generating the air jet when the air jet is returned to the starting position, so that it does not protrude from the injector when the next weft magazine is loaded, which leads to the risk of tangling, etc. could bring with it.

The device for carrying out the new method mentioned at the outset is characterized in accordance with the invention in that the injector is driven by its drive device at least during the insertion of the weft thread into the weft thread magazine of the respective weft thread carrier, starting from an initial position via a predetermined path at a predetermined speed reduction ratio the speed of the weft thread carrier is driven slower speed.

In a preferred practical embodiment, a slide guide can be arranged in the vicinity of the movement path of the weft thread carrier, on which the injector is slidably mounted. This sliding guide expediently consists of two parallel guide rails, between which the injector having a fitted sliding piece is guided.

With regard to the drive of the injector, the arrangement can be such that the drive device has a driver which can be automatically brought into engagement with the injector in the starting position and which can be uncoupled automatically from the injector after passing through the predetermined path, the injector then having a becomes effective, which brings it back into the starting position, which has about a return spring tension that can be tensioned when the injector moves with it.

Very simple, reliable constructive relationships result if the driver is arranged on a chain which is moved with a strand parallel to the movement path of the injector in the predetermined speed reduction ratio to the movement of the weft thread carrier and which is guided via deflection rollers at the beginning and at the end of the movement path of the injector through which the driver can engage or disengage from the injector.

The drive device, i.e. H. the chain is expediently driven via a toothed gear which is in engagement with a toothing on a part of the weft thread drive which is moved together with the respective weft thread carrier.

On the chain are at a preferred Aus In the embodiment, several drivers are arranged, the distance between which is greater than the path of the injector by an amount that enables the respective injector to be returned to the starting position. The time the injector takes to travel through one of the drivers corresponds to the filling time. As soon as the filling process is complete, the driver releases the injector so that it can be quickly returned to the starting position, from where it is moved forward either in synchronism with the next weft carrier either by the same driver or the next driver of the chain.

In order to achieve in the manner already mentioned that when the injector is returned to the starting position, the cut end of the weft does not protrude from the injector, it is expedient if a thread guide element is arranged in the thread path of the weft to the injector, through which the At the end of the insertion into the weft magazine, the weft thread is held at a point from which the thread travel path to the injector returned to the starting position is longer than to the injector which is moved to the end of its path.

As also already explained, the device can have a plurality of injectors, each of which is associated with its own weft thread; each injector can then optionally be coupled to the drive device. In this case, the injectors can be arranged next to one another to the side of the movement path of the weft thread carrier, one injector in each case being able to be moved into the starting position for the co-movement by means of an adjusting device.

If a sliding guide with guide rails is present, the injectors can each be mounted between two guide rails, while the guide rails themselves are adjustably mounted transversely to the path of movement of the weft thread carriers. As soon as the weft thread entry in a weft magazine has ended and the latter has left the injector, the guide rails are adjusted laterally, so that ineffective injectors can now return to their starting position without hindrance, while the injector intended for the next filling of the weft magazine moves into the starting position for the co-movement and there comes into engagement with the drive device.

When using weft yarn, the strength of which permits a high thread pull-off speed, so that an extension of the filling time of the weft thread magazine is not necessary, the injectors can also be arranged in a register which is adjustably mounted transversely to the movement path of the weft thread carrier. After the respective filling process, the register is shifted in the interval until the next weft magazine is filled so that the injector with the desired weft color is brought into the starting position for movement with the next weft carrier. This adjustment of the register can take place, for example, via a rack and pinion drive inevitably as a function of the movement of the weft thread carriers in accordance with a program which is contained on a suitable program carrier, for example a punch card or a cam chain or in a memory.

In addition, the injectors can be preceded by a measuring and delivery device which has a permanently driven thread drum, against the surface of which the weft threads of the injectors can be pressed at times by means of pressure rollers, the pressure movement of the individual pressure rollers being controlled as a function of the injector movement.

Each injector is assigned its own pressure roller, which supplies the weft thread according to the program. The axial length of the delivery drum is dimensioned such that the required number of pressure rollers can act side by side.

The explained co-movement of the respective injector with the weft thread carrier when inserting the weft thread into its weft thread magazine, as explained, increases the weft thread magazine filling time, the lengthening achieved being given by the selected speed reduction ratio between the weft thread carrier and the co-moving injector. In the same way, however, the running speed of the weft thread carriers can be increased in a corresponding manner while the weft thread pull-off speed is kept constant compared to the situation with a stationary injector, or, as a different alternative, double the weft thread length can be introduced into the weft thread magazine, which permits the same weft thread delivery speed to produce wider sections of fabric. It should be noted that a correspondingly larger number of weft thread carriers then also work in the fabric and this likewise results in a corresponding increase in the weaving performance.

• Figur 1 eine mehrsystemige Webmaschine mit erfindungsgemäßen Vorrichtungen zum Einbringen des Schußfadens in die Schußfadenmagazine der Schußfadenträger, in perspektivischer schematischer Darstellung,
• Figur 2 eine Vorrichtung zum Einbringen des Schußfadens der Webmaschine nach Figur 1, in perspektivischer schematischer Darstellung,
• Figur 3 die Vorrichtung nach Figur 2, geschnitten längs der Linie lll-lll der Figur 2, in einer Seitenansicht,
• Figur 4 die Vorrichtung nach Figur 3 in einer Draufsicht und im Ausschnitt,
• Figur 5 die Vorrichtung nach Figur 2, geschnitten längs der Linie V-V der Figur 4, in einer Seitenansicht,
• Figur 6 die Vorrichtung nach Figur 2 in einer abgewandelten Ausführungsform mit lediglich einem Injektor in einer Darstellung entsprechend Figur 2 und
• Figur 7 ein Injektorregister für eine weiter abgewandelte Ausführungsform einer Vorrichtung gemäß der Erfindung in schematischer Draufsicht zusammen mit einem Schußfadenträger.

Exemplary embodiments of the subject matter of the invention are shown in the drawing. Show it

• 1 shows a multi-system weaving machine with devices according to the invention for introducing the weft thread into the weft thread magazines of the weft thread carriers, in a perspective schematic illustration,
• FIG. 2 shows a device for inserting the weft thread of the weaving machine according to FIG. 1, in a perspective schematic illustration,
• FIG. 3 shows the device according to FIG. 2, cut along the line III-III of FIG. 2, in a side view,
• FIG. 4 shows the device according to FIG. 3 in a top view and in a detail,
• FIG. 5 shows the device according to FIG. 2, cut along the line VV of FIG. 4, in a side view,
• Figure 6 shows the device of Figure 2 in a modified embodiment with only one injector in a representation corresponding to Figure 2 and
• Figure 7 shows an injector register for a further modified embodiment of a device according to the invention in a schematic plan view together with a weft thread carrier.

FIG. 1 shows a multi-system weaving machine in a double-flat, so-called “back-to-back” construction. The machine is set up for the simultaneous production of four fabric webs 1, each of which is wound up into a bale of goods 3 mounted on the machine frame 2. The warp threads 5 drawn from the warp beams 4 rotatably supported on the underside of the machine frame 2 are progressively moved apart in the direction of an arrow 6 by healds 7 movable transversely to the fabric web 1 to form compartments 8, each compartment being traversed by a weft thread carrier 9, the shape of which can be seen in detail, for example, from FIGS. 2 and 7.

The weft thread carriers 9 run one behind the other at a predetermined distance in the manner shown in FIG. 3 on a guideway which is formed on one side by a reed 10 and on the other side by the shafts of the healds 7. They are driven via block-like segments 11, which are longitudinally movably guided on the machine frame 2 and are magnetically coupled to the individual weft thread carriers 9 via permanent magnets 12. The segments 11 are fastened to one another on an end-to-end chain 11a and passed over two vertical, polygonal drive rollers 13 rotatably mounted in the machine frame 2, as can be seen from FIG. The segments 11 carry, on their underside facing the healds 7, guide tracks (not shown in detail) into which feet formed on the healds of the healds 7 protrude, as is the case in principle in US Pat 963 208 is explained.

Between the reed 10, weft flap lamellae 15 project outwards through the warp threads, which serve to strike the respectively inserted weft thread between successive weft thread carriers 9, as is indicated at 16 in FIG. 1.

The machine has 1 z. B. eight weft carriers 9, d. H. eight web systems.

The insertion of the weft thread into the weft thread carrier 9 takes place in the area between two adjacent fabric webs 1 by means of a weft thread insertion device 17 assigned to each fabric web, one of which is illustrated in detail in FIGS. 2 to 5 and of which the weaving machine according to FIG. 1 has four pieces .

The weft insertion device 17 shown in the above-mentioned figures has a slide guide 19 mounted on two parallel main supports 18 of the machine frame 2, which consists of three parallel guide rails 19 which are fixedly connected to one another at a predetermined distance and which run parallel to the main rails 18 in two at the ends the main rails 18 fixed cross rails 21 are mounted transversely. Between two of the guide rails 19, a slide 22 is fitted, which carries an injector 23, to which a weft thread 24 is fed, which comes from a thread delivery device shown at 25 or 26, which in turn pulls it off from a package 27 or 28. As can be seen from FIG. 3, the injector 23 shown there in the middle opens in the immediate vicinity of the weft magazine of the weft carrier 9 shown at 29.

Below the sliding guide 19 runs laterally next to the warp threads delimiting the compartment 8, the upper run of an endless chain 30 which is guided over two deflection rollers 31 which are rotatably mounted on corresponding axes 32 and 33 on one of the main carriers 18. One of the deflection rollers 31 is connected in a rotationally fixed manner to a gearwheel 34, which meshes with a gearwheel 37 which is seated on a shaft 36 mounted in the main carriers 18 and which in turn is rotationally fixed with a gearwheel 38 located on the other side of the main carrier 18 connected is. The gear 38 is in engagement with a rack 39, which consists of individual rack sections, each having the length of one of the segments 11 to which they are attached.

As can be seen from FIG. 1, this results in a continuous rack 39 over the length of the weaving machine, which moves past the gears 38 of the weft insertion devices 17 at the speed of the segments 11 and thus the respective chain 30 via the gears 38, 37, 34 drives at a speed which is synchronized with the movement of the weft thread carriers 9 magnetically entrained by segments 11 and whose relative speed with respect to the weft thread carriers 9 is determined by the reduction of the gear transmission 34 to 38.

The chain 30 carries, as can be seen from FIG. 5, four driving teeth 40 in the exemplary embodiment shown, which are arranged at the same distance from one another. The upper run of the chain 30 is arranged parallel to the slide guide 19 such that each driver 40 grips the slide 22 of the injector 23 standing in the middle (FIG. 3) in a starting position I (FIG. 5) and along the slide guide 19 over a predetermined one Can move to a final position II. The respective driver is brought radially through the right deflection roller 31 in the manner shown in FIG. 5 to the slider 22 in the starting position I and brought into engagement therewith; while on the other hand the left deflection roller 31 in the end position II transports the driver 40 radially away from the slide guide 19 and him automatically disengages from the slider 22.

Each of the injectors 23 is connected to a return device which is designed in the form of a spring tension 41 acting on it, which is anchored at the end in a housing 42. A spring 43 is assigned to the spring balancer 41, against which the slide piece 22 which is in the starting position I abuts and which limits its return movement.

The slide guide 19 carries two laterally projecting coaxial bolts 44, 45 which are slidably guided in corresponding bores 46, 47 of the main carrier 18. The one bolt 44 on the outside of the main carrier 18 is under the action of a compression spring 48 which is supported at the end against the bottom of a spring sleeve 49 inserted in the associated main carrier 18 and which supports the sliding guide 19. Figure 3, in the illustrated right stop. position on the opposite main beam 19 presses.

The other pin 45 is supported at the end against a double-armed lever 52 which is pivotably mounted on a main support 18 at 51 and which bears a pressure roller 53 which can come into engagement with a cam track 54 arranged laterally on the respective segment 11 in the region of the rack 39 (FIG 4).

• Jeder der Injektoren 23 ist einem eigenen Schußfaden 24 bzw. 24a (Figur 2) zugeordnet, der von einer Druckrolle 56 bzw. 56a gegen den Umfang einer mit konstanter Drehzahl umlaufenden Fadenliefertrommel 57 einer der Schußfadeneinbringungsvorrichtung 17 zugeordneten Schußfadenmeß- und -liefervorrichtung 58 programmgemäß anpreßbar ist. Die Steuerung der Anpreßbewegung der griffigen Druckrollen 56, 56a erfolgt über ein mit dem Zahnrad 38 in Eingriff stehendes Zahnrad 59 in zwangsläufiger Abhängigkeit von der Bewegung der Schußfadenträger 9, wobei die beiden Druckrollen 56, 56a programmgemäß einzeln ansteuerbar sind.

The weft insertion device 17 described so far operates as follows:

• Each of the injectors 23 is assigned its own weft 24 or 24a (FIG. 2), which can be pressed according to the program by a pressure roller 56 or 56a against the circumference of a thread delivery drum 57 rotating at a constant speed and a weft measuring and delivery device 58 assigned to the weft insertion device 17 . The pressure movement of the gripping pressure rollers 56, 56a is controlled via a gear 59 which is in engagement with the gear 38, inevitably depending on the movement of the weft thread carriers 9, the two pressure rollers 56, 56a being individually controllable according to the program.

The weft thread carriers 9, driven by the segments 11, run through their respective compartment at a predetermined mutual distance and at a certain speed. When a weft carrier 9 comes into the area of a weft insertion device 17, as shown on the right in FIG. 5, one of the injectors 23 (the right one in FIG. 3) is in the starting position I, in which it is in the path of movement of the drivers 40. Starting from this starting position I, the injector 23 is taken along by a driver 40 and, synchronized with the movement of the weft thread carrier 29, is transferred to the end position II at a predetermined speed, in which the driver 40 comes out of engagement with the slider 22. The movement of the carriers 40 is matched to that of the weft thread carrier 29 in such a way that the injector 23 carried by a carrier 40 is moved along with the weft thread carrier 9 on its way between the starting position I and the end position II. The speed reduction ratio between the chain 30 and the weft carrier 9 is chosen so that during this movement of the slide 22 the injector 23 is displaced relative to the weft carrier 9 by the length of the weft magazine.

During this movement of the injector 23 with the weft thread carrier 9, the pressure roller 56 or 56a associated in the weft thread 24 or 24a feeding it is pressed against the thread delivery drum 57, so that this weft thread is inserted into the injector 23, which in turn is located at the mouth of the injector 23 is blown into the air-permeable weft magazine 29. As soon as the insertion of the weft thread has ended and the injector 23 has reached the end position II, the weft thread is cut off at the edge of the fabric by a cutting device, not shown, after it has been partially woven in, held in place and inserted by the continuing weft thread carrier 9 into the compartment of the fabric web 1 has been. Since the spring tension 41 has been tensioned during the co-movement of the injector 23 with the weft thread carrier 9, the slider 22 is immediately returned to the starting position I by the spring tension 41 after being released by the driver 40, in which position it rests on the stop 43.

The pitch circle circumference of the gear 38 corresponds exactly to the length of a weaving system (or a multiple thereof). The gear 34 is thus driven in a reduction ratio of 2: 1, the distance between the drivers 40 on the chain 30 corresponding to a quarter of the system length in the exemplary embodiment shown. With a system length of 24 cm, a driver moves 12 cm between the two positions and II.

If the length of the weft carrier magazine 29 is now 10 cm, the injector 23 accompanies the weft magazine 29 between positions I and II on a path of 10 cm during the reduction ratio 2: 1, which means that for the insertion of the weft thread into the weft magazine 29 a path is available which corresponds to a weft magazine length of 20 cm. Since the distance between the drivers 40 is 12 cm and the injector 23 is only moved over a distance of 10 cm when inserting the weft thread, a free remaining distance of 2 cm remains, which is used for the resulting free time, the slider 22 and thus returning the injector 23 from its end position II to the starting position I by means of the spring tension 41, as has been explained. This ensures that the slider 22 is properly in the starting position I before it is brought into engagement with the next driver 40 and in turn transported to the end position II.

• Wenn der in Figur 5 dargestellte linke Injektor, der dem mittleren Injektor nach Figur 3 entspricht, in seiner Endstellung II ankommt, läuft, wie aus Figur 4 zu ersehen, die Druckrolle 53 auf die Kurvenbahn 54 des Segmentes 11 auf. Damit wird bei der Weiterbewegung des Segmentes 11 über den Hebel 52 und dem Bolzen 45 die Gleitführung 19, bezogen auf Figur 3, nach links verschoben, so daß der dort rechts dargestellte Injektor 23 mit seinem Gleitstück 22 aus der seitlich neben der Kette 30 liegenden Ruhestellung in die Ausgangsstellung I überführt wird, in der sein Gleitstück 22 im Bewegungsweg der Mitnehmer 40 liegt. Gleichzeitig kommt der in der Endstellung II befindliche Injektor 23, der den Schußfadeneintrag abgeschlossen hat, außer Engriff mit seinem Mitnehmer 40, so daß er seitlich der Mitnehmer 40 und der Kette 30 zu dem Anschlag 43 zurücklaufen kann, während der zweite Injektor bereits von seinem Mitnehmer 40 mitgenommen wird und damit den Schußfadeneintrag beginnt. Die Stellung, die der erste Injektor 23 bei seiner Rückführung seitlich neben der Kette 30 einnimmt, ist in Fig. 3 links gestrichelt veranschaulicht.

The weft entry described can be Improve in the sense that the aforementioned remaining time required for returning the injector 23 from the end position II to the starting position I is also used. The second injector shown in FIGS. 3 to 5 is used for this purpose:

• When the left injector shown in FIG. 5, which corresponds to the middle injector according to FIG. 3, arrives in its end position II, as can be seen from FIG. 4, the pressure roller 53 runs onto the cam track 54 of the segment 11. Thus, when the segment 11 continues to move, the slide guide 19, based on FIG. 3, is shifted to the left via the lever 52 and the bolt 45, so that the injector 23 shown there on the right with its slide piece 22 from the rest position lying laterally next to the chain 30 is transferred to the starting position I, in which its slide 22 lies in the path of movement of the drivers 40. At the same time, the injector 23 located in the end position II, which has completed the weft thread entry, comes out of engagement with its driver 40, so that it can laterally return the driver 40 and the chain 30 to the stop 43, while the second injector is already from its driver 40 is taken along and thus the weft thread entry begins. The position which the first injector 23 assumes when it is returned laterally next to the chain 30 is illustrated in broken lines in FIG. 3.

As soon as the second injector has finished inserting the weft thread, the pressure roller 53 runs again from the cam track 54, so that the slide guide 19 moves to the right in relation to FIG. 3, and thus in turn the first injector on its slide 22 from the next driving tooth 40 is gripped while the other injector is now ineffective to the side of the chain 30, as shown in Figure 3 on the right. The two injectors 23 are thus used alternately to supply the weft.

If several injectors 23 are used, the control can also be pushed according to the program, for example by a programming device, so that a weft color change can be carried out by means of the injectors 23. The slide guide 19 is then controlled via a rack and a gearwheel by the programming device via a suitable adjusting device, which causes the slide guide 19 to be moved back and forth by the double-armed lever 52.

In principle, it is naturally possible to design the weft insertion device 17 in a simple embodiment instead of the exemplary embodiment with at least two injectors 23 in such a way that it only works with one injector 23. This is illustrated in Figure 6. Here, the same parts are provided with the same reference numerals, so that a further explanation is not necessary.

Finally, an embodiment is illustrated in FIG. 7, in which four injectors, designated 23a to 23d, are each joined together with their pressure pieces 22a to 22d to form a register which, like its sliding guide 19, can be adjusted transversely to the movement path 62 of the weft thread carrier 9. This makes it possible to supply successive weft thread carriers 9 with four different weft threads. The to-and-fro adjustment of the register formed by the injectors 23a to 23d, indicated by an arrow 63, is carried out according to the program via a programming device and an actuating device controlled by it.

The invention has been described above using a double-flat weaving machine. In principle, it can of course also be used for a circular loom or a loom with a different structure.

Between the thread delivery drum 57 and the associated injector 23, a thread guide element 65 in the form of a fixed pin (FIG. 2) is provided, which is arranged in such a way that the thread travel from the pin 65 holding the weft thread to the injector 23 in the starting position I is longer than to the injector in end position II. It is thereby achieved that after the weft thread has been cut off on the injector 23 standing in the end position 11 during the return movement of the injector 23 into the starting position I, the cut weft thread end is drawn into the injector 23 and does not protrude below.

In addition, in the manner indicated in FIG. 2, a tube 70, which can optionally also be designed as a flexible hose and is preferably transparent, is placed on the injector 23, which laterally guides the weft thread 24 or 24a on the way between the thread delivery drum 57 and the respective injector 23, so that the weft cannot accidentally emerge from the injector.

Claims (24)

1. A method of inserting the weft yarn pneumatically into the weft yarn magazine of the weft yarn carrier of a multi-system power loom wherein each of the weft yarn magazines of the weft yarn carriers is successively charged with one cut-off piece of weft yarn in a manner such that the piece of weft yarn is fed by an air jet into the weft yarn magazine while the weft yarn carrier is running, the air jet following the movement of the weft yarn carrier during the charging operation, characterized in that, starting from an initial position, the air jet is moved a predetermined path with the weft yarn carrier at a lower speed while charging a weft yarn magazine, and is returned to its initial position upon completion of the charging operation at the end of the said path.

2. A method in accordance with claim 1, characterized in that during inserting of the weft yarn into the weft yarn magazine, the air jet is displaced relative to the weft yarn carrier by an amount corresponding to the length of the weft yarn magazine.

3. A method in accordance with claim 1 or 2, characterized in that the weft yarn is guided laterally during at least part of its way to the air jet.

4. A method in accordance with any of the preceding claims, characterized in that at least two air jets coacting with separate weft yarns are used and that only one of the said air jets is moved at a time from its initial position with the weft yarn carrier for inserting the weft yarn into the weft yarn magazine, while the other air jet or air jets remain(s) ineffective for the said period of time.

5. A method in accordance with claim 4, characterized in that the ineffective air jet or air jets is/are retained laterally off the path of movement of the weft yarn carrier and that the air jet which is to move together with the weft yarn carrier is transferred to the corresponding initial position before inserting of the weft yarn into the weft yarn magazine begins.

6. A method in accordance with claim 4 or 5, characterized in that a second air jet is transferred to the initial position for moving together with the next following weft yarn carrier while the previous air jet is returned after inserting of the weft yarn into the weft yarn magazine has been completed.

7. A method in accordance with any of claims 4 to 6, characterized in that the selection of the air jets for inserting the weft yarn into the weft yarn magazine is effected in a programmed manner.

8. A method in accordance with any of the preceding claims, characterized in that the weft yarn is cut off at the edge of the fabric when inserting of the weft yarn into the weft yarn magazine has been completed, and that its end is automatically pulled into an injector producing the air jet during return of the air jet into its initial position.

9. A device for carrying out the method in accordance with any of the preceding claims, comprising an injector (23) to which compressed- air is admitted, to which the weft yarn (24) can be fed from a thread measuring and delivering device, and which is arranged near the path of movement of the weft yarn carriers (9) of a multi-system power loom for displacement along part of the said path of movement in a sense equal to the sense of movement of weft yarn carrier (9), and which is coupled with drive means (30, 40) operating in synchronism with the movement of the weft yarn carriers (9) and transmitting to the injector a correspondingly directed movement, characterized in that the injector (23) is driven by its drive means (30, 40), at least during inserting of the weft yarn (24) into the weft yarn magazine (29) of the respective weft yarn carrier (9), from an initial position (I) over a pre-determined speed- reduction ratio to the speed of the weft yarn carrier (9).

10. A device in accordance with claim 9, characterized in that a sliding guide carrying the injector (23) in sliding relationship is arranged near the path of movement of the weft yarn carriers (9).

11. A device in accordance with claim 10, characterized in that the sliding guide (19) consists of two parallel guide rails (20) for guiding between them the injector (23) which is provided with a fitting sliding piece (22).

12. A device in accordance with any of claims 9 to 11, characterized in that the driving means comprises a driver (40) which engages the injector (23) automatically when the latter is in its initial position (I) and which at the end of the pre-determined path of movement (I-II) of the injector (23) is disengaged automatically from the latter, and that the injector (23) is coupled with returning means (41, 42) which become active upon such disengagement to return it to its initial position (I).

13. A device in accordance with claim 12, characterized in that the returning means comprises a restoring spring (41) than can be tensioned when a dragged movement of the injector (23) is performed.

14. A device in accordance with claim 12, characterized in that the driver is arranged on a chain (30) one stringer of which extends in parallel to the path of movement of the injector (23), which is moved at a speed corresponding to the pre-determined speed reduction ratio relative to the movement of the weft yarn carrier (9), and which is guided at the beginning and the end of the path of movement (I-II) of the injector (23) on guide pulleys (31) by which the driver (40) can be moved towards and into engagement with the injector (23) or away from and out of engagement with the injector (23).

15. A device in accordance with any of claims 9 to 14, characterized in that the drive means is driven via a toothed gearing (34, 37, 38) which is in engagement with a toothing (39) provided on a part (11) of the weft yarn carrier drive which moves together with the respective weft yarn carrier (9).

16. A device in accordance with any of claims 12 or 13, characterized in that the chain (30) carries a plurality of drivers (40) spaced at a distance larger than the path (I-II) of the injector (23) by an amount permitting the respective injector (23) to be returned into its initial position (I).

17. A device in accordance with any of claims 9 to 16, characterized in that there is provided in the path traversed by the weft yarn (24, 24a) on its way to the injector (23) a thread guide element (65) which after insertion into the weft yarn magazine (29) has been completed retains the weft yarn at a point from which the path to be traversed by the thread to the injector (23) after return of the latter to its initial position is longer than the path to the injector (23) at the end (II) of its path of movement.

18. A device in accordance with any of claims 9 to 17, characterized in that it comprises a plurality of injectors (23) coating each with a separate weft yarn (24, 24a) and being arranged for selective engagement with the drive means (30, 40).

19. A device in accordance with claim 18, characterized in that the injectors (23) are arranged side by side laterally of the path of movement of the weft yarn carriers (9) and that control means (45, 52, 54) are provided for transferring one injector at a time into the initial position (I) for the dragged movement.

20. A device in accordance with claims 11 and 19, characterized in that each of the injectors (23) is seated between two guide rails (20) and that the guiding rails (20) are adjustable in a direction perpendicular to the path of movement of the weft yarn carrier (9).

21. A device in accordance with claim 20, characterized in that the guide rails (20) are coupled with the control means (45, 52, 54) which is in turn controlled positively by the movement of the weft yarn carrier (9).

22. A device in accordance with claim 19, characterized in that the injectors (23a to 23d) are arranged in a register which is adjustable in a direction transverse to the path of movement of the weft yarn carriers (9).

23. A device in accordance with any of claims 18 to 22, characterized in that the injectors (23, 23a to 23d) are preceded by a constantly driven yarn drum (58) comprising a measuring and delivering device (58), that the weft yarns (24, 24a) of the injectors can be temporarily pressed against the surface thereof by means of pressure rollers (56, 56a) and that the pressing motion of the individual pressing rollers (56, 56a) is controlled positively in response to the movement of the injectors.

24. A device in accordance with any of claims 9 to 23, characterized in that each injector (23, 23a to 23d) is preceded by a tube (70), which may also be elastic, providing a lateral guide for the weft yarn (24, 24a).

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